封闭小通道内液态碱金属热驱动换热实验研究

EXPERIMENTAL STUDY OF THERMALLY DRIVING HEAT TRANSFER CHARACTERISTICS OF LIQUID ALKALI METALS IN A MICRO-CIRCULAR ENCLOSURE

本文选用钠钾合金工质来研究封闭循环小通道内液态碱金属的热驱动换热性能。主要研究了热驱动现象产生的条件，冷热端壁面温度分布特性及浮力数Bu、旋转雷诺数Rew对热驱动换热强度的影响。研究发现，热驱动现象出现在旋转莱利数Raw大于等于6．88×10^6时；在研究参数范围内，换热增强因子随Rew和Bu增加，都呈线性增大趋势，实验验证了二者是影响热驱动换热的主要因素。

Experiments were performed to investigate heat transfer characteristics of liquid alkali metals in a micro-circular enclosure. The main goals of this study were to determine the condition which induced thermally driving phenomena, temperature distribution of heated and cooled walls, and the contributions of Bu and Rew number to enclosure heat transfer enhancement factor. The results of the experiments show that thermally driving phenomena appears when the value of Raw number reaches 6.88×10^6 and the heat transfer enhanced factor increases linearly along with the growth of Bu and Rew value.