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1、Elementsofelectricalpowerstationdesign=电站设计基础/M.V.Deshpande.─WheelerPublishing,1981Wherewaterresourcesareavailable,hydro-electriepowerstationareusedtosupplyelectricalenergytoconsumers.Thistypeofstation,however,cannotbelocatedeverywhere.First,theremustbeanamplequantityofwateratsuffic
2、ienthard,andsuitablesitemustbeavailable.Streamflowdateforanumberofyearsshouldbestudied.Thepossibilityofconstructingadamatasuitablesitetostorewaterinthecatchmentareaandtheavailabilityofwaterthroughouttheyeararedecisivefactors.Theamountofpowerthatcanbedevelopeddependsonthequantityofwa
3、teravailable,therateatwhichitisavailable,thehead,etc.Hydro-electricprojectsinvolvealargeamountofcivilengineeringconstructionwork.Oftentheprojectisamultipurposeoneembracingirrigationandpower,floodcontrolandpower,orfloodcontrol,navigationandpower.Onemightimaginethathydro-electricpower
4、shouldbeverycheapaswaterdoesnotcostanythingandthereisnofuelcost,This,however,isnottrue.Tostorewateratenoughhead,itisnecessarytohaveadamandcivilengineeringconstructionworks.Thiscostsmoney,andincreasesinvestmentcostsandfixedcostswhicharenotrequiredforothertypesofpowerplants,Wheneverah
5、ydro-electricprojectisconsideredforpowerpurposes,itisalwaysnecessarytoworkouttheeconomicscomparinghydro-electricpowercostswiththecostsforotherformsofstation.7.2HydrologyWhenconsideringthepossibilityofahydro-electricproject,thefirstrequirementistoobtaindataregardingthestreamflowofwat
6、erthatwouldbeavailable,andtopredicttheyearlypossibleflowfromthedata,Thewatercycleingeneralconsistsofevaporationfromseasoroceansand/orotherwatersurfacesontheearthduetoheatfromthesun,theformationofmoistairandclouds,thecirculationinformofrain,hailorsnow.Determinationoftheamountofstream
7、flowanditsvariationinvolvesastudyofhydrography(orhydrology)whichdealswiththeoccurrenceandundertheearth'ssurface.Thescienceofhydrologyisbasedonmeteorology,geology,agriculturalphysics,chemistry,botanyanddataobtainedbyobservationandmeasurement.Itisnecessarytocalculatethemeanannualrainf
8、allintheareaunderco