The effect of fuel injection pressure and in cylinder temperature on igniton delay, combustion performance and emission

The mixture formation prior to the ignition process plays as a key element in the diesel combustion. The objective of this research was to help an understand of the effects of air fuel mixing process during the ignition delay period and initial heat release in combustion process that strongly affects the exhaust emissions. This study investigated effects of ambient temperature,Ti and injection pressure, Pinj on the heat release process during ignition delay periods. Rapid compression machine (RCM) was used to simulate actual phenomenon inside the combustion chamber. This study used of 5vol%, 10vol%, and 15vol% blending of palm oil methyl ester with a standard diesel as fuels in diesel engines called as B5, B10, and B15 and standard diesel itself. The injection pressures were varied from 80 MPa to 140 MPa while an ambient temperature of RCM varied from 750 K to 950 K. For all tested fuels, the ignition delay period decreased with the increase in ambient temperature and injection pressure. The initial heat release becomes more delayed for lowering the ambient temperatures and its peak was found to increase progressively and shorten ignition delay period. Increased injection pressures make spray tip penetration longer and promotes a greater amount of fuel-air mixing occurs during ignition delay which is gives early rise of heat release rate. Higher injection rate was promoted both mixing and atomization increase heat release rate as well as shorten ignition delay. The effects of high injection and ambient temperature showed a reduction on emission, especially HC, CO and CO2. Increased in injection pressure, leads to decrease in NOx emission and due to superior air–fuel mixture resulting from increase in injection pressure, CO2, CO and HC emission decreases. Higher blending ratio from B5 to B15 increases the oxygen content, which makes the combustion more complete, thus, promotes the reduction of emissions specifically for CO, CO2, and HC, but the NOx emissions increase.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Universiti Tun Hussein Onn Malaysia

Year dc:date.issued

2020

Author dc:creator

• Mohmad Jaat, Md Norrizam

• TP315-360 Fuel

Language dc:language

en