Heat pump energized by low-grade heat source

• US 5,729,988 A
• Filed: 01/04/1988
• Issued: 03/24/1998
• Est. Priority Date: 11/04/1974
• Status: Expired due to Fees

• Current Assignee: Dimiter I. Tchernev
• Original Assignee: Dimiter I. Tchernev
• Inventors: Tchernev, Dimiter I.
• Primary Examiner(s): Sollecito, John M.
• Application Number:
  US07/140,890
• Time in Patent Office: 3,732 Days
• Field of Search: 62/235.1, 62/480, 62/490, 126/428, 165/142, 165/486, 22/106
• US Class Current: 62/106
• CPC Class Codes: F25B 17/08 the absorbent or adsorbent being a solid, e.g. salt F25B17/12 takes precedence
• CPC Class Codes: F25B 27/007 in sorption type systems
• CPC Class Codes: F28D 20/003 using thermochemical reactions
• CPC Class Codes: Y02A 30/27 Relating to heating, ventilation or air conditioning [HVAC] technologies
• CPC Class Codes: Y02A 30/272 Solar heating or cooling
• CPC Class Codes: Y02B 10/20 Solar thermal
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]
• CPC Class Codes: Y02B 30/62 Absorption based systems
• CPC Class Codes: Y02E 60/14 Thermal energy storage

Abstract

A heat pump using zeolite as an adsorbent wherein thermal energy from adsorbent zeolite in one hermetically sealed space is used to heat desorbing zeolite located in another hermetically sealed space, such heat being conveyed by heat exchanger conduits containing a heat transfer fluid which, before heating the desorbed zeolite, has its temperature increased to within a range of about 200° F. (93° C.) to 400° F. (205° C.) by a gas flame or other heat source, the adsorption and desorption phases being changed between the zeolites in each cycle by reversing the fluid flow in the conduits. Cooling and heating for a building or other purposes are provided through the condenser and evaporator respectively for the working gas (water) which is desorbed and adsorbed into the zeolites. A propagating temperature front is established through the fluid-to-zeolite heat exchanger conduits to provide a utilization of as much as 90% of thermal energy available during the desorption/adsorption phases. The heating and cooling capacity of the system is modulated by varying (1) the heat transfer fluid flow rate, (2) the heat output from the heat source, or (3) the amount of the temperature increase of the heat transfer fluid when its flow is reversed.

Claims

1. An efficient system for heat utilization which comprises:

a container defining an hermetically sealed space which contains heat exchange means, a refrigerant, an adsorbent material in thermal communication with said heat exchange means adapted to adsorb said refrigerant in response to temperature changes of said heat exchange means, condenser means for condensing said refrigerant and evaporator means for evaporating said refrigerant;

said heat exchange means comprising conduit means extending through said container and defining a passageway therethrough hermetically separate from said space;

circulation means operatively associated with said heat exchange means for selectively causing a fluid to flow through said conduit means, said fluid propagating a relatively sharp temperature from in said material which is sufficiently hot that as said refrigerant is desorbed from said material along said temperature front, the pressure of vapor of said refrigerant said space is increased, said vapor received by said condenser means is condensed into liquid and collected in said evaporator means, and further selectively and successively reversing fluid flow through said conduit means, said reversed flow fluid propagating a relatively sharp low temperature front to cool said adsorbent material whereby said refrigerant is reabsorbed along said low temperature front said material from said evaporator means and pressure of said vapor in said space is lowered;

control means for said selective and successive reversing of said fluid flow substantially on the respective completions of the propagation of each of said temperature fronts through said conduit means; and

means for extracting energy from said condenser and said evaporator means.

2. A system in accordance with claim 1, wherein said adsorbent material is zeolite.

3. A system in accordance with claim 2, wherein said refrigerant is water.

4. A system in accordance with claim 2, wherein said first fluid after passing through said conduit means and having its temperature increased thereby is thereafter utilized as said reversed flow fluid and is heated by a low-grade heat source before being caused to flow through a further like heat exchange means in a further like container.

5. A system in accordance with claim 4, wherein said low-grade heat source is a mixture of air and combustion products.

6. A system in accordance with claim 4, wherein said low-grade heat source is waste heat.

7. A system in accordance with claim 4, wherein said low-grade heat source is solar energy.

8. A system in accordance with claim 4, wherein said fluid is substantially air.

9. A system in accordance with claim 4, wherein said conduit comprises a closed recirculating space which extends through said further like container.

10. A system in accordance with claim 9, wherein said fluid is a high temperature oil.

11. A system in accordance with claim 10, wherein said conduit in each said container is serpentine and has relative flat spaces between turns, said adsorbent material being received between said flat spaces and in surface to surface contact with said conduit.

12. A system in accordance with claim 11, wherein said conduit is composed of copper.

13. A system in accordance with claim 11, wherein said conduit is received in said container so as to prevent injurious vertical expansion by said conduit when the interior of the container surrounding said conduit and said adsorbent material is subjected to a partial vacuum.

14. A system in accordance with said claim 11, wherein said conduit in each said container is about thirty-five to sixty feet (10.6 to 18.3 meters) long.

15. A system in accordance with claim 14, wherein said conduit in each said container is about thirty-six feet (10.9 meters) long.

16. A system in accordance with claim 15, wherein said conduit'"'"'s flat spaces have a height of about one-half inch (12 mm) and a horizontal depth of at least six inches (15.2 cm) and said adsorbent material between said flat spaces has a thickness throughout of about 1/4" (6 mm).

17. A system in accordance with claim 10, wherein said conduit includes selectively reversible pumping means.

18. A system in accordance with claim 2, wherein said material is in an immediate thermal conduction arrangement with said conduit means and such components perform the function of causing said sharp temperature front to be propagated through said material in the direction of movement of said fluid when flowing therethrough.

19. A system in accordance with claim 1, wherein said container has substantially cylindrical sides and comprises said condenser means and said evaporator means with further conduit means Which circulates a liquid for cooling said condenser means and heating said evaporator means being incorporated in said sides.

20. Apparatus which receives its energy from a low-grade heat source and provides heating and cooling for the interior of a building, said apparatus being operable to execute reversible adsorption heat pump cycle, said apparatus comprising:

I. Two hermetically sealed spaces, each space including;

(a) an adsorbent material and a refrigerant, said adsorbent material being in thermal communication with a heat transfer fluid whereby in a desorption mode said fluid will provide heat to said material to desorb said refrigerant therefrom and in an adsorption mode said fluid will remove heat from said material to adsorb said refrigerant;

(b) condensing and vaporizing means for said refrigerant in thermal communication with said heat exchanger operative to exchange heat with said interior and selectively to heat or cool same;

II. Conduit means for conveying said heat transfer fluid which has been heated in the adsorption mode in one said space to be further heated by a low-grade heat source and received by other said space to heat said adsorbent in its desorption mode whereby heat may be supplied to said interior of a building from the respective condensing means of the spaces in the desorption mode or cooling supplied to said interior of a building from the respective vaporizing means of the spaces in the adsorption mode; and

III. control means to reverse the flow of said heat transfer fluid upon substantial completion of the adsorption mode in one space and the desorption mode in the other space.

21. Apparatus in accordance with claim 20, wherein said adsorbent material is zeolite.

22. Apparatus in accordance with claim 21, wherein said refrigerant is water.

23. Apparatus in accordance with claim 21, wherein said low-grade heat source is a gas flame.

24. Apparatus in accordance with claim 21, wherein the thermal communication between said material and said heat exchange fluid is provided by a heat exchanger characterized by a relatively low longitudinal thermal conductivity and a thermal communication with said material sufficiently efficient so that a relatively sharp temperature front is propagated through said heat exchanger when said first heat exchange fluid is conveyed therethrough.

25. Apparatus in accordance with claim 24, wherein said heat exchangers are composed of an alloy metal having a thermal conductivity in quantity of heat in calories transmitted per second through a plate one centimeter across in an area of one square centimeter with a temperature difference of 1°

C. which is not more than about 0.10.

26. Apparatus in accordance with claim 25, wherein said heat exchangers comprise tubes having a thickness of about one millimeter of less.

27. Apparatus in accordance with claim 26, wherein said material comprises sliced natural zeolite having thicknesses nor more than ten millimeters.

28. Apparatus in accordance with claim 20, wherein said heat transfer fluid is a high-temperature oil.

29. Apparatus in accordance with claim 28, wherein said conduit means comprises a closed recirculation channel which also includes selectively reversible pumping means.

30. A process for heating and cooling an interior space by using a low-grade heat source, the process comprising the steps of:

I. Providing first and second pressure tight enclosures, each enclosure having a working refrigerant, an adsorbent material, a condenser and evaporator means therein, said adsorbent material being in thermal communication with a conduit which is provided through each enclosure, said adsorbent material being capable of adsorbing said refrigerant exothermically;

II. Providing a low-grade heat source and means for it to be in selective thermal communication with said conduit for each said enclosure;

III. Raising the temperature of said material in a first of said enclosures in thermal communication with said conduit along a relatively sharp propagating temperature front said low-grade heat source;

IV Raising the vapor pressure of said refrigerant in said first enclosure and desorbing the refrigerant from said adsorbent material therein along said temperature front using said low-grade heat source;

V Allowing refrigerant vapor in said first enclosure to be received by said condenser therein, condensing said refrigerant vapor, and transferring said refrigerant'"'"'s heat of condensation to said internal space or to the atmosphere;

VI. Lowering the temperature of said material in the second of said enclosures in thermal communication with said conduit along a relatively sharp propagation temperature front, lowering the vapor pressure of said refrigerant in said second enclosure by absorbing said refrigerant by said absorbent along said temperature front and transferring the heat of adsorption thereby generated to said first enclosure in combination with heat from said low-grade heat source via said conduits; and

VIII. Repeating steps III through VII alternately in said enclosures upon substantial completion of the adsorption or desorption cycle therein.

31. A process in accordance with claim 30, wherein said adsorbent material is zeolite.

32. A process in accordance with claim 31, wherein said working, refrigerant is water.

33. A process in accordance with claim 31, wherein said low-grade heat source is a gas flame.

34. A process in accordance with claim 33, wherein said vapor pressure in step IV is increased to about fifty millimeters of murcury absolute.

35. A process in accordance with claim 33, wherein said refrigerant vapor in step V is condensed by said condenser at a temperature of about 100°

F. (38°

C.).

36. A process in accordance with claim 35, wherein said vapor pressure in step VI is reduced to at least ten millimeters of murcury absolute.

37. Apparatus for exchanging heat between a liquid and a solid adsorbent which comprises a conduit for said liquid which is composed of copper and has an effective thickness of about 0.5 millimeters or less, the thermal conductivity of said solid adsorbent being substantially less than said conduit, said solid adsorbent mounted on said conduit in immediate thermal communication therewith and having a thickness of not more than about six millimeters, said conduit and said solid adsorbent thereon being so arranged that a heat transfer takes place between said liquid flowing in said conduit and said solid adsorbent wherein said liquid and said solid adsorbent have different initial temperatures along a relatively sharp temperature front which moves along said solid adsorbent in the direction of said liquid'"'"'s movement, the temperature of said solid behind said front being about the same as said liquid behind said front and the temperature of said solid adsorbent remaining at about its initial temperature forward of said front.

38. Apparatus in accordance with claim 37, wherein said solid adsorbent is zeolite.

39. Apparatus in accordance with claim 38, wherein said initial temperature is about 100°

F. (38°

C.).

40. Apparatus in accordance with claim 39, wherein said temperature of said zeolite at said front is about 400°

F. (205°

C.).

41. Apparatus in accordance with claim 40, wherein said liquid comprises a high-temperature oil having a maximum viscosity in the range of about five to ten centistokes.

42. An efficient apparatus for heat utilization comprised of two separate hermetically-sealed solid-gas adsorption systems, heat exchange means connecting said systems, said beat exchange means including conduit means for the passage of a heat exchange fluid, said conduit means received in said system in a heat exchange relationship with adsorption material therein, said connection of said systems by said heat exchange means being arranged so that heat generated during the adsorption cycle of one said system is used in substantial part through said heat exchange means in the desorption cycle of the other said system, said conduit means being arranged with respect to at least one said system so as to be in an immediate thermal conduction relationship with said adsorption material which is disposed in limited quantity therealong so that a relatively sharp temperature front is propagated through said material in the direction of movement of said fluid flowing therethrough having a significantly different temperature than the temperature of said material forward of said propagated temperature front, whereby the need for external energy input for said desorption is greatly reduced.

43. Apparatus in accordance with claim 42, wherein zeolite is said adsorbent in each said system.

44. Apparatus in accordance with claim 43, wherein H₂ O is the adsorbate which is adsorbed and desorbed by said zeolite in said systems.

45. Apparatus in accordance with claim 42, wherein said heat exchange means is similarly arranged with respect to both said systems so that relatively sharp temperature fronts are propagated substantially simultaneously through both said systems.

46. Apparatus in accordance with claim 42, wherein said fluid comprises air.

47. Apparatus in accordance with claim 42, wherein said fluid is a high-temperature oil.

48. A method of operating a heat pump system between an upper operating temperature and a lower operating temperature comprising two solid adsorbent beds connected to the condenser and evaporator in a heat pump circuit so that desorbed refrigerant can flow from the bed by being heated into the condenser and refrigerant from the evaporator can flow into the bed being cooled comprising the steps of:

a) placing a separate heat exchanger in a heat transfer relationship with each bed and connecting the heat exchangers in series with each other in a closed fluid loop so that heat transfer fluid flows around the closed loop serially through the heat exchangers;

b) heating the heat transfer fluid passing between one of the ends of the beds to the upper operating temperature;

c) cooling the heat transfer fluid passing between the other ends of the beds to the lower operating temperature;

d) circulating the heat transfer fluid around the closed fluid loop serially through the heat exchangers so that the heat transfer fluid passes generally lengthwise of both beds where the circulation rate of the heat transfer fluid is such that the heated heat transfer fluid passing into the end of the bed heats the solid adsorbent bed from an initial cool bed temperature in the vicinity of the lower operating temperature while the bed cools the heat transfer fluid from the upper operating temperature down to about the initial cool bed temperature in a distance less than the length of the bed and with the cooled heat transfer fluid passing into the end of the other bed cooling the solid adsorbent bed from an initial hot bed temperature in the vicinity of the upper operating temperature while the bed heats the heat transfer fluid from the lower operating temperature up to about the initial hot bed temperature in a distance less than the length of the bed;

e) when the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by a prescribed amount less than about fifty percent (50%) of the difference between the initial bed temperature and inlet fluid temperature in step (b), changing the circulation of the heat transfer fluid so that the heated heat transfer fluid passes through the cooled bed and the cooled heat transfer fluid passes through the heated bed; and

f) when the exit temperature of the heat transfer fluid passing our of either of the beds shifts from the initial temperature of that bed by said prescribed amount in step (c), changing the circulation of the heat transfer fluid to step (b) to cycle the beds between the upper and lower operating temperatures.

49. The method of claim 48 wherein the heat transfer fluid is serially circulated through the beds in a first direction lengthwise of the beds during step (b) and in the opposite direction during step (c).

50. The method of claim 48 wherein the initial bed temperature of each of the beds during heating is the temperature to which the bed is raised from the lower operating temperature by pressurizing the bed from evaporator pressure to condenser pressure and the initial bed temperature of each of the beds during cooling is the temperature to which the bed is lowered from the upper operating temperature by depressurizing the bed from condenser pressure to evaporator pressure.

51. A heat pump system comprising:

a pair of solid adsorbent beds (136/183 in 120 and

     121);

a heat pump circuit (120/121, 122,

     124) connected to said solid adsorbent beds (136/183) so that said heat pump circuit (120/121, 122,

     124) is driven in response to the heating and cooling of said beds (136/183);

a heat transfer fluid (air, including, if heated by gas fuel, some combustion gases);

a pair of bed heat exchange means (120/125, 121/125), one of said bed heat exchange means operatively associated with each of said beds (136/183) so that the heat transfer fluid passing through each of said heat exchange means passes lengthwise (FIG.

     9) of said bed associated therewith in a single pass and each of said heat exchange means having opposed ends (192);

heating means (130) adapted to heat said exchange fluid to a prescribed upper operating temperature (400°

F.) connecting (by 127 and

     131) one of the ends of both of said bed heat exchange means (120/125, 121/125);

cooling means (170, 171,

     172) adapted to cool said heat exchange fluid to a prescribed lower operating temperature (100°

F.) connecting (via 126,

     132) the other of the ends of both of said bed heat exchange means (120/125, 121/125) so that said heat transfer fluid can flow serially from said heating means (130), through one of said bed heat exchange means (121/125), through said cooling means, through the other of said bed heat exchange means (120/125) and back to said heating means (130) to define a heat transfer circuit;

circulation means (151 or

     152) for alternatively circulating said heat transfer fluid (air) in one direction around the heat transfer circuit so that one of said beds (120, 136/183) is cooled while the other of said/beds (121, 136/183) is heated, and in the alternate direction around the heat transfer circuit so that said other of said beds (121, 136/183) is cooled while said one of said beds (120, 136/183) is heated where the circulation rate of the heat transfer fluid is such that the heated heat transfer fluid passing into the end of one of said heat exchange means heats said solid adsorbent bed associated therewith from an initial cool bed temperature (100°

F., FIG.

     4) in the vicinity of the lower operating temperature (100°

F.) while said bed cools the heat transfer fluid from the upper operating temperature (400°

F.) down to about the initial cool bed temperature (100°

F.) in a distance less than the length of said bed and with the cooled heat transfer fluid passing into the end of the other of said heat exchanger means cooling said ,solid adsorbent bed associated therewith from an initial hot bed temperature (400°

F., FIG.

     4) in the vicinity of the upper operating temperature (400°

F.) while said bed heats the heat transfer fluid from the lower operating temperature (100°

F.) up to about the initial hot bed temperature (400°

F.) in a distance less than the length of the bed in order for heat exchanged between said heat transfer fluid and each of said beds to generate a thermal wave in the temperature profiles lengthwise of said beds moving through each of said beds (see FIGS. 6, 15 and

     16); and

control means (sensors in 126, 127, 131 and

     132) operatively associated with said heat transfer fluid passing out of said beds and with said circulation means (151 or

     152) to cause said circulation means to reverse the circulation direction of said heat transfer fluid (air) around said heat transfer circuit when either of the thermal wave reaches that end of said bed (136/183) from which said heat transfer fluid (air) exits.

52. A method of operating a heat pump system including a heat pump loop and a heating loop where the heat pump loop includes a pair of solid adsorbent beds connected to a condenser and an evaporator with an expansion device therebetween so that refrigerant flows from the bed being heated to the condenser while the refrigerant can flow from the evaporator to the bed being cooled, and where the heating loop includes a heat exchanger associated with each bed design so that when a heat transfer fluid is flowing therethrough, a thermal temperature gradient or wave will be generated along the bed together with a cooling heat exchanger between one of the ends of the beds and a heating means between the other ends of the beds comprising the steps of:

circulating the heat transfer fluid around the heating loop until the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by at least about twenty percent (20%) of the difference between the initial bed temperature and inlet fluid temperature; and

then reversing the flow of the heat transfer fluid around the heating loop each time the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by at least about twenty percent (20%) of the difference between the initial bed temperature and inlet fluid temperature.

53. A heat pump system comprising:

a pair of solid adsorbent beds;

a heat pump circuit connected to said solid adsorbent beds so that said heat pump circuit is driven in response to the heating and cooling of said beds;

a heat transfer fluid;

a pair of bed heat exchange means, one of said bed heat exchange means operatively associated with each of said beds so that the heat transfer fluid passing through each of said heat exchange means passes lengthwise of said bed associated therewith in a single pass and each of said heat exchange means having opposed ends;

heating means adapted to heat said heat exchange fluid to a prescribed upper operating temperature connecting one of the ends of both of said bed heat exchange means;

cooling means adapted to cool said heat exchange fluid to a prescribed lower operating temperature connecting the other ends of both of said bed heat exchange means so that said heat transfer fluid can flow serially from said heating means, through one of said bed heat exchange means, through said cooling means, through the other of said bed heat exchange means and back to said heating means to define a heat transfer circuit;

circulation means for alternatively circulating said heat transfer fluid in one direction around the heat transfer circuit so that one of said beds is cooled while the other of said beds is heated, and in the alternate direction around the heat transfer circuit so that said other of said beds is cooled while said one of said beds is heated where the circulation rate of the heat transfer fluid is such that the heated heat transfer fluid passing into the end of one of said heat exchange means heats said solid adsorbent bed associated therewith from an initial cool bed temperature in the vicinity of the lower operating temperature while said bed cools the heat transfer fluid from the upper operating temperature down to about the initial cool bed temperature in a distance less than 0.8 times the length of said bed and with the cooled heat transfer fluid passing into the end of the other of said heat exchanger means cooling said solid adsorbent bed associated therewith from an initial hot bed temperature in the vicinity of the upper operating temperature while said bed heats the heat transfer fluid from the lower operating temperature up to about the initial hot bed temperature in a distance less than 0.8 times the length of the bed in order for heat exchanged between said heat transfer fluid and each of said beds to generate a thermal wave in the temperature profiles lengthwise of said beds moving through each of said beds; and

control means operatively associated with said heat transfer fluid passing out of said beds and with said circulation means to cause said circulation means to reverse the circulation direction of said heat transfer fluid around said heat transfer circuit when either of the thermal wave reaches that end of said bed from which said heat transfer fluid exits.

64. The system of claim 53 wherein said control means is constructed and arranged to reverse the direction of heat transfer fluid flow when the exit temperature of the heat transfer fluid flow passing out of either of the beds shifts from the initial temperature of that bed by at least about twenty percent (20%) of the difference between the initial bed temperature and inlet fluid temperature.

65. The system of claim 53 wherein the thermal wavelength is less than about 0.7 times the bed length.

54. A method of operating a heat pump system including a heat pump loop and a heating loop where the heat pump loop includes a pair of solid adsorbent beds connected to a condenser and an evaporator with an expansion device therebetween so that refrigerant flows from the bed being heated to the condenser while the refrigerant can flow from the evaporator to the bed being cooled, and where the heating loop includes a heat exchanger associated with each bed designed so that when a heat fluid is flowing therethrough, a thermal temperature gradient or wave will be generated along the bed together with a cooling heat exchanger between one of the ends of the beds and a heating means between the other ends of the beds comprising the steps of:

circulating the heat transfer fluid around the heating loop to drive the heat pump loop; and

varying the heat transfer fluid flow rate to vary the heating and cooling capacity of the system.

55. A method of operating a heat pump system including a heat pump loop (200c, 207, 234, 235) and a heating loop (205-202-200c-201-204-201-200c-202) where the heat pump loop includes a pair of solid adsorbent beds (196, 190) connected to a condenser (200c, 196, 190) and an evaporator (200c, 196, 190) with an expansion device (234, 235, 236, 232) therebetween so that refrigerant flows from the bed being heated (196, 190) to the condenser (200c, 207) while the refrigerant (water) can flow from the evaporator (200c, 207) to the bed (196, 190) being cooled,

and where the heating loop (205-202-200c-201-204-201-200c-202) includes a heat exchanger (196, 194) associated with each bed (196, 190) designed so that when a heat fluid is flowing therethrough, a thermal temperature gradient or wave (FIGS. 15, 16) will be generated along the bed (196, 190) together with a cooling heat exchanger (Page 36, lines 18-20) between one the ends (FIG. 22) of the beds (196, 190) and a heating means (205) between the other ends (FIG. 22) of the beds (196, 190) comprising the steps of:

circulating (by variable speed gear pump

     204) the heat transfer fluid (high temperature oil) around the heating loop (205-202-200c-204-201-200c-202) at a prescribed flow rate (inherent in pump

     204) to drive the heat pump loop (200c, 207, 234,

     235); and

varying the heat output of the heating means (thermostatically controlled boiler

     205) to vary the heating cooling capacity of the system (inherent in system).

56. A method of operating a heat pump system including a heat pump loop and a heating loop where the heat pump loop includes a pair of solid adsorbent beds connected to a condenser and an evaporator with an expansion device therebetween so that refrigerant flows from the bed being heated to the condenser while the refrigerant can flow from the evaporator to the bed being cooled, and where the heating loop includes a heat exchanger associated with each bed designed so that when a heat fluid is flowing therethrough, a thermal temperature gradient or wave will be generated along the bed together with a cooling heat exchanger between one of the ends of the beds and a heating means between the other ends of the beds comprising the steps of:

circulating the heat transfer fluid around the heating loop until the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by a prescribed percentage of the difference between the initial bed temperature and inlet fluid temperature;

then reversing the flow of the heat transfer fluid around the heating loop each time the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by said prescribed percentage of the difference between the initial bed temperature and inlet fluid temperature; and

varying the heating capacity of the system by varying said prescribed percentage whereby the heating capacity is increased as said prescribed percentage is increased and vice versa.

57. The method of claim 56 further including the step of configuring the beds and heat exchangers so that the thermal wave generated in the beds has a wavelength less than about 0.8 times the bed length.

58. The method of claim 56 further including the step of varying the heat transfer fluid flow rate to vary the heating and cooling capacity of the system.

59. The method of claim 56 further including the step of varying the heating capacity of the system by varying the percentage above twenty percent (20%) of the exit temperature shift of the heat transfer fluid with respect to the difference between initial bed temperature and inlet fluid temperature before the flow of heat transfer fluid is reversed.

60. The method of claim 56 further including the step of varying the output temperature of the heat transfer fluid from the heating means to vary the heating and cooling capacity of the system.

61. The method of claim 57 wherein the thermal wavelength is less than about 0.7 times the bed length.

62. The method of claim 61 further including the step of varying the heat transfer fluid flow rate to vary the heating and cooling capacity of the system.

63. The method of claim 62 where the system is designed based on a prescribed set of operating parameters and further includes the step of varying the heating and cooling capacity of the system by:

(a) varying the heating and cooling capacity by varying the heat transfer fluid flow rate when the system is operating below said prescribed set of operating parameters; and

(b) varying the heating capacity by varying the percentage above twenty percent (20%) of the exit temperature shift of the heat transfer fluid with respect to the difference between initial bed temperature and inlet fluid temperature before the flow of heat transfer fluid is reversed when the system is operating above said prescribed set of operating parameters.

66. An efficient system for heat utilization which comprises:

a container defining an hermetically sealed space which contains heat exchange means, a refrigerant, an adsorbent material in thermal communication with said heat exchange means adapted to adsorb and desorb said refrigerant in response to temperature changes of said heat exchange means, condenser means for condensing said refrigerant and evaporator means for evaporating said refrigerant;

said heat exchange means comprising conduit means extending through said container and defining a passageway therethrough hermetically separate from said space;

circulation means operatively associated with said heat exchange means and with control means for selectively causing a heated fluid to flow through said conduit means, said conduit means being in sufficiently effective thermal communication with said fluid and said adsorbent material that said fluid propagates a relatively sharp high temperature front that moves in said adsorbent material in the same direction as said fluid flows in said conduit means and causes said refrigerant to be desorbed from said adsorbent material along said temperature front, whereby the pressure of vapor of said refrigerant in said space is raised, said condenser means adapted to receive said vapor and condense it into liquid whereupon said evaporator means receives said condensed liquid, said circulation means and said control means further selectively and successively reversing fluid flow through said conduit means so that said relatively cool reversed flowing fluid propagates a relatively sharp low temperature front to cool said adsorbent material whereby said refrigerant is reabsorbed by said adsorbent material along said low temperature front, said refrigerant being evaporated from said evaporator means and pressure of said vapor in said space being lowered;

said control means adapted to effect said selective and successive reversing of said fluid flow substantially on respective completions of the propagation of each of said temperature fronts through said adsorbent material; and

means for extracting energy selectively from said condenser means and said evaporator means.

67. A method of operating a heat pump system between an upper operating temperature and a lower operating temperature comprising two solid adsorbent beds connected to condenser means and evaporator means in a heat pump circuit so that desorbed refrigerant can flow from the bed by being heated into the condenser means and refrigerant from the evaporator means can flow into the bed being cooled, the method comprising the steps of:

(a) placing a separate heat exchanger in a heat transfer relationship with each bed and connecting the heat exchangers in series with each other in a fluid loop so that heat transfer fluid flows in the loop serially through the heat exchangers;

(b) heating the heat transfer fluid passing between one of the ends of the beds to the upper operating temperature;

(c) cooling the heat transfer fluid passing between the other ends of the beds to the lower operating temperature;

(d) circulating the heat transfer fluid in the fluid loop serially through the heat exchangers so that the heat transfer fluid passes generally through the effective length of both beds, the circulation rate of the heat transfer fluid being such that the heated heat transfer fluid passing into the end of the bed heats that solid adsorbent bed from an initial cool bed temperature while that bed cools the heat transfer fluid from the upper operating temperature down to about the initial cool bed temperature in a distance less than the effective length of that bed and with the cooled heat transfer fluid passing into the end of the other bed cooling such other solid adsorbent bed from an initial hot bed temperature in the vicinity of the upper operating temperature while such other bed heats the heat transfer fluid from the lower operating temperature up to about the initial hot bed temperature in a distance less than the effective length of such other bed;

(e) upon the exit temperature of the heat transfer fluid passing out of either of the beds shifting from the initial temperature of that bed by a selected amount which is less than about fifty percent (50%) of the difference between the initial bed temperature and inlet fluid temperature in step (b), changing the circulation of the heat transfer fluid so that the heated heat transfer fluid passes through the just cooled bed and the cooled heat transfer fluid passes through the just heated bed; and

(f) upon the exit temperature of the heat transfer fluid passing out of either of the beds shifting from the initial temperature of that bed by said selected amount in step (c), changing the circulation of the heat transfer fluid to step (b) to cycle the beds between the upper and lower operating temperatures.

68. The method of claim 67 wherein each of said beds comprises a plurality of tiles composed of zeolite.

69. A heat pump system comprising:

a pair of solid adsorbent beds;

a heat pump circuit connected to said solid adsorbent beds so that said heat pump circuit is driven in response to the heating and cooling of said beds;

a heat transfer fluid;

a pair of bed heat exchange means, each one of said bed heat exchange means operatively associated with a respective one of said beds so that the heat transfer fluid passes through the effective length each of said heat exchange means associated therewith each respective bed in a single pass, each said heat exchange means having opposed ends;

heating means adapted to heat said heat exchange fluid to a prescribed upper operating temperature connecting one of the ends of both of said bed heat exchange means;

cooling means adapted to cool said heat exchange fluid to a prescribed lower operating temperature connecting the other of the ends of both of said bed heat exchange means so that said heat transfer fluid can flow from said heating means, through one of said bed heat exchange means, through said cooling means and back through the other of said bed heat exchange means to said heating means to define a heat transfer circuit;

circulation means for alternatively circulating said heat transfer fluid in one direction in the heat transfer circuit so that one of said beds is cooled while the other of said beds is heated, and in the alternate direction in heat transfer circuit so that said other of said beds is cooled while said one of said beds is heated, the circulation rate of the heat transfer fluid being such that the heated heat transfer fluid passing into the end of one of said bed heat exchange means heats said solid adsorbent bed associated therewith from an initial cool bed temperature in the vicinity of the lower operating temperature while said bed cools the heat transfer fluid from the upper operating temperature down to about the initial cool bed temperature in a distance less than the length of said bed and with the cooled heat transfer fluid passing into the end of the other of said bed heat exchanger means cooling said solid adsorbent bed associated therewith from an initial hot bed temperature in the vicinity of the upper operating temperature while said bed heats the heat transfer fluid from the lower operating temperature up to about the initial hot bed temperature in a distance less than the length of the bed in order for heat exchanged between said heat transfer fluid and each of said beds to generate a thermal wave in the temperature profiles moving through the effective length of each of said beds; and

control means operatively associated with said heat transfer fluid passing out of said beds and with said circulation means to cause said circulation means to reverse the circulation of said heat transfer fluid around said heat transfer circuit when either of the thermal wave reaches that end of said bed from which said heat transfer fluid exits.

70. The heat pump system of claim 69 wherein each of said beds comprises a plurality of tiles which are composed of zeolite.

71. A method of operating a heat pump system that includes a pair of solid adsorbent beds connected to condenser means and evaporator means so that refrigerant flows from the bed being heated to said condenser means while the refrigerant flows from said evaporator means to the bed being cooled, and includes a bed heat exchanger associated with each bed which is designed so that when a heat transfer fluid flows therethrough, a thermal temperature gradient or wave is generated along each bed, the method comprising the steps of:

circulating the heat transfer fluid through said bed heat exchangers until the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by at least about twenty percent (20%) of the difference between the initial bed temperature and inlet fluid temperature; and

then reversing the flow of the heat transfer fluid in each of said beds each time the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by at least about twenty percent (20%) of the difference between the initial bed temperature and inlet fluid temperature.

72. A heat pump system comprising:

a pair of solid adsorbent beds;

a heat pump circuit connected to said solid adsorbent beds so that said heat pump circuit is driven in response to the heating and cooling of said beds;

a heat transfer fluid;

a pair of bed heat exchange means, each one of said bed heat exchange means operatively associated with a respective one of said beds so that the heat transfer fluid passes through each of said bed heat exchange means in a single pass, each of said bed heat exchange means having opposed ends;

heating means adapted to heat said heat exchange fluid to prescribed upper operating temperature connecting one of the ends of both of said bed heat exchange means;

cooling means adapted to cool said heat exchange fluid to a prescribed lower operating temperature connecting the other of the ends of both of said bed heat exchange means so that said heat transfer fluid flows from said heating means, through one of said bed heat exchange means, through said cooling means, back through the other of said bed heat exchange means to said heating means to define a heat transfer circuit;

circulation means for alternatively circulating said heat transfer fluid in one direction around the heat transfer circuit so that one of said beds is cooled while the other of said beds is heated, and in the alternate direction around the heat transfer circuit so that said other of said beds is cooled while said one of said beds is heated, the rate of circulation rate the heat transfer fluid being such that the heated heat transfer fluid passing into the end of one of said bed heat exchange means heats said solid adsorbent bed associated therewith from an initial cool bed temperature in the vicinity of the lower operating temperature while said bed cools the heat transfer fluid from the upper operating temperature down to about the initial cool bed temperature in a distance less than about 0.8 times the effective length of said bed and with the cooled heat transfer fluid passing into the end of the other of said bed heat exchanger means cooling said solid adsorbent bed associated therewith from an initial hot bed temperature in the vicinity of the upper operating temperature while said bed heats the heat transfer fluid from the lower operating temperature up to about the initial hot bed temperature in a distance less than about 0.8 times the effective length of the bed in order for heat exchanged between said heat transfer fluid and each of said beds to generate a thermal wave in the temperature profiles lengthwise of said beds moving through each of said beds; and

control means operatively associated with said heat transfer fluid passing out of said beds and with said circulation means to cause said circulation means to reverse the circulation direction of said heat transfer fluid around said heat transfer circuit about when either of the thermal wave reaches that end of said bed from which said heat transfer fluid exits.

73. A method of operating a heat pump system including a heat pump loop and a heating loop where the heat pump loop includes a pair of solid adsorbent beds connected to a condenser and an evaporator with an expansion device therebetween so that refrigerant flows from the bed being heated to the condenser while the refrigerant flows from the evaporator to the bed being cooled, and where the heating loop includes a heat exchanger associated with each bed designed so that when a heat fluid is flowing therethrough, a thermal temperature gradient or wave is generated along each bed, together with a cooling heat exchanger between one of the ends of the beds and a heating means between the other ends of the beds, the method comprising the steps of:

circulating the heat transfer fluid around the heating loop to drive the heat pump loop; and

providing means for varying the heat transfer fluid flow rate to vary the heating and cooling capacity of the system.

74. A method of operating a heat pump system including a heat pump loop and a heating loop where the heat pump loop includes a pair of solid adsorbent beds connected to a condenser and an evaporator with an expansion device therebetween so that refrigerant flows from the bed being heated to the condenser while the refrigerant can flow from the evaporator to the bed being cooled, and where the heating loop includes a heat exchanger associated with each bed designed so that when a heated fluid is flowing therethrough, a thermal temperature gradient or wave is generated along the bed, together with a cooling heat exchanger between one of the ends of the beds and a heating means between the other ends of the beds, the method comprising the steps of:

circulating the heat transfer fluid around the heating loop at a selected flow rate to drive the heat pump loop; and

varying the heat output of the heating means to vary the heating and cooling capacity of the system.

75. A method of operating a heat pump system including a heat pump loop and a heating loop where the heat pump includes a pair of solid adsorbent beds connected to condenser means and evaporator means with an expansion device between said beds so that refrigerant flows from the bed being heated to said condenser means while the refrigerant flows from said evaporator means to the bed being cooled, and where the heating loop includes a heat exchanger associated with each bed designed so that when a heated fluid is flowing therethrough, a thermal temperature gradient or wave is generated along the bed, together with a cooling heat exchanger between one of the ends of the beds and a heating means between the other ends of the beds, the method comprising the steps of:

circulating the heat transfer fluid around the heating loop until the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the Initial temperature of that bed by a prescribed percentage of the difference between the initial bed temperature and inlet fluid temperature;

then reversing the flow of the heat transfer fluid around the heating loop each time the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by said prescribed percentage of the difference between the initial bed temperature and inlet fluid temperature; and

varying the heating capacity of the system by varying said prescribed percentage whereby the heating capacity is increased as said prescribed percentage is increased and vice versa.

76. A heat pump system comprising:

a pair of solid adsorbent beds;

a heat pump circuit connected to said solid adsorbent beds so that said heat pump circuit is driven in response to the heating and cooling of said beds;

a heat transfer fluid;

a pair of bed heat exchange means, one of said bed heat exchange means operatively associated with each of said beds so that the heat transfer fluid passing through each of said heat exchange means passes lengthwise of said bed associated therewith in a single pass and each of said heat exchange means having opposed ends;

heating means adapted to heat said heat transfer fluid to a prescribed upper operating temperature connecting one of the ends of both of said bed heat exchange means so that said heat transfer fluid can flow serially from said heating means, through one of said bed heat exchange means, through the other of said bed heat exchange means and back to said heating means to define a heat transfer circuit;

circulation means for alternatively circulating said heat transfer fluid in one direction around the heat transfer circuit so that one of said beds is cooled while the other of said beds is heated, and in the alternate direction around the heat transfer circuit so that said other of said beds is cooled while said one of said beds is heated where the circulation rate of the heat transfer fluid is such that the heated heat transfer fluid passing into the end of one of said heat exchange means heats said solid adsorbent bed associated therewith from an initial cool bed temperature in the vicinity of the heat transfer fluid'"'"'s lower operating temperature while said bed cools the heat transfer fluid from the upper operating temperature down to about the initial cool bed temperature in a distance less than the length of said bed and with the cooled heat transfer fluid passing into the end of the other of said heat exchanger means cooling said solid adsorbent bed associated therewith from an initial hot bed temperature in the vicinity of the upper operating temperature while said bed heats the heat transfer fluid from the lower operating temperature up to about the initial hot bed temperature in a distance less than the length of the bed in order for heat exchanged between said heat transfer fluid and each of said beds to generate a thermal wave in the temperature profiles lengthwise of said beds moving through each of said beds; and

control means operatively associated with said heat transfer fluid passing out of said beds and with said circulation means to cause said circulation means to reverse the circulation direction of said heat transfer fluid around said heat transfer circuit when either of the thermal wave reaches that end of said bed from which said heat transfer fluid exits.

77. A heat pump system in accordance with claim 76 wherein means adapted to cool said heat exchange fluid to lower operating temperature is provided between the other ends of both said bed heat exchange means and is included in said heat transfer circuit.

78. A method of operating a heat pump system including a heat pump loop and a heating loop where the heat pump loop includes a pair of solid adsorbent beds connected to a condenser and an evaporator with a pressure reducing device therebetween so that refrigerant flows from the bed being heated to the condenser while the refrigerant can flow from the evaporator to the bed being cooled,

and where the heating loop includes a heat exchanger associated with each bed designed so that when a heat fluid is flowing therethrough, thermal temperature gradient or wave will be generated along the bed together with a heating means between one of the ends of the beds comprising the steps of:

circulating the heat transfer fluid around the heating loop at a prescribed flow rate to drive the heat pump loop; and

varying the heat output of the heating means to vary the heating and cooling capacity of the system.

79. A method in accordance with claim 78 wherein the heat pump system comprises a heat exchanger which cools said heat fluid provided between the other ends of the beds.

80. A method of operating a heat pump system that includes a pair of solid adsorbent beds connected to condenser means and evaporator means so that refrigerant flows from the bed being heated to said condenser means while the refrigerant flows from said evaporator means to the bed being cooled, and includes a bed heat exchanger associated with each bed which is designed so that when a heat transfer fluid flows therethrough, a thermal temperature gradient or wave is generated along each bed, heating means for heating said transfer fluid between the first ends of the beds, a cooling heat exchanger between the other ends of the beds, the method comprising the steps of:

circulating the heat transfer fluid through said bed heat exchangers until the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by at least about twenty percent (20%) of the difference between the initial bed temperature and inlet fluid temperature; and

then reversing the flow of the heat transfer fluid in each of said beds each time the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by at least about twenty percent (20%) of the difference between the initial bed temperature and inlet fluid temperature.

81. A heat pump system comprising:

a pair of solid adsorbent beds;

a heat pump circuit connected to said solid adsorbent beds so that said heat pump circuit is driven in response to the heating and cooling of said beds;

a heat transfer fluid;

a heat transfer circuit adapted to serially pass said heat transfer fluid through said beds with said heat transfer fluid entering the end of one of said beds at the upper operating temperature and with the heat transfer fluid entering the end of the other of said beds at the lower operating temperature;

a pair of bed heat exchange means, one of said bed heat exchange means operatively associated with each of said beds so that the heat transfer fluid passing through each of said heat exchange means passes lengthwise of said bed associated therewith in a single pass and each of said heat exchange means having opposed ends;

circulation means for alternatively circulating said heat transfer fluid in one direction around the heat transfer circuit so that one of said beds is cooled while the other of said beds is heated, and in the alternate direction around the heat transfer circuit so that said other of said beds is cooled while said one of said beds is heated where the circulation rate of the heat transfer fluid is such that the heated heat transfer fluid passing into the end of one of said heat exchange means heats said solid adsorbent bed associated therewith from an initial cool bed temperature in the vicinity of the lower operating temperature while said bed cools the heat transfer fluid from the upper operating temperature down to about the initial cool bed temperature in a distance less than the length of said bed and with the cooled heat transfer fluid passing into the end of the other of said heat exchanger means cooling said solid adsorbent bed associated therewith from an initial hot bed temperature in the vicinity of the upper operating temperature while said bed heats the heat transfer fluid from the lower operating temperature up to about the initial hot bed temperature in a distance less than the length of the bed in order for heat exchanged between said heat transfer fluid and each of said beds to generate a thermal wave in the temperature profiles lengthwise of said beds moving through each of said beds; and

control means operatively associated with said heat transfer fluid passing out of said beds and with said circulation means to cause said circulation means to reverse the circulation direction of said heat transfer fluid around said heat transfer circuit when either of the thermal waves reaches that end of said bed from which said heat transfer fluid exits.

82. A method of operating a heat pump system that includes a pair of solid adsorbent beds connected to condenser means and evaporator means so that refrigerant flows from the bed being heated to said condenser means while the refrigerant flows from said evaporator means to the bed being cooled, and includes a bed heat exchanger associated with each bed which is designed so that, when a heat transfer fluid flows therethrough, a thermal temperature wave or front is generated along each bed, the method comprising the steps of:

circulating the heat transfer fluid through said bed heat exchangers until the thermal temperature wave or front reaches the end of the bed; and

then reversing the flow of the heat transfer fluid in each of said beds each time the thermal temperature wave or front reaches the end of the bed.

83. A heat pump system comprising:

a pair of solid adsorbent beds;

a heat pump circuit connected to said solid adsorbent beds so that said heat pump circuit is driven in response to the heating and cooling of said beds;

a heat transfer fluid;

a heat transfer circuit adapted to serially pass said heat transfer fluid through said beds with said heat transfer fluid entering the end of one of said beds at the upper operating temperature and with the heat transfer fluid entering the end of the other of said beds at the lower operating temperature;

a pair of bed heat exchange means, one of said bed heat exchange means operatively associated with each of said beds so that the heat transfer fluid passing through each of said heat exchange means passes lengthwise of said bed associated therewith in a single pass and each of said heat exchange means having opposed ends;

circulation means for alternatively circulating said heat transfer fluid in one direction around the heat transfer circuit so that one of said beds is cooled while the other of said beds is heated, and in the alternate direction around the heat transfer circuit so that said other of said beds is cooled while said one of said beds is heated where the circulation rate of the heat transfer fluid is such that the heated heat transfer fluid passing into the end of one of said heat exchange means heats said solid adsorbent bed associated therewith from an initial cool bed temperature in the vicinity of the lower operating temperature while said bed cools the heat transfer fluid from the upper operating temperature down to about the initial cool bed temperature in a distance less than the length of said bed and with the cooled heat transfer fluid passing into the end of the other of said heat exchanger means cooling said solid adsorbent bed associated therewith from an initial hot bed temperature in the vicinity of the upper operating temperature while said bed heats the heat transfer fluid from the lower operating temperature up to about the initial hot bed temperature in a distance less than the length of the bed in order for heat exchanged between said heat transfer fluid and each of said beds to generate a thermal wave in the temperature profiles lengthwise of said beds moving through each of said beds; and

control means operatively associated with said heat transfer fluid passing out of said beds and with said circulation means to cause said circulation means to reverse the circulation direction of said heat transfer fluid around said heat transfer circuit when the temperature of said heat transfer fluid exiting either of said beds changes a prescribed amount less than about fifty percent (50%) of the difference between the temperature of said bed when said heat transfer fluid circulation direction was last reversed and the temperature of the heat transfer fluid entering the bed.

84. A method of operating a heat pump system that includes a pair of solid adsorbent beds connected to condenser means and evaporator means so that refrigerant flows from the bed being heated to said condenser means while the refrigerant flows from said evaporator means to the bed being cooled, and includes a bed heat exchanger associated with each bed which is designed so that when a heat transfer fluid flows therethrough, a thermal temperature gradient or wave is generated along each bed, the method comprising the steps of:

circulating the heat transfer fluid through said bed heat exchangers until the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by less than about fifty percent (50%) of the difference between the initial bed temperature and inlet fluid temperature; and

then reversing the flow of the heat transfer fluid in each of said beds each time the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed by less than about fifty percent (50%) of the difference between the initial bed temperature and inlet fluid temperature.

85. A method of operating a heat pump system including a heat pump loop and a heating loop where the heat pump loop includes a pair of solid adsorbent beds connected to a condenser and an evaporator with an expansion device therebetween so that refrigerant flows from the bed being heated to the condenser while the refrigerant can flow from the evaporator to the bed being cooled, and where the heating loop includes a heat exchanger associated with each bed designed so that when a heat transfer fluid is flowing therethrough, a thermal temperature gradient or wave will be generated along the bed together with a cooling heat exchanger between one of the ends of the beds and a heating means between the other ends of the beds comprising the steps of:

circulating the heat transfer fluid around the heating loop to drive the heat pump loop; and

varying the heating and cooling capacity of the system by one of the following substeps;

a) varying the heat transfer fluid flow rate,

b) varying the heat output of the heating means, or

c) varying the prescribed percentage of the difference between the initial bed temperature and inlet fluid temperature that the exit temperature of the heat transfer fluid passing out of either of the beds shifts from the initial temperature of that bed whereby the heating capacity is increased as said prescribed percentage is increased and vice versa.