蒸发压力和冷凝温度对船用柴油机余热回收有机朗肯循环系统性能的影响

Influence of evaporation pressure and condensation temperature on organic Rankine cycle waste heat recovery system of marine diesel engine

以柴油机废气余热作为研究对象,利用MATLAB软件建立有机朗肯循环余热回收系统热力学模型,对比6种工质的物性参数,选择苯为工质,仿真研究系统净输出功率、热效率、功耗因子和[火用]效率等热力学性能参数随蒸发压力以及冷凝温度的变化规律。仿真结果表明:蒸发压力增大,净输出功率和[火用]效率先增大后减小,热效率和功耗因子增大;蒸发压力为0.6 MPa时净输出功率最大,为4358 k W;蒸发压力为1.6 MPa时[火用]效率最大,为54.5%;冷凝温度升高,系统净输出功率、热效率和[火用]效率减小,功耗因子增大。

The waste heat of marine diesel engine is taken as the research object,and the thermodynamic model of organic Rankine cycle(ORC)waste heat recovery system is established by MATLAB software.Compared with the physical property parameters of six working substances,benzene is selected as the working substance.The change rule of net output power,thermal efficiency,power dissipation factor and exergic efficiency of the system as the results of evaporation pressure and condensation temperature are simulated.The simulation results show that as evaporation pressure increased,net output power and exergic efficiency increased first and then decreased,while thermal efficiency and power consumption factor increased.The maximum net output power is 4358 kW when the evaporation pressure is 0.6 MPa.Exergy efficiency peaked at 54.5%when evaporation pressure is 1.6 MPa.As condensation temperature increased,net output power,thermal efficiency and exergic efficiency of the system decreased,while power consumption factor increased.