Fotovoltayik-fototermik dönüştürücülerde verim optimizasyonu
Küçük Resim Yok
Tarih
1998
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
ÖZET FOTOVOLTAYİK-FOTOTERMİK DÖNÜŞTÜRÜCÜLERDE VERİM OPTİMİZASYONU ERKAYA, Kubilay Doktora Tezi, Güneş Enerjisi Ana Bilim Dalı Tez Yöneticisi: Prof. Dr. Metin ÇOLAK Şubat 1999, 74 Sayfa AMAÇ VE KAPSAM Fotovoltayik enerji ile, termal enerjinin eş zamanlı olarak aynı alanda üst üste konulan Fotovoltayik (PV) modül ve kollektörden (PV/T sistemi) elde edilmesinin mümkün olduğu Loferski et al, (1982) (1), ve Takashıma et al., (1994)(2)'ın yaptıkları araştırmalarda ortaya çıkmıştı. Ancak PV modülün kollektör içine yerleştirildiği sistemde (1) kollektörden sıcak su elde edilmesine karşın kollektördeki ısının PV modüle yayılması sonucunda PV modülün ısınıp veriminin azalmasına neden olduğu bilinmektedir. PV/T sisteminde kollektör ısısının PV modüle yayılmasını önleyerek daha iyi verime ulaşılması amacıyla birbirinden hava kanalı ile izole edilmiş yeni bir sistem düşünülmüş ve matematiksel maddeleme ile araştırılması yapılmıştır (2). PV modül ve kollektör arasındaki hava kanalının optimum mesafesinde yeni sistemden maximum verim alındığı deklare edilmiştir. Bu çalışmada yukarıda anlatılan hava aralıklı PV/T sisteminin (2) İzmir Bornova şartlarında modelleme ve ölçme ile verimi optimize edilmiştir. KULLANILAN YÖNTEMLER PV modülün hücreleri di ş ı nda kalan kılıfı özenle soyularakII %10 geçirimli hale getirilmiştir. PV modülle aynı ölçülerde bir sıcak su kollektörü dizayn edilerek imal ettirilmiş, aralarındaki mesafenin kolayca değiştirilebileceği özel bir sehpaya yerleştirilmiştir. Sistemin verimi önce matematiksel olarak çözülmüştür. Çözümde bir yıl boyunca ortalama maximum ışınımın o yerin enlem derecesindeki düzlem açısında meydana geldiği bilindiğinden İzmir Bornova şartlarında İzmir'in enlem derecesi 38°de eğik düzleme gelen ışınım hesaplanmıştır. Bu ışınımda PV modül ve kollektörün ısıl analizi incelenmiş, verimleri bulunmuş ve ara mesafenin 0.01 m den 0. İm ye kadar değişimine göre optimize edilmiştir. Isıl analizde sistem elemanlarının herbiri için enerji bilançosu yapılarak çözüme ulaşılmıştır. Sistemin çözümü bilgisayarda Excel ve Basic programlama dili ile yapılmıştır. Ölçümde PV modül ile kollektör önce ayrı ayrı, daha sonra PV/T sisteminde PV modül-kollektör ana mesafesinin 0.01 m den O.lm.ye kadar her bir değeri için test edilmişlerdir. Ölçümde hava sıcaklığı rüzgar hızı, 38° eğik düzleme gelen ışınım, PV modülün alt ve üst cam sıcaklıkları, akım ve gerilim değerleri, kollektörün cam sıcaklığı, su giriş ve çıkış sıcaklıkları, ana kanaldan havanın çıkış sıcaklık değerleri alınmıştır. Hesaplamalar ve ölçümler arasında büyük farklılıklar bulunmamaktadır. Sonuç olarak PV/T sisteminde, maximum PV modül verimi ara mesafenin O.lm değerinde % 10.93 olarak, kollektör verimi ara mesafenin 0.0 İm değerinde %10.10, sistemin toplam verimi, verime asıl etki eden faktör kollektör olduğundan 0.0 İm' de maximuma ulaşmıştır. O.Olm'de PV modül ısısı artmakla birlikte verimin ısı ile değişimi 0.004/C0 olduğundan toplam verimi küçük miktarda etkilemektedir. Toplamda maximum verim %20.98'dir.IH İzmir şartlarında sistemin kurulacağı yerden tasarruf sağlamak amacıyla geliştirilmiş bulunan bu tür bir PV/T sistemindeki PV modül verimin de PV modülü ayrı olarak kullanılması durumundaki verimine göre önemli bir değişiklik olmamaktadır. Kollektör verimi ise yaklaşık %10'dur. Kollektörün ayrı olarak kullanılması durumundaki verimiyle (%60) karşılaştırıldığında oldukça düşük bulunmuştur sonuç olarak, İzmir Bornova şartlarında bu tür bir PV/T sisteminin rantabl olacağı düşünülmemektedir. Anahtar kelime: Fotovoltayik ve Termal sistem (PV/T) birbirinden hava kanalı ile izoleli, enerji bilançosu denklemleri, ara mesafenin değişimine göre verim optimizasyonu
IV ABSTRACT THE EFFICIENCY OPTIMIZATION OF THE PHOTOVOLTAIC-PHOTOTHERMIC TRANSFORMERS ERKAYA, Kubilay Ph. D. İn Solar Energy Supervisor: Prof. Dr. Metin ÇOLAK February, 1999, page 74 PURPOSE AND SCOPE It was appeared with the researchs made by Loferski et al., (1982)(1), and Takashime et. 1., (1994)(2) that it is probable to obtain photovoltaic (PV) and thermal energy at the same time with the system, called as PV/T system, and with the PV module and collector that are put one on top of the other in the same field. On the other hand, it is known that, in the system that PV module is placed the inside of the collector (1), in spite of the fact that the hot water was obtained from the collector, because of the spread of the heat in the collector to the PV module, PV module warms and its efficiency reduces. For the aim of attaining better efficiency by removing the heating problem of the PV module in PV/T system, the system that isolated from each other by the air channel was thought and its research was made by the mathematical model (2). It was declared that, at the optimum distance of the air channel, that situated between the PV module and collector, the maximum efficiency was obtained from the new system. In this study, the efficiency of the air-spaced PV/T system (2) that is mentioned above, is optimized by measuring and by designing under the conditions of Bornova.METHODS THAT ARE USED In this aforementioned PV/T system, mono crystal 75 W silicon PV module was used and the radiation of the module became 10% permeable by taking off carefully the cover of the- field that is outside of the cells, PV module with the dimensions of 1.14x0.52 and a warmwater collector at the same dimensions were designed and were produced. PV module and collector were placed to a special coffee table that the distance between them can be easily changed. The efficiency of the system, is solved mathematically at first. In the solution, since it was known that the maximum radiation came into existence at the plane angle of the parallel degree of that place, under the conditions of İzmir, Bornova the radiation, that came to the oblique plane at the Izmir's parallel degree of 38°, was calculated. In this radiation the ray analysis' of P V module and collector were examined, their efficiency were found and were optimized according to the change of the interval distance from 0.01m to 0.1m At the ray analysis, solution was found by making the balance sheets of energy for each members of the system. The solution of the system was made in computer with the programs of Excel and Basic Excel and Excel Visual Basic. At measuring, first of all, the PV module and collector measured separately, then, in the PV/T system, PV module-collector were tested for the each value of the interval distance from 0.01m to the 0.1m At measuring, the values of the weather temperature, speed of the wind, radiation that came to the 38° oblique plane, the heat of the PV module's bottom and top windows, values of current and tension, heat of the windows of theVI collector, the entrance and exit warmth of the water, the exit temperature of the air from the interval channel were taken. There is no great difference between the calculations and measurings. Consequently, in the PV/T system, the maximum efficiency of the PV module, becomes, 10.93% at the value of 0.01 of interval distance, and the efficiency of the collector at the 0.01m value of the interval distance becomes 10.10% and since the real factor that affects the efficiency is the collector, the total efficiency of the system reached the maximum point at 0.01m It is because, at the 0.01m, although the heat of the PV increases, the change of the efficiency by heat is at a very small value as 0.004/°C. Totally, the maximum efficiency is 20.98%. In such kind of PV/T system, that was developed for the aim of saving place from the area that system will be founded, there is no important change at the efficiency of the PV module under the conditions of İzmir. As for the efficiency of the collector is about 10%. When this was compared with the efficiency of the collector in the situation of using it separately (60%), it was found as very low, therefore, it was not thought that such kind of a PV/T system can be profitable under the conditions of Izmir, Bornova. Key words: Photovoltaic and thermal energy system (PV/T), eachother by the air channel, balance sheets of energy. Efficiency optimization according to the change of the interval distance.
IV ABSTRACT THE EFFICIENCY OPTIMIZATION OF THE PHOTOVOLTAIC-PHOTOTHERMIC TRANSFORMERS ERKAYA, Kubilay Ph. D. İn Solar Energy Supervisor: Prof. Dr. Metin ÇOLAK February, 1999, page 74 PURPOSE AND SCOPE It was appeared with the researchs made by Loferski et al., (1982)(1), and Takashime et. 1., (1994)(2) that it is probable to obtain photovoltaic (PV) and thermal energy at the same time with the system, called as PV/T system, and with the PV module and collector that are put one on top of the other in the same field. On the other hand, it is known that, in the system that PV module is placed the inside of the collector (1), in spite of the fact that the hot water was obtained from the collector, because of the spread of the heat in the collector to the PV module, PV module warms and its efficiency reduces. For the aim of attaining better efficiency by removing the heating problem of the PV module in PV/T system, the system that isolated from each other by the air channel was thought and its research was made by the mathematical model (2). It was declared that, at the optimum distance of the air channel, that situated between the PV module and collector, the maximum efficiency was obtained from the new system. In this study, the efficiency of the air-spaced PV/T system (2) that is mentioned above, is optimized by measuring and by designing under the conditions of Bornova.METHODS THAT ARE USED In this aforementioned PV/T system, mono crystal 75 W silicon PV module was used and the radiation of the module became 10% permeable by taking off carefully the cover of the- field that is outside of the cells, PV module with the dimensions of 1.14x0.52 and a warmwater collector at the same dimensions were designed and were produced. PV module and collector were placed to a special coffee table that the distance between them can be easily changed. The efficiency of the system, is solved mathematically at first. In the solution, since it was known that the maximum radiation came into existence at the plane angle of the parallel degree of that place, under the conditions of İzmir, Bornova the radiation, that came to the oblique plane at the Izmir's parallel degree of 38°, was calculated. In this radiation the ray analysis' of P V module and collector were examined, their efficiency were found and were optimized according to the change of the interval distance from 0.01m to 0.1m At the ray analysis, solution was found by making the balance sheets of energy for each members of the system. The solution of the system was made in computer with the programs of Excel and Basic Excel and Excel Visual Basic. At measuring, first of all, the PV module and collector measured separately, then, in the PV/T system, PV module-collector were tested for the each value of the interval distance from 0.01m to the 0.1m At measuring, the values of the weather temperature, speed of the wind, radiation that came to the 38° oblique plane, the heat of the PV module's bottom and top windows, values of current and tension, heat of the windows of theVI collector, the entrance and exit warmth of the water, the exit temperature of the air from the interval channel were taken. There is no great difference between the calculations and measurings. Consequently, in the PV/T system, the maximum efficiency of the PV module, becomes, 10.93% at the value of 0.01 of interval distance, and the efficiency of the collector at the 0.01m value of the interval distance becomes 10.10% and since the real factor that affects the efficiency is the collector, the total efficiency of the system reached the maximum point at 0.01m It is because, at the 0.01m, although the heat of the PV increases, the change of the efficiency by heat is at a very small value as 0.004/°C. Totally, the maximum efficiency is 20.98%. In such kind of PV/T system, that was developed for the aim of saving place from the area that system will be founded, there is no important change at the efficiency of the PV module under the conditions of İzmir. As for the efficiency of the collector is about 10%. When this was compared with the efficiency of the collector in the situation of using it separately (60%), it was found as very low, therefore, it was not thought that such kind of a PV/T system can be profitable under the conditions of Izmir, Bornova. Key words: Photovoltaic and thermal energy system (PV/T), eachother by the air channel, balance sheets of energy. Efficiency optimization according to the change of the interval distance.
Açıklama
Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.
Anahtar Kelimeler
Enerji, Energy, Dönüştürücüler, Transformers, Fotovoltaik sistemler, Photovoltaic systems, Verim ögeleri, Yield components, Yalıtım, Insulation
