低温烟气余热ORC系统性能分析及多目标优化  

Performance analysis and multi-objective optimization of ORC system driven by low temperature flue gas waste heat

作　　者：冯军胜 吴豪 程新妮 严亚茹 赵亮 董辉 FENG Junsheng;WU Hao;CHENG Xinni;YAN Yaru;ZHAO Liang;DONG Hui(School of Environment and Energy Engineering,Anhui Jianzhu University,Hefei 230601,Anhui,China;School of Metallurgy,Northeastern University,Shenyang 110819,Liaoning,China)

机构地区：[1]安徽建筑大学环境与能源工程学院,安徽合肥230601 [2]东北大学冶金学院,辽宁沈阳110819

出　　处：《钢铁研究学报》2024年第11期1388-1398,共11页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(51974087,51904074);安徽省高校自然科学研究基金资助项目(2022AH050262);安徽建筑大学科研基金项目(2020QDZ02)。

摘　　要：以360 m^(2)烧结机配套的环冷机四段出口烟气余热为研究对象,通过烟气换热器将循环水加热后作为有机朗肯循环(ORC)系统热源,建立系统热力学模型和经济模型,研究不同循环工质下ORC热力学参数对系统热力性能和经济性能的影响,并采用基于遗传算法的多目标优化方法确定ORC系统最佳工质和热经济性能。研究结果表明,过热度和蒸发器节点温差越小,蒸发温度越高,系统[火用]效率越大。系统发电成本随蒸发温度的增加逐渐变小,而随过热度和蒸发器节点温差的增加先减小后增加。当系统热力参数最佳时,R245fa的系统[火用]效率和发电成本均优于R600a和R236ea,应优先被选择为低温烧结烟气余热ORC系统循环工质。此时,ORC系统的最大[火用]效率为46.34%,最小发电成本为0.121 23$/(kW·h)。The flue gas waste heat at the fourth stage exit of annular cooler equipped with 360 m^(2) sintering machine was taken as the research object,and the circulating water heated through the flue gas heat exchanger was selected as the heat source of organic Rankine cycle(ORC)system.The thermal and economic models of system were established firstly,and the effects of ORC thermodynamic parameters on the system thermal performance and economic performance under different working mediums were investigated.Furthermore,a multi-objective optimization method based on the genetic algorithm was adopted to determine the optimal cycle working medium of ORC system,as well as the best thermal performance and economic performance.The results indicate that,the smaller the superheat degree and pinch-point temperature difference in evaporator are,and the higher the evaporation temperature is,the larger the system exergy efficiency is.The system electricity production cost gradually reduces with rising the evaporation temperature,and reduces first and then rises with rising the superheat degree and pinch-point temperature difference in evaporator.When the system thermal parameters are optimum,the system exergy efficiency and electricity production cost of R245fa are better than those of R600a and R236ea,so it should be preferentially selected as the circulating working medium of ORC system driven by the low temperature sinter flue gas waste heat.At this time,the maximum exergy efficiency of ORC system is 46.34%,and the minimum electricity production cost is 0.12123$/(kW·h).

关 键 词：环冷机 余热回收 有机朗肯循环 [火用]效率 发电成本 遗传算法 

分 类 号：TK115[动力工程及工程热物理—热能工程]