Risk modelling of hydrogen-enriched natural gas on pipelines and gas-electric coupled systems

The use of natural gas pipeline networks to transmit hydrogen energy is an important form of hydrogen energy utilisation. The coupling of hydrogen-enriched natural gas pipeline network and power grid involves the energy conversion of electricity-hydrogen-electricity, so the assessment is crucial because the system is complex, and the hazards to the system can be identified. This paper proposes a risk assessment method for gas-electric coupling of hydrogen-enriched natural gas pipeline networks and a three-stage risk assessment model to assess the life cycle risk of natural gas pipelines; a material energy-based risk transfer model considering gas-electric coupling is proposed to describe the risk transfer process of hydrogen-enriched natural gas between the gas network and the grid. By comparing and analysing the risk of natural gas blending ratio to the pipeline and the risk of pipeline pressure to the pipeline, the validity of the model is verified, which provides safety support for the connection of the natural gas pipeline system to the grid and ensures the efficient use of hydrogen energy.