不同工质的有机朗肯循环系统变工况特性对比研究  

Comparative Analysis on the Off-Design Performance of Organic Rankine Cycle Systems with Different Working Fluids

作　　者：田华[1] 井东湛 舒歌群[1] 王轩[1] 刘鹏[1] TIAN Hua;JING Dongzhan;SHU Gequn;WANG Xuan;LIU Peng(State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300350

出　　处：《西安交通大学学报》2018年第3期25-33,共9页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51676133)

摘　　要：针对分布式能源系统中内燃机负荷变化较大、传统的有机朗肯循环(ORC)工质优选未能关注变工况性能的问题,开展了基于变工况特性的ORC工质优选研究。首先,基于MATLAB平台构建了基于变工况特性的工质优选模型,涉及系统设计参数获取、变工况仿真和热经济性分析3个层面,具有较高的模型精度。然后,基于该模型,针对8种典型实用性工质,分析了变工况循环性能及典型全日电负荷下的热经济性能。研究表明:水在高负荷工况时的净输出功率较多,适合运行在高负荷工况条件下,而甲苯在低负荷工况时展现出较大的性能优势,适合运行在低负荷工况条件下;在考虑实际运行情况下,水的发电成本和折旧回收期为0.131美元·(kW·h)^(-1)和8.08a,而甲苯的分别为0.127美元·(kW·h)^(-1)和6.75a。这些规律进一步表明,水适用于电负荷稳定的建筑类型,而甲苯适用于电负荷瞬变的建筑类型。Focusing on the problem that engine loads frequently vary in distributed energy system,and the traditional working fluid selection is only on the basis of the rated engine working condition,the working fluid selection based on off-design performance is investigated in this paper.A model of working fluid selection consisted of system design parameters,off-design simulation,thermal-economic analysis is established by MATLAB.Then,the effects of engine working conditions on the cycle performance are studied and the thermal-economic performance analysis of ORC using eight potentially applicable working fluids is conducted according to the all-day electricity demand of a hotel.The results show that water is more suitable for waste heat recovery under high engine working load,while toluene shows its advantage for the low loading conditions.Electricity production cost E O and depreciated payback period D O of water,taking into account changing operating conditions,are0.131$·(kW·h)-1and8.08years E O and D O of toluene are0.127$·(kW·h)-1and6.75years,respectively.These results indicate that water is suitable for the building types with steady electricity demand,while toluene is suggested for the building types with transient electricity demand.

关 键 词：内燃机余热回收 有机朗肯循环 工质优选 变工况特性 

分 类 号：TK11[动力工程及工程热物理—热能工程]