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Öğe 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 Effects of ethanol addition to biodiesel fuels derived from cottonseed oil and its cooking waste as fuel in a generator diesel engine(Taylor & Francis, 2020-03) Karakaya, HakanExploration of energy sources such as renewable and non-edible vegetable oils has been continued during the recent two decades of 2000s. Cottonseed oil is a non-edible, abundant oil and is generally used as cooking oil. In the present study, the usability of biodiesel derived from both cottonseed oil and its cooking wastes was investigated by blending them with ULSD or ethanol in 50 percentages. B50, WB50, B50E50 and WB50E50, biodiesel and ethanol-contained fuels and ULSD were prepared for experiments. Combustion, performance, and emissions tests were conducted on a diesel engine used for power-producing electrical generator. In the combustion tests, cylinder pressure, HRR, CHR, MGT, and MFB were analyzed while MFC, BSFC, exhaust manifold temperature, and thermal efficiency were obtained in the performance tests. In the emissions tests, CO, HC, and NOx emissions were measured and compared with the results of ULSD. Combustion and performance findings of ULSD contained biodiesel blends were found more similar to those of ULSD. The duration of combustion stage can clearly be seen to be narrowed for ethanol-contained blend because of the rabid combustion characteristics of ethanol. Besides, the peak of HRR was found 10% higher for B50E50 while it was found averagely 8% for WB50E50 blends. NOx emissions were found 48% lower averagely for ethanol contained biodiesel blends that it is the most important finding of ethanol using with biodiesel. Besides, HC emissions were also found about 75% for biodiesel contained diesel fuel blends.Öğe Numerical and experimental study of air flow by natural convection in a rectangular open cavity cooled top and bottom surfaces(Batman Üniversitesi, 2016-12-28) Karakaya, Hakan; Durmuş, AydınBu çalışma ile ilk olarak kapalı kübik hacmin ön yüzeyinin çevreye açılmasıyla kübik boşluk haline gelen hacimde, alt ve üst yüzeyinden soğutma sınır şartında, laminer durumda doğal taşınım deneysel ve teorik olarak araştırılmıştır. Elde edilen ölçümler Fluent 6.3 paket programı yardımı ile çözülmüş ve deneysel veriler ile karşılaştırılmıştır. Doğal taşınım şartlarını sağlayabilmek için bu deneysel çalışma ile 2x2x1,8m ebatlarında bir şartlandırma odası uygulamaya dahil edilmiştir. Ayrıca deney düzeneğinin giriş ağzı bu şartlandırma odasına verilmiştir. Son olarak bu çalışma ile sıcaklık değişimi, hız vektörleri ve akım fonksiyonu grafikleri elde edilmiştir. Buna ek olarak Nusselt sayısının zamana bağlı değişimi teorik ve deneysel çalışmalar sonucunda elde edilmiştir.Öğe Analysis of sunshine hours and global solar radiation for Mardin of Turkey(ISITES, 2015) Karakaya, Hakan; Kallioğlu, Mehmet Ali; Avcı, Ali SerkanHaving a strategic area, the energy industry has a critical importance in development policy of a country. Demands of renewable energy have increased in recent years due to energy price, global warming and climatic change. Therefore, the concerns about solar energy, one of the most important clean energy sources, have risen in the last decades. In this study, the empirical solar correlations developed in Turkey and some other countries were investigated for the province of Mardin, Turkey. The compatibility of solar radiation models inspected in terms of statistics was tested by determining the nearest model according to measured data. In addition to climate data which is specific to this region, prediction of Angstroms model was developed to estimate global solar radiation in Mardin. These models, since the mathematical models with the highest compatibility represent the measured data statistically well, it is understood that it can easily be used for daily global solar radiation on horizontal surfaces. The data of the model were obtained from Solar Energy Potential Atlas (GEPA) of Electrical Power Resources Survey Administration (EIE). Angstrom-type model parameters were developed to forecast sunshine average and to compute empirical coefficients for Mardin. Monthly predicted global solar radiation mean values were compared with observed values using statistical parameter coefficient of regression analysis (R²), mean bias error (MBE), root mean square error (RMSE), mean percentage error (MPE), mean absolute percentage error (MAPE), t-statistic (tsat) and the percent error (e) method developed in order to test the compliance of the models. The best developing ideal model was found to be quadric H/H0=-1,3049 (S/S0 ) 2 +2,2791(S/S0)-0,4143 and R 2 0,9492 determined in terms of utilizing the solar radiation potential in Mardin, TurkeyÖğe Phase changing material usage to increase the efficiency of photovoltaic panels(Balkan Yayın, 2020-01-31) Karakaya, Hakan; Şen, İzzetin EnesThe energy demand from renewable energy sources has been proportionally increased due to population growth. In renewable energy production, not only energy production but also efficient use is crucial. In recent years, photovoltaic panels, which are increasingly used and highly important in terms of renewable energy production, have warmed on the surface due to the radiation energy emitted by the sun, and this warmth reduces the efficiency of the panel. In this study, it is aimed to reduce this efficiency loss by using phase changing material with latent heat which is one of the thermal energy storage methods. One of the two solar panels placed parallel to the ground was filled with phase changing material. With this, it is aimed to cool photovoltaic panel by using calcium chloride hexahydrate phase changing material; and then radiation, air temperature, current, voltage, power, surface temperature, efficiency graphs were obtained. As a result of simultaneous measurements, the increase in yield was found to be 2.95%.Öğe Investigation of the usability of wind energy potential in Batman(Batman Üniversitesi, 2018) Karakaya, Hakan; Avcı, Ali Serkan; Kallioğlu, Mehmet Ali; Ercan, UmutÖğe Examination of energy capacities of hydroelectric power plants in Batman(Batman Üniversitesi, 2018) Karakaya, Hakan; Avcı, Ali Serkan; Kallioğlu, Mehmet Ali; Avcı, Ali Serkan; Durmuş, AydınÖğe Environmental impact of optimum insulation thickness for Kayseri province case(Erciyes Üniversitesi, 2017) Karakaya, Hakan; Kallioğlu, Mehmet Ali; Ercan, Umut; Avcı, Ali Serkan; Genç, ÖmerÖğe Estimating Kilis regions solar radiation by location based statistical models(Kilis 7 Aralık Üniversitesi, 2016) Karakaya, Hakan; Kallioğlu, Mehmet Ali; Ercan, Umut; Avcı, Ali SerkanÖğe Effect of climate change on some meteorological data: Batman example(ISITES, 2015) Karakaya, Hakan; Kallioğlu, Mehmet Ali; Yılmaz, AdemIncreasing Energy need in the global economy and tendency to utilization of poor quality fossil fuels have led to significant changes in world climate in recent years. Nowadays, global climate change has started taking part in the upper parts of the agenda. Human health, ecosystems even climate change evaluated as a problem to cause threat in terms of maintaining the human race have come forefront as basic ıssue of scientists and governments especially in recent years. In this study, an evaluation has been carried out about meteorological data of Batman Province, which has been developing rapidly in recent years and is located in the Southeastern Anatolian Region where climate change is felt severely. Within this context, meteorological data belonging to the years between 1993 and 2013 were provided by State Meteorology Affairs General Directorate. At twentyyear time, monthly average alterations of data in solar radiations, in wind power and in the amount of precipitation and temperature relations among them have been investigated by means of statistical analyses. As a result of the study, some significant changes in meteorological data of the region searched have been found and suggestions on solutions have been proposed.
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