遮风挡板对腔式吸热器的对流热损失影响  

Effects of windshield on the convective heat loss of a cavity receiver

作　　者：万振杰 魏进家[2,3] 方嘉宾 Wan Zhenjie;Wei Jinjia;Fang Jiabin(College of Building Environmental Engineering,Zhengzhou University of Light Industry,Zhengzhou 450001,China;School of Chemical Engineering and Technology,Xi'an Jiaotong University,Xi'an 710049,China;State Key Laboratory of Multiphase Flow in Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]郑州轻工业大学建筑环境工程学院,河南郑州450001 [2]西安交通大学化学工程与技术学院,陕西西安710049 [3]西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《可再生能源》2025年第4期468-475,共8页Renewable Energy Resources

基　　金：国家自然科学基金国际(地区)合作与交流项目(51961135102);河南省科技攻关项目(222102320298);郑州轻工业大学博士启动金(2021BSJJ046)。

摘　　要：腔式吸热器的内部高温面积大,由于受环境风速、风向等因素的影响,吸热器的对流热损失会改变,光热效率不稳定。为了降低环境风导致吸热器的对流热损失和光热转换效率的变化,文章提出了一种带遮风挡板的腔式吸热器结构设计方案。在腔体开口面布置遮风挡板,降低腔体内部流场扰动强度,削弱吸热面与环境空气之间的对流传热,实现减少吸热器对流热损失的目的。建立光-热耦合数值计算模型,研究了遮风挡板材料、风速、风向等因素对热损失和转换效率的影响规律。结果表明:遮风挡板材料会影响对流热损失大小,固体壁面遮风挡板会导致对流热损失增大,多孔材料遮风挡板可减少吸热器对流热损失;多孔材料的惯性阻力系数及厚度是影响遮风挡板性能的关键因素,随着惯性阻力系数的增大,最优厚度减小;惯性阻力系数和厚度最优时,多孔材料遮风挡板可以降低吸热器对流热损失约53.0%。文章研究结果可为设计高效光热转换的腔式接收器提供理论及技术指导。Due to a large area of heat absorbing surfaces and effects of uncertain windy condition,both the convective heat loss and solar-thermal conversion efficiency of cavity receivers were unsteady.In order to reduce effects of wind on the cavity receiver performance,a novel cavity receiver design which had a windshield on its opening was investigated in the present study.The windshield could reduce the fluid flow disturbance inside the cavity,so that the convective heat transfer between the heat absorbing surfaces and ambient air were weakened,and the convective heat loss of the cavity receiver would be reduced.A solar-thermal coupling numerical model was established firstly,and then effects of windshield material and wind were studied.The results showed that the material of windshield had a big influence on the receiver convective heat loss,and the convective heat loss would increase with a solid wall windshield,while with a porous material windshield,the convective heat loss would decrease.The pressure-jump coefficient and thickness of the porous material windshield were key factors affecting its performance.As the pressure-jump coefficient increased,the optimal thickness decreased.For the optimal pressurejump coefficient and thickness,the convective heat loss could be reduced by about 53.0%.The results in the present study could provide theoretical and technical guidance for design of cavity receivers.

关 键 词：塔式热发电 腔式吸热器 对流热损失 遮风挡板 

分 类 号：TK519[动力工程及工程热物理—热能工程]