Heat transfer and hydraulics for a novel receiver pipe of solar parabolic trough: a computational approach

Abstract

The effect of symmetrical convex-concave corrugations on receiver pipe of a parabolic trough solar collector is numerically investigated. Twelve distinct geometrically configured receiver pipes with corrugations have been examined for this purpose. The computational study is conducted for varying corrugation pitch (4 mm to 10 mm) and height (1.5 mm to 2.5 mm). Heat transfer enhancement, flow behavior, and overall thermal performance of fluid moving through a pipe under non-uniform heat flux condition are all determined in this work. The Reynolds number ranges from 5000 to 50,000. The findings reveal that presence of corrugations leads to axial whirling and vortices in the receiver pipe, thus enhancing the heat transfer. The receiver pipe having corrugations of 8 mm pitch and 2 mm height gave the best results. The maximum enhancement in average Nusselt number over smooth pipe has been observed as 28.51%. In addition, relationships of Nusselt number and friction factor against selected design parameters and operating conditions are also displayed as correlations.

Keywords: Double corrugated receiver; Hydraulic characteristics; Parabolic trough receiver; Passive methods; Symmetrical convex and concave corrugations; Thermal performance.