Synergistic inhibition of methane/air explosions by NaHCO3 particles with a bimodal size distribution

Abstract

To reveal the inhibitory effect of stoichiometric methane/air explosions, NaHCO3 with a bimodal distribution were selected as inhibitors. A 5 L vertical transparent duct was used. All the results revealed that Blend82, whose mass fraction contained 80% OP500–600 and 20% OP200–220 NaHCO3, exhibited the optimal inhibitory effect. For the bimodal distribution of NaHCO3, assessing the inhibitory effect solely on the basis of a single particle size parameter is unreliable. Synergistic effects between particles of different sizes should be considered when the interaction index IS < 1. Multiple size classes of bimodal NaHCO3 were proposed for use in response surface methodology to predict the inhibitory effect of methane/air flames. Furthermore, we employed a detailed chemical kinetic model to quantify the endothermic and chemical effects of NaHCO3 on the laminar burning velocity of methane/air flames and established a good relationship between the explosion parameters and laminar flame properties.