Abstract :
Experimentsarecarriedouttoinvestigatetheeffectsofthenaturalconvectionofsuperheatedgasaswellasthoseofthestandpipesonthetemperaturedistributionsofthecomponentsandtheheatremovalperformanceinthewater-coolingpanelsystemfortheMHTGRfordecayheatremoval,andtoverifyreliabilityofthedesignandevaluationmethods.ThenumericalresultsofthecodeTHANPACST2arecomparedwiththeexperimentaldatatoverifythenumericalmethodsandaxi-symmetricmodelproposed,whichcansimulatethethree-dimensionalconfigurationofthestandpipesontheupperheadofthepressurevesselbyusingporousbodycells.Theexperimentsrevealedthattemperaturesincreasedwithelevationontheupperhead,becausethestandpipesrestrictradiationheattransfertotheuppercoolingpanelandreducetheheattransferareaontheupperhead,whichwassuperheatedbynaturalconvectionofheliumgasinthepressurevessel.Inthepresumedaccidentconditioninwhichthermalradiativeheattransferisresponsibleforthemajorityofthetotalheattransfer,thenumericalmethodswereabletocloselyduplicatethepatternoftherisingtemperatureprofilewithelevationaroundthetopoftheupperheadasobservedintheexperiments.
