摘要
针对常见的三级串联朗肯循环液化天然气(LNG)冷能发电系统未能有效地利用工质冷量的问题,提出了一种改进型三级串联多股流联合循环(MS-3CC)系统。通过加入多股流换热器,该系统多级利用了LNG和系统内循环工质冷量,有效降低了系统复杂程度,提升了系统热力学性能和经济性。通过遗传算法优化计算,当天然气(NG)排气压力为5.5 MPa、系统内各级循环工质均选取丙烷时,MS-3CC系统的最大净输出功为6027 kW,相比三级串并联合循环(P-3CC)系统和单级联合循环(SCC)系统分别提高了5.4%和80.3%,而其年净收益则分别提高了16.9%和68.0%。比较了64种工质组合,发现采用CH_(2)F_(2)+CH_(2)F_(2)+C_(3)H_(8)时MS-3CC系统的净输出功最高。MS-3CC系统的提出为实际工业中更为有效地多级利用LNG冷量提供了参考。
The conventional three-stage cascade Rankine cycle system for liquefie natural gas(LNG)cold energy power generation fails to effectively utilize the working fluid’s cold energy,therefore an improved multi-stream three-stage cascade combined cycle(MS-3CC)system was proposed.By adding a multi-stream heat exchanger,the system can utilize the cold energy of LNG and working fluid in multiple stages,effectively reducing the complexity of the system and improving its thermodynamic performance and economy.Through genetic algorithm optimization calculation,when the exhaust pressure of natural gas(NG)is 5.5 MPa,and the working fluid is selected as propane in all syetems,the maximum net output power of the MS-3CC system is 6027 kW,which is 5.4%and 80.3%higher than that of the parallel three-stage cascade combined cycle(P-3CC)system and single-stage combined cycle(SCC)system,respectively,and its annual total net income increases by 16.9%and 68.0%,respectively.Comparing 64 working fluid combinations,it is found that the net output power of the MS-3CC system is highest when using CH_(2)F_(2)+CH_(2)F_(2)+C_(3)H_(8).The proposal of MS-3CC system provides a reference for more effective multi-stage utilization of LNG cold energy in industrial practice.
作者
蔡东旭
王荧光
刘豪爽
胡大鹏
CAI Dongxu;WANG Yingguang;LIU Haoshuang;HU Dapeng(Department of Chemical Machinery and Safety,School of Chemical Engineering,Dalian University of Technology,Dalian 116012,Liaoning,China;PipeChina Engineering Technology Innovation Co.,Ltd.,Tianjin 300450,China;State Key Laboratory of Fine Chemicals,Frontier Science Center for Smart Materials,Dalian University of Technology,Dalian 116012,Liaoning,China)
出处
《低碳化学与化工》
CAS
北大核心
2024年第11期122-132,共11页
Low-Carbon Chemistry and Chemical Engineering
基金
国家重点研发计划(2018YFA0704602)
中央高校基本科研业务费(DUT22LAB604)
国家石油天然气管网集团有限公司科研项目(DTXNY202202)。
关键词
LNG冷能发电
三级朗肯循环
多股流换热
经济性分析
工质选择
遗传算法
LNG cold energy power generation
three-stage Rankine cycle
multi-stream heat exchange
economic analysis
working fluid selection
genetic algorithm
