Air conditioning compressor unloading control system

摘要

The pumping capacity of an unloadable air conditioning compressor is switched between full and part capacity states. The part capacity state is established during on/off cycling of the compressor, and air conditioning load conditions are sensed during operation of the compressor to control capacity switching in a manner to provide efficient and responsive performance. Refrigerant pressure at the evaporator outlet is used to control on/off cycling as well as capacity cycling, and the rate of decrease of such pressure is used as an indication of the air conditioning load.