Modeling of the effect of nano-enhanced phase change material on the performance of a large-scale wallboard

Leyli Bahrami,Alibakhsh Kasaeian,Fathollah Pourfayaz,Sahar Ghafarian

doi:10.18186/thermal.1051259

Abstract

The main goal of this present study is to investigate the effects of the application of PCM and Nano-enhanced PCM as wallboard on the thermal behavior of a room. For this purpose, a room was modeled in two dimensions under Tehran's summer weather conditions through computational fluid dynamics (CFD). The effect of using the PCM as a wallboard in the southern wall in both pure and enhanced with nanoparticles was investigated. The indoor temperature, the wall surface temperature, and the interior wall heat flux, in both cases, were reported and compared. At the end of this study, the acquired results were compared with the pre-modified room, and thermal improvement was reported. The results indicate that the use of solid nanoparticles in PCM reduces the energy consumption of air-conditioning system by 7.4% compared to the conventional room. In the case of the Nano-enhanced PCM wallboard, the room has better thermal performance than the pure PCM, with 4.37% more energy storage, about 0.273 reductions in temperature decrement factor, and a 21.6 min increase in the time delay to peak temperature. Compared to the conventional room and room with pure PCM, the room’s temperature fluctuation, modified by Nano-enhanced PCM, reduces by 52% and 31%, respectively. This study's obtained results could help the researchers and designers have a more appropriate PCM selection for building ventilation system applications.

Highlights

According to the International Energy Agency (IEA), 36% of the energy consumption and 40% of the total indirect and direct CO2 emissions in the world are driven by building and building construction sectors [1]
The selected phase change material (PCM) should be melted during the day, which effectively works in a high ambient temperature
In the Nano-enhanced PCM case, the indoor temperature within the heat release hours is more than pure PCM one due to the heat transfer enhancement

Summary

Introduction

According to the International Energy Agency (IEA), 36% of the energy consumption and 40% of the total indirect and direct CO2 emissions in the world are driven by building and building construction sectors [1]. The application of phase change material in buildings would be one of the best solutions for achieving less energy consumption and less CO2 emissions. The PCMs have been identified as sustainable and environment-friendly materials, which have higher energy storage density and reversibility than the sensible heat storage materials. These materials can reduce building energy consumption and maintain the building temperature comfortable and have benefits in other applications such as distillation and batteries [2,3,4]. Phase change materials have been applied in the building sector as thermal storage from the beginning of the 1980s [5]. The PCM-incorporated building materials as wallboard, wall, roof, floor, and venetian blind are appropriate alternatives for thermal energy storage (TES)

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Conclusion