天然气站场三通不等壁厚连接结构优化

Optimization of unequal wall thickness connection structure of tee in natural gas station

针对当前工程应用最大三通规格P 12 MPa,DN1400 mm×1200 mm的X80钢级站场三通,提出扩大三通内径及传统三通采用新型孔锥型坡口两种与工艺管道等内径连接方案,采用弹塑性有限元分析方法,结合基于响应曲面的参数优化方法,确定三通等内径连接设计的最优方案为壁厚59 mm,内切坡口深度35 mm,实现了连接区域内无应力集中点。运用水压试验爆破方法验证了此结构的安全性,解决了大口径、高压力、高钢级、大壁厚差三通与工艺管道不等壁厚连接问题。此研究结果可为我国今后大口径天然气三通设计制造提供参考依据。

For the largest X80 steel tee for NG station with a specification P 12 MPa,DN1400 mm×1200 mm in current engineering application,two connection schemes of expanding the inner diameter of the tee and using a new hole cone groove for the traditional tee to connect with the process pipeline of equal inner diameter were proposed.The elastic-plastic finite element analysis method and the parameter optimization method based on response surface were used to determine the optimal scheme for connection design of the tee of equal inner diameter:wall thickness 59 mm,inner groove depth 35 mm,realizing no stress concentration point in the connection area.The safety of the structure was verified by hydraulic test bursting method,and the connection between tee with large diameter,high pressure,high steel grade and large wall thickness difference and process pipeline was solved.The research results can provide a reference for the design and manufacture of large-diameter natural gas tee in China in the future.