溶液堆内气-液两相流流动及换热特性数值研究

Numerical Investigation on Gas-Liquid Flow and Heat Transfer Characteristics in a Liquid-Reactor

在溶液堆台架模型数值模拟研究的基础上,对实际堆结构的堆芯内气-液两相流流动及冷却盘管与堆内溶液间的换热特性进行了数值模拟研究。采用欧拉两相流模型描述堆芯内气-液两相流流动,MUSIG(MUltiple-SIze-Group)模型描述堆芯内气泡尺度分布和相互作用,流-固耦合模型描述溶液与盘管间换热。数值计算得到了堆芯内的温度、速度、气泡组分等分布及冷却盘管的换热效率。数值计算结果表明:在有气泡扰动时堆内温度分布比没有气泡时均匀,冷却盘管可将堆内产生的85%热量带出,与试验测量结果一致。额定功率时,不同气体产生量对于冷却盘管换热影响的研究表明,随着堆内气泡产生量的增加,溶液与冷却盘管之间的换热得到强化。

Gas-liquid flow and heat transfer in a nuclear reactor were investigated by the numerical simulation, on the base of former numerical study of the experimental model in this paper. The Euler two phase flow model, the MUSIG model and the fluid-solid coupling model are applied to describe, respectively, the gas-liquid two phase flow, the bubble size distribution and interaction in the core and the heat transfer between cooling-pipe and liquid. The temperature distribution, velocity distribution, bubble diameter distribution in the nuclear reactor and heat transfer coefficient of the cooling coils were obtained by numerical method. The numerical results show that the temperature distribution in the core is more even when there is bubble disturbing, and the cooling pipe may achieve 85% heat transfer, which agrees with the test results. The study on the effect of different gas generation on the heat transfer of cooling pipe at nominal power shows that the heat transfer between the liquid and cooling pipe can be enhanced as the increase of bubble generation.