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Principles and technology for stepwise utilization of resources for mitigating deep mine heat hazards

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Principles and technology for stepwise utilization of resources for mitigating deep mine heat hazardsof,and,for,AND

    Principles and technology for stepwise utilization of resources for mitigating deep

    mine heat hazards

    Availableonlineafwww.sciencedirect.corn

    'I,

    ae,ScienceDirect

    MiningScienceandTechnology20(2010)0020-0027

    MlNING

    SCIENCEAND

    TECHNOLOGY

    www.elsevier.com/locate/jcuret

    Principlesandtechnologyforstepwiseutilizationof

    resourcesformitigatingdeepmineheathazards

    HEManchao'',CAOXiuling,XIEQiao,YANGJiahua5,

    QIPing,YANGQing,CHENXueqian

    SchoolofMechanicsandCivilEngineering,ChinaUniversityofMining&Technology,Beq'ing100083,China

    StateKeyLaboratoryofDeepRockMechanicsandEngineering,ChinaUniversityofMining&Technology,

    Beijing100083,China

    ~ShijiazhuangUniversityofEconomics,Sh~iazhuang050031,China

    TsinghuaTongfangArtificialEnvironmentCo.Ltd.,Beijing100083,China SXuzhfJCoalMinPBre".Xuzh0221000,Chin

    Abstract:AsiswelIknown,deepminesarehot.Asminingdepthincreases,thetemperatureofthesurroundingrockalsoincreases.

    Thisseriouslyaffectsminesafetyandproductionandhasrestrictedtheexploitationofdeepco

alresources.Therefore.reducingthe

    workingfacetemperaturetoimproveworkingconditionsbycontrollingtheseheathazardsisanurgentproblem.Consideringprob.

    1emsincoolingdeeDminesbothdomesticallyandabroadalongwiththeactualconditionsoftheZhangshuangloucoalmine,we

    proposeaHEMStechnologythatusesheatresourcesfromdeepminesinastepwisemanner.HEMSmeansahightemperatureex.

    changemachinerysystem.Mineinrush.waterisusedasasourceofcooling.Twicetheenergyisextractedfromthemineinrush

    water.Heatisusedforbuildingheatinginthewinterandcoldwaterisusedforcoolingbuildingsinthesummer.Thisopensanew

    technologyforstepwiseutilizationofheatenergyindeepmines.Energyconservationandreducedpollution,animprovedenvi

    ronmentandsustainableeconomicdevelopmentarerealizedbythistechnique.Theeconomicandsocialeffectsareobviousand

    illustrateagoodprospectfortheapplicationandextensionofthemethod. Keywords:coolingsystem;heatresourcesjndeepmine;heathazardcontrol;minewaterinrush;stepwiseutilization

    1Introduction

    Theaggregatedemandandper-capitaconsumption

    ofenergyincreasesannuallvasboththescaleof

    industryandpersonaIIivingstandardsincreasein

    China.Coalhasbeenthemajorenergysourcein

    Chinafora1ongtime.accountingforabout7O%of

    theenergysupply.Shallowcoalresourceshave

    becomeincreasinglyexhaustedduetolongperiodsof

    exploitation.Thereforemostcoalmineshave

    resortedtodeepexploitation.Asminingdepths

    increase.thetemperatureofthesurroundingrockalso

increasessothetemperatureintheneandatthe

    workingfacecanreach3040.Cj.Regulations

    stipulatethatworkersshouldstopworkwhentheair temperatureattheworkingfaceexceeds30.CJ. Therefore,itisurgenttoreducetheworkingsurface temperatures,toimproveworkingconditionsandto findwaystocontrolheathazards.

    Received10September2009;accepted13November2009 Correspondingauthor.Tel:861062331091

    E.mailaddress:hemodlchao@263.net

    doi:101016/S16745264(09)60155-1

    Atpresent,therearetwokindsofcooling

    technologiesused,bothathomeandabroad.TheV

    arenonartificialandartificialcoolingtechniques. Non.artificialcoolingcontrolstheheathazards throughmineventilation.Practicehasshownthatthis techniqueprovidesonlyalowcoolingabilityand cannotmeettheneedsofcoalminingingeneral, whereseriousheathazardsarepresent.Itis.however, ausefulbackupinothermeasuresemploying

    artificialcoolingtechnology.Artificialcooling technologycanbecategorizedaseitherwatercooling systemsoricecoolingsystems.Wlatercoolingisthe technologyappliedinmineaiconditiOning,which

    usescompressionrefrigerationequipmenttocoolthe workingface,withfreonastherefrigerant.The disadvantagesofthissystemisitshighoperationcost andhighpowerconsumptionL.".Icecooling consistsofsprinklingiceattheworkingface,where theiceisproducedbyanicemachine.Heatis

    exchangedduringtheprocessoficemeltinginto waterandthetemperaturedecreasesItz-13j.Practice hasshownthatthereareproblemsindesigning pipelinesforicetransportation:thekeyproblemisice

    HEManchaoetalPrinciplesandtechnologyforstepwiseutilizationofresourcesfor21

    blockageinthepipe.Aswell,themethodrequires highstandardsofoperationalmanagementand ctro116-191.

    一一

    Anewtypeofcoolingmodeisproposedwhere minewaterinrushprovidesaheatsource.The methodemploysHighTemperatureExchange MachinerySystems(HEMS)coolingtechnology.The equipmentrealizesastepwiseutilizationofheat resourcesindeepmines.Thistechniquenotonly coolstheworkingfaceandcontrolstheheathazards intheminebutalsomakesfu11useoftheheatenergY forprovidingheatinginthewinterorcoolinginthe summer.Thesystemturnsaharmfulconditionintoa beneficialoneandwasteintosomethingusefu1.It improvestheenvironmentandsavesenergyandis therebyofgreatimportanceinheating.aircondi

    Uonlng,energysavingandenvironmentalprotection. 2HEMS

    HEMScoolingtechnologywasdevelopedforheat hazardcontrolindeepmines.Theworldngprinciple istoextractthecoldfrominrushingminewateratall levelsandtoexchangeheatfromthehighair temperatureattheworkingface.Thetemperatureand

    humidityattheworkingfacearetherebydecreased.A diagramoftheHEMScoolingtechnologyisshownin Fi1f2o].

    

    Groundstation

    35~38?臣亟固

    Workingface

    Fig.1DiagramoftheHEMScoolingtechnique Thesystemcomprisesaclosedloop1iquidwater recirculationsystemandanopenloopaircirculation system.

    ThedesignoftheHEMSIcoolingworkstation

    mustfirstconsiderthecalculatedheatloadfromthe workingface.Energylossduringtheoperationofthe systemshouldbeconsideredandtheHEMSIcooling

    workstationshoulddrawenoughheattoprovide adequateandcoolenergy.

    ThedesignoftheHEMS.IIstationisbasedonthe energythatmaybedissipatedbytheHEMSIstation.

    Heatexchangebetweencoldwaterandthehotair fromtheworkingfaceallowsthetemperatureatthe workingfacetobedecreased.

    TheHEMS.PTstationisapressuretransition station,whichdecreasesthepressureofthe equipment.TheHEMSIandHEMSIIstationsare

    locatedatdifferentlevels.A1argeelevationdifference betweenthehigherandlowerlevelsofthewater circulationsystemproduceshighpressureatthe lowerlevels.Itisdifficulttoselectproperconstruc

    tionmaterialforthepipesandrelatedequipment.Ifa

    HEMSPTstationislocatedinthecirculationsystem. thentwoclosedcirculationsystemsmaybeusedand conventionalequipmentcanwithstandthewater pressure[2_22_一一

    Thecoldsourceofthesystemistheinrushingmine water.FulluseofgeothermalenergYismadeand sustainableutilizationanddevelopmentofthe resourcesisensured.Theentireclosedcirculation systemispollutionfreeanddecreasesthedischarge ofwastegasandsolidwasteenormously.This protectstheenvironmentandhasmarkedeconomic andsociabenefits.

    3Stepwiseutilizationofdeepmineheat 3.1Systemforstepwiseutilizationofdeepmine heat

    FortheZhangshuanglOucoalmineanditsparame

    tersofthegroundtemperaturefield,wedesigneda stepwiseprocessingsystemandimplementedthe projecttoworkinthismine.Theoperatingprinciple isshowninFig.2.

    PhaseI

    匝圜:=:.:::匝亟画

    ..一一一一...一一....一一..,.一一

    ::':.:'::.:j.一一

    祭囤?

    750

    Windcirculation

    ??—-_1000

    500

    PhaseII

一……

    Fig.2Diagramofheatrecyclinginadeepmine andontheground

    Theworkingprincipleisthataheatutilization systemfirstextractsheatfrominrushingminewater. Thisheatmaythenbeusedforheatingbuilding, showers,foodprocessing,clothesdryingandsoon.

    Atthesametime,wecancoolthebuildinginthe Sumnle

    Theentiresystemconsistsoftwoparts:aground levelheating(cooling)systemandthecoolingsystem inthemine.

    PhaseI:groundlevelheating(cooling)system AHEMS.IIIheatfcold)workstationlocatedat groundlevelextractsheatfcold)frominrushingmine water.Thehot(cold)Wateristransmutedtoatankon 案赫

    MiningScienceandTechnologyVb1.

    2ONo.1

    thegroundthroughtheHEMSTandthenheatis

    suppliedforheatingbuildings,showersandwel1.head heatingthroughtheHEMSIIIsystem.Theground

    heating(cooling)systemreplacestheboilerand providesnon-pollutingheatforbuildings. PhaseII:coolingsysteminadeepmine

    1)TheHEMS.Theatexchangeworkstationisset upatlevel-500munderground.Coldfrominmshing minewateristransfencedtotheHEMS.PT,the pressuretransferworkstation.

    2)Thepressuretransferworkstationisinstalledat

    level750m.Thisisusedtodecreasepressureonthe equipment.Coldistransferredfromthistothe HEMS.Icoolingworkstation.

    3)ThecoldwaterfromtheHEMSIcoolingwork

    stationispumpedintotheHEMSIIsystem.

    4)Atthe-1000mleveltheHEMS.IIcoolingwork stationisestablished.Thiscauseshightemperatures attheworkingfacetodecrease.

    3.2Characteristicsoftheprocessingsystem Theheatsourceisinrushingminewater.The systemmakesfu11useofthegeothermalenergyand ensuresasustainableutilizationanddevelopmentof resources.Asaproductionsystemitispollution.free anddecreasesthedischargeofwastegasandsolid wastetoagreatextent.Ithasmarkedenvironmental andsocialbenefits.

    Theheatenergyextractedfromtheinrushingmine waterisstoredintheformofhotwater.Thehotwater ispumpedtothegroundlevelthroughtheHEMSI?

    toprovideheatenergyforheatingbuildings,showers, wellheadheating,foodprocessing,clothesdrying

    andsoon.Theentiresystemincludesanentirewater circulatingsystem.Itprovidesdeepminecoolingand groundheatinganddecreasestherunningcostofthe heatingsystemontheground.Heathazardsare controlledinthedeepmine.Thesystemprovides significanteconomicbenefits.

    500mand InphaseI,thereisatankonlevel

    anotheroneat-750m.Theminewaterinthesetwo tanksispumpedintothebalancingtankatground

    1eve1.Thewatertemperatureis28.C.Heatjs extractedfromtheinrushingminewaterthroughthe HEMSmsystem.Thisheatissuppliedtoheating buildings,showers,wel1.headheatingandsoon.A stepwiseutilizationmethodisusedtoextracttheheat energyfromtheminewater:thetemperatureis decreasedfrom22tO14.Candthenfrom14to6.C sowecanmakefu11useOfthisheatsource.The entiresystemconsistsofsixparts:themachineroom. thepipenetworksystem,theshowersystem,the wellheadheatingsystem.thewatersourcesystem andanautomaticcontrolsystem.Thedesigndiagram isshowninFig.3.

    SourcesofheatMachineroomPipelinesandtheuserend Fig.3DiagramofthestepwisedevelopmentandutilizationofheatenergyintheZhangshuang

    loucoalmine

    4Keytechnologies

    Thedesignofthemachineroomisthekey.Wle shouldselectasuitabletypeofHEMS.assembleits parts.makefuI1useofthepropertiesoftheunitsand meetthecirculationneedsofthesystem.Atthesame time,weshouldconsiderthenecessarystockof safetyequipment.Thedesignandinstallationofthe systemmustconsiderthefollowingthreeparts:the HEMSIII;theaccessories.suchastheheatexchange system(HEMST),thecirculatingpump,the

    water-solteningplantandtheconstantpressure makeupwaterand,finally,thepipelinelayoutinthe machineroom.

    4.1Energytransformationandextraction

techniques

    1)ComponentsandprinciplesoftheHEMS一?

    TheHEMSIIIsystemhasfourparts:aflooded evaporator;ascrewcompressor;throttlevalvesanda shellandtubecondenser.AdiagramoftheHEMS.?I

    systemisshowninFig.4.

    Theworkingsubstanceofthissystemisrefrigerant R134a.Heatcomesfromtwosources"oneisthelow temperatureminewaterinrush(25.C),which accountsfor70%-75%andtheotherthemechanical system.whichaccountsfor25%30%.Inthewinter

    theHEMS.IIIfollowsaCarnotcycle.whileinthe summertheworkingprincipleisareverseCamot HEManchaoeta1Principlesandtechnologyforstepwiseutilizationofresourcesfor

    cycle.TheHEMSIIIcannotberestrainedby

    temperaturechanges.Itmustworkeffectivelyeven whenthetemperatureis-20.Cduringcoldwinters. Duringsummercooling,lowgradeheatintheair (water)isconvertedintohighgradeheat. water

    25.C

    l3.C

    Fig.4DiagramofHEMSIIIsystem

    Thissystemisaheatpump.Itconsistsoftwo isobaricprocesses,evaporationandcondensation,an adiabaticthrottlingprocessandadiabaticcompres

    sion.Fig.5showsthedetailsoftheprocess.Inthis figure.thepathfrom1tO2isanisentropicadiabatic compressionprocess;thepathfrom2to3isan isobaricexothermicprocesswheretherefrigerant

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