Refrigerant circuit expansion valve control
AssigneeTrane International Inc.
InventorsDaniel Gorman, Daryl Keys, Benjamin Elias Dingel
Life of this patent
Estimating the term…
Abstract
A method is for operating an expansion valve in a refrigerant circuit that includes a compressor, a condenser, the expansion valve, an evaporator, and a working fluid. The method includes determining a modified subcooling value based on a condenser working fluid discharge temperature, a condenser discharge subcooling setpoint, and one or more of a compressor discharge temperature and an evaporator approach temperature. The method also includes adjusting the expansion valve according to the modified subcooling value. A refrigerant circuit for a heating, ventilation, air conditioning, and refrigeration system includes a controller configured to operate the expansion valve according to a modified subcooling value.
Claims20
A method of operating an expansion valve in a refrigerant circuit, the refrigerant circuit including a compressor, a condenser, the expansion valve, and an evaporator that are fluidly connected, the refrigerant circuit containing a working fluid, the method comprising:
- determining a modified subcooling value based on a condenser working fluid discharge temperature, a condenser discharge subcooling setpoint, and one or more of a compressor discharge temperature and an evaporator approach temperature, wherein the modified subcooling value incorporates an offset that is based on the one or more of the compressor discharge temperature and the evaporator approach temperature;
- and
- adjusting the expansion valve according to the modified subcooling value.
A refrigerant circuit for a heating, ventilation, air conditioning, and refrigeration system, comprising:
- a compressor to compress a working fluid;
- a condenser to condense the working fluid compressed by the compressor using a first process fluid;
- an expansion valve to expand the working fluid condensed by the condenser;
- an evaporator to evaporate the working fluid expanded by the expansion valve using a second process fluid;
- sensors for one or more of the working fluid and the second process fluid, the sensors including at least one temperature sensor and at least one pressure sensor;
- a controller for the refrigerant circuit, the controller configured to:
- detect, via the at least one temperature sensor and the at least one pressure sensor, one or more temperatures of the working fluid and the second process fluid and at least one pressure of the working fluid,
- determine a modified subcooling value based on a condenser working fluid discharge temperature, a condenser discharge subcooling setpoint, and one or more of a compressor discharge temperature and an evaporator approach temperature, wherein the condenser working fluid discharge temperature, the condenser discharge subcooling setpoint, and the one or more of the compressor discharge temperature and the evaporator approach temperature are based on the detected one or more temperatures of the working fluid and the second process fluid and the detected at least one pressure of the working fluid, and the modified subcooling value incorporates an offset that is based on the one or more of the compressor discharge temperature and the evaporator approach temperature;
- and
- adjust the expansion valve according to the modified subcooling value.
Dependencies are inferred from the claim text.