Reducing uncertainties in the numerical simulation of melting processes in phase change materials by a systematic model analysis using temperature dependent material properties

固/液相变相变潜热储能系统(LTE)是一种具有低温差储能功能的新型储能系统。越来越多的模拟方法被用来辅助这些仓库的设计。尽管一些潜在的模型已经开发了很久，但它们仍然没有得到足够的验证。因此，在该项目的头几年，对简单几何形状的熔化过程进行了详细的检查和验证。结果表明，热物性是造成数值计算结果与实验结果偏差的原因，而文献中的热物性变化很大。相反，使用平均依赖于温度的热物理性质导致数值结果和实验结果之间的一致性在5%到10%之间。由于这对于一个技术系统来说是足够的，我们将重点放在将结果转化为技术应用上，因此，本项目旨在通过实验和模拟来展示输入参数对这些存储设备的设计有多么强烈的影响。

Latent thermal energy storages (LTES) with solid/liquid phase change are attractive for storing thermal energy at low temperature differences. More and more simulations methods are used to assist in the design of these storages. Although some of the underlying models have been developed a long time ago, they are still insufficiently validated. Therefore, in the first years of the project, the melting process in a simple geometry was examined and validated in detail. It turned out that the thermophysical properties, which vary largely in the literature, were responsible for the deviation between numerical and experimental results. In contrast, the use of average temperature-dependent thermophysical properties led to an agreement within 5 to 10 % between numerical and experimental results. Since this is sufficient for a technical system, we focus on the transfer of the results to technical applications.Hence, this project aims to demonstrate through experiments and simulations how strongly the input parameters influence the design of these storages.