3 sonuçlar
Arama Sonuçları
Listeleniyor 1 - 3 / 3
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 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.
