Effects of High EGR Rate on Dimethyl Ether (DME) Combustion and Pollutant Emission Characteristics in a Direct Injection Diesel Engine

Energies

Seung Hyun Yoon¹  Seung Chul Han¹ 

[1] Division of Automotive Engineering, Yeungnam College of Science & Technology, 170 Hyeonchung-ro, Nam-gu, Daegu 705-703, Korea; E-Mails:

关键词: dimethyl ether;    alternative fuel;    combustion characteristics;    exhaust gas recirculation;    particle emission;   

DOI  :  10.3390/en6105157

来源: mdpi

【 摘 要 】

This study investigated the effects of high exhaust gas recirculation (EGR) rates on dimethyl ether (DME) fuel combustion performance, exhaust emissions and particle emission characteristics in a small direct injection diesel engine under various injection timings. To examine the effect of EGR and injection timings, the experiment was performed under high EGR rates (0%, 30%, 50%) and injection timings were varied from 40° before top dead center (BTDC) to top dead center (TDC) of the crank angle to examine the effects of early injection of DME fuel. The combustion pressures and heat release rates for different EGR rates followed similar trends. As the injection timing was advanced, the indicated mean effective pressure (IMEP) differed little in response to EGR rate in the range from TDC to 25° BTDC, and more for crank angles beyond 25° BTDC. DME combustion exhibited very little soot emission, but soot emission increased slightly with EGR rate. The use of high EGR during combustion produced very low NO_x concentrations but increased HC and CO emissions for advanced injection timings from 25° BTDC to 40° BTDC. The use of EGR increased both the emissions of total particle number and particle volume over the whole range of the injection timings; for all cases, total particle volume decreased as injection timing was advanced.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.