METHODS AND SYSTEMS FOR CONTROLLING AIR CONDITIONING SYSTEMS HAVING A COOLING MODE AND A FREE-COOLING MODE

摘要

An air conditioning system having a cooling mode and a free-cooling mode. The system having a refrigeration circuit having a compressor and a pump; a suction pressure sensor for measuring a suction pressure of the compressor; a discharge pressure sensor for measuring a discharge pressure of the compressor; a controller for selectively operating in the cooling mode by circulating and compressing a refrigerant through the refrigeration circuit via the compressor or operating in the free-cooling mode by circulating the refrigerant through the refrigeration circuit via the pump; and a recover-refrigerant sequence resident on the controller, the recover-refrigerant sequence being configured to pump the refrigerant in a portion of the refrigeration circuit not used in the free-cooling mode to remaining portions of the refrigeration circuit used in the free-cooling mode when the controller switches from the cooling mode to the free-cooling mode.