کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
659687 1458105 2011 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of copper surface wettability on the evaporation performance: Tests in a flat-plate heat pipe with visualization
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Effect of copper surface wettability on the evaporation performance: Tests in a flat-plate heat pipe with visualization
چکیده انگلیسی

The effects of copper surface wettability on the evaporation performance of a copper mesh wick were experimentally studied in an operating flat-plate heat pipe. Different degrees of wettability were obtained by varying the exposure times in air after the wicked plates were taken out of the sintering furnace. Three different working fluids: water, methanol and acetone, which possess different figures of merit, were investigated at the same volumetric liquid charge. The surface wettability was quantified by the static contact angle of sessile water drops on a flat copper surface. While the static contact angles of water drops varied from 10° to 40° for different degrees of wettability, the methanol and acetone drops still fully wetted the copper surface. A two-layer 100 + 200 mesh copper wick, 0.26 mm in thickness, was sintered on a 3 mm-thick copper base plate. A glass plate was adopted as the top wall of the heat pipe for visualization. Uniform heating was applied to the base plate near one end, and a cooling water jacket was connected at the other end. With increasing heat load, the evaporative resistance decreased with liquid film recession until a critical heat load showing the minimum evaporative resistance. Afterwards, partial dryout began from the front end of the evaporator. With decreasing wettability, the evaporating water film receded faster with increasing heat load and the critical heat loads were significantly reduced. In contrast, the critical heat loads for methanol and acetone seemed hardly affected by different wettability conditions. The minimum evaporative resistances, however, remained unaffected by surface wettability for all the three working fluids.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Heat and Mass Transfer - Volume 54, Issues 17–18, August 2011, Pages 3921–3926
نویسندگان
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