talk=t;run(1,1)
PHOTON USE
autoplot
upause 1
file; phi 5
cl; da 1; yco2; da 1; yo2; da 1; yco; scale; cola 1; col3 2
colf 3
msg
msg
msg Mass fractions of CO2 - yellow, O2 - blue,
msg CO - red ................................more
pause; cl; da 1; yh2o; da 1; YH2; scale; col3 1; colf 2
msg
msg
msg Mass fractions of H2O - blue and H2 - red ...mor
pause; cl; da 1; fcl; da 1; YN2; scale; col3 1; colf 2
msg
msg
msg Mass fractions of N2 - red and
msg coal-derived gas - blue ........more
pause; cl; da 1; temp; colF 1;
msg
msg
msg Temperature of gas, K .......more
pause; cl; da 1; w1; col7 1;scale;
msg
msg
msg Gas velocity, m/s
enduse
GROUP 1. Run title and other preliminaries
TEXT( Ore reduction in a packed bed
DISPLAY
Ore reduction in a packed bed:
One-phase, 1D, one space, coke combustion,
mass transfer related ore reduction sources only.
ENDDIS
Coal-combustion model.
Reactions: C (s) + 0.5 O2 > CO
CO + 0.5 O2 > CO2
C(s) + CO2 > 2CO
C(s) + H2O > CO + H2
H2 + 0.5 O2 > H2O
The numerical values which appear below are:-
* the mass fractions of O2 and N2 in air, namely: 0.232 and 0.
* the molecular weights of O2, N2, CO2, CO, H2O, H2, -
32.0, 28.0, 44.0, 28.0, 18.0 and 2.0
* the Universal Gas Constant, GASCON: 8.314
* the heat of reaction for C + O2 -> CO2, HCCO2: 3.279
* the heat of reaction for C + 0.5*O2 -> CO , HCCO : 9.208
* the heat of reaction for H2 + 0.5*O2 -> H2O, HHH2O: 1.209
* the specific heat at constant pressure, CP : 1.100
all in SI un
CINCL, the mass fraction of C in the coal;
HINCL, the mass fraction of H in the fuel;
NINCL, the mass fraction of N in the fuel;
AINCL, the mass fraction of ash in the fuel.
REAL(HINCL,CINCL,NINCL,AINCL,GASCON)
REAL(AIRO2,AIRN2)
REAL(MN2,MC,MO2,MH2,MCO,MCO2,MH2O)
GASCON=8.3143e3
HINCL=0.05
CINCL=0.95
NINCL=0.0
AINCL=1.-CINCL-HINCL-NINCL
AIRO2=0.232
AIRN2=0.768
MN2=28.; MC=12.; MO2=32.; MH2=2.; MCO=28.; MCO2=44.; MH2O=18.
REAL(HCCO2,HCCO,HHH2O,HCHX,HCOCO2)
HCCO2 =3.279E7
HCCO = 9.208E6
HHH2O = 1.209E6
REAL(FS,BURNRATE, WIN)
** FS is the mass of fuel per unit mass of air/fuel mixture
to convert all carbon and oxygen to carbon monoxide.
FS=0.232/(0.232 + CINCL*16.0/12.0)
** The heat of combustion per unit mass of co is hcco2 minus hcco
the mass of c per unit mass of co, ie 12/28
HCOCO2=(12.0/28.0)*(HCCO2-HCCO)
** The heat of coal combustion per unit mass of carbon
HCHX=(CINCL*HCCO2+HINCL*HHH2O)*(HINCL*MH2+CINCL*MC+NINCL*MN2)/MC
** The rate of burning
BURNRATE=3.
** The inlet gas velocity
WIN=5.
GROUP 4. Y-direction grid specification
NY=1;GRDPWR(Y,NY,NY,1.0)
GROUP 5. Z-direction grid specification
NZ=10;GRDPWR(Z,NZ,10.,1.0)
GROUP 7. Variables stored, solved & named
** FCL - carbon element mass fraction;
** The specific heat at constant pressure, CP =1.100E3
H = CP*T + HCHX*YCHX + HCOCO2*YCO * HHH2*YH2
SOLVE(P1,W1,H1,FCL)
REAL(CP,TFUEL,HGIN,TGIN)
TGIN = 350.0
CP= 1100.
HGIN = CP*TGIN
STORE(RMIX,HSUB,TEMP,YN2,YH2,YO2,YCO,YCO2,YH2O)
STORE(DEN1,FLIM,FRAC,GO,GC,GH,GOFU,GOPA)
SOLUTN(P1 ,Y,Y,Y,P,P,P)
SOLUTN(FCL,Y,Y,Y,P,P,P)
SOLUTN(H1 ,Y,Y,Y,P,P,P)
GROUP 8. Terms (in differential equations) & devices
TERMS(FCL,N,Y,N,P,P,P)
TERMS(H1 ,N,Y,N,P,P,P)
GROUP 9. Properties of the medium (or media)
REAL(RHOIN1,WAIR)
PRESS0=1.e5
WAIR=32.
RHOIN1=PRESS0*WAIR/(8314.*TGIN)
RHO1=GRND
DEN1=PRESS0/(RMIX*TEMP)
DEN1=AMIN1(VARMAX(140),AMAX1(0.0,DEN1,VARMIN(140)))
ENUL=0.0
GROUP 11. Initialization of variable or porosity fields
FIINIT(W1)=1.
STORE(VPOR)
FIINIT(VPOR)=0.25
FIINIT(FCL)=1.
FIINIT(P1)=1.3E-4
GROUP 13. Boundary conditions and special sources
** Inlet Boundaries
INLET(INLET,LOW,1,NX,1,NY,1,1,1,1)
VALUE(INLET,P1 , RHOIN1*WIN)
VALUE(INLET,W1 , WIN)
VALUE(INLET,FCL , 0.0)
VALUE(INLET,H1 , HGIN)
** Frictional momentum transfer
PATCH(FRICTION,VOLUME,1,NX,1,NY,1,NZ,1,1)
COVAL(FRICTION,W1,100.,0.0)
**Outlet boundary
PATCH(OUTLET,HIGH,1,NX,1,NY,NZ,NZ,1,1)
COVAL(OUTLET,P1,fixp,0.0)
Carbon mass transfer related sources:
------------------------------------
PATCH(CARGAS,CELL,1,NX,1,NY,1,NZ,1,1)
(1) Transfer of mass leading to increase of gas flow rate:
- VPOR is volume fraction of lump coal
VAL=:BURNRATE:*(1.-VPOR)*(:FS:-FCL)
COVAL(CARGAS,P1,FIXFLU,GRND)
(2) Transfer of carbon leading to increase of mixture
fraction at the same rate:
- CO=1. signifies that mass tarnsfer brings in
material which is 100% carbon
COVAL(CARGAS,FCL,ONLYMS,1.)
(3) Transfer of enthalpy and heat leading to increse of
gas enthalpy at the same rate:
- Interphase gas temperature is assumed as TEMP.
- HSUB = HCOCO2*YCO * HH2*YH2
VAL=:CP:*TEMP+:HCHX:+HSUB
COVAL(CARGAS,H1,ONLYMS,GRND)
Ore reduction mass transfer related sources:
--------------------------------------------
REAL(AGS,HGS,ORE)
AGS=150.
HGS=20.
ORE=0.6
(1) Transfer of mass leading to increase of gas flow rate:
m31 = Ags.(Rco2-Rco), kg/m^3/s
PATCH(OREGAS,VOLUME,1,NX,1,NY,1,NZ,1,1)
VAL=0.01*150.*((1.+84./160.)*132./244.-3.*28./160.)
COVAL(OREGAS,P1,FIXFLU,GRND)
(2) Transfer of carbon element leading to decrease of
coal-derived gas mass fraction:
Sfcl,co = -Rco.Mc/Mco.FCL
PATCH(CO4FCL,VOLUME,1,NX,1,NY,1,NZ,1,1)
CO=3.*:HGS:*YCO*:ORE:/:CP:*:AGS:*28./160.*12./28.
COVAL(CO4FCL,FCL,GRND,0.)
(2) Transfer of carbon element leading to increase of
coal-derived gas mass fraction:
Sfcl,co2 = Rco2.Mc/Mco2.(FS-FCL)
PATCH(COO4FCL,VOLUME,1,NX,1,NY,1,NZ,1,1)
CO=20.*YCO*0.6/1100.*150.*(1+84./160.)*132./244.*12./28.
COVAL(COO4FCL,FCL,GRND,FS)
In which, Rco = 3.Ro.Ags.28/160
Ro = hgs.Yco.Yore/Cpgas
Rco2= Ro.Ags.(1+84/160).132/244
To be considered,
- the mass transfer related enthalpy and heat transfer.
GROUP 15. Termination of sweeps
LSWEEP=350
RESFAC=0.0001
GROUP 16. Termination of iterations
LITHYD=10
VARMAX(FCL)=1.0;VARMIN(FCL)=0.0
VARMIN(TEMP)=TGIN;VARMAX(TEMP)=3000.
VARMIN(DEN1)=0.001;VARMAX(DEN1)=3.
GROUP 17. Under-relaxation devices
RELAX(P1,LINRLX,0.25)
RELAX(W1,FALSDT,0.025)
RELAX(V1,FALSDT,0.025)
RELAX(FCL,FALSDT,0.025)
RELAX(H1,FALSDT,0.025)
RELAX(DEN1,LINRLX,0.2)
GROUP 22. Monitor print-out
IZMON=NZ-1;IYMON=NY-1;UWATCH=T
GROUP 23. Field print-out and plot control
NPLT=1;NYPRIN=1;NZPRIN=1
NYPRIN=1;IYPRF=1;IYPRL=30
TSTSWP=-1
namsat=mosg
Coal oxidation is presumed to proceed in two stages, viz:
(1) to create CO2 and H2O, and then
(2) to create CO and H2, as more fuel is added.
The gas composition diagram, taking account of the elemental
mass fractions of O, C and H, has got three regions:
(1) Region 1 containing O2, CO2 & H2O
(2) Region 2 containing CO2, H2O, H2 & CO
(3) Region 3 containing H2 & CO.
The values of oxygen fraction GO at which the formulae exbibit
discontinuities of slope are called:-
GOPA, where the oxygen has consumed part of the fuel, so as
create CO and H2; and
GOFU, where the products of combustion are CO2 and H2O.
** Cell-wise composition parameters
--------------------------------
FLIM=:AIRO2:/(:AIRO2:+:CINCL:*:MO2:/:MC:+$
:HINCL:*:MO2:/(2*:MH2:))
GO=:AIRO2:*(1-FCL)
GC=:CINCL:*FCL
GH=:HINCL:*FCL
GOPA=GC*:MO2:/(2*:MC:)/(1-GO+GC*:MO2:/(2*:MC:)+TINY)
GOFU=(GH*:MO2:/(2*:MH2:)+GC*:MO2:/:MC:)/$
(1.-GO+GH*:MO2:/(2*:MH2:)+GC*:MO2:/:MC:+TINY)
FRAC=(GO-GOPA)/(GOFU-GOPA+TINY)
** For all regions
---------------
YN2=:NINCL:*FCL+:AIRN2:*(1.-FCL)
** Region 1
--------
YH2O=:HINCL:*FCL*:MH2O:/:MH2:
IF(FCL.LE.FLIM)
YCO2=:CINCL:*FCL*:MCO2:/:MC:
IF(FCL.LE.FLIM)
YO2 =:AIRO2:*(1-FCL)-:CINCL:*FCL*:MO2:/:MC:-$
:HINCL:*FCL*:MO2:/(2.*:MH2:)
IF(FCL.LE.FLIM)
YCO=0.0
IF(FCL.LE.FLIM)
YH2=0.0
IF(FCL.LE.FLIM)
** Region 2
--------
YH2O=:HINCL:*FCL*:MH2O:/:MH2:*FRAC*(1-GOFU)/(1-GO+TINY)
IF(FCL.GT.FLIM.AND.FRAC.GE.0.)
YCO2=:CINCL:*FCL*:MCO2:/:MC:*FRAC*(1-GOFU)/(1-GO+TINY)
IF(FCL.GT.FLIM.AND.FRAC.GE.0.)
YO2=0.0
IF(FCL.GT.FLIM.AND.FRAC.GE.0.)
YCO=:CINCL:*FCL*:MCO:/:MC:*(1-FRAC)*$
(1-GOPA)/(1-GO+TINY)
IF(FCL.GT.FLIM.AND.FRAC.GE.0.)
YH2=:HINCL:*FCL*(1-FRAC)*(1-GOPA)/(1-GO+TINY)
IF(FCL.GT.FLIM.AND.FRAC.GE.0.)
** Region 3
--------
YH2O=0.0
IF(FCL.GT.FLIM.AND.FRAC.LT.0.)
YCO2=0.0
IF(FCL.GT.FLIM.AND.FRAC.LT.0.)
YO2=0.0
IF(FCL.GT.FLIM.AND.FRAC.LT.0.)
YCO=:AIRO2:*(1-FCL)*2*:MCO:/:MO2:
IF(FCL.GT.FLIM.AND.FRAC.LT.0.)
YH2=:HINCL:*FCL
IF(FCL.GT.FLIM.AND.FRAC.LT.0.)
*******************************
YH2 =AMAX1(0.,YH2 )
YH2O=AMAX1(0.,YH2O)
YCO =AMAX1(0.,YCO )
YCO2=AMAX1(0.,YCO2)
YN2 =AMAX1(0.,YN2 )
YO2 =AMAX1(0.,YO2 )
HSUB=0.0
IF(FCL.LE.FLIM)
RMIX=:GASCON:*(YO2/:MO2:+YH2O/:MH2O:+YCO2/:MCO2:+$
YN2/:MN2:)
IF(FCL.LE.FLIM)
HSUB=YCO*:HCOCO2:+YH2*:HHH2O:
IF(FCL.GT.FLIM.AND.FRAC.GE.0.)
RMIX=:GASCON:*(YH2O/:MH2O:+YCO/:MCO:+YCO2/:MCO2:+$
YH2/:MH2:+YN2/:MN2:)
IF(FCL.GT.FLIM.AND.FRAC.GE.0.)
HSUB=YCO*:HCOCO2:+YH2*:HHH2O:
IF(FCL.GT.FLIM.AND.FRAC.LT.0.)
RMIX=:GASCON:*(YCO/:MCO:+YH2/:MH2:+YN2/:MN2:)
IF(FCL.GT.FLIM.AND.FRAC.LT.0.)
** Calculation of absolute gas temperature
--------------------------------------
TEMP=(H1-HSUB)/:CP:
TEMP=AMIN1(VARMAX(147),AMAX1(100.,TEMP,VARMIN(147)))
store(ysum)
YSUM=YN2+YO2+YCO+YCO2+YH2O+YH2
dmpstk=t
LIBREF=104
STOP