Purpose

Multiple encapsulated phase change materials (PCMs) are used in a wide range of applications, including convective drying, electronic cooling, waste heat recovery and air conditioning. Therefore, it is important to understand the performance of multiple PCMs in channels with flow separation and develop methods to increase their effectiveness. The aim of the study is to analyze the phase transition dynamics of multiple encapsulated PCMs mounted in a U-shaped tube under inclined magnetic field by using ternary nanofluid.

Design/methodology/approach

The PCMs used in the upper horizontal channel, vertical channel and lower horizontal channel are denoted by M1, M2 and M3. Magnetic field is uniform and inclined while finite element method is used as the solution technique. Triple encapsulated-PCM system study is carried out taking into account different values of Reynolds number (Re, ranges from 300 to 1,000), Hartmann number (Ha ranges from 0 and 60), magnetic field inclination (between 0 and 90) and solid volume fraction of ternary nanofluid (between 0 and 0.03). The dynamic response of the liquid fraction is estimated for each PCM with varying Re, Ha and t using an artificial neural network.

Findings

It is observed that for PCMs M2 and M3, the influence of Re on the phase transition is more effective. For M2 and M3, entire transition time (t-F) lowers by approximately 47% and 47.5% when Re is increased to its maximum value, whereas it only falls by 10% for M1. The dynamic characteristics of the phase transition are impacted by imposing MGF and varying its strength and inclination. When Ha is raised from Ha = 0 to Ha = 50, the t-F for PCM-M2 (PCM-M3) falls (increases) by around 30% (29%). For PCMs M1, M2 and M3, the phase transition process accelerates by around 20%, 30% and 28% when the solid volume fraction is increased to its maximum value.

Originality/value

Outcomes of this research is useful for understanding the phase change behavior of multiple PCMs in separated flow and using various methods such as nano-enhanced magnetic field to improve their effectiveness. Research outputs are beneficial for initial design and optimization of using multiple PCMs in diverse energy system technologies, including solar power, waste heat recovery, air conditioning, thermal management and drying.

中文翻译：

---

三元纳米流体 MHD 下 U 形通道中多个封装 PCM 的相变

 目的

多种封装相变材料 (PCM) 具有广泛的应用，包括对流干燥、电子冷却、废热回收和空调。因此，了解流分离通道中多种 PCM 的性能并开发提高其有效性的方法非常重要。本研究的目的是利用三元纳米流体分析安装在 U 形管中的多个封装 PCM 在倾斜磁场下的相变动力学。

设计/方法论/途径

上水平通道、垂直通道和下水平通道中使用的PCM由M1、M2和M3表示。磁场均匀且倾斜，采用有限元法作为求解技术。考虑到雷诺数（Re，范围从 300 到 1,000）、哈特曼数（Ha 范围从 0 到 60）、磁场倾角（0 到 90 之间）和固体体积的不同值，进行三重封装-PCM 系统研究三元纳米流体的分数（0 到 0.03 之间）。使用人工神经网络估计具有不同 Re、Ha 和 t 的每种 PCM 的液体部分的动态响应。

 发现

可以看出，对于 PCM M2 和 M3，Re 对相变的影响更为有效。对于 M2 和 M3，当 Re 增加到最大值时，整个过渡时间 (t-F) 降低约 47% 和 47.5%，而 M1 仅降低 10%。相变的动态特性受到施加 MGF 以及改变其强度和倾斜度的影响。当 Ha 从 Ha = 0 提高到 Ha = 50 时，PCM-M2 (PCM-M3) 的 t-F 下降（增加）约 30% (29%)。对于PCM M1、M2和M3，当固体体积分数增加到最大值时，相变过程加速约20%、30%和28%。

 原创性/价值

这项研究的成果有助于理解分离流中多种相变材料的相变行为，并使用纳米增强磁场等各种方法来提高其有效性。研究成果有利于在不同能源系统技术中使用多种相变材料的初始设计和优化，包括太阳能、废热回收、空调、热管理和干燥。