Patent ID: 8769973

Claim:
A refrigeration system comprising: an evaporator for exchanging heat; a load to be chilled to within a selected temperature range, the load placing a variable heat load on the refrigeration system based upon the volume of a product delivered over a selected cycle time; an adjustable expansion valve for metering a refrigerant to said evaporator at a selected flow rate; a variable speed compressor for delivering refrigerant to said expansion valve at selected flow rates determined by the speed of operation of said compressor, the refrigerant being metered by said expansion valve to said evaporator to cool said evaporator to chill the load; a sensor that senses the variable heat load placed on the refrigeration system based upon the volume of a product delivered over a selected cycle time; a microprocessor electrically coupled to the expansion valve, the variable speed compressor, and the sensor, wherein the microprocessor determines a chilling requirement of the load based on a signal from the sensor; and wherein the microprocessor controls a speed of the variable speed compressor, and an expansion of the expansion valve, to deliver a sufficient amount of a refrigerant to the evaporator to satisfy the chilling requirement.