Dynamic Thermal Analysis of an External Cylindrical Receiver in an Object-Oriented Modelling Paradigm

The components exposed to the highest temperature and heat fluxes in Solar Tower plants are the tubes of the panels composing the central receiver. Their structural integrity is weakened due to fatigue and creep phenomena, likely worsened by a corrosive environment, and their solar power harvesting performance suffers from diminished absorptance of their coating. This paper describes a 2D dynamic thermal model of the tubes of a central receiver, developed following an Object-Oriented modelling paradigm, and applies the model to assess the impact of degradation phenomena such as corrosion, coating deterioration, and soiling of heliostats. The model is verified against steady-state data available in literature both on overall receiver metal maximum temperature, HTF outlet temperature and absorbed heat, and on detailed circumferential analysis of the metal external temperature for a specific tube. The dynamic behavior of the receiver is also assessed, with focus on the impact of cloud events and the induced thermal transients.