聚丙烯（Polypropylene, PP）Horizone氣相製程中，第一反應器前段區域常因聚合反應劇烈與熱移除效率不足，導致局部溫度突升與熱點生成，進而影響反應穩定性與產品品質。本研究針對此問題進行計算流體力學（Computational Fluid Dynamics, CFD）模擬與分析，建構具備反應熱釋放機制之三維多重參考系（Multiple Reference Frame, MRF）模型，並採用體積分率模型（Volume of Fluid, VOF）與離散相模型（Discrete Phase Model, DPM）模擬反應器中相間混合行為與驟冷液以液滴噴灑入料形式。聚合反應部分則透過自定義函數（User-Defined Functions, UDFs）引入以蒸發速率為依據之兩種反應熱釋放條件，分別為僅考慮液滴於計算域中蒸發速率的寬鬆條件，與基於真實反應中反應物接觸PP相中的觸媒後進行反應，而加入液滴於PP相中蒸發方可釋放反應熱的嚴苛條件，模擬不同放熱門檻對反應器流場分布與溫度場的影響。模擬結果顯示，驟冷液進料口下方兩相交界處為蒸發與放熱最旺盛區域，亦為熱點最易形成位置。寬鬆條件下易引發連鎖效應，造成溫度失控；而嚴苛條件則可抑制局部熱累積，提升系統穩定性。進一步對驟冷液進料流量進行敏感度分析顯示，減半雖降低產率但可穩定溫度場，倍增則提升反應速率卻易產生溫度異常。因此，本研究以驟冷液進料流量倍增之操作條件作為基礎，針對攪拌葉片轉速、循環氣進料流量與PP初始體積分率進行敏感度分析，結果顯示可藉由提升氣體擾動強度與調控有效蒸發面積，有效改善熱場分布，實現溫度穩定與產能提升之雙重目標。本研究成果除可作為實廠操作參數優化之依據，亦可延伸應用於其他高放熱氣相聚合反應器之CFD模擬與反應熱控制之操作策略。未來可進一步導入反應動力學、催化劑與單體進料機制，並進行完整暫態模擬，以提升模型之準確性與預測能力。

In the Horizone gas-phase polypropylene (PP) process, localized temperature spikes and hot spot formation often occur in the front section of the first reactor due to intense polymerization and insufficient heat removal. This study conducts Computational Fluid Dynamics (CFD) simulations by constructing a three-dimensional Multiple Reference Frame (MRF) model incorporating heat release mechanisms. The Volume of Fluid (VOF) and Discrete Phase Model (DPM) were employed to simulate phase interactions and droplet-based quench liquid injection. Polymerization heat was introduced via User-Defined Functions (UDFs), with evaporation rate-dependent release under two threshold schemes: loose and strict. Results indicate that heat accumulation is most severe near the quench inlet and phase interface. The loose condition triggers runaway heating, whereas the strict condition stabilizes the temperature field. Sensitivity analysis of quench flow shows that halving the flow improves stability but reduces yield, while doubling enhances productivity but risks overheating. Further adjustments to stirrer speed, recycle gas rate, and initial PP volume fraction demonstrate that enhancing gas turbulence and controlling effective evaporation area can simultaneously stabilize temperature and increase output.

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