Refrigerating apparatus

• US 5,934,087 A
• Filed: 09/02/1997
• Issued: 08/10/1999
• Est. Priority Date: 10/18/1996
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Wakabayasl, Hisao, Watanabe, Yasushi, Yasuda, Toru
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US08/921,835
• Time in Patent Office: 707 Days
• Field of Search: 62/125, 62/126, 62/127, 62/129, 62/130, 62/209, 62/208
• US Class Current: 62/126
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2500/222 Detecting refrigerant leaks
• CPC Class Codes: F25B 2700/2117 of an evaporator
• CPC Class Codes: F25B 2700/21172 at the inlet
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25B 9/006 the refrigerant containing more than one component F25B9/004 takes precedence

Abstract

An apparatus for detecting refrigerant leak in a refrigerating apparatus using refrigerant and a heat pump type refrigerating apparatus at low cost is presented. A refrigerant leak is judged from the differential temperature and the running time, by comprising a refrigeration system including a compressor, an evaporator, an expansion device, and a condenser, being sequentially coupled annularly by a conduit, a first temperature detector for detecting the air temperature of suction port of the evaporator, a second temperature detector for detecting the refrigerant temperature at the middle part of the evaporator, a differential temperature detector for calculating the differential temperature of the detectors, and a running time detector for storing the cumulative running time of the compressor.

Claims

1. A refrigeration system comprising:

a compressor, an evaporator having an air suction side and including conduit in which refrigerant is located, an expansion device, and a condenser, coupled together;

a first temperature detector for measuring temperature of air entering said evaporator;

a second temperature detector for measuring temperature of refrigerant inside said evaporator; and

a differential temperature detector for calculating the difference between

a) the temperature measured by the first temperature detector and

b) the temperature measured by the second temperature detector to determine whether refrigerant leak has occurred.

2. A refrigeration system according to claim 1, wherein said refrigerant is one of

(a) HFC-32;

and

(b) HFC-32 and HFC-125.

6. The refrigerant system according to claim 1 or 3, wherein said temperature of refrigerant inside the evaporator is a temperature of refrigerant at a position between an inlet and outlet of the evaporator conduit.

7. The refrigerant system according to claim 1 or 3, wherein said second temperature detector is located adjacent the evaporator conduit and between an inlet and outlet of the evaporator conduit.

8. The refrigerant system according to claim 1 or 3, wherein said temperature of refrigerant inside the evaporator is a temperature of refrigerant substantially at a middle of the evaporator conduit relative to an inlet and outlet of the evaporator conduit.

9. The refrigerant system according to claim 1 or 3, wherein said temperature of refrigerant inside the evaporator is a temperature of refrigerant at an intermediate position between an inlet and outlet of the evaporator conduit.

3. A refrigeration system comprising:

a compressor, an evaporator having an air suction side and including conduit in which refrigerant is located, an expansion device, and a condenser, coupled together;

a first temperature detector for measuring temperature of air entering said evaporator;

a second temperature detector for measuring temperature of refrigerant inside said evaporator;

a differential temperature detector for calculating the difference between

a) the temperature measured by the first temperature detector and

b) the temperature measured by the second temperature detector, and

a running time detector for measuring running time of said refrigeration system;

wherein the difference between the temperature measured by the first temperature detector and the temperature measured by the second temperature detector and the accumulated running time of said refrigeration system are used to determine whether refrigerant leak has occurred.

4. A refrigeration system according to claim 3 wherein said refrigerant is one of

(a) HFC-32;

and

(b) HFC-32 and HFC-125.

5. A refrigeration system according to claim 3, wherein said evaporator includes an inlet coupled to said expansion device and an outlet coupled to said compressor wherein said second temperature detector is located between said inlet and said outlet of said evaporator.

10. A heat pump system comprising:

a compressor, a reversing valve, a first heat exchanger having an air suction side and including conduit in which refrigerant is located, an expansion device, and a second heat exchanger coupled together;

a first temperature detector for measuring temperature of air entering said first heat exchanger;

a second temperature detector for measuring temperature of refrigerant inside said evaporator; and

a differential temperature detector for calculating the difference between

a) the temperature measured by the first temperature detector and

b) the temperature measured by the second temperature detector to determine whether refrigerant leak has occurred.

11. A system according to claim 10 wherein said refrigerant is one of

(a) HFC-32;

and

(b) HFC-32 and HFC-125.

18. The heat pump system according to claim 10, 12, or 15, wherein said temperature of refrigerant inside the evaporator is a temperature of refrigerant at a position between an inlet and outlet of the evaporator conduit.

19. The heat pump system according to claim 10, 12 or 15, wherein said second temperature detector is located adjacent the evaporator conduit and between an inlet and outlet of the evaporator conduit.

20. The heat pump system according to claim 10, 12 or 15, wherein said temperature of refrigerant inside the evaporator is a temperature of refrigerant substantially at a middle of the evaporator conduit relative to an inlet and outlet of the evaporator conduit.

21. The heat pump system according to claim 10, 12 or 15, wherein said temperature of refrigerant inside the evaporator is a temperature of refrigerant at an intermediate position between an inlet and outlet of the evaporator conduit.

12. A heat pump system comprising:

a compressor, a reversing valve, a first heat exchanger having an air suction side and including conduit in which refrigerant is located, an expansion device, and a second heat exchanger, coupled together;

a first temperature detector for measuring temperature of air entering said first heat exchanger;

a second temperature detector for measuring temperature of refrigerant inside said evaporator;

differential temperature detector for calculating the difference between

a) the temperature measured by the first temperature detector and

b) the temperature measured by the second temperature detector, and

a running time detector for measuring running time of said refrigeration system;

wherein the difference between the temperature measured by the first temperature detector and the temperature measured by the second temperature detector and the accumulated running time of said refrigeration system used to determine whether refrigerant leak has occurred.

13. A heat pump system according to claims 12, wherein said refrigerant is one of

(a) HFC-32;

and

(b) HFC-32 and HFC-125.

14. A heat pump system according to claim 12, wherein said first heat exchanger includes a first coupler and a second coupler wherein said first coupler is one of an inlet or outlet wherein said second coupler is another of the inlet or the outlet wherein said second temperature detector is located between said inlet and said outlet of said heat exchanger.

15. A heat pump system comprising:

a compressor, a reversing valve, a first heat exchanger having an air suction side and including conduit in which refrigerant is located, an expansion device, and a second heat exchanger, coupled together;

a first heat exchanger adjacent a first location;

a second heat exchanger adjacent a second location;

wherein said first heat exchanger operates as an evaporator when said first location has a lower temperature than said second location,

a first temperature detector for measuring temperature of air entering said first heat exchanger;

a second temperature detector for measuring temperature of refrigerant inside said evaporator;

differential temperature detector for calculating the difference between

a) the temperature measured by the first temperature detector and

b) the temperature measured by the second temperature detector and

a running time detector for measuring running time of said refrigeration system;

wherein the difference between the temperature measured by the first temperature detector and the temperature measured by the second temperature detector and the accumulated running time of said refrigeration system are used to determine whether refrigerant leak has occurred.

16. A heat pump system according to claim 15, wherein said refrigerant is one of

(a) HFC-32;

and

(b) HFC-32 and HFC-125.

17. A heat pump system according to claim 15, wherein said first heat exchanger includes a first coupler and a second coupler wherein said first coupler is one of an inlet or outlet wherein said second coupler is another of the inlet or the outlet wherein said second temperature detector is located between said inlet and said outlet of said evaporator.

22. A method for detecting refrigerant leakage in a refrigeration system which includes a compressor, an evaporator having an air suction side and including conduit in which refrigerant is located, an expansion device, an a condenser coupled together, said method comprising the steps of:

a) measuring temperature of air entering said evaporator;

b) measuring temperature of refrigerant inside said evaporator; and

c) calculating the difference between the temperature measured in steps a) and b) to determine if refrigerant leakage has occurred.

23. A method of detecting refrigerant leakage in a refrigeration system according to claim 22, wherein said refrigerant is one of

(a) HFC-32;

and

(b) HFC-32 and HFC-125.

32. The method according to claim 22, 24, 26, 28 or 30, wherein said temperature of refrigerant inside the evaporator is a temperature of refrigerant at a position between an inlet and outlet of the evaporator conduit.

33. The method according to claim 22, 24, 26, 28 or 30, wherein said second temperature detector is located adjacent the evaporator conduit and between an inlet and outlet of the evaporator conduit.

34. The method according to claim 22, 24, 26, 28 or 30, wherein said temperature of refrigerant inside the evaporator is a temperature of refrigerant substantially at a middle of the evaporator conduit relative to an inlet and outlet of the evaporator conduit.

35. The method according to claim 22, 24, 26, 28 or 30, wherein said temperature of refrigerant inside the evaporator is a temperature of refrigerant at an intermediate position between an inlet and outlet of the evaporator conduit.

24. A method of detecting refrigerant leakage in a refrigeration system which includes a compressor, an evaporator having an air suction side and including conduit in which refrigerant is located, an expansion device, and a condenser coupled together and, said method comprising the steps of:

a) measuring temperature of air entering said evaporator

b) measuring temperature of refrigerant inside said evaporator;

c) calculating the difference between the temperature measured in stages a) and b);

d) measuring accumulated running time of said refrigeration system; and

e) using the difference calculated in step c) and running time measured in step d) to determine if refrigerant leakage has occurred.

25. A method of detecting refrigerant leakage in a refrigeration system according to claim 24, wherein said refrigerant is one of

(a) HFC-32;

and

(b) HFC-32 and HFC-125.

26. A method of detecting refrigerant leakage in a heat pump system which includes a compressor, a reversing valve, a first heat exchanger having an air suction side and including conduit in which refrigerant is located, an expansion device, and a second heat exchanger coupled together, said method comprising the steps of:

a) measuring temperature of air entering said a first heat exchanger;

b) measuring temperature of refrigerant inside said evaporator; and

c) calculating the difference between the temperature measured in stages a) and b) to determine if refrigerant leakage has occurred.

27. A method of detecting refrigerant leakage in a heat pump system according to claim 26, wherein said refrigerant is one of

(a) HFC-32;

and

(b) HFC-32 and HFC-125.

28. A method of detecting refrigerant leakage in a heat pump system which includes a compressor, a reversing valve, a first heat exchanger having an air suction side and including conduit in which refrigerant is located, an expansion device, and a second heat exchanger coupled together said method comprising the steps of:

a) measuring temperature of air entering said evaporator;

b) measuring temperature of refrigerant inside said evaporator;

c) calculating the difference between the temperature measured in stages a) and b);

d) measuring accumulated running time of said refrigeration system; and

e) using the difference calculated in step c) and running time measured in step d) to determine if refrigerant leakage in a heat pump system.

29. A method of detecting refrigerant leakage in a heat pump system according to claim 28, wherein said refrigerant is one of

(a) HFC-32;

and

(b) HFC-32 and HFC-125.

30. A method of detecting refrigerant leakage in a heat pump system which includes a compressor, a reversing valve, a first heat exchanger having an air suction side and including conduit in which refrigerant is located, an expansion device, and a second heat exchanger coupled together, wherein the first heat exchanger is operable as an evaporator when the location of said first heat exchanger has a lower temperature than the location of said second heat exchanger, said method comprising the steps of:

a) measuring temperature of air entering said evaporator;

b) measuring temperature of refrigerant inside said evaporator;

c) calculating the difference between the temperature measured in stages a) and b);

d) measuring accumulated running time of said refrigeration system; and

e) using the difference calculated in step c) and running time measured in step d) to determine if refrigerant leakage in a heat pump system.

31. A method of detecting refrigerant leakage in a heat pump system according to claim 30, wherein said refrigerant is one of

(a) single refrigerant of HFC-32;

and

(b) mixed refrigerant of HFC-32 and HFC-125.