墙体传导传递函数计算方法的适用性研究.doc

ApplicabilityofCalculationMethodsforConductionTransferFunctionsofBuildingConstructions墙体传导传递函数计算方法的适用性研究YoumingChena,b,,DanFisherbaCollegeofCivilEngineering,HunanUniversity,Changsha,Hunan410082,ChinabSchoolofMechanicalandAerospaceEngineering,OklahomaStateUniversity,Stillwater,Oklahoma74078-5016,USAAbstractConductiontransferfunctions(CTFs),Laplacetransform(LP)method,state-space(SS)methodandfrequency-domainregression(FDR)-,buildingsimulationandenergyanalysis,conductionheattransferisusuallymodeledasaone-dimensional,transientprocesswithconstantmaterialproperties(McQuiston,).ThesimplifiedheatdiffusionequationinCartesiancoordinatesisshowninequation(1)(Incropera,). (1)where T=Temperature,CorF x=Heatflowdirection,morft a=Thermaldiffusivity,m2/sorft2/st=Time,secFourier’slaw,equation(2),specifiestheconductionheatfluxintermsofthethermalconductivityofthematerialandtemperaturegradientacrossadifferentialthickness. (2)where q”=Heatflux,W/m2orBtu/(hr-ft2) l=Thermalconductivity,W/(m-C)orBtu/(hr-ft-F)Sinceequation(1)isapartialdifferentialequation,thesystemisusuallysolvednumerically,’(3)and(4)(McQuiston,). (3) (4)where q”ko=Heatfluxatexteriorsurface,W/m2orBtu/(hr-ft2) q”ki=Heatfluxatinteriorsurface,W/