A Comparative Experimental and CFD Simulation Performance Analysis of Two Different Flat Plate Solar Collector Configurations

Abstract

Two flat plate collectors are studied experimentally and theoretically side by side under the same weather conditions. The First collector (C1) is used to heat air only while the second collector (C2) is used for dual heating of air and water simultaneously. The air duct is configured in the absorber plate with dimensions of (5x20 cm) in both collectors. Two parallel circular copper pipes, each with diameter of (0.01905 m) and length of (12 m) configured in a serpentine path run parallel to the air duct, are used to heat water in collector (C2). The air duct in both collectors has the same cross-sectional area (0.01m²), but have different turn aspect ratio (R_Outer/R_Inner). The absorber plate and air duct are made from the same material which is stainless-steel. Both Collectors are tested under the weather conditions in the University of Babylon Campus located in Hilla city, middle of Iraq (long. 44,25^o E and lat. 32,3^o N). The study is carried out through a period of eight months (July 2018 to March 2019) with different tilt angles (11.5^o, 19.4^o, 31.08^o, 43.3^o, 53^o, 57.3^o, 55^o and 47.4^o). Different air and water mass flow rates are tested. The performance of both collectors is analyzed experimentally and theoretically. A three dimensional steady state analysis is performed using ANSYS Fluent 16 software. The air, water and absorber temperatures, pressure drop are measured and predicted in addition to collector efficiency. The results show that as the mass flow rate for air and water decrease the temperature for water ,air and absorber temperatures will increase, while the efficiency decrease. The maximum measured temperatures for air, water and absorber plate were (65°C), (54°C) and (87°C) respectively, which obtained in summer. Simulation results show a good agreement with the experimental results.