正戊烷热稳定性和材料相容性对超临界ORC系统设计的影响  

The Influences of n-Pentane Thermal Stability and Material Compatibility on Supercritical ORC System Design

作　　者：戴晓业[1] 史琳[1] 骞伟中[2] DAI Xiao-Ye;SHI Lin;QIAN Wei-Zhong(Key Laboratory of Thermal Science and Power Engineering of Ministry of Education of China,Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China;Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology,Department of Chemical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学能源与动力工程系,热科学与动力工程教育部重点实验室,北京100084 [2]清华大学化学工程系,绿色反应工程与工艺北京市重点实验室,北京100084

出　　处：《工程热物理学报》2020年第4期803-808,共6页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51806117,No.51236004);国家自然科学基金创新研究群体(No.51621062);中国博士后科学基金资助项目(No.2018M630155);国家重点研发计划(No.2016YFB0901405)。

摘　　要：有机朗肯循环(Organic Rankine Cycle,ORC)在可再生能源和工业余热领域都有着良好的应用前景,特别是超临界ORC系统目前得到广泛关注。工质的热稳定性和材料相容性是工质的重要物性,对系统设计有很大的影响。本文以正戊烷为例,对热稳定性和材料相容性对超临界ORC系统设计的影响进行研究。提出了一种冷凝器改造装置方案,并建立ORC系统仿真模型对其改善效果进行验证;计算结果表明本文提出的改造方案可以明显改善正戊烷热分解带来的负面影响。同时对中高温工况下正戊烷的材料相容性进行实验研究。实验结果表明,304不锈钢相对铜材料有更优的相容性,从材料相容性角度来说是更合适的蒸发器材料。三元乙丙橡胶(EPDM)被证明会吸收正戊烷,因此不能用于正戊烷超临界ORC系统中;聚四氟乙烯(PTFE)相比氟橡胶(FKM)有更优的相容性,从材料相容性角度来说是更合适的膨胀机出口密封材料。The organic Rankine cycles(ORCs)have wide application prospects in the renewable energy utilization and industry waste heat recovery.The supercritical ORCs have attracted more interests because of their high thermal and exergy efficiencies.The thermal stability and material compatibility of working fluids are key properties for fluid selection and system design at high temperatures.This paper presented the influences of fluid thermal stability and material compatibility on supercritical ORC system design with n-pentane as test fluid.A condenser improvement method was designed to weaken the influences of n-pentane decomposition on ORCs and a ORC model was built to verify the improvement effect.The results showed that the condenser improvement method could obviously weaken the decomposition influences.The material compatibility of n-pentane at high temperatures were measured.The results showed that the 304 stainless steel had better compatibility than copper with n-pentane and PTFE had good material compatibility as sealing materials.EPDM absorbed the n-pentane at 120℃,so it could not be used in ORCs with n-pentane.

关 键 词：有机朗肯循环 热稳定性 材料相容性 系统设计 

分 类 号：TK123[动力工程及工程热物理—工程热物理]