Evaluation of heat transfer performance of two-phase nanofluid flow in a parabolic solar collector with eccentric absorber and solid insulation

In this study, the flow field analysis and heat transfer of two-phase nanofluid flow in a parabolic solar collector with eccentric absorber and solid insulation have been investigated. The fluid used in this collector is nanofluid of water - Aluminium. The main aim of current study is to investigate the effect of using eccentric absorber system and solid insulation on the energy efficiency of linear parabolic collectors. For this purpose, energy efficiency has been measured and presented for different states (including ambient temperature, fluid inlet temperature, nanofluid volume fraction, nanoparticle diameter and geometric characteristics). The study is in turbulent flow regime and in order to model it, the k epsilon turbulence model has been used. In order to solve the survival equations, the finite volume method and the SIMPLE C algorithm have been used. Different optimal models are introduced in terms of having the highest energy efficiency, and the best model is determined. Based on obtained results, the highest energy efficiency in different Reynolds is related to the novel collector and two-phase model(TPM). In the next positions, respectively, are the novel collector and single-phase model(SPM), the basic collector and two-phase model, and at the end, the basic collector and single-phase model. It was also found that as the Reynolds number increases, all modes have an uptrend. The maximum amount of energy efficiency was for the novel collector and the two-phase model at Reynolds 15000, Which is equal to 68%. Also, the maximum energy efficiency for eccentricity 20 mm at Reynolds 15000, which is equal to 74.9%.