Improvement of micro-combustion stability through electrical heating

This experiment investigates the performance of a micro combustor under different operation conditions, and its improvement with electrical heating inside. According to the results, extinction and blow out occurred at 0.08 and 0.4 L/min, respectively. Electrical heating enhanced the stability effectively. With electrical heating power of 1.05 and 4.70 W, the equivalence ratio ranges of stable combustion are extended from 0.362 – 6.52 to 0.178 – 7.66 and 0.126 – 9.43 on average, respectively, and it is more effective in the lean and low-flow-rate cases. The micro flame shows obvious shift downstream at high flow rates. The flames in the lean cases have higher robustness, their reaction region are closer to the nozzle outlet around 1.17 mm on average than in the rich cases. The heat loss and heat conduction of the micro combustor surface are found to be related to its performance. The rich cases at moderate flow rates have 0.086 W lower heat loss on average than the lean cases, which enhances the stability effectively. However, the rich cases have 0.013 W lower heat conduction on average at moderate flow rates, thus more severe shift downstream occurs.