负载电阻与热源温度对小型ORC发电系统性能协同影响的实验探究  

An experimental investigation for the influence of load resistances and heat source temperatures on performance of small scale ORC power systems

作　　者：许永超 吴玉麒 马庆旭 沙浩瀚 罗思义[1] 左宗良 XU Yongchao;WU Yuqi;MA Qingxu;SHA Haohan;LUO Siyi;ZUO Zongliang(College of Environmental and Municipal Engineering,Qingdao University of Science and Technology,Qingdao 266520,China;Linyi Wisdom New Energy Technology Co.,Ltd.,Linyi 276002,China)

机构地区：[1]青岛理工大学环境与市政工程学院,山东青岛266520 [2]临沂智慧新能源科技有限公司,山东临沂276002

出　　处：《热力发电》2025年第2期79-87,共9页Thermal Power Generation

基　　金：山东省科技型中小企业创新能力提升工程项目(2023TSGC0423)。

摘　　要：有机朗肯循环(organic Rankine cycle,ORC)发电系统可以将低温(<150℃)热能转换为机械能进而发电。为提高小型ORC发电系统运行性能,搭建了涡旋膨胀机直连发电机形式的ORC实验台,在24k W变温热源与工质五氟丙烷(R245fa)条件下,分析了负载电阻在50~200Ω与热源温度在75~95℃变化对ORC系统性能的协同影响。结果表明:ORC系统输出轴功与热效率随负载电阻增加呈现出先增加再减少的趋势,即存在最优负载电阻使系统输出轴功或热效率最大化,且最优负载电阻值会随热源温度变化;当热源温度为95℃时,系统输出轴功和热效率在负载电阻100Ω时达到最大,分别达722 W,2.30%;然而,当热源温度在75℃时,系统输出轴功则在负载电阻200Ω达到最大,为532 W,系统热效率在负载电阻150Ω达到最大,为1.7%;负载电阻与热源温度变化均会引起涡旋膨胀机转速变化,并进而影响系统流量,导致负载电阻与热源温度同时变化,产生协同作用。该研究结果强调了ORC发电系统热源温度与电力负载协调匹配的重要性,为ORC发电系统设计优化提供了指导与实验数据。Organic Rankine cycle(ORC)power systems can convert low-temperature(<150℃)thermal energy into mechanical energy to generate electricity.To improve the performance of small-scale ORC power systems,an ORC test-rig was built,which has a scroll expander directly connected to the generator.With a 24 kW variable-temperature heat source and the work fluid R245fa,the effects of the variations of load resistance(50~200Ω)and the heat source temperatures(75~95℃)on the performance of the ORC test-rig were explored.The results indicate that,both the output shaft work and the thermal efficiency initially increase and then decrease with rising the load resistance.An optimal load resistance exists to maximize either the output shaft work or thermal efficiency,and this value varies with the heat source temperature.When the heat source temperature is 95℃,the output shaft work and thermal efficiency both reach the maximum at 100Ωload resistance value,which is 722 W and 2.30%.When the heat source temperature is 75℃,the output shaft work reaches the maximum at 200Ωload resistance,which is 532 W,but the thermal efficiency reaches the maximum at 150Ωload resistance,which is 1.7%.The variation of the resistive load or the heat source temperature can change the scroll expander rotation speed and thus affect system flow rate.Therefore,the simultaneous changes of the resistance load and the heat source temperature have a synergistic effect on the system performance.The results highlight the importance of matching the resistance load and the heat source temperature.The experimental data also provide a direction for optimizing the ORC power systems.

关 键 词：有机朗肯循环 电子负载 低温热源 涡旋膨胀机 系统性能 

分 类 号：TM61[电气工程—电力系统及自动化]