6 sonuçlar
Arama Sonuçları
Listeleniyor 1 - 6 / 6
Öğe Biofuels derived from Turkish industry wastes - A study of performance and emissions in a diesel engine(Wiley-Blackwell, 2015-08-13) Altun, Şehmus; Rodríguez-Fernández, JoséRecently, research has focused on the biofuel production from local industrial wastes due to the risk of greenhouse emissions derived from land-use change (both directly and indirectly) of conventional feedstock and the social concern about the effect of conventional biofuel production on oil prices and its availability (the so-called food vs. fuel debate). Therefore, with the aim to evaluate the use of biofuels derived from wastes from traditional manufacturing industries in Turkey, biodiesel fuels from leather fat, obtained as a by-product in the leather industry, waste anchovy fish oil, derived from the fish-processing industry, and waste frying cottonseed oil achieved from food industry, have been tested in a three-cylinder DI diesel engine at a steady-state condition. In a previous work, the viability of these fuels was evaluated by analyzing measured and estimated properties and indicators for main diesel emissions, and recommendations were made on their alternative use to conventional biodiesels with the benefit of potentially lower life-cycle greenhouse emissions. The experimental results, which were compared with ULSD operation, demonstrated that the engine performance was not significantly affected, while a substantial change in emissions was observed with the use of biofuels. In general, the emission results reported here are in a similar range to those obtained with the use of conventional biodiesel fuels. Nonetheless, the exact magnitude of these changes depended upon the biodiesel origin. Lubricity of alternative biofuels was also tested, revealing an enormous capacity for protecting the fuel system from wear, in line with conventional biodiesel fuels.Öğe Effects of isopropanol-butanol-ethanol (IBE) on combustion characteristics of a RCCI engine fueled by biodiesel fuel(Journals & Books, 2021-10) Altun, Şehmus; Okcu, Mutlu; Varol, Yasin; Fırat, MüjdatThe reactivity controlled compression ignition (RCCI) strategy using fuels with different reactivity’s has attracted attention due to its high thermal efficiency as well as very low NOx and PM emissions in comparison to conventional combustion. As previous studies have shown that the type and amount of low reactivity fuel have a significant contribution to the in-cylinder reactivity, thus RCCI combustion, in this study, Iso-Propanol-Butanol-Ethanol (IBE), which has comparable characteristics to n-butanol and ethanol, is employed as low reactivity fuel (LRF) in a RCCI engine fueled by petroleum based EN590 fuel and commercial biodiesel. The IBE mixture was in volumetric ratios of 3:6:1 as in the fermentation process of butanol, that is to say; 30% Iso-Propanol, 60% Butanol and 10% Ethanol. In each experimental condition, keeping the total energy of the fuel supplied to the engine in conventional combustion mode for each cycle as constant, the premixed ratio (Rp) in case RCCI combustion was applied as 0%, 15%, 30%, 45% and 60% (the amount of LRF in energy basis) over this energy amount. The effect of premixed ratio of IBE on combustion characteristics were investigated in a single-cylinder RCCI engine under different loads with using both petroleum diesel and biodiesel as high-reactivity fuels (HRF), respectively. According to experimental results, a higher in-cylinder pressure was measured by using diesel in both conventional and RCCI mode compared to the use of biodiesel. Considering the peak in-cylinder pressure and rate of heat release, the premixed ratio (Rp) of up to 45% was found as optimum for all loads while it was up to 30%Rp for the NOx emissions. In addition, the biodiesel-fueled RCCI engine produced the lowest smoke opacity in all loads and it gradually decreased by up to 97% with the application of the RCCI strategy. Furthermore, the results showed that a simultaneous reduction in NOx and smoke opacity could be obtained under 60% load and up to 30% Rp with a marginal increase in unburned HC emissions.Öğe The use of waste transformer oil as alternative fuel in a diesel power generator(International Journal of Automotive Engineering and Technologies, 2019-10-31) Altun, Şehmus; Yıldız, AbdulkerimIn this study, waste transformer oil (WTO) was investigated as a fuel candidate for a diesel power generator set in terms of its fuel and combustion characteristics. Kinematic viscosity, which is the most restrictive property of WTO (9.6 mm2 /s at 40 oC), was measured on different blends with a conventional diesel fuel (in 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100% by volume) in order to detect the suitable blending ratio to be used in engine without any modification, and to propose some blending strategies to optimize engine performance and emissions. The blended fuels containing WTO up to 50% with diesel by volume were found to have a viscosity which is within standard value specified for conventional diesel fuels, i.e., 2.0-4.5 mm2 /s in EN590, and in case 60% WTO, it agrees with EN14214 (3.5-5.0 mm2 /s) alternative diesel fuel standards. It is also found that a fuel blend containing 20% WTO and 80% diesel have a kinematic viscosity and density which are very close to conventional diesel’ values. Therefore, WTO was blended with diesel at the rate of 20% by volume and then tested in a 4-stroke and 4-cylinder diesel engine powered generator set under constant speed-variable load conditions. Measured and calculated results were compared with the results of conventional diesel tested under the same conditions. Experimental results showed that specific fuel consumption, NOx and unburned HC emissions reduced when using blended fuel instead of conventional diesel. Cylinder gas pressure was higher for blended fuels than that of conventional diesel while the start of combustion was later in the case of blended fuelsÖğe Effect of biodiesel addition in a blend of isopropanol-butanol-ethanol and diesel on combustion and emissions of a CRDI engine(Taylor & Francis, 2021-05-21) Altun, Şehmus; İlçin, KutbettinThe increasing demand for energy and the fact that petroleum, which is the most used energy source, has a limited reserve, have led researchers to search for new and renewable energy sources. In this context, biofuels such as biodiesel and bio alcohols have been studied and used in internal combustion engines for a long time. However, with the developments in technology, the production and use of such alternative fuels in different engine technologies is still a subject of research. In this regard, isopropanol-butanol-ethanol (IBE) has received an increasing attention over standard alcohols and its potential as a substitute for other alcohol fuels in internal combustion engines has been researched recently. Therefore, the purpose of the experimental study is to investigate the effect of biodiesel addition at rates of 20% and 40% by volume in a blend of IBE (30% v/v) with petroleum-based diesel (70% v/v) on the combustion and emission characteristics of a single-cylinder common-rail direct injection engine at constant engine speed of 2400 rpm and 60% load conditions. Experimental results showed that all blended fuels presented a potential to reduce smoke opacity by 27% − 41%, CO emissions by 44% − 66% and unburnt HC emissions (up to 31.8%) but increase NOx emissions by 5% − 24.6% compared to diesel. However, adding biodiesel caused to a slight increase in smoke opacity and CO emissions while decrease in unburned HC and NOx emissions compared to the blend of IBE and diesel. Combustion analysis also showed that the use of blended fuels led to the increase of peak cylinder pressure (by 7%) and the significant improvement in the rate of heat release was observed, which further increased with the addition of biodiesel to blend of IBE and diesel. It was concluded that ternary blends was performed better than the blend of IBE and diesel while biodiesel addition was found to be beneficial in terms of reduction of unburnt HC and NOx emissions along with improved performance.Öğe Emissions from a diesel power generator fuelled with biodiesel and fossil diesel fuels(SAGE Journals, 2015-08-01) Altun, ŞehmusThe aim of this work was to compare the emission characteristics of a biodiesel derived from waste cooking sunflower oil and two fossil diesel fuels (ultra-low sulphur diesel and its type of containing gas-to-liquid). The tests were conducted on a direct-injection diesel engine-powered generator set, which is the type of generator applied in institutional facilities, under variable load and constant engine speed conditions. Experimental results showed that diesel containing gas-to-liquid and biodiesel reduced smoke opacity while NOx emissions were slightly higher for both fuels. An increase in fuel consumption was also observed for biodiesel compared with both fossil diesels. Unburned HC emissions were high for biodiesel, but overall level of CO emissions remained very low for all fuels testedÖğe Determining optimal artificial neural network training method in predicting the performance and emission parameters of a biodiesel-fueled diesel generator(International Journal of Automotive Engineering and Technologies, 2019-04-03) Altun, Şehmus; Ertuğrul, Ömer FarukArtificial neural network (ANN) methods were employed and suggested in modeling the emissions and performance of a diesel generator fueled with waste cooking oil derived biodiesel during steady-state operation. These papers are generally built on determining optimal network structure, but the modelling accuracy of an ANN is also highly dependent on employed training method. In modeling, operating conditions and fuel blend ratio were used as the inputs while the performance and emission parameters were the outputs. The modeling results obtained by conventional ANNs that were trained by back propagation (BP) learning algorithm, radial basis function (RBF), and extreme learning machine (ELM) were compared with experimental results and each other. The accuracy of the estimations by ELM was above 95% for all the output parameters except for specific fuel consumption and thermal efficiency. Moreover, ELM performed better than BP and RBF with lower mean relative error (MRE) in case where the emissions were estimated. The ELM provided correlation coefficients of 0.987, 0.950 and 0.996 for unburned hydrocarbons (HCs), nitrogen oxides (NOx) and smoke opacity (SO), respectively, while for BP, they were 0.973, 0.818, 0.993, and for RBF, 0.975, 0.640 and 0.981. The most suitable training function for each emission and performance parameters of diesel generator was determined based on obtained accuracies.
