Yazar "Ceylan, İlhan" seçeneğine göre listele
Listeleniyor 1 - 20 / 26
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe The artificial neural network model to estimate the photovoltaic modul efficiency for all regions of the Turkey(Elsevier Science Sa, 2014) Ceylan, İlhan; Gedik, Engin; Erkaymaz, Okan; Gürel, Ali EtemArtificial neural network (ANN) is a useful tool that using estimates behavior of the most of engineering applications. In the present study, ANN model has been used to estimate the temperature, efficiency and power of the Photovoltaic module according to outlet air temperature and solar radiation. An experimental system consisted photovoltaic module, heating and cooling sub systems, proportional integral derivative (PID) control unit was designed and built. Tests were realized at the outdoors for the constant ambient air temperatures of photovoltaic module. To preserve ambient air temperature at the determined constant values as 10, 20, 30 and 40 degrees C, cooling and heating subsystems which connected PID control unit were used in the test apparatus. Ambient air temperature, solar radiation, back surface of the photovoltaic module temperature was measured in the experiments. Obtained data were used to estimate the photovoltaic module temperature, efficiency and power with using ANN approach for all 7 region of the Turkey. The study dealing with this paper not only will beneficial for the limited region but also in all region of Turkey which will be thought established of photovoltaic panels by the manufacturer, researchers and etc. (C) 2014 Elsevier B.V. All rights reserved.Öğe Assessment of a novel defrost method for PV/T system assisted sustainable refrigeration system(Pergamon-Elsevier Science Ltd, 2022) Karaağaç, Mehmet Onur; Ergun, Alper; Gürel, Ali Etem; Ceylan, İlhan; Yıldız, GökhanEnergy consumption has continuously increased depending on the rapidly growing human population, enlarging economies, advancing technologies, and improving living standards. A noteworthy share of the energy consumption has been arising from the buildings all across the world. Refrigeration, heating, and air conditioning systems have accounted for a significant portion of the energy consumption in the buildings. Therefore, it is possible to both reduce energy consumption, and mitigate the carbon footprints by efficiently designing, constructing, and operating these systems. In this framework, the present research has centered on the refrigeration systems, and aimed to develop a novel defrost method for photovoltaic thermal (PV/T) assisted sustainable refrigeration systems. In the conventional refrigeration systems, the frost process occurs when air condenses on the evaporator surface as a result of the evaporator surface temperature being below the freezing point of water or the dew point temperature of the air in the conditioned space. Differently in the present work, PV/T system is used to prevent the frost process in the refrigeration system, unlike the conventional systems. Accordingly, the efficiency loss caused by the temperature increment will be prevented by cooling the PV module, and it is aimed to be more efficient by reducing the daily power consumption as an alternative solution method to the frost that occurred on the evaporator in refrigeration systems. On this purpose, a novel evaporator design is developed, and used for defrosting in this study. Accordingly, this novel design includes a refrigerant line inside the evaporator and a hot water line from the PV/T in this design. In the results, it is noticed that the system designed for winter conditions could be used for defrosting. While an average of 605 W for heat energy was used for each defrost process, the average defrost duration was recorded to be approximately 4 min. While the average electrical efficiency of the PV module was found to be 13.6%, the average total efficiency was found to be 38%. Besides, Average PV module surface temperature was determined as 36.4 degrees C, average water storage tank temperature was determined as 26.4 degrees C. In addition, the coefficient of performance (COP) of the refrigeration system is calculated to be 4.18. COP increased by an average of 9% during defrosting. Furthermore, the environmental economic cost was calculated to be 14.6 $/h. In the conclusion, it is proven that the novel defrost method proposed in the present work can be used for refrigeration systems, and contribute to both the reduction of energy consumption and mitigation of carbon emissions arising from the buildings.Öğe Assessment of a solar-assisted infrared timber drying system(Wiley, 2017) Aktaş, Mustafa; Ceylan, İlhan; Ergün, Alper; Gürel, Ali Etem; Atar, MusaThis study investigates convective-infrared drying characteristics of timber. The biggest disadvantage of infrared heating systems is the uncontrollable rise of the surface temperature up to extremely high values, which causes damage to the product. In this study, the power of an infrared system was controlled and adjusted according to the surface temperature of the product. In doing so, the surface temperature of the infrared heater was prevented from reaching up to values that could damage the product. During the analysis, the surface temperature of the timbers was kept at an average of 65 degrees C, while the bottom temperature was kept at an average of 45 degrees C. The air collector used in the system was found to be 50% efficient. At the end of a 13-h drying period, the moisture content of pine timbers could be reduced from 1.42 to 0.0948 g water/g dry matter. During the system analysis, parameters such as moisture content, mass diffusion coefficient, and useful energy rate were taken into consideration. (c) 2017 American Institute of Chemical Engineers Environ Prog, 36: 1875-1881, 2017Öğe Cooling of a photovoltaic module with temperature controlled solar collector(Elsevier Science Sa, 2014) Ceylan, İlhan; Gürel, Ali Etem; Demircan, Hüsamettin; Aksu, BahriThe efficiency of photovoltaic modules decreases with heating, so there has been an increase with regard to the solution of the problem. Photovoltaic module converts the incoming solar radiation into heat and electric energy. Due to this heating feature of photovoltaic modules, it is likely to produce heat energy from PV modules as well. Such systems are called as both a photovoltaic and thermal systems in the literature. A lot of experimental studies were done by special processing on the PV module. Since the studies require special processing on the module, they remain as laboratory work only. In this study, different PV/T systems were experimentally analyzed for the cooling photovoltaic modules. A simple pipe was placed on PV module as a spiral heat exchanger in order to provide active cooling. Also, the system can easily be applied to large-scale systems. As a result of experimental research, the module efficiencies with cooling were calculated as 13%, and the module efficiencies without cooling were about 10%. As the set temperature increased, module temperature can be increased or decreased. The module temperature was changed according to solar radiation and set temperature. As the solar radiation increased the module temperature decreased in this experimental system. The solar radiation has nothing to do with set temperature for this system. (C) 2014 Elsevier B.V. All rights reserved.Öğe Determination of the heat transfer coefficient of PV panels(Pergamon-Elsevier Science Ltd, 2019) Ceylan, İlhan; Yılmaz, Sezayi; İnanç, Özgür; Ergün, Alper; Gürel, Ali Etem; Acar, Bahadır; Aksu, Ali İlkerIn this study, the efficiency of the rear-panel air velocity in cooling was investigated based on the temperature and solar radiation in the environment where the panels are located. During the cooling of the panels, the rear-panel temperature decreases, and accordingly, the open-circuit voltage of the panels increases. At present, the most important losses in panels are due to the increase in panel temperature depending on the solar radiation and outdoor air temperature. In this study, the rear-panel temperature changes were observed at 0-5 m/s air velocities and 10-40 degrees C. The calculations reveal that in winter weather conditions, the temperature of the panels did not increase at a level that would require cooling. This study investigated the heat transfer from the surface depending on the outdoor air temperature of the rear-panel air velocity and the changing rear-panel temperature. The effect of different outdoor air temperatures on the rear-panel heat transfer is minimal. When the air velocity was 5 m/s and the outdoor air temperature was 10-40 degrees C, the heat transfer in the Poly Crystal Solar panel was calculated as 11.6 W/m(2)K. (C) 2019 Elsevier Ltd. All rights reserved.Öğe Energy Analysis of a New Design of a Photovoltaic Cell-Assisted Solar Dryer(Taylor & Francis Inc, 2013) Ceylan, İlhan; Kaya, Metin; Gürel, Ali Etem; Ergün, AlperIn this study, a new type of solar dryer was designed and manufactured. This new solar dryer is composed of a heat pipe collector, a drying chamber, a load cell, an air circulation fan, photovoltaic cells (PvC), batteries, and halogen lamps. In this experimental study, tomatoes were used to test the drying process. The drying air was heated by the heat pipe collector and forced through the tomatoes by a blower fan during the daytime. The photovoltaic cells, which were used to run the fan, were also used to charge the batteries during the day. These charged batteries were used for running the halogen lamps during the night, when the halogen lamps were used to heat the drying-air-assisted photovoltaic cells. During the drying period, the drying air temperature, relative humidity, air flow rates, solar radiation, and loss of mass were measured in the solar dryer. Then, the measured data were used for energy analysis.Öğe Environmental and economic assessment of a low energy consumption household refrigerator(Elsevier B.V., 2019) Gürel, Ali Etem; Ağbulut, Ümit; Ergün, Alper; Ceylan, İlhanEnergy consumption is the biggest obstacle in the economic growth of a country. In recent years, Turkey has imported around at the rate of three-quarters of its total energy demand. Upon the past 10-years running, Turkey paid nearly half a trillion dollars for its total energy bill. The big share of energy consumption has emerged from buildings. Therefore, energy savings have great importance, particularly in the buildings. A refrigerator is responsible for the most dominant electrical energy consumption rate with 32% in a house. Therefore, this paper proposes a novel household refrigerator design for reducing energy consumption. In the proposed design, the necessary air for the cooling process will be provided from outdoor ambient in appropriate weather condition. The compressor work will, thus, be decreased via this way, and contribute to a reduction in energy consumption. The results indicated that this system in 63 provinces can be effectively used between 1 and 4 months and help to reduce 36 million $ in Turkish electric energy bill with the use of only 1 year period. Additionally, a reduction of approximately 850,000 tons of CO2 annually in Turkey can be achieved by applying the proposed design in this study. Hereby, Turkey can contribute not only to be sustained economic growth but also to reduce harmful gas emissions arising from electricity generation methods in the country. © 2019 Karabuk UniversityÖğe Exergetic analysis of a new design photovoltaic and thermal (PV/T) System(Wiley, 2015) Ceylan, İlhan; Gürel, Ali EtemPhotovoltaic (PV) module converts the incoming solar radiation into heat and electric energy. Due to this heating feature of photovoltaic modules, it is likely to produce heat energy from PV modules as well. Such systems are known as photovoltaic and thermal systems in the literature. In this study, a new design PV/T system was experimentally analyzed for cooling photovoltaic modules while heating water at the same time. PV/Tis a forced circulation system without pump. Therefore, these systems are different from those described in the literature. For all PV/T system, step-by-step exergy analysis has been performed according to obtained experimental results. PV module thermal exergy, solar collector thermal exergy, and PV module electrical exergy variations have been calculated for this exergy analysis. Overall, exergy efficiency was obtained as about 17% for 45 degrees C set temperature and 21% for 55 degrees C set temperature. (c) 2015 American Institute of Chemical Engineers Environ Prog, 34: 1249-1253, 2015Öğe Exergetic, economic and environmental analysis of temperature controlled solar air heater system(Elsevier Ltd, 2022) Gürel, Ali Etem; Yıldız, Gökhan; Ergün, Adem; Ceylan, İlhanSolar energy systems are widely utilized to obtain environmentally friendly and sustainable electrical and thermal energy that able to be used in many applications. Temperature-controlled solar air heater (SAH) system with a zigzag finned plate and flat plate was designed, manufactured, and tested experimentally in this study. It was determined that the set temperature was 15% higher than the flat plate SAH outlet temperature. The most important cause for this increase, the air is exposed preheating in the first collector. As the heat transfer surface area raised thanks to the zigzag fins in the second collector, the temperature of the air increases even more. SAH system's energy efficiency was found to be 71.15% on average. SAH system's maximum exergy efficiency was determined as 3.7%. The SAH system's average exergy destruction is calculated to be 651.58 W on average. According to the enviroeconomic analysis of the system, hourly CO2 mitigation was found to be 1.04 kg CO2/h and the environmental cost was 1.508 ¢/h. The energy cost was calculated as 0.0834 $/kWh, while the exergoeconomic parameter was calculated as 0.1931 kWh/$. In addition, the energy payback period was determined as 1.35 years, while the exergy payback period was determined as 45.9 years. © 2021Öğe Exergy, sustainability and performance analysis of ground source direct evaporative cooling system(Elsevier, 2022) Yıldız, Gökhan; Ergun, Alper; Gürel, Ali Etem; Ceylan, İlhan; Ağbulut, Ümit; Eser, Servet; Afzal, AsifA significant portion of global energy consumption is due to energy consumption in the buildings. Heating, cooling, and air conditioning systems have the largest share in this energy consumption. Evaporative cooling systems, which have the advantage of being economical, zero pollution, and easy maintenance are preferred to reduce energy consumption in buildings. These systems are used in many areas such as greenhouses, broiler houses, and warehouses. In this study, analyzes of exergy, sustainability, and cooling efficiency in four different situations of a ground source direct evaporative cooling system were made. The system was studied in four different cases. While the highest exergy efficiency was obtained in case 3 with 20.83%, the exergy efficiencies in other cases were obtained as 16.83%, 17.49%, and 18.36%, respectively. In addition, the highest specific exergy loss was determined as 100.51 J/kg in case 2, while it was calculated as 73.08 J/ kg, 80.23 J/kg, and 73.05 J/kg for the other cases, respectively. It is seen that the sustainability values are in parallel with the exergy efficiency when the evaporative cooling system is examined for four different cases. The sustainability values were determined as 1.20 for case 1, 1.21 for case 2, 1.26 for case 3, and 1.22 for case 4. It is determined that the exergy efficiency gives precise information about the usability and sustainability of the system when these situations are evaluated. The exergetic improvement potential (EIP) was determined as 0.061 for case 1, 0.082 for case 2, 0.063 for case 3, and 0.059 for case 4, respectively. Although the highest exergy efficiency is obtained in case 3, it has a higher recovery potential than case 1 and case 4. In addition, cooling efficiencies for four different cases were obtained as 33.70%, 34.81%, 41.69%, and 36.95%, respectively. The temperature differences between the room and ambient temperatures were determined as 1.45 degrees C, 1.21 degrees C, 1.6 degrees C, and 1.48 degrees C for each case, respectively.Öğe Güneş Enerjisi Santrallerinin Türkiye ve Avrupa’daki Geri Ödeme Sürelerinin Karşılaştırması(Düzce Üniversitesi, 2023) Gyam, Mohannad; Ceylan, İlhan; Gürel, Ali Etem; Yıldız, GökhanDünya’da enerjinin önemi her geçen gün artmaktadır. Ülkelerin büyük bir bölümü ihtiyaç duydukları enerji gereksinimini fosil yakıtlar tarafından karşılanmaktadır. Fosil yakıtların tükenecek olması, artan fiyatı ve çevreye vermiş olduğu zararlardan dolayı araştırmacılar alternatif enerji kaynaklarına yönelmişlerdir. Yenilenebilir enerji kaynaklarına son yıllarda alternatif enerji olarak talep büyük oranda artmıştır. Güneş enerjisi, yenilenebilir enerji kaynakları arasında en popüler ve tüm dünyada yaygın olarak kullanılan enerji kaynaklarından birisidir. Bu sebeple, Türkiye ve Avrupa ülkelerinde güneş enerjisi kullanımı artırılmaya çalışılmaktadır. Türkiye güneş ışınım miktarı yüksek olmasına rağmen beklenen seviyelere ulaşamamıştır. Bu çalışmada, Türkiye ile Avrupa ülkeleri arasındaki şebekeye bağlı 1 MW’lık bir güneş enerjisi santralinin geri ödeme süreleri karşılaştırılmıştır. Karşılaştırılan ülkeler, kendilerine özgü solar radyasyon değerlerinde %22,6 verimliliğe sahip bir monokristal güneş panellerinin kullanıldığı varsayılmıştır. Ayrıca, Rusya-Ukrayna savaşının enerji fiyatlarına etkisi nedeniyle güneş enerjisi santralinin geri ödeme süresi iki senaryo üzerinden değerlendirilmiştir. Elde edilen sonuçlara göre, birinci senaryoda en yüksek geri ödeme süresi 2,75 yıl ile Karaman’da, ardından 3,17 yıl ile Türkiye gelmektedir. İspanya, Fransa ve Almanya’daki geri ödeme süreleri sırasıyla 3,6, 5,6 ve 5,7 yıl olarak hesaplanmıştır. İkinci senaryoda ise (Rusya-Ukrayna savaşı sonrası), en yüksek geri ödeme süreleri 2,22 yıl ile Almanya ve 3,27 yıl ile Fransa olarak belirlenmiştir. İspanya, Karaman ve Türkiye’de geri ödeme süreleri sırasıyla 2,41, 2,75 ve 3,17 yıl olarak tespit edilmiştir.Öğe Havalı Güneş Kolektörlerinin Hacim Isıtma Uygulamalarında Kullanımı(2021) Gürel, Ali Etem; Yıldız, Gökhan; Ceylan, İlhanGüneş enerjisi, doğrudan güneşten elde edilen temiz ve yenilenebilir bir enerji kaynağıdır. Güneş enerjisi sistemleri üzerine yapılan çalışmalar, enerji fiyatlarındakiartışlar, küresel ısınma ve sera etkisi gibi çevresel etkiler nedeniyle özellikle son yıllarda ciddi bir artış göstermiştir. Türkiye güneş enerjili sıcak su ısıtma sistemlerinden önemli ölçüde yararlanmaktadır. Bunun yanında fotovoltaik teknoloji üzerinde,özellikle getirilen yeni yasal düzenlemeler ve coğrafi konumun da avantajları ileTürkiye özelinde önemli yatırımlar yapılmaktadır. Ancak havalı güneş kolektörleriile hacim ısıtma uygulamalarından Türkiye’de yeterli ölçüde yararlanılmamaktadır. Oysa bu tip kolektörler, %100 taze havalı klima sistemlerinde ön ısıtma/ısıtma, hayvan barınaklarının ısıtılması, sera ısıtılması, kargo depolarının ısıtılması,kurutma vb. pek çok uygulama için oldukça elverişlidirler. Bu çalışmada, havalıgüneş kolektörlerinin hacim ısıtılmasında kullanımına yönelik dünyadaki farklı uygulamalar incelenecektir. Bunun yanında havalı güneş kolektörleri ile hacim ısıtılmasına dair önerilen farklı tasarımlar da verilecektir. Bu inceleme ve tasarımlarneticesinde çeşitli öneriler getirilecektir.Öğe Havalı Güneş Kolektörlerinin Hacim Isıtma\rUygulamalarında Kullanımı(2022) Gürel, Ali Etem; Yıldız, Gökhan; Ceylan, İlhanGüneş enerjisi, doğrudan güneşten elde edilen temiz ve yenilenebilir bir enerji kaynağıdır.\rGüneş enerjisi sistemleri üzerine yapılan çalışmalar, enerji fiyatlarındaki\rartışlar, küresel ısınma ve sera etkisi gibi çevresel etkiler nedeniyle özellikle son yıllarda\rciddi bir artış göstermiştir. Türkiye güneş enerjili sıcak su ısıtma sistemlerinden\rönemli ölçüde yararlanmaktadır. Bunun yanında fotovoltaik teknoloji üzerinde,\rözellikle getirilen yeni yasal düzenlemeler ve coğrafi konumun da avantajları ile\rTürkiye özelinde önemli yatırımlar yapılmaktadır. Ancak havalı güneş kolektörleri\rile hacim ısıtma uygulamalarından Türkiye’de yeterli ölçüde yararlanılmamaktadır.\rOysa bu tip kolektörler, %100 taze havalı klima sistemlerinde ön ısıtma/ısıtma,\rhayvan barınaklarının ısıtılması, sera ısıtılması, kargo depolarının ısıtılması,\rkurutma vb. pek çok uygulama için oldukça elverişlidirler. Bu çalışmada, havalı\rgüneş kolektörlerinin hacim ısıtılmasında kullanımına yönelik dünyadaki farklı uygulamalar\rincelenecektir. Bunun yanında havalı güneş kolektörleri ile hacim ısıtılmasına\rdair önerilen farklı tasarımlar da verilecektir. Bu inceleme ve tasarımlar\rneticesinde çeşitli öneriler getirilecektir.Öğe ISI POMPALI VE PARABOLİK OLUKLU GÜNEŞ KOLEKTÖRLÜ AKIŞKAN YATAKLI KURUTUCULARIN DENEYSEL ANALİZİ(Turkish Soc Thermal Sciences Technology, 2015) Gürel, Ali Etem; Ceylan, İlhan; Yılmaz, SezayiIn this study, both a heat pump and parabolic trough solar fluidized bed dryer were designed and manufactured. They were experimentally analyzed by first and second laws of thermodynamics and a comparison was made between the two. Drying air temperatures were controlled as PID for 40 degrees C set temperatures. Drying air temperature was controlled with a sensitivity of +/- 0.254 degrees C in heat pump dryer system and +/- 0.369 degrees C in parabolic trough solar dryer. In the heat pump dryer system, whole system heating coefficient of performance (COPts) was calculated as average 1.91. In parabolic trough solar dryer, heating performance coefficient (IPK) was calculated as average 3. Exergy loss was found to be 203.97 J/kg in the heat pump dryer, and 32.08 J/kg in parabolic trough solar dryer. Average exergy efficiency was found to be 31.1% in the heat pump dryer, and 63.37% in parabolic trough solar dryer.Öğe Klima Santrallerinde Yoğuşan Suyun Geri Kazanımı İçin Alternatif Yöntemler(2018) Gürel, Ali Etem; Ceylan, İlhan; Ergün, Alper; Acar, BahadırMerkezi ısıtma ve soğutma sistemlerinin en önemli parçası olan klima santrallerinde soğutucu serpantinüzerinden büyük miktarda su yoğuşmakta ve bu su genellikle en yakın gidere verilmektedir. Uygulamada da busu, büyük bir atık olarak nitelendirilmektedir. Hâlbuki özellikle %100 dış hava ile çalışan sistemlerdeki bu soğuksu depolanarak evaporatif soğutma da dâhil olmak üzere birçok uygulamada değerlendirilebilir. Bu çalışmada,klima santrallerinde yoğuşan suyun yeniden kullanımına yönelik farklı tasarımlar önerilmiştir. Çalışmada üçfarklı sistem üzerinde incelemeler gerçekleştirilmiştir. Birinci sistemde %100 taze havalı bir klima santralindenelde edilen yoğuşma suyunun, karışım havalı bir klima santralinin serpantininde ön soğutucu olarak kullanılmasıincelenmiştir. İkinci sistemde ise %100 taze havalı veya karışım havalı klima santralinin soğutucu serpantinindeyoğuşan suyun, bir soğutma kuleli chiller cihazında besleme suyu olarak değerlendirilmesi araştırılmıştır.Üçüncü sistemde ise %100 taze havalı veya karışım havalı klima santralinin soğutucu serpantininde yoğuşansuyun, hava soğutmalı kondenserli bir chiller cihazında kullanımı incelenmiştir. Yapılan psikrometrikhesaplamalar, %100 taze hava ile çalışan bir klima santralinde yaklaşık 80 kW’lık gizli ısının, tasarlanan busistemler aracılığıyla duyulur ısı olarak kullanılabileceğini göstermiştirÖğe The mathematical modeling of concentrated photovoltaic module temperature(Pergamon-Elsevier Science Ltd, 2017) Ceylan, İlhan; Gürel, Ali Etem; Ergün, AlperIn this study, we examined the effect of the use of paraffin wax on the panel temperature of concentrated solar panels. Some tests were performed on various days for three months (including spring, summer, and winter months). With the help of the experimental results, new approaches have been made as concentrator ratio, area ratio, concentrator efficiency and power coefficient. As a result of this approaches the concentrator ratio was found to be 3. When the concentrator ratio was 3, the panel temperature of the system with paraffin was found to be between 80 and 100 degrees C, while that of the other system was found to be above 100 degrees C. Panel efficiency might be reduced down to 10% at these temperatures. The study also included the development of a mathematical model of the changes in the panel temperature of the concentrated systems in which paraffin was not used. The temperature at the back of the panels could be calculated by this mathematical model, depending on the ambient temperature and the concentrated solar radiation. The correlation coefficient of the mathematical model was found to be 0.929. The test results of two days, which were not included in the model, were used to determine the reliability of the model, and the panel temperatures were calculated using the correlation coefficients of 0.933 and 0.966. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Öğe Meyve ve Sebzelerin Kurutma Parametrelerinin İncelenmesi(2016) Gürel, Ali Etem; Ceylan, İlhan; Aktaş, MustafaKurutma, tarımsal ürünlerin bozulmadan korunması için kullanılan en eski yöntemdir. Kurutma işlemi ile birlikte gıda ürünlerindeki su aktivitesi değeri düşer ve böylece gıdaların bozulma süreci yavaşlar. Kurutma işlemi ile gıdaların uzun süre korunması sağlanır. Kurutma birçok aşamadan oluşan karmaşık bir uygulamadır. Bu süreç kurutma öncesi işlemleri, kurutma işlemini ve kurutma sonrası analizleri kapsamaktadır. Kurutma öncesi işlemler, ürünlerin hazırlanmasını, önişlemleri, nem içeriklerinin belirlenmesi aşamalarını kapsar. Kurutma sonrası analizler ise, ürünün renk, doku, büzülme, gözeneklilik, tat, su aktivitesi, rehidrasyon, raf ömrü, besin değerleri vb. değerlendirmeleri kapsar. Kurutma işleminin başarılı sayılabilmesi için bütün bu süreçlerin dikkatli bir biçimde gerçekleştirilmesi gerekmektedir. Bu çalışmada, gıda kurutulması işlemleri sırasında uygulanan kurutma prosedürleri incelenmiştirÖğe Performance analysis of a concentrated photovoltaic and thermal system(Pergamon-Elsevier Science Ltd, 2016) Ceylan, İlhan; Gürel, Ali Etem; Ergün, Alper; Tabak, AbdulsamedThe purpose of the present study is PV/T system, which designed and implemented in order to reuse of thermal energy while increasing of electric production. Solar radiation was increased with the concentrator about two folds and electrical power gains were increased. A paraffin wax was used to store latent heat as a thermal energy storage. Thermal energy was combined with a greenhouse like air drier and used to dry the product. Thermal and electrical energy gain in the concentrated and non-concentrated panels were compared and total system efficiency was analyzed. The maximum temperature obtained at the back of the panel was calculated as 37 degrees C and the panel efficiency was 11% at mean solar radiation was 2000 W/m(2). (C) 2016 Elsevier Ltd. All rights reserved.Öğe Performance analysis of using CuO-Methanol nanofluid in a hybrid system with concentrated air collector and vacuum tube heat pipe(Pergamon-Elsevier Science Ltd, 2019) Kaya, Metin; Gürel, Ali Etem; Ağbulut, Ümit; Ceylan, İlhan; Çelik, Selim; Ergün, Alper; Acar, BahadırAn experimental study was conducted to determine the effects of adding copper oxide (CuO) with 50 nm diameter into neat methanol (CH3OH) on the energetic and exergetic analysis of a concentrated air collector with vacuum tube heat pipe at different air velocities (1, 2 and 3 m/s). The experimental results clearly indicated that the nanofluid application enhanced the thermal properties and provided better performance for heat pipe applications. Considering all air velocities together, the average efficiency for neat methanol and CuO-Methanol nanofluid was achieved by 65% and 64%, respectively. Additionally, the average specific exergy outlet values for neat methanol and CuO-Methanol nanofluid were calculated as 206 J/kg and 298 J/kg, respectively. In the experiments, it is seen that the efficiency values of the system using the CuO-Methanol nanofluid reached higher values, as the solar radiation values were higher. In conclusions, this paper distinctly suggests that the presence of copper oxide in the base fluid can be used in a concentrated air collector with vacuum tube heat pipe particularly at the high radiation conditions and positively affects the performance of the system.Öğe The prediction of photovoltaic module temperature with artificial neural networks(Elsevier Ltd, 2014) Ceylan, İlhan; Erkaymaz, Okan; Gedik, Engin; Gürel, Ali EtemIn this study, photovoltaic module temperature has been predicted according to outlet air temperature and solar radiation. For this investigation, photovoltaic module temperatures have been determined in the experimental system for 10, 20, 30, and 40 °C ambient air temperature and different solar radiations. This experimental study was made in open air and solar radiation was measured and then this measured data was used for the training of ANN. Photovoltaic module temperatures have been predicted according to solar radiation and outside air temperature for the Aegean region in Turkey. Electrical efficiency and power was also calculated depending on the predicted module temperature. Kutahya, U§ak and Afyon are the most suitable cities in terms of electrical efficiency and power product in the Aegean region in Turkey.
