Research on simulation of human body electrostatic discharge on detonating gas in coal mines

Static electricity is one of the reasons for gas explosions in coal mines. When miners leave the narrow tunnel exit of a coal mine, the body voltage may increase by more than ten times with the body capacitance decreasing quickly to 1/10 of its original value, and the body electrostatic discharge (ESD) energy can increase greatly to become a dangerous gas ignition source. In this work, simulation research of human body ESD detonating the gas in a coal mine was conducted. Based on the analysis of the human body electrostatic leakage rules, it is found that electrostatic half-life is mainly relative to the medium resistivity. Therefore it is important to establish a standard for anti-static attire. A series of gas explosion experiments were also conducted by the simulation system, and the results showed that the gas in coal mines might be detonated when the human body capacitance was in the range of 100-1800 pF and the discharge gap between 0.3-1.2 mm. Moreover, gas concentration at approximately 8.5% was most likely to induce an explosion.