Abstract:The microscale combustor is an important part of microscale power system. Experiments on dimethyl ether/air catalytic combustion were carried out in quartz microchannels. The experiments mainly focused on the catalytic combustion and dynamic flame such as the effects of equivalence ratio Φ and inlet flow rate V on the stable combustion range, flame feature, wall temperature and the mole fraction of the exhaust gas. The experimental results showed that the stable combustion range was significantly higher after adding quartz wool in the combustors. When there was no quartz wool, the flame could be stable only under the condition of that the Φ varied from 1.2 to 1.4, and the flame was asymmetric. If Φ>1.4, the flame would oscillate and the oscillation cycle could be divided into three main stages; when Φ<1.2, there was no flame. Flame stationed at the quartz wool after adding quartz wool and the height of the flame was increased with the increase of V. The wall temperature distribution along the centerline of the wall was symmetrical and it was increased with the increase of V. Simultaneously, the location of the peak temperature was moved to the outlet of the combustor with the increase of V. The mole fraction of CO2 of the exhaust gas was first increased and then decreased with an increasing equivalence ratio Φ, and reached a maximum value 13.44% when Φ=1. The mole fractions of CO and H2 of the exhaust gas were increased with the increase of equivalence ratio Φ. When Φ<1, there was little CO and H2 in the exhaust gas. In contrast, some CO and H2 existed in the exhaust gas under the richfuel conditions.
