The Experimental Study on Ignition Mechanism and Combustion Characteristics of Micro Gas Engine

In this article, the experimental studies on ignition mechanisms and combustion characteristics of the micro combustor have been made for the designs and ignition of the combustor. A set of special experimental devices of ignition are designed and fabricated based on Si-based MEMS technology. The combustors of the experimental devices are the square cavity that varied from 1mm to 9mm in length and from 0.5mm to 4mm in height. The spark electrodes are Au electrodes. The gaps of electrodes are 10μm, 40μm, and 100μm. The experiments of the ignition mechanisms of premixed H₂/air, the concentration limit of ignition, residence time, ignitor-breakdown voltage, and heat transfer have been made on the devices. The ignition mechanisms and combustion characteristics of H₂/air in micro combustor have been discussed based on the results of experiments. The experimental results indicate that the ignition of the premixed H₂/air in micro combustor is feasible. The range of the ignitable concentration has a significant reduction. The combustion is subject to the back-fire and liable to suffer from flame extinction. The height is at least larger than 0.61mm. The ignitor-breakdown voltage is at least 350V when the gap of ignition electrodes is 10μm.