太陽能級多晶硅生產(chǎn)工藝研究及數(shù)值模擬.pdf

1、寧夏大學(xué)碩士學(xué)位論文太陽能級多晶硅生產(chǎn)工藝研究及數(shù)值模擬姓名：王長春申請學(xué)位級別：碩士專業(yè)：固體力學(xué)指導(dǎo)教師：李進(jìn)20100301AbstractBecauseoftheshortageofconventionalsourceof@n∞gy，newsourceofenergymaderapidexpansioninrecentyears，Solarentitywill80011beingreatdemandsinceitisinexha

2、ustibleandmuchcleanerthananyotherconventionalenagyn囂ourcesWiththehighlyperformanceandlowcostpolysiliconhasbecomethemainrawmaterialformanufacturingsolarcells，F(xiàn)orthepreparationforpolysiliconhaslongproducecyclehigllexpensea

3、ndriskthenumericalsimulationhasbecameainexpensiveeffectivemethodplayingamoreandmorevitalroleinitsproductiontechnologyThethesisputtheemphasisontheoptimizationofpolysiliconproductiontechnologyThedevelopmentofthecurrentstat

4、usofsolarenergyindustryathomeandabroadarecarefullydescribed；ThePVindustrychainandthepreparationofpolysiliconingotsarecarefullystudied；Astheimpuritiesplayaimportantrolehavearelatedtothepropertiesofpolysilicon，Whilecommoni

5、mpuritiessuchas0，C，NCanremovedeffectivelythroughdirectionalsolidificationprocess，becausephosphorusimpurities’SsegregationcoefficientinmoltonsiliconisSOhighthatitishardtemovedbyusingthedirectionalsolidificationmethod，howt

6、oeffectivlyremovingphosphorusimpuritiesisatechnicalproblemsthatmostpolysiliconenterprisesmustfacedforthemomentInthethesis，thetechnologyprocessofvacuumelectronbeammethodremovingphosphorusimpuritiesiscarefullyreseached，The

7、experimentsresultshowedthatitisfeasibletemoveimpurities；polysiliconingotthroughtheentireproductionprocesstostudyInthispaperthefiniteelementmethodhasbeenusedtosimulatethethermaltemperaturedistributioninpolysiliconheatedpr

8、ocessunderpowerloadThroughmodeling，gridcuttinginhalfThevariationourveofnodetemperaturealong麗tllthetimeWasobtainedfromtheresultandalso也ecloudchartofsolidificationprocesstemperatureTheresultsshowthattemperaturedistribution

9、isnonuniformdistributionduringtheprocess，whichisclosetoswirlinginthecrucibleThepossiblereasonmaybethatasthetemperatureincreasing，theinitialmoltonpolysiliconhavethefluideffect，causethenaturalconvectionandforcedconvection，

10、resultingintheflowofpolysiliconThenumericalsimulationresultandtheexperimentbasicallyfiteachotherTheresearchresultprovidesguidancetosupportthefurtheroptimizingforpolysiliconproduction，whichhasanimportantsignificanceinsust