本文以逆算法與CFD軟體搭配實驗方法探討板鰭管式熱交換器熱傳特性的研究，並探討鰭片間距、正向風速與管徑對所得結果之影響。由於鰭片上的熱傳係數分布是不均勻的，因此將鰭片劃分為數個子區域並假設各子區域之熱傳係數為常數，再搭配有限差分法、最小平方法及實驗溫度量測值之逆算法來預測鰭片上的熱傳係數。本文亦利用CFD軟體求得速度分佈、鰭片表面之溫度以及熱傳係數，為了求出本研究較正確之熱傳及流體流動特性，選用適當的流動模式及網格格點數所求得之鰭片上的量測點溫度及熱傳係數，須盡可能接近實驗溫度量測值與逆運算結果。本文之結果顯示在自然對流與混合對流中，RNG k-ε模式所求得結果皆較為準確。

The present study applies the inverse method and CFD software in conjunction with the experimental method to predict the heat characteristics of plate-fin and tube heat exchangers. The effects of parameters such as fin pitch, air velocity and tube diameter are examined. Since the heat transfer coefficient on the fin is not uniform, the fin is divided into several sub-regions and the heat transfer coefficient in each sub-regions is assumed to be a constant. Later, the inverse method applies finite difference method in conjunction with the least-squares scheme and the experimental data to estimate the heat transfer coefficient on the fins. Furthermore, how to choose the appropriate flow model and the effect of grid points are also investigated. Velocity, temperature and heat transfer coefficient distributions of the fin are determined using the CFD software. More accurate results can be obtained if the heat transfer coefficient is closed to the inverse results and matches the existing correlations. The results obtained using the RNG-k-ε turbulence flow model are more accurate for natural convection and mixed convection.

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