직접구동 피에조 인젝터의 CRDi 단기통 디젤엔진 연소 특성 분석

Abstract

Abstract : In this study, experimental approaching method was applied under and single-cylinder engine to research the performance of direct needle-driven piezo injector (DPI) for CR direct-injection. As key-point factor of this DPI that relies on direct-acting operating of injector needle, unlike conventional hydraulic-servo, its nozzle needle can be directly driven by piezo actuator. Thus, effect of direct-acting injection of DPI on diesel combustion and emission characteristics was investigated under common-rail single-cylinder direct-injection engine, equipped with three different driving mechanism, including indirect-acting solenoid, piezo and DPI system. As main results, it found that a direct-acting piezo injector has higher of IMEP. And it has higher heat release rate during premixed combustion and mixing controlled combustion phase due to its higher heat release, even though nitrogen oxide (NOx) formations were increased slightly. Key words : Direct needle-driven piezo injector(직접구동 피에조 인젝터), Servo-hydraulic indirect-driven piezo injector(서보유압 간접구동 피에조 인젝터), CRDi(커먼레일 직접분사), Single-cylinder diesel engine(단기통 디젤 엔진), Diesel combustion(디젤 연소)