Study On Propagation Law Of Gas Explosion And Explosion Venting Of Forward Chamber In Excavation Roadway

The gas explosion in this semi-enclosed space at the excavation roadway,due to space limitations,explosions temperature,explosion pressures,and explosion speeds,have caused much more damage and destruction than normal gas explosions.In order to study the propagation rule of gas explosion in excavation roadway and reduce the damage of explosion to roadway,based on the analysis of explosion theory,the article uses numerical simulation methods to establish the explosion model of excavation roadway.The overpressure propagation law and flame temperature law were studied under the condition of forward venting chamber and explosion venting wall.The overpressure,explosive impulse,pressure rise rate and temperature of each measuring point of the roadway are analyzed and compared,and the explosion venting effect is analyzed based on this.The simulation results show that during the propagation process,there are wall reflection,the reflection at the excavation roadway head and the reflection inside the forward venting chamber after breaking the explosion venting wall.Multiple reflection superposition leads to the oscillation of overpressure curve,after several ups and downs,it finally became stable,and there are more oscillations in the overpressure curve of the vent chamber and the explosion venting wall.The temperature of the flame slowly rises first,when the flame front reaches the measuring point,the temperature suddenly rises.Then,due to the uneven combustion at the outlet and the backflow of the gas,the temperature curve at the later stage shows a fluctuating state.After the flame turns into the roadway,the temperature drops.Obviously,it shows that the turning of the roadway hinders the spread of the flame.The overpressure reduction range is about 10%,the explosion impulse is about 8.5%,the maximum pressure rise rate is about 25%,which shows that the vent chamber has a certain relief effect.When the explosion venting pressure of the wall is 50 kPa,the explosion venting effect is the best,the reduction of overpressure is around 30%,and the decrease of explosive impulse is about 31%,and the maximum pressure rise rate is about 38%.Explosion vent chambers and vent walls with different venting pressures have little effect on the temperature of each measurement point in the roadway after a gas explosion.