Numerical simulation and theoretical analysis of heat transfer in a moving packed bed with the local internal heat source

Highlights: • The correlation between the particle velocity and the outlet temperature of the channel of moving packed beds were obtained. • The total radial conductive heat flow was smaller and that was only 1–4% of the heating power. • The temperature maximum was located the heating zone outlet. • The temperature in the channel decreased with the particle velocity increasing. - Abstract: The particle velocity has a major influence on heat transfer in a channel of moving packed beds with internal energy source. The outlet temperatures of the channel and the heated zone were calculated by theoretical correlations. These correlations between the particle velocity and the outlet temperature were obtained based on the basic principles of heat transfer. The theoretical analysis indicated that the outlet temperatures of the channel and the heated zone decreased as the particle velocity decreased. Numerical simulations of a three-dimensional moving packed bed model were performed to investigate the effect of particle velocity on the temperature distribution and heat transfer. Good agreement was obtained between numerical results and the theoretical correlations. The temperature field and heat transfer of the channel of moving packed beds with the internal energy source were predicted and analysed. Temperature distributions along the radius and the z-direction for various particle velocities were compared including the outlet temperature and borderline temperature of the heated zone, the outlet temperature and the centre temperature of the channel. The results showed that the particle velocity was the decisive factor for the heat transfer and temperature distribution in the channel. The total radial conductive heat flow through the channel wall was only 1–4% of the heating power and decreased as the particle velocity increased. The vast majority of heat flow continuously kept moving downward with the particles. The outlet temperatures of the heated zone and the channel, the centre temperature, and the heating zone borderline temperature decreased as the particle velocity increased