U.S. patent application number 13/088593 was filed with the patent office on 2012-10-18 for cooling system utilizing a conical body.
Invention is credited to Serguei Charamko.
Application Number | 20120260676 13/088593 |
Document ID | / |
Family ID | 47005365 |
Filed Date | 2012-10-18 |
United States Patent
Application |
20120260676 |
Kind Code |
A1 |
Charamko; Serguei |
October 18, 2012 |
COOLING SYSTEM UTILIZING A CONICAL BODY
Abstract
Cooling via acceleration of a compressible fluid is disclosed.
The fluid is accelerated by a rotatable body to a velocity that may
be equal to or greater than the speed of sound in the fluid. No
conventional mechanical pump is required to accelerate the fluid. A
phase change of the fluid may be utilized to transfer heat from an
element to be cooled.
Inventors: |
Charamko; Serguei; (Novato,
CA) |
Family ID: |
47005365 |
Appl. No.: |
13/088593 |
Filed: |
April 18, 2011 |
Current U.S.
Class: |
62/56 ;
62/467 |
Current CPC
Class: |
F25D 3/00 20130101; F25B
23/00 20130101 |
Class at
Publication: |
62/56 ;
62/467 |
International
Class: |
F25D 31/00 20060101
F25D031/00; F25D 3/00 20060101 F25D003/00 |
Claims
1. A cooling system, the system comprising: a rotatable body
positioned in a fluid flow path; a stationary housing for the
rotatable body; and a driving mechanism that provides a motive
force to induce rotation of the rotatable body, the rotation of the
rotatable body accelerating a fluid in the fluid flow path and
imparting a rotational velocity to the fluid to change the pressure
of the fluid so that the temperature of the fluid is reduced to
allow heat to be exchanged with an element to be cooled.
2. The system of claim 1, wherein, the rotatable body is generally
conical in shape.
3. The system of claim 1, wherein rotation of the rotatable body
accelerates fluid and imparts a rotational velocity as the fluid
flows through acceleration grooves in the stationary housing.
4. The system of claim 1, wherein rotation of the rotatable body
generates cavitation via shear forces and a lowered pressure area
in the fluid in the fluid flow path.
5. The system of claim 1, further including an enclosure
surrounding the fluid flow path, the enclosure being thermally
coupled to the element to be cooled.
6. The system of claim 1, wherein the acceleration of the fluid by
the rotation of the rotatable body creates a region in the fluid
flow path in which the fluid undergoes a phase change as the
pressure of the fluid changes.
7. The system of claim 1, wherein the fluid pressure changes
between a high pressure region and a low pressure region, the
pressure change created by the acceleration of the fluid and a
rotational velocity imparted to the fluid.
8. The system of claim 7, wherein the high pressure region of the
fluid is at a pressure greater than 100 PSI.
9. The system of claim 7, wherein the low pressure region of the
fluid is at a pressure less than 20 PSI.
10. A method for cooling, the method comprising: rotating a body to
accelerate the flow of a fluid in a fluid flow path and to impart a
rotational velocity to the fluid to establish a low pressure region
in the fluid flow path; forming a compression wave in the fluid as
the fluid passes from a high pressure region to the low pressure
region; and exchanging heat introduced into the fluid flow path
during a phase change of the fluid that occurs as the fluid flows
from the high pressure region to the low pressure region.
11. The method of claim 10, wherein exchanging heat occurs at least
in part as a result of at least one heat conductive surface being
thermally coupled to the fluid flow path.
12. The method of claim 10, wherein acceleration of the flow of the
fluid is initiated by rotating a conical body located in a conical
depression in a stationary housing of an evaporator.
13. The method of claim 10, further comprising creating a
cavitation effect by rotating the conical body to generate shear
forces and to impart a rotational velocity to the fluid.
14. The method of claim 10, wherein the rotation of the body
creates suction that draws the fluid through an inlet in the fluid
flow path.
15. The method of claim 10, further comprising effectuating a phase
change in the fluid as a result of a pressure change generated by
the rotation of the body.
16. The method of claim 15, wherein the pressure change of the
fluid occurs within a range of approximately 20 PSI to 100 PSI.
17. The method of claim 15, wherein the pressure change of the
fluid involves a change to a pressure greater than or equal to 100
PSI.
18. The method of claim 15, wherein the pressure change of the
fluid involves a change to a pressure less than or equal to 20
PSI.
19. The method of claim 10, wherein the fluid shocks up to an
elevated pressure as the fluid exits the low pressure region.
20. The method of claim 19, wherein the elevated pressure is an
ambient pressure.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to cooling via a
fluid flow cycle. More specifically, the present invention is
related to cooling systems that establish a cooling cycle using a
rotatable body.
[0003] 2. Description of the Related Art
[0004] Vapor compression systems are used in many cooling
applications such as air conditioning and industrial refrigeration.
A vapor compression system generally includes a compressor, a
condenser, an expansion device, and an evaporator. In a prior art
vapor compression system, a gas in a saturated vapor state is
compressed to raise the temperature of that gas, the gas then being
in a superheated vapor state. The compressed gas is then run
through a condenser and turned into a liquid, and heat is rejected
from the system. The condensed and liquefied gas is then taken
through an expansion device, which drops the pressure and the
corresponding temperature. The resulting refrigerant is then boiled
in an evaporator, with the refrigerant absorbing heat. The
saturated vapor is then returned to the compressor.
[0005] FIG. 1 illustrates a vapor compression system 100 as might
be found in the prior art. In the prior art vapor compression
system 100 of FIG. 1, compressor 110 compresses the gas to
(approximately) 238 pounds per square inch (PSI) and a temperature
of 190.degree. F. Condenser 120 then liquefies the heated and
compressed gas to (approximately) 220 PSI and 117.degree. F. The
gas that was liquefied by the condenser 120 is then passed through
the expansion valve 130 of FIG. 1. By passing the liquefied gas
through expansion valve 130, the pressure is dropped to
(approximately) 20 PSI.
[0006] A corresponding drop in temperature accompanies the drop in
pressure, which is reflected as a temperature drop to
(approximately) 34.degree. F. in FIG. 1. The refrigerant that
results from dropping the pressure and temperature at the expansion
value 130 is boiled at evaporator 140. Through boiling of the
refrigerant by evaporator 140, a low temperature vapor results. The
vapor is illustrated in FIG. 1 as having a temperature of
(approximately) 39.degree. F. and a corresponding pressure of 20
PSI.
[0007] The cycle carried out by the system 100 of FIG. 1 is an
example of a vapor compression cycle. Such a cycle generally
results in a coefficient of performance (COP) between 2.4 and 3.5.
The COP, as illustrated in FIG. 1, is the evaporator cooling power
or capacity divided by compressor power. It should be noted that
the temperature and PSI references that are shown in FIG. 1 are
exemplary and are for the purpose of illustration only.
[0008] FIG. 2 illustrates the performance that might be expected of
a vapor compression system similar to that illustrated in FIG. 1.
The COP illustrated in FIG. 2 corresponds to a typical home or
automotive vapor compression system operating at an ambient
temperature of (approximately) 90.degree. F. The COP shown in FIG.
2 corresponds to a vapor compression system utilizing a fixed
orifice tube system.
[0009] A system like that illustrated in FIG. 1 and FIG. 2
typically operates at an efficiency rate or COP that is far below
that of system potential. To compress gas in a conventional vapor
compression system like that illustrated in FIG. 1 (system 100)
typically takes 1.75-2.50 kilowatts for every 5 kilowatts of
cooling power. This exchange rate is less than optimal and directly
correlates to the rise in pressure times the volumetric flow rate.
Degraded performance is similarly and ultimately related to
performance (or lack thereof) by the compressor 110.
[0010] Haloalkane refrigerants such as tetrafluoroethane
(CH.sub.2FCF.sub.3) are inert gases that are commonly used as
refrigerants in refrigerators and automobile air conditioners.
Tetrafluoroethane has also been used to cool over-clocked
computers. These gases are referred to as R-134 gases. The volume
of an R-134 gas can be 600-1000 times greater than its
corresponding liquid form. This multiplier shows that the
theoretical efficiency of a system utilizing an R-134 gas is much
higher than is currently being realized, and evidences the need for
an improved cooling system that more fully recognizes system
potential and overcomes technical barriers related to compressor
performance.
[0011] In light of the theoretical efficiencies of systems using
haloalkanes or other fluids, there is a need in the art for an
improved cooling system that more fully recognizes system potential
and overcomes technical barriers related to compressor performance.
There is a further need for a cooling system that operates without
the use of a conventional mechanical pump.
SUMMARY OF THE CLAIMED INVENTION
[0012] A first claimed embodiment is for a cooling system that
includes a rotatable body positioned in a fluid flow path. The
system further includes a stationary housing for the rotatable body
and a driving mechanism that provides a motive force to induce
rotation of the rotatable body. The rotation of the rotatable body
accelerates a fluid in the fluid flow path and imparts a rotational
velocity to the fluid to change the pressure of the fluid.
Concurrent with the pressure change, the temperature of the fluid
is reduced and heat is exchanged with an element to be cooled.
[0013] A cooling method is also claimed. The claimed method
includes rotating a body to accelerate the flow of a fluid in a
fluid flow path and to impart a rotational velocity to the fluid to
establish a low pressure region in the fluid flow path. The method
further includes forming a compression wave in the fluid as the
fluid passes from a high pressure region to the low pressure
region. Heat is exchanged during a phase change of the fluid that
occurs as the fluid flows from the high pressure region to the low
pressure region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic diagram of a vapor compression cooling
system as may be found in the prior art.
[0015] FIG. 2 is a pressure-enthalpy graph for a vapor compression
cooling system like that illustrated in FIG. 1.
[0016] FIG. 3 is an exemplary pressure-enthalpy graph for a cooling
system as described herein.
[0017] FIG. 4 is a sectional view of an exemplary cooling unit.
[0018] FIG. 5 illustrates an exemplary evaporator utilizing a
rotatable conical body.
[0019] FIG. 6 illustrates an exemplary conical body.
[0020] FIG. 7 shows a stationary housing of the evaporator.
[0021] FIG. 8 illustrates the underside of the stationary
housing.
[0022] FIG. 9 illustrates a method of cooling.
DETAILED DESCRIPTION
[0023] Embodiments of the present invention implement a cooling
cycle that may utilize rotating flow and that increases efficiency
as compared to prior art cooling systems. While the system will be
described herein generally in terms of a cooling system, those
skilled in the art will recognize that the system may be
implemented as a heat pump, and thereby serve to heat a given
element.
[0024] A system utilizing the present invention may operate at a
COP of 2 or greater, 3 or greater, 4 or greater, 5 or greater, 6 or
greater, 7 or greater, 8 or greater, 9 or greater, 10 or greater,
or 20 or greater due to the elimination of certain hardware
elements. Nor do embodiments of the present invention require a
compressor or a conventional mechanical pump to operate. Only an
electric motor or some other driving mechanism to impart a rotating
force is required.
[0025] Part of the increase in COP for systems utilizing the
cooling cycle that may utilize rotating flow and that utilizes a
rotatable body is due to the fact that such systems do not need to
compress a gas as otherwise occurs at compressor 110 in a prior art
vapor compression system 100 like the one shown in FIG. 1. A
pressure-enthalpy chart of an exemplary cooling system is
illustrated in FIG. 3. The performance curve illustrated is one
that might be expected for a cooling system as described
herein.
[0026] An exemplary cooling system 400, as illustrated in FIG. 4,
operates by accelerating a working fluid, which may be water, in an
evaporator 500 (see FIG. 5). Due to the operating cycle of the
cooling system 400, the system does not require the use of a
condenser 120 or a conventional mechanical pump as does the prior
art compression system 100 of FIG. 1. The cooling system 400
instead utilizes the evaporator 500 that employs a rotatable body.
The rotatable body accelerates the working fluid in the cooling
system 400 and may generates a compression wave. While various
configurations of the rotatable body may be acceptable within the
principles of the present invention, the description herein will
describe the operation of the system with reference to a rotatable
conical body 410.
[0027] The cooling system 400 may operate in the critical flow
regime of the working fluid. In this regime, in which the fluid is
accelerated to supersonic velocity, the pressure of the fluid in
the system 400 will remain almost constant and then `jump` or
`shock up` to the ambient pressure.
[0028] Because the cooling system 400 accelerates and creates a
pressure differential in the working fluid through rotational
movement of the conical body 410, the cooling system 400 does not
require the use of a conventional mechanical pump. The reduced
amount of hardware required to operate a cooling system 400--there
is no need for a compressor or a conventional mechanical
pump--gives rise to a greatly improved coefficient of performance
(COP) for the system.
[0029] The conical body 410 may be mounted in an interior
stationary housing 420. The motive force required to spin the
conical body 410 may be supplied by any number of driving
mechanisms known to those skilled in the art. An example of a
suitable driving mechanism is an electric motor with a drive axis
coupled to the conical body 410.
[0030] A lower section of the stationary housing 420 may include
one or more flow apertures 430. The flow apertures 430 (visible in
FIGS. 5 and 6) allow the working fluid to enter the interior of the
housing 420, and may be considered to be the starting point of a
fluid flow path.
[0031] The rotation of the conical body 410 creates suction that
draws the working fluid upward through an inlet 440. The inlet 440
is also shown in FIG. 7. The inlet 440 is coupled to a plurality of
acceleration grooves 450. The acceleration grooves 450 are formed
in a surface of the stationary housing 420 that forms a conical
depression to receive the conical body 410.
[0032] As the working fluid is accelerated through the acceleration
grooves 450, a cavitation effect may be generated at least in part
due to shear forces created between the rotatable conical body 410
and the acceleration grooves 450 formed in the stationary housing
420. The cavitation effect helps to turn the liquid working fluid
into a two phase fluid, which aids the formation of a compression
wave in the working fluid.
[0033] As the fluid is accelerated in the acceleration grooves 450,
the fluid is induced to spin within the grooves 450. The rotation
imparted to the fluid within the acceleration grooves 450 adds a
rotational velocity to the linear velocity, thereby creating a
centrifugal effect. The centrifugal effect creates a low pressure
area in the acceleration grooves 450. In the acceleration grooves
450, the rotational acceleration is equal to velocity squared
divided by the radius of rotation. Therefore small radii of
rotation yield large acceleration forces with minimal velocities.
This is another factor that provides improved efficiencies for the
cooling system 400.
[0034] The centrifugal forces created by the rotational velocity
within the acceleration grooves 450 create a lowered pressure area
near the center of rotation. The lowered pressure promotes
evaporation within the acceleration grooves 450, which assists the
cooling effect of the system 400. The lowered pressure area may
induce cooling prior to the fluid reaching supersonic velocity.
[0035] As the working fluid is accelerated in the acceleration
grooves 450, the fluid is accelerated to a speed equal to or
greater than the speed of sound in the fluid. The resultant phase
change contributes to the desired cooling effect of the system
400.
[0036] The working fluid shocks up as it exits the acceleration
grooves 450 and returns to ambient pressure. The fluid flows
through a pathway 460 formed between the surface of the stationary
housing 420 and a system enclosure 470. The liquid working fluid
then pools at the lower end of the stationary housing portion 420
where it returns to the flow apertures 430.
[0037] The fluid flow path of the working fluid may be seen as
beginning at the flow apertures 430 in the lower section of the
stationary housing 420. The liquid working fluid is sucked into the
inlet 440 in the stationary housing 420 by suction (vacuum) created
by the acceleration of the fluid due to the rotation of the conical
body 410. The working fluid flows upward through the acceleration
grooves 450 formed in the stationary housing 420. Post shock, the
fluid exits the acceleration grooves 450 and flows downward through
the pathway 460 formed between the stationary housing 420 and the
system enclosure 470.
[0038] As is explained in further detail below, a phase change
occurs in the working fluid as the fluid is accelerated in the
acceleration grooves 450. As the working fluid travels through the
fluid flow path, the system 400 generates a cooling effect via the
method delineated in FIG. 9. In a step 910, the motive force for
the fluid is provided by spinning the rotatable conical body 410
mounted in the stationary housing 420. The desired rotational speed
of the rotatable conical body 410 is determined by the parameters
of the system and the selected working fluid. In one embodiment of
the system 400, the rotatable conical body 410 may be spun at from
approximately 5,000 rpm to approximately 10,000 rpm or faster. In
various other embodiments, system conditions may be such that the
rotatable conical body 410 may rotate at far slower speeds, such as
less than 10 RPM. The rotational speed of the rotatable conical
body 410 may vary with the requirements of a given application, and
will vary inversely with the size of the body 410.
[0039] In a step 920, the working fluid is drawn through inlet 440
in the stationary housing 420 by suction created by the phase
change due at least in part to acceleration of the fluid as the
conical body 410 rotates.
[0040] In a further step 930, as the fluid is accelerated through
the acceleration grooves 450, a rotational velocity is imparted to
the working fluid in the grooves 450 in addition to the linear
velocity. The evaporator 500 may be constructed such that a
cavitation effect is created by shear forces generated between the
surface of the rotatable conical body 410 and the stationary
housing 420, and by a lowered pressure area generated by the
centrifugal force created by spinning the rotatable body 410 to
accelerate the working fluid through the acceleration grooves 450.
The cavitation lowers the speed of sound in the fluid, and thereby
assists in the phase change and resultant lowered temperature of
the fluid to create a cooling effect in the evaporator 500 in step
940.
[0041] Critical flow rate, which is the maximum flow rate that can
be attained by a compressible fluid as that fluid passes from a
high pressure region to a low pressure region (i.e., the critical
flow regime), allows for a compression wave to be established and
utilized in the critical flow regime established in the evaporator
500. Critical flow occurs when the velocity of the fluid is greater
than or equal to the speed of sound in the fluid. In critical flow,
the pressure in the evaporator 500 will not be influenced by the
exit pressure. In step 950, the working fluid may `shock up` to the
ambient conditions as the fluid exits the acceleration grooves
450.
[0042] The pressure change of the fluid in the system 400 may
include a range of approximately 20 PSI in the low pressure region
to 100 PSI in the high pressure region. In some instances, the
pressure may be increased to more than 100 PSI, and in some
instance, the pressure may be decreased to less than 20 PSI.
Depending upon the characteristics of a given system, the pressure
change range may vary from that described immediately above.
[0043] The cooling effect of the system 400 may be realized in an
object to be cooled by putting the object in direct contact with
the system enclosure 470. Another method of transferring heat from
the object to be cooled into the system 400 may be accomplished in
an optional step 960. In optional step 960, the cooled working
fluid is coupled to a heat exchanger. The heat exchanger may
transport a heated circulating fluid from the object to be cooled
to the cooling system 400.
[0044] While various embodiments have been described above, it
should be understood that they have been presented by way of
example only, and not limitation. The descriptions are not intended
to limit the scope of the invention to the particular forms set
forth herein. Thus, the breadth and scope of a preferred embodiment
should not be limited by any of the above-described exemplary
embodiments. It should be understood that the above description is
illustrative and not restrictive. To the contrary, the present
descriptions are intended to cover such alternatives,
modifications, and equivalents as may be included within the spirit
and scope of the invention as defined by the appended claims and
otherwise appreciated by one of ordinary skill in the art. The
scope of the invention should, therefore, be determined not with
reference to the above description, but instead should be
determined with reference to the appended claims along with their
full scope of equivalents.
* * * * *