液体密封端面倾斜椭圆孔上游泵送特性
|
摘要
气液异相介质隔离密封的实现有赖于密封端面几何型槽的上游泵送特性,为探索多孔端面实现液封气密封的设计途径,对液体密封端面倾斜椭圆孔上游泵送特性开展研究.考虑空化效应,采用有限差分方法对转速、密封间隙、密封压力等操作参数和孔深、倾斜角、方向因子、孔数等结构参数对开启力和泄漏率的影响规律进行了数值分析.结果显示:液体润滑条件下端面倾斜椭圆孔可产生明显的上游泵送效应,增加周向孔数和方向因子可实现被密封介质的完全零泄漏,同时可产生明显的流体动压效应使端面开启力提高50%以上.文中密封压力条件下,孔深取5～10μm,倾斜角取45°,周向孔数大于80,方向因子大于3时,密封可实现完全反向泵送,反向泄漏率的增加与随着孔数、方向因子和孔深的增加而增加.
The realization of the gas-liquid heterogeneous medium isolation seal depends on the upstream pumping characteristics of the geometric groove of the sealing face. In order to explore the design approach of the liquid sealing gas seal for the porous face, the upstream pumping characteristic of inclined-ellipse-dimples on liquid seal face was theoretically analyzed. Considering the cavitation effect, the finite difference method was used to numerically analyze the influences of operating parameters(e.g. rotation speed, seal clearance and seal pressure) and the structural parameters(e.g. dimple depth, inclination angle, slender ratio and dimple number on the open force and leakage rate).Results show that the inclined-ellipse-dimple liquid face seals may present significant upstream pumping and hydrodynamic effects, which led to open force improved more than 50% greater in the analysis. A complete backward leakage may be achieved by the inclined-ellipse-dimple upstream pumping face seals by increasing dimple number and slender ratio. A complete backward leakage can be achieved under pressure condition in the cases of 5～10 μm dimple depth, 45° inclination angle, greater than 80 dimple number and greater than 3 slender ratio. Meanwhile, the increase in reverse leakage rate increased with the dimple number, slender ratio, and dimple depth.
The realization of the gas-liquid heterogeneous medium isolation seal depends on the upstream pumping characteristics of the geometric groove of the sealing face. In order to explore the design approach of the liquid sealing gas seal for the porous face, the upstream pumping characteristic of inclined-ellipse-dimples on liquid seal face was theoretically analyzed. Considering the cavitation effect, the finite difference method was used to numerically analyze the influences of operating parameters(e.g. rotation speed, seal clearance and seal pressure) and the structural parameters(e.g. dimple depth, inclination angle, slender ratio and dimple number on the open force and leakage rate).Results show that the inclined-ellipse-dimple liquid face seals may present significant upstream pumping and hydrodynamic effects, which led to open force improved more than 50% greater in the analysis. A complete backward leakage may be achieved by the inclined-ellipse-dimple upstream pumping face seals by increasing dimple number and slender ratio. A complete backward leakage can be achieved under pressure condition in the cases of 5～10 μm dimple depth, 45° inclination angle, greater than 80 dimple number and greater than 3 slender ratio. Meanwhile, the increase in reverse leakage rate increased with the dimple number, slender ratio, and dimple depth.
引文
[1]Lebeck A O.Experiments and modeling of zero leakage backward pumping mechanical face seals[J].Tribology Transactions,2008,41(4):289-29.
[2]Xie Jing,Bai Shaoxian.Hydrodynamic characteristics of gas upstream pumping face seals texturing with inclined-ellipsedimples[J].Tribology,2017,37(2):233-239(in Chinese)[谢静,白少先.倾斜椭圆孔端面上游泵送气体密封流体动压特性[J].摩擦学学报,2017,37(2):233-239].doi:10.16078/j.tribology.2017.02.013.
[3]Salant R F,Hoiller S J.The effect of shallow groove patterns on mechanical seal leakage[J].Tribology Transactions,1992,35(1):142-148.doi:10.1080/10402009208982101.
[4]Salant R F,Hoiller S J.Stiffness and leakage in spiral groove upstream pumping mechanical seals[J].Tribology Transactions,1993,36(1):55-60.doi:10.1080/10402009308983132.
[5]Ding Xuexing,Lu Junjie,Zhang Weizheng,et al.Comparison between two optimized groove configuration and their performance for upstream pumping mechanical seal[J].Journal of Lanzhou University of Technology,2015,41(6):74-78(in Chinese)[丁雪兴,陆俊杰,张伟政,等.上游泵送机械密封两种优化槽形及性能的对比[J].兰州理工大学学报,2015,41(6):74-78].doi:10.3969/j.issn.1673-5196.2015.06.015.
[6]Li Guiyong,Hao Muming,Yan Mingqiang,et al.Numerical computations of the seal performance of upstream pumping mechanical seals with spiral grooves[J].Lubrication Engineering,2010,35(9):56-59(in Chinese)[李贵勇,郝木明,闫明强,等.螺旋槽上游泵送机械密封密封特性数值计算[J].润滑与密封,2010,35(9):56-59].doi:10.3969/j.issn.0254-0150.2010.09.013.
[7]Lai T.Development of non-contacting,non-leaking spiral groove liquid face seals[J].Lubrication Engineering,1994,50(8):625-631.
[8]Song Pengyun.An analysis of factors affecting the characteristics of a upstream pumping mechanical seal[J].Lubrication Engineering,2000,(3):50-55(in Chinese)[宋鹏云.螺旋槽上游泵送机械密封性能影响因素分析[J].润滑与密封,2000,(3):50-55].doi:10.3969/j.issn.0254-0150.2000.03.021.
[9]Wang Q,Chen H L,Liu T.Research on performance of upstream pumping mechanical seal with different deep spiral groove[J].Earth and Environmental Science,2013,15:072019.
[10]Song Pengyun,Chen Kuangmin,Dong Zongyu,et al.A theoretical analysis of spiral groove upstream pumping mechanical seal[J].Lubrication Engineering,1999,(4):5-7(in Chinese)[宋鹏云,陈匡民,董宗玉,等.螺旋槽上游泵送机械密封性能的解析计算[J].润滑与密封,1999,(4):5-7].
[11]Bai S X,Peng X D,Li J Y,et al.Experimental study on hydrodynamic effect of orientation micro-pored surfaces[J].Science China,Technological Sciences,2011,54(3):659-662.doi:10.1007/s11431-010-4265-0.
[12]Bai L Q,Bai S X.Frictional performance of a textured surface with elliptical dimples:geometric and distribution effects[J].STLETribology Transactions,2014,57:1122-1128.doi:10.1080/10402004.2014.939317.
[13]Zhang J Y,Meng Y G.Direct observation of cavitation phenomenon and hydrodynamic lubrication analysis of textured surfaces[J].Tribology Letters,2012,46(2):147-158.doi:10.1007/s11249-012-9935-6.
[14]Payvar P,Salant R F.A computational method for cavitation in a wavy mechanical seal[J].Journal of Tribology,1992,114(1):199-204.doi:10.1115/1.2920861.
[15]Bai S X,Peng X D,Li Y F,et al.Gas lubrication analysis method of step-dimpled face mechanical seals[J].ASME Journal of Tribology,2012,134(1):011702-1-9.
[16]Bai Shaoxian,Wen Shizhu.Gas thermo-hydrodynamic lubrication and seals[M].Beijing:Tsinghua University Press,2016(in Chinese)[白少先,温诗铸.气体热动力润滑与密封[M].北京:清华大学出版社,2016].
[2]Xie Jing,Bai Shaoxian.Hydrodynamic characteristics of gas upstream pumping face seals texturing with inclined-ellipsedimples[J].Tribology,2017,37(2):233-239(in Chinese)[谢静,白少先.倾斜椭圆孔端面上游泵送气体密封流体动压特性[J].摩擦学学报,2017,37(2):233-239].doi:10.16078/j.tribology.2017.02.013.
[3]Salant R F,Hoiller S J.The effect of shallow groove patterns on mechanical seal leakage[J].Tribology Transactions,1992,35(1):142-148.doi:10.1080/10402009208982101.
[4]Salant R F,Hoiller S J.Stiffness and leakage in spiral groove upstream pumping mechanical seals[J].Tribology Transactions,1993,36(1):55-60.doi:10.1080/10402009308983132.
[5]Ding Xuexing,Lu Junjie,Zhang Weizheng,et al.Comparison between two optimized groove configuration and their performance for upstream pumping mechanical seal[J].Journal of Lanzhou University of Technology,2015,41(6):74-78(in Chinese)[丁雪兴,陆俊杰,张伟政,等.上游泵送机械密封两种优化槽形及性能的对比[J].兰州理工大学学报,2015,41(6):74-78].doi:10.3969/j.issn.1673-5196.2015.06.015.
[6]Li Guiyong,Hao Muming,Yan Mingqiang,et al.Numerical computations of the seal performance of upstream pumping mechanical seals with spiral grooves[J].Lubrication Engineering,2010,35(9):56-59(in Chinese)[李贵勇,郝木明,闫明强,等.螺旋槽上游泵送机械密封密封特性数值计算[J].润滑与密封,2010,35(9):56-59].doi:10.3969/j.issn.0254-0150.2010.09.013.
[7]Lai T.Development of non-contacting,non-leaking spiral groove liquid face seals[J].Lubrication Engineering,1994,50(8):625-631.
[8]Song Pengyun.An analysis of factors affecting the characteristics of a upstream pumping mechanical seal[J].Lubrication Engineering,2000,(3):50-55(in Chinese)[宋鹏云.螺旋槽上游泵送机械密封性能影响因素分析[J].润滑与密封,2000,(3):50-55].doi:10.3969/j.issn.0254-0150.2000.03.021.
[9]Wang Q,Chen H L,Liu T.Research on performance of upstream pumping mechanical seal with different deep spiral groove[J].Earth and Environmental Science,2013,15:072019.
[10]Song Pengyun,Chen Kuangmin,Dong Zongyu,et al.A theoretical analysis of spiral groove upstream pumping mechanical seal[J].Lubrication Engineering,1999,(4):5-7(in Chinese)[宋鹏云,陈匡民,董宗玉,等.螺旋槽上游泵送机械密封性能的解析计算[J].润滑与密封,1999,(4):5-7].
[11]Bai S X,Peng X D,Li J Y,et al.Experimental study on hydrodynamic effect of orientation micro-pored surfaces[J].Science China,Technological Sciences,2011,54(3):659-662.doi:10.1007/s11431-010-4265-0.
[12]Bai L Q,Bai S X.Frictional performance of a textured surface with elliptical dimples:geometric and distribution effects[J].STLETribology Transactions,2014,57:1122-1128.doi:10.1080/10402004.2014.939317.
[13]Zhang J Y,Meng Y G.Direct observation of cavitation phenomenon and hydrodynamic lubrication analysis of textured surfaces[J].Tribology Letters,2012,46(2):147-158.doi:10.1007/s11249-012-9935-6.
[14]Payvar P,Salant R F.A computational method for cavitation in a wavy mechanical seal[J].Journal of Tribology,1992,114(1):199-204.doi:10.1115/1.2920861.
[15]Bai S X,Peng X D,Li Y F,et al.Gas lubrication analysis method of step-dimpled face mechanical seals[J].ASME Journal of Tribology,2012,134(1):011702-1-9.
[16]Bai Shaoxian,Wen Shizhu.Gas thermo-hydrodynamic lubrication and seals[M].Beijing:Tsinghua University Press,2016(in Chinese)[白少先,温诗铸.气体热动力润滑与密封[M].北京:清华大学出版社,2016].