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核电安全日益受到关注,非能动系统作为第三代核电系统具有很高的安全性。采用FLUENT流体体积分数(volume of fraction,VOF)模型和k-ε湍流模型对非能动安全壳冷却系统(passive containment cooling system,PCCS)三维平板降膜流动进行数值模拟。结果表明:1)在降膜过程中有波动现象,最终波动趋于平缓;2)水与空气逆流流动过程中发生轻微的液滴夹带;3)降膜流动受重力、表面张力与壁面黏滞力共同作用,液膜厚度沿横向分布均匀,沿高度方向平均液膜厚度越来越小,并且受进口水流速度与入口宽度影响,水流量一定时增加进口水流速度与入口宽度,平均液膜厚度增大,空气入口流速对水膜厚度影响相对较小。
Increasing attention has been paid to nuclear power safety. As a third generation nuclear power system, passive systems have high safety. The FLUENT volume of fraction (VOF) model and the k-ε turbulence model were used to simulate the 3D falling-film flow in passive containment cooling system (PCCS). The results show that: 1) there is fluctuation in falling film, and the final fluctuation tends to be gentle; 2) there is a slight droplet entrainment in the process of countercurrent flow of water and air; 3) the flow of falling film is affected by gravity, surface tension and wall stickiness Force, the thickness of the liquid film is evenly distributed along the horizontal direction, the average thickness of the liquid film along the height direction is smaller and smaller, and influenced by the inlet flow velocity and the inlet width. When the water flow is constant, the inlet flow velocity and the inlet width are increased, Increase, the air inlet flow rate on the impact of the thickness of the water film is relatively small.