Improvements in the measurement of high solar irradiance on a 300 kWth volumetric receiver

Abstract

The current solar tower plants demand the measurement of high solar irradiance on the receiver. This measurement would facilitate the operation of the plant, the estimation of the receiver efficiency and would contribute to the safety of the receiver. Nowadays, these plants don't have a system to measure the flux because there are some limitations, as the difficulty to add new elements to the design and the structure of the tower. It is necessary to include a flux measurement system in the planning and construction of the commercial plants. This work presents a validation of the new indirect method to measure the flux which only use the surface of the receiver, a radiometer and a digital camera. In the context of an international project, the new method to measure the flux has been tested with a different receiver and with different working conditions. The receiver tested in this project is a volumetric receiver made of silicon carbide. The flux measurements have been done in the solar tower facility of the Plataforma Solar de Almería, the SSPS-CRS. The results obtained with this system have been compared to the results obtained with the reference flux measurement system based on a white lambertian target, obtaining a good level of agreement. This reference method can't be extrapolated to the commercial plants because it has moving parts that can't be added to the design of the towers. The new method avoids these moving elements and simplify the measurement of the flux distribution on the receiver.