System and method for dynamically determining refrigerant film thickness and dynamically controlling refrigerant film thickness at rolling-element bearing of an oil free chiller
AssigneeTrane International Inc.
InventorJay H. Johnson
Life of this patent
Estimating the term…
Abstract
Methods are directed towards dynamically determining refrigerant film thickness at the rolling-element bearing and for dynamically controlling refrigerant film thickness at the rolling-element bearing. Further, an oil free chiller system is configured for dynamically determining refrigerant film thickness at the rolling-element bearing of the oil free chiller system, wherein the oil free chiller system is also configured for dynamically controlling refrigerant film thickness at the rolling-element bearing of the oil free chiller system.
Claims20
A chiller system, comprising:
- a refrigeration circuit configured to circulate a refrigerant, including:
- an oil-free compressor having a drive motor and a bearing, the bearing configured to receive a flow of the refrigerant;
- a condenser;
- an evaporator;
- a liquid temperature affecting device configured to affect a temperature of the flow of the refrigerant, the liquid temperature affecting device configured to receive liquid refrigerant from between the condenser and the evaporator of the chiller system;
- and
- a controller configured to:
- determine a film thickness of refrigerant at the bearing;
- and
- adjust an output temperature of the liquid temperature affecting device based on the film thickness.
A controller for a chiller system, configured to:
- receive refrigerant lubrication parameters including at least one of a temperature of refrigerant at a bearing in an oil-free chiller and a speed of rotation of a drive motor of the chiller system;
- determine film thickness of the refrigerant at the bearing in the oil-free chiller based only on the temperature and the speed of rotation;
- and
- direct adjustment of a temperature of a flow of the refrigerant from a liquid temperature affecting device to the bearing based on the determined film thickness, the liquid temperature affecting device configured to receive liquid refrigerant from the chiller system.
A method for controlling a chiller system, comprising:
- obtaining refrigerant lubrication parameters including at least one of a temperature of refrigerant at a bearing in an oil-free chiller, a condenser pressure of the chiller system, or a speed of rotation of a drive motor of the chiller system;
- determining, using a controller, film thickness of the refrigerant at the bearing in the oil-free chiller based on the refrigerant lubrication parameters;
- and
- adjusting a temperature of a flow of the refrigerant from a liquid temperature affecting device to the bearing based on the determined film thickness, the liquid temperature affecting device configured to receive liquid refrigerant from between a condenser and an evaporator of the chiller system.
Dependencies are inferred from the claim text.