Thermal analysis of a Serpentine Flat Plate Collector and investigation of the flow and convection regime

Abstract

In this paper a special kind of Flat Plate Collectors (FPCs) was examined in detail through CFD analysis. The distinctiveness of the current model has to do with the piping system was applied which is a Serpentine flow conduit. The operation of the collector was examined at four different inclination an-gles (0°,15°, 30° and 45°) and several values of the inlet water temperature (10°C-80°C per 10°C) by providing the same heat perpendicular to the cov-er in each case. The thermal efficiency as well as the temperature fields of the collector were determined first. Furthermore, the overall heat losses were calculated and compared to these arisen from the Cooper-Dunkle as-sumption while the mean divergence between these two solutions was around 5%. Moreover, the natural convection inside the gap as well as the tube to water convection was examined and the heat transfer coefficients were validated from theoretical models in horizontal position. In particular, the simulation results found to diverge from the theoretical ones about 12.5% and 7% as regards the pipe flow and the air gap respectively. In ad-dition, a remarkable flow phenomenon was observed at the bends of the pipe and the nature of it was explained in detail. Last but not least, the inclination angle seems that affects significantly the collector's performance since the higher the slope the lower the convection losses. Solidworks and its simula-tion program ''Flow Simulation'' were used to design and simulate the whole collector.