Investigating the explosive characteristics of hydrogen/ n-butane blended fuel: Experimental and kinetic insights

Investigating the explosive characteristics of H₂/n-C₄H₁₀ mixtures is crucial for the safe utilization of this blended fuel. Our study focused on varying equivalent ratios and hydrogen blending ratios within a closed 20-L spherical explosion vessel. Additionally, the microscopic kinetics of the reactions were analyzed through chemical reaction simulation. Our findings indicate that the most violent explosion occurred at an equivalent ratio of 1.2. Increasing hydrogen content intensified combustion reactions, reducing flame thickness and inducing cellular structures along the flame front. This escalation also increased explosion pressure, flame temperature, and flame propagation speed, elevating explosion risk. Moreover, the equilibrium molar fraction of O₂ and CO₂ decreased while that of H₂O increased with higher hydrogen blending ratios. Correspondingly, the heat release rate and generation rates of H•, O•, and OH• radicals increased. Notably, the peak time of C₂H₄ and CH₄ consumption rates preceded. Additionally, R5: O₂ + H• = O• + OH• and R978: C₄H₁₀ + H• = SC₄H₉ + H₂ represented crucial promoting and inhibiting steps, respectively. These insights deepen our understanding of the explosion mechanism of H₂/n-C₄H₁₀ mixtures, providing a theoretical basis for designing safer protective measures and evaluating explosion risks in industrial production.