Bir fotovoltaik termal (PV/T) kolektörde metal-oksit ve bor esaslı nanoparçacık kullanımının performansa etkisinin deneysel olarak araştırılması
Küçük Resim Yok
Tarih
2024
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Düzce Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Yenilenebilir enerji kaynakları, kullanılan fosil kökenli yakıtların sınırlı olması ve enerji ihtiyacının sürekli artması nedeniyle günümüzde sürekli gündemde yer almaktadır. Enerji ihtiyacı ve fosil yakıtların sebep olduğu çevresel sorunlar göz önüne alındığında gelecekte de gündemdeki yerini korumaya devam edecektir. Bu kaynaklar arasında ise güneş enerjisi, önemli bir konuma sahiptir. Günümüzde güneş enerjisinden ısı enerjisi ve elektrik enerjisi üretimi yaygındır. Fotovoltaik (PV) güneş panelleri, üzerlerine düşen güneş enerjisinin sınırlı bir kısmını elektrik enerjisine dönüştürebilirler. PV panellerde elektriğe dönüştürülemeyen güneş enerjisinin oluşturduğu ısı, elektriksel verimi azaltmaktadır. Bu ısıyı sistemden uzaklaştırmak ve aynı zamanda faydalı enerjiye dönüştürmek amacı ile fotovoltaik termal (PV/T) kolektörler kullanılmaktadır. PV/T kolektörlerin bir kısmı sıvı soğutmalıdır. Sıvı soğutmalı PV/T sistemlerde farklı akışkanlar kullanılarak sistemin verimini arttırma çalışmaları yaygındır. Yapılan çalışmaların bir kısmı cebri dolaşım (pompa kullanılarak) bir kısmı ise doğal dolaşım (termosifon etki) ile yapılmıştır. Bu çalışmada, doğal dolaşımlı endirekt ısıtmalı bir PV/T sistem tasarlanmıştır. PV/T kolektör içerisinde dolaşan suya, verimi artırmak amacıyla, farklı konsantrasyonlarda Al2O3, ZnO ve BN nanoparçacık ilavesi yapılmıştır. Sistem performansı; güneş ışınımı, dış hava sıcaklığı, akışkan giriş - çıkış sıcaklığı gibi farklı parametrelere göre değerlendirilmiştir. Deney sonuçlarına göre PV/T sistemde soğutma sıvısına nanoparçacık eklenmesi ile termal verim ve toplam verimde (termal + elektriksel) artış meydana gelmiştir. En yüksek toplam verimler 0,03 g/L konsantrasyonda nanoparçacık kullanılan deneylerde sırasıyla ZnO, BN, Al2O3 %58,25, %52, 62 ve % 47,60 olarak elde edilmiştir. Soğutma yapılmayan panelde ise verim sadece elektriksel verim olarak % 14,14 olmuştur. En yüksek ekserji verimliliği ve sürdürülebilirlik indeksi ZnO nanoakışkanın 0,03 g/L konsantrasyonda sırasıyla %17,155 ve 1,207 olarak elde edilmiştir. Çalışma sonuçlarına göre pasif soğutmalı PV/T sistemlerin evler, yurtlar, fabrikalar ve otellerde kullanımının uygun olduğu sonucuna varılmıştır.
Renewable energy sources are constantly on the agenda today because the fossil fuels used are limited and the need for energy is constantly increasing. Considering the energy need and environmental problems caused by fossil fuels, it will continue to maintain its place on the agenda in the future. Among these resources, solar energy has an important position. Nowadays, heat energy and electrical energy production from solar energy is common. Photovoltaic (PV) solar panels can convert a limited portion of the solar energy falling on them into electrical energy. The heat created by solar energy that cannot be converted into electricity in PV panels reduces electrical efficiency. Photovoltaic thermal (PV/T) collectors are used to remove this heat from the system and at the same time convert it into useful energy. Some of the PV/T collectors are liquid cooled. It is common to try to increase the efficiency of the system by using different fluids in liquid-cooled PV/T systems. Some of the studies were carried out with forced circulation (using a pump) and some with natural circulation (thermosiphon effect). In this study, a natural circulation indirect heated PV/T system was designed. Different concentrations of Al2O3, ZnO and BN nanoparticles were added to the water circulating in the PV/T collector in order to increase the efficiency. System performance was evaluated according to different parameters such as solar radiation, outdoor air temperature, fluid inlet and outlet temperature. According to the experimental results, an increase in thermal efficiency and total efficiency (thermal + electrical) occurred with the addition of nanoparticles to the cooling liquid in the PV/T system. The highest total yields were obtained as 58.25%, 52,626% and 47.6% in ZnO, BN, Al2O3, respectively, in experiments using 0,03 g/L concentration of nanoparticles. In the panel without cooling, the efficiency was only 14.14% in terms of electrical efficiency. The highest exergy efficiency and sustainability index were determined as 17.155% and 1.207, respectively, at 0.03 g/L concentration of ZnO nanofluid. According to the study results, it was concluded that passive cooling PV/T systems are suitable for use in houses, dormitories, factories and hotels.
Renewable energy sources are constantly on the agenda today because the fossil fuels used are limited and the need for energy is constantly increasing. Considering the energy need and environmental problems caused by fossil fuels, it will continue to maintain its place on the agenda in the future. Among these resources, solar energy has an important position. Nowadays, heat energy and electrical energy production from solar energy is common. Photovoltaic (PV) solar panels can convert a limited portion of the solar energy falling on them into electrical energy. The heat created by solar energy that cannot be converted into electricity in PV panels reduces electrical efficiency. Photovoltaic thermal (PV/T) collectors are used to remove this heat from the system and at the same time convert it into useful energy. Some of the PV/T collectors are liquid cooled. It is common to try to increase the efficiency of the system by using different fluids in liquid-cooled PV/T systems. Some of the studies were carried out with forced circulation (using a pump) and some with natural circulation (thermosiphon effect). In this study, a natural circulation indirect heated PV/T system was designed. Different concentrations of Al2O3, ZnO and BN nanoparticles were added to the water circulating in the PV/T collector in order to increase the efficiency. System performance was evaluated according to different parameters such as solar radiation, outdoor air temperature, fluid inlet and outlet temperature. According to the experimental results, an increase in thermal efficiency and total efficiency (thermal + electrical) occurred with the addition of nanoparticles to the cooling liquid in the PV/T system. The highest total yields were obtained as 58.25%, 52,626% and 47.6% in ZnO, BN, Al2O3, respectively, in experiments using 0,03 g/L concentration of nanoparticles. In the panel without cooling, the efficiency was only 14.14% in terms of electrical efficiency. The highest exergy efficiency and sustainability index were determined as 17.155% and 1.207, respectively, at 0.03 g/L concentration of ZnO nanofluid. According to the study results, it was concluded that passive cooling PV/T systems are suitable for use in houses, dormitories, factories and hotels.
Açıklama
Anahtar Kelimeler
Enerji, Energy
