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Publication numberUS20020162339 A1
Publication typeApplication
Application numberUS 10/138,310
Publication dateNov 7, 2002
Filing dateMay 6, 2002
Priority dateMay 4, 2001
Publication number10138310, 138310, US 2002/0162339 A1, US 2002/162339 A1, US 20020162339 A1, US 20020162339A1, US 2002162339 A1, US 2002162339A1, US-A1-20020162339, US-A1-2002162339, US2002/0162339A1, US2002/162339A1, US20020162339 A1, US20020162339A1, US2002162339 A1, US2002162339A1
InventorsHoward Harrison, Jeffrey Brown
Original AssigneeHarrison Howard R., Brown Jeffrey Russell
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
High performance thermoelectric systems
US 20020162339 A1
Abstract
A high performance thermoelectric system is taught which is capable of rapidly cooling a thermal load with a thermoelectric module. A thermal ballast is in simultaneous thermal communication with both the thermoelectric module and the thermal load, and compensates for the difference between the characteristics of the thermoelectric module and the demands of the thermal load, allowing a thermoelectric module to handle significantly larger thermal loads than would normally be possible, albeit for a reduced period of time. Also taught is a means to implement a demand cooler for drinking water. Also taught is a means to implement a high performance cooler for removable fluid containers, adaptable to the rapid cooling of wine bottles and the like.
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Claims(26)
We claim:
1. A high performance thermoelectric system comprising:
a. A thermoelectric module,
b. A heat sink,
c. A thermal ballast,
d. A thermal load, and
e. A thermal conduit.
Said thermoelectric module, said thermal ballast, and said thermal load being in simultaneous thermal communication through said thermal conduit, said thermal ballast configured to rapidly absorb heat from said load through said thermal conduit, said thermoelectric module configured to simultaneously pump additional heat from said thermal load through said thermal conduit, said thermoelectric module further configured to pump said heat from said thermal ballast through said thermal conduit at a slower rate over time, said thermoelectric module in thermal communication with said heat sink to disperse said heat and said additional heat into the ambient air.
2. The high performance thermoelectric system as claimed in claim 1 wherein said thermal conduit may be extended around a cavity to form a fluid reservoir.
3. The high performance thermoelectric system as claimed in claim 1 further comprising a thermally conductive spacer block between said thermal conduit and said thermoelectric module, said spacer block extending through said thermal ballast to be in direct thermal communication with said thermal conduit.
4. The high performance thermoelectric system as claimed in claim 1 wherein said thermal ballast may be a Phase Change Material with a characteristic freezing point slightly below the desired temperature of said thermal load.
5. The high performance thermoelectric system as claimed in claim 1 wherein said thermal ballast may be a Phase Change Material in liquid or powder format, said Phase Change Material in liquid or powder format being further contained in a confined space in thermal communication with said thermal conduit through a thermal interface, said confined space being configured to position any air gaps that might form due to the settling of, downward flow of, or volumetric changes in said Phase Change Material in liquid or powder format away from said thermal interface.
6. The high performance thermoelectric system as claimed in claim 1 wherein said thermal conduit has thermally conductive protrusions extending into said thermal ballast.
7. The high performance thermoelectric system as claimed in claim 1 further comprising a second thermal ballast in thermal communication with said heat sink through a second thermal conduit.
8. The high performance thermoelectric system as claimed in claim 1 further comprising an auxiliary spacer block, an auxiliary heat sink, an auxiliary fan, and an auxiliary thermal load, wherein said auxiliary spacer is in thermal communication with said thermal conduit, said auxiliary heat sink is in thermal communication with said auxiliary spacer block, and wherein said auxiliary fan is adapted to control the flow of heat from said auxiliary load to said auxiliary heat sink.
9. A flow through demand cooler for fluids comprising:
a. A thermoelectric module,
b. A heat sink,
c. A thermal ballast,
d. A fluid heat exchanger, and
e. A thermal conduit.
Said thermoelectric module, said thermal ballast, and said fluid heat exchanger being in simultaneous thermal communication through said thermal conduit, said thermal ballast configured to rapidly absorb heat from said fluid heat exchanger through said thermal conduit, said thermoelectric module configured to simultaneously pump additional heat from said fluid heat exchanger through said thermal conduit, said thermoelectric module further configured to pump said heat from said thermal ballast through said thermal conduit at a slower rate over time, said thermoelectric module in thermal communication with said heat sink to disperse said heat and said additional heat into the ambient air.
10. The flow through demand cooler for fluids as claimed in claim 9 wherein said fluid heat exchanger may also be said thermal conduit.
11. The flow through demand cooler for fluids as claimed in claim 9 further comprising a thermally conductive spacer block between said thermal conduit and said thermoelectric module, said spacer block extending through said thermal ballast to be in direct thermal communication with said thermal conduit.
12. The flow through demand cooler for fluids as claimed in claim 9 wherein said thermal ballast may be a Phase Change Material with a characteristic freezing point slightly below the desired temperature of the fluid within said fluid heat exchanger.
13. The flow through demand cooler for fluids as claimed in claim 9 wherein said thermal ballast may be a Phase Change Material in liquid or powder format, said Phase Change Material in liquid or powder format being further contained in a confined space in thermal communication with said thermal conduit through a thermal interface, said confined space being configured to position any air gaps that might form due to the settling of, downward flow of, or volumetric changes in said Phase Change Material in liquid or powder format away from said thermal interface.
14. The flow through demand cooler for fluids as claimed in claim 9 wherein said thermal conduit has thermally conductive protrusions extending into said thermal ballast.
15. The flow through demand cooler for fluids as claimed in claim 9 further comprising a second thermal ballast in thermal communication with said heat sink through a second thermal conduit.
16. The flow through demand cooler for fluids as claimed in claim 9 wherein said fluid heat exchanger is comprised of a cavity with vertical or longitudinal partitions, and wherein the fluid within said fluid heat exchanger must travel around said vertical or longitudinal partitions in a zigzag pattern.
17. The flow through demand cooler for fluids as claimed in claim 9 wherein said fluid heat exchanger is comprised of an extruded cavity with sliding longitudinal partitions, said sliding longitudinal partitions inserted into pre-formed slots within said extruded cavity, said sliding longitudinal partitions held in place with a bonding agent, said longitudinal partitions also held in place by the crimped sides of said pre-formed slots, and wherein the fluid within said fluid heat exchanger must travel around said sliding longitudinal partitions in a zigzag pattern.
18. The flow through demand cooler for fluids as claimed in claim 9 further comprising an auxiliary spacer block, an auxiliary heat sink, an auxiliary fan, and an auxiliary thermal load, wherein said auxiliary spacer block is in thermal communication with said fluid heat exchanger, said auxiliary heat sink is in thermal communication with said auxiliary spacer block, and wherein said auxiliary fan is adapted to control the flow of heat from said auxiliary load to said auxiliary heat sink.
19. A high performance cooler for removable fluid containers comprising;
a. A thermoelectric module,
b. A heat sink,
c. A thermal ballast,
d. A removable fluid container, and
e. A thermal conduit.
Said thermoelectric module, said thermal ballast, and said removable fluid container being in simultaneous thermal communication through said thermal conduit, said thermal ballast configured to rapidly absorb heat from said removable fluid container through said thermal conduit, said thermoelectric module configured to simultaneously pump additional heat from said removable fluid container through said thermal conduit, said thermoelectric module further configured to pump said heat from said thermal ballast through said thermal conduit at a slower rate over time, said thermoelectric module in thermal communication with said heat sink to disperse said heat and said additional heat into the ambient air.
20. The high performance cooler for removable fluid containers as claimed in claim 19 wherein said thermal conduit may be in intimate thermal contact with said removable fluid container, and wherein said thermal conduit may form a support for said removable fluid container.
21. The high performance cooler for removable fluid containers as claimed in claim 19 further comprising a thermally conductive spacer block between said thermal conduit and said thermoelectric module, said spacer block extending through said thermal ballast to be in direct thermal communication with said thermal conduit.
22. The high performance cooler for removable fluid containers as claimed in claim 19 wherein said thermal ballast may be a Phase Change Material with a characteristic freezing point slightly below the desired temperature of fluid within said removable fluid container.
23. The high performance cooler for removable fluid containers as claimed in claim 19 wherein said thermal ballast may be a Phase Change Material in liquid or powder format, said Phase Change Material in liquid or powder format being further contained in a confined space in thermal communication with said thermal conduit through a thermal interface, said confined space being configured to position any air gaps that might form due to the settling of, downward flow of, or volumetric changes in said Phase Change Material in liquid or powder format away from said thermal interface.
24. The high performance cooler for removable fluid containers as claimed in claim 19 wherein said thermal conduit has thermally conductive protrusions extending into said thermal ballast.
25. The high performance cooler for removable fluid containers as claimed in claim 19 further comprising a second thermal ballast in thermal communication with said heat sink through a second thermal conduit.
26. The high performance cooler for removable fluid containers as claimed in claim 19 wherein said removable fluid container further contains a fluid and a wine bottle, said wine bottle being immersed in said fluid, said wine bottle in thermal communication with said fluid, and said fluid in thermal communication with said thermal conduit through said removable fluid container.
Description
CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. patent application serial No. 60/288,418 filed May 4, 2001, which application is pending.

FIELD OF THE INVENTION

[0002] This invention relates to an optimized configuration for high performance thermoelectric systems. A thermal ballast functions as an auxiliary thermal storage device that is in simultaneous thermal communication with both the thermoelectric module and the load, and compensates for the different thermal characteristics of the thermoelectric module and the load. A thermal ballast configured in this manner allows a single thermoelectric module to handle significantly larger thermal loads than would normally be possible, albeit for a reduced period of time.

BACKGROUND OF THE INVENTION

[0003] Thermoelectric modules have been around for a number of years and offer several advantages over compressor based cooling systems including small size, portability, durability, and environmental safety. However one significant drawback of these devices is their relatively low cooling (or heating) rates.

[0004] There have been several attempts to improve the cooling rates through various thermoelectric module configurations (e.g. parallel and/or serial configurations), and improved thermoelectric module technical designs to provide higher heat pumping rates and higher temperature differentials across the module. Also, designers have attempted to improve the thermal interfaces between the thermoelectric module, heat sink, and load to improve the overall performance of the system. More recent developments include the use of a thermal battery to store the cold (or lack of heat) or heat produced by a thermoelectric module, or some other type of cooling or heating device, for later use.

[0005] U.S. Pat. No. 6,370,884 issued Apr. 16, 2002 to Kelada teaches a form of high performance thermoelectric system, however the performance is obtained by deploying a multiple of thermoelectric devices with one illustration showing a quantity of eight such devices so deployed. It is doubtful that the large quantity of heat produced by such a configuration could be dissipated rapidly enough to maintain the water flowing through the system at the stated 40F for any length of time. Further, this is an extremely expensive way to build a high performance thermoelectric system.

[0006] U.S. Pat. No. 6,247,522 issued Jun. 19, 2001, to Kaplan, et al, teaches a thermal storage unit designed for the storage and later use of thermal energy on a larger scale, for example the later use of energy purchased during low cost off-peak hours. Energy is transferred to and from the thermal storage unit using a heat transfer fluid. While this patent suggests the use of phase change material in the thermal storage unit, it does not address the use of this material in, nor is it adaptable to, high performance thermoelectric systems.

[0007] U.S. Pat. No. 6,105,659 issued Aug. 22, 2000 to Pocol, et al teaches a device for the storage and transfer of thermal energy with the storage or recharge function being accomplished through one thermal interface and the further transfer of the stored thermal energy being accomplished through a second thermal interface, the configuration being optimized for the transfer of energy between the device and a gas. This patent focuses on the two thermal interfaces (e.g. the use of metallic powders that may be attractively positioned on membrane walls) but does not address such practical matters as the removal of heat produced by the thermoelectric heat pump(s) used to recharge the system. The design is inherently inefficient because it does require two separate thermal interfaces rather than one, and it does not seem to address the issues of thermal conductivity within the phase change material used for energy storage. Further, it does not lend itself to such common and practical applications as rapidly chilling a quantity of fluid with a single thermoelectric module.

[0008] U.S. Pat. No. 4,951,481 issued Aug. 28, 1990, to Negishi (assigned to Sanden Corporation, Japan) teaches a cold preserving container including a cold accumulator enclosing a cold regenerative material. The cold regenerative material is cooled by circulating a cooling medium through an evaporating tube located between the cold accumulator and the container. This is not adaptable to high performance thermoelectric systems since it requires a circulating medium, and the configuration is optimized for the rapidly cooling the cold accumulator rather than the container. It is a well-known fact that a thermoelectric module provides a much slower rate of cooling than a compressor/evaporator system. The Negishi patent will not provide rapid cooling with a single thermoelectric module given these constraints.

[0009] The inventors of the subject invention are also the inventors of U.S. Pat. No. 5,469,708, issued Nov. 28, 1995, and U.S. Ser. No. 09/522,929, to be issued on or about May 1, 2002, the disclosures of which are incorporated herein by reference. These patents describe a water cooler and a combination ice maker and cooler, respectively, both based on thermoelectric technology.

[0010] It is an objective of the present invention to produce rapid cooling with a single thermoelectric module, making possible such devices as a demand cooler for drinking water, a high performance cooler for removable fluid containers, a rapid chiller for wine bottles, and several other embodiments not possible given the prior art. These and other objectives and advantages of the present invention will become apparent from the reading of the attached specification and appended claims.

SUMMARY OF THE INVENTION

[0011] The present inventors have optimized the performance of thermoelectric systems by configuring a thermal ballast as an auxiliary thermal storage device in order to accommodate the difference in thermal characteristics between the thermoelectric module and the load, and to maximize the combined thermal transfer rates of both the thermal ballast and the thermoelectric module when a load is present. The thermal ballast, thermoelectric module, and the load are in simultaneous thermal communication through a thermal conduit that links the three components together. (The singular term “thermoelectric module” is understood to represent one or more thermoelectric modules, as may be required by a particular application, unless otherwise stated throughout this document.)

[0012] In most cases thermal loads are intermittent and require a high rate of heat transfer for a relatively short period of time. A thermoelectric module, on the other hand, has a substantially different characteristic since it performs best with a steady thermal load that requires a relatively low rate of heat transfer. This relatively low rate of heat transfer determines the maximum cooling rate in almost all thermoelectric applications. The usual approach is to leave the thermoelectric module on for an extended period of time such that the required amount of heat is eventually removed from the load. This does work, however it takes much longer than desirable from a user's perspective.

[0013] The present inventors have addressed this problem by devising a way to configure a thermal ballast, or auxiliary thermal storage device, such that it is in simultaneous thermal communication with both the thermoelectric module and the load. This facilitates the interflow of heat between the thermal ballast, thermoelectric module, and the load, and allows the thermoelectric module to be located where it can be configured with an appropriate heat sink to dissipate heat into the ambient air.

[0014] A thermal ballast is generally a passive component capable storing either “heat” or “cold” (i.e. the lack of heat). Further, a thermal ballast may absorb or release heat at various transfer rates. A maximum heat transfer rate may be achieved by increasing the surface area of the thermal interface between the thermal ballast and the load, and by keeping the thermal ballast relatively thin so as to not encounter limitations related to thermal conductivity within the thermal ballast itself. In a cooling application the thermoelectric module may pump heat slowly out of the thermal ballast until it is fully charged. Then the thermal ballast is ready to absorb heat very rapidly from the load over a short space of time. The thermal ballast serves as an auxiliary thermal storage device that ideally matches the basic characteristics of both the thermoelectric module and the load.

[0015] It follows that a thermal ballast may satisfy the load requirements while operating under the constraints of the thermoelectric module. The intermittent characteristic of the load means that the imbalance in heat transfer rates will only need to be supported for a short period of time. This will work providing that the total heat absorbed by the thermoelectric module from the thermal ballast substantially equals the total heat absorbed by the thermal ballast from the load over a given period of time.

[0016] The configuration may be further improved by allowing the thermoelectric module and the thermal ballast to simultaneously absorb heat from the load. This contrasts sharply with current configurations which utilize a thermal battery, rather than a thermal ballast, configured as a passive “flow through” component—i.e. the thermoelectric module can only remove heat from the thermal battery which then in turn can only remove heat from the load.

[0017] The thermal ballast, thermoelectric module, and the load are in simultaneous thermal communication through a thermal conduit that links the three components together. This allows the thermoelectric module and the thermal ballast to simultaneously absorb heat from the load, effectively increasing the rate at which heat may be removed from the load and reducing cooling times substantially. The same thermal conduit may then be used by the thermoelectric module to remove heat from the thermal ballast in preparation for the next load cycle. The thermal conduit allows for this universal flow of heat between the components as determined by standard thermodynamic principles.

[0018] A suitable analogy in this case might be a simple savings account that is used to accumulate funds for an annual vacation. The cost of the vacation (i.e. the load) is high and intermittent. On the other hand the savings rate (i.e. the thermoelectric module) will be slow and steady. The ATM network (i.e. the thermal conduit) allows the user to maximize vacation spending by accessing the saved amount (i.e. the thermal ballast) plus any further savings that might be automatically deposited during this time (additive effect of thermoelectric module while load is present) Similar to the thermal system described above, the imbalance in cash transfer rates only needs to be supported for a short period of time, and the effect may be to reduce the savings account balance to zero by the end of the vacation. Then, regular savings will resume to increase the account balance in time for the next annual vacation.

[0019] Just as in the case of the savings account, which must be “sized” to fund the annual vacation, the thermal ballast must be sized to match the characteristics of the load. Similar to the savings rate, the heat transfer rate provided by the thermoelectric module must be sufficient to ensure that the thermal ballast is prepared for the next load cycle. Whereas the savings account operates on a cash balance basis, the thermal ballast will operate on a heat energy balance basis.

[0020] There are several benefits to using a thermal ballast within a thermoelectric system, including the requirement for a smaller thermoelectric module, a smaller heat sink, and a smaller (and quieter) fan. These are significant benefits since one of the major challenges in thermoelectric design is to quickly and quietly dissipate the heat produced by the thermoelectric module into the ambient air. Since a thermoelectric module is a heat pump, the heat that must be dissipated equals the electrical energy input plus the heat removed from the load. In other words the heat must be dissipated at a greater rate than the thermoelectric module's cooling rate. Thus, a reduction in the cooling requirement by “x” watts will reduce the heat dissipation requirements by substantially more than “x” watts.

[0021] The thermal ballast itself may be made of any material that can store thermal energy, and release it at varying rates. This may be a solid, a liquid, or some combination thereof. A purely solid or liquid thermal ballast will store sensible heat, meaning that the temperature will rise as heat is absorbed or conversely drop as the heat is removed.

[0022] A combined solid/liquid thermal ballast will also store thermal energy, however in this case it is stored as latent heat as the material changes state. This type of thermal ballast may be made from a specialized Phase Change Material (PCM) that is designed to change state a very specific temperature.

[0023] A PCM thermal ballast has two important benefits: (1) the latent heat stored during the change of state is substantially greater than the sensible heat that may be stored by changing the temperature within a given state and (2) the change of state occurs at a constant temperature. The first benefit means that a PCM thermal ballast may be much smaller and compact than a solid or liquid thermal ballast. However the second benefit is of particular importance since thermoelectric systems do not have a great deal of inherent thermal stability—i.e. the temperatures within the system tend to fluctuate widely. The addition of a PCM thermal ballast may stabilize the load temperature at a steady level, and the thermoelectric module will simply act as a heat pump to transfer energy out of the PCM thermal ballast at that steady temperature.

[0024] While not as effective or compact as a PCM thermal ballast, a solid or liquid thermal ballast may be less expensive in certain applications. This type of thermal ballast may be implemented by simply adding thermal gel, water, or a metal such as copper or aluminium to the existing thermal conduit between the thermoelectric module and the load. A solid or liquid thermal ballast may not function at a steady temperature, but it will add to the thermal stability of the system since a greater amount of heat transfer will be required to effect a given temperature change.

[0025] A thermal ballast may also be used on the hot side of a thermoelectric module to increase the stability of the thermal system. Thermoelectric modules generally operate with a fixed temperature differential between the thermal interfaces, and therefore any change in the hot side temperature also tends to affect the cold side temperature. Given that hot side temperature changes are most often caused by changes in the ambient temperature, it follows that thermoelectric module cold side temperatures are also affected by ambient conditions. This sensitivity can be reduced by placing a PCM thermal ballast in thermal communication with the hot side of the thermoelectric module and the heat sink in order to keep the hot side temperature relatively constant as the ambient temperature fluctuates. The ability to accommodate changes in heat dissipation rates caused by the now fluctuating differential between hot side and ambient temperatures is an inherent function of the PCM thermal ballast as described above.

[0026] While the primary function of a thermal ballast is to act as an auxiliary thermal storage device, it can also be designed to aid in the heat transfer process by accommodating differences in the surface area of components that must be in thermal communication and/or by accommodating the impact of a variable heat flux over these surfaces. Thermoelectric modules are generally quite small with a high but constant heat flux across the thermal interfaces—i.e. they are capable of pumping a tremendous amount of heat through a relatively small surface area. Quiet often the challenge is to collect this heat from a much larger surface area and “funnel” it through the thermoelectric module. In some applications this larger surface area has a variable heat flux—i.e. the heat transferred through the surface varies from point to point across the surface, and these different heat transfer rates can fluctuate independently over time. This is, in fact, one of the major concerns when designing a cooling system for electronic components such as Intel's Pentium IV processor.

[0027] A thermal ballast is capable of transferring heat at different rates across its surface, and therefore it is effective when used in these variable heat flux applications. Further, a PCM thermal ballast may be used to effectively hold the temperature of the device constant across the surface regardless of the variations in heat flux. Finally, a thermal ballast may be designed to “collect” the heat from a large surface at varying rates, and to “funnel” the heat into the much smaller thermoelectric module at a slow but steady rate. The efficiency of this “funnelling” process may be increased by utilizing a high heat transfer rate dispersion plate as a thermal conduit between the thermal ballast and the thermoelectric module, effectively increasing the surface area of the thermoelectric module.

[0028] A dispersion plate may be used to accommodate for differences in surface area on both the cold side and the hot side of a thermoelectric module. Further, the dispersion plate may be made from a solid piece of material, one or more phase change heat pipes, a self contained circulation of heat conducting fluid, or some combination of thereof. On the hot side of the thermoelectric module, it is possible that the combination of a dispersion plate, a thermal ballast, and a heat sink with sufficient surface area and sufficient natural convection characteristics, as might be possible with some ceramic materials, may be sufficient to preclude the requirement for a forced convection cooling system. In an efficient design this type of heat sink could be built into the exterior surface of the cabinet surrounding the thermoelectric system to reduce the overall size of the device.

BRIEF DESCRITION OF THE DRAWINGS

[0029] Embodiments of the invention are described by way of example with reference to the following diagrams in which;

[0030]FIG. 1 provides an overview of a high performance thermoelectric system with a thermal ballast and a thermal conduit,

[0031]FIG. 2 is a side section view of a high performance thermoelectric system designed to rapidly chill a fluid,

[0032]FIG. 3 is a side section view of a demand fluid cooler utilizing vertical partitions,

[0033]FIG. 4 is a bottom section view of a demand fluid cooler utilizing longitudinal partitions,

[0034]FIG. 5 is an exploded view of demand fluid cooler heat exchanger,

[0035]FIG. 6 is a side section view of reservoir fluid cooler with an auxiliary chilled cabinet,

[0036]FIG. 7 is a partial section view of fluid cooler for removable fluid bottles,

[0037]FIG. 8 is a partial section view of a rapid chiller for wine bottles, and

[0038]FIG. 9 is a side section view of a high performance thermoelectric system with a hot side thermal ballast and a hot side thermal conduit.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0039]FIG. 1 illustrates a high performance thermoelectric system 1 with thermoelectric module 2, thermal load 6, and thermal ballast 14. The purpose of this system is to remove heat from, or cool, thermal load 6 and disperse this heat into the ambient air through heat sink 4. All components except heat sink 4, and the hot side of thermoelectric module 2, are surrounded by insulation 12 to substantially prevent the ingress of heat from the warmer ambient air.

[0040] Thermal conduit 10 facilitates the simultaneous interflow of heat between thermoelectric module 2, thermal load 6, and thermal ballast 14. Thermal conduit 10 allows heat from thermal load 6 to be absorbed rapidly by thermal ballast 14 through a large surface area of thermal load 6, and then later pumped out of thermal ballast 14 by thermoelectric module 2 through a much smaller surface area of spacer block 8. Thermal ballast 14 and thermal conduit 10 will remain at substantially the same temperature since they are in direct thermal communication.

[0041] Spacer block 8 allows for the installation of sufficient insulation 12 between heat sink 4 and thermal conduit 10, such that heat does not flow directly back from heat sink 4 to thermal conduit 10. In this application spacer block 8 and thermal conduit 10 may be further integrated to form one composite part in order to avoid any possible thermal losses in the interface between the two underlying components.

[0042] Thermoelectric module 2 may initially pump heat from thermal ballast 14 through thermal conduit 10 and spacer block 8. In a cooling application thermal ballast 14 acts as an auxiliary thermal storage device by retaining this absence of heat.

[0043] When thermal ballast 14 is constructed of a solid or liquid material, the temperature of thermal ballast 14 and thermal conduit 10 will fall as sensible heat is removed from the combined assembly. The rate at which the temperature of thermal conduit 10 falls will be reduced by the presence of thermal ballast 14 since more heat must be removed for each degree of temperature change due to the increased mass of the combined assembly.

[0044] When thermal ballast 14 is made of Phase Change Materials (PCM), then the temperature of PCM thermal ballast 14 and thermal conduit 10 will fall to the freezing temperature of the PCM and remain at that temperature until PCM thermal ballast 14 completely changes state. The latent heat that must be removed to change the state of the PCM is substantially greater than the sensible heat that must be removed to change the temperature of the PCM while it remains in a single state. Therefore PCM thermal ballast 14 is capable of storing the absence of a much greater amount of heat than a solid or liquid thermal ballast 14.

[0045] The freezing point of PCM thermal ballast 14 may be selected to be somewhat below the desired temperature of thermal load 6 such that a thermal gradient will exist between thermal load 6 and thermal ballast 14, encouraging the natural flow of heat from the former to the latter through thermal conduit 10. Note that the freezing point of PCM thermal ballast 14 may be any temperature within a very wide range, and does not necessarily mean the freezing point of water or the temperature at which ice forms. The freezing point of PCM thermal ballast 14 is the temperature at which the material within PCM thermal ballast 14 changes state from liquid to solid.

[0046] During normal operation thermoelectric module 2 may be turned on before thermal load 6 is applied to the system, and will continue to operate until the temperature of thermal ballast 14 and thermal conduit 10 reaches a preset value. In the case of a PCM thermal ballast 14, this preset value may be set at a temperature somewhat below the PCM freezing point, ensuring that the PCM has completely changed state and that a maximum amount of heat has been removed from PCM thermal ballast 14 before thermoelectric module 2 is turned off again.

[0047] Thermal load 6, when introduced to the system, may be at a much higher temperature than thermal ballast 14 and thermal conduit 10. Thermal ballast 14 will immediately begin to absorb heat from thermal load 6, through thermal conduit 10. The temperature of thermal load 6 will drop more rapidly than possible with only thermoelectric module 6 because thermal ballast 14 is able to absorb heat much more rapidly than possible with a thermoelectric heat pump.

[0048] In the case of PCM thermal ballast, the temperature of PCM thermal ballast 14 will remain at the PCM freezing point as heat is being rapidly absorbed from thermal load 6 unless the net amount of heat absorbed by PCM thermal ballast 14 exceeds the latent heat required to melt the PCM contained within PCM thermal ballast 14. This is an extremely important feature of a PCM thermal ballast since it means that an optimum temperature gradient will always exist between thermal load 6 and thermal ballast 14, ensuring that heat from thermal load 6 will be absorbed by thermal ballast 14 at a maximum rate.

[0049] The heat absorbed by thermal ballast 14 will cause its temperature to rise, further causing the power to be applied to thermoelectric module 2 by a control circuit. In the case of a PCM thermal ballast 14 the temperature will initially rise to the freezing point of the PCM material, and then remain at that point as the PCM material absorbs heat and begins to melt. The control circuit will sense this initial rise in temperature, and cause power to be applied to thermoelectric module 2, since the preset value for turning off thermoelectric module 2 may be set at a temperature just below the PCM freezing point as described in a previous paragraph.

[0050] Thermoelectric module 2 will then be turned on again to simultaneously pump additional heat from thermal load 6, through thermal conduit 10 and spacer block 8, and out through heat sink 4 to be dispersed into the ambient air using natural and/or forced convection. This will further increase the rate of cooling of thermal load 6 beyond that possible with only thermal ballast 14. This combined cooling effect is possible since thermal load 6, thermoelectric module 2, and thermal ballast 14 are in simultaneous thermal communication through thermal conduit 10.

[0051] Thermoelectric module 2 will continue to pump heat from thermal load 6 until such time as thermal load 6 and thermal ballast 14 are in thermal equilibrium. Then, thermoelectric module 2 will remain on to continue to pump heat from thermal load 6 and thermal ballast 14 until a set point is reached, indicating that thermal load 6 has reached its target temperature and that a maximum amount of heat has been removed from thermal ballast 14—i.e. that the system is completely prepared for a next thermal load 6. In the case of a solid or liquid thermal ballast, this set point may be determined by sensing the temperature of thermal ballast 14 and thermal conduit 10 at a value somewhat below the desired temperature of thermal load 6. In the case of a PCM thermal ballast 14, the steady state temperature of thermal load 6 will be closely linked to the fixed PCM freezing point, and the set-point may be determined by sensing a temperature of PCM thermal ballast 14 that is somewhat below the PCM freezing point.

[0052] A variable temperature control may be more easily implemented with a solid or liquid thermal ballast 14 because of the direct relationship between sensible heat and temperature, however performance will not match that of a PCM thermal ballast 14. It is possible to implement a variable temperature control with a PCM thermal ballast 14, however this is best suited to a variance of set points at or below the inherent set point based on the PCM freezing point. This is because a PCM thermal ballast 14 will act as a PCM thermal ballast 14 until frozen, and then it will act as a solid thermal ballast 14 and be responsive to sensible heat. A set point which is above the inherent set point (based on the PCM freezing point) would not allow the system to take advantage of the large latent heat absorption capabilities of the PCM material at its freezing point. Alternate strategies for variable set points may include the use of multiple PCM thermal ballasts having various freezing points within the required range of set-point temperatures. In this case the multiple PCM thermal ballasts would also be capable of storing a greater total amount of latent heat, contributing to the overall performance of the system.

[0053]FIG. 2 is a side view of a high performance thermoelectric system designed to rapidly chill a fluid flowing through fluid chamber 20 having inlet 22 and outlet 24. Thermal conduit 10 may be in thermal communication with thermal ballast 14, and with thermoelectric module 2 through spacer block 8. In this case spacer block 8 has been extended to create a greater space between thermoelectric module 2 and thermal conduit 10, allowing thermal ballast 14 to be located in this area. Thermal ballast 14, spacer block 8, and thermal conduit 10, containing fluid chamber 20, may be surrounded by insulation 12 to substantially prevent the absorption of heat from the surrounding air.

[0054] The thermal communication between thermal conduit 10 and thermal ballast 14 may be improved through the use of thermal fins 11. Ultimately, thermal fins 11 improve the rate at which thermal ballast 14 may absorb heat from the load, in this case the fluid within fluid chamber 20.

[0055] Of note is the fact that thermal ballast 14 may be comprised of a PCM in a powder or liquid format. These types of PCM will naturally tend to flow or settle down against thermal barrier 10 and thermal fins 11 when the high performance thermoelectric cooling system is in the illustrated orientation, and this will ensure the best possible thermal interface between thermal ballast 14 and thermal conduit 10. Air gap 15 will naturally form at the top of thermal ballast 14 as a powder based PCM settles down, or as a liquid based PCM flows down and/or changes volume during a change of state. This will not affect system performance since air gap 15 forms between thermal ballast 14 and insulation 12 (i.e. not between thermal ballast 14 and thermal conduit 10).

[0056] It follows that the high performance thermoelectric cooling system in FIG. 2 will function best in the orientation shown with thermoelectric module 2 at the top of the system. The system will also function well with the same component configuration and with thermoelectric module 2 at any side of the system since air gap 15 would then form at either end of thermal ballast 14, perhaps exposing a small portion of thermal conduit 10 to air but otherwise not substantially affecting system performance. However the thermoelectric system in FIG. 2 will not function well with thermoelectric module 2 at the bottom of the system since air gap 15 would then form between thermal ballast 14 and thermal conduit 10, substantially reducing thermal communication between these two components.

[0057] The thermal communication between thermal conduit 10 and the fluid contained within fluid chamber 20 may be improved by extending thermal conduit 10 such that it surrounds fluid chamber 20 on all sides, thereby establishing maximum thermal contact between thermal conduit 10 and the fluid within fluid chamber 20. This thermal contact may be further improved by pressurizing the fluid within fluid chamber 20, and ensuring that there are no gas bubbles trapped within the system that might form a gap between the fluid within fluid chamber 20 and any part of thermal conduit 10.

[0058] The system may be used to rapidly chill a fluid flowing through fluid chamber 20 by first using thermoelectric module 2 to pump as much heat as possible from thermal ballast 14 through thermal conduit 10 and spacer block 8. In the case of a PCM thermal ballast 14, thermoelectric module 2 must pump all of the latent heat from the PCM material in order to ensure that it is completely frozen. This process may take place over an extended period of time based on the relatively slow heat pumping capacity of thermoelectric module 2.

[0059] Once thermal ballast 14 is prepared in this manner, fluid may be allowed to flow into fluid chamber 20. Thermal ballast 14 rapidly absorbs heat from the fluid through thermal conduit 10, extended to form the walls of fluid chamber 20. Thermoelectric module 2 may also absorb heat from the fluid through thermal conduit 10, albeit at a much slower rate. As a result the temperature of the fluid within fluid chamber 20 will drop more rapidly than possible with only thermoelectric module 2 or thermal ballast 14.

[0060] The freezing point of the PCM material contained in thermal ballast 14 may be selected to be substantially below the desired temperature of the fluid leaving fluid chamber 20 in order to establish a wide temperature differential between the two, thus encouraging the rapid flow of heat between the two. However the PCM freezing point must be above the freezing point of the fluid so that any fluid remaining in fluid chamber 20 will not become frozen and block the further flow of fluid through fluid chamber 20. If the fluid is water, then the PCM freezing point must be above 0 C. (32 F.) to prevent the formation of ice within fluid chamber 20.

[0061] In the case of a PCM thermal ballast, the temperature of PCM ballast 14 will remain constant unless the net amount of heat absorbed by thermal ballast 14 (i.e. the heat absorbed from the fluid in fluid chamber 20 minus the heat pumped out by thermoelectric module 2) exceeds the latent heat required to melt the PCM contained within PCM thermal ballast 14. The latent thermal capacity of PCM thermal ballast 14 and the heat pumping capacity of thermoelectric module 2 may be designed to ensure that the temperature of PCM thermal ballast 14 does remain constant for a given total fluid flow through fluid chamber 20. Further, the heat pumping capacity of thermoelectric module 2 may be designed to ensure that all of the latent heat within PCM thermal ballast 14 is removed prior to the next requirement for chilled fluid.

[0062] The temperature of any fluid remaining in fluid chamber 20 between uses will eventually approach that of thermal ballast 14. This temperature will be below the required chilled fluid temperature because the fluid is not flowing through fluid chamber 20. In some cases this may be undesirable since the first fluid leaving the system at outlet 24 will be much colder than normal.

[0063] The initial “plug” of colder than normal fluid in fluid chamber 20 may be mixed with warmer fluid flowing through fluid bypass 26 to achieve the desired fluid temperature at outlet 24 as controlled by fluid mixing valve 28. Besides preventing a potentially undesirable situation, this process actually improves the efficiency of the system by taking advantage of the excess sensible heat that has been removed from the fluid remaining in fluid chamber 20 between uses. Fluid mixing valve 28 may also be used to facilitate temperature control by providing a range of warmer than normal fluid temperatures at outlet 24.

[0064] The contact surface area between fluid chamber 20 and thermal conduit 10 may be designed to achieve the required heat transfer rate between the fluid flowing through fluid chamber 20 and the combined heat absorption capabilities of thermal ballast 14 and thermoelectric module 2. The required heat transfer rate is dependent upon (1) the temperature of fluid entering fluid chamber 20, (2) the required temperature drop as the fluid flows through fluid chamber 20, (3) the fluid flow rate through fluid chamber 20, (4) the contact area between the fluid and thermal conduit 10, (5) the steady state temperature of thermal ballast 14 (i.e. the PCM freezing temperature), (6) the specific heat of the fluid, and other design parameters. Once established, the heat transfer rate between the fluid in fluid chamber 20 and thermal conduit 10 will remain relatively the same for as long as the underlying parameters, including the temperature of thermal ballast 14, remain constant.

[0065]FIG. 3 depicts a configuration that substantially increases the contact area between the fluid within fluid chamber 20 and thermal conduit 10, thereby allowing for a greater flow of fluid through fluid chamber 10, providing that the combined capacity of thermal ballast 14 and thermoelectric module meets the increased heat absorption requirements. If designed correctly, this configuration may be used to chill a fluid to a desired temperature as it flows through the system, i.e. it may be used to chill a fluid on demand.

[0066] Flow through chamber 21 may be comprised of down flow channels 23 and up flow channels 25. Fluid flowing into inlet 22 must first flow along down flow channel 23, and then along up flow channel 25, and so on before exiting at outlet 24. The fluid flowing along this extended path is in greater thermal contact with thermal conduit 10, now extended through vertical thermal partitions 27, allowing thermal conduit 10 to absorb a substantially greater amount of heat from the fluid flowing in this manner. Fluid remaining in flow through channel 21 after flow has stopped will eventually reach the set-point temperature of thermal ballast 14, as previously described, and may be mixed with warmer water flowing through fluid bypass 26 to achieve the desired fluid temperature at outlet 24 as controlled by fluid mixing valve 28, again as previously described.

[0067]FIG. 4 provides a bottom cross sectional view of a demand fluid chiller that may be used to chill a quantity of fluid to a required temperature as it flows through longitudinal flow chamber 29. Fluid enters the system through inlet 22, then flows in a first direction as indicated by forward flow arrow 35, then flows in a second direction as indicated by backward flow arrow 33, then repeats this process until it exist through outlet 24. Longitudinal flow chamber 29 may be defined as having a length equal to the total length of all longitudinal sections as separated by longitudinal thermal partitions 31.

[0068] As this is a bottom cross sectional view, thermal conduit 10 extends up and over the top of longitudinal thermal partitions 31. Thermal conduit 10 is in direct thermal communication with longitudinal thermal partitions 31, and is ideally formed of the same material as longitudinal thermal partitions 31 as indicated in FIG. 4. Spacer block 8, thermoelectric module 2, and heat sink 4 are all located above thermal conduit 10 and therefore appear as hidden lines in FIG. 4. The chilled components are surrounded by insulation 12 as in previous examples.

[0069] Thermal ballast 14 (reference FIG. 3) is not shown in FIG. 4 for clarity, however it is a necessary system component and must be present for the system to function properly. It should be noted, however, that the system will not function efficiently in the upside down position depicted in FIG. 4 since this orientation may cause air gap 15 to form between thermal ballast 14 and thermal conduit 10 (reference FIG. 3).

[0070] This configuration substantially increases the contact area between the fluid flowing through longitudinal flow chamber 29 and thermal conduit 10 as well as the duration of time that the fluid spends in longitudinal flow chamber 29 as it flows through longitudinal flow chamber 29, thereby allowing for a greater reduction in the temperature of the fluid as it flows through the system—providing that the combined capacity of thermal ballast 14 and thermoelectric module 2 meets the increased heat absorption requirements. This configuration may be used to build a demand water cooler for drinking water using a single thermoelectric module 2 and a sufficient quantity of thermal ballast 14 (reference FIG. 3).

[0071] This configuration further enhances thermal communication between the fluid flowing through longitudinal flow chamber 29 and the large top and bottom sections of thermal conduit 10 since the fluid is in constant contact with the large top and bottom sections of thermal conduit 10. In particular, the fluid is in constant contact with the main body of thermal conduit 10, i.e. the large top part of thermal conduit 10 that lies closest to thermal ballast 14 and thermoelectric module 2 (reference FIG. 3). For these reasons longitudinal thermal partitions 31 may be made of substantially thinner material than the large top and bottom portions and sides of thermal conduit 10 since their primary function is the containment of fluid flow rather than thermal conductivity.

[0072] A plurality of longitudinal thermal partitions 31, of thin format as described above, may be used to maximize the total length of longitudinal flow channel 29, therefore optimizing the thermal contact, including surface area and duration, between the fluid flowing through longitudinal flow channel 29 and thermal conduit 10. Ultimately this will maximize the amount of heat that may be absorbed by thermal conduit 10 from the fluid, further reducing the temperature of the fluid and increasing the effectiveness of the demand chiller.

[0073]FIG. 5 illustrates a method whereby longitudinal flow channel 29 (reference FIG. 4) may be constructed from extruded thermal conduit 41, inserted thermal partitions 43, and end caps 45. Extruded thermal conduit 41 is first formed as a hollow extrusion with longitudinal grooves 47 a, 47 b, 47 c, and 47 d using standard extruding techniques.

[0074] Thermal partitions 43 a, 43 b, 43 c, and 43 d are independently formed having a length less than the length of extruded thermal conduit 41 so as to allow the flow of fluid past one end or the other after being inserted into extruded thermal conduit 41. Thermal partitions 43 a, 43 b, 43 c, and 43 d are ideally made from thermally conductive material.

[0075] A first thermal partition 43 a may be inserted into longitudinal groove 47 a as indicated by insertion arrow 49 until the rear edge of thermal partition 43 a is flush with the rear edge of extruded thermal conduit 41. Then, a second thermal partition 43 b may be inserted into longitudinal groove 47 b, however in this case it must be inserted until the front edge of thermal partition 43 b is flush with the front edge of extruded thermal conduit 41. It follows that thermal partition 47 c must be inserted until the rear edge is flush, and that thermal partition 47 d must be inserted until the front edge is flush in an alternating pattern so as to create the required longitudinal flow chamber 29 as depicted in FIG. 4.

[0076] Thermal partitions may be press fit, bonded in place with an adhesive, or crimped in place by forcing the sides of each longitudinal grooves 47 a, 47 b, 47 c, and 47 d against the respective thermal partitions, once inserted. The crimping process may be conveniently completed by forcing a slightly oversized tool between the thermal partitions such that the sides of the longitudinal grooves are forced outward against the partitions, thereby holding the partitions in place.

[0077] End caps 45 a and 45 b may be affixed with using machine screws or some other convenient method, and sealed with gaskets 51 a and 52 b respectively, to complete the construction process and form longitudinal flow chamber 29 (reference FIG. 4). Alternatively end caps 45 a and 45 b may be welded in place. Finally, fixtures for inlet 22 and outlet 24 may be added at either end of longitudinal flow chamber 29 (reference FIG. 4).

[0078] Thermal interface area 53 may be lapped on the top surface of extruded thermal conduit 41 to facilitate the thermal interface between extruded thermal conduit 41 and spacer block 8 (reference FIG. 2). Thermal ballast 14 (reference FIG. 2) may also be added to the top surface of extruded thermal conduit 41 as previously described.

[0079]FIG. 6 is a side view of a high performance thermoelectric cooling system with two loads. This system is designed to improve the performance of a chilled water reservoir, and to provide the supplementary capability to further chill an area proximal to the chilled water reservoir.

[0080] Chilled reservoir 30 is typical of many water coolers where a small amount of water is allowed to drain into, or is pumped into, a reservoir, which is then chilled by a thermoelectric or compressor based cooling system. The chilled water is then dispensed, allowing additional warm water to enter the reservoir. One of the characteristic problems with this configuration, especially when a thermoelectric cooler is used, is the amount of time taken to chill the next “batch” of water, particularly after the entire reservoir has been drained of chilled water.

[0081] The performance of chilled water reservoir 30 may be improved with the addition of thermal conduit 10 and thermal ballast 14. Thermal ballast 14, the first load, i.e. the water within chilled reservoir 30, and thermoelectric module 2 are in thermal communication through thermal conduit 10. Thermoelectric module 2 may simultaneously pump heat from the fluid contained within chilled reservoir 30 and thermal ballast 14 through thermal conduit 10 and spacer block 8. In the case of a PCM thermal ballast 14, thermoelectric module 2 will pump all of the latent heat from PCM thermal ballast 14 such that the material contained therein becomes completely frozen. The freezing point of a PCM thermal ballast 14 may be selected to be slightly below that of the desired fluid temperature within chilled reservoir 30, but not to the extent that this fluid could itself become frozen.

[0082] Warm fluid will enter chilled reservoir 30 through inlet 32 in response to the dispensing of chilled fluid through outlet 34. Heat from this warm fluid is immediately absorbed by thermal ballast 14, which acts as an intermediate heat sink to reduce the temperature of the fluid much more rapidly than would normally be possible with only thermoelectric module 2. The heat absorbed by thermal ballast 14 is then pumped out by thermoelectric module 2 and dissipated through heat sink 4 over time. In the case of a PCM thermal ballast 14, the temperature of reservoir 30 will remain much more constant as governed by the characteristic freezing temperature of the PCM material. Also, a much smaller PCM thermal ballast may be used since the latent heat absorbed per unit volume is substantially greater than the sensible heat that could be absorbed by a solid or liquid thermal ballast having the same unit volume of material.

[0083] In some cooler designs it may be desirable to simultaneously cool a food storage area 38 and chilled reservoir 30 with a single thermoelectric module 2. Auxiliary heat sink 42 may also be in thermal communication with thermal conduit 10 through auxiliary spacer block 44. Alternatively, auxiliary heat sink 42 may be in thermal communication with thermal conduit 10 through a heat pipe or any other means as may be required to provide the desired thermal characteristics over the required distance.

[0084] In this case thermal ballast 14, a first load, i.e. the water within chilled reservoir 30, a second auxiliary load, represented by auxiliary heat sink 42, and thermoelectric module 2 are in thermal communication through thermal conduit 10.

[0085] Auxiliary heat sink 42 may absorb heat from food storage area 38 slowly through natural convection or more quickly through forced convection by turning on auxiliary fan 40. The rate of heat absorption may be further controlled by controlling the speed of auxiliary fan 40. In this manner auxiliary heat sink 42 presents a steady state auxiliary load on thermoelectric module 2 when auxiliary fan 40 is off (i.e. natural convection) and an increased controllable load on thermoelectric module 2 and thermal ballast 14 when auxiliary fan 40 is on (i.e. forced convection). Thermoelectric module 2 must be specified to manage at least this incremental auxiliary load in addition to the thermal loads presented by reservoir 30.

[0086] Auxiliary fan 40 may be left off at all times except when the controller has determined that the fluid within reservoir 30 is at the correct chilled temperature and that all of the sensible and latent heat has been removed from thermal ballast 14. This condition indicates that the reservoir is ready to dispense chilled fluid and that thermal ballast 14 is conditioned to absorb a maximum amount of heat when warm fluid enters chilled reservoir 30 to replace the dispensed chilled fluid. At that time auxiliary fan 40 may be turned on to allow auxiliary heat sink 42 to absorb heat at a greater rate from food storage area 38 such that this heat may be further absorbed by thermal ballast 14. This will cause the controller to again turn on thermoelectric module 2 so that this incremental heat, originally from food storage area 38, may be pumped from thermal ballast 14 and dispersed into the ambient air through heat sink 4. This process will continue until such time as auxiliary fan 40 is turned off, i.e. when food storage area 38 has reached its target temperature or when additional cooling is required in reservoir 30 as a result of chilled fluid being dispensed through outlet 34.

[0087]FIG. 7 is a side view of high performance thermoelectric cooler with a cold saddle 48 in intimate thermal contact with a removable fluid container 46. Cold saddle 48 is a specialized type of thermal conduit that has been formed to mate with removable fluid container 46 over a large surface area in order to provide intimate thermal contact with removable fluid container 46, and also to support removable fluid container 46. Cold saddle 48 may be constructed of any rigid material of suitable thermal conductivity, or any flexible material of suitable thermal conductivity in order to adapt to different removable container 46 geometries. The load, represented by removable fluid container 46, thermal ballast 14, and thermoelectric module 2 are in thermal communication through the thermal conduit which is, in this case, cold saddle 48.

[0088] Removable fluid container 46, as shown in FIG. 7, is a partial view of an inverted standard 3.0 or 5.0 gallon removable fluid container. It should be noted that the principles taught here may be universally applied to any removable fluid container 46 whether in an upright, sideways, inverted or any other physical orientation.

[0089] Thermoelectric module 2 pumps heat from the fluid contained in removable fluid container 46, through cold saddle 48 and spacer block 8, and into heat sink 4 where it may be dispersed into the ambient air. Removable fluid container 46 is typically housed within an insulated container such that the entire bottle of fluid may be efficiently chilled.

[0090] Thermoelectric module 2 may simultaneously pump heat from thermal ballast 14 through cold saddle 48. In the case of a PCM thermal ballast 14, a large amount of latent heat may be pumped from PCM thermal ballast 14 at the characteristic freezing point of the phase change material. This freezing point should be selected to be slightly below the desired water temperature, but not to the extent that it would cause the fluid to freeze. Thermoelectric module 2 may be turned off when the water has reached the desired temperature and all of the latent heat has been removed from PCM thermal ballast 14.

[0091] At such time as a new removable fluid container 46 is placed in the system, thermal ballast 14 will immediately absorb heat from the fluid contained therein at a rate that is faster than would normally be possible with only thermoelectric module 2. As a result, the temperature of the water will drop faster than would normally be possible with only thermoelectric module 2. This addresses one of the characteristic problems of a thermoelectric water cooler, that being the cool down rate of a new removable fluid container 46, and effectively increases the performance of the overall system.

[0092]FIG. 8 illustrates a high performance thermoelectric cooler that may be adapted to rapidly chill various sizes of wine bottles, water bottles, and the like. In this case fluid container 46 may be an open container, containing water or some other liquid that may further surround and provide intimate thermal contact with wine bottle 49, and sized to accommodate the largest anticipated wine bottle 49. Fluid container 46 may be designed to provide intimate thermal contact with cold saddle 48 as in the previous example, and may be removed for serving and for cleaning purposes. Further, fluid container 46 may be constructed of thermally conductive material to facilitate the rapid transfer of heat through its walls. Insulation 12 may be extended to provide an insulated area above cold saddle 48 such that multiple bottles may be stored above cold saddle 48, with or without fluid container 46 in place.

[0093] Thermoelectric module 2 pumps heat from the fluid contained within removable fluid container 46, through cold saddle 48 and spacer block 8, and into heat sink 4 where it may be dispersed into the ambient air. Thermoelectric module 2 may simultaneously pump heat from thermal ballast 14 through cold saddle 48. In the case of a PCM thermal ballast 14, a large amount of latent heat may be pumped from PCM thermal ballast 14 at the characteristic freezing point of the phase change material. This freezing point should be selected to be slightly below the desired water temperature, but not to the extent that it would cause the fluid to freeze. Thermoelectric module 2 may be turned off when the water has reached the desired temperature and all of the latent heat has been removed from PCM thermal ballast 14.

[0094] At such time as wine bottle 49 is introduced to the system, the fluid in removable fluid container 46 will immediately begin to absorb heat from wine bottle 49, and the temperature of the fluid will begin to rise. Thermal ballast 14 will then absorb heat from the fluid at a rate that is faster than would normally be possible with only thermoelectric module 2, keeping the temperature of the fluid at a low level where it may continue to absorb heat from wine bottle 49. As a combined result, the temperature of wine bottle 49 will drop faster than would normally be possible with only thermoelectric module 2. It should be noted that in this case the fluid contained within removable fluid container 46 acts as a type of intermediate thermal ballast to directly absorb heat from wine bottle 49 and add to the temperature stability of the system.

[0095] Thermal ballast 14 has the ability to absorb heat at different rates across its surface. This will contribute to the performance of the system since the temperature of removable fluid container 46 will be varied in this application. The temperature of wine bottle 49 will be warmer than that of the fluid contained within removable fluid container 46 when wine bottle 49 is first introduced to the system, and this will cause the temperature of removable fluid container 46 to rise in the area where it contacts wine bottle 49. This will cause thermal ballast 14 to more rapidly absorb heat through cold saddle 48 in this area of direct contact. Thermal ballast 14 may be of thicker depth under the bottom of cold saddle 48 to take advantage of this characteristic and contribute to the overall performance of the system.

[0096]FIG. 9 illustrates the use of a hot side thermal ballast 92 to improve the capabilities of the high performance thermoelectric system first presented in FIG. 2. Thermoelectric module 2 operates on a fixed temperature differential between cold and hot sides, as is characteristic of all thermoelectric modules. As a consequence, any increase in the hot side temperature will also increase the cold side temperature, negatively impacting the thermoelectric modules ability to pump heat from the load. The temperature of heat sink 4 is closely related to the hot side temperature of thermoelectric module 2. It follows that a stable heat sink 4 temperature will contribute to the overall stability of the high performance thermoelectric system.

[0097] Heat sink 4 has been extended to form hot side thermal conduit 90. This may be accomplished using standard extruding techniques, or by affixing hot side thermal conduit 90 such that it is in thermal communication with heat sink 4.

[0098] Hot side thermal ballast 92 may be in hot side thermal conduit 90 as shown. Should hot side thermal ballast 92 include a PCM, the PCM may be selected to have a characteristic melt point that equals the desired stable temperature for heat sink 4. PCM hot side thermal ballast 92 will then be able to absorb a maximum amount of latent heat at this temperature, and contribute to the overall temperature stability of the system. Hot side air gap 94 may form as PCM hot side thermal ballast 92 settles downwards in the case of a powder, or flows downwards in the case of a liquid. Hot side air gap 94 will have a minimal affect on the thermal communication between PCM hot side thermal ballast 92 and hot side thermal conduit 90 since it is formed on the top rather than the bottom surface of PCM hot side thermal ballast 92.

[0099] Thermoelectric module 2 is in simultaneous thermal communication with heat sink 4 and hot side thermal ballast 92 through hot side thermal conduit 90. A sudden increase in the amount of heat pumped by thermoelectric module 2, perhaps due to the introduction of a load within fluid chamber 20, would normally cause the temperature of heat sink 4 to rise. However in this configuration the sudden increase in the amount of heat pumped by thermoelectric module 2 may be first absorbed by hot side thermal ballast 92. Then, this heat may be dispersed through heat sink 4 and into the ambient air, at a slower rate over time and without substantially affecting the temperature of heat sink 4. Normal operation of thermoelectric module 2 may continue throughout this process since heat sink 4 may simultaneously disperse heat from thermoelectric module 2 and hot side thermal ballast 92 as delivered to heat sink 4 through hot side thermal conduit 90.

[0100] Cooling fan 96 may be added to the high performance thermoelectric system to increase the rate at which heat may be dispersed from heat sink 4 and into the ambient air. This will be particularly important for systems using hot side thermal ballast 92 since the heat contained therein must also be dispersed into the ambient air. Cooling fan 96 may be left on during a thermoelectric module 2 “off” cycle to ensure that this heat is fully dissipated prior to the next thermoelectric module 2 “on” cycle.

[0101] It should also be noted that the performance of all high performance thermoelectric systems may be further improved by implementing thermal persist technology as first introduced by the present inventors as part of U.S. utility patent application Ser. No. 09/522,929. This teaches that a small forward voltage may be left on the thermoelectric module during what would normally be the “off” cycle to prevent the reverse flow of heat back through the thermoelectric module during this time. Thermal persist will be particularly important in high performance thermoelectric systems utilizing hot side thermal ballast 92 since net amount of heat stored in heat sink 4 and hot side thermal ballast 92 is substantial, to the extent that it increase the temperature of and possibly damage the load being cooled should this heat be allowed to flow in a reverse direction.

[0102] The high performance thermoelectric systems with thermal ballast of the present invention allow for many applications, and may be implemented in various applications to cool fluids, gasses, and many other types of thermal loads. Although reference is made to the embodiments listed above, it should be understood that these are only by way of example and to identify the preferred use of the device known to the inventors at this time. It is believed that the high performance thermoelectric systems of the present invention have many additional uses and implementations which will become obvious once one is familiar with the fundamental principles of the invention.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7171955 *Aug 31, 2004Feb 6, 2007Perkins Michael TFlowing fluid conditioner
US8061148May 19, 2006Nov 22, 2011Sg ProductionsPortable temperature-controlled container
US8104295Jan 30, 2007Jan 31, 2012Amerigon IncorporatedCooling system for container in a vehicle
US8333569 *Dec 30, 2003Dec 18, 2012Intel CorporationMethod and apparatus for two-phase start-up operation
US8596496 *Jul 22, 2011Dec 3, 2013Vinocopia, Inc.Wine storage and dispensing apparatus
US20120018450 *Jul 22, 2011Jan 26, 2012Vinocopia, Inc.Wine storage and dispensing apparatus
US20130019611 *Oct 27, 2010Jan 24, 2013John SimsPersonal Temperature Control System
WO2006122428A1 *May 19, 2006Nov 23, 2006Gaetan BeauprePortable temperature-controlled container
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Classifications
U.S. Classification62/3.7, 62/3.2
International ClassificationB67D1/08, F25B21/02, H01L35/30
Cooperative ClassificationH01L35/30, B67D1/0869, F25B2400/24, F25B21/02
European ClassificationF25B21/02, H01L35/30, B67D1/08D4