【作者】 戴维奇；

【导师】 蔡纪宁；

【作者基本信息】 北京化工大学 ， 化工过程机械， 2008， 硕士

【摘要】 目前流体动压式机械密封是密封技术中最活跃的领域,而关于流体静压式的研究相对较少,关于收敛间隙密封的研究更为欠缺。收敛间隙密封属于流体静压平衡、非接触式、液膜式轴向端面密封。收敛楔形间隙流体静压机械密封常被应用于核电站主泵机械密封的第一级密封。静压流体膜对摩擦副提供充分的润滑和冷却,使静压机械密封能在高速高压条件下运行。本文旨在通过建立与核电站主泵机械密封符合的三维收敛间隙机械密封的数学模型,对机械密封间隙流场进行数值模拟研究。通过GAMBIT软件建立了收敛楔形间隙机械密封流场的三维结构网格模型,基于有限体积法,采用流体力学软件FLUENT,对密封间隙中的液膜进行三维数值模拟。得到了密封端面间隙中液膜的压力和速度分布。分析端面各结构参数及操作参数对密封性能的影响。并计算得到启动及稳定工况下的工作膜厚及泄漏量。本文通过对流体静压式收敛间隙密封流场特性的研究,为密封的工程设计及应用提供理论支持,为以后的动态、力变形和热变形等研究打下理论基础。更多还原

【Abstract】 Hydrodynamic mechanical seal is the most active fields in modern sealing technology, while there are few studies on hydrostatic mechanical seal relatively, the study on convergent gap mechanical seal is hardly paid more attention to. Convergent gap mechanical seal belongs to controlled leakage, hydrostatic balanced, non-contact and liquid-film type face seal. It is often applied in the lower primary sealing assembly of the reactor coolant pump of the nuclear power plant. Hydrostatic liquid film makes the best lubrication and cooling of the friction pairs, so that, the hydrostatic mechanical seal can be operated under high pressure and high speed. By setting up three-dimensional numerical model of the radically tapered mechanical seal, which is agreed with the actual physical model, this paper carries out the numerical simulation of the flow field for the liquid film of the seal gap and makes ready for the further research later.A theoretical analysis model was developed for the flow in convergent gap mechanical seal by the software GAMBIT. This paper is on the basis of computational fluid dynamics, founded on the finite volume method (FVM), used the software FLUENT, a three-dimensional numerical simulation of the pressure-velocity coupling was preformed for the liquid film of the seal gap. The pressure and the velocity distributions of the liquid film were carried out. The effect of sealing structure parameters (width of sealing surface and cone angle) and operation parameters on sealing performance was analyzed. The gap and leakage in steady station and under a special condition were calculated.In a word, through deeply studying the flow field performances of hydrostatic convergent gap mechanical seal, this dissertation offers theoretical support for the engineering design and application of the reactor coolant pump mechanical seal. And a theoretical basis is made for the further study such as dynamic stability, mechanical and thermal deformations.更多还原