US20070101737A1 - Refrigeration system including thermoelectric heat recovery and actuation - Google Patents

Abstract

A vapor-compression circuit may be used to meet the temperature/load demands for conditioning one or more spaces. Excess heat generated in the vapor-compression circuit may be utilized to generate an electric current that may power other components of the vapor-compression circuit. A thermoelectric device may be placed in heat-transferring contact with the excess heat and generate the electrical current. The electric current generated may be used to power another thermoelectric device to provide further cooling or heating of a fluid in heat-transferring relation therewith to supplement the vapor-compression circuit and the conditioning of the space.

Description

BACKGROUND
• Refrigeration systems incorporating a vapor-compression cycle may be utilized to condition the environment of open or closed compartments or spaces. The vapor-compression cycle utilizes a compressor to compress a phase-changing working fluid (e.g., a refrigerant), which is then condensed, expanded and evaporated. Compressing the working fluid generates heat, which, in cooling applications, is waste heat that is discharged to ambient from the compressor and condenser. Because the waste heat is not used or recovered, the lost energy of the waste heat represents an inefficiency of most refrigeration systems.
• In heating applications, such as in a heat pump system, heat stored in the compressed working fluid is extracted through the condenser to heat a space or compartment. Because efficiency of the heat pump system decreases with ambient temperature, heating may be supplemented at low ambient temperatures by a radiant electrical heat source. Radiant electrical heat sources, however, are typically inefficient and, thus, lower the overall efficiency of the heating application.
• In some cooling applications, an air flow may be chilled to a very low temperature to reduce the humidity. The low temperature required to remove humidity, however, may be too low for the conditioned space or compartment within a space or compartment to be. In these cases, the dehumidified chilled air may be reheated by electric radiant heat or hot-gas bypass heat to an appropriate temperature while maintaining the low humidity level. Use of radiant electrical heat and a hot gas bypass heat to reheat over-chilled air represents inefficiencies in this type of cooling application.
SUMMARY
• A vapor-compression cycle or circuit may be used to meet the temperature or load demands for conditioning one or more spaces or compartments. Waste heat generated by components of the vapor-compression circuit may be used to generate an electric current that may power other components of the vapor-compression circuit. A thermoelectric device may be placed in heat-transferring relation with the generated waste heat and produce the electrical current, which may be used to generate an electric current to power another device or another thermoelectric device. The other devices may include sensors, switches, controllers, fans, valves, actuators, pumps, compressors, etc. The other thermoelectric device may provide cooling or heating of a fluid in heat-transferring relation therewith to supplement the vapor-compression circuit and facilitate the conditioning of the space or compartment. The utilization of the generated waste heat as an energy source for powering other components or loads may improve the efficiency of the system.
• The present teachings disclose a method of operating a refrigeration system including transferring heat generated in the system through a thermoelectric device, generating an electric current with the heat flowing through the thermoelectric device, and powering a load with the generated electric current. The load may be another device or another thermoelectric device.
• A refrigeration system may be operated by supplying power to a thermoelectric device in a heat-transferring relation with a working fluid flowing through a vapor-compression circuit downstream of a condenser. A first heat flow may be generated with the thermoelectric device. The first heat flow may be transferred to a first fluid medium. A second heat flow may be transferred from the first fluid medium to a second fluid medium.
• Further areas of applicability of the present teachings will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the teachings.
BRIEF DESCRIPTION OF THE DRAWINGS
• The present teachings will become more fully understood from the detailed description and the accompanying drawings, wherein:
• FIGS. 1-3 are schematic diagrams of the use of thermoelectric devices according to the present teachings;
• FIG. 4 is a schematic diagram of a thermoelectric device according to the present teachings;
• FIG. 5 is a schematic diagram of a compressor with thermoelectric devices according to the present teachings;
• FIG. 6 is a schematic diagram of a top portion of another compressor with a thermoelectric device according to the present teachings;
• FIG. 7 is a schematic diagram of a bank of compressors and a thermoelectric device according to the present teachings;
• FIG. 8 is a schematic diagram of a refrigeration system according to the present teachings;
• FIG. 9 is a schematic diagram of a refrigeration system according to the present teachings;
• FIG. 10 is a schematic diagram of a refrigeration system according to the present teachings;
• FIGS. 11-13 are schematic diagrams of heat pump systems according to the present teachings; and
• FIG. 14 is a schematic diagram of a refrigeration system according to the present teachings.
DETAILED DESCRIPTION
• The following description is merely exemplary in nature and is in no way intended to limit the teachings, their application, or uses. In describing the various teachings herein, reference indicia are used. Like reference indicia are used for like elements. For example, if an element is identified as10 in one of the teachings, a like element in subsequent teachings may be identified as110,210, etc., or as10′,10′,10′″, etc. As used herein, the term “heat-transferring relation” refers to a relationship that allows heat to be transferred from one medium to another medium and includes convection, conduction and radiant heat transfer.
• Thermoelectric elements or devices are solid-state devices that convert electrical energy into a temperature gradient, known as the “Peltier effect,” or convert thermal energy from a temperature gradient into electrical energy, known as the “Seebeck effect.” With no moving parts, thermoelectric devices are rugged, reliable and quiet.
• In use, power is applied from a battery or other DC source to the thermoelectric device, which will have a relatively lower temperature on one side, a relatively higher temperature on the other side, and a temperature gradient therebetween. The lower and higher relative temperature sides are referred herein as a “cold side” and “hot side,” respectively. Further, the terms “cold side” and “hot side” may refer to specific sides, surfaces or areas of the thermoelectric devices.
• In one application, the hot and cold sides of the thermoelectric device may be placed in heat-transferring relation with two mediums. When power is applied to the thermoelectric device, the resulting temperature gradient will promote heat flow between the two mediums through the thermoelectric device. In another application, one side of the thermoelectric device may be placed in heat-transferring relation with a relatively higher temperature medium providing a heat source and the other side placed in heat-transferring relation with a relatively lower temperature medium providing a heat sink, whereby the resulting hot and cold sides generate electric current. As used herein, the term “heat transfer medium” may be a solid, a liquid or a gas through which heat may be transferred to/from. Thermoelectric devices can be acquired from various suppliers. For example, Kryotherm USA of Carson City, Nev. is a source for thermoelectric devices.
• One or more thermoelectric devices may generate electric current from waste heat generated in a vapor-compression circuit using the “Seebeck effect.” The electric current generated may be used to power other electrical devices or other thermoelectric devices, which may generate a temperature gradient using the “Peltier effect” to transfer heat therethrough. A power supply may be used to supply a current flow to a thermoelectric device to provide a desired temperature gradient thereacross through the “Peltier effect” and transfer heat therethrough to a desired medium.
• InFIG. 1, a firstthermoelectric device20auses waste or excess heat Q_wasteto generate an electric current I that is used to form a temperature gradient across a secondthermoelectric device20bto produce recovered heat Q_recovered.Hot side22aofthermoelectric device20ais in heat-transferring relation to a source of waste heat Q_waste.Cold side24aofthermoelectric device20ais in heat-transferring relation to a heat sink that Q_wastecan be expelled thereto.
• The temperature gradient formed across firstthermoelectric device20agenerates an electric current I that is supplied to a secondthermoelectric device20b. The electric current flowing therethrough generates a temperature gradient across secondthermoelectric device20bresulting in ahot side22band acold side24b. The temperature gradient causes a recovered heat Q_recoveredto flow throughthermoelectric device20b.Hot side22bof secondthermoelectric device20bis in heat-transferring relation with a medium into which recovered heat Q_recoveredis conducted, whilecold side24bof secondthermoelectric device20bis in heat-transferring relation to a heat source. Thus, inFIG. 1 a firstthermoelectric device20ais exposed to waste heat Q_wasteto cause a secondthermoelectric device20bto generate recovered heat Q_recovered.
• The electric current generated by athermoelectric device20 may also be used to activate or drive an electrical device or meet an electrical load (hereinafter referred to asload26 and/or “L”) as shown inFIG. 2. Again, waste heat Q_wasteis utilized to generate a temperature differential between hot andcold sides22,24 and generate electric current1. Thus, inFIG. 2,thermoelectric device20 is placed in heat-transferring relation to a source of waste heat Q_wasteand a heat sink to generate electric current I that is used topower load26.Load26 is utilized generically herein to refer to any type of device requiring an electric current. Such devices, by way of non-limiting example, include compressors, pumps, fans, valves, solenoids, actuators, sensors, controllers and other components of a refrigeration system. The sensors may include, such as by way of non-limiting example, pressure sensors, temperature sensors, flow sensors, accelerometers, RPM sensors, position sensors, resistance sensors, and the like and may be represented by “S” in the drawings. The various valves, solenoids and actuators may be represented by “V” in the drawings.
• Referring now toFIG. 3, apower supply28 is connected to athermoelectric device20 to generate a desired heat Q_desire. Power supply28 may supply a current flow I tothermoelectric device20 to cause a temperature gradient to be formed between hot andcold sides22,24. The temperature gradient generates a desired heat Q_desire. Hot side22 may be placed in heat-transferring relation with a medium into which heat Q_desiredis conducted.Power supply28 may modulate current flow I to maintain a desired temperature gradient and produce a desired heat Q_desire. Thus, inFIG. 3, apower supply28 provides an electric current I withinthermoelectric device20, which generates a source of desired heat Q_desire.
• Thermal enhancing devices orthermal conductors30,32 may be placed in heat-transferring relation withsides22,24 of one or morethermoelectric devices20 to enhance or facilitate heat transfer through thethermoelectric device20 and a medium, as shown inFIG. 4. Athermoelectric device20 having one or morethermal conductors30,32 is referred to herein as a thermoelectric module (TEM)33, which may include multiplethermoelectric devices20.Thermal conductors30,32 may be referred to herein as hot and coldthermal conductors30,32, respectively. It should be appreciated, that the terms “hot” and “cold” are relative terms and serve to indicate that that particular thermal conductor is in heat-transferring relation with the respective hot or cold side of athermoelectric device20.
• Heat transfer may be enhanced by increasing the heat-conductive surface area that is in contact with the medium into which the heat is to be conducted. For example, micro-channel tubing may accomplish the enhancing of the heat flow. The fluid medium flows through the micro channels therein and the hot or cold side of the thermoelectric device is placed in heat-transferring contact with the exterior surface of the tubing. When the medium is a gas, such as air, the thermal conductor may be in the form of fins which may accomplish the enhancement of the heat transfer to/from the medium.
• To enhance heat transfer, the thermal conductor may be shaped to match a contour of a heat source. For example, when it is desired to place a thermoelectric device in heat-transferring relation with a curved surface, the thermal conductor may have one surface curved so that it is complementary to the surface of the solid through which the heat is to be conducted while the other side of the thermal conductor is complementary to the hot or cold side of thethermoelectric device20.
• Enhanced heat transfer may be accomplished through heat-conducting materials, layers or coatings on thethermoelectric device20.Thermal conductors30,32 may include materials, layers or coatings having a high thermal conductivity whereby heat transfer through thethermoelectric device20 is conducted efficiently. By way of non-limiting example, materials having a high thermal conductivity include aluminum, copper and steel. Moreover, heat-conducting adhesives may also be used asthermal conductors30,32. Regardless of the form, thethermal conductors30,32 have a high thermal conductivity.
• In a vapor-compression cycle or circuit, acompressor34 compresses a relatively cool working fluid (e.g., refrigerant) in gaseous form to a relatively high temperature, high-pressure gas. The compressing process generates waste heat Q_wastethat is conducted through the compressor to ambient. Waste heat Q_wastemay be utilized by athermoelectric device20 to power anotherthermoelectric device20, and/or aload26.
• Referring toFIG. 5, a schematic view of portions of an exemplary compressor, in this case anorbital scroll compressor34 by way of a non-limiting example, generally includes a cylindricalhermetic shell37 having welded at the upper end thereof acap38 and at the lower end thereof abase58. Arefrigerant discharge passage39, which may have a discharge valve (not shown) therein, is attached to cap38. Other major elements affixed to shell37 include a transversely extendingpartition40 that is welded about its periphery at the same point that cap38 is welded to shell37, upper and lower bearing assemblies (not shown) and amotor stator41 press-fitted therein. A driveshaft orcrankshaft42 is rotatably journalled in the upper and lower bearing assemblies. The lower portion ofshell37 forms asump43 that is filled with lubricating oil which gets internally distributed throughoutcompressor34 during operation.
• Crankshaft42 is rotatably driven by an electricmotor including stator41, with windings passing therethrough, and arotor44 press-fitted oncrankshaft42. Upper and lower surfaces ofrotor44 have respective upper andlower counterweights45,46 thereon. An Oldham coupling (not shown) couples crankshaft42 to anorbiting scroll member47 having a spiral vane or wrap48 on the upper surface thereof. Anonorbiting scroll member49 is also provided having awrap50 positioned in meshing engagement withwrap48 of orbitingscroll member47.Nonorbiting scroll member49 has a center-disposeddischarge passage51 that is in fluid communication with adischarge muffler chamber52 defined bycap38 andpartition40. Aninlet port53 onshell37 allows refrigerant to flow into a suction side orinlet chamber54.
• Compressor34 also includes numerous sensors, diagnostic modules, printed circuit board assemblies, solenoids, such as internal and external capacity modulation solenoids, switches, such as a switch to change resistance ofmotor36 to provide a first resistant for start-up and a second resistance for continuous operation, and other electrically-actuated devices or loads26. These electrical devices may be internal or external to the compressor and may be stationary or rotating with the rotating components of the compressor.
• During operation,motor36 causesrotor44 to rotate relative tostator41, which causescrankshaft42 to rotate. Rotation ofcrankshaft42 causes orbitingscroll member47 to orbit relative tononorbiting scroll member49. Working fluid withinsuction chamber54 is pulled into the space betweenwraps48,50 and progresses toward the central portion due to the relative movement therebetween.
• Pressurized working fluid is discharged fromscroll members47,49 throughdischarge passage51 and flows intodischarge chamber52. The working fluid withindischarge chamber52 is at a relatively high temperature and pressure. Compressed high-temperature, high-pressure working fluid flows fromdischarge chamber52 throughdischarge passage39 and onto the other components of the vapor-compression circuit within whichcompressor34 is employed.
• During operation, waste heat Q_wasteis generated throughoutcompressor34. This waste heat Q_wastemay be conducted to athermoelectric device20. Waste heat Q_wastemay be generated byrotor44, which gets hot when rotated and is cooled by the internally distributed lubricant and the working fluid (suction gas) withinsuction chamber54. The heat flow fromrotor44 to the lubricant and/or suction side working fluid represents a source of waste heat Q_wastethat may be conducted to athermoelectric device20.
• As shown inFIG. 5, aTEM33a, which may be attached torotor44, includes athermoelectric device20awithhot side22a.Hot side22ais in heat-transferring relation torotor44 whilecold side24ais in heat-transferring relation with the lubricant and working fluid withinsuction chamber54. The temperature differential between the hot andcold sides22a,24acauses a heat Q_ato flow throughTEM33a, which generates an electric current that is supplied to aload26a. Attached to movingrotor44,TEM33apowers load26athat is also rotating withrotor44 orshaft42. For example, load26amay include a resistance switch that changes the resistance of the rotor so that a higher resistance is realized for a startup and a lower resistance is realized during nominal operation, a temperature sensor, an RPM sensor, and the like. WhileTEM33ais shown as being attached to the upper portion ofrotor44, it should be appreciated thatTEM33acan be attached to other portions ofrotor44, such as a middle, lower or internal portion, made integral with upper orlower counterweight45,46, or in direct contact with lubricant withinsump43.
• Partition40, which separates the relatively hot discharge gas withindischarge chamber52 from the relatively cooler suction gas withinsuction chamber54, conducts waste heat Q_waste, which may be used to generate electrical power within athermoelectric device20. By attaching aTEM33bto partition40 with hotthermal conductor30bin heat-transferring relation withpartition40 and coldthermal conductor32bin heat-transferring relation with the suction gas withinsuction chamber54, waste heat Q_bmay be transferred frompartition40 throughTEM33band into the suction gas withinsuction chamber54. Waste heat Q_bgenerates an electric current inthermoelectric device20bofTEM33b.TEM33bmay be connected to an internalelectric load26b₁or an externalelectric load26b₂.TEM33bmay be attached in a fixed manner to a stationary component, such aspartition40, which facilitates the attachment to stationary loads either internal or external tocompressor34. By positioningthermoelectric device20 in heat-transferring relation with a stationary component conducting waste heat Q_waste, an electric current to power aload26 either internal or external tocompressor34 may be generated.
• Waste heat Q_wastefrom the relatively hot discharge gas withindischarge chamber52 is conducted throughcap38 to the ambient environment within whichcompressor34 is located. ATEM33cmay be attached to cap38 with a hotthermal conductor30cin heat-transferring relation with the exterior surface ofcap38 and the coldthermal conductor32cin heat-transferring relation with the ambient environment. As shown inFIG. 5, coldthermal conductor32cincludes fins over which the ambient air flows and hotthermal conductor30cincludes a contoured surface matched to the exterior contour ofcap38. Hotthermal conductor30chas a greater surface area in contact withcap38 than in contact with hot side22cofthermoelectric device20c. The temperature differential between the ambient air andcap38 causes waste heat Q_cto flow throughTEM33cand generate an electric current that powers load26c, which may be external (26c₁,) or internal (26c₂) tocompressor34.Thermoelectric device20 may be placed in heat-transferring relation to the relatively hot discharge gas in discharge chamber52 (via cap38) and the relatively cold ambient environment to provide a temperature gradient that may be used to generate electric current to power a load.
• Because of the temperature differential between discharge gas withindischarge passage39 and the ambient environment, aTEM33dattached to dischargepassage39 with the hotthermal conductor30din heat-transferring relation to dischargepassage39 and the coldthermal conductor32din heat-transferring relation to the ambient environment causes heat Q_dto flow throughTEM33d. Thethermoelectric device20dofTEM33dgenerates electric current that may be used topower load26d. Thus, athermoelectric device20 may be disposed in heat-transferring relation to the relatively hot gas within the discharge passage and the ambient environment to generate an electric current that can be used to power a load.
• During the compressing of the refrigerant betweenwraps48,50 of orbiting andnon-orbiting scroll members47,49, the temperature and pressure of the working fluid increases as it approachcentral discharge passage51. As a result, the temperature differential between the relatively cool suction gas on one side of orbitingscroll member47 and the relatively hot discharge gas neardischarge passage51 generates waste heat Q_e. A TEM33emay be attached to orbiting-scroll member47 adjacent or opposite to dischargepassage51. Specifically, hotthermal conductor30eofTEM33eis placed in heat-transferring relation to a bottom surface of orbitingscroll member47 generally oppositedischarge passage51. Coldthermal conductor32eofTEM33eis disposed in heat-transferring relation to the suction gas and lubricant flowing withinsuction chamber54. As waste heat Q_eflows throughTEM33e, thethermoelectric device20eofTEM33egenerates electric current that may be used topower load26e. Thus, athermoelectric device20 may be disposed in heat-transferring relation to the discharge gas and suction gas adjacent the orbiting scroll member to generate electric current that can be used to power a load.
• During operation,stator41 generates waste heat Q_fthat is transferred to the internally distributed lubricant and/or suction gas in thesuction chamber54. ATEM33fmay be attached tostator41 with the hotthermal conductor30fin heat-transferring relation tostator41 and coldthermal conductor32fis in heat-transferring relation to the lubricant and/or suction gas insuction chamber54. The temperature differential betweenstator41 and the lubricant and/or suction gas withinsuction chamber54 causes waste heat Q_fto flow throughTEM33f, whereinthermoelectric device20fgenerates electric current that may be used topower load26f. WhileTEM33fis shown as being attached to the upper portion ofstator41, it should be appreciated thatTEM33fcan be attached to other portions ofstator41, such as a middle, lower or internal portion, or in direct contact with lubricant withinsump43. Thus, a thermoelectric device may be disposed in heat-transferring relation to the stator and the lubricant or suction gas to generate electric current that can be used to power a load.
• The lubricant withinsump43 ofcompressor34 is relatively hot (relative to the ambient environment) and heat waste Q_gis conducted from the lubricant throughshell37 to the ambient environment. ATEM33gmay be positioned with coldthermal conductor32gin heat-transferring relation to the ambient environment and hotthermal conductor30gin heat-transferring relation to the lubricant withinsump43. This may be accomplished by integratingTEM33gwithin the wall ofshell37. The temperature differential between the lubricant and ambient causes waste heat Q_gto flow throughthermoelectric device20ginTEM33gand generate electric current that may be used topower load26g. Thus, athermoelectric device20 disposed in heat-transferring relation to the relatively hot lubricant and relatively cool ambient environment may be used to generate electric current to power a load.
• Referring toFIG. 6, a partial schemataic view of a top portion of another exemplary compressor, in this case anorbital scroll compressor34′ having a direct discharge by way of non-limiting example is shown.Compressor34′ is similar tocompressor34 discussed above with reference toFIG. 5. Incompressor34′, however,discharge passage39′ communicates directly withdischarge passage51′ ofnon-orbiting scroll member49′ such that the compressed working fluid (discharge gas) flows directly intodischarge passage39′ fromdischarge passage51′. Amuffler56′ is attached to dischargepassage39′. The relatively hot compressed working fluid flows throughmuffler56′. Waste heat Q_wastefrom the relatively hot discharge gas withinmuffler56′ is conducted through the walls ofmuffler56′ to the ambient environment within whichcompressor34′ is located. ATEM33′ may be attached tomuffler56′ with hotthermal conductor30′ in heat-transferring relation with the exterior surface ofmuffler56′ and coldthermal conductor32′ in heat-transferring relation with the ambient environment. Coldthermal conductor32′ may include fins over which the ambient air flows and hotthermal conductor30′ may include a contoured surface matched to the exterior contour ofmuffler56′ to facilitate heat transfer. The temperature differential between the ambient air andmuffler56′ causes waste heat Q to flow throughTEM33′ and generate an electric current that powersload26′. Thus,thermoelectric device20′ may be placed in heat-transferring relation to the relatively hot discharge gas inmuffler56′ (via the exterior surface ofmuffler56′) and the relatively cold ambient environment to provide a temperature gradient that may be used to generate electric current to power a load.
• Referring toFIG. 7, amulti-compressor system60 including compressors34₁-34_nare arranged in parallel with the relatively hot, high-pressure discharge gas from eachcompressor34 flowing into acommon discharge manifold61 is shown. The temperature differential between the discharge gas and ambient causes waste heat Q to flow from the discharge gas to the ambient environment throughmanifold61. Positioning aTEM33adjacent discharge manifold61 with a hotthermal conductor30 in heat-transferring relation to dischargemanifold61 and coldthermal conductor32 in heat-transferring relation to the ambient air aboutdischarge manifold61 may generate electric current from waste heat Q flowing throughthermoelectric device20 withinTEM33. The electric current may be used topower load26. Thus, in a multi-compressor system having a common discharge manifold, a thermoelectric device may be positioned between the relatively hot discharge gas in the manifold and the ambient environment to generate an electric current from the waste heat Q to power aload26.
• Referring toFIG. 8, anexemplary refrigeration system64 includes acompressor65, acondenser66, anexpansion device67 and anevaporator68 all connected together to thereby form a vapor-compression circuit69.Condenser66 transfers a heat Q₃from the relatively hot working fluid flowing therethrough to an airflow flowing there across and condenses the working fluid.Evaporator68 is operable to extract a heat flow Q₄from an airflow flowing there across and transfer it to the relatively cool and expanded working fluid flowing therethrough.
• Refrigeration system64 includesvarious loads26 that require electricity to operate.Loads26 may include electrically drivenfans70,71 which push air acrosscondenser66 andevaporator68, respectively, various valves, solenoids oractuators72 andvarious sensors73. Additionally, load26 may include acontroller74, which may be used to control or communicate withvalves72,sensors73,compressor65,fans70,71 and other components ofrefrigeration system64. The various power requirements ofrefrigeration system64 may be met by apower distribution member75 which supplies current to power thevarious loads26 ofrefrigeration system64.
• The power demands of thevarious loads26 may be provided by apower supply76, which may provide both AC current and DC current, through power-distribution block75. The electric current may be supplied by individual connections directly topower supply76, through one or more power distribution devices, and/or throughcontroller74.
• Waste heat Q_wastegenerated byrefrigeration system64 may be conducted to one or morethermoelectric devices20 to generated electric current supplied to load26. As shown inFIG. 8, aTEM33amay capture waste heat Q₁fromcompressor65 and generate current I supplied to power-distribution block75. Additionally,TEM33bmay extract waste heat Q₂from the relatively high-temperature working fluid flowing through vapor-compression circuit69, particularly compressed working fluid that has not been condensed, and generate current I supplied to power-distribution block75.
• During startup ofrefrigeration system64, aTEM33 will not produce power to supplyload26. Rather, during startup, power may be supplied bypower supply76. Oncerefrigeration system64 reaches steady state (nominal) operation, waste heat Q_wastewill be generated andTEM33 may produce electric current.
• As the electric current production by one ormore TEM33 increases, the use ofpower supply76 may be reduced. Power demands ofload26 may be partially or fully met by the electric current generated by one ormore TEM33, which may also supply current to power one or more low-power-consuming components whilepower supply76 supplies current to meet the power demand of high-power-consuming components, such ascompressor65.
• An energy-storage device78 may provide temporary startup power to one or more components ofrefrigeration system64. Energy-storage devices, such as rechargeable batteries, ultra capacitors, and the like, may store a sufficient quantity of power to meet the requirements, particularly at system startup, of some or all of the components ofrefrigeration system64 up until thetime TEM33 is able to produce sufficient current to power those components. Excess current generated byTEM33 may be utilized to recharge energy-storage device78 for a subsequent startup operation. Thus,energy storage device78 may be part ofload26.
• Inrefrigeration system64,thermoelectric devices20 may use waste heat Q_wasteto generate electric current that can power various components ofrefrigeration system64. The electric current supplied by thermoelectric devices may be used to supplement electric current frompower supply76 and/or meet the demand of the refrigeration system. Additionally, an energy-storage device78 may provide the initial startup power requirements ofrefrigeration system64 until one or morethermoelectric devices20 are able to replace the electrical power supplied by energy-storage device78.
• Referring now toFIG. 9, arefrigeration system164 includes a vapor-compression circuit169 andTEM133.TEM133, which produces an electric current I to power aload126, may extract heat Q₁₀₂from the relatively high-temperature, non-condensed working fluid flowing through vapor-compression circuit169 betweencompressor165 andcondenser166, thereby de-superheating the working fluid flowing intocondenser166.
• Working fluid may exitcompressor165 at, by way of non-limiting example, 182° F. and arrive atTEM133 at about 170° F. If the ambient environment is at say 95° F., a 75° F. temperature differential acrossTEM133 produces waste heat Q₁₀₂to flow from the working fluid to the ambient throughTEM133, which reduces the temperature of the working fluid prior to flowing intocondenser166. Because the heat Q₁₀₃required to be extracted bycondenser166 to meet the needs ofevaporator168 is reduced,compressor165 may operate more efficiently or at a lower capacity or at a lower temperature, such as by way of non-limiting example 115°F. Thermoelectric device20 may power load126 while de-superheating non-condensed working fluid thereby meeting part of all of the power demand and increasing the efficiency of the system. De-superheating the working fluid enablescondenser166 to operate more efficiently or be sized smaller than what would be required if no de-superheating were to occur, further helping thermoelectric device meet system power requirements.
• Referring toFIG. 10, arefrigeration system264 includes a pair ofthermoelectric modules233a,233bfor subcooling the condensed workingfluid exiting condenser266. Firstthermoelectric module233aextracts waste heat Q₂₀₁fromcompressor265 and generates an electric current I that is supplied to secondthermoelectric module233b, which is in heat-transferring relation to vapor-compression circuit269. The current supplied byfirst TEM233adrives the temperature gradient acrosssecond TEM233bto allow the removal of heat Q₂₀₅from condensed working fluid in vapor-compression circuit269. Cold side224bofthermoelectric device220bis in heat-transferring relation to the condensed working fluid within vapor-compression circuit269 exitingcondenser266, where heat Q₂₀₅is extracted from the condensed working fluid and transferred to the ambient. To enhance the removal of heat Q₂₀₅from the condensed working fluid to the ambient environment, the flow of air caused byfan270 may be directed over hotthermal conductor230bofsecond TEM233b.
• Second TEM233bmay remove heat Q₂₀₅to sub-cool the condensed working fluid therein and increase the cooling capacity ofrefrigeration system264.Condenser266 may reduce the working fluid temperature to approximately ambient temperature and secondthermoelectric module233bmay further cool the condensed working fluid to below-ambient temperature by extracting heat Q₂₀₅therefrom. The lower-temperature condensed working fluid provides a larger cooling capacity forevaporator268, which can extract a larger quantity of heat Q₂₀₄from the air flowing acrossevaporator268, thus achieving a greater cooling capacity.
• Referring toFIG. 11, arefrigeration system364 operated as a heat pump is shown. In this system, athermoelectric module333 is utilized to supplement the heating capacity ofrefrigeration system364. Hotthermal conductor330 ofTEM333 is in heat-transferring relation with a portion of the relatively high-temperature, high-pressure workingfluid exiting compressor365 and flowing through anauxiliary flow path380. Coldthermal conductor332 ofTEM333 is in heat-transferring relation with the condensed workingfluid exiting condenser366.Power supply376 selectively supplies electric current toTEM333 thereby forming a temperature gradient acrossTEM333 which extracts heat Q₃₀₆from the condensed working fluid and transfers the heat Q₃₀₆to the portion of the relatively high-temperature, high-pressure working fluid flowing throughauxiliary flow path380, further increasing the temperature of the working fluid.
• This higher-temperature working fluid is directed through anauxiliary condenser382 to supplement the heat transfer to the air flowing overcondenser366. The air flow generated byfan370 flows overcondenser366 thenauxiliary condenser382.Auxiliary condenser382 transfers heat Q₃₁₂from the higher-temperature working fluid flowing therethrough to the air flowing thereacross, thereby increasing the temperature of the air flow and providing additional heat transfer to the air flow.
• The condensed working fluid exitingauxiliary condenser382 joins with the condensed workingfluid exiting condenser366 prior to flowingpast TEM333. The condensed working fluid flows throughexpansion device367 andevaporator368 wherein heat Q₃₀₄is extracted from the air flowing thereacross. Accordingly, a thermoelectric device inrefrigeration system364 transfers heat to a portion of the relatively high-temperature, high-pressure working fluid exiting the compressor which is subsequently transferred to an air flow flowing across an auxiliary condenser, thereby supplementing the overall heat transferred to the air flow. The electric current supplied to the thermoelectric device is modulated to provide varying levels of supplementation of the heat Q₃₁₂transferred to the air flowing over the condenser and the auxiliary condenser.
• Referring toFIG. 12, arefrigeration system464 operated as a heat pump is shown. Inrefrigeration system464, athermoelectric module433 selectively transfers heat to a single-phase fluid flowing through a single-phase, heat-transfer circuit486 which supplements the heating capacity ofrefrigeration system464. Heat-transfer circuit486 includes apump487 and aheat exchanger483 arrangedadjacent condenser466 such that air flow generated byfan470 flows across bothcondenser466 andheat exchanger483.
• Coldthermal conductor432 is in heat-transferring relation with the condensed workingfluid exiting condenser466 which extracts heat Q₄₀₆therefrom. Hotthermal conductor430 is in heat-transferring relation with the single-phase fluid flowing through heat-transfer circuit486 and transfers heat Q₄₀₆thereto. Power supply476 modulates the current flowing tothermoelectric device420 withinTEM433 to generate and maintain a desired temperature gradient thereacross, thereby resulting in a desired quantity of heat Q₄₀₆transferred to the single-phase fluid and increasing the temperature of the single-phase fluid to a desired temperature. Pump487 pumps the single-phase fluid throughheat exchanger483 which transfers heat Q₄₁₂from the single-phase fluid to the air flowing thereacross, which raises the temperature of the air flow. A variety of single-phase fluids can be utilized within heat-transfer circuit486. By way of non-limiting example, the single-phase fluid may be a potassium formate or other types of secondary heat transfer fluids, such as those available from Environmental Process Systems Limited of Cambridgeshire, UK and sold under the Tyfo® brand, and the like. Inrefrigeration system464, a thermoelectric device transfers heat Q₄₀₆from the condensed working fluid exiting the condenser to a single-phase fluid flowing through a heat-transfer circuit which transfers heat Q₄₁₂to the air flowing acrossheat exchanger483.
• Referring toFIG. 13, arefrigeration system564 operated as a heat pump is shown.Refrigeration system564 is similar torefrigeration system464 with the addition of a second single-phase, heat-transfer circuit588. Second heat-transfer circuit588 includes apump589 and asubcooler590.Subcooler590 is in heat-transferring relation with condensed workingfluid exiting condenser566 and the single-phase fluid flowing through heat-transfer circuit588.Subcooler590 transfers heat Q₅₀₇from the condensed working fluid flowing therethrough to the single-phase fluid flowing therethrough, which increases the temperature of the single-phase fluid.
• Coldthermal conductor532 ofTEM533 is in heat-transferring relation with the single-phase fluid flowing through heat-transfer circuit588. Hotthermal conductor530 ofTEM533 is in heat-transferring relation with the single-phase fluid flowing through heat-transfer circuit586.Power supply576 modulates the current flowing tothermoelectric device520 to maintain a desired temperature differential thereacross which transfers heat Q₅₀₈from the single-phase fluid within heat-transfer circuit588 to the single-phase fluid in heat-transfer circuit586 throughthermoelectric device520. Heat Q₅₀₈increases the temperature of the single-phase fluid flowing through heat-transfer circuit586. Heat Q₅₁₂is transferred from the single-phase fluid flowing through heat-transfer circuit586 to the air flowing acrossheat exchanger583, thereby increasing the temperature of the air flow.Refrigeration system564 uses two single-phase fluid heat-transfer circuits586,588 in heat-transferring relation to one another throughthermoelectric device520 to supplement the heating of the air flow flowing acrosscondenser566.
• Referring toFIG. 14, arefrigeration system664 providing a dehumidification and reheating of the cooling air provided thereby is shown.Refrigeration system664 includes vapor-compression circuit669 having a working fluid flowing therethrough.Evaporator668 is operated at a very low temperature and extracts heat Q₆₀₄from the air flow flowing thereacross which lowers the humidity and temperature of the air flow. First and second heat-tranfer circuits691,692 in heat-transferring relation throughTEM633 transfer heat to the air flow to raise the temperature thereby making the air flow suitable for its intended application.
• First heat-transfer circuit691 includes apump693 and asubcooler694 and has a single-phase fluid flowing therethrough.Subcooler694 transfers heat Q₆₀₉from the condensed workingfluid exiting condenser666 to the single-phase fluid flowing through first heat-transfer circuit691 which increases the temperature of the single-phase fluid. Coldthermal conductor632 is in heat-transferring relation with the single-phase fluid flowing through first heat-transfer circuit691 while hotthermal conductor630 is in heat-transferring relation with the single-phase fluid flowing through secondheat transfer circuit692.Power supply676 modulates the current flowing tothermoelectric device620 inTEM633 to maintain a desired temperature gradient thereacross and transfer heat Q₆₁₀from the single-phase fluid flowing through first heat-transfer circuit691 to the single-phase fluid flowing through second heat-transfer circuit692 throughthermoelectric device620.
• Heat Q₆₁₀increases the temperature of the single-phase fluid flowing through second heat-transfer circuit692. Apump695 pumps the single-phase fluid in second heat-transfer circuit692 through areheat coil696. The air flow induced byfan671 flows across bothevaporator668 and reheatcoil696.Reheat coil696 transfers heat Q₆₁₁from the single-phase fluid flowing therethrough to the air flow flowing thereacross. Heat Q₆₁₁increases the temperature of the air flow without increasing the humidity.Refrigeration system664 utilizes two single-phaseheat transfer circuits691,692 in heat-transferring relation therebetween with a thermoelectric device to reheat an air flow dehumidified and chilled by the evaporator of the vapor compression circuit.
• While the present teachings have been described with reference to the drawings and examples, changes may be made without deviating from the spirit and scope of the present teachings. It should be appreciated that the orbiting scroll compressors shown inFIGS. 5 and 6 are by way of a non-limiting example and may not show all of the components therein. Orbital scroll compressors are shown and described in greater detail in U.S. Pat. No. 6,264,446 entitled “Horizontral Scroll Compressor”; U.S. Pat. No. 6,439,867 entitled “Scroll Compressor Having a Clearance for the Oldham Coupling”; U.S. Pat. No. 6,655,172 entitled “Scroll Compressor with Vapor Injection”; U.S. Pat. No. 6,679,683 entitled “Dual Volume-Ratio Scroll Machine” and U.S. Pat. No. 6,821,092 entitled “Capacity Modulated Scroll Compressor”, all assigned to the assignee of the present invention and incorporated by reference herein. Other types of compressors generate waste heat that can be utilized with one or more thermoelectric devices to generate a current flow that can be used elsewhere. For example, the compressors can be either internally or externally-driven compressors and may include rotary compressors, screw compressors, centrifugal compressors, and the like. Moreover, whileTEM33gis shown as being integrated in the wall ofshell37, it should be appreciated that TEMs may be integrated into other components, if desired, to be in direct contact with a heat source or heat sink. Furthermore, while the condensers and evaporators are described as being coil units, it should be appreciated that other types of evaporators and condensers may be employed. Additionally, while the present teachings have been described with reference to specific temperatures, it should be appreciated that these temperatures are provided as non-limiting examples of the capabilities of the refrigeration systems. Accordingly, the temperatures of the various components within the various refrigeration systems may vary from those shown.
• Furthermore, it should be appreciated that additional valves, sensors, control devices and the like can be employed, as desired, in the refrigeration systems shown. Moreover, thermal insulation may be utilized to promote a directional heat transfer so that desired hot and cold sides for the thermoelectric device are realized. Accordingly, the description is merely exemplary in nature and variations are not to be regarded as a departure from the spirit and scope of the teachings.

Claims (31)

1. A system including a vapor-compression circuit including a source of waste heat and a thermoelectric device positioned in heat-transferring relation to said source of waste heat and that generates an electric current from said source of waste heat.

2. The system ofclaim 1 wherein said vapor compression circuit includes a compressor that compresses a working fluid.

3. The system ofclaim 2, wherein said compressor includes a member separating high-pressure working fluid from low-pressure working fluid and said thermoelectric device is disposed in heat-transferring relation between said high-pressure working fluid and said low-pressure working fluid.

4. The system ofclaim 3, wherein said member is a scroll member and said thermoelectric device is positioned adjacent said scroll member.

5. The system ofclaim 4, wherein said scroll member is one of an orbiting scroll member and a nonorbiting scroll member and said thermoelectric device is positioned adjacent said orbiting scroll member.

6. The system ofclaim 3, wherein said member is a partition and said thermoelectric device is positioned adjacent said partition.

7. The system ofclaim 3, wherein said member is a compression member and said thermoelectric device is positioned adjacent said compression member.

8. The system ofclaim 2, wherein said compressor includes a motor and said source of waste heat includes said motor.

9. The system ofclaim 8, wherein said compressor uses a lubricant, said motor includes a rotor, and said thermoelectric device is disposed in heat-transferring relation between said rotor and at least one of said lubricant and said working fluid within said compressor.

10. The system ofclaim 8, wherein said compressor uses a lubricant, said motor includes a stator, and said thermoelectric device is disposed in heat-transferring relation between said stator and at least one of said lubricant and said working fluid within said compressor.

11. The system ofclaim 2, wherein said vapor compression circuit further includes an evaporator that evaporates said working fluid and a condenser that condenses said working fluid.

12. The system ofclaim 11, further comprising another thermoelectric device that is powered by said electric current and transfers heat from said working fluid to an ambient environment.

13. The system ofclaim 12, wherein said another thermoelectric device subcools said working fluid downstream of said condenser in said vapor-compression circuit.

14. The system ofclaim 2, wherein said compressor includes a shell and said thermoelectric device is disposed adjacent said shell.

15. The system ofclaim 14, wherein said compressor includes a discharge chamber containing working fluid at discharge pressure and separated from an ambient environment by said shell and said thermoelectric device is disposed in heat-transferring relation to said working fluid and said ambient environment.

16. The system ofclaim 2, wherein said thermoelectric device is in heat-transferring relation to a component of said compressor.

17. The system ofclaim 2, wherein said compressor includes a shell and a sump including lubricant and said thermoelectric device is disposed in heat-transferring relation to said lubricant and said ambient environment.

18. The system ofclaim 2, wherein said compressor includes a discharge passage for compressed working fluid and wherein said thermoelectric device is disposed in heat-transferring relation to said compressed working fluid and an ambient environment.

19. The system ofclaim 2, wherein said compressor discharges compressed working fluid through a muffler external to said compressor, and said thermoelectric device is disposed in heat-transferring relation to said compressed working fluid within said muffler and an ambient environment.

20. The system ofclaim 1, wherein said electric current generated by said thermoelectric device is operable to power a load.

21. The system ofclaim 20, wherein said load is another thermoelectric device.

22. The system ofclaim 21, wherein said another thermoelectric device transfers heat from said working fluid to an ambient environment.

23. The system ofclaim 20, wherein said vapor-compression circuit includes a compressor that compresses a working fluid and said load is internal to said compressor.

24. The system ofclaim 1, further comprising a load and wherein said electric current generated by said thermoelectric device is operable to power said load.

25. The system ofclaim 24, wherein said load is another thermoelectric device.

26. The system ofclaim 25, wherein said another thermoelectric device transfers heat from a working fluid in said vapor-compression circuit to an ambient environment.

27. The system ofclaim 24, wherein said load is a system power supply and said thermoelectric device at least supplements said power supply.

28. A refrigeration system including the system ofclaim 1.

29. An air conditioning system including the system ofclaim 1.

30. A refrigerator including the system ofclaim 1.

31-79. (canceled)

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