聚变堆螺旋流道液态第一壁流动稳定性分析

Flow Stability Analysis of Liquid First Wall Blanket with Spiral Channels for Fusion Reactor

聚变堆包层第一壁材料所面临高能粒子辐照、电磁辐射、高热负荷、复杂的机械负荷和相应的物理化学腐蚀制约其服役性能和使用寿命,是聚变能发展的瓶颈问题。液态第一壁由于液态工质自身的特点可以承受更高的热负载、中子壁负载以及更高的出口温度,且由于液态工质的不断更新不存在中子辐照损伤问题,在未来聚变堆应用中很具有吸引力。但由于液态金属在聚变堆强磁场作用下流动形成磁流体(Magnetohydrodynamic MHD)效应,维持液态第一壁在复杂的几何结构和苛刻的工作条件的稳定流动性是现有液态壁研究的难点问题。本文针对自由表面液态金属流动时产生的MHD特性,提出了螺旋流道液态壁流动方案,通过在真空室背壁上设置沿磁场方向的螺旋型流道,使流道内液态金属沿磁场运动,进而减少切割磁场产生的MHD效应。并参考典型聚变堆FDS-Ⅱ,建立了外包层三维模型与真实磁场位型,对方案进行MHD分析与优化,分析结果表明该方案可以在真空室表面形成完整、稳定的液态金属包裹,验证了该方案在磁场作用下液态第一壁流动稳定性与初步可行性。

The first wall material issue of fusion reactor blanket is one of the bottlenecks in the development of fusion energy.Due to the characteristics of liquidity and continuous renewing,the liquid first wall can withstand higher loads of thermal,neutron and temperature,with no limit in the service life.It＇s an attractive blanket design in the future application of fusion energy.In the existing designs of the liquid first wall,flow stability problem is still unsolved under the complex geometric structure with such severe operating conditions.One important aspect is flow instability caused by MHD（magneto hydrodynamics） effect.This paper presents a liquid first wall design utilizing spiral flow channels to reduce the MHD effect.Liquid metal flows in the spiral channels along the magnetic direction to avoid cutting the magnetic line.And the flow stability of this free surface liquid wall in a D shape gradient magnetic field is verified through VOF method.The analysis result shows a stable and integrated liquid first wall can be formed and the Lorentz force caused by magnetic field is very small compared to the driving force.