管型对波动管热分层现象的影响分析

Analysis of Effect of Pipe Type on Surge Line Thermal Stratification

为分析评价压水堆核电厂稳压器波动管管型对热分层现象的影响,提出采用螺纹管来减弱热分层的措施。利用计算流体力学(CFD)分析方法,对升温、升压阶段波动管原型和改进模型的热分层现象进行数值模拟,得到两种模型不同波动流速下沿波动管轴线方向的截面最大温差分布以及流场分布。对比分析结果表明:波动管结构由光管改为螺纹管后流场紊动加强并出现涡流,冷热流体间的混合增强,与原型相比可使波动管的截面温差减小约1/3,从而有效地减弱热分层的影响。

In order to analyze and evaluate the effect of pipe type on thermal stratifica-tion for PWR pressurizer surge line ,computational fluid dynamics （CFD） method was used for the current and improved screw surge line during heating up condition .The maximum temperature differences and velocity distribution along the surge line axis under different velocities were obtained .Comparative analysis indicates that replacing current smooth tube with screw pipe can enhance the turbulent flow and the mixing effects between the hot and cold fluids . The temperature differences in flow cross-sections along the screw surge line axis are reduced by about 1/3 compared with current smooth surge line ,yielding effectively mitigation to the influence of thermal stratifica-tion .