Preliminary CFD simulations of a lab-scale novel design of a particle receiver for CSP applications

Abstract

In the present work, a preliminary CFD analysis of a novel design of particle receiver for CSP applications was performed. The particle receiver is a new lab-scale prototype consisting in a thin fluidized bed in which the walls are made of glass to permit thermal radiation to pass through. The working fluid is air and the thermal performance has been studied for the case in which i) only gas flows through the receiver (no particles) and ii) particles are placed in the receiver. The addition of the particles enhances the heating process by increasing the heat transfer coefficient from the heated wall to both the bed of particles and the gas resulting in an increase of more than 55 % in the air temperature at the outlet of the receiver. Then, the bed dynamics have been studied in detailed as a function of the superficial gas velocity and the static bed height of the system. The analysis comprises the time evolution of the temperature of the gas and solid phases, the position of the centre of mass (that can be increased by more than 25 % during the heating process) and the bubble characteristics. It has been found that when the gas velocity is increased by 66 % the average temperature of the solids is only decreased 10 %; while, for the static bed height, when the number of particles is increased 3 times the average temperature of the particles is increased by 18 %.

Keywords

• Fluidized bed
• Concentrated solar power
• CFD
• Heat transfer