圆管内液态铅铋合金强制对流换热特性研究

Investigation on the Characteristics of Forced Convection Heat Transfer of Liquid Lead Bismuth Eutectic in Circular Tube

圆管内液态铅铋合金的强制对流换热特性研究对加速器驱动的次临界核能系统的发展具有重要意义。运用大涡模拟方法,对恒热流密度条件下三维圆管内液态铅铋合金强制对流换热特性进行了数值计算,对比发现模拟结果和实验数据及关联式吻合良好。对比了不同入口速度条件下流场的速度和温度分布、传热Nu数、无量纲时均温度、无量纲均方根温度和湍流涡分布等,进一步分析了不同雷诺数对圆管内液态铅铋合金强制对流换热特性的影响规律。在恒热流密度条件下,随着Re数的增加,液态铅铋合金的Nu数逐渐增大,圆管不同截面的温差逐渐减小,湍流涡分布增多,提高Re数能够增强液态铅铋合金的传热性能。

The study on the characteristics of the forced convection heat transfer of liquid lead bismuth eutectic（LBE） in circular tube is of great significance for the development of the acceleratordriven system（ADS）.In this paper,the numerical simulations on the forced convection heat transfer characteristics of LBE in a three-dimensional circular tube under the condition of constant heat flux are carried out based on the approach of large eddy simulation.It is found that the numerical results are in good agreement with the experimental results and the empirical correlations.The velocity and temperature distributions in the flow field,the Nusselt number,the dimensionless time averaged temperature,the dimensionless root mean square temperature and the distribution of the turbulent vortex are analyzed under the condition of different inlet velocities.The effects of Reynolds number on the forced convection heat transfer characteristics of LBE are further analyzed.The results show that as the Reynolds number decreases,the Nusselt number and the turbulent vortex distributions will gradually increase,while the temperature difference of the different cross sections will decrease under the constant heat flux conditions.It is also found that improving the Reynolds number can enhance the heat transfer performance of LBE.