Experiment on combustion stability and laminar burning characteristics of biomass gas

In order to gain the combustion stability and laminar burning characteristics of biogas, the laminar flame propagation characteristics of biogas over the equivalence ratio range of 0.7－1.4, the initial pressure range of 0.1－0.5MPa, and the initial temperature range of 290－380K were measured in the constant volume combustion bomb. Furthermore, the main influential factors of the combustion stability and laminar burning velocity of biogas in laminar combustion were investigated. Results showed that the buoyancy instability would appear in the flame propagation process and the flame core would fly upward if the value of the laminar burning velocity was below 0.15m/s. With the increasing of the initial pressure or decrease of the equivalence ratio, the Markstein length decreased and the instability of the flame front increased. However, the effect of the initial temperature on the Markstein length was not obvious. With the increasing of the equivalence ratio, the unstretched flame propagation speed and the laminar burning velocity increased initially and then decreased, and the maximum values were measured at the equivalence ratio of 1.1. Furthermore, the laminar burning velocity of biogas decreased with the decreasing of initial temperature or the increasing of initial pressure.