Molybdenum disulfide/water nanofluid morphology effects on the solar collector: first and second thermodynamic law analysis

Abstract

This study presented an investigation on a flat plate sheet and tube-based solar collector located in Abu-Musa Island (in the Persian Gulf) in Hormozgan province, Iran, based on the first and second thermodynamics laws. The referred solar collector is used from water-molybdenum disulfide (MoS2) nanofluids having various nanoparticle shapes as working fluid. The main goal of the presented investigation is to study the morphology influence of MoS2 dispersed particles in the water on the heat transfer performance, fluid flow, and generated entropy. Due to fulfilling of this object, analysis of four different nanoparticle shapes (blades, platelets, bricks, and cylinders) of MoS2 is chosen. Nusselt number, outlet fluid temperature, pressure drop, performance evaluation criterion (PEC), friction factor, and entropy generation considering various nanoparticle shapes and nanoparticles volume fractions up to 4% for turbulent flow regime considering mass flow equal to 0.75 and 0.5 kg/s are reported. According to obtained results, the PEC of the case with ϕ = 3% having bricks nanoparticle shape with ṁ = 0.5 kg/s is the best among all studied cases, and its value is around 1.269. In the case with ṁ = 0.75 kg/s, the value of PEC for nanofluid with ϕ = 4% having bricks nanoparticle shape is found to be about 1.182. Also, it is shown that for ṁ = 0.5 kg/s, employing the bricks and blade shape particles is not recommended based on the second thermodynamics law viewpoint, while for 0.75 kg/s mass flow using volume fractions of 1% and 4% for bricks and blade shapes nanoparticles can decrease the entropy generation in comparison with water base fluid till 8%.