U.S. patent application number 15/662006 was filed with the patent office on 2018-02-01 for thermoelectric heat pump system.
The applicant listed for this patent is Peter M. Thomas, Stephen M. Thomas. Invention is credited to Peter M. Thomas, Stephen M. Thomas.
Application Number | 20180031285 15/662006 |
Document ID | / |
Family ID | 61009602 |
Filed Date | 2018-02-01 |
United States Patent
Application |
20180031285 |
Kind Code |
A1 |
Thomas; Peter M. ; et
al. |
February 1, 2018 |
THERMOELECTRIC HEAT PUMP SYSTEM
Abstract
A single or multi stage liquid loop thermoelectric heat pump
system for cooling and/or heating is disclosed that can achieve
higher delta temperature and COP then previous thermoelectric heat
pump systems.
Inventors: |
Thomas; Peter M.; (Raleigh,
NC) ; Thomas; Stephen M.; (Raleigh, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Thomas; Peter M.
Thomas; Stephen M. |
Raleigh
Raleigh |
NC
NC |
US
US |
|
|
Family ID: |
61009602 |
Appl. No.: |
15/662006 |
Filed: |
July 27, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62367458 |
Jul 27, 2016 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 2321/0252 20130101;
F25D 17/06 20130101; F25B 2321/025 20130101; F25B 21/04
20130101 |
International
Class: |
F25B 21/04 20060101
F25B021/04; F25D 17/06 20060101 F25D017/06 |
Claims
1. A thermoelectric heat pump system operable in a cooling and/or
heating mode, comprising: a thermoelectric apparatus; a liquid heat
exchanger block apparatus thermally coupled to a first side of the
thermoelectric apparatus, the liquid heat exchanger block apparatus
including at least one passage for flow of a heat transfer liquid
therethrough; a radiator for rejecting heat from the heat transfer
fluid when the thermoelectric pump system operates in a cooling
mode and absorbing heat in the heat transfer fluid when the
thermoelectric pump system operates in a heating mode; a convective
fan associated with the radiator for increasing the heat transfer
coefficient of the radiator; and a conduit system coupling the
liquid heat exchanger block apparatus and the radiator for
circulating the heat transfer fluid between the liquid heat
exchanger block apparatus and the radiator; wherein a second side
of the thermoelectric apparatus opposite from the first side is
thermally coupled to a heat source when the thermoelectric heat
pump system operates in a cooling mode or to a cold source when the
thermoelectric heat pump system operates in a heating mode, wherein
the thermoelectric apparatus can be powered to pump heat from the
heat source in the cooling mode and pump heat to the cold source in
the heating mode.
2. The system of claim 1, wherein the heat source or the cold
source comprises a second liquid heat exchanger block apparatus
thermally coupled to the second side of the thermoelectric
apparatus, the second liquid heat exchanger block apparatus
including at least one passage for flow of a second heat transfer
liquid therethrough; a second radiator for rejecting heat from the
second heat transfer fluid when the thermoelectric pump system
operates in a heating mode and absorbing heat in the second heat
transfer fluid when the thermoelectric pump system operates in a
cooling mode; and a second conduit system coupling the second
liquid heat exchange block apparatus and the second radiator for
circulating the second heat transfer fluid between the second
liquid heat exchanger block apparatus and the second radiator,
wherein the first and second conduit systems have a counterflow
configuration.
3. The system of claim 1, wherein the thermoelectric apparatus
comprises a plurality of thermoelectric modules in a cascaded
arrangement.
4. The system of claim 1, wherein the thermoelectric apparatus
comprises a plurality of thermoelectric modules spaced apart from
one another, each of said thermoelectric modules having one side in
thermal contact with the liquid heat exchanger block apparatus and
an opposite second side in thermal contact with the heat source or
the cold source.
5. The system of claim 1, wherein the thermoelectric apparatus
comprises a plurality of discrete thermoelectric modules spaced
apart from one another, and wherein the liquid heat exchanger block
apparatus comprises a plurality of discrete liquid heat exchanger
blocks arranged in series for flow of the heat transfer fluid
sequentially therethrough, each of said thermoelectric modules
having one side in thermal contact with a different one of the
discrete liquid heat exchanger blocks and an opposite second side
in thermal contact with the heat source or the cold source, wherein
the heat source or cold source comprises a plurality of second
discrete liquid heat exchanger blocks, each thermally coupled to a
different one of said discrete thermoelectric modules, a second
radiator, and a second conduit system for circulating a heat
transfer fluid sequentially through the second liquid heat
exchanger blocks and the second radiator.
6. The system of claim 1, wherein the thermoelectric apparatus
comprises a plurality of discrete thermoelectric modules spaced
apart from one another, and wherein the liquid heat exchanger block
apparatus comprises a plurality of discrete liquid heat exchanger
blocks arranged in series for flow of the heat transfer fluid
sequentially therethrough, each of said thermoelectric modules
having one side in thermal contact with one of the discrete liquid
heat exchanger blocks and an opposite second side in thermal
contact with the heat source or the cold source, wherein the heat
source or cold source comprises a plurality of second discrete
liquid heat exchanger blocks, each thermally coupled to one of said
discrete thermoelectric modules, a second radiator, and a second
conduit system for circulating a heat transfer fluid sequentially
through the second liquid heat exchanger blocks and the second
radiator, wherein the discrete liquid heat exchanger blocks, the
discrete thermoelectric modules, and the second discrete liquid
heat exchanger blocks are in a stacked arrangement with each
discrete thermoelectric module having a discrete liquid heat
exchanger block on one side and a second discrete liquid heat
exchanger block on the opposite side.
7. The system of claim 1, further comprising a second stage
thermoelectric heat pump comprising: a second stage thermoelectric
apparatus; a second stage liquid heat exchanger block apparatus
thermally coupled to a first side of the second stage
thermoelectric apparatus, the second stage liquid heat exchanger
block apparatus including at least one passage for flow of a second
stage heat transfer liquid therethrough; a second stage radiator
for rejecting heat from the second stage heat transfer fluid when
the thermoelectric pump system operates in a cooling mode and
absorbing heat in the second stage heat transfer fluid when the
thermoelectric pump system operates in a heating mode; a second
stage convective fan associated with the second stage radiator for
increasing the heat transfer coefficient of the second stage
radiator; and a second stage conduit system coupling the second
stage liquid heat exchanger block apparatus and the second stage
radiator for circulating the heat transfer fluid between the second
stage liquid heat exchanger block apparatus and the second stage
radiator; wherein the system further comprises an additional liquid
heat exchanger block apparatus coupled in series to the conduit
system for flow of the heat transfer fluid therethrough, and
wherein the additional liquid heat exchanger block apparatus is
thermally coupled to a second side of the second stage
thermoelectric apparatus opposite from the first side.
8. The system of claim 7, further comprising a third stage
thermoelectric heat pump comprising: a third stage thermoelectric
apparatus; a third stage liquid heat exchanger block apparatus
thermally coupled to a first side of the third stage thermoelectric
apparatus, the third stage liquid heat exchanger block apparatus
including at least one passage for flow of a third stage heat
transfer liquid therethrough; a third stage radiator for rejecting
heat from the third stage heat transfer fluid when the
thermoelectric pump system operates in a cooling mode and absorbing
heat in the third stage heat transfer fluid when the thermoelectric
pump system operates in a heating mode; a third stage convective
fan associated with the third stage radiator for increasing the
heat transfer coefficient of the third stage radiator; and a third
stage conduit system coupling the third stage liquid heat exchanger
block apparatus and the third stage radiator for circulating the
heat transfer fluid between the third stage liquid heat exchanger
block apparatus and the third stage radiator; wherein the system
further comprises an additional second stage liquid heat exchanger
block apparatus coupled in series to the second stage conduit
system for flow of the second stage heat transfer fluid
therethrough, and wherein the additional second liquid heat
exchanger block apparatus is thermally coupled to a second side of
the third stage thermoelectric apparatus opposite from the first
side.
9. The system of claim 8, wherein the second stage and/or third
stage thermoelectric apparatus comprises a plurality of
thermoelectric modules in a cascaded arrangement.
10. The system of claim 8, wherein the second stage and/or third
stage thermoelectric apparatus comprises a plurality of
thermoelectric modules spaced apart from one another, and having a
liquid heat exchanger block apparatus on opposite sides
thereof.
11. The system of claim 8, wherein the second stage and/or third
stage thermoelectric apparatus comprises a plurality of discrete
thermoelectric modules spaced apart from one another, and having
separate liquid heat exchanger block devices on opposite sides
thereof.
12. The system of claim 1, wherein a pump for circulating heat
transfer fluid in the conduit system is integrated in a housing of
the liquid heat exchanger block apparatus.
13. The system of claim 1 wherein the liquid heat exchanger block
apparatus includes a plurality of microchannel fins for enhanced
heat transfer.
14. The system of claim 1 wherein the liquid heat exchanger block
apparatus includes a plurality of copper microchannel fins in a
plastic housing.
15. The system of claim 1, wherein the thermoelectric apparatus is
made with metallurgical Bi2Te3 powder.
16. The system of claim 1, further comprising an evaporative cooler
associated with the radiator for further cooling the heat transfer
fluid in the cooling mode.
17. The system of claim 1, further comprising quick disconnects
fittings on thermal conduit system to allow easy installation and
swapping of different length of thermal conduit for depending on
distance for custom installations.
18. The system of claim 1, wherein the heat transfer fluid
comprises propylene glycol.
19. The system of claim 1, further comprising a refillable
reservoir for the heat transfer fluid.
20. The system of claim 1, further comprising an indoor
radiator/heat exchanger and an outdoor radiator heat exchanger
connected to the heat pump using thermal conduit for indoor cooling
and/or heating for air conditioning, HVAC, or to replace vapor
compressor heat pump technology in its dual cooling and heating
functionality in small and large scale applications.
21. The system of claim 20, further comprising a conduit to move
condensate water to the outside for window mounted and portable
thermoelectric heat pump systems.
22. The system of claim 1, further comprising an indoor
radiator/heat exchanger and an outdoor radiator heat exchanger
connected to the heat pump using thermal conduit for indoor cooling
and/or heating using a blower and bladeless fan for directing the
cooling or heating air flow to the occupant for localized cooling
and heating.
23. The system of claim 1, further comprising a vapor compressor
HVAC system connected to the thermoelectric heat pump using
Freon/heat transport fluid heat exchanger connected with thermal
conduit to an outdoor heat exchanger radiator heat exchanger with
fan for to provide additional delta temperature on demand at high
COPs. This hybrid HVAC system would provide higher COP with smaller
heat exchanger since the heat rejection temperature could be much
higher improving heat transfer and the hot side of the vapor
compressor condenser coil would be cooled by the thermoelectric
heat pump providing higher indoor out door delta temperature
increasing the efficiency of the hybrid system over a conventional
vapor compressor. This two stage hybrid heat pump system would have
higher efficiency and larger delta temperature capability for
cooling and heating in extreme climates.
24. The system of claim 1, further comprising an indoor
radiator/heat exchanger and an outdoor radiator heat exchanger
connected to the heat pump using thermal conduit for indoor cooling
and/or heating using a blower and bladeless fan for directing the
cooling or heating air flow to the occupant for localized cooling
and heating.
25. The system of claim 1, further utilizing a smart system that
incorporates functions of sensing, actuation, and control in order
to describe and analyze heating or cooling requirements, and make
decisions based on the available data in a predictive or adaptive
manner, thereby performing smart actions to 1) minimize delta
temperatures across thermoelectric devices in series discrete loop
and heat pumps in 2 stage configuration by controlling the power to
each subsystem heat pump to provide heating and cooling at peak
system efficiency 2) turn off a portion of thermoelectric modules
when thermal demand is lower to reduce power consumption and
increase efficiency. 3) To provide precooling and preheating of
dwelling when occupant is expected to return based on learned
behaviors of occupant and shut off or reduce cooling and heating
demand when occupant is not present. The smart system would provide
autonomous operation to optimize energy efficiency based on closed
loop control and networking capabilities as well.
26. The system of claim 1, further comprising a hot water heater
water tank where on hot side of heat pump with heat being absorbed
from ambient air using radiator with fan, in ground heat conduit
loop, or solar absorption panel with heat conduit loop for
absorbing heat from the sun.
27. System of claim 26, where solar adsorption panel could be
integrated with roof solar panels or be a separate flexible mat
with heat integrated heat conduit loop that goes between solar
roofing tiles (Tesla/Solar City) and roof to provide roof cooling
and low grade heat which can be up converted to by thermoelectric
heat pump for suppling the water heater.
28. The system of claim 26, further comprising thermal conduit
transporting heating from the hot water tank to heat exchanger in
forced air HVAC system to replace fossil fuel based heating systems
such as natural gas and old burner systems to enable heating from
electricity derived from solar power.
29. The system of claim 26, further comprising a natural gas burner
in addition to thermoelectric heat pump heating to provide backup
heating if solar or battery power gets low for northern climates
where continuous heating is essential. This hybrid solid
state/natural gas water heater system enables the use of high
efficiency solar powered heating in northern climates during the
during the warmer seasons while providing additional or back up
natural gas heating during the winter time.
30. The system of claim 1, further comprising a thermoelectric heat
pump for upgrading waste heat to higher temperature heat. Heat from
the incoming low grade waste heat fluid stream can pumped out of
the low grade waste heat stream to the another steam to upgade the
fluid temperature to provide high COP heating for industrial
process heating applications.
31. A thermoelectric heat pump system operable in a cooling and/or
heating mode, comprising: a thermoelectric apparatus; a liquid heat
exchanger block apparatus thermally coupled to a first side of the
thermoelectric apparatus, the liquid heat exchanger block apparatus
including at least one passage for flow of a heat transfer liquid
therethrough; and a conduit system coupled to the liquid heat
exchanger block apparatus for circulating the heat transfer fluid
through the liquid heat exchanger block; wherein a second side of
the thermoelectric apparatus opposite from the first side is
thermally coupled to a heat source when the thermoelectric heat
pump system operates in a cooling mode or to a cold source when the
thermoelectric heat pump system operates in a heating mode, wherein
the thermoelectric apparatus can be powered to pump heat from the
heat source in the cooling mode and pump heat to the cold source in
the heating mode.
32. The system of claim 31, further comprising: a radiator coupled
to the liquid heat exchanger block by the conduit system for
rejecting heat from the heat transfer fluid when the thermoelectric
pump system operates in a cooling mode and absorbing heat in the
heat transfer fluid when the thermoelectric pump system operates in
a heating mode; and a convective fan associated with the radiator
for increasing the heat transfer coefficient of the radiator.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Patent Application No. 62/367,458 filed on Jul. 27, 2016 entitled
HIGH EFFICIENCY THERMOELECTRIC COOLING HEATING (TECH) AIR
CONDITIONER, HEAT PUMP, HVAC SYSTEM WITH DUAL COUNBCAMTER FLOW
LIQUID LOOPS AND SERIAL DISCRETE TECH-HEAT EXCHANGER ARRAY and from
U.S. Provisional Patent Application No. ______ filed on Apr. 28,
2017 entitled HIGH DELTA TEMPERATURE AND COP SINGLE OR MULTI-STAGE
LIQUID LOOP THERMOELECTRIC HEAT PUMP SYSTEM FOR COOLING AND HEATING
HVAC AC, both of which are hereby incorporated by reference.
BACKGROUND
[0002] Heating, ventilation, and air conditioning (HVAC) systems
using vapor compression (VC) apparatus are inefficient, heavy,
bulky, costly to install and operate, and use refrigerants like
Freon, which is detrimental to the ozone layer and the environment.
Typical VC cooling systems take advantage of the energy absorption
of a chemical refrigerant while it changes phase between a liquid
and a gas. The operating temperature of the cold-side heat
exchanger (evaporator coil) of the system comes as a result of a
delicate balance between the boiling point of the refrigerant, and
the relative flow-rates of refrigerant and air. The boiling point
is set by the absolute pressure of the refrigerant, which is in
turn determined by mechanical means. The result is that the
system's cold-side heat-exchanger temperature is not directly
controlled, but rather targeted to a general value that can only be
true over a narrow range of boundary conditions. In order to
regulate humidity, the coil temperature needs to be below that of
the dew-point temperature of the living space. This temperature is
typically below 45.degree. F. For typical systems, the heat-pumping
capacity is fixed. Each unit is sized for the maximum estimated
instantaneous heat-load. Part-load response is accomplished by
simply turning the unit on and off. Power cycling is made tolerable
by the relatively large heat-capacity of the indoor space, which
act to minimize the resulting temperature fluctuation.
BRIEF SUMMARY OF THE DISCLOSURE
[0003] A thermoelectric heat pump system in accordance with one or
more embodiments is operable in a cooling and/or heating mode. The
system comprises a thermoelectric apparatus and a liquid heat
exchanger block apparatus thermally coupled to a first side of the
thermoelectric apparatus. The liquid heat exchanger block apparatus
includes at least one passage for flow of a heat transfer liquid
therethrough. The system includes a radiator for rejecting heat
from the heat transfer fluid when the thermoelectric pump system
operates in a cooling mode and absorbing heat in the heat transfer
fluid when the thermoelectric pump system operates in a heating
mode. A convective fan associated with the radiator increases the
heat transfer coefficient of the radiator. A conduit system couples
the liquid heat exchanger block apparatus and the radiator for
circulating the heat transfer fluid between the liquid heat
exchanger block apparatus and the radiator. A second side of the
thermoelectric apparatus opposite from the first side is thermally
coupled to a heat source when the thermoelectric heat pump system
operates in a cooling mode or to a cold source when the
thermoelectric heat pump system operates in a heating mode. The
thermoelectric apparatus can be powered to pump heat from the heat
source in the cooling mode and pump heat to the cold source in the
heating mode.
[0004] In accordance with one or more embodiments, a single or
multi stage liquid loop thermoelectric heat pump system for cooling
and/or heating is disclosed that can achieve higher delta
temperature and COP then previous thermoelectric heat pump systems.
Various embodiments disclosed herein utilize liquid to air heat
exchangers, which have a higher heat transfer coefficient of 350
W/m2 K and therefore are more efficient at absorbing or rejecting
heat compared to thermoelectric heat sinks, which have a heat
transfer coefficient of 100-150 W/m2K. Various embodiments also
utilize block or plate liquid heat exchangers with skived fins
microchannel copper face plates in a plastic housing to increase
the heat transfer confident and heat pump power density to decrease
size, weight and costs of the heat pump system. Various embodiments
also use multiple serial discrete plate heat exchangers to decrease
delta temperature on the multiple discrete thermoelectric devices
over the average delta temperature of a single larger
thermoelectric plate heat exchanger of the same heat pumping power.
Various embodiments use multiple serial discrete heat pumps within
each liquid loop in a two stage configuration comprising three
liquid loops. Single stage and multiple stage versions are also
disclosed. Evaporative cooling may be provided on the heat
rejection heat exchanger to further improve the COP of the system.
The solid state thermoelectric heat pump described herein can be
utilized in air conditioning, HVAC, refrigeration, domestic and
commercial tank and tankless hot water heaters, industrial heating
and cooling for process temperature control, among other
applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIGS. 1A and 1B illustrate an exemplary thermoelectric heat
pump system operable in heating and cooling modes in accordance
with one or more embodiments.
[0006] FIGS. 2A-2D illustrate an exemplary liquid heat exchanger
block usable in a thermoelectric heat pump system in accordance
with one or more embodiments.
[0007] FIG. 3 illustrates another exemplary liquid heat exchanger
block usable in a thermoelectric heat pump system in accordance
with one or more embodiments.
[0008] FIG. 4 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0009] FIG. 5 is a schematic illustrating DT reduction through a
counter-flow arrangement in accordance with one or more
embodiments.
[0010] FIG. 6 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0011] FIG. 7 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0012] FIG. 8 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0013] FIG. 9 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0014] FIG. 10 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0015] FIG. 11 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0016] FIG. 12 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0017] FIG. 13 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0018] FIG. 14 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0019] FIG. 15 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0020] FIG. 16 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0021] FIG. 17 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0022] FIG. 18 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0023] FIG. 19 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0024] FIG. 20 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0025] FIG. 21 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0026] FIG. 22 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0027] FIG. 23 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments.
[0028] FIGS. 24A-24C illustrate an exemplary liquid heat exchanger
block usable in a thermoelectric heat pump system in accordance
with one or more embodiments.
[0029] FIGS. 25A-25C illustrate an exemplary liquid heat exchanger
block usable in a thermoelectric heat pump system in accordance
with one or more embodiments.
DETAILED DESCRIPTION
[0030] Various embodiments disclosed herein relate to
thermoelectric (TE) heat pump systems, which can be used in various
heating and/or cooling applications.
[0031] In contrast to the mechanical VC cooling systems described
above, TE devices move heat electronically. A TE heat pump is a
solid-state active heat pump, which transfers heat from one side of
the device to the other with consumption of electrical energy,
depending on the direction of the current. In general, heat is
transported across the device by the flow of charge carriers
through a matrix of p-type and n-type semi-conductor materials.
Since the heat is moved electronically, the module's instantaneous
heat-pumping capacity can be adjusted by changing the supplied
electrical current. This enables real-time fine-adjustment of the
thermal capacity to compensate for changing conditions.
Additionally, TE modules, as their name implies, are modular in
nature and thermal systems can quite easily be constructed that
contain a multitude of smaller independent cooling units working in
series, in parallel or in multiple stages. These units can be
arbitrarily activated or deactivated changing the effective thermal
requirements of the system. This is analogous to, but far less
complex than, a VC system composed of multiple independent (and
proportionally smaller) compressor-coil sub-systems. This modular
re-sizing acts to greatly expand the range of heat-load powers over
which the system operates at peak efficiency. Unlike mechanical
systems where the system's efficiency is generally highest at full
load, TE coolers are most efficient at 20% to 40% of their maximum
capacity. This fundamental difference allows TE-based HVAC systems
to be sized smaller, so that they operate more efficiently at the
average heat-load, but still maintain significant additional
emergency capacity.
[0032] Among other advantages, TE heat pump systems in accordance
with various embodiments achieve higher efficiencies than prior art
TE heat pump systems that use thermoelectric to air heat
exchangers. TE heat pump systems in accordance with various
embodiments can be lighter in weight, more compact, less expensive
to install and operate, and more efficient than mechanical based
vapor phase systems in certain applications. Also, systems in
accordance with various embodiments do not utilize Freon, which is
detrimental to the environment but uses non-toxic water based
refrigerants. Various embodiments disclosed herein provide
significant improvements to current technology. Systems in
accordance with one or more embodiments achieve higher efficiency
then previous TE air conditioning configurations, which use
TE-to-air heat exchangers that are low in efficiency. Systems in
accordance with one or more embodiments can utilize one, two, or
more separate heat pumps in a dual or three or more liquid loop
counter flow system: one loop for heat load (e.g., room
conditioning), one loop for heat rejection or adsorption, and
optional additional loops in between the heat load and heat
rejection loops for improved delta temperature and COP (coefficient
of performance). A serial discrete TECH (thermoelectric
cooler/heater)-heat exchanger array can be used to reduce delta
temperature even further. Additional improvements include use of
high efficiency BCAM (bipolar couple assembled module) TE modules
with metallurgical sintered TE materials, evaporative cooling on
the heat rejection heat exchanger, and advanced plastic or polymer
liquid to thermoelectric heat exchangers with skived micro-channels
copper face plates to increase heat exchanger efficiency and system
overall COP while decreasing materials cost substantially compared
to conventional liquid plate heat exchangers that are made
completely out of one metal like copper or aluminum. Systems in
accordance with one or more embodiments can be solar and/or battery
powered as well since TEs work with DC current.
[0033] In conventional thermoelectric air conditioners or heat
pumps, the heat transfer coefficient for heat sink air heat
exchangers is .about.100-200 W/m 2K. Also the conventional TE
cooling heating systems utilize TE devices made with crystal grown
Bi2Te3 which has very low ZT of 0.6-0.8 resulting in low
efficiency.
[0034] Various embodiments disclosed herein utilize TE to liquid to
air heat exchangers (radiators), which have a higher heat transfer
coefficient of 350 W/m 2K and therefore are more efficient at
absorbing or rejecting heat than TE to air finned heat sink heat
exchangers in accordance with the prior art. The heat transfer of a
radiator can be increased even further by using a fan to increase
air convective heat transfer from the fluid. Systems in accordance
with one or more embodiments also utilize heat block or plate
exchangers with skived fin microchannel copper face plates in a
plastic housing to increase the heat transfer coefficient and
system COP, while decreasing materials and total system costs. Also
various embodiments utilize TE devices made with metallurgical
Bi2Te3 powder fabricated under high pressures, which has a higher
ZT of 1-1.4 resulting in higher efficiency. Systems in accordance
with one or more embodiments can use one or two or more discrete
heat pumps in a two or more liquid loop multistage system to
achieve higher delta temperature with high COP. Evaporative cooling
may also be used on the heat rejection heat exchanger to further
improve COP of the system.
[0035] FIGS. 1A and 1B illustrate an exemplary thermoelectric heat
pump system operable in heating and cooling modes in accordance
with one or more embodiments. The system includes a thermoelectric
device 10. A liquid heat exchanger block 12 is thermally coupled to
a first side 11 of the thermoelectric device 10. As will be
described below, the liquid heat exchanger block 12 includes at
least one passage for flow of a heat transfer liquid there through.
The system includes a radiator 14 for rejecting heat from the heat
transfer fluid when the thermoelectric pump system operates in a
cooling mode and absorbing heat in the heat transfer fluid when the
thermoelectric pump system operates in a heating mode. A convective
fan 16 is associated with the radiator for increasing the heat
transfer coefficient of the radiator. A conduit system 18 couples
the liquid heat exchange block 12 and the radiator 14, and with
pump 19 circulates the heat transfer fluid between the liquid heat
exchanger block 12 and the radiator 14.
[0036] A second side 20 of the thermoelectric device 10 opposite
from the first side 11 is thermally coupled to a heat source when
the thermoelectric heat pump system operates in a cooling mode or
to a cold source when the thermoelectric heat pump system operates
in a heating mode. The thermoelectric device 10 can be powered to
pump heat from the heat source in the cooling mode and pump heat to
the cold source in the heating mode, depending on the direction of
current flowing through the thermoelectric device 10.
[0037] The heat source or cold source can be a variety of objects
or environments to be heated or cooled including, e.g., spaces to
be air conditioned and objects. In the FIGS. 1A and 1B, the heat
source or the cold source is depicted by a second liquid heat
exchanger block 30 thermally coupled to the second side 20 of the
thermoelectric device 10. The second liquid heat exchanger block 30
includes at least one passage for flow of a second heat transfer
liquid therethrough. A second radiator 32 rejects heat from the
second heat transfer fluid when the thermoelectric pump system
operates in a heating mode and absorbs heat in the second heat
transfer fluid when the thermoelectric pump system operates in a
cooling mode. A second conduit system 34 coupling the second liquid
heat exchange block 30 and the second radiator 32 circulates the
second heat transfer fluid between the second liquid heat exchanger
block 30 and the second radiator 32. The first and second conduit
systems 18, 34 have a counterflow configuration.
[0038] FIGS. 2A-2C illustrate top, side, and bottom views,
respectively, of an exemplary liquid heat exchanger block usable in
a thermoelectric heat pump system in accordance with one or more
embodiments. Heat transfer fluid flows through a circuitous path
through the block, exchanging heat with the block. The block can be
made of high temperature plastic to reduce costs compared to a
block made of all aluminum or copper. The bottom of the plastic
block can include a copper plate thermal interface to increase
thermal conductivity. The block could also be made out of aluminum,
copper, or other metals or alloys.
[0039] FIG. 2D illustrates a modified heat exchanger block in
accordance with one or more embodiments, which includes an
integrated pump for pumping heat transfer fluid through the conduit
system.
[0040] FIG. 3 illustrates an exemplary radiator usable in a
thermoelectric heat pump system in accordance with one or more
embodiments. The radiator is a Dual Pass design radiator with flat
copper fluid tubes.
[0041] FIG. 4 illustrates an exemplary thermoelectric heat pump
system, in which a plurality of TE devices 10 and heat exchanger
blocks 12, 30 are in a stacked arrangement. Each device 10 has a
block 12 coupled to the cold loop on one side and a block 30
coupled to the hot loop on the opposite side. The blocks 12 are
connected in series in the cold loop, and the blocks 30 are
connected in series in the hot loop. The heat transfer fluids in
the hot and cold loops are in a counterflow configuration.
[0042] Note that the radiators can be replaced by any thermal
source or other types of heat exchangers.
[0043] FIG. 5 is a schematic showing a way to reduce DT through a
counter-flow arrangement. In this configuration, the total required
TE module size (TEC "B") is divided into a larger number of
proportionally smaller TE modules (TEC "A"). (Note that TEC "B" in
this example is 33% the size of TEC "A" so that the total size is
equal for each case.) The coolant is then passed from one TEC A
module's heat exchanger to another in a serial fashion. The heat
transfer fluids flow in opposite directions to each other on
opposite sides of the TE device. The coolant changes temperature as
it passes through each heat exchanger, becoming progressively
warmer or cooler respectively. The counterflow arrangement allows
the profiles to "nest" into each other and results in the reduction
of each "segment's required DT over the monolithic (TEC "A") case.
Note that the number of segments shown in is small to simplify the
example. There is no limit on the number of segments outside of
practical concerns. As the segment number increases, the DT
decreases and approaches the value TH4-TC1. For the HVAC case, the
counter-flow configuration reduces the DT by >20.degree. F.
(>11.degree. C.).
[0044] FIG. 6 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments, in which a
plurality of TE devices and heat exchanger blocks are in a serial
arrangement. The heat transfer fluids in each loop are in a
counterflow configuration. Note that the radiators can be replaced
by any thermal source.
[0045] FIG. 7 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments having a serial
counter flow discrete TE heat exchanger array arrangement. Note
that the radiators can be replaced by any thermal load or
source.
[0046] FIG. 8 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments having a serial
discrete TE heat-exchanger array condensed arrangement. Heat
insulation is provided between pairs of heat exchanger blocks due
to the direction of heat flow. Note that the radiators can be
replaced by any thermal load or source.
[0047] FIG. 9 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments having a
plurality of thermoelectric modules (TECH-1 and TECH-2) in a
cascaded arrangement.
[0048] FIG. 10 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments having a
plurality of thermoelectric modules (TECH-1 and TECH-2) that are
spaced apart from one another, each of said thermoelectric modules
having one surface in thermal contact with the liquid heat
exchanger block apparatus and an opposite second side in thermal
contact with the heat source or a heat exchanger to radiator.
[0049] FIG. 11 illustrates an exemplary thermoelectric heat pump
system in accordance with one or more embodiments having a
plurality of discrete thermoelectric modules spaced apart from one
another. Each module is coupled to a separate liquid heat exchanger
block. The blocks are arranged in series for flow of heat transfer
fluid sequentially therethrough.
[0050] FIG. 12 illustrates an exemplary two stage thermoelectric
heat pump system in accordance with one or more embodiments. In
this embodiment, the heat load loop interfaces with liquid loop #1
through a first TE-heat exchanger module. Liquid loop #1 interfaces
with liquid loop #2 through a second TE-heat exchanger module. Heat
is pumped from loop #1 to loop #2, raising the temperature in
liquid loop #2 and lowering the temperature in liquid loop #1.
[0051] FIGS. 13-17 illustrate alternative exemplary two stage
thermoelectric heat pump system in accordance with one or more
embodiments, showing alternative TE module configurations.
[0052] FIGS. 18-23 illustrate various alternative two and three
stage thermoelectric heat pump systems in accordance with one or
more embodiments, showing alternative TE module configurations.
[0053] FIGS. 24A-24C illustrate top, side, and bottom views,
respectively, of an exemplary liquid heat exchanger block usable in
a thermoelectric heat pump system in accordance with one or more
embodiments. Heat transfer fluid flows between a series of skived
microchannel fins through the block, increasing the thermal
interface area. The block can be made out of copper or aluminum or
be made out of high temperature plastic to lower the cost and
weight of the system. The bottom of the plastic block includes a
copper plate with skived microchannel fins for improved heat
transfer coefficient to increase heat transfer between the liquid
and the thermoelectric heat pump module.
[0054] FIGS. 25A-25C illustrates a modified heat exchanger block
similar to the block of FIGS. 24A-24C, but with an integrated pump
for pumping heat transfer fluid through the conduit system.
[0055] A TE/liquid block heat exchanger is much more thermally
efficient then a TE/air heat exchanger. In addition, a TE/liquid
block heat exchanger can transfer much higher heat densities then a
TE/air heat exchanger. This reduces the required area of
thermoelectric devices decreasing weight, size and thermoelectric
and heat exchanger costs.
[0056] For small applications only 1 TE device with a hot and cold
liquid heat exchanger can be used. However, for larger heat loads,
multiple isolated or discrete TE/heat exchanger units can be used
to effectively pump larger heat loads with a sufficient delta
temperature between the two loops in a single or two stage system.
Larger liquid to air heat exchangers can be used for larger heat
loads. In applications where a higher delta temperature is
required, multi-stage heat pumps can be utilized to achieve higher
delta temperatures at lower COP compared to single stage systems
with single layer or multi layered stacked thermoelectric devices
in a cascade configuration.
[0057] Advances in higher COP TE devices will result in a higher
COP heat pump system. Water condensation from the cold liquid to
air heat exchanger can be pumped to the heat rejection liquid to
air heat exchanger and evaporated on the fins of the heat exchanger
to add additional cooling and increase the system COP even
further.
[0058] This same configuration can be used for cooling a
refrigerator and will be more efficient and cool faster than a
conventional TE/air heat exchanger.
[0059] Thermoelectric heat pump systems in accordance with various
embodiments can be used in various heating and/or cooling
applications. For example, the systems can be set up to be used in
a window or could be used remotely in the room using longer
tubes/hoses to the radiator out the window. Also the systems can be
scaled to larger size to be used to cool and heat the large spaces
such as a whole house using a similar indoor liquid to air heat
exchanger and liquid to air outdoor heat exchanger that is used in
conventional vapor compression however the tubes would be filled
with water/antifreeze mixture instead of Freon. Additionally, the
systems in the same configuration can be used for cooling a
refrigerator/freezer and will be more efficient and cool faster
than a conventional TE/air heat exchanger.
[0060] Other exemplary applications of the thermoelectric heat pump
include water heating for domestic tank and tankless water heaters
and for industrial heating and cooling for processing and other
applications.
[0061] Having thus described several illustrative embodiments, it
is to be appreciated that various alterations, modifications, and
improvements will readily occur to those skilled in the art. Such
alterations, modifications, and improvements are intended to form a
part of this disclosure, and are intended to be within the spirit
and scope of this disclosure. While some examples presented herein
involve specific combinations of functions or structural elements,
it should be understood that those functions and elements may be
combined in other ways according to the present disclosure to
accomplish the same or different objectives. In particular, acts,
elements, and features discussed in connection with one embodiment
are not intended to be excluded from similar or other roles in
other embodiments. Additionally, elements and components described
herein may be further divided into additional components or joined
together to form fewer components for performing the same
functions. Accordingly, the foregoing description and attached
drawings are by way of example only, and are not intended to be
limiting.
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