在鋼廠中，鋼胚需經過一連串的生產製程，鋼胚在進入下游的熱軋延製程前，鋼胚需要再加熱到達塑性變形之溫度，此階段的加熱爐為本文要探討的主題，為使後續之熱軋延製程順利進行，關鍵技術之一為加熱爐之溫控技術。本文以兩個主題進行探討(1)在相同燃料質量流率下，改變加熱爐各區段之燃料比例，對鋼胚均溫性之影響(2)已知鋼胚升溫曲線的情況下，利用數值方法來反求加熱爐各區的燃料質量流率。
本研究建立三維鋼胚加熱爐(reheating furnace)模型，透過數值模擬分析加熱爐内之流場與溫度場，並將模擬值與實測值進行比對，結果顯示爐溫平均誤差為11%，鋼胚平均誤差為6.5%。並以六種操作條件，研究在相同燃料質量流率下，改變加熱爐各區段之燃料比例，對鋼胚均溫性之影響，結果指出燃料比例的多寡會直接影響到各區鋼胚之溫度，然而，在均溫區增加燃料比例，會導致鋼胚出口處的溫度不均勻，使冷痕效應(Skid mark severity)更加嚴重。
此外，探討在已知鋼胚升溫曲線的情況下，利用數值方法來反求加熱爐各區的燃料流率，在此部份發展二維模型來反求燃料流率，在已知實際三維升溫曲線之情況下，能快速反求各區之燃料質量流率，較三維模型可減少99%之計算時間，並使用兩組升溫曲線進行反求燃料之數值運算，結果顯示反求的數值解與實際之升溫曲線誤差為5.2%。

Three-dimensional numerical simulation is performed to predict the heat transfer performance in a walking-beam type reheating furnace. The furnace uses a mixture of COG (coke oven gas) as a heat source to reheat the slabs. The fuel is injected into the furnace at four zones: preheating zone, first heating zone, second heating zone, and soaking zone. This numerical model considers turbulent reactive flow coupled with radiative heat transfer in the furnace; meanwhile, the conjugated conduction, convection, radiation heat transfers in the slabs. This study contains two topics(1) Examining six cases of different fuel feed ratio at the four zones under constant total fuel feed condition. (2) Estimating the fuel mass flow rate at each zone of the reheating furnace when the slab heating curve is given. The numerical predictions of the slab temperature and furnace gas deviations with the in-situ data are about 6.5% and 11%, respectively. In addition, this study examines six cases of different fuel feed ratio at the four heating zones under constant total fuel feed condition. It is found that decrease fuel mass flow rate in the preheating zonee can enhance heat efficiency, while increasing the fuel mass flow rate in the soaking zone can lead the slab temperature non-uniformity. When the slab heating curve is given, an initial iterative method is proposed to estimate the fuel flow rate at each zone of the reheating furnace in 2-D model. The maximum errors for the temperature of slabs between the 2-D and 3-D numerical are 6.0% and 6.9% for case1 and case2, respectively. The maximum temperature relative error of the slab between 3-D numerical simulation and the exact 3-D solution is 5.2%.

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