Ventilation method for exploiting short distance coal bed in fire zone based on positive pressure ventilation system

Abstract

The invention discloses a ventilation method for exploiting short distance coal bed in a fire zone based on a positive pressure ventilation system. The method is established on the basis of the positive pressure ventilation system and comprises the following steps of: firstly, on the basis of judging connectivity between a coalface and an upper part fire zone, determining danger that harmful gas of the upper part fire zone abnormally flows into an operation face exists; determining an area with a lowest pressure energy of the operation face, namely, a safe pressure range at a position of a air returning corner; determining wind resistance from the air returning corner to an air returning air window of the coalface through ventilation parametric measurement of the coalface and a law of conservation of energy; finally calculating a differential pressure safe regulation interval of the air returning air window of the positive pressure system of the coalface; afterwards, on the basis of the differential pressure safe regulation interval of the air returning air window and combined with an automatic control technology, therefore, real-time automatic regulation control of the air returning air window and alarming by an alarm can be realized when a differential pressure before and after the air returning air window on coalface is changed and when an air pressure is changed suddenly caused by collapse of a large area of a top plate of an upper goaf, and safe exploitation on the coalface can be ultimately ensured.

Description

technical field [0001] The invention relates to the field of coal mine safety mining, in particular to a ventilation method for short-distance coal seam mining under a fire zone based on a positive pressure ventilation system. Background technique [0002] The coal seam resources of many mines in western my country are buried shallowly, and small kiln coal mines grow in the upper part. Due to the chaotic management of small kiln coal mines, backward production technology, and lack of geological data, private mining and excessive mining are serious, and often cross-border mining. Most of the small coal kilns adopt the mining method of room-and-pillar or excavation instead of mining. The recovery rate is low, there are many coal residues, the roadways communicate with each other, and the surface subsides seriously. When the lower coal seam is mined, under the influence of mining, the air leakage channels in the upper fire zone increase, which not only intensifies the developme...

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Problems solved by technology

When the lower coal seam is mined, under the influence of mining, the air leakage channels in the upper fire zone increase, which not only intensifies the development of the upper fire zone, but also often faces the danger of abnormal influx of toxic and harmful gases such as CO in the upper fire zone into the working face. It poses a serious threat to the safe production of the lower coal seam working face

According to statistics, mine fires caused by small kiln mining account for more than 95% of spontaneous combustion fires. Due to the close coal seam coal mining face, the upper fire area has many and complex air leakage channels, relatively disordered air leakage rules, and strong concealment of high-temperature fire sources. characteristics, which brings great difficulty to the fire prevention work

At present, when dealing with the fire area in the upper part of the coal seam at a short distance, there are mainly spontaneous ignition prediction technology, fire source detection technology and fire prevention and extinguishing technology. Among them, the spontaneous ignition prediction technology is an effective means to predict the degree and scope of spontaneous combustion in the goaf, mainly including measurement temperature method, index gas analysis method, etc., and due to the many air leakage channels and the limited monitoring range, when abnormal temperature and gas are detected in the goaf of the coal seam at a short distance, the high-temperature fire area has often formed, so that the fire prevention and extinguishing work is very passive; the fire source The detection technology is mainly to determine the location and range of the high-temperature fire source in the upper fire area, and then carry out targeted fire prevention and extinguishing work in the upper fire area, mainly including radio wave method, radar method, dual-element tracer method, resistivity method, isotope However, due to the large influence range of the upper fire area and the complicated air leakage channels, it is often difficult to accurately determine the high-temperature fire source area before the upper fire area develops to a certain extent

At present, the relatively mature fire prevention technologies mainly include grouting fire prevention, gel fire prevention, inhibitor fire prevention, inert gas fire prevention, pressure equalization fire prevention and air plugging technology, etc. However, due to the high temperature fire source point cannot Timely and accurate determination and complex air leakage laws have brought great blindness and lag to the fire extinguishing work. At the same time, the cost of fire extinguishing materials is high and the process is complicated, which cannot meet the needs of large-area rapid fire extinguishing and emergency fire extinguishing. The case of poor effect

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