Electronic expansion valve without pressure sensor reading

摘要

An system and process for controlling an electronic exchange valve for an transport refrigeration system evaporator in the absence of a evaporator outlet pressure transducer reading is disclosed. The process includes monitoring for the absence of reliable evaporator outlet pressure readings, monitoring the supply air temperature, and supplying the supply air temperature to a processor within a controller for use in an algorithm so as to approximate the saturation reference temperature and superheat levels to derive the necessary control signals for the EXV.