کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7051536 | 1457378 | 2018 | 43 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
R245fa condensation heat transfer in a phase separation condenser
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
جریان سیال و فرایندهای انتقال
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چکیده انگلیسی
The R245fa condensation heat transfer is investigated in a phase separation shell-tube condenser with mesh tubes inserted. The condenser has three copper tubes which have an inner diameter of 14.70â¯mm and a heat transfer length of 1600â¯mm. Four mesh tubes with mesh pore width of 15â¯Î¼m are arranged in each copper tube. The comparative experiments are conducted for condensers with or without mesh tubes inserted. The flow pattern visualization is investigated to explore heat transfer enhancement mechanisms. The results showed that, with vapor mass qualities and mass fluxes increased, condensation heat transfer coefficients and friction pressure drops are increased, but heat transfer enhancement ratios and performance evaluation parameters are decreased. At low mass fluxes, the heat transfer coefficients behave a slow decrease trend with increase of inclination angles. The pressure difference between annular region and core region drives liquid flow towards core region, reducing liquid film thickness on tube bottom and increasing vapor void fractions near tube wall. With increase of inclination angles, the pressure difference is reduced but liquid film thickness on tube bottom is increased. For horizontal flow, there is an optimal match between pressure difference of annular region and core region and liquid-mesh tube contact area. Under such circumstance, the heat transfer enhancement ratios reach maximum.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Thermal and Fluid Science - Volume 98, November 2018, Pages 346-361
Journal: Experimental Thermal and Fluid Science - Volume 98, November 2018, Pages 346-361
نویسندگان
Shuang Cao, Xianbing Ji, Jinliang Xu,