Characterization of Swirling Distributed Combustion

摘要

Colorless Distributed Combustion (CDC) has been shown to provide substantial performance improvement in terms of ultra-low emissions, uniform thermal field, combustion stability and enhanced efficiency. CDC has been examined under both swirling and non-swirling configurations for enhanced performance. Different injection velocities have been examined for its role on the extent of distributed combustion. CDC performance has also been evaluated at different operational temperatures and equivalence ratios. The results from several experiments are analyzed to determine the key factors that affect distributed combustion regime. Data showed key parameters for distributed combustion are recirculation ratio (defined as the ratio of the recirculated mass in the combustor to the mass of the fresh mixture), flow injection velocity, and other operating conditions. The results showed that increase in recirculation ratio and air injection velocity foster distributed reaction conditions. Impact of temperature and pressure varied with the operating equivalence ratio. A hybrid combination of the above parameters provides distribution index (DI) that reveals how well the chemical reaction zone is distributed within the combustion regime.