20147463-Thermal-Power-Plants.ppt

apresentationonsteamgenerator coaltoelectricity basics majorenergysourcesofindia whycoal shareofcoalinpowergeneration advantagesofcoalfuelabundantlyavailableinindialowcosttechnologyforpowergenerationwelldeveloped easytohandle transport storeanduse shortcomingsofcoallowcalorificvaluelargequantitytobehandledproducespollutants ashdisposalofashisproblematicreservesdepletingfast india scoalreservesareestimatedtobe206billiontonnes presentconsumptionisabout450milliontonnes costofcoalforproducing1unitofelectricity costofcoalrs1000 mt isrs0 75 costofgasforproducing1unitofelectricity costofgasrs6 smc isrs1 20 knowingmoreaboutcoal coalproductionsurfaceminingundergroundmining coaltransportationrailtruckconveyorship coalpropertiescalorificvaluegradeofcoal uhv proximateanalysisultimateanalysisashandmineralsgrindabilityrankphysicalcharacteristics coalbeneficiationwhy processeseffectiveness coalproductionsurfaceminingundergroundmining usefulheatvalue uhv uhv 8900 138 a m boiler steamgenerator steamgeneratingdeviceforaspecificpurpose capabletomeetvariationinloaddemandcapableofgeneratingsteaminarangeofoperatingpressureandtemperatureforutilitypurpose itshouldgeneratesteamuninterruptedlyatoperatingpressureandtemperatureforrunningsteamturbines boiler steamgenerator rawmaterialsfordesignofboilerscoalfromminesambientairwaterfromnaturalresources river ponds generatingheatenergyairforcombustionworkingfluidforsteamgeneration possessingheatenergy a500mwsteamgeneratorconsumesabout8000tonnesofcoaleverydayitwillbeconsideredifitrequiresabout200cubicmeterofdmwaterinadayitwillproduceabout9500tonnesofcarbondioxideeveryday coalanalysis typicalcomposition proximateanalysis 1 fixedcarbon2 fuelash3 volatilematerial4 totalmoisture5 sulfurhighcalorificvalue lowercalorificvalue kcal kg hardgroveindex hgi combustionofcoal carbon hydrogen sulfuraresourcesofheatoncombustionsurfacemoistureremovedonheatingduringpulverization inherentmoistureandvolatilesarereleasedathighertemperature makingcoalporousandleadingtochar cokeformation thermalpreparationstage fueloil threeliquidfuelsusedinpowerplants1 heavyfueloil hfo 2 lshs lowsulfurheavystock 3 highspeeddiesel hsd oilfiringisprecededbyloweringviscosityandincreasingflowabilityonheatingforbettercombustioningiventurndownratio 125oc dropletformationonatomization bysteam compressedair mechanicalpressurization combustioninitiationbyhighenergysparkignition combustionofreactants reactionratedependsonconcentrationofoneofthereactantsconcentrationvariesonpartialpressureofthereactants partialpressureisafunctionofgastemperature therefore reactionratedependsontemperatureandsubstancethatenterthereaction combustionreactions carbon mainreactions2c o2 2co 3950btu lb deficitair c o2 co2 14093btu lbsecondaryreactions2co o2 2co2 4347btu lbc co2 2co 7 25mj kg combustionreactions carbon carbonreaction2c o2 2co eco 60kj mol c o2 co2 eco2 140kj mol reactionat1200oc4c 3o2 2co 2co2 ratio1 1 reactionat1700oc3c 2o2 2co co2 ratio2 1 itisdesirabletosupplycombustionairatlowertemperatureregimeinfurnace combustionreaction h2 s hydrogenreaction2h2 o2 2h2o 61095btu lbsulfurreactions o2 so2 3980btu lb undesirable coalforcombustion anthracitesemi anthracitebituminoussemi bituminouslignitepeat highcv lowvmhighcv lowvmmediumcv mediumvmmediumcv mediumvmlowcv highvm hightmverylowcv highvm tm heatgenerationinfurnace heatinputinthefurnaceefficiencyofthermalpowerplantsis37 45 fordifferenttypesofcyclefortypicalconventionalp f boilers coalflowrateis290 350t hrfor500mwunits120 145t hrfor200mwunits tangentialfiringsystem mainequipmentsoffuel firingsystem millsorpulverisersfeddersburners typesoffeedersvolumetricfeedresgravimetricfeeders pulverizers objectivestocrushedthecoalredcedtoafinenesssuchthat70 80 passesthrougha200meshsieve advantagesofpulverisedcoalfiring efficientutilisationofcheapergradeofcoalsflexibilityinfiringwithabilitytomeetfluctuatingloadsbettercoalcombustionincreasingtheboilerefficiencyhighavailibility bowlmill modelno basecapacity t hr 623xrp18 4703xrp26 4763xrp33 8803xrp36 5883xrp51 1903xrp54 11003xrp68 11043xrp72 0 basecapacity t hr athgi 55totalmoisture 10 fineness 70 thru200mesh ball racemill emill modelno basecapacity t hr 7e9258 5e10358 5e94010e105510 9e116110 9e107010 9e880 tubemill modelno basecapacity t hr bbd476083bbd477290 airanddraftsystem objectivestheairweneedforcombustioninthefurnaceandfluegasthatwemustevacuatetransportanddrythepulverisedcoalsealingofbearingsfromcoal dust draftsystem draftmeansthediffrencebetweentheatmosphericpressreandpressureexistinginthefurnacenaturaldraft obtainedbytallchimneyinduceddraft byidfansforceddraft byfdfansbalancedraft byidandfdfansgenerallyinpowerplantbalancedraftsystemisused fansinpowerplant forceddraftfaninduceddraftfanprimaryairfansealairfanscannerairfan thebasicinformationneededtoselectafanareairorgasflow kg hrdensity functionoftemperatureandpressure systemresistance losses airpreheaters objectivestoraisethetemperaturesofprimaryandsecondaryairbyutilisingheatfromfluegasatlowtemperature advantagesofairpreheaters increasetheboilerefficiencystabilityofcombustionimprovedbyuseofhotairpermittingtoburnpoorqualitycoal ljungstromtypebisector twopassboilerarrangement electrostaticprecipitator toremoveflyashfromthefluegaseselectrostaticprecipitatorsareused theyhavecollectionefficiencyover99 5 theefficiencydependsonvariousparameterssuchasvelocityofflow quantityofgas resistivityofash voltageoffields temperatureetc principleofoperation thefluegasladenwithflyashissentthroughductshavingnegativelychargedplateswhichgivetheparticlesanegativecharge theparticlesarethenroutedpastpositivelychargedplates orgroundedplates whichattractthenownegatively chargedashparticles theparticlessticktothepositiveplatesuntiltheyarecollectedbyperiodicallyrapping selectionofboilertypeofboilerbasedonsteamparameter subcritical supercritacalbasedonsteam watercircuit oncethrouh drumtypebasedonair fluegaspath tower twopath t typetypeoffuel coalfired oilfiredtypeofdraftsystem typeofburnerarrangement tangential front opposedselectionoffiringsystem typeofmillssinglereheat doublereheattypeofwaterwalltube plain rifledtypeoftubingarrangement spiral straight tubeleakagesfromboilerpressureparts erosionoftubesduetohighashcontentandvelocitiesoverheatingoftubespassingfromvalvescausingdifficultyinmaintainingtheparametersfailureorincorrectnessofmeasuredparametersoverloadingofboilerduetoverypoorqualityofcoaldepositionofash clinkers onfurnacewalls difficultiesinremovalofashfromtheboilerreducedeffectivenessofheattransferleadingtolossofefficiency impropercombustionofcoalintheboiler typicalboilerproblems airingressfromthenosearch penthouseandboilersecondpassandquantificationthereofdifferencebetweenonlinereadingandtheactualoxygeninthefluegasductdifferencebetweenactualand online temperaturemeasurementofairheaterair gasoutlettemperaturesfoulingandslagginghighunburntcarboninflyashorbottomashhighairheaterleakageboileroperationathighexcessair typicalboilerproblemscontd afewwordsonsupercriticalboiler definition critical isathermodynamicexpressiondescribingthestateofasubstancebeyondwhichthereisnocleardistinctionbetweentheliquidandgaseous