The effect of some components on performance of flat plate solar water collectors

Abstract

Copper and aluminum type flat plate solar water collectors are widely used for supplying hot water for domestic applications in the world. It is possible to see many studies about thermal efficiency of any type of flat plate solar collector in the literatures. However, not enough test results are reported in the literature on the effect of solar water collector components. Therefore, in this experimental study, the effects of some components such as construction materials (copper and aluminum), absorber surfaces (black painted copper sheet, black cooper selective surface and black painted aluminum sheet), covers (normal flat glass, prismatic glass and normal tempered glass) and radiation reflector material located between insulation and absorber surfaces on performance of solar water collectors were investigated. All tests were conducted according to EN (European Norms) 12975-2 (2003) (Anon., 2003). The solar water collectors were tested in summer conditions (in August, in Samsun, Turkey). Each collector was tested four days for each component and 5 hours (10:00 to 15:00) for each day. Four different fluid inlet temperatures were used for each test. Fluid inlet temperatures were changed between 35 degrees C...60 degrees C while the ambient air temperature changed between 28 degrees C...34 degrees C, during experiments. The results showed that thermal efficiencies of 1) copper type collector with black painted copper absorber surface and normal flat glass cover, 2) copper type collector with black copper selective absorber surface and normal flat glass cover, 3) copper type collector with black painted copper absorber surface and prismatic glass cover, 4) copper type collector with black copper selective absorber surface, 5) normal flat glass and radiation reflector, aluminum type collector with black painted aluminum absorber surface and normal flat glass cover, and 6) aluminum type collector with black painted aluminum absorber surface and normal tempered glass cover were 56.26 %, 63.39 %, 65.63 %, 64.51 %, 58.19 % and 67.82 %, respectively.