Numerical modeling and parametric study of the heat storage process of the 1.05 MW molten salt furnace

The implementation of thermal storage technology in the steel industry has the potential to reduce carbon emissions and contribute to a more sustainable future for the planet. Utilizing molten salt furnaces to convert waste heat from blast furnace gas into thermal energy from molten salt is an innovative approach. In this study, the heat flux density data calculated using ANSYS FLUENT were imported into a MATLAB calculation program developed based on the multi-section lumped parameter method to model the three-dimensional transient thermal performance calculations of the molten salt furnace. A benchmark energy storage experiment on a 1.05 MW furnace validated simulation results. The experimental molten salt outlet temperature is 566.5 °C, 13.92 °C higher than the simulation data with 2.46% deviation. The study investigates the dynamic characteristics of thermal energy storage in molten salt furnaces by disturbing external parameters. Results show that molten salt temperature rise is linearly related to heat flux density, molten salt inlet temperature, and mass flow rate. Notably, every 0.8 kg/s increase in molten salt mass flow rate reduces the outer coil temperature by 6.59%. The highly accurate model provides a reference for the design, control and commissioning of molten salt heating and thermal storage systems.