Benchmark and analysis of a particle receiver 1D model
Luis F. González-Portillo, Víctor Soria-Alcaide, Kevin Albrecht, Clifford K. Ho, Brantley Mills
Abstract
This study presents a one-dimensional (1D) model for free-falling particle receivers able to be integrated into system models thanks to its simplicity and agreement with high fidelity simulations. The receiver thermal efficiencies calculated with the 1D model are benchmarked against the efficiencies obtained with a more complex CFD model, showing a great fit with a coefficient of determination R2 = 0.996 when there is no wind and R2 = 0.949 when there is wind. The 1D model is used to present some of the most relevant results specific to free-falling particle receivers. Under no wind conditions, the receiver efficiencies obtained with different aperture areas are very similar, although there is a slight decrease in efficiency when the aperture area grows. These trends change with wind depending on the wind speed and direction. The receiver efficiency also increases with the absorptivity. Low-absorptivity particles not only result in lower efficiencies, but also prevent operation of the receiver when the incident solar radiation is small. A similar trend is observed for large particle diameters where the thermal efficiency approaches zero when the incident solar radiation is small. While the presented 1D model is specific to free-falling particle receivers, the main parts of the model could be extrapolated to other designs.