Coupled optical and CFD parametric analysis of an open volumetric air receiver of honeycomb type for central tower CSP plants

• Published in: Solar energy 2017-10, Vol.155, p.523-536
• Main Authors: Cagnoli, M., Savoldi, L., Zanino, R., Zaversky, F.
• Format: Article
• Language: English
• Subjects: Central tower; CFD; Open volumetric receiver; Parametric analysis; Ray-tracing; Single channel
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2017.06.038

•An open volumetric air receiver is analyzed at the single channel level.•The methodology applied consists of an optical (Monte Carlo based)+CFD analysis.•The influence of key-parameters on the receiver performance is identified.•The occurrence of the volumetric effect is monitored. The performance of an open volumetric solar air receiver of honeycomb type (multiple parallel channels) for central tower CSP plants is evaluated numerically. A parametric study is conducted at the single channel level in order to investigate the influence of the main geometrical variables and of the air mass flow rate on the receiver performance. The adopted methodology consists of two steps: the first one is the optical analysis that is conducted using Tonatiuh, an open-source Monte-Carlo based ray-tracing software, providing the distribution of the absorbed heat flux on the channel inner surfaces, to be finally exploited as input data in the second step, i.e. the numerical evaluation of the thermal fluid dynamic performance of the channel. Using the commercial CFD software ANSYS Fluent, the convective heat transfer between the air flow and the absorber and the radiative heat transfer among the absorber inner walls and the channel aperture are simulated, computing the heat losses to the ambient. Different channel configurations are simulated, identifying the influence of the three key-parameters (the tilt angle with respect to the horizontal, the channel size and the air mass flow rate) on the receiver performance, in terms of solar-to-electricity efficiency.