天然气管道在役焊接径向变形数值模拟

Numerical simulation on radial deformation of in-service welding gas pipeline

采用焊接模拟软件SYSWELD研究了压力及修复时间对天然气管道在役焊接径向变形的影响,并进行了试验验证.结果表明,在0~4 MPa压力范围内,径向变形量随压力的增大而增大,在4~6 MPa压力范围内,径向变形随着压力的增大而减小,并在6 MPa压力时近似等于常压焊接的变形量;随着焊接修复时间的增加,径向变形量逐渐增大,具有时间效应;预测焊接烧穿时,瞬时径向最大变形法优于内部点径向变形法.

The software SYSWELD was used to simulate how the internal pressure and the welding repair time affect the radial direction deformation of pipeline for the in-service welding The results of simulation was verified by the experiment. When the in-service welding was carried out in the pipeline with an internal pressure range of 0-4 MPa,the radial direction deformation increased with the increase of the pressure. When the internal pressure was in the range of 4-6 MPa,the deformation decreased with the increase of pressure. The deformation at the internal pressure of 6MPa was almost equally as that at that one at normal pressure. When the repair welding process progressed,the amount of deformation was gradually increased. In order to predict the occurrence of burned hole,the utilization of instantaneous radial deformation is better than using the radial deformation of the internal point.