Purpose

This study aims to focus on understanding how different jet angles and Reynolds numbers influence the phase change materials’ (PCMs) melting process and their capacity to store energy. This approach is intended to offer novel insights into enhancing thermal energy storage systems, particularly for applications where heat transfer efficiency and energy storage are critical.

Design/methodology/approach

The research involved an experimental and numerical analysis of PCM with a melting temperature range of 22 °C–26°C under various conditions. Three different jet angles (45°, 90° and 135°) and two container angles (45° and 90°) were tested. Additionally, two different Reynolds numbers (2,235 and 4,470) were used to explore the effects of jet outlet velocities on PCM melting behaviour. The study used a circular container and analysed the melting process using the hot air inclined jet impingement (HAIJI) method.

Findings

The obtained results showed that the average temperature for the last time step at Ф = 90° and Re = 4,470 is 6.26% higher for Ф = 135° and 14.23% higher for Ф = 90° compared with the 45° jet angle. It is also observed that the jet angle, especially for Ф = 90°, is a much more important factor in energy storage than the Reynolds number. In other words, the jet angle can be used as a passive control parameter for energy storage.

Originality/value

This study offers a novel perspective on the effective storage of waste heat transferred with air, such as exhaust gases. It provides valuable insights into the role of jet inclination angles and Reynolds numbers in optimizing the melting and energy storage performance of PCMs, which can be crucial for enhancing the efficiency of thermal energy storage systems.

中文翻译：

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热空气倾斜射流冲击容器对控制相变材料储能的影响：实验和数值研究

目的

本研究旨在重点了解不同的喷射角度和雷诺数如何影响相变材料 (PCM) 的熔化过程及其存储能量的能力。这种方法旨在为增强热能​​存储系统提供新颖的见解，特别是对于传热效率和能量存储至关重要的应用。

设计/方法论/途径

该研究涉及在不同条件下熔化温度范围为 22°C–26°C 的 PCM 的实验和数值分析。测试了三种不同的喷射角度（45°、90°和135°）和两种容器角度（45°和90°）。此外，还使用两个不同的雷诺数（2,235 和 4,470）来探索射流出口速度对 PCM 熔化行为的影响。该研究使用圆形容器，并使用热空气倾斜射流冲击（HAIJI）方法分析了熔化过程。

发现

所得结果表明，与 45° 射流角相比，Ф = 90° 和 Re = 4,470 时最后一个时间步的平均温度在 Ф = 135° 时高出 6.26%，在 Ф = 90° 时高出 14.23%。还观察到，喷射角，特别是当 Ф = 90° 时，是能量存储中比雷诺数更重要的因素。换句话说，射流角度可以作为能量存储的被动控制参数。

原创性/价值

这项研究为有效储存通过空气传递的废热（例如废气）提供了新的视角。它为射流倾角和雷诺数在优化相变材料熔化和储能性能方面的作用提供了宝贵的见解，这对于提高热能存储系统的效率至关重要。