Investigation of the three-phase spiral countercurrent heat exchange and fluid dynamics in an innovative high-temperature particle waste heat recovery system

A novel steel slag rapid cooling and heat recovery system has been proposed. Gas-liquid–solid coupled heat transfer is adopted to recover waste heat. It only needs very little air velocity and air volume, which greatly reduces the energy consumption. The key component (the spiral coil) has been simulated to study the kinetic energy transfer and heat exchange process. This study examines both the heat transfer characteristics and the fluid dynamics of particles throughout the entire spiral coil. The distribution of particles across the flow path has also been subjected to analysis. Additionally, this study has focused on evaluating the heat transfer efficiency. The performance of the novel system is evaluated with different parameters. It shows that When m_slag is 0.5 kg/s, u_{air_in} is 1 m/s, the system waste heat recovery performance reaches the maximum (Q_water = 16.33 kW, Q_air = 1.08 kW, Q_blower = −0.82 kW). The present work provides a theoretical basis for further improving the steel slag waste heat recovery efficiency.