Experimental and numerical analysis of a parabolic trough solar collector for water heating application

The aim of this study is to obtain hot water utilizing a parabolic trough solar collector. The copper tube and aluminum absorber tube were placed separately through the focus point of the parabolic reflector. The steady mass flow rate of water was changed for five cases of 0.0017 to 0.0083 kg/s and the thermal efficiency of the system was computed for each absorber tube. The amount of solar radiation, mass flow rate as well as water temperatures at inlet and outlet of the absorber tube were measured during the investigation to have the experimental data. The maximum efficiency values were found as 74.5% for copper tube absorber while it was 72.7% for copper tube absorber when mass flow rate was 0.0083 kg/s. The problem was also modeled with CFD and temperatures at the outlet of absorber tube were found by numerical simulations (area-weighted average method) which showed a deviation of 6.5% as an average compared to experimental results.