International Journal of Hydrogen Energy, Vol.44, No.12, 6271-6277, 2019
On the explosion characteristics of hydrogen-air mixtures in a constant volume vessel with an orifice plate
In this study, we performed experiments in a cylinder vessel with a single orifice plate to study the explosion characteristics of hydrogen-air mixtures at room temperature (298K) and ambient pressure (1atm). The blockage ratio (BR) and position of the orifice plate were various. Explosion characteristics, i.e., maximum explosion pressure (P-max), combustion duration (theta) and maximum pressure rise rate ((dp/dt)(max)) were derived based on the pressure evolution. The results show that both the maximum explosion pressure and combustion duration are independent of the orifice plate. However, the effects of the orifice plate on the maximum rate of pressure rate are significant. Depending on the position and blockage ratio, the effects are different. The orifice plate acts as a heat sink when the distance between the orifice plate (S) is very close, making (dp/dt)(max) decrease (compared with that obtained without the orifice plate). The orifice plate acts as "turbulence-generator" as S increases; thus, (dp/dt)(max) increases. Further, the influences of the blockage ratio as well as laminar burning velocity on the maximum pressure rise rate are also analyzed. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.