Abstract This paper aims to perform the entropy analysis and thermal performance evaluation of a wavy-channels triplex-tube latent heat storage heat exchanger (LHSHE) during melting and solidification mechanisms. The system with different wave amplitudes was examined for different temperatures and Reynolds numbers of the heat transfer fluid (HTF). Water is passed in the inner and outer tubes in opposite directions and the PCM is placed in the middle tube. The heat exchanger was analysed based on the temperature, liquid fraction and velocity of the PCM as well as thermal ( S T ‴ ) and frictional ( S f ‴ ) entropy generation rates. The results show that for a higher wave amplitude, shorter melting and solidification times are achieved. Both frictional and thermal entropy generation rates increase to the maximum values and then decrease during the melting and solidification. The frictional entropy generation rate reaches almost zero quickly during the solidification. For both melting and solidification, the magnitude of S T ‴ is significantly higher than S f ‴ in the phase change problem. The maximum values of S T ‴ are 0.05 and 0.13 W/Km3 for the melting and solidification mechanisms, respectively, for the dimensionless wave amplitude of 0.3. The results show the crucial role of entropy generation on the performance of the LHSHE.

中文翻译：

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波浪形通道三联管式换热器中PCM熔化和凝固机制的熵和热性能分析

摘要 本文旨在对波浪形通道三联管潜热蓄热换热器（LHSHE）在熔化和凝固过程中进行熵分析和热性能评估。针对不同温度和传热流体 (HTF) 的雷诺数检查具有不同波幅的系统。水以相反的方向通过内外管，PCM放置在中间管中。基于 PCM 的温度、液体分数和速度以及热 (ST ‴ ) 和摩擦 ( S f ‴ ) 熵生成率来分析热交换器。结果表明，对于更高的波幅，实现了更短的熔化和凝固时间。在熔化和凝固过程中，摩擦和热熵产生率均增加到最大值，然后降低。凝固过程中摩擦熵产生率很快几乎为零。对于熔化和凝固，在相变问题中，ST ‴ 的大小明显高于 S f ‴。对于 0.3 的无因次波幅，熔化和凝固机制的 ST ‴ 最大值分别为 0.05 和 0.13 W/Km3。结果显示了熵生成对 LHSHE 性能的关键作用。对于 0.3 的无因次波幅，熔化和凝固机制的 ST ‴ 最大值分别为 0.05 和 0.13 W/Km3。结果显示了熵生成对 LHSHE 性能的关键作用。对于 0.3 的无因次波幅，熔化和凝固机制的 ST ‴ 最大值分别为 0.05 和 0.13 W/Km3。结果显示了熵生成对 LHSHE 性能的关键作用。