Transcritical Refrigeration With Pressure Addition Relief Valve

• US 20080184717A1
• Filed: 12/31/2005
• Published: 08/07/2008
• Est. Priority Date: 03/18/2005
• Status: Abandoned Application

• Current Assignee: Carrier Commercial Refrigeration Incorporated (Carrier Global Corporation)
• Original Assignee: Carrier Commercial Refrigeration Incorporated (Carrier Global Corporation)
• Inventors: Chen, Yu, Sienel, Tobias H., Verma, Parmesh, Huff, Hans-Joachim
• Application Number:
  US11/908,619
• Publication Number:
  US 20080184717A1
• Time in Patent Office: Days
• US Class Current: 62/115
• CPC Class Codes: F25B 2309/061 with cycle highest pressure above the supercritical pressure
• CPC Class Codes: F25B 2400/0411 for the expansion valve or capillary tube
• CPC Class Codes: F25B 2500/18 Optimization, e.g. high integration of refrigeration components
• CPC Class Codes: F25B 2600/2525 Pressure relief valves
• CPC Class Codes: F25B 41/335 via diaphragms
• CPC Class Codes: F25B 9/008 the refrigerant being carbon dioxide
• CPC Class Codes: F25D 31/007 Bottles or cans

Abstract

A refrigeration system (20) includes a pressure addition relief valve (62) in parallel with an expansion device (63).

Claims

1. A cooler system comprising:

a compressor (22) for driving a refrigerant along a flow path in at least a first mode of system operation;

a first heat exchanger (24) along the flow path downstream of the compressor in the first mode so as to act as a gas cooler;

a second heat exchanger (28) along the flow path upstream of the compressor in the first mode so as to act as an evaporator to cool contents of an interior volume of the system;

an expansion device (63) in the flow path downstream of the first heat exchanger (24) and upstream of the second heat exchanger (28); and

a pressure addition relief valve (62) in parallel with the expansion device.

2. The system of claim 1 wherein:

the pressure addition relief valve (62) is a purely mechanical valve.

3. The system of claim 1 wherein:

the expansion device (63) is a purely mechanical device.

4. The system of claim 1 wherein:

the pressure addition relief valve (62) is normally closed and configured to open responsive to a combined force produced by pressures essentially respectively immediately downstream of the first heat exchanger and upstream of the second heat exchanger.

5. The system of claim 4 wherein:

a bias force acts opposite the combined force, the bias force comprising at least one of;

a supplemental spring (94) bias force;

a bias force provided by a system condition sensor (110); and

a bias force exerted by ambient air pressure.

6. The system of claim 1 wherein:

the pressure addition relief valve (62) is integral with the expansion device (63).

7. The system of claim 1 wherein:

the expansion device (63) comprises a fixed orifice (120) in a common body (70) of the pressure addition relief valve.

8. The system of claim 1 wherein:

the expansion device (63) comprises non-EEV device.

9. The system of claim 1 wherein:

the pressure addition relief valve comprises a sheet metal spring membrane (84) and no other spring.

10. The system of claim 1 wherein:

the pressure addition relief valve comprises a membrane (84) and a coil biasing spring (94).

11. The system of claim 1 wherein:

flowpath portions upstream (76) and downstream (78) of the expansion device have effective counterbias areas of the pressure addition relief valve, the lesser being no less than 10% of the greater.

12. The system of claim 1 being a self-contained externally electrically powered beverage cooler positioned outdoors.

13. The system of claim 1 wherein:

the refrigerant comprises, in major mass part, CO₂; and

the first and second heat exchangers are refrigerant-air heat exchangers.

14. The system of claim 1 wherein:

the refrigerant consists essentially of CO₂; and

the first (24) and second (28) heat exchangers are refrigerant-air heat exchangers each having an associated fan (30;

32), an air flow across the first heat exchanger being an external to external flow and an airflow across the second heat exchanger being a recirculating internal flow.

15. The system of claim 1 in combination with said contents which include:

a plurality of beverage containers in a 0.3-4.0 liter size range.

16. The system of claim 15 being selected from the group consisting of:

a cash-operated vending machine;

a transparent door front, closed back, display case; and

a top access cooler chest.

17. A transcritical CO₂ refrigeration system comprising:

a compressor (22) for driving a refrigerant along a flow path in at least a first mode of system operation;

a first heat exchanger (24) along the flow path downstream of the compressor in the first mode so as to act as a gas cooler;

a second heat exchanger (28) along the flow path upstream of the compressor in the first mode so as to act as an evaporator;

an expansion device (63) in the flow path downstream of the first heat exchanger (24) and upstream of the second heat exchanger (28); and

a pressure addition relief valve (62) in parallel with the expansion device.

18. A method for operating a transcritical CO₂ refrigeration system comprising:

compressing and driving a refrigerant along a flow path in at least a first mode of system operation;

cooling the compressed refrigerant along the flow path downstream of the compressing;

expanding the cooled refrigerant; and

heating the expanded refrigerant;

wherein;

the expanding comprises a mechanically automated varying of an effective flow restriction based upon an additive combination of forces from pressures respectively upstream and downstream of the restriction.

19. A method for remanufacturing a transcritical CO₂ refrigeration system or reengineering a configuration thereof wherein a baseline configuration comprises:

a compressor (22) for driving a refrigerant along a flow path in at least a first mode of system operation;

a first heat exchanger (24) along the flow path downstream of the compressor in the first mode so as to act as a gas cooler;

a second heat exchanger (28) along the flow path upstream of the compressor in the first mode so as to act as an evaporator; and

an expansion device (26) in the flow path downstream of the first heat exchanger (24) and upstream of the second heat exchanger (28),

the method comprising at least one of;

adding a pressure addition relief valve (62) in parallel with the expansion device (26); and

replacing the expansion device (26) with a pressure addition relief valve (62) and a structurally different expansion device (63).