Effect of the equivalence ratio on the effectiveness of inhibition of laminar premixed hydrogen-air and hydrocarbon-air flames by trimethylphosphate

This paper reports results of an experimental study and numerical simulation of the effect of the equivalence ratio ($\varphi$ = 0.6–1.6) on the burning velocity of laminar, premixed atmospheric methane-air and propane-air flames without additives and with 0.06% trimethylphosphate (TMP). The effect of the equivalence ratio ($\varphi$ = 0.7–4.5) on the burning velocity of hydrogen-air flames without additives and with 0.1% TMP was studied by simulation. The experimental and simulation results show that, in hydrocarbon flames doped with TMP, the inhibition effectiveness decreases sharply with a growth in $\varphi$ from 1.2–1.3 to 1.4–1.6 and in hydrogen-air flames, the inhibition effectiveness increases with a rise in $\varphi$ from 1.5 to 4.5. The reactions determining the dependence of the inhibition effectiveness on the equivalence ratio were found by analyzing the flame velocity sensitivity coefficients to changes in reaction rate constants.