Abstract: Following the plasma parameters of the HL-3 tokamak gradually improving, the thermal loads that the first wall needs to withstand also gradually increase, especially the residual power of the first wall at the neutral beam shine-through area would be more than 1.0 MW·m^-2 and duration 5 s. Based on the thermal conduction and the convective heat transfer equations, numerical simulation and parameters optimization were conducted on key first wall structural design variables influencing the heat transfer performance, such as the graphite thickness, heat sink plate thickness, flow channel diameter and thermal contact conductance between combined surfaces in the high flux zones, using the orthogonal experimental technique. The results indicate that the above four factors are reversely correlated with the surface temperature of first wall for HL-3 tokamak pulsed plasma operation. Besides, the graphite thickness is the greatest impact on the heat transfer performance of the carbon-based first wall, followed by the thermal contact conductance between the graphite and the heat sink plate,while the thickness of the heat sink plate 316L and the cooling pipe diameter are relatively low impact on that.

Key words: Tokamak, Orthogonal design, First wall, Thermal transfer analysis

摘要： 随着 HL-3 装置的运行参数逐渐提升，第一壁结构需承受的热负荷也逐渐增加，尤其是 NBI 穿透等离子体后的残余功率直接打击的第一壁，其区域的平均热负荷将达到 1 MW·m^-2 以上，持续时间 5 s。基于热传导和对流换热方程，利用正交试验方法对高热负荷区影响传热性能的第一壁的石墨厚度、热沉板厚度、流道直径以及界面接触热阻等关键传热结构设计变量进行了数值计算和参数优化研究。结果表明，对于 HL-3 装置脉冲等离子体运行来说，上述 4 个参数均与第一壁表面温度呈负相关。同时，石墨厚度变量对碳基第一壁传热结构性能影响最大，其次是石墨与热沉板间的界面接触传热系数变量，而热沉板 316L 厚度与管道冷却直径对它的影响较小。

关键词: 托卡马克, 正交设计, 第一壁, 传热分析