2024 年 17 巻 p. E24-004-1-E24-004-6
In order to cool a high heat density of a SiC-based inverter installed in electric vehicles, this study evaluates the influence of scale inhibitor EDTA (Ethylenediaminetetraacetic acid) on heat transfer performance of subcooled flow boiling of Long-life-coolant (LLC) in a narrow channel. The boiling surface is smooth and flat, and the inlet temperature of the LLC solution at 30 vol% is 60°C (the liquid subcooling is approximately 40 K). The average flow velocities of the coolants in the narrow channel are 1 m/s and 5 m/s. The heat transfer tests verify that the utilization of EDTA prevents the cooling performance of the LLC solution from deteriorating under the flow boiling conditions. This is conceivable because EDTA not only suppresses the scale deposition but also dissolves the scale on the boiling surface. For instance, the heat flux in the case of the LLC solution with EDTA at the flow velocity of 5 m/s increases by 3 MW/m2 at the wall superheat of 50 K, compared to the case without EDTA. Inhibitor EDTA is certainly useful and effective in preventing the cooling performance from deteriorating under flow boiling conditions.
