Surface Temperature Distribution Characteristics of Marangoni Condensation for Ethanol-Water Mixture Vapor Based on Thermal Infrared Images
Surface Temperature Distribution Characteristics of Marangoni Condensation for Ethanol-Water Mixture Vapor Based on Thermal Infrared Images
复制标题
基于热红外图像的乙醇-水混合物蒸气Marangoni缩合表面温度分布特征
DOI：
10.3390/en13226057
复制
发表时间：
2020
期刊：
影响因子：
3.2
通讯作者：
Wang Jinshi
中科院分区：
文献类型：
--
作者：
Zhang Guilong;Ma Ziqiang;Li Heng;Wang Jinshi
Marangoni冷凝是由于冷凝液表面局部温度或浓度梯度引起的表面张力梯度而形成的，因此研究冷凝液表面温度分布特性对揭示冷凝机理和传热特性至关重要。对凝结水表面温度分布的研究较少。利用热红外图像测量了乙醇-水混合蒸汽在Marangoni冷凝过程中冷凝液表面的温度分布。结果表明，单个液滴表面温度分布不均匀，冷凝液滴边缘存在较大的温度梯度，约为15.6 ℃/mm。液滴表面最大温差达到8 ℃。在凝结过程中，单个液滴的平均表面温度先快速上升，然后缓慢上升，直至接近某一温度;而凝结液表面的平均温度则先快速上升，然后呈余弦曲线周期性变化。本文的结果将用于获得冷凝表面的局部热流密度和换热系数，并进一步建立换热与温度分布特性之间的关系。
Marangoni condensation is formed due to the surface tension gradient caused by the local temperature or concentration gradient on the condensate surface; thus, the investigation of the surface temperature distribution characteristics is crucial to reveal the condensation mechanism and heat transfer characteristics. Few studies have been conducted on the temperature distribution of the condensate surface. In this study, thermal infrared images were used to measure the temperature distributions of the condensate surface during Marangoni condensation for ethanol-water mixture vapor. The results showed that the surface temperature distribution of the single droplet was uneven, and a large temperature gradient, approximately 15.6 degrees C/mm, existed at the edge of the condensate droplets. The maximum temperature difference on the droplet surface reached up to 8 degrees C. During the condensation process, the average surface temperature of a single droplet firstly increased rapidly and then slowly until it approached a certain temperature, whereas that of the condensate surface increased rapidly at the beginning and then changed periodically in a cosine-like curve. The present results will be used to obtain local heat flux and heat transfer coefficients on the condensing surface, and to further establish the relationship between heat transfer and temperature distribution characteristics.