变工况柴油机余热回收系统中混合工质模拟研究

针对柴油机变工况下的排气特点,设计了一套有机朗肯循环余热回收系统.通过实验和理论计算,研究共沸混合工质和非共沸混合工质在不同蒸发压力下对车用柴油机不同运行工况的有机朗肯循环余热回收系统性能的影响.研究结果表明,柴油机变工况下,非共沸混合工质R415B的ORC系统(火用)损率平均值比共沸混合工质R508A低38％.通过对比分析,非共沸混合工质R415B最适用于变工况车用柴油机有机朗肯循环余热回收系统,最大净输出功率约为27.60 kW.

Simulation of Mixed Refrigerant for Diesel Engine Waste Heat Recovery System under Variable Conditions

According to the characteristics of exhaust gas of diesel engine under variable conditions, a waste heat recovery system of organic Rankine cycle was designed. Under the different evaporation pressures, the effects of azeotropic mixtures and zeotropic mixtures on the performance of waste heat recovery system of organic Rankine cycle of vehicle diesel engine in variable conditions were discussed. Combined with the practical projects, the mixtures which was the most suitable for this system was chosen. The results showed that the mean value of exergy destruction rate of the ORC system using the zeotropic mixtures R415B was 38% lower than the azeotropic mixtures R508A under variable conditions. Through the comparative analysis, the zeotropic mixtures R415B was the most suitable for the waste heat recovery system of organic Rankine cycle of vehicle diesel engine under variable conditions, the maximum net power output value was about 27.60kW.