An experimental study on the effect of inlet diesel fuel temperature on mass flow choking, flame penetration, temperature, radiative characteristics and NOx pollutant emission of an oil burner

The aim of the present work is to investigate the effect of inlet diesel fuel temperature of an oil burner on mass flow choking, flame penetration, temperature, radiative characteristics and NOx pollutant emission. Diesel fuel was heated up, in an insulated reservoir tank containing a thermostat, to the selected temperatures of 15, 45 and 75 degrees C, and then, flame characteristics were measured. SBG01 water cooled heat flux sensor and TES-1332A digital luminance meter were used to determine the total and luminous radiations of the flame. Furthermore, a KIGAS 310 gas analyzer measured the concentrations of pollutant emissions. It was found that increase in inlet fuel temperature resulted in no mass flow choking, no cavitation and insignificant change in the effective area of the oil burner nozzle. However, increase in fuel temperature increased the droplets injection velocity and the flame penetration length. Furthermore, increase in fuel temperature reduced the droplets size, improved the spray atomization and accelerated the droplets evaporation and, consequently, increased the flame temperature. Also, when the fuel temperature increased from 15 to 75 degrees C, the average flame radiation heat flux was enhanced as much as 44.5%, and NOx emission decreased significantly from 33 to 13 ppm.