Compressor diagnostic and protection system and method

• US 20050235663A1
• Filed: 04/04/2005
• Published: 10/27/2005
• Est. Priority Date: 04/27/2004
• 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 7,878,006 B2
• Time in Patent Office: Days
• US Class Current: 62/126
• CPC Class Codes: B23P 15/26 heat exchangers or the like making heat exchangers by methods covered by other subclasses B21D53/02
• CPC Class Codes: F04C 2270/18 Pressure
• CPC Class Codes: F04C 2270/19 Temperature
• CPC Class Codes: F04C 2270/80 Diagnostics
• CPC Class Codes: F04C 28/00 Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
• CPC Class Codes: F25B 1/04 with compressor of rotary type F25B1/005, F25B1/10 take precedence
• CPC Class Codes: F25B 2500/06 Damage
• CPC Class Codes: F25B 2500/19 Calculation of parameters
• CPC Class Codes: F25B 2700/151 of the compressor motor
• CPC Class Codes: F25B 2700/1931 Discharge pressures
• CPC Class Codes: F25B 2700/1933 Suction pressures
• CPC Class Codes: F25B 2700/2106 of fresh outdoor air
• CPC Class Codes: F25B 2700/21151 at the suction side of the compressor
• CPC Class Codes: F25B 2700/21152 at the discharge side of the compressor
• CPC Class Codes: F25B 2700/2116 of a condenser
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25D 2400/36 Visual displays
• CPC Class Codes: Y10T 29/49353 Heat pipe device making

Abstract

A system and method includes a compressor operable in a refrigeration circuit and including a motor, a current sensor detecting current supplied to the motor, a discharge line temperature sensor detecting discharge line temperature of the compressor, and processing circuitry receiving current data from the current sensor and discharge line temperature data from the discharge line temperature sensor and processing the current data and the discharge line temperature data to determine a capacity of the refrigeration circuit.

Claims

1. A system comprising:

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

a current sensor detecting current supplied to said motor;

a discharge line temperature sensor detecting discharge line temperature of said compressor; and

processing circuitry receiving current data from said current sensor and discharge line temperature data from said discharge line temperature sensor and processing said current data and said discharge line temperature data to determine a capacity of said refrigeration circuit.

2. The system of claim 1, wherein said capacity is calculated using non-measured operating parameters of said refrigeration circuit.

3. The system of claim 2, wherein said non-measured system operating parameters include at least one of condenser temperature, evaporator temperature, suction superheat, and discharge superheat.

4. The system of claim 3, wherein said condenser temperature is a function of current.

5. The system of claim 3, wherein said evaporator temperature is a function of said condenser temperature and discharge line temperature.

6. The system of claim 3, wherein said discharge superheat is a function of said condenser temperature and discharge line temperature.

7. The system of claim 3, wherein said suction superheat is a function of said discharge superheat.

8. The system of claim 3, wherein said processing circuitry is operable to detect a floodback condition based on a comparison of discharge superheat temperature to a predetermined discharge superheat temperature.

9. The system of claim 8, wherein said predetermined discharge superheat is approximately equal to forty degrees Fahrenheit or less.

10. The system of claim 3, further comprising memory having a predetermined compressor map, wherein said condenser temperature is a function of said evaporator temperature, said current data, and said predetermined compressor map.

11. The system of claim 10, wherein said predetermined compressor map includes compressor-specific parameters.

12. The system of claim 3, wherein said evaporator temperature is a function of said discharge line temperature data and said condenser temperature.

13. The system of claim 3, wherein said evaporator temperature is a product of an iterative process.

14. The system of claim 3, wherein said compressor capacity is a function of said condenser temperature and said evaporator temperature.

15. The system of claim 14, further comprising a sensor detecting blower current wherein a capacity of an evaporator coil is a function of said compressor capacity and said blower current.

16. The system of claim 15, wherein a system efficiency is a function of said evaporator coil capacity, said current data, and said blower current.

17. The system of claim 1, further comprising a system controller in communication with said processing circuitry.

18. The system of claim 17, wherein said system controller receives said current data and said discharge line temperature data and is operable to verify said capacity calculated by said processing circuitry.

19. The system of claim 17, wherein said system controller includes at least one hand-held computer.

20. The system of claim 19, wherein said hand-held computer is at least one of a personal data assistant and a cellular telephone.

21. A method comprising:

generating a high-side signal indicative of an operating condition of a high-pressure side of a refrigeration circuit;

generating a low-side signal indicative of an operating condition of a low-pressure side of said refrigeration circuit;

processing said high-side signal and said low-side signal to determine system operating parameters that are not directly measured; and

determining a capacity of said refrigeration circuit based on said non-measured system condition.

22. The method of claim 21, wherein said generating a high-side signal includes detecting current.

23. The method of claim 21, wherein said generating a low-side signal includes detecting a discharge line temperature.

24. The method of claim 21, wherein said determining system operating parameters includes determining at least one of condenser temperature, evaporator temperature, suction superheat, and discharge superheat.

25. The method of claim 24, further comprising deriving said condenser temperature as a function of said evaporator temperature, said high-side signal, and a predetermined compressor map.

26. The system of claim 25, wherein said predetermined compressor map includes compressor-specific parameters.

27. The system of claim 24, further comprising deriving said evaporator temperature as a function of said low-side signal and said condenser temperature.

28. The system of claim 27, further comprising using an iterative process to derive said evaporator temperature.

29. The system of claim 24, further comprising deriving said compressor capacity as a function of said condenser temperature and said evaporator temperature.

30. The system of claim 29, further comprising deriving a capacity of an evaporator coil as a function of said compressor capacity and a measured blower current.

31. The system of claim 30, further comprising deriving a system efficiency as a function of said evaporator coil capacity, said high-side signal, and said measured blower current.

32. The method of claim 21, further comprising sending said system condition to a system controller.

33. The method of claim 32, further comprising verifying at said system controller said system condition determination received from said processing device.

34. The method of claim 33, further comprising said high-side signal and said low-side signal to said processing circuitry and verifying said capacity of said refrigeration circuit based on said high-side signal and said low-side signal.

35. The method of claim 33, further comprising said system controller detecting said high-side operating condition and said low-side operating condition and verifying said capacity of said refrigeration circuit based on said detected high-side operating condition and said low-side operating condition.