A novel numerical model for billet reheating furnace

Abstract

A numerical model of billet reheating furnace is proposed, which includes heat fluxes calculation around four billet surfaces and two-dimensional conduction calculation inside billet. Radiation and convection heat fluxes on top and bottom surfaces are calculated simultaneously, based on quartic and linear difference between furnace gas and billet surface temperatures, while furnace gas temperature is determined according to thermocouple values along furnace length together with billet surface temperature. Lateral fluxes are also calculated considering angle factor on billets interval. Two-dimensional partial differential equation is acquired for billet conduction to determine temperature distribution, which is discretised and solved by Alternating Direction Implicit and TriDiagonal Matrix Algorithm. Two embedded thermocouple experiments were carried out to verify furnace gas temperature, the effect of billet interval on lateral heat flux calculation as well as billet temperature. It met agreement well with experiments on billet temperature, which could be a better prerequisite for further reheating furnace automatic control.

Keywords:

• Billet reheating furnace
• 2D numerical model
• ADI
• TDMA