塔式太阳能熔盐吸热器光-热-力耦合模拟及性能分析  

Optical-thermal-stress coupling simulation and performance analysis of molten salt solar receiver

作　　者：贾朋森 王坤 张翔[1,2] 杨历 闵春华[1,2] JIA Pengsen;WANG Kun;ZHANG Xiang;YANG Li;MIN Chunhua(School of Energy and Environmental Engineering,Hebei University of Technology,Tianjin 300401,China;Hebei Key Laboratory of Thermal Science and Energy Clean Utilization,Hebei University of Technology,Tianjin 300401,China)

机构地区：[1]河北工业大学能源与环境工程学院,天津300401 [2]河北工业大学热能科学与能源清洁利用河北省重点实验室,天津300401

出　　处：《河北工业大学学报》2022年第6期54-63,72,共11页Journal of Hebei University of Technology

基　　金：天津市青年人才托举工程(TJSQNTJ-2020-04);国家自然科学基金(51906059)。

摘　　要：外露式吸热器因其具有耐高温、结构简单等优点成为塔式太阳能发电系统中最具发展前景的吸热器形式之一。非均匀太阳能流对吸热器安全高效运行有着直接影响,有必要对整个外露式吸热器在非均匀能流下的换热特性及应力分布开展研究。本文基于蒙特卡洛光线追踪法、有限体积法、有限元法构建了外露式吸热器光-热-力耦合数值模型,分析了外露式吸热器在不同工况下的光热转换性能,对非均匀热流下外露式吸热器整体应力分布及局部应力特性进行了探讨。研究发现光热效率的变化与DNI的变化具有伴随性;吸热器外壁温度与内部熔盐温度变化趋势一致;吸热器迎风侧对流换热系数较大,具有较高的对流损失;吸热器表面非均匀的太阳辐射能流会导致吸热壁面温度分布不均从而产生较大的集中应力;特别是北侧高热流密度区集中应力均大于南侧,吸热管内外侧温差导致受光侧和背光侧交接处应力集中。The cylinder external receiver has become one of the most promising receivers in the tower solar power generation system because of its high-temperature resistance and simple structure.The non-uniform solar flux has significant impact on the safe and efficient operation of the receiver.So it is necessary to study the heat transfer characteristics and stress distribution of the entire cylinder external receiver under the non-uniform solar flux.In this paper,an optical-thermal-mechanical coupled numerical model is developed based on Monte Carlo ray tracing method,finite volume method and finite element method,and the optical-thermal conversion characteristics of the cylinder external receiver under different working conditions are analyzed.The stress distribution and local stress characteristics of the receiver are discussed.The resutls showed that the change of photothermal efficiency was accompanied by the change of DNI.The temperature of the outer wall of the receiver was consistent with the temperature of the internal molten salt.The convective heat transfer coefficient on the windward side of the receiver is larger than that on the leeward side of the receiver,which resulted in a higher convective heat loss.The non-uniform solar flux on the surface of the receiver would lead to non-uniform temperature distribution on the receiver wall,resulting in large concentrated stress.In particular,the concentrated stress in the high solar flux area on the north side was greater than that on the south side.The temperature difference between the inside and outside of the receiver tube caused the stress concentration at the junction of the light-receiving side and the backlight side.

关 键 词：塔式太阳能吸热器 对流换热 光热力耦合 热应力 光热转换效率 

分 类 号：TM615[电气工程—电力系统及自动化]