Abstract:
This research investigates the influence of fuel injection pressure on the combustion efficiency and exhaust emissions of the burner used in asphalt sprayers operating in the construction project of the 3rd Runway at Suvarnabhumi Airport. The self-propelled asphalt sprayer, equipped with an asphalt tank mounted on a truck, faces a significant issue of emitting large amounts of black smoke during operation or while heating asphalt in the burner. In this study, diesel fuel was injected at pressures ranging from 40 to 80 psi. The variables studied included the air-to-fuel ratio, equivalence ratio, fuel consumption rate, combustion efficiency, burner efficiency, and exhaust emissions such as CO2 CO, NOX, and black smoke. The findings revealed that increasing the fuel injection pressure tends to reduce the air-to-fuel ratio by 4.1-4.6%, while the equivalence ratio increased by 11.4-54.3%. The fuel consumption rate increased by 1.7-5.2%, and combustion efficiency showed an improvement of 3.7- 6.4%. Higher injection pressure also contributed to a reduction in fuel droplet size and enhanced mixing rates. In terms of exhaust emissions, it was observed that increasing the fuel injection pressure resulted a rise in CO2 emissions by 0.6-2.7% and NOX emissions by 14-32%, whereas CO levels decreased by 20.3-95.4%. However, black smoke emissions exceeded the standard limit of 50% when the injection pressure was above 65 psi.