本文以實驗方法與數值逆算法來預測於改變圓管上下距離、鰭片間距及外界風速下，四支圓管為交錯排列(Staggered arrangement)之板鰭管式熱交換器的平均熱傳係數 與等溫平均熱傳係數 ，其中也探討在鰭片後方增加出口風扇對於熱傳效能之影響。此四支圓管的溫度可能都不相同，因此鰭片上之熱傳係數可能為不均勻分佈，故於進行數值逆算法分析之前，將先整個鰭片被分割成數個子區域，且每個子區域上之平均熱傳係數假設為一未知的常數。而後，本文以有限差分法（Finite difference method）配合最小平方法(Least squares scheme)、外界空氣溫度量測值及鰭片溫度量測值之逆算法來求得本文結果。結果顯示於自然對流條件下， 及 會隨著鰭片間距以及圓管上下距離的增加而增加。於強迫對流條件下， 及 會隨著外界風速、鰭片間距及圓管間距離增加而增加。其中在兩種條件下，因圓管間距離增加所造成 增加的幅度會隨著圓管間距離的增加而變小。所以本文發現，在圓管間距離較大時，散熱的效果較佳。其他的發現為於第二排圓管後方之子區域的熱傳係數一般皆會比其他區域的值低，此乃由於此下游區域會有低速的尾流區發生所致，所以增加出口風扇從本文結果發現可以有效改善此問題。為了證明本文結果之可靠性，本文之 值將與目前存在之經驗公式與文獻或商業計算流體力學軟體所求得之結果相比較。此外，本文也利用量測出的實驗數據配合商用軟體Fluent以求得鰭片間之流場的流動狀態及鰭片上溫度分布的情形。

The present study applies the experimental and numerical inverse methods to predict the average heat transfer coefficient and heat transfer coefficient under the isothermal situation on a vertical square fin of the four-tube plate finned-tube heat exchangers for staggered arrangements and various tube pitch, fin spacings and air velocities, and also investigate the effect on heat transfer characteristics by using another fan behind the fins. These tubes may not have the same temperature in the present study. Due to the non-uniform distribution of the heat transfer coefficient, the whole plate fin is divided into several sub-fin regions before performing the inverse scheme, and the average heat transfer coefficient on each sub-fin region is assumed to be unknown. Later, the inverse scheme of the finite difference method in conjunction with the Least squares scheme and experimental measured temperatures is applied to determine the present results. Results show that and in nature convection increase with increasing the tube pitch and fin spacing S. However, and in force convection increase with increasing the , S and air velocity, under both conditions, Due to the increasing tube pitch caused by the increased amplitude becomes smaller with increasing distance between tube. So present study shows the larger tube pitch the better heat dissipation we have. Other findings are that the average heat transfer coefficients in the upstream and wake fin regions of the 2nd row may be generally lower than these on other sub-fin regions, so we use the outlet fan to improve this problem. In order to validate the accuracy and reliability of the present results, the values are compared with those obtained from the existing correlations or computational fluid dynamics commercial code. Besides, the present study also applies the commercial software, Fluent, in conjunction with the present experimental data to obtain the inter-fin flow field of the plate finned-tube heat exchanger and temperature measurements at various measurement locations of the fin.

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