核主泵用镶嵌式直线深槽流体动压型机械密封性能研究

发布时间：2018-04-06 21:41

本文选题：直线深槽　切入点：流体动压效应　出处：《浙江工业大学》2013年硕士论文

【摘要】：近期,国家为了治理环境污染、碳排放问题,提出了发展核电宏伟计划。在核电站中,核主泵用机械密封对核电安全生产起到重要的作用,而我国对这种机械密封不能够自主生产,且受到国外相关技术的封锁,因此严重影响了我国的核电发展计划和我国核电运行的整体安全性。本课题以国家“十二五”科技支撑计划为依托,在自主设计的核主泵用试验台和机械密封的基础上,对全尺寸的核主泵用镶嵌式直线深槽流体动压型机械密封(简称为MSL-MS)进行理论和试验的相关研究。核主泵用机械密封使用工况为高压、高温等苛刻条件,密封端面的压力变形对密封性能有较大影响。通过建立优化后的MSL-MS流、固耦合模型,研究密封性能的变化规律,并对所设计的单级MSL-MS进行了试验研究,主要研究内容和结论如下： 1)考虑润滑液膜空化和镶嵌配合等因素,采用有限元商业软件和自编有限差分程序,实现有限元软件和编写程序求得相关数据的相互调用,建立了完整的流、固耦合模型,分别求解密封环的变形方程和液膜的压力控制方程,为后期数值模拟仿真奠定了基础。 2)基于已建立的流、固耦合模型,研究了操作参数对密封性能的影响规律。结果表明,泄漏率随着压力的升高而增大,而摩擦系数随着压力的升高而减小。 3)研究了密封环组件和端面直线深槽的几何结构参数对端面变形和密封性能的影响。研究发现,影响端面锥度和波度几何尺寸的结构参数是相互独立的,即静环外径、静环辅助O型圈的位置、密封环镶嵌过盈量以及端面槽台比等参数是影响端面锥度的主要因素,而直线深槽的槽数和槽径比则主要影响端面的波度；给出了镶嵌环配合公差的推荐值,并建议为保持优良密封性端面槽数宜选为8-12个,槽径比不宜小于0.9553。 4)采用核主泵单级密封试验台,对MSL-MS分别进行静压试验、磨合前运转试验以及磨合后的运转试验,研究了操作参数变化对密封性能的影响,分析了运转后密封环的表面形貌。静压试验表明,泄漏率随着压力的升高而不断减小,磨合前后的动压试验表明,泄漏率随着压力的升高均是先增大后减小。本文通过理论和试验研究了MSL-MS的密封性能,初步掌握了高参数下深槽机械密封的设计方法,为以后开发核主泵用深槽机械密封的深度开发奠定了理论和试验基础。
[Abstract]:Recently, in order to control environmental pollution and carbon emissions, the state put forward a grand plan to develop nuclear power.In the nuclear power plant, the mechanical seal of the nuclear main pump plays an important role in the safe production of nuclear power, but the mechanical seal of our country cannot be produced independently, and is blocked by the relevant technology of foreign countries.Therefore, the nuclear power development plan and the overall safety of nuclear power operation in China are seriously affected.This subject is based on the national "12th Five-Year Plan" science and technology support plan, on the basis of the independently designed test bed and mechanical seal for the nuclear main pump.The theoretical and experimental research on the inlaid linear deep groove hydrodynamic mechanical seal (MSL-MSM) for the nuclear main pump is carried out in this paper.The working condition of mechanical seal for nuclear main pump is high pressure, high temperature and so on. The pressure deformation of seal face has great influence on sealing performance.Through the establishment of optimized MSL-MS flow and solid coupling model, the variation of seal performance is studied, and the experimental study of the single stage MSL-MS is carried out. The main research contents and conclusions are as follows:1) considering the factors of lubricating film cavitation and mosaic, the commercial finite element software and the finite difference program are used to realize the mutual transfer of the relevant data between the finite element software and the program, and a complete flow and solid coupling model is established.The deformation equations of the seal ring and the pressure control equations of the liquid film are solved respectively, which lays a foundation for the later numerical simulation.2) based on the established flow and solid coupling model, the effect of operation parameters on sealing performance is studied.The results show that the leakage rate increases with the increase of pressure and the friction coefficient decreases with the increase of pressure.3) the effect of geometric structure parameters of seal ring assembly and end face straight deep groove on the end face deformation and sealing performance is studied.It is found that the structural parameters that affect the geometric dimensions of the end taper and wavenumber are independent of each other, namely, the outer diameter of the static ring, the position of the auxiliary O-ring of the static ring,The inlay interference of seal ring and the ratio of the end face to the groove are the main factors affecting the taper of the end face, while the number of slots and the ratio of the groove to the diameter of the straight line deep groove mainly affect the waveness of the end face, and the recommended value of the tolerance of the inlaid ring matching is given.It is suggested that the number of slots should be chosen as 8-12 and the ratio of groove diameter should not be less than 0.9553in order to maintain good sealing performance.4) the static pressure test, running-in test and running-in test were carried out on the nuclear main pump single-stage sealing test rig. The influence of the operation parameters on the seal performance was studied, and the surface morphology of the seal ring after operation was analyzed.The static pressure test shows that the leakage rate decreases with the increase of pressure, and the dynamic pressure test before and after running-in shows that the leakage rate increases first and then decreases with the increase of pressure.In this paper, the sealing performance of MSL-MS is studied theoretically and experimentally, and the design method of deep groove mechanical seal under high parameters is preliminarily mastered, which lays a theoretical and experimental foundation for the further development of deep groove mechanical seal for nuclear main pump.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TH136

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