【作者】 于明彬；

【导师】 彭旭东； 白少先；

【作者基本信息】 浙江工业大学 ， 化工过程机械， 2010， 硕士

【摘要】 机械密封作为核主泵的关键部件,其性能和可靠性直接影响主泵的稳定和安全运行。深槽端面流体动压型机械密封是核主泵轴封常采用的主要密封类型之一。论文研究了高参数状态下机械密封的密封性能、磨损性能及其作用机理,该项研究对我国自主开发高性能的机械密封具有重要的理论意义和工程应用价值。首先,基于流体润滑理论,建立了圆弧深槽流体动压型机械密封的数学分析模型,采用有限元方法,分析了端面形貌几何参数对密封性能的影响规律,结果表明在不考虑变形时深槽机械密封动压效应较小,主要为静压效应;在泵启动过程且转速较小时,较浅槽机械密封的端面更容易打开。其次,建立了高参数下密封环压力变形的三维计算模型,引入弹压比参数作为变形影响分析的判断依据,对压力分布与表面变形耦合影响作了研究,结果表明,密封环的变形对密封性能影响明显,主要表现为增加了密封的刚度和刚漏比,有利于密封的稳定运行。最后,针对容易产生磨损的二级密封,结合U型槽端面密封的应用实例,建立了磨损端面机械密封性能分析模型,采用有限元计算了端面磨损形式对密封性能的影响规律,结果表明可以通过密封监测数据判断其磨损状态,进行预防性维护,从而避免紧急停堆带来的重大损失。更多还原

【Abstract】 As one of the key parts of a reactor coolant pump(RCP), mechanical seal can strongly influence the pump’s stability and security. A hydrodynamic face seal with deep grooves was usually used in a RCP. The sealing performance, wear behavior and principle of such a seal used at high pressure was studied in this thesis. The results are valuable to our country to develop independently such high-performance seals.First of all, the Reynolds equations was employed. Then a mathematical model was developed to analysis the performance of circular arc groove hydrodynamic mechanical seal, which based on lubrication theory. Then the finite element method(FEM) was used to solve the governing equations for circular arc deep groove hydrodynamic seal. It is suggested that the dynamic effect of deep groove mechanical seal is unobvious when the face’s deformations is neglected. The static effect, which is more obvious than shallow groove mechanical seal, will help to open the mechanical face when starting the pump and then the velocity is small.Secondly, three dimensional numerical model of mechanical seal was built to analysis the deformations of the seal rings, both stator and rotor. A parameter named the ratio of elastic modulus and pressure of outside surrounding was introduced as the criterion to analysis the effect of deformation. The coupling effect of pressure distribution and face deformations was studied. It is suggest that it is obviously different when take the deformation into account. The deformation, which can be divided into radial taper deformation and circumferential wave deformation, can increase the stiffness and the ratio of stiffness and leakage which is benefit for stability.Lastly, an abrasion model was developed to study the seal’s performance when it is wore. The leakage trend was calculated after wore. It is suggested that one can judge the seal condition by indicating the leakage rate, thus it can be managed previously to prevent urgent shutdown, which may involve great losses.更多还原