Energy Storage Science and Technology ›› 2025, Vol. 14 ›› Issue (8): 3100-3109.doi: 10.19799/j.cnki.2095-4239.2025.0132

• Energy Storage Materials and Devices • Previous Articles    

Numerical analysis of thermal storage characteristics of gradient-porosity copper foam-enhanced phase change materials

Yanping YUAN1(), Qifa GAO2, Nan ZHANG2, Qinrong SUN1   

  1. 1.School of Civil Engineering and Architecture, Chongqing University of Science and Technology, Chongqing 401331, China
    2.School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, Sichuan, China
  • Received:2025-02-13 Revised:2025-03-08 Online:2025-08-28 Published:2025-08-18
  • Contact: Yanping YUAN E-mail:ypyuan@home.swjtu.edu.cn

Abstract:

Copper foam, owing to its high thermal conductivity, enhances the conductive heat transfer of phase change materials (PCMs); however, its porous structure can inhibit convective heat transfer. To optimize the overall heat transfer enhancement, this study proposes the use of copper foam with a gradient-porosity structure to improve the thermal performance of PCMs. Numerical simulations were conducted to investigate the influence of gradient direction and porosity span on the heat transfer behavior. The results indicate that one-dimensional horizontal gradient porosity improves heat transfer, with the heat transfer rate increasing with porosity span for positive gradients and decreasing for negative gradients. The maximum improvement observed was 5.8% for a negative gradient span of 4%. For one-dimensional vertical gradients, positive gradients yielded superior enhancement, with a maximum increase of 11.5% at a 10% span. In the case of two-dimensional gradients, placing lower porosity at the bottom led to improved heat transfer performance, with a maximum increase of 5.5%. Overall, vertically oriented one-dimensional positive gradient copper foam with a 10% porosity span demonstrated the most effective heat transfer enhancement.

Key words: phase change materials, copper foam, design of gradient, phase change heat transfer, numerical simulation

CLC Number: