【摘要】 基于计算流体动力学(Computational Fluid Dynamic, CFD)方法对核电厂机组烟囱流场及示踪物质的输运情况开展流体动力学计算分析，仿真结果表明，对于机组5种运行工况(正常停堆、功率运行、最大排风、最小排风、失去厂外电)下的速度分布、气旋角度、示踪气体浓度分布、示踪气溶胶浓度分布等指标，在采样监测口位置标高截面处，均符合ANSI N13.1—2011标准的混合均匀性定量指标要求。通过分析比较不同工况下混合均匀性指标随风量变化的影响得出结论：示踪气溶胶受支路通风量影响波动较大，但在一定的范围内，各项混合均匀性指标均随着核电厂烟囱总通风量的增大而减小，示踪剂浓度分布(2/3COV)值越小，混合均匀性越好。更多还原

【Abstract】 This paper conducts a computational fluid dynamics(CFD) analysis of the stack flow field and tracer material transport in nuclear power plants. The CFD simulation results show that for 5 operational conditions(normal shutdown, power operation, maximum exhaust, minimum exhaust, and loss of off-site power) the velocity distribution, cyclone angle, tracer gas concentration distribution, tracer aerosol concentration distribution and other indicators all meet the quantitative index requirements of ANSI N13.1-2011 standard for mixing uniformity at the elevation section of the sampling monitoring port position. By analyzing and comparing the influence of airflow variations on mixing uniformity index under different operational conditions, it is concluded that: Tracer aerosols exhibit significant fluctuations due to branch ventilation flow variations, but within a certain range, all mixing uniformity indicators decrease as the total ventilation flow of the nuclear power plant stack increases. The smaller the tracer concentration distribution(2/3COV) value, the better the mixing uniformity.更多还原