U.S. patent application number 16/016380 was filed with the patent office on 2018-11-29 for power saver apparatus for refrigeration.
The applicant listed for this patent is Jack Dowdy, III. Invention is credited to Jack Dowdy, III.
Application Number | 20180340713 16/016380 |
Document ID | / |
Family ID | 64400265 |
Filed Date | 2018-11-29 |
United States Patent
Application |
20180340713 |
Kind Code |
A1 |
Dowdy, III; Jack |
November 29, 2018 |
Power saver apparatus for refrigeration
Abstract
Power-saver apparatus modifying the physics of the closed-loop
vapor-circuit compression-refrigeration cycle by scavenging the
kinetic energy of the hot compressed liquid-vapor with at least one
micro-turbine driven permanent-magnet power-generator inserted into
said loop between the compressor and the condenser of said circuit,
whereas said cycle repeats indefinitely in closed-loop
vapor-pipe-line of one or more refrigeration stages, each having at
least one of the following devices in the following sequence: a)
electric-motor-driven-compressor, b) micro-turbine-power-generator,
c) condenser-radiator, d) throttle and e) evaporator-radiator,
whereas said generator is sealed in said pipe-line and generates
low-voltage direct-current, which is converted to high-voltage
alternating-current, which, using an inverter, is utilized to
offset the power consumption of said refrigerator by feeding the
generated power back to the grid, which powers said compressor, and
wherein the refrigerated space comprising the said evaporator is
separated from the rest of said devices and their interconnecting
vapor-pipe-lines by heat insulation.
Inventors: |
Dowdy, III; Jack; (Croydon,
UT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dowdy, III; Jack |
Croydon |
UT |
US |
|
|
Family ID: |
64400265 |
Appl. No.: |
16/016380 |
Filed: |
June 22, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 2600/2501 20130101;
F25B 9/06 20130101; F25B 11/02 20130101; F25B 49/02 20130101; F25B
2400/141 20130101 |
International
Class: |
F25B 11/02 20060101
F25B011/02; F25B 9/06 20060101 F25B009/06 |
Claims
1. Power saver apparatus modifying the physics of the closed loop
vapor circuit compression refrigeration cycle by scavenging the
kinetic energy of the hot compressed liquid-vapor with at least one
micro-turbine driven permanent-magnet power-generator inserted into
said loop between the compressor and the condenser of said circuit,
whereas said cycle repeats indefinitely in closed-loop
vapor-pipe-line or one or more refrigeration stages, each having at
least one of the following devices in the following sequence: a)
electric-motor-driven-compressor, b) micro-turbine-power-generator,
c) condenser-radiator, d) throttle and e) evaporator-radiator,
whereas said generator is sealed in said pipe-line and generates
low-voltage direct-current, which is converted to high-voltage
alternating-current, which, using an inverter, is utilized to
offset the power consumption of said refrigerator by feeding the
generated power back to the grid, which powers said compressor, and
wherein the refrigerated space comprising the said evaporator is
separated from the rest of said devices and their interconnecting
vapor-pipe-lines by heat insulation.
2. Apparatus as per claim 1, whereas said generated low-voltage
direct-current electric power converted to said high-voltage
alternating current power is fed back to the grid power by being
plugged-in via grid-plug.
3. Power saver apparatus modifying the physics of the closed loop
vapor circuit compression refrigeration cycle by scavenging the
kinetic energy of the hot compressed liquid-vapor with at least one
micro-turbine driven permanent-magnet power-generator inserted into
said loop between the compressor and the condenser of said circuit,
whereas said cycle repeats indefinitely in closed-loop
vapor-pipe-line of one or more refrigeration stages, each having at
least one of the following devices in the following sequence: a)
electric-motor-driven-compressor, b) selector-bypass-valve c)
micro-turbine-power-generator, d) condenser-radiator, e) throttle
and f) evaporator-radiator, whereas said generator is sealed in
said pipe-line and generates low-voltage direct-current, which is
converted to high-voltage alternating-current, which, using an
inverter, is utilized to offset the power consumption of said
refrigerator by feeding the generated power back to the grid, which
powers said compressor, and wherein said valve is used to bypass
said generator, when bypassing is selected, and wherein the
refrigerated space comprising the said evaporator is separated from
the rest of said devices and their interconnecting vapor-pipe-lines
by heat insulation.
4. Apparatus as per claim 3, whereas said generated low-voltage
direct-current electric power converted to said high-voltage
alternating current power is fed back to the grid power by being
plugged-in via grid-plug.
5. Apparatus as per claim 3, whereas said inverter has at least one
direct-current power-out-line plugged to at least one low-voltage
socket.
6. Method for seeing power consumption of refrigerators operating
by vapor compression in indefinite cycles by scavenging the kinetic
energy of said vapor in its hot phase using micro-turbine driven
power generator and feeding back the generated power to the power
source of said refrigerators.
7. Method as per claim 6, whereas said feeding back comprises
alternating current converted from direct current using an
inverter.
8. Method as per claim 6, whereas said feeding back comprises
direct current.
9. Method as per claim 6, whereas said scavenging is bypassed using
at least one manual vapor-line valve.
10. Method as per claim 6, whereas said scavenging is bypassed
using at least one electrical-electronic vapor-line servo-valve.
Description
FIELD OF THE INVENTION
[0001] This invention relates to improvements in closed vapor
compression cycle cooling or refrigerating devices, including most
refrigerators and some HVAC equipment.
BACKGROUND OF THE INVENTION
[0002] Most household and industrial refrigerators work by
continuously repeating a vapor compression cycle in closed and
sealed fluid flow circuit, which comprises a gas compressor, a hot
side vapor condenser coil, an expansion valve or a capillary coil
or other throttling device and a cold side liquid evaporator coil,
using Freon or other coolant or refrigerant liquid, while the
compressor is powered by electricity from the grid which supplies
120-460V AC, whereas said hot and cold sides are separated by heat
insulation and the cold side is in the space to be cooled and the
hot side is out side of it, so the refrigerator transports heat
from inside out.
[0003] The cold space in a household refrigerator is a heat
insulated food storage cabinet, often split to deep freezer and
regular freezer compartments, while these two spaces may be
separated by doors lids or drawers. The evaporator coil or radiator
may also be split accordingly. The throttling device typically
receives plus 90-45.degree. C., 8 bar liquid and passes -20.degree.
C., 0.6 bar vapor as gas. Depending on the cooled state of the food
stored in the cold compartments, the compressor typically receives
-20.degree. C. 0.6 bar vapor at low speed and passes plus
90.degree. C., 8 bar vapor as gas at high speed.
[0004] The kinetic energy of the compressor's discharge gas is not
utilized. Improvement on the state of art is therefore in
order.
[0005] The objective of the invention is to convert the
compressor's discharge gas kinetic energy to electricity to feed it
back to the grid, thereby reducing overall electrical power
consumption of refrigeration.
[0006] It is proposed that a closed and sealed impact turbine be
inserted in the pipeline connecting the compressor and the
condenser, while the turbine would drive a permanent magnet
alternator or generator (PMA/PMG), generating 12-48V low voltage
DC, which passing through an inverter would be plugged in to the
wall socket, next to the socket used to take AC power to run the
compressor. After some heat and electrical losses, the overall
efficiency of the refrigeration improves considerably, alas at the
expense of a slight lengthening of the refrigeration time. Should
rapid initial refrigeration be required for warm food cooling, the
turbine may be bypassed temporarily, controlled by thermostat or
other electronic controller, which would actuate the bypass
valve.
SUMMARY OF THE INVENTION
[0007] The above problems and others are at least partially solved
and the above objects and others realized in a process, which
according to the teachings of this invention, uses a power saving
apparatus in the vapor compression cycle, inserted in the pipeline
connecting the compressor and the condenser in two distinct
ways:
[0008] In one embodiment, the apparatus comprises [0009] a) A
sealed impact micro-turbine, [0010] b) A permanent magnet
alternator (PMA) generating direct low voltage direct current (DC),
[0011] c) An inverter converting the DC to high voltage alternating
current (AC), and [0012] d) An electrical power-out connector
suitable to plug into common grid power receptacle.
[0013] In another embodiment, the apparatus comprises [0014] a) An
sealed impact micro-turbine, [0015] b) A permanent magnet
alternator (PMA) generating direct low voltage direct current (DC),
[0016] c) An inverter converting the DC to high voltage alternating
current (AC), [0017] d) An electrical power-out connector suitable
to plug into common AC grid power receptacle, [0018] e) A vapor
bypass line branched off using an electronically controlled
electrical three-way-valve, [0019] f) A servo-valve actuator,
[0020] g) A servo-valve electronic controller, and [0021] h) An
electrical power-out connector suitable to plug into common DC
power receptacle.
[0022] In both configurations, the AC power may be switched,
on-and-off manually or controlled electronically and the
servo-valve may be substituted by manual valve.
[0023] The micro-turbine reduces flow rate and temperature of the
hot vapor. The more resistance it has against the vapor flow, the
longer the refrigeration cycle is extended by more time needed to
cool the food in the refrigerator. Cooling time however seldom
considered. The overall refrigeration efficiency may increase by
32% and the vapor cycle efficiency by 13%.
[0024] To compare refrigeration technologies, the industry uses the
Coefficient of Performance (CoP) indicator. The energy balance is
expressed as P.sub.INPUT+Q.sub.ABSORBED=Q.sub.REJECTED, where
P.sub.INPUT is the supplied electrical power, Q.sub.ABSORBED is the
heat absorbed from the food in the refrigerator via the evaporator,
inside the heat insulated space, and Q.sub.REJECTED is the heat
added to the room around the refrigerator via the condenser,
outside the heat insulated space.
[0025] For the state of art refrigerator,
CoP=Q.sub.ABSORBED/P.sub.INPUT. For the modified refrigerator as
per the teachings of the invention,
CoP.sub.M=Q.sub.ABSORBED/(P.sub.INPUT-P.sub.OUTPUT), where
P.sub.OUTPUT is the electrical power generated by the PMA. Since
P.sub.OUTPUT is always higher than zero, even at marginal power
generation, CoP.sub.M>CoP.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Referring to the drawings:
[0027] FIG. 1 is a diagram illustrating a state of art vapor
compression cycle refrigeration system.
[0028] FIG. 2 is a diagram illustrating an improved compression
cycle refrigeration system as per the teachings of the
invention.
[0029] FIG. 3 is a diagram illustrating a further improved
compression cycle refrigeration system as per the teachings of the
invention.
[0030] FIG. 4 is a plot illustrating the physics of the state of
art and the modified novel vapor compression refrigeration
cycles.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0031] Attention is now turned to FIG. 1, which is a diagram
illustrating a single-stage STATE-OF-ART vapor compression cycle
refrigeration system with components and flow attributes
labeled.
[0032] The coolant is selected to suit the application and the
environment. For household refrigerator, due to environmental
considerations and regulations thereof, the classical
Chemorous/DuPont made/owned Freon group of R-12, R-13B1, R-22,
R-502 and R-503 (CFC group) is now replaced by the HFC group of
R-410A, R-404A, R-406A, R-407A, R-407C, R-408A, R-409A, R-410A,
R-438A, R-500 and R-502. For other applications, ammonia,
hydro-chlorofluorocarbons (HCFCs), sulfur dioxide, methyl chloride
and other liquids or ethylene, propane, nitrogen, helium or other
gases are used. It is common to add some synthetic oil to lubricate
the compressor, but only the one, which needs lubrication.
[0033] The refrigeration capacity is commonly defined in "tons of
refrigeration" (T.sub.R). 1 T.sub.R is the rate of heat removal
required to freeze a short ton (2,000-lbs) 32.degree. F. (0.degree.
C.) water. Since the rate of fusion for water is 144 Btu/lbs, 1
T.sub.R=12,000 Btu/h=3.517 kW. Common household food and beverage
refrigerators are in the 1-5 tons (3.5-18 kW) region. Other
applications include commercial, industrial, food processing,
transport, electronics, medical and cryogenic refrigeration.
[0034] The circulating refrigerant transports heat from the heat
insulated closed Refrigerated Space to outside of it. The coolant,
almost always in liquid-with-vapor phase, is cold after passing the
Throttle and before entering the Compressor, which is powered by
grid AC from the Grid Plug across the Main Switch, which may
interrupt the AC current flowing to the electrical motor of the
Compressor. The coolant is hot after passing the Compressor and
before entering into the Throttle. The heat rejection in the
Condenser is at constant high temperature. The heat absorption in
the Evaporator is at constant low temperature. The vapor is
saturated before entering and superheated after leaving the
Compressor. The vapor enters and leaves the Throttle saturated
while undergoing adiabatic sudden expansion, which lowers the vapor
temperature. The vapor absorbs heat from the food in the Evaporator
and rejects it in Condenser, both as constant low and high
temperature correspondingly. Both the Condenser and Evaporator are
radiator type flat pipe-snakes, panels or coils.
[0035] The cold half loop is at -20.degree. C. temperature at 0.6
bar pressure, while the hot half loop is at 90.degree. C. to
45.degree. C. temperature at 8 bar pressure. At ideal steady state
flow Condenser heat transfer rate, the after Compressor temperature
is conserved, up to the Throttle entry point. That is achieved with
pure convection heat transfer. For instant, by chimney effect, when
the air is stagnant around the refrigerator.
[0036] Fan may be added however to increase the airflow of the
evaporator and water may be used as heat exchanging fluid for the
condenser. To reduce cost and complexity, household refrigerators
avoid such complications.
[0037] The STATE-OF-ART cycle of FIG. 1 is further explained in
FIG. 4, where loop 1-2-A-3-4-1 represents the unmodified (state of
art) and 1-2-A-2*-3*-4*-1 the modified (proposed novel) cycle.
[0038] Attention is now turned to FIG. 2, which is a diagram
illustrating an improved single-stage vapor compression cycle
refrigeration system modified as per the teachings of the
invention, with components and flow attributes labeled as
above.
[0039] Shortly after the Compressor, Micro-turbine-PMA is inserted
into the hot vapor half loop. The temperature and pressure drops on
the turbine, which drives a permanent magnet alternator (PMA) or
power generator (PMG). The generated DC is passed through the
Inverter and the generated electrical power is returned as AC to
the grid via another Grid Plug. The rest of the process remains
intact. Should the Micro-turbine-PMA be needed to he bypassed
temporally, further improvement is needed, as that is illustrated
next.
[0040] Attention is now turned to FIG. 3, which is a diagram
illustrating a further improved single stage vapor compression
cycle refrigeration system modified as per the teachings of the
invention, with components and flow attributes labeled likewise
before.
[0041] In this embodiment, the Selector-Valve directs the vapor
either to the Micro-turbine-PMA via the direct line (full line) or
to the Condenser via the bypass line (dashed). The generated AC
power now is diverted from the Inverter via Isolation Switch 2 to
the AC-out Plug. Alternatively, the DC power via Isolation Switch 1
is passed to the Grid Plug as described above. The condenser thus
either gets hot (90.degree. C.) or warm (45.degree. C.) vapor. The
Selector Valve may be operated manually or preferably
electronically by a controlled electrical actuator coil.
[0042] To the skilled in the art of refrigerator building, it shall
be obvious that the generated AC power may be directed to the
compressor, instead to the Grid Plug.
[0043] Attention is finally turned to FIG. 4, which is a Cartesian
Pressure-Volume (P-V) plot, which illustrates the physics of the
state of art vapor compression cycle (1-2-3-A-4-1 in thick heavy
full line) and the modified novel vapor compression refrigeration
cycle (1-2-A-2*-3*-4*-1 in thick heavy full and dotted lines).
[0044] The state of art cycle works as follows:
[0045] The liquid-vapor phase is within the hot shape dashed line
boundary. The cycle starts at point 1. Branch 1-2 is the
compression phase, which elevates the vapor pressure and
temperature from T.sub.c cold to T.sub.h hot temperatures in the
vapor phase by the addition of P.sub.in input power of the
electricity driving the Compressor.
[0046] At constant pressure and temperature the vapor first goes to
liquid-vapor at point A, then up to point 3, to the boundary of the
phase states. This happens in the Condenser at T.sub.h temperature,
while Q.sub.out heat, as heat output, is rejected to the
environment (branch 2-3) outside of the heat insulated refrigerated
closed space.
[0047] In the Throttle, the liquid-vapor suddenly drops
temperature, down to T.sub.c cold and loses pressure (phase change
3-4).
[0048] In the 4-1 closing Branch, in the Evaporator, the
liquid-vapor expands at constant pressure, reaching the vapor phase
boundary at point 1. In this Branch, the heat Q.sub.in, as heat
input, of the food in the insulated refrigerated closed space is
absorbed.
[0049] The process repeats indefinitely from hereon.
[0050] The modified novel cycle works as follows:
[0051] Up to point A, the same. At point A, which is at the phase
state boundary, the liquid-vapor drops pressure and temperature to
T.sub.w warm (branch A-2*) while DC power P.sub.out, as output
power is scavenged. The rest of the process (2*-3*-4*-1) is similar
to process 2-3-4-1. The process modification is indicated by labels
in parenthesis.
[0052] From heron, the process repeats indefinitely.
[0053] Thermodynamics assures that the input and output heats are
the same (Q.sub.in=Q.sub.out) and the difference between the two
process-loop areas is equal the output power (P.sub.out), while the
modified process is somewhat slower than the state of art process.
To the skilled in refrigeration technology, it shall be obvious
that the refrigerated space must be heat insulated and its doors
must be closed at all times, except for food and beverage
loading-and-unloading, otherwise the refrigerator would consume
power indefinitely without significantly cooling the
food-and-beverage. Also that the added power-saver must scavenge
only a limited portion of the power needed for vapor compression,
while the food and beverage to be refrigerated is merely exemplary
here.
[0054] Refrigerating power may be saved in proportion to
V.sub.2-A/V.sub.2-3, where V.sub.2-A and V.sub.2-3 correspond to
the vapor volumes of state transitions 2-A and 2-3 correspondingly.
Observing FIG. 4, one may conclude that compressors working at
higher pressure are more candidates for power saving by this novel
method.
[0055] To the skilled in the art of refrigeration system design and
technology, it shall be obvious that the proposed power saver
device improves refrigeration economy without adding much
complexity and price and can be added to any refrigeration system
as aftermarket device or be integrated into the original
refrigerator built for domestic or industrial use. It shall also be
obvious that the generated power may be used within the
refrigerator, for instance to drive a fan blowing ambient air to
the condenser or to power the refrigerator's low voltage controls
and door opening-closing actuators to eliminate their inverter.
[0056] The present invention is described above with reference to a
preferred embodiment. However, those skilled in the art will
recognize that changes and modifications may be made in the
described embodiment without departing from the nature and scope of
the present invention. For instance, adding thermocouples for
supplemental DC power generation by bridging the hot and cold side,
or using other than turbine kinetic impeller, or using multiple
gate valves or servo-valves instead of a selector-valve, or
generating AC, or multi-staging is intuitive and hereby instructive
over the teachings of the invention and considered being within its
scope.
[0057] Various further changes and modifications to the embodiment
herein chosen for purposes of illustration will readily occur to
those skilled in the art. To the extent that such modifications and
variations do not depart from the spirit of the invention, they are
intended to be included within the scope thereof.
[0058] Having fully described the invention in such clear and
concise terms as to enable those skilled in the art to understand
and practice the same, the invention claimed is:
* * * * *