PROTECTION AND DIAGNOSTIC MODULE FOR A REFRIGERATION SYSTEM

• US 20080209925A1
• Filed: 07/12/2007
• Published: 09/04/2008
• Est. Priority Date: 07/19/2006
• Status: Active Grant

• Current Assignee: Copeland Corporation LLC (Emerson Electric Company)
• Original Assignee: Emerson Climate Technologies Incorporated (Emerson Electric Company)
• Inventors: Pham, Hung M.
• Granted Patent: US 8,590,325 B2
• Time in Patent Office: Days
• US Class Current: 62/126
• CPC Class Codes: F25B 2500/19 Calculation of parameters
• CPC Class Codes: F25B 2700/151 of the compressor motor
• CPC Class Codes: F25B 2700/2106 of fresh outdoor air
• CPC Class Codes: F25B 2700/21152 at the discharge side of the compressor
• CPC Class Codes: F25B 2700/21163 of the refrigerant at the outlet of the condenser
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25B 49/022 Compressor control arrangements

Abstract

A system includes a compressor and a compressor motor functioning in a refrigeration circuit. A sensor produces a signal indicative of one of current and power drawn by the motor and a liquid-line temperature sensor provides a signal indicative of a temperature of liquid circulating within the refrigeration circuit. Processing circuitry processes the current or power signal to determine a condenser temperature of the refrigeration circuit and a subcooling value of the refrigeration circuit from the condenser temperature and the liquid-line temperature signal.

Claims

1. A system comprising:

a compressor operable in a refrigeration circuit and including a motor;

a sensor producing a signal indicative of one of current and power drawn by said motor;

a liquid-line temperature sensor providing a signal indicative of a temperature of liquid circulating within said refrigeration circuit; and

processing circuitry processing said current or power signal to determine a condenser temperature of said refrigeration circuit and a subcooling value of said refrigeration circuit from said condenser temperature and said liquid-line temperature signal.

3. The system of claim 1, further comprising a compressor map stored in said processing circuitry for determining said condenser temperature.

10. The system of claim 1, wherein said processing circuitry determines an efficiency of said refrigeration circuit based on a ratio of said subcooling value and said condenser temperature.

11. The system of claim 1, wherein said refrigeration circuit includes an evaporator, said processing circuitry determining a house load based on a capacity of said evaporator and a run time of said compressor.

12. The system of claim 11, wherein said processing circuitry determines an overall load of said refrigeration circuit based on said house load and said run time of said compressor.

2. (canceled)

4-9. -9. (canceled)

13-17. -17. (canceled)

18. A system comprising:

a compressor operable in a refrigeration circuit and including a motor;

a liquid-line temperature sensor providing a signal indicative of a temperature of subcooled liquid circulating within said refrigeration circuit; and

processing circuitry determining a condenser temperature using a compressor map and determining a subcooling value of said refrigeration circuit from said condenser temperature and said liquid-line temperature signal.

19. The system of claim 18, further comprising one of a current signal and a power signal indicative of one of a current drawn by said motor and a power drawn by said motor.

20. The system of claim 19, wherein said processing circuitry references said current or power signal on said compressor map to determine said condenser temperature.

27. The system of claim 18, wherein said processing circuitry determines an efficiency of said refrigeration circuit based on a ratio of said subcooling value and said condenser temperature.

28. The system of claim 18, wherein said refrigeration circuit includes an evaporator, said processing circuitry determining a house load based on a capacity of said evaporator and a run time of said compressor.

29. The system of claim 28, wherein said processing circuitry determines an overall load of said refrigeration circuit based on said house load and said run time of said compressor.

21-26. -26. (canceled)

30-34. -34. (canceled)

35. A system comprising:

a compressor operable in a refrigeration circuit and including a motor;

an ambient temperature sensor providing a signal indicative of ambient temperature;

a discharge-line temperature sensor providing a signal indicative of a discharge-line temperature of said compressor; and

processing circuitry determining a condenser temperature using a compressor map and determining a discharge superheat value of said refrigeration circuit from said ambient temperature signal, said discharge-line temperature signal, and said condenser temperature.

36. The system of claim 35, further comprising one of a current signal and a power signal indicative of one of a current drawn by said motor and a power drawn by said motor.

37. The system of claim 36, wherein said processing circuitry references said current or power signal on said compressor map to determine said condenser temperature.

38. The system of claim 35, further comprising a liquid-line temperature sensor providing a signal indicative of a temperature of liquid circulating within said refrigeration circuit.

45. The system of claim 35, wherein said refrigeration circuit includes an evaporator, said processing circuitry determining a house load based on a capacity of said evaporator and a run time of said compressor.

46. The system of claim 45, wherein said processing circuitry determines an overall load of said refrigeration circuit based on said house load and said run time of said compressor.

39-44. -44. (canceled)

47-51. -51. (canceled)

52. A system comprising:

a compressor operable in a refrigeration circuit and including a motor;

one of a current sensor and a power sensor producing a signal indicative of a current drawn by said motor or a power drawn by said motor;

a discharge-line temperature sensor producing a signal indicative of a discharge-line temperature of said compressor;

an ambient temperature sensor producing a signal indicative of an ambient temperature;

a liquid-line temperature sensor providing a signal indicative of a liquid circulating within said refrigeration circuit; and

processing circuitry processing said current signal or said power signal to determine a condenser temperature of said refrigeration circuit and processing at least two of said condenser temperature, said current or power signal, said discharge-line temperature signal, said ambient temperature signal, and said liquid-line temperature signal to determine at least one of a subcooling value of said refrigeration circuit, a condenser temperature difference, and a discharge superheat of said refrigeration circuit.

53. The system of claim 52, wherein said condenser temperature is a saturated condenser temperature.

60. The system of claim 52, wherein at least one of said subcooling value, said condenser temperature difference, and said discharge superheat are compared to a predetermined value to determine a refrigerant charge level within the refrigeration circuit.

61. The system of claim 52, wherein each of said subcooling, said condenser temperature difference, and said discharge superheat are compared to a predetermined value to determine a refrigerant charge level within the refrigeration circuit.

62. The system of claim 52, wherein a ratio of said subcooling over said condenser temperature difference is used to determine a refrigerant charge level within said refrigeration circuit.

64. The system of claim 52, wherein said processing circuitry determines an efficiency of said refrigeration circuit based on a ratio of said subcooling value and said condenser temperature.

65. The system of claim 52, wherein said refrigeration circuit includes an evaporator, said processing circuitry determining a house load based on a capacity of said evaporator and a run time of said compressor.

66. The system of claim 65, wherein said processing circuitry determines an overall load of said refrigeration circuit based on said house load and said run time of said compressor.

54-59. -59. (canceled)

63. (canceled)

67-71. -71. (canceled)