Mine liquid nitrogen fire preventing and extinguishing system and using method thereof

Abstract

The invention discloses a mine liquid nitrogen fire preventing and extinguishing system. The system comprises a liquid nitrogen container tank vehicle, a low-temperature liquid pump, a buffer tank and a liquid nitrogen gasification device. The liquid nitrogen container tank vehicle is connected with the low-temperature liquid pump through a conveying hose. The conveying hose is provided with a first control valve. The low-temperature liquid pump is connected with the buffer tank through a thermal insulation pipe. The thermal insulation pipe is provided with a vacuum valve. A second control valve is arranged between the vacuum valve and the buffer tank. The vacuum valve is connected with a low-temperature vacuum pump. The bottom of the buffer tank is provided with a buffer tank bottom opening. The buffer tank bottom opening is connected with a liquid nitrogen injection pipe. The liquid nitrogen injection pipe is provided with a third control valve. The buffer tank bottom opening is further connected with a conveying pipe. The conveying pipe is connected with an input opening of the liquid nitrogen gasification device and provided with a fourth control valve. An output opening of the liquid nitrogen gasification device is connected with a gaseous nitrogen injection pipe. The gaseous nitrogen injection pipe is provided with a fifth control valve. The invention further discloses a using method for preventing and extinguishing fire through the mine liquid nitrogen fire preventing and extinguishing system.

Description

technical field [0001] The invention relates to the technical field of liquid nitrogen fire prevention and extinguishing, in particular to a liquid nitrogen fire prevention and extinguishing system used for filling mines with liquid nitrogen in coal mines and a method for using the same. Background technique [0002] In my country's key state-owned coal mines, mines with the risk of spontaneous combustion account for about 51.3%, and fires caused by spontaneous combustion account for more than 90% of the total number of fires. Conventional fire prevention and extinguishing technologies commonly used at this stage mainly include yellow mud sand grouting, gel, inhibitor, foam, etc. The above-mentioned technology needs to consume a large amount of sediment or water, has poor permeability, is not easy to disperse into the coal body, has a small coverage area, and also deteriorates the underground working environment, affects coal quality, and corrodes underground equipment. Nit...

AI Technical Summary

Problems solved by technology

However, at present, the normal temperature nitrogen and liquid nitrogen fire prevention systems require two sets of independent transportation pipelines, which increases the cost of fire prevention and extinguishment.

Moreover, when liquid nitrogen starts to be injected into the pipeline, due to the influence of normal temperature gas in the pipeline, gas plugs and other phenomena will appear in the pipeline, making it difficult for liquid nitrogen to enter the well, causing system instability and threatening system safety.

These reasons make it difficult to greatly improve the fire prevention and extinguishing efficiency of normal temperature nitrogen and liquid nitrogen under the existing production technology conditions

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