KGH 25th Mijuca et al

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PRIMENA TRODIMENZIONE METODE KONANIHPRIMENA TRODIMENZIONE METODE KONANIH

ELEMENATA U PROCENI ENERGETSKEELEMENATA U PROCENI ENERGETSKE

EFIKASNOSTI OMOTAA ZGRADEEFIKASNOSTI OMOTAA ZGRADE

Dr Dubravka Mijuca*, Dr Duan Gaji**, Marko Vukobrat**Dr Dubravka Mijuca*, Dr Duan Gaji**, Marko Vukobrat***Matematiki fakultet, Univerzitet u Beogradu, P. FAH 550*Matematiki fakultet, Univerzitet u Beogradu, P. FAH 550

**Institut "Kirilo Savi", Beograd**Institut "Kirilo Savi", [email protected]@matf.bg.ac.yu

ON THE THREEDIMENSIONAL FINITE ELEMENTON THE THREEDIMENSIONAL FINITE ELEMENT

METHOD IN THE ENERGY EFFICIENCY OFMETHOD IN THE ENERGY EFFICIENCY OF

BUILDINGS ENVELOPEBUILDINGS ENVELOPE

35. MEUNARODNI KONGRES35. MEUNARODNI KONGRESO KLIMATIZACIJI, GREJANJUO KLIMATIZACIJI, GREJANJU

I HLAENJUI HLAENJUBeograd, 1Beograd, 1--3. decembra 2004.3. decembra 2004.

35th CONGRESS ON AIR35th CONGRESS ON AIRCONDITIONING, HEATINGCONDITIONING, HEATING

AND REFRIGIRATINGAND REFRIGIRATINGBelgrade, December 1Belgrade, December 1--3, 20043, 2004


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ENERGIJA KOJA SE TROSI U ZGRADAMAENERGIJA KOJA SE TROSI U ZGRADAMABUILDING ENERGY USEBUILDING ENERGY USE

Energy used in buildings (to heat, cool, light, andprovide other important energy services) accounts for

about one-fourth to one-third of all energy used inCentral and Eastern Europe.

Na energiju koja se koristi u zgradama (za zagrevanje,hladjenje, osvetljavanje, i zadovoljavanje drugih vanihenergetskih usluga) otpada oko celokupne energije

upotrebljene u centralnoj i istonoj Evropi


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MOTIVMOTIV -- MOTIVEMOTIVE

Projektovanje graevinskih objeProjektovanje graevinskih objekkata primenomata primenomsavremenih metodasavremenih metoda raunske mehanikeraunske mehanike je danas bre,je danas bre,efikasnije i jeftinije, aefikasnije i jeftinije, a strukturalnistrukturalni kvalitetkvalitetii energetskaenergetska

efikasnostefikasnostprojektovanog, rekonstruisanog iliprojektovanog, rekonstruisanog ilirevitalizovanog objekta se njenom primenom poveava.revitalizovanog objekta se njenom primenom poveava.

Contemporary design in the civil engineering becomesContemporary design in the civil engineering becomesshorter in time, more efficient and less expensive by theshorter in time, more efficient and less expensive by the

use of numerical methods ofuse of numerical methods ofcomputational mechanicscomputational mechanics,,whilewhile structural qualitystructural quality andand energetic efficiencyenergetic efficiency areareincreasedincreased


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CILJCILJ -- GOALGOAL

Pokazati da je analizaPokazati da je analiza energetske efikasnostienergetske efikasnostigraevinskih objekatagraevinskih objekata i bri bra i jeftinija korienjema i jeftinija korienjemtrodimenzionalne metode konanih elemenatatrodimenzionalne metode konanih elemenata

To show that analysis of the energy efficiency of the civilTo show that analysis of the energy efficiency of the civilfacilities is faster and cheaper by the use offacilities is faster and cheaper by the use of

threedimensional finite element methodthreedimensional finite element method


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ORIGINALNOST ISTRAIVANJAORIGINALNOST ISTRAIVANJAORIGINALITY OF THERESEARCHORIGINALITY OF THERESEARCH

Upotreba originalnog inUpotreba originalnog in--house softvera FEMIX baziranoghouse softvera FEMIX baziranogna meovitoj metodi konana meovitoj metodi konanih elemenata, a koji jenih elemenata, a koji jepotupno integrisan u pre i post processing komercialnogpotupno integrisan u pre i post processing komercialnogkoda Straus7koda Straus7

The use of the original inThe use of the original in--house software FEMIX basedhouse software FEMIX basedon the mixed finite element method, which is fullyon the mixed finite element method, which is fully

integrated in the pre and postintegrated in the pre and post--processing of theprocessing of thecommercial code Straus7commercial code Straus7


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KLJUKLJUNEREINEREI -- KKEYWORDSEYWORDS

omota zgradeomota zgrade nehomogeni zidnehomogeni zid prenos toploteprenos toplote

matematiki modelmatematiki model numerika simulacijanumerika simulacija energetska efikasnostenergetska efikasnost mmetodaetoda--konakonanihnih

elemenataelemenata KGH sistemKGH sistem CAD, CAECAD, CAE UU--vrednostvrednost

building envelopebuilding envelope nonnon--homogenous wallhomogenous wall heat transferheat transfer

mathematical modelmathematical model numerical simulationnumerical simulation energy efficiencyenergy efficiency finite element methodfinite element method CAD, CAECAD, CAE HVACHVAC UU--valuevalue


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LITERATURALITERATURA -- REFERENCESREFERENCES Hellen T. How to Use Elements Effectively. NAFEMS LtdHellen T. How to Use Elements Effectively. NAFEMS Ltd he International Association forhe International Association forEngineering Analysis Community, http://www.nafems.org, 2002Engineering Analysis Community, http://www.nafems.org, 2002

G+DComputing, Straus7, Finite element analysis system software package, AustraliaG+DComputing, Straus7, Finite element analysis system software package, Australiahttp://www.strand.aust.comhttp://www.strand.aust.com

Mijuca D. On hexahedral finite element HC8/27 in elasticity, Computational Mechanics, 33Mijuca D. On hexahedral finite element HC8/27 in elasticity, Computational Mechanics, 33(2004), 6, pp 466(2004), 6, pp 466--480480

Mijuca D, iberna A, Medjo B. A New multifield finite element method in steady state heatMijuca D, iberna A, Medjo B. A New multifield finite element method in steady state heatanalysis. Thermal Science, 2004; accepted for publishinganalysis. Thermal Science, 2004; accepted for publishing

Todorovi B, Projektovanje postrojenja za centralno grejanje, Mainski fakultet UniverzitetaTodorovi B, Projektovanje postrojenja za centralno grejanje, Mainski fakultet Univerzitetau Beogradu,1966u Beogradu,1966

Todorovi M, ivkovi B. Prednosti numerike simulacije termikog ponaanja zgrade priTodorovi M, ivkovi B. Prednosti numerike simulacije termikog ponaanja zgrade priprojektovanju sistema za klimatizaciju, Zbornik radova Trideset drugog kongresa oprojektovanju sistema za klimatizaciju, Zbornik radova Trideset drugog kongresa ogrejanju, hlaenju i klimatizaciji, Beograd, 2001grejanju, hlaenju i klimatizaciji, Beograd, 2001

Balocco C, A simple model to study a ventilated facade energy performance. Energy andBalocco C, A simple model to study a ventilated facade energy performance. Energy andBuildings, 34 (2002) pp. 469Buildings, 34 (2002) pp. 469--475475

Mijuca D, Gajic D, Vukobrat M. ThreeMijuca D, Gajic D, Vukobrat M. Three--dimensional finite element method in energeticdimensional finite element method in energetic

efficiency of buildings Termotehnika, accepted for publication (in Serbian)efficiency of buildings Termotehnika, accepted for publication (in Serbian) CEN. 1996. Building components and building elementsCEN. 1996. Building components and building elements -- Thermal resistance and thermalThermal resistance and thermal

transmittancetransmittance -- Calculation method. European Committee for Standardization, rue deCalculation method. European Committee for Standardization, rue deStassart36, BStassart36, B--1050 Brussels, Belgium. Ref. No. EN ISO 6946:1996.1050 Brussels, Belgium. Ref. No. EN ISO 6946:1996.

Bazjanac V. Building energy performance simulation as part of interoperable softwareBazjanac V. Building energy performance simulation as part of interoperable softwareenvironments, Building and Environment, 39 (2004), 8, pp. 879environments, Building and Environment, 39 (2004), 8, pp. 879--883883

CEN. 1995. Thermal bridges in building constructionCEN. 1995. Thermal bridges in building construction -- Heat fows and surface temperaturesHeat fows and surface temperatures-- Part1: General calculation methods. European Committee for Standardization, rue dePart1: General calculation methods. European Committee for Standardization, rue deStassart36, BStassart36, B--1050 Brussels, Belgium. Ref. No. EN ISO 102111050 Brussels, Belgium. Ref. No. EN ISO 10211--11


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METODA KONANIH ELEMENATAMETODA KONANIH ELEMENATA

FIN

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THOD 33--DD metoda konanih elemenatametoda konanih elemenata koristi se zakoristi se za analizanalizuustacionarnogstacionarnog problemaproblema prostiranja toplote krozprostiranja toplote kroznehomogeninehomogeni omota zgradeomota zgrade

33--D finite element method is used for the analysis ofD finite element method is used for the analysis ofthe steadythe steady--state building inhomogeneous envelopestate building inhomogeneous envelope

heat transferheat transferPlease note that present research is now standard in thePlease note that present research is now standard in the

developed countries !!!developed countries !!!

Therefore in this presentationTherefore in this presentation -- nothing is new or before time,nothing is new or before time,

except the use of original mixed FE approach!except the use of original mixed FE approach!


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METODA KONANIH ELEMENATAMETODA KONANIH ELEMENATA

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THOD? A_ a _ a!K T F

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2 FEAmethods

Primal approach

Software package Straus7

Mixed approachOriginal in-house software FEMIX


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SAVREMENO PROJEKTOVANJE ZGRADASAVREMENO PROJEKTOVANJE ZGRADASTATE OF THE ART IN THE BUILDING DESIGNSTATE OF THE ART IN THE BUILDING DESIGN

The calculation of temperature and heat flow throughThe calculation of temperature and heat flow throughthe walls, windows and roof of a building is the firstthe walls, windows and roof of a building is the first

step instep in estimates of energy efficiency of buildings, asestimates of energy efficiency of buildings, aswell as inwell as in preventing problems arising from thermalpreventing problems arising from thermalstresses and condensation.stresses and condensation.

ProraProraun temperature i toplotnog fluksa kroz zidove,un temperature i toplotnog fluksa kroz zidove,prozore i krovove zgrada je prvi korak proceni uprozore i krovove zgrada je prvi korak proceni uenergetske efikasnosti zgrade, kao i u preventivienergetske efikasnosti zgrade, kao i u preventivi

problema koji nastaju usled termalnih napona iproblema koji nastaju usled termalnih napona ikondenzacije.kondenzacije.

[1] Canadian Building Digest 52: Heat Transfer at Building Surfaces


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Numerical examplesNumerical examples

Heat flow through inhomogeneous wallHeat flow through inhomogeneous wall

To determine heat losses throughout the structures. Heat flow through a cornerHeat flow through a corner

Investigation of dependence of heat transfer coefficient (Uvalue)on the material properties of wall components.

[3] CEN. 1995. Thermal bridges in building construction - Heat fows and surface temperatures -Part1: General calculation methods. European Committee for Standardization, Ref. No. EN ISO

10211-1

[2] CEN. 1996. Building components and building elements - Thermal resistance and thermaltransmittance - Calculation method. European Committee for Standardization, Ref. No. EN ISO6946:1996.

To investigate change of heat losses if the thermally efficientmaterials are used the thermalvision camera effects

Four storey buildingFour storey building


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Heat flow through inhomogeneous wallHeat flow through inhomogeneous wallgeometrygeometry

The inhomogeneous wall build of light expanded clay aggregateblock filled with polystyrene, mortar, with or withoutmineral wool isconsidered.


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Heat flow through inhomogeneous wallHeat flow through inhomogeneous wallnumerical results and convergencenumerical results and convergence


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Without mineral wool strip

With mineral wool strip


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Heat flow through a cornerHeat flow through a corner

This example deals with heat flow through a cornerThis example deals with heat flow through a cornerand a single floor.and a single floor.


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Temperature Straus7 Temperature FEMIX


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From the results obtained, we may see that with acomputationally inexpensive mesh (7 sec) we successfullymeet the target results.

Heat Flux Straus7 Heat Flux FEMIX


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Heat flow through a cornerHeat flow through a corneranimationanimation

Heat Flux Straus7


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FourFour--storey buildingstorey buildingthermalvision camera like effectsthermalvision camera like effects

By the use of different material on the the last two floorsBy the use of different material on the the last two floors

of buildings envelopeof buildings envelope energetic efficiency is increasedenergetic efficiency is increased


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ConclusionConclusion DDescribedescribed FEAFEA methodmethodss aarere cheapcheaperer, more efficient and, more efficient and

preciseprecise,, in regard to standardin regard to standard handhand--outout calculatingcalculatingmethods.methods.

ItIt gives wide opportunities in the design process of thegives wide opportunities in the design process of the

buildings and prediction of its thermal behavior.buildings and prediction of its thermal behavior. TheThe threethree--dimensional visualization of the calculateddimensional visualization of the calculated

temperature and heat fluxtemperature and heat flux fields is providedfields is provided..

OOptimization of the cost/energy efficiency rate is enabledptimization of the cost/energy efficiency rate is enabledin the design process of the buildings envelope and HVACin the design process of the buildings envelope and HVACsystem.system.


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CONTACTCONTACT

Dr. Dubravka MijucaDr. Dubravka MijucaFaculty of MathematicsFaculty of Mathematics

Department of MechanicsDepartment of Mechanics

University of BelgradeUniversity of BelgradeStudentski trg 16Studentski trg 1611000 Belgrade11000 Belgrade

P.O.Box 550P.O.Box 550Serbia and MontenegroSerbia and Montenegro

Phone 064Phone 064--1515--1212--780780www.matf.bg.ac.yu/~dmijucawww.matf.bg.ac.yu/~dmijuca

QUESTIONSQUESTIONS

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