US20040134200A1

US20040134200A1 - Torus semiconductor thermoelectric chiller

Info

Publication number: US20040134200A1
Application number: US10/340,885
Authority: US
Inventors: Jon Schroeder; Gerald Hirsel
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-01-13
Filing date: 2003-01-13
Publication date: 2004-07-15

Abstract

An improved torus multi-element semiconductor thermoelectric heater and chiller utilizes torus thermoelectric generator to provide high current to force heat flow. Overall efficiency of heat conversion is improved by coupling a thermoelectric generator directly to a torus heater and chiller. A thermoelectric generator exhaust heat drives a second thermoelectric generator connected to a thermoelectric heater and chiller to produce heat flow in the heater and chiller using air, gas, or liquid to convey heat into and away from the thermoelectric device.

Description

TECHNICAL FIELD

This invention relates to a circular array of semiconductor and conductive elements that comprise a thermoelectric chiller. Energy generated by a current circulating in said thermoelectric chiller causes a temperature differential between hot and cold fins. When current flows in the thermoelectric device use can be made of the hot fins for heating. Alternatively depending on the season use can be made of the cold fins for chilling. A thermoelectric torus being used for chilling has improved efficiency over mechanically driven air conditioning and refrigeration systems.

Various forms of electrical energy and heat energy can be used to efficiently cause electrical current to circulate in a torus thermoelectric chiller. Fluid, gas or ambient air passing over heated and chilled fins of the thermoelectric chiller is used to move heat from an interior to exterior of a particular environment, or from one region of a mechanism to another region of a mechanism. The thermoelectric chiller can be tied to a current producing thermoelectric device wherein current needed to produce heat differential between hot and cold fins in the chiller is generated by heat sources alone in the thermoelectric generator. Examples of heat sources for a torus thermoelectric chiller hybrid include such items as carbon based fuels including coal, steam, machinery exhaust heat and solar radiation.

Improved efficiency can be obtained by combining an electrically driven torus thermoelectric chiller with two or more thermoelectric electric generators. In another version excess heat from the burner of a first thermoelectric generator is sent to second thermoelectric torus. In so doing otherwise wasted heat is also converted to available cooling when the waste heat from the first thermoelectric generator produces current in a second thermoelectric generator and this resulting current is used in the thermoelectric chiller component.

RELATED APPLICATIONS

Application Ser. No. 10/145/757, entitled Torus semiconductor thermoelectric device to Schroeder-Hirsch discloses a circular arrangement of semiconductor elements used as a thermoelectric generator.

BACKGROUND ART

Thermoelectric chilling devices have been used for many years for specific applications where the simplicity of design warrants their use despite low energy conversion efficiency.

The heat flow produced by a thermoelectric device depends on the Peltier effect of the dissimilar metals used. Peltier effects are higher for some semiconductor materials especially n-type and p-type elements made primarily from mixtures of bismuth, tellurium, antimony, and selenium.

To compete with more traditional forms of chilling devices such as Freon expansion and absorption chilling, the torus heating and cooling thermoelectric chiller must be as efficient as possible. A preferred means to achieve such high efficiency is to arrange the thermoelectric elements in a circle with only a very small region used to import or extract the energy produced by the thermoelectric elements. Patent PCT/US97/07922 teaches the use of a circular array of thermoelectric elements. Art teaching in this case focused on 3 means to extract energy for the high current in the ring of elements; 1—a vibrating mechanical switch, 2—a Hall effect generator and 3—a Colpits oscillator. Coatings of hot and cold elements of the thermoelectric device are claimed for selenium, tellurium and antimony among others but not for mixtures of these elements.

U.S. Pat. No. 6,222,242 to Konishi, et al. discloses semiconductor material of the formula AB.sub.2, X.sub.4 where A is one of or a mixture of Pb, Sn, or Ge, B is one of or a mixture of Bi and Sb and X is one of or a mixture of Te and Se. These represent Pb, Sn or Ge doped bismuth telluride.

U.S. Pat. No. 6,274,802 to Fukuda, describes a sintering method of making semiconductor material whose principle components include bismuth, tellurium and selenium and antimony.

U.S. Pat. No. 6,340,787 to Simeray discloses a thermoelectric component of bismuth doped with antimony and bismuth tellurium doped selenium wherein said components are arranged into a rod. Very low voltages are converted using a self-oscillating circuit.

U.S. Pat. No. 6,172,427 describes the use of a thermoelectric device on the exhaust portion of a combustion-based car using electrically drive wheel wherein excess heat energy is converted to electric power for the vehicle.

U.S. Pat. No. 5,515,682 describes a Peltier control circuit that detects a temperature of a device and controls a current flowing through the Peltier devices so as to keep the temperature at a predetermined value.

U.S. Pat. No. 6,418,729 describes a domestic refrigerator with Peltier effect.

U.S. Pat. No. 6,023,481 describes a Peltier element thermally coupled to the element having the temperature response, and a capacitance component electrically coupled to the Peltier element.

U.S. Pat. No. 6,055,814 describes a method of and apparatus for cooling an operating system using Peltier effect when the temperature in the system is above a certain level, heat in the system is absorbed by a Peltier module utilizing a Peltier effect.

U.S. Pat. Nos. 6,246,100 and 6,399,872 describe a thermal coupler utilizes Peltier heating and cooling to transmit a thermal signal across an electrical isolation barrier

It is a purpose if this invention to improve energy to cooling conversion over low efficiency electrically driven compressor type air conditioning systems. This is accomplished by taking utility grid alternating current, rectifying this current, converting it to high frequency alternating current which drives a voltage down-converting transformer to produce high current, then rectifying this high current to produce multi-ampere direct current in a torus thermoelectric chiller. Fluid, gas, or air to be chilled is passed over the cold fins to get the chilling effect.

It is a further purpose of this invention to provide a physical or electronic means to exchange the direction of flow of current thereby switching from a cooling effect to a heating effect without moving the arrangement of the thermoelectric chiller.

DISCLOSURE OF THE INVENTION

To illustrate this invention figures are drawn to show components of a few implementations of the invention. It should be understood that these figures do not in any way limit this invention as described in the claims.

The invention comprises an energy source producing current that passes through a plurality of thermoelectric coupons arranged in a ring, a means for extracting heat energy from one side of said ring through hot fins and a means of sinking heat through cold fins using fluid, gas, or air circulation. Electrical energy in the form of current is circulated through a plurality of coupons causing heat to flow from the cold fins through the P- and N-type coupons to the hot fins caused by the Peltier effect. The current, induced by any of a number of means causes the hot fins to become hotter and the cold fins to become lower in temperature. The term coupon is used herein to identify the combination of hot fins, cold fins and constituents attached thereto. Multiple coupons are assembled to make a ring. The ring conformation is important in reducing significant losses that would otherwise occur if a conductor were used to electrically connect ends of a linear array of coupons.

The current source can be any of a myriad of means. One such is direct connection to the utility grid, where the electrical energy is transformed into low voltage at high current by a switching power supply that powers said torus thermoelectric chiller directly. Two examples are push-pull and forward converters. In a preferred embodiment a switching power supply modulates current using a primary winding with center tap for push-pull operation and secondary high current windings are used to modulate current flow. The switching power supply may be modified to provide variable output. Dc current can also be obtained using a step down transformer with rectified output. Modulation can be accomplished using a powerstat, a manual electric range burner control duty cycle element or a programmable triac and other means. Electric energy can also be obtained from other generating sources such as an internal combustion powered generator.

In a preferred embodiment the current is derived from a fuel-powered thermoelectric torus generator that is heated by combustible materials such as gases of hydrogen, methane, ethane, propane, butane, etc, liquids such as gasoline, kerosene or crude oil, and solids such as wood, used tires, straw and other celluloid materials and coal. In addition the heat needed for electricity production can come from concentrated sunlight. Waste heat from other combustion activities can also be used such as the exhaust of another thermoelectric torus generator producing electricity for another application.

Several means can be used to generate heat in a thermoelectric generator to produce current needed for the torus thermoelectric chiller. Hot gasses are passed over the hot fins of the current generator to heat them. In a preferred embodiment gas or liquid is combusted directly under the hot fins. In another preferred configuration the hot fins project inward with regard to a circle or torus of coupons and the hot gas is passes through or combustion occurs adjacent to the hot fins of the current generator.

In another preferred embodiment the rate of fuel combustion is controlled to match the current demand of the chiller.

In the case of gas or liquid being combusted near the hot fins it is preferred that infrared radiation which passes through or is given off from the hot fins is radiated back on the hot fins by a reflective metallic dome.

In another preferred embodiment the thermoelectric generator current driver for torus thermoelectric chiller uses an insulating layer that backs the reflective dome.

In one form of the invention an opening is made in the top dome of the thermoelectric current driver to allow hot gas to escape.

A preferred embodiment of the invention is to directly combine a heat dependent thermoelectric generator with a thermoelectric chiller. In this case, current generated in the torus being heated at the hot fins is transferred directly to the torus of the chiller.

By regulating the temperature of hot fins of the chiller component a temperature lower than would occur otherwise in the torus chiller component is achieved. By regulating the temperature of cold fins of the chiller component a hot fin temperature higher than would occur otherwise in the torus chiller component is achieved.

In another preferred embodiment hot gases escaping from a first thermoelectric generator are conveyed or allowed to move into a second thermoelectric generator wherein current produced in said second thermoelectric generator directly powers a torus thermoelectric chiller component. This hybrid version having two thermoelectric generators includes a means to allow excess heat to be removed from a first thermoelectric generator. This may be as simple as creating an opening in the top of a reflective dome in the combustion chamber. Alternatively a fan can be used to move hot air through a duct to the thermoelectric generator providing current to the chiller component. The amount of fuel being provided to the first thermoelectric generator can be controlled by manual means. For example a variable fuel pressure regulator can be manually adjusted to the desired amount of electrical energy output. Liquid fuel sources can be similarly modulated with similar liquid feed controls. Also many fuels can be electrically controlled with fuel-injector-type control valves.

In a preferred embodiment fuel is digitally controlled by opening and closing valves with fixed fuel flow capacity in ratios of 1:2:4:8. Fuel amounts from 1 to 15 can be controlled depending on which valves are open or closed under digital control.

In another preferred embodiment a physical means is provided to exchange hot output and cold output in said chiller hybrid to allow an environment that was otherwise chilled to be heated and an environment that was heat to be chilled. This feature allows the switching from heating to cooling for a fixed ducted system. Thus if heat were being dumped to the outside of a building while chiller air were being circulated within a house and the need arose to heat the house, this means would cause hot air to circulate within the house while cold air was dumped to the outside.

In another preferred embodiment cold liquid gas, or air from a first thermoelectric chiller is directed to the hot fins of a second electrically driven torus chiller to increase the effectiveness of the chiller overall by increasing the differential temperature in a cascaded manner. An efficient method-combining element is to have the cold fins of a first chiller in common with the hot fins of a second torus thermoelectric chiller element. One implementation of the cascade thermoelectric chiller utilizes current from the utility grid. Current from the grid is utilized in the same manner as for a single stage torus thermoelectric chiller. Current can be directed to an ac/dc high frequency down converter by one or more connections to the grid.

Another preferred embodiment of the chiller invention is a cascade of components including torus thermoelectric generators. A principle version is a torus thermoelectric chiller driven by two thermoelectric generators. Greater temperature differential can be obtained by combining more stages of chiller and power sources.

A unique method is used to direct the high current flowing in the thermoelectric chiller. An insulator is used to force current around the ring. This insulator is placed between any two coupons. On each side of the insulator is a conductor terminal, which extends outward from the torus of coupons. The conductor terminals of the chiller are connected directly to the thermoelectric generator terminals. The current driver terminal may be a fuel powered current ring or the terminals of a down-switching power supply driven from the utility grid. Another embodiment places low impedance, electrically alterable switches between the secondary of the current driver and the electrically driven torus thermoelectric chiller. This allows a change in the direction of current in the thermoelectric chiller and therefore the direction of heat flow. Also it modulates the heat flow in the torus thermoelectric chiller by alternately transferring heat in either one way or the other, some time one way and the balance in the other direction for modulation, or no heat flow under thermostatic feedback control or by manual means.

In a preferred embodiment current flow is controlled in one or the other direction by MOSfet switches inserted in the secondary circuit that connects current driver and thermoelectric chiller component to serve as an electrically alterable current direction switch. This modulates heat flow and serves as a summer-winter switch in the case of home heating and air conditioning, eliminating eight electromechanical valves otherwise required to redirect the fluid lines serving the chiller. The number of MOSfet switches employed in a torus thermoelectric chiller component is determined by the maximum thermal gradient generated by the chiller ring and depends on the current producing capacity of the current driver and the current carrying capacity of MOSfet switches used for heat flow reversing.

In another preferred embodiment a pulse-width modulator chip is used to alternately control MOSfet switches to alternately drive rectified utility current in the primary winding of the down-converter as a push-pull topology. The secondary high current winding of the current driver consists of two center-taped turns, the center-tap connected directly to one terminal of torus thermoelectric chiller component the ends connected to the other terminal of torus thermoelectric chiller component through MOSfet switch banks controlled synchronous by the signals of the primary pulse-width modulator chip to deliver secondary current to the torus thermoelectric chiller component in one direction or the opposite direction if pulse-width drive signals are changed from one MOSfet switch bank to the other. Alternate switch connections for MOSfet switch bank drive can be made by electronic means to reverse the direction of current flow of the secondary current in the torus thermoelectric chiller component changing the direction of heat flow in the chiller component. If a simple oscillating circuit is used, current input to the chiller cannot be modulated by pulse width and the heat flow in the chiller will be at full capacity. The number of windings needed in the primary of the down-converter primary depends on the secondary current required to drive the electrically driven torus thermoelectric chiller component, typically 1,000 Amperes, and can be determined by those skilled in the electronic arts.

There are other means of modulating input current to torus thermoelectric chiller driven by utility grid. This involves intermittently selecting a 220 vac input winding in the down converter, or using 120 vac to power this input winding, or by providing open circuit control to the primary winding.

Another means of controlling the heat flow in torus thermoelectric chiller is to reduce cooling to the hot fins. This is done by reducing the fan or fluid pump flow across the hot fins under feedback control from a thermostat. This causes the cold fins to be less effective because the hot fins have a higher thermal gradient to push against to expel heat. In versions having a leak proof chamber of hot fins and cold fins fluid flow is controlled by the speed of a pump moving fluid in the same manner.

Transfer of heat by electrical current flow is improved in a closed loop thermoelectric device by utilizing a combination of n-type and p-type semiconductors. These produce a high Peltier effect thereby producing a higher heat flow for torus thermoelectric chiller component producing a given thermal differential. The temperature differential is a function of current and the ability of the air, gas, or fluid medium to carry heat. As a rule of thumb, for 5-kW of electrical energy into a torus thermoelectric chiller, the heat flow would be 60,000 BTU/hr and the temperature differential can be adjusted to between 10 C to 200 C. The differential temperature depends on air, gas, or fluid flow around the fins. Example 1 shows performance characteristics for a typical electrically driven torus thermoelectric chiller component. Btu/hr data were calculated using the mass of copper and the temperature differential heat change with time for a particular current flow.

EXAMPLE 1

Performance Characteristics for One Coupon of a Current Driven Chiller

[0041]

Current Btu/hr

0 Amps 0

1 Amp 2

10 Amps 20

100 Amps 208

250 Amps 440

500 Amps 825

700 Amps 1,098

1,000 Amps 1,468
Tight junctions, very low levels of contaminating elements, single crystals and special surfaces are required to produce a uniform device. [0042]
Driving high current energy around a circle of thermoelectric elements or coupons requires a special drive system made up of a utility fed down-converter to produce the high currents necessary and rectification of this current into dc. Another means is to make use of a gas-powered, steam or exhaust powered thermoelectric generator ring to supply high current to the thermoelectric chiller. An important feature involved in the extraction of electrical energy is an electrically alterable dual MOSfet switch bank connected in the secondary windings of the current source and the thermoelectric chiller ring. This allows current reversal in the thermoelectric chiller ring and likewise a change in heat flow direction due to electronic switching. [0043]
The dc current used by the thermoelectric chiller can be obtained from batteries. Batteries in turn can be recharged by various means including solar radiation. In this case the optimal voltage needed by the thermoelectric ring is provided from batteries such as lead batteries using a dc-dc down converter. [0044]
This thermoelectric chiller is very quiet when running thus providing an opportunity to replace noisy electromechanical and gas driven absorption refrigeration systems and appliances. [0045]
There are a variety of ways that heat can be exhausted to an environment or cold transferred to an environment to accommodate particular needs. A simple version uses a fan close to hot fins or cold fins to blow hot or cold air away to a nearby environment. In a version with leak proof chambers either a gas or liquid can move heat from a chamber to another environment for heat exchange. [0046]
To provide these benefits details are given for making and using a simple circular collection of coupons. Each coupon is made by alternating a hot fin, that is a metal fin to be heated, an n-type semiconductor, then a cold fin, that is a fin that is heat reduced by the current flow or allowed to cool, then a p-type semiconductor. Such coupons are place in registry, that is hot fin, n-type, cold fin, p-type, hot fin, n-type, cold fin, p-type and so on until a circle is completed. When the fins are made flat, a wedge piece is added to produce continuity to the circle. A single insulator is placed in the circle across which current is injected and removed as desired. A heat flow is produced when current is passed around the ring and one set of fins become heated while the others are reduced in heat, that is cooled by the current flow. This heat flow is proportional to the current flow in the ring causing a temperature differential between heated hot fins and the fins being cooled. [0047]
Useful heat capacity depends on the number of coupons and the differential temperature of hot and cooled fins while an air, gas, or liquid flows to supply and remove heat from the thermoelectric chiller. [0048]
For clarity of the disclosure and definition of the claims the following terms are defined: [0049]
“Semiconductor” means: a mixture of one or more elements that has the property of allowing either electrons or holes to move through the mixture depending on whether the mixture has an excess n-type or p-type dopant. The semiconductor nature of thermoelectric wafers is well established in the thermoelectric literature. [0050]
“Torus thermoelectric chiller” means a circular array of n-type and p-type semiconductors and plated fins wherein electrical current is introduced to the ring to cause one set of fins to become hot and the other to become cool depending on the direction of dc current. The chilling function is emphasized but both the cooling and heating effects can be utilized. [0051]
“Fin” means: an elongated metal slab with optional tapered end which is connected on one side to an n-type semiconductor and on the other side to a p-type semiconductor or on either side to a conductive wedge. [0052]
“Cold fin” means: a fin to be cooled or a fin to be allowed to cool in a thermoelectric generator and a fin to receive heat from gas or liquid in a thermoelectric chiller. [0053]
“Hot fin” means: a fin that is to be heated in a thermoelectric generator and a fin from which heat is extracted in a thermoelectric chiller. [0054]
“Coupon” means a repeating component of the thermoelectric device made up of at least one n-type semiconductor, one hot fin, one p-type semiconductor, and one cold fin. In the device having a wedge component with each set of fins and semiconductors a coupon includes the wedge component. [0055]
“Kester's solder” means: lead free solder paste containing tin, copper and silver. [0056]
“Belleville disk spring” means: deflecting washers that maintain constant compressive pressure through thermal expansion and contraction of other members. [0057]
“Wafer” means: an n-type or p-type semiconductor made in the shape of thin slab where the thickness of the shortest dimension is from 1% to 20% of the either of the other dimensions. [0058]
“Wafer side” means: the surface area denoted by the larger dimension of the wafer. [0059]
“Wafer edge” means: the surface area denoted by the smallest dimension and one or the other dimensions. [0060]
“Current driver” means: a source to provide current input to one or more thermoelectric chillers. [0061]
“Torus element” means: the thermoelectric ring. [0062]
“Component” means either the thermoelectric generator or the thermoelectric chiller in a thermoelectric hybrid or combination. [0063]
Before describing how to produce the invention figures are provided that illustrate working versions. Examples are intended to illustrate the basic principles and elements of the device and is in no way is intended to limit the scope of the invention as described in the claims. [0064]
FIG. 1 illustrates a p-[0065] type 1 and an n-type 2, crystalline wafer. These wafers are made by casting the n-type or p-type semiconductor material.
FIG. 2 illustrates an exploded view of the elements consisting of a [0066] cold fin 3, a hot fin 4, a p-type crystalline wafer 1 and an n-type crystalline wafer 2 along with a wedge 5 that comprises a coupon of the invention.
FIG. 3 illustrates an assembled view of the elements of the coupon and the relative position they will occupy when they are assembled as a complete coupon. p-[0067] type crystalline wafer 1 positions to one side of cold fin 3, which has a layer of solder paste in the region where the p-type wafer 1 will bond to cold fin 3. Cold fin 3 has a layer of solder paste on the opposite side in the region where n-type wafer 2 will bond on cold fin 3. Hot fin 4 has solder paste in the regions that will bond it to the wedge 5 and to n-type wafer 2 completing the coupon. FIG. 3 illustrates the final positions of the elements of the coupon seen in FIG. 2, 62 of these coupons are used in the completed thermoelectric ring illustrated in FIG. 4. This number can be varied depending on the operating current and voltage of the power supply. The Peltier effect also determines how much heat flow is produced for a given current and the current also determines the temperature differential between the hot and cold fins. It should be understood that the cold fins need not be directed at 90 degrees to the hot fins. Furthermore it is possible to fashion the shape of either the hot fin or the cold fin or both to preclude the need for a wedge component.
FIG. 4 illustrates the assembled [0068] thermoelectric chiller ring 6, made up of 62 coupons of FIG. 3, along with two special cold fins 7 and 8. One of these is an extra cold fin used to allow a cold fin rather than a hot fin for connection to an ac-dc high frequency down-converter. Alternatively the extra cold fin is connected directly to the terminals of a high current thermoelectric generator. These cold fins are separated by an insulator preferably a mica insulator, 9. The purpose of the cold fins and mica is to provide terminals for the ac-dc high frequency down-converter or high current thermoelectric generator connections. The mica insulator breaks the electrical circuit of the ring and allows the current to travel around the ring and flow back into the negative terminal of the current supply. In FIG. 4, the cold fin 3, the p-type wafer 1, the hot fin 4, the n-type wafer 2, and the wedge 5 can be seen in their assembled position, like coupons repeating all the way around the ring with the single interruption of the substitution of two cold fins 7 and 8 separated by insulator 9.
FIG. 5 illustrates how the [0069] strap 10 fits around the top portion of the ring to compress the elements by the tensioning of the strap with bolt 11. The tension on the strap, and likewise the compression of the elements is maintained at operating temperatures as well as at ambient temperature by a series of Belleville washers 12, compression maintained at approximately 500 pounds on the strap 10. In FIG. 5, the tips of hot fins converge at the center to leave a hole in this configuration that can be plugged.
FIG. 6 illustrates a cross section of a current driven version of the [0070] thermoelectric chiller invention 13. A double bowl 14 is insulated with heat barrier material between the bowls. This serves to prevent heat from flowing from the hot chamber 15 of the thermoelectric chiller into the cold chamber 16 while allowing a gas or air or fluid to heat exchange with the hot fins. Inlet pipe 17 and outlet pipe 18 allow air, gas, or fluid to enter the hot chamber to heat exchange with the fins. Inlet pipes 19 and outlet 20 allow a gas, air or fluid to enter the cold chamber 16 to heat exchange with the cold fins. The double insulated bowl 21 and 22 in combination provide structural integrity when bowl flange 23 is bonded to ring 6. This is important to maintain the thermoelectric chiller ring in a circle, thus preventing it from going egg-shaped and failing in the electrical conductivity mode. Welded together bowls 21 and 22 are bonded to chiller ring 6 with room temperature vulcanizing rubber, such as General Electric high temperature silicone adhesive. This material is also used to attach the cold fins 3 to the supporting ring 23. Lower liquid containment bowl 24 mounts to fiberboard ring 25 that connects to the thermoelectric chiller ring 6. This lower bowl 14 provides structural integrity for the thermoelectric chiller, a base for the system. Inlet- outlet pipes 17, 18 are welded to the upper double bowls 21 and 22. Inlet- outlet pipes 19, 20 are welded to 24 to receive and exhaust air, gas, or fluids from the thermoelectric chiller. Terminals 26 and 27 of the thermoelectric chiller 13 connect to the current driving power supply.
FIG. 7 illustrates one implementation of the thermoelectric chiller. The [0071] utility grid plug 28 provides power for the thermoelectric chiller and ac-dc high frequency down-converter 29. Normal 50 or 60 Hertz alternating current is first converted to direct current. Next the direct current is converted to a high frequency alternating current to prevent saturation of the ferrite core as described later with regard to FIG. 22. The secondary winding's high frequency ac is then rectified into high amperage direct current. The rectified high amperage current produces heat in the hot fins and cools the cold fins in a unit as described as 13 in FIG. 6. The inverter 29 is driven by a PC board 30 and cooled by blower 31 driven by motor 32. Inverter 29, board 30 and blower 31 and motor 32 are encased in a metal case 33 and together comprise a power supply unit 34.
In a preferred embodiment all fins are assembled vertically in a [0072] thermoelectric chiller 35 so as to facilitate flow of a gas, air or fluid across the fins as shown in FIG. 8. Diaphragm 36 separates the gas, air, or fluid of the hot chamber 37 from the cold chamber 38, having insulating properties to reduce heat flow. Flange 39 is a support around the ring. Inlet 40 and outlet 41 allow a gas, air, or liquid to cool the hot fins in the hot chamber 37. Inlet 42 and outlet 43 allow a gas, air or liquid to exchange heat in the cold chamber 38. Baffle 44 seals the end of the hot fins 4, and baffle 45 seals the ends of cold fins 3. Current from the utility grid-driven down converter 29 in 34 enters the chiller 35 through leads 46 and 47.
FIG. 9 illustrates another preferred implementation, a thermoelectric chiller, thermoelectric generator hybrid. Current for the chiller component is obtained from a gas-powered [0073] thermoelectric generator 48. In FIG. 9 generator 48 is illustrated in cross section. This is a version of a gas or liquid combustion generator. 49 shows a burner bowl with attached perforated metal 50 that holds mesh 51. This serves to prevent incoming air-fuel mixture from combusting before entering the combustion chamber. Inlet pipe 52 allows an air-fuel mixture to enter the burner bowl. Support ring 53, an insulator, lifts the generator ring so that burner inlet pipe 52 can pass underneath without having to shorten any of the cooling fins 3. 54 is a top burner bowl with an exhaust vent 55 that is attached to the ring 6. 54 is a larger, outer bowl that serves to give the ring 6 strength when welded-together in double-bowel combination. FIG. 9 illustrates an air blower 56 open to the top and driven by motor 57 with power cord and plug 58. Output terminals 59 and 60 from the thermoelectric generator are ohmically connected to cold fins 7 and 8 of chiller component 35 by brazing, welding or soldering.
In a preferred embodiment the output terminals [0074] 59 and 60 are tapped to provide some electricity for ancillary or control systems. A standard dc to ac converter provides one or more ac or dc voltages needed to drive electrical parasitic operation.
In a preferred embodiment hot gas used to power the thermoelectric portion of a thermoelectric generator-thermoelectric chiller hybrid is produced in a remote combustion chamber. Hot gas from the combustion chamber is circulated over the hot fins of the thermoelectric generator. Chiller demand is controlled by restricting make up air while venting exhaust. In another preferred embodiment fuel addition is automated. The remote combustion chamber can also be used in a hybrid that produces both electricity for miscellaneous uses and current for the chiller hybrid. The benefit of a remote combustion feature is that many different sources of combustion can be used. Examples include coal, wood, agricultural byproducts, garbage and waste oils. [0075]
FIG. 10 illustrates another preferred implementation of the thermoelectric chiller hybrid utilizing exhaust heat from [0076] 61, a thermoelectric generator and part of the combination 62. In this case exhaust heat 63 of a thermoelectric generator 61 producing electricity for other purposes enters a second thermoelectric generator 64. This provides electrical current for the chiller component 35 in the same manner as in FIG. 8. The total device shown is a normal thermoelectric generator 61 having one or more voltage outlets, another thermoelectric generator 64 taking the exhaust heat from the first generator 61 and a third thermoelectric torus 35 which gets electrical current from said second generator 64 and thereby allows production simultaneously of electricity, and heating or cooling. This model of the invention has the cold fins and the hot fins vertically opposed. Use is made of either or both the hot section of the chiller component or the cold section of the chiller component in the same manner as a thermoelectric chiller driven by ac or dc current sources. Heat and cold are utilized in a variety of ways by passing a gas, or air or a fluid over hot fins and cold fins respectively and moving that gas, air or fluid to a heat exchanger or an environment to be heated or chilled. As with other versions of the chiller component a means is provided to electrically or mechanically reverse the current coming from the thermoelectric generator component. In this manner a fixed connection to a heat exchanger within a central air conditioning system need not be modified when switching from heating to cooling. Similarly this version of thermoelectric generator chiller hybrid utilizes a means to adjust the amount of heat flowing to the chiller component. For example a heated gas bypass can be installed to allow hot gas escaping from the first thermoelectric generator to by pass the second thermoelectric generator. This is especially useful if waste heat is being use to heat water.
In thermoelectric chiller hybrids where electricity is being produced in addition to heating and cooling the hybrid device is improved by adding a battery backup to accommodate immediate needs for electricity. This is accomplished by traditional methods of dc to ac conversion as discussed elsewhere. In some cases it is desirable to recharge the batteries from the utility grid so a means to connect to the grid and a means for converting ac to dc needs to be provided. [0077]
FIG. 11 illustrates a steam, hot gas, hot air or hot fluid driven thermoelectric generator combined with a [0078] thermoelectric chiller 35. This torus thermoelectric generator 65 is comprised of ring 66, hot fins 4, circular array of n-type and p-type semiconductors, 1,2, diaphragm 67 in the center of the ring separates the hot chamber 68 from the cold chamber 69, flange 70 which extends in the plane of the diaphragm around the rim, hot chamber enclosure 71, cold chamber enclosure 72, hot baffle 73, cold baffle 74, hot inlet pipe 75, hot outlet pipe 76, cold inlet pipe 77, outlet pipe 78, and current transfer terminals 79 and 80. Current produced in said generator 65 when heated and cooled is transferred to a torus chiller component 35 through current terminals 81 and 82. The connection between the generator and chiller must be an ohmic connection, accomplished by brazing, welding or soldering. The torus thermoelectric chiller 35 can be identical to the thermoelectric generator 65. Alternatively the chiller component can be made larger or smaller by varying the number of fins, thickness or cross section of the semiconductors, or size of the fins. In a preferred embodiment enclosures 71 and 72 are insulated.
Hot gas for the compartmentalized chiller hybrid may be any of a variety of heat exhaust sources. Example include automobile exhaust, air circulating around a hot engine, gas from a remote combustion chamber, steam exhaust, and gas turbine exhaust. [0079]
In a preferred embodiment remotely generated hot liquid heated in a boiler-type appliance is used to power the thermoelectric portion of a thermoelectric generator-thermoelectric chiller hybrid. Hot liquid from coils in the combustion chamber is pumped through [0080] inlet 75 over hot fins 4 of the thermoelectric generator 65 illustrated in FIG. 11. Chiller demand is controlled by restricting make up air while venting exhaust or by controlling fuel addition. The benefit of a remote combustion feature is that many different sources of combustion can be used. Examples include coal, wood, agricultural byproducts, garbage and waste oils.
Alternatively, hot gas from a remote combustion chamber is circulated or passed through [0081] 75 in FIG. 11 or in lieu of combustion gas in FIGS. 9 and 10.
FIG. 12 illustrates a three component cascade thermoelectric chiller hybrid. Current is produced in [0082] thermoelectric generators 84 and 85. These generators are the same as 65 shown in FIG. 11. The chiller component 83 is a cascade of two thermoelectric rings that share common intermediate fins 86. The chiller component is comprised of ring 87, hot fins 4, and circular array of n-type and p- type semiconductors 1,2. Diaphragm 88 in the center of the ring separates the first hot chamber 89, from the common chamber 90, flange 91 which extends in the plane of the diaphragm around the rim, a second diaphragm 92 which separates the common chamber 90 from the chilled chamber 93, cold chamber enclosure 94, hot baffle 95, cold baffle 96, hot inlet pipe 97, hot outlet pipe 98, cold inlet pipe 99, outlet pipe 100, current transfer terminals 101 through 108. Current produced in both generators, 84 and 85 when heated and cooled is transferred to the torus chiller 83 by connecting terminals 105 to 101, 102 to 106, 108 to 103, and 107 to 104. The connections between the generators and cascade chiller must be ohmic connections with lowest resistance possible. This is accomplished by keeping leads as short as possible and by brazing, welding or soldering connections. A single generator of the 84, 34, 48 or 64 type or more than one 84, 34, 48 or 64 type generator can drive the thermoelectric chiller component 83. While shown in FIG. 12 with long leads from 85 through 107 and 108 to chiller component 83, the preferred arrangement is for 85 to be connected to 83 with leads as short as possible.
In a preferred embodiment common hot fins [0083] 86 in section 90 are replaced by overlapping fins, a first set extending opposite from fins 4 of section 89 and a second set extending opposite from coldest fins 3 in section 93. In another preferred embodiment an insulator is inserted between both sets of overlapping fins to reduce the likelihood of an electrical short. To improve performance a heat conducting, electrical non-conducting liquid is contained in chamber 90. This arrangement allows thermoelectric generator 85 to connect through leads 103 and 104 opposite to leads 101 and 102. In multiple cascades serial thermoelectric generators can be arranged at 90 degrees to one another thereby keeping current connections as short as possible. It is also possible to have a cascade chiller effect by pumping a gas, air or a fluid between to physically separated chiller components wherein fluid is circulated between the cold fins of a first chiller component and the hot fins of a second chiller component. This can be continued in the same manner for three or more chiller components.
As with other chiller configurations dc current needed to drive the chiller can be obtained from the utility grid ac by a switching power supply which converts 50 or 60 cycle ac to higher frequency as current and then to dc current. This switching power-supply can be modulated to vary the output current and thereby control the amount cooling. Control can also be maintained using a powerstat, or triac or manual electric range burner control duty cycle element. [0084]
The compartmentalized version of the thermoelectric chiller can be run from current supplied by a thermoelectric generator or by electricity from an internal combustion generator. [0085]
Many other sources of heating or cooling can be used to power the thermoelectric generator portion of thermoelectric chiller hybrids. Examples include coal gas, biogas, methane, propane, ethane, and gasoline. [0086]
In thermoelectric chiller hybrids that provide electricity in addition to cooling and heating it is preferred to have one or more batteries to provide energy while the thermoelectric generator is powering up. Ac current is provided by traditional means of converting dc to ac. [0087]
FIGS. 1 through 12 illustrate preferred forms of this invention being a tabletop type arrangement. It should be understood that the general nature of the thermoelectric devices could be fitted to many forms, uses and sizes. By tapping current from leads [0088] 59 and 60 in FIG. 9, ac or dc energy can be made available in addition to cooling. For example the arrangement as described in FIG. 9 can be made to be carried in a back pack allowing the user to carry around a source of 120/240 volt alternating current while at the same time providing refrigeration and freezing capability for portable and stationary environmental enclosures. Such a backpack would allow the use of tools that normally run on alternating current while providing refrigeration, climate control and safe storage for food and medical supplies. Still smaller versions could be used to replace a battery pack and satisfy the refrigeration requirements of instrumentation. Such a backpack version could replace rechargeable batteries and could be used with standard rechargeable battery tools that can benefit from cooling.
In a preferred embodiment a hybrid thermoelectric chiller device and mechanical tool is constructed which comprises an electric motor to drive the mechanical tool and a chiller to provide cooling. An advantage of the hybrid tool is that feedback from the tool can be used to control the rate that fuel is burned and the cooling rate. An example is the use of a hybrid system for electricity to drive a cryostat and for cooling to freeze tissues to be sectioned. This would be useful in obtaining pathology forensic slides in the field. In another preferred embodiment a general version of said hybrid tool has a uniform thermoelectric component that is fitted to a variety of mechanical components where refrigeration is beneficial. This feature allows a single hybrid thermoelectric component to be exchanged among several tool types. Another example of hybrid use is for cutting brick and tile. Electricity drives the diamond-cutting wheel while cooling is provided for the water used to wet the cutting blade. [0089]
FIG. 13 illustrates a variation of the utility powered thermoelectric chiller of FIG. 8 where air passes over the heating fins circulated by [0090] motor 109 driving dual blower 110. This device 111 is powered by utility plug 112 through diode bridge and push-pull driver 113, which drives the primary winding of a down-converter transformer 114. Current from the down-converter powers the thermoelectric chiller through terminals 115 and 116 to heat the hot fins and cool the cold fins. Enclosure grill 117 is used to cover the cold section 118 and diaphragm 119 separates the hot section 120 from 118. Baffle 121 separates incoming air to the hot chamber 120 and the exit air. The unit 111 is a self-contained reversible heating and cooling device that has utility as a climate control device.
FIG. 14 illustrates the application of a [0091] 111 thermoelectric chiller in the ceiling and outside wall of a home 122, an office or commercial building. The heat given off by the chiller device 111 when mounted in the ceiling can be drawn out of the attic space with an exhaust fan 123. In the case of the outside wall mounted chiller device 124, ambient air is used to remove heat from the hot fins and the heated air is exhausted to ambient. Unit 124 can also be window mounted. Both units 111 and 124 are receiving power from electrical plug outlets 125 and 126. Thermostats 127 and 128 control units 111 and 124.
FIG. 15 illustrates the installation of a [0092] 111 thermoelectric chiller in existing climate control ducts as shown for ductwork 129 and 130 in the attic 131 of a building 132. The original air conditioning and heating system 133 can remain in place with the 111 thermoelectric chiller installed in ductwork 130 and connected to electrical power plug 134 and thermostat 135. Inlet/outlet air grills are shown as 136, 137, 138 and 139 to provide climate control for room 140 and 141. This technique can be used in new construction or retrofitted to existing systems.
FIG. 16 illustrates the front and side view of a packaged [0093] unit 142 that can supply the electricity, hot water, air conditioning and heating for existing buildings or new construction. 142 is designed to fit into places where floor space is at a premium or to be hung on a wall inside a building or mounted outside any floor of the building. The idea is to be able to provide all the utilities for a building without having to rewire or re-plumb the building. All that is needed is a single fuel supply such as a natural gas or propane gas pipe. 142 uses a battery bank 143 powering an inverter 144 that connects to the dc side of the thermoelectric generator 145. The battery bank 143 and inverter 144 can be charged by the utility grid or the generator, providing the building or facility with high reliability even during grid failure. Using the battery allows the generator 145 to go to sleep at night when electric loads are low, restarting during morning when loading increases, using fuel controller 146 to burn minimum fuel to run at the edge of current requirements. Exhaust heat current driver 147, similar to 64 in FIG. 10 produces drive current to power the thermoelectric chiller 35 to air condition the premises. Water heater 148, heated by waste heat supplies re-circulating hot water throughout the premises with circulating pump 149. Switch 150 is an A-B switch that allows the user to select power from the grid or depend on the packaged system 142 for all power needs. The last stage of the exhaust exits vent 151. 152 shows brackets for floor mounting.
FIG. 17 illustrates the preferred embodiment as a closed and opened door floor mounted or [0094] wall hanging unit 142. Air ventilation for the cabinet is through grill 153.
FIG. 18 illustrates the system of FIG. 17 configured as a flowerbed model, to be installed outside the residence or building, or on the roof with [0095] water heater 148, pump 149 and exhaust vent 151 mounted external to the cabinet 154. Air ventilation is through grills 155. The unit has self-supporting foundation 156.
FIG. 19 illustrates the unit of FIG. 18 with [0096] foundation 156, fuel control 146, thermoelectric generator 145, exhaust driven thermoelectric current source 147 for thermoelectric chiller component 35, the battery bank 143 drives the inverter-up-converter 144 from the utility grid or the bank 143 is charged directly from the generator. The inverter-up-converter 144 connects to the generator's dc bus to peak shave until the generator can increase heating and assume the full load, approximately 30 seconds or less. The flowerbed model is a configuration that is traditional for Freon and absorption air conditioning and heating applications on the United States. The wall hanging unit of FIGS. 16, 17 will find utility in older buildings where they can be mounted on an outside wall, above the ground. In the case where the unit is mounted two stories or higher, a small balcony or veranda, accessible through a window would provide a means for servicing the thermoelectric generator-chiller hybrid 142 and could serve as a balcony for the residence.
FIG. 20 illustrates a solar version for powering a thermoelectric current driver that powers a [0097] thermoelectric chiller component 35. Motor 157 and blower scroll 158, cool hot fins 4 as in hot section 120 of FIG. 13. Solar energy is collected by reflective cone 159 and focused on hot fins 4 of thermoelectric generator torus 6. Blower 160 circulates air to cool cold fins 3 of the generator ring 6. Cold fins are shielded from solar radiation 161. The complete assembly 162 can be mounted to track the sun and thereby use the collected solar radiation to provide air conditioning and refrigeration for a process, home, office or building. This 162 works best when air-conditioning loading is high at midday. In addition to the use of cones to focus sunlight on the thermoelectric generator portion of the thermoelectric generator/chiller hybrid, sunlight may be focused by a lens situated over the thermoelectric generator or by surrounding the thermoelectric generator with a reflective dish which focuses the sunlight on a second dish situated in the focal path of the first dish and reflecting sunlight on the hot fins of the thermoelectric generator.
FIG. 21 illustrates a solar [0098] air conditioning device 162 mounted on a sun-tracking mount 163, maintaining 162 pointing to the sun by actuator device 164. A water-glycol mixture, or any other suitable fluid is circulated through the thermoelectric chiller component 35 and then piped through a pipe loop 165 through building 166 where coil 167 is used to cool the inside air of building 166. The fluid is then returned to the chiller component 35 to have heat in the fluid expelled to ambient air and fluid refrigerated. The return fluid in one embodiment is delivered to insulated tank 168 with insulated cover 169 to serve as cold store. Fluid 170 can be water, glycol, water-glycol, brine, or any other suitable fluid. Fluid then exits tank 168 through circulating pump 171 to thermoelectric chiller component 35. Using cold storage tank 168, the building 166 can be cooled well after sunset by circulating fluid that was refrigerated well below ambient during daytime operation. FIG. 21 shows two solar units 162 with chiller component 35 operating in tandem. 162 can also be used with individual loops and operated with fluid from a single loop operated in parallel. Another variant uses liquid cooling to replace the blower and motor air cooling of the hot fins 4 as with the chiller component 35 in FIG. 11. An alternative means to provide solar heated hot fluid to the thermoelectric generator is to place a metal tube in the center of linear parabolic reflective member which is located in an east-west axis. As the seasons change the angle to the sun is adjusted. As the sun rises, passes across the sky to setting, sunlight is focused on the metal tube where it heats the fluid inside. A pump circulates the fluid to the hot fins of the thermoelectric generator portion of the thermoelectric generator/chiller hybrid.
FIG. 22 illustrates a [0099] chiller ring 6 driven by MOSfet drivers 172 controlled by pulse width modulator chip 173. This configuration uses ac power from the utility grid 174 or from other sources processed through bridge rectifier 175 into dc power to drive the primary winding 176. The magnetic core 177 couples the primary winding 176 with the secondary windings 178 and 179. MOSfet switches 180 and 181, controlled by pulse width modulator chip 173 driving through double-pole-double-throw switch 182 switch secondary windings 178 and 179 open or closed. The drive current directions in the secondary windings 178 and 179 are determined by switch 182 and timing of switches 180, 181. The direction of drive current 183 in the chiller ring 6 is always the same for a particular 182 switch mode setting. This is because of the arrangement of leads 184 connected to chiller ring 6. Drive current direction is due to the position of switch 182 and the timing of switches 180, 181. 182 describes a two-mode switch that determines the direction of heat flow across chiller ring 6. 185 is a side view of the switch-mode down converter that shows how drive terminals are connected in 184 to cause current to flow in one direction only 183 when switch 182 is in one mode or current in the opposite direction 186 when switch 182 is in the other mode. Electrically operated switch 182 can be used to control the average heat flow in chiller ring 6 by operating switch 182 in one mode for a longer or shorter period than switch 182 is in the other mode.
FIG. 23 illustrates an electrically [0100] alterable switching bridge 187 connected to secondary 188 controlled by electrical input 189 that determines the direction of current 190 and 191 in chiller ring 6. FIG. 23 illustrates chiller current reversal caused by control signal to lead 189 causing heat flow reversal when an ac input 174 is used to drive chiller ring 6. Secondary winding 188 produces an ac input to bridge 187 outputting dc current from bridge 187 into chiller ring 6 under electronic control of lead 189.
A preferred embodiment of the thermoelectric generator part of the thermoelectric hybrid uses hot fins coated with a combustion catalyst when combustion occurs at or near the hot fins. The n-type and p-type semiconductors play an important role in allowing high heat flow efficiency. Example 3 gives the range of elements and a preferred amount of elements making up the n-type semi-conductor. [0101]

EXAMPLE 3

n-Type Semiconductor Composition

[0102]

Element Range Preferred Amount

Selenium

5%-10% 6%

Bismuth

40%-60% 47%

Tellurium remainder to 100% 47%
Example 4 gives the range and preferred amount of the p-type semiconductor. [0103]

EXAMPLE 4

p-Type Semiconductor Composition

[0104]

Element Range Preferred Amount

Antimony

28%-30% 29.1%

Bismuth

8%-10% 9.5%

Tellurium remainder to 100% 61.4%
Copper and other elements greatly degrade performance of these semiconductor components therefore high purity elements are preferred. Each chemical element should be at least 99.9% pure and preferably 99.999% pure. In a preferred embodiment said elements are combined and melted to a temperature of about 700 degrees before being cast into a desired shape. [0105]
Slow cooling of the combined elements makes high quality semiconductors. A preferred size for the wafers is 1.5 mm thick by 2-cm by-2 cm. For ease of presentation the 2-cm by 2-cm sides are called faces and the 1.5-mm×2-cm sides are called “sides”. To achieve slow cooling combined melted semiconductor material is poured into a mold of the desired shape having the thin direction cast vertically, that is, sides are facing horizontally. In a preferred embodiment the wall of the mold is coated with hollow ceramic spheres obtained from fly-ash material that floats on water. The ceramic spheres are in the form of a powder that has relatively uniform size of less than 10 microns. Preferably the powder is held together in the mold by propylene glycol or milk of magnesia. In a preferred embodiment cast faces of the semiconductor are lightly smoothed using a belt sander with 100-grit aluminum oxide sandpaper. Properly cast wafers have a crystal grain size that microscopically appears to approach 2-mm. Transfer of electrons across the semiconductor is improved when some portions of the semiconductor are without a boundary barrier in the direction of flight of the electrons. [0106]
Semiconductors are protected from infiltration of copper atoms and components of solder by coating them entirely with a thin layer of nickel, ranging from 1 to 10 microns thick. The edges of the semiconductors are further coated with a non-conducting insulator to reduce heat conduction not progressing through the fin. In a preferred embodiment the coating is a high temperature polymer, such as Tempilaq, manufactured by Air Liquide America Corp. of South Plainfield, N.J. 07080, USA. The sides of the semiconductor are further coated with an additional thickness of nickel of at least 20 microns, preferably 20 to 30 microns. [0107]
In a preferred embodiment fins are made of copper. To reduce corrosion and prevent migration of copper into the semiconductor the fins are coated with metal more resistant to oxidation, preferably nickel. In a preferred embodiment the fins are tapered on the opposite end connecting to the semiconductor to allow complete metal filling of the circle. In another preferred embodiment the ends of the hot fins facing the center of the circle are tapered to reduce the likelihood of an electric short caused by fins touching. [0108]
An alternative approach to achieve uniform metal-semiconductor filling of the circle is to have straight ends on the fins and to insert coated copper wedges periodically around the circle. Preferably the copper wedges are coated with nickel and placed in registry with each coupon. [0109]
A single insulator is placed in the ring and preferably an additional cold fin with adjacent semiconductor. In a preferred embodiment the insulator is made of mica. [0110]
Placing solder between the surfaces of the fins and the semiconductors completes assembly the thermoelectric device. Preferably prior to assembly solder is applied to both sides of the hot and cold fins at a thickness of between 50 and 100 microns. Kester's solder is preferred but an additional 4% of silver needs to be added for optimal performance. [0111]
A considerable outward radial force occurs when current is applied to the hot fins and current flows in the torus. To prevent collapse of the device compressive force needs to be supplied. This is accomplished by tightening a metal strap around the device. To prevent shorting by the metal strap and insulating material is place around the ring before attaching the metal strap. Preferably the insulating wrapping is heat shrinkable polyamide. In another preferred embodiment the steel band is held in compression using one or more Belleville disk spring washers. These allow compression to be retained when the device cools. Non-metallic thermo-stable plastic can be used in lieu of a metal band with electrical insulator. Prior to assembly each coupon is tested for its thermoelectric activity. [0112]
After assembly and application of inward compression by the metal ban the device is heated. In a preferred embodiment the rate of heating is 10 degrees per minute to a temperature of 270 degrees C. The device is removed and allowed to cool in air. In another preferred embodiment the cold fins are positioned downward so any excess solder drips along the cold fins creating extra surface area for heat exchange. [0113]
In a preferred embodiment the thermoelectric chiller device claimed herein is combined with a mechanical compressor and air storage chamber to provide a portable, quite and efficient air compressor system for sanitary power tools, plus the ability to flash freeze foods or tissue being processed. [0114]
In addition to thermoelectric tools, which benefit from cooling the thermoelectric device disclosed here can replace other means of supplying energy with refrigeration to appliances. Thus a thermoelectric generator/chiller hybrid can be used to power a common household refrigerator or freezer while supplying electricity to power lighting, stoves, dishwashers and fans. Similarly, gas or liquid fuel can power electric stoves by utilizing a thermoelectric device that also chills and electrifies the appliance. Such appliances fitted to burn wood would be especially useful in remote areas where wood is abundant and electricity is not present, but refrigeration is always needed for food preservation and for creature comfort. As with thermoelectric tools thermoelectric appliances have the benefit of allowing feedback to control the rate of combustion and heat rate for refrigeration. [0115]
In another preferred embodiment a thermoelectric powered generator/chiller hybrid and water heater and water harvesting machine is designed to be affixed to the outside of an apartment, townhouse, condominium or the floor of an office to provide electricity, climate control and water independent of the building's services, needing only a fuel supply. Such a system will make retrofit of existing facilities easier providing an alternative to high cost, unreliable utilities and nuclear source power in Europe and elsewhere in the world. Various conservation of energy features of the thermoelectric chillers and chiller hybrids provide great diversity for implementing heating, cooling and energy storage systems. For example thermoelectric devices can be utilized in new housing construction. A basic version is the utility grid-driven central heat and air conditioning system. Placed in a closet, attic or basement, a grid-driven thermoelectric unit can utilize a short return air and minimum amounts of ducting. Waste heat can be utilized during the summer to keep water hot for bathing. The thermoelectric generator-chiller hybrid can be used in the home the same way, with electrical energy for the home provided by fuel combustion, air conditioning and heating requirements supplied from the exhaust heat. In this way, supplemental options can include not only the heating of sanitary water, but also the heating of a water reservoir as an energy store and the chilling of another store as a freezing water storage bank, this energy drawn out as needed to satisfy house requirements. Another option for the thermoelectric generator-chiller hybrid is a solar feature wherein a means is provided to concentrate sunlight to heat hot fins, thereby saving fuel. Still another option is in heating the hot fins using a separate or remote combustor or boiler that can operate with any fuel. Still a further option is to add a water electrolysis system, with a means to store hydrogen and oxygen. A thermoelectric system with solar collector can produce electricity as needed, with any surplus electricity converted into hydrogen gas during daylight hour. Later, the hydrogen can be burned to produce electricity while supplying environmental heating, cooling and sanitary hot water. Similarly, the thermoelectric generator, driving stand-alone versions of the thermoelectric heater-chiller components can also supply the electrical requirements of other applications. This variant, although less efficient than the hybrid form that produces drive current for the thermoelectric chiller component using only waste heat from the generator, is more versatile in that electrical output can be provided for many other purposes when heating or cooling is not needed. [0116]
A very important aspect of the thermoelectric chiller is that either or both the hot and cold fins can be used to produce energy storage. For example when a house needs to be heated and the chiller provides hot air to the house, cold liquid or air being circulated to the cold fins can provide water chilling or freezing, which a form of stored energy that can be utilized at a later time. Stored cold water can be used to condense water from high humidity air. This is especially useful in arid regions where the cooling of nighttime high humidity air allows the condensation of large quantities of moisture can be a source of pure water. [0117]
It is also possible to add to these systems a molten salt heat storage system. Excess heat from the chiller can be transfer to a storage reservoir and used as needed by extracting heat from the store by circulating fluid, air or gas through the store using a heat exchanger in the molten salt to supplement the performance of the thermoelectric chiller as needed. [0118]
Cooling applications, that use the utility grid to supply current to the torus thermoelectric chiller device, include environmental central air conditioning and heating systems, individual room cooling and heating systems installed in either the ceiling, wall or window mounted stand-alone configurations. In retrofit applications, the chiller can replace both the cooling and heating features of a failed system, by inserting one or more thermoelectric chiller-heaters into existing ducts. Individual rooms can also be climate controlled by placing units in the ceilings, walls or windows. [0119]
Utility driven thermoelectric chillers can be used in appliances. Refrigerators, freezers and combinations will be simpler to manufacture and cheaper to operate with a thermoelectric chiller in the top, another in the bottom or wall of the refrigerator or walk-in appliance. Thermoelectric chillers will operate quietly, more efficiently than electromechanical versions. A fan can circulate cold air inside the refrigerator-freezer while another fan removes heat from hot fins on the outside. Defrosting of these refrigerator-freezers is by simple current reversal. [0120]
In frozen food production applications, thermoelectric cascade chillers can freeze air that can then be poured over just-cooked food, assuring sealed in freshness. [0121]
Cold air or liquid, chilled by a thermoelectric chiller can be used as a dehumidifier in the home, business or institution. This means can be used for condensing outside moisture in the atmosphere to provide a water supply. In a preferred embodiment, chilled water is sprayed in droplet form through a flow of ambient high humidity air. Water droplets facilitate the condensation of water from the cooled ambient air, trapping the moisture as a water supply. [0122]
During winter months, by reversing the current flow in the thermoelectric chiller, it can serve as the heating source for the home, office or institution needs. For new or retrofit applications the same system used for cooling in summer can provide heat in the winter. This is accomplished by either reversing the direction of the current in the torus, or by reversing the input/output ducting of the torus chiller. [0123]
Heat from a thermoelectric chiller can be used for cooking. A hybrid appliance can be both a refrigerator and a stove in the same appliance, so that food can be kept cold until time for cooking, then the food cooked for a prescribed time, ready to be eaten at a pre-set time. This is accomplished by reversing the current in the chiller; fins of the thermoelectric that were chilling food so it now provides heat for cooking in the same chamber. Industrial thermoelectric chillers can be used to cook food on a continuous basis, with the additional feature that at the end of the cooking cycle the food can be quenched with liquid air harvested from a cascade version of the torus chiller to seal in freshness. The processed food can then be passed into a cold storage environment maintained by thermoelectric chillers that also provide the heat for cooking. Both heating and cooling possibilities are provided, at the same time, by the thermoelectric torus chiller. [0124]
A thermoelectric chiller can be used as a hot water heater while the cold fins provide a cold water energy store that can later be used as a cold bank to enhance the performance of the same or other chillers. [0125]
The above-described applications apply the same for direct current-driven, waste-heat-driven, and grid-driven thermoelectric chiller systems. The same advantages and applications mentioned above apply to thermoelectric generator-chiller hybrids having soldered or brazed tight electrical connection between the generator and chiller. An added feature of the generator-chiller hybrid is that some of the electrical energy from the torus can be taped from terminals between the generator and chiller and used to power fans and electronic controls, making the unit independent of outside electrical power source needs. [0126]
When electrical energy is needed for a household, along with environmental heating, cooling, and sanitary hot water, the thermoelectric generator, with a waste heat-driven thermoelectric generator-chiller hybrid is the preferred variant. This version can be used to operate a stand-alone clothes washer-dryer combination appliance. Electrical energy for this appliance is produced in the first generator to drive motor and control mechanisms, while the waste heat that is converted into current is used to drive the chiller-heater component. In this way, the home can be air conditioned while the heat of the hot fins and exhaust of the generator heat water for washing and then dry the clothes with heat. [0127]
In the waste heat-driven generator-chiller version, as well as other chiller versions, any excess electrical energy can be converted into hydrogen by the electrolysis of water, the hydrogen stored in a bladder or compressed into a pressure vessel for storage. The hydrogen can then be consumed as needed as fuel to recovery energy, converting it back into electrical energy and used to drive electrical loads, heating or cooling applications. Although the water-to-hydrogen electrolytic process is at best 70% efficient, the other 30% of the energy becomes heat that can promote a methane formation reaction. When the hydrogen producing electrolytic process is located within a biogas generator, the heat helps methane producing bacteria convert cellulose and sanitary waste into methane gas, the methane-hydrogen fuel mixture can be stored in a pressure vessel or in a roll-out bladder. This fuel mixture is a suitable fuel to burn as needed in thermoelectric generators and generator-chiller hybrids. [0128]
Thermoelectric generator-chiller hybrids can be used in mechanical applications as well as with self-powered appliances. Generator-chiller hybrids can be used to power a car or other vehicles with first a thermoelectric generator providing the electrical energy for locomotion. Exhaust heat passing through a second thermoelectric generator produces heating, chilling, air conditioning and refrigeration for inside the vehicle and for the cargo hold. A thermoelectric, fuel-driven, chiller hybrid truck can be used in city; between and in remote places to keep food cold or frozen as needed and provide transportation. [0129]
A thermoelectric cascade chiller can be used to liquefy methane to allow convenient cryogenic storage onboard vehicles in insulated vessels and used as needed for transportation fuel. [0130]
A thermoelectric, fuel-driven, chiller hybrid powered vehicle or stand-alone chiller unit can be used to provide the electricity to drive pumps and at the same time to produce heat to lower viscosity when spraying viscous polymers, chilling the material to set the polymer after coating. [0131]
A thermoelectric fuel-driven chiller hybrid can supply electrical energy to control and drive an injection molding system and at the same time provide heat to melt polymers and provide cooling for the injection molds. A thermoelectric chiller can provide cooling for a personal refrigeration suit. Alternatively a thermoelectric fuel driven chiller hybrid could provide for electrical needs as well as personal cooling. [0132]
The thermoelectric systems described herein have the unique advantage of being able to take otherwise wasted heat or waste cooling and conserve the wasted energy. FIG. 24 illustrates just one scheme for storing and recovering energy in this manner. The illustrated scheme uses the waste heat version of a packaged thermoelectric chiller hybrid shown in front view as a [0133] 142 of FIG. 16. Some components of 142 are illustrated separately; a first thermoelectric generator 145, a second thermoelectric generator component 147 utilizing waste heat from 145 ohmically connected to a compartmentalized thermoelectric chiller component 35. Heat energy not utilized by the second thermoelectric generator 147 is passed to a hot water heater 148. In another example hot gas from a re-circulating fuel combustor 192 can be used to supply heat to the generator 145. Heat from 192 is transferred to the first thermoelectric current driver 64 that is inside 147 and thermoelectric generator 61 that is inside 145 operating on hot gas.
[0134] Pump 193 circulates hot gas, air or fluid from the hot fins of the chiller component 35 and pump 194 circulates chilled gas, air or fluid over cold fins of chiller 35. Hot gas, air, or fluid pumped by 193 passes through lines that are connected to one or more heated appliance 195, 196 and household environment 197. The hot gas, air, or fluid line also connects to a heat exchange which stores energy in a molten salt reservoir 198. These lines also connect to a heat exchanger in a biogas producing pool or pond 199. Also in line is a heat exchanger 200 that allows excess heat to be dumped to the atmosphere when needed. Valves control when, for how long, and what amount of heat is used by each component in the circulating lines pumped by 193. Pump 194 circulates chilled gas, air, or liquid to one or more appliances to be cooled 201, household environment 202, and to an ice storage reservoir 203. The chilled lines also connect to heat exchanger 204 that dumps excess chilling to the atmosphere as needed. Also connected to lines pumped by 194 is a water collection system 205 using heat exchangers 206 and 207. Heat exchanger 206 chills water used to make droplets from nozzles 208 to increase the collection of water from humid air chilled by heat exchanger 206. Heat exchanger 207 takes fluid cooled by air exiting water collection system 205 and returns cooled fluid to the loop of pump 193 to aid in cooling the hot fins of chiller 35 when the chilling loop of pump 194 requires the extra chill capacity and heating system requirements are low. Any excess electricity produced by thermoelectric generator 145 is used to produce hydrogen, which is formed in electrolysis vessel 209 in biogas pond 199, stored in a roll-out bladder 210, or the gas travels by line 211 to pressurizing pump 212, where the hydrogen-methane gas mixture is stored in pressure vessel 213. The gas mixture can be burned as needed, traveling by line 114 to thermoelectric generator 145. Large arrow 214 represents energy in the form of the heat energy from burning gas, or burning a gas mixture, or the heat energy from a re-circulating fuel combustor 192, or heat from a boiler type combustion system. The heat flow represented by 214 can be seen exiting 145 in two ways, the larger of this part entering 147, the largest part entering 148, and the largest part of the flow exiting 148 is in the form of heated water through pump 149. These large arrows represent an energy balance for the system. The bulge 215 in the heat flow arrow that passes through chiller 35, represents the Joule heating contribution made by current circulating in the torus ring of chiller 35, causing more heat to exit chiller 35 than heat is removed by cold fins. The electrical output 216 of thermoelectric generator 145 powers the electrical needs of household 217. Any surplus electricity can be used to electrolyze hydrogen in pond 199 with electrolysis vessel 209. Medical grade oxygen is also produced by the electrolysis of water into hydrogen, pure oxygen gas can be delivered by pipe to the household to benefit patients with respiratory problems, or oxygen can be pressurized in bottles, stored for use elsewhere as needed. Solar energy 218 passes into biogas pond 199 to stimulate methane production as needed.
In a preferred embodiment re-circulating [0135] fuel combustor 192 is replace by a boiler type combustion system which delivers hot fluid to and then is returned from a compartmentalized thermoelectric generator that is ohmically connected to chiller component 35. Re-circulating hot fluid lines can be connected as well from one or more solar collectors to the compartmentalized thermoelectric component 35 of the generator-chiller hybrid. In this system, ambient temperature liquid can be pumped to the cold fins of chiller 35 to improve efficiency.
Thus having described the method of manufacture of components, the assembly of components, and an efficient means to extract energy produced by a temperature differential, a means to improve the overall efficiency of causing heat to flow by electricity by combining said thermoelectric generator device with a thermoelectric chiller device and by having given a variety of examples as to how to combine said thermoelectric devices operate with other components to provide a broad range of useful products, we claim: [0136]

Claims

We claim:

1. A chiller electrically driven torus heating and cooling thermoelectric device comprising a means for input of ac electricity, a switching power supply to convert alternating current to high frequency ac current and then to dc current, a torus thermoelectric element and a means to transfer heated fluid, gas or air and cooled fluid, gas or air from said chiller.

2. A chiller according to claim 1 wherein said switching power supply can be modulated to provide variable output.

3. A chiller according to claim 2 wherein said switching power supply comprises a primary winding with center tap for push-pull operation and secondary high current windings.

4. A chiller according to claim 2 wherein said means to modulate current is a powerstat.

5. A chiller according to claim 2 wherein said means to modulate current is manual electric range burner control duty cycle element.

6. A chiller according to claim 2 wherein said means to modulate current is a triac programmed to adjust the input duty cycle.

7. A chiller according to claim 1 wherein said means for input of electricity is an electrical connection to the electric utility grid.

8. A chiller according to claim 1 wherein said means for input of electricity is an electrical connection to the output of a thermoelectric generator.

9. A chiller according to claim 1 wherein said means for input of electricity is an electrical connection to the output of an internal combustion generator.

10. A chiller according to claim 1 wherein said means to transfer heated gas or air and cooled gas or air from said thermoelectric torus is an electrically driven fan that blows air over heated or cooled fins.

11. A chiller according to claim 1 wherein said means to transfer heated fluid and cooled fluid from said thermoelectric torus is an electrically driven pump that circulates fluid over the heated or cooled fins.

12. A chiller according to claim 1 wherein hot fins and cold fins are enclosed each in a leak proof chamber.

13. A chiller according to claim 1 wherein heated or cooled gas, air or fluid is exhausted to an environment to be heated or cooled.

14. A chiller according to claim 13 wherein said chiller is placed in one or more climate control ducts.

15. A chiller according to claim 13 wherein said chiller is placed in a window.

16. A chiller electrically driven torus heating and cooling thermoelectric device comprising a means for input of dc electricity, a torus thermoelectric element and a means to transfer heated fluid, gas or air and cooled fluid, gas or air from the thermoelectric torus.

17. A chiller according to claim 16 further comprising a means to change the polarity of the dc current in said torus thermoelectric device.

18. A chiller according to claim 17 wherein said means to change the polarity of said dc current is a set of electrically alterable switching bridges.

19. A chiller according to claim 17 wherein said means to change the direction of said dc current is a manual switch.

20. A chiller according to claim 16 wherein said means to transfer heated gas or air and cooled gas or air from said chiller is one or more electrically driven fan that blows air over the hot or cold fins.

21. A chiller according to claim 16 wherein said means to transfer heated fluid and cooled fluid from said thermoelectric torus is two or more electrically driven pumps that circulate fluid over the hot or cold fins.

22. A chiller according to claim 16 wherein said means for input dc electricity is one or more batteries having voltage reduced current increased using a dc-dc voltage down converter.

23. A chiller according to claim 22 wherein the amount of power to said chiller is controlled by a thermostat.

24. A chiller hybrid comprising a chiller electrically driven heating and cooling thermoelectric component and a thermoelectric generator component wherein said thermoelectric generator comprises a heat source, a means to convey heat to hot fins of said thermoelectric generator, a means to allow excess heat to be removed from said thermoelectric generator a means to cool cold fins of said generator, and a means to directly connect said generator to said torus thermoelectric chiller element.

25. A chiller hybrid according to claim 24 further comprising a thermostatic control to regulate said heat source.

26. A chiller hybrid according to claim 24 further comprising a manual control to regulate said heat source.

27. A chiller hybrid according to claim 24 further comprising a digital fuel control system wherein multiple nozzles of various sizes operate in an open or closed mode as needed to control fuel levels.

28. A chiller hybrid according to claim 24 wherein said means to connect said generator to said chiller is a solid connection of each output terminal of said generator to its corresponding input terminal of said chiller element by welding, brazing or soldering.

29. A chiller hybrid according to claim 24 wherein said means to connect said generator to said chiller component is an electrically alterable MOSfet switching bridge.

30. A chiller hybrid according to claim 24 further comprising a means to switch current polarity in the chiller component of said generator hybrid thereby heating fins that were otherwise cooled and cooling fins that were otherwise heated.

31. A chiller hybrid according to claim 24 further comprising a physical means to exchange hot output means and cold output means in said chiller hybrid to allow an environment that was otherwise chilled to be heated and an environment that was heat to be chilled.

32. A chiller hybrid according to claim 24 wherein said switching means is an electrically, mechanically or pneumatically controlled manual double pole double throw switch.

33. A thermoelectric generator-chiller hybrid comprising a first torus thermoelectric generator producing electricity, a second thermoelectric generator utilizing heat exhausted from said first thermoelectric generator to produce current to derive a torus thermoelectric chiller component.

34. A chiller hybrid according to claim 33 wherein said chiller component has a means to transfer heated fluid, gas or air and cooled fluid, gas or air from said chiller component.

35. A chiller hybrid according to claim 34 wherein said chiller hybrid further comprises a means to electrically or manually reverse current flow direction through said chiller component thereby altering the direction of heat flow.

36. A chiller hybrid according to claim 33 wherein said chiller further comprises a means to electrically or manually adjust current flow in the thermoelectric chiller to alter heat flow in said chiller.

37. A chiller hybrid according to claim 33 wherein said chiller has a means to electrically or manually reverse current direction and magnitude into said thermoelectric chiller.

38. A chiller system according to claim 33 further comprising a battery system to provide short term energy while other components equilibrate.

39. A thermoelectric heating and cooling generator system according to claim 38 further comprising a means to connect and convert grid electricity to said batteries.

40. A chiller hybrid comprising a chiller electrically driven heating and cooling thermoelectric component having compartmentalized chambers for heat exchange and a thermoelectric generator component wherein said thermoelectric generator comprises compartmentalized section where hot fins are heated, a means to convey heat to said compartment of said generator, a compartment where heat is removed from cold fins and a means to allow excess heat to be removed from said cold fins, and a means to electronically connect said generator component to said chiller component.

41. A chiller hybrid according to claim 40 further comprising a means of tapping dc current to power motors and control systems.

42. A cascade torus thermoelectric chiller comprising two or more compartmentalized chiller electrically driven torus thermoelectric components wherein the cold fins of a first chiller are thermally connected to hot fins of a second torus chiller, a means to supply current to said cascade chiller and a means to transfer heat from hot fins of a first compartment and a means to transfer heat from a last compartment.

43. A cascade chiller according to claim 42 wherein cold fins from a first component and hot fins of a second component are a common element.

44. A cascade chiller according to claim 42 wherein cold fins from a first chiller component are adjacent to hot fins of a second chiller component.

45. A cascade chiller according to claim 42 wherein fluid surrounding cold fins from a first chiller component is pumped to a chamber containing hot fins of said second chiller component.

46. A cascade chiller according to claim 42 wherein air surrounding cold fins from said first chiller component is pumped to a chamber containing hot fins of said second chiller component.

47. A cascade chiller according to claim 42 wherein said means for input of electricity is a switching power supply to convert alternating current to high frequency ac current and then to de current.

48. A cascade chiller according to claim 47 wherein said switching power supply can be modulated to provide variable output.

49. A cascade chiller according to claim 42 wherein said means to supply current is a switching power supply comprising a primary winding with center tap for push-pull operation and secondary high current windings.

50. A cascade chiller according to claim 42 wherein said means to supply current is a powerstat.

51. A cascade chiller according to claim 42 wherein said means to supply current is manual electric range burner control duty cycle element.

52. A cascade chiller according to claim 42 wherein said means to supply current is a triac programmed to adjust the input duty cycle.

53. A cascade chiller according to claim 42 wherein said means to supply current is an electrical connection to the electric utility grid.

54. A cascade chiller according to claim 42 wherein said means to supply current is an electrical connection to the output of a thermoelectric generator.

55. A cascade chiller according to claim 42 wherein said means to supply current is an electrical connection to the output of an internal combustion generator.

56. A cascade chiller according to claim 42 wherein said means to transfer heat is to move hot gas or air and cooled gas or air from said thermoelectric torus by one or more electrically driven fan.

57. A cascade chiller according to claim 42 wherein said means to transfer heat is to move heated fluid and cooled fluid from said thermoelectric torus using one or more electrically driven pump.

58. A cascade chiller according to claim 42 further comprising two or more torus thermoelectric generators each generator driving at least one chiller component of said torus cascaded chiller.

59. A chiller system according to claims 24 and 40 wherein heat energy is obtained from concentrated sunlight.

60. A chiller system according to claim 59 wherein sunlight is concentrated by a solar tracking cone, a solar tracking Fresnel focusing lens, a solar tracking single or double parabolic mirror, or a stationary parabolic reflector trough.

61. A solar powered thermoelectric heating and cooling system according to claim 59 further comprising thermal storage component.