将临界温度相近的干流体和湿流体应用于有机朗肯循环以回收中低温余热,采用基于热源流体进口温度和质量流量的蒸发器换热模型,在变蒸发温度和变热源流体进口温度时,对有机朗肯循环性能进行分析与对比。研究结果表明:在相同工况下,与采用湿流体的有机朗肯循环的相比,采用干流体的有机朗肯循环的蒸发压力、冷凝压力、热源流体出口温度、循环热效率和第二定律效率较小,而其净功率、循环总不可逆损失和总热量回收效率则较大;工质的临界温度对有机朗肯循环性能参数的变化趋势无显著影响。
Adopting the heat exchange model based on the inlet temperature and mass flow rate of the hot fluid in the evaporator,the performances of the organic Rankine cycles were analyzed and compared using dry and wet fluids with nearly identical critical temperatures for recovering low-and-medium temperature waste heat during the variations of the evaporation temperature and the inlet temperature of the hot fluid.The results show that during the same working conditions,the evaporation pressure,the condensing pressure,the outlet temperature of the hot fluid,the thermal efficiency and the second law efficiency of the organic Rankine cycle using a dry fluid are less than those of the organic Rankine cycle using a wet fluid,but its net power,total cycle irreversible loss and total heat-recovery efficiency are larger. The critical temperature of the working fluid has little effect on the variation trend of the performance parameters of the organic Rankine cycle.