Optical-thermal-stress analysis of an ultra-high-temperature solar receiver combining a secondary concentrator and a tungsten cavity

Abstract

This work proposes an ultra-high-temperature cavity-type solar receiver that integrates a secondary concentrator and a double-deck tungsten cavity, utilizing molten tin as the heat transfer fluid. A coupled numerical model is developed and validated to analyze the optical-thermal-stress characteristics of the receiver. Firstly, to strike a balance between performance and safety, the receiver design with a cavity cylinder length of 200 mm is recommended. Subsequently, the influences of operating parameters on receiver performance are examined, finding that an increased flow rate of tin enhances receiver efficiency and mitigates thermal stress. Moreover, the receiver efficiency can reach 61.5%–89.5% within a wide inlet temperature range of 573∼1573 K and an incident power range of 200∼800 kW. Additionally, thermal stress analysis confirms that the designed receiver remains within safe limits even under the most extreme condition. This study provides valuable insights for the development of efficient and reliable ultra-high-temperature solar thermal systems.