Effect of Injection Pressure and Air-Fuel Ratio on the Self-Ignition Properties of 1-Butanol-Diesel Fuel Blends: Study Using a Constant- Volume Combustion Chamber

摘要

One of the ways to reduce the negative impact of diesel engines on the natural environment is to reduce the smoke opacity and emissions of nitrogen oxides. For this purpose, suitably programmed fuel injection strategies and exhaust after-treatment systems can be used. Another way to reduce the toxicity of diesel exhaust is to use oxygenated fuels. This approach is particularly important, as it also allows a reduction of the use of fuels processed from crude oil. As a potential oxygen additive, 1-butanol can be used. Because of the work cycle of a diesel engine, it is particularly important to determine the self-ignition properties of diesel fuels with such alcohol additives. In this study, the self-ignition properties of 1-butanol diesel fuel blends were investigated, with the 1-butanol percentage up to 25% by volume. The experiments were conducted in a constant-volume combustion chamber, enabling the determination of the impact of the fuel injection pressure (ranging from 80 to 140 MPa) and the air-fuel ratio (ranging from 35 to 95) on the ignition and combustion delay periods for the fuel samples. The maximum and average combustion chamber pressure rise rates were studied, and investigations of self-ignition properties were conducted at an ambient gas temperature of 650 degrees C. It was observed that with the increasing 1-butanol volume percentage, ignition and combustion delay increased linearly, and an increase in the fuel injection pressure and air-fuel ratio affected the length of these periods to different degrees. Regardless of the volume percentage of 1-butanol, the fuel injection pressure, unlike the air-fuel ratio, had only a slight effect on the maximum and average combustion chamber pressure rise rates.