【作者】 李骏；

【导师】 黄晓明；

【作者基本信息】 华中科技大学 ， 工程热物理， 2016， 硕士

【摘要】 近些年来,随着现代工业、农业和科学技术的迅速发展,人们对静密封装置的性能要求越来越高。闸门作为典型的贯穿件,通常是安全壳当中受力薄弱的环节,保持闸门密封结构的完整性可以避免发生灾难事故。螺栓-法兰-垫片结构是闸门最为典型的密封装置,该装置的密封性能研究非常重要。本文在基于紧密度理论的基础上对该密封结构做了泄漏率影响因素分析,然后提出了基于渗流理论的微观泄漏机理模型,结合有限元方法给出了针对该密封结构一套完整的泄漏率分析方案。为了评价该密封结构泄漏率各因素的影响程度,本文在紧密度设计方法基础上,采用正交试验法分析了四个主要因素对泄漏率的影响程度,获得了各因素耦合作用下的最优化搭配。结果表明,垫片宽度和介质压力对密封结构泄漏率的影响最大。由于该理论分析的局限性,本文应用基于多孔渗漏理论和Hertz接触理论而提出的静密封界面微观泄漏机理模型对圆形闸门的密封特性进行了定量分析。采用有限元软件对闸门密封元件进行力学分析,获得不同载荷条件下的平均接触应力和实际接触宽度,然后代入泄漏机理模型,最终获得泄漏率随载荷的变化。该方法有效耦合了微观细致结构和宏观力学特性对闸门泄漏率的影响,且不包含任何实验回归系数,可以实现对各种密封结构的理论预测。本文模型及研究方法不仅能应用于本文所提到的闸门密封结构,也能用于类似隔离阀、球阀、电气贯穿件等密封结构的密封泄漏分析。该泄漏预测模型具有应用前景广泛,适用性强,预测准确的特点,值得推广。更多还原

【Abstract】 In recent years, with the rapid development of modern industry, agriculture and science technology, people request on the performance of the static sealing device more strictly. As the typical sealing part, the gate is usually the weakest link in the security shell, To maintain the integrity of the gate sealing structure can avoid the occurrence of disaster. Bolt-flange-gasket structure is the most typical sealing device of the gate. It is of importance to study the sealing performance of this device. In the paper, based on the tightness theory, evaluation of influence factors of sealing structure leakage has been made, then, new leakage rate prediction model based on porous media seepage theory has been proposed. Combined with the finite element method, a complete set of leakage rate analysis scheme for this seal structure was presented.In order to evaluate the influence factors of sealing structure leakage, an analysis and comparison of the major influence factors of sealing structure leakage was made based on the tightness analysis method. By analyzing the influence of four main factors on leakage rate, the optimization collocation of the main factors was achieved through the orthogonal experiment method. The results showed that width of the gasket and the Medium pressure are relatively obvious impact on the leakage.Due to the limitations of the theoretical analysis, based on the new leakage rate prediction model proposed by the combination of porous media seepage theory and Hertz contact theory, quantitative analysis of sealing performance of circular gate was made. The main method to get the variation law of leakage rate with load was to combine leakage rate prediction model with mechanical analysis of gate sealing elements through the finite element way. the contact mean stress and actual contact width under different loads was brought into the model. The method could make a coupling analysis of the influence of interface microscopic structure and material mechanical behaviors. Finally, the leakage rate could be calculated independent with any experimental data.The model and method can not only be applied to the gate seal structure mentioned in this paper, but also can be used for the seal leakage analysis of the seal structure such as the isolation valve, ball valve and electric penetration piece. The prediction model has the characteristics of wide application prospect, strong applicability, accurate prediction, and it is worth popularizing.更多还原