Combustion Particulates Mitigation Investigation Using a Well-Stirred Reactor

Abstract

Combustion generated particulates can increase exhaust plume visibility and maintenance costs in gas turbine engines. Research is being conducted to determine particulate formation chemical mechanisms , understand precursors to particulate formation , and identify mitigation strategies. This paper describes a robust well -stirred reactor (WSR) combustion rig and facility that was constructed to study particulate formation. Preliminary experimental tests of particulate formation fr om premixed fuel -rich (2.6> �>1.8) ethylene/air mixtures have been completed . Multiple measurement techniques were used in the investigation including smoke measurement, particle counting, carbon burn -off and GC -MS analysis. Information gained from these investigations is used to provide details for combustion models of pollutant formation, kinetics, and particle formation and destruction. Particulate samples were collected from the plug flow region downstream of the WSR and it was found that the smoke nu mber results for ethylene compared well with previous data from the literature. Lower particle counts and smoke numbers were observed as the reactor residence time was decreased suggesting that increased mixing or reduced time at elevated temperatures for soot formation was responsible for decrease in soot formation. The effect of using the oxygenated fuel additive, ethanol, as an additive to the ethylene was also examined and it was found that ethanol increased soot production compared to neat ethylene f uel. NOMENCLATURE EI = emissions index (gm/kg fuel) CPC