臺灣博碩士論文加值系統

本實驗是針對波浪高度為1.18 mm、1.32 mm和1.58 mm等三種不同的波浪
高度作為主要研究，主要在探討波浪高度對波浪型鰭管式熱交換器的熱傳
及壓降效應。實驗測試本體總共有二十五個鰭管式熱交換器，其中有二十
一個波浪型鰭片表面和四個平板型鰭片表面之鰭管式熱交換器來作測試。
在實驗進行時，熱水入口溫度保持在65 0.3℃，熱交換器的正向風速約
從0.3 m/漸增至6.5m/s。所有數據均在空氣側與水側的能量平衡誤差3﹪
以下的測試條件下取得。由測試結果將波浪型鰭片與平板型鰭片做比較，
探討不同波浪型鰭片高度對熱傳增加率的影響。發現熱傳係數與壓降會隨
著波浪高度增加而增加；此外，隨著正向風速的增加，波浪高度對熱傳及
壓降的效應會更加明顯。在風速Vfr<2.5 m/s時，波浪高度Pd=1.18mm和平
板型鰭片表面做比較，所得熱傳增加率非常小，可以被忽略；但在此同時
，壓降卻約上升15~20%。對於大波浪高度Pd=1.58mm，熱傳效率受鰭片間
距的影響很大；而在小波浪高度時，熱傳效率受鰭片間距影響就顯得很小
。

An experimental study was carried out to examine the effect of
waffle height, including three different values oh waffle
height: 1.18 mm, 1.32 mm and 1.58 mm, on the heat transfer and
friction characteristics of typical fin-and-tube heat exchanger
having wavy fins. A total of twenty seven samples of heat
exchangers, including twenty one of them having wavy fins and
the other four having plain fin configurations were tested.
During the experiments, the water inlet temperature was held at
65.0±0.3℃, Frontal The test results indicate that the effect
of waffle height on the heat transfer enchancement ratio,
compare to plain-fin counterpart, the heat transfer coefficient
and pressure drop are increased as the waffle height is
increased. In addition, as the frontal velocity is increased,
the effects of waffle height on heat transfer coefficient and
pressure drop are more significant. The enchancement of heat
transfer coefficient for the small waffle height Pd=1.18 mm
relative to the plain fin surface is negligibl