摘要 |
A method is disclosed for controlling initiation of a defrost cycle of an evaporator heat exchanger of a refrigeration system operatively associated with a refrigerated transport cargo box. The method includes the steps of establishing an return air-saturation temperature differential equal to the difference of a sensed air temperature of an air flow returning from the cargo box to pass over the heat exchange surface of the evaporator heat exchanger minus a refrigerant saturation temperature of a flow of refrigerant passing through the evaporator heat exchanger, comparing the return air-saturation temperature differential to a set point threshold defrost temperature differential, and if the return air-saturation temperature differential exceeds the set point threshold defrost temperature differential, initiating a defrost cycle for defrosting the evaporator heat exchanger. |