一体化反应堆自然循环流动传热特性分析
Analysis of Natural Circulation Flow and Heat Transfer Characteristics in an Integrated Reactor

某型号一体化反应堆采用内置螺旋管式换热组件的部分一体化布置形式和取消主泵的全自然循环设计理念，其堆内结构和驱动力与传统大型压水反应堆存在较大区别。本文采用商业计算流体力学软件Star ccm + 10.02，针对该型号的一体化反应堆开展了堆内自然循环三维流场分析。计算结果表明，冷却剂由于冷热段的高差和密度差形成的驱动力可以和堆内阻力匹配，堆芯支承下板的压降约占反应堆一回路总压降的12%，整个上腔室约占反应堆一回路总压降的30%，反应堆内冷却剂的最高流速为2.2 m/s左右，流速最高的位置出现在堆芯支承下板流水孔中。同时，该堆型堆芯入口流量分配较为均匀，最大流量分配因子为1.05，最小流量分配因子为0.93。
A certain type of integrated reactor adopts the partially integrated arrangement and the whole natural circulation design which the spiral-tube heat exchangers are internally installed and cancel the primary pump. Based on above reasons, the reactor’s structure and driving force are quite different from traditional commercial pressurized water reactor. In this paper, Star ccm + 10.02, a commercial computational fluid dynamics software, is used to analyze the natural circulation characteristics of this integrated reactor. The results show that driving force caused by the height and density difference of the coolant in the hot and cold sections can match the resistance inside the reactor. The pressure drop of the lower core support plate accounts for about 12% of the total pressure drop in the primary loop, and the upper plenum pressure drop accounts for about 30% of the total pressure drop in the primary loop. The maximum flow velocity of the coolant in the reactor is about 2.2 m/s. The highest flow velocity located in the drain hole of lower core support plate. The core inlet flow distribution is even, with the maximum flow distribution factor of 1.05 and the minimum flow distribution factor of 0.93.