离心式杂质泵内部固液两相湍流场数值计算与磨损分析

发布时间：2018-04-23 22:32

本文选题：离心杂质泵 + 固液两相流　；参考：《合肥工业大学》2017年硕士论文

【摘要】：离心式杂质泵在水利输送方面应用非常广泛,但是目前该类泵仍然存在一些关键技术难题,第一个是由于固相颗粒的存在而导致泵的效率下降,第二个是由于固相颗粒对泵过流零部件的冲蚀磨损导致泵的可靠性变差,这两项技术难题严重阻碍了离心杂质泵研究与应用。本文以离心杂质泵为研究对象,阐述离心式杂质泵的研究背景,建立离心泵三维全流道模型,选用合适的湍流计算模型模拟离心泵内部流场,分析固相颗粒在离心泵内部的受力情况在运动轨迹,探讨固相颗粒对过流零部件的冲蚀磨损机理,选用适合离心杂质泵的Finnie冲蚀磨损模型对离心泵过流零部件做磨损预测。采用欧拉多相流模型对离心泵内部固液两相湍流场进行定常计算,比较不同固相颗粒直径和固相体积分数对离心泵流动特性以及扬程效率的影响。发现随着固相体积分数和固相颗粒直径的增加,固相跟随性变差,液相流动性变差,离心泵内部压力增加,扬程和效率下降,磨损也随之增加。固相浓度分布呈现出下降趋势,但是分布更趋于均匀。利用DPM模型在不同固相颗粒直径和冲击速度工况下对离心泵过流零部件磨损进行分析,计算平均磨损率发现磨损部位主要存在蜗壳流道、叶片背面后段与叶片头部和后盖板导流锥附近;另外还研究了固相颗粒直径和固相冲击速度变化对过流零部件磨损率分布的影响,得到随着固相颗粒直径和冲击速度的变化,蜗壳的磨损范围扩大,磨损率有所上升,叶片磨损分布由叶片背面尾部扩展到叶片背面的中部,后盖板的磨损率明显增加,效率下降明显,扬程下降缓慢。
[Abstract]:Centrifugal impurity pump is widely used in water conservancy transportation, but at present there are still some key technical problems in this kind of pump. The first is that the efficiency of the pump is reduced because of the existence of solid particles. The second one is that the reliability of the pump becomes worse due to the erosion and wear of the solid particles to the flow parts of the pump. These two technical problems seriously hinder the research and application of centrifugal impurity pump. In this paper, the centrifugal impurity pump is taken as the research object, the research background of the centrifugal impurity pump is expounded, the three-dimensional full-channel model of the centrifugal pump is established, and the suitable turbulence calculation model is selected to simulate the flow field inside the centrifugal pump. This paper analyzes the movement track of solid particles acting on the centrifugal pump, discusses the erosion and wear mechanism of the solid particles on the overflowing parts, and selects the Finnie erosion wear model suitable for the centrifugal impurity pump to predict the wear of the over flow parts of the centrifugal pump. Eulerian multiphase flow model was used to calculate the turbulent field of solid and liquid in centrifugal pump. The effects of different solid particle diameter and solid volume fraction on the flow characteristics and lift efficiency of centrifugal pump were compared. It is found that with the increase of solid volume fraction and solid particle diameter, the solid following becomes worse, the liquid flow becomes worse, the internal pressure of centrifugal pump increases, the lift and efficiency decrease, and the wear increases. The distribution of solid concentration showed a decreasing trend, but the distribution tended to be more uniform. The wear of centrifugal pump overflowing parts was analyzed by using DPM model under different solid particle diameter and impact velocity conditions. The main worsted runner was found to exist in the wear area by calculating the average wear rate. In addition, the influence of the change of solid particle diameter and solid impact velocity on the wear rate distribution of overflowing parts is also studied, and the change of solid particle diameter and impingement velocity is obtained with the change of solid particle diameter and impact velocity. The wear range of the volute is enlarged and the wear rate is increased. The wear distribution of the blade extends from the rear tail of the blade to the middle of the back of the blade. The wear rate of the rear cover plate increases obviously the efficiency decreases obviously and the head drops slowly.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH311

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