基于数值计算方法的双螺杆真空泵气体输运过程研究
|
摘要
基于双螺杆真空泵气体输运的特点,将泵腔内级间的泄漏通道简化为不同类型的真空管路,采用相邻级间的平均压强确定不同压强下级间泄漏气体的流态,计算得到级间泄漏的质量流量。根据质量守恒定律,建立了双螺杆真空泵气体输运过程的数学模型。以渐开线型端面的等螺距螺杆真空泵为研究对象,计算分析了泵从大气压到极限真空的整个抽气过程。对不同入口压强下的级间泄漏量与抽速进行了研究,研究表明:不同的泄漏通道对级间泄漏的影响有所不同。在排气端,齿顶圆与泵腔内壁之间的泄漏通道对级间泄漏的影响较大;在吸气端,两转子齿顶齿根面之间、斜齿面之间以及凹齿面之间这三种泄漏通道对级间泄漏的影响较大。
The gas transport in the double-screw vacuum pump,from atmosphere to base pressure,was empirically approximated,mathematically modeled,numerically simulated and experimentally measured. The inter-stage leakage was assumed as the gas-flow via a small hole between adjacent sections of a rectangular pipe driven by their averaged pressure difference. The mass flow-rate of the back-flow was evaluated with the model. The leakage-path lengths and viscous/molecular flow-rates,of the constant pitch screw vacuum pump with involute end face,were calculated to understand its pumping behavior. The impact of the inlet pressure on the total leakage rate and pumping speed of each inter-stage leakage path was investigated. The simulated results show that each inter-stage leakage path has different impact on the pumping speed and total leakage rate. For example,at the highest inlet pressure,the leakage path between the addendum-circle and cavity-wall has a major impact at the exhaust side,but a minor impact at the suction side.
The gas transport in the double-screw vacuum pump,from atmosphere to base pressure,was empirically approximated,mathematically modeled,numerically simulated and experimentally measured. The inter-stage leakage was assumed as the gas-flow via a small hole between adjacent sections of a rectangular pipe driven by their averaged pressure difference. The mass flow-rate of the back-flow was evaluated with the model. The leakage-path lengths and viscous/molecular flow-rates,of the constant pitch screw vacuum pump with involute end face,were calculated to understand its pumping behavior. The impact of the inlet pressure on the total leakage rate and pumping speed of each inter-stage leakage path was investigated. The simulated results show that each inter-stage leakage path has different impact on the pumping speed and total leakage rate. For example,at the highest inlet pressure,the leakage path between the addendum-circle and cavity-wall has a major impact at the exhaust side,but a minor impact at the suction side.
引文
[1]张世伟,赵凡,张杰,等.无油螺杆真空泵螺杆转子设计理念的回顾与展望[J].真空,2015,52(5):1-12
[2]赵瑜,张世伟,徐成海.螺杆泵内部级间泄露通道的计算研究[C].真空技术学术交流会,2007
[3]李卓慧,王庆生,王国栋,等.螺杆真空泵返流特性的研究[J].真空科学与技术学报,2015,35(11):1295-1299
[4]潘成程,徐飞,谭昱全,等.双螺杆真空泵封闭容积间压力和泄漏特性研究[J].真空,2015(03):21-25
[5]Ohbayashi T,Sawada T,Hamaguchi M,et al.Study on the Performance Prediction of Screw Vacuum Pump[J].Applied Surface Science,2001,169(621):768-771
[6]张以忱.真空系统设计[M].北京:冶金工业出版社,2012
[7]陈长琦,贾寅,郑定保,等.螺杆真空泵单头等螺距内凹转子型线研究[J].真空,2011,48(03):8-11
[8]奚梅成.数值分析方法[M].合肥:中国科学技术大学出版社,1995
[9]Carnahan B,Luther H A,Wilkes J O.Applied Numerical Methods[J],1969
[10]范平.全压强范围内矩形截面长管道流导计算[J].深圳大学学报(理工版),2000,17(Z1):1-6
[11]巫修海,张宝夫,陈文华.渐变式螺杆真空泵设计与试验[J].真空科学与技术学报,2015,35(10):1238-1244
[12]Li H F,Tu J Y,Subic A,et al.The Leakage Analysis in a Twin-Screw Supercharger by Using an Integrated CAD/CFD Three-Dimensional Model[M].Computational Methods.Springer Netherlands,2006:1919-1923
[13]Pfaller D,Brümmer A,Kauder K.Optimized Rotor Pitch Distributions for Screw Spindle Vacuum Pumps[J].Vacuum,2011,85(12):1152-1155
[14]Wang Y Q,Jiang R,Hu M B,et al.Phase Transition in a Mesoscopic Ring with Multiple Diffusive Channels[J].Computer Physics Communications,2014,185(11):2823-2828
[2]赵瑜,张世伟,徐成海.螺杆泵内部级间泄露通道的计算研究[C].真空技术学术交流会,2007
[3]李卓慧,王庆生,王国栋,等.螺杆真空泵返流特性的研究[J].真空科学与技术学报,2015,35(11):1295-1299
[4]潘成程,徐飞,谭昱全,等.双螺杆真空泵封闭容积间压力和泄漏特性研究[J].真空,2015(03):21-25
[5]Ohbayashi T,Sawada T,Hamaguchi M,et al.Study on the Performance Prediction of Screw Vacuum Pump[J].Applied Surface Science,2001,169(621):768-771
[6]张以忱.真空系统设计[M].北京:冶金工业出版社,2012
[7]陈长琦,贾寅,郑定保,等.螺杆真空泵单头等螺距内凹转子型线研究[J].真空,2011,48(03):8-11
[8]奚梅成.数值分析方法[M].合肥:中国科学技术大学出版社,1995
[9]Carnahan B,Luther H A,Wilkes J O.Applied Numerical Methods[J],1969
[10]范平.全压强范围内矩形截面长管道流导计算[J].深圳大学学报(理工版),2000,17(Z1):1-6
[11]巫修海,张宝夫,陈文华.渐变式螺杆真空泵设计与试验[J].真空科学与技术学报,2015,35(10):1238-1244
[12]Li H F,Tu J Y,Subic A,et al.The Leakage Analysis in a Twin-Screw Supercharger by Using an Integrated CAD/CFD Three-Dimensional Model[M].Computational Methods.Springer Netherlands,2006:1919-1923
[13]Pfaller D,Brümmer A,Kauder K.Optimized Rotor Pitch Distributions for Screw Spindle Vacuum Pumps[J].Vacuum,2011,85(12):1152-1155
[14]Wang Y Q,Jiang R,Hu M B,et al.Phase Transition in a Mesoscopic Ring with Multiple Diffusive Channels[J].Computer Physics Communications,2014,185(11):2823-2828