Abstract: Based on the computational fluid dynamics analysis software ANSYS CFX, the gas flow of tritium monitoring branch in leak detection system of gas injection system (GIS) is simulated. It is found that the branch structure with half inches and 90 degrees cannot meet the demand of branch pipe air flow detection. Therefore, the structure is optimized by changing the angle between the bypass pipe and the main pipe or increasing the diameter of the branch pipe. The optimized results show that increasing the inner radius of the branch pipe to more than 6.9mm or reducing the included angle to less than 30° can make the leak detection pipeline meet the requirements of air inlet under various working conditions. 

Key words: Numerical simulation, ANSYS CFX, Branch air flow, Structure optimization 

摘要： 利用计算流体力学分析软件 ANSYS CFX，对气体注入系统的检漏系统中氚监测支路气体流量进行了数值模拟，发现在支管管径 1/2in 且与主管夹角成 90°的情况下，当主路流量为 33m^3 .h⁻¹ 时，支管进气量只有 0.2354m^3 .h⁻¹ ，不满足 0.36~3.6m^3 .h⁻¹的设计要求。采取改变支管与主管之间的夹角和增大支管管径两种方式对支路结构进行了优化。优化后的结果显示，将支管内半径增大至 6.9mm 以上或减小支管与主管的夹角至 30°以下均可使检漏管路满足各工况下的进气量要求。

关键词: 数值模拟, ANSYS CFX, 支管进气量, 结构优化