Numerical Study of Using Nano Fluid as Media for Compound Parabolic Solar Collector Based on Optimum Inner Diameter

The collector is one of the ways to achieve clean thermal energy, and the most important of these systems can be pointed out to the compound parabolic concentrator (CPC). This paper focuses on measuring the amount of heat transfer in a CPC containing two water pipes as well as a water-based nano-fluid. In this research, a 3D model using Fluent software (Finite volume Method) was used to simulate and solve the governing equations (continuity, momentum and energy) in a collector with 500 and 55 mm for length and diameter, respectively.Based on the numerical results, for a collector with diameter of 55 mm, the use of 6 mm water pipes will achieve the highest heat transfer rate around 1.974 C for 8% volume fraction. The results indicate that the vortices formed around the cold water pipe are larger than vortices around the hot water pipe in all nano volume fractions (0, 2, 4, 6, 8 and 10%) for a pipe with diameter of 6 mm and this is because of the high temperature gradient between the walls and the cold pipe.