CABSA程序的力平衡模型气溶胶再悬浮模块开发

Development of Aerosol Re-suspension Module in CABSA by Force Balance Model

核电厂严重事故情况下,裂变产物以气溶胶形式释放并沉积在结构表面。事故晚期,氢燃或氢爆等作用产生的气流会使沉积的气溶胶发生再悬浮而重返气空间。中国原子能科学研究院的CABSA程序中采用力平衡模型开发了再悬浮模块,并利用STORM试验数据进行了计算,分析了边界条件对气溶胶再悬浮的影响。模型通过气溶胶所受的提升力和附着力的平衡得出的临界直径来判定气溶胶的再悬浮条件。研究表明:提升力、附着力均随气溶胶直径增大而增大;表面粗糙度越小,附着力越大;流体速度越大,提升力越大;提高表面粗糙度、提升流体速度能够减小临界直径;减小临界直径能够提高悬浮比例。

When nuclear power plant is under severe accident,fission products release as aerosol and deposit on solid surface.In late phase of accident,fluid generated by hydrogen burning or explosion may resuspend aerosol into air space.Utilizing force balance model,China Institute of Atomic Energy have developed resuspension module in CABSA code,calculation have been accomplished with data in STORM tests to analysis the effective affected by boundary conditions to aerosol resuspension.The model determines resuspension condition by the critical diameter obtained from the balance of lift force and adhesive force.The result shows that:lift force and adhesive force gets larger on particles with larger diameter;the smaller surface roughness gets larger adhesive force;the larger fluid velocity gets larger lift force;increasing the surface roughness and fluid velocity can decrease critical diameter;decreasing the critical diameter can increase the resuspension fraction.