中文摘要：

为了研究塔式太阳能多孔介质吸热器的非稳态传热特性,建立了该吸热器的非稳态传热模型,通过最小二乘拟合提出适合该类型吸热器多孔介质的体积对流换热系数模型,采用数值方法求解,分别分析典型的非稳态无量纲温度场以及平均颗粒直径、孔隙率、厚度与入口空气速度对非稳态无量纲温度场的影响.结果表明：为了减小吸热器的热应力破坏,相关参数选择应按照平均颗粒直径小、孔隙率小、厚度小与入口空气速度大的原则.

英文摘要：

In order to analyze the unsteady heat transfer characteristics of solar porous media power tower receiver,first,unsteady heat transfer models are established.Then,a volumetric convective heat transfer coefficient model suitable for the receiver is proposed based on the least squares method.Finally,the models are solved by numerical method to analyze the typical unsteady dimensionless temperature field,and to further reveal the influences of the average particle diameter,the porosity,the thickness and the air inlet velocity on the unsteady dimensionless temperature distribution.The results show that porous media with small particles,low porosity,low thickness and high air inlet velocity benefit the reduction of thermal stress-induced destruction.