Frontiers in Energy Research ( IF 3.4 ) Pub Date : 2020-05-27 , DOI: 10.3389/fenrg.2020.00129 Chengqi Wang , Xiaodong Sun , Piyush Sabharwall
One of the key postulated accidents in a high-temperature gas-cooled reactor (HTGR) is the pressurized loss of forced cooling (P-LOFC) of the primary loop, which can be triggered by its primary helium circulator trip or turbine trip. If the reactor shutdown cooling system (SCS) fails during a P-LOFC accident, part of the reactor decay heat is absorbed by the reactor core materials and the rest removed by the reactor cavity cooling system (RCCS). In the extended period of P-LOFC accident, compounded with SCS failure, the core decay heat is supposed to be removed by conduction, natural circulation/convection, and radiation. Three-dimensional computational fluid dynamics (CFD) simulations were performed in this research to study the long-term heat removal mechanisms in the General Atomics' Modular High Temperature Gas-cooled Reactor (MHTGR) design during a P-LOFC accident. The reactor core temperature distribution and flow field were obtained at different decay power levels. The sensitivity of the natural circulation flow to the bypass gap width was investigated. The natural circulation flow intensity is relatively weak but very sensitive to the width of the bypass gaps.
中文翻译:
P-LOFC事故中MHTGR自然循环和衰减热消除的CFD研究
高温气冷堆(HTGR)中假定的关键事故之一是主回路的强制冷却(P-LOFC)压力损失,这可能是由其主氦循环器跳闸或涡轮机跳闸引起的。如果在发生P-LOFC事故期间反应堆关闭冷却系统(SCS)发生故障,则反应堆的部分衰变热将被反应堆堆芯材料吸收,其余部分将被反应堆腔冷却系统(RCCS)清除。在长时间的P-LOFC事故中,加上SCS失效,应该通过传导,自然循环/对流和辐射消除堆芯衰减热。在这项研究中进行了三维计算流体动力学(CFD)模拟,以研究通用原子的长期排热机理。P-LOFC事故期间的模块化高温气冷堆(MHTGR)设计。在不同的衰减功率水平下获得了反应堆堆芯温度分布和流场。研究了自然循环流对旁路间隙宽度的敏感性。自然循环流强度相对较弱,但对旁路间隙的宽度非常敏感。