Vapor injection, Rotary compressor
On the vapor compression refrigeration system, Vapor injection (VI, the phase separator type injection or the internal heat exchanger type injection) compression cycleâ€™s superiority over non-injection cycle has been well known. VI system produces the high heating/cooling capacity, and its power consumption is less than the non-injection system. But if a VI compression cycle uses a single rotary compressor, there is the problem that refrigerant injection increases the indicated power by mixture loss. If we use a two-stage rotary compressor, indicated power also increases because of its two times exhaust process. To solve these problems, we developed a new dual-cylinder rotary compressor for VI systems, one of the cylinders is used to compress the gas from the evaporator, and the other is used to compress the gas from the phase separator (flash-tank). Its design method is discussed and its performance under different conditions is analyzed.