Patent ID: 8141376

Claim:
An air conditioning system comprising: an outdoor heat-exchanging unit having an outdoor heat exchanger and a main compressor; at least one indoor heat-exchanging unit having an indoor heat exchanger; a gaseous refrigerant line connected between the outdoor heat-exchanging unit and the indoor heat-exchanging unit, to allow a refrigerant in a gaseous state to flow between the outdoor heat-exchanging unit and the indoor heat-exchanging unit, the gaseous refrigerant line including a first gaseous refrigerant line connected to the outdoor heat-exchanging unit and a second gaseous refrigerant line connected to the indoor heat-exchanging unit; a liquid refrigerant line connected between the outdoor heat-exchanging unit and the indoor heat-exchanging unit, the liquid refrigerant line being separate from the gaseous refrigerant line; and a pressure compensation device for increasing a pressure of the gaseous refrigerant flowing through the gaseous refrigerant line, the pressure compensation device including: a sub-compressor having an inlet and an outlet, the sub-compressor being configured to compress the gaseous refrigerant flowing through the gaseous refrigerant line, the first gaseous refrigerant line being connected to the inlet of the sub-compressor, and the second gaseous refrigerant line being connected to the outlet of the sub-compressor; a first guide line connected to the first gaseous refrigerant line at one end of the first guide line and connected to the second gaseous refrigerant line at the other end of the first guide line; a second guide line connected to the first gaseous refrigerant line at one end of the second guide line and connected to the second gaseous refrigerant line at the other end of the second guide line; a first flow control valve arranged in the first gaseous refrigerant line; a second flow control valve arranged in the second gaseous refrigerant line; a first bypass valve arranged in the first guide line; a second bypass valve arranged in the second guide line; and a valve controller configured to control the first bypass valve, the second bypass valve, the first flow control valve, and the second flow control valve to control refrigerant flow through the first and second guide lines to guide gaseous refrigerant to the inlet of the sub-compressor, wherein the first flow control valve is arranged in the first gaseous refrigerant line between a point where the first gaseous refrigerant line is connected with the first guide line and a point where the first gaseous refrigerant line is connected with the second guide line, and the second flow control valve is arranged in the second gaseous refrigerant line between a point where the second gaseous refrigerant line is connected with the first guide line and a point where the second gaseous refrigerant line is connected with the second guide line.