EXERGETIC AND ENERGETIC EVALUATION OF AN INNOVATIVE SOLAR AIR HEATING SYSTEM COATED WITH GRAPHENE AND COPPER OXIDE NANOPARTICLES

Abstract

In the 21th century, renewable energy has to play very important role in socio-economic and industrialdevelopment. This paper evaluates the exergy- energy analysis, which is based on the second law of thermodynamics.The triangular solar heater is developed to determine the heat transfer rate, thermal efficiency, exergy efficiency andBejan number. In addition, we have examined the effects of entropy generation with respect to solar radiation andambient temperature of air. Absorber plates coated with graphene and copper oxide nano-particles by the differentpercentages (0.1%, 0.2%, 0.3% & 0.4%) doped into black paint which increases the absorption of heat. The Reynoldsnumber (4500 ≤ 𝑅 ≤ 22700) varies for the fixed selective coating on absorber plate and mass flow rate. Theexperimental observations were performed for constant mass flow rate of air ranging from 0.0035kg/s to 0.018 kg/s.The experimental result gives the average thermal efficiency enhancement of 3.58% for 0.3% graphene/CuO-blackpaint. Entropy generation is more for 0.1% and minimum for 0.3% graphene/CuO-black paint coating. The entropygeneration analysis concludes that the entropy generation increases with increasing the mass flow rate. Exergyefficiency enhancement can be found 0.169%for 0.3% with respect to 0.1% graphene/CuO-black paint.