混合工质泄漏对有机朗肯循环发电系统性能的影响

基于有机朗肯循环系统中各部件、管道等密封导致的实际系统运行过程中不可避免地存在着循环工质的泄漏问题，结合余亥姆霍兹自由能状态方程、混合法则和等温泄漏模型，研究了非共沸混合工质R245fa/R601a（初始质量配比为0.6/0.4）在ORC发电系统蒸发器中泄漏率为0~50%时对混合工质配比以及循环性能的影响.结果表明:非共沸混合工质泄漏会造成混合工质配比及工质热物性的变化，系统循环性能也会改变，且蒸发出口段发生液相泄漏时对循环性能影响最大.随着泄漏率的增大，比净输出功减少率可达12.23%. 

Effect of Leakage in Evaporator on the System Performance of the Organic Rankine Cycle with Binary Non-Azeotropic Mixtures

The leak of working fluids is inevitably in the actual operation, since the sealing problems in organic Rankine cycle (ORC) such as in components, pipes, etc. Combined Helmholtz free energy model, mixing rule and isothermal leakage model, the variation of mass fraction ratio and cycle performance along with the leakage rate within 0~50% in different positions in the evaporator by using the R245fa/R601a as the working fluid of ORC system were analyzed. The results show that when leakage occurred, the change of the mass fraction ratio of mixed working medium, the thermal properties as well as system performance will take place. With the leakage rate increasing, the specific net work even reduces 12.23%. In addition, the liquid leak in the outlet section of evaporation makes a greatest influence on the system performance.