Importance of radiative heat transfer in industrial furnaces: insights from numerical simulation of single and multi-part heating

Moreno Marc - Transvalor S.A. (France)

The modelling of industrial furnace behaviour is critical for optimizing heat treatment processes, improving energy efficiency, and ensuring precise temperature control in parts for metallurgical purposes. Current work aims at proposing a method based on Finite Element (FEM) simulations to predict thermal kinetics of heavy parts in industrial furnaces with confidence. It also points out the great importance of considering heat transfers by radiation.

Two practical cases are addressed to highlight the relevance of such modelling challenges in industrial situation.

First, a standard billet (nickel-based alloy) was heated in a gas furnace. Temperatures were recorded at multiple locations inside billet and furnace walls during the heating cycle. The primary challenge was achieving a close match between simulated and recorded temperatures.

The second case introduced a more complex scenario involving two billets of different materials inside the furnace. This configuration permits to highlight reciprocal effects of radiative heat transfer between initial cold parts, in addition to the energy provided by the furnace walls. The study revealed how mutual radiative effects influence temperature gradients and heating uniformity, underscoring their importance in multi-part heating scenarios. It also points out the need to have accurate knowledge about furnace insulating materials.

This work demonstrates the capability of FEM modelling to accurately predict the thermal behaviour of parts in industrial furnaces. In both cases, the dominance of radiative heat transfer was evident, emphasizing the need for detailed radiation modelling to achieve reliable results. Furthermore, the second study illustrated the sensitivity of thermal evolutions to part positioning, surface properties and concomitant presence of multiple parts, providing valuable insights for optimizing furnace operations.

The presentation will discuss the modelling methods, calibration with experimental data, and the implications for industrial practices, such as part placement and furnace design.