水蒸气润滑螺旋槽干气密封性能分析
|
摘要
水蒸气润滑干气密封是一类特殊的干气密封,端面的润滑气体为水蒸气。为了研究水蒸气润滑干气密封的性能,采用无限窄槽理论,并采用RK方程来表达水蒸气的实际气体的行为。对螺旋槽的气膜压力控制方程进行了修正,分析水蒸气润滑干气密封的开启力、气膜刚度、泄漏率、气膜摩擦力矩和热平衡气膜厚度。结果表明:低压时,泄漏率随膜厚增加先减小再增加,中高压时,泄漏率随膜厚增加而增加,实际气体行为对泄漏率的影响较大;摩擦力矩随膜厚增加而减小,实际气体行为对摩擦力矩无影响;当温度为300℃,压力为0.5 MPa时,在常见的工作膜厚范围内,剪切发热速率始终大于膨胀吸热速率,不能获得热量平衡膜厚,压力为2和5 MPa时,实际气体的热量平衡膜厚均小于理想气体,两者相差分别为0.886%和2.932%。
Steam-lubricated dry gas seal is a special kind of dry gas seal,and the lubricating gas is steam.To study the performance of steam-lubricated dry gas seals,the infinite-groove theory was used,and the RK equation was used to express the actual gas behavior of water vapor.The gas film pressure control equation of the spiral groove was modified to analyze the opening force,gas film stiffness,leakage rate,film friction torque and thermal equilibrium film thickness of the vapor-lubricated dry gas seal.The results show that the leakage rate is first decreased and then increased with the increasing of film thickness at low pressure,and is increased with the increasing of film thickness at medium and high pressure.The actual gas behavior has much influence on the leakage rate.The friction moment is decreased with the increasing of film thickness,and the actual gas behavior has no influence on the friction moment.When the temperature is 300 ℃,and the pressure is 0.5 MPa,within the scope of the common working film thickness,the shear heating rate is always greater than the expansion heat absorption rate,and the heat balance film thickness cannot been obtained.When the pressure is 2 MPa and 5 MPa,the heat equilibrium film thickness of the actual gas is less than that of the ideal gas,and the difference between them is 0.886% and 2.932%,respectively.
Steam-lubricated dry gas seal is a special kind of dry gas seal,and the lubricating gas is steam.To study the performance of steam-lubricated dry gas seals,the infinite-groove theory was used,and the RK equation was used to express the actual gas behavior of water vapor.The gas film pressure control equation of the spiral groove was modified to analyze the opening force,gas film stiffness,leakage rate,film friction torque and thermal equilibrium film thickness of the vapor-lubricated dry gas seal.The results show that the leakage rate is first decreased and then increased with the increasing of film thickness at low pressure,and is increased with the increasing of film thickness at medium and high pressure.The actual gas behavior has much influence on the leakage rate.The friction moment is decreased with the increasing of film thickness,and the actual gas behavior has no influence on the friction moment.When the temperature is 300 ℃,and the pressure is 0.5 MPa,within the scope of the common working film thickness,the shear heating rate is always greater than the expansion heat absorption rate,and the heat balance film thickness cannot been obtained.When the pressure is 2 MPa and 5 MPa,the heat equilibrium film thickness of the actual gas is less than that of the ideal gas,and the difference between them is 0.886% and 2.932%,respectively.
引文
[1]魏琳健,李春清,高雷,等.汽轮机密封技术的应用和发展探究[J].热能动力工程,2005,20(5):455-458.WEI L J,LI C Q,GAO L,et al.Application and development of steam turbine sealing technologies[J].Journal of Engineering for Thermal Energy and Power,2005,20(5):455-458.
[2]曾宪平,任建兴.大型汽轮机汽封技术及其经济性分析[J].上海电力学院学报,2011,27(2):119-122.ZENG X P,REN J X.Large steam turbine steam seal technology and its economic analysis[J].Journal of Shanghai University of Electric Power,2011,27(2):119-122.
[3]布兰登工程公司.关于汽轮机汽封及其间隙的有关问题和最近发展的介绍[M].美国加利福尼亚洲:Brandon Engineering Inc,1998.
[4]JOHN CRANE.TYPE 28ST:non-contacting,steam turbine gas seal[OL].[2018-06-12].http://johncrane.chinaepu.com.
[5]宋鹏云.氢气实际气体对螺旋槽干气密封性能的影响[J].润滑与密封,2010,35(8):1-3.SONG P Y.Effects of the real-gas characteristics of the hydrogen on the performance of the spiral groove dry gas seal[J].Lubrication Engineering,2010,35(8):1-3.
[6]孙雪剑,宋鹏云.输送天然气离心式压缩机干气密封性能分析[J].排灌机械工程学报,2018,36(1):55-62.SUN X J,SONG P Y.Analysis on performance of dry gas seal in centrifugal compressor for transporting natural gas[J].Journal of Drainage and Irrigation Machinery Engineering,2018,36(1):55-62.
[7]宋鹏云,胡晓鹏,许恒杰.实际气体对T槽干气密封动态特性的影响[J].化工学报,2014,65(4):1344-1352.SONG P Y,HU X P,XU H J.Effect of real gas on dynamic performance of T-groove dry gas seal[J].CIESC Journal,2014,65(4):1344-1352.
[8]许静,彭旭东,白少先,等.气体热黏效应对干气密封性能影响的数值分析[J].上海交通大学学报,2012,46(5):722-728.XU J,PENG X D,BAI S X,et al.Numerical analysis of gas thermal viscosity effect on performance of a spiral-groove gas face seal[J].Journal of Shanghai Jiaotong University,2012,46(5):722-728.
[9]马方波.T槽气膜密封低速运转动态气膜力特性研究[D].昆明:昆明理工大学,2012.
[10]W瓦格纳,A克鲁泽.水和蒸汽的性质[M].北京:科学出版社,2003.
[11]陈钟秀,顾飞燕,胡望明.化工热力学[M].北京:化学工业出版社,2011:184-185.
[12]MUIJDERMAN E A.Spiral groove bearings[M].New York:Springer-Verlag,1966:17-21.
[13]宋黎明.大轴径干气密封国内外发展现状及国产化应用[J].化工设备与管道,2016,53(1):39-42.SONG L M.Current development of dry gas seal used with large diameter shaft at home and abroad and application in China[J].Process Equipment&Piping,2016,53(1):39-42.
[14]毛文元,宋鹏云,邓强国,等.螺旋槽底表面粗糙度对干气密封性能的影响[J].润滑与密封,2017,42(1):27-33.MAO W Y,SONG P Y,DENG Q G,et al.Influence of surface roughness of spiral groove bottom on dry gas seal performance[J].Lubrication Engineering,2017,42(1):27-33.
[15]宋鹏云,产文.螺旋槽干气密封端面摩擦力矩的简化计算[J].润滑与密封,2014,39(6):95-98.SONG P Y,CHAN W.A simplified calculation method of the interfacial frictional torque of spiral groove dry gas seal[J].Lubrication Engineering,2014,39(6):95-98.
[16]产文,宋鹏云.螺旋槽干气密封的热量平衡膜厚研究[J].润滑与密封,2015,40(4):5-8.CHAN W,SONG P Y.Research on heat equilibrium film thickness of spiral groove dry gas seal[J].Lubrication Engineering,2015,40(4):5-8.
[2]曾宪平,任建兴.大型汽轮机汽封技术及其经济性分析[J].上海电力学院学报,2011,27(2):119-122.ZENG X P,REN J X.Large steam turbine steam seal technology and its economic analysis[J].Journal of Shanghai University of Electric Power,2011,27(2):119-122.
[3]布兰登工程公司.关于汽轮机汽封及其间隙的有关问题和最近发展的介绍[M].美国加利福尼亚洲:Brandon Engineering Inc,1998.
[4]JOHN CRANE.TYPE 28ST:non-contacting,steam turbine gas seal[OL].[2018-06-12].http://johncrane.chinaepu.com.
[5]宋鹏云.氢气实际气体对螺旋槽干气密封性能的影响[J].润滑与密封,2010,35(8):1-3.SONG P Y.Effects of the real-gas characteristics of the hydrogen on the performance of the spiral groove dry gas seal[J].Lubrication Engineering,2010,35(8):1-3.
[6]孙雪剑,宋鹏云.输送天然气离心式压缩机干气密封性能分析[J].排灌机械工程学报,2018,36(1):55-62.SUN X J,SONG P Y.Analysis on performance of dry gas seal in centrifugal compressor for transporting natural gas[J].Journal of Drainage and Irrigation Machinery Engineering,2018,36(1):55-62.
[7]宋鹏云,胡晓鹏,许恒杰.实际气体对T槽干气密封动态特性的影响[J].化工学报,2014,65(4):1344-1352.SONG P Y,HU X P,XU H J.Effect of real gas on dynamic performance of T-groove dry gas seal[J].CIESC Journal,2014,65(4):1344-1352.
[8]许静,彭旭东,白少先,等.气体热黏效应对干气密封性能影响的数值分析[J].上海交通大学学报,2012,46(5):722-728.XU J,PENG X D,BAI S X,et al.Numerical analysis of gas thermal viscosity effect on performance of a spiral-groove gas face seal[J].Journal of Shanghai Jiaotong University,2012,46(5):722-728.
[9]马方波.T槽气膜密封低速运转动态气膜力特性研究[D].昆明:昆明理工大学,2012.
[10]W瓦格纳,A克鲁泽.水和蒸汽的性质[M].北京:科学出版社,2003.
[11]陈钟秀,顾飞燕,胡望明.化工热力学[M].北京:化学工业出版社,2011:184-185.
[12]MUIJDERMAN E A.Spiral groove bearings[M].New York:Springer-Verlag,1966:17-21.
[13]宋黎明.大轴径干气密封国内外发展现状及国产化应用[J].化工设备与管道,2016,53(1):39-42.SONG L M.Current development of dry gas seal used with large diameter shaft at home and abroad and application in China[J].Process Equipment&Piping,2016,53(1):39-42.
[14]毛文元,宋鹏云,邓强国,等.螺旋槽底表面粗糙度对干气密封性能的影响[J].润滑与密封,2017,42(1):27-33.MAO W Y,SONG P Y,DENG Q G,et al.Influence of surface roughness of spiral groove bottom on dry gas seal performance[J].Lubrication Engineering,2017,42(1):27-33.
[15]宋鹏云,产文.螺旋槽干气密封端面摩擦力矩的简化计算[J].润滑与密封,2014,39(6):95-98.SONG P Y,CHAN W.A simplified calculation method of the interfacial frictional torque of spiral groove dry gas seal[J].Lubrication Engineering,2014,39(6):95-98.
[16]产文,宋鹏云.螺旋槽干气密封的热量平衡膜厚研究[J].润滑与密封,2015,40(4):5-8.CHAN W,SONG P Y.Research on heat equilibrium film thickness of spiral groove dry gas seal[J].Lubrication Engineering,2015,40(4):5-8.