Method and apparatus for controlling a refrigeration system

Abstract

A control method and device for controlling the operation of various components of a refrigeration system provides more efficient operation of those components. Energization of the compressor is delayed upon power interruption, and high pressure is relieved through operation of a valve. The compressor runs is energized if the cabin temperature exceeds a specified temperature for a predetermined length of time, is is de-energized if the cabin temperature drops below a specified temperature. The condenser fan is energized based on the temperature of the condenser coil inlet and the ambient temperature. The evaporator fan is energized based on the cabin temperature and the temperature of the evaporator coil outlet.

What is claimed is:  
     
         1 . A control for controlling the operation of a refrigeration system having a compressor, an evaporator having an inlet and an outlet, a condenser having an inlet and an outlet, an evaporator fan disposed to move a fluid adjacent said evaporator in heat transfer relation thereto and a condenser fan disposed to move a fluid adjacent said condenser in heat transfer relation thereto, said control comprising a first control logic configured to energize the condenser fan when the condenser inlet temperature is greater than ambient temperature adjacent said condenser plus a predetermined temperature difference.  
     
     
         2 . A method for controlling the operation of a refrigeration system having a compressor, an evaporator having an inlet and an outlet, a condenser having an inlet and an outlet, an evaporator fan disposed to move a fluid adjacent said evaporator in heat transfer relation thereto and a condenser fan disposed to move a fluid adjacent said condenser in heat transfer relation thereto, said method comprising the steps of: 
 a. energizing the condenser fan when the condenser inlet temperature is greater than ambient temperature adjacent said condenser plus a first predetermined temperature difference; and    b. de-energizing the condenser fan when the condenser inlet temperature is less than ambient temperature adjacent said condenser plus a second predetermined temperature difference.