Performances and combustion characteristics of dimethyl ether fueled light duty direct injection diesel engine

作者：Zhou Longbao^*; Wang Hewu; Huang Yongcheng; Jiang Deming; Huang Zuohua

来源：Journal of Xi'an Jiaotong University, 2000, 34(1): 9-13.

• Combustion characteristics
• Dimethyl ether fueled diesel engine

This paper is concerned with and experimental study of a light duty direct injection diesel engine operating on dimethyl ether (DME). The effects of plunger diameter, nozzle type, fuel delivery advance angle, vertical distance of nozzle tip into cylinder, injection pressure and swirl ratio on performances and emissions of DME engine are investigated. The indicator diagrams and needle valve lifts are recorded. The combustion and emission characteristics are evaluated and compared with those for an engine operating on diesel fuel. The results show that the thermal efficiency improves for larger diameter injection plunger and total orifice flow area injector. The average thermal efficiency of DME engine is about 2%-3% higher than that of diesel engine. The former can reduce NOx emission significantly and achieve smokeless combustion. Combustion characteristics include injection and ignition delays, the rate of pressure rise and the maximum cylinder pressure and the heat release for DME engine are compared with diesel engine. The experimental and calculating results show that the injection delay (in crank-angle) is longer because of the lower acoustic velocity in liquid DME. The ignition delay is much shorter and the peak pressure is far lower due to less premixing combustion. The diffusion combustion of DME operation is much faster and this leads to the reduction of smoke, PM, hydrocarbon and monoxide emissions. The study demonstrates that DME is an excellent alternative fuel for compression ignition engine.

• 出版日期2000