Flow and heat transfer analysis of a gas–particle fluidized dense suspension in a tube for CSP applications

Abstract

This work presents a numerical study of the flow of particles in a gas–particle fluidized dense suspension for CSP applications using the Multi-Phase Particle in Cell (MP-PIC) method, implemented in CPFD-Barracuda software. The study covers two different numerical simulations. The first is a cold and isothermal model in which the fluctuations and control of the mass flow of particles ascending along the vertical tube was studied. In the second, a high-temperature boundary condition was imposed on the external surface of the tube and the energy equation was solved. In this second case, the heat transfer coefficient between the inner surface of the tube and the particles was numerically computed.The numerical results in the cold model are highly consistent with experimental data available in the literature (with values up to 150kg/h and differences of approximately ±10kg/h) and underline the significant impact of the pressure at the bottom of the bed and of the aeration flow rate on the mass flow of particles. The results of the non-isothermal case present heat transfer coefficients in the range of 300–400W/(m2K) with transient fluctuations during the fluidization process. These fluctuations may be an influence on the mechanical damage of the tube, which is exposed to high levels of concentrated irradiation.