中文摘要：

给出了在低热流密度下有限空间内沸腾-凝结共存的相变传热特性的实验研究结果。沸腾工质为去离子水，换热表面材料为紫铜，有限空间的高度为16mm，充液液面高度分别为5mm、6mm、7mm和8mm。实验观察和测试结果表明，沸腾和凝结之间存在明显的相互作用和影响，且随着液面高度的增加，沸腾和凝结表面传热系数均先增加后减小。存在一个使沸腾和凝结表面传热系数最大的充液高度，这为优化平板热管均热器等存在沸腾-凝结共存现象的装置的设计提供了参考。

英文摘要：

The experimental results of boiling and condensation co-existing phase change heat transfer characteristics in a small confined space under low heat flux conditions are presented. The working medium used is de-ionized water, the heating and condensed surfaces are polished copper. The gap of the confined space is 16 mm, and the water level in the gap is set at 5 mm, 6 mm, 7 mm and 8 mm, respectively. Experimental observation and results show that boiling and condensation processes are strongly inter-related and have significant influences over each other. As the water level increases, both the boiling and the condensation heat transfer coefficient increases first and then decrease. The experimental results also disclose that there exists an optimum water filling amount at which both the boiling and the condensation heat transfer coefficient acquire their maximum value.