Experimental study on composite gas indexes optimization for coal spontaneous combustion predictio

Abstract

Changing rule of composite gas indexes under different dry air flow and oxygen concentration was analyzed through coal temperature-programmed experiment. The experimental results show that φ(O2)/(φ(CO)+φ(CO2)) should be selected as gas indexes for coal spontaneous combustion prediction in the case of uncertain dry air flow. φ(O2)/(φ(CO)+φ(CO2)) can be used as gas indexes for coal spontaneous combustion prediction when coal temperature is below 100 °C. φ(C2H4)/φ(CH4) and φ(CO)/φ(CO2) can be used as gas indexes for coal spontaneous combustion prediction when coal temperature exceeds 100 °C. φ(C2H4)/φ(CO) can also be used as gas indexes for coal spontaneous combustion when coal temperature exceeds 160 °C and oxygen volume fraction is approximately 5%.

Keywords

• coal spontaneous combustion
• composite gas indexes
• temperature-programmed experiment
• dry air flow
• oxygen concentratio