Refrigeration control system for modulating electrically-operated expansion valves

Abstract

A refrigeration control system for modulating an electrically-operated expansion valve in which a modulating, electrically-operated expansion valve is connected to the evaporator inlet, and first and second condition-responsive electrical sensors are positioned to respond to conditions at selected location in the system. An electrical amplifier circuit connects the condition-responsive electrical sensors to the valve for regulating the opening and closing of the valve in response to differences in the conditions sensed by the sensors. Refrigerant is fed to at least one of the sensors so as to cause modulation of the expansion valve. More particularly, the condition-responsive sensors are temperature-responsive, the first sensor being positioned to respond to the temperature of the liquid refrigerant expanded to suction pressure, and the second sensor being positioned to respond to suction line sensible temperature. The valve will then modulate to control superheat in response to the differences in the temperatures sensed by the sensors.

Dependencies are inferred from the claim text.