WordEffect of a superheating and sub-cooling heat exchanger to t Energy44(2022)996e1004 ContentslistsavailableatSciVerseScienceDirect Energy journalhomepage:/lo cate/energy Effectofasuperheatingandsub-coolingheatexchangertotheperformanceofagroundsourceheatpumpsystem KadirBakirci*,DeryaColak1 DepartmentofMechanicalEngineering,AtatrkUniversity,25240Erzurum,Turkey articleinfo Articlehistory: Received15November2022Receivedinrevisedform13April2022 Accepted20April2022 Availableonline7June2022Keywords: GroundsourceheatpumpGroundheatexchangerColdclimateHeating SuperheatingSub-cooling abstract Theaimofthisstudyistoevaluatetheeffectofasuperheatingandsub-coolingheatexchanger(SHCHE)totheperformanceofgroundsourceheatpumpsystemforclimaticconditionofErzurumhavingcoldclimateinTurkey.Forthispurpose,anexperimentalset-upwasconstructed.Theexperimentalapparatusconsistsofaseriesgroundheatexchanger(GHE),aliquid-to-liquidvaporcompressionheatpump,watercirculatingpumpsandothermeasurementequipments.Inthisstudy,theperformanceofthesystemswithandwithoutSHCHEwasexperimentallyinvestigated.Theexperimentswereperformedin2022forJanuaryandFebruarywhicharethecoldestmonthsoftheheatingseason.Theexperimentallyobtainedresultswereusedtocalculatethepowervaluesofthemainsystemequipments,thecoef cientofperformanceoftheheatpump(COP)andtheoverallsystem(COPS)forsystemswithandwithoutSHCHE. 2022ElsevierLtd.Allrightsreserved. 1.Introduction Turkeysdemandforenergyandelectricityisincreasingrapidly.Turkeyisheavilydependentonexpensiveimportedenergyresourcesthatplaceabigburdenontheeconomy.Aswouldbeexpected,therapidexpansionofenergyproductionandconsumptionhasbroughtwithitawiderangeofenvironmentalissuesatthelocal,regional,andgloballevels.Withrespecttoglobalenvironmentalissues,Turkeyscarbondioxide(CO2)emissionshavegrownalongwithitsenergyconsumption.Stateshaveplayedaleadingroleinprotectingtheenvironmentbyreducingemissionsofgreenhousegases.Inthisregard,renewableenergyresourcesappeartobeoneofthemostef cientandeffectivesolutionsforcleanandsustainableenergydevelopmentinTurkey.Turkeysgeographicallocationhasseveraladvantagesforextensiveuseofmostoftheserenewableenergysources1. Infuturetheworldsenergysupplymustbecomemoresustainable.Thiscanbeachievedbothbyamoreef cientuseofenergyandbyrelyingonrenewablesourcesofenergy,particularlywind,hydropower,solarandgeothermalenergy2.Turkeyisan *Correspondingauthor.Fax:904422360957.E-mailaddress:abakirciatauni.edu.tr(K.Bakirci).1 Presentaddress:Directoryofthe12thRegionofHighways,25080Erzurum, Turkey. 0360-5442/$eseefrontmatter2022ElsevierLtd.Allrightsreserved.doi:10.1016/j.energy.2022.04.049 energyimportingnationwithmorethanhalfofourenergyrequirementsmetbyimportedfuels.Airpollutionisbecomingasigni cantenvironmentalconcerninthecountry.Achievingsolutionstoenvironmentalproblemsthatwefacetodayrequireslong-termpotentialactionsforsustainabledevelopment.Forthegovernmentsorsocietiestoattainsustainabledevelopment,muchefforthastobedevotedtoutilizingsustainableenergyresourcesintermsofrenewableenergies3,4. TheGSHP(groundsourceheatpump)isoneoftheef cientandsustainablemethodstoprovidespaceheatingandhotwaterforvariouskindsofbuildings.TheGSHP,worksbymeansofthevaporcompressioncycle,whichcoolsacirculating uidthat owsthroughasystemofclosedloops.Theseloopsareburiedwithinthegroundeitherhorizontally,iflandspacepermits,orverticallybymeansofboreholes.Thedirectionofheat owisfromthegroundtothecooler uidandthisheatisupgradedtoahighertemperaturethroughthevaporcompressioncyclefordeliverytothebuilding5.Thegroundsourceheatpumpsprovideanewandcleanwayofheatingbuildingsintheworld.Theymakeuseofrenewableenergystoredintheground,providingoneofthemostenergy-ef cientwaysofheating.Theyaresuitableforawidevarietyofbuildingtypesandareparticularlyappropriateforlowenvironmentalimpactprojects6. Intheliterature,anumberofinvestigationshavebeencon-ductedbysomeresearchersinthedesign,modelingandtestingoftheGSHPsystems7e18.HealyandUgursal8haveinvestigated - 5 -