The Engine Test with Modified GDI Engine Under Fuel Lean Two Stage Injection

• Main Authors: Hong-Tao Wu, 吳弘韜
• Other Authors: Kuo-Liang Shih
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/02029782940485740653

碩士 === 國立雲林科技大學 === 機械工程系 === 102 === This study applied a 500C.C. modified GDI engine with common rail injection pressure at 100 bars. The 1st: and @ns injection ratio (F1:F2=6：4、7：3、8：2) is varied at different engine speed (3000、4000、5000rpm) and load (TPS20%、30%、40%). Then the combustion equivalence rati is slightly decreased to from Φ=1 to Φ=0.9 to exam the engine performance and emissions. The first stage result indicates when the pilot injection is increased, the homogeneous charge inside the combustion chamber cause better combustion so that the engine toque and emission are improved. However, if F1:F2=8：2, the combustion is not stable under high engine speed and load condition. Thus, a F1:F2=7：3 case has best results. The 2nd stage result indicates when from Φ=1 is reduced to Φ=0.9, the volumetric efficiency is increased so that the engine torque is improved. The Co and HC are also reduced. NOX is also reduced. The BSFC is also improved under load engine speed and load conditions. This research reveals the engine output and emissions are improved when the overall equivalence ratio is reduced. However, this Air-Guided engine geometry has flat piston surface which may cause non GDI engine operation.