船舶主机余热梯级利用系统工质比较分析

Comparative Analysis of Working Fluids for Waste Heat Utilization System of Marine Main Engine

本文以WARTSILA RT-flex96C型柴油机为研究对象,设计了船舶柴油机余热梯级利用系统——双级朗肯循环余热利用系统。选择四种工质组合方案针对所设计的系统进行热力计算,计算结果表明,以水和R113的组合方案热力性能最佳。计算了在高温循环的蒸发压力为0.79MPa、窄点温度为30℃、过热度为50℃,低温回路的蒸发压力为1.46MPa、窄点温度为15℃,冷凝温度均为30℃的情况下,系统的输出净功、热效率和㶲效率分别为3872.7kW、23.67%和61.71%。最后本文研究了高温回路蒸发温度、过热度以及窄点温度这三种参数对系统性能的影响。

The WARTSILA RT-flex96C diesel engine is taken as the research object,and the shipboard diesel engine waste heat cascade utilization system(two-stage Rankine cycle waste heat utilization system)is designed.The four working fluid combinations were selected for the thermal calculation of the designed system.The calculation results showed that the combination of water and R113 had the best thermal performance.The evaporation pressure at the high temperature cycle is calculated to be 0.79 MPa,the narrow spot temperature is 30℃,the superheat is 50℃,the evaporation pressure of the low temperature circuit is 1.46 MPa,the narrow spot temperature is 15℃,and the condensing temperature is 30℃.The net output,thermal efficiency,and efficiency of the system are 3872.7kW,23.67%,and 61.71%,respectively.At last,this paper mainly studies the effects of three parameters,such as the evaporation temperature of the high temperature circuit,the superheat and the narrow point temperature,on the system performance.