中文摘要：

介绍了一种应用于塔式太阳能热发电站的腔式高温空气吸热器，建立了吸热器内部空气流动及传热过程模拟数学模型，并通过数值方法，模拟了吸热器内部的空气流场和温度场。结果得知：空气进入吸热器后，沿内壁面轴向高速流动，随着深度的增加，速度越来越小，到达底部时速度最小；在压差的作用下，进入吸热器内部的空气会不断流向和冲刷针肋及壁面，而主流方向的流量不断减少；空气通过冲刷高温针肋及壁面不断吸收热量，温度不断升高；由于吸热器底部空气速度较小，对流换热系数较小和热流密度较大，因此该处温度较高，是整个吸热器的最脆弱部位；在高辐照强度情况下，虽然加大空气流量可降低吸热器壁面的温度，但由于其对流换热系数与空气流速不成正比例，壁面温度一般还会有所升高。

英文摘要：

This paper introduces an air cavity heat absorber that is used in solar tower power plant and the corresponding mathematical models are proposed for the air flow and heat transfer in the absorber. Based on the numerical simulation, the flow field, the temperature field, and the heat transfer property in the absorber are studied. The following conclusions are drawn： After the air enters the absorber, it flows along the inner wall of the absorber at a high velocity, it becomes slower and slower, and reaches the minimum value at the bottom. Under the function of pressure difference, the air can scatter and erode the porcupine absorber and inner wall of the absorber, while the air velocity drops continuously along the main flow direction. The air absorbs heat from the eroding process, and the temperature rises increasingly. As the air velocity at the bottom of the receiver is the least in the absorber, the heat transfer coefficient is very small and the heat flux is very high, which causes the temperature is rather high and the absorber bottom to be the weakest place of the whole absorber body. Ahhougb the increased air flux can cool down the absorber wall to a certain degree, the temperature will still be raised generally under high radiation since heat transfer coefficient cannot be proportional to the air flow.