螺旋离心泵内固液两相非定常流动的数值计算与分析

发布时间：2018-05-12 16:34

本文选题：螺旋离心泵 + 固液两相流　；参考：《兰州理工大学》2012年硕士论文

【摘要】：螺旋离心泵是一种具有极好的无堵塞、无缠绕与损伤少的新型杂质泵。它在污水的排放以及食品、造纸等工业部门已得到了广泛的应用。螺旋离心泵和一般离心泵的主要区别在于装有螺旋离心叶轮，叶轮进口部分为螺旋叶片，，出口部分近似于混流叶片，螺旋部分有容积泵的作用，离心部分将叶轮能量在蜗壳内转化成输送介质向外的压力能，其独特的结构使其具有螺旋泵和离心泵的双重优点。目前螺旋离心泵两相流的数值模拟大多采用定常的数值模拟，虽然能在一定程度上能反应其内部流场的特性，但它没有较真实地反映螺旋离心泵内部的复杂流动情况，造成分析内特性时不够精确，进而对提高螺旋离心泵的外特性方面产生了不利的影响，本课题拟对螺旋离心泵内的固液两相流进行非定常的数值计算，从而得到比较反映物理真实的螺旋离心泵内部固液两相流流场的特性，为提高其性能提供理论依据和参考。本课题的主要研究内容如下： 1、根据螺旋离心泵的结构特点以及其内部两相流场特点，忽略轮毂与后盖板间的间隙流动，对螺旋离心泵流动区域进行了简化，并将其划分为进口区域、叶轮旋转区域和蜗壳三个区域； 2、利用PRO/E对150×100LN-32型螺旋离心泵进行三维实体建模，利用ICEM对三个流动区域分别进行网格的划分，再分别导入FLUENT进行合并； 3、利用FLUENT软件对150×100LN-32型螺旋离心泵进行了非定常数值模拟，对其外特性跟内流场进行了分析，获得了螺旋离心泵外特性与内流场随着叶轮的旋转在不同时刻下的变化规律； 4、利用FLUENT软件对150×100LN-32型螺旋离心泵在5种不同流量、5种不同固相体积浓度下的内部多相流流场进行了数值模拟与分析，获得了不同流量和不同固相体积浓度对其外特性跟内流场（压力、速度、流线）的影响。本课题的创新点如下： 1、对150×100LN-32型螺旋离心泵内部多相流进行了深入的研究，提出采用Mixture多相流模型、标准k ε湍流模型以及滑移网格技术对螺旋离心泵内部流场进行了非定常数值模拟的方法； 2、通过设置监测点方法获得了螺旋离心泵的压力脉动特性以及轴向力、径向力等诱导力特性。本课题的结论如下： 1、通过对清水介质在额定工况下一个周期的非定常数值计算，得出效率、扬程、轴向力、径向力随叶轮相位角变化的波动规律以及蜗壳中截面压力和流道轴截面流线随叶轮的旋转在不同时刻的变化规律； 2、通过对含沙水在不同流量下一个周期的非定常计算，得出蜗壳出口面压力、叶轮所受轴向力、径向力以及扭矩随流量的改变在一个周期内的波动规律，并且分析了叶片工作面、背面、蜗壳中截面的压力以及固相体积浓度在不同流量下不同时刻的变化规律； 3、通过对含沙水在不同固相体积浓度下一个周期的非定常计算，得出了蜗壳出口面压力、叶轮所受径向力、轴向力、扭矩以及蜗壳壁面监测点随固相体积浓度的改变在一个周期内的波动规律，并且分析了叶片工作面、背面、蜗壳中截面的压力、速度、固相体积浓度分布以及轴截面流线在不同固相体积浓度下不同时刻的变化规律。
[Abstract]:The spiral centrifugal pump is a new type of impurity pump which has excellent non - clogging , no winding and less damage . The main difference between the spiral centrifugal pump and the general centrifugal pump has been widely applied . The main difference between the spiral centrifugal pump and the general centrifugal pump is that the spiral centrifugal impeller is installed , the inlet part of the impeller is helical blade , the outlet part is similar to the mixed flow blade , the spiral part has the function of volume pump , and the centrifugal part transforms the energy of the impeller in the volute to the outward pressure energy , and the unique structure makes it have the double advantages of the screw pump and the centrifugal pump .

The numerical simulation of the two - phase flow of the spiral centrifugal pump mostly adopts constant numerical simulation , although it can reflect the characteristics of the internal flow field to a certain extent , it does not accurately reflect the complex flow situation inside the spiral centrifugal pump , which leads to an unfavorable influence on the external characteristics of the spiral centrifugal pump , and the characteristic of the solid - liquid two - phase flow field in the spiral centrifugal pump is proposed to be compared and the theoretical basis and reference for improving the performance of the spiral centrifugal pump are obtained .

The main research contents of this subject are as follows :

1 . According to the structure characteristics of the spiral centrifugal pump and the characteristics of the two - phase flow field in the spiral centrifugal pump , the clearance flow between the hub and the back cover plate is neglected , the flow area of the spiral centrifugal pump is simplified , and the spiral centrifugal pump is divided into three areas of the inlet area , the impeller rotating area and the volute casing ;

2 . Using PRO / E to model a 150 脳 100LN - 32 screw centrifugal pump , we use ICEM to divide the three flow areas separately , and then import FLUENT for merging .

3 . The unsteady numerical simulation of 150 脳 100LN - 32 screw centrifugal pump is carried out by FLUENT software . The external characteristics and the internal flow field are analyzed , and the change law of the outer characteristic and inner flow field of the spiral centrifugal pump with the rotation of the impeller at different times is obtained .

4 . The internal multiphase flow field of 150 脳 100LN - 32 screw centrifugal pump was numerically simulated and analyzed by FLUENT software . The effects of different flow rate and different solid phase volume concentration on the internal flow field ( pressure , velocity and flow line ) were obtained .

The innovation points of this subject are as follows :

1 . The multiphase flow in the 150 脳 100LN - 32 spiral centrifugal pump is studied deeply , and the unsteady numerical simulation method for the internal flow field of the spiral centrifugal pump is put forward by using the Mixture multiphase flow model , the standard k 蔚 turbulence model and the slip grid technology .

2 . The pressure pulsation characteristic and axial force , radial force and so on of the screw centrifugal pump are obtained by setting the monitoring point method .

The conclusions of this subject are as follows :

1 . Through the unsteady numerical calculation of one cycle of the clean water medium under the rated working condition , the variation law of efficiency , lift , axial force and radial force with the phase angle of the impeller and the change law of the cross section pressure and the section flow line of the flow passage along with the rotation of the impeller at different times are obtained .

2 . Through the unsteady calculation of one cycle of sand - containing water at different flow rates , the pressure of the outlet surface of the volute , the axial force , the radial force and the torque of the impeller in one cycle are calculated , and the variation law of the pressure of the cross section in the working face , the back surface and the volute and the concentration of the solid phase at different times are analyzed .

3 . Based on the unsteady calculation of sediment concentration at different solid phase volume concentrations , the fluctuation law of the pressure , radial force , axial force , torque and the surface monitoring point of volute wall on one cycle are obtained . The variation law of pressure , velocity , solid phase volume concentration distribution and axial cross section flow line at different solid phase volume concentrations are analyzed .

【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH311

【引证文献】