Abstract This paper presents a method for fast estimation of the enthalpy-temperature function of Phase Change Materials (PCMs). The method combines a simple experimental setup with a non-iterative, reliable mathematical algorithm that allows retrieving the enthalpy-temperature function from measurements of heat flux and temperature at a single point. Distilled water was used as reference PCM for validation purposes because its enthalpy function is known with high accuracy. Moreover, water is characterized by sharp melting/solidification processes and very high enthalpy of melting, which is challenging for the estimation method proposed. The results achieved show quite good accuracy in the determination of melting point ( ± 0 . 06 ° C ), latent heat of melting ( ± 1 . 5 % ) and specific heats ( ± 5 − 8 % ). To prove that the estimation method also works with PCMs undergoing progressive instead of sharp melting, a composite material made of a graphite-foam enclosing a solid–solid PCM was also tested. Finally, the potential interest of the method for identifying and diagnosing PCM degradation in thermal cycling tests was shown by testing a PCM with leakage problems. Compared to Differential Scanning Calorimeter (DSC) in step-scan mode, which is the reference method for determining the enthalpy-temperature function of a PCM, our method shows comparable accuracy while providing significant advantages, such as short testing time (less than 2 h instead of days) and low-cost experimental equipment. The proposed method could hence be of great value to accelerate PCMs development and benchmark, as well as for databases building-up.

中文翻译：

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快速估计相变材料的焓-温度函数

摘要 本文提出了一种快速估计相变材料 (PCM) 的焓-温度函数的方法。该方法将简单的实验设置与非迭代、可靠的数学算法相结合，该算法允许从单点的热通量和温度测量值中检索焓-温度函数。蒸馏水被用作用于验证目的的参考 PCM，因为它的焓函数以高精度已知。此外，水的特点是急剧的熔化/凝固过程和非常高的熔化焓，这对所提出的估计方法具有挑战性。所得结果表明，在确定熔点 (± 0 . 06 °C)、熔化潜热 (± 1 . 5 % ) 和比热 (± 5 − 8 % ) 方面具有非常好的准确性。为了证明该估计方法也适用于经历渐进式而非急剧熔化的 PCM，还测试了一种由石墨泡沫制成的复合材料，该复合材料包裹着固体-固体 PCM。最后，通过测试具有泄漏问题的 PCM 显示了在热循环测试中识别和诊断 PCM 退化的方法的潜在兴趣。与步进扫描模式下的差示扫描量热仪 (DSC) 相比，该方法是确定 PCM 的焓-温度函数的参考方法，我们的方法显示出相当的准确性，同时提供了显着的优势，例如测试时间短（小于 2 小时）而不是几天）和低成本的实验设备。因此，所提出的方法对于加速 PCM 开发和基准测试以及数据库构建具有重要价值。