液膜密封非定常工况下的瞬态特性

doi:10.11949/j.issn.0438-1157.20170817

摘要/Abstract

摘要：

运行工况的瞬时变化严重影响密封性能。利用Matlab建立密封环端面间隙液膜三维模型，采用有限差分法离散基于JFO空化边界条件的雷诺方程，应用SOR迭代求解液膜压力分布，进一步耦合求解雷诺方程与瞬态动力学方程，分析工况连续变化及压力扰动对密封瞬态特性的影响。结果表明：相比于转速瞬时变化，压力瞬时变化过程中挤压效应对密封性能的影响更为显著，密封端面趋近速度越大，由液膜挤压产生的承载能力越高，端面流体被排出的速度越大；压力瞬时变化易引发静环轴向速度振荡，压差越大，振荡幅值越大；压力扰动情况下，空化率与泄漏量急剧突变后趋于稳定，压力突升相比于压力突降更易恢复稳定状态；摩擦扭矩在变工况过程中平稳变化，无较大幅度波动。

关键词: 液膜密封, 非定常工况, 瞬态性能, 动力学分析

Abstract:

Transient change of the operating parameters has a serious influence on the stability of liquid film seals. Three-dimensional model of sealing clearance was established based on Matlab. Reynolds equation considering JFO cavitation boundary was discretized by finite difference method. SOR iteration was used to solve fluid film pressure distribution. By further solved coupled Reynolds equation and transient dynamic equations, the influence of continuous change of working conditions and pressure disturbance on transient characteristics were analyzed. The results show that squeeze effect of liquid film during transient change of pressure has more significant influence on sealing performance than speed change. The faster approach speed of seal face, the higher carrying capacity of liquid film extrusion and the greater the velocity of the discharge of the end face fluid. Instantaneous change of pressure easily leads to the axial velocity oscillation of stator ring. The greater the pressure difference, the greater shock amplitude. Leakage rate and cavitation ratio has a large disturbance tends to be stable after abrupt mutation in the case of differential pressure disturbance. Pressure rise compared to pressure drop is more easily to restore stable state. Friction torque varies smoothly during the condition changing without significant fluctuation.

Key words: liquid film seals, unsteady condition, transient performance, kinetic analysis

中图分类号:

TH136

徐鲁帅, 郝木明, 李勇凡, 杨文静, 王赟磊, 曹恒超. 液膜密封非定常工况下的瞬态特性[J]. 化工学报, 2018, 69(4): 1547-1557.

XU Lushuai, HAO Muming, LI Yongfan, YANG Wenjing, WANG Yunlei, CAO Hengchao. Transient characteristics of liquid film seals under unsteady conditions[J]. CIESC Journal, 2018, 69(4): 1547-1557.

参考文献 31

[1]	郝木明, 庄媛, 章大海, 等. 考虑空化效应的螺旋槽液膜密封特性数值研究[J]. 中国石油大学学报(自然科学版), 2015, 39(3):132-137. HAO M M, ZHUANG Y, ZHANG D H, et al. Numerical study on sealing performance of spiral groove liquid film seal considering effects of cavitation[J]. Journal of China University of Petroleum (Edition of Natural Science), 2015, 39(3):132-137.
[2]	LEBECK A O. Principles and Design of Mechanical Face Seals[M]. New York:John Wiley & Sons Inc., 1991:360-370.
[3]	BUCK G S, VODEN D. Upstream pumping:a new concept in mechanical sealing technology[J]. Lubrication Engineering, 1990, 46(4):213-217.
[4]	顾永泉. 机械端面密封[M]. 东营:石油大学出版社, 1994:3-8. GU Y Q. Mechanical Face Seal[M]. Dongying:Petroleum University Press, 1994:3-8.
[5]	李振涛, 郝木明, 杨文静, 等. 波度和锥度对液体润滑机械密封空化特性影响[J]. 化工学报, 2016, 67(5):2005-2014. LI Z T, HAO M M, YANG W J, et al. Effects of waviness and taper on cavitation characteristics of liquid lubricated mechanical seals[J]. CIESC Journal, 2016, 67(5):2005-2014.
[6]	陈汇龙, 吴强波, 左木子, 等. 机械密封端面液膜空化的研究进展[J]. 排灌机械工程学报, 2015, 33(2):138-144. CHEN H L, WU Q B, ZUO M Z, et al. Overview on liquid film cavitation in mechanical seal faces[J]. Journal of Drainage and Irrigation Machinery Engineering, 2015, 33(2):138-144.
[7]	PENG X D, XIE Y B, GU Y Q. Evaluation of mechanical face seals operating with hydrocarbon mixtures[J]. Tribology International, 2003, 36(36):199-204.
[8]	孟祥铠, 彭旭东, 王乐勤. 瞬态启停机械密封轴对称动力学模型与密封行为分析[J]. 化工学报, 2011, 62(6):1620-1625. MENG X K, PENG X D, WANG L Q. Axisymmetric dynamic model and seal behavior analysis of mechanical seals during startup and shutdown operation[J]. CIESC Journal, 2011, 62(6):1620-1625.
[9]	赵一民, 胡纪滨, 吴维, 等. 螺旋槽旋转密封环润滑状态转变预测[J]. 机械工程学报, 2013, 49(9):75-80. ZHAO Y M, HU J B, WU W, et al. Prediction of lubrication condition transition for spiral groove rotary seal rings[J]. Journal of Mechanical Engineering, 2013, 49(9):75-80.
[10]	张国渊, 袁小阳, 赵伟刚, 等. 螺旋槽端面密封脱开转速的理论及试验[J]. 机械工程学报, 2008, 44(8):55-60. ZHANG G Y, YUAN X Y, ZHAO W G, et al. Theoretical and experimental approach of separation speed of spiral groove face seals[J]. Journal of Mechanical Engineering, 2008, 44(8):55-60.
[11]	BO R. Numerical modeling of dynamic sealing behaviors of spiral groove gas face seals[J]. Journal of Tribology, 2002, 124(1):186-195.
[12]	MILLER B A, WOODRUFF G W. Numerical formulation for the dynamic analysis of spiral-grooved gas face seals[J]. Journal of Tribology, 2001, 123(2):395-403.
[13]	BLASIAK S, ZAHORULKO A V. A parametric and dynamic analysis of non-contacting gas face seals with modified surfaces[J]. Tribology International, 2016, 94:126-137.
[14]	HARP S R, SALANT R F. Analysis of mechanical seal behavior during transient operation[J]. Journal of Tribology, 1998, 120(2):191-197.
[15]	SALANT R F, CAO B. Unsteady analysis of a mechanical seal using Duhamel's method[J]. Journal of Tribology, 2005, 127(3):1017-1023.
[16]	GREEN I, BARNSBY R M. A parametric analysis of the transient forced response of non-contacting coned-face gas seals[J]. Journal of Tribology, 2002, 124(1):9-16.
[17]	刘录, 张学忠. 变工况条件下机械密封端面稳定性实验研究[J]. 润滑与密封, 2009, 34(4):64-66. LIU L, ZHANG X Z. Experimental study of mechanical seal face stability in changing conditions[J]. Lubrication Engineering, 2009, 34(4):64-66.
[18]	ZHAO Y M, YUAN S H, HU J B, et al. Nonlinear dynamic analysis of rotary seal ring considering creep rotation[J]. Tribology International, 2015, 82:101-109.
[19]	陈汇龙, 付杰, 李述林, 等. 螺旋槽上游泵送机械密封端面间液膜压力脉动特性[J]. 排灌机械工程学报, 2015, (6):504-509. CHEN H L, FU J, LI S L, et al. Pressure fluctuation characteristic of mechanical sealing clearance of spiral groove in upstream pumping[J]. Journal of Drainage and Irrigation Machinery Engineering, 2015, (6):504-509.
[20]	VARENY P, GREEN I. Impact phenomena in non-contacting mechanical face seals[J]. Journal of Tribology, 2016, 139(2):197-231.
[21]	胡松涛, 黄伟峰, 刘向锋, 等. 螺旋槽干气密封压差扰动下的瞬态特性研究[J]. 流体机械, 2017, 45(2):22-27. HU S T, HUANG W F, LIU X F, et al. Transient response analysis of spiral groove gas face seal under pressure-drop fluctuation[J]. Fluid Machinery, 2017, 45(2):22-27.
[22]	郝木明, 胡丹梅, 郭洁. 新型上游泵送机械密封的性能研究[J]. 化工机械, 2001, 28(1):12-15. HAO M M. HU D M, GUO J. Performance study of the new upstream pumping mechanical seal[J]. Chemical Machinery, 2001, 28(1):12-15.
[23]	顾永泉. 流体动密封[M]. 东营:石油大学出版社, 1990. GU Y Q. Fluid Dynamic Seal[M]. Dongying:Petroleum University Press, 1990.
[24]	郝木明, 李振涛, 任宝杰, 等. 机械密封技术及应用[M]. 2版. 北京:中国石化出版社, 2014:76-78. HAO M M, LI Z T, REN B J. et al. Mechanical Seal Technology and Application[M]. 2nd ed. Beijing:China Petrochemical Press, 2014:76-78.
[25]	RUAN B, SALANT R F, GREEN I. A mixed lubrication model of liquid/gas mechanical face seals[J]. Tribology Transactions, 1997, 40(4):647-657.
[26]	赵一民, 苑士华, 胡纪滨, 等. 基于质量守恒边界条件的螺旋槽旋转密封性能分析[J]. 机械工程学报, 2014, 50(22):142-149. ZHAO Y M, YUAN S H, HU J B, et al. Performance analysis of spiral-groove rotary seals considering mass conserving boundary condition[J]. Journal of Mechanical Engineering, 2014, 50(22):142-149.
[27]	佘宝瑛, 彭旭东, 孟祥铠, 等. 不同形状方向性型孔液体润滑端面密封性能对比[J]. 化工学报, 2014, 65(6):2202-2210. SHE B Y, PENG X D, MENG X K, et al. Comparison on seal performance of liquid-lubricated end face seals with different shapes inclined dimples[J]. CIESC Journal, 2014, 65(6):2202-2210.
[28]	徐华, 朱均. 螺旋槽式液体机械密封的动力学性能分析[J]. 西安交通大学学报, 2004, 38(5):474-478. XU H, ZHU J. Analysis of dynamic performance of spiral seals for liquid[J]. Journal of Xi'an Jiaotong University, 2004, 38(5):474-478.
[29]	GREEN I, BARNSBY R M. A simultaneous numerical solution for the lubrication and dynamic stability of non-contacting gas face seals[J]. Journal of Tribology, 2001, 123(2):388-394.
[30]	丁雪兴, 张伟政, 俞树荣, 等. 螺旋槽干气密封系统非线性动力学行为分析[J]. 中国机械工程, 2010, (9):1083-1087. DING X X, ZHANG W Z, YU S R, et al. Nonlinear dynamics behavior analysis of a spiral grooved gas seal system[J]. China Mechanical Engineering. 2010, (9):1083-1087.
[31]	HEATH M T. Scientific Computing:An Introductory Survey[M]. New York:McGraw-Hill Higher Education, 1997.