工業煉焦爐耐火磚牆上積碳(carbon deposits)的持續累積，是冶金工程中一項關鍵的營運問題。雖然在煉焦爐內導入空氣噴入技術為一實用的積碳移除策略，但爐內的高溫環境（1000 - 1100 °C）對於直接進行原位（in-situ）量測的可行性頗具難度，導致將此移除技術應用於實際煉焦爐操作時，往往僅能仰賴試誤法（trial-and-error）。為突破此限制，本研究旨在開發一個暫態、三維的計算模型，以模擬煉焦爐內紊流狀態下的積碳燃燒消除過程。
本模型透過結合 SST k-ω 紊流模型與雙膜反應模型（two-film reaction model），解決了此高度耦合的物理問題。為了精確捕捉紊流與化學反應之交互作用，模型中導入了預設 β 形狀機率密度函數（presumed β-PDF）方法。經由實驗室尺度的熱重分析數據(thermo-gravimetric data; TG data)進行驗證後，本研究進一步擴展計算尺度，模擬中國鋼鐵公司（China Steel Corporation, CSC）的全尺寸工業煉焦爐膛。
模擬結果揭示，在通風受限（欠氧）的煉焦爐環境中持續噴入空氣，並不會產生穩態流場；相反地，它會觸發一種自我維持的熱氣動脈動循環（thermo-aeraulic pulsatile cycle），此現象在宏觀上呈現出「呼吸狀」（breathing-like）特徵。本研究進一步進行了基於循環特性的參數分析，評估噴槍插入深度、裝煤孔位置選擇以及空氣噴注流量對積碳移除效率的影響。
研究發現，高效率的積碳移除主要取決於如何有效利用誘發的自然通風（natural draft）效應，而非僅僅增加主動噴入空氣的流速。此外，研究發現在極端的高噴注率下會產生噴流「僵化效應」（stiffening effect），這將破壞爐膛從裝煤孔被動卷吸空氣的能力，進而導致整體的積碳清除效能下降。本研究建構之理論模型與數值方法，成功為實際煉焦爐操作中的空氣噴入進行除碳(decarbonization)過程，建立了一個嚴謹且基於物理機制的基礎。

Progressive accumulation of pyrolytic carbon deposits on the refractory walls of industrial coke ovens presents a critical operational problem in metallurgical engineering. While the implementation of air injection in the coke oven is a practical removal strategy, the severe thermal environment (1000 – 1100 °C) precludes direct in-situ measurement within coke oven, resulting in a way that the trial-and-error approach must be employed for applying this removal technique to a practical coke oven. To bypass this restriction, the study aims at developing a transient, three-dimensional computation model to simulate the turbulent carbon-deposit burning-off process in a coke oven.
The model resolves the highly coupled physical problem by integrating the SST k-ω turbulence model with a two-film reaction model. To accurately capture the turbulence-chemistry interactions, a presumed β-shape probability density function (PDF) approach is employed in the modeling. Following a validation against the laboratory-scale thermogravimetric data, the study is upscaled to simulate a full-scale industrial coke oven chamber in China Steel Corporation. The simulations reveal the fact that the continuous injection of air in the coke oven with under-ventilated environment does not produce a steady-state flow field. Instead, it triggers a self-sustaining thermo-aeraulic pulsatile cycle which is observed as “breathing-like” phenomenon. A cycle-based parametric study is conducted to evaluate the influences on removal efficiency in terms of the blowing lance insertion depth, charging-hole selection for inserting, and air injection rates.
The findings show that efficient carbon removal is governed primarily by exploiting the induced natural draft rather than merely increasing the active air-injection flow rate velocity. Furthermore, the study identifies a stiffening effect at extreme injection rates, which disrupts the chamber's passively entraining capability from the charging holes and consequently degrades overall cleaning performance for deposited carbon. This research study develops a theoretical modeling and numerical approach enabling establish a rigorous, physics-driven basis on the decarbonization process via air injection technique for the practical operation of coke oven.

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