回热式地热双循环发电系统工质选择  

Selection of working fluid for regenerative geothermal dual cycle power generation system

作　　者：刘亮德 刘超 赵伟 徐泽宇 杨绪飞 刘广林[3] LIU Liangde;LIU Chao;ZHAO Wei;XU Zeyu;YANG Xufei;LIU Guanglin(China Petroleum Engineering&Construction Corporation North China Company,Renqiu,Hebei 062550,China;School of Mechanical Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China;School of Energy Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]中国石油工程建设有限公司华北分公司,河北任丘062550 [2]北京石油化工学院机械工程学院,北京102617 [3]华北电力大学能源动力与机械工程学院,北京102206

出　　处：《河北工业科技》2024年第5期376-381,共6页Hebei Journal of Industrial Science and Technology

基　　金：国家自然科学基金(51776064)。

摘　　要：为了解决不同工质地热双循环发电系统热力学性能差异较大的问题,采用EES(engineering equation solver)软件对1 MW回热式地热双循环发电系统进行了分析,研究地热源温度为90~150℃时,不同工质发电系统的吨水净发电量、净效率、膨胀比等热力学参数的变化规律,通过对比以上参数获得综合性能最优的工质,使双循环发电系统的热力学性能达到最优。结果表明:在冷热源温度等参数恒定条件下,系统吨水净发电量随工质蒸发温度的增加存在一个最大值;系统最大吨水净发电量、净效率和膨胀比随地热源温度的升高而增大,工质质量流量的变化趋势则相反;相同冷热源参数条件下,R134a的吨水净发电量最大,R245fa的净效率和膨胀比最大,在地热源温度为110℃时,工质R134a的吨水净发电量为3.035(kW·h)/t,工质R245fa的净效率为6.24%、膨胀比为3.146;综合对比工质的系统热力学性能参数和工质物性,工质选用R245fa。研究成果可为回热式地热双循环发电系统的参数设计提供指导。In order to solve the problem of large difference in thermodynamic performance of geothermal dual cycle power generation system with different working fluid,EES software was used to analyze the 1 MW regenerative geothermal dual cycle power generation system,and the change law of thermodynamic parameters such as net generation per ton of water,net efficiency and expansion ratio of the power generation system was studied when the geothermal heat source temperature was 90~150℃.Through the comparison of the above parameters,the working fluid with the best comprehensive performance was obtained,and the thermodynamic performance of the dual-cycle power generation system was optimized.The results show that under constant parameters such as temperature of the cold and heat sources,there exists a maximum net power generation per ton of water in the system as the evaporation temperature of the working fluid increases.The maximum net power generation per ton of water,net efficiency,and expansion ratio of the system increase with the increase of heat source temperature,while the trend of changes in the mass flow rate of the working fluid is opposite.Under the same cold and heat source parameters,R134a has the highest power generation per ton of water,while R245fa has the highest net efficiency and expansion ratio.For example,at a heat source temperature of 110℃,the net power generation per ton of water using R134a is 3.035(kW·h)/t,and the net efficiency of R245fa is 6.24%,the expansion ratio is 3.146.Based on a comprehensive comparison of the thermodynamic performance parameters and physical properties of the working fluid,it is recommended to use R245fa working fluid.The research results can provide guidance for the parameter design of regenerative geothermal dual cycle power generation systems.

关 键 词：工程热力学 双循环回热系统 工质 系统优化 地热发电 

分 类 号：TK123[动力工程及工程热物理—工程热物理]