第9卷‧第1期,
198101
, pp. 3-14
液滴?於冷卻塔中之散熱研究
- 作者:
周賢福; 林能富
- 作者服務機構:
國立臺灣大學機械工程學研究所
- 中文摘要:
本文以實驗方式測定冷卻空氣速度、液滴溫度、液滴流量與液滴滴落高度等因素予冷卻水塔散熱速率之影響。液滴之產生係用精密之醫用不誘鋼注射針頭於某一控制液面高度下形成。實驗涵蓋之範圍為塔中冷卻空氣速度在 130~325 cm/sec 之間,被冷卻水進入冷卻塔之溫度在 32°~41°C之間,液滴在冷卻塔中之流量在 25.8~46 /sec之間,而液滴滴落距離則在48.3~113 cm之間。 實驗結果顯示:Nusselt 數數 Nu 於試驗範圍內與液滴溫度及液滴流量無關,而與 Reynolds歡 Re 及 Prandtl 數 Pr 之關係為: (方程式無法摘錄)式中 g 乃是與液滴懸垂固定於氣流中實驗結果比較之修正因子,可以 (方程式無法摘錄)表示。 本實驗之結果,明白指出提高冷卻空氣速度及增大液滴滴落高度,均對冷卻水塔之效率有所裨益,且當液滴溫度與大氣溫度相差愈大時,散熱效果亦愈佳。
- 英文摘要:
The phenomenon of heat and mass transferof liquid drops in gas flow has been widelystudied on account of its practical usage. Dueto the complexity, however, research has beenconcentrated on a single drop instead of theliquid drop group which is the more practicalsituation. Present investigation offers a gross study onthe heat transfer of water drops in cooling tower.Experiments have been performed to determinethe rate of cooling on the water drops both bydirect contact heat transfer and by vaporization.The results as compared with the correlationsfor single drop shows a correction factor g isneeded: (方程式無法摘錄)Where (方程式無法摘錄)and (X/D) is ratio of the falling distance ofliquid drop to its average diameter in the cool-ing tower.
- 中文關鍵字:
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- 英文關鍵字:
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