隨著快速的經濟發展，近年來環境保護的議題逐年受到重視，為了達到節能減碳、綠色生產的目標，中鋼公司使用先進的冶煉、軋延及冶金技術來生產優良鋼材，達到高效率、低能耗的水準，藉此提升產業競爭力、提高產值。鋼胚的溫度分佈將影響鋼材的機械性質，因此加熱爐內的溫度控制將是影響鋼胚品質的關鍵技術之一。為提升加熱爐之效能，降低操作成本，亟需建立完整的加熱爐設計及溫控核心技術。
本研究利用數值方法分析鋼胚於加熱爐內的升溫特性效應，並探討不同幾何構造對於鋼胚的影響，分為兩個模型進行模擬，第一種為給定爐壁溫，未考慮燃燒及流場效應；第二種為求解鋼胚和加熱爐以燃燒所產生的高溫氣體進行耦合計算，從而得到加熱爐內溫度分佈、流場分佈以及鋼胚的溫度分佈。三維加熱爐模型內包含支撐墊塊、靜動樑系統、冷卻水道、燃燒噴嘴與鋼胚，全文分為四個部份進行分析，首先使用第一種模型（定壁溫無燃燒，一塊鋼胚）探討墊塊高度，接著使用第二種模型建立三維燃燒模組，探討爐內氣體溫度及鋼胚的溫度分佈情況，第三部分使用第一種模型（定壁溫無燃燒，一塊鋼胚）探討接觸熱阻及第四部分使用第一種模型（定壁溫無燃燒，三塊鋼胚）鋼胚間距對於鋼胚的升溫性以及溫度分佈的影響。
討論不同墊塊高度，分別為60mm、90mm及120mm下進行數值運算。結果顯示其整體的上下表面溫差依序為42.8K、38.0K及34.4K。因墊塊高度越高，會減少所受輻射遮蔽效應的影響，使鋼胚的溫度分佈均勻性較佳。鋼胚升溫曲線與中鋼實驗值比較，整體平均誤差在10%以內。
建立三維燃燒模組，結果顯示超過90%的熱傳機制為輻射熱傳。燃燒求得的平均爐壁溫與定爐壁溫之各區結果誤差依序為3.9%、4.5%、2.1%、0.6%及1.3%，並求得不同墊塊高度下其出口溫度最大誤差小於3%，印證定爐壁溫模擬結果的合理性。因墊塊高度增加，降低冷痕現象的溫差，並與第一種模型升溫曲線進行比對，整體平均誤差約為9.1%。
考慮不同接觸熱阻，分別為未考慮接觸熱阻、hc=23000W/m2-K及hc=18000W/m2-K三種狀況。結果顯示接觸熱阻可稍微減緩冷痕效應。
討論不同鋼胚間距，分別為50mm、75mm及100mm下進行數值運算。結果顯示其較受影響位置位在邊緣y-z截面，其上下表面溫差依序為67.2K、62.2K及58.2K。而中心y-z截面因距離邊緣較遠，較不受影響，其上下表面溫差依序為77.2K、76.3K及75.5K。其整體的上下表面溫差依序為74.7K、72.8K及71.3K，結果顯示當鋼胚間距越大時，因所受的側面輻射熱傳較大，能有效降低冷痕現象的溫差。

Two 3-D mathematical transient heat transfer models for the prediction of temperature distribution within the slab has been developed by considering the thermal radiation in the reheating furnace. The slabs are heated through non-firing, preheating, 1st-heating, 2nd-heating, and soaking zones, respectively. There are two physical models considered in this thesis. (1) model 1: there is no combustion, only thermal radiation is considered and the wall temperature is function of time (2) model 2: includes the burners, and combustion/radiation/convection are all considered. Model 2 is used to check accuracy of mode l. Comparison with the in-situ experimental data from Steel Company in Taiwan shows that the present heat transfer model works well for the prediction of thermal behavior of the slab. The results showed when the skid button height is 60mm, 90mm, and 120mm, respectively, the temperature difference between the upper and lower surfaces is 42.8K, 38.0K, and 34.4K. It means the skid mark can be improved by increasing the height of the skid button. And the numerical predictions of the slab temperature error are less than 10% compared with those of experimental data. Is shown that model 1 is reasonable because the radiation heat transfer dominates the heating process. The results showed the thermal contact resistance can slightly improve the effects of the skid mark. In the last part, the results showed that when the gap distance is 50mm, 75mm, and 100mm, respectively, the edge surfaces temperature difference between the upper and lower surfaces is 67.2K, 62.2K, and 58.2K. It means that the effect of gap distance is important only for the edge surfaces. And the bigger gap distance can effectively improve the slab skid mark

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