本文以三維CFD軟體配合逆算法及實驗溫度來求得多管板鰭式熱交換器於水平通道的熱流特性，探討入口風速、鰭片間距、鰭片擺放高度及加熱管距之影響。由於空氣流經板鰭管式熱交換器時會產生複雜三維流動，使得鰭片上的熱傳係數非均勻分布，故劃分數個子區域並設定其熱傳係數為常數，使用差分法搭配最小平方法，進行逆向求解，以取得逆算之鰭片熱傳參數，本文透過實驗量取鰭片表面之溫度，接著將量測數據代入逆算法求出鰭片表面熱傳係數及熱傳量，接著使用CFD軟體進行數值模擬選取最佳網格劃分及流動模式，最後將數值結果及熱傳現象變化之趨勢進行分析及討論。於本文自然對流案例中，吾人經測試驗證後選用Zero-Equation紊流模型作為流動模式選取；於混合對流下入口風速Va = 1m/s及Va = 3m/s之案例中，RNG k-ε紊流模式經比較結果及誤差後推論為本文選用之最適流動模式，而當入口風速增至Va = 5m/s時結果顯示標準k-ε紊流模式為結果更加精準之流動模式。在本研究參數範圍內，隨鰭片擺放高度下降，風速加快、鰭片間距增大及加熱管距增加皆會使熱傳係數提升，對應各參數變化之趨勢也會有所不同。

This study uses 3D CFD software with inverse algorithm to investigate the heat transfer characteristics of a multi-tube finned tube heat exchanger in a horizontal channel, and discusses the influence of air inlet speed, fin spacing, fin height and heating tube distance. Since air flowing through the heat exchanger will cause a complex three-dimensional flow, Therefore, divide several sub-regions on the fin and set the heat transfer coefficient as a constant. Use the difference method and the least square method to solve the problem in inverse to obtain the heat transfer coefficient of the fin, and then numerical simulation is performed with CFD software to select the best mesh division and The flow model, and finally the numerical results and the trend of heat transfer phenomena are analyzed and discussed. In the case of natural convection, after testing and verification, we choose the zero-equation turbulence model as the choice of flow mode. In the case of mixed convection with inlet velocity Va = 1m / s and Va = 3m / s, after comparing the results and errors, it is found that the RNGk-ε turbulence model is the most suitable flow mode selection. When the inlet air speed increases to Va = 5m/s, the results show that the standard k-ε turbulence model is a more accurate flow model. Finally, as the fin height decreases, the air speed increases, the distance between the fins increases, and the distance between the heating tubes increases, the heat transfer coefficient will increase, and the trends of the corresponding parameters will be different.

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