A Study on Homogeneous Charge Compression Ignition (HCCI) Combustion of Diesel Fuel with External Mixture Formation
- Author Naveenkumar.P
- Co-Author Tamil Selvan.V, Moorthy.R, D.Manivasagan
- Country : India
- Subject : Engineering
Conventional diesel engines operate at higher compression ratios than SI engines. In this type of engine, the air-fuel mixture auto-ignites because of piston compression instead of ignition by spark plug. The in-cylinder temperature in a conventional diesel engine is about 2700 K, which leads to a significant production of Oxides of Nitrogen (NOx) emissions. In the present work, homogeneous mixture was prepared outside the combustion chamber by using Ultrasonic fuel injection (USFI) system and Diesel fuel vaporizer system. The investigation was carried out at different fuel injection frequencies to study the combustion, emission and performance characteristics. Similarly, in the second approach, the Diesel fuel vaporizer receives fuel in liquid state and it converts into vapour form by means of an external power source, and effectively mixes with the incoming air to form a uniform fuel-air mixture. The investigation was carried out with diesel vapour induction with and without EGR to study the combustion, emission and performance characteristics. The experimental results show that, NOx and smoke reduces by about 80 % and 92 % respectively with USFI system. Whereas, in Diesel fuel vaporizer (DFV) system, the NOx and smoke reduction is about 95 % and 83 % respectively. The brake thermal efficiency decreases by about 2-8 % in both the systems. The engine operated from no load to 75 % load without any problem in the case of diesel fuel vaporizer system, whereas in USFI system the engine operated between 25% to 75% load only.