Experimental verification of suitability of insulation testing rig in determining thermophysical properties of insulating materials
Verificationofsuitabilityofinsulationtestingrig(ITR)indeterminingthe thermophysicalpropertiesofinsulatingmaterials(IM)isstronglybasedonthemeasurementoftemperaturesontheinner/outer surfacesoftheinsulators(whitecotton fabric,moldedash,moldedricehuskandmoldedsawdust),outersurfaceofmildsteel, andthetemperaturesoftheexternal/internalheattransferfluids(air/water).The dimensionlessexcesstemperature(heatrejectionfactor(HRF)) wasdeterminedasthe ratioofIMtomildsteelexcesstemperature.ThermalbalanceontheIMledtomechanisticthermalequationwhosecoefficientyieldedtheinsulationparameter,whichis synonymouswiththefinparameter.Thethermalconductivityoftheinsulatorswas uniquelydeterminedasafunctionofHRF,geometricshapesoftheinsulator/mildsteel, andtheinternal/externalfluidproperties.Distinctively,thethermaldiffusivitywas determinedasfunctionofrateofdimensionlessexcesstemperatureandtheinsulation parameterratherthanasratioofthermalconductivitytothermalstoragecapacity. Essentially,thethermalconductivitydeterminedfortheabove-mentionedIMwere; 0.0597,0.0377–0.0555,0.0251–0.0344and0.0110–0.0293W/mK,respectively.The thermaldiffusivityobtainedfortheaforementionedIMwere;3.443,1.3008–1.9302, 1.0384–1.4418and0.2499–0.8384m2/s,respectively.Theempiricalresultsproducedthe numericalvaluesofthefourcardinalthermophysicalproperties,whichunanimously agreedwiththeestablishedresultsinliterature.Thisagreementsubstantiatesthefact thatITRisquitesuitableindeterminingthethermophysicalpropertiesoffutureinsulators.Therefore,thisstudystronglyendorses theapplicationofITRforcharacterization anddevelopmentoffibrousagriculturalwastesasinsulators.