Calculation On The Ignition Energy Of The Antistatic Property Testing System And Its Mechanism Analysis

High polymer materials are widely used as electrical insulation in mine and otherindustrial areas and many improved material with lower density and higher hardnesshave also been used in mines. Due to the electrostatic charge accumulation on thesurface of these material, it is a huge potential hazard to the industrial production,especially for the coalmine production. In a long time, the measure to test the antistaticproperty of a non-metallic product is testing its surface resistance. Testing the surfaceresistivity is an easier way, but it can’t reflect the material’s antistatic property directly.A testing system is designed in this paper called antistatic property testing system whichcould be used to test the material’s antistatic property directly and analyzed the ignitionmechanism of the system based on the fluid-chemical reaction model. The maincontents and achievements of the paper are as follows:①A testing system is designed which can be used to test the antistatic property ofnonmetal materials. The sizes of the friction room and explosion room are set accordingto the field conditions, as well as the parameters which are used to control theexperimental environment. Three key technologies involved in the testing process areproposed.②The MIE of the methane-air mixed gases in the system is calculated and theinfluence factors are analyzed. The results indicate that the MIE increase with theelectrode distance get wider, and the MIE reaches to0.47mJ when the electrode distancereaches to5mm.③According to the electromagnetic energy difference value before and afterdischarge, a new method to calculate the spark discharge energy in this system isproposed. The maximum energy which can be used to ignition is also ascertained. Thethreshold of ignition energy coupling coefficient is obtained. The ignition voltage andthe critical charge are calculated by the distributed capacitance matrix. The results showthat the threshold of ignition energy coupling coefficient increases with the increase ofelectrode gap. The threshold of ignition voltage is13.3959kV and the critical charge is0.0807μC at the electrode distance is5mm. According to the results, a six gradesclassification standard for the nonmetal materials is established. A verificationexperiment for the system is designed in this paper and the error in which is about2.16%. The accuracy of the system is certificated. ④A two-dimensional hybrid model of spark discharge based on fluid-chemicalreaction is established. In the view of microscopic particles collision and chemicalreaction, the process of spark breakdown is analysed. According to the analysis of themicroscopic particles collision, the result shows that the arc joule heat in the sparkbreakdown process provides the energy for the microscopic particles collision. Theelastic collision and inelastic collision make the energy to transfer from one particle toanother or loss as joule heat, which explains the energy source for spark ignition processin the methane-air mixed gas.