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ISSN Online: 2377-424X

ISBN Print: 1-56032-797-9

International Heat Transfer Conference 11
August, 23-28, 1998, Kyongju, Korea

THE EFFECT OF LIGHT GASES IN NONCONDENSABLE MIXTURES ON CONDENSATION HEAT TRANSFER

Get access (open in a dialog) DOI: 10.1615/IHTC11.540
pages 415-420

Аннотация

The presence of hydrogen in the noncondensable mix-ture within the containment can affect heat transfer from the bulk gas to the walls. In spite of past studies, there is no consensus to the understanding of the actual role of a light gas (helium as simulant) in these scenarios. In an ef-fort to resolve this open issue a theoretical analysis using a simple condensation theory has been conducted which ad-dresses the expected conditions in the AP600 design during a postulated accident. Light gas concentration is a key variable on the heat transfer due to its influence on steam diffusivity, buoyancy, and conductivity across the gas boundary layer. At low and moderate Helium con-centrations the diffusivity increase is compensated by the buoyant force decrease. At much higher light gas content the buoyancy reduction becomes dominant and the heat transfer is reduced. However, these high concentrations of light gas are above what may be expected in the bulk atmosphere of the AP600 design.