Convection heat transfer anisotropy in a bubbling viscous pool - Application to molten core-concrete interactionFunded under: FP7-EURATOM
In the absence of bubbling, natural convection in an internally heated pool is largely anisotropic. There are large heat transfers to the upper and lateral walls, while the heat transfer to the cooled lower surface is small. Bubbling is a well-known mean of increasing the heat transfer coefficients, especially at the lower wall. The heat transfer between an internally heated pool and its walls has been experimentally studied while air bubbles were produced through a grid drilled with holes installed at the lower interface. Sugar solutions have been used as simulant the high temperature corium melts that would be produced during molten core-concrete interaction with respect to heat transfer model. Without any gas bubbling, natural convection in the pool exhibits a large anisotropy with a small heat transfer to the bottom wall. This is due to the building of a thermal gradient through the pool height. Bubbling with superficial gas velocity as low as 1 mm/s is sufficient to destabilize these layers in water and homogenize the pool. For more viscous fluids, it has been possible to determine a threshold between these regimes.
Bibliographic Reference: An article published in: Nuclear Engineering and Design, Article in Press, Corrected Proof
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://dx.doi.org/10.1016/j.nucengdes.2008.10.020
Record Number: 200910126 / Last updated on: 2009-01-23
Original language: en
Available languages: en