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Öğe Combustion, performance and emissions of a diesel power generator fueled with biodiesel-kerosene and biodiesel-kerosene-diesel blends(Elsevier, 2017-02-05) Bayındır, Hasan; Işık, Mehmet Zerrakki; Argunhan, Zeki; Yücel, Halit Lütfi; Aydın, HüseyinHigh percentages of biodiesel blends or neat biodiesel cannot be used in diesel engines due to high density and viscosity, and poor atomization properties that lead to some engine operational problems. Biodiesel was produced from canola oil by transesterification process. Test fuels were prepared by blending 80% of the biodiesel with 20% of kerosene (B80&K20) and 80% of the biodiesel with 10% of kerosene and 10% diesel fuel (B80&K10&D10). Fuels were used in a 4 cylinders diesel engine that was loaded with a generator. Combustion, performance and emission characteristics of the blend fuels and D2 in the diesel engine for certain loads of 3.6, 7.2 and 10.8 kW output power and 1500 rpm constant engine speed were experimented and deeply analyzed. It was found that kerosene contained blends had quite similar combustion characteristics with those of D2. Mass fuel consumption and Bscf were slightly increased for blend fuels. HC emissions slightly increased while NOx emissions considerably reduced for blends. It was resulted that high percentages of biodiesel can be a potential substitute for diesel fuel provided that it is used as blending fuel with certain amounts of kerosene.Öğe Aspir ve kanola biyodizeli kullanımının egzoz emisyonu ve motor performansına etkilerinin incelenmesi(Küresel Mühendislik Çalışmaları Dergisi, 2016-04-01) Aydın, Hüseyin; Işık, Mehmet Zerrakki; Ziyadanoğulları Budak, Neşe; Oktay, Hasan; Bayındır, Hasan; Yücel, Halit LutfiBiodiesel fuel, which can be produced from crude or waste vegetable oil, is an important alternative renewable fuel for diesel engines. Particularly the use of vegetable oils for diesel engines has found an important place in several surveys. Biodiesel can be used alone, or blended with petrodiesel in any proportions. Biodiesel is suitable for usage at conventional diesel engines without modification. In this study, canola and safflower oil biodiesel methyl is realized by using the esterification method.. The produced biodiesels were blended in %(50) (in volume) with diesel fuel. The blends were tested in a four cycle, four cylinder Diesel engine. The effects of biodiesel addition to Diesel No. 2 on the performance and emissions of the engine were examined at full load. The resulting performance values were found to be similar to diesel fuel. In general, specific fuel consumption of biodiesel is higher than diesel at all engine loads. Significant difference between the exhaust temperature is not determined. AB50 biodiesel compared to diesel HC emissions at high loads began to decline. NOx, CO2 and O2 emissions ratio has increased at high loads for Biodiesel fuels. Experimental results showed that the produced biodiesels can be partially substituted for the diesel fuel at most operating conditions in terms of the performance parameters and emissions without any engine modification and preheating of the blends.Öğe Konsantrik boru tip ısı değiştiricilerinde türbülatörlerin kanat delik geometrisinin ısı transferine ve basınç düşüşüne etkisi(Fırat Üniversitesi, 2011) Işık, Mehmet Zerrakki; Argunhan, Zeki; Yıldız, CengizThe effect of wing hole geometry of the vortex generator on heat transfer and pressure drop in concentric tube type heat exchangers has been investigated in this study.For experiments, two type of hole geometrywereselected.One has four rectengular hole with 2x7mm in dimension andthe other four circular hole with 5mm in diameter andapplied for 55-65-75-90 degree blade angles. Turbulator diameter is 60 mm and includes 6 blades. Air was used as hot stream, whereas water as cold stream. Experimental results were scrutinized.Heat transfer and pressure drop werefound high with usage of circular holes geometry.Öğe Analysis of ethanol RCCI application with safflower biodiesel blends in a high load diesel power generator(Elsevier, 2016-11-15) Işık, Mehmet Zerrakki; Aydın, HüseyinThe effects of RCCI in a diesel power generator by using safflower oil biodiesel-diesel blends were experimentally investigated. Ethanol was premixed as PFI by rates of 30% and 50% of total mass fuel consumption of the engine. Tests were conducted at constant engine speed of 1500 rpm and fixed load 10.8 kW engine power. The purpose of blending biodiesel with diesel is to increase the fuel reactivity of primary fuel in order to easily initiate the combustion. Therefore, test fuels were prepared by blending 10% of the biodiesel with 90% of diesel, 20% of the biodiesel with 80% of diesel and 50% of the biodiesel with 50% of diesel. The most important combustion, performance and emission indicators of the engine under various conditions have been deeply investigated and results have been presented. The ethanol RCCI operation increased peak pressure values especially with using of B50 as high reactivity fuel while combustion was retarded for both RCCI modes. Overall, many indicators of the combustion was improved. Performance parameters were developed. Especially, bsfc was considerably increased. NOx, emissions were considerably decreased while CO and HC emissions were a bit increased.Öğe Combustion parameters of canola oil kerosene blend in different loading operations of a diesel engine power generator(Kilis 7 Aralık Üniversitesi, 2016) Aydın, Hüseyin; Işık, Mehmet ZerrakkiÖğe Comparison of CLTD and TETD cooling load calculation methods for different building envelopes(Mugla Sitki Kocman University, 2020-06-30) Oktay, Hasan; Yumrutaş, Recep; Işık, Mehmet ZerrakkiThe estimation of the cooling load through the building envelope is an essential task in the selection of proper HVAC system components that influences the building’s performance. For this task, ASHRAE has presented several methods to calculate the building cooling load due to heat gain, such as the total equivalent temperature difference method (TETD), the cooling load temperature difference method (CLTD), and the radiant time series method (RTS). The present study aims to explore the accuracies of those calculation methods in terms of energy efficiency. In this regard, an analytical solution method utilizing Complex Finite Fourier Transform Technique (CFFT) was developed for the calculation of cooling load due to heat gain to compare the temperature differences obtained from the TETD and CLTD methods. Then, a computer program was prepared in MATLAB to perform the calculations based on an analytical methodology. Besides, the estimated CLTD and TETD values by the CFFT were compared with those values presented in the Handbook of the ASHRAE. The calculation results revealed there is a good agreement between the analytical and presented results in the ASHRAE Manual for the selected building envelopes. However, several differences were found between the estimated TETD and CLTD cooling load values and those presented in the Handbook of ASHRAEÖğe An investigation of the influence of thermophysical properties of multilayer walls and roofs on the dynamic thermal characteristics(Mugla Sitki Kocman University, 2016-06-09) Oktay, Hasan; Argunhan, Zeki; Yumrutaş, Recep; Işık, Mehmet Zerrakki; Budak Ziyadanoğulları, NeşeThe growing concern about energy consumption of heating and cooling of buildings has led to a demand for improved thermal performances of building materials. To achieve this goal, in this study, an investigation is performed to analyze the influence of thermophysical properties and thickness of various multilayer building walls or roofs in a building on the dynamic thermal characteristics, such as the decrement factor (DF), time lag (TL) and heat gain. In order to find the thermal performance characteristics of building structures, such as briquette, brick, blockbims and autoclaved aerated concrete (AAC), which are commonly used in Turkey, an analytical solution method was developed in a computer program in MATLAB and results are compared to determine suitable wall or roof material. Calculation method for the heat flow is based on solution of transient heat transfer problem for the multilayer structures. The program is executed to calculate hourly heat gain values for these samples over a period of 24 h during design day for Gaziantep, Turkey. It was found that thermophysical properties of roofs or walls have a very profound effect on the time lag (TL), decrement factor (DF) and also heat gain.Öğe Evaluation of combustion, performance and emission indicators of canola oil-kerosene blends in a power generator diesel engine(Elsevier, 2017-03-05) Aydın, Hüseyin; Işık, Mehmet Zerrakki; Bayındır, HasanDirect use of vegetable oils as fuel in diesel engines leads to some important engine operational problems that need to be solved in order to make their usability possible. Canola oil was blended with kerosene by percentages of 90% canola oil-10% kerosene (C90&K10), 75% canola oil-25% kerosene (C75&K25) and 50% canola oil-50% kerosene (C50&K50). These blend fuels were initially analyzed by means of physicochemical fuel properties and comparisons were made with standard diesel fuel. Blend fuels and standard diesel fuel (D2) were than tested in a diesel power generator with 4 cylinders in order to investigate the combustion, performance and emission characteristics of the blend fuels and compare them with the petroleum based diesel fuel (D2). All experiments were carried out at specified output power values of 3.6, 7.2 and 10.8 kW and 1500 rpm constants speed. The combustion characteristics of canola oil kerosene blends have found be quite similar to those of D2. Mass fuel consumption and brake specific fuel consumption (bsfc) were slightly increased for blend fuels. Nitrogen oxide (NOx) emissions and exhaust smoke opacities were considerably reduced for blends while carbon monoxides (CO) and unburned hydrocarbon (HC) emissions were a bit increased. It can be concluded that kerosene blended vegetable oils can be used as fuel with improved combustion and performance characteristics compared to those of pure vegetable oils.Öğe The effect of n-butanol additive on low load combustion, performance and emissions of biodiesel-diesel blend in a heavy duty diesel power generator(Elsevier, 2017-04) Işık, Mehmet Zerrakki; Bayındır, Hasan; İşcan, Bahattin; Aydın, HüseyinDiesel power generators are often used under partially load conditions. Especially, under low load conditions, it is crucial to find a solution for their considerably high brake specific fuel consumption (bsfc) and exhaust output emissions. Other points are the usability of waste cooking oil and an oxygenated alternative fuel in low load conditions of diesel generator. In this point of view, 10% n-butanol and 10% biodiesel mixture was blended with 80% of ultra low sulfur diesel fuel named here as BB20 was used and comparisons have been made with 20% biodiesel/80% diesel fuel named here as B20 and ultra low sulfur diesel fuel named here as (D2). Previously, main important physical and chemical fuel properties of test fuel have been found. These fuels were tested in low load operations of a diesel engine generator in order to find out the effects of blend fuels on combustion characteristics, performance and emissions of the test engine. The test results are presented in this paper and seem to raise quite interesting points. Butanol addition to diesel and biodiesel blends can be considered as a good solution for reducing density, viscosity and thus sustainable usability of biodiesel and increase thermal efficiency and lower carbon monoxide (CO) and oxides of nitrogen (NOx) under comparatively lower load conditions in diesel power generator engines.Öğe Bina duvarlarının termofiziksel özellikleri arasındaki ilişkilerin kullanılarak bu özelliklerin ısı kazancına olan etkisinin incelenmesi(Fırat Akademi A.Ş, 2017) Oktay, Hasan; Yumrutaş, Recep; Argunhan, Zeki; Işık, Mehmet ZerrakkiBinaların ısıtılması ve soğutulması için tüketilen enerjinin gün geçtikçe artması ısıl performansı yüksek olan inşaat malzemelerinin geliştirilmesine ihtiyaç duyulmuştur. Malzemelerin ısıl performansı ise direk olarak bu malzemelerin termofiziksel özelliklerine bağlıdır. Her ne kadar literatürde termofiziksel özelliklerin ısıl performans kriterleri olan ısı kazanç, zaman kayması gibi dinamik ısıl karakterlerine olan etkileri incelense de, bu özelliklerin birbiri arasındaki ilişkiler göz ardı edilmiştir. Bu amaçla; her bir termofiziksel özelliğin ısı kazancına olan etkisini incelemek için bir çalışma gerçekleştirilmiştir. Farklı bileşimli 102 beton duvar numunesi üretilerek, termofiziksel özellikleri ASTM ve EN standartlarına göre ölçülmüş ve aralarındaki ilişkiler yeni ifadelerle tanımlanmışır. Daha sonra bu ilişkiler kullanılarak, Gaziantep’ te sıcak bir günde herhangi duvar ve tavanda oluşan ısı kazancını hesaplamak amacıyla kompleks Fourier dönüşüm tekniği (CFFT) kullanılarak MATLAB tabanlı bir bilgisayar programı hazırlanmış ve elde edilen sonuçlar irdelenmiştir. Sonuç olarak, bu yapılan çalışma sayesinde herhangi bir termofiziksel özelliği belli olan duvarların ısı kazançları kolaylıkla hesaplanabilmektedir.
