焊接管道LBB分析中泄漏速率的研究  

Study on the leak rate of fluid in welded pipes in leak-before-break analysis

作　　者：王金生[1] 张玉凤[2] 霍立兴[2] 邓彩艳[2] 

机构地区：[1]海洋石油工程股份有限公司,天津300452 [2]天津大学材料科学与工程学院,天津300072

出　　处：《焊接技术》2007年第5期21-23,共3页Welding Technology

基　　金：国家自然科学基金资助项目(50375109)

摘　　要：先泄后断(LBB)技术已经广泛地应用于焊接压力容器及管道的设计中,该理论是指在压力容器和管道中的裂纹达到失稳状态以前,可以检测到通过该裂纹的流体的泄漏。使用计算机程序模拟了通过裂纹的流体泄漏速率;通过有限元分析程序Fluent,对简单情况下的单相流体在压力管道中裂纹不同张开方向上的泄漏速率进行模拟计算,并对其结果进行比较分析。得出泄漏速率与裂纹张开位移(COD)和裂纹长度的关系均不是线性关系,并且COD的扩展对泄漏速率的影响要大于裂纹长度对其的影响。因此,COD的扩展值是影响管道内流体泄漏速率的主要因素。The leak-before-break(LBB) concept has been widely applied to the design of welded pipes. When performing LBB deterministic analysis, it should be demonstrated that leak monitoring systems would be able to detect leaking before the crack reaches the critical size. This paper presents a computer model base on FLUENT to calculate the leak rate of one-phase fluid through a circumferential crack growing in two different directions. The analysis show that the leak rate is not a constant value in analytical codes but changing with crack opening displacement (COD), as well as crack length. And the influence of the COD value on the leak rate is greater than that of the crack length. So the COD value is a major parameter for the leak rate.

关 键 词：先泄后断 焊接管道 泄漏速率 FLUENT 

分 类 号：TG457.6[金属学及工艺—焊接]