A study on the leakage consequence and risk analysis of hydrogen-blended natural gas pipeline in different failure modes

To transport hydrogen-blended natural gas with existing natural gas pipelines is a flexible and economical reutilization, but the flammability and explosivity of hydrogen bring more safe uncertainty to natural gas pipeline. The consequences and risk in leakage and explosion accidents of hydrogen-blended natural gas pipeline in different failure modes are studied in this paper. Results show that the trend of horizontal diffusion distance in rupture mode changing with hydrogen blending ratio is opposite to that of crevice and hole mode. The radiation intensity of hole and rupture modes decreases rapidly and positively correlates with hydrogen blending ratio in the initial part of jet fire, and the lower radiation intensity and shorter radiation distance are observed in crevice mode. Finally, the potential impacts radius formulas in different modes are modified with wind speed and hydrogen blending ratio as independent variables for the convenient risk assessment.