Simulation study on the thermal response characteristics of the encapsulated perfluorohexanone extinguishing agent

Perfluorohexanone microcapsules are an innovative extinguishing agent that integrates the efficient extinguishing properties of perfluorohexanone with the intelligent, responsive characteristics of microcapsules, aiming to achieve adaptive suppression of fires in confined spaces. However, existing research primarily focuses on the extinguishing effects of perfluorohexanone microcapsules, and there is a significant gap in research on their thermal response characteristics. This study employs numerical simulation to investigate the thermal response characteristics by observing the phase changes of microcapsules in confined spaces and their spatial cooling effects. It establishes a numerical heat transfer model and validates its effectiveness through experiments. Based on contour plots and temperature changes recorded at specific measurement points in a given space, the thermal response of perfluorohexanone microcapsules is investigated by adjusting their spatial arrangement and placement. The results indicate that perfluorohexanone microcapsules can produce a cooling effect in confined spaces, achieving an 80% reduction in localized peak temperatures within 1 second. Compared to sensible heat effects, latent heat effects exhibit a 28% broader cooling coverage area and more sustained cooling effects. When the number of microcapsules is fixed, a single-row arrangement yields superior cooling effects, with a 15% faster thermal response speed compared to multi-row configurations. For multi-row arrangements, increasing the number of rows can lower the temperature at the least favorable point in the space without compromising the phase change duration. When the heat source and protected area are located on opposite sides of the space, placing the extinguishing agent between them can maximize the phase change rate and cooling effect.