EXPANSION VALVE CONTROL FOR HEAT TRANSFER SYSTEM

摘要

A compressor is connected with an evaporator, a condenser, and an electrically controlled valve for circulating a working fluid in a system for recovering waste heat to provide heated water for human use. A suction superheat temperature is determined from a measured compressor suction temperature and a suction saturation temperature. The electrically controlled valve is adjusted to maintain the suction superheat temperature at a suction superheat set point. The electrically controlled valve may be incrementally closed when a compressor suction pressure exceeds a maximum suction pressure. A discharge superheat temperature can be determined from a measured compressor discharge temperature and a discharge saturation temperature. The electrically controlled valve may be incrementally closed when the discharge superheat temperature falls below a minimum discharge superheat temperature.

主权项

1. A heat transfer system comprising:
a compressor for circulating a working fluid, the compressor having an inlet and an outlet; a condenser connected to the outlet of the compressor; an electrically controlled valve positioned to receive working fluid from the outlet of the condenser; an evaporator connected between an outlet of the electrically controlled valve and the inlet of the compressor; a suction pressure sensor located between the outlet of the electrically controlled valve and the inlet of the compressor; a suction temperature sensor located at the inlet of the compressor; and a controller connected to the suction pressure sensor, the suction temperature sensor, and the electrically controlled valve, the controller configured to adjust the electrically controlled valve to maintain output of the suction pressure sensor and the suction temperature sensor at above a saturation point of the working fluid.