Compressors for providing automatic capacity modulation and heat exchanging system including the same

• US 20020187057A1
• Filed: 01/29/2002
• Published: 12/12/2002
• Est. Priority Date: 06/11/2001
• Status: Active Grant

• Current Assignee: Kulthorn Kirby Public Company Limited
• Original Assignee: Bristol Compressors International Incorporated (Kulthorn Kirby Public Company Limited)
• Inventors: Chumley, Eugene Karl, Goodnight, Tom Evans, Trent, Mark Randall, Hatzikazakis, Panteleimon V., Loprete, Joe Frank, Douglas, Robert Desmond, Xin, Rongchang, Simerly, Tyrone Scott, Monk, David Turner, Narney, John K. II
• Granted Patent: US 6,663,358 B2
• Time in Patent Office: Days
• US Class Current: 417/313
• CPC Class Codes: F04B 49/16 by adjusting the capacity of dead spaces of working chambers
• CPC Class Codes: F04B 49/24 Bypassing
• CPC Class Codes: F04C 28/16 using lift valves
• CPC Class Codes: F04C 28/18 characterised by varying the volume of the working chamber by changing the positions of inlet or outlet openings F04C28/10
• CPC Class Codes: F04C 28/24 characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valvesF04C28/10 takes precedence
• CPC Class Codes: F25B 2600/02 Compressor control
• CPC Class Codes: F25B 49/022 Compressor control arrangements

Abstract

A compressor for providing automatic capacity modulation is disclosed. The compressor comprises a compression chamber, a compressing member, a reexpansion area, a flow passage, a valve member, and a biasing member. The flow passage is in fluid communication with the compression chamber and the reexpansion area. In one position, the valve member permits flow through the flow passage and in a second position it prevents flow. The valve member is subjected to a first operating condition of fluid on one side and a second operating condition of the fluid on the other side. The biasing member exerts a biasing force on the valve member. When the first operating condition reaches a predetermined point relative to the second operating condition, the valve member moves and effects a change in the capacity of the compressor.

Claims

1. A variable compressor, comprising:

a compression chamber;

a reexpansion area;

a flow channel between the compression chamber and the reexpansion area;

a valve member movable between first and second positions, the valve member in the first position allowing flow between the compression chamber and the reexpansion area and the valve member in the second position preventing flow between the compression chamber and the reexpansion area, whereby the compressor operates at a first capacity when the valve member is in the first position and at a second, increased capacity when the valve member is in the second position; and

a control, associated only with the compressor, for moving the valve member between the first and second positions as a function of an operating parameter of the compressor, whereby the compressor is automatically modulated based on the operating parameter.

2. The variable compressor of claim 1, wherein the operating parameter is pressure.

3. The variable compressor of claim 2, wherein the valve member moves from the first position to the second position when a discharge pressure of the compressor reaches a predetermined value relative to a suction pressure of the compressor.

4. The variable compressor of claim 3, wherein the suction pressure of the compressor is applied to one side of the valve member and the discharge pressure of the compressor is applied to an opposite side of the valve member.

5. The variable compressor of claim 4, wherein a biasing member is applied against the valve member, biasing the valve member toward the first position.

6. The variable compressor of claim 5, wherein the biasing member and the suction pressure are applied to push the valve member toward the first position and the discharge pressure is applied to push the valve member toward the second position.

7. The variable compressor of claim 1, wherein the operating parameter is temperature.

8. The variable compressor of claim 7, wherein the valve member moves from the first position to the second position when a discharge temperature of the compressor reaches a predetermined value.

9. The variable compressor of claim 8, wherein a suction pressure of the compressor is applied to one side of the valve member and a temperature element is applied to an opposite side of the valve member.

10. The variable compressor of claim 9, wherein a biasing member is applied against the valve member, biasing the valve member toward the first position.

11. The variable compressor of claim 10, wherein a discharge pressure of the compressor is applied to the opposite side of the valve member.

12. The variable compressor of claim 11, wherein the biasing member and the suction pressure are applied to push the valve member toward the first position and the discharge pressure and the temperature element are applied to push the valve member toward the second position.

14. The compressor of claim 13, wherein the first operating condition of the fluid is a discharge condition of the fluid.

15. The compressor of claim 14, wherein the discharge condition of the fluid has a discharge pressure and a change in the discharge pressure causes the valve member to move between the first and second positions.

16. The compressor of claim 15, wherein the compressor is a reciprocating compressor including a reciprocating piston.

17. The compressor of claim 16, wherein the valve member moves perpendicular to the movement of the reciprocating piston.

18. The compressor of claim 16, wherein the valve member moves parallel with the movement of the reciprocating piston.

19. The compressor of claim 16, wherein the reexpansion area is a reexpansion chamber formed in a crankcase of the reciprocating compressor.

20. The compressor of claim 19, wherein the flow passage is defined by a valve plate mounted on the crankcase and a recess formed in the crankcase.

21. The compressor of claim 19, wherein the flow passage is formed in the crankcase.

22. The compressor of claim 19, wherein the valve member is positioned within the reexpansion chamber.

23. The compressor of claim 16, wherein the reexpansion area includes a suction channel of the reciprocating compressor.

24. The compressor of claim 23, wherein the flow passage is located between a bottom dead center position and a top dead center position of the reciprocating piston.

25. The compressor of claim 15, wherein the compressor is a scroll compressor and the compressing member is a movable scroll member.

26. The compressor of claim 25, wherein the flow passage is formed in a fixed scroll member intermeshed with the movable scroll member.

27. The compressor of claim 25, wherein the reexpansion area includes a suction channel of the scroll compressor.

28. The compressor of claim 15, wherein the valve member includes a head portion exposed continuously to the discharge pressure and a stem portion connected to the head portion.

29. The compressor of claim 28, wherein the valve member further includes a projection formed on the head portion and the projection has a surface not exposed to the discharge pressure when the valve member is in the first position and exposed to the discharge pressure when the valve member is in the second position.

30. The compressor of claim 28, wherein the head portion is configured to prevent flow through the flow passage when the valve member is in the second position.

31. The compressor of claim 28, wherein the valve member further includes a tail portion connected to the stem portion and the tail portion is exposed continuously to a suction pressure of the fluid.

32. The compressor of claim 31, wherein the head, tail, and stem portions are circular in shape and have the same diameter.

33. The compressor of claim 28, wherein the stem portion is configured to prevent flow through the flow passage when the valve member is in the second position.

34. The compressor of claim 33, wherein the stem portion includes a front surface exposed continuously to the fluid in the compression chamber.

35. The compressor of claim 14, wherein the discharge condition of the fluid has a discharge pressure and a discharge temperature and a change in the discharge temperature causes the valve member to move between the first and second positions.

36. The compressor of claim 35, further comprising a temperature element to exert a thermal force on the valve member in the first direction.

37. The compressor of claim 36, wherein the valve member is exposed to the discharge pressure to exert a force on the valve member in the first direction such that the first force exerted on the valve member is the thermal force exerted by the temperature element plus the force exerted by the discharge pressure.

38. The compressor of claim 37, wherein the temperature element is an element that expands as it is heated.

39. The compressor of claim 37, wherein the temperature element is a bladder having a hollow enclosure and gas is filled in the hollow enclosure.

40. The compressor of claim 39, wherein the gas is a refrigerant.

41. The compressor of claim 37, wherein the temperature element includes at least one bi-metal disk

42. The compressor of claim 36, wherein the valve member is not exposed to the discharge pressure and the first force exerted on the valve member is the thermal force exerted by the temperature element.

43. The compressor of claim 14, wherein the second operating condition of the fluid is a suction condition of the fluid.

44. The compressor of claim 14, wherein the second operating condition of the fluid is a condition of the fluid in the compression chamber.

46. The heat exchanging system of claim 45, wherein the operating parameter is pressure and a change in the pressure causes the actuating element to move between the first and second positions.

47. The heat exchanging system of claim 46, wherein the compressor is a reciprocating compressor.

49. The method of claim 48, wherein the first and second pressures are suction and discharge pressures.

50. The method of claim 49, wherein the compressor is in fluid communication with a condenser exposed to outside air and the method further comprises the step of selecting the biasing force such that the movable component moves to the second position when the temperature of the outside air is greater than a predetermined temperature.

51. The method of claim 50, wherein the predetermined temperature is in the range of 75 to 94°

F.

52. The method of claim 49, wherein the compressor includes a reexpansion area and a flow passage in fluid communication with a compression chamber at one end and the reexpansion area at the other end, and wherein the movable component in the first position permits flow through the flow passage and in the second position prevents flow through the flow passage.

53. The method of claim 52, wherein the compressor is a reciprocating compressor and the reexpansion area is a reexpansion chamber formed in a crankcase of the reciprocating compressor.

54. The method of claim 52, wherein the compressor is a reciprocating compressor and the reexpansion area includes a suction channel of the reciprocating compressor.

55. The method of claim 52, wherein the compressor is a scroll compressor and the reexpansion area includes a suction channel of the scroll compressor.

57. The method of claim 56, wherein the first operating condition of the fluid is a discharge condition of the fluid.

58. The method of claim 57, wherein the second operating condition of the fluid is a suction condition of the fluid.

59. The method of claim 58, wherein one side of the valve member is exposed to a discharge pressure of the fluid and an opposite side of the valve member is exposed to a suction pressure of the fluid.

60. The method of claim 56, wherein the second operating condition of the fluid is a condition of the fluid in the compression chamber.

61. The method of claim 60, wherein one side of the valve member is exposed to a discharge pressure of the fluid and an opposite side of the valve member is exposed to a pressure of the fluid in the compression chamber.

62. The method of claim 56, wherein the compressor further includes a temperature element associated with the valve member and the temperature element is subjected to the first operating condition to exert a thermal force on the valve member in the first direction.

63. The method of claim 62, wherein the first operating condition of the fluid is a discharge condition of the fluid.

64. The method of claim 63, wherein the second operating condition of the fluid is a suction condition of the fluid.

65. The method of claim 64, wherein the fluid at the first operating condition contacts the temperature element.

66. The method of claim 65, wherein one side of the valve member is exposed to a discharge pressure of the fluid such that the first force exerted on the valve member is the thermal force exerted by the temperature element plus a force exerted by the discharge pressure, and an opposite side of the valve member is exposed to a suction pressure of the fluid such that the suction pressure exerts the second force on the valve member.

67. The method of claim 64, wherein the fluid at the first operating condition does not contact the temperature element.

68. The method of claim 67, wherein the first force exerted on the valve member is the thermal force exerted by the temperature element and one side of the valve member is exposed to a suction pressure of the fluid such that the suction pressure exerts the second force on the valve member.

69. The method of claim 63, wherein the second operating condition of the fluid is a condition of the fluid in the compression chamber.

70. The method of claim 69, wherein the fluid at the first operating condition contacts the temperature element.

71. The method of claim 70, wherein one side of the valve member is exposed to a discharge pressure of the fluid such that the first force exerted on the valve member is the thermal force exerted by the temperature element plus a force exerted by the discharge pressure, and an opposite side of the valve member is exposed to a pressure of the fluid in the compression chamber such that the pressure of the fluid in the compression chamber exerts the second force on the valve member.

72. The method of claim 69, wherein the fluid at the first operating condition does not contact the temperature element.

73. The method of claim 72, wherein the first force exerted on the valve member is the thermal force exerted by the temperature element and one side of the valve member is exposed to a pressure of the fluid in the compression chamber such that the pressure of the fluid in the compression chamber exerts the second force on the valve member.

74. The method of claim 56, wherein the compressor is in fluid communication with a condenser exposed to outside air and the method further comprises the step of selecting the biasing force such that the movable component moves to the second position when the temperature of the outside air is greater than a predetermined temperature.

75. The method of claim 74, wherein the predetermined temperature is in the range of 75 to 94°

F.

13. A compressor, comprising:

a compression chamber;

a compressing member movable to compress fluid entering the compression chamber;

a flow passage in fluid communication with the compression chamber at one end and a reexpansion area at the other end; and

a valve member associated with the flow passage and movable between a first position permitting flow through the flow passage and a second position preventing flow through the flow passage, the valve member being continuously subjected to a first operating condition of the fluid such that a first force is continuously exerted on the valve member in a first direction, the valve member being continuously subjected to a second operating condition of the fluid such that a second force is continuously exerted on the valve member in a second direction opposite to the first direction; and

a biasing member exerting a biasing force on the valve member in the second direction such that when the first force overcomes the biasing force and the second force combined together, the valve member moves from the first position to the second position and modulates the capacity of the compressor.

45. A heat exchanging system having fluid flowing therethrough in a cycle, comprising:

a condenser;

an expansion device in fluid communication with the condenser;

an evaporator in fluid communication with the expansion device; and

a compressor in fluid communication with the evaporator and the condenser, the compressor including an actuating element movable between a first position and a second position as a function of an operating parameter of the compressor, such that the compressor operates at a first capacity when the actuating element is in a first position and at a second capacity when the actuating element is in the second position; and

a control for turning the compressor on or off, based on the demand for heating or cooling.

48. A method of operating a variable capacity compressor, the method comprising the steps of:

operating the compressor at a first capacity;

applying first and second pressures to a movable component in the compressor, the movable component causing the compressor to operate at the first capacity when the movable component is in a first position and at a second increased capacity when the movable component is in a second position; and

applying a biasing force to bias the movable component toward the first position, such that the movable component moves to the second position when the relative differential between the first and second pressures reaches a predetermined value, whereby the compressor automatically modulates its capacity based on the relative values of the first and second pressures.

56. A capacity modulation method, comprising the steps of:

providing a compressor comprising a compression chamber and a compressing member movable to compress fluid entering the compression chamber;

providing a flow passage in fluid communication with the compression chamber at one end and a reexpansion area at the other end;

providing a valve member associated with the flow passage and movable between a first position permitting flow through the flow passage and a second position preventing flow through the flow passage;

subjecting the valve member continuously to a first operating condition of the fluid such that a first force is continuously exerted on the valve member in a first direction;

subjecting the valve member continuously to a second operating condition of the fluid such that a second force is continuously exerted on the valve member in a second direction opposite to the first direction; and

exerting a biasing force on the valve member in the second direction such that when the first force overcomes the second force and the biasing force combined together, the valve member moves from the first position to the second position and thereby modulates the capacity.