柴油机排气余热有机朗肯循环系统工质选择

工质的合理选择对有机朗肯循环回收柴油机排气余热产生重要影响。通过试验和理论计算,分析某6缸柴油机变工况下排气余热能的分布特性,提出有机工质初选条件,进而对满足条件的8种有机工质进行柴油机排气余热有机朗肯循环系统的热力学性能和经济性能对比分析。结果表明:在8种有机工质的蒸发压力范围内,R420A的系统热效率最大,为6.83%;在柴油机变工况下,R420A的系统总净输出功率、系统最大净输出功率和系统平均净输出功率均高于其他工质,分别为306.81kW,9.769kW和2.005kW;采用R420A的系统初期投资成本较少,仅次于R417A和R437A,但其单位能量产出成本(LEC)最小。

Working Fluid Selection of Organic Rankine Cycle System for Diesel Engine Exhaust Waste Heat

The selection of working fluid has great influence on the organic Rankine cycle(ORC)for diesel engine exhaust waste heat recovery.Through the experiment and theoretical calculation,the exhaust waste heat characteristics of a 6-cylinder diesel engine under transient operating conditions were analyzed,the initial conditions for organic working fluid selection were proposed,then the thermodynamic performance and economic performance of the ORC system for diesel engine exhaust waste heat with eight organic working fluids met initial conditions were compared and investigated.The results show that the ORC system with R420A can reach the maximum thermal efficiency of 6.83% in the evaporation pressure range of eight organic working fluids and its total net power output,maximum net power output and average net power output are higher than those of other organic working fluids which are 306.81 kW,9.769 kW and 2.005 kW respectively under diesel engine transient operating conditions.The system with R420A has lower initial investment cost,which is only second to R417A and R437A,but its levelized energy cost (LEC) is the lowest.