A 3D numerical study to evaluate optimum collector inclination angle of Manzanares solar updraft tower power plant.

• 15 models were developed with different collector angle (θ) to analyse the impact. • Velocity, pressure, power, collector and overall efficiencies were estimated. • Enhancement of air velocity and theoretical power were noticed at θ = 6°. • θ more than 6° created extensive recirculation and vortices inside the canopy. • A correct turbine location was proposed for Manzanares plant. In this paper, a three-dimensional turbulent study was carried out on Manzanares (Spain) plant to study the effects of collector inclination angle (θ). Different ranges of θ (30–0°) with more than 15 models were considered for the analysis. An optimized θ has been proposed based on the estimated parameters such as air velocity, pressure drop, absorber and air temperatures, power developed, collector efficiency, and overall efficiency (η coll and η o). At θ = 6°, an increment of 9.16% in theoretical power (P th) and a 10.68% increase in air velocity were observed at the chimney base (CB) compared to the horizontal collector plant. Any further increase in θ (greater than 7°) resulted in recirculation of air particles within the collector canopy, leading to obstruction of flow. Any value of θ lesser than 6° resulted in a drop in the major outputs such as P th , η coll, and η o. Eventually, θ = 6° has been proposed as optimized inclination. The dynamic pressure difference was maximum at a chimney height of 2.5 m from CB; therefore, this was the preferred location for turbine fitment. The results were compared with the experimental data of the Manzanares plant, and a very favorable agreement was noticed. [ABSTRACT FROM AUTHOR]