低温热能有机朗肯循环工质选择及性能分析

Working fluid selection and thermodynamic analysis for low-temperature organic Rankine cycle system

工质的性能是影响有机朗肯循环性能的重要因素之一。基于工质热力性质、环保性等要求,选择R123、R600a、R601a、R245fa、R236ea、R245ca、R142b及R601作为循环工质,在不同的蒸发温度下,对其热力循环性能进行计算分析,从热效率、系统净输出功、效率等方面进行比较。结果表明:R123是适合低温热能有机朗肯循环系统的循环工质。同时研究分析了膨胀机进口温度和进口压力对系统性能的影响,发现工质以饱和蒸汽状态进入膨胀机膨胀做功,可以使系统性能达到最佳。

The properties of working fluid have a significant effect on performance of organic Rankine cycle （ORC） system. Taking R123, R600a, R601 a, R245fa, R236ea, R245 ca, R142b and R601 as working fluids considering their thermodynamic properties and environmental protection, thermodynamic cycle performance of the ORC system was studied during different evaporating temperature, thermal efficiency, net power output and exergy efficiency were respectively calculated and compared. Results show that R123 is the available working fluid for low - temperature organic Rankine cycle system. The effect of the turbine inlet temperature and pressure on the system performance was studied, finding that working fluids working in the turbine as saturated vapor state can get the best system performance.