AnumericalstudyofradiationheattransferinsodiumpoolcombustionandresponsesurfacemodelingofluminousflameemissivityOriginalResearchArticle

Aresponsesurfacemodeloftheluminousflameemissivityofsodiumpoolfirehasbeenproposedforuseinsafetyanalysiscomputercodesofaliquidmetalfastreactor.Theliquidsodiumburnsinairresultinginnotonlyheatgenerationbutalsoreleaseofsodiumoxideaerosolsofsub-microndiameters.Aerosolslevitatinginairareradiativeandtheyinfluencetheallocationofcombustionheatfromtheflametoatmosphericgasorsodiumpool.Theemissivityoftheflameneedstobequantified,asitisoneofuser-specifiedparametersofthecomputercodesforthesodiumfireanalysis.Theresponsesurfacemodeloftheflameemissivityisdevelopedbasedonnumericalexperimentsonthephysicsofmassandheattransferandbehavioroftheaerosol.Thermal-hydraulicequationshavebeensolvedcoupledwithaerosoldynamicsandchemicalreaction.Threeinfluentialvariablesontheemissivityareidentifiedaspooltemperature,gastemperatureandoxygenmolarfractionintheair.Ithasbeenfoundthattheemissivityiscalculatedreasonablyasafunctionofthethreevariables.Theproposedresponsesurfacemodelcanbeeasilyemployedinthesodiumfireanalysiscodesbecauseitisasimplequadraticexpression.Forthesafetyevaluationofthesodiumfire,combineduseisrecommendedoftheproposedmodelandthelumped-masszonemodelcode.