Design, simulation and on-sun experiments of a modified sliding-bed particle solar receiver for coupling with tower concentrating system

A modified sliding-bed particle solar receiver was proposed to realize the coupling with upward concentrating system, which was a challenge for the previous designs. The newly added secondary reflection structure could not only adjust the optical path, but also preheated the particles flowing behind it. The overall principle of the receiver, the regulation mechanism of the particle layer thickness and the control and measurement method of the particle flowrate have all been described in detail. After the cold-state research on flow pattern, on-sun experiments based on a tower concentrating system were conducted to evaluate the receiver performance. Experimental results showed that the maximum outlet temperature of ∼860°C and single-pass temperature rise of ∼510°C were achieved. Under various DNI and time, the average outlet temperature ranging from ∼535 °C to 782 °C, and positive efficiency ranging from ∼51 % to 66 % were obtained. A concentrating-receiving coupled model was proposed to analyze the energy transfer process during the experiments, and to predict the receiver performance under higher incident power. Simulation results showed that the thermal loss rate could be reduced from 28.48 % to 13.22 % with 5 times magnification of the incident power, but the local overheating risk of the secondary reflective surface required attention.