Symbol0003.19483.194263202800253.2Qflue0KJ/s0Qs6925.5555555556KJ/s00Qflue>Qs?0RefuseThru
put0T/dy0NCV0Kcal/kg0.000Mw500Kg/ton%unburnt0%Blowdown0.222222222242%heat
loss0%2800253.2Qrefuse0KJ/sRH in
air0.1Mwpri0Kg/sMwsec0Kg/s0Mwflue0Kg/s1.0342250hw25deg0KJ/kghw250deg0KJ/kghw850deg0KJ/kgQin
req0KJ/sCan
Tflue>850deg?0Blowdown14.86111111114014.8611111111362801250.3333244029.722222222234.33322435From
SH(2)2.459.583055296.42.96416666671.123.00305555560.0532688.42102.62335.233.91.3051.88274813323.00305555560.05313833.923.00305555565.3925.96722222225.3913833.2429.1312532894102.3
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AnalysisProject: PRC Senzhen Incineration PlantTitle: Thermal
dynamics analysisBy:EK Gohdate: 20/11/2000(air25)Air density @ 25
degC1.177Kg/m3Flue density @ 25 degC1.177Kg/m3Flue density @ 200
degC0.7483Kg/m3Flue density @ 1300 degC0.2246Kg/m3Cp
[email protected]/KgKCp
[email protected]/KgKCp
[email protected]/KgKCp
[email protected]/KgK1.0247assumedCp
[email protected]/KgK1.065approxCp
[email protected]/KgK1.163assumedCp
[email protected]/KgK1.2181assumedAtm air temp25degC298degKFlue
Temp @ inlet of boiler850degC1123degKFlue temp @ inlet of
superheater1300degC1573degKPri air first pre-heated
temp80degC353degKCx Ts of HeaterPri air sec pre-heated
temp250degC523degK1 b4 acceptDesired emission Temp200degC473degKV
flue @25 DegC23295Nm3/hrContain gases given off frm refuseM flue
@25 DegC7.616Kg/sPV/T = CV air pri @25 DegC10616Nm3/hrM air pri @25
DegC3.471Kg/sV air sec @25 DegC7289.3Nm3/hrM air sec @25
DegC2.383Kg/sMoisture content0.01Kg/Kg airMoisture content in
refuse500Kg/TonRefuse thru-put per line150Ton/dyNCV
refuse1450Kcal/KgNo of line10lineEstimated unburnt0.02Estimated
Heat loss0.02NCV fuel10000Kcal/Kg41868KJ/KgFuel cost$1,000$/TonUnit
rate of power sold$150.00Per MWhrKnown enthalpy stateh1 = hg @
37b2802KJ/KgKh3 @ 34.3b = h10 @ 4b3303KJ/KgKh4 @ 0.16b2208KJ/KgKh5
= h6192KJ/KgKh7 = h8546KJ/KgKh9
@37b632KJ/KgKh11=h@4b,300C3067KJ/KgKh12 = hf@4b605KJ/KgKh13 =
hf@37b1066KJ/KgKOther assumptionBoiler pressure37barBoiler
saturated steam temp246degCSuperheater pressure34.3barSuperheater
steam temp435degCCondenser pressure0.1barCondenser saturated
temp45.8degCH(2) Expansion valve pressure4barH(2) Expansion valve
temp before water injection414degCH(2) Expansion valve controlled
temp300degCH(2) saturated temp @4b143.6degCH(1) expansion vlv
pressure4barH(1) expansion vlv temp = Tsat @4bar143.6degCDeaerater
tank pressure3barDeaerater tank outlet temp130degCFeedwater
temp150degCDiff press of FD fan (A2)90mbarassumedIsentropic
eff0.9assumedFlue velocity in superheater6m/sassumedFlue velocity
in stack3m/sassumedAir velocity in fan duct12m/sassumedCpf Cooling
water4.181KJ/KgKCooling Water Inlet Temp27degCLimit of Cooling
water discharge37degCdelta T=10degCRemarks:1Values in red are
dependent on selected operating condition.Do not change without
changing these parameters.2Values in blue are dependent on
conditions in PRC.Plse change accordingly.3Values in green are
selected operating condition.Plse change
accordingly.IncinerationQin refuse per line=Mrefuse x
NCVrefuse10539.69KJ/sActual Qin refuse per
line=(1-%unburnt-%heatloss)xQin refuse10118.10KJ/sMw in pri air=M
pri air x %moisture0.035Kg/sMw in sec air=M sec air x
%moisture0.024Kg/sMw in refuse=M refuse x %moisture0.868Kg/sMw in
flue gas=Total M water
content0.927Kg/shw@850deg,atm4958KJ/Kghw@250deg,atm2975KJ/Kghw@25deg,atm2675KJ/KgTo
heat pri air, sec air, all moisture to 850 degCQin pri=Qair(250 to
850) + Qw(250 to 850)3114.36KJ/sQin sec=Qair(25 to 850) + Qw(25 to
850)2720.94KJ/sQin refuse water=Mw refuse x(hw25 to
hw850)1981.77KJ/sTotal Qin required7817.07KJ/sIs Qin refuse >
Qin required ?0Can the temp b4 boiler be higher or0more steam than
the design load can begenerated?BoilerEnergy air side = Energy
steam sideMsi
=Mwi=MfluexCp(850-200)/(h9-h1)3.111Kg/s11.1993413893Ton/hrAt Air
Heater (1)MsH1=Mpair x Cp(80-25)/(h1-h13)0.113Kg/sAt Air Heater
(2)MsH2=Mpair x Cp(250-80)/(h11-h13)0.261Kg/sMass balance for
turbineMst=(Msi - MsH1)x10 Lines29.980Kg/sMst + Mcw - Ms - MsH3 -
10MsH2= 0Ms+MsH3-Mcw= Mst - 10MsH227.373Kg/sEnergy balance for
Deareater (refer to
Sheet-Deareater)SolvingMsH33.179Kg/sMcw0.542Kg/sMs24.735Kg/sIs
energy in balance?0At Superheater and feedwater heaterQ
superheater=Mst(h3-h1)15019.76KJ/sQ feedwater
heater=10xMwi(h9-h8)2675.40KJ/sQ required frm fuel= Q sh + Q
fw17695.16KJ/sM a2= Qtotal/(CpT1300-CpT200)11.48Kg/sValue include
1.5 time excess airV a2@1300DegC= M a2 /
[email protected]/sV
a2@200DegC= M a2 /
[email protected]/sV a2@25DegC= M a2 /
[email protected]/sDiameter of
furnance=Va2@1300/Vel3.29mDiameter of
Stack=Va2@200/Vel2.55mDiameter of FD Fan=Va2@25/Vel1.02mTemp after
superheater384degCApprox value onlyFD Fan Pwr
@60%eff146.30KWDisplacement35113.04m3/hrAt FurnanceMass fuel
consumed=Ma2(CpT1300-CpT25)/Cvfuel0.486Kg/s42.02Ton/dyFuel cost per
year$15,339,056per yrAt TurbineMech power output=Ms(h3-h4) x Eff
isen24.4MWRevenue on power alone$32,030,521per yrAt CondenserActual
enthalpy h4'=h3 - (h3-h4)xEff isen2317.5KJ/kgQ rejection= Ms(h4' -
h5)52.57MWM cooling
water=Qrej/Cpw(T37-T27)1257.46Kg/s4526.84Ton/HrToo large, reservior
water may not be sufficient. Probably a cooling tower will be more
appropriateThermal AnalysisTotal Qin frm refuse=10xMrefuse x
NCVrefuse105396.88Total Qin frm fuel= Mfuel x NCV
fuel20364.52Thermal Efficiency= Pwr out/Total Qin19.38%
Mst
Ms
Mcw
MsH3
10MsH2
DeareaterMass balance for
turbineMst=29.98Ms+MsH3-Mcw=27.37Therefore,Ms=27.37- MsH3 +
Mcweqn(1)At Deareaterh13,10MsH110MsH2, h12MsH3,
h11Ms+10MsH1+10MsH2+MsH3Ms, h6h7(Ms + MsH3 + 10MsH1 +
10MsH2)h7=Msxh6 + MsH3xh11 + 10MsH1xh13 +10MsH2xh12Ms(h7-h6) -
MsH3(h11-h7)=10MsH1(h13-h7) +
10MsH2(h12-h7)354Ms-2521MsH3=741.27eqn(2)At Expansion
Valveh3,10MsH2 + MsH3Mcw, h810MsH2(h3-h11)h11,10MsH2 + MsH3 +
Mcw(10MsH2 + MsH3)h3 + Mcwxh8=(10MsH2 + MsH3 +
Mcw)h1110MsH2(h3-h11)=Mcw(h11-h8) + MsH3(h11-h3)Mcw(h11-h8) -
MsH3(h3-h11)=10MsH2(h3-h11)2521Mcw-236MsH3=615.24eqn(3)Sub
(1)in(2)354(27.37-MsH3+Mcw) - 2521MsH3=741.27-354Mcw +
MsH3(2521+354)=354x27.37 -
741.27-354Mcw+2875MsH3=8948.63eqn(4)(4)x7.12=>-2521Mcw+20474.2231638418MsH3=63727.42eqn(5)(5)+(3)0Mcw+20238.2231638418MsH3=64342.66SolvingMsH3=3.1792643658Kg/sMcw=0.5416693471Kg/sMs=24.74Kg/sChecking
for balancing (At Deareator)Energy in=Msxh6 + MsH3xh11 + 10MsH1xh13
+10MsH2xh12=17281.4192373394Energy Out=(Ms + MsH3 + 10MsH1 +
10MsH2)h7=17281.4192373394Balance?=0=>Answer is correct!
Flow diagramLegendSteam
flowAirflowKg/sKJ/Kgkg/sKJ/kgKbardegCm3/sdegC11.48001328941.16538429.9803303Superheater34.343511.48001328941.318113000.542546Fuel5.24533030.54254637130Furnance44144143.624.7353303Common
steam headerTo other line34.34356.328306711.48001328941.0049FD
fan(2)4300Turbine3.11128029.82537246Superheated steam
header3.1793067PWR
=24.4MW43000.11328020.2613067372467.61617083331.12474300Heater(1)3.47084222221.00492007.61617083331.263Heater(2)3.47084222221.00842.948888888925Boiler8508024.73522080.145.8FD
fan(1)Cooling water3.1116320.2616050.113106637150150T/dy RefuseSec
air2.38319613891.00494143.6372462.024805555625common return
header0.1131066Incinerator4143.61.130106624.7351923143.60.145.82.6076053.179306711.48001328941.12473.47084222221.03423143.63300200250feedwater31.651546heater3713024.735192345.831.651546Common
feed header31.1096323130Deareater371500.54254637130
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