Page 118 - 2024年第55卷第3期
P. 118
AnalysisoftheevolutionoficecharacteristicsintheYellowRiverunderfutureclimatescenarios
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ZHOUZhongyuan ,WANGTao,SUNYafei,CHENYuzhuang,LUJinzhi
(1.StateKeyLaboratoryofSimulationandRegulationofWaterCycleinRiverBasin,ChinaInstituteof
WaterResourcesandHydropowerResearch ,Beijing 100038,China;
2.DepartmentofHydraulicEngineering,TsinghuaUniversity,Beijing 100084,China)
Abstract:Understandinghowfutureclimatechangewillaffectrivericecharacteristicsiscriticalforstudyingice
floodhazards ,hydropowerproduction,anddam management.Basedonthemeteorologicalobservationsinthe
YellowRiverbasinandthedailyaveragetemperaturedatafromeightGCMsoftheCMIP6 ,thesimulationcapabili
tyofeachGCMforthedailymeantemperatureoftheYellowRiverBasinduringthefloodingperiodbeforeandafter
thecorrectionofthequantiledeltamappingbiaswasevaluated ,andthefuturetemperaturetrendoftheYRBduring
theicefloodingperiodwaspredicted.Thepredictionmodelsofmaximumicethicknessandfreeze - updurationwere
establishedrespectively.Thefuturetrendsofmaximumicethicknessandfreeze - updurationintheNingxia - Mongo
liareachesoftheYellowRiverwerepredicted.Thestudyshowsthattheaveragetemperaturewarmingratesduring
theperiod2015 —2100intheYellowRiverBasininthethreeclimatescenariosofSSP1 - 2.6,SSP2 - 4.5,and
SSP5 - 8.5are0.014,0.031,and0.067℃ perdecade,respectively.ThemaximumicethicknessvaluesatBay
angaoleareexpectedtodecreaseby8.5,19.5,and39.5cm duringthiscentury,respectively.TheSSP2 - 4.5
scenarioshowsthatafter2070onlyacertainwidthofbankiceremainsintherivercross - sectionandalargeclear
channelexistsinthemiddleoftheriverwilloccurfrequently.Inthefuture,thefreezingdurationoftheYellow
River、SanhuhekouandToudaoguaisectionsoftheYellowRiverwillshowdifferentdegreesofshorteningtrend,a
mongwhichtheshorteningtrendofBayangaoleisthemostobvious,thefreezingdurationofthethreeclimatesce
nariosisshortenedby0.13 ,0.28and0.66daysperdecade,respectively,andthefreezingdurationoftheSanhu
hekouandtheToudaoguaisectionisrelativelyclose,whichis0.07,0.15,0.36daysperdecadeand0.08,0.17,
0.39daysperdecade,respectively.
Keywords:CMIP6;icefloodingperiod;rivericeconditions;climatechange;YellowRiverBasin
(责任编辑:李福田)
(上接第 354页)
EnergylossandflowcharacteristicsanalysisofamodelpumpturbineintheS - shaperegion
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WANGLike,YAOLiang,FENGJianjun ,ZHUGuojun ,LUJinling ,RUANHui
(1.StateKeyLaboratoryofEco - hydraulicsinNorthwestAridRegion,Xi’anUniversityofTechnology,Xi’an 710048,China;
2.InstituteofWaterResourcesandHydroelectricEngineering,Xi’anUniversityofTechnology,Xi’an 710048,China;
3.InstituteofHydraulicTechnology,Xi’anAeronauticalUniversity,Xi’an 710077,China)
Abstract:Inordertoadjustthestabilityofthepowergrid,thepumpedstoragepowerstationneedstostartand
stopfrequentlyandoperateunderdifferentworkingconditions.ThepumpturbineeasilyenterstotheScharacter
isticregion ,whichleadstotheincreaseinunitvibration,andtheunitinterconnectedfailure.Amodelpumptur
binewassetastheresearchobjectinthispaper.Theentropyproductiontheorywasusedtoanalyzetheenergy
losslawsunderdifferentoperatingconditionsintheS - shaperegion ,andtherelationshipbetweentheentropypro
ductiondistributionandtheinternalflowstructurewasclarified.Thetotalentropyproductionneartherunaway
conditionisthelargest ,whichisabout5.1timesofthatinthedesigncondition.Theproportionoffluctuationen
tropyproductioniscloseto80%.Asthedischargedecreases,theproportionofrunnerentropyproductiongradu
allydecreases ,whiletheproportionofguidevaneanddraftincreases.Thereisasignificantvortexfirstappeared
neartheshroudoftherunnerinlet,leadingtoahighentropyproductionareainthevanelessregion.Thevortex
graduallydevelopedtowardsthehubandthetangentialvelocityincreasedwhenthepumpturbineoperatesinthe
turbinebreakcondition.Awaterringwasformedattherunnerinlet ,hinderingthewaterflowintotherunner.A
highentropyproductionregionwithcirculardistributionappearedinthevanelessregion.Underthereversepump
condition ,thewaterflow collideswiththecounterclockwiserotatingbladesatthelow - pressureside,which
makesitdifficultforthewatertoentertheinteriorofthebladesandformsalarge - scalereversevortexstructure.
Thedoublerowcascadeisfilledwithalargenumberofvortexstructures ,leadingtoanincreaseintheentropy
productionrateoftheguidevane ,andpropagatedtowardsthestayvane.
Keywords:pumpturbine;S - shapedcharacteristics;entropyproduction;reversevortex
(责任编辑:王 婧)
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