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RTD software for identification of spatially
localised models and data standardisation
R.Žitný, J.Thýn
Czech Technical University in Prague
.History of RTD software development at CTU
• Radiotracers group UVVVR since 1965. • First generation of RTD (mainframe), 1973-1980• Second generation (HP Basic), 1978-1989• Third generation (IBM PC), 1989-1999
• Fourth generation ?
First generation of RTD
R TD 1L ag u erre fu n c tion s
R TD 2Tim e d om ain
R TD 3Id en tifica tion
R TD in te rp re t
• Portability (Fortran 4, file oriented I/O)• Transparency (easy modifications)• Simple (user friendly) definition of batch
Example of batch (identification)
– INPUT(1)
– INPUT(2)
– NORM2(1,2)
– ECOEF2(1,2,3)
– TPOINT(3)
– STOP
– data (ti,ci) for time curve 1 – inlet stream
– data (ti,ci) for time curve 2 – outlet stream.
Third generation of RTD
R TD 0c (T) p rocess in g
n on -eq u id is tan t fu n c tion scorrec tion s
R TD 1Tim e/F ou rie r d om a in
con vo lu tion /d econ vo lu tionsp lin es , L ag u erre , F F T
R TD 2N u m erica l so l. O D E
id en tifica tionin te rac tive m od e ls M D F
R TD
Interactive Fortran77, (Matrix Editor, PF) Regularisation in time, Fouriere, Laguerre domain Identification of mixed type parameters (integer/real) Definition of models using MDF
Flow un it characterised by
(t,E or by Fourier series)C onvo lution and deconvolu tion
IMPULSE RESPONSES
Flow unit characterised by
(first o rder, non linear)N um erica l in teg ra tion
DIFFERENTIAL EQUATIONS
RTD1
RTD2
Black - Gray box analysis
Model definition file (MDF)C______1 series & backmixing [P1] Backmixing ratio [email protected] [P2] Mean residence time [email protected] [P3] Number of units @3F6.0\\INITreal tm,f,aux integer if=p(1) neq=p(3) tm=p(2)/neq c(1)=1/tm\\MODELdc(1)=(x+f*c(2)-(1+f)*c(1))/tmi=1while i<neq-1 do begin i=i+1 aux=(1+f)*c(i-1)+f*c(i+1)-(1+2*f)*c(i) dc(i)=aux/tm enddc(neq)=((1+f)*(c(neq-1)-c(neq)))/tmy=c(neq)\\PARAM
Models defined by users
variable flow/volume, axial dispersion collimation characteristics, heat transfer multiple inlets/outlets, heterogeneous system batch systems
RTD0 application
• Steam velocity. Venturimeter calibration;(NZ)
• Effective volume, holdup. Waste stabilization pond (Ph; Ml), Holding tanks (Alumina
industry) (Au), Rotary kiln (Cz)
• Parallel flows, bypass,channeling. Tank with settler - pilot plant (K), Ethylalcohol
reactor (Cz), Precipitation tanks (Au), Holding tanks (Au)
• Mixing characteristic, axial dispersion
• Recirculation flowrate ratio• Separation effect,tracer balance. Cement industry -Cyclone (K)
M om ents , peaksvarian ce , a rea , P ec le t
C orrec tionsb ackg rou n d ra ise , ta il, d ecay
D ecom pos itionreg ress ion (exp on en tia l, p ow er)
Z -trans form ationvariab le flow
O p era tion s
RTD1 application
C rosscorre la tiont im e d e lay, P R B S , freq u en cy ch ar.
S plines (l in ear/cu b ic) F F T (s in ,cos) L aguerre func tions
(D e)convolution - regula r isa tionE (t) id en tifica tion , resp on se p red ic t ion
S ystem s w ith recyc lesid en tifica tion , resp on se p red ic tion s
O p era tion s
• Flow rate measurement. Steam velocity measur.(NZ), flowrate measurement (K), incinerator
(NZ), temperature disturbances (extremely slow flowrate) (Cz)
• RTD functions: E(t), F(t), (t). Fluidized catalytic cracking (Au, Fi), Settling tank;
waste water treatment (Cz), Heat exchanger (In,K), Evaporator (In), Aniline reactor (In), Indirect rotary dryer (In), Mercury removal unit (Th), Electron beam gas chamber (K), Direct ohmic heating (Cz)
• Smoothing, disturbance attenuation. Waste water treatment (Cz)
• Transfer functions, Frequency characteristics, Waste water treatment
(Cz), furnace for glass (Cz)
RTD2 application
M ultip le in le tsresp on ses , id en tifica tion
Im pulse responsesid en tifica tion
T im e dom ain m ode lsP red ic tion s , id en tifica tion
L aplace trans form ation
L aplace dom ain m ode lsId en tifica tion , resp on se p red ic t ion
• Pilot plants. Mixed Tank (K); Extractor (Tl), Hygienization irradiator for waste water (batch system)
• Waste water treatment. Tank of activated sludge (TAS), air tubes (Ge), aeration turbines (Cz)
Gold system of activation (Cz), Sedimentation tanks (Cz), Equalization unit (Cz) Facultative oxidation Pond (Ph,Ml)
• Heat exchangers. Tubular heat exchanger (In),(K)
• Evaporation, dehydratation. Semi-Kestner (sugar industry) (In), Rotary dryer (In),
Dehydratation rotational furnace (pigment production) (Cz)
• Reactors. Production of aldehydes (Cz), Production of aniline (In), FCC crackinkg (1)Au, (2) Fi),
• Alumina production (Au). Precipitators; digestors; agglomeration, holding tanks
• Electron beams gas chamber (K). Chamber with baffles, chamber without baffles
• Disintegration effect Hammer mill (Cz), drum furnace (Cz)
Process modelling, LPM and CFD
• Lumped Parameter (LPM)• Computer fluid dynamics (CFD)• Combined Models (CM)
0102030405060708090
100
Past Present Future
LPMCFDCMEXP
?tracer
EXPeriments
Why spatially localised models?
• Improved description and design of processes
• Improved diagnostics• Residence time and temperature time T(t)• Thermal or irradiation treatment
Reaction is where?
I(z)
z
H1
H2 u(r)
D
Spatially localised LPM
• Series
• Parallel
Constant concentration in the view field
Distance=?
Distance=?
Non-uniform concentration in the view field
LPM & collimation algorithm
dccore/dxmeasured
10
100
1
1000 dcwall/dxmeasured
excentricity [-]
r/R=0.1
r/R=0.9r/R=0.1
r/R=0.9c C x C x
c C x C xcore
wall
11 1 12 2
21 1 22 2
dc
dxC C
dc
dxC C
core
wall
112
122
212
222
FCC -Fluidised Cracking Core - Anulus model (ccore, cwall =?)
EXP & collimation algorithm
CollimatedDetector
DirectOhmicHeating
CFD & collimation algorithm
CollimatedDetector
DirectOhmicHeating
FEM-COSMOS/M
CV-FLUENT (600000 nodes, 600 MB results)
CFD/EXP collimation algorithm
RdR
d h z
z1 22 2
;
( )
h
de
z
r
ehr
z
S Rb
eRR
b
eRb 1
2
122
2
arcsin arcsin
dJSz
r zc t r r z dz dr rd
4 2 2 3 2
( )( , cos , sin , )/
b R R e R R 1
24 1
222 2
12
22 2( )
Focused collimation algorithm
Focusedcollimateddetector
4th generation RTD software
• Project file
• Script
• Programs
Optimisedparameters
$MDFname\\icon {bitmap file reference)<! comment keywordsINTEGER, REAL,IF THENWHILE DOBEGIN END operators+ - * / ** = <= >= <> | & () functionssin,cos,exp,log,abs,min,max,erf,gama,rnd,atn,bj,by (Bessel funct.,Laguerre, Legendre, Cheb. polyn.)COLC(), COLS() - collimators system variablesT,X,Y,C(),DC(),P(),NEQ,NP,..>\\INITIAL....initial conditions
\\MODEL... diff. equations defining model
$PARnamename MDF<! model parameters>p1,...
$CTname<!time course (dt=time step)>\\dtc1
....cN
$CFnamename CT<! Fourier transform>\\dfRe1 Im1
...
ReN, ImN
$JOURNALname<! >
$MDF-FTPname<! model definition >URL
$COLLIMname<! comment>geometry,window,...
$CONNECTnamename XYZ<!connectivity matrix forCFD results>el1 M1 i1 ...iM1
...
$XYZname<! nodal points coordinates(CFD results)>coordinate system1 x1 y1 z1
...
$CTNnamename XYZ<! Predicted nodal valuesat a specified time>time1 c1
2 c2
...
$TUPLEXINname<! example of "foreign"CFD program>
Data manager(filters)
Model solver(MDF)numericalintegration
Model solver(fixed models)numericalintegration
FFT
Deconvolution(regularisation)
Rxx Rxy
Convolution
Normalisation
Comparion(optim. criteria)
Collimator/detector
Fluentconversion
Cosmosconversion
SCRIPTsequence ofcalledprograms andspecificationof data, i.e.PROG [namesof sections $..]
Working files
OPTIM
Conventions adopted:- section begins with $ in the
first column- name-arbitrary name of a
specific instance- <! ...> any comments
Conceptualscheme
CORE
• Project file
• Script
• Programs
FRONTEND
• Windows
• Visual studio?
• Linux
GTK libraryfor Windows and Unix
UNIX orWindows ? B.G.makes
stars from secretaries and idiots from experts