﻿ 串联离心泵过流部件空化及磨损的数值模拟

# 串联离心泵过流部件空化及磨损的数值模拟Numerical Simulation of Cavitation and Wear of Flow Passage Parts in Series Centrifugal Pumps

Abstract: In order to analyze the flow of sand-containing water through the centrifugal pump, the damage of the flow-through components is due to the influence of sediment abrasion or cavitation; and a series centrifugal pump model is designed. Based on CFturbo software to model the centrifugal pump in series, and optimized by UG software, using ICEM for meshing. Finally, the numerical simulation of the internal flow field of a centrifugal pump in series with sandy water medium was performed by CFX software. The results show: Cavitation damage to the centrifugal pump can be reduced by in-creasing the inlet pressure of the sandy water medium into the centrifugal pump. It does not change the position where the centrifugal pump’s flow passage components are worn out. Centrifugal pump cavitation damage is mainly concentrated in the impeller inlet. The inlet of the suction surface of the blade and the outlet of the pressure surface are locations where the centrifugal pump is mainly exposed to sediment.

1. 引言

2. 计算区域及设置

2.1. 离心泵的基本设计参数

2.2. 离心泵三维建模及网格划分

Figure 1. Three-dimensional model of the water body of the centrifugal pump

Figure 2. Mesh division of water body of centrifugal pump

2.3. 边界条件设置

1) 进口边界条件：计算进口边界处，以进口总压作为进口条件，并假定进口压力垂直于进口表面，且进口处含沙水颗粒体积分数均匀分布。

2) 出口边界条件：以质量流量速率作为出口条件。

3) 固壁边界条件：过流部件的壁面边界设置为无穿透、无滑移边界条件。

2.4. 相的设置

3. 计算模型基本方程

$\frac{\partial {\varnothing }_{f}}{\partial \tau }+\frac{\partial \left({\varnothing }_{f}{V}_{fi}\right)}{\partial {x}_{i}}=0$ (3.1)

$\frac{\partial {\varnothing }_{p}\text{​}}{\partial \tau }+\frac{\partial \left({\varnothing }_{p}{V}_{pi}\right)}{\partial {x}_{i}}=0$ (3.2)

$\begin{array}{l}\frac{\partial }{\partial t}\left({\varnothing }_{f}{V}_{fi}\right)+\frac{\partial }{\partial {x}_{k}}\left({\varnothing }_{f}{V}_{fi}{V}_{fK}\right)\\ =-\frac{1}{{\rho }_{f}}{\varnothing }_{f}\frac{{\partial }_{p}}{\partial {x}_{i}}+{\theta }_{f}\frac{\partial }{\partial {x}_{k}}\left[{\varnothing }_{f}\left(\frac{\partial {V}_{fi}}{\partial {x}_{k}}+\frac{\partial {V}_{fk}}{\partial {x}_{i}}\right)\right]-\frac{B}{{\rho }_{f}}{\varnothing }_{f}{\varnothing }_{p}\left({V}_{fi}-{V}_{pi}\right)+{\varnothing }_{fgi}\end{array}$ (3.3)

$\begin{array}{l}\frac{\partial }{\partial t}\left({\varnothing }_{f}{V}_{fj}\right)+\frac{\partial }{\partial {x}_{k}}\left({\varnothing }_{f}{V}_{fj}{V}_{fK}\right)\\ =-\frac{1}{{\rho }_{f}}{\varnothing }_{f}\frac{{\partial }_{p}}{\partial {x}_{j}}+{\theta }_{f}\frac{\partial }{\partial {x}_{k}}\left[{\varnothing }_{f}\left(\frac{\partial {V}_{fj}}{\partial {x}_{k}}+\frac{\partial {V}_{fk}}{\partial {x}_{j}}\right)\right]-\frac{B}{{\rho }_{f}}{\varnothing }_{f}{\varnothing }_{p}\left({V}_{fj}-{V}_{pj}\right)+{\varnothing }_{fgj}\end{array}$ (3.4)

$\begin{array}{l}\frac{\partial }{\partial t}\left({\varnothing }_{p}{V}_{pi}\right)+\frac{\partial }{\partial {x}_{k}}\left({\varnothing }_{p}{V}_{pi}{V}_{pK}\right)\\ =-\frac{1}{{\rho }_{p}}{\varnothing }_{p}\frac{{\partial }_{p}}{\partial {x}_{i}}+{\theta }_{p}\frac{\partial }{\partial {x}_{k}}\left[{\varnothing }_{p}\left(\frac{\partial {V}_{pi}}{\partial {x}_{k}}+\frac{\partial {V}_{pk}}{\partial {x}_{i}}\right)\right]-\frac{B}{{\rho }_{p}}{\varnothing }_{f}{\varnothing }_{p}\left({V}_{fj}-{V}_{fi}\right)+{\varnothing }_{pgj}\end{array}$ (3.5)

4. 模拟结果及分析

4.1. 串联离心泵过流部件压力分析

Figure 3. Pressure distribution of the back cover of the tandem centrifugal pump

Figure 4. Pressure distribution of the front cover of the tandem centrifugal pump

Figure 5. Pressure distribution of pressure surface of series centrifugal pump

Figure 6. Pressure distribution on the suction surface of a tandem centrifugal pump

4.2. 串联离心泵过流部件磨损分析

Figure 7. Distribution of sand particles in the back cover of the tandem centrifugal pump

Figure 8. Sand distribution in the front cover of the tandem centrifugal pump

Figure 9. Distribution of sand particles on pressure surface of tandem centrifugal pump

Figure 10. Distribution of sand particles on the suction surface of a tandem centrifugal pump

5. 结论

NOTES

*通讯作者。

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