基于FLUENT的双蜗壳离心泵径向力数值分析

Numerical Analysis of Radial Force of Centrifugal Pump with Double Volutes Based on FLUENT

利用CFD软件Fluent对HD型石油化工流程泵的不同工况作流场计算.采用雷诺时均方程和标准κ-ε湍流模型,压力和速度耦合采用SIMPLEC算法,对双蜗壳离心泵内部流场进行模拟,分析了双蜗壳泵静压力和速度场的分布规律,并对径向力进行了计算分析.通过模拟计算发现,数值模拟计算外特性曲线与试验曲线趋势一致,两者相对误差小于10%,说明应用数值计算结果建立的离心泵径向力计算模型具有一定的准确性.利用离心泵径向力的数学计算模型,得出各个工况下叶轮所受的径向力的大小和方向.结果表明,双蜗壳结构泵能有效地减小径向力,在设计点运行时径向力最小且不为0,偏离设计工况下径向力逐渐增大,但不同工况下径向力的变化不大,验证了双蜗壳能有效地平衡径向力.

The CFD software Fluent was used to calculate the internal flow field of the HD-type petrol chemical process pump in different working conditions. The Reynolds Averaged N--S equation,κ-ε model and SIMPLEC algorithm were adopted to simulate the internal flow field of a centrifugal pump with double volutes, and analyze the distribution of static pressure and velocity field, and calculate the radial force. By comparing the numerical values with the experimental results, the tendency of the two curves are consistent and the relative error is less than 10% ,which proves the practical application of the numerical model to calculate the radial force of the centrifugal pump with sufficient accuracy. By using the calculation model of centrifugal radial force, the size and direction of the impeller radial force in different working conditions are obtained and the results show that the centrifugal pump with double volutes can effectively reduce the radial force. The radial force is minimum when the pump runs in design conditions and gradually increases in off-design conditions, but the radial force shows a slight change in different conditions,which confirms that double volutes can effectively balance the radial force.