Energy saving evaluation of microencapsulated phase change materials embedded in building systems. (May 2022)

• Record Type: Journal Article
• Authors: Sierra, Valentina; Chejne, Farid
• Is Part Of: Journal of energy storage. Volume 49(2022)
• Publication Date: 2022-05
• Subjects: Microencapsulated phase change materials -- Mathematical model -- Mortar -- Reduction -- Energy storage; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2022.104102
• Languages: English
• ISSNs: 2352-152X

Abstract

Highlights: Integration of two scales, continue wall, and discrete microcapsules with a Gaussian distribution function. Designed mortar/MPCM dosage that fulfills thermal and mechanical requirements. Model satisfactorily validated with experimental data taken from the literature. Abstract: In this work, a mathematical model that serves as a design tool for constructive systems with thermally efficient microencapsulated phase change materials (MPCM) incorporated in mortar was developed. The model allows quantifying how is influenced room internal temperature due to design variables, such as % wt. MPCM in the mortar mix, mortar and brick wall thickness, calculate the walls of the room that must have mortar with MPCM incorporated, application of mortar in the external or internal layer of the room, and consumption of electrical energy. This was done by taking into account the integration of two scales: microcapsules and wall. MPCM was incorporated as a source term that considers melting and solidification time, a solid-liquid interface while the phase change is happening, and energy storage by latent heat. Furthermore, the particle size distribution for the microcapsules was included by means of a Gaussian function. The results highlight that a suitable MPCM dosage in mortar is 15% wt. MPCM/mortar external application can reduce the internal room temperature up to 9 °C without consuming electrical energy, while the internal application allows the room to be kept at approximately a uniform temperature of 23 °C. Therefore, both implementations gave positive results; the choice will depend on the environment where the designed MPCM/mortar system will be applied. In conclusion, by incorporating 15% wt. MPCM in the mortar mixture on two walls of the room with a mortar wall thickness of 7 cm, HVAC demand would be reduced by up to 80%. Finally, this model was endorsed with experimental data taken from the literature. Additionally, the fact that the mechanical behavior was also evaluated experimentally for the obtained mortar dosage is highlighted, a relevant aspect in the final design of the construction system.