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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 comp

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.

대표청구항 ▼

1. An air conditioning system having a cooling mode and a free-cooling mode, comprising: a refrigeration circuit having a compressor and a pump;a suction pressure sensor for measuring a suction pressure of said compressor;a discharge pressure sensor for measuring a discharge pressure of said compres

1. An air conditioning system having a cooling mode and a free-cooling mode, comprising: a refrigeration circuit having a compressor and a pump;a suction pressure sensor for measuring a suction pressure of said compressor;a discharge pressure sensor for measuring a discharge pressure of said compressor;a controller for selectively operating in the cooling mode by circulating and compressing a refrigerant through said refrigeration circuit via said compressor or operating in the free-cooling mode by circulating said refrigerant through said refrigeration circuit via said pump; anda recover-refrigerant sequence resident on said controller, said recover-refrigerant sequence being configured to pump the refrigerant in a portion of said refrigeration circuit not used in the free-cooling mode to remaining portions of said refrigeration circuit used in the free-cooling mode when said controller switches from the cooling mode to the free-cooling mode;wherein said refrigeration circuit further comprises an controllable expansion device, said recover-refrigerant sequence being configured to maintain said expansion device in a predetermined open position until a pressure differential across said compressor reaches a threshold pressure differential, the controllable expansion device being restricted when the pressure differential across said compressor reaches the threshold pressure differential. 2. The air conditioning system of claim 1, wherein said refrigeration circuit further comprises a three-way valve, said controller adjusting an alignment of said three-way valve so that the refrigerant in said portion of said refrigerant circuit not used in the free-cooling mode is pumped to remaining portions of said refrigeration circuit used in the free-cooling mode when said controller switches from the cooling mode to the free-cooling mode. 3. The air conditioning system of claim 1, wherein said recover-refrigerant sequence is configured to turn off said compressor when said suction pressure reaches a suction pressure threshold. 4. The air conditioning system of claim 1, wherein said recover-refrigerant sequence is initiated when the air conditioning system is in an off state. 5. The air conditioning system of claim 1, wherein said recover-refrigerant sequence is initiated when the air conditioning system is operating in the cooling mode. 6. The air conditioning system of claim 1, wherein said refrigeration circuit further comprises an evaporator in heat exchange communication with said refrigerant and a working fluid. 7. The air conditioning system of claim 6, wherein said working fluid comprises ambient indoor air. 8. The air conditioning system of claim 6, wherein said working fluid comprises a secondary loop fluid. 9. The air conditioning system as in claim 1, wherein said controllable expansion device is controlled by said controller.