Explosion Pressure Characteristics of Coal Gas

Abstract

An experimental study was performed on pressure evolution during 20 L cylindrical vessel explosions of coal gas–air 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.

Keywords:

• Deflagration index
• Maximum explosion pressure
• Maximum rates of pressure rise
• Suppression

ACKNOWLEDGMENT

This work was supported by the National Natural Science Foundation of China (50674047, 50534090, 50574093, 51004048).