Promotion of steam condensation heat transfer by using solutal marangoni condensation
Promotion of steam condensation heat transfer by using solutal marangoni condensation
复制标题
利用溶液马兰戈尼冷凝促进蒸汽冷凝传热
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
Shixue Wang
中科院分区：
文献类型：
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作者：
Y. Utaka;Shixue Wang
尽管在大多数有关二元蒸气混合物冷凝的先前研究中，据报道冷凝率低于纯蒸气的冷凝率，但众所周知，可以通过使用添加剂形成所谓的正系统（溶液马兰戈尼冷凝）来实现传热增强。该研究的目的是阐明乙醇混合到蒸汽中对冷凝传热的影响。首先，对水和乙醇的蒸气混合物的乙醇浓度进行了宽范围的精确测量。由于蒸汽速度为0.4和1.5 m/s时，冷凝特性曲线中最大传热系数的峰值分别为0.12和0.18 MW/m2K，并且出现在乙醇蒸汽质量分数约1%处，因此表明混合非常有效，特别是在小乙醇浓度范围内。冷凝传热比纯蒸汽增强约2～8倍。此外，还研究了决定蒸气层扩散阻力和冷凝模式的现象的机制。
Although the condensation rates are reported to be less than that for pure vapors in most of previous studies concerning the condensation of binary vapor mixtures, it is known that the heat transfer enhancement can be realized by using additives to form so-called positive system (solutal Marangoni condensation). The objective of the study is to clarify the effect of ethanol mixing into steam on condensation heat transfer. First, the precise measurement was performed for wide range of ethanol concentration of vapor mixture of water and ethanol. Since the peaks of the maximum heat transfer coefficients in condensation characteristic curves were 0.12 and 0.18 MW/m2K for vapor velocities of 0.4 and 1.5 m/s, respectively, and appeared at about 1% ethanol vapor mass fraction, it was shown that the mixing was extremely effective especially in the range of small ethanol concentration. The condensation heat transfer was enhanced about 2∼8 times as large as that of pure steam. Further, the mechanisms determining the phenomena concerning the diffusion resistance in the vapor layer and the condensate modes were also investigated.