Pool boiling on a superhydrophilic surface
Pool boiling on a superhydrophilic surface
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DOI：
10.1002/er.861
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发表时间：
2003-02
影响因子：
4.6
通讯作者：
Y. Takata;S. Hidaka;M. Masuda;Takehiro Ito
中科院分区：
文献类型：
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作者：
Y. Takata;S. Hidaka;M. Masuda;Takehiro Ito
二氧化钛（TiO2）是一种具有独特特性的光催化剂。在紫外光照射下，TiO2表面对水表现出极高的亲和力，接触角几乎减小到零。相反，当表面被紫外线屏蔽时，接触角增加。这种超亲水性使涂层表面具有自清洁效果，并已应用于一些建筑材料，汽车涂料等。我们将这一特性应用于提高沸腾传热。为了明确高润湿性对换热特性的影响，进行了纯水池沸腾实验。传热表面为直径为17mm的垂直铜圆柱，测量是在饱和温度和稳态下进行的。采用涂覆和未涂覆两种表面进行比较。在实验前，将TiO2涂层表面暴露在紫外光下几个小时，发现其最大热流密度（CHF）约为未涂层表面的两倍。超亲水表面的最低热流密度温度比普通表面高100 K。超亲水表面是理想的传热表面。版权所有©2002约翰威利父子有限公司
Titanium Dioxide, TiO2, is a photocatalyst with a unique characteristic. A surface coated with TiO2 exhibits an extremely high affinity for water when exposed to UV light and the contact angle decreases nearly to zero. Inversely, the contact angle increases when the surface is shielded from UV. This superhydrophilic nature gives a self‐cleaning effect to the coated surface and has already been applied to some construction materials, car coatings and so on. We applied this property to the enhancement of boiling heat transfer. An experiment involving the pool boiling of pure water has been performed to make clear the effect of high wettability on heat transfer characteristics. The heat transfer surface is a vertical copper cylinder of 17 mm in diameter and the measurement has been done at saturated temperature and in a steady state. Both TiO2‐coated and non‐coated surfaces were used for comparison. In the case of the TiO2‐coated surface, it is exposed to UV light for a few hours before experiment and it is found that the maximum heat flux (CHF) is about two times larger than that of the uncoated surface. The temperature at minimum heat flux (MHF) for the superhydrophilic surface is higher by 100 K than that for the normal one. The superhydrophilic surface can be an ideal heat transfer surface. Copyright © 2002 John Wiley & Sons, Ltd.