A liquid nitrogen fire extinguishing system and method

Abstract

The invention discloses a liquid nitrogen fireproof fire extinguishing system, comprising a liquid nitrogen tank car; the liquid nitrogen tank car is connected with a pump, a vertical shaft and a liquid nitrogen conveying main pipe in sequence; the liquid nitrogen conveying main pipe is connected with a liquid nitrogen direct injection pipe for injecting liquid nitrogen into a goaf and a liquid nitrogen gasifying device for gasifying the liquid nitrogen into nitrogen and then injecting the nitrogen into the goaf; the goaf is integrally provided with an exhaust pipe connected with an air return pipeline; the exhaust pipe is provided with a first control valve; the goaf is internally provided with a sensor for monitoring pressure. The invention also discloses a liquid nitrogen fireproof fire extinguishing method. The liquid nitrogen fireproof fire extinguishing system and the method have the beneficial effects that the exhaust pipe is arranged in the goaf, when the pressure in the goaf is larger than a preset value, air in the goaf can be exhausted, so the pressure of the goaf is reduced, the nitrogen filling speed is improved, and inert gas and harmful gas in the goaf are prevented from escaping from cracks in upper edges corners of the goaf into a working area under action of high pressure.

Description

technical field

[0001] The invention relates to coal mine underground fire prevention and cooling technology, in particular to a liquid nitrogen fire prevention and fire extinguishing system and method. Background technique

[0002] According to statistics, mines with the risk of spontaneous combustion in my country's key state-owned coal mines account for about 51.3%, and fires caused by spontaneous combustion account for more than 90% of the total number of fires. problem.

[0003] Conventional fire prevention and extinguishing techniques commonly used at this stage mainly include grouting, inhibitor injection, nitrogen injection, etc. The use of nitrogen for fire extinguishing can not only quickly extinguish a large fire area of ​​tens of thousands of meters, but also suppress the explosion of combustible gas in the fire area, and improve the safety during the fire extinguishing process. Especially the use of liquid nitrogen to extinguish the fire, liquid nitrogen will a...

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