Thermal characteristic and analysis of closed loop oscillation heat pipe/phase change material (CLOHP/PCM) coupling module with different working media

Aimed to understand the thermal characteristic of closed loop oscillation heat pipe/phase change material (CLOHP/PCM) coupling module filled with different working media for thermal energy storage and thermal management application, experimental investigation on the heat charge and discharge process of the coupling module under different conditions was carried out. The main result shows that the CLOHP filled with self-rewetting fluid (SRWF) and not placed horizontally has better thermal transfer performance relative to the water case as the heat load is low. But, the CLOHP filled with water has better thermal transfer performance than the SRWF case in horizontal condition especially under low heat load. The rise speed of temperature in the heating section increases when the phase transition completes. The highest temperature of the PCM locates in the middle region. Standard deviation (STD) of PCM temperature keeps relative stable for a long time and then increases rapidly and the rise speed has a positive correlation with the heat load. The uniformity of PCM temperature has been greatly improved for those three cases compared to that without working medium. During the discharge process, the fluctuation occurs only when the temperature of evaporation exceeds about 60 °C.