Comparison of ignition strategies for catalytic microburners

Ignition of propane-air combustion in a Pt-coated microburner is numerically investigated. Three startup modes are compared: heating the inlet feed above its ignition temperature, resistive heating using electric power, and spatially distributed (stratified) resistive heating. Depending on wall conductivity, velocity, and inlet temperature (for preheated feed) Or power Supplied (for resistive heating), the fuel lights off either at the entrance (front-end ignition), towards the exit (back-end ignition) or in the middle of the reactor. The cumulative propane emissions are the highest For resistive heating of microburners. Promoting front-end ignition. via locally heating the initial section of the reactor or by feed preheating, significantly reduces the ignition time and the emissions. Lower conductivity materials show shorter ignition times and lower emissions for all start-up modes. The time to steady state depends oil start-up mode and materials' conductivity. A good start-up strategy Would be to ignite the microburner with a low flow rate and then increase it. (C) 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved.