太阳能光热资料汇总(英文版)

HowSolarHeatingSystemWorks???Asolarwaterheatingsystemcomprisessolarcollectors,astoragetank

and

interconnectingpipework.Thesolarcollectorsareusuallymountedonroofofabuildingtocapturesolarradiation.Smalltubesrunthroughthesolarcollectorsandcarryliquid–eitherwaterorheattransferliquidwithlowboilingpoint.Theheatpipeabsorbsheatfromthesolarcollectorsandtransfersheattoincomingwater.Benefits

ofsolarwaterheating

Hotwaterthroughouttheyear:thesystemworksallyearround,thoughyou'llneedtoheatthewaterfurtherwithaboilerorimmersionheaterduringthewintermonths.Cutyourbills:sunlightisfree,soonceyou'vepaidfortheinitialinstallationyourhotwatercostswillbereduced.

Cutyourcarbonfootprint:solarhotwaterisagreen,renewableheatingsystemandcanreduceyourcarbondioxideemissionsIngeneral,solarwaterheatingsystemsfallsinto2types:Activeand

Passive.Common

TypesofSolarWaterHeatingSystemsAnactivesystemusesanelectricpumptocirculatewaterorheattransferfluidfromstoragetanksthroughthecollector.Whereasapassivesystemreliesongravity

andthetendencyforwatertonaturallycirculateasitisheated,allowingwaterorheattransferfluidtomovethroughthesystemwithouttheuseofacirculatingpump.Activesolarwaterheatingsystems:Activesolarwaterheatingsystemsarecharacterizedaseitherdirect(alsocalled“openloop”)orindirect(alsocalledclosedloop)dependingonwhethertheincomingwaterisheateddirectlyinthecollectorsorindirectlyheatedviaaheatexchanger.AutomaticsolarcontrollerTemperaturesensoroncollectorTemperaturesensoronstoragetankSolarcirculationpumpColdwaterinflowHotwaterrun-offTemperaturesensorforadditionalheatingElementsofasolarheatingsystemforhotwater:DirectsolarheatingsystemPumpscirculatehouseholdwaterthroughthecollectorsandintothehome.Theyworkwellinclimateswhereitrarelyfreezes.ActiveindirectwaterheaterAlsoknownasanactiveclosed-loopsystem,asolarheaterthatcirculatesafluidotherthanwater(suchasdilutedantifreeze)throughacollector.Thecollectedheatistransferredtothehouseholdwatersupplyusingaheatexchanger.Indirectsolarwaterheatersarepopularinclimatespronetofreezingtemperatures.

Passivesolarwaterheatingsystems:Integralcollector-storagepassivesystem

Thermosyphonsystem

AthermosyphonsystemAthermosyphonsystem,alsoknownasapassivesystem,doesnotrequireapumptocirculatethewaterbutinsteadreliesondensitydifferentialswherethewarmerwaterrisestothehighestpoint.Forthissystemtofunctionthetankmustbemountedabovethecollector,relativetothehorizontal.

ComparisonbetweenActiveandPassiveheatingsystemsAdvantageofActiveoverPassive(Thermosyphon）AdvantageofPassive(Thermosyphon)overActiveGreatercontroloversystemSimpleSystemsetupSuperiorefficiencyMoreCostEffectiveFlexibilityinpositioningofstoragetankOperateswithoutpowerEasiertoovercomefreezingCanbeusedwithbothlowpressure

andhighpressuresystemsTheMainFactorsthatgovernthechoiceoftypesofsystemtobeinstalledincludetheclimaticcondition,hotwaterdemand,sizeofthesystemandspaceavailabilityforplacingextracomponents,etc.Forexample,lowmaintenancedirectsystemcanbeusedinsmallerfacilitieswithlowhotwaterdemandwhereasactiveindirectsystemisusuallyinstalledinlargerfacilitieswithhigherhotwaterdemand.

MaintenanceandExpectedLifeThemaintenancerequirementsforsolarwaterheatingsystemvarydependingonthesystemconfiguration.Ingeneral,solarthermalcollectorshavenomovingpartsandthemaintenancerequirementsareverylow.Awell-made,properlymaintainedsystemshouldlast15to20yearsormore.IssuestobeconsideredwheninstallingsolarwaterheatingsystemSolarCollectorsOrientationSolarcollectorsneededtobelocatedwhereplentyofsunshinestrikesitssurface.Solarcollectorscanbemountedfromhorizontaltoaninclinedangle.Tomaximizetheamountofannualsolarenergythatsolarcollectorscanreceive,theyshouldbeideallytiltedatlatitude(around37ºinJinan)ofthelocationonasouth-facingroof.Itisalsonecessarytoavoidobstructionssuchasbuildingsortrees,etcthatcouldpreventsolarcollectorsfromsolarcollectorsgettingadequateexposuretosolarradiation.TypesofSolarCollectors:SolarCollectorsFlat-platesolarcollectorsEvacuatedtubesolarcollectors

Flat-plateSolarCollectorsFlat-platecollectorsarethemostcommonsolarcollectorsforuseinsolarwater-heatingsystemsinhomesandinsolarspaceheating.Aflat-platecollectorconsistsbasicallyofaninsulatedmetalboxwithaglassorplasticcover(theglazing)andadark-coloredabsorbingplate.Solarradiationisabsorbedbytheabsorbingplateandtransferredtoafluidthatcirculatesthroughthecollectorintubes.

Sketchofflat-platecollector

DirectflowevacuatedtubecollectorsTheseconsistofagroupofglasstubesinsideeachofwhichisaflatorcurvedaluminumfinattachedtoametal(usuallycopper)orglassabsorberpipe.Thefiniscoveredwithaselectivecoatingthatabsorbssolarradiationwellbutinhibitsheatloss.Theheattransferfluidiswaterandcirculatesthroughthepipes,oneforinletfluidandtheotherforoutletfluidHeatpipeevacuatedtubeCollectors.TheVacuumSolarTube

absorbsthesolarenergyandtransferintotheheatenergy,thenpassittotheheatpipe,whichtransfertheheattotheworkingmedia.Thereisnowaterinthevacuumtube,sothetubewillnotbreakinwater,itissteadyandcredibleandcanbecombinedwiththearchitectureperfectly.Itcanbecombinedwithexistingpipelineandevenoperateintheeventofoccasionaltubebreakages.FlatplatecollectorsVS

EvacuatedtubecollectorsCheaperMoreefficientLongerservicelifeNofreezeEasyinstallationBetterperformanceincloudydaysClimatelimitationMorereliableFlatplatecollectorsareGood,EvacuatedtubecollectorsareBetter!!!VacuumSolarTube:WhatIsSolarCollectorTubeThevacuumsolarcollectortubeisasimpleandeffectiveenergyconverter,whichabsorbsthesolarenergyandconvertsitintoheatforuseviatheselectiveabsorbingcoating.?

Eachevacuatedtubeconsistsoftwo

glasstubesmadefromextremelystrongborosilicateglass.Theoutertubeistransparentallowinglightraystopassthroughwithminimalreflection.Theinnertubeiscoatedwithaspecialselectivecoatingwhichfeaturesexcellentsolarradiationabsorptionandminimalreflectionproperties.Thetopofthetwotubesarefusedtogetherandtheaircontainedinthespacebetweenthetwolayersofglassispumpedoutwhileexposingthetubetohightemperatures.This"evacuation"ofthegassesformsavacuum,whichisanimportantfactorintheperformanceoftheevacuatedtubes.

Inordertomaintainthevacuumbetweenthetwoglasslayers,abariumgetterisused.Duringmanufactureoftheevacuatedtubethisgetterisexposedtohightemperaturewhichcausesthebottomoftheevacuatedtubetobecoatedwithapurelayerofbarium.ThisbariumlayeractivelyabsorbsanyCO,CO2,N2,O2,H2Ofromthetube,thushelpingtomaintainingthevacuum.Thesilvercoloredbariumlayerwillturnwhiteifthevacuumiseverlost.BasicSpecificationsofEvacuatedtube

Length(nominal)1500/1800mmOutertubediameter58mmInnertubediameter47mmTubethickness1.6mmMaterialBorosilicateGlass3.3AbsorbingcoatingGradedAl-N/AlAbsorption>92%(AM1.5)Emission<8%(80℃)VacuumP<3.0x10-3PaStagnationtemperature>230℃Heatloss<0.8W/(m2℃)Maximumstrength0.6MPaAll-glassevacuatedsolarcollectortubesProduction:

pull-seal（拉封）innertube&outertube

rinsing（清洗）:deionizedwater

drying（烘干）:140℃,30minutes

coating（镀膜）:onetarget&threetargetsealing（封口）:fuse

annealing（退火）:eliminatestress

evacuating（排气）:1hour,P<3.0x10-3Pa

firing（烤消）:getter,extraair

packing（包装）:cartonwithfoam

inspection（质检）Coating（镀膜）:Coatingmethod:

磁控溅射镀膜

One-targetcoating（单靶镀膜）blue，red,black

Three-targetcoating（三靶镀膜）blue,black,redCoatingtypes:

Double-target（双靶镀膜）Ti-tube,purple

Coatinglayers：absorptionlayer(SS-ALN)reflectionlayer(copper)anti-reflectionlayer(ALN)