Publications

Research outputs, reports, policy briefs and knowledge products from KIU scholars and partners.

2019 School of Engineering and Applied Sciences Cogent Engineering

Experimental verification of suitability of insulation testing rig in determining thermophysical properties of insulating materials

Nnamchi, O. A. Nnamchi, O. S. Odebiyi, O. O. Edosa1 and T. Wanazusi

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.