Working face open type local inerting explosion suppression and fire extinguishing technology

The invention belongs to a safety production technology in the coal industry, and particularly relates to an open type local inerting explosion suppression and fire extinguishing technology for a working face of an underground coal mine. When a fire happens to the high-gas working face and the working face is forced to be closed, firstly, the working face is closed, air inlet sealing is conducted, then liquid nitrogen is vaporized into nitrogen through an emergency large-flow vaporizer of a mine, then a nitrogen conveying pipe network with the diameter larger than phi 350 mm is formed by a nitrogen injection pipe, a grouting pipe, an air pressing pipe and a water pipe which are led to the working face through the ground, and the nitrogen is conveyed to the underground. The large-flow nitrogen is injected into the air inlet seal, the oxygen concentration of the working face in the air inlet seal can be reduced to be lower than 12% within 3 h, the fire area is inerted and exploded, then the air return seal is f