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提出了一种利用发动机排气余热作为热源驱动的喷射式制冷系统,选取R134a作为制冷工质,建立系统的热力模型。计算结果表明,在热源发生温度为tg=80oC,冷凝温度为tc=40oC,蒸发温度为te=5oC下,喷射系数为u=0.15～0.5之间时,制冷量Q0达到5kW,性能系数COP可达到0.5,完全能满足作为车辆空调的使用。利用喷射器取代了传统制冷系统的压缩机,节省了压缩机所消耗的能量,提高了发动机的功率。并对排气余热加以利用,有效地提高了发动机的热效率。
A kind of jet refrigeration system driven by engine exhaust heat is proposed as a heat source. R134a is selected as refrigerant and a thermal model of the system is established. The calculation results show that when the temperature of the heat source is tg = 80oC, the condensing temperature is tc = 40oC, the evaporating temperature is te = 5oC and the ejecting coefficient is u = 0.15 ~ 0.5, the cooling capacity Q0 reaches 5kW. Reached 0.5, fully able to meet the use of vehicle air conditioners. The use of ejectors to replace the compressor of a conventional refrigeration system saves the energy consumed by the compressor and increases the power of the engine. And exhaust exhaust heat to be used to effectively improve the thermal efficiency of the engine.