Operation strategies for falling particle receivers

Kurzfassung

Solar thermal tower power plants with a falling particle receiver are a promising concept for large scale electricity generation. To yield high power plant efficiencies, particle outlet temperatures of 800 °C or more are desired, to drive a high efficiency power block. Different design parameters and operation strategies have been assessed with an advanced CFD-Model. In this CFD-Model all significant physical effects are included and therefore the simulations can provide detailed information about the receiver efficiency and the different receiver losses. With this CFD model different operation strategies have been assessed. A falling particle receiver with 394 MW thermal design power was evaluated with different operating strategies, assuming a temperature increase from 300 °C to 800 °C and a face-down cavity configuration. Simulation results indicate that receiver efficiencies in excess of 90 % can be reached. In the simulated test case the receiver efficiency in part load (50 % solar input) increases with three recirculations by 16 % compared to the case with no recirculation. Thus the receiver efficiency is calculated to be higher than 80% even in 50 % part load. Different recirculation options are also discussed.