The phase change thermal storage (PCTS) technique is essential for renewable energy utilization. To strengthen the heat-discharge performance, an innovative PCTS unit with a fractal space-filling matrix is proposed. Based on the established solidification model, the solidification interface transformation and temperature field evolution of the innovative PCTS unit are numerically analyzed and compared with those of conventional units. Moreover, the roles of the structural parameters of PCTS units are investigated in terms of the resulting solidification behavior, and the metal matrix is optimized in terms of the solidification duration. The results show that the fractal space-filling matrix effectively improves the heat-discharge performance. Compared to conventional PCTS units, the proposed PCTS unit with a fractal space-filling matrix produces a more uniform temperature field and enhances the solidification rate by approximately 40%. Regarding the trade-off between cost and performance, a fractal level of two is suggested to maximize the heat-discharge enhancement and minimize the manufacturing cost. To minimize the solidification duration, the optimal length and thickness ratios of the fractal space-filling matrix are found to be 0.4 and 0.5, respectively, for practical engineering applications.

中文翻译：

---

利用分形填充矩阵提高相变储热单元的放电性能

相变储热（PCTS）技术对于可再生能源的利用至关重要。为了增强散热性能，提出了一种具有分形填充矩阵的创新型PCTS装置。在建立的凝固模型的基础上，对创新型PCTS装置的凝固界面转变和温度场演化进行了数值分析，并与常规装置进行了比较。此外，根据所得的凝固行为研究了PCTS单元的结构参数的作用，并且根据凝固的持续时间对金属基体进行了优化。结果表明，分形填充矩阵有效地提高了散热性能。与传统的PCTS单元相比，建议的带有分形填充矩阵的PCTS单元可产生更均匀的温度场，并使凝固速率提高约40％。关于成本和性能之间的折衷，建议使用分形水平为2的形式，以最大程度地提高散热效果并最小化制造成本。为了使固化时间最短，对于实际工程应用，分形空间填充基质的最佳长度和厚度比分别为0.4和0.5。