Vapor-liquid interface form determination at the subcooled liquid film boiling*

Kryukov A.P., Puzina Yu.Yu.

Moscow Power Engineering Institute

A film boiling model on a hemispherical heater in subcooled water is presented. The work investigation theme is influence of the heat mass transfer processes near the interface on the vapor film formation at film boiling conditions when hot object is immersed in subcooled liquid. The combination of the gas dynamics methods and molecular-kinetic theory is used. The processes in which heat from the heater to the interface surface goes through the vapor film are studied. The corresponding heat transfer (convection in liquid, thermal conduction and radiation in vapor film) is considered. The equations system of the model has been obtained. Different cases are then analyzed with this model based on the numerical solution. One is for the constant curvature of interface; another is for the shape dependence.

Problem

Experiments of Ivochkin et al. (2004-2009)

Heater: Rw=5 мм, Tw=500°C, Water: Tb=40°C

Model

Mathematical description

Solution results

Data comparison

Conclusion

The problem about axial symmetric vapor film shape was solved with some assumptions. The mathematical description is based on the methods of continuum mechanics and molecular-kinetic theory. The calculations were done using the existing program. Different cases are described. One with constant curvature of vapor-liquid interface is lead to the differential equation about vapor film thickness. Another one is when equations system is transformed to the one sophisticated equation about curvature. The solution gives the dependence of coordinates and corresponding parameters.

This work is supported by the Russian Foundation for Basic Research (project №12-08-00657)

* Kryukov A.P., Puzina Yu.Yu. Vapor-liquid interface form determination at the subcooled liquid film boiling. // Proceeding of the ECI 8th International Conference on Boiling and Condensation Heat Transfer, 3-7 June 2012 Lausanne, Switzerland. P_1515.

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