Research on consequence parameter evaluation of gas leakage in typical scenarios of long distance pipeline

Hydrogen as a renewable energy has been developing in recent years. Natural gas doped with hydrogen is often burned at a distance following leaking. It is a low-equivalent combustion with flame characteristics and explosion hazards different from those of complete combustion. The problem is solved by configuring a real multi-component natural gas and using experimentation to determine the characterization parameters of flame characteristics and explosion hazard for natural gas/H2/air. Results show that as the equivalency ratio increases, laminar burning velocity (LBV) decreases from 0.33 to 0.61 m/s to 0.10–0.16 m/s. As the hydrogen content (η) rises, the LBV increases from 0.10 m/s∼0.33 m/s to 0.16 m/s∼0.61 m/s. Low-equivalent conditions cause the Lewis number and flame thickness to increase. There is a reduction in hydrodynamic and thermal diffusion instability. Flame stability increases as the number of surface cracks decreases. As η increases, the instability of hydrodynamics and thermal diffusion are both amplified. The number of flame cracks grows abruptly. At low equivalence, the explosion hazard is reduced by 5 %–50 %. When η increases, it is enhanced by 30 %–200 %. The findings provide valuable guidance for the handling and disposal of emergencies, and transportation of hydrogen-doped natural gas.