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On Model Libraries for Thermo-hydraulic Applications

Eborn, Jonas LU (2001) In PhD Theses TFRT-1061.
Abstract (Swedish)
Popular Abstract in Swedish

Om modellbibliotek för termo-hydrauliska tillämpningar.



Matematiska modeller och simulering är viktiga verktyg för att hantera tekniska system. Speciellt som trenden idag är att öka komplexiteten i system genom integrerad produktion och processoptimering. Att hantera dessa komplexa system kräver kunskaper inom många områden samtidigt. Modellbibliotek är ett bra sätt att paketera kunskap. Kommersiella simuleringsprogram tillandahåller bra modellbibliotek, men de är ofta ämnes-specifika och tillåter ingen insyn. Komplexa, multi-displinära system kräver öppna modellbibliotek skrivna i ett generellt modelleringsspråk. Modelica är ett sådant modelleringsspråk som stödjer... (More)
Popular Abstract in Swedish

Om modellbibliotek för termo-hydrauliska tillämpningar.



Matematiska modeller och simulering är viktiga verktyg för att hantera tekniska system. Speciellt som trenden idag är att öka komplexiteten i system genom integrerad produktion och processoptimering. Att hantera dessa komplexa system kräver kunskaper inom många områden samtidigt. Modellbibliotek är ett bra sätt att paketera kunskap. Kommersiella simuleringsprogram tillandahåller bra modellbibliotek, men de är ofta ämnes-specifika och tillåter ingen insyn. Komplexa, multi-displinära system kräver öppna modellbibliotek skrivna i ett generellt modelleringsspråk. Modelica är ett sådant modelleringsspråk som stödjer objekt-orienterad modellering av dynamiska system. Modelica har specificerats genom ett europeiskt samarbete och är en öppen standard.



Avhandlingen beskriver principer för objekt-orienterade och ekvations-baserade modellbibliotek. Tillämpningen är modellering av termo-hydrauliska system, dvs processer som innefattar flöden av värme och vätska eller gas. Två olika modellbibliotek presenteras; ett kallat K2, som är utvecklat för simulering av termiska kraftverk; det andra kallat ThermoFlow. ThermoFlow är ett av flera basbibliotek i det nya modelleringsspråket Modelica, och är mer generellt tillämpbart för termo-hydrauliska system. Modellerna bygger på fysikaliska principer med kontrollvolymer som innehåller dynamiska balansekvationer för massa, energi och rörelsemängd. Basbiblioteket är byggt på ett flexibelt sätt. Den grundläggande kontrollvolymen kan innehålla olika vätskor/gaser, med en eller flera komponenter, och den kan diskretiseras i flödesriktningen för en noggrannare beskrivning. Flera specifika tillämpningar beskrivs i avhandlingen: ångsidan av ett kombikraftverk, en dom-ångpanna och en modell för flödessvängningar i ett stigar-rör, där t.ex. vatten kokas till ånga. (Less)
Abstract
Mathematical modelling and simulation are important tools when dealing with engineering systems that today are becoming increasingly more complex. Tightly integrated production and process optimization are trends that give rise to heterogeneous systems, which are difficult to handle without expertise in several engineering disciplines. Model libraries provide an excellent way to package engineering knowledge of systems and units to be reused by non experts. Many commercial simulation packages provide good model libraries, but they are usually domain specific and closed. Heterogeneous, multi-domain systems requires open model libraries written in general purpose modelling languages. Modelica(TM) is such an open standard for an... (More)
Mathematical modelling and simulation are important tools when dealing with engineering systems that today are becoming increasingly more complex. Tightly integrated production and process optimization are trends that give rise to heterogeneous systems, which are difficult to handle without expertise in several engineering disciplines. Model libraries provide an excellent way to package engineering knowledge of systems and units to be reused by non experts. Many commercial simulation packages provide good model libraries, but they are usually domain specific and closed. Heterogeneous, multi-domain systems requires open model libraries written in general purpose modelling languages. Modelica(TM) is such an open standard for an object-oriented modelling language for dynamic systems.



The thesis describes principles for object-oriented equation-based model libraries. The main topic is modelling of thermo-hydraulic applications. Two different model libraries are presented, the Omola model library K2 for thermal power plants and the Modelica base library ThermoFlow for general thermo-hydraulic applications. The models are based on first principles. Lumped or 1D-discretized control volumes contain the thermodynamic balance equations. The base library is built for flexibility; the control volume can have different medium descriptions, single- or multi-component, and the momentum dynamics can be replaced by static descriptions. Some applications of the libraries are also described: a heat recovery steam generator, a drum-boiler model and a model of evaporating two-phase flow in a pipe.



The thesis consists of four articles. Papers I and II describe the two model libraries. Paper III covers the two-phase flow application and gives a simplified physical analysis that shows under what conditions there will be pressure-drop oscillations in an evaporating pipe. Model libraries for industrial use must be validated against measured data. Paper IV describes how parameter estimation methods can be used for model structure validation. The thesis also has a short discussion on other model validation methods. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Preisig, Heinz, TU Eindhoven
organization
publishing date
type
Thesis
publication status
published
subject
keywords
modeling, simulation, Matematik, Automation, Termisk teknik, control systems, nonlinear models, parameter estimation, proces s control, thermo-hydraulic systems, model validation, Thermal engineering, applied thermodynamics, termodynamik, Automatiska system, robotics, control engineering, reglerteknik, robotteknik, Mathematics, object-oriented
in
PhD Theses
volume
TFRT-1061
pages
135 pages
publisher
Department of Automatic Control, Lund Institute of Technology (LTH)
defense location
M:B, M-building, Ole Römers väg 1
defense date
2001-03-02 10:15
ISSN
0280-5316
language
English
LU publication?
yes
id
260ff604-e7f6-4786-b24e-b4120f555353 (old id 41340)
date added to LUP
2007-06-21 09:51:55
date last changed
2018-08-17 19:17:11
@phdthesis{260ff604-e7f6-4786-b24e-b4120f555353,
  abstract     = {Mathematical modelling and simulation are important tools when dealing with engineering systems that today are becoming increasingly more complex. Tightly integrated production and process optimization are trends that give rise to heterogeneous systems, which are difficult to handle without expertise in several engineering disciplines. Model libraries provide an excellent way to package engineering knowledge of systems and units to be reused by non experts. Many commercial simulation packages provide good model libraries, but they are usually domain specific and closed. Heterogeneous, multi-domain systems requires open model libraries written in general purpose modelling languages. Modelica(TM) is such an open standard for an object-oriented modelling language for dynamic systems.<br/><br>
<br/><br>
The thesis describes principles for object-oriented equation-based model libraries. The main topic is modelling of thermo-hydraulic applications. Two different model libraries are presented, the Omola model library K2 for thermal power plants and the Modelica base library ThermoFlow for general thermo-hydraulic applications. The models are based on first principles. Lumped or 1D-discretized control volumes contain the thermodynamic balance equations. The base library is built for flexibility; the control volume can have different medium descriptions, single- or multi-component, and the momentum dynamics can be replaced by static descriptions. Some applications of the libraries are also described: a heat recovery steam generator, a drum-boiler model and a model of evaporating two-phase flow in a pipe.<br/><br>
<br/><br>
The thesis consists of four articles. Papers I and II describe the two model libraries. Paper III covers the two-phase flow application and gives a simplified physical analysis that shows under what conditions there will be pressure-drop oscillations in an evaporating pipe. Model libraries for industrial use must be validated against measured data. Paper IV describes how parameter estimation methods can be used for model structure validation. The thesis also has a short discussion on other model validation methods.},
  author       = {Eborn, Jonas},
  issn         = {0280-5316},
  keyword      = {modeling,simulation,Matematik,Automation,Termisk teknik,control systems,nonlinear models,parameter estimation,proces s control,thermo-hydraulic systems,model validation,Thermal engineering,applied thermodynamics,termodynamik,Automatiska system,robotics,control engineering,reglerteknik,robotteknik,Mathematics,object-oriented},
  language     = {eng},
  pages        = {135},
  publisher    = {Department of Automatic Control, Lund Institute of Technology (LTH)},
  school       = {Lund University},
  series       = {PhD Theses},
  title        = {On Model Libraries for Thermo-hydraulic Applications},
  volume       = {TFRT-1061},
  year         = {2001},
}