中文摘要：

该文提出背压式汽轮机组耦合有机朗肯循环（organicRankine cycle,ORC）的热电联产系统。通过提高背压式汽轮机组的蒸汽流量,多余排汽供ORC发电,以实现提高背压汽轮机组效率,增加系统发电量的目的。该系统可同时满足热负荷和电负荷的调节。ORC的热效率随主气温度的提高而上升,但是其主气温度受背压式汽轮机排汽冷凝温度的限制。为了获取最大热效率,优化了R600a、R245fa、R123和R113这4种工质的运行压力。结果表明R113运行压力最低而热效率最高,其净发电量比R600a约高10%。随热负荷的降低该联产系统的燃料利用系数降低,但是火用效率会高于原工况。

英文摘要：

This paper presents a cogeneration system in which a back-pressure steam turbine generating unit is coupled with an organic Rankine cycle（ORC）.By way of increasing the turbine live steam flow rate to supply ORC with excess exhaust steam,the efficiency of the back-pressure generating unit and the power output of the system were increased.The heat and power loads can both be regulated by adjusting the live steam flow rate.The thermal efficiency of ORC increases with the live steam temperature at the turbine inlet.However,the live steam temperature is limited by the condensation temperature of exhaust steam.To obtain the maximum thermal efficiency,the operating parameters of ORC were optimized for R600a,R245fa,R123 and R113 as working fluids using the GRG algorithm.Results indicate that the turbine inlet pressure of ORC is the lowest with R113 but the corresponding thermal efficiency is the highest.The net power output from the ORC with R113 is about 10% greater than with R600a.Economic analysis of the cogeneration system shows that the energy utilization factor of the cogeneration system decreases as the heat load decreases due to the cold source loss in the ORC.However,the exergy efficiency of the system is higher than that of the original design because the power output is increased.