液化天然气球罐安全评定研究

发布时间：2018-05-01 23:48

本文选题：球罐 + 安全评定　；参考：《河北科技大学》2017年硕士论文

【摘要】：本文以含缺陷液化天然气球罐作为研究对象,采用有限元方法开展应力强度因子分析工作,并依据国标GB/T19624-2004在用含缺陷压力容器安全评定编写了Matlab计算程序进行安全评定工作。选题具有一定的工程意义和应用价值,论文工作对于保障液化天然气球罐的安全具有一定的意义。以某内径为12m、壁厚为40mm、工作压力为1.6MPa的Q345R液化天然气球罐作为研究对象,采用有限元分析软件ANSYS建立三维模型,分析了裂纹尖端区域的应力分布状况。依据有限元分析结果采用“应力拟合法”得到了含裂纹结构的应力强度因子,通过与按照GB/T19624-2004计算得到的结果进行对比发现,有限元分析得到应力强度因子与按照标准计算得到的应力强度因子相差不超过10%,表明分析结果可靠。根据GB/T19624-2004规定的平面缺陷常规评定方法,针对含有表面半椭圆裂纹球罐和含有埋藏椭圆形裂纹球罐两种结构,分别采用标准推荐公式及有限元分析两种方法求得应力强度因子,并编写了相应的安全评定程序。采用安全评定程序分别对缺陷尺寸在4mm×4mm到32mm×320mm之间的球罐结构进行了安全评定。评定结果发现,对于含表面裂纹结构,当缺陷尺寸在32mm×128mm时,球罐依然能够满足强度要求;对于含有埋藏裂纹的球罐,当裂纹尺寸达到32mm×320mm时,结构依然满足强度要求。分析结果表明,相同缺陷尺寸时,含埋藏裂纹的球罐强度高于含有表面裂纹的球罐,埋藏裂纹的危险性小于表面裂纹。
[Abstract]:In this paper, using the finite element method (FEM) to carry out the stress intensity factor analysis of the spherical tank containing defective liquefied natural gas (LNG), and according to the national standard GB/T19624-2004, the safety assessment program of the pressure vessel containing defects has been compiled Matlab calculation program to carry out the safety assessment work. It has certain engineering significance and application value, and the work of this paper has certain significance to ensure the safety of LNG spherical tank. A Q345R liquefied natural gas spherical tank with an internal diameter of 12 m, a wall thickness of 40 mm and a working pressure of 1.6MPa was used as the research object. The finite element analysis software ANSYS was used to establish a three-dimensional model to analyze the stress distribution in the crack tip region. Based on the results of finite element analysis, the stress intensity factors of cracked structures are obtained by "stress fitting method". The results are compared with those obtained by GB/T19624-2004 calculation. The difference between the stress intensity factor obtained by finite element analysis and that obtained by standard calculation is not more than 10, which indicates that the analysis results are reliable. According to the conventional evaluation method of plane defects prescribed by GB/T19624-2004, the stress intensity factor is obtained by two kinds of structures: spherical tank with surface semi-elliptical crack and spherical tank with buried ellipse crack, respectively, by using two methods: standard recommended formula and finite element analysis. The corresponding safety assessment program is compiled. The structure of spherical tank with defect size between 4mm 脳 4mm and 32mm 脳 320mm was evaluated by safety assessment program. The results show that for the structure with surface crack, the spherical tank can still meet the strength requirements when the defect size is 32mm 脳 128mm, and for the spherical tank with buried cracks, when the crack size reaches 32mm 脳 320mm, the structure still meets the strength requirement. The results show that the strength of spherical tanks with buried cracks is higher than that of spherical tanks with surface cracks, and the danger of buried cracks is less than that of surface cracks.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE88

【参考文献】