Heat losses in a trapezoidal cavity receiver of a linear Fresnel collector: A CFD approach

This paper presents a thermal study of cavity receiver designed for Fresnel-type linear solar collector (LFC). The utilizes two-dimensional computational fluid dynamics (CFD) model implemented in ANSYS Fluent. behavior air inside the Fresnel is extensively examined. consists trapezoidal with set six parallel absorber tubes, through which circulates. has aluminum reflectors on inner walls and glass window closing aperture facing primary collector. numerical represents cross-section receiver, aims to provide results that allow algebraic correlations predicting heat losses from wall temperature each individual tubes compose it. developed transient, utilizing k-ε turbulent model. In addition, completed an analysis surrounding cavity, evaluate its performance. For this purpose, velocity contours obtained are discussed. Correlations know flux between loss any combination temperatures pair what not been studied literature yet. reveals radiative contribute 81% total losses, outer being main responsible these losses. Furthermore, dimensionless examines relationship Nusselt Rayleigh numbers comparison reference problems based canonical geometries dominated by buoyancy-driven flows. performance found be similar downward hot flat plate.