非共沸工质分离压缩再混合有机朗肯循环综合性能分析  

Comprehensive Performances Analysis of Organic Rankine Cycle With Separation,Compression and Remixing of Zeotropic Mixtures

作　　者：卜淑娟 杨新乐[1] 李惟慷[1] 苏畅[1] 戴文智[1] 王新[1] 刘旭南[1] BU Shujuan;YANG Xinle;LI Weikang;SU Chang;DAI Wenzhi;WANG Xin;LIU Xunan(Liaoning Technical University,School of Mechanical Engineering,Fuxin 123000,Liaoning Province,China)

机构地区：[1]辽宁工程技术大学机械工程学院,辽宁省阜新市123000

出　　处：《中国电机工程学报》2023年第18期7184-7192,共9页Proceedings of the CSEE

基　　金：辽宁省自然科学基金项目(2022-MS-398);辽宁省教育厅项目(LJKZ0367);辽宁工程技术大学学科创新团队项目(LNTU20TD-15)。

摘　　要：为利用非共沸工质在蒸发器内“温度滑移”的优势,避免在冷凝器内“组分迁移”的不利影响。构建了非共沸工质分离压缩再混合有机朗肯循环系统(ORC with separation,compression,and remixing,SCRM-ORC)。采用分凝器将非共沸混合工质分离成2种纯工质,分别进入气液热交换器两空间进行气液换热,再对纯工质压缩、混合再利用。以120℃地热水为热源,R134a/R245fa为工质,建立热力、经济与环境性能模型,分析R134a质量分数对系统综合性能的影响,并与采用R134a的乏气压缩再循环ORC系统(compression recycling,CR-ORC)性能进行对比。采用遗传算法进行多目标优化,揭示系统最优性能与工况参数。结果表明:与CR-ORC系统相比,非共沸工质SCRM-ORC系统可有效降低冷凝热的释放量,在R134a质量分数较低时提高冷凝热回收利用量,同时具有较好的综合性能。将分凝器与气液热交换器看作整体与CR-ORC系统中新型冷凝器相比,二者[火用]损失之和与投资成本之和小于CR-ORC系统中冷凝器的。在R134a质量分数为0.2181时,系统综合性能最优,此时净输出功为3412.1kW,投资回收期为2.237年,年当量CO_(2)减排量为4520.6×10^(3)kg。In order to make full use of the“temperature glide”of zeotropic mixtures in the evaporator,and avoid the adverse effects of the"component shift"in the condenser.An ORC system with separation,compression and remixing of zeotropic mixtures(SCRM-ORC)is proposed in the paper.Zeotropic mixtures are separated into two pure fluids by a partial condenser,and they enter different spaces of gas-liquid heat exchanger respectively for gas-liquid heat exchange.Then the pure fluids are compressed,mixed and reused.Using 120℃ geothermal water as heat source,R134a/R245fa as working fluid,thermodynamic,economic,and environmental models are established to analyze the effects of mass fraction of R134a on comprehensive performances of SCRM-ORC system,and then they are compared with CR-ORC system using R134a.Multi-objective optimization using genetic algorithm is performed to reveal the optimal performance and operating parameters of the system.The results show that compared with the CR-ORC system,the SCRM-ORC system can effectively reduce the release of condensation heat,and improve the recovery of condensation heat when the mass fraction of R134a is low,and it has better comprehensive performance.The partial condenser and gas-liquid heat exchanger are considered as a whole to compare with the novel condenser in the CR-ORC system,the sums of the two exergy losses and the investment costs are still smaller than those of the condenser in the CR-ORC system.When the mass fraction of R134a is 0.2181,the comprehensive performance of the system is optimal,the net output power is 3412.1kW,the investment payback period is 2.237 years,and the annual equivalent CO_(2) emission reduction is 4520.6×10^(3) kg.

关 键 词：非共沸工质分离压缩再混合 有机朗肯循环 综合性能 多目标优化 

分 类 号：TK11[动力工程及工程热物理—热能工程]