Exploring the process safety aspects of converting existing natural gas pipelines for hydrogen transmission
Using pipelines to transport hydrogen is a relatively economical mid to long-distance hydrogen transmission option.Compared with the construction of new pure hydrogen pipelines or the option of having hydrogen blended into natural gas pipelines for transmission,the use of existing pipelines to transport hydrogen has the advantages of flexible utilization of pipeline assets,promoting efficient use of hydrogen energy,and improving energy substitution.In recent years,the actual operation of new hydrogen pipelines has been carried out both at home and abroad.However,comprehensive,large-scale research and the practice of converting existing natural gas pipelines to hydrogen transmission have not yet been carried out.Basing on the comparison of the characteristics of hydrogen and natural gas,this paper outlines the key technical points for evaluating conversion of existing pipelines for hydrogen transmission.It also analyzes and discusses operating pressure,transmission medium flow rate,safety assurance,and other process and safety issues.The study shows that the current international codes and standards have proposed a method to further improve the safety of pipelines by limiting the hoop stress for pipelines converted into hydrogen service,but this reduces the maximum operating pressure of the pipeline.Following the transition to hydrogen transmission,attention should be paid to issues such as impurity control and vortex-induced vibration of inserted instruments in the station.Once converted into hydrogen service,the potential impact range following a leak is reduced,but the evaluation and adjustment of the external fire protection separation distance of the station still need to be systematically demonstrated.With hydrogen as the new medium,the thermal radiation range of the pipeline vent and flare system is reduced,and the risk of deflagration and detonation of the vent and flare system should be controlled.The research results can provide reference for the subsequent evaluation of converting existing natural gas pipelines for hydrogen transmission.
HydrogenExisting natural gas pipelineConversion of transmission mediumProcess safetyDiscussion
万方数据
维普
