多级罗茨干式真空泵相邻级间流动区域多相流研究

发布时间：2018-04-19 18:01

本文选题：多级罗茨干式真空泵 + 气固两相流　；参考：《东北大学》2014年硕士论文

【摘要】：多级罗茨干式真空泵具有工作压力范围宽、可直排大气、维护成本低、抽速大等优点,因此在半导体、制药、冶金、石油化工、航空航天等领域被广泛应用。在PECVD、刻蚀等工艺过程中,多级罗茨干式真空泵往往面临复杂苛刻的抽气环境,如泵内含有腐蚀性气体、颗粒粉尘及存在温度变化和压力的脉动等,甚至在泵腔内存在复杂的物理变化和化学反应。因此在苛刻条件下工作的同时保证多级罗茨泵的综合性能意义深远。本文采用计算流体力学的方法对多级罗茨泵相邻级流动区域进行了多组数值模拟,并对计算的结果进行了对比分析。首先,本文利用三维建模软件(Solidworks)按照设计尺寸建立了多级罗茨干式真空泵相邻级流动区域的三维几何模型,并根据模型各部分的几何特征及运动特点分别进行了网格划分。对于泵腔流动区域,运用外接Fortran程序的方法,分别对转子与转子间啮合区域、转子与泵腔间啮合区域采用两种网格更新方式,控制网格节点的运动,实现了动网格模拟。其次,根据多相流基本理论,采用欧拉-拉格朗日方法,利用ANSYS CFX软件实现了多级罗茨干式真空泵相邻级流动区域在大气压条件下的气固两相流模拟,得到了收敛良好的计算结果。之后根据模拟结果分析了注入流场粒子的运动规律、迹线特征以及通过-沉积情况,对比了单向耦合、完全耦合两种计算方法对模拟结果的影响,验证了数值模拟结果与稀相气固两相流理论的相符性。最后,考虑到多级罗茨干式真空泵在实际工作中面临的不同抽气环境,分别对粒子直径、粒子与壁面相互作用、压力-压缩比、壁面粗糙度四个影响因素进行了多组对比数值模拟。根据每组模拟的结果详细分析了在不同工况下各因素对流场内固体粒子运动参数影响的侧重点以及通过-沉积特性。为工程实际中多级罗茨干式真空泵的改进优化提供了理论参考。
[Abstract]:Multistage Roots dry vacuum pump is widely used in semiconductor, pharmaceutical, metallurgy, petrochemical, aerospace and other fields because of its advantages such as wide range of working pressure, direct discharge of atmosphere, low maintenance cost and high pumping speed.In the process of PECVD, etching and so on, multistage Roots dry vacuum pump is often faced with complicated and harsh air extraction environment, such as corrosive gas, particle dust, temperature change and pressure pulsation, etc.Even in the pump cavity there are complex physical changes and chemical reactions.Therefore, it is of great significance to ensure the comprehensive performance of multistage Roots pump while working under harsh conditions.In this paper, the flow region of adjacent stages of multistage Roots pump is simulated by the method of computational fluid dynamics, and the results are compared and analyzed.Firstly, according to the design size, the 3D geometric model of the flow region of the adjacent stage of the multistage Roots dry vacuum pump is established by using the 3D modeling software Solidworks. and the mesh is divided according to the geometric characteristics and the motion characteristics of each part of the model.For the flow region of the pump cavity, two mesh updating methods are used to control the movement of the mesh nodes in the rotor-rotor meshing region and the rotor-pump cavity meshing region by using the method of external Fortran program, and the dynamic mesh simulation is realized.Secondly, according to the basic theory of multiphase flow, using Euler-Lagrangian method and ANSYS CFX software, the gas-solid two-phase flow simulation of adjacent stage flow region of multistage Roots dry vacuum pump under atmospheric pressure is realized.The calculation results with good convergence are obtained.Then, according to the simulation results, the movement law, trace characteristics and travers-deposition of injected particles are analyzed, and the effects of unidirectional coupling and complete coupling on the simulation results are compared.The agreement between the numerical simulation results and the theory of rarefied gas-solid two-phase flow is verified.Finally, considering the different pumping environment of the multistage Roots dry vacuum pump in practice, the particle diameter, the interaction between particle and wall, the pressure-compression ratio are respectively considered.Four factors affecting the roughness of the wall are numerically simulated.According to the results of each group of simulations, the effects of various factors on the motion parameters of solid particles in the convection field are analyzed in detail, as well as the travers-deposition characteristics.It provides a theoretical reference for the improvement and optimization of multistage Roots dry vacuum pump in engineering practice.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB752

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