On MILD Combustion in a Perfectly Stirred Reactor with Exhaust Gas Recirculation

摘要

The characteristics and criteria of the moderate and intensive low oxygen dilution (MILD) combustion in a perfectly stirred reactor (PSR) were studied with special attentions paid to the effect of exhaust gas recirculation (EGR). The well-known PSR S-curve theory was expended to the cases with EGR and the mathematical criteria for MILD combustion in a PSR with EGR was addressed. Results demonstrated that EGR helped establish a MILD combustion by first decreasing the self-ignition temperature of the mixture and second reducing the temperature increase with respect to the temperature of initial fresh mixture. Based on the PSR MILD combustion criteria, the combustion regime map diagram was exhibited, classifying 5 different combustion regimes: 1) no combustion; 2) unstable combustion; 3) feedback combustion; 4) MILD combustion and 5) high-temperature combustion. Including EGR in the process considerably enlarged the area the MILD combustion regime in the combustion regime map.