化工学报2017，Vol.68Issue(5)：1852-1859,8.DOI:10.11949/j.issn.0438-1157.20161587
非均匀润湿性微通道表面池沸腾换热特性
Pool boiling heat transfer on heterogeneous wetting microchannel surfaces
摘要
Abstract
Three types of microchannel surface (TS#1, TS#2, and TS#3) with non-uniform wettability were fabricated on bare copper surfaces by surface modification technology and electrical discharge machining (EDM). Each microchannel had the same rectangular cross section with a depth of 800μm and width of 600μm. The width of fin between two successive microchannels was also 600μm. All these three microchannel surfaces had the same contact angle of 113.2° for the sidewall and bottom surfaces, but for the top surfaces, the contact angles were 8.6°(TS#1), 88.1°(TS#2) and 156.1°(TS#3), respectively. During the EDM fabrication process, cavities of 10μm in size was formed due to the electric sparking. Thus, the fabricated microchannel surfaces were multiscale surfaces. The statured pool boiling heat transfer characteristics of deionized water on these three types of microchannel surface as well as the bare copper surface were investigated experimentally. Compared with the bare copper surface (BS,θ=88.6°), all these three microchannel surface with non-uniform wettability manifested a better heat transfer performance. The critical heat fluxes for TS#1 and TS#3 were increased by 61% and 35% compared with BS, while the maximum heat transfer coefficients were increased by 2.3 and 6 times. The bubble dynamics on the heated microchannel surfaces was visualized with a high speed camera. It was found that the surface property of non-uniform wettability can postpone bubble column coalescence, thus the gaps among bubble columns can provide the effective routes for the liquid supplementary to the heated surface, avoiding the occurrence of dry-out and enhancing the critical heat flux.关键词
非均匀润湿性/微通道/传热/气泡/临界热通量Key words
heterogeneous wettability/microchannels/heat transfer/bubble/critical heat flux分类
能源科技引用本文复制引用
柴永志,张伟,李亚,赵亚东..非均匀润湿性微通道表面池沸腾换热特性[J].化工学报,2017,68(5):1852-1859,8.基金项目
国家自然科学基金项目(51476057) （51476057）
中央高校基本科研业务费专项资金项目(2015MS47).supported by the National Natural Science Foundation of China (51476057) and the Special Funds for the Fundamental Scientific Research of Central Universities (2015MS47). （2015MS47）
