Introduce

Coal, as the main energy source in China, occupies a very important position in the energy structure of the national economy. Mine fires are one of the major disasters in coal mines. On the one hand, mine fires not only burn a large amount of resources, materials, and production equipment, but also seriously disrupt the normal production order of coal mines due to the need to close the fire area; On the other hand, combustion consumes oxygen in the airflow, causing a decrease in the volume fraction of oxygen in the airflow. At the same time, it generates a large amount of thermal energy, toxic gases, and dust, seriously polluting the environment. The prevention and control of coal seam spontaneous combustion fires not only require mines to have a reasonable development system and mining methods, a reasonable ventilation system, reliable special prevention and control measures and management systems, but also corresponding fire prevention and extinguishing technologies, complete fire prevention and extinguishing systems and equipment. Only in this way can the safety production of mines be guaranteed.
The essence of nitrogen fire prevention and control is to inject a certain flow rate of nitrogen into the oxidation zone or fire zone of the goaf, using liquid nitrogen as a raw material, which is a subsidiary product of coal chemical production. This reduces the oxygen content to 10% or less than 3%, achieving the goal of fire prevention and control. Its function is to eliminate the danger of gas explosion and prevent natural heating and spontaneous combustion of coal; Reduce combustion intensity; Prevent airtight air leakage.
The system mainly consists of a liquid nitrogen boosting device, a liquid nitrogen gasification device, an electric heating auxiliary heating device, a voltage and flow stabilizing device, a metering device, a storage tank boosting device, an air release device, and a control system.