Experimental Investigation and Performance Evaluation of Parabolic Trough Solar Collector for Hot Water Generation

The parabolic trough solar collector (PTSC) is one of the most established solar concentrated systems in the solar thermal applications worldwide. The current paper presents experimental results on a PTSC designed and tested under Hungarian weather conditions in October and November 2020 regarding generation of hot water. The PTSC was made of aluminum sheet of parabolic shape to reflect and concentrate solar radiation into an absorber tube located at the focus point. The absorber tube was made of copper or stainless steel with diameters of 12 and 10 mm, respectively, with and without a glass cover tube. The efficiency of the PTSC was investigated depending on the time of the day at four flow rates under various conditions. The experimental results show that the copper tube coupled with the glass cover worked well at a mass flow rate of 0.0035 kg/s. Furthermore, the glass cover reduced the heat loss, and the performance of the PTSC was enhanced through improvement of the greenhouse effect between the glass and tube.