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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 using bioethanol as fuel on start-up and warm-up exhaust emissions from a diesel power generator(Taylor & Francis, 2021-09-01) Altun, Şehmus; Adin, Mehmet Şükrü; Adin, Muhammed ŞakirThe present work investigates the effects of bioethanol as fuel additive on a diesel power generator’s exhaust emission (especially under transient conditions) characteristics, during the start-up followed by idling and warm-up periods, from no load to loaded cases up to 50% at ambient conditions. Experiments with diesel/bioethanol blends in 10% and 15% proportions (denoted as BE10 and BE15, respectively) were achieved in a diesel power generator following the practical operating conditions of the gen-sets. Regarding emissions, CO increased first when bioethanol is used during start-up at no load, then it starts to decrease by increasing bioethanol fraction in diesel and load applied. Unburnt HC emissions were also measured as highest for all fuels tested during start-up, while they were slightly higher for BE15 than others in the rest of the test. NOx was highest with petroleum diesel, while it was lowest with BE15 at start-up. Despite higher NOx was measured with BE10, those of petroleum diesel and BE15 were similar during warm-up together with applying load. Smoke opacity was lowest in BE15; however, BE10 was highest. By applying load, it increased and the highest NOx was measured with BE10, while the lowest was with BE15.Öğe The effect of microalgae biodiesel on combustion, performance, and emission characteristics of a diesel power generator(VINCA Institute of Nuclear Sciences, 2018) Yaşar, Fevzi; Altun, ŞehmusMicroalgae oil is expected to be a relevant source of biofuel in the future as it is more favorable to confront the problems of food shortages and greenhouse emission challenges raised by conventional biofuels. Therefore, in this study, a most common kind of microalgae that have a great potential, Chlorella protothecoides, was evaluated as fuel in terms of its combustion and emission characteristics in a Diesel engine-powered generator set at constant engine speed of 1500 rpm under various loads after converting its oil to biodiesel by typical base-catalyzed transesterification process. A biodiesel/diesel blend at the rate of 20% by volume was tested too. According to results obtained, using biodiesel resulted in an increase in fuel consumption, in a slight reduction of efficiency, and in sharp reductions in both unburned hydrocarbon emissions and smoke opacity especially at light loads, despite increasing NOx emissions were observed when compared with conventional petroleum diesel. In addition, premixed combustion ratio was higher for biodiesel than for diesel while total combustion duration took shorter for biodiesel especially at higher loads. The overall results of the study reveals that the combustion parameters of the biodiesel studied here are within the typical ranges of conventional biodiesel fuels.Öğe 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.
