High outdoor ambient and high suction pressure oil pump out mitigation for air conditioners

Patent metadata

Field	Value
Publication number	US-10473377-B2
Application number	US-201715711504-A
Country	US
Kind code	B2
Filing date	Sep 21, 2017
Priority date	Sep 26, 2016
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A method of operating an air conditioning system including: operating a refrigerant compression device at a demand speed to circulate refrigerant through a refrigeration circuit; monitoring, using a temperature sensor, a temperature of external ambient air; monitoring, using a pressure sensor, a pressure of the refrigerant within the refrigerant circuit; detecting, using a controller, when the temperature of external ambient air is greater than a selected temperature; detecting, using the controller, when the pressure of the refrigerant is greater than a selected pressure; and reducing the speed of the refrigerant compression device to a selected speed for a first duration of time when the temperature of external ambient air is greater than the selected temperature and the pressure of the refrigerant is greater than the selected pressure.

First claim

What is claimed is:

1. A method of operating an air conditioning system, the method comprising:
operating a refrigerant compressor at a demand speed to circulate refrigerant through a refrigeration circuit;
monitoring, using a temperature sensor, a temperature of external ambient air;
monitoring, using a pressure sensor, a pressure of the refrigerant within the refrigerant circuit, wherein the pressure is suction pressure of the refrigerant flowing into the refrigerant compressor;
detecting, using a controller, when the temperature of external ambient air is greater than a selected temperature;
detecting, using the controller, when the pressure of the refrigerant is greater than a selected pressure; and
reducing the speed of the refrigerant compressor to a selected speed for a first duration of time when the temperature of external ambient air is greater than the selected temperature and the pressure of the refrigerant is greater than the selected pressure.

2. The method of claim 1 , further comprising:
increasing the speed of the refrigerant compressor by a selected speed increment after reducing the speed of the refrigerant compression device when the temperature of external ambient air is greater than the selected temperature and the pressure of the refrigerant is greater than the selected pressure.

3. The method of claim 2 , further comprising:
detecting, using the controller, when the pressure of the refrigerant is greater than a designated pressure associated with the speed of the refrigerant compressor; and
decreasing the speed of the refrigerant compressor by a second selected speed increment when the pressure of the refrigerant is greater than the designated pressure associated with the speed of the refrigerant compressor.

4. The method of claim 2 , further comprising:
detecting, using the controller, when the pressure of the refrigerant is less than a designated pressure associated with the speed of the refrigerant compressor;
detecting, using the controller, if the speed of the refrigerant compressor is greater than or equal to the demand speed; and
increasing the speed of the refrigerant compressor by the selected speed increment when the pressure of the refrigerant is less than the designated pressure associated with the speed of the refrigerant compressor and the speed of the refrigerant compressor is less than the demand speed.

5. The method of claim 4 , further comprising:
operating the refrigerant compressor at the demand speed if the speed of the refrigerant compressor is greater than or equal to the demand speed.

6. The method of claim 2 , further comprising:
storing, using the controller, a benchmark pressure;
detecting, using the controller, if the pressure is greater than or equal to a second selected pressure;
detecting, using the controller, if the speed of the refrigerant compressor is greater than or equal to the demand speed;
detecting, using the controller, when the pressure has decreased by at least a third selected pressure from the benchmark pressure; and
increasing the speed of the refrigerant compressor by the selected speed increment when the pressure of the refrigerant pressure has decreased by at least a third selected pressure from the benchmark pressure and the speed of the refrigerant compressor is less than the demand speed.

7. A controller of an air conditioning system comprising:
a processor;
a memory comprising computer-executable instructions that, when executed by the processor, cause the processor to perform operations, the operations comprising:
operating a refrigerant compressor at a demand speed to circulate refrigerant through a refrigeration circuit;
monitoring a temperature of external ambient air;
monitoring a pressure of the refrigerant within the refrigerant circuit;
detecting when the temperature of external ambient air is greater than a selected temperature;
detecting when the pressure of the refrigerant is greater than a selected pressure, wherein the pressure is suction pressure of the refrigerant flowing into the refrigerant compressor; and
reducing the speed of the refrigerant compressor to a selected speed for a first duration of time when the temperature of external ambient air is greater than the selected temperature and the pressure of the refrigerant is greater than the selected pressure.

8. The controller of claim 7 , wherein the operations further comprise:
increasing the speed of the refrigerant compressor by a selected speed increment after reducing the speed of the refrigerant compressor when the temperature of external ambient air is greater than the selected temperature and the pressure of the refrigerant is greater than the selected pressure.

9. The controller of claim 8 , wherein the operations further comprise:
detecting when the pressure of the refrigerant is greater than a designated pressure associated with the speed of the refrigerant compressor; and
decreasing the speed of the refrigerant compressor by a second selected speed increment when the pressure of the refrigerant is greater than the designated pressure associated with the speed of the refrigerant compression.

10. The controller of claim 8 , wherein the operations further comprise:
detecting when the pressure of the refrigerant is less than a designated pressure associated with the speed of the refrigerant compressor;
detecting, using the controller, if the speed of the refrigerant compressor is greater than or equal to the demand speed; and
increasing the speed of the refrigerant compressor by the selected speed increment when the pressure of the refrigerant is less than the designated pressure associated with the speed of the refrigerant compressor and the speed of the refrigerant compressor is less than the demand speed.

11. The controller of claim 10 , wherein the operations further comprise:
operating the refrigerant compressor at the demand speed if the speed of the refrigerant compressor is greater than or equal to the demand speed.

12. The controller of claim 8 , wherein the operations further comprise:
storing a benchmark pressure;
detecting if the pressure is greater than or equal to a second selected pressure;
detecting if the speed of the refrigerant compressor is greater than or equal to the demand speed;
detecting when the pressure has decreased by at least a third selected pressure from the benchmark pressure; and
increasing the speed of the refrigerant compressor by the selected speed increment when the pressure of the refrigerant pressure has decreased by at least a third selected pressure from the benchmark pressure and the speed of the refrigerant compressor is less than the demand speed.

13. An air conditioning system comprising:
a refrigerant compressor comprising a refrigerant compressor inlet, the refrigerant compressor in fluid communication with a refrigerant heat rejection heat exchanger, an expansion device, and a refrigerant heat absorption heat exchanger to form a refrigerant circuit;
wherein the refrigerant compressor is configured to operate at a demand speed to circulate a refrigerant through the refrigerant circuit when operating in a cooling mode;
a controller operably coupled to the refrigerant compressor;
a temperature sensor operably coupled to the controller, the temperature sensor configured to measure an external ambient air temperature; and
a pressure sensor disposed on the refrigerant circuit, the pressure sensor configured to measure a refrigerant pressure, wherein the refrigerant pressure is suction pressure of the refrigerant flowing into the refrigerant compressor;
wherein the controller is configured to reduc

Assignees

• Carrier Corp

Inventors

• Lee Jun Pyo
• Das Sathish R
• Lumpkin Everett
• Gervais Mathew

Classifications

• F25B49/022 Primary

  Compressor control arrangements · CPC title

• F25B2600/0253

  with variable speed · CPC title

• F25B2700/171

  of the compressor · CPC title

• F25B2500/07

  Exceeding a certain pressure value in a refrigeration component or cycle · CPC title

• F25B2500/16

  Lubrication · CPC title