Yeni geliştirilen havalı güneş kollektörünün enerji ve ekserji parametrelerinin belirlenmesi
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Tarih
2018
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info:eu-repo/semantics/openAccess
Özet
Yapılan bu çalışmada yeni tasarlanan poroz yüzeyli havalı güneş kolektörünün enerji ve ekserji analizi yapılmıştır. Deneysel çalışmalar için üç ayrı deney düzeneği hazırlanmıştır. İlk deney düzeneğinde, emici yüzeyine herhangi madde serilmeden düz yüzey kullanılmıştır, ikinci çalışmada emici plaka üzerine bakır elek teli serilmiştir, üçüncü çalışmada emici plaka üzerine bakır yünü serilmiştir. Bu şekilde emici plakanın makro düzeyde seçici yüzey gibi davranması ve akışın ısıl sınır tabakasının bozulmasıyla emici plakanın daha fazla ısı absorbe etmesi hedeflenmiştir. Deneyler farklı kolektör tipleri için 0.030, 0.035, 0.044 ve 0.055 kg/s kütlesel debilerde tekrarlanmıştır. Verim hesaplaması için, kolektöre giren ve çıkan havanın sıcaklığı, havanın hızı, ışınım şiddeti ve kolektörde meydana gelen basınç farkı ölçülmüştür. Düzey yüzeyli kolektörlerde 0.035 kg/s kütlesel debi değeri için maksimum ısıl verim %50; 0.044 kg/s kütlesel debi değeri için maksimum ısıl verim % 68 bulunmuştur. Bakır elek teli serilen kolektörde 0.035 kg/s kütlesel debi değeri için maksimum ısıl verim %58; 0.044 kg/s kütlesel debi değeri için maksimum ısıl verim %77 bulunmuştur. Birinci ve ikinci deney düzeneği farklı kollektör açılarında incelenmiştir. Ayrıca ikinci çalışmada yeni tasarlanan poroz yüzeyli havalı güneş kolektörünün ve düz yüzeyli kollektörün termal performansı, farklı kolektör açılarında araştırarak incelenmiştir. Aynı kütlesel debide düz yüzeye sahip kolektörün 35° eğim açısındaki verimi ile bakır elek telli kolektörün 25° eğim açısındaki verimleri karşılaştırıldığında kolektör açısının, kolektör emici yüzeyine göre verimi daha çok etkilediği görülmüştür. Emici yüzeye bakır yünü serilen kolektörün, 0.035 kg/s kütlesel debi değeri için maksimum ısıl verim %57; 0.044 kg/s kütlesel debi değeri için maksimum ısıl verim %73 olarak bulunmuştur. Kolektörlere ait termal-hidrolik verim değerleri %20- %70 arasında tespit edilmiştir. Deneysel sonuçlara göre hesaplanan ekserji verimleri %2 -%11 arasında hesaplanmıştır.
This experimental investigation has been carried out to study on energy and exergy analyses of newly designed solar air collector with porous surface by preparing three different experimental setups. For the first experimental setup, a flat surface was used without spreading any substance on the absorbent surface, copper wire mesh was laid on the absorber plate in the second setup, copper wool was laid on the absorber plate in the third setup In this way, the absorber plate was aimed to absorb more heat and impair the the thermal boundary layer of the flow. The tests were repeated for different collector types at 0.030, 0.035, 0.044 and 0.055 kg /s mass flow rates. For the efficiency calculation, the temperature difference of the air entering and leaving the collector, the velocity of the air, the intensity of the radiation and the pressure difference in the collector were measured. The maximum thermal efficiency of flat surface collectors at the rate of 0.035 kg/h mass flow rate was found 50%; the maximum thermal efficiency at the rate of 0.044 kg/h was found to be 68%. The maximum thermal efficiency of the collector for which copper wire mesh was laid on the absorber plate was found 58% at the 0.035 kg/h mass flow rate and 77% at the 0.044 kg/h mass flow rate. The first and second experimental setups were checked out at different collector angles. In addition, the thermal performance of the newly designed solar air collector with porous surface and the thermal performance of the collector with flat surface were examined at different collector angles. By comparison with the efficency of the collector having flat surface at the angle of 35° and the efficiency of the collector with wire mesh at 25° at the same mass flow rate, it has been found that the angle of collector has more important role on the efficiency rather than the absorbent surface of collector. Maximum thermal efficiency of 57% for a mass flow rate of 0.035 kg/s for a collector with copper wool laid on the absorbent surface; The maximum thermal efficiency for the mass flow rate of 0.044 kg/h was found to be 73%. The thermal-hydraulic efficiency values of the collectors are between 20% and 70%. Exergy efficiency calculated from the experimental results are estimated to be between 2% and 11%.
This experimental investigation has been carried out to study on energy and exergy analyses of newly designed solar air collector with porous surface by preparing three different experimental setups. For the first experimental setup, a flat surface was used without spreading any substance on the absorbent surface, copper wire mesh was laid on the absorber plate in the second setup, copper wool was laid on the absorber plate in the third setup In this way, the absorber plate was aimed to absorb more heat and impair the the thermal boundary layer of the flow. The tests were repeated for different collector types at 0.030, 0.035, 0.044 and 0.055 kg /s mass flow rates. For the efficiency calculation, the temperature difference of the air entering and leaving the collector, the velocity of the air, the intensity of the radiation and the pressure difference in the collector were measured. The maximum thermal efficiency of flat surface collectors at the rate of 0.035 kg/h mass flow rate was found 50%; the maximum thermal efficiency at the rate of 0.044 kg/h was found to be 68%. The maximum thermal efficiency of the collector for which copper wire mesh was laid on the absorber plate was found 58% at the 0.035 kg/h mass flow rate and 77% at the 0.044 kg/h mass flow rate. The first and second experimental setups were checked out at different collector angles. In addition, the thermal performance of the newly designed solar air collector with porous surface and the thermal performance of the collector with flat surface were examined at different collector angles. By comparison with the efficency of the collector having flat surface at the angle of 35° and the efficiency of the collector with wire mesh at 25° at the same mass flow rate, it has been found that the angle of collector has more important role on the efficiency rather than the absorbent surface of collector. Maximum thermal efficiency of 57% for a mass flow rate of 0.035 kg/s for a collector with copper wool laid on the absorbent surface; The maximum thermal efficiency for the mass flow rate of 0.044 kg/h was found to be 73%. The thermal-hydraulic efficiency values of the collectors are between 20% and 70%. Exergy efficiency calculated from the experimental results are estimated to be between 2% and 11%.
Açıklama
Anahtar Kelimeler
Poroz yüzey, Havalı güneş kollektörü, Ekserji, Porous surface, Solar air collector, Exergy
