Refrigeration system including thermoelectric module

• US 7,310,953 B2
• Filed: 11/09/2005
• Issued: 12/25/2007
• Est. Priority Date: 11/09/2005
• Status: Active Grant

• Current Assignee: Copeland Corporation LLC (Emerson Electric Company)
• Original Assignee: Emerson Climate Technologies Incorporated (Emerson Electric Company)
• Inventors: Pham, Hung M., Warner, Wayne R.
• Primary Examiner(s): Tapolcai; William E.
• Application Number:
  US11/272,109
• Publication Number:
  US 20070101748A1
• Time in Patent Office: 776 Days
• Field of Search: 62 31- 37, 622/67, 623/35, 62430-439
• US Class Current: 62/3.2
• CPC Class Codes: F25B 21/04 reversible
• CPC Class Codes: F25B 25/00 Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00

Abstract

A refrigeration system for multi-temperature and single-temperature applications combines a refrigeration circuit and a single-phase fluid heat-transfer circuit in heat-conducting contact through a thermoelectric device. A vapor compression cycle provides a first stage of cooling and the thermoelectric device in conjunction with the heat-transfer circuit provides the second stage of cooling. Polarity of the thermoelectric device can be reversed to provide a defrost function for the refrigeration system.

Claims

1. A refrigeration system comprising:

a thermoelectric device that forms a temperature gradient between first and second sides;

a compressible working fluid flowing through a refrigeration circuit in heat-transferring relation to said first side of said thermoelectric device;

a heat transfer fluid flowing through a heat-transfer circuit in heat-transferring relation to said second side of said thermoelectric device;

wherein heat is extracted from one of said compressible working fluid and heat transfer fluid and transferred to the other of said compressible working fluid and heat transfer fluid through said thermoelectric device.

2. The refrigeration system of claim 1, further comprising a compressor in said refrigeration circuit and wherein said compressible working fluid is compressed by said compressor.

3. The refrigeration system of claim 2, further comprising a condenser and an expansion device in said refrigeration circuit, said condenser operable to extract heat from said compressible working fluid.

4. The refrigeration system of claim 3, further comprising an evaporator in said refrigeration circuit in heat-transferring relation with a first air flow, wherein a first portion of said compressible working fluid flows in heat-transferring relation with said evaporator and a second portion of said compressible working fluid flows in heat-transferring relation with said first side of said thermoelectric device, such that said first and second portions flow in parallel in said refrigeration circuit.

5. The refrigeration system of claim 4, wherein said expansion device is a first expansion device and further comprising a second expansion device in said refrigeration circuit, said first and second expansion devices regulating the respective flow of said first and second portions of said compressible working fluid.

6. The refrigeration system of claim 4, further comprising a heat exchanger in said heat-transfer circuit in heat-transferring relation with a second air flow such that said heat-transfer fluid is in heat-transferring relation with both said second air flow and said second side of said thermoelectric device.

7. The refrigeration system of claim 6, further comprising:

a first space maintained at a first temperature and through which said first air flow travels;

a second space maintained at a second temperature different than said first space and through which said second air flow travels;

wherein said heat exchanger extracts heat from said second air flow and transfers said second air flow extracted heat to said heat-transfer fluid, said thermoelectric device transfers said second air flow extracted heat from said heat-transfer fluid to said second portion of said compressible working fluid, and said evaporator extracts heat from said first air flow and transfers said first air flow extracted heat to said first portion of said compressible working fluid.

8. The refrigeration system of claim 3, further comprising a heat exchanger in said heat-transfer circuit in heat-transferring relation with said heat-transfer fluid, said heat exchanger operable to transfer heat between said heat-transfer fluid and an air flow, wherein said expansion device regulates flow of said compressible working fluid.

9. The refrigeration system of claim 8, further comprising a space maintained at a predetermined temperature and through which said air flow travels, and wherein said heat exchanger extracts heat from said air flow and transfers said heat to said heat-transfer fluid, said thermoelectric device transfers said heat from said heat transfer fluid to said compressible working fluid, and said condenser transfers said heat to the ambient environment thereby maintaining said space at said predetermined temperature.

10. The refrigeration system of claim 1, wherein said heat-transfer fluid is a single-phase fluid in said heat-transfer circuit.

11. A refrigeration system comprising:

a heat-transfer circuit operable to transfer heat between a heat-transfer fluid flowing therethrough and a first refrigerated space;

a vapor compression circuit operable to transfer heat between a refrigerant flowing therethrough and an air flow;

a thermoelectric device in heat-transferring relation with said heat-transfer circuit and said vapor compression circuit, said thermoelectric device operable to transfer heat between said heat-transfer fluid and said refrigerant.

12. The refrigeration system of claim 11, wherein said heat-transfer circuit maintains said first refrigerated space at a first predetermined temperature and said heat-transfer circuit includes:

a fluid pump pumping said heat-transfer fluid through said heat-transfer circuit; and

a heat exchanger transferring heat between said heat-transfer fluid and said first refrigerated space.

13. The refrigeration system of claim 12, wherein said vapor compression circuit includes:

a compressor compressing said refrigerant;

a condenser transferring heat between said refrigerant and said air flow; and

an expansion device regulating flow of said refrigerant.

14. The refrigeration system of claim 13, wherein said vapor compression circuit maintains a second refrigerated space at a second predetermined temperature and said vapor compression circuit includes an evaporator transferring heat between said refrigerant and said second refrigerated space.

15. The refrigeration system of claim 14, wherein different portions of said refrigerant flow through said evaporator and in heat-transferring relation with said thermoelectric device and rejoin prior to flowing through said compressor.

16. The refrigeration system of claim 15, wherein said vapor compression circuit includes a pressure regulating device downstream of said evaporator and creating a pressure differential across said evaporator.

17. The refrigeration system of claim 11, further comprising a power supply operable to selective supply an electric current flow to said thermoelectric device.

18. The refrigeration system of claim 11, wherein said heat-transferring fluid is a single-phase fluid in said heat-transfer circuit.

19. A refrigeration system comprising:

a thermoelectric device including a temperature gradient between first and second sides;

a first air flow flowing through a first space in heat-transferring relation with said first side;

a compressible working fluid flowing through a refrigeration circuit in heat-transferring relation with said second side;

wherein heat is extracted from one of said first air flow and said working fluid and transferred to the other of said first air flow and said working fluid through said thermoelectric device.

20. The refrigeration system of claim 19, further comprising a compressor in said refrigeration circuit and wherein said working fluid is compressed by said compressor.

21. The refrigeration system of claim 20, further comprising an evaporator in said refrigeration circuit in heat-transferring relation with a second air flow flowing through a second space, said evaporator extracting heat from said second air flow thereby cooling said second space.

22. The refrigeration system of claim 21, wherein said second side of said thermoelectric device is in heat-transferring relation with said working fluid flowing through said evaporator.

23. The refrigeration system of claim 19, wherein heat is extracted from said first air flow and transferred to said working fluid through said thermoelectric device.

24. A method comprising:

transferring heat between a fluid flowing through a heat-transfer circuit and a first side of a thermoelectric device;

transferring heat between a refrigerant flowing through a vapor compression circuit and a second side of said thermoelectric device.

25. The method of claim 24, further comprising:

removing heat from a first refrigerated space with the heat-transfer circuit;

transferring said removed heat to a cold side of said thermoelectric device;

transferring said removed heat to said ref rifrigerant through a hot side of said thermoelectric device.

26. The method of claim 25, further comprising transferring said removed heat from said refrigerant to the ambient environment with a condenser.

27. The method of claim 25, further comprising:

removing heat from a second refrigerated space with said refrigerant;

transferring said heat removed from said first and second refrigerated spaces from said refrigerant to the ambient environment with a condenser in the vapor compression circuit.

28. The method of claim 27, further comprising:

transferring said heat removed from said first refrigerated space to a first portion of said refrigerant in heat transferring relation with said hot side of said thermoelectric device;

transferring heat from an air flow through said second refrigerated space to a second portion of said refrigerant in heat transferring relation with an evaporator;

joining said first and second portions of said refrigerant together prior to said refrigerant flowing through a compressor.

29. The method of claim 28, further comprising operating said hot side of said thermoelectric device and said evaporator at approximately a same temperature.

30. The method of claim 28, further comprising operating said hot side of said thermoelectric device and said evaporator at different temperatures.

31. The method of claim 25, wherein removing heat from said first refrigerated space includes:

transferring heat from said first refrigerated space to said heat-transfer fluid within said heat exchanger; and

transferring heat from said heat-transfer fluid to said cold side of said thermoelectric device.

32. The method of claim 24, further comprising:

supplying an electric current flow to the thermoelectric device thereby creating a temperature gradient between said first and second sides of said thermoelectric device;

cooling a first refrigerated space by transferring heat from said heat-transfer fluid to said refrigerant flow through said thermoelectric device;

defrosting heat exchanger in said heat-transfer circuit by transferring heat to said heat-transfer fluid through said thermoelectric device.

33. The method of claim 24, further comprising maintaining said heat-transfer fluid in a single-phase throughout the heat-transfer circuit.

34. The method of claim 24, further comprising:

removing heat from a first refrigerated space by circulating an air flow through said first refrigerated space and in heat-transferring relation with a cold side of said thermoelectric device;

transferring said removed heat to said refrigerant through a hot side of said thermoelectric device.

36. The method of claim 24, further comprising creating a temperature gradient between said first and second sides of said thermoelectric device by supplying an electric current flow to said thermoelectric device.

35. A method comprising:

transferring heat between a fluid and a first side of a thermoelectric device;

transferring heat between a refrigerant flowing through a vapor compression circuit and a second side of said thermoelectric device;

removing heat from a first refrigerated space by circulating an air flow through said first refrigerated space and in heat-transferring relation with a cold side of said thermoelectric device;

transferring said removed heat to said refrigerant through a hot side of said thermoelectric device;

removing heat from a second refrigerated space with said refrigerant;

transferring said heat removed from said first and second refrigerated spaces from said refrigerant to the ambient environment with a condenser in the vapor compression circuit.

37. The method of claim 35, further comprising creating a temperature gradient between said first and second sides of said thermoelectric device by supplying an electric current flow to said thermoelectric device.

38. The method of claim 37, wherein said first side has a first temperature, said second side has a second temperature, and said first temperature is lower than said second temperature.

39. The method of claim 35, wherein circulating an air flow through said first refrigerated space and in heat-transferring relation with a cold side of said thermoelectric device includes circulating said air flow in direct contact with at least one heat transfer fin which is in heat-transfer relation with said cold side of said thermoelectric device.

40. The method of claim 35, wherein transferring said removed heat to said refrigerant include transferring said removed heat from said hot side of said thermoelectric device to said refrigerant in an evaporator and removing heat from said second refrigerated space includes transferring said heat from said second refrigerated space to said refrigerant in said evaporator.