煤矿电气安全关键技术研究

分析了2005—2009年全国重特大瓦斯爆炸事故的火源,得出了由电气火源引爆瓦斯事故最多且达48.1%的结论,并分析了矿用电气设备的安全性能,提出了矿用电气设备的使用场所及安全要求:(1)煤矿监控、通信、控制、信号等弱电系统和设备应优选本质安全型电气设备,设备之间传输的信号必须是本质安全型信号;(2)大功率电气设备应优选隔爆型电气设备,隔爆型电气设备宜将接线腔与主腔分腔布置;(3)当瓦斯浓度达到爆炸浓度时严禁开关特殊型矿灯;(4)低瓦斯矿井井底车场等非爆炸性环境宜选用矿用防爆型电气设备;(5)煤与瓦斯突出矿井严禁使用架线电机车和矿用一般型电气设备;(6)井下电气设备的欠压保护和失压保护应有延时措施,减少局部通风机停电次数;(7)井下排水设备宜选用大功率潜水泵;(8)开关等电气设备应设置在全风压进风处,若不能满足,必须设置甲烷传感器,并具备甲烷超限断电闭锁功能。文章对提高煤矿电气安全性、避免或减少瓦斯爆炸和淹井等事故发生具有指导作用。

Research of Key Technologies about Electrical Safety of Coal Mine

The paper analyzed fire sources of domestic gas explosion accidents from 2005 to 2009 and got a conclusion that gas explosion accidents were mostly caused by electrical fire source,which accounted for 48.1%.It analyzed safety performances of mine-used electrical devices and proposed operation places and safety requirements of each type of electrical devices.Firstly,systems and devices with weak current for coal mine monitoring,communication,control and signals should primarily be intrinsically safe and signals transmitting between the devices must be intrinsically safe.Secondly,electrical devices with large power should be flameproof type devices and wiring cavity of the devices should be separated from main cavity.Thirdly,special cap-lamp cannot be operated on or off when gas concentration achieves explosion concentration value.Fourthly,explosion-proof electrical devices should be used in non-explosion places such as underground shaft station of mine with low gas concentration.Fifthly,trolley locomotive and normal mine-used electrical devices cannot be used in mine with coal and gas outburst.Sixthly,time-delay measures should be used in under-voltage and no-voltage protection of underground electrical devices so as to decrease cutting off times of local ventilator.Seventhly,immersible pumps with large power should be used for underground draining devices.Eighthly,switches should be set at air-intake places of total wind pressure,otherwise methane sensors should be set with functions of power-off and interlocking when methane is over limit.The paper provides some guidance to improve electrical safety performance of coal mine and avoid or decrease accidents of gas explosion and mine submerging.