煤矿井下瓦斯抽采PVC管静电场试验

 针对矿井瓦斯抽采在PVC 管壁电荷积聚产生强静电场而导致静电放电的危害，通过搭建塑性管瓦斯流动静电场测试装置，模拟测试瓦斯流动过程中塑性管道的静电场，同时数值计算静电放电有效点火能量。研究结果表明，改变瓦斯流速、管径和瓦斯浓度，PVC 管静电场总体趋势是开始时电场随时间逐渐增大，而后趋于稳定，流动瓦斯与PVC 管壁面摩擦产生电荷积聚而导致的静电场可达20 kV/m 以上。以甲烷的最小点燃能量0.28 mJ 为标准，大多时刻PVC 管静电放电有效点火能量小于0.28mJ，处于安全状态，但某些时刻有效点火能量大于0.28 mJ，使得瓦斯处于爆炸的最小点火能量范围。从试验分析瓦斯抽采PVC 管静电场及有效点火能量，可为矿井瓦斯抽采防静电措施提供科学依据。

Electrostatic Voltage Test of Coal Mine Gas Drainage Pipeline of PVC

Electrostatic discharge caused by strong electrostatic voltage due to charge accumulation on the PVC pipe wall has potential damages to coal mine gas drainage. In this paper, a set of device is built to test the electrostatic voltage of the PVC pipe during coal mine gas drainage process, and effective ignition energy of electrostatic discharge is calculated. The test results show that with variation of the gas flow velocity, PVC pipe diameter, and gas concentration, the electrostatic voltage of the PVC pipe increases gradually with time at the beginning, and then tends to be stable. Due to friction between the gas and PVC pipe wall, charge accumulation on the wall causes strong electrostatic field of more than 20 kV/m. With the minimum ignition energy of 0.28 mJ for methane taken as the standard, the effective ignition energy for electrostatic discharge in PVC pipe is usually less than 0.28 mJ, which is under safe conditions. However, at some moments, the effective ignition energy is larger than the safe value, making the gas in the minimum ignition energy range of explosion. This study may provide scientific basis for anti-static measures during coal mine gas extraction.