Search

Abstract: An optically accessible single-cylinder high-speed direct-injection (HSDI) diesel engine was used to investigate the spray and combustion processes for biodiesel blends under different injection strategies. The experimental results indicated that the heat release rate was dominated by a premixed combustion pattern and the heat release rate peak became smaller with injection timing retardation. The ignition and heat release rate peak occurred later with increasing biodiesel content. Fuel impingement on the wall was observed for all test conditions. The liquid penetration became longer and the fuel impingement was stronger with the increase of biodiesel content. Early and late injection timings result in lower flame luminosity due to improved mixing with longer ignition delay. For all the injection timings, lower soot luminosity was seen for biodiesel blends than pure diesel fuel. Furthermore, NO x emissions were dramatically reduced for premixed combustion mode with retarded post-TDC injection strategies. [Copyright &y& Elsevier]

Abstract: This study investigated polycyclic aromatic hydrocarbon (PAH) and regulated harmful matter (traditional pollutant) emissions, fuel consumption, and the assessment of the inferior condition of engine oil from heavy-duty diesel engines (HDDEs) fueled with palmbiodiesel–PDF (premium diesel fuel) blends and paraffinic–palmbiodiesel blends under brand-new (the mileage was zero) engines accumulated mileage test. Experimental results indicated that the emissions of THC and CO increased with operation time but the emissions of NO x and PAHs decreased with operation time between 0 and 300h (18,000km). Using palmbiodiesel–PDF blends or paraffinic–palmbiodiesel blends instead of PDF in HDDEs reduced the emissions of THC (10.7–44.2%), CO (0.664–15.6%), CO2 (0.763–2.55%), NO x (1.25–4.97%), PM (6.11–26.8%), total PAHs (43.0–90.2%) and total BaPeq (63.1–89.6%) significantly. [Copyright &y& Elsevier]

Abstract: This work investigated the effects of induction of hydrogen and oxygen mixture (H2/O2) to a heavy-duty diesel engine (HDDE) on the thermal performance, fuel consumption and emission characteristics. The HDDE was tested at one low load steady-state condition, 24.5% of the max load (40km/h), using neat diesel and seven H2/O2 mixtures: 10–70L/min, interval 10L/min. The results show that brake thermal efficiency is increased from 31.1% for neat diesel to 39.9% for 70L/min of H2/O2 mixture. For 10–40L/min of H2/O2 mixture addition, the brake specific fuel consumption (BSFC) was higher than that of neat diesel. However, for 50, 60 and 70L/min of H2/O2 mixture addition, the BSFC was lower than that of neat diesel by about 3.2%, 9.9% and 10.5%, respectively. Due to improved combustion efficiency, the emission concentrations of hydrocarbon, carbon dioxide and carbon monoxide were all lowered, while those of the nitrogen oxides were increased. [Copyright &y& Elsevier]