The Effective Thermal Conductivity of Composite Phase Change Materials with Open-Cellular Metal Foams

  • PDF / 1,205,754 Bytes
  • 12 Pages / 439.37 x 666.142 pts Page_size
  • 70 Downloads / 215 Views

DOWNLOAD

REPORT


The Effective Thermal Conductivity of Composite Phase Change Materials with Open‑Cellular Metal Foams H. F. Abbasov1  Received: 29 August 2020 / Accepted: 30 September 2020 / Published online: 12 October 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020

Abstract Due to their high thermal conductivity, open-cellular metal foams are frequently used to improve the thermal conductivity of phase change materials. In this paper, the effective thermal conductivity of open-cellular foam filled with PCM with cubic units containing 12 solid tubular ribs was determined using an effective medium theory for composites. It was shown that metal foams with a large ratio of the radius of the tubular rib to its length can reach higher thermal conductivity. The case was also analyzed when the surface of the foam ribs was covered with a thin layer of another metal with high thermal conductivity. The results predicted by the proposed model were compared with the theoretical results of other models and with experimental data for some metal foam filled with phase change materials. A good agreement was achieved between present model predictions and experimental data. Keywords  Effective medium theory · Latent heat thermal energy · Metal foam · Phase change materials · Thermal conductivity

1 Introduction The thermal energy storage technology with phase change materials (PCM) is based on the principle of latent heat thermal energy, where solid–liquid and liquid–solid transitions are used due to their efficiency [1, 2]. Latent heat storage technology is characterized by a large energy storage capacity and an almost constant temperature during phase change process, chemical stability and low cost [3–5]. The low thermal conductivity of PCMs is their main drawback [5–7], which prolongs the charging and discharging periods of these systems due to poor heat exchange between PCM and heat transfer fluid. Various methods have been proposed

* H. F. Abbasov [email protected] 1



Oil Gas Scientific Research Project Institute, SOCAR​, H. Zardabi 88a, AZ1122 Baku, Azerbaijan

13

Vol.:(0123456789)

164  Page 2 of 12

International Journal of Thermophysics (2020) 41:164

to increase the PCM thermal conductivity: adding particles with high thermal conductivity, using metal foams, fins or extended surfaces, etc., [1–3, 8–17]. To enhance the thermal conductivity of PCMs Ibrahim et al. [1] proposed the use of porous materials. Among the ways to improve the thermal properties of PCM, porous materials such as metal foams with high thermal conductivity, are considered as more effective candidates to increase the thermal conductivity of PCMs [18–22]. For example, by impregnating porous graphite matrices with the paraffin, Mills et al. [13] showed that the composite matrix has a thermal conductivity that is 20–130 times greater than the thermal conductivity of pure PCM. Xiao et al. [18] demonstrated that the thermal conductivities of the paraffin/nickel foam and paraffin/copper foam composite PCMs dramatically increased and reac