干式螺杆真空泵内部泄漏过程建模及分析  

Modeling and Analysis for the Leakage Process in Dry Screw Vacuum Pumps

作　　者：李丹童 何志龙[1] 邢子文[1] LI Dantong;HE Zhilong;XING Ziwen(School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《真空科学与技术学报》2021年第10期959-968,共10页Chinese Journal of Vacuum Science and Technology

摘　　要：准确掌握螺杆真空泵内部泄漏规律是设计高性能螺杆转子的基础。本文基于螺杆真空泵内部简化的泄漏通道几何结构与广泛的狭缝通道流动模型调研,对螺杆真空泵内部涉及分子流、粘滞流、过渡流三种流态及泊肃叶流、库爱特流两种流动方式的泄漏过程进行了建模。基于所构建的泄漏模型搭建了螺杆真空泵内部工作过程模拟程序,分析了极限真空下等螺距螺杆转子的内部泄漏过程。分析结果表明,不同间隙与转速下,齿顶泄漏通道内泊肃叶流动始终为影响转子内泄漏的主要因素,转子尖点啮合处泄漏通道内泊肃叶流动为影响转子外泄漏的主要因素,齿顶与齿间接触线处泄漏通道内库爱特流动因素不可忽略。螺杆真空泵内部气体的主要泄漏路径为:排气侧工作腔内气体首先通过齿顶泊肃叶流动内泄漏至吸气侧工作腔,而后通过转子尖点啮合处外泄漏至吸气腔。The design of high-performance screw vacuum pumps is based on the accurate prediction model of the leakage process in dry screw vacuum pumps.In this paper,we summarized the models describing the Poiseuille and Couette flow in screw vacuum pumps’leakage channels based on literature research,which was suitable for the simulation of molecular,viscous and transitional flow regimes of gas.Thermodynamic simulation procedure was developed based on the above models to predict the leakage process in screw vacuum pumps.The leakage process was analyzed in detail for a fixed-pitch screw vacuum pump under the condition of ultimate vacuum.Results showed that the Poiseuille flow at the rotors’tooth top was always the main factor affecting the internal leakage process in the screw vacuum pump under different rotor clearances and rotating speeds.The leakage at the rotor cusp had a great influence on the external leakage process.The leakage caused by Couette flow in tooth top and tooth meshing leakage channels should not be neglected.The main gas leakage route in screw vacuum pumps was summarized as follows:the gas in the high-pressure working chamber first leaked into the low-pressure working chamber through the tooth top of rotors,and then leaked into the suction chamber through the rotor cusp region.

关 键 词：螺杆真空泵 热力模拟 泄漏模型 泄漏分析 

分 类 号：TB752[一般工业技术—真空技术]