周向非均匀热流边界条件下太阳能高温吸热管内湍流传热特性研究

周向非均匀高密度热流引发的过热问题一直影响着太阳能热发电站中高温吸热器的运行安全。该文建立了太阳能高温吸热管对流换热电加热实验台和数值计算模型,通过实验研究和模拟计算,研究了周向非均匀热流边界条件下吸热管壁温度分布规律。研究结果显示:周向非均匀热流边界条件下吸热管壁温度分布与截面圆心角余弦呈函数关系,实验测量结果与数值计算结果吻合较好;经典Dittus-Boelter公式仍可用于计算周向非均匀热流边界条件下吸热管内的换热计算,但不适用于管壁温度分布计算。文中给出了周向非均匀热流边界条件下吸热器管壁温度计算关联式。

Turbulent Heat Transfer Characteristics in Solar Thermal Absorber Tubes With Circumferentially Non-uniform Heat flux Boundary Condition

The overheating issue which caused by circumferentially non-uniform high flux has been affecting the safety of receiver operation in solar thermal power plant.This paper presented experimental and numerical studies of the turbulent heat transfer in solar thermal absorber tubes.The results of experimental and simulation of this study show that under the circumferentially non-uniform heat flux boundary conditions,the tube wall temperature distribution on cross section is a function of the cosine of circular angle and experimental results agree well with the numerical results.Dittus-Boelter equation is still applicable to calculate the heat transfer in circular tube with non-uniform heat flux,but it is not suitable to calculate the wall temperature distribution in this condition.The wall temperature distribution of circular tube with non-uniform heat flux varies with the circular angle of cross section,and this study gave this correlation.