Heat transfer enhancement in a loop thermosyphon with microencapsulated phase change material suspension

Abstract

The microencapsulated phase change material suspension (MPCMS) is a novel functional thermal fluid. The application of MPCMS to loop thermosyphon is an innovative attempt, which can effectively improve the heat transfer efficiency of loop thermosyphon. In this paper, a three-phase loop thermosyphon using water-based MPCMS as the medium is developed. A comprehensive experimental investigation was conducted to study the heat transfer performance by varying the filling ratio (50 %, 60 %, and 70 %), heat flux (25 − 125 W/cm2), and mass concentration (0 %, 0.1 wt%, and 1 wt%). The findings of this study indicate that the loop thermosyphon incorporating MPCMS exhibits improved heat transfer performance compared to a two-phase loop thermosyphon utilizing pure water. The addition of MPCMS has been observed to reduce the wall temperature by up to 6.6 °C and decrease the loop thermal resistance by 13.5 %. Furthermore, the loop thermosyphon with MPCMS demonstrates superior start-up characteristics and thermal homogeneity when compared to water-based systems.