THERMOSTATIC EXPANSION VALVE FOR REFRIGERATION SYSTEM

摘要

A thermostatic expansion valve for use in a refrigeration system of the vapor-compression type. Valve actuation is made responsive to the combined effect of evaporator coil temperature and pressure as independently monitored through separate control inputs. A slotted ball is pivotally rotated in its seat in a direction determined by the net pressure differential applied to the control inputs to present a gradually and uniformly varying flow orifice profile. One control input monitors internal coil pressure directly while the other control input senses the gas pressure produced within a thermostatic bulb in contact with the coil exterior. Calibration means are provided to balance the net pressure differential under desired steady-state cooling conditions and position the valve accordingly.