Experimental Research On Gas Adsorption And Desorption Of Coal Sample In Electrostatic Field

Combining experimental research, theoretical analysis and mathematical analysis, the changed characteristics of gas adsorption and the radiation under the effect of different classes and different failure types of coal sample in electrostatic field were studied. Using the contrast method, the change rule of the adsorption isotherm curve in coal samples and adsorption constants of a and b was analyzed to gain that b agreed with the increase of gas absorption in different static voltage. By changing the way of testing, this paper analyzed the change characteristics of the gas radiation in coal samples in electrostatic field effect to gain the change rule of gas radiation in different static voltage, gained that electrostatic field enhanced gas radiation, and tectonic coal of bitumite had the highest degree of influence, then original structure coal of bitumite, original structure coal of anthracite, tectonic coal of anthracite had the lowest degree of influence, which just agreed with distribution rule of the free radical concentration in different coal ranks. The obvious phenomenon in the test was analyzed:the speed of gas radiation has obvious characteristics of particle size and time memory effects under the effect of electrostatic field. Using grey correlation analysis, this paper analyzed which factor of the own factors affecting gas radiation in coal under the effect of electrostatic field was dominant, and gained the conclusion that the coefficient of variation in the degree of correlation in fixed carbon was biggest, which confirmed that electrostatic field changed the speed of gas radiation by influencing fixed carbon in components of coal and rock and gave quantitative basis for mechanism analysis. This paper established interaction potential model of coal-gas system, calculated the variable quantity of one d potential trap in electrostatic field, and from the angle of the electric dielectric polarization in the added electric field, analyzed the impact of electrostatic field to adsorption potential on coal surface, which all gained the theory of gas adsorption, that is adsorption potential on coal surface was increased. Based on that researches, the relationship of both the adsorption potential with gas adsorption quantity and gas diffusion coefficient was analyzed to gain the theory,that is the increase of the gas adsorption leaded to the increase of concentration gradient of gas and the pressure gradient, while the reduced diffusion coefficient was bad to gas diffusion.