Vakum Tüplü U-Borulu Güneş Kollektörünün Güneş Simülatöründeki Test Sonuçlarının Analizi

Bu çalışmada iç ortam şartlarında güneş simülatöründe vakum tüplü U-borulu bir güneş kollektörü test edilerek verim eğrisi oluşturuldu. Farklı akışkan debilerinde güneş kollektörünün basınç düşümü belirlendi. Simülatörden güneş kollektörü üzerine gelen ışınlar halojen lambalarla sağlanmakta olup, ışınımlar kollektör üzerine güneş ışınları gibi birbirine paralel olarak gelmediğinden verim hesabında, absorber izdüşüm alanının kullanılmasının yanıltıcı olacağı görüldü. Daha gerçekçi bir yaklaşım olarak, ışınımların geldiği açısal absorber alanının hesaplanması ile ilgili bir yöntem geliştirildi. Kollektör absorber izdüşüm alanına bağlı kollektör verimi %116 ile %80 arasında değişirken, açısal absorber alanına bağlı kollektör veriminin %56 ile %38 arasında değiştiği görüldü. Deneysel çalışmadan elde edilen bu sonuçlar, güneş simülatöründe vakum tüplü güneş kollektörü testlerinde verim hesabında kullanılacak alanın belirlenmesinin önemini ortaya çıkardı. Ayrıca kollektördeki akışkan debisinin kollektör verimine ve basınç düşümüne etkisi de incelendi. Kollektördeki akışkan debisi arttıkça basınç düşümünün de arttığı, göreceli olarak akışkan debisi ile verimde de bir artış gözlendi.

Anahtar Kelimeler:

Güneş enerjisi, vakum tüplü güneş kollektörü, u-borulu güneş kollektörü, güneş simülatörü

Analysis of the Test Results on the Solar Simulator of the U-Pipe Evacuated Tube Solar Collector

In this study, a U-pipe evacuated tube solar collector was tested in a solar simulator under indoor conditions and an efficiency curve was formed. The pressure drop of the solar collector was determined for different mass flow rates. Beams that come from the simulator to the solar collector are provided with halogen lamps. Since beams from the lamps do not come parallel to the collector like solar beams, it would be misleading to use the absorber projection area in the calculation of efficiency. As a more realistic approach, a method that calculates the angular absorber area of beams was developed. While collector efficiency that depends on the collector absorber projection area varies between 116% and 80%, collector efficiency that depends on the field of the angular absorber has changed between 56% and 38%. These results obtained from the experimental study reveal the importance of determining the collector’s area to be used in the solar simulator for the efficiency calculation of evacuated tube solar collector tests. The effect of fluid flow on collector efficiency and pressure drop is also investigated. As the fluid flow in the collector increases, the pressure drop also increases and a relatively increase in the efficiency is observed.

Keywords:

Solar Energy, evacuated tube solar collector, u-pipe solar collector, solar simulator,

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