U.S. patent application number 13/795412 was filed with the patent office on 2014-09-18 for thermoelectric power generation condenser.
This patent application is currently assigned to HUSSMANN CORPORATION. The applicant listed for this patent is HUSSMANN CORPORATION. Invention is credited to Raymond P. Twohy.
Application Number | 20140262178 13/795412 |
Document ID | / |
Family ID | 49920050 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140262178 |
Kind Code |
A1 |
Twohy; Raymond P. |
September 18, 2014 |
THERMOELECTRIC POWER GENERATION CONDENSER
Abstract
A heat exchanger includes an inlet header configured to receive
refrigerant and an outlet header configured to discharge the
refrigerant. First and second tubes in fluid communication with and
extending between the inlet header and the outlet header direct
refrigerant from the inlet header to the outlet header. Each of the
tubes has a first side and a second side. The first side of the
first tube is oriented to face the second side of the second tube.
A first thermoelectric generator is in thermal communication with
the first side of the first tube and a second thermoelectric
generator is in thermal communication with the second side of the
second tube. A plurality of fins is in thermal contact with the
first thermoelectric generator and the second thermoelectric
generator and with a surrounding environment.
Inventors: |
Twohy; Raymond P.; (St.
Peters, MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HUSSMANN CORPORATION |
Bridgeton |
MO |
US |
|
|
Assignee: |
HUSSMANN CORPORATION
Bridgeton
MO
|
Family ID: |
49920050 |
Appl. No.: |
13/795412 |
Filed: |
March 12, 2013 |
Current U.S.
Class: |
165/173 |
Current CPC
Class: |
F25B 27/00 20130101;
F28D 2021/007 20130101; F28F 1/00 20130101; F25B 39/04 20130101;
F28D 1/05391 20130101; H01L 35/30 20130101 |
Class at
Publication: |
165/173 |
International
Class: |
F28F 1/00 20060101
F28F001/00 |
Claims
1. A heat exchanger comprising: an inlet header configured to
receive refrigerant; an outlet header configured to discharge the
refrigerant; first and second tubes in fluid communication with and
extending between the inlet header and the outlet header to direct
refrigerant from the inlet header to the outlet header, each of the
tubes having a first side and a second side, the first side of the
first tube oriented to face the second side of the second tube; a
first thermoelectric generator in thermal communication with the
first side of the first tube; a second thermoelectric generator in
thermal communication with the second side of the second tube; and
a plurality of fins in thermal contact with the first
thermoelectric generator and the second thermoelectric generator
and with a surrounding environment.
2. The heat exchanger of claim 1, wherein the surrounding
environment comprises air.
3. The heat exchanger of claim 2, wherein at least one of the first
thermoelectric generator and the second thermoelectric generator is
electrically coupled to a fan operable to generate a stream of air
across the first and second tubes.
4. The heat exchanger of claim 1, wherein the heat exchanger is a
condenser within a refrigeration circuit, and wherein at least one
of the first thermoelectric generator and the second thermoelectric
generator is electrically coupled to a component of the
refrigeration circuit.
5. The heat exchanger of claim 1, wherein at least one of the first
thermoelectric generator and the second thermoelectric generator is
electrically coupled to a battery.
6. The heat exchanger of claim 1, further including a third
thermoelectric generator in thermal communication with the first
side of the first tube and with the plurality of fins.
7. The heat exchanger of claim 1, wherein the first and second
tubes are microchannel tubes.
8. A heat exchanger comprising: an inlet header configured to
receive refrigerant; an outlet header configured to discharge
refrigerant; at least one tube in fluid communication with and
extending between the inlet header and the outlet header, the at
least one tube having a first side and an opposing second side and
configured to pass the refrigerant from the inlet header to the
outlet header; a first thermoelectric generator in thermal
communication with the first side of the at least one tube and with
a surrounding environment; and a second thermoelectric generator in
thermal communication with the second side of the at least one tube
and with the surrounding environment.
9. The heat exchanger of claim 8, wherein the at least one tube is
a microchannel tube.
10. The heat exchanger of claim 8, wherein the surrounding
environment comprises air.
11. The heat exchanger of claim 10, wherein at least one of the
first thermoelectric generator and the second thermoelectric
generator is electrically coupled to a fan, and further wherein the
fan is at least partially powered by the at least one of the first
thermoelectric generator and the second thermoelectric
generator.
12. The heat exchanger of claim 11, wherein the fan is operable to
generate a stream of air across the at least one tube.
13. The heat exchanger of claim 8, wherein the heat exchanger is a
condenser within a refrigeration circuit, and wherein at least one
of the first thermoelectric generator and the second thermoelectric
generator is electrically coupled to a component of the
refrigeration circuit.
14. The heat exchanger of claim 8, further including a third
thermoelectric generator in thermal communication with the first
side of the at least one tube and with a surrounding
environment.
15. The heat exchanger of claim 14, further including a fourth
thermoelectric generator in thermal communication with the second
side of the at least one tube and with a surrounding
environment.
16. The heat exchanger of claim 8, wherein at least one of the
first thermoelectric generator and the second thermoelectric
generator is thermally coupled to a plurality of fins, the fins
disposed within the surrounding environment.
17. The heat exchanger of claim 8, wherein the first thermoelectric
generator and the second thermoelectric generator are electrically
connected in a series configuration.
18. The heat exchanger of claim 8, wherein the first thermoelectric
generator and the second thermoelectric generator are electrically
connected in a parallel configuration.
19. A method of operating a refrigerated merchandiser having a
refrigeration system, the refrigeration system including a
refrigerant condenser receiving compressed refrigerant from a
compressor and discharging condensed refrigerant to a refrigerant
evaporator, the condenser including at least one tube for directing
refrigerant, the tube defining a surface area for exchanging heat
from the refrigerant to the surrounding environment, the method
comprising: operating the refrigeration system; extracting thermal
energy from the surface area; converting the thermal energy to
electrical energy; and transferring the electrical energy to an
electrical device of the refrigerated merchandiser.
20. The method of claim 19, wherein transferring the electrical
energy to an electrical device of the refrigerated merchandiser
means transferring the electrical energy to an electrically-powered
device.
21. The method of claim 20, wherein the electrically-powered device
is a fan operable to generate a stream of air through the
condenser.
22. The method of claim 20, wherein the electrically-powered device
is a heater.
23. The method of claim 20, wherein the electrically-powered device
is a light.
24. The method of claim 20, wherein the electrically-powered device
is a valve of the refrigeration system.
25. The method of claim 19, wherein transferring the electrical
energy to an electrical device of the refrigerated merchandiser
means transferring the electrical energy to an electrical storage
device.
Description
BACKGROUND
[0001] The present invention relates to a condenser for condensing
a thermal medium, and more particularly, to a microchannel
refrigerant condenser with thermoelectric power generation.
[0002] The primary components of a typical refrigeration circuit
include a compressor, a condenser, an expansion valve, and an
evaporator. The condenser receives compressed refrigerant gas from
the compressor and liquefies it, rejecting the superheat and latent
heat of vaporization to a surrounding environment. This rejected
heat represents a source of unrecovered energy.
SUMMARY
[0003] In one construction of the invention a heat exchanger
includes an inlet header configured to receive refrigerant and an
outlet header configured to discharge the refrigerant. First and
second tubes in fluid communication with and extending between the
inlet header and the outlet header direct refrigerant from the
inlet header to the outlet header. Each of the tubes has a first
side and a second side. The first side of the first tube is
oriented to face the second side of the second tube. A first
thermoelectric generator is in thermal communication with the first
side of the first tube and a second thermoelectric generator is in
thermal communication with the second side of the second tube. A
plurality of fins is in thermal contact with the first
thermoelectric generator and the second thermoelectric generator
and with a surrounding environment.
[0004] In one construction of the invention a heat exchanger
includes an inlet header configured to receive refrigerant and an
outlet header configured to discharge refrigerant. At least one
tube is in fluid communication with and extends between the inlet
header and the outlet header, has a first side and an opposing
second side, and is configured to pass the refrigerant from the
inlet header to the outlet header. A first thermoelectric generator
is in thermal communication with the first side of the at least one
tube and with a surrounding environment. A second thermoelectric
generator is in thermal communication with the second side of the
at least one tube and with the surrounding environment.
[0005] In one embodiment of a method of operating a refrigerated
merchandiser having a refrigeration system, in which the
refrigeration system includes a refrigerant condenser receiving
compressed refrigerant from a compressor and discharging condensed
refrigerant to a refrigerant evaporator, and in which the condenser
includes at least one tube for directing refrigerant that defines a
surface area for exchanging heat from the refrigerant to the
surrounding environment, the method includes operating the
refrigeration system and extracting thermal energy from the surface
area. The method also includes converting the thermal energy to
electrical energy. The method further includes transferring the
electrical energy to an electrical device of the refrigerated
merchandiser.
[0006] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic of a refrigeration system including a
condensing heat exchanger embodying the present invention.
[0008] FIG. 2 is a perspective view of the condenser of the system
of FIG. 1.
[0009] FIG. 3 is a perspective view of another condenser for use in
the system of FIG. 1.
[0010] FIG. 4 is a plan view of the condenser of FIG. 2.
[0011] FIG. 5 is a partial plan view of the condenser of FIG.
2.
[0012] FIG. 6 is a partial perspective view of the condenser of
FIG. 2.
[0013] FIG. 7 is a schematic view of a control system for the
refrigeration system.
DETAILED DESCRIPTION
[0014] Before any embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of components set forth in the following description or illustrated
in the following drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways.
[0015] FIG. 1 illustrates a refrigeration circuit 10 for use with a
refrigerated merchandiser or other heating, ventilation, air
conditioning or refrigeration system (not shown). The refrigeration
circuit 10 includes a compressor 14 that discharges gaseous
refrigerant to a condenser or heat exchanger 20, which cools the
refrigerant via heat exchange with air or another medium (not
illustrated) flowing through and around the heat exchanger 20. A
receiver 24 receives the condensed refrigerant, which is then
directed through an expansion valve 28 to an evaporator 40. The
evaporator 40 cools a medium (e.g., an airflow through a
refrigerated display case) via heat exchange between refrigerant
flowing through the evaporator 40 and the medium. As one of
ordinary skill in the art will appreciate, the refrigeration
circuit 10 can include other components depending on design
parameters and the conditioning needs for which the refrigeration
circuit 10 is being used. The heat exchanger 20 to be described
herein is not limited in its application to a refrigerated
merchandiser, or to a refrigeration circuit, but may be used in any
application in which heat is exchanged between a thermal medium and
a surrounding environment.
[0016] With reference to FIGS. 1 and 2, the heat exchanger 20
includes an inlet port 50 that fluidly couples refrigeration system
piping (not shown) to a first header 54 to direct gaseous
compressed refrigerant from the compressor 14 to the heat exchanger
20. The first header 54 is partitioned into a first section 60 in
fluid communication with the inlet port 50, and a second section 64
in fluid communication with an outlet port 68. The sections 60, 64
are fluidly separated from each other by a barrier 72. Compressed
refrigerant is directed through the first section 60 and enters a
first portion 80 of a plurality of spaced apart tubes 84. As
understood by one of ordinary skill in the art, refrigerant is
condensed within the tubes 84 by heat exchange with a cooling
medium, such as air, flowing through and around the heat exchanger
20. In other applications, the medium can be a liquid (e.g.,
water). Refrigerant from the tubes 84 collects in a second, or
intermediate header 88 at an intermediate point in the
cooling/condensing process and is directed to a second portion 92
of the plurality of tubes 84, from which additional heat is
exchanged with the surrounding environment. The condensed
refrigerant collects in the second section 64 of the first header
54 and is discharged through the outlet port 68, which is fluidly
coupled to the evaporator 40 via additional refrigeration system
piping (not shown).
[0017] FIG. 3 illustrates another heat exchanger 20a that is
similar to the heat exchanger 20 described with regard to FIG. 2.
The heat exchanger 20 has an non-partitioned first header 100
through which the compressed refrigerant flows from an inlet port
104 to each of the tubes 84. The refrigerant is condensed within
the tubes 84, collects in an outlet header 108, and is thereafter
discharged through an outlet port 112 fluidly coupled to the
evaporator 40 of the circuit 10.
[0018] In other constructions, the heat exchanger 20, 20a can
include multiple inlet ports along the first header 54, 100 and
multiple outlet ports along the outlet header 108 that are
transversely spaced apart from each other to more uniformly
distribute refrigerant to and from the tubes 84. The heat exchanger
20 can also include other devices used for uniformly distributing
refrigerant, such as a manifold with or without baffles.
[0019] With reference to FIGS. 4-6, the illustrated tubes 84 are
flat tubes fluidly coupled to and extending between the first
header 54, 100 and the second header 88, 108. Each flat tube 84
defines a generally flat or planar first surface 120 and a
generally flat or planar second surface 124 opposing the first
surface 120. The flat tubes 84 are spaced apart from each other by
a predetermined distance, although the spacing between adjacent
flat tubes 84 can vary substantially based on the application in
which the heat exchanger 20, 20a is used. In addition, the wall
thickness of the tubes 84 can vary substantially due to material,
operating environment, and working pressure requirements. The flat
tubes 84 can be formed from any suitable material and method, for
example, extruded aluminum or folded aluminum.
[0020] Referring to FIG. 6, in some applications the flat tubes 84
define a plurality of internal passageways or microchannels 128
that are each smaller in size than the internal passageway of a
heat exchanger coil in a conventional fin-and-tube heat exchanger.
The microchannels 128 are defined by a rectangular cross-section,
although other cross-sectional shapes are possible and considered
herein. Each illustrated tube 84 has between fifteen to thirty
microchannels 128, with each microchannel being about 1 mm in
height and about 1 mm in width. In other constructions, the
microchannels 128 can vary substantially, for example, from as
small as 0.5 mm by 0.5 mm to as large as 4 mm by 4 mm. The size and
configuration of the microchannels 128 within the tubes 84 can vary
to accommodate the variations in tube construction noted above. The
precise length, width, and quantity of microchannels 128 are a
function of the amount of thermal fluid, e.g., refrigerant, needed
for the particular application to maximize heat transfer while
minimizing system pressure drop. The microchannels 128 are fluidly
coupled to and extend between the first/inlet and second/outlet
headers 54, 100 and 88, 108. In other embodiments, the tubes 84
need not be microchannel tubes and can include a single internal
passageway.
[0021] With further reference to FIGS. 4-6, one or more
thermoelectric generators 140 are thermally coupled to at least one
of the first surface 120 and the second surface 124 of each tube
84. Each thermoelectric generator 140 includes a first surface 144
configured for thermal communication with a source of heat, and a
second surface 148 configured for thermal communication with a heat
sink. Thermoelectric generators 140 are solid-state devices
consisting of pairs of n-type and p-type semiconductor materials,
as will be understood by one of ordinary skill in the art. When the
thermoelectric generator 140 is in thermal communication with a
heat source and a heat sink, the thermoelectric generator 140 is
capable of power generation by virtue of the Seebeck effect, the
details of which are known to those of ordinary skill in the
art.
[0022] Referring to FIGS. 4-6, one or more thermoelectric
generators are positioned partially or entirely along the first
surface 120 and/or the second surface 124 of the tube 84 from the
first/inlet header 54, 100 to the second/outlet header 88, 108,
depending on the application. Specifically, the first surface 144
of each thermoelectric generator 140 is coupled to the one of the
first or second surfaces 120, 124 of a tube 84 such that the first
surface 144 is in thermal communication with the tube surface. The
second surface 148 of each thermoelectric generator 140 is coupled
to a fin arrangement 160 of the heat exchanger 20, 20a. As
illustrated in FIGS. 2-6, the fin arrangement 160 has a plurality
of fins 164 that extend between the second surface(s) 148 of one or
more thermoelectric generators 140 coupled to one tube 84 and the
second surface(s) 148 of one or more thermoelectric generators 140
coupled to an adjacent tube 84. In other applications, a fin
arrangement 160 or plurality of fins 164 is absent, and the second
surface 148 of each thermoelectric generator 140 is in thermal
communication with the cooling medium without the assistance of
fins. In these applications, the tubes 84 are supported by other
structure.
[0023] The fins 164 generally aid in heat transfer between the
cooling fluid passing through the heat exchanger 20 and the thermal
fluid (refrigerant) flowing within the tubes 84 by increasing the
surface area of thermal contact. As illustrated, the fins 164 are
arranged in a zigzag pattern between opposing thermoelectric
generators 140. The fin density measured along the length of the
tubes 84 can vary depending on the application, and may also
include additional surface features and/or shapes to provide
additional heat transfer area (e.g., triangular, wavy, perforated,
etc.). The thickness of the fins 164 can also vary depending on the
desired heat transfer characteristics and other design
considerations.
[0024] Because thermoelectric power generation is dependent upon
the temperature differential between the heat source and the heat
sink, the number and arrangement of thermoelectric generators 140
can vary depending on the application (i.e., on the temperature of
the heat source and the temperature of the surrounding
environment). In some embodiments, for example, only sensible heat
is extracted from the thermal fluid, and thermoelectric generators
140 may therefore only extend a portion of the way along the tube
surfaces 120, 124 from the first header 54, 100 to the second
header 88, 108 as the temperature of the thermal fluid decreases
within the tube between the headers. That is, the temperature
differential from the heat source to the heat sink within some
portion of the heat exchanger 20, 20a may not be preferable for the
application of a thermoelectric generator. In other applications in
which primarily latent heat is extracted, the temperature of the
heat source will stay substantially constant, and thermoelectric
generators 140 may be positioned along the full length of the tubes
84.
[0025] In operation of the heat exchanger 20, the thermal fluid
(e.g., compressed refrigerant from the compressor 14) enters the
inlet port 50 of the first section 60 of the first header 54, flows
through the first section 60 and enters the microchannels 128 of
the first portion 80 of the one or more tubes 84. As the fluid
flows within the first portion of tubes 84, the temperature
differential between the relatively hot fluid and the cooler
surrounding environment creates a temperature gradient. The
thermoelectric generators 140 disposed within this temperature
gradient (i.e., between the surfaces 120, 124 of the tube 84 and
the surrounding environment, with or without the aid of fins 164)
generate power from the temperature differential in a process known
to those of skill in the art (i.e., based on the Seebeck effect).
Partially cooled and/or condensed thermal fluid from the first
portion 80 enters the second or intermediate header 88 and is
directed to the second portion 92 of the tubes 84. Power is again
generated and delivered by the associated thermoelectric generators
140 by virtue of the existing temperature differential between the
tubes 84 and the environment. Cooled and/or condensed thermal fluid
collects in the second section 64 of the first header 54 and is
discharged through the outlet port 68 to the remainder of the
system.
[0026] During operation of the heat exchanger 20a as illustrated in
FIG. 3, thermal fluid (e.g., compressed refrigerant) enters the
inlet port 104 of the inlet header 100, flows through the inlet
header 100 and enters the microchannels 128 of each tube 84. As the
refrigerant passes through the tubes 84 to the outlet header 108,
power is generated and delivered by the thermoelectric generators
140 coupled to the tubes 84 in the same manner as described with
regard to the heat exchanger 20.
[0027] The power generated by the thermoelectric generators 140 is
delivered through wiring to components of the system, or elsewhere,
depending on the system configuration. For example, as shown in
FIG. 7, the generated power can be delivered to a controller 170,
which further conditions the voltage and current to appropriate
levels for use in other system components. These system components
can include, for example, the condenser fan 174 or other loads 178
(e.g., other fans, lights, valves, heaters, etc.) that can be at
least partially powered by the power generated by the
thermoelectric generators 140. In other embodiments, the power may
be sent to a battery or bank of batteries 182 for power storage. In
still other embodiments, the power, if within proper limits, may be
delivered directly to these system components without conditioning
by a controller. Multiple thermoelectric generators 140 can be
electrically connected in a parallel or series configuration as
necessary to meet system requirements.
[0028] Various features and advantages of the invention are set
forth in the following claims.
* * * * *