Experimental Evaluation of Phase Change Material Blister Panels for Building Application

Abstract

Introduction Phase change materials (PCMs) absorb, store, and passively release available thermal energy via latent heat transfer during phase change, thereby reducing peak demand and improving thermal comfort (Salunkhe and Shembekar, 2012; Kalnaes and Jelle, 2015; Wang et al., 2020). The thermal performance of PCMs is based on their melting point, thermal conductivity, and energy storage density. For this reason, when applied as energy storage, they require an instant melting and solidification point (Ji et al., 2014; Ma, Lin and Sohel, 2016). Paraffins, salt hydrates, and fatty acids are the most commonly used PCMs, having a melting temperature within human thermal comfort, making them suitable for building applications. However, such materials have major drawbacks, including low thermal conductivity, especially for organic PCMs. As a result, performance enhancements of PCMs are eagerly researched, to develop improved techniques (Fan and Khodadadi, 2011). Such methods require the addition of highly conductive materials, which can be done by modification of the encapsulation material, the shape of the container, using heat pipes, heat exchangers, micro-and macro-encapsulation, or the addition of highly conductive nanoparticles in the base fluid, creating nano-enhanced PCM (Babaei, Keblinski and Khodadadi, 2013; Ma, Lin and Sohel, 2016). Further techniques proposed the integration of metallic fins, foam wools, and graphite (Ji et al., 2014; Fan et al., 2013). The literature views of PCM enhancement materials have identified graphite, aluminium, and carbon as the most frequently applied materials for organic PCM enhancement. There are two methods to integrate PCM in building elements. The first method, "shape-stabilized", considers the direct addition of the PCM into a building element, such as a gypsum wall (Silva, Vicente and Rodrigues, 2016). The second method requires the PCMs to be encapsulated for technical use, as otherwise the material would disperse from the location (Cabeza et al., 2011). For this reason, the encapsulation method is the most commonly used form of integration and has become a topic of analysis in recent years. The geometry of the encapsulation can take any shape, but the most popular forms are tubes, pouches, spheres, and panels. Encapsulation geometry could potentially be harnessed as a heat enhancement method, improving the thermal conductivity of the PCMs (Amin, Bruno and Belusko, 2014). Additional benefits of encapsulation include the capacity to counteract phase segregation, which is a regular phenomenon particularly prevalent with salt hydrates, in which the high storage density of the material disperse in layers, leading to the decline in the storage efficiency.

Towards Phase Change Materials for Thermal Energy Storage: Classification, Improvements and Applications in the Building Sector

“…The addition of PCMs in the construction can be by adding a single layer of PCM [100,101] or by adding a multilayer of different types of PCMs [102,103]. Additionally, another approach is the development of floor panels with capillary network for PCM circulation [104], or the use of PCMs along with an electrical powered system for diminishing the demanded energy consumption [105]. Finally, PCMs can also be integrated in the raw materials used for construction, such as concrete [91].…”

Experimental Evaluation of Thermal Energy Storage (TES) with Phase Change Materials (PCM) for Ceiling Tile Applications

“…According to the manufacturer data the thermal conductivity of the S23 is 0.54 W/(m•K), this value is higher than the obtained results and it is due to the encapsulation material. In the case of the salt hydrates, their corrosiveness reduce the encapsulation options, thus plastic materials are an appealing solution (Velasco-Carrasco et al, 2020). The importance of the container material is pivotal for the PCM to perform adequately in indoor environments and in this case, it is expected a slight reduction from the plastic capsule in comparison to the natural thermal conductivity of the PCM.…”

“…The mathematical model concluded that the energy storage ratio of the phase change energy storage system was higher in comparison of a concrete ceiling (Qunli et al, 2017). Ceiling tiles are a practical method to integrate the PCMs into building structure, increasing thermal mass, reducing temperature fluctuations, and assisting in energy performance by regulating the indoor temperature (Velasco-Carrasco et al, 2020). Memon et al investigated the thermal performance of lightweight aggregate concrete (LWAC) containing macro encapsulated paraffin in Hong Kong.…”

Cellulose nanofiber/melanin hybrid aerogel supported phase change materials with improved photothermal conversion efficiency and superior energy storage density

“…The application of phase change materials in solar thermal energy conversion can greatly improve energy utilization e ciency and overcome the problem of solar radiation interval. Organic solid-liquid phase change materials are widely used in thermal energy storage systems because of their excellent structural stability, excellent energy storage density, adjustable phase transition temperature, and non-toxic properties (Weigand and Fleischer 2014;Velasco-Carrasco et al 2020). However, the large-scale application of PCMs in solar energy conversion is limited by the problem of liquid leakage during the phase change process (Pielichowska et al 2015;Han et al 2017;Woods et al 2021).…”