Centrifugal heat transfer engine and heat transfer systems embodying the same

• US 20030145621A1
• Filed: 10/04/2002
• Published: 08/07/2003
• Est. Priority Date: 06/12/1992
• Status: Active Grant

• Current Assignee: Kelix Heat Transfer Systems, LLC
• Original Assignee: Kelix Heat Transfer Systems, LLC
• Inventors: Kidwell, John E.
• Granted Patent: US 6,964,176 B2
• Time in Patent Office: Days
• US Class Current: 62/499
• CPC Class Codes: F25B 21/02 using Peltier effect; using Nernst-Ettinghausen effect
• CPC Class Codes: F25B 25/00 Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00
• CPC Class Codes: F25B 3/00 Self-contained rotary compression machines, i.e. with compressor, condenser and evaporator rotating as a single unit

Abstract

A heat transfer engine having cooling and heating modes of reversible operation, in which heat can be effectively transferred within diverse user environments for cooling, heating and dehumidification applications. The heat transfer engine of the present invention includes a rotor structure which is rotatably supported within a stator structure. The stator has primary and secondary heat exchanging chambers in thermal isolation from each other. The rotor has primary and secondary heat transferring portions within which a closed fluid flow circuit is embodied. The closed fluid flow circuit within the rotor has a spiraled fluid-return passageway extending along its rotary shaft, and is charged with a refrigerant which is automatically circulated between the primary and secondary heat transferring portions of the rotor when the rotor is rotated within an optimized angular velocity range under the control of a temperature-responsive system controller. During the cooling mode of operation, the primary heat transfer portion of the rotor carries out an evaporation function within the primary heat exchanging chamber of the stator structure, while the secondary heat transfer portion of the rotor carries out a condenser function within the secondary heat exchanging chamber of the stator. During the cooling mode of operation, a vapor-compression refrigeration process is realized by the primary heat transfer portion of the rotor performing an evaporation function within the primary heat exchanging chamber of the stator structure, while the secondary heat transfer portion of the rotor performs a condenser function within the secondary heat exchanging chamber of the stator. During the heating mode of operation, a vapor-compression refrigeration process is realized by the primary heat transfer portion of the rotor performing a condenser function within the primary heat exchanging chamber of the stator structure, while the secondary heat transfer portion of the rotor performs an evaporation function within the secondary heat exchanging chamber of the stator. By virtue of the present invention, a technically feasible heat transfer engine is provided which avoids the need for conventional external compressors, while allowing the use of environmentally safe refrigerants. Various embodiments of the heat transfer engine are disclosed, in addition to methods of manufacture and fields and applications of use.

Claims

1. A heat transfer engine for transferring heat between first and second heat exchanging circuits, comprising:

a stationary housing having first and second heat transfer chambers, and a thermal isolation barrier disposed therebetween, said first and second heat transfer chambers each having first and second ports and a continuous passageway therebetween; and

a rotatable heat transfer structure rotatably supported within said stationary housing about an axis of rotation and having a substantially symmetrical moment of inertia about said axis of rotation, said rotatable heat transfer structure having

a first end portion disposed within said first heat transfer chamber,

a second end portion disposed within said second heat transfer chamber, and

an intermediate portion disposed between said first and second end portions and including a means for,

said rotatable heat transfer structure embodying a closed fluid circuit symmetrically arranged about said axis of rotation, and having

a return portion extending along the direction of said axis of rotation and at least a subportion of said return portion having a helical geometry, and

an interior volume for containing a predetermined amount of a heat carrying medium contained within said closed fluid circuit which automatically circulates within said closed fluid circuit as said rotatable heat transfer structure is rotated about said axis of rotation and therewhile undergoes a phase transformation within said closed fluid circuit in order to carry out a heat transfer process between said first and second portions of said rotatable heat transfer structure,

said first end portion of said rotatable heat transfer structure being disposed in thermal communication with said first heat exchanging circuit,

said second end portion rotatable heat transfer structure being disposed in thermal communication with said second heat exchanging circuit,

said intermediate portion being physically adjacent to said thermal barrier so as to present a substantially high thermal resistance to heat transfer between said first and second heat transfer chambers during operation of said heat transfer engine, and

said heat carrying medium being characterized by a predetermined heat of evaporation at which said heat carrying medium transforms from liquid phase to vapor phase, and a predetermined heat of condensation at which said heat carrying medium transforms from vapor phase to liquid phase, and wherein the direction of phase change of said heat carrying liquid is reversible; and

a flow restriction means disposed along said intermediate portion for restricting the flow of said heat carrying fluid through said closed fluid circuit as said rotatable heat transfer structure is rotated within about said axis of rotation;

,

2. The heat transfer engine of claim 1, which further comprises:

torque generation means for imparting torque to said rotatable heat transfer structure and causing said rotatable heat transfer structure to rotate about said axis of rotation; and

torque control means for controlling said torque generating means in response to the temperature of said heat exchanging medium sensed at said inlet and outlet ports in said first and second heat transfer chambers.

3. The heat transfer engine of claim 2, wherein said torque generating means comprises:

a motor having a drive shaft operably connected to said rotatable heat transfer structure, wherein the angular velocity of said drive shaft is maintained within a predetermined range of angular velocity by said torque controlling means.

4. The heat transfer engine of claim 2, wherein said torque generating means comprises

turbine blades disposed on at least one of said first and second end portions of said rotatable heat transfer structure, such that said turbine blades are imparted torque by a first or second heat exchanging medium flowing through said first or second heat transfer chambers during the operation of said heat transfer engine.

5. The heat transfer engine of claim 2, wherein said torque generating means comprises:

a steam turbine having a drive shaft operably connected to said rotatable heat transfer structure, for imparting torque to said rotatable heat transfer structure, and wherein said torque controlling means comprises means for controlling the angular velocity of the drive shaft of said steam turbine.

6. The heat transfer engine of claim 1, wherein the first end portion of said rotatable heat transfer structure functions as an evaporator and the second end portion of said rotatable heat transfer structure functions as a condenser when said rotatable heat transfer structure rotates in a clockwise direction.

7. The heat transfer engine of claim 1, wherein the first end portion of said rotatable heat transfer structure functions as an condenser and the second end portion of said rotatable heat transfer structure functions as an evaporator when said rotatable heat transfer structure rotates in a counter-clockwise direction.

8. The heat transfer engine of claim 1, wherein said rotatable heat transfer structure comprises a rotor portion having a substantially symmetrical moment of inertia about said axis of rotation, and said closed fluid circuit is realized as a three-dimensional flow passageway of closed loop design formed in said rotor portion, said three-dimensional flow passageway comprising a first, second, third and fourth spiral flow passageway portions connected in a series configuration about said axis of rotation, in the named order.

9. The heat transfer engine of claim 1, wherein said rotor portion comprises a plurality of rotor discs assembled together to form a unitary structure, wherein each said rotor disc has formed therein a section of grooving which relates to a portion of said three-dimensional flow passageway formed in said rotor portion.

10. The heat transfer engine of claim 1, wherein said rotatable heat transfer structure comprises a rotor shaft along which said return portion of said closed fluid circuit extends, and wherein said closed fluid circuit is realized as a three-dimensional tubing configuration supported about said rotor shaft having a first, second, third and fourth spiral tubing sections continuously connected in a series configuration about said axis of rotation, in the named order.

11. The heat transfer engine of claim 1, wherein said return portion has a helical geometry which extends substantially along the entire extend of said rotor shaft.

12. The heat transfer engine of claim 1, which further comprises:

first connection means for interconnecting a first heat exchanging circuit to said first and second ports of said first heat transfer chamber, so as to permit a first heat exchanging medium to flow through said first heat exchanging circuit and said first chamber during the operation of said reversible heat transfer engine; and

second connection means for interconnecting a second heat exchanging circuit to said first and second ports of said second heat transfer chamber, so as to permit a second heat exchanging medium to flow through said second heat exchanging circuit and said second heat transfer chamber during the operation of said reversible heat transfer engine, while said first and second heat exchanging circuits are in substantial thermal isolation of each other.

13. The heat transfer engine of claim 12, which further comprises temperature sensing means for measuring the temperature of said heat exchanging medium flowing through said inlet and outlet ports of said first and secondary heat transfer chambers.

14. The heat transfer engine of claim 12, wherein said first heat exchanging medium flow through said first heat exchanging circuit is air, and said second heat exchanging medium flow through said second heat exchanging circuit is air.

15. The heat transfer engine of claim 12, wherein said first heat exchanging medium flow through said first heat exchanging circuit is water, and said second heat exchanging medium flow through said second heat exchanging circuit is air.

16. The heat transfer engine of claim 12, wherein said first heat exchanging medium flow through said first heat exchanging circuit is water, and said second heat exchanging medium flow through said second heat exchanging circuit is water.

17. The heat transfer engine of claim 12, wherein said first heat exchanging medium flow through said first heat exchanging circuit is air, and said second heat exchanging medium flow through said second heat exchanging circuit is water.

50. A vehicle with on-board heat transfer capabilities comprising:

a platform for transporting objects; and

the heat transfer engine of claim 1mounted aboard said platform.

18. A heat transfer engine for transferring heat between first and second heat exchanging circuits, comprising:

a stationary housing having first and second heat transfer chambers, and a thermal isolation barrier disposed therebetween, said first and second heat transfer chambers each having first and second ports and a continuous passageway therebetween; and

a rotatable heat transfer structure rotatably supported within said stationary housing about an axis of rotation and having a substantially symmetrical moment of inertia about said axis of rotation, said rotatable heat transfer structure having

a first end portion disposed within said first heat transfer chamber,

a second end portion disposed within said second heat transfer chamber, and

an intermediate portion disposed between said first and second end portions,

said rotatable heat transfer structure embodying a closed fluid circuit symmetrically arranged about said axis of rotation, and having

a return portion extending along the direction of said axis of rotation, and

an interior volume for containing a predetermined amount of a heat carrying medium contained within said closed fluid circuit which automatically circulates within said closed fluid circuit as said rotatable heat transfer structure is rotated about said axis of rotation and therewhile undergoes a phase transformation within said closed fluid circuit in order to carry out a heat transfer process between said first and second portions of said rotatable heat transfer structure,

said first end portion of said rotatable heat transfer structure being disposed in thermal communication with said first heat exchanging circuit,

said second end portion rotatable heat transfer structure being disposed in thermal communication with said second heat exchanging circuit,

said intermediate portion being physically adjacent to said thermal barrier so as to present a substantially high thermal resistance to heat transfer between said first and second heat transfer chambers during operation of said heat transfer engine,

said heat carrying medium being characterized by a predetermined heat of evaporation at which said heat carrying medium transforms from liquid phase to vapor phase, and a predetermined heat of condensation at which said heat carrying medium transforms from vapor phase to liquid phase, and wherein the direction of phase change of said heat carrying liquid is reversible, and

said rotatable heat transfer structure having predetermined range of angular velocity over which said heat transfer engine is capable of transferring heat between said first and second end portions of said rotatable heat transferring structure;

a flow restriction means disposed along said intermediate portion for restricting the flow of said heat carrying fluid through said closed fluid circuit;

torque generation means for imparting torque to said rotatable heat transfer structure and causing said rotatable heat transfer structure to rotate about said axis of rotation; and

torque control means for controlling said torque generating means in response to the temperature of said heat exchanging medium sensed at either said inlet and outlet ports in said first and second heat transfer chambers, so that the angular velocity of said rotatable heat transfer structure is maintained with said predetermined range.

19. The heat transfer engine of claim 18, wherein said torque generating means comprises:

a motor having a drive shaft operably connected to said rotatable heat transfer structure, wherein the angular velocity of said drive shaft is maintained within a predetermined range of angular velocity by said torque controlling means.

20. The heat transfer engine of claim 18, wherein said torque generating means comprises:

a motor having a drive shaft operably connected to said rotatable heat transfer structure, wherein the angular velocity of said drive shaft is maintained within a predetermined range of angular velocity by said torque controlling means.

21. The heat transfer engine of claim 18, wherein said torque generating means comprises

turbine blades disposed on at least one of said first and second end portions of said rotatable heat transfer structure, such that said turbine blades are imparted torque by a first or second heat exchanging medium flowing through said first or second heat transfer chambers during the operation of said heat transfer engine.

22. The heat transfer engine of claim 18, wherein said torque generating means comprises:

a steam turbine having a drive shaft operably connected to said rotatable heat transfer structure, for imparting torque to said rotatable heat transfer structure, and wherein said torque controlling means comprises means for controlling the angular velocity of the drive shaft of said steam turbine.

23. The heat transfer engine of claim 18, wherein the first end portion of said rotatable heat transfer structure functions as an evaporator and the second end portion of said rotatable heat transfer structure functions as a condenser when said rotatable heat transfer structure rotates in a clockwise direction.

24. The heat transfer engine of claim 18, wherein the first end portion of said rotatable heat transfer structure functions as an condenser and the second end portion of said rotatable heat transfer structure functions as an evaporator when said rotatable heat transfer structure rotates in a counter-clockwise direction.

25. The heat transfer engine of claim, 18, wherein said rotatable heat, transfer structure comprises a rotor portion having a substantially symmetrical moment of inertia about said axis of rotation, and said closed fluid circuit is realized as a three-dimensional flow passageway of closed loop design formed in said rotor portion, said three-dimensional flow passageway comprising a first, second, third and fourth spiral flow passageway portions connected in a series configuration about said axis of rotation, in the named order.

26. The heat transfer engine of claim 18, wherein said rotor portion comprises a plurality of rotor discs assembled together to form a unitary structure, wherein each said rotor disc has formed therein a section of grooving which relates to a portion of said three-dimensional flow passageway formed in said rotor portion.

27. The heat transfer engine of claim 18, wherein said rotatable heat transfer structure comprises a rotor shaft along which said return portion of said closed fluid circuit extends, and wherein said closed fluid circuit is realized as a three-dimensional tubing configuration supported about said rotor shaft having a first, second, third and fourth spiral tubing sections continuously connected in a series configuration about said axis of rotation, in the named order.

28. The heat transfer engine of claim 18, wherein at least a subportion of said return portion has a helical geometry.

29. The heat transfer engine of claim 28, wherein said return portion has a helical geometry which extends substantially along the entire extend of said rotor shaft.

30. The heat transfer engine of claim 18, wherein said first heat exchanging medium flow through said first heat exchanging circuit is air, and said second heat exchanging medium flow through said second heat exchanging circuit is air.

31. The heat transfer engine of claim 18, wherein said first heat exchanging medium flow through said first heat exchanging circuit is water, and said second heat exchanging medium flow through said second heat exchanging circuit is air.

32. The heat transfer engine of claim 18, wherein said first heat exchanging medium flow through said first heat exchanging circuit is water, and said second heat exchanging medium flow through said second heat exchanging circuit is water.

33. The heat transfer engine of claim 18, wherein said first heat exchanging medium flow through said first heat exchanging circuit is air, and said second heat exchanging medium flow through said second heat exchanging circuit is water.

34. The heat transfer portion of claim 18, which further comprises:

first connection means for interconnecting a first heat exchanging circuit to said first and second ports of said first heat transfer chamber, so as to permit a first heat exchanging medium to flow through said first heat exchanging circuit and said first chamber during the operation of said reversible heat transfer engine; and

second connection means for interconnecting a second heat exchanging circuit to said first and second ports of said second heat transfer chamber, so as to permit a second heat exchanging medium to flow through said second heat exchanging circuit and said second heat transfer chamber during the operation of said reversible heat transfer engine, while said first and second heat exchanging circuits are in substantial thermal isolation of each other.

35. The heat transfer engine of claim 34, which further comprises temperature sensing means for measuring the temperature of said heat exchanging medium flowing through said inlet and outlet ports of said first and secondary heat transfer chambers.

44. The heat transfer engine of claim 18, wherein at least a subportion of said return portion has a helical geometry.

45. The heat transfer engine of claim 44, wherein said return portion has a helical geometry which extends substantially along the entire extend of said rotor shaft.

49. The heat transfer engine of claim 18, wherein said first heat exchanging medium flow through said first heat exchanging circuit is air, and said second heat exchanging medium flow through said second heat exchanging circuit is water.

52. A vehicle with on-board heat transfer capabilities comprising:

a platform for transporting objects; and

the heat transfer engine of claim 18 mounted aboard said platform.

53. The vehicle of claim 52, wherein said platform is either an ground transportable structure, an air supportable structure, and/or water transportable structure.

36. A heat transfer engine for transferring heat between first and second heat exchanging circuits, comprising:

a stationary housing having first and second heat transfer chambers, and a thermal isolation barrier disposed therebetween, said first and second heat transfer chambers each having first and second ports and a continuous passageway therebetween; and

a rotatable heat transfer structure rotatably supported within said stationary housing about an axis of rotation and having a substantially symmetrical moment of inertia about said axis of rotation, said rotatable heat transfer structure having

a first end portion disposed within said first heat transfer chamber,

a second end portion disposed within said second heat transfer chamber, and

an intermediate portion disposed between said first and second end portions,

said rotatable heat transfer structure embodying a closed fluid circuit symmetrically arranged about said axis of rotation, and having

a return portion extending along the direction of said axis of rotation, and

an interior volume for containing a predetermined amount of a heat carrying medium contained within said closed fluid circuit which automatically circulates within said closed fluid circuit as said rotatable heat transfer structure is rotated about said axis of rotation and therewhile undergoes a phase transformation within said closed fluid circuit in order to carry out a heat transfer process between said first and second portions of said rotatable heat transfer structure,

said first end portion of said rotatable heat transfer structure being disposed in thermal communication with said first heat exchanging circuit,

said second end portion rotatable heat transfer structure being disposed in thermal communication with said second heat exchanging circuit,

said intermediate portion being physically adjacent to said thermal barrier so as to present a substantially high thermal resistance to heat transfer between said first and second heat transfer chambers during operation of said heat transfer engine, and

said heat carrying medium being characterized by a predetermined heat of evaporation at which said heat carrying medium transforms from liquid phase to vapor phase, and a predetermined heat of condensation at which said heat carrying medium transforms from vapor phase to liquid phase, and wherein the direction of phase change of said heat carrying liquid is reversible;

a flow restriction means disposed along said intermediate portion for restricting the flow of said heat carrying fluid through said closed fluid circuit;

first connection means for interconnecting a first heat exchanging circuit to said first and second ports of said first heat transfer chamber, so as to permit a first heat exchanging medium to flow through said first heat exchanging circuit and said first chamber during the operation of said reversible heat transfer engine;

second connection means for interconnecting a second heat exchanging circuit to said first and second ports of said second heat transfer chamber, so as to permit a second heat exchanging medium to flow through said second heat exchanging circuit and said second heat transfer chamber during the operation of said reversible heat transfer engine, while said first and second heat exchanging circuits are in substantial thermal isolation of each other;

temperature sensing means for measuring the temperature of said heat exchanging medium flowing through said inlet and outlet ports of said first and secondary heat transfer chambers;

torque generation means for imparting torque to said rotatable heat transfer structure and causing said rotatable heat transfer structure to rotate about said axis of rotation; and

torque control means for controlling said torque generating means in response to the temperature of said heat exchanging medium sensed at said inlet and outlet ports in said first and second heat transfer.

37. The heat transfer engine of claim 36, wherein said torque generating means comprises;

a motor having a drive shaft operably connected to said rotatable heat transfer structure, wherein the angular velocity of said drive shaft is maintained within said predetermined range by said torque controlling means.

38. The heat transfer engine of claim 36, wherein said torque generating means comprises

turbine blades disposed on at least one of said first and second end portions of said rotatable heat transfer structure, such that said turbine blades are imparted torque by said first or second heat exchanging medium flowing through said first or second heat exchanging circuit and said first or second heat transfer chamber during the operation of said heat transfer engine.

39. The heat transfer engine of claim 36, wherein said torque generating means comprises;

a steam turbine having a drive shaft operably connected to said rotatable heat transfer structure, for imparting torque to said rotatable heat transfer structure, and wherein said torque controlling means comprises means for controlling the angular velocity of the drive shaft of said steam turbine.

40. The heat transfer engine of claim 36, wherein the first end portion of said rotatable heat transfer structure functions as an evaporator and the second end portion of said rotatable heat transfer structure functions as a condenser when said rotatable heat transfer structure rotates in a clockwise direction.

41. The heat transfer engine of claim 36, wherein the first end portion of said rotatable heat transfer structure functions as an condenser and the second end portion of said rotatable heat transfer structure functions as an evaporator when said rotatable heat transfer structure rotates in a counter-clockwise direction.

42. The heat transfer engine of claim 36, wherein the return portion of said closed fluid circuit has a helical geometry extending from said first end portion to said second end portion.

43. The heat transfer engine of claim 36, wherein said rotatable heat transfer structure comprises a rotor portion having a substantially symmetrical moment of inertia about said axis of rotation, and said closed fluid circuit is realized as a three-dimensional flow passageway of closed loop design formed in said rotor portion, said three-dimensional flow passageway comprising a first, second, third and fourth spiral flow passageway portions connected in a series configuration about said axis of rotation, in the named order.

46. The heat transfer engine of claim 36, wherein said first heat exchanging medium flow through said first heat exchanging circuit is air, and said second heat exchanging medium flow through said second heat exchanging circuit is air.

47. The heat transfer engine of claim 36, wherein said first heat exchanging medium flow through said first heat exchanging circuit is water, and said second heat exchanging medium flow through said second heat exchanging circuit is air.

48. The heat transfer engine of claim 36, wherein said first heat exchanging medium flow through said first heat exchanging circuit is water, and said second heat exchanging medium flow through said second heat exchanging circuit is water.

54. A vehicle with on-board heat transfer capabilities comprising:

a platform for transporting objects; and

the heat transfer engine of claim 36 mounted aboard said platform.

55. The vehicle of claim 54, wherein said platform is either an ground transportable structure, an air supportable structure, and/or water transportable structure.

51. The vehicle of claim 51, wherein said platform is either an ground transportable structure, an air supportable structure, and/or water transportable structure.

56. A heat transfer engine comprising:

a stationary housing having first and second heat transfer chambers;

a heat transfer structure rotatably supported within said stationary housing about an axis of rotation;

torque generation means for imparting torque to said heat transfer structure and causing said heat transfer structure to rotate about said axis of rotation; and

torque control means for controlling said torque generating means within a closed control loop during the transfer of heat between said a first and second heat transfer chambers;

.

57. A method transferring heat between first and second heat exchanging circuits, comprising the steps:

(a) installing between first and second heat exchanging circuits a heat transfer engine which includes

a stationary housing having first and second heat transfer chambers operably connected to said first and second heat exchanging circuits, respectively, and

a rotatable heat transfer structure rotatably supported therewithin about an axis of rotation,

wherein said rotatable heat transfer structure has first and second heat transfer portions and a substantially symmetrical moment of inertia about said axis of rotation and embodies a closed fluid circuit symmetrically arranged about said axis of rotation and contains a predetermined amount of a heat carrying medium for carrying out a thermodynamic-based heat transfer process between said first and second portions of said rotatable heat transfer structure when said rotatable heat transfer structure is rotated within said stationary housing about said axis of rotation at an angular velocity within a predetermined range of angular velocities;

(b) imparting torque to said rotatable heat transfer structure so as to cause said rotatable heat transfer structure to rotate about said axis of rotation and said heat carrying medium automatically circulate within said closed fluid circuit; and

(c) controlling the angular velocity of said rotatable heat transfer structure within said predetermined range of angular velocities during step (b) so that said thermodynamic-based heat transfer process is conducted between said first and second portions of said rotatable heat transfer structure and that heat is transferred between said first and second heat transfer chambers.

58. A method transferring heat between first and second heat exchanging circuits, comprising the steps:

(a) installing between first and second heat exchanging circuits a heat transfer engine which includes

a stationary housing having first and second heat transfer chambers operably connected to said first and second heat exchanging circuits, respectively, and

a rotatable heat transfer structure rotatably supported therewithin about an axis of rotation,

wherein said rotatable heat transfer structure has first and second heat transfer portions and a substantially symmetrical moment of inertia about said axis of rotation and embodies a closed fluid circuit symmetrically arranged about said axis of rotation and having a return portion which extends along said axis of rotation and has a subportion with a helical geometry, and

said rotatable heat transfer structure further contains a predetermined amount of a heat carrying medium for carrying out a thermodynamic-based heat transfer process between said first and second portions of said rotatable heat transfer structure when said rotatable heat transfer structure is rotated within said stationary housing about said axis of rotation at an angular velocity within a predetermined range of angular velocities; and

(b) imparting torque to said rotatable heat transfer structure so as to cause said rotatable heat transfer structure to rotate about said axis of rotation and said heat carrying medium automatically circulate within said closed fluid circuit and undergo pressurization as said flow heat carrying medium flows along the subsection of said return portion having helical geometry; and

(c) controlling the angular velocity of said rotatable heat transfer structure within said predetermined range of angular velocities during step (b) so that said thermodynamic-based heat transfer process is conducted between said first and second portions of said rotatable heat transfer structure and that heat is transferred between said first and second heat transfer chambers.