非導電性流體於平行微流道之冷凝熱傳研究

A Study of Condensation Heat Transfer of Di-electric Fluid in Parallel Micro-channels

張家豪(Chia-Hao Chang)

指導教授 ： 簡良翰

國立臺北科技大學/機電學院/能源與冷凍空調工程系碩士班/碩士(2014年)

https://doi.org/10.6841/NTUT.2014.00780

摘要

本研究主旨在探討非導電性流體應用在平行微流道熱交換器之冷凝熱傳性能研究。工作流體為FC-72與HFE-7100，測試區微流道使用紅銅塊加工製成，下方部份為冷卻水流道，非導電流體與冷卻水呈逆向流。其微流道長度為250mm，測試區入口飽和溫度FC-72為58.12 – 62.87oC、HFE-7100為 62.35 – 64.93 oC，體積流率範圍為50 - 150 g/s，其入口接近飽和氣態。實驗結果顯示，FC-72與HFE-7100在體積流率30 – 150 ml/min所對應不同水側質量流率之乾度所對應之冷凝熱傳係數htp，整體而言非導電流體FC-72與HFE-7100的流量控制對冷凝熱傳係數影響力遠比水側質量流率來的大。以定入口溫度62oC最為平均冷凝熱傳比較依據，FC-72最高平均冷凝熱傳係數發生在中高流量( 90 – 150 ml/min ) htp,avg = 3.91 - 4.68 kW/m2K，而HFE-7100則發生在中流量( 60 – 90 ml/min ) htp,avg = 4.54 – 5.55 kW/m2K，以實驗最高平均冷凝熱傳係數相比，HFE-7100比FC-72高出18%，最低平均冷凝熱傳係數作為比較HFE-7100比FC-72高出21%。

關鍵字

冷凝熱傳 ； 平行微流道 ； 非導電流體 ； FC-72 ； HFE-7100

並列摘要

This study investigates the condensation heat transfer of di-electric fluid , FC-72 and HFE-7100, in parallel micro-channels of 1 mm by 1 mm and 250 mm in length, with three-side cooled. Test module is made by copper block. The cooling water flows in a channel on the bottom of the copper block. The saturation temperature of the inlet of test section is 58.12-62.87 oC for FC-72 and 62.35-64.93 oC for HFC-7100. The fluid volume flow rate varied from 30 to 150 ml/min.
The test results showed that the heat transfer coefficient increased as volume flow rate. Condensation heat transfer coefficient of HFE-7100 was higher than that of FC-72 in parallel micro-channels. The average condensation heat transfer coefficient for HFE-7100 and FC-72 were 4.54–5.55 and 3.91–4.68, respectively. The condensation heat transfer coefficient increases with increasing volume flow rate because of the increased interfacial shear stress and resulting liquid film thinning. The average condensation heat transfer coefficient of HFE-7100 is higher than that of FC-72 by 18-21%.

並列關鍵字

Condensation heat transfer ； Parallel Mrico-channel ； Di-electric fluid

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