Investigation on heat transfer characteristic of deformable high aspect-ratio biomass particle system in rotary drums with baffles

Abstract

With the development of carbon reduction technologies, the energy conversion efficiency of the wet biomass particle system has attracted increasing attention. Heat transfer within these systems is a critical factor influencing combustion performance. In this study, experimental and simulation methods were used to investigate the behaviour of deformable high aspect-ratio biomass particles within different structural rotary drums. The particle heat transfer model of deformable high aspect-ratio biomass particles was established and validated. By comparing the simulation results with experimental data, good consistency was demonstrated. It systematically investigates the effects of drum rotation speed, the number of baffles, and drum temperature on the mixing and heat transfer processes of the biomass particle system. It was found that increasing the drum rotation speed facilitates heat transfer in the particles. The best heat transfer efficiency was observed at a speed of 10 r min⁻¹. As the mixing index improved, the heat exchange between particles became more efficient, and higher mixing index led to improved heat transfer efficiency. The highest mixing index reached 0.55, resulting in a notable increase in temperature. Moreover, increasing the number of baffles improved the uniformity of the particle temperature distribution, and optimising the drum temperature further enhanced heat transfer. The optimal results were achieved with 6 baffles and the drum wall temperature of 403.15 K. These findings provide valuable insights for improving energy efficiency in biomass systems.