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8/3/2019 Jet Za Internet Celotna - Volume 2 - Issue 3 - August 2009
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8/3/2019 Jet Za Internet Celotna - Volume 2 - Issue 3 - August 2009
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8/3/2019 Jet Za Internet Celotna - Volume 2 - Issue 3 - August 2009
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JOURNAL OF ENERGY TECHNOLOGY
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VOLUME 2 / Issue 3
RevijaJournalofEnergyTechnology(JET)jeindeksiranavnaslednjihbazah:INSPEC,CambridgeScientific Abstracts: Abstracts in New Technologies and Engineering (CSA ANTE), ProQuest'sTechnologyResearchDatabase.The JournalofEnergyTechnology (JET) is indexedandabstracted in the followingdatabases:INSPEC
,CambridgeScientificAbstracts:Abstracts inNewTechnologiesandEngineering (CSA
ANTE),andProQuest'sTechnologyResearchDatabase.
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JOURNAL OF ENERGY TECHNOLOGY
Ustanovitelji/FOUNDERSFakultetazaenergetiko,UNIVERZAVMARIBORU/
FACULTYOFENERGYTECHNOLOGY,UNIVERSITYOFMARIBOR
Izdajatelj/PUBLISHER
Fakultetazaenergetiko,UNIVERZAVMARIBORU/
FACULTYOFENERGYTECHNOLOGY,UNIVERSITYOFMARIBOR
Izdajateljskisvet/PUBLISHINGCOUNCIL
Zasl.Prof.dr.DaliONLAGI,
UniverzavMariboru,Slovenija,predsednik/UniversityofMaribor,Slovenia,President
Prof.dr.BrunoCVIKL,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.ddr.DenisONLAGI,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.dr.DaniloFERETI,
SveuiliteuZagrebu,Hrvaka/UniversityinZagreb,Croatia
Prof.dr.RomanKLASINC,
TechnischeUniversittGraz,Avstrija/GrazUniversityOfTechnology,Austria
Prof.dr.AlfredLEIPERTZ,
UniversittErlangen,Nemija/UniversityofErlangen,Germany
Prof.dr.MilanMARI,UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.dr.BranimirMATIJAEVI,SveuiliteuZagrebu,Hrvaka/UniversityinZagreb,Croatia
Prof.dr.BorutMAVKO,
IntitutJoefStefan,Slovenija/JozefStefanInstitute,Slovenia
Prof.dr.GregNATERER,
UniversityofOntario,Kanada/UniversityofOntario,Canada
Prof.dr.EnrikoNOBILE,
UniversitdegliStudidiTrieste,Italia/UniversityofTrieste,Italy
Prof.dr.IztokPOTR,UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.dr.AndrejPREDIN,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Profdr.MatjaRAVNIK,IntitutJoefStefan,Slovenija/JozefStefanInstitute,Slovenia
Prof.dr.JoeVORI,UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.dr.KoichiWATANABE,
KEIOUniversity,Japonska/KEIOUniversity,Japan
Odgovorniurednik/EDITORINCHIEF
AndrejPREDIN
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Uredniki/COEDITORS
JurijAVSEC
GorazdHREN
MilanMAR
I
IztokPOTR
JanezUSENIK
JoeVORI
JoePIHLER
Urednikiodbor/EDITORIALBOARD
Prof.dr.JurijAVSEC,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.ddr.DenisONLAGI,
UniverzavMariboru,Slovenija/UniversityofMaribor,SloveniaProf.dr.RomanKLASINC,
TechnischeUniversittGraz,Avstrija/GrazUniversityOfTechnology,Austria
Prof.dr.JurijKROPE,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.dr.AlfredLEIPERTZ,
UniversittErlangen,Nemija/UniversityofErlangen,Germany
Prof.dr.BranimirMATIJAEVI,
SveuiliteuZagrebu,Hrvaka/UniversityofZagreb,Croatia
Prof.dr.MatejMENCINGER,
UniverzavMariboru,
Slovenija
/University
of
Maribor,
Slovenia
Prof.dr.GregNATERER,
UniversityofOntario,Kanada/UniversityofOntario,Canada
Prof.dr.EnrikoNOBILE,
UniversitdegliStudidiTrieste,Italia/UniversityofTrieste,Italy
Prof.dr.IztokPOTR,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.dr.AndrejPREDIN,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.dr.AleksandarSALJNIKOV,
UniverzaBeograd,Srbija/UniversityofBeograd,Serbia
Prof.dr.BraneIROK,
UniverzavLjubljani,Slovenija/UniversityofLjubljana,Slovenia
Prof.ddr.JanezUSENIK,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.dr.JoeVORI,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Doc.dr.TomaAGAR,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Doc.dr.FrancERDIN,
UniverzavMariboru,Slovenija/UniversityofMaribor,Slovenia
Prof.dr.KoichiWATANABE,KEIOUniversity,Japonska/KEIOUniversity,Japan
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Tehnikapodpora/TECHNICALSUPPORTJankoOMERZU
SonjaNOVAK
Izhajanjerevije/PUBLISHINGRevijaizhajatirikratletnovnakladi300izvodov.lankisodostopninaspletnistranirevije
www.fe.unimb.si/si/ejet/index.php.
Thejournalispublishedfourtimesayear.Articlesareavailableatthejournalshomepage
www.fe.unimb.si/si/ejet/index.php.
Lektoriranje/LanguageEditingTerryT.JACKSON
Produkcija/PRODUCTIONVizualnekomunikacijecomTECd.o.o.
Oblikovanjerevijeinznakarevije/JOURNALANDLOGODESIGNAndrejPREDIN
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Slovenijanapotivnizkoogljinodrubo?
Trajnostni razvoj energetike v Slovenijimora biti oblika razvoja, ki zadoa potrebam poenergiji, ne da bi pri tem ogroal okolje in s tem monosti ivljenja in razvoj prihodnjim
generacijam,da prav tako zadostijo svojim potrebam.V tej smeri (vsajupam tako)je bilspisan tudi dokument Republike Slovenije, sveta vlade RS za konkurennost, StratekidokumentsektorskerazvojneskupineENERGETIKAINTRAJNOSTNIVIRIENERGIJE,zdne10
novembra,2008.Vodseku,kjernavajapremogje zapisano,dapremogdanespredstavlja
pomembenprimarnivirzaproizvodnjoelektrineenergije(vstrukturiproizvodnjepriblinotretjino proizvodnje elektrine energije v RS). Predvideno je, da se bo v prihodnosti
proizvodnjaelektrineenergijeizpremogadoleta2030celopodvojila!?Vduhuzapisanega
stratekegadokumentamebegaodloitev vladeRS, ki sejeodloila za izgradnjonovegablokaTE6,zzastarelotehnologijoseiganjapremogovegaprahupripovianemtlaku(CCT).Tatehnologijasejepojavilav90.letihprejnjegastoletja.(kombiniraniplinskoparniproces
PCCinFBCtehnologiji).eboljerazmislimoinobpoznavanjutrendovrazvoja,bisemoralavlada odloiti vsaj za IGCC (Integrated Gasification Combined Cycle) tehnologijo, ki bi
omogoalaVelenjskiotanjski regijinadaljnji razvojnapodrojuenergetike, tudikobodoizrpanezalogepremogavVelenju.Grezakombiniranplinskoparniprocesspredhodnim
uplinjanjempremoga.Prednosttetehnologijejevmonostiuporabealternativnihgoriv,kotso: lesnabiomasa,odpadnaolja,naftniodpadki, komunalniodpadki.Ob temje zanimiva
monost uporabe zemeljskega plina ob prikljuitvi Slovenije na Juni tok ruskegaplinovoda. V tem primeru je tehnoloki del elektrarne sestavljen iz turbin, ki lahkokoristijo razline vrste plinastih goriv. Ta novozgrajen blok bi v tem primeru deloval v
strukturitrajnostnegaenergetskegarazvojaSlovenije.Strukturnobilahkobilvkljuenvsedo
takrat,kobodotehnologijauporabeobnovljivihvirovenergije(OVE)takorazvita,dabomov
Slovenijilahkopokrilivseenergetskepotrebe.
IsSloveniaonthewaytolowlevelcarbonsociety?
Sustainable energy development in Slovenia should perform as a development to fulfil
today'senergyneedswithoutcompromisingtheenvironmentand,aboveall,giving future
generations the possibilities of quality life and development of their own needs. In this
direction (at least Ihopeso)waswrittentheStrategyPlanofDevelopmentofEnergyand
SustainableEnergySourcesby theCouncilonCompetitivenessof theRepublicofSlovenia
(dated10November,2008).Inthecoalsection, it isstatedthattodaycoal isan importantprimarysourceforelectricityproduction(representingonethirdofelectricityproductionin
Sloveia).Itisenvisagedthatinthefuture,by2030,electricityproductionfromcoalwillhave
doubled. In the spirit of the above strategy document, I am very surprised by the
Government's decision for the implementation of a new TES 6 block, with outdated
technology burning pulverised coal at an elevated pressure. This technology is from the
1990s(combinedgassteamprocessPCCandFBCtechnology).Abetterconsiderationonthe
partofthegovernment,withtheknowledgeoftodaysdevelopmenttrends,wouldbetheIGCC (Integrated Gasification Combined Cycle) technology, allowing the Velenjeotanjregion further development in the energy field, after the coal reserves in Velenje are
exhausted. IGCC is a combined gassteam process with previous coal gasification. Theadvantage of this technology is in its possibility of using alternative fuels such aswood
biomass,wasteoil, andmunicipalwaste. Italsohas theopportunityofusingnatural gas
when Slovenia is connected to the South Stream pipeline from Russia. In this case, the
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technology of the powerplant consists of gas turbines,which can benefit fromdifferenttypes of gaseous fuels. This newly built block could be integrated into the structure ofsustainable energy development, providing much needed energy until the technology ofalternativeenergysourceswillbefullydevelopedtomeetallenergyneedsinSlovenia.
Krko,August2009
AndrejPREDIN
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Table of Contents /
Kazalo
Nuclearrenaissanceasaviablesolutionforreducinggreenhousegasestheenvironmentalimpactofdifferentenergytechnologies/Jedrska energija zmanjuje emisije toplogrednih plinov vplivi razlinih tehnologij za
proizvodnjoelektrineenergijenaokolje
Tomaagar,RobertBergant,SamoFrst................................................................................11
Mathematicalmodelofthepowersupplysystemcontrol/Matematinimodelupravljanjaenergetskegasistema
JanezUsenik...............................................................................................................................29
The calculationof thermodynamicproperties forhydrochloric and copper compounds in ahydrogenproductionprocess/Izraun termodinaminih lastnosti v hidroklorovih in baker klorovih komponentah v procesu
proizvodnjevodika
JurijAvsec,GregF.Naterer,AndrejPredin...............................................................................47
InvestmentsinrenewableenergysourcesandcasesofgoodpracticesoffiscalstimulationinEU/InvesticijevobnovljiveenergetskevireinprimeridobrepraksefiskalnihspodbudvEUMejraFesti.................................................................................................................................65
Cavitationswirlattheentranceofcentrifugalpump/KavitacijskivrtinecnavstopuvradialnorpalkoAndrejPredin,BotjanGregorc,IgnacijoBilu..........................................................................85
Instructionsforauthors..............................................................................................................99
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JETVolume2(2009),p.p.1128
Issue3,August2009
http://www.fe.unimb.si/si/ejet/index.php
NUCLEAR RENAISSANCE AS A VIABLE
SOLUTION FOR REDUCING GREENHOUSE
GASES THE ENVIRONMENTAL IMPACTOF DIFFERENT ENERGY TECHNOLOGIES
JEDRSKA ENERGIJA ZMANJUJE EMISIJETOPLOGREDNIH PLINOV - VPLIVI
RAZLINIH TEHNOLOGIJ ZAPROIZVODNJO ELEKTRINE ENERGIJE NA
OKOLJE
Tomaagar,1,RobertBergant2,SamoFrst3
Keywords:emissions,environment,technology,electricityproduction
Abstract
Climate change is happening and represents one of the greatest environmental, social and
economicthreats
facing
the
planet.
The
Intergovernmental
Panel
on
Climate
Change
(IPCC),
an
associationofscientistsfromallovertheworld,cametotheconclusionthatthemainreasonistheenhancedgreenhouseeffect.
Tomaagar,PhD.,GENenergija,d.o.o.,Tel.:+386(7)4910132,Fax:+386(7)4901118,
Emailaddress:[email protected] Tomaagar,PhD.,UniversityofMaribor, FacultyofEnergyTechnology, Tel.:+386 (7)62022102
Robert
Bergant,
PhD.,
GEN
energija,
d.o.o.,
Tel.:
+386
(7)
491
0404,
Fax:
+386
(7)
490
1118,
Emailaddress:[email protected],GENenergija,d.o.o.,Tel.:+386(7)4910136,Fax:+386(7)4901118,
Emailaddress:[email protected]
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PhD.Tomaagar,PhD.RobertBergant,SamoFrst JETVol.2(2009) Issue3
The production of electricity is, beside transportation, the most harmful contributor to the
enhancedgreenhouseeffect.Unfortunately,themajorityofelectricityproduction isstillbased
onacombustionoffossilfuels,e.g.coal,oilandgas.Renewablesourcessuchashydro,solaror
wind
are
becoming
increasingly
preferable.
Nuclear
energy
is
also
an
important
low
carbon
energy sourcewith insignificant impacton theenvironment. Itswholecycleemissionsareat
leastaslowastheemissionsofabovementionedrenewablesources.Besidesitsenvironmental
benefits,nuclearenergyhasalsoeconomical, spatial and socialadvantagesover someother
renewablesources.
The purpose of the article is to present integrated environmental impacts for different
technologychainsused forelectricityproduction.Two separateand independent studiesare
shown in this intention.A summaryofdifferent studies,madebyOrganization forEconomic
CooperationandDevelopment (OECD),presents thecomparisonofenvironmental impactsof
differenttechnologychainsfortheelectricityproductionsector,basedondatasuppliedbythe
OECD organizations members. The study of the company GEN energija is focused on thecomparison of environmental impacts of different technology chains that are feasible for
electricity production in Slovenia, i.e. technologies such as nuclear, coal, gas, different
renewablesourcesandamixtureofrenewablesources,whichincludethehydro,biomass,wind
andphotovoltaicproduction.
Theevaluationoftheenvironmentalimpactsfordifferentenergytechnologiesisimplemented
withinradius10kmoftheexistinglocationofNuklearnaelektrarnaKrko(NEK)site,inorderto
evaluateandpresenttheenvironmentalconsequencesofdifferentelectricalpowerproducing
energy technologies.Electricalpowerproduction from fourpotentialnuclear reactordesigns,
imported coalfired power generation, combinedcycle gasfired generation, and renewable
power generation sources, including hydroelectric generation, solar photovoltaic generation,windgeneration,biomasscogeneration,andgeothermalelectricgenerationareconsidered.
Twoassumptionsforelectricalpowerproducingtechnologiesareaninstalledcapacityof1,100
MWeanda90%BaseloadCapacityFactor.Therenewablesourcesareevaluatedasaresource
mix (RESMix)andarenotcapable reaching the required90%BaseloadCapacityFactor. It is
assumedtohaveacombined34%BaseloadCapacityFactoriftheevaluationregionisexpanded
tothewholeofSlovenia.FortheRESMix,32%hydroelectricgeneration,36%windgeneration,
32% biomass cogeneration,
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NuclearRenaissanceasViableSolution forreducingGreenhouseGasesEnvironmentalImpactofdifferentEnergyTechnologies
goriv, ki imajonajvejidoprinos kemisijam toplogrednihplinov. Zaradipotrebpo znievanjuspecifinihemisijnapomembnostizopetpridobivatudijedrskaenergija,kisodivnizkoogljinoproizvodnjoenergije.Pravtakosonjeniskupnivplivinaokoljeindrubougodnejialivsajtako
ugodnikotvpliviobnovljivihvirov.
Namen prispevkaje prikaz celostnih vplivov na okolje pri proizvodnji elektrine energije pri
uporabi razlinih tehnologij.V tanamen staprikazanidve loeni inneodvisni tudiji, in sicerpovzetekrazlinihtudijmednarodneorganizacijezagospodarskosodelovanjeinrazvoj(OECD)in tudija podjetja GEN energija. Povzetek tudij organizacije OECD obravnava primerjavovplivov na okolje razlinih tehnolokih verig za pridobivanje elektrine energije na osnovipodatkov, ki jih organizaciji OECD posredujejo njene lanice. tudija GEN energije pa jeosredotoena na primerjavo vplivov na okolje obravnavanih tehnologij, ki so smiselne ter
izvedljive za proizvodnjo elektrine energije v slovenskem prostoru in sicer jedrske,premogovne,plinske,obnovljivihvirov inmeaniceobnovljivihvirov,medkaterespadavodna,biomasna,vetrnainfotovoltainaproizvodnja.
Oje obmoje prikazanih vplivov obsega 10km radij okoli obstojee lokacije NuklearneelektrarneKrko.Cilj tudijejeocenitev katera izmed tehnologijpredstavljanajnijocelostnoobremenitev okolja pri pasovni proizvodnji proizvodni elektrine energije na lokaciji ob
obstojeiNuklearnielektrarniKrko.Zahtevizanovoproizvodnoenotostainstaliranaelektrinamo1100MWeinfaktorrazpololjivostienote90%.Ocenjenoje,dameanicaobnovljivihvirovnemore zadostiti osnovni zahtevi faktorja razpololjivosti 90% pri instalirani elektrinimoi1100MWe.Dosee levrednost34%,ob raziritvipredvidenegaobmojanacelotnoSlovenijo.Deleposameznetehnologijevmeaniciobnovljivihvirovpredstavlja32%vodna,36%vetrna,
32%biomasna,
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PhD.Tomaagar,PhD.RobertBergant,SamoFrst JETVol.2(2009) Issue3
1 INTRODUCTION
Climatechange
is
aresult
of
increasing
greenhouse
gas
emissions
and
growing
problem
that
requiresinterdisciplinarycooperationacrosstheworld.TheKyotoProtocolAlliancesignatories
havetheobjectiveofa20%greenhouseemissionsreductionin2020,comparedto1986levels.
The instrumentsforachievingthisaredifferentacrosscountries,but ingeneralallsignatories
havetobecomelowcarbonsocietiesinallareas.Anespeciallysensitiveandimportantareain
the transition to a lowcarbon society is the sectorof energyproduction,whichhas a large
contributiontogreenhousegasemissions.Therefore,itisimportantforeachcountrytohavea
detailedplanforthefurtherdevelopmentofthissector;thisalsohasan important impacton
theeconomicperformanceofthecountry.Itisimportanttopursuedevelopmenttowardslow
carbon,economicallyjustifiedandsustainabletechnologies.
2 ELECTRICITY PRODUCTION IN SLOVENIA
Theenergyproduction sectorcombinesheatproductionandelectricityproduction. In recent
years, Slovenias electricityproductionhasbeen insufficient, since annual average electricity
importhasreachedover20%.Suchhighinputlevelshavebeenreducingthecompetitivenessof
the domestic economy; therefore, new investments in the modernization of the electricity
productionaswellasexpansionofcurrentcapacityarenecessary.Amongthemost important
technologies forSlovenianelectricityproductionarenuclear, coal,gas,hydroand renewable
energysources
technologies.
Inaccordancewiththelegalcommitmentsregardingthereductionofgreenhousegasemissions
setby theEU202020objectives,whichcall for20% fewerGHGemissions,20% lower final
energy consumption and a 20% share of renewables in final energy consumption by 2020,
production economy resources aims, greater economic competitiveness and sustainable
developmentobjectives,andallproductiontechnologiesshouldbecomparedunderthesame
principle before the decision for a particular technology in the process of extending the
electricityproductioncapacityshouldbemade.Thecomparisonshouldbebasedonthesame
basicplatformaswellasontheevaluationofindividualtechnologies.
Slovenia
has
a
similar
procedure,
as
the
one
mentioned
above,
in
the
process
of
spatial
planning
called a strategic/comprehensive environmental impact assessment and an environmental
impactassessment.Thesetwoprocessesarenotacomparisonwithothertechnologiesandthe
choiceof theoptimal solution,butonlyevaluationof theenvironmentalacceptabilityof the
individual plans without intervention on site. The Republic of Slovenia therefore has no
legislation for the comparison of technologies thatwould serve foroptimal decisions in the
processofproductioncapacityexpansion.
Similar comparison studiesaremore common abroad.One such stuywas completedby the
OrganizationforEconomicCooperationandDevelopment(OECD),whichhas largestdatabase
for the comparison of technologies based on energy production factors. The analyses
performedby
the
OECD
were
based
on
current
actual
data,
delivered
by
countries
all
around
theworld.Therefore,wewanttopresentthemostimportantresultsofsomeOECDanalysisas
wellasourstudyofenvironmental impactsofdifferentenergy technologyoptions,enhanced
withanalysisanddata,basedonglobalscaleexpertise.
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NuclearRenaissanceasViableSolution forreducingGreenhouseGasesEnvironmentalImpactofdifferentEnergyTechnologies
GEN energija is an energy company thatwants to play an active role in the new cycle of
investment in new electricity production capacity in Slovenia. To enhanceGENs technology
decision with substantiated facts, the study of environmental impacts of different energy
technologyoptions
for
electricity
production
in
Slovenia
[1]
was
ordered
from
an
internationally
recognized engineering firm, the Washington Group International (a division of URS
Corporation),whichhasastrongteamofenvironmentalexperts.
3 RESULTS OF OECDs TECHNOLOGY COMPARISONS STUDIES
TheOrganization forEconomicCooperationandDevelopment (OECD)made thecomparison
analysesofdifferenttechnologychains[2].Thesestudieswerebasedon informationsupplied
by the organizations individualmember states, aswell as by countries that are not OECD
members.Thestudies included theenvironmental,socialandeconomicaspectsof theentireenergychainfromthebeggingtotheend(lifecycleassessmentLCA).
Sciencebased, industrial, international lifecycleassessment (LCA)and lifecyclemanagement
(LCM)datafromallovertheworldcanbefoundonhttp://www.ecoinvent.org/.Theecoinvent
Centre is theworld's leading supplierof consistent and transparent life cycle inventory (LCI)
dataofknownquality.TheresultspresentedbelowarebasedonreportsofDonesetal.[46].
Environmental (greenhouse gas emissions, SOX, NOX, nonradioactive waste, land use and
accidentrisks),social(humanhealthimpacts)andeconomicindicators(useofenergyandnon
energeticresources)arepresented.
3.1 Greenhouse gas emissions
Greenhousegasemissionshaveaglobalimpactontheenvironment,withamajorroleinglobal
warming and climate change. Figure1 shows a comparisonof greenhouse gasemissions for
eachelectricityproductiontechnologychain.
Foreachtechnology,theaveragedatavalueispresentedtogethernetmaximumandminimum
values.Themaxandminvaluesarealsolabeledwithcountrycodes,indicatingtheoriginofthe
data.
Emissions are expressed in kgCO2 equivalent per unit of generated energy. Lignite has the
highestemissions
in
the
UCTE
(The
Union
for
the
Co
ordination
of
Transmission
of
Electricity)
average, slightly above 1.2 kgCO2eq./kWh; coal has a slightly lower level, with the UCTE
average of around 1.07 kgCO2eq./kWh. The chain of natural gas has the lowest level of
emissionsoffossilsystemswithUCTEaverageslightlyabove0.6kgCO2eq./kWhandaround0.4
kgCO2eq./kWh for cogeneration.Greenhouse gas emissions from the nuclear chain and the
renewableenergy sources chains are twoordersofmagnitudebelow theemissionsof fossil
fuelschains.TheUCTEaverage fornuclear isabout8gofCO2eq./kWh,5gCO2eq./kWh for
hydro,11gCO2eq./kWhforcostalwindturbines,14gCO2eq./kWhforoffshorewindturbines,
60gCO2eq./kWhforPV(photovoltaics) [7]and100gCO2eq./kWhforwoodcogeneration.
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PhD.Tomaagar,PhD.RobertBergant,SamoFrst JETVol.2(2009) Issue3
Figure1:CO2equivalentgreenhousegasemissionsforeachelectricityproductiontechnologychains
3.2 Other atmospheric emissions
Whilethegreenhousegasemissionshaveimpactsonglobalwarmingandclimatechange,SOX,
andNOXhavemoreregionalandlocalimpacts.Inaddition,thesepollutantsareimportantalso
fromregularpointofview.ThereareSEVESOEUandnationalregulationsandEnvironmental
protectionActlimitingtheSOXandNOXemissions.
SO2emissionsaredominatedbythedirectemissionsfrompowerplants.Thelevelofemissions
dependsonthesulfurcontentoffuelsandtheemissioncontrolcriteria..AsshowninFigure2
brown
coal
and
oil,
with
a
UCTE
average
of
around
7
g/kWh,
have
the
highest
level
of
SO2
emissions.HardcoalhasaUCTEaverageofabout3g/kWh,whilethechainofnaturalgashasa
UCTEaverageofabout0.2g/kWhemissions,whichistheminimumbetweenthechainsoffossil
fuels.TherateofSO2emissions inthenuclearchainandtherenewableenergysourceschains
aremorethantwoordersofmagnitudebelowtheemissionsoffossilfuelschains.Hydroand
windhavethelowestlevelofSO2emissionsamongrenewableenergysourceschains.
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NuclearRenaissanceasViableSolution forreducingGreenhouseGasesEnvironmentalImpactofdifferentEnergyTechnologies
Figure2:SO2emissionsforeachelectricityproductiontechnologychains
Oilhas thehighest levelofNOXemissionsofall theenergy chain,with theUCTE averageat
around2.8
g/kWh
(see
Figure
3).
Levels
of
NOXemissions fromcoalchainsareslightly lower,
with theUCTEaverageofaround2.2g/kWh.Thechainofnaturalgashas the lowest levelof
NOXemissionsamongfossilsystemswithaUCTEaverageofaround0.7g/kWh.ThelevelofNOX
emissionsfornuclear,hydroandwindtechnologyisuptotwoordersofmagnitudelowerthan
therateoffossilfuelsNOXemissions.
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Figure3:NOxemissionsforeachelectricityproductiontechnologychains
3.3 Non-radioactive waste
Figure4:Productionofnonradioactivewastefordifferentenergychains
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ProductionofnonradioactivewastefordifferentenergychainsisshowninFigure4.Hardcoal
and lignite power chains produce the largest quantities of nonradioactive waste with UCTE
averagesofaround1.18kg/kWh.Withinthelignitechain,amajorcontributionisashproduced
duringpower
plant
operation,
while
within
hard
coal
chains
asubstantial
proportion
of
the
wastecomesfromexcavation.Thenaturalgasandnuclearchainsproduceaminimumquantity
ofnonradioactivewaste.Theamountofnonradioactivewasteinhydroandwindchainsistwo
ordersofmagnitudehigherthanforthenuclearchain.
3.4 Land use
Landuse, shown inFigure5, ismeasured inm2/kWhand refers to areas which are modified
from natural or primary habitat to different habitat states as a result of human intervention
insidethe
whole
energy
chain.
Figure5:LandusefordifferentenergychainsDue to the forestryand logging thatarerequired for theuseofbiomass,woodcogeneration
requires the largest land use, followed by coal and oil energy chains. Exploitation and
productionofoil,aswellastheextractionofhardcoal,requireconsiderablespace.
3.5 Accident risks
The data are derived from a comprehensive severe accidents databases, ENSAD (the Energy
relatedSevere
Accident
Database),
with
an
emphasis
on
the
energy
sector.
Databases
enable
a
comprehensiveanalysisofaccidentsrisks,whicharenotlimitedtoelectricitypowerplantsbut
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covertheentireenergychain, includingexploration,extraction,processing,storage,transport
andwastemanagement.
ENSAD currently contains 18,400 accidents, of which approximately 89% occurred between
1969
and
2000.
Human
causes
of
accidents
represent
70%
of
all
accidents,
while
natural
disastersrepresent30%.Allaccidentsrelatedtoenergyrepresenting35%ofallaccidentsand
50%ofhumancausedaccidents.Among theenergyassociatedaccidents, theshareofsevere
accidentsis49%,amongwhich67%accidentsarewithfiveormorefatalities.Accidentsthatare
not related to energy and natural disasters have secondary importance within ENSAD. More
detaileddatacanbeseeninTable1.
Table1:ENSADreportoverviewforaccidentswithatleastfivefatalitiesforperiodfrom1969to2000
Energy OECD EU15 nonOECD
chain
Accidents Fatalities
Accidents Fatalities Accidents Fatalities
Coal 75 2,259 11 234 102
1,044(a)
4,83118,017
(a)
Oil 165 3,789 58 1,141 232 16,494
Naturalgas 80 978 24 229 45 1,000LPG 59 1,905 19 515 46 2,016
Hydro 1 14 0 0 10 29,924(b)
a)Firstlinewithout China,secondlinewithChina
b)BanqiaoandShimantandamfailurestogethercaused26,000fatalities
Figure6:SevereaccidentsindicatorsforOECDandnonOECDcountriesforperiodfrom1969to2000
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ChinahasexceptionalaccidentsstatisticforhydroastheresultoftheBanqiaoandShimantan
dam failures,whichoccurred in1975.Bothdamswerebrokenasaresultofconstructionand
engineeringerrors,whichbecamecriticalduringahugefloodin1975.Asaresultofthesetwo
damfailures,
62
dams
were
destroyed
flooding
an
area
of
55
km
by
15
km.
Some
reports
indicatethetotalnumbersoffatalitiesaresomewherebetween90,000and230,000[3].
Figure6representsthefatalitiesnormalizedtotheunitofenergyproducedperGWeyear.The
highestvalueoffatalitieswascausedbyLPGenergychain,duetothedangerofhandlingLPG.
ThesecondhighestvalueiswiththehydroenergychainduetotheabovementionedBanqiao
andShimantandamfailures.Thecoalenergychainisonthirdplaceduetotheminingprocess,
whichisespeciallydangerousinChina,wheresafetyisatlowlevel.ValuesforOECDandEU15
memberstatesarealmostthesamefortheselectedtechnologychainduetothehighersafety
culturelevel.
3.6 Human health impacts from normal operation
Effectsonhumanhealth inrelationtothenormaloperationcanberepresentedbymortality.
Mortalityisdefinedasareductionofexpectationsoflife,expressedintermsofyearsoflifelost
(YOLL). The consequences of diseases could be evaluated, but it is difficult to combine in a
completelyobjectivemanner,becausetheendresult,yearsoflifelost,andpopulationvalues,
providedbymonetaryrelationschangedramaticallydependingon localconditions,densityof
thepopulation,theprospectof lifeexpectancyandthemedicalassistancethat isavailablefor
theaffectedpopulation.Figure7showsanexampleofmortalitythatistheresultofemissions
ofmajorpollutants,specifictothecurrentGermanenergychains,alsotakingintoaccountthe
radioactiveemissions
[8].
The
methodology
for
assessment
of
health
impacts
was
developed
within the European ExternE project and later revised by Friedrich et al. [9] and Bickel and
Friedrich[10].
Figure7:MortalityassociatedwithnormaloperationofGermanenergychainsintheyear2000
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Nuclear,windandhydroenergychainshavelowmortalityinrelationtotheirnormaloperation.
Themortality fornatural gas and solar PV chainsare comparable. Fossil systemsother than
natural gas indicate a greater impact than other options.Mortality due to air pollution is
strongly
dependent
on
the
location,
which
determines
the
number
of
people
affected
by
the
emissionsand the technology,whichwilldetermine thequantityofemissions.The figure for
YOLLpertonofSO2releasedinChinaisonaveragealmostseventimeshigherthantheaverage
of the EuropeanUnion,mainly due to drastic differences in population density around the
plants.
3.7 Use of energy resources
Fossilresourceshavebeenselectedasan indicatorofenergyproductuseduetotheir lackof
stock andusefulnesswithinother sectors.Thishas adirect impacton the longtermenergy
sustainability,ifwe
intend
to
preserve
resources
for
chemical
and
other
uses,
and
not
just
for
energy.
Theconsumptionoffossilfuelsforelectricityproductiondifferentchainsaregiven inFigure8
andcoversthememberstatesofUCTEandsomeotherEuropeancountries.
Figure8:RequirementsoffossilresourcesfordifferentenergychainsConsumptionis,ofcourse,muchgreaterinthefossils,coal,gasandoilchains,thaninthecase
ofnuclearandrenewableenergysourceschains.Chainswithcombinedgaspowerplantshave
the lowest consumption of fossil chains, which is expected due to their effectiveness.
Renewableenergysourcesandnuclearchainsindirectlyusefossilfuelsforheatandelectricity
consumptionwithintheirchains.Hydroenergyhasthelowestconsumptionoffossilfuels.
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3.8 Use of non-energy resources
Usageofothernonrenewableresourcessuchasfossilfuelsanduraniumisthemeasurementof
electricityproduction
impact
to
the
environment,
and
therefore
is
included
in
economic
indicators.Copperwasselectedasthereferencematerialforthe limitedmetalresources,but
the consumption of othermaterials could also be used. Figure 9 shows the comparison of
copperneedsforvariouselectricitytypesofproduction inUCTEcountries.SolarpanelsorPV
showsthehighestneedforcopper,whichexceededtheneedsoftheotherchainsbyafactorof
five; solar is followed by the wind energy chain. Chains of fossil fuels, nuclear, and wood
cogenerationhavecomparableneedsforcopper,whicharelowerbyafactorof10comparedto
PV.Hydroenergyshowsthelowestrequirementsforcopper.
Figure9:Requirementsofcopperfordifferentenergychains
4 ENVIRONMENTAL IMPACTS OF DIFFERENT ENERGYTECHNOLOGY OPTIONS FOR ELECTRICITY PRODUCTION INSLOVENIA
Sloveniaisinthedecisionmakingprocessforitsfutureenergyproductionsectordevelopment.
Thedecisionforaspecifictechnologymustbebasedonfactsderivedbyenvironmentalimpact
comparisons liketheOECDstudies,as indicatedabove.Therefore,GENenergijahasordereda
widened environmental impact assessment study with comparisons of different technology
optionsforelectricityproductioninSlovenia.
Thisstudy
was
done
by
URSs
team
of
environmental
experts.
The
basic
position
was
the
technology isavailable inSloveniaand, ifpossibletobe locatedwitharangeof10kmaround
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Table2:Summaryofenergytechnologyimpacts
The summary table (Table3) of the sitespecificdecision factorswas used for assessing and
ranking the relative feasibilityanddesirabilityof the fourprimaryenergy technologyoptions
evaluatedin
the
study.
The summary table decision factors are land requirements per kWh, green house gases per
kWh,energysupplysecurity,baseloadcapacity factor,ability to locate in regionof influence,
cost per kWh, existing infrastructure, uncertainty risk, economictechnology feasibility,
aggregateenvironmentalimpacts.Allthesedecisionfactorswereevaluatedaccordingtoseven
differentrankings:Xexcellent,Ggood,Ffair,Ppoor,Uundesirable,Nnotavailableor
notapplicableandSwherewassourcedepended.
Nuclear technology is evaluated as the most optimal technology for the expansion of
productioncapacities
in
Slovenia.
Renewable energy sources, whose potential in Slovenia is already heavily utilizing, are
estimatedtobe fair toundesirableandcanserveonlyascomplementary technologiestothe
basicscenariofortheexpansionofproductioncapacity.
Nuclear
ImportedCoa
l
NaturalGas
CombinedCycle
Hydroelectric
Solar
(Photovoltaic)
W
ind
Biomass
Cogeneration
Geothermal
ZeroOption
RESMixOption
*
Climate B E D A-B B-C C C C X C
Ai r B D D A A B C B A C
Surface Water and Groundwater C C C B A A C B B C
Noise C B B B B C B B A C
Ground and Agricultural Surfaces B C-D C A A-D C C-D B-D B D
Landscape C C C A A-B C C C B C
Nature and Natural Areas C B-D B C-D B B-D B-D B B D
Waste M anagement System C D A A A A C A A C
Human and Environmental Health Risks C B B A A-B D-E B B B E
Ionizing Radiation C C-D B A-B A A A A-B X B
Inhabi tants and their Environment A-B E C-D A D-E A C-D A D-E A-C
Cumulations with other Regional Projects B D C A A-D B-D B-D C-D A D
Cultural Heritage B C B B B B B B B B
Protected Areas and Zones B C B D B D B B X D
Integrated Ranking C D D C C D D C C D
Features
Impacted
Summary of Energy Technology Impacts
Energy Technologies
A = No Impac t/ positive impact; B = Insubstantial impact; C = In substantial impacts with mitigation ;
D = Substantial impact; E = Destructive impact; X = Establishing impact not possible
* RES Mix is 32% hydro, 36% wind, 32% biomass
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NuclearRenaissanceasViableSolution forreducingGreenhouseGasesEnvironmentalImpactofdifferentEnergyTechnologies
Table3:Summaryofdecisionfactorsfortechnologyselection
6 CONCLUSION
Thedecisionmakingprocessforshortand longtermenergyfuturesolutionsshouldbebased
onsolidenvironmentalimpactscomparisons.
GENenergijaordered thepresentedcomparative study to substantiate itsbusinesspurposes
andthe
decisions,
but
the
main
purpose
is
to
convince
all
who
are
involved
in
the
decision
makingprocessesofhow the futuredevelopmentofenergy for Slovenia shouldentitled the
environmental,economicandsustainablepointofview.
Nuclear technology is at the top of the environmental acceptability on the global scale, as
shownbytheOECDstudies,aswell locally,whichhasshownbytheURSGENstudy.Froman
environmental point of view, nuclear energy is one of the optimal technology choices for
Slovenia,whileincombinationwithotherdecisionmakingfactorsitbecomesthemostoptimal.
Itisalsotheonlybaseloadelectricityproducer,whoseinstalledpowercanbeincreasedalmost
without any impact to the environment, as evidencedby the study. In addition to baseload
electricityproduction,newnuclearpowerplantsarealsocapableofoperating in load follow
production.By
increasing
the
share
of
nuclear
energy
in
final
energy
consumption,
Slovenia
could also greatly reduce greenhouse gas emissions and could achieve the EU and national
targetsforreducingsuchemissions.
If Slovenia wants to stay environmentally conscious, if wants to keep or even increase the
competitiveness of the economy and meet the requirements of sustainable development,
nuclearenergyistheoptimalsolutionforthefuture.
References
[1] URS Washington Group: Preliminary Report on Environmental Impacts of Different
EnergyTechnologyOptionsforSlovenia,April2009,URS
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[2] OECDNuclearEnergyAgency:NuclearEnergyRisksandBenefits,2007,OECDNEA
[3] http://en.wikipedia.org/wiki/Banqiao_Dam
[4] DonesR.,BauerC.,BolligerR.,BurgerB.,FaistEmmeneggerM.,FrischknechtR.,HeckT.,
JungbluthN.andRderA.,2004a,LifeCycle InventoriesofEnergySystems:Resultsfor
CurrentSystems inSwitzerlandandotherUCTECountries.Final reportecoinvent2000
No.5.PaulScherrerInstitut/Villigen,SwissCentreforLifeCycleInventories/Duebendorf,
Switzerland.
[5] DonesR.,BauerC.,BolligerR.,BurgerB.,FaistEmmeneggerM.,FrischknechtR.,HeckT.,
JungbluthN.andRderA.,2004b,SachbilanzenvonEnergiesystemen:Grundlagen fr
den kologischen Vergleich von Energiesystemen und den Einbezug von
EnergiesystemeninkobilanzenfrdieSchweiz.Finalreportecoinvent2000No.6.Paul
Scherrer Institut/Villigen, Swiss Centre for Life Cycle Inventories/Duebendorf,
Switzerland.
[6] DonesR.,ZhouX.,TianC.,2003,LifeCycleAssessment.In:EliassonB.andLeeY.Y.(Eds):Integrated Assessment of Sustainable Energy Systems in China The China Energy
Technology Program, Book Series: Alliance forGlobal Sustainability Series: Volume 4,
KluwerAcademicPublishers,Dordrecht/Boston/London(2003)319444.(Bookincl.DVD,
Hardbound ISBN 1402011989, Paperback ISBN 1402011997). Available at:
http://www.springeronline.com/sgw/cda/frontpage/0,11855,5403567233707785
0,00.html
[7] http://re.jrc.cec.eu.int/pvgis/pv/imaps/imaps.htm
[8]
HirschbergS.,
Dones
R.,
Heck
T.,
Burgherr
P.,
Schenler
W.
and
Bauer
C.,
2004a,
SustainabilityofElectricitySupplyTechnologiesunderGermanConditions:AComparativeEvaluation,PSIreportNo.0415PaulScherrerInstitut,Villigen,Switzerland.
[9] FriedrichR.,MarkandyaA.,HuntA.,OrtizR.A.,DesaiguesB.BounmyK.,AmiD.,Masson
S.,RablA.,SantoniL.,SalomonM.A.AlberiniA.,ScarpaR.,KrupnickA.,DeNockerL.,
Vermoote S.,Heck T., Bachmann T.M., Panis L.I., Torfs R., Burgherr P.,Hirschberg S.,
PreissP.,GressmannA.,DrosteFrankeB.,2004,NewElements for theAssessmentof
External Costs from Energy Technologies (NewExt). Final Report to the European
Commission, DG Research, Technological Development and Demonstration (RTD),
September 2004. http://www.ier.uni
stuttgart.de/forschung/projektwebsites/newext/newext_final.pdf
[10] Bickel,P.andFriedrich,R. (Editors),2005,ExternEExternalitiesofEnergyMethodology2005 Update. European Commission, Directorate General for Research, SustainableEnergySystems,EUR21951.
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JETVolume2(2009),p.p.2946
Issue3,August2009
http://www.fe.unimb.si/si/ejet/index.php
MATHEMATICAL MODEL OF THE POWER
SUPPLY SYSTEM CONTROL
MATEMATINI MODEL UPRAVLJANJAENERGETSKEGA SISTEMA
JanezUSENIK
Keywords:powersupplysystem,control,optimalenergycapacities,Laplacetransform,
fuzzylogic;
Abstract
Inthisarticle,asimplemathematicalmodelofacontinuousstochasticpowersupplysystem isdescribed. Some analytical approaches have been developed to describe the influence of
productionand stock, i.e.additionalcapacitiesonahierarchical spatialpatternanddemand.
UsingtheLaplacetransform, it ispossibletosolvethesystemofdifferentialequations,which
arerepresentedwiththecontinuousmodel.Duetothestochasticnatureofsysteminputs,the
optimality criteria with the Wiener filter are satisfied. The inverse Laplace transform is
calculated with residues in the complex space. Furthermore, an interesting and efficient
approachwithfuzzylogicisused,whichispresentedattheendofthisarticle.
Povzetek
V lankujepredstavljenmatematinimodelupravljanjazveznega stohastinegaenergetskega
sistema.Razvitisonekaterianalitinipristopi,skaterimiopiemomedsebojnivplivproizvodnje
terzalog,v taknihsistemihso tododatnekapacitete,nahiearhinoporazdeljenoprostorsko
dogajanje/porabooziromapovpraevanje.ZuporaboLaplaceovetransformacijereimosistem
diferencialnihenab,kiopisujejodinamikozveznegasistema.Pogojuoptimalnostilahkozaradi
stohastinih vhodov sistema zadostimo z uporabo Wienerjevega filtra. Inverzno Laplaceovo
transformacijoopravimozuporaboresiduov.Vnadaljevanju lankaprikaemoekot izjemno
zanimiv in zlasti zelo uinkovit nain pristopa k reevanju taknega problema tudi monost
uporabemehkelogike.
Corresponding author: Prof. JanezUSENIK, PhD.,University ofMaribor, Faculty of Energy
Technology,tel.+38631751203,Fax:+38676202222,Mailingaddress:Hoevarjevtrg1,8270
Krko,emailaddress:[email protected]
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1 DEFINING THE PROBLEM
Every model of optimal control is determined by a system, input variables and the
optimality
criterion
function.
The
system
represents
a
regulation
circle,
which
generally
consists of a regulator, a control process, a feedback loop, and input and output
information (DiStefano, 1987). In this article, we will only discuss linear dynamic
stationary continuous systems (Usenik et all, 2008). The optimality criterion is the
standardagainstwhichthecontrolqualityisevaluated.The termcontrolqualitymeans
optimalandsynchronizedbalancingofplannedandactualoutputfunctions.
Let us consider aproductionmodel in a linear stationarydynamic system inwhich the
input variables indicate the demand for products manufactured by a company. These
variables, i.e. the demand in this case, can be a onedimensional ormultidimensional
vector functionon the onehandand deterministic, stochasticor fuzzyon the other. In
thisarticle,
stochastic
variables
and
an
outline
of
afuzzy
approach
are
presented.
Let ustakeastationaryrandomprocessXwiththe knownmathematicalexpectationE(X)
and autocorrelationRXX(t) asthe demand inastochasticsituationthatshouldbemet, if
possible,bythe currentproduction.The differencebetweenthe currentproductionand
demand isthe inputfunctionfor the controlprocess,the outputfunctionofwhich isthe
current stock/additional capacities.When the difference ispositive, the surpluswillbe
stockedand when it isnegative,the demandwillalsobecoveredfromstock.Ofcourse,
in the caseofpower supplywedonot have stock in the usual sense (suchas in caror
computeretc.);energycannotbeproducedinadvanceforaknowncustomernorcanstockbe
builtupforunknowncustomers.Thedemandofenergyservicesisneitheruniformintimenor
knownin
advance.
It
varies,
has
its
ups
(peaks)
and
downs
(minima)
and
it
can
only
be
met
by
installingandactivatingadditionalpropertechnologicalcapacities.Becauseofthis,thefunction
of stock in the energy supply process belongs to all the additional technological
potential/capacities, largeenough tomeetperiodsof extrademand. Thedemandofenergy
servicesisnotgivenandpreciselyknowninadvance.Withmarketresearch,wecanonlylearn
about theprobabilityofourspecificexpectationsof intensityofdemand.Thedemand isnot
givenwithexplicitlyexpressedmathematicalfunction;weonlyknowtheshapeandtypeofthe
familyof functions.Demand is,according to these facts,a randomprocess forwhichall the
statisticalindicatorsareknown.
Thesystem inputrepresentsthedemandfortheproducts/services thatagivensubjectoffers.
Let demand be a stationary random process with two known statistical characteristics:
mathematical expectation and autocorrelation function (Usenik, 2001). Any given demand
should be met with current production. The difference between the current capacity of
production/services and demand is the input function for the object of control. The output
function measures the amount of unsatisfied costumers or unsatisfied demand in general.
When thisdifference ispositive, i.e.when thepowersupplycapacityexceeds thedemand,a
surplus of energy will be made. When the difference is negative, i.e. when the demand
surpassesthecapacities,extracapacitieswillhavetobeaddedor,iftheyarenotenough,extra
purchasing fromoutsidewillhave tobedone.Otherwise, therewillbedelays,queuesetc. In
thenewcycle,therewillbeasystemregulator,whichwillcontainallthenecessarydataabout
thetrue
state
and
which
will,
according
to
given
demand,
provide
basic
information
for
the
productionprocess.Inthisway,theregulationcircuitisclosed(Fig.1).Withoptimalcontrolwewill understand the situation in which all costumers are satisfied with the minimum
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Mathematicalmodelofthepowersupplysystemcontrol
involvement of additional facilities. On the basis of the described regulation circuit, we can
establishamathematicalmodelofpowersupplycontrol,i.e.asystemofdifferentialequations
forcontinuoussystems(Bogataj,Usenik,2005)inoursituation.
Figure1:Regulationcircuitofthepowersupplysystem
The task istodeterminethe optimumproductionand stock/capacities,sothatthe total
costwillbeaslow aspossible.
2 EQUATIONS OF THE MODEL
Notationsfor 0t areasfollows:
Z t additionalcapacities(stocks)atagiventimet,
u t productionattimet,
d t demandforproductattimet,
leadtime
Let Z t , u t and d t bestationarycontinuousstationaryrandomvariables/functions; theyarecharacteristicsofcontinuousstationaryrandomprocess.
Nowthe
system
will
be
modelled
with
the
known
equations:
Z t v t d t (2.1)
v t u t (2.2)
0
t
u t G Z t d (2.3)
In the equation (03) the function G t is the weight of the regulation that must be
determinedat
optimum
control,
so
that
the
criterion
of
minimum
total
cost
is
satisfied.
The parameter ,namedleadtime, isthe timeperiodneededtoactivatethe additionalcapacities inthe powersupplyprocess.Weusedarealsituation inwhichany goodscan
demand powerstation capacity,potential
production
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be sold to the customeronly from the storehouseof finishedgoods,becauseonly in
this case can the information flow of a company be updated and in accordance with
legislation.
Assumingthat
the
input
variable
demand
is
astationary
random
process,
we
can
also
considerproduction and stock/additional capacities tobe stationary randomprocesses
for reasonsofthe linearityofthe system.Let usconsiderthe functions Z t , u t and d t
tobecontinuousstationaryrandomprocesses.
Let us express the total cost, the minimum ofwhichwe are trying to define,with the
mathematicalexpectationofthe squareofrandomvariables Z t and u t :
2 2Z uQ t K E Z t K E u t (2.4)
In(2.4)
ZKand
uK arepositive
constant
factors,
attributing
greater
or
smaller
weight
to
individualcosts.Both factorshavebeendeterminedempirically for the productand are
thereforeinthe separateplant(Usenik,Bogataj,2005).
Equations (2.1)(2.4)representa linearmodelofcontrol inwhichwehave todetermine
the minimumofthe meansquareerror,ifbymeansofaparallelshiftwecausethe ideal
quantitytoequalzero.
Functionsofthesystemare normallytransferred intothe complexareabymeansofthe
Laplace transform. Let be L Laplace operator and Z s , D s , u s , v s Laplacetransforms:
Z s Z t
D s d t
U s u t
V s v( t )
L
L
L
L
Whennow the Laplacetransform isperformedon the functionsofthe system (01)(03),
weobtainthe expressions:
1
Z s v s d s
s
(2.5)
sv s e u s (2.6)
u s G s Z s (2.7)
nthe simplifiedversiontheexpressionsare defined,asfollows
pD s G s d s (2.8)
fV s G s u s (2.9)
f f pG s G s G s (2.10)
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Mathematicalmodelofthepowersupplysystemcontrol
1
f
G sW s
G s G s
(2.11)
wemaydrawthe flowchartinan usualcascadeform(Figure2).
Figure2:The cascadeflowchart
The function (2.4), the minimum of which we are trying to determine, is written in
accordancewiththedefinition ofthe autocorrelationinthe followingform:
0 0 Z ZZ u uuQ K R K R
or,divided
by
0ZK
2
2
0 0 ZZ uu
Z
u
Z
P R A R
QP
K
KA
K
(2.12)
FromFigure2wecansee:
u s W s D s (2.13)
1fZ s W s G s D s (2.14)
Spectraldensitiesfrom ZZR t and uuR t are asfollows:
0
1 1st
ZZ ZZ ZZ f f DDs R t R t e dt W s G s W s G s s
L (2.15)
0
st
uu uu uu DDs R t R t e dt W s W s s
L (2.16)
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Bothequations(2.15)(2.16)are transformedinthe realtimespaceand insertedintothe
equation(2.12):
2
1 1 2 1 2 2
1 1 2 2 3 3 4 1 2 3 4 4
2
1 1 2 1 2 2
0 0
0 2
ZZ uu
DD f DD
f f DD
DD
P R A R
R W t dt G t R t t dt
W t dt G t dt W t dt G t R t t t t dt
A W t dt W t R t t dt
(2.17)
Weare looking for the minimumof the equation (2.17).Thisoptimum isobtainedwith
thevariation
calculus:
optW t W t W t (2.18)
In(2.18),thefunction W t isavariationofthe function W t , representsavariation
parameterand optW t isthe optimalsolutionof(2.18).Function 0W t for 0t .From
(2.17)and(2.18),theWienerHopfequationisderived
2
3 3 2 2 4 1 2 3 4 4 1 3
2 1 2 2 10 for 0
opt f f DD DD
f DD
W t dt G t dt G t R t t t t dt A R t t
G t R t t dt t
(2.19)
The second variation 2
2
d P
d
is obviously positive for every 1 0t and the solution
optW t ofthe equation(2.19)istheminimum.
3 SOLUTION OF THE WIENER-HOPF EQUATION
The WienerHopf equation (2.19) is solved by the spectral factorisation method
(Schneeweiss,1971).From (2.19) theWienerHopfequation isobtained inthe following
form:
0 for ,optW t d t t
(3.1)
Thisequation isanordinary integralequationof the firstorder,whichcan besolvedby
theFourier/Laplace
transform:
0optW s s s
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andfinally
opt
sW s
s
(3.2)
The function s has its zeros(i.e.polesof(3.2))onlyonthe leftsideofthecomplex
plane (s1,s2, s3 inFigure3).Similarly,the function s has itszeroson the rightsideofthecomplexplane(s4,s5, s6inFigure3).
Figure3:Polesofthefunction(21)
Alsothefunction s has itspolesonly inthe lefthalfcomplexplane,whereas s onlyintherighthalfcomplexplane.
The optimalsolution for the cascadeoperator isobtained in formaldesignby (3.2).The
functionsinthe formula(3.2)are definedwithexpressionsinthe Laplaceform:
2 f DD
f f
G s ss
G s G s A
2 f f DDs G s G s A s
4 THE INVERSE LAPLACE TRANSFORM AND RESIDUES
The Laplace transform method solves differential equations and corresponding initial and
boundary value problems. The solution of the subsidiary equation in the complex plane is
transformedback to realplane to obtain the solutionof the given problem. In theend,we
determinethe
inverse
transform -1 f t F sL , i.e. the solution of the problem. This is
generally themostdifficultstep,and in itwemayuse the tableofLaplace transformsor the
residues(Kreyszig,1999).
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The purpose of the residue integrationmethod is the evaluation of integrals C
f s ds ,
takenaroundasimpleclosedpathC.Iff(s)isanalyticeverywhereonCand insideC, such
an integralequalszero: 0C
f s ds .Iff(s) has a singularity at the point
0s s inside C, but is otherwise analytic on C and
insideC,the function f(s)assumestheLaurentseries:
0
0 10
2 3 31 2
0 1 0 2 0 3 0 2 3
0 0 0
k k
k kk k
b f s a s s
s s
bb ba a s s a s s a s s
s s s s s s
(4.1)
thatconvergesinall pointsnear0
s s (exceptats=s0itself), insomedomainofthe form
0, 0s s R R .The coefficient 1b ofthe firstnegativepowerofthisseriesisobtainedby
theformula
11
2 Cb f s ds
i
(4.2)
Wecanuse the formula(4.2)toevaluatethe integral:
12C
f s ds ib Herewe integratecounterclockwisearound the simple closedpath containing
0s s in
its interior, but noothersingularpointsoff(s)onorinsideC.
The coefficientb1iscalledthe residueoff(s)at 0s s andisdenotedby
0
1Re
2s s
C
s f s f s ds
i
(4.3)
Residue integrationcanbeextended from thecaseofasinglesingularity to the caseof
severalsingularitieswithinthe contourC.Thisisthepurposeofthe residuetheorem:Let
f(s)beanalytic insideasimpleclosedpathCand onC,except for finitelymanysingular
points s1, s2,, sn insideC (Figure4). Then the integralof f(s) taken counterclockwise
aroundCequals2itimesthe sum ofthe residuesoff(s)ats1,s2,,sn.
1
2 Rej
n
s sjC
f s ds i s f s
(4.4)
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Figure4:The residuetheorem
The formulafor theresidueatapoleofany orderisgivenby(Kreyszig,1999):
1
11Re lim 1,2,3,1 ! kk
N
NkNs ss s
ds f s s s f s k N ds
(4.5)
Inthisformula,f(s)has apoleofNthorderat ks s ,and nisthenumberofall poles.Inparticular,for asimplepoleat 0s s theformulais:
00
0Re lim
s ss ss f s s s f s
(4.6)
The residueswillbeusedtocomputethe inverseLaplacetransform:
1 lim2
c i st
c i
f t F s F s e dsi
L-1
(4.7)
In(4.7),wehaveto integrateoverthe lineRe(s)=c.Thislineisbasedonthe assumption
thatall the singularities(poles)ofthe functionF(s)are onthe leftsideofthe line(Fig.5).
Figure5:Integrationoverthe lineRe(s)=c
Ifwe
are
to
apply
the
residue
theorem,
we
have
to
integrate
over
the
counter
clockwise
closed path d . An integral taken over the line Re s c is given as follows. We can
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describeacirclewiththecentreinthe point0and withsucha largeradiusdthatallthe
singularitiesofthe functionf(s)are insidethiscircle(Figure6)
Figure6:Path d andthe insidesingularitiesofthe function f s
Following the residuetheorem, weshallnow write
1 Re2 k
st st
s skd
F s e ds s F s ei
(4.8)
The integraloverthepath d ispossiblydividedintwoparts:the integraloverthe line
AB andthe integral overthe restofthe circle BCDEA .
st st st d AB BCDEA
F s e ds F s e ds F s e ds
(4.9)
Becausethe secondintegral in(4.9)equalszero,weget the followingequationfrom(4.8)
and(4.9):
Rek
st st
s skd
F s e ds s F s e
(4.10)
andthe integral(28)equalsthe sum ofthe residuesof stF s e at 1 2 3, , , , ks s s s toleftofthelineRe(s)=c:
1
lim Re2 k
c ist st
s skc i
f t F s F s e ds s F s ei
L
-1
(4.11)
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5 AN EXAMPLE
For the problem (2.1)(2.4), let the autocorrelation function of demand be known, for
example:
ddR e
(5.1)
Comparing(2.5)(2.7)with(2.8)(2.10)wecanwrite:
1
p
s
f
f f
s
p
G ss
G s e
G s G s
eG s
s
(5.2)
The spectraldensityofthegivenautocorrelationfunctionis,asfollows:
2
2
1dd dd s R t
s
L (5.3)
From
p
d sD s G s d s
s weget
2 2
2
1DD
ss s
andinthe righthalfplane
1
1DD s
s s
Due to
2 1f fG s G s A As
and 2 1
f fG s G s A A
s
wecanobtaintheoptimalcascadeoperator
1
1opt
s CsW s
As
(5.4)
where
1
1
A eC
A
Nowwecanobtainthe operatorofthe optimumregulation
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1
1 1 1
opt
s
opt f
W s s CsG s
W s G s As e Cs
inorder
to
get:
a) theoptimalproduction:
1
1 1opt opt p
Csu s W s G s d s
As s
(5.5)
b) theoptimalstock/additionalcapacities:
1
11
s
opt f opt
CsZ s G s u s D s e D s
As
(5.6)
Withthe inverseLaplacetransformweobtainthesefunctionsinthe timearea.
a)the optimalproduction:Informula (5.5),thereare two singlepoles
1
1s A
and2
1s and consequentlytwo
residues:
1
11 1Re lim
1 11
t
st A
sA
Cs e A C es s s
A A A A A s sA
1
1 1Re 1 lim 1
1 11
st t
s
Cs e C es s s
A A s s
A
Consequently,the functioninthe realtimespaceis, asfollows:
2
1
1Re
1 1k
t tAst
opts s
k
A C e C eu t s F s e
A A A
and finally
1
11
t
tAopt
C Au t e C e
A A
(5.7)
Similarlyit
is
possible
to
obtain:
b)the productionwhichreachesthe storehousewiththe delayoftimeunits:
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1
1 1
t
tAA C C
v t u t e eA A
(5.8)
c)the
total
demand
in
agiven
time
interval
with
avariable
upper
limit:
1 t D t D s e L-1 (5.9)
d)the totaloptimalstock/additionalcapacities:
t
tAopt
Z t M e Ke
(5.10)
whereKand Mare constants:
1
1
CK e
A
and 1
C AM
A
6 FUZZY CONDITIONS
6.1 Fuzzy logic
Fuzzy logic isan innovative formof logicthatallowsadescriptionofthe desiredsystem
behaviourusing spoken language.Many successfulapplicationshavebeenachievednot
with conventional mathematical modelling but with fuzzy logic. As a theoreticalmathematical discipline, fuzzy logic is designed to react to continuously changing
variables and to challenge traditional logic by not being restricted to the conventional
binaryvaluesof0and 1.Fuzzy logicallowsthe interpretationthatsomething isnot only
trueorfalse,but isalsoapplicabletopartialormultivaluedtruths.Thisdiscipline is
especially useful with problems that cannot be simply represented by classical
mathematicalmodelling for reasons of incomplete data or an overly complex process.
Statements using subjective categories have a major role in the decision making
processes of the humans. The contents of these statements may be quantitative,
uncertain, imprecise or ambiguous, but people can use them successfully for complex
evaluations.
A mathematical model is required to implement the human logic into engineering
solutions. Fuzzy logic makes the representation of the human decision and evaluation
processespossibleinalgorithmicform.Fuzzylogicoperateswithtermssuchasfuzzyset,
fuzzy variable, fuzzynumber, fuzzy relation, fuzzy reasoning etc.A classicalBooleanor
binary logic isbasedon two crisp extremes: yesnow. Yesornow is an answerbeyond
doubt.The set in thiscase isdefinedbycrispboundaries,whereanelement iseithera
memberof some crisp setor it isnot,or its membership can be representedwith the
special functionwhose values are 0 or 1. Fuzzy logic, however, has unclear threshold.
Fuzzy set is not defined by crisp boundaries, some elements are members with
membership1,
some
elements
are
members
with
membership
0,
but
certain
elements
canalsobemoreor lessmembersof this set an theirmembershipcanbebetween0
and 1. Membership mapping the objects onto the unit interval [0, 1]. The degree of
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membership inafuzzyset,for examplenamedA, isexpressedbyacontinuousfunction,
calledthemembershipfunction A x .The combinationofimpreciselogicrulesinasinglecontrolstrategyiscalledapproximate
orfuzzy
reasoning.
Thus,
the
fuzzy
inference
is
the
process
of
mapping
from
agiven
input
to an output, using fuzzy logic. Generally, there are five parts of the fuzzy inference
process: fuzzificationof the inputvariable,applicationof the fuzzyoperator (and/or) in
the antecedent, implication from the antecedent to the consequent,aggregationof the
consequentsacrossthe rules,andfinally,defuzzification(Ross,2007).
In fuzzy logic, different values of a given linguistic variable represent concepts, not
numbers.LinguisticvaluesortermsassociatedwiththelinguisticvariablePRICEcanbe
obtainedby specific fuzzy sets like LOW, MEDIUM, HIGH etc.A technicalquantity
PRICE ismeasuredwithnumbers(crispvalue),for example1,000EUR. Incontrast,the
fuzzy approach uses terms, not numbers. Each fuzzy set like LOW or MEDIUM or
HIGHis
formed
by
its
membership
function.
This
function
represents
acertain
degree
to
whichacrispvaluebelongstoagivenfuzzyset.Fromexperience,weknowthatapriceof
10EURor20EUR isLOW,apriceof1,000EURor5,000EUR isHIGH,but 10EUR is
less than 20 EUR, so the degree of membership of the fuzzy set LOW for the crisp
number10isgreaterthanfor the crispnumber20. Theprocedureoftransformationcrisp
numbersintofuzzytermsiscalledfuzzification.Asinglefuzzyruleassumesthe form:
if x isSET_A,thenyisSET_B,where SET_A and SET_B are linguistic values defined by fuzzy sets in the universes of
discourseXandY,respectively.The ifpartofthe ruleiscalledthe antecedentorpremise,while
the
then
part
is
called
the
consequent
or
conclusion.
The
variables x
and
y
are
definedonthe setsXandY.The output of the fuzzy process can be the logical union of two or more fuzzy
membership functions defined in the universe of discourse of the output variable.
Defuzzification is the conversionofagiven fuzzyquantity toaprecisecrispquantity. In
literature, at least seven methods (Ross, 2007) are common for defuzzifying: max
membership principle, centroid method, weighted average method, meanmax
membership,centreofsums,centreofthe largestarea,first(last)ofmaxima.6.2 Fuzzy reasoning
Inprincipleeverysystemcanbemodeled,analyzedandsolvedbymeansof fuzzy logic.
Due to the complexityof the givenproblemand the subjectivedecisionsof customers,
which are better described with fuzzy reasoning, it is advisable to introduce a fuzzy
approach. Some basic solutions of the control problems using fuzzy reasoning were
presented inthe paper (Usenik,Bogataj,2005).For someproblemsaboutthe controlof
the powersupplysystem,weproposefuzzyreasoning.Itisobviousthatdecisionmakers,
whensolvingeverydayproblems incontrolofsystems,operatewithfuzzy logic(Terano,
1992).
Our proposed fuzzymodelwillbebasedon these assumptions,whereby the usual five
stepshave
to
be
taken:
fuzzification
of
the
input
and
output
variables,
application
of
the
fuzzy operator in the antecedent, implication from the antecedent to the consequent,
aggregationofthe consequentsacrossthe rules,and defuzzification.
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6.3 Fuzzification
In the fuzzification phase we have to define fuzzy sets for all fuzzy variables (input and
output)and definetheirmembershipfunctions.
Let us assume for example that the demand id at the location jz depends on a) the
market area, b) the density of the area, c) price, d) season and d) uncertainty. The
demand is in fact the basic variable, on which the behaviour of all retailers depends
(Figure7).
Figure7:Outputfuzzyvariabledemanddependson5inputfuzzyvariables
We assume that all expressions are fuzzy variables, market area, density of the area,
price, season and uncertainty are input fuzzy variable, and demand is an output fuzzy
variable.Everyfuzzyvariableispresentedbymoreterms,for example:
a) inp utfuzzyvariableMARKETAREAisrepresentedby: SMALL,BIG,
b) inp ut fuzzy variable DENSITY OF THE AREA is represented by: WEAK, MEDIUM,
STRONG,
c) inputfuzzyvariablePRICEisrepresentedby: LOW,MEDIUM,HIGH,
d) inp utfuzzyvariableSEASONisrepresentedby: LOW,HIGH,
e) inp ut
fuzzy
variable
UNCERTAINTY
is
represented
by:
SMALL,
MEDIUM,
BIG,
VERY_BIG,
f) output fuzzy variable DEMAND is represented by: VERY_LOW, LOW, MEDIUM,
HIGH,EXTREMELY_HIGH.
For everyfuzzysetand for everyfuzzyvariable, wehavetocreatemembership functions.
For the fuzzy variable DEMAND they could be as shown in Figure 8. On the xaxis, we
measurethevariableDEMANDgiveninunitslikekWh,MWh and soon, dependingonour
data. On the yaxis, we measure membership for every possible demand and for every
fuzzyset VERY_LOW,LOW,MEDIUM,HIGH,EXTREMELY_HIGH.
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Figure8:MembershipsfunctionsoffuzzysetsforfuzzyvariablePRICE
6.4 Fuzzy model
Inourcasewecandefinenphasemodelwithatleastnruleblocksandnsetsofinput/output
fuzzyvariables(Fig.9),(Usenik,2009).
Figure9:Thestructureofthefuzzysystem
These fuzzy variables can solve the problem in general and can introduce quite a good
startingpointfor furtheractionsand stepstobetakeninthe processofdecisionmaking.
Due to the simplicity of this process, all membership functions will be of a simple
triangular and trapezoidal shape. Of course, in further iterations and studies of market
behaviour relevant for the customers demands and requests, we shall state more
sophisticatedconditionstofindanswerstoquestionsinrealworldsituations.6.5 Fuzzy rules inference
The computationof fuzzy rules iscalled fuzzy inferenceandconsistsof threesteps: the
application of the fuzzy operator (and/or) in the antecedent, the implication from the
antecedent to the consequentand the aggregationof the consequentsacross the rules.
The firststepdeterminesthe degreetowhichthe completeIFpartofthe ruleissatisfied.
In thisstep,weusuallyuse theoperatorOR for the minimumand the operatorAND for
the maximum.The secondstepmakesuse ofthe supportofthepreconditiontocalculate
thesupport
of
the
consequence.
Finally,
the
aggregation
step
determines
the
maximum
degreeofsupportfor eachconsequence.
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In our work, we applied FuzzyTech software (FuzzyTech, 2000). In accordance of this
softwaretool,the ruleswereautomaticallycreated.
6.6 Defuzzification
The resultfromthe evaluationoffuzzyrules isfuzzy.Defuzzification isthe conversionof
a given fuzzyquantity to aprecise crispquantity. The most frequentlymethodused in
praxis isCoMdefuzzification (theCenterofMaximum).Asmore than one output term
can beacceptedasvalid, the defuzzificationmethod shouldbea compromisebetween
differentresults.The CoM methoddoesthisbycomputingthe crispoutputasaweighted
averageofthe termmembershipmaxima,weightedbythe inferenceresults(Ross,2007).
CoM is a kindof compromise between the aggregated resultsofdifferent termsjof a
linguisticoutputvariableandisbasedonthemaximumYjofeachtermj.
7 CONCLUSION
Inthisarticle,the modelofthe controlofthe powersupplysystemhas beenpresented,
provided that the input functions (and for reason of linearity and stationarity, also an
outputfunction)weregivenasstochasticorfuzzyprocesses.Onthe basisofthe specific
items of the systems, the mathematical model of a system for the possibility of
input/outputfunctionsbeingrandomprocesseswas createdandsolved. Incaseoffuzzy
conditions, demand and other functionswere represented as fuzzy sets. In the future,
researchwill
have
to
be
done
in
order
to
create
amathematical
model
of
the
power
supplysystemfor fuzzyconditionsingeneral,showninFig.8.Oneofthe veryinteresting
and highly realisticpossibilities is the creationof the fuzzymodel forsolvingor,better,
predicting optimal energy capacities and technologies for permanent and reliable
electricitysupply,consideringriskcontrol(Fabijan,Predin,2009).Thisresearchispartof
the realizationofthat.
References
[1]
DiStefano,
J.J.,
Stubberud,
A.R.,
Williams,
I.,J.:
Theoryand
Problems
of
Feedback
and
ControlSystems,McgrawHillBookCompany,1987.
[2] Usenik, J., Vidiek, M., Vidiek M., Usenik, J.: Control of the logistics system using
Laplacetransformsandfuzzylogic.Logisticsandsustainabletransport,2008,vol.1,issue1,pp.119.
[3] Usenik,J.:ControlofTrafficSystem inConditionsofRandomorFuzzy InputProcesses,
PrometTrafficTraffico,2001,Vol.13No.1,p.18.
[4] Bogataj,M.,Usenik,J.:Fuzzyapproachtothespatialgamesinthetotalmarketarea.Int.j.prod.econ.[Printed.],2005,vol.9394,pp.493503.
[5] Usenik, J., Bogataj, M.:A fuzzy set approach for a locationinventorymodel. Transp.plann.technol.,2005,vol.28,no.6,pp.447464.
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[6] Schneeweiss, C.: Regelungstechnische stochastische Optimierung Verfahren inUnternehmensforschungundWirtschsaftstheorie,SpringerVerlag,Berlin,1971.
[7] Kreyszig, E.:Advanced Engineering Mathematics, JohnWiley& Sons, Inc.,New York,1999.
[8] Ross,J.,T.:FuzzyLogicwithEngineeringApplications,2nded.,JohnWileySonsLtd,TheAtrium,SouthernGate,Chichester,England,2004,reprinted2005,2007.
[9] Terano, T., Asai, K., Sugeno, M.:FuzzySystemsTheoryand itsAplicactions,AcademicPress,Inc.,SanDiego,London,1992.
[10] Usenik,J.:Fuzzyapproach inprocessofmultipleattributedecisionmaking,JETJournalofEnergytechnology,Volume1(2009),p.p.4358.
[11] FuzzyTech,UsersManual,2000,INFORMGmbH,InformSoftwareCorporation.
[12]
Fabijan,D.,Predin,A.:Optimalenergycapacitiesand technologies forpermanentandreliable electricity supply, considering risk control, JET Journal of Energy technology,
Volume2(2009),p.p.6984.
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JETVolume2(2009),p.p.4764
Issue3,August2009
http://www.fe.unimb.si/si/ejet/index.php
THE CALCULATION OF THERMODYNAMIC
PROPERTIES FOR HYDROCHLORIC AND
COPPER COMPOUNDS IN A HYDROGEN
PRODUCTION PROCESS
IZRAUN TERMODINAMINIH LASTNOSTIV HIDROKLOROVIH IN BAKER KLOROVIH
KOMPONENTAH V PROCESU
PROIZVODNJE VODIKA
JurijAvsec1,GregF.Naterer2,AndrejPredin11UniversityofMaribor,FacultyofEnergyTechnology,
Hoevarjevtrg1,8270Krko,SLOVENIA
2UniversityofOntarioInstituteofTechnology,Oshawa,Ontario,Canada
Keywords:Hydrogenproduction,CuClcycle,thermophysicalproperties,statistical
thermodynamics
Abstract
Efficientand sustainablemethodsofclean fuelproductionareneeded inallcountriesof the
world in the faceofdepletingoil reservesand theneed to reducecarbondioxideemissions.
With commitments for a hydrogen village, a hydrogen airport and a hydrogen corridor, the
CanadianprovinceofOntariohasalreadybeguntomovetowardahydrogenfueledeconomy.
However,akeymissingelement isa largescalemethodofhydrogenproduction.Asacarbon
based technology, the predominant existing process (steammethane reforming (SMR)) is
unsuitable.
Correspondingauthor:Assoc.Prof.JurijAvsec,,Tel.:+38676202217,Fax:+38626202222,
Mailingaddress:Hoevarjevtrg1,8270Krko,SLOVENIA
Emailaddress:[email protected]
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J.Avsec,G.F.Naterer,A.Predin JETVol.2(2009) Issue3
This paper focuses on a copperchlorine (CuCl) cycle, and the models of calculating
thermodynamic properties. It discusses the mathematical model for computing the
thermodynamicpropertiesforpuresubstancessuchasH2,CuClandHCl,whichareimportantin
hydrogenproduction
in
their
fluid
phase,
with
the
aid
of
statistical
chain
theory.
The
constants
requiredmakethiscomputation,suchasthecharacteristictemperaturesofrotation,electronic
stateetc.,andthemomentsof inertiaareobtainedanalytically,byapplyingtheknowledgeof
theatomicstructureofthemolecule.Theproceduresforcalculatingessentialthermodynamic
propertiessuchaspressure,speedofsound,thespecificheat,volumetricexpansioncoefficient,
enthalpyandentropyarepresented.Tocalculate the thermodynamicpropertiesofLennard
Joneschains,wehaveusedtheLiuLiLuandTangLumodels.Thethermodynamicpropertiesof
theLennardJonesmixturesareobtainedusingtheonefluidtheory.
Inrecentyears,thermodynamictheoriesbasedonstatisticalthermodynamicshavebeenrapidly
developed.Fluidswithchainbondingandassociationhavealsoreceivedmuchattention.The
interestin
these
fluids
isdue
to
the
fact
that
they
cover
much
wider
range
of
real
fluids
than
sphericalones.Agood theory for these fluidswillbeverybeneficial forchemicalengineering
applications, by reducing the number of parameters, and making them more physically
meaningfulandmorepredictable.
Intechnicalpractice,energyprocessesareofvitalimportance.Inordertodesigndevicesinthis
field of activity, it is necessary to be familiar with the equilibrium and nonequilibrium
thermodynamicpropertiesofstateinaoneandtwophaseenvironmentforpurerefrigerants
andtheirmixtures.Tocalculatethethermodynamicpropertiesofreal fluid,theLiuLiLu(LLL)
(revisited Cotterman) equation of state, based on simple perturbation theory and SAFTVR
equationofstateforLJchainfluidwasapplied.Wedevelopedthemathematicalmodelforthe
calculationof
all
equilibrium
thermodynamic
functions
of
state
for
pure
hydrocarbons
and
their
mixtures.
Inthispaper,wehavedevelopedananalyticalmodelbasedonthestatisticalthermodynamics
andchaintheoryforpurecomponentssuchasH2,CuClandHClinthefluidregion.
PovzetekToplogredni plini, ki nastajajo pri zgorevanju fosilnih goriv, predstavljajo veliko potencialno
nevarnost za prihodnost obstoja loveka. Zaradi zmanjevanja emisije ogljikovega dioksida v
ozraju inzaradizmanjevanjazalog fosilnihgorivv svetujepotrebnopreitivprihodnostina
novetehnologijepridobivanjagoriv.Kanadajezrazvojemvodikovihvasi,vodikovihletalie
priela z aplikacijo vodikovih tehnologij. V principu manjka za primer irokomasovneproizvodnjelemetodazapridobivanjevodikavvelikihkoliinah.
lanekopisujebakerklorovprocesintermodinaminelastnostivomenjenemprocesu.Vlanku
jeprikazanmodel,kako izraunati termodinamine lastnostikomponentkotsovodik,CuCl in
HCl.Omenjene komponente so zelopomembne vproizvodnemprocesupridobivanja vodika.
Omenjenametodajepovsemanalitina inzadoloevanjetermodinaminih lastnostiuporablja
statistinomehanikoinmolekularnostrukturomaterialov.
Talanekopisujemodelizraunatermodinaminihlastnosti,kotsonaprimertlak,hitrostzvoka,
specifinetoplote,volumetriniekspanzijskikoeficientinentropija.Vtanamensmozaizraun
LennardJonesovih
verig
uporabili
Liu
LiLu
jev
model.
Termodinami
ne
lastnosti
zmesi
so
izraunanenaosnovienofluidneteorije.Predstavljenmodelpredstavljaprvitovrstenposkusv
svetovni literaturi za izraun termodinaminih veliin, ki se uporabljajo v bakerklorovem
procesu.
8/3/2019 Jet Za Internet Celotna - Volume 2 - Issue 3 - August 2009
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JET
Thecalculationofthermodynamicpropertiesforhydrochloricandcoppercompoundsinahydrogenproductionprocess
1 INTRODUCTION
Currently, the world consumes about 85 million barrels of oil and 104 trillion cubic feet of
natural
gas
per
day,
releasing
greenhouse
gases
that
lead
to
global
warming.
In
contrast,
hydrogenisacleanenergycarrier.Somehavequestionedwhetherthehydrogeneconomyis
feasible inthenearfutureorremainsadistant ideal.However,theglobalhydrogenmarket is
alreadyvaluedatover$282billion/year,growingat10%/year,risingto40%/yearby2020,and
reaching several trillions of dollars by 2020. In Alberta, Canada, the oil sands need large
amounts of hydrogen to convert bitumen to synthetic crude and remove impurities. A key
challengefacingthehydrogeneconomyisamoreefficient,sustainableandlowercostmethod
of hydrogen production. As a carbonbased technology, the predominant existing process
(steammethanereforming(SMR)isunsustainable.
Ratherthanderivinghydrogenfromfossilfuels,apromisingalternative isthethermochemical
decompositionofwater.Electrolysis isaproven,commercial technologythatseparateswaterinto hydrogen and oxygen using electricity. Net electrolysis efficiencies (including both
electricity and hydrogen generation) are typically about 24%. In contrast, thermochemical
cycles to produce hydrogen promise heattohydrogen efficiencies up to approximately 50%.
This article examines the thermophysical properties of a specific cycle called the copper
chlorine (CuCl) cycle, with particular relevance to nuclearproduced hydrogen. A conceptual
schematicoftheCuClcycleisshowninFig.1.
IntheCuClcycle,waterisdecomposedintohydrogenandoxygenthroughintermediateCuCl
compounds [4,5]. Nuclearbased water splitting requires an intermediate heat exchanger
betweenthe
nuclear
reactor
and
hydrogen
plant,
which
transfers
heat
from
the
reactor
coolant
to the thermochemical cycle. An intermediate loop prevents exposure to radiation from the
reactorcoolant in thehydrogenplant,aswellascorrosive fluids inthethermochemicalcycle
enteringthenuclearplant.
This paper develops new models for calculating the thermodynamic properties of copper
chlorinecompoundsintheCuClcycle.Statisticalassociatingfluidtheoryisusedtocalculatethe
thermodynamicproperties,basedontheCottermanequationofstate[13],aswellastheTang
Lu model [3] from the OrnsteinZernike equation of state and perturbation chain theory.
Predictive mod