Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B27/00—Machines, plants or systems, using particular sources of energy
  • F25B27/02—Machines, plants or systems, using particular sources of energy using waste heat, e.g. from internal-combustion engines
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D3/00—Hot-water central heating systems
  • F24D3/18—Hot-water central heating systems using heat pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B27/00—Machines, plants or systems, using particular sources of energy
  • F25B27/002—Machines, plants or systems, using particular sources of energy using solar energy
  • F25B27/005—Machines, plants or systems, using particular sources of energy using solar energy in compression type systems
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A30/00—Adapting or protecting infrastructure or their operation
  • Y02A30/27—Relating to heating, ventilation or air conditioning [HVAC] technologies
  • Y02A30/274—Relating to heating, ventilation or air conditioning [HVAC] technologies using waste energy, e.g. from internal combustion engine
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
  • Y02B30/12—Hot water central heating systems using heat pumps

Definitions

• the present invention applies to the art of vapor-compression mechanical refrigeration and more specifically relates to methods and apparatus for using renewable energy sources to reduce the amount of mechanical work required to operate a vapor-compression refrigeration system.
• a vapor compression refrigeration system comprises three basic elements: an evaporator, a compressor and a condensor.
• the refrigerant boils or evaporates at a temperature low enough to absorb heat from the medium, such as air or water that is being cooled.
• the boiling point is controlled by the pressure maintained in the evaporator, since the higher the pressure, the higher the boj/ling jDoint.
• the compressor removes the vapor as it is formed, A-aT* a ⁇ e at Ae> ⁇ sufficiently rapid to maintain the desired pressure.
• This vapor is then compressed and delivered to the condensor.
• the condensor dissipates heat to some heat exchange medium such as water or air.
• the condensed liquid refrigerant is then reduced sharply in pressure by passage through an expansion valve.
• the refrigerant's pressure and temperature drop until they reach the evaporator's pressure and temperature, thus allowing the cycle to be repeated.
• the process is one in which the refrig ⁇ erant absorbs heat at a low temperature and then, under the action of mechanical work, the refrigerant is compressed and raised to a sufficiently high temperature to permit rejection of this heat.
• Mechanical work or energy supplied to the compressor as power is al- ways required to raise the temperature of the system.
• Air conditioning One type of mechanical vapor compression refrigeration is referred to commonly as “air conditioning”, which is used to produce cooling in public buildings or homes. Air conditioning very often makes use of a central refrigeration plant and distributes cooling to various areas of a house or building, either as air or chilled water.
• Renewable resources such as wood, provide a relatively low-level energy base which is easily and safely produced. Free energy in the form of solar and wind power is available in usable amounts most anywhere. They also produce a broad, low-level energy base for general application. Both renewable and free energy re ⁇ sources are attractive in that they require no locating costs, entail minimal environmental hazard, and are available indefinitely.
• Yet another purpose of the present invention is to provide a vapor compression refrigeration system that can be powered entirel by solar or low-grade thermal energy, i.e. energy that is easily obtained in the developing countries of the third world.
• Another purpose of the present invention is to provide an entirely self-contained vapor compression refrigeration system capable of being used in a remote location without the requirement that large amounts of electric power be generated at the remote site
• Yet still a further purpose of the present invention is to provide an integrated heating and cooling system capable of control ⁇ ling the thermal environment using only solar or other alterna ⁇ tive sources of heat.
• the present invention is a method and a variety of appar ⁇ atus for using a renewable heat source to power a vapor compression refrigeration system.
• the compressible working fluid passing from the system's evaporator is heated prior to being introduced to the compressor.
• Apparatus embodiments of the present invention include: 1 1. A solar heat/refrigeration system.
• An integrated climate control system comprising a wood or coal-burning double-wall stove with appropriate blowers and heat
• the present invention may receive its heat input from solar collectors, flue gases, or any other renewable heat source. It may use the refrigeration system's own waste heat or the heat of
• FIGURE 1 is a temperature entropy diagram illustrating the thermodynamic operation of a mechanical vapor compression refriger ⁇ ation apparatus constructed according to teachings of the prior art
• FIGURE 2 is a schematic diagram illustrating the major 20 elements of the present invention and their associated thermodynamic values
• FIGURE 3 is a temperature entropy diagram of a vapor heating compression refrigeration apparatus constructed according to the preferred embodiment of the present invention
• 25 FIGURE 4 shows the present invention utilizing a hybrid solar thermal/solar electric array to provide thermal and electrical energy to the present invention
• FIGURE 5 is a double-walled stove constructed according to the preferred embodiment of the present invention
• 3 Q FIGURE 6 shows the present invention operating in syner- gistic interaction with the flue of a stove wherein hot flue gas both preheats the refrigerant and provides mechanical -power for the compressor of the present invention
• FIGURE 7 is a stove incorporating a means for preheating 35 the refrigerant utilized by the preferred embodiment of the present invention.
• FIGURE 1 shows a temperature versus entropy thermodynamic diagram of a vapor compression refrigeration apparatus constructed according to the prior art.
• Liquid refrigerant at the condensor temperature is intro ⁇ quizd into an evaporator through a regulating or throttling valve. small portion of the refrigerant evaporates and reduces the temper ⁇ ature of is shown ant continues at the constant temperature T- , absorbing heat from a working fluid outside the evaporator. This process is shown in FIGURE 1 by line B-C. Vapor is then compressed by a mechanical com ⁇ pressor along the line C-D in FIGURE 1 to the temperature T 2 when, by passing the refrigerant through a heat exchange condensor, heat i rejected from the refrigerant at a constant temperature T and the vapor is condensed along the line D-A of FIGURE 1.
• FIGURE 2 shows a functional block diagram of an apparatus capable of practicing the method of the present invention.
• refrigeration system 100 comprises a conden ⁇ sor heat exchange 102 whose output end 104 is in fluid communication with transfer line 106.
• the end of transfer line 106 opposite the end connected to condensor heat exchange 102 is connected to the input of control throttling valve 108.
• control throttling valve 108 is placed in fluid communication with the input of evaporator 110 by fluid line 112.
• the output of evaporator 110 is placed in fluid communi ⁇ cation with heat exchange 114 by line 116.
• the output of heat exchange 114 is placed in fluid communi cation through appropriate valving, not shown, with the low pressure side 118 of compressor 120.
• O ⁇ ' refrigeration engineering Specifically, they will be stainless steel or copper tubes weldedj braised, soldered, or otherwise placed in hermetic sealing connection with one another and with the heat exchangers and valves that comprise the invention.
• a working fluid i.e. refrigerant
• compressor 120 a working fluid
• heat Qu is removed from the refrigerant by heat exchange with air, water, or some other heat exchange medium.
• this energy exchange is isothermal and results in the
• the refrigerant in line 106 is a saturated liquid that passes into and through control valve 108. A portion of this working refrigerant evaporates and changes the tem ⁇ perature of the remainder of the liquid refrigerant to temperature T, , as shown on FIGURE 1 by line A-B. This liquid and saturated T vapor undergoes isothermal energy exchange in evaporator 110. This energy is represented by Q. in FIGURE 2.
• the refrigerant, as a saturated vapor then exits the evaporator, passes through line 116 and enters into heat exchanger 114. At this point in the process, some amount of heat energy Q c is put into the refrigerant by its
• Example 1 (Prior art, i.e. no energy input at Cv.)
• heat ( . is considered to be free of cost as would be the case using solar heat.
• Example 3 (Q c input sufficient to add 30°F. to refrigeran
• heat Q c is considered to be free of cost as would be the case using solar heat.
• FIGURE 3 shows a temperature entropy thermodynamic cycle diagram that applicant believes corresponds to the embodiment of the present invention described in connection with FIGURE 2 above.
• an initial temperature drop of A-B in FIGURE 3 is caused by the evaporative cooling of the refrigerant.
• Refrigerant then undergoes isothermal energy exchange along line B-C, which corresponds to the cooling in the evaporator of the present invention.
• Line segment C-D of FIGURE 3 represents the relatively low-grade heat energy input Q c to heat exchanger 114 in FIGURE 2.
• the work done by compressor 120 thus need only be.
• line segment D-E of FIGURE 3 before condensor 102 can isothermally condense the saturated vapor, which is represented by line E-A of FIGURE.3. 1]
• FIGURE 4 illustrates a solar powered embodiment of the present invention.
• hybrid solar collector 400 has an upper solar thermal collector portion 402 and a lower solar voltaic array 404.
• the sun 406 is shown providing radiation to hybrid collector 400.
• the lower portion 408 of solar thermal collec ⁇ tor 402 is in fluid communication with.the low pressure side of pump 410 by means of fluid conduit 412.
• the high pressure output end 414 of pump 410 is in fluid communication with the input of condensor 416 by means of fluid line 418;
• the output of condensor 416 is in fluid communication with the high pressure side of throttling valve 420 by means of fluid communication line 422.
• the low pressure or output side of throttling valve 420 is in fluid communication with the input side of evaporator 424 by means of fluid transfer line 426.
• the output side of evaporator 424 is in fluid communication with the upper input side 428 of solar thermal collector 402 by means of fluid transfer line 430.
• Solar voltaic array 404 is electrically connected to electric power transfer line 432.
• Electric power transfer line 432 is electrically connected by means of compressor connecting line
• Electric power output line 432 is also electrically connected to-electric prime mover 436 which drives evaporator fan 438 and condensor fan 440.
• FIGURE 4 All of the elements described in FIGURE 4 are standard air conditioning components available from any large supply house such as Thermal Supply in Houston, Texas. All fluid conduits, whether for vapor or liquid fluids are low pressure copper tubing. The entire system is hermetically sealed and could use, for example, Freon-12 a a refrigerant.
• any desired analog or digital control system can be used in conjunction with the present invention to optimize its performance.
• the portion of sunlight from sun 406 falling on solar thermal collector 402 provides the Q c low level heat required to preheat the refrigerant prior to its compression as taught by the present invention.
• saturated vapor from evapor ator 424 is passed through line 430 into the upper end 428 of col- lector 402.
• Thermal radiation from the sun heats the refrigerant such that it achieves a, for example, 10 to 30 degree temperature rise by the time it exits the bottom 408 of collector 402 and returns through line 412 to the low pressure end of compressor 410.
• FIGURE 7 illustrates a stove, which is one method of practicing the present invention using wood or coal as an alternative to electricity or fuel oil.
• Stove 700 has an outer firebox 702 equipped with access doors 704 and 706.
• Firebox 702 has straight-wall sections 708 and an infundibularform flue transition section 710.
• a flue duct 712 is shown in sche ⁇ matic cross-section.
• Flue section 712 has external straight-wall members 714 which are connected at their upper end by welding or any 0 other convenient means to infundibularform stack transistion section 716.
• Stack transistion section 716 is joined at its upper end by welding or any other convenient means to smoke stack 718, which is in fluid communication with the atmosphere.
• the outer wall of stove 700 may be made of steel, brick or 5 any other convenient material sufficiently.refractory to withstand the heat generated by the stove's operation.
• the interior of the firebox section 708 of stove 700 is preferably lined with firebrick and is provided with a fluid communication to the atmosphere, not shown, by which fresh air may enter to support the combustion pro- o cess.
• flue passageway 724 is equipped with a damper 730 adapted to controllably open and shut flue section 724.
• flue section 726 is fitted with a controllable damper 732 and flue section 728 is fitted with a controllable damper 734.
• Damper 734 is shown open while dampers 732 and 730 are shov/n closed. 0 Any convenient manual or automatic control means may be used to control these dampers.
• a general utility heat exchanger 736 is 'shown operatively inplaced within flue segment 724.
• a source of cold fluid such as
• wood or some other renewable fuel is burned in the firebox 702 of stove 700.
• the fire either drawing air in from the room around it or from an outside source to avoid heat loss in the winter, the hot gas at several hundred degrees
• flue transistion section 710 Fahrenheit passes up through flue transistion section 710 into any of the flue segments 724, 726 or 728, whose damper is open. If all dampers are open equally, flue gas will flow through flue section 726 preferentially since this section contains no mechanical impedance, i.e. no heat exchanger.
• any desired energy flow through a given flue section may be accomplished, subject only to the total availability of heat coming from the fire burning in firebox 702.
• This relatively low grade flue heat generated by combustion process of wood or some other renewable fuel in the firebox of stove 700 passes in countercurrent heat exchange through exchangers 736, 114 with a cold fluid and refrigerant, respectively. This allows the present invention to be practiced through the use of alternative fuels.
• FIGURE 5 is a schematic detail of another embodiment of FIGURE 7 illustrating the use of a double-walled firebox in conjunc ⁇ tion with the present invention.
• a fluid communication passage 502 has one end 504 in fluid communication with the interior of unobstructed flue 726.
• Hot gas passageway 502 is in fluid communication at its other end 506 with the low pressure side of blower fan 508.
• the high pressure output side of fan 508 is. in fluid communication with hot gas passage 510, which, in turn, is in fluid communication with the annular interior 512 of double-walled firebox 514.
• Double-walled firebox 514 has a base 516 joined by welds or any other convenient means to outer wall 518.
• Outer wall 518 is preferably made of some material such as galvanized steel that is capable of readily transmitting heat from interior 512 to the ex ⁇ ternal environment.
• a layer of insulation 520 insulates base 516 from the interior firebox 522.
• Annularly, inwardly surrounding, but spaced apart from, wall 518 is an inner wall 524, which is heavily insulated with fiberglass, firebrick and the like.
• Output fluid duct 526 is in fluid communication with a portion of double-walled firebox interior 512 sufficiently distant from the entry point of inlet duct 510 that flue gas is forced to circulate essentially through the entirety of interior chamber 512 in its passage from inlet duct 510 to outlet duct 526.
• outlet duct 526 penetrates wall 722 in unobstructed flue 726 and is in fluid communication with the flue gas stream in vent 526.
• double-walled firebox 514 is well insulated and cool even if a fire is present in firebox 522.
• Modern insulating material is capable of maintaining a temperature differential of over 1000° Fahrenheit in the space of only a few inches.
• One example is the special insulation material developed for the Space Shuttle program, which is now available on the civilian market. The interior of a piece of this insulation may be white hot so that it glows while the other portion of the insul ⁇ ation may be cool enough to pick up and handle bare-handed without discomfort.
• the stove shown in FIGURE 5 will be operated in its insulated mode. This would allow wood or some other renewable fuel to be burned in a house without adversely affecting the system's operation designed to cool the house.
• FIGURE 6 shows the vapor compression refrigeration system illustrated schematically in FIGURE 2 adapted for use with the stove illustrated by FIGURES 7 and 5 above.
• an additional provision has been made to use flue gas to provide the mechanical work required to drive compressor 120 of the present invention.
• numbers that are the same as the numbers in FIGURES 2, 5 and 7 illustrate similar structures to the structures shown in the referenced figures.
• infundibularform transition member 710 and straight flue section 714 contain, in addition to first and second flue dividers 722 and 720, a third interior flue dividing wall 602.
• the provision of this additional wall creates an additional flue 604 as a companion to flues 728, 726 and 724.
• Flue 604 is equipped with an annular inverted cone-shaped nozzle 606 beneath and proximate turbine assembly 608, which may be a low-speed Pelton Wheel geared through a gear box 610 to rotate a shaft 612, which penetrates wall 714.
• turbine 608 may drive a generator or alter ⁇ nator and the electricity produced may be used to drive an electric prime mover to provide the work W p required to operate compressor 120.
• flue sections 724, 726, 728 and 604 in FIGURE 6 are shown as equal in size for ease of schematic illustration of the present invention, it should be understood that these flues may differ in size as is necessary to obtain the thermal or mechanical energy required to derive the heat exchange or mechanical energy that must be extracted from the flue gas to make the present invention a self-contained device.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Sorption Type Refrigeration Machines (AREA)

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• 1980
  • 1980-04-07 WO PCT/US1980/000355 patent/WO1981002923A1/en unknown
  • 1980-04-07 EP EP81900343A patent/EP0049242A1/de not_active Withdrawn

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