基于分子动力学的有机朗肯循环Cu/R123纳米有机工质能量研究

ergy analysis of a Cu/R123 nano-organic working fluidbased on molecular dynamicsin organic Rankine cycle

为探究有机朗肯循环(ORC)Cu/R123纳米有机工质的能量变化特性,采用分子动力学方法,对不同工况下的Cu/R123纳米有机工质能量进行模拟。研究结果表明:加入纳米颗粒可使有机工质微观结构发生改变。在微观状态下,范德华能随体积分数增大而减小,键合能随温度升高而增加,气相时范德华能增大,压力对体系影响很小。通过计算焓差发现,在相同蒸发温度下,采用纳米有机工质的ORC做功较大;纳米有机工质具有较高的导热系数,可提升ORC低品位热能回收效率。

To investigate the energy variation characteristics of the Cu/R123 nano-organic working fluidin organic Rankine cycle(ORC),molecular dynamics simulations were conducted to analyze the energy behavior of the Cu/R123 nano-organic working fluidunder different operating conditions.The results indicate that the addition of nanoparticles can alter the microstructure of the organic working fluid.Specifically,in a microscopic state,van der Waals energy decreases with increasing volume fraction,bond energy increases with rising temperature,van der Waals energy increases in gasphase,and pressure has minimal impact on the system.Furthermore,calculation of enthalpy difference reveals that at equivalent evaporation temperatures,ORC using nano-organic working medium performs more work.Additionally,it is observed that nano organic working medium exhibits high thermal conductivity which can enhance low-grade heat recovery efficiency of the ORC.