Explosion evolution characteristic of methane-acetylene mixtures under constant volume space.

To investigate the explosion pressure characteristics of methane-acetylene gas mixtures, explosion pressure evolution curves of methane-acetylene mixture gas under different equivalent ratio and doping ratio was obtained by using a 20L spherical explosion test system. The variation in intermediate reactions during the explosion process was studied through numerical simulation. Parameters such as peak reaction pressure (<italic>P</italic>max), maximum pressure rise rate <italic>(dp/dt)</italic>max, and combustion duration (<italic>t</italic>c) were obtained for the gas mixture to analyse the rates of production(ROP) and reaction pathways. The results show that the explosive process of the gas mixture becomes more intense with increasing acetylene volume fraction. Furthermore, according to the acetylene volume fraction of 35% and 80%, the premixed system is divided into three combustion stages: methane combustion stage (I), transition stage (II) and acetylene combustion stage (III). Chemical kinetics analysis based on the USC Mech 2.0 mechanism showed that the addition of acetylene accelerated reactant consumption time, significantly promoted O*-containing elementary reactions during the reaction process, shortened the number of reaction path levels of methane, and therefore promoted the forward progress of the mixed combustible gas reaction and enhanced the intensity of the reaction. The results of the phase division of methane-acetylene mixture gas are of great significance to the accidental explosion suppression of various kinds of leakage in industrial production. [ABSTRACT FROM AUTHOR]