局部壁厚减薄CNG储气瓶应变分布与爆破压力研究  

Strain Distribution and Bursting Pressure of CNG Cylinder with Local Wall Thinning

作　　者：李丽锋 夏若琛 廖凯 许多林 柳磊 杜洋[2] 王维鑫 LI Lifeng;XIA Ruochen;LIAO Kai;XU Duolin;LIU Lei;DU Yang;WANG Weixin(State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials,CNPC Tubular Goods Research Institute,Xi′an,Shaanxi 710077,China;College of Mechanical and Electrical Engineering,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Shu′nan Gas-mine Field,PetroChina Southwest Oil&Gasfield Company,Luzhou,Sichuan 646000,China;PetroChina Yumen Oilfield Company Machine Plant,Jiuquan,Gansu 735200,China)

机构地区：[1]中国石油集团工程材料研究院有限公司,石油管材及装备材料服役行为与结构安全国家重点实验室,陕西西安710077 [2]中国石油大学(华东)机电工程学院,山东青岛266580 [3]中国石油西南油气田分公司蜀南气矿,四川泸州646000 [4]中国石油天然气股份有限公司玉门油田分公司机械厂,甘肃酒泉735200

出　　处：《石油管材与仪器》2023年第6期28-34,共7页Petroleum Tubular Goods & Instruments

基　　金：国家重点研发计划“典型危险化学品储存设施安全预警与防护一体化关键技术研究与应用示范”(编号:2016YFC0801200);国家自然科学基金“基于率型损伤演化与流固耦合的内爆炸下管道裂纹动态扩展机理与预测研究”(编号:51805544)。

摘　　要：针对钢质压缩天然气(CNG)储气瓶因局部壁厚减薄而发生强度失效的问题,采用有限元方法结合材料真实本构关系和弧长法分析了CNG储气瓶的爆破压力和减薄区域的应力应变分布,并与现有经验公式的计算结果对比分析。结果表明,随内压升高,减薄区域中心外壁面处首先发生塑性变形,而后塑性区不断向周围扩展;临近爆破压力时,减薄区塑性应变迅速增长,且最大塑性应变由外壁面向壁厚中心处移动;随着减薄深度增加,CNG储气瓶爆破压力下降幅度逐渐增加;对于局部减薄容器爆破压力的计算,经验公式相比有限元法的结果均偏保守,GB/T 19624标准与有限元法的预测结果较为接近。In view of the strength failure of compressed natural gas(CNG)cylinder due to local wall thinning,the stress and strain distribution in the thinned area and the blasting pressure of CNG cylinder are analyzed by using finite element method combined with the real constitutive relation of materials and arc length method,and the results are compared with those of existing empirical formulas.The results show that with the increase of internal pressure,the plastic deformation occurs at the center of the thinning zone,and then the plastic zone expands to the surrounding area.When the bursting pressure is about to be reached,the plastic strain in the thinning zone increases rapidly and the maximum plastic strain moves from the outer wall to the center of the thickness.With the increasing of thinning depth,the decreasing range of bursting pressure of CNG storage cylinder increases gradually.For the calculation of blursting pressure in locally reduced vessels,the empirical formula is more conservative than that of the finite element method,and the prediction results of GB/T 19624 standard and the finite element method are close to each other.

关 键 词：CNG储气瓶 局部减薄 有限元分析 应变分析 爆破压力 

分 类 号：TE972[石油与天然气工程—石油机械设备]