Calculation and analysis of potential impact radius for hydrogen-doped natural gas and hydrogen pipelines

The transmission of hydrogen through dedicated pipelines and the conveyance of hydrogen-doped natural gas via in-service gas pipelines are both effective methods for long-distance hydrogen transportation. To investigate and analyze the potentially hazardous consequences of ruptured hydrogen-doped natural gas and hydrogen pipelines, this study derived the calculation process for the release rate decay factor of these pipelines, as well as the calculation formula for the potential im pact radius (PIR) from the perspective of jet fire damage. The release rate decay factor and PIR coefficient were subse quently calculated and analyzed, considering various hydrogen blending ratios. The calculation results indicate that higher hy drogen blending ratios correspond to only minimal decreases in both the decay factor and the PIR coefficient. When the hydro gen blending ratio is below 10%, the coefficient of 0.099, as specified in GB 32167-2015, can be used to calculate the PIR of hydrogen-doped pipelines. Conversely, for blending ratios exceeding 10%, it is more rational to use the coefficients estab lished in this study for PIR calculations. Additionally, the release rate decay factor for hydrogen pipelines was calculated and analyzed across various pipeline diameters. The proposed derivation method is considered applicable for calculating the PIR of other multi-component lightweight combustible gas pipelines. Emphasis is placed on the need to verify the applicability of the resulting PIR formulas based on actual accident cases.