不同黏度下熔盐泵非定常流动的数值分析

Numerical analysis of unsteady flow in molten salt pump for different viscosities

为了研究熔盐泵高温下的内部流动状态,采用三维雷诺时均(Navier-Stokes)方程和标准k-ε湍流模型,对熔盐泵内部非定常流动进行了数值模拟,分别分析了不同黏度和不同叶片与蜗舌之间的夹角(α)下泵内流场的变化情况。结果表明:在设计流量下,熔盐泵出口静压受黏度影响不大;压力随α角的变化规律几乎不受黏度影响;叶轮内流场整体呈现比较理想的流动状态,吸力面速度较大;低速区集中在叶片压力面中间位置,面积大小同时受到黏度和α角的影响,当α为35°时,最靠近蜗舌的流道内出现最大低速区。该研究可为揭示熔盐泵内部流动现象提高熔盐泵水力性能提供参考。

To study the flow in molten salt pump at high temperatures,the unsteady flow in molten salt pump was numerically analyzed based on the three-dimensional Reynolds-Averaged Navier-Stokes equations and the standard k-ε turbulence model. The internal flow fields with different viscosities and different blade-volute angles α were analyzed. Results showed that,in the designed flow,the static pressure at the outlet of molten salt pump was little affected by viscosity. The regularity of pressure change with the angle α was also little affected by viscosity. The flow field in the impeller presented ideal state and the velocity on the suction surface was relatively high. The low velocity zone appeared in the middle position of the blade pressure surface and was affected by both viscosity and the blade-volute angle（ α）. When the angle α was 35°,the largest low velocity zone appeared in the impeller passage nearest the volute tongue. The research provided a reference for revealing the flow phenomenon and improving the hydraulic performances of the molten salt pump.