太阳能高温异型热管接收器吸热面结构优化分析

Structural optimization analysis of solar energy high-temperature special-shape heat pipe receiver endothermic surface

高温热管作为太阳能高温热管反应器的核心集热/传热元件,如何提高其光热转化效率、降低其局部温度过高是当前的研究重点。本文对高温异型热管接收器的光热转换特性进行模拟分析,重点考察不同吸热面结构(平板吸热面、椭球吸热面)的影响,并与其在碟式太阳能模拟器工况下的光热转换特性进行对比验证。光学仿真结果表明:当入射光功率为5.78 kW时,椭球吸热面异型热管接收功率为2.7 kW,为平板吸热面异型热管接收功率的1.3倍。热应力仿真结果表明:椭球吸热面结构与平板吸热面结构相比可降低最大热应力约9.1%。此外,搭建电加热实验平台测试新型高温异型热管的启动及均温特性,当截面热流密度为139.7 kW/m^(2)时,启动时间仅为39 min,轴向温差小于89℃。因此,椭球吸热面结构在降低热应力以及聚光方面有更佳的表现,且可以满足反应器运行需求。

As the core component of solar energy high-temperature heat utilization/heat transportation,the research target of solar energy high-temperature heat pipe receiver is to improve its photo-thermal conversion efficiency and reduce the local high temperature.In this paper,the characteristics of the photo-thermal conversion of high temperature special-shape heat pipe receiver were simulated and analyzed,therefore,focusing on the influence of diverse heating surface structures(flat endothermic surface,ellipsoid endothermic surface),and then compared with the properties of photo-thermal conversion of the dish solar simulator.The optical simulation results showed that when the incident light power was 5.78 kW,the received power of special-shaped heat pipe with ellipsoid endothermic surface was 2.7 kW,which was 1.3 times of the flat endothermic surface.The thermal stress simulation results showed that the maximum thermal stress could be reduced about 9.1%by using ellipsoid endothermic surface structure.In addition,the electric heating experimental platform was constructed to test the start-up and isothermal properties.When the heat flux of the cross-section was 139.7 kW/m^(2),the start-up time was only 39 minutes,and the axial temperature difference was less than 89℃.In conclusion,the ellipsoid endothermic surface structure has better performance in reducing thermal stress and concentrating light as well as meet the working condition of the reactor.