Application of impedance test method in the simulation experiment of mine gas hydrate outburst prevention

Impedance method can be used to monitor the changes of the binding and movement of various solid,liquid inner and interface charges. The impedance characteristic monitoring experiment devices of mine gas hydrate curing process of outburst coal are used to estimate the impedance changes during the process of mine gas hydrate curing with the same porosity in coal under the condition of different mass fractions of NaCl solution which is used as the coal pore liquid. The experimental results show that the impedance variation in the experimental reactor is divided into three lay- ers and the curve of impedance variation of mine gas hydrate curing process is analyzed that the amount of mine gas hydrate formation is larger in the upper layer and the impedance reduces gradually in the lower layer without mine gas hydrate formation. The water conversation of hydration is obtained by using the calibration of NaCl mass fraction curve; the mine gas hydrate growth model is established based on the PR state equation and the changes of mine gas,and the gas content of mine gas hydrate is calculated according to the results of chromatography analysis.