Flameless combustion mode as a promising trend: A review on its fundamental, role towards emissions reduction, fuel consumption and performance enhancement.

Abstract

Flameless combustion techniques have created a huge opportunity in the patronizing high number of combustible fuel materials. This opportunity is connected with its potential in providing acceptable features of the combustion regime, mostly centered on mixing the working medium (reactants) above the temperature of auto-ignition of the fuel. Recent research has provided some potential of flameless combustion towards pollution reduction and energy generation. However, this technology still requires more attention to improve its versatility. The effect of flameless combustion on emissions reduction and its performance enhancement both on biofuels and fossil products is reported in this paper. Flameless combustion follows mixture before oxidizes in the combustion process, thus generates lower NOx emissions with clear and flameless of very little visible radiation. Similar values in the area of pollutant emissions for all studied fuels, especially with bio-fuel showed that flameless combustion yields good results both on conventional and diluted fuels. The review still points that flameless combustion regime modelling might not be capable of predicting intermediate species for reducing the emissions to zero level due to some inherited properties in the operation. Assessing the thermal performance of flameless combustion, showed similar temperature distribution for all the fuels studied, although bio-fuel temperature observed little below, due to the inert gases of CO2 of large amount towards cooling the reactants. Challenges like wall-flame quenching and residence time were discovered on micro-scale combustors. The report suggests that little modifications on the flameless combustor in the area of wall-flame quenching will contribute to solving the NOx emission problems.