Design and evaluation of a lab-scale tungsten receiver for ultra-high-temperature solar energy harvesting

The key to raising the cycle efficiency of the solar power tower plant is to improve the operating temperature of the solar receiver. However, only a few receivers can operate at a temperature above 1573 K, and it is still very challenging to harvest solar energy safely and efficiently under such ultra-high temperatures. In this paper, firstly, a lab-scale tungsten receiver with the designed thermal power of 7 kWth was designed for ultra-high-temperature solar energy harvesting. Then, an optical-thermal–mechanical coupling model was constructed and validated with experimental data. Based on this model, the receiver performance under different cylinder lengths was evaluated. It is found that the solar receiver with a 150 mm length cylinder was able to operate safely and efficiently under the most extreme condition, which was suggested as the optimized design. Then, the effects of key operating parameters on the performance of the optimized receiver were analyzed, finding that the receiver efficiency increases with increasing inlet mass flow rate, decreasing inlet temperature, or increasing incident power. Moreover, performance evaluation indicates that high receiver efficiency of 81.88%-89.08% can be achieved by the optimized receiver while the inlet mass flow rate is within 0.07–0.12 kg·s−1, the average fluid temperature is within 833.9–1384.7 K, and the incident power is within 5.5–8.0 kW. Results from the present study can provide a reliable and useful reference for developing ultra-high-temperature solar receivers.