An ultra-high-temperature cavity receiver with a simple flat absorber for safe and efficient solar-thermal conversion

Abstract

Improving the operating temperature to >1573 K is promising to enhance the generating efficiency of solar thermal power. However, such extremely ultra-high temperature inevitably brings severe challenges to solar-thermal conversion. Therefore, a cavity receiver with a simple flat absorber was designed and optimized in this study. Firstly, the receiver cavity was designed to be made of machinable insulation material, and its crucial absorbing surface was a flat absorber assembled from individual tungsten panels to simplify the structure. Then, an optical-thermal-mechanical model was established to identify the suggested configuration. It was found the partially coated receiver with a 130-mm-depth cavity and a down-in flow pattern can operate safely and efficiently under ultra-high temperatures, which was regarded as the optimized design. Finally, the performance of the optimized receiver was evaluated when the mass flow rate was within 22.0–32.0 g·s−1 and the inlet temperature was within 623∼873 K. The results indicated the highest outlet temperature reached 1579.2 K with receiver efficiency ranging from 69.9%–80.8%. Additionally, the maximum thermal losses from the glass and the insulation reached 860.2 W and 365.9 W, respectively, pointing out the crucial adiabatic directions for ultra-high-temperature receivers. The obtained results can offer promising insights to ultra-high-temperature solar receivers.