基于焓法的凝固/熔化模型,在考虑自然对流的情况下,建立管壳式相变换热器的熔化模型,并研究管翅片布局和热边界条件对相变材料瞬态熔化行为的影响机理。针对均匀的管翅片布局和恒定壁温热边界条件,设计一种具有方形波动热源的偏心结构,并对两者之间的强化传热规律进行比较和分析。结果表明,偏心布局可使相同传热面积中热传递盲区的熔化得到改善,而方形波动热源可增强前熔化阶段中央区域的自然对流;能量存储参数对比表明,相比原始结构,偏心布局结构或方形波动热源的熔化时间分别缩短12.5%和6.25%,而同时优化热源和结构的熔化时间缩短31.25%。方形波动热源和偏心结构能显著提高换热器的熔化速率。
Abstract
Based on the solidification/melting model of the enthalpy method, a melting model of a shell-and-tube type phase change heat exchanger is developed with consideration of natural convection, and the mechanism of the influence of tube fin layout and thermal boundary conditions on the transient melting behavior of the phase change material is investigated. We design an eccentric structure with a fluctuating heat source for a uniform tube fin layout and constant wall temperature thermal boundary conditions and compare and analyze the enhanced heat transfer law between them. The results show that the eccentric layout improves melting in the heat transfer blind area with the same heat transfer area, while the fluctuating heat source enhances natural convection in the central region of the pre-melting stage. The comparison of energy storage parameters shows that the eccentric layout structure or the fluctuating heat source reduces the melting time by 12.5% and 6.25%, respectively, compared to the original structure, and both the optimized heat source and structure reduce the melting time by 31.25%. The fluctuating heat source and eccentric structure can significantly improve the heat exchanger's melting rate.
关键词
相变材料 /
传热性能 /
管壳式 /
传热盲区 /
自然对流 /
数值模拟 /
强化传热
Key words
phase change materials /
heat transfer performance /
shell and tube heat exchangers /
heat transfer blind zones /
natural convection /
numerical simulation /
heat transfer enhancement
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基金
云南省基础研究计划（202301AS07）; 云南省“万人计划/青年拔尖人才”项目（YNWR-QNBJ-2018-162）
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