Effects of gasoline and iso-butanol addition on combustion and pollutant emissions of a common-rail diesel engine at different injection timing

• Published in: Fuel (Guildford) Vol. 256; p. 115853
• Main Authors: Li, Song, Liu, Jinping, Wang, Fei, Li, Yu, Wei, Mingrui, Xiao, Helin, An, Zhaojie
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.11.2019; Elsevier BV
• Subjects: Air pollution; Butanol; Carbon monoxide; Combustion; Combustion characteristics; Diesel; Diesel engine; Diesel engines; Diesel fuels; Diesel/gasoline/iso-butanol; Emission; Fuels; Gasoline; High pressure; Injection; Injection timing; Mixtures; Nitrogen oxides; Nucleation; Oxides; Particulate emissions; Particulate matter; Particulates; Photochemicals; Pollutants; Pressure; Emission; Diesel engine; Combustion characteristics; Diesel/gasoline/iso-butanol; Injection timing
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2019.115853

•Effects of injection timing and diesel/gasoline/iso-butanol were investigated.•The addition of iso-butanol to DGBF can enhance the engine efficiency.•PM emitted from blends exhibit a higher ratio of sub-10 nm particle numbers.•The addition of iso-butanol to DGBF can improve the NOx-PM trade-off. Combustion and pollutant emissions from a high pressure common-rail diesel engine using ternary diesel/gasoline/iso-butanol blends were investigated experimentally in order to improve combustion process and farther decrease emissions of diesel/gasoline blends. The experiments were carried out at five injection timings under medium engine load. Four fuels were tested in this work, D100 (pure diesel) was tested for baseline comparison, the other three fuels were DG (30% gasoline in diesel fuel by mass), DGB (15% gasoline and 15% iso-butanol in diesel fuel) and DB (30% iso-butanol in diesel fuel). Experimental results indicate that DG, DGB and DB delayed the ignition timing periods and shortened the combustion durations, resulting in higher levels of premixed combustion and maximum pressure rise rates (MPRRs). Meanwhile, DGB and DB showed higher brake thermal efficiencies (BTEs) than DG and D100. It was also found that adding gasoline and iso-butanol, substantial decrease in carbon monoxide (CO) emissions, particulate diameters, nucleation mode (NM) and accumulation mode (AM) particle numbers were achieved, but the emissions of unburned hydrocarbons (HC) and nitrogen oxides (NOx) were increased slightly. DGB and DB produced better NOx-particulate matter (PM) trade-off than DG and D100 in combination with retarded injection timing. Furthermore, PM emitted from blend fuels showed higher ratios of sub-10 nm particle number concentrations, the sequence is D100 < DG < DGB < DB, which may be more harmful to human health.