Influence of Long Life Coolant for Cooling a SiC Power Device on Subcooled Flow Boiling Heat Transfer

Abstract

Long Life Coolant (LLC), which has been used as a coolant for an automobile engine, is also expected as a coolant for a next generation SiC inverter. In this study, subcooled flow boiling heat transfer characteristics of LLC heated by a SiC device are discussed under high heat flux conditions in order to clarify the applicability of LLC to the cooling system with boiling heat transfer. The subcooled flow boiling heat transfer performance in a narrow channel is evaluated using TOYOTA LLC at the concentration of 30 vol% and distilled water. Although the heat transfer coefficient of TOYOTA LLC is approximately 1/2 lower than that of distilled water at the heat flux of 300W/cm² and the flow velocity of 1.0 m/s, it is confirmed that the maximum heat flux exceeds 300 W/cm² for all the flow velocities in our experiments.