Thermostatic expansion valves and methods of control
AssigneeCarrier Corporation
InventorsDouglas Auyer, Gilbert B. Hofsdal, William C. Silliman, Raymond L. Senf, Jr.
Life of this patent
Estimating the term…
Abstract
A method of operating a refrigeration system is provided. The method includes activating an evaporator heater (306), monitoring a pressure differential within the refrigeration system (308), when the pressure differential reaches a predetermined value (310), deactivating the evaporator heater (312), and activating one or more evaporator fans (314), after deactivating the evaporator heater, to cause a thermostatic expansion valve to open.
Claims13
A method of operating a refrigeration system comprising:
- determining that the refrigeration system failed to start prior to activating an evaporator heater based on a detected current draw of a compressor, wherein a failed start is based on a current draw of the compressor exceeding a predetermined current;
- activating the evaporator heater;
- monitoring a pressure differential within the refrigeration system;
- when the pressure differential reaches a predetermined value, deactivating the evaporator heater;
- activating one or more evaporator fans, after deactivating the evaporator heater, to cause a thermostatic expansion valve to open;
- and
- restarting the refrigeration system.
A refrigeration system comprising:
- a compressor;
- a condenser having one or more condenser fans;
- an evaporator having an evaporator heater and one or more evaporator fans;
- a thermostatic expansion valve;
- a fluid path fluidly connecting the compressor, the condenser, the evaporator, and the thermostatic expansion valve;
- and
- a controller configured to:
- determine that the refrigeration system failed to start prior to activating the evaporator heater based on a detected current draw of the compressor, wherein a failed start is based on a current draw of the compressor exceeding a predetermined current;
- activate the evaporator heater;
- monitor a pressure differential within the fluid path;
- when the pressure differential reaches a predetermined value, deactivate the evaporator heater;
- activate the one or more evaporator fans to cause the thermostatic expansion valve to open, and
- restart the refrigeration system.
A method of operating a refrigeration system comprising:
- determining that the refrigeration system failed to start based on a detected current draw of a compressor, wherein a failed start is based on a current draw of the compressor exceeding a predetermined current;
- increasing a temperature at a bulb of a thermostatic expansion valve system within the refrigeration system;
- increasing a suction pressure at an inlet side of an evaporator in the refrigeration system;
- monitoring a pressure differential within the refrigeration system and when the pressure differential reaches a predetermined value, activating one or more evaporator fans to open a thermostatic expansion valve;
- restarting the refrigeration system;
- and
- starting the compressor of the refrigeration system.
Dependencies are inferred from the claim text.