氢环境中有轴向裂纹管道的承载能力评估

Bearing capacity assessment of pipeline with axial crack in hydrogen Environment

针对天然气输送工程中存在着管道的氢损伤问题，根据内聚力损伤模型，结合权函数方法，通过计算数学裂纹长度，提出了有轴向裂纹管道在内压和温差作用下及氢环境中承载能力的评估方法。分析表明，随着裂纹尖端氢浓度的增大，数学裂纹长度增大，管道的承载能力大大降低；裂纹的原始长度越大，管道的承载能力越低。因此，用管道输送天然气应尽量降低氢杂质（如硫化氢）的含量；在管道的生产和安装过程中应尽量控制其裂纹的长度，以提高管道在氢环境下的承载能力；若管道存在原始裂纹，应确定管道是否有足够的承载能力。

Hydrogen damage on pipeline occurs frequently in natural gas transportation engineering. On the basis of cohensive force degrading mechanism, by means of calculation of mathematical crack length with weight function method, the method for assessing tile bearing capacity of pipeline with axial cracks in hydrogen environment under the action of opera tion pressure and temperature difference is presented. Analysis shows that, with the increase of hydrogen concentration incrack tip, the cohensive force decreases and mathematical crack length enlarges, this results in the degrading of bearing capacity of the pipeline, and the longer the original cracks, the lower the bearing capacity. Therefore the content of hydrogen in natural gas should be reduced as low as possible and the length of cracks in pipelines should be controlled to improve the bearing capacity of the pipeline.