随机填充球床通道内氦气流动特性实验研究

在聚变堆氦冷固态包层氚增殖区，球床通道内氦气流动压降特性对泵功率的设计具有重要意义。以氦冷固态包层氚增殖区为背景，研究了氦气流速、球床颗粒直径及球床通道长度对球床通道内氦气流动压降特性的影响。实验段采用20 mm×20 mm×500 mm的矩形通道，实验中氦气流速为0.1～0.6 m/s，球床颗粒直径为0.5、0.8、1.0、1.5、2.0 mm。实验结果表明，压降与氦气流速以及球床通道长度呈正相关，与球床颗粒直径呈负相关。对比Ergun关系式发现，在球床颗粒直径较小时，Ergun关系式预测值低于实验值，这主要是由于氦气可压缩性的影响。通过动量方程，理论推导出经可压缩性修正的Ergun关系式，结果发现修正后的Ergun关系式预测值与实验值符合良好。本研究为氦冷固态包层氚增殖区设计提供了数据支撑，为球床通道内流动特性的数值模拟提供了验证手段。

Experimental Study on Helium Flow Characteristic in Randomly Packed Pebble Bed

In the tritium breeding regions of helium cooled solid blanket of fusion reactor, the pressure drop characteristics of helium in packed pebble beds are of great significance to the design of the pump power. Based on the background of the tritium breeding regions, the effects of helium flow rate, particle diameter, and the channel length on the pressure drop characteristics were investigated in packed pebble beds. The test section is a rectangular channel with the size of 20 mm×20 mm×500 mm. Flow rate is within 0.1-0.6 m/s and particle diameter is 0.5, 0.8, 1.0, 1.5, 2.0 mm in this experimental study. The experimental results show that pressure drop is positively correlated with the helium flow rate and channel length of beds, and pressure drop is negatively correlated with particle diameter. Compared with Ergun correlation, the experimental values are higher than the calculated values of Ergun correlation in condition with smaller particle diameters due to the effects of the compressibility. Ergun correlation modified with the compressibility was deduced by the momentum equation. The results show that the calculated values of Ergun correlation modified with the compressibility are in good agreement with the experimental data. This study would provide the data support for the design of the tritium breeding regions and the verification for the numerical simulation.