DOI: 10.1615/ICHMT.2015.THMT-15
ISBN Print: 978-1-56700-427-4
ISBN CD: 978-1-56700-428-8
The effects of natural and mixed convection on heat transfer across adjacent micro-channels, in extreme pressure and temperature conditions.
RESUMO
This abstract summarizes an experimental investigation of heat transfer across an insulation pack specimen used to protect the Hot Box Dome of an advanced gas cooled nuclear reactor under reactor operating conditions. The pack consists of multiple stainless steel layers forming narrow channels, less than 1 mm wide, between them. The experimental facility developed, can operate at pressures up to 40 bar and temperatures of differences of 500°C, at horizontal and inclined orientations. Measurements led to the calculation of the effective conductivity and also the mapping of the temperature variation across the pack for a range of flow rates through it and also for angles to the horizontal between 0° and 30°. The most striking finding is the strong influence of buoyancy for all flow rates investigated, even for the horizontal cases. Tests at inclined orientations suggest the presence of flow reversal. Preliminary CFD analysis for a simplified 2-D model confirms the effects of angle of inclination on the thermal development.