Heat transfer and thermodynamic analysis of individual and simultaneous effects of revolution, microporous media, magnetic inductor, and nanoparticles in concentrating solar collectors

Abstract

A huge amount of accumulated heat is lost in concentrating solar collectors due to the weak thermal performance of working fluid. High temperature concentration on absorber tube increases the exergy destruction as well as the damage of cover glass in this type of solar collector. A novel and cost-effective method is employed to obviate such deficiencies by furnishing the collector with a revolutionary receiver, microporous metal foam, and magnetic nanofluid. In the new design, the collector is manipulated in such a way that first, a thin metal foam as a porous fin is attached inside the tube to increase the heat transfer area of the absorber tube. Then, while the nanofluid flows through the plain region in the center of the tube, a revolution in the tube circulates the nanofluid and pushes it toward the porous fin by a centrifugal force. For more agitation, a magnetic force is inducted on nanoparticles by a magnetic field inducer as a stimulus in the collector. The hybrid technique improves both convection and conduction mechanisms in the collector. Besides, less pumping power is needed in the present configuration of porous media compared to previous designs since the momentum is prepared by the centrifugal force. Results reveal that 62.7% of lost heat is managed and restored in the collector by applying the new method. Also, the first and second law efficiencies rise by 16.5% and 8.3% in the manipulated system.