Study on the calculating methods of gas expansion energy base on thermo kinetic of outburst

Abstract：Gas expansion energy is the main energy which causes coal and gas outburst, the temperature variation of coal in the course of coal and gas outbursts was studied through testing in lab, numerical simulation and theoretical analysis.Based on this, the calculating methods of gas expansion energy which worked to the outbursts were put forward.The results show that the process of coal and gas outbursts is not an adiabatic process, which is accepted by most researchers, but a polytropic process that is nearly an isotherm process.The polytropic index can be calculated by the experiment data of coal temperature, the free gas expansion work and adsorbed gas work can be calculated by using polytropic index.

Keyword：coal and gas outburst;thermodynamic;gas expansion energy;polytropic process;