Experimental study on the explosion characteristics of methylcyclohexane/toluene-air mixtures with methanol addition at elevated temperatures

Explosion characteristics of methylcyclohexane (MCH)-methanol- and toluene-methanol-air mixtures were investigated in a closed vessel at 0.1 MPa covering wide blending ratio range. The explosion hazard was evaluated by determining important explosion parameters. Comparisons were made between MCH- and toluene-air mixtures and the effects of methanol addition were identified. Results show that MCH-air yields approximate peak explosion pressure with toluene-air mixture but higher maximum rate of pressure rise. For the blend-air mixtures, the methanol addition exerts limited effect on the peak explosion pressure. For the maximum rate of pressure rise, the 20% methanol addition results in slight variation and further addition of methanol causes significant increase tendency. Regarding explosion phase parameters, toluene-air has longer explosion delay and burn period than MCH-air does. At the lean mixture side, the methanol addition generates slight decreases of explosion delay and burn period. At the rich mixture side, 20% methanol addition slightly extends the explosion delay and yields limited effect on the burn period. Further addition of methanol could significantly decrease the explosion delay and burn period simultaneously. Finally, the deflagration index was exponentially correlated with the explosion delay or burn period with the fitting constants listed.