Explosion Pressure Characteristics of Coal Gas

An experimental study was performed on pressure evolution during 20L cylindrical vessel explosions of coal gasair mixtures in systems with various initial concentrations, temperatures, and pressures. The influence of initial pressure, temperatures, coal gas concentration, and inert gas on explosion pressures is discussed for some of the systems examined. A series of conclusions was reached: (1) In explosions of quiescent mixtures, the maximum explosion pressure and maximum rate of pressure rise are linear functions of total initial pressure at a constant initial temperature and fuel/oxygen ratio. (2) The maximum explosion pressure decreases inversely with a drop in initial temperature. (3) The maximum explosion pressure and the maximum rate of pressure rise reach maximum at approximately the stoichiometric concentration. These parameters tend to decrease if their concentration is lower or higher than the stoichiometric concentration. (4) The maximum explosion pressure and maximum rate of pressure rise are both inversely related to the addition of N-2. The experimental values are in good agreement with computed or relevant literature values.