采用MATLAB软件模拟非共沸混合工质在不同冷热源条件下对有机朗肯循环(ORC)系统性能的影响。选取R245fa/R1234ze和R245fa/R600a作为混合工质，热源温度取120和200 ℃，分别在冷凝露点温度为40 ℃和冷却水温升为5，10，15 ℃的工况条件下，利用热力学第一定律和火积理论对系统性能进行分析。结果表明：热源温度为200 ℃时，R245fa，R1234ze和R600a系统净输出功率分别为89.83，61.87和77.74 kW，使用R245fa系统性能优于其混合工质；热源温度为120 ℃、固定冷凝露点温度时，混合工质R245fa/R600a(90%〖DK〗∶10%)净输出功率比R245fa和R600a分别提高了27.6%和27%，R245fa/R1234ze(60%〖DK〗∶40%)净输出功率比R245fa和R600a分别提高了26%和20.5%；火积耗散和单位面积做功量与净输出功率变化相反，提高冷却水温升时，增大了系统火积耗散，且流向环境中的火积耗散在总火积耗散中占比增大，导致系统的传热不可逆损失增加。

The influence of zeotropic mixture on the performance of organic Rankine cycle (ORC) system under different heat and cold source conditions is simulated by Matlab software. R245fa/R1234ze and R245fa/R600a are selected as zeotropic mixtures. The heat source temperatures are 120 ℃ and 200 ℃. Under the conditions of condensation dew point temperature of 40 ℃ and cooling water temperatures of 5 ℃，10 ℃ and 15 ℃，the system performance is analyzed by the first law of thermodynamics and entransy theory. The results show that when the heat source temperature is 200 ℃，the system net output power using R245fa，R1234ze and R600a are 89.83 kW，61.87 kW and 77.74 kW respectively. The system performance using R245fa is better than that using its mixture working fluid. When the heat source temperature is 120 ℃ and the condensation dew point temperature is fixed，the net output power of the mixture working fluid R245fa/R600a (9∶1) are 27.6% and 27% higher than that using R245fa and R600a solely， and the net output power of R245fa/R1234ze (6∶4) are 26% and 20.5% higher than that using R245fa and R600a respectively. The changes of entransy dissipation and unit area power are opposite to the net output power. When the cooling water temperature increases，the entransy dissipation of the system increases. The proportion of entransy dissipation in the total entransy dissipation in the flow direction environment increases，resulting in an increase in the irreversible loss of heat transfer in the system.

TM6

河南省科技攻关计划项目(162102310504)；河南省高等学校重点科研项目(19A480005)