Transient heat transfer characteristics in an electrically heated continuous steel-strip annealing furnace
摘要
This work applies a previously validated 3-D transient CFD model to elucidate radiation-dominated heat transfer in an electrically heated continuous annealing furnace during strip charging. The six heater furnace is simulated using a coupled electro-thermal framework with surface-to-surface radiation and temperature-dependent emissivity. Immediately after entry, buoyancy-driven natural convection intensifies, raising peak sectional velocities up to 2.2× over the no-load state. The openings preheat the lateral faces yet introduce localized losses; due to view factor advantages, the side faces heat earlier than the top/bottom surfaces. Heat flux decomposition shows that ∼98 % of the net radiative input converts to conduction in the strip. Varying strip width (50–150 mm) markedly reshapes the radiative field and widthwise uniformity. The findings identify opening design, heater placement/spacing, and edge-compensated power distribution as primary levers for achieving target temperature and uniformity.