Compressor discharge control on a transport refrigeration system

Patent metadata

Field	Value
Publication number	US-9599384-B2
Application number	US-200913057337-A
Country	US
Kind code	B2
Filing date	Sep 21, 2009
Priority date	Sep 26, 2008
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

In a refrigeration system having a compressor, a condenser, an evaporator, and a controller for controlling an expansion valve, a process for controlling compressor discharge during a cooling cycle includes monitoring a compressor discharge temperature, operating the expansion valve in a base mode wherein the expansion valve is controlled in response to a difference between actual superheat and desired superheat of the evaporator; and controlling the expansion valve in response to a difference between a set point and a compressor discharge parameter when the ambient air temperature, the return air temperature and the compressor discharge temperature meet respective limits.

First claim

We claim:

1. A refrigerant vapor compression system comprising:
a compressor for compressing a refrigerant, the compressor having a suction port, a discharge port, and a compressor discharge temperature sensor operatively coupled to the discharge port, the compressor discharge temperature sensor configured to provide a compressor discharge temperature;
an air-cooled heat exchanger operatively coupled to the discharge port of the compressor;
an evaporator heat exchanger operatively coupled to the air-cooled heat exchanger and the suction port of the compressor, and at least one of an evaporator outlet pressure sensor and an evaporator outlet temperature sensor operatively coupled to the evaporator;
an expansion valve coupled to the inlet of the evaporator for at least partially vaporizing the refrigerant entering the evaporator;
an ambient air temperature sensor for monitoring an ambient air temperature;
a return air temperature sensor for monitoring a return air temperature; and
a controller operatively associated with the expansion valve, the controller configured to:
operate the expansion valve in a base mode wherein the expansion valve is controlled in response to a difference between actual superheat and desired superheat of the evaporator; and
in response to the ambient air temperature, the return air temperature and the compressor discharge temperature meeting respective limits, exiting the base mode to control the expansion valve in response to a difference between a set point and the compressor discharge temperature instead of the difference between actual superheat and desired superheat of the evaporator.

2. The refrigerant vapor compression system of claim 1 , wherein the controller comprises a proportional-integral-derivative controller.

3. The refrigerant vapor compression system of claim 1 , wherein the expansion valve is an electronic expansion valve.

4. The refrigerant vapor compression system of claim 1 , wherein the controller is configured to control the expansion valve in response to the difference between the set point and the compressor discharge temperature when the compressor discharge temperature is greater than 118° C.

5. The refrigerant vapor compression system of claim 4 , wherein the controller further configured to control the expansion valve in response to the difference between the set point and the compressor discharge temperature when the return air temperature sensor reads less than −18° C.

6. The refrigerant vapor compression system of claim 4 , wherein the controller further configured to control the expansion valve in response to the difference between the set point and the compressor discharge temperature when the ambient air temperature sensor reads greater than 43° C.

Assignees

• Weyna Paul V
• Dudley Eliot W
• Abbott Alan D
• Senf Jr Raymond L
• Carrier Corp

Inventors

• Weyna Paul V
• Dudley Eliot W
• Abbott Alan D
• Senf Jr Raymond L

Classifications

• F25B2700/21152

  at the discharge side of the compressor · CPC title

• F25B2700/2106

  of fresh outdoor air · CPC title

• F25B2600/2513

  Expansion valves · CPC title

• F25B2700/21172

  at the inlet · CPC title

• F25B49/027 Primary

  Condenser control arrangements · CPC title