Compressor diagnostic and protection system and method

• US 20050235661A1
• 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 7,905,098 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 providing a high-side signal indicative of an operating condition of a high-pressure side of the refrigeration circuit, a discharge line temperature sensor providing a low-side signal indicative of an operating condition of a low-pressure side of the refrigeration circuit, and processing circuitry processing the high-side signal and the low-side signal to indirectly determine a non-measured operating parameter of the refrigeration circuit.

Claims

1. A system comprising:

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

a current sensor providing a high-side signal indicative of an operating condition of a high-pressure side of the refrigeration circuit;

a discharge line temperature sensor providing a low-side signal indicative of an operating condition of a low-pressure side of the refrigeration circuit; and

processing circuitry processing said high-side signal and said low-side signal to indirectly determine a non-measured operating parameter of the refrigeration circuit.

2. The system of claim 1, wherein said non-measured operating parameter is selected from the group comprising:

condenser temperature, evaporator temperature, suction superheat, and discharge superheat.

3. The system of claim 2, wherein said condenser temperature is a function of current.

4. The system of claim 2, wherein said evaporator temperature is a function of said condenser temperature and discharge line temperature.

5. The system of claim 2, wherein said discharge superheat is a function of said condenser temperature and discharge line temperature.

6. The system of claim 2, wherein said suction superheat is a function of said discharge superheat.

7. The system of claim 2, 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.

8. The system of claim 7, wherein said predetermined discharge superheat is approximately equal to forty degrees Fahrenheit or less.

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

10. The system of claim 9, wherein said system controller receives said high-side signal and said low-side signal and is operable to verify said non-measured operating parameter determined by said processing circuitry.

11. The system of claim 9, wherein said system controller includes at least one hand-held computer.

12. The system of claim 11, wherein said hand-held computer is at least one of a personal data assistant and a cellular telephone.

13. A method comprising:

generating a high-side signal indicative of high-pressure operating conditions at a compressor in a refrigeration circuit;

generating a low-side signal indicative of low-pressure operating conditions at said compressor in said refrigeration circuit; and

processing said high-side signal and said low-side signal to indirectly determine a non-measured operating parameter of said refrigeration circuit.

14. The method of claim 13, wherein said measuring a high-side signal includes detecting current.

15. The method of claim 13, wherein said measuring a low-side signal includes detecting a discharge line temperature.

16. The method of claim 13, wherein said determining said non-measured operating parameter includes determining at least one of condenser temperature, evaporator temperature, suction superheat, and discharge superheat.

17. The method of claim 16, further comprising calculating a condenser temperature difference and said discharge superheat to diagnose said refrigeration circuit.

18. The method of claim 17, wherein said calculating includes deriving an ambient temperature and subtracting said ambient temperature from said condenser temperature.

19. The method of claim 18, wherein said step of deriving includes measuring discharge line temperature at compressor start-up.

20. The method of claim 13, further comprising communicating said non-measured operating parameter of said refrigeration circuit to a system controller.

21. The method of claim 20, further comprising verifying said non-measured operating parameter of said refrigeration circuit determination at said system controller.

22. The method of claim 21, wherein said verifying includes calculating said non-measured operating parameter of said refrigeration circuit based on said high-side signal and said low-side signal communicated to said system controller by said processing circuitry.

23. The method of claim 21, wherein said verifying includes calculating said non-measured operating parameter of said refrigeration circuit based on said high-side signal and said low-side signal detected by said system controller.