초록 ▼

A refrigeration system including a solenoid actuated on-off modulated expansion valve and a controller for controlling the expansion valve is disclosed. The controller includes a low ambient start-up means responsive to the presence of liquid refrigerant at the inlet end of the expansion valve for o

A refrigeration system including a solenoid actuated on-off modulated expansion valve and a controller for controlling the expansion valve is disclosed. The controller includes a low ambient start-up means responsive to the presence of liquid refrigerant at the inlet end of the expansion valve for overriding normal operations of the valve and maintaining the expansion valve open for refrigerant flow therethrough when liquid refrigerant is not present at the expansion valve. The low ambient start-up means includes temperature sensors upstream and downstream from the expansion valve to detect the temperature differential across the expansion valve. The temperature differential is compared to a threshold value and depending upon the comparison, either overrides the expansion valve to permit full flow therethrough or to allow the expansion valve to operate in response to the controller.

대표청구항 ▼

A refrigeration system having in a closed loop connection a compressor having an inlet and an outlet end, a condenser connected to the outlet end of said compressor and responsive to a high pressure gaseous phase recirculating refrigerant for condensing the refrigerant from its gaseous to its liquid

A refrigeration system having in a closed loop connection a compressor having an inlet and an outlet end, a condenser connected to the outlet end of said compressor and responsive to a high pressure gaseous phase recirculating refrigerant for condensing the refrigerant from its gaseous to its liquid phase, an evaporator having an inlet and an outlet end and connected to said condenser and to the inlet end of said compressor, an expansion valve having an inlet and an outlet end and connected between the outlet end of said condenser and the inlet end of said evaporator, said condenser delivering high pressure liquid refrigerant to the inlet end of said expansion valve, said refrigerant expanding as it flows through said expansion valve, a controller circuit responsive to the superheat of the refrigerant in said evaporator for controlling the flow of refrigerant through said expansion valve, and a low ambient start-up means responsive to the presence of liquid refrigerant at the inlet end of said expansion valve for overriding normal operations of said valve and maintaining said expansion valve open for refrigerant flow therethrough when liquid refrigerant is not present, said low ambient start-up means returning control for normal operations of said valve when liquid refrigerant is present.