强内热源球床通道单相对流换热特性实验研究

球床水冷反应堆的堆芯为球形燃料元件堆积成的多孔通道，具有显著的强化换热作用。球床通道内的孔隙因具有多变性、随机性的特点，换热情况非常复杂，相关研究较少。为了研究含内热源球床通道内的换热特性，本文用直径为8 mm碳钢球堆积形成球床，以蒸馏水为工质，采用电磁感应加热方式对球床进行整体加热，研究球床通道内部的换热特性。通过对实验数据进行分析，得到了球床通道内部的功率分布和换热系数随热流密度、工质Re的变化规律，根据实验数据拟合得到了球床通道内平均换热系数的无量纲准则关联式，拟合结果与实验结果的相对偏差在12%以内，符合良好。

Experimental Study on Single-Phase Convection Heat Transfer Characteristics of Pebble Bed Channels With Internal Heat Generation

The water-cooled pebble bed reactor core is the porous channels stacked with spherical fuel elements, having evident effect on enhancing heat transfer. Owing to the variability and randomness characteristics of it’s interstice, pebble bed channels have a very complex heat transfer situation and have little correlative research. In order to research the heat transfer characters of pebble bed channels with internal heat source, electromagnetic induction heating method was adopted for overall heating the pebble bed which was composed of 8 mm diameter steel balls, and the internal heat transfer characteristics were researched. By comparing and analyzing the experimental data, the rule of power distribution and heat transfer coefficient with heat flux density, inlet temperature and working fluid’s Re were got. According to the experimental data fitting, the dimensionless average heat transfer coefficient correlation criteria was got. The fitting results are good agreement with the experimental results within 12% difference.