Numerical investigation on conventional and PCM heat sinks under constant and variable heat flux conditions

摘要

In this study, a numerical model is developed to study the behaviour of conventional heat sink and phase change material (PCM) heat sink for electronics cooling applications. Two different PCMs, RT35HC (△T_m= 34-36 °C and △H=240 kJ/kg) and RT44HC (△T_m= 41-44 °C and △H=250 kJ/kg), are selected for the analysis. A comparison has been made between conventional heat sink and PCM-based heat sink under constant and variable heat flux conditions. Further, four different hybrid heat sink design configurations are studied during the cooling period (solidification) and compared with PCM-based heat sink. During the heating period, the conventional heat sink is subjected to different convective cooling environments (h=10-50 W/m~2-K). The results showed that the PCM heat sink achieved base temperature equivalent to the conventional heat sink with the heat transfer coefficient between 30 and 40 W/m~2-K under the constant heat flux condition. Under the variable heat flux condition, the base temperature of the PCM heat sink is very much less than the conventional heat sink subjected to 50 W/m~2-K. During the cooling period, hybrid heat sinks reduced the heat transfer coefficient by ten times less than that of the PCM heat sink.