اميرحسين اسماعيلي فرد

In recent years, phase change materials (PCMs) have garnered significant attention due to their ability to store and conserve energy. In this study, computational fluid dynamics (CFD) was used to eva‎luate the efficiency and select suitable PCMs for satellite solar cells. These cells are a critical component of satellite power systems. To enhance the properties of these materials, the microencapsulation method was investigated. We selected noctadecane and n-nonadecane as the core materials for the microcapsules, with polyurethane and silicon dioxide as the shell materials. Using established relationships from polymer science literature, the thermal properties of the microencapsulated materials were calculated. The results show that the thermal conductivity coefficient improved by 75 %for n-octadecane with a polyurethane shell, 33 %for n-octadecane with a silicon dioxide shell, and 76 %for n-nonadecane with a polyurethane shell. Additionally, the melting enthalpy of these materials decreased by 0.01%, 0.03%, and increased by 12%, respectively. The findings of this study were validated against three different studies, with the maximum deviation between the simulations and existing data being 6%. Furthermore, given the improved properties achieved through microencapsulation, these materials were simulated in a satellite solar cell located in a 400 km orbit above Earth. The solar cell is subjected to a heat flux of 1618.18 W/m² from the Sun, leading to temperature rise and reduced efficiency. The use of microencapsulated materials helps prevent excessive temperature increases and enhances the cell's performance. Simulation results show that when microcapsules of n-octadecane with a polyurethane shell, n-octadecane with a silicon dioxide shell, and n-nonadecane with a polyurethane shell are applied to the solar cell's electronic board, these materials melt after 13, 15, and 19 minutes, respectively, effectively preventing overheating during this period. Among the three materials, n-nonadecane with a polyurethane shell demonstrated the best performance and is proposed as the final outcome of this research.

مواد تغييرفازدهنده , ميكروكپسوله سازي , سلول خورشيدي ماهواره , ماهواره , كنترل دما , شبيه‌سازي ديناميك سيالات محاسباتي

Phase change materials , microencapsulation , satellite solar cell , satellite , temperature control , CFD simulation

Amirhossein Esmaeilifard

Seyedhasan Hashemabadi