Challenge to improve drastically cooling performance by nucleate boiling of immiscible mixtures

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13887
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Thermal engineering
• Research Institution: Kyushu University
• Principal Investigator: OHTA Haruhiko 九州大学, 工学研究院, 教授 (50150503)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 熱工学 / 沸騰 / 高性能冷却 / 非共溶性混合媒体 / 半導体冷却

Outline of Final Research Achievements

Superior cooling performance was expected in boiling of immiscible liquid mixtures. In pool boiling experiments, high subcooling was imposed to the less-volatile liquid by the high vapor pressure of more-volatile component. As a consequence, the critical heat flux was increased when the less-volatile liquid contact the heating surface. Furthermore, the surface temperature was reduced by the generation of bubbles from more-volatile liquid. In flow boiling experiments using a circular tube, the distribution of fluid temperature along the tube axis was proposed to evaluate the local heat transfer coefficients. The effects of flow rate ratio and heat flux on the heat transfer characteristics were clarified. In flow boiling experiments using rectangular narrow channels, experiments were conducted for gap sizes of 2, 1, and 0.5 mm. In some cases, boiling of more-volatile liquid accelerates the deterioration forced convection or flow boiling heat transfer to the less-volatile component.

Free Research Field

伝熱工学