VEHICLE REFRIGERATOR HAVING A LIQUID LINE SUBCOOLED VAPOR CYCLE SYSTEM

• US 20130047630A1
• Filed: 08/23/2011
• Published: 02/28/2013
• Est. Priority Date: 08/23/2011
• Status: Active Grant

• Current Assignee: B/E Aerospace, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: B/E Aerospace, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Lu, Qiao
• Granted Patent: US 9,134,053 B2
• Time in Patent Office: Days
• US Class Current: 62/3.6
• CPC Class Codes: F25B 21/02 using Peltier effect; using Nernst-Ettinghausen effect
• CPC Class Codes: F25B 2313/029 Control issues
• CPC Class Codes: F25B 40/00 Subcoolers, desuperheaters or superheaters
• CPC Class Codes: F25B 40/02 Subcoolers
• CPC Class Codes: F25B 47/022 hot gas defrosting
• CPC Class Codes: F25B 49/02 for compression type machines, plants or systems

Abstract

A vapor cycle refrigeration system includes a thermoelectric device (TED) as a sub-cooler to sub-cool liquid refrigerant exiting a condenser to increase cooling capacity of an evaporator and pull down temperature within a refrigerated compartment quickly. The TED sub-cooler is turned off after initial temperature pull down and is not operated during steady state operation for maintenance of the compartment temperature.

Claims

1. A refrigeration system that cools a compartment, the refrigeration system comprising:

a compressor,

a condenser,

a thermoelectric device (TED) sub-cooler,

an expansion valve,

an evaporator, and

tubing adapted to transport refrigerant through the refrigeration system in a circulation order from the compressor to the condenser to the TED sub-cooler to the expansion valve to the evaporator and back to the compressor again.

2. The refrigeration system of claim 1, wherein the TED sub-cooler sub-cools the refrigerant exiting the condenser by at least approximately ten degrees Farenheit.

3. The refrigeration system of claim 1, wherein the TED sub-cooler operates when a difference between a measured temperature in the compartment is greater than or equal to a preset threshold, and does not operate when the difference is less than the preset threshold.

4. The refrigeration system of claim 3, wherein the preset threshold is between approximately two and ten degrees.

5. The refrigeration system of claim 1, further comprising a condenser fan that circulates air to cool both the condenser and a hot side heat sink of the TED sub-cooler.

6. The refrigeration system of claim 1, wherein the TED sub-cooler is powered by direct electrical current.

7. The refrigeration system of claim 1, wherein the TED sub-cooler is controlled using a Pulse Width Modulation control signal.

8. The refrigeration system of claim 1, further comprising an enclosure that encloses the compartment and the refrigeration system, the enclosure having a door that provides closeable access to the compartment and vents through which a condenser fan outputs condenser exhaust and inputs ambient air for cooling the condenser.

9. The refrigeration system of claim 1, further comprising a controller that controls the refrigeration system according to sensor data from temperature and pressure sensors in the refrigeration system.

10. The refrigeration system of claim 9, wherein the controller is remotely controlled using a computer system which communicates with the controller over a data communications network.

11. The refrigeration system of claim 1, further comprising a refrigerant heat exchanger that superheats refrigerant entering the compressor using refrigerant before entering the expansion valve.

12. A method of controlling a refrigeration system comprising a compressor, a condenser, a thermoelectric device (TED) sub-cooler, an expansion valve, an evaporator, and tubing adapted to transport refrigerant through the refrigeration system in a circulation order from the compressor to the condenser to the TED sub-cooler to the expansion valve to the evaporator and back to the compressor again, the method comprising:

inputting sensor data;

determining whether a measured temperature of the compartment is greater than or equal to a preset threshold;

controlling the TED sub-cooler when the temperature is greater or equal to the preset threshold;

not operating the TED sub-cooler when the temperature is less than the preset threshold; and

controlling motors and valves of the refrigeration system according to the sensor data to maintain a set temperature of the compartment within a predetermined maintenance range.

13. The method of claim 12, wherein the TED sub-cooler sub-cools the refrigerant exiting the condenser by at least approximately ten degrees Farenheit (F.).

14. The method of claim 12, wherein the preset threshold is between approximately two and ten degrees F.

15. The method of claim 12, further comprising circulating air to cool both the condenser and a hot side heat sink of the TED sub-cooler using a fan.

16. The method of claim 12, wherein the TED sub-cooler is powered by direct electrical current.

17. The method of claim 12, wherein the TED sub-cooler is controlled using a Pulse Width Modulation control signal.

18. The method of claim 12, wherein the sensor data is received from temperature and pressure sensors in the refrigeration system.

19. The method of claim 12, further comprising remotely controlling the refrigeration system using a computer system which communicates with the controller over a data communications network.

20. The method of claim 12, further comprising superheating the refrigerant before entering the compressor by a refrigerant heat exchanger using refrigerant before entering the expansion valve.