Closed Solar Thermal Receiver for Air at Ambient Pressure

Abstract

The concept for a closed solar thermal receiver for air at ambient pressure integrates robust heat storage with solids for concentrated solar power plants. The scalable modular receiver design features large internal surface areas for an efficient heat transfer and provides cavity effects to recover externally reflected radiation and heat. A competitive thermal efficiency was preliminarily calculated for the receiver design. The simulations of receivers with 2 MW and 150 MW thermal output indicate that the velocities of the heat transfer fluid and the temperatures of the receiver components remain in manageable magnitudes. The manufacturability of a fine cooling structure with thousands of cooling pins inside the ceramic receiver cap is demonstrated. Black coating of the outer receiver cap surface significantly increases the absorption of solar radiation. First tests for a single receiver module indicate feasibility of the concept. Further tests will be carried out and a pilot plant is to be prepared.