Simulation of Hydrogen Distribution in Pipeline with Double Corrosion Defects
To deliever mixed natural gas and hydrogen with the existed natural gas pipelines is an important way to achieve efficient hydrogen transportation.However,corrosion defects present on these aged pipelines will affect the diffusion and enrichment of hydrogen atoms,potentially causing hydrogen embrittlement in the pipeline steel and further leading to the pipeline failure.In addition,corrosion defects on pipelines often exist in the form of adjacent double corrosion defects and even multiple corrosion de-fect groups.The interaction between adjacent defects can complicate the hydrogen diffusion and enrich-ment behavior,and ultimately affect the hydrogen induced failure behavior of the pipeline.In order to study the distribution of hydrogen concentration on pipelines containing double corrosion defects,a finite element model coupled with stress field and diffusion field was developed.The influence mechanism of corrosion defect length,defect spacing and applied tensile strain on hydrogen diffusion and enrichment behavior in steel was investigated in terms of the stress coupling behavior between the two corrosion de-fects.The results showed that the existence of corrosion defects caused the accumulation of hydrogen at-oms in steel,and the value and location of the maximum hydrogen concentration in accumulation area changed with tensile strain,defect length and defect spacing.However,when the distance between the two defects is large enough,they will not have a superposition effect on the hydrogen diffusion and en-richment,and thus they can be regarded as two independent defects.This study provides a theoretical reference for the safety assessment of hydrogen damage in hydrogen transmission pipelines with double corrosion defects.
double corrosion defectshydrogen distributionfinite element modelingX52 pipeline steel
郭诗雯、吴浩志、董绍华、陈林、程玉峰
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中国石油大学(北京)安全与海洋工程学院 北京 102249
中国石油大学(北京)应急管理部油气生产安全与应急技术重点实验室 北京 102249
Schulich School of Engineering,University of Calgary,Calgary T2N 1N4