U.S. patent application number 12/313908 was filed with the patent office on 2009-10-08 for coaxial-flow heat transfer structures for use in diverse applications.
This patent application is currently assigned to Kelix Heat Transfer Systems, LLC. Invention is credited to Michael L. Fraim, John E. Kidwell.
Application Number | 20090250200 12/313908 |
Document ID | / |
Family ID | 36954042 |
Filed Date | 2009-10-08 |
United States Patent
Application |
20090250200 |
Kind Code |
A1 |
Kidwell; John E. ; et
al. |
October 8, 2009 |
Coaxial-flow heat transfer structures for use in diverse
applications
Abstract
An coaxial-flow heat exchanging structure having a proximal end
and a distal end for exchanging heat between a source of fluid at a
first temperature and the environment (e.g. air, ground, water,
slurry etc.) at a second temperature. The coaxial-flow heat
transfer structure comprises: a thermally conductive outer tube
section, and an inner tube section having an inner flow channel and
being coaxially arranged within the outer tube section. An outer
flow channel is formed between the inner and outer tube sections,
and helically-extending turbulence generator is provided along the
outer flow channel, so as to create turbulence along the flow of
heat exchanging fluid flowing between the inner and outer flow
channels, and thereby increasing the heat transfer through the
walls of the outer tube section to the ambient environment.
Inventors: |
Kidwell; John E.; (Tulsa,
OK) ; Fraim; Michael L.; (Corrales, NM) |
Correspondence
Address: |
Thomas J. Perkowski , Esq., P. C.
Soundview Plaza, 1266 East Main Street
Stamford
CT
06902
US
|
Assignee: |
Kelix Heat Transfer Systems,
LLC
|
Family ID: |
36954042 |
Appl. No.: |
12/313908 |
Filed: |
November 25, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11413975 |
Apr 28, 2006 |
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12313908 |
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11372224 |
Mar 9, 2006 |
7363769 |
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11413975 |
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11076428 |
Mar 9, 2005 |
7347059 |
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11372224 |
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Current U.S.
Class: |
165/154 ;
165/184 |
Current CPC
Class: |
F28F 1/36 20130101; Y02E
10/10 20130101; F28D 7/106 20130101; Y02E 10/125 20130101; F24T
10/17 20180501; F28D 7/12 20130101; F25B 30/06 20130101; F24S
2080/05 20180501; F24F 3/001 20130101; F24T 2010/56 20180501; C10L
3/10 20130101; H01Q 1/02 20130101 |
Class at
Publication: |
165/154 ;
165/184 |
International
Class: |
F28D 7/10 20060101
F28D007/10; F28F 1/36 20060101 F28F001/36 |
Claims
1. A coaxial-flow heat transferring structure for installation in
an ambient environment and facilitating the transfer of heat energy
between an external heat energy producing system and said ambient
environment, comprising: a proximal end and a distal end for
exchanging heat between a source of fluid at a first temperature
and the environment at a second temperature; an input port,
provided at the proximal end, for receiving a heat (energy)
transferring fluid at a first temperature from an external heat
energy producing system, and an output port, provided at the
proximal end, for outputting said heat transferring fluid at a
second temperature to the heat energy producing system; an inner
tube section having an outer wall surface extending between the
proximal and distal ends, and supporting an inner flow channel
having a substantially uniform inner diameter along its length and
into which the heat exchanging fluid can be introduced from the
input port and along which the heat exchanging fluid can flow in a
substantially laminar manner towards said distal end; an outer tube
section, disposed coaxially around the inner tube section, and
having an inner wall surface extending between said proximal and
distal ends, and the outer tube section being in thermal
communication with the ambient environment; wherein an outer flow
channel is provided between the outer wall surface of the inner
tube section and the inner wall surface of the outer tube section,
and capable of conducting heat exchanging fluid from the distal
extend, along the outer flow channel towards the proximal end, and
exiting from the second port; and wherein a turbulence generating
structure is disposed along a substantial portion of the length of
the outer flow channel so as to introduce turbulence into the flow
of said heat exchanging fluid flowing along the outer flow channel,
from the distal end towards the proximal end, and thereby improving
the transfer of heat energy between the heat exchanging fluid and
the ambient environment along the length of the outer flow
channel.
2. The coaxial-flow heat exchanging structure of claim 1, wherein
the turbulence generating structure comprises a helically arranged
fin structure disposed along a substantial portion of the outer
flow channel.
3. The coaxial-flow heat exchanging structure of claim 3, wherein
the helically arranged fin structure is mounted to the outer
surface of the inner tube section.
4. The coaxial-flow heat exchanging structure of claim 1 wherein
the laminar fluid flow along the inner tube section provides an
insulating effect between the wall of the inner tube section and
the inner flow channel.
5. The coaxial-flow heat exchanging structure of claim 1, for
sinking heat into the ground during cooling operations, or sourcing
heat from the ground during heating operations.
6. The coaxial-flow heat exchanging structure of claim 1, wherein
the coaxial-flow heat exchanging structure functions as a primary
system, a system sub-component, or a sub-component kit of the heat
pump system.
7. The coaxial-flow heat exchanging structure of claim 1, wherein
said thermally-conductive outer tube has an outer heat exchanging
surface area which is increased by fluting the surface thereof.
8. The coaxial-flow heat exchanging structure of claim 1, wherein
said thermally conductive outer tube section is thermally-cemented
into a bore drilled in the Earth.
9. The coaxial-flow heat exchanging structure of claim 8, wherein
said bore extends through an aquifer.
10. The coaxial-flow heat-transfer structure of claim 8, wherein
the temperature of the heat transfer fluid is substantially
maintained until it reaches the bottom of the bore, so that a
higher temperature difference is maintained between the turbulent
flowing fluid in said helical flow channel, thereby increasing the
rate of heat transfer into the inside wall of said outer tube
section and consequently into the Earth, rock, and aquifer, if an
aquifer exists.
11. A coaxial-flow heat transfer system comprising: a
thermally-conductive outer tube section, and an inner tube section
having an inner flow channel having a substantially uniform inner
diameter along its entire length and being coaxially installed
within said outer tube section supporting helically-arranged
turbulence generator fins on the outer surface of said inner tube
section, so as to form at least one helically-extending outer flow
channel between said inner and outer tube sections, so that heat
energy contained within a heat exchanging fluid flowing down said
inner flow channel and along the helically-arranged outer flow
channel, is exchanged through the walls of said outer tube section
and into the ambient environment.
Description
RELATED CASES
[0001] This application is a Continuation of U.S. application Ser.
No. 11/413,975 filed Apr. 28, 2006; which is a Continuation-in-Part
of U.S. application Ser. No. 11/372,224 filed Mar. 9, 2006, now
U.S. Pat. No. 7,363,769 B2; which is a Continuation-in-Part of U.S.
application Ser. No. 11/076,428 filed Mar. 9, 2005, now U.S. Pat.
No. 7,347,059 B2; each said Application being owned by Kelix Heat
Transfer Systems, LLC of Tulsa, Okla. and incorporated herein by
reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a novel method of and
apparatus for transferring heat using heat exchanging fluids that
are safely isolated from the environment above and below the
Earth's surface and circulated within a sealed heat exchanging
structure so as to improve the heat transfer performance of
aqueous-based fluid heat transfer systems, wherein the ground, a
lake, a river, or sea water is used as the primary or secondary
heat sink or heat source in the sealed heat exchanging
structure.
[0004] 2. Brief Description of the State of Knowledge in the
Art
[0005] The development of refrigeration processes, associated
equipment, and two-phase chemical refrigerants evolved primarily in
response to mankind's need to preserve food. Over the years,
several different kinds of heat transfer systems have been
developed for dissipating heat removed from the food to the
exterior of the food storage container.
[0006] One type of heat transfer system is a typical refrigeration
system which includes an evaporator for absorbing heat from one
location, a condenser for dissipating heat to another location, a
compressor for compressing the vaporous two-phase refrigerant
exiting the evaporator for delivery into the condenser where the
refrigerant is condensed back into a liquid, and a two-phase
throttling device connected to the evaporator inlet for receiving
the liquid refrigerant and refrigerant expansion, to complete a
refrigeration cycle.
[0007] Condensers can be constructed in various configurations,
namely: as an arrangement of tubing with air-cooled fins, or as a
water-cooled "tube and shell configuration".
[0008] In FIGS. 1 and 1A, the fluid flow characteristics of
conventional tubing used in heat exchangers is schematically
depicted. FIG. 1 illustrates how the velocity of a fluid traveling
through a tube decreases from the center of the tube towards the
inner surface of the tube. As shown, fluid enters tube A through
inlet opening C. A laminar fluid flow profile D is caused by
friction along a boundary layer E on the inner surface of the tube
A. In the general, the annular region of flow B does not contain
eddy currents during laminar flow. The shape of the laminar fluid
flow profile D is influenced by the viscosity of the fluid passing
through the tube. Fluids having lower viscosities cause a thinner
boundary layer E to form, whereas fluids with higher viscosities,
such as propylene glycol mixture (anti-freeze) and other viscosity
increasing additives, causes a thicker boundary layer E to form,
which reduces heat transfer. Fluids with lower viscosities, such as
pure water, can transition into turbulent flow at lower fluid
velocities.
[0009] Turbulence can be regarded as a highly disordered motion of
matter (e.g. water, air etc.) resulting from the growth of
instabilities in an initially laminar flow, and it is generally
agreed that the transition from laminar to turbulent flow may be
described as a series of events that take place more or less
continuously. Additionally, it is known that turbulent fluid flow
characteristics, due to eddy currents, can increase heat transfer
across heat conducting surfaces. During turbulent flow, the annular
flow region contains eddy currents which increase heat transfer.
Fluids with higher viscosities, such as propylene-glycol, require
higher fluid velocities in order to transition into turbulent flow.
This requires more pump energy to transfer the same quantity of
heat energy as pure water. Also, tubing with a rough inner surface
allows the fluid to transition into turbulent flow at a lower fluid
velocity.
[0010] FIG. 1A illustrates how flow velocities within annular
regions of fluid flow B, C and D are influenced by frictional
forces generated from boundary layer E. Within the boundary layer
E, against the inner surface of the tube, the velocity of the heat
transfer fluid can be zero. In the annular flow region B, the fluid
is shown moving at 3 feet per minute, and faster in areas closer
toward the annular flow region C, which has a flow velocity of 3
feet per minute. The fluid in the annular flow region D has the
highest velocity of 10 feet per minute. Typically, the reduction in
fluid flow velocity adjacent the inside surface of a tube results
in a decrease in the rate of heat energy transferred from the fluid
into the tube material.
[0011] The primary method of compensating for such heat transfer
constraints (imposed by laminar fluid flows through conventional
tubing structures) has been to use larger tubes and more powerful
pumps in conventional heat transfer systems, which has resulted in
higher installation costs at lower operating efficiencies.
[0012] At this juncture, it is appropriate to continue surveying
prior art systems with such considerations in mind.
[0013] In the water-cooled tube and shell condenser, the rate of
heat transfer between the refrigerant in the refrigeration-sealed
system, and the water flowing around the tube and shell condenser
tube, is much higher than the rate of heat transfer between the
refrigerant in the refrigeration-sealed system and air flowing
around the tubes of the air-cooled fin and tube condenser. A
water-cooled tube and shell condenser is normally connected with
pipes to a cooling tower and a water pump. The heat is absorbed by
the water while circulated through the condenser. The heat in the
water entering the cooling tower is then dissipated into the
atmosphere from the water, completing a closed-loop water-cooled
refrigeration process.
[0014] Environmental concerns have caused strict restrictions to be
placed on water-cooled tube and shell condenser systems utilizing a
water pump to gather water from natural sources such as a lake, a
river, sea water, and other fluid systems, for circulation through
the water-cooled tube and shell condenser of such heat transfer
systems. Environmental contaminations vary but are mostly related
to chemical concentrations and temperature variations being
dispensed into the water source.
[0015] A water-cooled tube and shell condenser can be connected to
a ground-source heat transfer well using pipes, to dissipate heat
into the Earth. In various manufacturing processes, the required
operating temperature and capacity (i.e. volume) of heat transfer
fluid circulated through the ground source heat transfer well, may
not require adding refrigeration to the system.
[0016] Ground loop heat transfer installations vary from trenched
horizontal loops to multiple vertical loops. In FIGS. 1B and 1C,
vertical installations are schematically illustrated in two
different heat transfer modes.
[0017] In FIG. 1B, a (field assembled) conventional "U" tube type
heat transfer tube is shown buried in the Earth for the purpose of
dissipating heat energy from the system into the Earth. Typically,
tube sections G and I are buried beneath the Earth a few inches
apart from one another. During operation, a heat transfer fluid
flows into inlet F in a laminar manner at 110 degrees Fahrenheit,
and is forced to flow down tube section G. Heat energy in the
laminar flowing fluid is transferred into the Earth at 55 degrees
Fahrenheit, along the entire outer surface of the tube G. As
illustrated, a portion of the heat from tube section G is actually
transferred into tube section I after the heat transfer fluid has
reversed its flow direction when flowing along elbow section H.
Using this ground loop arrangement, the net amount of heat energy
actually transferred into the Earth is diminished due to the heat
transfer from tube section G into tube section I. Thus, the overall
heat transfer capacity offered by this system design is
significantly diminished due to (i) the laminar flow profile of the
heat transfer fluid within the "U" tube construction (illustrated
in FIG. 1), and (ii) the comingling of heat energy exchanges
between underground tube sections G and tube I.
[0018] In FIG. 1C, a (field assembled) conventional "U" tube type
heat transfer tube is shown buried in the Earth for the purposes of
collecting heat energy therefrom. In this configuration, a heat
transfer fluid flows at 40 degrees Fahrenheit into inlet F in a
laminar manner, and is forced to flow down tube section G into the
Earth. Along the entire outer surface of the tube section G, heat
energy is transferred from within the 55 degree Fahrenheit Earth,
into the heat transfer fluid maintained at 40 degree Fahrenheit.
Since the degree Fahrenheit temperature difference between the heat
transfer fluid inside tube section G is higher than that of the
heat transfer fluid occupying tube section I, more heat energy is
absorbed by tube section G than is absorbed by tube section I.
Also, a portion of the heat energy transferring into tube section G
originates from tube section 4 and is actually transferred into
tube section G after the heat transfer fluid has reversed its flow
direction along elbow section H. Again, the overall heat transfer
capacity offered by this system design is significantly diminished
due to (i) the laminar flow profile of the heat transfer fluid
within the "U" tube construction (illustrated in FIG. 1), and (ii)
the comingling of heat energy exchanges between underground tube
sections G and tube I.
[0019] Residential and commercial comfort air conditioning systems
using "air-cooled condensers" are also well known in the art.
Air-cooled condensers are also used extensively world-wide on air
conditioners employing heat pumps. In contrast, "water-cooled tube"
and shell condensers are typically used in large tonnage commercial
and industrial applications such as in high-rise buildings, natural
gas dehydration, and liquefied natural gas gasification
systems.
[0020] A heat pump, originally called a reverse refrigeration
system, reverses the refrigeration process through the use of
sealed system valves and controls causing the evaporator to
dissipate heat while causing the condenser to absorb heat. In its
cooling mode of operation, an air conditioning system employing a
ground-source heat-pump will dissipate heat into the Earth while,
and absorb heat from the Earth in its heating mode of
operation.
[0021] Over the years, the ground/water source type heat pump has
proven very useful as a very efficient form of heating and cooling
technology. The use of ground/water source type heat pumps have
three distinct advantages over air source type heat pumps, namely:
during the peak cooling and heating seasons, the ground/water
source usually has a more favorable temperature difference than the
atmospheric air; the liquid-refrigerant exchanger on the heat pump
permits a closer temperature approach than an air-refrigerant
exchanger; and there is no concern with frost/snow/ice/dirt buildup
or removal on the heat exchanger.
[0022] In general, prior art heat pump installations have employed
undersized ground loops (constructed using conventional U type
tubing) because refrigerant-based fluids can provide a sufficient
temperature difference between the fluid and the ground so that
enough heat is transferred to and from the ground to match the
heating/cooling load on the heat pump. However, the use of
undersized ground loops is also known to reduce the SEER rating of
the heat-pump system. Also, the design goals of prior art heat pump
systems have been to minimize the length of the metal pipe (i.e.
tubing) used in the ground loop, while just passing the minimum
standards for efficiency.
[0023] When prior art heat pump systems experience peaks or spikes
in heating/cooling loads during daily operations, thermal storage
solutions are oftentimes added to the system in order to average
the load over the time period of interest. Thermal storage
solutions also help reduce the cost of the ground loop by allowing
the loop to be sized for the average base load over the day, week
or season. In fact, many large buildings and residences use thermal
storage solutions in order to reduce the cost of heating and
cooling by (i) using less expensive night-time electrical loads to
heat/cool the thermal mass, and then (ii) using the thermal mass to
heat/cool the building during the day. In order to reduce capital
cost of the heat pump system, prior art heat pump system
installations often use the metal rebar in the foundation or piling
as a major part of the thermal mass of the ground loop portion of
the heat pump system.
[0024] Ground source or water source type heat pumps can use a
closed or open loop as a heat exchanger. Open loops include water
circulated to cooling towers; water circulated between wells,
geothermal steam wells, water circulated in a body of water such as
a river or lake. Closed loops include aqueous-based fluids and
refrigerant-based fluids circulated in cooling/heating coils that
transfer heat to air, water, and ground. Most power plants use at
least one open loop to generate steam (the burner exhaust) and one
open loop (cooling towers or lake) to condense the steam back to
water. The de-ionized steam source water is preserved in a close
loop to prevent scale buildup in the heat exchanger. Most
conventional refrigerators, freezers and air conditioners use a
closed loop of refrigerant to cool the load and an open loop of
external air to condense the refrigerant.
[0025] The shortcomings and drawbacks of using air to transfer heat
from the condenser coil is that air requires a high temperature
differential and a large condenser coil surface area to achieve
reasonable heat transfer rates. The high temperature differentials
translate to a high-pressure differential which implies higher
energy costs to transfer a unit of heat. When a heat pump uses a
liquid, from a water or ground loop, to transfer heat from the
condenser coil, a smaller coil and a lower temperature and pressure
differential can be used to transfer the same unit of heat as the
air cool condenser coil which, in turn, improves efficiency and
reduces energy costs.
[0026] When closed loops are used in the ground or water source of
a heat pump system, there is a trade off between using (i) metal
tubing with a high heat transfer coefficient (i.e. which is subject
to corrosion and thermal expansion), and (ii) plastic tubing with a
low heat transfer coefficient, which is resistant to corrosion and
thermal expansion. For average soil conditions, plastic tubing
usually will require about three (3) times the heat transfer area
of the metal tubing to maintain an equivalent heat transfer rate.
Metal tubing is usually reserved for refrigerant-based fluids due
to the high fill pressures and the reactivity of the refrigerant
with plastic tubing.
[0027] While protective coatings and grouting can reduce the
corrosion rates of metal tubing, pin holes in the coating or grout
can actually concentrate the anode corrosion rate in the pin-hole
area. Electrical measurements have shown that circulating aqueous
based fluids between the ground loop and heat pump can cause the
flow of a low level current between the building and the
ground.
[0028] In accordance with convention, a close-loop ground/water
source heat pump can use a refrigerant based fluid or an
aqueous-based fluid. With refrigerant-based fluids, the heat pump
can use a high differential temperature to transfer heat between
the ground and the fluid in the tubing, but extra energy load
reduces the SEER rating of the heat pump system. Metal tubing is
used to contain the pressurized refrigerant-based fluid and
minimize the volume of refrigerant in the ground loop system due to
the high heat transfer coefficient of the metal.
[0029] As discussed in U.S. Pat. No. 5,025,634 to Dressler,
refrigerant based fluids have very high maintenance cost when a
small leak develops in the ground/water loop and a very high
environmental impact when there is a release of the refrigerant.
Also, over a long period of time, field experience has shown that
high pressure head loss can develop in the closed ground/water
source loop when lubricating oil from the compressor collects low
spots in horizontal loop or at the bottom of the bore hole in
vertical loop.
[0030] With most aqueous-based fluid ground/water source loops, the
heat pump uses a small close-loop refrigerant heat exchanger to
transfer heat to or from the aqueous fluid. The small heat
exchanger reduces the capital cost of the heat pump and reduces the
chances of refrigerant releases to the environment. In areas with
ground movement, such as earthquakes zones, subsidence bowls, and
deep freeze/thaw zones, the borehole thermally-conductive outer
tube and transfer piping can develop leaks due to repeated damage
over time as discussed in U.S. Pat. No. 4,993,483 to Kurolwa.
[0031] As disclosed in U.S. Pat. No. 4,644,750 to Lockett and
Thurston and in U.S. Pat. No. 4,325,228 to Wolf, a horizontal
ground loop's performance is affected by fluctuation in atmospheric
surface temperature and soil moisture content, whereas, the ground
loop based on multiple bore holes has a stable fluid temperature
and heat transfer coefficient for both heating and cooling thermal
loads. For heat and cooling loads located on small land surfaces or
arid land, the ground loop heat exchanger based on multiple bore
holes can provide a heat pump with a stable heat sink or source as
described in U.S. Pat. No. 4,392,531 to Ippolito.
[0032] The first major improvements to ground loop fluid heat
transfer using metal tubing and refrigerant based fluids are
disclosed in U.S. Pat. No. 5,816,314 to Wiggs et. al, U.S. Pat. No.
5,623,986 to Wiggs, U.S. Pat. No. 5,461,876 to Dressier, U.S. Pat.
No. 4,867,229 to Mogensen, and U.S. Pat. No. 4,741,388 by Kurolwa
where metal tubing was bent into a helix shape to increase heat
transfer between the refrigerant and the ground. These five patents
disclose that the `vertical helical heat exchanger` or the
`bore-hole helical heat exchanger` provides the heat pump with a
stable heat sink or source for heating and cooling. The shortcoming
of these designs is the increased capital cost of helical bending
of the tubing and the increased installation cost involved in
running bent helical tubing in a deviated well.
[0033] Another popular technique used in prior art heat pumps
involves insulating the metal, fluid-return tube from the bottom of
the bore hole so to prevent heat transfer from incoming fluid,
which significantly improves the heat exchanger performance. The
deficiency of such prior art insulating methods has caused a
significant increase in installation costs and a significant
increase in capital cost associated with insulating materials.
Notably, as the return line was far enough away from the loop to
not cause any significant thermal interference, insulating the
fluid return tube was not required for earlier horizontal ground
loop heat exchangers.
[0034] U.S. Pat. No. 5,623,986 to Wiggs also discloses that
external helically shape fins can be used to drill short vertical
heat exchangers into sand-loam soils or mud bottoms, but field
experience has shown that there is too much fin damage when
installing vertical heat exchangers in hard rock/ground
surfaces.
[0035] U.S. Pat. No. 5,937,665 to Kiessel et al., discloses other
improvements to refrigerant based groundloops, wherein an air heat
exchanger is used to the system to reduce the load on the ground
loop.
[0036] U.S. Pat. No. 6,138,744 by Coffee discloses using a large
storage tank of water to a horizontal ground loop that is
continuously replenished by an external water source such as water
well. This technique involves combining an open water loop and a
lose ground loop.
[0037] U.S. Pat. No. 6,615,601 by Wiggs discloses combining a solar
heating loop and a water evaporative cooling loop to the ground
loop so as to supplement the heating and cooling load.
[0038] U.S. Pat. No. 6,212,896 to Genung discloses a ground loop
with large well bores to make room for a vertical thermal siphon to
enhance the heat transfer in the large well bore. The shortcoming
of this idea is that the heat is transfer to the
thermally-conductive outer tube wall with a laminar flow of
fluid.
[0039] U.S. Pat. No. 6,672,371 to Amerman et al. created a ground
loop by drilling multiple well bores from one pad and using plastic
U-tubes for the heat exchanger. By using many plastic U-tubes with
low heat transfer in series, an equivalent metal heat exchanger
performance can be achieved in the ground loop.
[0040] Also, U.S. Pat. No. 6,789,608 to Wiggs discloses a technique
for extending the performance of the U-tube heat exchanger by
installing an insulating plate between the tubes to make two close
separate half wells with minimal thermal interference between each
well.
[0041] Thus, while various advances have been made in heat transfer
system design and implementation, there is still a great need in
the art for an improved method of and apparatus for transferring
heat from above or below the Earth's surface using a sealed fluid
circulation system, while overcoming the shortcomings and drawbacks
of prior art methodologies and equipment.
SUMMARY AND OBJECTS OF THE PRESENT INVENTION
[0042] Accordingly, it is a primary object of the present invention
is to provide a coaxial-flow heat exchanging (i.e. transferring)
structure for installation in an ambient environment and
facilitating the transfer of heat energy between an external heat
energy producing system and the ambient environment, while
overcoming the shortcomings and drawbacks of prior art
methodologies.
[0043] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure having a proximal end and a
distal end for exchanging heat between a source of fluid at a first
temperature and the environment (e.g. ground, water, slurry, air,
etc.) at a second temperature.
[0044] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure having an input port,
provided at the proximal end, for receiving a heat (energy)
transferring or carrying fluid at a first temperature from the
external heat energy producing system, and an output port, also
provided at the proximal end, for outputting the heat transferring
fluid at a second temperature to the heat energy producing system
or the like.
[0045] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure further comprising an inner
tube section having an outer wall surface extending between the
proximal and distal ends, and supporting an inner flow channel
having a substantially uniform inner diameter along its entire
length, and into which the heat exchanging fluid can be introduced
from the input port, and along which the heat exchanging fluid can
flow in a substantially laminar manner towards the distal end.
[0046] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure further comprising an outer
tube section, disposed coaxially around the inner tube section, and
having an inner wall surface extending between the proximal and
distal ends, and the outer tube section being in thermal
communication with the ambient environment.
[0047] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure, wherein an outer flow
channel of helical geometry is provided between the outer wall
surface of the inner tube section and the inner wall surface of the
outer tube section, and capable of conducting heat exchanging fluid
from the distal end, along the outer flow channel towards the
proximal end, and exiting from the output port.
[0048] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure, wherein a turbulence
generating structure is disposed along a substantial portion of the
length of the outer flow channel so as to introduce turbulence into
the flow of the heat exchanging fluid flowing along the outer flow
channel, from the distal end towards the proximal end, and thereby
improving the transfer of heat energy between the heat exchanging
fluid and the ambient environment along the length of the outer
flow channel.
[0049] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure, wherein the turbulence
generating structure comprises a helically-arranged fin structure
disposed along a substantial portion of the outer flow channel.
[0050] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure, wherein the
helically-arranged fin structure is mounted to the outer surface of
the inner tube section.
[0051] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure, wherein the laminar fluid
flow along the inner tube section provides an insulating effect
between the wall of the inner tube section and the inner flow
channel.
[0052] Another object of the present invention is to provide such a
coaxial-flow heat exchanging structure, for sinking heat into the
ground during cooling operations, or sourcing heat from the ground
during heating operations.
[0053] Another object of the present invention is to provide a heat
pump system employing the coaxial-flow heat exchanging structure of
the present invention, wherein the heat transfer performance of
aqueous-based fluid heat transfer is substantially improved, and
wherein the ground, a lake, a river, or sea water can be used as
the primary or secondary heat sink or heat source.
[0054] Another object of the present invention is to provide such a
heat pump system which may or may not incorporate the use of a
refrigeration subsystem.
[0055] Another object of the present invention is to provide such a
heat pump system, wherein the heat transfer performance of
aqueous-based fluids is substantially improved by using heat-pump
heating/cooling heat exchangers where the ground is used as the
primary or secondary heat sink/source in a closed loop.
[0056] Another object of the present invention is to provide such a
heat pump system, wherein capital/installation cost of the total
heat pump system is substantially reduced.
[0057] Another object of the present invention is to provide a heat
pump system employing a coaxial-flow heat exchanging structure
which is installed into the Earth, a lake, a river, sea water or
other heat sink or heat source to absorb heat or dissipate (i.e.
radiate) heat energy into or from the heat transfer fluid by
isolating the heat transfer fluid entering the center insulating
tube, from the helically flowing fluid exiting the assembly. The
interior surface of the thermally-conductive outer tube section is
the primary heat transfer surface of the coaxial-flow heat
exchanging assembly.
[0058] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure that can be used in diverse
kinds of heat pump systems, wherein the coaxial-flow heat
exchanging structure can be manufactured as a primary system, a
system sub-component, or a sub-component kit.
[0059] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure for use in a heat pump
system, wherein the heat exchanging surface area of the structure
is increased by fluting the plastic surface of the outer
thermally-conductive outer tube and by increasing the length of the
bore into the ground (bore length) as a result of drilling
deviated-type wells in aquifer zones of the Earth.
[0060] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure for use in a heat pump
system, wherein as the heat transfer surface area and the contact
volume of the ground/water source loop increase, the circulating
fluid temperature will approach the average ground temperature
through out the full duration of the heating and cooling
seasons.
[0061] Another object of the present invention is to provide such a
heat pump system, wherein a uniform bore hole is drilled into an
aquifer zone and a smooth metal pipe or a fluted plastic pipe is
installed within the bore hole so that the coaxial-flow heat
exchanging structure of the present invention can be constructed
within most geologic ground types, without major changes in
installation/construction procedures.
[0062] Another object of the present invention is to provide a
method of and apparatus for enhancing the heat transfer in aqueous
based fluid ground/water source loop systems so that a low
differential temperature, high mass-rate heat pump can be used to
cool or heat a thermal load from a building or industrial
process.
[0063] Another object of the present invention is to provide a
ground/water source heat-pump system that has a SEER rating that
exceeds air-source heat pump systems and ground-source heat-pump
systems using a refrigerant-based heat-transfer fluid.
[0064] Another object of the present invention is to provide an
improved heat pump system, wherein the aqueous-based fluid contains
a biodegradable anti-freeze and dye to minimize the environmental
impact of leaks in the ground loop and improve leak detection in
the ground loop multi-well grid.
[0065] Another object of the present invention is to provide
apparatus for manufacturing the helically-finned tubing employed
within the coaxial-flow heat transfer (exchanging) structure of the
present invention.
[0066] Another object of the present invention is to provide a
coaxial-flow heat-transfer structure, wherein the temperature of
the heat transfer fluid is substantially maintained until it
reaches the bottom of the well, so that a higher temperature
difference is maintained between the turbulent flowing fluid in the
outer flow channel between the inner tube section and the outer
tube section, thereby increasing the rate of heat transfer into the
inside wall of the outer tube section and consequently into the
grout cement and eventually into the Earth, rock, and aquifer, if
an aquifer exists.
[0067] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure which employs a fluid return
and injection manifold employing a plurality of small holes formed
in a cap structure to achieve a low friction-created pressure drop,
or alternatively, a single medium size hole for achieving a higher
friction-created pressure drop.
[0068] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure which employs a fluid return
and injection manifold cooperating with a compression-ring type cap
installed on the proximal end of the coaxial-flow heat exchanging
structure, to seal the system and prevent fluid leaks.
[0069] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure which employs a fluid return
and injection manifold cooperating with a clamped-type cap
installed on the coaxial-flow heat exchanging structure, wherein
the cap has an O-ring or U-ring seal around the proximal portion of
the thermally-conductive outer tube section to prevent fluid
leaks.
[0070] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein a manifold is
joined to a plurality of small holes formed in a cap portion
provided on the proximal portion of the outer tube section, so that
heat exchanging fluid exits perpendicular to central axis of the
thermally-conductive outer tube section.
[0071] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein a manifold is
joined to a plurality of small holes formed in a cap portion
provided on the proximal portion of the outer tube section, so that
heat exchanging fluid exits parallel to central axis of the
thermally-conductive outer tube section.
[0072] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein a pair of tube
fittings are welded or fused to the side of the
thermally-conductive outer tube section, for the injection and
returning heat exchanging fluids to the inner and outer flow
channels realized therein.
[0073] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, which is installed in a
deviated well bore in the Earth, wherein the horizontal section of
the structure is drilled into an aquifer zone and the vertical
section thereof connects the horizontal section back to the Earth's
surface.
[0074] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, which is installed in a
near horizontally bored well in the side of a mountain, mesa, or
hill, wherein the well bore path is deviated to follow an aquifer
zone if available at the site, and wherein, for buildings with a
deep basement or built on the side of a hill, the deviated well
bores are drilled in the wall of the basement.
[0075] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, which is installed in a
well bore that is capped below the surface to prevent significant
heat transfer to the ground/water surface or atmosphere, and
wherein for areas that have significant ice or freeze/thaw
movement, the distribution pipes would be protected against damage
and, if possible, the well should be capped below the frost
line.
[0076] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, which is installed
vertically in foundations or pilings of a bridge pier or like
structure.
[0077] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, which is installed
horizontally in the foundations or pilings of a building, bridge,
or other structure.
[0078] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, which is suspended
horizontally in an aqueous solution or mud.
[0079] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, which is installed in a
bridge component or piling, wherein in earthquake areas, the
pilings are wrapped in a metal sheath to prevent structural damage
in the earthquake, and helically extending outer flow channels
provide a ground/water source heat to prevent icing of the road way
or sidewalks during the winter.
[0080] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, which is installed within
the Earth about a residential home, wherein an optional thermal
bank tank is provided for night time operation when the electrical
energy costs are cheaper, or for daytime operation when solar cells
can provide electrical energy.
[0081] Another object of the present invention is to provide a
plurality of coaxial-flow heat exchanging structures installed
below the ground so as to prevent icing or snow accumulation on
side walks, bridges and heavily traveled intersections or steeply
pitched roads.
[0082] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein sea water is used
as the heat-pump heat sink for gas dehydration and oil de-waxing,
and wherein one or more coaxial-flow heat exchanging structures of
the present invention are installed in the ocean above the ocean
floor, for the purpose of extracting heat from the gas so as to
cause the temperature thereof to drop, thereby condensing water
vapor and/or light hydrocarbon vapors in the gas stream.
[0083] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein ballast water is
used as the heat-pump heat sink for gas dehydration and oil
de-waxing, and wherein one or more coaxial-flow heat exchanging
structures of the present invention are installed in the ocean
above the ocean floor, for the purpose of extracting heat from the
gas so as to cause the temperature thereof to drop, thereby
condensing water vapor and/or light hydrocarbon vapors in the gas
stream.
[0084] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, employed in a ground-loop
heat exchanging system, designed for dehydrating, on shore,
pipeline-quality gas produced from remote offshore wells
[0085] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, installed in a ground-loop
heat exchanger used in a natural gas dehydration and condensate
separation system constructed on land for a platform well or a
gathering system.
[0086] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure within a natural gas
dehydration system, wherein the gas in the liquid separator is
cooled to a temperature near the aquifer temperature, and then gas
is cooled with a heat pump to a temperature near the gas hydrate
temperature using a rotating heat exchanger.
[0087] Another object of the present invention is to provide a
submarine employing a coaxial-flow heat exchanging structure of the
present invention installed within a seawater heat exchanging
subsystem for centralized air conditioning and equipment
cooling.
[0088] Another object of the present invention is to provide a
submarine employing a coaxial-flow heat exchanging structure of the
present invention installed within a seawater heat exchanging
subsystem for decentralized air conditioning and equipment
cooling.
[0089] Another object of the present invention is to provide an
air-conditioning system employing a plurality of coaxial-flow heat
exchangers of the present invention, wherein the outer tubes of the
heat exchangers are made of metal and are provided with external
fins so as to provide maximum heat transfer with the ambient
environment.
[0090] Another object of the present invention is to provide a
plurality of coaxial-flow heat exchanging structures of the present
invention installed within a plurality of deviated wells, wherein
each coaxial-flow heat exchanger is installed in
thermally-conductive cement, and connected together using piping so
as to form a heat pumping network.
[0091] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein segmented,
helically-extending finned inner tube sections having alternating
left and righted handed twists are installed within
thermally-conductive outer tube sections, so that a mixing zone is
provided for turbulently mixing the heat exchanging fluid flowing
along the helically-extending outer flow channel, to break up
boundary layers that may form on the outer flow channel wall
surfaces, and thereby increasing the efficiency of the system to
exchange heat energy with the ambient environment.
[0092] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein a segmented
helically-finned inner tube section, with integrated mixing zones,
is installed in the outer tube sections of the coaxial-flow heat
exchanging structure.
[0093] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein segmented
helically-finned inner tube sections, with fluid mixing zones
formed there-between, are realized using tube segments made of
extruded pieces that are joined together by plastic couplings that
are glued or welded together.
[0094] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an inner tube section
with helically-finned segments applied to the outer surface
thereof.
[0095] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an inner tube section
with wrap-around type single fin segments applied thereabout so as
to realize helically-finned inner tube sections within the
thermally-conductive outer tube section of the structure.
[0096] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an inner tube section
with wrap-around single fin segments applied to the outer surface
of the inner tube section, wherein the wrap-around single fin
segments have an integrated base layer that has been extruded flat
and parallel while heated to its plastic point, and wherein the
segment can be wrapped around a mandrel so as to provide the fin
with a helical pitch to match the tubing or hose size to be
employed within a coaxial-flow heat exchanging structure.
[0097] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an inner tube section
with a plurality of wrap-around single fin segments applied to the
outer surface thereof, wherein said fin segments have a left hand
twist.
[0098] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an inner tube section
with a plurality of single helical fin segments installed on the
outer surface thereof, and the inner tube section contained within
the outer tube section, and provided with a re-mixing zone between
the helical fin segments for the turbulent mixing of heat
exchanging fluid along a helically-extending outer flow channel
realized between the inner and outer tube sections.
[0099] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an inner tube section
supporting segmented single helical fin segments, having
alternating left and righted handed twists, and providing a
re-mixing zone between the helical fin segments for the turbulent
mixing of heat exchanging fluid along a helically-extending outer
flow channel realized between the inner and outer tube
sections.
[0100] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an inner tube section
with multiple-fin segments applied about the outer surface thereof
so as to realize a helically-finned inner tube section employed in
the coaxial-flow heat exchanging structure.
[0101] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an inner tube section
with multiple-fin segments applied about the outer surface thereof
so as to realize the helically-finned inner tube sections employed
in the coaxial-flow heat exchanging structure.
[0102] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an helically-finned
that is formed using plastic molding techniques.
[0103] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an helically-finned
inner tube section that is formed using extrusion techniques.
[0104] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an helically-finned
inner tube section that is formed using plastic molding
techniques.
[0105] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an helically-finned
inner tube section constructed from molded plastic fin segments,
wherein the pitch on the fin segments is selected based on the
amount of rotational fluid flow needed in the helically extending
outer flow channel formed between the inner and outer flow channels
of the coaxial-flow heat exchanging structure.
[0106] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an helically-finned
inner tube section constructed from molded plastic fin segments,
wherein tabs and slots are provided on the base of the fin segments
so as to snap together the segments about the outer surface of the
inner tube section, after which the connection points can be glued
or welded together.
[0107] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an helically-finned
inner tube section constructed from molded plastic fin segments,
wherein at least one pair of the fin segments have the same twist
directions within the outer tube section for supporting a mixing
zone along the helically-extending outer flow channel formed
between the inner and outer tube sections.
[0108] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein a pair of
multi-finned segmented tubing sections with (flow-guiding) fins
having alternating twist directions are installed within an outer
tube section for supporting a mixing zone along a
helically-extending outer flow channel formed between the inner and
outer tube sections.
[0109] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure installed within a well bore
formed in Earth, and surrounded by thermally-conductive cement
containing carbon and/or aluminum oxide flakes, or metallic fibers
or other thermal conductivity enhancing particles.
[0110] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure installed in a well bore
formed in the Earth and surrounded by thermally-conductive cement
that was pumped within the well bore and filled up the interstices
of the well bore during the installation phase.
[0111] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having an helically-finned
inner tube section, a thermally-conductive outer tube section, and
a fluid re-mixing zone along an outer flow channel formed between
the inner and outer tube sections, for mixing a helically-rotating
fluid flowing there-along so as to increase the heat transfer
efficiency of the system.
[0112] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having a thermally-insulated
inner tube section, a thermally-conductive outer tube section and
an outer flow channel formed therebetween, wherein a plurality of
rows of zig-zagging fluid turbulence generators/projections are
provided as segments on the outer surface of the inner tube section
for the purpose of generating turbulence in the heat exchanging
fluid flowing through the outer flow channel.
[0113] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having a thermally-insulated
inner tube section, a thermally-conductive outer tube section and
an outer flow channel formed therebetween, wherein a plurality of
fluid turbulence generators/projections provided on the outer
surface of the inner tube section for the purpose of generating
turbulence in the heat exchanging fluid flowing through the outer
flow channel.
[0114] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure having a thermally-insulated
inner tube section, a thermally-conductive outer tube section and
an outer flow channel formed therebetween, wherein the inner tube
section and its plurality of helically extending fins are formed by
an extrusion process, and subsequently inserted within the outer
tube section to form the helically-extending flow channels between
the inner and outer tube sections.
[0115] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein the inner tube
section has a single helically-extending fin structure, of discrete
structure, disposed along the outer flow channel between the inner
and outer tube sections, for the purpose of generating turbulence
in the flow of exchanging fluid along the outer flow channel.
[0116] A coaxial-flow heat exchanging structure of the present
invention, wherein the inner tube section has multiple rows of
discrete fin segments helically-extending along the outer flow
channel between the inner and outer tube sections, and formable as
flexible planar segments (through modeling techniques) and then
applied about the outer surface of the inner tube structure.
[0117] Another object of the present invention is to provide a
coaxial-flow heat exchanging structure, wherein a continuous
helically-extending turbulence generating structure along the outer
flow channel between the inner and outer tube sections.
[0118] Another object of the present invention is to provide a heat
transfer system comprising at least one coaxial-flow heat transfer
(i.e. exchanging) structure, wherein its thermally conductive outer
tube section is installed within a well bore and surrounded by
beads of graphite, synthetic graphic, carbon and graphite mixtures,
or other metallic (aluminum pellets) or non-metallic heat transfer
enhancing pellets, used to form a thermally-conductive region
between layers of cement presented at the top and bottom of the
well bore.
[0119] Another object of the present invention is to provide a heat
transfer system comprising at least one coaxial-flow heat transfer
structure, wherein the entire space between the outer tube section
and the inner surface of the bore hole is shown filled up with
beads of graphite, synthetic graphic, carbon and graphite mixtures,
or other metallic (aluminum pellets) or non-metallic heat transfer
enhancing pellets, so as to create an environment (with very high
heat transfer properties) surrounding the exterior surface of the
outer tube of the coaxial heat transfer structure.
[0120] Another object of the present invention is to provide such a
heat transfer system, wherein the small spaces (i.e. interstices)
between the pellets or beads eventually fill up with silt, earth or
rock formations from the surrounding environment, thereby creating
an environment (with very high heat transfer properties)
surrounding the exterior surface of the outer tube of the coaxial
heat transfer structure, for efficiently transferring heat to or
from the heat transfer fluid flowing through the co-axial flow heat
transfer structure.
[0121] Another object of the present invention is to provide a heat
transfer system comprising at least one coaxial-flow heat transfer
structure, wherein the outer tube section thereof is provided with
an end cap structure having one or more reverse hooks that are
connected thereto by way of bolts or pins, and which protract and
dig into the sides of the bore hole in response to upwardly
directed forces generated at the bottom of a bore hole into which
the outer tube section has been installed.
[0122] Another object of the present invention is to provide such a
heat transfer system comprising at least one coaxial-flow heat
transfer structure, wherein the entire space between the outer tube
section and the inner surface of the bore hole is shown filled up
with beads of graphite, synthetic graphic, carbon and graphite
mixtures, or other metallic (aluminum pellets) or non-metallic heat
transfer enhancing pellets, so as to create an environment (with
very high heat transfer properties) surrounding the exterior
surface of the outer tube of the coaxial heat transfer
structure.
[0123] These and other objects of the present invention will become
apparent hereinafter and in the Claims to Invention.
BRIEF DESCRIPTION OF DRAWINGS
[0124] For a more complete understanding of how to practice the
Objects of the Present Invention, the following Detailed
Description of the Illustrative Embodiments can be read in
conjunction with the accompanying Drawings, briefly described
below, in which visual descriptions are provided showing the
installation of the present invention in the ground, water, air,
and/or mud line environments, with like reference numerals
indicating like structures.
[0125] FIG. 1 is a schematic representation of a longitudinal
cross-section of a prior art tube section carrying a flowing fluid,
illustrating a laminar fluid flow profile across the interior of
the tube, in which the velocity of the fluid traveling through the
tube is maximum in the center of the tube and decreases from the
center to the inner surface of the tube.
[0126] FIG. 1A is a schematic representation of a traverse
cross-section of the prior art tube of FIG. 1, further illustrating
that the friction presented at the boundary surface layer between
the tube and the fluid causes (i) a gradient in velocities across
the tube (giving rise to different annular flow velocities), and
(ii) a corresponding reduction in capacity of heat energy transfer
from the fluid into the tube wall material during fluid flow.
[0127] FIG. 1B is a schematic representation of a prior art "U"
tube type heat transfer ground loop system buried in the Earth for
the purpose of transferring (i.e. sinking) heat energy into the
Earth, and illustrating that the overall capacity of the system to
transfer heat energy into the Earth is diminished due to the heat
energy exchange between adjacent tubes in the system.
[0128] FIG. 1C is a schematic representation of a prior art "U"
tube type heat transfer ground loop system buried in the Earth for
the purpose of extracting heat energy from the Earth, and
illustrating that the overall capacity of the system to transfer
heat energy into the Earth is diminished due to the heat energy
exchange between adjacent tubes in the system.
[0129] FIG. 2 is a schematic representation of a heat transfer
system employing conventional mechanical heat transfer equipment,
and at least one coaxial-flow heat transfer (i.e. exchanging)
structure of the present invention comprising (i) a thermally
conductive outer tube section, and (ii) an inner tube section
having an inner flow channel having a substantially uniform inner
diameter along its entire length and being coaxially installed
within the outer tube section, and supporting helically-arranged
turbulence generating fins on its outer surface, so as to form at
least one helically-extending outer flow channel between the inner
and outer tube sections, so that heat energy contained within a
heat exchanging fluid flowing down the inner flow channel and along
the helically-arranged outer flow channel, is exchanged through the
walls of the outer tube section and into the ambient
environment.
[0130] FIG. 3 is a front elevated view showing a section of
helically-finned inner tube section used to create the
helically-extending outer flow channel between the inner and outer
tube sections of the coaxial-flow heat exchanging structure of the
present invention;
[0131] FIG. 4 is a back elevated view of the section of
helically-finned inner tubing shown in FIG. 3;
[0132] FIG. 5 is a front elevated view showing an inner tube
section supporting, on its outer surface, double sets of
helically-extending fins for use in creating a double
helically-extending outer flow channel between the inner tube
section and the thermally-conductive outer tube section of the
coaxial-flow heat transfer structure of the present invention.
[0133] FIG. 6 is a front view showing a central tube section
inserted within an inner tube section supporting, on its outer
surface, single helically-extending fin, for use in creating a
single helically-extending outer flow channel between the inner
tube section and the thermally-conductive outer tube section shown
in FIG. 3;
[0134] FIG. 7 is the top view of a single helically-finned tube
subassembly shown in FIG. 6, wherein the gas gap between the
central tube section and the helically-finned inner tube section
provides thermal insulation to the heat transferring fluid flowing
along the inner flow channel of the central tube section, and
wherein the gap distance between the walls of these tube sections
remains substantially uniform along the length of the subassembly,
due to a plurality of standoffs provided on the outer surface of
the central tube section;
[0135] FIG. 8 is the front elevated view of an inner tube section
supporting, on its outer surface, a single helically-extending
(fluid-guide) fin that can be extruded with the inner tube section
for small diameters, or alternatively can be extruded over a tube
of larger diameter, wherein for diameters exceeding 18 inches or
0.5 meters, the helically extending fins can be rolled from flat
stock and welded on the outer surface of the inner tube.
[0136] FIG. 9 is the top view of the single helically-finned tube
subassembly shown in FIG. 8;
[0137] FIG. 10 is the top view of the double helically-finned tube
subassembly shown in FIG. 5, designed for installation within a
thermally-conductive outer tube section of the coaxial-flow heat
transfer structure of the present invention.
[0138] FIG. 11 is a front view of the central tube section that can
be installed in the coaxial-flow heat transfer structure of the
present invention, wherein its standoffs provide a gas gap needed
for insulation between the central tube section and the
helically-finned inner tube section, and wherein the insulation gas
can be argon, nitrogen, or even ethane.
[0139] FIG. 12 is the top view of a central tube section shown in
FIG. 11;
[0140] FIG. 13 is an elevated front view of a helically-finned
inner tube section fitted with a thermally-insulated central tube
section and a joint collar for use in coaxial-flow heat transfer
structures having outer tube sections with large diameters.
[0141] FIG. 14 is a bottom view of the thermally-insulated
helically-finned inner tube section shown in FIG. 13.
[0142] FIG. 15 is a cross-sectional view of the thermally-insulated
helically-finned inner tube section shown in FIG. 14, taken along
the line 15-15 thereof showing the insulated central inner tube
section or sleeve (e.g. made from high density, foamed plastic)
that is fusion welded on both ends inside the helically-finned
inner tube section of a coaxial-flow heat transfer structure of the
present invention, so as to provide a gas gap, filled with high
pressure argon or other gas before being fusion welded
together.
[0143] FIG. 16 is an elevated front view of a helically-finned
inner tube section fitted with a joint collar but without a
thermally-insulated central tube section, for use in coaxial-flow
heat transfer structures having outer tube sections with large
diameters.
[0144] FIG. 17 is a top view of the helically-finned inner tube
section shown in FIG. 16.
[0145] FIG. 18 is a cross-sectional view of the helically-finned
inner tube section shown in FIG. 16, taken along the line 18-18
thereof.
[0146] FIG. 19 is an elevated front view of a helically-finned
inner tube section fitted with a thermally-insulated central tube
section supporting, on its outer surface, double sets of
helically-extending fins for use in creating a double
helically-extending outer flow channel between the inner tube
section and the thermally-conductive outer tube section of the
coaxial-flow heat transfer structure of the present invention.
[0147] FIG. 20 is a front view of a tubing shoe structure that is
fusion welded to the bottom of the helically-finned inner tube
section of the coaxial-flow heat transfer structure of the present
invention, so as to protect the helically-extending fins during the
installation process.
[0148] FIG. 21 is a top view of the helically-finned tubing shoe
shown in FIG. 20.
[0149] FIG. 22 is a front view of a smooth thermally-conductive
outer tube section for use in the coaxial-flow heat transfer
structure of the present invention, wherein the outer tube section
is preferably made from metal to provide a high heat transfer
coefficient, and has threaded collars for attaching the joints of
tube sections together, and is grouted in the Earth using thermally
conductive cement to maximize
[0150] FIG. 23 is a top view of the thermally-conductive outer tube
section of FIG. 22.
[0151] FIG. 24 is a side view of the thermally-conductive outer
tube section of FIG. 26.
[0152] FIG. 25 is a front view of a fluted thermally-conductive
outer tube section for use with the coaxial-flow heat transfer
structure of the present invention, wherein the flutes on the
thermally-conductive plastic outer tube section provide additional
surface area to counteract the low heat transfer coefficient of the
plastic material, and provide the thermally-conductive plastic
outer tube additional strength when grouted in the Earth using
thermally conductive cement.
[0153] FIG. 26 is a top view of the fluted thermally-conductive
outer tube section of FIG. 25, taken along line 26-26 therein.
[0154] FIG. 27 is a side view of the fluted thermally-conductive
outer tube section of FIG. 26, taken along line 27-27 therein.
[0155] FIG. 28 is a partial cross-sectional view of a coaxial-flow
heat transfer structure of the present invention employing a single
helically-finned inner tube section installed within a thermally
conductive outer tube section, and shown being operated in its
forward flow direction, wherein a heat exchanging fluid is pumped
through its input port and down the inner flow channel of the inner
tube section, where upon reaching the bottom of the inner tube
section, the fluid reverses its direction at the distal portion of
the coaxial-flow heat transfer structure, and then flows along the
helically-extending outer flow channel and out the output port at
the proximal end.
[0156] FIG. 29 is a partial cross-sectional view of a coaxial-flow
heat transfer structure of the present invention employing a single
helically-finned inner tube section installed within a thermally
conductive outer tube section, shown operated in its reverse flow
direction, wherein a heat exchanging fluid is pumped through its
input port and down the outer helical flow channel between the
outer and inner tube sections, where upon it reverses direction at
the distal portion of the coaxial-flow heat transfer structure, and
then flows along the inner flow channel and out the output port at
the proximal end.
[0157] FIG. 30 is a partial cross-sectional view of a coaxial-flow
heat transfer structure of the present invention employing a double
helically-finned inner tube section installed within a thermally
conductive outer tube section, shown operated in its forward flow
direction, wherein a heat exchanging fluid is pumped through the
input port and down the inner flow channel of the inner tube
section, where upon it reverses direction at the distal portion of
the coaxial-flow heat transfer structure, and then flows along the
outer helical flow channel and out the output port at the proximal
end.
[0158] FIG. 31 is a front, partially cross-sectional view of a
coaxial-flow heat transfer structure of the present invention
having a fluted thermally-conductive outer tube section with a
single helically finned inner tube section installed therein so as
to provide a helically-extending outer flow channel that
corresponds with the fluted surfaces along the outer tube
section.
[0159] FIG. 32 is a cross-sectional view of the coaxial-flow heat
transfer structure of the present invention, taken along line 32-32
in FIG. 31.
[0160] FIG. 33 is a front, partially cross-sectional view of a
coaxial-flow heat transfer structure of FIGS. 31 and 32, showing
the helical flow pattern of heat exchanging fluid as it is pumped
down the helically-extending outer flow channel and flows up the
coaxially-arranged inner flow channel of the coaxial-flow
structure.
[0161] FIG. 34 is a front, partially cross-sectional view of the
coaxial-flow heat transfer structure of FIGS. 31 and 32, showing
the helical flow pattern of heat exchanging fluid as it is pumped
down the inner flow channel and flows up the coaxially-arranged
helically-extending outer flow channel of the coaxial-flow
structure.
[0162] FIG. 35 is a schematic representation of a heat transfer
system comprising conventional heat transfer equipment in
collaboration at least one coaxial-flow heat transfer structure of
the present invention, as generally depicted in FIG. 2.
[0163] FIG. 36 is an enlarged view of a section of the
helically-extending outer flow channel provided in the coaxial-flow
heat transfer structure of FIG. 35, showing that the
cross-sectional dimensions of the outer flow channel can be
selected/designed to produce fluid flows therealong having optimal
vortex characteristics that optimize heat transfer between the
fluid within the outer flow channel and the surface of the
thermally-conductive outer tube section.
[0164] FIG. 37 is a schematic representation of the cross-section
of the outer flow channel identified in FIG. 36, wherein when the
ratio of the sides of the outer flow channel cross-section
approaches 1/1.1 (i.e. indicative of a square-like flow control
volume), the resulting fluid flow through the outer flow channel
will typically have one vortex for flow rates of interest.
[0165] FIG. 38 is a schematic representation of the cross-section
of the outer flow channel identified in FIG. 36, wherein when the
ratio of the sides of the outer flow channel cross-section
approaches 1/2.5 (i.e. indicative of a rectangular-like flow
control volume), the resulting fluid flow through the outer flow
channel will typically have two vortices for flow rates of
interest.
[0166] FIG. 39 is a schematic representation of the cross-section
of the outer flow channel identified in FIG. 36, wherein when the
ratio of the sides of the outer flow channel cross-section
approaches 1/4.0 (i.e. indicative of a rectangular-like flow
control volume), the resulting fluid flow through the outer flow
channel will typically have two vortices (one near each helical
fin) with a laminar slot flow region in the center region, for flow
rates of interest.
[0167] FIG. 40 is a perspective partially cross-sectional view of
coaxial-flow heat transfer structure of the present invention
illustrated in FIG. 37, when the aspect ratio of the sides of the
outer flow channel cross-section approaches 1/1.1 (i.e. indicative
of a square-like flow control volume), and the resulting fluid flow
through the helically-extending outer flow channel will typically
have a single vortex (i.e. rotational flow) for flow rates of
interest.
[0168] FIG. 41 is a perspective partially cross-sectional view of
coaxial-flow heat transfer structure of the present invention
illustrated in FIG. 38, wherein when the aspect ratio of the sides
of the outer flow channel cross-section approaches 1/2.25 (i.e.
indicative of a rectangular-like control volume), the resulting
fluid flow through the helically-extending outer flow channel will
typically have two vortices for flow rates of interest.
[0169] FIG. 42 is a perspective partially cross-sectional view of
coaxial-flow heat transfer structure of the present invention
illustrated in FIG. 39, wherein when the aspect ratio of the sides
of the outer flow channel cross-section approaches 1/4.0 (i.e.
indicative of a rectangular-like flow control volume), the
resulting fluid flow through the helically-extending outer flow
channel will typically have two vortices (one near each helical
fin) with a laminar flow region in the center region, for flow
rates of interest.
[0170] FIG. 43 is a front, partially cross-section view of a
coaxial-flow heat transfer structure of the present invention,
having a corrugated thermally-conductive outer tube section and a
single helically-finned inner tube section, producing a helically
extending outer flow channel along which turbulence is produced in
the heat exchanging fluid flowing therealong.
[0171] FIG. 44 is a side, partially cross-sectional view of a
coaxial-flow heat exchanging structure, graphically illustrating
the fluid distribution from a piped manifold around the helically
extending annular outer flow channel of the coaxial-flow heat
exchanging structure, as well as around the end of the inner tube
section at the distal portion of the structure.
[0172] FIG. 45 is a side, partially cross-sectional view of a
coaxial-flow heat exchanging structure of the present invention
installed in a well bore in the Earth, showing locations of holes
punched or threaded into a manifold cap installed at the proximal
end, and to securely hold the helically-finned inner tube section
away from and off the bottom of the thermally-conductive outer tube
that has been grouted into the Earth with thermally-conductive
cement and provide field installed pipe connection to the manifold
cap shown.
[0173] FIG. 46 is a top view of coaxial-flow heat exchanging
structure shown in FIG. 45, with the fluid return and injection
manifold removed for clarity, and showing the use of several small
holes formed in the cap portion to achieve a low friction-created
pressure drop, or alternatively, the use of a single medium size
hole for a higher friction-created pressure drop.
[0174] FIG. 47 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure shown in FIG. 45, with the
fluid return and injection manifold removed for clarity of
illustration, showing a compression-ring type cap welded onto the
proximal end of the coaxial-flow heat exchanging structure of the
present invention, wherein the cap employs an O-ring or U-ring seal
around the proximal portion of the outer tube section to prevent
fluid leaks.
[0175] FIG. 48 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure shown in FIG. 49, with the
fluid return and injection manifold removed for clarity of
illustration, showing a clamped-type cap installed on the
coaxial-flow heat exchanging structure of the present invention,
wherein the cap has an O-ring or U-ring seal around the proximal
portion of the thermally-conductive outer tube section to prevent
fluid leaks.
[0176] FIG. 49 is a top view of the coaxial-flow heat exchanging
structure shown in FIG. 48, taken along line 49-49 in FIG. 48.
[0177] FIG. 50 is a side view of the structure shown in FIG. 44
showing the injection manifold field installed from commonly
acquired piping material and fittings.
[0178] FIG. 51 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention
ideal for use in concrete piling or pier installations, wherein a
pair of tube fittings are welded or fused to the side of the
thermally-conductive outer tube section, for the injection and
returning heat exchanging fluids to the inner and outer flow
channels realized therein.
[0179] FIG. 52 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention
ideal for use in concrete piling or pier installations, wherein a
pair of tube fittings are welded or fused to a welded or clamped
cap for the injection and returning heat exchanging fluids to the
inner and outer flow channels realized therein.
[0180] FIG. 53 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention
shown installed in a deviated well bore in the Earth, wherein the
horizontal section of the structure is drilled into an aquifer zone
and the vertical section thereof connects the horizontal section
back to the Earth's surface.
[0181] FIG. 54 is a side view of the coaxial-flow heat exchanging
structure of the present invention shown installed in a vertical
well bore in the Earth, for the purpose of distributing heat into
the Earth from the operation of a natural gas dehydration system
connected thereto.
[0182] FIG. 55 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention
shown installed in a near horizontally-bored well in the side of a
mountain, mesa, or hill, wherein the well bore path is deviated to
follow an aquifer zone if available at the site, and wherein, for
buildings with a deep basement or built on the side of a hill, the
deviated well bores are drilled in the wall of the basement.
[0183] FIG. 56 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention
shown suspended vertically in an aqueous solution, Earth, chemical
solution or mud.
[0184] FIG. 57 is a side, partially cross-sectional view of a
coaxial-flow heat exchanging structure of the present invention
that is ideal for use in foundation installations, wherein the tube
fittings are in a state of compression, and wherein a tube fitting
is welded to the side of the thermally-conductive outer tube
section for returning the heat exchanging fluid to the external
system.
[0185] FIG. 58 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention
shown installed vertically in foundations or pilings of a bridge
pier or like structure.
[0186] FIG. 59 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention
shown suspended vertically in an aqueous solution or mud, wherein
radially-extending metal heat exchanging fins are provided on the
outer tube section to increase the heat transfer area thereof,
thereby making the circulation of aqueous solution thereabout
function as an external thermo-siphon.
[0187] FIG. 60 is a side, partially cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention as
shown in FIG. 59 showing how the fins run along the exterior
surface of the outer tube.
[0188] FIG. 61 shows the coaxial-flow heat exchanging structure of
the present invention installed in a bridge component or piling,
wherein in earthquake areas, the pilings are wrapped in a metal
sheath to prevent structural damage in the earthquake, and
helically-extending outer flow channels provide a ground/water
source heat to prevent icing of the road way or sidewalks during
the winter season.
[0189] FIG. 62 shows the coaxial-flow heat exchanging structure of
the present invention installed in a bridge component or piling,
wherein in earthquake areas, the pilings are wrapped in a metal
sheath to prevent structural damage in the earthquake, and
helically extending outer flow channels provide a ground/water
source heat to prevent icing of the road way or sidewalks during
the winter.
[0190] FIG. 63 shows the coaxial-flow heat exchanging structure of
the present invention installed in a bridge component or piling,
wherein in earthquake areas, the pilings are wrapped in a metal
sheath to prevent structural damage in the earthquake, and the
helically-extending outer flow channels provide a ground/water
source of heat energy to prevent icing of the road way or sidewalks
during the winter season.
[0191] FIG. 64 is a schematic representation of a first application
of a single coaxial-flow heat exchanging structure of the present
invention installed within the Earth about a residential home.
[0192] FIG. 65 is a schematic representation of a first application
of a single coaxial-flow heat exchanging structure of the present
invention installed within the Earth about a residential home,
wherein an optional thermal bank tank is provided for night-time
operation when the electrical energy costs are less, or for daytime
operation when solar cells can provide electrical energy to the
home.
[0193] FIG. 66 is a schematic representation of a first application
of a three coaxial-flow heat exchanging structure of the present
invention installed within the Earth about a residential home.
[0194] FIG. 67 schematically illustrates a second application where
nine deviated wells are pad drilled in order to minimize the ground
surface impact, reducing heat loss from horizontal gathering piping
and reducing risk of accidental damage from contractor digging
operations, wherein long term operation allows the ground loop to
thermally bank heat from the cooling season for use in the winter
season, and for cooling loads only, a shallow horizontal loop can
be added to the ground-loop to remove heat from the thermal bank
during the winter season.
[0195] FIG. 68 illustrates the application shown in FIG. 67, taken
along line 68-68 in FIG. 68.
[0196] FIG. 69 is a schematic representation of a system comprising
eleven deviated wells, in which each coaxial-flow heat exchanger of
the present invention is installed in thermally-conductive cement,
and connected together using piping so as to form a heat pumping
network.
[0197] FIG. 70 is a schematic representation of a first application
using sea water as the heat-pump heat sink for gas dehydration and
oil de-waxing, wherein one or more coaxial-flow heat exchanging
structures of the present invention are installed in the ocean
above the ocean floor, for the purpose of extracting heat from the
gas so as to cause the temperature thereof to drop, thereby
condensing water vapor and/or light hydrocarbon vapors in the gas
stream.
[0198] FIG. 71 is a schematic representation of a second
application using ballast water as the heat-pump heat sink for gas
dehydration and oil de-waxing, wherein one or more coaxial-flow
heat exchanging structures of the present invention are installed
in the ocean above the ocean floor, for the purpose of extracting
heat from the gas so as to cause the temperature thereof to drop,
thereby condensing water vapor and/or light hydrocarbon vapors in
the gas stream.
[0199] FIG. 72 is a schematic representation of a third application
using ballast water as the heat-pump heat sink for gas dehydration
and oil de-waxing, wherein one or more coaxial-flow heat exchanging
structures of the present invention are installed below the ocean
floor, for the purpose of extracting heat from the gas so as to
cause the temperature thereof to drop, thereby condensing water
vapor and/or light hydrocarbon vapors in the gas stream.
[0200] FIG. 73 is a schematic representation of an application of
the coaxial-flow heat exchanging structure of the present invention
employed in a ground-loop heat exchanging system, designed for
dehydrating, on shore, pipeline-quality gas produced from remote
off shore wells.
[0201] FIG. 74 is a schematic representation of an application of a
number of coaxial-flow heat exchanging structures of the present
invention shown suspended in sea water, buried beneath the mud line
on the ocean floor, and used as a heat exchanger in the evaporative
section of the liquid natural gas gasification process equipment,
designed for gasifying liquid natural gas for storage and
distribution.
[0202] FIG. 75 is a schematic representation of a permanent or skid
mounted natural gas dehydration system, also shown in FIG. 73,
wherein the gas in the liquid separator is cooled to a temperature
near the aquifer temperature, the gas is then cooled using a
refrigeration system to a temperature near the gas hydrate
temperature, and wherein a glycol cycle or calcium chloride salt
cycle is used to remove moisture from the gas-hydrate temperature
to the -30 F dew point for pipeline sales, and wherein the system
reduces the energy costs of gas dehydration and eliminates the
release of benzene, toluene and other carcinogenetic hydrocarbon
vapors to the atmosphere.
[0203] FIG. 76 is a schematic representation of a submarine
employing the coaxial-flow heat exchanging structure of the present
invention installed within a seawater heat exchanging subsystem for
centralized air conditioning and equipment cooling.
[0204] FIG. 77 is a schematic representation of a submarine
employing the coaxial-flow heat exchanging structure of the present
invention installed within a seawater heat exchanging subsystem for
decentralized air conditioning and equipment cooling.
[0205] FIG. 78 is a side, partially cross-sectional view of a
coaxial-flow heat exchange structure of the present invention
constructed having fins about the outer tube exterior to be used as
a component of a heat exchanging refrigeration condenser,
refrigeration evaporator (cooling coil), heat pump heating and
cooling coil, combustion engine radiator, and a component of other
air or liquid heat exchangers having a fluid direction of flow as
shown.
[0206] FIG. 79 is a side, partially cross-sectional view of a
coaxial-flow heat exchange structure of the present invention
constructed having fins about the exterior of the outer tube
section to be used as a component of a heat exchanging
refrigeration condenser, refrigeration evaporator (cooling coil),
heat pump heating and cooling coil, combustion engine radiator,
and/or a component of other air or liquid heat exchangers having a
fluid flow direction as shown.
[0207] FIG. 80 is a side, partially cross-sectional view of a
plurality of coaxial-flow heat exchangers of the present invention,
shown used in a submarine application and other air conditioning
applications, wherein the outer tube sections are made of metal and
are finned so as to provide maximum heat transfer with the ambient
environment.
[0208] FIG. 81 is a first side view of the plurality of
coaxial-flow heat exchangers shown in FIG. 80, taken along line
81-81 therein.
[0209] FIG. 82 is a second side view of the plurality of
coaxial-flow heat exchangers shown in FIG. 80, taken along line
82-82 therein.
[0210] FIG. 83 is a front view of a plurality of coaxial-flow heat
exchanging structure of the present invention installed in a
pressure vessel used as an aqueous-based fluid-to-fluid, fluid to
air, and/or refrigeration evaporator (chiller) or condensing heat
exchanger (tube and shell heat exchanger).
[0211] FIG. 84 is a right side view of a coaxial-flow heat
exchanging structure of the present invention shown in FIG. 83.
[0212] FIG. 85 is a front view of a plurality of coaxial-flow heat
exchanging structures of the present invention shown used as an
aqueous-based, fluid to air, refrigeration evaporator (chiller) or
heat pump condensing heat exchanger.
[0213] FIG. 86 is a side partially cross-sectional view of the
aqueous-based fluid, and refrigerant evaporation based, fluid to
air heat exchanger shown in FIG. 85, taken along line 86-86
therein. wherein the outer tubes are made of metal and are finned
so as to provide maximum heat transfer with the ambient
environment, which can be made of plastic containing heat transfer
enhancing additives.
[0214] FIG. 87 is a rear view of the aqueous-based fluid, and
refrigerant evaporation based, fluid to air heat exchanger shown in
FIG. 86, taken along line 87-87 therein.
[0215] FIG. 88 is a schematic representation of a first application
of a coaxial-flow heat exchanging structure of the present
invention installed on the outlet of a furnace connected to an
outdoor compressor based condensing unit or heat pump, and
functioning as a refrigeration cooling coil or heat pump heating
and cooling coil
[0216] FIG. 89 is a schematic representation of the segmented
helically-finned inner tube section, with integrated mixing zones,
for installation in the outer tube sections of a coaxial-flow heat
exchanging structure as shown in FIG. 90.
[0217] FIG. 90 is a cross-sectional view of the segmented helically
finned inner tube section, with integrated mixing zones, installed
in the outer tube sections of a coaxial-flow heat exchanging
structure.
[0218] FIG. 91 is a schematic representation of a coaxial-flow heat
exchanging structure as shown in FIG. 90, wherein its segmented
helically-finned inner tube sections, with fluid mixing zones
formed therebetween, are realized using tube segments made of
extruded pieces that are joined together by plastic couplings that
are glued or welded together.
[0219] FIG. 92 is a schematic representation of a segment of a
coaxial-flow heat exchanging structure, wherein it has one
segmented helically-finned inner tube section on one end, and one
fluid mixing zone formed on the opposite end, wherein the extruded
pieces are joined together by plastic couplings that are glued or
welded together.
[0220] FIG. 93 is a schematic representation of a wrap-around type
single fin segment that can be applied about a section of flexible
or rigid (inner) tubing so as to realize the helically-finned inner
tube sections employed in the coaxial-flow heat exchanging
structure of FIG. 96.
[0221] FIG. 94 is a schematic representation of a wrap-around type
single fin segment shown as it would appear wrapped in one
direction about a section of flexible or rigid (inner) tubing so as
to realize the helically-finned inner tube sections employed in the
coaxial-flow heat exchanging structure of FIG. 96.
[0222] FIG. 95 is a schematic representation of a wrap-around type
single fin segment shown as it would appear wrapped in the opposite
direction as shown in FIG. 95 about a section of flexible or rigid
(inner) tubing so as to realize the helically-finned inner tube
sections employed in the coaxial-flow heat exchanging structure of
FIG. 96.
[0223] FIG. 96 is a schematic cross-sectional view of the segmented
helically-finned inner tube section shown installed within
thermally-conductive outer tube sections of the coaxial-flow heat
exchanging structure, so that a mixing zone is provided for
turbulently mixing the heat exchanging fluid flowing along the
helically-extending outer flow channel, to break up boundary layers
that may form on the wall surfaces of the outer flow channel,
thereby increasing the efficiency of the system to exchange heat
energy with the ambient environment.
[0224] FIG. 97 is a cross-sectional view of an alternative
illustrative embodiment of the coaxial-flow heat exchanging
structure of the present invention, wherein a segmented,
helically-extending finned inner tube sections having alternating
left and righted handed twists are installed within
thermally-conductive outer tube sections of the coaxial-flow heat
exchanging structure, so that a mixing zone is provided for
turbulently mixing the heat exchanging fluid flowing along the
helically-extending outer flow channel, to break up boundary layers
that may form on the outer channel wall surfaces, and thereby
increasing the efficiency of the system to exchange heat energy
with the ambient environment.
[0225] FIG. 98 is a perspective view of the wrap-around single fin
segment with its integrated base layer that has been extruded flat
and parallel while heated to its plastic point, wherein the segment
can be wrapped around a mandrel so as to provide the fin with a
helical pitch to match the tubing or hose size to be employed
within a coaxial-flow heat exchanging structure as shown in FIG.
90.
[0226] FIG. 99 is a side view of a wrap-around single fin segment
having a left hand twist--in comparison with a right hand
twist--provided to the wrap-around fin segment shown in FIG.
98.
[0227] FIG. 100 is a schematic representation of a segmented
helically-finned inner tube section employed in the coaxial-flow
heat transfer structure of FIG. 90.
[0228] FIG. 101 is a plan view of a molded or extruded
multiple-finned segment, shown prior to configuration about inner
tube sections installed within a coaxial-flow heat exchanging
structure as shown in FIG. 102.
[0229] FIG. 102 is a side partial cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention
constructed from single fin segments installed on one or more inner
tube sections contained within the outer tube (i.e. outer casing),
and provided with a re-mixing zone between helical fin segments for
the turbulent mixing of heat exchanging fluid along the helically
extending outer flow channel.
[0230] FIG. 103 is a side, partial cross-sectional view of the
coaxial-flow heat exchanging structure of the present invention
employing segmented single fin segments, having alternating left
and righted handed twists, installed on a inner tube sections
contained within the outer tube sections of the structure, and
providing a re-mixing zone between helical fin segments for the
turbulent mixing of heat exchanging fluid along the
helically-extending outer flow channel.
[0231] FIG. 104 is a schematic representation of a machine designed
to automatically attach single or multi-finned segments onto the
outer surface of flexible tubing as the tubing is being rolled off
a support spool, and for the assembled finned tubing structure to
then be rolled up onto a storage spool for subsequent transport to
a site where coaxial-flow heat transfer structures are to be
constructed in accordance with the present invention.
[0232] FIG. 105 is a schematic representation of a ground-supported
spool of multi-finned heat exchanging segments for use in
constructing coaxial-flow heat transfer structures according to the
present invention, wherein the spool of segments are shown being
loaded into an outer tube section (i.e. casing) that has been
installed within a well bore filled with thermally-conductive
cement.
[0233] FIG. 106 is a cross-sectional view of a well head
illustrating how commonly found metallic or plastic fittings can be
used to connect piping used to direct the heat transfer fluid to
and from heating, cooling or other heat transfer circulating
devices and equipment in connection with an arrangement of
coaxial-flow heat exchanging structures of the present
invention.
[0234] FIG. 107 is a perspective partially cross-sectional view of
a coaxial-flow heat exchanging structure of the present invention,
wherein a plurality of rows of zig-zagging fluid turbulence
generators/projections are provided as segments on the outer
surface of the inner tube section for the purpose of generating
turbulence in the heat exchanging fluid flowing through the outer
flow channel.
[0235] FIG. 108 is an elevated side view of the plurality of fluid
turbulence generators/projections provided on the outer surface of
the inner tube section of the coaxial-flow heat exchanging
structure of FIG. 107.
[0236] FIG. 109 is a cross-sectional view of the inner tube section
of the coaxial-flow heat exchanger, taken along line D-D shown in
FIG. 108.
[0237] FIG. 110 is a partially transparent perspective view of a
coaxial-flow heat exchanging structure of the present invention,
wherein the inner tube section and its plurality of helically
extending fins are formed by an extrusion process, and subsequently
inserted within the outer tube section to form the
helically-extending flow channels between the inner and outer tube
sections.
[0238] FIG. 111 is an elevated side view of a coaxial-flow heat
exchanging structure of the present invention, wherein the outer
tube section, inner tube section and helically-extending fins are
formed as a unitary product using a plastic extrusion process.
[0239] FIG. 112 is a perspective view of the coaxial-flow heat
exchanging structure of FIG. 111.
[0240] FIG. 113 is a cross-sectional view of the coaxial-flow heat
exchanging structure of FIG. 112, taken along line B-B therein.
[0241] FIG. 114 is a perspective, partially cutaway view of a
coaxial-flow heat exchanging structure of another embodiment of the
present invention, wherein the inner tube section has multiple rows
of discrete fin segments helically-extending along the outer flow
channel between the inner and outer tube sections, and formable as
flexible planar segments (through modeling techniques) and then
applied about the outer surface of the inner tube structure.
[0242] FIG. 115 is a perspective, partially cutaway view of a
coaxial-flow heat exchanging structure of another embodiment of the
present invention, employing a continuous helically-extending
turbulence generating structure along the outer flow channel
between the inner and outer tube sections.
[0243] FIG. 116 is a perspective view of a single helically-finned
turbulence generating structure having a solid shaft, designed for
insertion within conventional tubing for the purpose of generating
flow turbulence along the flow channel thereof, and increase heat
transfer through the tube walls.
[0244] FIG. 117 is a perspective view of a conventional U-tube
ground loop, as shown in FIGS. 1B and 1C, with the helically-finned
turbulence generating structure of FIG. 116 installed within the
flow channel thereof for the purposes of improving heat transfer
efficiency to the ambient environment.
[0245] FIG. 118 is a schematic diagram of an air conditioning
system employing a system of ground loop heat transferring wells
employing coaxial-flow heat transfer structures of the present
invention therein, functioning as a heat transfer sub-system
connected to a water-cooled ground source condensing unit found on
a typical air conditioning system, where an electric or gas fired
furnace is used during the heating mode of operation.
[0246] FIG. 119 is a schematic diagram of an air conditioning
system employing a system of ground loop heat transferring wells
employing coaxial-flow heat transfer structures of the present
invention therein, functioning as a heat transfer sub-system
connected to a water-to-water air conditioning heat pump.
[0247] FIG. 120 is a schematic representation of a RF (or
microwave) transmission/reception tower and accompanying base
station housing (i.e. shelter) sensitive electronic equipment
within an environment that is thermally controlled by a system
employing a plurality of coaxial-flow heat exchanging structures of
the present invention installed in a plurality of vertical well
bores, using thermally conductive cement.
[0248] FIG. 121 is a schematic representation of a heat transfer
system of the present invention employing conventional mechanical
heat transfer equipment, and at least one coaxial-flow heat
transfer (i.e. exchanging) structure of the present invention
wherein its thermally conductive outer tube section is shown
installed within a well bore and surrounded by beads of graphite,
synthetic graphic, carbon and graphite mixtures, or other metallic
(aluminum pellets) or non-metallic heat transfer enhancing pellets,
used to form a thermally-conductive region between layers of cement
presented at the top and bottom of the well bore.
[0249] FIG. 122 is an exploded diagram of the heat transfer
enhancing pellets or beads employed in the system of FIG. 122,
showing that the small spaces (i.e. interstices) between the
pellets or beads eventually fill up with silt, earth or rock
formations from the surrounding environment, thereby creating an
environment (with very high heat transfer properties) surrounding
the exterior surface of the outer tube of the coaxial heat transfer
structure, for efficiently transferring heat to or from the heat
transfer fluid flowing through the co-axial flow heat transfer
structure.
[0250] FIG. 123 is a schematic representation of the outer tube
section of the coaxial heat transfer structure of the present
invention that is provided with an end cap structure having one or
more reverse hooks that are connected thereto by way of bolts or
pins, and shown being lowered into a predrilled bore hole by way of
a guide cable.
[0251] FIG. 123A is a schematic representation of the outer tube
section of the coaxial heat transfer structure of FIG. 123, wherein
the reverse hooks of its end cap structure are shown protracted and
partially digging into the sides of the bore hole in response to
upwardly directed forces generated at the bottom of the bore
hole.
[0252] FIG. 123B is a schematic representation of the outer tube
section of the coaxial heat transfer structure of FIG. 123, wherein
the reverse hooks of its end cap structure are shown digging deeply
into the sides of the bore hole in further response to upwardly
directed forces.
[0253] FIG. 123C is a schematic representation of the outer tube
section of the coaxial heat transfer structure of FIGS. 123A and
123B, wherein the entire space between the outer tube section and
the inner surface of the bore hole is shown filled up with beads of
graphite, synthetic graphic, carbon and graphite mixtures, or other
metallic (aluminum pellets) or non-metallic heat transfer enhancing
pellets, so as to create an environment (with very high heat
transfer properties) surrounding the exterior surface of the outer
tube of the coaxial heat transfer structure.
[0254] FIGS. 124 and 125 are perspective and side views of a
machined or molded end cap portion of the end capture structure of
FIG. 123, respectively, which can be fitted, welded, or glued to
the distal end of the outer tube section of the coaxial heat
transfer structure of the present invention, as shown in FIGS. 123
through 123B.
[0255] FIG. 126 is a perspective view of one of the reverse hooks
used in the end capture structure shown in FIGS. 123 through 123C,
wherein the reverse hook has a machined slot for allowing the
reverse hook to rotate and fold closely against the outer tube
section when the outer tube section is being lowered into a bore
hole.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS OF THE PRESENT
INVENTION
[0256] Referring to the figures in the accompanying Drawings, the
various illustrative embodiments of the coaxial-flow heat
exchanging (i.e. transferring) structure of the present invention
will be described in great detail, wherein like elements will be
indicated using like reference numerals.
[0257] As shown in FIG. 2, the present invention relates to a
coaxial-flow type heat transfer structure 1 for installation in an
ambient environment 8 for facilitating the transfer of heat energy
between an external heat energy producing system 11, 12, and 13,
and the ambient environment. As shown in the illustrative
embodiment of FIG. 2, the coaxial-flow type heat transfer structure
1 comprises: a proximal end 7, and a distal end 5; an input port 9,
provided at the proximal end, for receiving a heat (energy)
transferring fluid at a first temperature from an external heat
energy producing system 11, 12 and 13; an output port 10, provided
at the proximal end, for outputting the heat transferring fluid at
a second temperature to the heat energy producing system; an inner
tube section 2 having an outer wall surface extending between the
proximal and distal ends, and supporting an inner flow channel 6
having a substantially uniform inner diameter along its entire
length, and into which the heat exchanging fluid can be introduced
from the input port, and along which the heat exchanging fluid can
flow in a substantially laminar manner towards the distal end; an
outer tube section 4, disposed coaxially around the inner tube
section 2, and having an inner wall surface extending between the
proximal and distal ends, and the outer tube section being in
thermal communication with the ambient environment.
[0258] As shown in FIG. 2, an outer flow channel 6B of annulus
geometry is provided between the outer wall surface of the inner
tube section and the inner wall surface of the outer tube section,
and capable of conducting heat exchanging fluid from the distal
extend, along the outer flow channel 6B towards the proximal end,
and exiting from the output port 10. A turbulence generating
structure (e.g. a helically-arranged fin structure) is disposed
along a substantial portion of the length of the outer flow channel
6B so as to introduce turbulence into the flow of the heat
exchanging fluid flowing along the outer flow channel, from the
distal end towards the proximal end, and thereby improving the
transfer of heat energy between the heat exchanging fluid and the
ambient environment along the length of the outer flow channel
6B.
[0259] In FIGS. 3 and 4, reference numeral 3 indicates the
turbulence generator realized as a single helically-extending fin
structure projecting from the surface of the inner tube section 2.
The helically-extending fin structure 3 can be made out of plastic
or metal depending on the static load on the fin 3. The outer wall
of the helically-finned inner tube section 2 can be made out of
metal or plastic depending on the crush, buckling or tensile load
of the tubing laying or hanging in the well bore.
[0260] As shown in FIGS. 3 and 4, a single helically-finned 3
insulated inner tube section 2 is used to create a
helically-extending outer flow channel 6B within the coaxial-flow
heat exchanging structure of the present invention. As shown, this
small-diameter, helically-finned inner tubing can be delivered
rolled on a large spool to install in the thermally-conductive
outer tube section 4 of the system, and the helically-finned inner
tubing can be cut to size and the well cap structure fused on as
shown in FIG. 106.
[0261] FIG. 5 shows the front view of double helically-finned inner
tube section. Reference numeral 2 points to the insulated
helically-finned inner tube section. Reference numeral 3 indicates
the first helically-indicating fin structure while 3A points to the
second helically-extending fin structure. The number of
helically-extending fin structures (e.g. turbulence generating
structures) used in any particular application is determined by the
cross-sectional shape of the outer flow channel and this topic is
discussed in detail with reference to FIGS. 35 through 42.
[0262] The linear, leading and trailing edges of a number of the
multiple angular fins can be angular or filleted. As shown in FIGS.
5 and 30, a double helically-extending fin set is shown used to
create helical fluid flow along the helically-extending outer flow
channels of between the inner and outer tube sections. In this
design, the friction pressure drop in the ground loop can be
reduced, and the number of fin sets can be increased to reduce the
flow path length in the well bore. Also, as the diameter of the
thermally-conductive outer tube increases, the number of
helically-extending fins can be increased to keep the aspect ratio
of the outer flow channel shape close to 2 to 1, as shown in FIGS.
35 through 42.
[0263] In FIGS. 6 and 7, a single thermally-insulated
helically-finned inner tubing section is shown for installation in
the thermally-conductive outer tube section 4 of FIG. 2. In this
inner tube section design, a gas gap 17 is formed between a central
insulated inner tube 14 and the helically-finned inner tube 2,
which provides thermal insulation between the inner and outer flow
channels. The gap distance between the walls remains uniform due to
the three standoffs 18, 19 and 20 provided on the central
insulation tube. Reference numeral 14 indicates the wall thickness
of the center tube in helically-finned inner tubing section. In the
illustrative embodiment, the wall thickness of the center tube is
calculated using the following factors: the material strength; the
buckling load of setting the inner tubing down on the
thermally-conductive tube shoe, shown in FIG. 20; the tensile load
of supporting the inner tubing from the thermally-conductive outer
tube cap, and the crush pressure rating of the tube.
[0264] In FIG. 6, reference numeral 15 indicates the inner flow
channel. The diameter of the inner flow channel is determined from
the amount of thermal storage required in the ground loop, or from
the friction pressure drop. Reference numeral 2 indicates the wall
thickness of the helically-finned inner tube section which must
support the tensile load of the tubing and turbulence generators 3
(i.e. helical fins) hanging from the cap component of the
thermally-conductive outer tube and it must support the shear
stress of installing the inner tubing in the thermally-conductive
outer tube 4. The surface of the fins 3 should be smooth to reduce
the pressure drop created by surface friction on the flowing fluid.
Reference numerals 18, 19 and 20 indicate the stand offs on the
center tube used to create the static or dead gas space 17 between
the center tube and the helically-finned inner tube section. The
standoffs can have a triangular shape for installation at the
factory, or a half cylinder shape for center tube installation in
the field. The number of standoffs used is determined by the center
tube diameter and center tube material. When used for insulating
the inner tube inside the assembly shown in FIG. 115, the center
tube 14 can be extruded as a whole assembly with standoffs 18, 19
and 20 integrated therewith.
[0265] For fin structures having small outside diameters, the edge
can be flat, but for fin structures having large diameters, the
edge should be radius to prevent fin damage caused by hanging up on
an edge in the thermally-conductive outer tube section. The static
or dead gas space 17 can also be filled with a ceramic fiber,
ceramic paper, or other suitable insulating material. The gas space
can be pressurized with an inert, non-condensable gas such as
argon, nitrogen, refrigerant gases, methane, or ethane. The charge
gas pressure should be equivalent to half the hydrostatic pressure
in the well bore. Reference numeral 16 indicates the interior
surface of the outer helically-finned inner tube section. The
surface should be smooth to reduce friction pressure loss and could
be curved to promote tangential rotation of the circulated heat
exchanging fluid. To reduce the heat transfer between the center
tube and outer tube, the surface could be coated with a reflective
metal such as aluminum, silver or gold or coated with a reflective
ceramic powder such as titanium dioxide.
[0266] In FIGS. 8 and 9, the single helically-finned inner tubing
section of FIGS. 6 and 7 is shown without the inner/central
insulation tube installed. In this design, the fins 3 can be
extruded with the tubing for small diameters or extruded over a
larger diameter tube section. For diameters exceeding 18 inches or
0.5 meters, the fins can be rolled from flat stock and welded on
the tubing section. Reference numeral 18 indicates the inner
diameter of the helically-finned inner tube section where in the
center tube will be assembled. Reference numeral 19 indicates the
exterior diameter of the helically-finned inner tube section. While
not shown in these figures, both the top and bottom surfaces of the
helical fin 3 can be curved to promote tangential rotation of the
fluid and to prevent slow flowing areas in the corners of the
helical outer flow channel.
[0267] As shown in FIG. 10, reference 18 indicates the interior
surface of the helically-finned inner tube section 2. This surface
could be coated with a reflective metal such as aluminum, silver or
gold or coated with a reflective ceramic powder such as titanium
dioxide. Reference numeral 19 indicates the exterior surface of the
helically-finned inner tube section. This surface should be smooth
to reduce the friction pressure of the circulating fluid. The
surface could also be fluted to promote the tangential rotation of
the circulating fluid. Reference numeral 20 shows the start of the
clock-wise rotation of the helical fin structure 3 and numeral 1
shows the start of the clock-wise rotation of the helical fin
structure 3A.
[0268] For fins having small outside diameters, the edge should be
flat to increase the friction pressure drop of the slot flow so the
circulating fluid follows (or is guided by) the helically-extending
fins instead of trying to bypass it. But for large diameters, the
edge should be radius with additional thickness to prevent
helically-extending fin damage by hanging up on an edge in
thermally-conductive outer tube collar. The difference in thickness
between reference numerals 18 and 19 indicates the wall thickness
of the helically-finned inner tube section. The wall thickness is
determined by the material used and the compressive, tensile and
shears loads the tubing wall will be exposed to during installation
and operation.
[0269] As shown in FIGS. 11 and 12, the standoffs 22, 23 and 24 on
the central tubing provide the gas gap needed for insulation
between the central insulation tube 14 inside surface 26 and
helically-finned inner tube, wherein the fill gas can be argon,
nitrogen, or even ethane. In this design, a vacuum is established
in the field to check for leaks, then the gap is filled with gas to
half of the bottom hole (well) pressure. Notably, the standoffs
shown in FIG. 12 have a cross-sectional rounded shape instead of
the triangular shape, for easier installation in the field and to
prevent damage to the edge of the standoffs during installation in
the field. Reference numeral 26 indicates the inside surface of the
central tube where a heat transfer fluid can pass through the
center 15.
[0270] In FIGS. 13, 14 and 15, thermally-insulated helically-finned
inner tubing is joined with a collar 28 for large diameter
helically-finned tubing that cannot be rolled on spool. In this
application, the collar can be fusion welded or threaded on the
inside surface 29 to the next joint in the field to make a
continuous piece of tubing for installation in the
thermally-conductive outer tube providing fluid flow through the
inner flow channel 6A to the distal end of the structure.
Preferably, the central tube 14 is fuse welded at the factory on
both ends 30 and 31 of the inner tube to provide the seal for the
gas gap between these two tube sections, to allow charging with gas
at the factory.
[0271] FIGS. 16, 17, and 18 show a helically-finned inner tubing
section 2 that has a (joining) collar 28 but not a central
insulating tube installed. In this application, the collar is
usually threaded for metal inner tubing sections, slip for short
lengths of plastic tubing, or even provide with a twisted lock with
O-ring seal for long lengths of plastic tubing. Preferably, the
wire coil in the collar can be used to fusion weld plastic tubing
in the field during installation.
[0272] In FIG. 19, illustrates how the structure in FIG. 5 can be
extruded with a (joining) collar as shown FIG. 16.
[0273] FIGS. 20 and 21 show a shoe structure (i.e. fin protection
structure). This structure can be fusion welded at points on
surface 32 to the bottom (i.e. distal) end of the helically-finned
inner tubing section. The shoe has a number of protectors 33, 34,
35 and 36 having a wider radial distance (from the shoe center)
than the outer diameter of the helically-finned inner tubing outer
diameter so as to provide a way of and means for protecting the
helical fins during the installation process.
[0274] In FIGS. 22, 23 and 24, a smooth thermally-conductive outer
tube section, sealed at the distal end 5 with a cap structure 37,
is shown from various views. During the installation process, this
outer tube structure 4 is grouted in the Earth using
thermally-conductive cement. Preferably, the smooth
thermally-conductive outer tube is constructed from metal to ensure
that it has a high heat transfer coefficient. In the illustrative
embodiment, the collars, threaded, thermally fused, and specialty
adhesives, are used to attach the outer tube sections together, and
the thermally-conductive outer tube shoe shown in FIG. 20 can
contain a cement valve and a plug catcher. Small diameter tubing is
used inside the thermally-conductive outer tube 4 to prevent grout
contamination therewithin and to flush the mud out of the outer
tube after grout placement. Such precautions should be taken
because hardened grout inside the outer tube can damage the plastic
helical edges during insulation as well as reduce the heat transfer
coefficient of the metal wall. One such precaution involves placing
a small diameter coiled tubing in the annulus space between the
well bore and the outer surface of the outer tube section, and
pumping through this coiled tubing to fill the annulus at
substantially the same rate as the coiled tubing is pulled our of
the annulus to the Earth's surface. A quantity of grouting material
should be left to set up at the bottom of the hole to hold the
outer tube in place during the rest of the grouting procedure.
Water can be added inside the outer tubing 4 giving it weight,
guarding against excessive buoyancy and possible crushing which can
occur during the grouting procedure before the grout has time to
solidify.
[0275] In FIGS. 25, 26 and 27, a fluted thermally-conductive outer
tube section 4A is shown. In this design, the flutes on a
thermally-conductive outer tube provides additional surface area to
counteract the low heat transfer coefficient of the plastic. The
flutes also provide the thermally-conductive outer tube with
additional strength. If the desired thermally-conductive outer
tubing material has sufficient burst pressure strength. The
thermally-conductive outer tube cap 5 can also have metal forks to
dig into the wall of the hole to prevent the thermally-conductive
outer tube from floating when the grout is pumped to surface. An
option to prevent the thermally-conductive outer tube from floating
off the bottom of the hole is to flash set a small volume of grout
in the bottom of the hole. This will serve to hold the
thermally-conductive outer tube down while the rest of the grout is
pumped to the
[0276] In FIGS. 28 and 29, the forward flow pattern 15 and 38 and
the reverse flow pattern 39 are illustrated in a coaxial-flow heat
transfer structure having a smooth thermally-conductive outer tube
section and single helically-finned inner tube section. During the
cooling season, pumping heat exchanging fluid down the outer flow
channel provides the best approximation to a cross flow heat
exchanger for liquid-gas mixtures where the liquid adsorbs the gas
phase when the pressure increases as the mixture is pumped down the
thermally-conductive outer flow channel. As the gas phase is
absorbed, the fluid temperature increases with depth, which in turn
increases the heat transfer to the ground or water. During heating
season or winter operation, pumping a cold aqueous fluid down the
outer flow channel provides the best approximation to a cross flow
heat exchanger due to the ground temperature increasing with depth.
For horizontal or deviated wells, it is better to pump the fluid
down the inner flow channel to maximize heat transfer at the distal
end of the well.
[0277] In FIG. 30, the forward flow pattern 15 and 41 is
illustrated in a coaxial-flow heat transfer structure having a
smooth thermally-conductive outer tube section and inner tube
section 2 having multiple helical fins.
[0278] FIGS. 31 and 32 show a coaxial-flow heat transfer structure
having a fluted thermally-conductive outer tube 4A and a single
helical-fin inner tube section 2, forming a single
helically-extending outer flow channel. In this design, the pitch
of the helical fins 3, and the fluted thermally-conductive outer
tube surface, should be practically close for maintaining the
helical flow pattern in the outer flow channel. The fluid will
bypass the fins around the space in the flutes. The whole assembly
can be extruded together as a tubing-thermally-conductive outer
tube joint combination, and the joint combination can be fusion
welded in the field with preinstalled wire coils in the collars. To
grout the outer tube in a well bore, a small diameter coiled tubing
is installed in the annulus of the hole, as described above. The
small diameter coiling tubing is then pulled to the surface at
substantially the same rate as the grout fills the annulus of the
well bore. Water can be added inside the outer tubing 4 giving it
weight, guarding against excessive buoyancy and possible crushing
which can occur during the grouting procedure before the grout has
time to solidify. As shown, 48 illustrates the eccentric offset of
the proximal end circular surface.
[0279] FIG. 33 illustrates the helical flow pattern 39 and 40
within the coaxial-flow heat transfer structure, as the fluid is
pumped down the helically-extending outer flow channel and up inner
flow channel. For near vertical well bores gives, pumping fluid
down the outer flow channel provides the best approximation to a
cross flow heat exchanger for ground temperatures close the
surface. For a coaxial-flow heat transfer structure installed in
horizontal or deviated wells in aquifers, it is better to pump
fluid down the inner flow channel to maximize the heat transfer at
the distal end of the well bore.
[0280] FIG. 34 illustrates the forward flow pattern 15 and 41 for a
coaxial-flow heat transfer structure having a double
helically-finned inner tube section. In this design, the multiple
helical fins are used for large diameter thermally-conductive outer
tube. For large diameters, the helically-finned tubing joints can
be pre-installed in the thermally-conductive outer tube joints for
shipment. O-ring seals are used in the helically-finned tube
collars, so when thermally-conductive outer tube joints are joined
together, the O-ring seals the helically-finned tubing also. This
helps reduce installation cost and shipping cost for large diameter
ground loops.
[0281] FIG. 35 is a schematic representation of a heat transfer
system comprising conventional heat transfer equipment 11 in
combination with least one coaxial-flow heat transfer structure 8
of the present invention, as generally depicted in FIG. 2. As shown
in FIG. 35, a heat transfer fluid is pumped through the mechanical
heat transfer equipment 11, including a heat exchanger, by a fluid
pump. The heat transfer fluid travels to the co-axial heat transfer
structure 8 through pipe 9, entering the center tube of the
co-axial heat transfer structure at the proximal end through input
port 7 where the heat transfer fluid begins to travel in a laminar
flow profile as shown in FIGS. 1 and 1A down the length of the
inner flow channel 6A of the inner tube section 2. The fluid then
reverses its flow direction, transitioning into a turbulent flow
profile as it travels toward the surface through outer flow channel
6B, along which it encounters helically-extending fin structures
(i.e. turbulence generators). The conditioned heat transfer fluid
is then returned to the mechanical heat transfer equipment 11
through pipe 10 for conditioning in the system and subsequent
recirculation through the co-axial heat transfer structure.
[0282] FIG. 36 shows an enlarged view of a section of the helically
extending outer flow channel 6 provided for in the coaxial-flow
heat transfer structure of FIG. 35. As shown, the cross-sectional
dimensions of the outer flow channel 6 between the interior surface
of the outer tube section 4, the exterior surface of the inner tube
section 2, and the helical flow guide fins 2 can be
selected/designed to produce fluid flows therealong having optimal
vortex characteristics that optimize heat transfer between the
fluid within the outer flow channel 6 and the surface of the
thermally-conductive outer tube section 4.
[0283] FIG. 37 illustrates the rotational flow characteristics of
fluid 43 flowing along the outer flow channel identified in FIG. 36
when the ratio of the sides of the outer flow channel cross-section
(i.e. flow channel slot ration 42) approaches 1/1.1 (i.e.
indicative of a square-like control volume). Under such geometrical
conditions, the resulting fluid flow through the outer flow channel
6 will typically have one vortex 43 for flow rates of interest
(e.g. 25 to 35 GPM) at lower than desired velocity with a lower
rate of system heat transfer capacity caused by a less affective
rotational flow profile 43.
[0284] FIG. 38 illustrates the rotational flow characteristics of
fluid flowing along the outer flow channel identified in FIG. 36
when the ratio of the sides of the outer flow channel cross-section
44 approaches 1/2.5 (i.e. indicative of a rectangular-like control
volume). Under such geometrical conditions, the resulting fluid
flow through the outer flow channel 44 will typically have two
vortices 45 and 46 for flow rates of interest (e.g. 17 to 24 GPM)
at optimum velocity with optimum rate of system heat transfer
capacity caused by an optimum turbulent flow profile. Optimizing
turbulent flow characteristics further disturbs the boundary layer
shown in FIGS. 1 and 1A, thereby increasing heat transfer into
surfaces in contact with the heat transfer fluid during fluid
flow.
[0285] FIG. 39 illustrates the rotational flow characteristics of
fluid flowing along the outer flow channel identified in FIG. 36
when the ratio of the sides of the outer flow channel cross-section
47 approaches 1/4.0 (i.e. indicative of a rectangular-like control
volume). Under such geometrical conditions, the resulting fluid
flow through the outer flow channel 6 will typically have two
vortices 48 and 49 (one near each helical fin) with a laminar slot
flow region in the center region, for flow rates of interest (e.g.
12 to 20 GPM) at higher than desired velocity with lower rate and
heat transfer capacity caused by laminar flow 4 and a smaller
turbulent flow profile. The aspect ratio shown as FIG. 39 increases
restriction to fluid flow. Increasing pressure will increase the
size of the laminar flow 50 decreasing turbulent flow profile shown
in FIG. 38.
[0286] FIG. 40 is a graphical representation of the helical flow
characteristics of fluid 42 flowing along the outer flow channel
between the outside surface of inner tube section 2 and the inside
surface of outer tube section 4, identified in FIG. 37, when the
aspect ratio of the sides of face area of the outer flow channel
cross-section approaches 1/2.25 (i.e. indicative of a
rectangular-like control volume). FIG. 40 also illustrates the
laminar flowing fluid 15 flowing through the inner tube section
2.
[0287] FIG. 41 is a graphical representation of the helical flow
characteristics of fluid flowing along the outer flow channel
between the outside surface of the inner tube 2 and the inside
surface of the outer tube 4, identified in FIG. 38, when the aspect
ratio of the sides of face area of the outer flow channel
cross-section approaches 1/2.25 (i.e. indicative of a
rectangular-like control volume). FIG. 41 also illustrates the
laminar flowing fluid 15 flowing through the inner tube 2.
[0288] FIG. 42 is a graphical representation of the helical flow
characteristics of fluid flowing along the outer flow channel 47
between the outside surface of inner tube 2 and the inside surface
of the outer tube 4, identified in FIG. 39, when the aspect ratio
of the sides of face area of the outer flow channel cross-section
approaches 1/4.0 (i.e. indicative of a rectangular-like control
volume). FIG. 42 also illustrates the laminar flowing fluid 15
flowing through the inner tube 2.
[0289] FIG. 43 shows a coaxial-flow heat exchanging structure
having a helically-finned inner tube section 2 installed coaxially
in a corrugated thermally-conductive outer tube 4C, between which a
helically-extending outer flow channel is formed generating
turbulence 45 and 46 in the heat exchanging fluid flowing
therealong. A heat transfer fluid enters at 15 and passes through
the inner tube 2 to the end of the inner tube where the fluid
passes a shoe 32, (FIGS. 19 and 20) whereupon the fluid direction
of flow is reversed and redirected into a helical flow channel. The
heat transfer fluid flow transitions into a turbulent flow profile
along the length of the outer flow channel. In this design, the
corrugated outer tube wall 4C increases the surface area (i.e.
compared to a smooth wall pipe or tube), and strength of the
thin-walled thermally-conductive outer tube. The period of the
corrugation flutes is at least one quarter or less of the helical
fin to prevent significant fluid bypass around the fins 3. While
the corrugations increase the pressure drop along the outer flow
channel by a factor of about 10%, these corrugations will also
increase the heat transfer rate and heat exchange surface area by a
factor of about 40%. As shown an end cap 5 is welded, glued or
otherwise affixed to the distal end of the coaxial-flow
structure.
[0290] FIG. 44 shows a coaxial heat transfer structure showing heat
transfer fluid inlet 51 and outlet 52, in which the
helically-finned inner tube section is supported in the
thermally-conductive outer tube section by way of a well cap
structure. As shown, the well cap holds the helically-finned inner
tube 2 off the bottom of the thermally-conductive outer tube so as
to prevent buckling of the plastic helically-finned tubing while
sealing the helically-extending outer flow channel from fluid leaks
from and into the environment. In order to prevent buckling of the
plastic helically-finned tube section, at least 2/3 of the
helically-finned tubing should be hung in tension from the well
cap. Using the O-ring seal, well cap provides an easy way to remove
the helically-finned inner tubing in the even there is a fluid leak
in the thermally-conductive outer tube. The well cap can be
attached to the thermally-conductive outer tube section 4 by way of
threads, by way of compression bolts, or by way of a compression
ring.
[0291] In FIGS. 45 and 46, a coaxial-flow heat exchanging structure
of the present invention is shown employing a well cap 53, at the
proximal end thereof, and a shoe structure disposed at the bottom
of the thermally-conductive outer tube (i.e. distal end). A O-ring
seal 54 is shown sealing the cap to the outer tube 4 exterior
surface. In this application, a manifold structure, shown in FIG.
50 is provided for enabling fluid return and injection has been
removed for purposes of clarity of illustration. As shown FIGS. 45
and 46, the well cap has a plurality of small holes 55, 56, 57, 58,
and 59. Inner tube 2 is shown extending through a hole cut to size
for the outside diameter of the inner tube 2 extending from the
well cap for connection to piping associated with mechanical heat
transfer system. This design provides a low friction pressure drop
through the cap structure. Alternatively, a single medium size hole
60 can be formed, or drilled, in the cap for communication with the
manifold structure, resulting in a little higher pressure drop due
to frictional forces. When using the single medium sized hole and a
single pipe, threads can be used for establishing the pipe
connection.
[0292] FIG. 47 shows weld joints 61 and 62 connecting a metal cap
to a metal outer tube section 4 to hold the cap permanently in
place.
[0293] FIGS. 48 and 49 shows coaxial-flow heat exchanging structure
containing a inner tube 2, fitted with compression ring 54 under a
clamped well cap 53. In this design, the cap structure 53 can
employ an O-ring 54, or U-ring seal around the proximal end of the
thermally-conductive outer tube so as to prevent fluid leaks. The
clamps 62 and 63 welded or bolted onto the outer surface of the
thermally-conductive outer tube section are provided to prevent
fluid pressure from forcing the well cap off the
thermally-conductive outer tube section in cases of shallow helical
tubing depths or high fluid pressures. For permanent installations
in cement structures, the well cap structure can be fusion welded,
as shown in FIG. 47 so as to reduce the risk of leaks.
[0294] FIG. 50 shows the coaxial-flow heat exchanging structure
employing an exemplary manifold structure 64 comprising welded or
threaded pipe fittings connected to cap structure 53 and sealed by
O-Ring 54.
[0295] FIG. 51 shows a pipe connection arrangement where the
coaxial-flow heat exchanging structure uses tube fittings 66, 67,
68 and 69 welded to the side of the thermally-conductive outer tube
section 4 for fluid inlet through pipe 68 and 66, then through an
internal reducing pipe elbow 70, and into the inner flow channel of
inner tube 2. The heat transfer fluid is returned to the heat
transfer fluid outlet 69 along the outer flow channel between the
inner tube 2 and the outer tube 4 through reducer fitting 67. This
arrangement is suitable for use in foundation installations when
the tube fittings are in a state of compression. Reference numeral
5 indicates an end cap welded on the distal end of the outer tube 4
to seal against leakage from or into the surrounding
environment.
[0296] FIG. 52 shows the low pressure coaxial-flow heat exchanging
structure using a set of first tube fittings 75, 76 and 77 welded
to the medium size hole in cap structure 53 for fluid injection
into or withdrawal of fluid from the outer flow channel, and a
second set of tube fittings for fluid injection or withdrawal of
fluid from the inner flow channel.
[0297] In FIG. 53, the coaxial-flow heat exchanging structure 78 is
shown installed in a deviated well bore to form a ground-loop
system for exchanging heat energy with an aquifer below the Earth's
surface. To install this system, a well is drilled with a radius
turn (approximately 50 ft. radius) into the aquifer zone.
Thereafter, the metal thermally-conductive outer tube 4 is cemented
with sanded grout to surface so as to prevent aquifer contamination
and increase the heat transfer coefficient to the ground. After
cementing operations, the thermally-conductive outer tube is
cleaned with a mild acid solution with surfactant to remove mud,
mill scale and grout tailings. The helical pitch and number of fins
on the helically-finned tubing component are selected to rotate the
fluid at the desired circulation rate. Once these parameters have
been determined, the helically-finned (insulated) inner tubing is
inserted into the interior of the installed outer tube and run to
the bottom of the outer tube shoe and sealed off at the
thermally-conductive outer tube cap using fusion welding.
[0298] As shown in FIG. 53, the design goal for the ground/water
source loop of the heat transfer system of the present invention 1
has been to provide enough heat-transfer surface area and
ground/water volume to insure the circulating fluid temperature of
the ground/water source loop does not go above/below the average
ground temperature by 7.degree. F. or 3.degree. C., under
continuous load during peak of the heating/cooling season. By
maintaining a return fluid temperature within 7.degree. F. or
3.degree. C. of the ground/water source temperature, the SEER
rating of the heat pump system will be maximized for the whole
heating/cooling season. A commercial objective of the design has
been to use a combination of metal and plastic tubing to increase
heat transfer to/from the ground while reducing the life-time cost
of the ground loop which includes the capital, maintenance and
operational cost averaged over the life-time of the system.
[0299] If the time averaged heat and cooling loads are nearly
equivalent over the thermal seasons, then the core volume of the
ground loop can be designed to store heat during the cooling season
and, subsequently, the heat can be extracted from the core volume
during the heating season. If the time averaged thermal load is
mostly heating or cooling, then ground loop is designed to transfer
heat without significant storage in the ground volume.
[0300] For small spikes over base load, larger well bore diameter
or the iron mass in the foundation can be used for thermal storage
to average out the operational temperature of the fluid. It has
been discovered that when using a helical fin design and a slot
(i.e. outer flow channel) aspect ratio (i.e. ratio of dimensions of
the helically-extending outer flow channel) ranging from a 1 to 1
square to a 1 to 2.5 rectangle, tubing diameters can exceed 36
inches or 1 meter without significantly reducing heat transfer
coefficient to the ground/water source. For large spikes over base
load, a larger tank volume can be added to the ground loop for
additional thermal storage.
[0301] For an estimated yearly thermal load, a thermal simulator
can be used to determine the number wells used in the ground loop
array, the amount of thermal storage needed to average out the
daily peak loads and the amount of core volume needed in the array
to store heat from the cooling season to use in the heating season.
For large thermal projects, the simulator can be used to optimize
capital cost of drilling (horizontal well bore length versus number
of wells in array), material cost of the thermally-conductive outer
tube (thermally-conductive outer tube diameter versus metal or
plastic), the approach temperature of the ground loop and the
refrigerant used by the heat-pump system. However, the actual heat
transfer rate and time coefficient of the ground-loop array of
wells should be determined with a transient temperature test of the
ground loop and the actual heat storage of the ground loop should
be determined with a complete year of history of circulating fluid
temperature and load data.
[0302] The well design parameters such as grout thickness,
thermally-conductive outer tube material, helical pitch, number of
helical fins, insulated wall thickness of inner tube, and fluid
composition can be optimized using analytical equations for steady
state operation. Most of the well array design parameters such as
well depth, well length, well spacing should be optimized for the
given aquifer properties with a thermal simulator over a multi-year
load to account for the thermal storage of Earth and the seasonal
transients. Most of thermal storage parameters for the insulated
volume of fluid in a tank or in the array of well bores, or the
insulated volume of concrete in the foundation, can be empirically
fit with simple equations so that the peak loads can be averaged
over the daily operation of the heat pump. The design goal is to
install a ground loop with thermal storage so that it can transfer
the daily thermal load from the heat pump for the minimum capital
cost and operational cost.
[0303] As shown in FIGS. 67, 68 and 69, an array of similar wells
can be drilled and coaxial-flow heat transfer structures installed
therein, and interconnected to gathering lines for series or
parallel operation as a heat exchanger coaxial-flow heat exchanging
structures. Finally, the ground loop is filled with an aqueous heat
transfer fluid and the air is bled out of the high spots in the
system to achieve optimum performance. Using the coaxial-flow heat
exchanging structure of the present invention, the installation
cost and material costs associated with constructing deviated wells
is substantially reduced.
[0304] FIG. 54 shows a natural gas dehydration system using
mechanical heat transfer equipment 83 of the present invention,
wherein a deviated well 81 is drilled in an aquifer to create a
ground loop employing the coaxial-flow heat transfer system of the
present invention.
[0305] FIG. 55 shows the coaxial-flow heat exchanging structure of
the present invention 85 installed in a near horizontally bored
well in the side of a mountain, mesa, hill, or other man made
earthen structure. In this application, the well bore path is
deviated to follow an aquifer zone if available at the site. For
buildings having a deep basement or built on the side of a hill,
the deviated well bores can be drilled in and through the wall of
the basement. As shown the heat transfer fluid piping is connected
to mechanical heat transfer equipment 86.
[0306] FIG. 56 shows the coaxial-flow heat exchanging structure of
the present invention installed within an earth, mud, aqueous
solution or chemical solution. The coaxial-flow heat exchanging
structure is capped below the surface to prevent significant heat
transfer to the ground/water surface or ambient atmosphere. For
areas that have significant ice or freeze/thaw movement, the
distribution pipes 87 and 88 should be protected against damage
and, if possible, the structure should be capped below the frost
line.
[0307] FIGS. 57 and 58 shows the coaxial-flow heat exchanging
structure of the present invention installed vertically, (although
it can be horizontally installed) in bridge piers and foundations,
or bridge components and foundations and piers of a building or
other similar structure. The heat exchanger of the present
invention can take advantage of the metal rebar used in the
concrete to increase the effective surface area of the outer tube
and any thermal storage quality the concrete may have. By
installing the co-axial flow heat transfer structure in the ground
or water below the structure, the cement/concrete sheath can
perform two functions: (1) structural support, and (2) heat
transfer to the water or ground. If the heating load is small
enough and the temperature difference large enough, then the
coaxial-flow heat exchanger can be used in the thermo-siphon mode
using the density difference between cold and warm aqueous
solution. Otherwise a coaxial-flow heat-pump can be used to
increase the heat transfer rate, and as the piling spacing is very
close in building foundations, the whole volume of ground contained
between the pilings can be converted to a thermal bank for peak
loads or even to store heat from the cooling season to be used in
the heating season. Also, if the top of basement foundation is
isolated with insulation, then cement structure and some
surrounding ground can be converted into a thermal bank for peak
load averaging during winter heating and summer cooling. The heat
transfer fluid enters the co-axial heat transfer structure shown
through pipe 87. The heat transfer fluid exits the output port of
the co-axial heat transfer structure through pipe 88.
[0308] FIGS. 59, 60 and 61 shows the coaxial-flow heat exchanging
structure of the present invention suspended in an aqueous solution
or mud, e.g. in both horizontal and vertical orientations. In these
applications, the thermally-conductive outer tube section has
radially-extending metal fins arranged around its outer surface for
the purpose of increasing the heat transfer area of the outer tube
section 4, i.e. by making it behave as an external thermo-siphon
for aqueous solution circulation about such metallic fins. The
width of such external metallic fins to its thickness aspect ratio
should be less than 10 to 1 so as to optimize the use of metal and
heat transfer to the aqueous solution or mud. For installations in
bodies of water, se fins can be coated for anode operation to
prevent bio-film growth and scaling, which reduces the heat
transfer to the aqueous solution.
[0309] FIG. 59 shows a cross-section cut-line for a top view FIG.
60 and a co-axial heat transfer structure submersed horizontally in
water, mud, or chemical. As shown, the heat transfer fluid enters
through pipe 87 and exits the structure through pipe 88. An
external fin structure 91 can be installed onto the exterior
surface of the co-axial heat transfer structure 1.
[0310] FIG. 60 is a top cut-away view of FIG. 59 showing the
external radially-extending heat transfer fins 91 attached to the
exterior surface of the co-axial heat transfer structure outer tube
4. The top view shows the a central tube 14 with standoffs 23, 24
and 25, as shown in FIGS. 11 and 12, allowing a laminar fluid to
flow through the center insulating central tube 14.
[0311] FIG. 61 shows the coaxial-flow heat exchanging structure of
FIGS. 59 and 60 installed in a bridge component or piling 92 and
submersed below the water line above the bridge component. As shown
the external radial fins 91 are arranged radially and laterally
around the exterior of the coaxial-flow heat exchanging structure
outer tube. The heat transfer fluid is circulated through the
structure through pipes 87 and 88.
[0312] FIGS. 62 and 63 show small and large coaxial-flow heat
exchanging structures of the present invention installed in ground
to prevent icing or snow accumulation on bridges, walkways (i.e.
side walks, heavily traveled intersections or steeply pitched roads
and driveways). In such applications, the ground heat can keep the
road surface from icing up and increase the evaporation rate of
moisture on the road, providing numerous safely benefits. During
spring and summer operations, the system can thermally bank (i.e.
store) heat for intermittent winter surface de-icing. In order to
reduce energy cost, the pump operation can be remotely
computer-controlled by the local authorities before the bad weather
conditions move in the area, causing the transfer of heat energy of
and preventing the road conditions from becoming dangerous.
[0313] FIG. 62 shows a number of coaxial-flow heat transfer
structures of the present invention, connected in series with pipe
93, installed within and beneath a bridge component 90 for the
purpose of circulating enough heat transfer fluid, using pump 96,
through a piped grid 94, sufficient enough to maintain the bridge
floor 95 and walkway above freezing temperatures.
[0314] FIG. 63 shows a number of coaxial-flow heat transfer
structures of the present invention, connected in series with pipe
93, installed adjacent a bridge component 90 for the purpose of
circulating enough heat transfer fluid, using pump 96, through a
piped grid 94, sufficient enough to maintain the bridge floor 95
and walkway above freezing temperatures.
[0315] FIGS. 64 and 65 show the application of a single
coaxial-flow heat transfer structure 1 for a residential home. FIG.
64 shows a building with a self-contained central air conditioning
heat pump 97 equipped with a water-cooled refrigeration condenser
section therein. Through pipes 98 and 99, pump 100 circulates a
heat transfer fluid through the water cooled refrigeration
condenser and the coaxial-flow heat transfer structure 1 to either
transfer heat into the earth or absorb heat from the earth for
distribution within the interior spaces of the building.
[0316] FIG. 65 shows the application of a single coaxial-flow heat
transfer structure 1 for a building. In this application, an
optional thermal bank tank 103 is connected with pipes 102 and 103
provided for night time and mild climate cooling mode of operation
during times when electrical energy expense is less for night time
modes of operation, and colder day time operation when solar panels
can provide heat energy for hydronic heating modes of operation.
The said modes of operation can be called the economizer modes of
operation. The solenoid valves are used to valve the thermal bank
tank either in series with the coaxial-flow heat transfer structure
or parallel (shunted).
[0317] FIG. 66. shows the building of FIG. 64 but with a number of
coaxial-flow heat transfer structures arranged in a parallel
configuration with supply pipes 98 and return pipes 99. This system
configuration provides three times as much thermal capacity as
shown in the system of FIG. 64.
[0318] For cooling applications, the addition of soluble gases to
the aqueous-based fluid improves the heat transfer to the
ground/water source. As the pressure increases with depth of fluid
column, the soluble gases are adsorbed by the aqueous fluid; the
gases release their stored heat to the fluid, and in turn raise the
temperature of the fluid which in turn increases the temperature
differential between the fluid and the ground/water source. Carbon
dioxide (CO2) and ammonia (NH3) gases foamed with surfactants
create stable aqueous-based fluids used in this absorption process.
The fluid return line requires insulation to prevent the heat
absorption of heat as the gases come out of solution when the fluid
returns to the surface. The adsorption and de-sorption process acts
like a low differential temperature refrigerant cycle, but it can
be quite effective in increasing the heat transfer in the
ground/water source loop.
[0319] For heating applications, the addition of solid particles to
the heat exchanging flow can increase the heat capacity of the
aqueous-based fluid. Micron sized heavy metal or metal oxide
particles can be mixed with the aqueous based fluid and suspended
with a shear thinning polymer such as xanthan gum or borate
cross-linked polymer. The fluid must be kept in motion or the
particles will eventually settle out and plug the bottom of the
co-axial flow heat transfer structure. Micron-sized glass spheres
containing a low melting point salt can also be used to increase
the heat capacity of the fluid while maintaining a particle
specific gravity close to 1. Particle specific gravities near to 1
will prevent settling of the particles in the aqueous fluid, thus
allowing a ground loop section to be shut down with out the danger
of plugging the heat exchanger with settled particles. Field
experience has shown that the composition of the aqueous-based
fluid should remain simple to reduce capital cost and that
increasing fluid flow rate is a better solution to increase heat
capacity of the system, except where very high heat transfer rates
are required.
[0320] FIGS. 67 and 68 show an application of array pad-drilling
nine deviated wells, to minimize the ground surface impact while
maximizing the volume of ground contacted by the well bore. FIG. 68
is a front view of the vertical coaxial-flow heat transfer
structures shown in FIG. 67 connected in series where one is a
vertical well bore and the other is a deviated well bore. Long term
operation allows the coaxial-flow heat transfer structure to
thermally bank (i.e. store) heat during the cooling season for use
during the winter season. For cooling loads only, a shallow
horizontal coaxial-flow heat transfer structure can be added to the
coaxial-flow heat transfer array shown in FIG. 67 for the purposes
of removing heat from the thermal bank during the winter season.
The pad drilling process indicated in FIG. 67 also has the
advantage of reduced heat loss from horizontal gathering of piping
and reduced risk of accidental damage from contractor digging
operations.
[0321] FIG. 69 shows a system of eleven deviated wells according to
the present invention, connected together in a two series array
configuration. Pipe 98A and 99A supply and return heat transfer
fluid to the center array, while pipes 98B and 99B supply and
returns heat transfer fluid to the outer array. Each well contains
a coaxial-flow heat transfer structure of the present invention. As
shown, the coaxial-flow heat transfer structure of the present
invention can be combined in various ways to realize improved heat
transfer systems and networks capable of handling diverse thermal
loads.
[0322] FIGS. 70 and 71 show, respectively, applications using
seawater or ballast water in a condensing system and heat sink for
gas dehydration, and oil de-waxing used on a drilling platform 107.
In such applications, the coaxial-flow heat exchanging structures 1
of the present invention can be used on off-shore drilling
facilities floating or supported on pier 108 to extract heat from
the gas to cause the temperature of the gas to drop which then
condenses water vapor and/or light hydrocarbon vapors into
disposable liquids. The coaxial-flow heat exchanging structure can
also be used to extract heat from oil with a cold structure to
cause the wax to build up on the cold finger structure instead of
on the pipeline wall transporting the oil to shore 110. A
reversible refrigeration condensing system 109 (i.e. heat pump)
connected to the coaxial-flow heat exchanging structure can be used
to heat the oil to prevent or clean the wax buildup on the pipeline
wall. The coaxial-flow heat transfer structure can be submerged in
the open seawater, as shown in FIG. 70, or submerged in the ballast
water in the structure as shown in FIG. 71. For open sea water, as
shown in FIG. 70, the exterior of the coaxial-flow heat exchanger
is coated for anode operation to prevent bio-film growth on the
outer tube surface thereof. Using a closed-loop coaxial-flow heat
exchanging structure submerged in seawater in locations teaming
with sea life, greatly reduces the maintenance cost of other types
of heat exchangers especially, the type of heat exchangers used in
power plants.
[0323] FIG. 72 illustrates how multiple coaxial-flow heat
exchanging structures 1 can be installed below the ocean floor or
plowed into a mud like along shore to prevent conditions such as
over heating or excessive cooling of the surrounding sea water
which can compromise biological life forms residing therein.
Coaxial-flow heat exchanging structures used on or in connection
with oil and gas production systems shown in FIGS. 70, 71 and 72
can be as shown or combinations of floating, hanging, buried and
other field constructed applications of the present invention.
[0324] FIG. 73 shows the application of the coaxial-flow heat
exchanging structure of the present invention 1 in a ground-loop
heat exchanging system used on-shore for pipeline quality gas
dehydration. As shown, natural gas produced from a remote off-shore
platform 107 is pumped to an on shore plant through pipe 110 to
dehydration processing equipment 111 and delivery to process and
distribution facilities through pipe 112.
[0325] FIG. 74 shows a platform, or shore based, liquid natural gas
(LNG) receiving port, gasification and storage facility 113
supported on piers 114. The Special Provision for Monitoring (SPM)
115, normally, is in the same location or near to the point where
liquid natural gas tanker ships off-load the liquid natural gas for
gasification of storage. The natural gas can be stored in a salt
cavern 124 through pipe 122, located in a salt cavern storage area
encompassing one or more salt caverns, or the natural gas can be
fed directly into the gasification process equipment located in the
facility. The liquid natural gas is fed through pipe 116 to the
gasification equipment, such as gas turbine engines, pumps and
generators, as the natural gas changes in state from a liquid to a
gas (evaporates) inside the heat exchanger 117 it requires a large
amount of heat to cause the change in state. Generally, sea water
is taken into the heat exchanger where the heat contained in the
water is transferred into the gas. The sea water is then returned
back to the sea locally which can have negative environmental
consequences, damaging the local aquatic life forms and having a
biological impact thereof. To prevent this problem, a heat transfer
fluid is circulated through the heat exchanger 117 via pipe 121
from a subsurface grid (array) of a number of deviated coaxial-flow
heat transfer structures 81 of the present invention. As shown,
these structures 81 are connected together in parallel, with
manifold 119, and a secondary array of a number of suspended
coaxial-flow heat transfer structures 1, shown connected in
parallel with manifold 120. In this arrangement, the heat transfer
fluid travels through pipe 118 back to the heat exchanger 117 for
heat dissipation and recirculation through the coaxial-flow heat
transfer structures shown. If the gasified natural gas is not to be
stored but piped to a processing and distribution center, it is
normally pumped into on shore or undersea pipeline 125 to a
facility on shore. Using a grid of co-axial flow heat transfer
structures, installed in deviated wells, beneath the mud line of
the ocean floor, prevents damage to the aquatic environment and
provide a source of heat rather than burning a portion of the
product (natural gas) during the gasification process. The
coaxial-flow heat transfer structure shown in FIGS. 83 and 84 can
be used to replace conventional heat exchangers currently in
use.
[0326] FIG. 75 shows a pair of coaxial-flow heat exchanging
structures 130 and 138 of the present invention connected to a
skid-mounted gas dehydration and condensate separation system 127
(e.g. in an application having a single well or gathering system).
The gas enters the system from a well 126 and delivered to process
and distribution facilities through pipe 144. In this system,
natural gas and other liquids are produced from the well 126 that
is completed in the gas zone. The natural gas moves through the
separator 128, typically a tube 120 and shell type assembly, where
brackish water and hydrocarbon liquids are separated from the
natural gas. A heat transfer fluid cooled to a temperature
substantially less than the gas temperature by the coaxial-flow
heat transfer structure 130 is circulated to the tubes 129 inside
the separator shell, via pipe 132 and returned to the coaxial-flow
heat transfer structure 130 through pipe 131, causing brackish
water and hydrocarbon liquids to condense from the gas for
collection for disposal. The natural gas then moves through pipe
134 into the evaporator section 135 of the refrigerated dehydrator
136 where the temperature of the gas is reduced further to condense
the water vapor and heavier hydrocarbon vapors from the gas. As
shown, heat transferred into a heat transfer fluid from the
condenser section 137 travels through pipe 139 to coaxial-flow heat
transfer structure 138, where the heat is dissipated into the
Earth, and the cooled heat transfer fluid returns back to the
condenser section through pipe 140. Finally, the partially
dehydrated natural gas passes through pipe 142 and is then polished
by a small glycol unit 143 to remove the last traces of water vapor
for shipment via natural gas production supply lines.
[0327] Notably, in the natural gas dehydration system shown in FIG.
75, the deviated well provides fluid, heated to ground temperature,
for the purpose of dehydrating natural gas in a natural gas
production environment. However, for other oil field heating and
cooling applications, additional large surface holes can be drilled
and the coaxial-flow heat transfer structure of the present
invention installed and thermally cemented therein.
[0328] FIG. 76 shows a submarine with a seawater intake 146 taking
in seawater and delivering it to seawater heat exchangers 1 of the
present invention installed in a seawater heat exchanging system
147 aboard a submarine for centralized and zoned air conditioning
and equipment cooling normally utilizing heating and cooling heat
exchangers 149, (also shown in FIGS. 78 through 82). The
conditioned air is then distributed to specific locations aboard
the submarine by air distribution ducting 151. In addition to
increased heat transfer efficiency, the coaxial-flow heat exchanger
helps to reduce noise generation and increase the safety in case of
a hull breach. After use, the seawater is then returned to the sea
through outlet 148.
[0329] FIG. 77 shows a submarine with a seawater intake 152 taking
in seawater and delivering it to seawater heat exchangers 1 of the
present invention. As shown, these exchangers are installed in a
seawater heat exchanging system 153 aboard a submarine for
centralized and zoned air conditioning and equipment cooling
normally utilizing heating and cooling heat exchangers 155 and 156,
(also shown in FIGS. 78 through 82). In addition to increased heat
transfer efficiency, the coaxial-flow heat exchanger helps to
reduce noise generation and increase the safety in case of a hull
breach. After use, the seawater is then returned to the sea through
outlet 154. It is suggested that a mixed oxidant is injected into
the seawater or a saltwater chlorinator so as to treat the seawater
and prevent bio-film buildup on the fins. The heated seawater can
be pre-diluted with fresh seawater to prevent production of a
thermal plume around the submarine.
[0330] FIG. 78 is an elevated cross-sectional side view a
coaxial-flow heat transfer structure of the present invention. As
shown the structure 1A is a component of a heat exchanger assembly
shown in FIGS. 80 through 87 showing the heat transfer fluid (i.e.
liquid refrigerant from a refrigeration condenser) (i) entering
through tube 159, having a turbulent flow profile as shown in FIGS.
38 and 41, (ii) passing through the outer flow channel along the
outer tube 4 inside surface, and (iii) returning through the
helically-finned center tube 2, having a laminar flow profile (as
shown in FIGS. 1 and 1A) to the heat transfer fluid source (i.e.
refrigeration compressor) through pipe 158.
[0331] FIG. 79 is an elevated cross-section, side view a
coaxial-flow heat transfer structure of the present invention. As
shown the structure 1A is a component of a heat exchanger assembly
shown in FIGS. 80 through 87 showing the heat transfer fluid (i.e.
liquid refrigerant from a refrigeration condenser) (i) entering
through tube 162, having a laminar flow profile as shown in FIGS. 1
and 1A, (ii) passing through the helically-finned center tube 2,
and (iii) returning through the outer flow channel along the outer
tube 4 inside surface, having a turbulent flow profile (as shown in
FIGS. 38 and 41) to the heat transfer fluid source (i.e.
refrigeration compressor) through pipe 161.
[0332] FIG. 80 is a front and cross-sectional view of an array of
coaxial-flow heat transfer structures 1A of the present invention,
arranged in what is traditionally called a horizontal or block
style heating or cooling coil. These coaxial-flow heat transfer
structures are securely held in place by compression fitted or
welded openings in end plates 163 and 164. The inner tube section
of each coaxial-flow heat transfer structure 158 is connected to a
manifold tube 165 to provide heat transfer fluid flow through each
coaxial-flow heat transfer structure. Preferably, the heat transfer
fluid flow is evenly distributed through each coaxial-flow heat
transfer structure in the assembly into manifold tube 165. Also,
the outer flow channel of each coaxial-flow heat transfer structure
is connected by a tube 159 to a manifold tube 167 having an inlet
168 to provide heat transfer fluid flow through each coaxial-flow
heat transfer structure. Preferably the heat transfer fluid is
evenly distributed through each coaxial-flow heat transfer
structure. While traveling through each outer flow channel, as
described in FIGS. 38 and 41, the heat transfer fluid is guided by
helical fins 3 and transfers heat energy into air, fluid or gases
passing over fins 157 attached to the exterior surface of outer
tube 4 of the coaxial-flow heat transfer structures 1A mounted in
the assembly. The horizontal coaxial-flow cooling and heating coil
of the present invention can be used to transfer heat into or out
of air, fluid or gas passing over its external surfaces. The
horizontal cooling and heating coil can also be used to transfer
heat into or out of air, fluid or gas passing over it by
circulating a or metered refrigerant into tube 168 provided the
refrigerant can evaporate while passing through the coaxial-flow
heat transfer structures 1A mounted in the assembly. The horizontal
heating or cooling coil of the present invention can be constructed
of a variety of materials consisting of metallic and plastic
components, considering compatibility of materials and heat
transfer fluids and refrigerants. This embodiment of coaxial-flow
heat transfer structure can also be used as a radiator to cool a
combustion engine.
[0333] FIG. 81 is an end view of the horizontal heating or cooling
coil of the present invention shown in FIG. 80. The end plate 164
is shown holding four coaxial-flow heat transfer structures 1A in
their respective positions in the assembly. FIG. 81 shows the tube
166 of manifold tube 165 extended at an angle from the manifold
tube 165 and the alignment of manifold tube 165 with each
coaxial-flow heat transfer structure tube 158. FIG. 81 also shows
the tube 168 of manifold tube 167 extended at an angle from the
manifold tube 167 and the alignment of manifold 167 with each
coaxial-flow heat transfer structure tube 159.
[0334] FIG. 82 shows the location of holes 169, 170, 171 and 172
punched in the end plate 163 so as to hold the coaxial-flow heat
transfer structures in place.
[0335] As shown in FIG. 83, a plurality of coaxial-flow heat
exchanging structures 1A are contained in a pressure vessel 173
which is used as an aqueous-based fluid-to-fluid, fluid to air, and
refrigeration evaporator (chiller) or condensing heat exchanger
(tube and shell heat exchanger) having a heat transfer fluid (i.e.
refrigerant) inlet tube 168 and a heat transfer fluid (i.e.
refrigerant) outlet tube 166.
[0336] As shown in FIG. 84, process fluid enters through inlet tube
176 to be heated or cooled as it passes by the fins of the
coaxial-flow heat transfer structures 1A. The entering process
fluid side of the pressure vessel is separated by the outlet side
by separator plate 175. After passing over the fins of the
coaxial-flow heat transfer structures the conditioned process fluid
exits the assembly through tube 177. End plate 164 is welded to the
pressure vessel along weld bead 174 to prevent leakage of the
process fluid.
[0337] In FIG. 85, two coaxial-flow heat transfer structures
(functioning as horizontal heating and cooling coils) are connected
together at an angle with brackets 185 and 187 which are secured to
end plates 164 with screws (i.e. rivets or spot welding) 186 and
188. In this application, the heat exchanger (heating and cooling
coil) is configured in an `A` frame style. The two coaxial-flow
heat transfer structure (i.e. horizontal heating or cooling coils)
are connected/plumbed in a parallel configuration having both
manifold tubes 165 and 179 connected together by tube 180 forming a
common outlet connection providing a combined fluid flow through
tube 178. Manifold tubes 167 and 181 are connected together with
tube 182 at wye connector 183 providing combined flow of heat
transfer fluid into tubes 167 and 181 from tube 184.
[0338] As shown in FIG. 86, an array of coaxial-flow heat transfer
structures 1A of the present invention are assembled as components
in the "A" style heating and cooling coil shown in FIG. 85. The
coaxial-flow heat transfer structures are securely held in place by
compression fitted or welded openings in end plates 163 and 164.
The inner tube of each coaxial-flow heat transfer structure is
connected to a manifold tube 179 to provide a heat transfer fluid
flow through each coaxial-flow heat transfer structure 1A.
Preferably, the heat transfer fluid flow is evenly distributed
through each coaxial-flow heat transfer structure in the assembly.
As shown, each coaxial-flow heat transfer structure flow channel is
connected by an inlet manifold tube 181 having an inlet 184 to
provide heat transfer fluid flow through each coaxial-flow heat
transfer structure. Preferably the heat transfer fluid is evenly
distributed through each coaxial-flow heat transfer structure in
the assembly. While traveling through each flow channel, the heat
transfer fluid can transfer heat into air, fluid or gases passing
over fins attached to the outer tubes of the coaxial-flow heat
transfer structures mounted in the assembly. The horizontal
coaxial-flow cooling and heating coil of the present invention can
be used to transfer heat into or out of air, fluid or gas passing
over its external surfaces. The horizontal coaxial-flow cooling and
heating coil of the present invention can also be used to transfer
heat into or out of air, fluid or gas passing over it by
circulating a or metered refrigerant into tube 184 provided the
refrigerant can evaporate while passing through the coaxial-flow
heat transfer structures 1A mounted in the assembly. The
coaxial-flow heating or cooling coil of the present invention can
be constructed of a variety of materials consisting of metallic and
plastic components, considering compatibility of materials and heat
transfer fluids.
[0339] As shown in FIG. 87, the two horizontal cooling coils 199
are connected at an angle with brackets 189 and 191 which are
secured to end plates 163 with screws (i.e. rivets or spot welding)
190 and 192.
[0340] In FIG. 88, a building 193 is shown with a central air
conditioning system comprising an electric or gas furnace with an
`A` style heating and cooling coil 199 (as shown in FIGS. 86 and
87) arranged in the air flow provided by blower 198. The air
passing through the heating and cooling coil 199 is evenly
distributed through air ducts 200 and 201. The outdoor aid
condensing unit, (i.e. heat pump) is connected to the heating and
cooling coil with a liquid refrigerant tube (high side line) 196
and a return tube (suction line) 197.
[0341] As taught in the above illustrative embodiments, the
coaxial-flow heat exchanging structures of the present invention
can be manufactured in various lengths, for example, in ten, twenty
or thirty foot lengths, using plastic extrusion techniques, which
are then joined and fused using various possible techniques (e.g.
PVC cement, ultra-sonic welding, adhesive bonding using glue,
etc.). However, in alternative embodiments of the present
invention, the coaxial-flow heat exchanging structure of the
present invention.
[0342] For example, as will be described in greater detail below,
the helically finned inner tubing component, installed within the
outer tube section of the coaxial-flow heat exchanging structure,
can be manufactured as relatively short (single or multiple) fin
segments that are then applied to the outer surface of flexible
inner tubing, as shown in FIG. 89. Thereafter, the flexible tubing,
with the applied helical fin segments, can be wound up on a storage
spool, and subsequently removed and installed within the outer
casing of the coaxial-flow heat transferring structure that has
been installed within a bed of thermally conductive cement pumped
into well bore at an installation site. Technical details of this
embodiment of the present invention will be described
hereinafter.
[0343] FIG. 89 shows a segmented helically-finned flexible inner
tube section 206 employed in the outer tube section of the
coaxial-flow heat exchanging structure of FIG. 90. Reference
numeral 202 indicates the repeated segments of a single
helically-extending fin structure, 203 and 204. Reference numeral
205 indicates the smooth section in the outer flow channel where
the wakes of fluid flow, from each fin, mix before being cut once
again by the next set of fins. The segmented helical fins allow the
fluid flow to transition from laminar to turbulent-like flow at
lower Reynolds numbers, while moderately increasing heat transfer
and friction pressure drop. Preferably, the dimensionless twist
ratio, y, of the fins should range from about 2 to 8, while the
dimensionless spacing ratio, z, of the fins should range from about
2 to 10. In the illustrative embodiments, calculations indicate
that the segmented fins should enhance heat transfer by a factor of
about 1.1 to 1.5, while increasing the friction pressure drop by a
factor of about 1.2 to 1.9 when compared to a continuous helical
fin type center tube.
[0344] To create a stabilized helical flow within a
coaxially-extending outer flow channel, the fluid should preferably
travel at least 1/2 rotation or 180 degrees per linear foot of
fluid travel. For a large diameter outer tube section, the number
of fins used in the outer flow channel is selected so the slot
width to depth ratio ranges from about 1.0 to 3, while the slot
length to depth ratio ranges from about 1.5 to 6. Otherwise, too
few fins or too many fins create laminar slot flow having minimal
or no rotational component, providing additional friction pressure
drop, and offering minimal heat transfer enhancement.
[0345] FIG. 90 shows the segmented helically-finned inner tubing
section 2 installed in outer tube section (i.e. casing) 4 of the
coaxial-flow heat exchanging structure of FIG. 1. Reference
numerals 203 and 204 indicate the enhanced heat transfer zones of
the outer tube 4, while reference numeral 205 indicates the
remixing zone provided within the heat transfer structure of the
present invention. The mixing zone allows the core fluid in the
slot between the helical fins 3 to mix with the fluid that contacts
the wall of the outer tube section 4, thus increasing heat
transfer. Reference numeral 206 indicates the fluid entering the
insulated inner tubing section 2, whereas reference numeral 207
indicates the fluid exiting the helically-extending outer flow
channel.
[0346] FIGS. 91 and 92 shows an example of segmented
helically-finned inner tubing where the segments 203 and 204 are
made from extruded pieces of plastic material. This construction
method is suited for large diameter thermal storage well bores
where the tubing or hose cannot be rolled onto a spool. FIG. 91
shows separate extrusions for the finned 203 and 204 and smooth
inner tube sections 2, while FIG. 92 shows an integral smooth 205
and finned section 204. Reference numerals 203 and 204 indicate the
single helically-finned inner tube section, while reference
numerals 2 and 205 indicate the smooth section thereof. Reference
numeral 208 indicates the threaded or slip couplings used to join
the insulated inner tube sections 203, 2 and 204 together. The
couplings can be glued or plastic welded together. Segments shown
in FIGS. 91 and 92 can be made of a metallic material and welded or
threaded together to length.
[0347] FIG. 93 shows that the single wrap-around single fin 211 and
its integrated base layer 210 can be extruded flat and parallel
while heated to its plastic point, and then wrapped around a
mandrel so as to give the fin a helical pitch to match the tubing
or hose size to be employed within a coaxial-flow heat exchanging
structure as shown in FIG. 96. Reference numeral 209 represents the
cut length of the segment to be shaped. Preferably, the diameter of
the plastic fin shaping mandrel should be about 5-10% smaller than
the smallest installed inner tubing or hose in the field because
air gaps prevent good glue adhesion. If the fin is made of metal,
then the mandrel should be about 5% larger than insulated tubing
and it should be tack welded to the tubing wall.
[0348] FIG. 94 show a wrap-around single fin segment for
application about a section of flexible tubing or hose to be used
to realize the insulated helically-finned inner tubing component
employed in the coaxial-flow heat exchanging structure of FIG. 89.
The single fin 211 and base 210 are adapted for flexing due to the
gap indicated by reference numeral 212. The fin can be glued or
plastic welded to a hose to prevent movement during installation
and use. With this design, the flexible hose with fins can be
spooled for shipment to the installation site and unspoiled without
damage to the fin shape during installation.
[0349] FIG. 95 is a wrap-around segment shown in FIGS. 93 and 94
but with wrapped twist in the opposite direction around the tubing
or hose.
[0350] FIG. 96 shows a length 213 of segmented coaxial-flow heat
transfer center tube and helically extended finned 211, single
wrap-around fin segments 210 creating a mixing zone 205 between
turbulent zones 203 and 204 applied on a section of inner tubing or
flexible hose 2 installed in a section of outer tube (i.e. casing).
The fin segment 210 can be glued or plastic welded to the flexible
hose and rolled on a spool for installation in the field.
[0351] FIG. 97 shows a wrap-around single fin segment 210 having a
left hand twist, in comparison with a right hand twist, provided to
the wrap-around fin segment shown in FIG. 96. The alternating left
and right hand twist combination shown in FIG. 97 is used for large
thermal well bores, or where the fluid has a high viscosity or
where a laminar flow regime exists in the outer flow channel and
should be turbulently disrupted.
[0352] FIG. 98 shows an elevated side view of a multiple-finned
segment applied about a section of inner tubing or hosing to be
used to realize the thermally-insulated helically-finned inner
tubing component employed in the coaxial-flow heat exchanging
structure of FIG. 96. As shown, the glued-on segment is used for
small annular widths where the single fin segment could not create
helical flow for enhanced heat transfer. The small annular widths
are required for minimum flow velocity when low flow rates are used
in large diameter thermal storage wells or when fluids have high
viscosity. As shown, reference numeral 216 shows the flexible base,
while reference 217 points to the glue seam. Reference numeral 218
points to the tab and slot used to snap together the segment on the
inner tube or hosing section during the gluing or welding
procedure.
[0353] FIG. 99 shows a segment 219 like the one shown in FIG. 98
except segment 219 has no tab and slot shown in FIG. 98. The
removal of the tab and slot can facilitate the high speed welding
of numerous segments onto the surface of rolled tubing by an
automatic welding machine shown in FIG. 104.
[0354] FIG. 100 shows a multiple-finned segment applied about a
section of inner tubing or hosing 2 to be used to realize the
thermally-insulated helically-finned tubing component employed in
the coaxial-flow heat exchanging structure of FIG. 96. Reference
numeral 220 indicates the flexible plastic base while 3 indicates
the smooth fin wall. If tall fins are used, then there can be some
buckling of the fin wall when the segment is wrapped around the
inner tube or hose section if the storage spool is too small in
diameter. Reference numeral 221 indicates the tab and slot used to
snap together the opposing ends of the multi-finned segment.
[0355] FIG. 101 shows a molded or extruded multiple-finned segment
employed within a coaxial-flow heat exchanging structure as shown
in FIG. 96. As illustrated, this segment is provided with a number
of fins after it has been molded or cut from a continuous sheet.
Reference numeral 222 indicates the flexible base, whereas
reference numeral 223 indicates one of the fins. Reference numerals
224 and 225 point to the tab and slot used to join together the
edges while the segment is glued to the outer surface of the inner
tube section. Unlike the single fin segment as shown in FIG. 93,
the multiple-finned segment length 226 is plus or minus 2 percent
for the outside diameter of the inner tubing section that it will
be glued to in the field or mechanically as shown in FIG. 104. For
factory created multiple-finned segmented inner tube sections, the
base of each segment can be straight cut without gluing tabs, as
shown in FIG. 99, to length from a roll of molded material and
plastic welded to the flexible inner tubing.
[0356] FIG. 102 shows a cross-sectional view of the coaxial-flow
heat exchanging structure of the present invention employing
segmented-type single helically-extending fin segments, as shown in
FIG. 98, installed on the surface of an inner tube section 2. As
shown, the finned inner tube section is installed within a
thermally-conductive outer tube section (i.e. casing) 4, that has
been cemented within a well bore, and a re-mixing zone 230 being
provided between its helically-extending outer flow channel.
Reference numerals 228 and 229 indicate the segment lengths, while
reference numeral 230 indicates the spacing length of the fluid
re-mixing zone. As shown, the base 222 from which fin 213 extends
is glued to the outer surface of inner tube section 227. For
similar fin pitch and number, the extruded segmented fins in FIG.
98 and flexible segmented fins in FIG. 102 should demonstrate
substantially the same fluid heat transfer performance through the
outer wall of the outer tube section.
[0357] FIG. 103 shows the coaxial-flow heat exchanging structure of
the present invention employing segmented single fin segments
having alternating left and righted handed twists. As shown, the
helically-finned inner tube section 231 is installed within the
outer tube section 4, and a re-mixing zone 234 provided along the
helically-extending outer flow channel. The spacing length of the
remixing zone is indicated by reference numeral 234. As shown,
reference numerals 232 and 233 indicate the right and left handed
twist fins. This arrangement is used for enhancing heat transfer in
large-diameter outer tubes, with low-velocity laminar flow or
highly viscous flow characteristics in the helically-extending
outer flow channel. This arrangement can be also used to enhance
heat transfer in short metal pipe runs along beaches, river banks
and shores where there is natural water movement in the soil to
remove the heat from the near well bore area.
[0358] FIG. 104 shows a machine 235 designed to automatically
attach single or multi-finned segments 239, fed into machine 235
through bin 240 onto the outer surface of flexible inner tubing 236
as the inner tubing is being rolled off a spool 237 supported on a
stand 238. As shown, the assembled segmented finned tubing
structure 241 is then rolled up onto a storage spool 242 supported
by stand 243, for subsequent transport or shipment to a well
site.
[0359] FIG. 105 shows a ground-supported spool of coaxial-flow heat
exchanging multi-finned segments of the present invention, being
loaded into a casing that has been installed within a well bore
filled with thermally-conductive cement. Reference numeral 244
indicates a section of tubing (i.e. hose) with the segmented fins
attached thereto. Reference numeral 245 indicates the manual or
power spool used to lower and raise the segmented fin tubing into
the outer casing 248. In the illustrative embodiment, a pulley or
wheel 247 is used to prevent pinching the segmented finned inner
tubing as it is lower into the outer tube section (i.e. casing).
The base 246 of the manual or power spool should be massive enough
or anchored to the ground so as to prevent sliding as the segmented
finned tubing is lowered into outer tube section 248 cemented into
the ground, during construction of the coaxial-flow heat transfer
structure of the present invention.
[0360] FIG. 106 illustrates how fluid inlet and outlet ports (i.e.
well head) associated with the coaxial-flow heat transfer structure
of the present invention can be constructed from conventional
metallic or plastic fittings. Specifically, as shown, a tee 250 is
threaded, welded, or glued to the proximal end of the outer tube
section 4. Multi-finned inner tubing section 2 passes through a
reducer fitting 249 extending beyond the top run of the tee a short
distance 2 for connection to the heat transfer fluid supply piping.
Other pipe fittings, not shown, such as reducers, bell pipe
fittings and nipples can be connected to the branch of the tee
returning the heat transfer fluid back to heating, cooling or other
heat transfer devices and equipment. The well head can be installed
subsurface to prevent damage thereto due to freezing or vehicular
traffic. The direction of heat transfer fluid flow shown in FIG.
106 can be reversed resulting in the same heat transfer
characteristics.
[0361] FIG. 107 shows a coaxial-flow heat transfer structure
employing a number of non-helical turbulence generators 252
arranged on the outer surface of the inner tube section. As shown,
multiple discrete turbulence generators 252 of identical or
different lengths can be strategically placed on the exterior
surface 251 of the inner tube 2 so as to create a significant
amount of turbulence along the outer flow channel, between the
inner tube and the outer tube 4. The turbulent flow structure shown
can be installed inside the entire length of the outer tube section
4 or connected in combination with other said segments along the
length as part of the coaxial-flow heat transfer structure.
[0362] FIG. 108 shows the coaxial-flow heat transfer structure of
the present invention shown in FIG. 107.
[0363] FIG. 109 shows the outer tube 4 and the turbulent flow
generators 252.
[0364] FIG. 110 shows a large diameter coaxial-flow heat transfer
structure comprised of a number of helically extended fins 3,
between the center tube surface 2 and the outer tube 4 inner
surface.
[0365] In FIG. 111, a coaxial-flow heat exchanging structure of the
present invention is shown, wherein the outer tube section 4, inner
tube section 2 and helically-extending fins 3 are formed as a
unitary product using a plastic extrusion process. Notably, a
rotatable die structure will be used to manufacture this
product.
[0366] FIG. 112 is a cross-sectional side view of the coaxial-flow
heat transfer structure of the present invention shown in FIG.
111.
[0367] FIG. 113 is a cut-away view, section B-B, of the
coaxial-flow heat transfer structure of the present invention shown
in FIG. 111 having internally extruded flow guide fins 3 between
the inner flow channel tube 2 and outer tube 4 and showing the
center tube opening therethrough.
[0368] In FIG. 114 is a perspective, partially transparent, view of
a coaxial-flow heat transfer structure showing the outer tube 4 and
a coaxial-flow heat transfer structure wherein the inner tube
section 2 has multiple rows of fin segments 254 helically extending
along the outer
[0369] FIG. 115 shows a coaxial-flow heat transfer structure
employing a helical turbulence generator structure 255 that is
constructed from a solid, hollow-flat, or tubular metallic, plastic
or fiberglass material and installed between the inner tube section
2 and outer tube section 4. As in the other illustrative
embodiments described above, the helical structure 255 creates
helically-extending outer flow channel(s) along which turbulence
fluid flows are generated.
[0370] FIG. 116 shows a coaxial turbulent flow generator having a
number of helically-extending (flow guide) fins 257 and 258
extending from a solid (or hollow) center core shaft 256. The
turbulent flow generator is designed for insertion along the
central axis of tubular heat exchangers (e.g. tubes or pipes) which
require repair or otherwise require an increase its efficiency
through the generation of an optimum turbulence in the fluid
flowing therethrough. Installation environments include, for
example: "U" tube type ground source loops as shown in FIG. 117;
tube and shell heat exchangers found in heating, cooling and
refrigeration systems; combustion engine radiators; and a variety
of other tubular heat transfer systems and components. It could be
less expensive to add to or modify heat exchangers of these types
using this turbulence flow generator of the present invention
rather than replacing the heat exchanger or radiator which can be
more costly. The number of flow guide fins, helically-arranged
along the length of the center core shaft, can be increased or
decreased to produce the desired heat transfer rate and heat
transfer fluid flow rate. The coaxial turbulent flow generator
shown can be constructed of a plastic or metallic materials
depending on fluid and other material compatibilities.
[0371] In FIG. 117, there is shown a conventional heat pump ground
source loop normally fabricated in the field using commonly
available tubing and fittings such as PVC, polypropylene,
polyethylene, copper, aluminum, and steel pipe and fittings. A heat
transfer fluid is pumped into and out or either of tubes 260 and
261. The "U" bend fitting shown as 262 can be made from a converted
plumbing fitting called a "P" trap, but is usually fabricated using
two 90 degree (quarter bend) ells glued or welded in place to form
a "U" bend as shown. By installing the coaxial turbulent flow
generators 259 of the present invention along the linear lengths of
the ground loop, the laminar flow profile along the "U" tubes will
transition into turbulent flowing profiles shown in FIGS. 38 and
41, thereby increasing the heat transfer efficiency of the tube.
The number and thickness of the flow guide fins and the helical
linear pitch of the flow guide fins 157 and 158 can be adjusted
during manufacturing to arrive at a desired turbulent flow profile
inside flow channels existing between the flow guide fins and the
inside diameter of the tube or pipe into which the coaxial
turbulent generator is to be inserted. The coaxial turbulent
generator can be made from plastic, metal or other materials, and
can be made flexible so that it can be rolled up into spools for
storage and delivery to site locations where it is to be
deployed.
[0372] FIG. 118 shows an air conditioning system employing a system
of coaxial-flow heat transfer structures of the present invention.
The coaxial-flow heat transfer structures 308, 309 and 310 function
as a heat transfer sub-system connected to a water-cooled ground
source condensing unit 283 found on a typical direct expansion air
conditioning system where an electric or gas fired furnace is used
during the heating mode of operation. The heat transfer fluid being
pumped by pump 269 through the ground loop coaxial-flow heat
transfer structures first passes through pipe 270 and a hydronic
air vent 271 to remove air that might be in the fluid piping
system.
[0373] In the cooling mode, during times when the outdoor air
temperature is higher than the heat transfer fluid entering the
coaxial-flow heat transfer structures, through pipe 272, valve 268
is open and valve 267 is closed. When the outdoor air temperature
is below the temperature of the heat transfer fluid valve 268 is
closed and valve 267 is open allowing the heat transfer fluid to
flow through outdoor air heat exchanger 266 allowing heat to be
extracted from the heat transfer fluid before it enters the
coaxial-flow heat transfer structures through pipe 272. This
function increases the heat transfer efficiency of the entire
system and promotes heat recovery time of the ground loop and
extending the overall life of the coaxial-flow heat transfer
structures conductivity. The outdoor air heat exchanger 266 can be
constructed without a fan (i.e. natural draft) or with a fan (i.e.
forced draft).
[0374] In the cooling mode, heat is extracted from the heat
transfer fluid as it passes through coaxial-flow heat transfer
structures. The heat transfer fluid leaving the coaxial-flow heat
transfer structure 308 is transferred to the coaxial-flow heat
transfer structure 309 by pipe 173 where more heat is extracted
from the heat transfer fluid. The heat transfer fluid leaving
coaxial-flow heat transfer structure 309 is transferred to
coaxial-flow heat transfer structure 310 by pipe 274 where more
heat is extracted from the heat transfer fluid into the Earth. The
heat transfer fluid is returned to the water cooled condenser of
the air conditioning condensing unit 283 through pipe 275. The heat
transfer fluid direction of flow can be reversed entering the
ground source wells through pipe 275 and exiting the wells through
pipe 272.
[0375] As shown in FIG. 118 high pressure, high temperature
refrigerant is supplied through pipe 276 to expansion valves 277
and 278 for refrigerant metering (throttling) into evaporators 264
and 265. Once the heat is absorbed by the liquid refrigerant inside
the evaporators 264 and 265 the liquid refrigerant changes state
into a gas, it is returned to the compressor in the condensing unit
263 through return pipe 279 where it is compressed and re-condensed
into a liquid refrigerant for recirculation. The condensing unit
263 shown in FIG. 118 can be a water-cooled heat pump unit with
cooling and heating modes of operation.
[0376] FIG. 119 shows an air conditioning system employing three
coaxial-flow heat transfer structures of the present invention 311,
312 and 313, which function as a heat transfer sub-system connected
to a water to water air conditioning unit 281 with hydronic cooling
coils 296 and 297. The heat transfer fluid being pumped by pump 291
through the coaxial-flow heat transfer structures 311, 312 and 313
first leaves the water cooled condenser section 280 through pipe
289 passing through a hydronic air vent 290, to remove air that
might be in the fluid piping system. In the cooling mode during
times when the outdoor air temperature is higher than the heat
transfer fluid entering the coaxial-flow heat transfer structures,
through pipe 285, valve 284 is open and valve 283 is closed. When
the outdoor air temperature is below the temperature of the heat
transfer fluid valve 284 is closed and valve 283 is open allowing
the heat transfer fluid to flow through outdoor air heat exchanger
282 allowing heat to be extracted from the heat transfer fluid
before into the ambient air before it enters the ground source
wells through pipe 285. This function increases the heat transfer
efficiency of the entire system and promotes heat recovery time of
the coaxial-flow heat transfer structures and extending the overall
life of the ground loop wells. The outdoor air heat exchanger 282
can be constructed without a fan (i.e. natural draft) or with a fan
(i.e. forced draft).
[0377] In the cooling mode, heat is extracted from the heat
transfer fluid as it passes through the coaxial-flow heat transfer
structures 311, 312 and 313 124C. The heat transfer fluid leaving
coaxial-flow heat transfer structure 311 is transferred to
coaxial-flow heat transfer structure 312 by pipe 286 where more
heat is extracted from the heat transfer fluid. The heat transfer
fluid leaving coaxial-flow heat transfer structure 312 is
transferred to coaxial-flow heat transfer structure 313 by pipe 287
where more heat is extracted from the heat transfer fluid. The heat
transfer fluid is returned to the condenser section 281 of the air
conditioning heat pump. Heat contained in the heat transfer fluid
entering the evaporator section 292 of the air conditioning heat
pump is transferred to the condenser section 280 using a
conventional refrigeration compressor and associated valves and
piping. The heat transfer fluid entering the condenser section
absorbs heat as it passes through the water cooled condenser
section 280 and moves the heat into the coaxial-flow heat transfer
structures 311, 312 and 313. The circulation of the heat transfer
fluid can be continuous or cyclic depending on the application. The
heat transfer fluid direction of flow can be reversed entering the
ground source wells through pipe 288 and exiting the wells through
pipe 285.
[0378] During operation of the system, heat is absorbed by the heat
transfer fluid circulated heat exchangers 297 and 298. Heat is
extracted from the heat transfer fluid in the evaporator section
292 of the air conditioning heat pump 281. The heat transfer fluid
is pumped from the evaporator section 292 by pump 293. From the
pump 293, the fluid passes through hydronic air vent 295 which
removes air that might be in the heat transfer fluid. From the
hydronic air vent, the heat transfer fluid enters a thermal storage
tank 295 which adds to the internal heat transfer fluid volume of
the system. The amount or internal volume of heat transfer fluid is
determined by the amount of heat being absorbed by heat exchangers
296 and 297 as opposed to the amount of heat that the air
conditioning heat pump 281 is capable of transferring. In response
to the set point of temperature and conditions within the
conditioned spaces, a typical thermostat activates and deactivates
the air conditioning heat pump. Heat exchangers 296 and 297 can be
constructed with a fan (i.e. forced draft) or without a fan
(natural draft) and may be of the type shown in FIGS. 80 through
87.
[0379] A digital control system can be employed to monitor and
control the operation of the system based on indoor and outdoor
temperatures, and temperatures of fluid entering and leaving the
coaxial-flow heat transfer structures. Additionally, fans, blowers,
compressors, flow meters and flow controls can be monitored and
controlled according to a computer control program. Sensors
integrated into the manufacture of the coaxial-flow heat exchanging
structure of the present invention can be installed at certain
depths to further monitor and control heat transfer fluid flow
throughout the resulting system. In the event that water is used as
the heat transfer fluid, additives can be added to the system to
reduce the freezing temperature of the heat transfer fluid to
prevent slushing of the heat transfer fluid. Some heat transfer
additives can cause a reduction in heat transfer fluid
efficacy.
[0380] In the heating mode, heat is added to the heat transfer
fluid as it passes through ground coaxial-flow heat transfer
structures 311, 312 and 313. The heat transfer fluid leaving
coaxial-flow heat transfer structure 311 is transferred to
coaxial-flow heat transfer structure 312 by pipe 286 where more
heat is added to the heat transfer fluid. The heat transfer fluid
leaving coaxial-flow heat transfer structure 312 is transferred to
coaxial-flow heat transfer structure 313 by pipe 287 where more
heat is added to the heat transfer fluid. The heat transfer fluid
is returned to the condenser section 281 of the air conditioning
heat pump through pipe 288. In the heating mode, the air
conditioning heat pump 281 is in reverse cycle where the condenser
section 280 and evaporator section 292 interchange function, The
condenser section 280 begins to function like an evaporator
absorbing heat from the heat transfer fluid and transferring the
heat into the evaporator section 292 which begins to function like
a condenser using a conventional refrigeration compressor and
associated valves and piping, delivering the heat into heat
transfer fluid and exchangers 266 and 267 for transfer into the
conditioned space. The circulation of the heat transfer fluid can
be continuous or cyclic depending on the application. The heat
transfer fluid direction of flow can be reversed entering the
coaxial-flow heat transfer structures through pipe 288 and exiting
the coaxial-flow heat transfer structures through pipe 286. The
heat transfer fluid normally flows in one direction through the
coaxial-flow heat transfer structures and indoor heat exchangers
296 and 297. Certain applications may require the addition of
three-way valves to reverse the direction of heat transfer fluid
flow through the piping system.
[0381] FIG. 120 is a schematic representation of a RF (or
microwave) transmission/reception tower 301, next to the
accompanying base station housing 299 (i.e. shelter) containing
sensitive electronic equipment connected to antennae 300 by cable
302 and within an environment that is thermally controlled by an
air conditioner 303 employing a plurality of coaxial-flow heat
transfer structures 1 of the present invention installed in a
plurality of vertical well bores, using thermally conductive cement
and connected together in series with piping 305, 306 and 307.
[0382] Also, it is understood that the coaxial-flow heat transfer
structure of the present invention can be readily modified and
employing in heat-pipe systems employed in diverse applications
from ground-based heat pipes, or thermal management systems in
laptop computers. In such an embodiment of the present invention, a
coaxial-flow heat transfer structure as illustrated conceptually in
FIG. 2 has a proximal end and a distal end which would be installed
within an ambient environment having a differential in temperature
between the proximal and distal ends. The input and output ports of
the structure would be sealed off or otherwise interconnected,
after the inner and outer flow channels have been properly charged
(i.e. filled) with an appropriate volume of heat transferring fluid
(e.g. multi-phase fluid). Wicking or other fluid absorptive
material can be disposed along either or both the inner flow
channel as well as the helically-extending outer flow channel,
formed between the inner and outer tube sections. The advantages of
this heat pipe system design is that the length of the
helically-extending outer flow channel can be made substantially
longer that the length of the inner flow channel, providing more
effective surface area and linear length for the heat exchanging
fluid to conduct heat energy along the outer flow channel.
[0383] Referring to FIGS. 121 through 126, some improvements to the
coaxial heat transfer systems and methods of installation will now
be described.
[0384] As shown in FIG. 121, a cement cap 318 around the coaxial
heat transfer structure of the present invention may be required by
federal, state, or local water resources authorities to prevent
surface water and other fluids from contaminating any aquifer that
may be present. At the bottom of the bore hole, a layer of cement
317 is shown being used to hold the co-axial flow heat transfer
structure of the present invention firmly in the bore hole. Along
the length of the bore hole between, between cement layers 317 and
318 and the earth and the exterior surface of the outer tube of the
coaxial heat transfer structure, beads of graphite, synthetic
graphic, carbon and graphite mixtures, or other metallic (aluminum
pellets) or non-metallic heat transfer enhancing pellets 315 can be
used to create a thermally conductive region, instead of
heat-transfer enhanced cement as shown in FIGS. 35 and 36. As shown
in greater detail in FIG. 122, the use of high heat transfer
pellets 315 eliminates having to pump heat transfer enhanced cement
along the entire length of the bore hole. In general, the pellets
315 can be spherical, or near spherical, which allows them to be
poured, rather than pumped, from the surface into the bore hole
during installation of the coaxial heat transfer structure. As
shown in FIG. 122, the small spaces (i.e. interstices) 316 between
the pellets 315 eventually fill up with silt, earth or rock
formations from the surrounding environment, thereby creating an
environment (with very high heat transfer properties) surrounding
the exterior surface of the outer tube of the coaxial heat transfer
structure, for efficiently transferring heat to or from the heat
transfer fluid flowing through the co-axial flow heat transfer
structure. This technique helps to reduce installation costs while
improving the heat transfer efficiency between the coaxial heat
transfer structure of the present invention and its ambient
environment (e.g. ground material in the Earth).
[0385] As shown in FIGS. 123 and 124, 125 and 126, there is shown a
coaxial heat transfer structure provided with an end cap structure
322 having one or more reverse hooks 321 connected thereto by way
of bolts or pins 323. As shown, this end cap structure 322 is
fixedly attached to the distal end of the outer tube section 320
and serves the purpose of holding the outer tube 320 in place once
it is lowered (or pushed) to the bottom of the bore well, during
the installation process. As shown, holes 326 can be drilled in the
end cap 322 for attachment of a cable that can be used while
lowering the outer tube assembly into the bore hole. FIGS. 124 and
125 show that a machined or molded end cap can be fitted, welded,
or glued to the distal end of the outer tube by inserting the outer
tube into hole 325. The end cap is provided with drilled holes 329
for attaching the two reverse hook attachments 321 using bolts or
pins, passed through holes 331 formed in the end of each reverse
hook attachment. As shown in FIG. 126, each reverse hook 321 has a
machined slot 332 for allowing the reverse hooks to rotate and fold
closely against the outer tube section when the outer tube is being
lowered into the bore hole.
[0386] As shown in FIG. 123, as the outer tube is lowered to the
bottom of the bore hole, the reverse hooks 321 are retracted and
reside up against the outer surface walls of the outer tube.
However, as shown in FIG. 123A, if pressure or forces generated
from below the end cap structure attempts to drive the outer tube
section upward and out of the bore hole, then the reverse hooks 321
quickly grip into the walls of the bore hole 319, and securely hold
the outer tube section in place. FIG. 123B shows the reverse hooks
digging deeper in the walls of the bore hole. As shown in FIG.
123C, after the outer tube section(s) have been lowered to the
bottom of the bore hole and the outer tube section completed, then
heat transfer filler materials (e.g. graphite, carbon, or
thermally-conductive pellets, beads and/or cement) can be poured
into the space between the exterior surface of the outer tube 320
and the interior surface of the bore hole 319, to create a
thermally conductive environment about the outer tube section of
the coaxial heat transfer structure of the present invention.
Notably, this outer tube retention mechanism shown in FIGS. 123A
through 123C obviates the need for pumping a layer of cement 317 to
the bottom of the bore hole, to hold the outer tube firmly in
place, as shown in FIG. 121.
[0387] While various illustrative embodiments of the present
invention have been disclosed in great detail herein above, is
understood that the coaxial-flow heat-transfer technology employed
in heat pump and transfer systems of the illustrative embodiments
may be modified in a variety of ways which will become readily
apparent to those skilled in the art of having the benefit of the
novel teachings disclosed herein. All such modifications and
variations of the illustrative embodiments thereof shall be deemed
to be within the scope and spirit of the present invention as
defined by the Claims to Invention appended hereto.
* * * * *