多孔介质复合相变材料孔隙结构优化与传热强化研究

doi:10.19799/j.cnki.2095-4239.2025.0789

摘要/Abstract

摘要：

本文旨在系统研究梯级多孔骨架结构对复合相变材料（C-PCMs）传热与储热性能的优化机理，重点探究孔结构中孔径分布、孔径梯度与孔隙率分布对对相变过程的影响。通过构建孔隙尺度下的多孔介质物理模型，采用焓-孔隙度法进行数值模拟，分析不同孔隙结构下相变材料（PCMs）的熔化行为、液相流动及储热特性。研究结果表明，孔径分布在均匀孔隙率条件下对熔化过程具有显著影响。其中“大孔径布置于热源端、小孔径布置于远端”的分布方式能够最大程度发挥大小孔的自然对流与导热协同作用，熔化时间缩短16.8%。此外，横向连通的孔径梯度结构能够诱发局部微对流效应，尤其在大孔与小孔交界处，液相前沿弯曲更加明显，并在熔化后期使平均储热效率最高提升17.5%。相比之下，孔隙率分布对熔化过程的影响相对有限：前端低孔隙率比例增加虽可略微缩短熔化时间，但会导致总储热量和平均储热功率分别下降1.6%和1.7%。综上，本研究揭示了孔隙结构对C-PCMs熔化传热过程的作用机理，提出了通过合理设计孔径分布、梯度及孔隙率以实现高效储能的理论指导与方法依据，对多孔介质C-PCMs 的优化设计具有重要参考价值。

关键词: 复合相变材料, 多孔介质, 梯度孔骨架, 相变储热, 传热强化

Abstract:

This paper aims to systematically investigate the optimization mechanisms of graded porous skeleton structures on the heat transfer and thermal energy storage performance of composite phase change materials (C-PCMs), with a focus on the effects of pore size distribution, pore size gradient, and porosity distribution on the phase change process. By constructing a pore-scale physical model of porous media and employing the enthalpy-porosity method for numerical simulations, the melting behavior, liquid-phase flow, and thermal storage characteristics of phase change materials (PCMs) under different pore structures are analyzed. The results indicate that pore size distribution significantly influences the melting process under uniform porosity conditions. Specifically, arranging large pores near the heat source and small pores at the far end maximizes the synergistic effect of natural convection and conduction in large and small pores, reducing melting time by 16.8%. In addition, transverse gradient pore structures induce local micro-convection, particularly at the interfaces between large and small pores, where the liquid front exhibits pronounced curvature, enhancing average thermal storage efficiency by up to 17.5% during the late melting stage. By contrast, the impact of porosity distribution is relatively minor: although increasing the proportion of low-porosity regions near the heat source slightly shortens melting time, it also reduces total heat storage and average thermal storage power by up to 1.6% and 1.7%, respectively. In summary, this study clarifies the influence of pore structure on the melting heat transfer of C-PCMs and provides theoretical guidance and methodological insights for efficient energy storage through rational design of pore size distribution, gradient structures, and porosity, offering valuable reference for the optimization of inorganic porous C-PCMs.

Key words: Composite phase change materials, porous media, gradient pore skeleton, phase change thermal storage, heat transfer enhancement

中图分类号:

TK02

陶梦晓, 蔡锦龙, 姜峰, 凌祥. 多孔介质复合相变材料孔隙结构优化与传热强化研究[J]. 储能科学与技术, doi: 10.19799/j.cnki.2095-4239.2025.0789.

Mengxiao Tao, Jinlong Cai, Feng Jiang, Xiang Ling. Optimization of pore structure and heat transfer enhancement in porous composite phase change materials[J]. Energy Storage Science and Technology, doi: 10.19799/j.cnki.2095-4239.2025.0789.

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	模型	孔隙率	孔径	分布
孔径分布	Hole 11	0.48	20:10:5	1:1:1
	Hole 12	0.48	20:10:5	1:1:1
	Hole 13	0.48	20:10:5	4:3:2
	Hole 14	0.48	20:10:5	2:3:1
孔径梯度	Hole 21	0.47	30:15	-
	Hole 22	0.46	30:20:15	-
	Hole 23	0.47	30:15:30	-
	Hole 24	0.43	30:20:15:30	-
正梯度孔隙分布	Hole 31	0.5:0.53:0.56	10:8:6:4	1:1:1
	Hole 32	0.5:0.53:0.56	10:8:6:4	3:2:1
	Hole 33	0.5:0.53:0.56	10:8:6:4	1:2:3
	Hole 34	0.5:0.53:0.56	10:8:6:4	1:1

	相变温度℃	密度kg/m³	导热系数W/(m K)	比热J/(kg K)	潜热J/ g	运动粘度m²/s	热膨胀系数1/K
PCMs	659.9	1650	0.35	901	305	1.1e-6	0.0005
骨架		2290	0.4	842