Liquid Jet Fuel Property Impacts on Combustion Performance

Abstract

This paper investigates the influence of liquid jet fuel properties on flame lean blowout (LBO) using an annular coflow spray burner. This behavior has been studied before; however, inconsistent conclusions have been reached regarding the dependency of LBO performance on the properties that influence fuel atomization and mixture formation. LBO limits are measured at three different fuel flow rates to evaluate the influence of the atomization quality/regimes on LBO. It was found that the laboratory spray burner provides similar trends in LBO as a realistic gas turbine combustor but with less time and fuel consumption. Furthermore, the approach used in this work differs from traditional LBO measurements in that the fuel flow rate is kept constant while altering the air flow rate to allow for greater control of the atomization process, which is strongly affected by the fuel flow rate. The results suggest that, to an extent, higher amounts of liquid fuel entering the flame can enhance flame stability. They also suggest that testing at different fuel flow conditions and/or with variable injection hardware, coupled with testing of jet fuels exhibiting variations in key physical properties important in their atomization, is most likely the cause of discrepancy observed in previous works.