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

In this paper, a three-dimensional turbulent study was carried out on Manzanares (Spain) plant to study the effects of collector inclination angle (theta). Different ranges of theta (30-0 degrees) with more than 15 models were considered for the analysis. An optimized theta 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 (eta(coll) and eta(o)). At theta = 6 degrees, 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 theta (greater than 7 degrees) resulted in recirculation of air particles within the collector canopy, leading to obstruction of flow. Any value of theta lesser than 6 degrees resulted in a drop in the major outputs such as P-th, eta(coll), and eta(o). Eventually, theta = 6 degrees 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.