针对LNG在亚临界状态下的工作要求，利用VOF多相流模型对LNG在1 mm、1.5 mm、2 mm和2.5 mm共4种直径微小通道内的沸腾流动与换热特性进行研究，操作压力为0.1 MPa，热通量为40.9～385.4 kW/m2，质量通量为110～600 kg/m2·s。研究结果表明：在直径为1.5 mm、2 mm和2.5 mm的微小通道中，观察到了泡状流、弹状流、波状-环状流、过渡流和雾状流5种流型，而对于直径为1 mm的通道，没有观察到弹状流和过渡流，却出现了受限泡状流和柱塞流，且发现流型随通道直径的减小而转变加快，不同管径中的流型种类以及所占通道比例不同。当通道直径由2.5 mm减小到1 mm时，在波状-环状流区域对流换热系数提高了24.6%，但压降增加了50.1%。当质量通量增加到600 kg/m2·s，对流换热系数提高了22.6%，压降增加了55.8%。
Based on the working requirements of LNG in subcritical state, the boiling flow and heat transfer characteristics of LNG in the mini-channels with diameters of 1.5 mm, 2 mm and 2.5 mm were studied by using VOF phase change model. The operating pressure is 0.1MPa, the heat flux is 40.9 ~ 385.4 kW/m2, and the mass flux is 110 ~ 600 kg/m2·s. The results revealed that bubble, slug, wavy-annular, transition and mist flows in the mini-channels with diameters of 1.5 mm, 2 mm and 2.5 mm were observed. Whereas, for the 1 mm diameter channel, there was no slug and transition flows; however, the confined bubble and plug flows were observed. Also, the transition of flow pattern was accelerated with the decrease of channel diameter, and the type and proportion of flow patterns in different channel diameters were different. When the channel diameter reduced from 2.5 mm to 1 mm, the heat transfer coefficient in the wave-annular flow region was increased by 24.6% while the pressure drop increased by 50.1%. When the mass flux increased from 110 to 600 kg/m2·s, the heat transfer coefficient was enhanced by 22.6% and the pressure drop increased by 55.8%.
2024,46(5): 126-132 收稿日期：2023-03-14
DOI：10.3404/j.issn.1672-7649.2024.05.023
分类号：TE08
基金项目：江苏省海洋与渔业科技创新与推广项目（HY2017-8）
作者简介：龚慧芝(1996-),女,硕士研究生,研究方向为传热传质强化技术与数值模拟
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