Thermal assessment of solar concentrated system with utilizing CNT nanoparticles and complicated helical turbulator

Abstract

Turbulent flow of nanomaterial (mixture of CNT and water) within the circular tube of solar system as an absorber has been simulated numerically in this article. The circular tube has been equipped with complex swirl flow device to make the impingement of fluid with wall stronger and in this way warmer fluid can be achieved from this system. To concentrate the solar radiation, ten mirrors were utilized and geometric parameters have been calculated mathematically to reach the maximum optical performance. The maximum fraction of CNT is 0.025, thus involving single phase formulation is logical. Three configurations of device have been utilized in which two range of pitch ratio (S = 0.1, 0.25) were utilized in addition to configuration without twisting (WT). K-ϵ model was utilized in simulation which was based on finite volume method. Four ranges of flow rate (Q = 8, 12, 16, 20 Lit/min) was applied with inlet temperature of 291.15 K. As CNT utilizes with fraction of 0.025, the thermal performance (ηth) improves around 0.68% for Q = 20 which is 1.72 times stronger than that impact of Q = 8 L/min. Switching from WT to configuration of S = 0.1, leads to augmentation of ηth about 2.19% when Q = 20. When S = 0.1, elevate of Q causes friction factor (f) to decrease around 26.03% while convective factor (h) augments around 84.72%. As pitch ratio changes from 0.25 to 0.1, the amount of h increases around 14.13% while f augments around 47.88%.