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Öğe Şanlıurfa ilinde yatay yüzeye gelen anlık global güneş ışınımının modellenmesi(Dicle Üniversitesi, 2019-03-15) Karakaya, Hakan; Kallioğlu, Mehmet Ali; Avcı, Ali Serkan; Ercan, UmutBu çalışma ile Şanlıurfa ilinin iklim özellikleri ve topografik yapısı göz önüne alınarak yatay düzleme gelen aylık ortalama günlük global güneş radyasyonunun tespit edilebilmesi için literatürde yer alan 5 farklı model incelenmiştir. Sonuçlar istatistiksel karşılaştırma metotları, belirlilik katsayısı (R²), ortalama yüzde hata (MPE), sapma hatası (MBE), ortalama mutlak hata yüzdesi (MAPE), bağıl hata karesi (SSRE), bağıl standart hata (RSE), ortalama karekök hatası (RMSE), bağıl hata yüzdesi (e) ve t-istatistik (t-sat) ile olmak üzere dokuz farklı istatistik yöntemi ile karşılaştırılmıştır. Şanlıurfa ili için en uygun yaklaşım için bir sonuç verilmiştir. İstatistiksel hata sonuçlarına göre Cheegar ve Chibani Modeli yatay düzleme gelen global güneş ışınımı için Şanlıurfa ilinde kullanılacak en uygun model olarak belirlenmiştir. Sonuç olarak Şanlıurfa ili toplam güneş radyasyonu tahmini için polinom modelin tercih edilmesi önerilmiştir. Bu model verilerine göre Şanlıurfa ili için yıllık güneş enerjisi potansiyeli 4332,020 W/m2 /ay olarak belirlenmiştirÖğe Numerical and experimental investigation of solar chimney power plant system performance(Taylor & Francis, 2020-03-15) Karakaya, Hakan; Durmuş, Aydın; Avcı, Ali SerkanA prototype of a solar chimney power plant was performed by modeling in this study. The performed prototype was experimentally confirmed. Temperature, velocity, and radiation values were measured to actualize the confirmation. Experimental data that were obtained to determine the performance of solar chimney whose prototype was actualized by the help of measured values were computationally analyzed. The geometry of a solar chimney in the analysis was bidimensionally (2D) drawn on an axis of symmetry. The numerical simulation was analyzed with computational fluid dynamics (CFD) method. Since analysis results show that there is turbulent flow in system (RNG), k-ɛ turbulence model was used. Continuity, momentum, and energy equations were applied to the solar chimney system via the finite volume method. Moreover, DO (discrete ordinates) model was inserted in analysis to evaluate the radiation effect in the collector area. In addition to all these, correlation results between SPSS 17 statistics program and data obtained were evaluated. Finally, with reference to the comparison between numerical and experimental results, data obtained and numerical data are close to each other; the prototype is applicable to the real systems.Öğe Calculating energy-induced carbon footprint: Batman University case(European Journal of Technique (EJT), 2019-06-30) Karakaya, Hakan; Avcı, Ali SerkanThis study determined the energy-induced carbon footprint arising from energy consumption in Batman University. It is important for universities to do acts toward control the greenhouse gas emission based on energy consumption while performing activities. Therefore, there is need to know the components of carbon footprint. Electric energy, natural gas energy, and various oils as the energy consumption components in these institutions were scrutinized. Petrol, diesel fuel, and fuel oil were utilized as types of oil. It is seen that the component which considerably specifies the carbon footprint is 3.161.238 ton CO2 value and electric energy. Natural gas and fuel oil use contribute to carbon footprint at high ratios in winter months especially arising from heating. 361 ton CO2 based on natural gas use and 1.256.445 ton CO2 based on fuel oil use are other components which specify the carbon footprint. As a result, the primary carbon footprint for Batman University was determined by IPCC Methodology and Tier 1 approach; it is 3.162.855,445 ton CO2 for 2017Öğe Creating the optimum panel inclination angles of the southern aegean region(International Journal of Advances in Science Engineering and Technology, 2018-01) Karakaya, Hakan; Ercan, Umut; Kallioğlu, Mehmet Ali; Avcı, Ali Serkan; Genç, ÖmerValues that are used in solar energy applications are usually calculated by data for radiation reaching a horizontal plane. In order to achieve maximum efficiency in solar energy, panels must be at a suitable angle and position. This study determined monthly optimum panel angles for the Southern Aegean Region (Muğla) in Turkey and created three different correlations. In an annual course (January-December), panel angles varied in the order of 590 , 490 , 380 , 200 , 50 , 00 , 00 , 150 , 320 , 490 , 590 and 610 . The average annual panel inclination angle was 32.250 , and in the case of changing the angles monthly, the annual efficiency increased by 17.03% in comparison to horizontal position and reached the average annual radiation value of 5949 W/m2 -year. The best estimation model developed for the region was in the form of β . = 0,0002(δ) ଷ − 0,0092(δ) ଶ − 1,4379(δ) + 34,72. The statistical analysis values were R2 (0.9973), MBE (0.0031), RMSE (1.22) and t-sat (0.0085), while they successfully corresponded to the panel inclination values.Öğe Empirical modeling between degree days and optimum insulation thickness for external wall(Taylor & Francis, 2020-03) Karakaya, Hakan; Kallioğlu, Mehmet Ali; Ercan, Umut; Avcı, Ali Serkan; Fidan, CihatInsulating is the most effective method that is used to save energy in buildings. Samples from cities from different climatic zones from TS 825 (Turkey) first. Optimum insulation thickness () analysis is based on two types of insulating and four different fuels (natural gas, coal, fuel oil and electric) of related cities. Cost accounts, payback period and CO2-SO2 emission calculations were performed based on these analyses. Second of all, the relationship between a number of degree day (NDD) and optimum insulation thickness () was developed by linear, quadratic and cubic correlations. Thirty different mathematical correlations based on different fuel types by using XPS and EPS insulating materials. Twenty-four of these models that were developed were generated peculiar to the fuel type; six of them were generated based on average insulation thickness. R2 values of related correlations are between 0.9989 most and 0.9952 at least as well as it is pretty close to (R ≤ 1) one value. The model among these models is the cubic mathematical model that gives the best average value. a = 0.0036, b = 5E-05, c = – 7E-09 and d = 6E-13 are the values for XPS material. Following values are for EPS material; a = 0.0028, b = 5E-13, c = – 7E-09 and d = 4E-05. R2 determination coefficient of both two equations is pretty close to 0.9989 and 1; the models obtained are less-than-stellar. Optimum insulation thickness of the area can be known based on the type of material via the number of degree day without the need for long analyses. According to the R2 values, the use of all models is recommended for academic and industrial users.
