Combustion and exhaust emissions of canola biodiesel blends in a single cylinder DI diesel engine

In this study, effects of the canola biodiesel blends in 5%, 10%, 15% and 20% proportions (in vol.) with diesel fuel were investigated at four loads (4.8, 3.6, 2.4 and 1.2 bar BMEP) in a single-cylinder DI engine. Comprehensive combustion analyses showed that, although the start of injection timings were inadvertently advanced from the system response, the combustion of canola biodiesel blends generally resulted in shorter ignition delay period for all loads due to earlier combustion timing. The maximum heat release rate generally decreased gradually with the reduction of premixed combustion fractions and corresponding increase in the diffusion combustion fractions when the canola biodiesel ratio was increased. Slightly reducing the maximum in-cylinder pressures and maximum in-cylinder pressure rise rates were caused a slight retardation on the center of heat release locations and longer combustion durations. BSFC results increased up to 6.56% and BTE reduced up to 4.2% when the canola biodiesel ratio was increased to 20% at the high load. The canola biodiesel blends also resulted in higher NOx emissions of 8.9% as well as lower smoke, CO and THC but slightly higher CO2 emissions for all loads. © 2017 Elsevier Lt

Effects of retarded fuel injection timing on combustion and emissions of a diesel engine fueled with canola biodiesel

In this study, retarded injection timing was investigated to overcome higher NOx emissions of a direct injection diesel engine fueled with diesel fuel (90%)/canola biodiesel (10%) blend. The experiments were performed at the maximum torque speed (2200 rpm) under four loads (3.75 Nm, 7.5 Nm, 11.25 Nm and 15 Nm) and three injection timings (original −28 °CA, 26 °CA and 24 °CA bTDC). The effects of the retarded fuel injection timings on the performance, the emissions and the combustion were examined in detail. The changes in the cylinder pressure, the combustion timing, the heat release rate, the fractions and the durations of premixed and diffusion combustion phases, the injection and the ignition delays, NOx, total hydrocarbon, CO, CO2, smoke, break specific fuel consumption and break thermal efficiency were determined and presented in the paper. The experimental results showed that the injection retardation of 2 °CA could satisfy lower NOx and break specific fuel consumptions without significant adverse effects on the other engine parameters, while the further retarding of the injection timing deteriorated the parameters. The retarded injection timing of 2 °CA provided decreases in NOx up to 11% and in BSFC up to 2.7%. © 2020 Karabuk Universit

Combined effects of soybean biodiesel fuel addition and EGR application on the combustion and exhaust emissions in a diesel engine

In this study, soybean biodiesel fuel was blended in 20 vol.% with diesel fuel and tested in a single-cylinder, DI, four-stroke diesel engine under four different engine loads (15, 11.25, 7.5 and 3.75 Nm) and 2200 rpm engine speed with different EGR rates (5, 10, 15%). The results showed that the maximum heat release rate and maximum in-cylinder pressure were mostly increased with the combined effects of biodiesel fuel addition and EGR application. Premixed combustion fractions were generally increased at all the engine loads with corresponding decrease in the diffusion combustion fractions. Combustion durations were generally stable while the center of the heat release rates shifted toward TDC. Reasonable increments on the BSFC and reductions on BTE as a maximum 6% and 3% occurred with 15% EGR, respectively. NOx and smoke emissions were improved simultaneously up to 55% and 15% at the high engine load, respectively. THC emissions at the low and medium engine loads decreased while deteriorations were observed with more than 5% EGR at the high engine load. Although CO emissions showed insignificant changes, there were increments at the high engine load. However, CO2 emissions were slightly higher for all the engine loads. © 2015 Elsevier Ltd. All rights reserved