Exergy performance assessment of a novel air-cooled photovoltaic thermal collector with a double serpentine runner

Abstract

Despite the various technologies are used in enhancing the air-cooled photovoltaic thermal (PVT) collector through ranging baffles on the chamber, it still leads to a greater pressure loss, resulting in increasing the energy consumption of the fan. This problem is addressed in this work by rearranging the baffle to form a double serpentine runner for improving heat transfer characteristic and reducing the pressure drop of the air in the structure of the serpentine runner. A CFD (Computational Fluid Dynamics) module has been carried out to analyze the collector performance and verified by the experiments. Influences of the structural and operating parameters are studied to optimize the performance of the PVT collector and the results indicated that: (a) Large flow stagnation zones may result from improperly arranged baffles, significantly affecting heat transfer and producing considerable pressure loss. And the recommended values of the structural parameters are given: baffle height is in the range of 75–95 mm, baffle number is in the range of 10–14, and baffle length is in the range of 700–800 mm. (b) although the thermal and electrical efficiency are improved with increasing flow rate, the exergy efficiency increases first and then reduces. The value of the air mass rate is suggested in the range of 0.02–0.03 kg/s. (c) the value ranges of the thermal, electrical, total, and exergy efficiency of the collector for Lasa in November can be 37.2–42.3 %, 11.3–12.5 %, 41.3–51.1 %, and 9.8–11.8 %. (d) comparing this collector with previous studies, the thermal and electrical efficiency of this collector is similar to other collectors, and the pressure drop is significantly lower.