1. Analysis of the cause of gas explosion
1.1 gas explosion characteristics
According to the statistical analysis of coal mine gas explosion accidents for many years, it can be found that there are some characteristics: 1 gas explosion is mostly a big accident; 2 accident sites occur mostly in coal mining and heading face; 3 gas explosion causes a wide range of damage; 4 more For sparks detonation; 5 high gas mines, low gas mines have occurred; 6 gas explosions occurred in township coal mines; 7 infrastructure, technical upgrading mines and converted mine gas explosion accidents.
1.2 Analysis of the cause of the accident
Gas explosion accidents in coal mines are related to many factors, but in general, they are mainly related to natural factors, safety technical means, safety equipment level, safety awareness and management level. Gas explosion accidents are often caused by the interaction of the above factors. .
1.2.1 Poor mining conditions
According to statistics, in 2000, a total of 580 mines in state-owned key coal mines in the country were identified by gas ranks, including 160 high gas mines, 298 low gas mines, and 122 coal and gas outburst mines. There are 372 natural fire mines, accounting for 64%, and there are 427 mines with coal dust explosion hazards, accounting for 73.6%.
1.2.2 The existence of gas accumulation
There are many reasons for the accumulation of gas in coal mines, but the main reason is that the unreasonable ventilation system and poor local ventilation management are the main reasons for gas accumulation. For example, in the 34 large gas explosion accidents in 2004, 22 cases were mainly due to unreasonable ventilation systems, short-circuiting of wind currents, multiple series and circulating winds, resulting in insufficient air volume at the wind supply site, causing gas accumulation; 9 mainly Due to improper installation position of the local ventilator, the air duct does not extend to the supply point or fall off, the effective air volume of the air supply point is insufficient, resulting in gas accumulation; there are 2 accidents mainly caused by gas stoppage and gas accumulation; The gas accumulated in the blind lane was detonated.
1.2.3 Detonation of the existence of fire source
The fire sources for detonating gas in coal mines are: blasting sparks, electrical sparks, frictional impact sparks, static sparks, coal spontaneous combustion, etc. However, the sparks generated by shooting and electrical equipment are the main source of fire accidents. For example, among the 34 large gas explosion accidents in 2005, 16 were detonated by sparks generated by shooting; 15 accidents were caused by electrical equipment and power line electric sparks.
1.2.4 Insufficient equipment and management are not implemented
The mine safety equipment configuration is insufficient. The principle of “first pumping, mining, monitoring and monitoring, and wind production†has not been fully implemented. For example, in the 41 large gas accidents that occurred in 2005, some mines did not have a gas monitoring system installed or operated abnormally. Some mines were equipped with a monitoring system, but the number of sensors was insufficient, the installation position was incorrect, the line was faulty, and the display was not. Problems such as displaying data cannot effectively perform their due role. In addition, the extra-large gas accidents in township coal mines are not equipped with gas drainage systems or the pumping system cannot operate effectively, and the monitoring system cannot function effectively. For example, although a gas monitoring system was installed in a well of Wuyin Bayinsai Coal Coke Co., Ltd., Wuhai City, Inner Mongolia, there was no gas sensor in its actual mining area, which caused a large gas accident and killed 16 people.
1.2.5 Low management level
Many accidents found that illegal operations or improper management caused some accidents that could have been avoided, but did not attract attention, and eventually led to a large gas explosion. Therefore, the management level and the safety awareness of employees are very important for the long-term safe production of coal mines.
1.2.6 Enterprise technology management is weak
Due to the backward coal mining method, some coal mining enterprises have caused unreasonable mining layout and the ventilation system is not perfect. In addition, the operation procedures are not in line with reality, and the pertinence is not strong, which brings serious hidden dangers to safety production.
2. Technical measures to control gas explosion accidents
The prevention and control of gas explosion accidents can be divided into prevention of explosions and suppression of explosions. Explosion prevention mainly includes: optimizing ventilation network and ventilation system, preventing and controlling gas accumulation, conducting gas drainage, strengthening gas concentration and fire source monitoring, preventing the occurrence of ignition source, etc.; suppressing explosion mainly by using explosion-proof explosion-proof device to limit gas explosion to Within a certain range, thereby reducing the losses caused by casualties and disasters.
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