几种低沸点工质余热发电系统的热力性能比较  

Comparison of thermodynamic performance for waste heat power generation system with different low temperature working fluids

作　　者：王志奇[1,2] 周乃君[1] 罗亮[1] 张家奇[1] 童道辉[1] 

机构地区：[1]中南大学能源科学与工程学院,湖南长沙410083 [2]湘潭大学机械工程学院,湖南湘潭411105

出　　处：《中南大学学报（自然科学版）》2010年第6期2424-2429,共6页Journal of Central South University:Science and Technology

基　　金：科技部创新基金资助项目(08C26224302178);湖南省科技厅计划项目(2009GK2009);湘潭大学校级科研项目(08XZX21)

摘　　要：基于低品位余热的有机朗肯循环(ORC)发电系统,以某工业装置排出的流量为3×105 m3/h、温度为120℃的低温烟气为研究对象,针对几种高温有机工质,分析工质流量以及汽轮机膨胀比对系统性能的影响。研究结果表明:当工质流量小于15 kg/s时,汽轮机及循环热效率随着工质流量增大而迅速提高;但当工质流量超过15 kg/s时,汽轮机效率及热效率变化不大;工质的沸点越大,汽轮机内效率越高;随着汽轮机膨胀比的增加,系统所需的质量流量减小,而系统的热效率及效率提高;当工质流量或吸热量相同时,几种工质中R123的循环热效率最高,输出功率最大,是系统工质的较好选择。Based on the organic Rankine cycle（ORC） for low temperature heat recovery the relationship between system performance and mass flow rate and pressure ratio of several low temperature working fluids was researched.The heat resource is the flue gas whose volume flow rate is 3×105 m3/h and temperature is 120 ℃ from a industrial installation.The results show that when the mass flow rate is less than 15 kg/s,the efficiency of turbine and system increases rapidly with the increment of it.However,it changes little when mass flow rate is more than 15 kg/s.The turbine efficiency improves with the boiling point temperature of working fluids.Mass flow rate decreases with the increase of turbine pressure ratio.On the contrary,the system efficiency and exergy efficiency increase with the increment of turbine pressure ratio.For ORC system,R123 owns maximal thermal efficiency and net output at the same mass flow rate or heat input,R123 is the best choice among the several researched working fluids.

关 键 词：余热发电 低沸点工质 有机朗肯循环 热力性能 

分 类 号：TK11[动力工程及工程热物理—热能工程]