VARIABLE AREA REFRIGERANT EXPANSION DEVICE

摘要

A refrigerant flow metering device for use in a refrigeration system includes a body (20) having a flow passage extending therethrough. A piston (62) having a flow metering port (80) extending therethrough is movably disposed within the flow passage. An elongated member (60) extends into the metering port (80) of the piston (62) and cooperates with the port to define a flow metering passage (81) therebetween. The elongated member (60) is configured such that it will vary the cross-sectional area of the flow metering passage (81) as a function of the position of the member to the metering port. Means (70, 72) are provided for supporting the elongated member (60) within the housing and for controlling the relative axial position of the elongated member (60) and the piston (62) with respect to one another as a function of the differential pressure across the piston (62). The refrigerant expansion device is capable of responding to certain pressure and flow conditions within a refrigeration system to provide optimum expansion areas within the device for such pressure and flow conditions.