Numerical simulation on propagation characteristics of gas explosive shock waves in coalface tunnel network

To explore the propagation characteristics of shock waves in end-to-end tunnel network,the change laws of overpressure and temperature of gas explosive shock waves along intake airway and return airway were simulated by AutoReaGas.The results show that peak overpressure and maximum temperature decrease continuously as shock waves propagate in end-to-end tunnel network of coal face.The two face-to-face propagation shock waves can form superposition effect which makes the increase of peak overpressure.However,the two face-to-face propagation flame fronts can form inhibitory effect which makes the decrease of maximum temperature.The change law of maximum temperature along tunnel network is the same as peak overpressure before the midpoint of connection tunnel.Peak overpressures and maximum temperatures in corresponding points of intake and return airways are almost the same,and the propagation characteristics of shock waves are the same.Some relevant preventive measures can be taken to reduce the loss caused by gas explosion near the superposition positions where are destroyed seriously in underground coal mines.