Abstract
Keywords:
Combustion, Premixed Charge Compression Ignition (PCCI), Exhaust Gas Recirculation (EGR)
Abstract
In this study, direct fuel impingement and distribution system, named OSKA was applied to premixed charge compression ignition (PCCI) engine in order to reduce unburned hydrocarbon (UHC) emissions. The OSKA System employed which was composed of single-hole fuel injector, impinging part and re-entrant type combustion chamber. A single cylinder diesel engine (bore 118 / stroke 108 mm) was modified for the OSKA system. A fuel injector was located in the center of cylinder head and an impinging part was provided in the center of piston cavity. The injected fuel spray impinged onto an impinging part and spray grew radial direction symmetrically. As a results, most of fuel spray was trapped in the piston cavity and prevented the fuel spry quenching onto the cylinder wall and cylinder head, accordingly, UHC emissions was expected to reduce under the condition of very early fuel injection timing of PCCI engine. The experimental results showed that very low NOx emission by OSKA system PCCI engine. UHC emissions and soluble organic fraction (SOF) of PM were also reduced as compared with the conventional direct fuel injection PCCI engine. UHC emissions was reduced about half of the conventional direct fuel injection PCCI engine with multi hole fuel injector. UHC emissions reduction can be considered as a result of wall quenched fuel reduction by OSKA system.