Influence of equivalence ratio and H2 blended ratio on explosion propagation characteristics of DME/H2 blended gas in closed narrow space

Abstract

To reveal the explosion risk and propagation law of dimethyl ether (DME)/hydrogen (H2) blended gas, the explosion propagation characteristics of DME/H2 blended gas under different equivalence ratio (Φ) and hydrogen blended ratio (λ) was investigated based on experimental research and theoretical analysis. The results show that the peak overpressure (Pp), the peak pressure rise rate (dP/dt)p and the peak shock wave propagation velocity (Vp) show an increasing and then decreasing trend with the increase of Φ, and reach the maximum at Φ = 1.0. The effect of a little addition of H2 on the explosion hazards of blended gas is small, but when λ > 10%, the explosion hazards increase significantly. The magnitude of increase of Pp, (dP/dt)p and Vp is different with the increase of λ. Compared with the enhancement effect on Pp and (dP/dt)p, the enhancement effect on Vp is more obvious with the continuous blend of H2. Comprehensive analysis of the thermodynamic and chemical kinetic parameters of H2, the chemical kinetic parameters of H2 play a dominant role in the explosion risk of hydrogen-blended gases.