کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
658175 1458079 2013 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Evaporation/boiling heat transfer on capillary feed copper particle sintered porous wick at reduced pressure
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Evaporation/boiling heat transfer on capillary feed copper particle sintered porous wick at reduced pressure
چکیده انگلیسی

A test facility which can control the liquid level and the evaporation saturation pressure is developed to characterize the water evaporation/boiling on copper particle sintered porous wick under the conditions of capillary feeding at reduced pressures, the main factor determining the performance of a vapor chamber. Nine porous wick samples with different particle sizes, particle types and wick thicknesses are tested at the same reduced pressure. The effective heat transfer coefficient is obtained using an inverse heat transfer method. The experimental results indicate that for all of the tested samples the effective heat transfer coefficient at first increases and then decreases with the increasing of heat flux, and there is an optimum wick thickness at which the maximum effective heat transfer coefficient could be achieved when the particle size and type (or porosity) are fixed. The theoretical analysis indicates that bubble nucleation is much more difficult to occur at a reduced pressure compared to atmospheric pressure, and as a result, the boiling heat transfer may only occur when the heat flux is high enough and the liquid level has receded into the wick. Consequently, bubble nucleation normally cannot be visualized experimentally at a reduced pressure. The heat transfer model of the evaporation/boiling in thin porous wicks (<1 mm) under capillary feeding and reduced pressure conditions is also summarized and it can be used to explain all the present experimental phenomena.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Heat and Mass Transfer - Volume 63, August 2013, Pages 389–400
نویسندگان
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