Influence of methane concentration on laminar burning velocity of simulated coal-bed gas

Influence of methane concentration on laminar burning velocity of coal-bed gas under normal temperature and pressure is studied in constant volume combustion bomb with the help of high-speed camera digital schileren photography. Influence of methane variation on laminar propagation speed and laminar burning velocity of coal-bed gas under different equivalence ratios is obtained. The experimental results show that with the decrease of methane concentration, both stretched laminar propagation speed and unstretched laminar propagation speed of combustible mixture decrease under different equivalence ratios. The unstretched laminar propagation speed that corresponds to different methane concentrations varies greatly under stoichiometric conditions. The principle of methane variation to unstretched laminar burning velocity and propagation speed vary similarly with methane concentration.