Modeling, Prediction, and Control of Heating Temperature for Tube Billet

Table 1

Main technical parameters of annular furnace.

Furnace output	160 t/h
Specification of tube billet	Φ175 mm, 860–4500 mm in length, maximum weight per piece 850 kg
Furnace size	Intermediate diameter 35 m, effective width of furnace cavity 5 m, height of furnace cavity 3 m (one section in the preheating zone), 2.5 m (2 sections), 2 m (3–6 sections), total number of hearth batch bins 391, number of tube billets 381 pieces
Calorific value of combustion	Heavy oil 37620 Kj/kg, mixed gas 9196 Kj/m^3
Demand of combustion	Heavy oil 6755 kg/h, mixed gas 30545 m^3/h
Arrangement of burning nozzle	Total of 96 side burning nozzles for either oil or gas used in sections 1–6; heat is not provided in the preheating zone
Maximum furnace cavity temperature	Approximately 1400°C
Temperature of tube billet	Enter furnace at 20°C, leave furnace at 1280°C, cross-section temperature difference of leaving furnace ±10°C
Charging and discharging rhythm	Maximum 270 piece/h, equivalent to discharging interval of 13.3 s/piece