Quantification of Regional Thermal Responses and Zone-Wise Radiant-Tube Power Redistribution in an Industrial Continuous Annealing Furnace

Industrial continuous annealing furnaces contain numerous distributed radiant tubes operated through existing control regions. This study proposes a zone-wise radiant-tube power redistribution method based on quantified regional thermal responses. A three-dimensional thermal-process model was established under actual industrial operating conditions and evaluated against the measured strip outlet temperature. The simulated outlet temperature was 806.52 ∘C, compared with an industrial measurement of 801 ∘C, corresponding to a relative deviation of 0.69%. The model followed the eight existing control regions, P1–P8. Reducing the power of each tube in one region at a time by 10 kW produced outlet-temperature decreases of 6.56, 4.60, 3.74, 3.73, and 1.80 ∘C for P2–P6, respectively. These values describe the overall responses to the prescribed regional control actions. Guided by these responses, candidate zone-wise power configurations were screened using a maximum simulated outlet-temperature decrease of 2 ∘C from the baseline and the fuel-saving ratio as the energy metric. The selected configuration yielded a simulated outlet temperature of 804.55 ∘C and an estimated fuel-saving ratio of 1.17% relative to the historical baseline under the specified fuel-conversion conditions. The proposed method evaluates power configurations within the existing furnace control regions and provides an engineering-feasible approach for energy-efficient furnace operation without modifying the furnace structure or fundamental heating mode.