The Study on Combustion Characteristics of Biodiesel and Fossil Diesel in a DI Diesel Engine

• Main Authors: Chuang-yung Wang, 王創永
• Other Authors: 林百福
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/h9a4nn

碩士 === 國立臺北科技大學 === 車輛工程系所 === 96 === Higher density, kenimatic viscosity, cetane number and oxygen content are the main advantages of biodiesel. These advantages make injection pressure increase, injection timing advance; moreover, combustion efficiency is more improved by strengthening the fuel spray penetration that forms an ideal air-fuel mixture, superior ignition ability and combustion-supporting efficiency. Thus, four different kinds of biodiesel are compared with fossil diesel in this study. After engine experiment, the combustion characteristics demonstrated that the ending time at ignition delay period for four kinds of biodiesel is all advanced. Furthermore, entire fuel spraying into combustion chamber has been almost burned during premixed combustion phase, so that the peak value of heat release rate at this time is higher than fossil diesel, and closer to TDC makes engine performance higher. Since the fuel in premixed combustion phase has been burned entirely, it makes heat release rate in the next phrases of mixing-controlled combustion and late combustion decrease; consequently, it is the reason that exhaust gas temperature of biodiesel is lower than fossil diesel.