Computational Modeling of a Small-Scale, Solar Concentrating Device Based on a Fresnel-Lens Collector and a Flat Plate Receiver with Cylindrical Channels

The energy efficiency of a small-scale solar concentrating thermal device is investigated, based on Monte-Carlo Ray-Tracing (MCRT) and Computational Fluid Dynamics (CFD) modeling. consists Fresnel lens collector—engraved 1 m rectangular plate—and 10 cm sized plate receiver, with drilled cylindrical channels diameter mm. Inlet velocities heat transfer fluid (HTF) temperatures lie within the range 0.25–1 m/s 100–200 °C, respectively. configurations examined involve utilization selective coating absorbing surface increasing channel to 15 mm receiver size 20 cm, insertion glass envelope in front surface. Energy increases velocity up 80%, level beyond which no further improvement observed. contributes reduction losses; it brings substantial benefits for lower examined. increase also an efficiency, while dimensions leads opposite effect. cover does not improve performance collector, due optical losses.