基于弹塑性接触和渗流模型的静密封泄漏计算  

Evaluation of leakage rates of static seals based on elastic-plastic contact theories and seepage theories

作　　者：李顺洋 万力[1] 桂南[1] 杨星团[1] 屠基元[2] 姜胜耀[1] LI Shunyang;WAN Li;GUI Nan;YANG Xingtuan;TU Jiyuan;JIANG Shengyao(Institute of Nuclear and New Energy Technology,Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education,Tsinghua University,Beijing 100084,China;School of Engineering,Royal Melbourne Institute of Technology University,Melbourne VIC 3083,Australia)

机构地区：[1]清华大学核能与新能源研究院,先进反应堆工程与安全教育部重点实验室,北京100084 [2]澳大利亚皇家墨尔本理工大学工学院,澳大利亚墨尔本VIC3083

出　　处：《清华大学学报（自然科学版）》2023年第8期1264-1272,共9页Journal of Tsinghua University(Science and Technology)

基　　金：国家科技重大专项(2011ZX06901-003)。

摘　　要：针对核电厂静密封泄漏率的计算,该文使用弹塑性接触理论构建了密封界面的泄漏通道模型,使用渗流理论计算泄漏通道的泄漏率。研究了载荷、密封表面形貌参数对泄漏通道的孔隙、渗流特征的影响。计算结果表明:随着静密封所受载荷不断增加,静密封界面间泄漏通道的孔隙率、渗透率不断减小,使泄漏率持续减小。在不同载荷水平下,泄漏率减小的趋势也不同。密封面的表面形貌影响密封面抵抗变形的能力,在材料属性不变的前提下,塑性指数较高的密封面会对密封产生不利影响。泄漏通道呈现自相似特征,因此可以通过泄漏通道的孔隙率推测其渗透率。[Objective] The unintended leakage that occurs on the interface between the static seal and the flange leads to potential environmental pollution,economic loss,and safety accidents.The evaluation of leakage rates is a major concern in the industrial field.However,due to the problem's complexity,the leakage rates are usually calculated by a simplified or equivalent model,which deviates from the actual state of static seals.[Methods]In this study,a semi-analytical model is proposed to evaluate the leakage rates for static seals using the contacting model and seepage theory.The leakage rate is expressed as a function of working conditions,fluid properties,and leakage channel permeability.Working conditions,such as fluid pressure and fluid properties,including viscosity,are input parameters,while permeability needs to be inferred.Therefore,the deformation of asperities on the surfaces of static seals is calculated in advance by the elastic-plastic contact model.The porosity and permeability are calculated afterward.Several assumptions are made to simplify the calculations.First,the contacting process between the flange and the static seal is equivalent to the process of a rigid and rough surface.The distribution of asperity heights is then described using a Gaussian function,which is suitable for common materials.Finally,the leakage channel is assumed to be self-similar since the observation scale is much smaller than the characteristic scale of leakage channels.This assumption enables the relationship between permeability to porosity to be expressed explicitly.[Results]The deformation of asperities under different loads was investigated using this model.It was shown that the reduction of the dimensionless height of the leakage channel results in a lower porosity,and a larger load was required.During this process,the portion of the asperities subjected to plastic deformation also increased.The porosity of the leakage channel decreased rapidly under a lower load.However,the porosity decreased at a slower rate as the l

关 键 词：静密封 弹塑性接触理论 多孔介质 泄漏率 

分 类 号：TH136[机械工程—机械制造及自动化]