MOBE: Final Report: Modelling and Optimization of biomass-based Energy production

K Trangbæk; Brian Elmegaard

MOBE: Final Report: Modelling and Optimization of biomass-based Energy production

K Trangbæk, Brian Elmegaard

Publikation: Bog/antologi/afhandling/rapport › Rapport › Forskning

Abstract

Nærværende rapport er en samlet dokumentation af arbejdet som er udført i PSOprojektet MOBE, “Modellering og optimering af biomassebaseret energiproduktion”.
Målsætningen i projektet er at udvikle bedre reguleringsmetoder for kedler i de centrale kraftværker, således at værket som sådan opnår bedre reguleringsevne med hensyn til lastændringshastighed specielt i lavlastområdet omkring og under Bensonpunktet.
Rapporten indledes med en beskrivelse af de udfordringer som kraftværkerne står overfor i det moderne elmarked hvor vindkraft udgør en væsentlig prioriteret produktion og dermed sammen med forbrugssvingninger bidrager til fastlæggelse af driften på de centrale blokke.
Rapporten dokumenterer arbejdet udført for at udvikle en fælles simuleringsplatform for parterne i projektet og for fremtidigt modelarbejde. Resultatet af dette arbejde er en integration af DTU’s simuleringskode DNA med Matlab. Der foreslås desuden muligheder for andre værktøjer.
Modelarbejdet i projektet har resulteret i indledende undersøgelser af tidskonstanter i fordamperrør, en analyse som viser at Ledinegg-instabilitet ikke opstår i moderne kedler selv ved lav last, udvikling af en valideret fordampermodel som kan kobles med værktøjer der anvendes ved udvikling af reguleringsstrategier samt en analyse af virkningsgrad af to forskellige konfigurationer af lavlastanlæg for Bensonkedler.
Baseret på en valideret kraftværksmodel kunne reguleringsstrategier evalueres.
Da begrænsninger i styresignaler og temperaturgradienter er dominerende, anbefales
det at anvende en modelprædiktiv regulator. Det demonstreres, hvordan en
sådan regulator kan håndtere store lastgradienter uden at overskride fastsatte begrænsninger.
Ved at skifte mellem lineariserede modeller kan hele lastområdet
dækkes.
Projektet indikerer at Model Predictive Control kan forbedre regulering i lavlast
markant. Dette bør i fremtidige projekter afklares ved reelle tests, i første omgang
mod en simulator baseret på “first principles” og siden på et værk. Modelarbejdet
i MOBE har lagt grunden for en model anvendelig model, men denne
skal yderligere udvikles med henblik på bedre forståelse af fordamperprocessen og
kobling til resten af kedlen, specielt mellemoverhedning. De udviklede modeller er
baseret på flere simplificerende antagelser. Disse antagelser bør granskes nøjere i
kommende arbejder hvor der bør fokuseres yderligere på reel drift af Bensonkedler
med forskellige brændsler.

Originalsprog	Engelsk

Forlag	DONG Energy
Status	Udgivet - 2008

Bibliografisk note

Endelig rapport for PSO-projekt nr. 4114

AUB Link

Søg efter materialet i Aalborg Universitetsbiblioteks søgemaskine

Citationsformater

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title = "MOBE: Final Report: Modelling and Optimization of biomass-based Energy production",

abstract = "The present report is the documentation of the work in the PSO-project MOBE,“Modelling and Optimization of biomass-based Energy production”. The aim ofthe project is to develop better control methods for boilers in central power plantunits, so the plant will achieve better controllability with respect to load changes.in particular focus is on the low load operation near and below the Benson point.The introduction of the report includes a description of the challenges the centralpower stations see in the modern electricity market where wind power deliversa signigicant prioritized production, and thus, in connection with consumptionvariations, contributes to the load requirements of the central units.The report documents the work on development of a common simulation platformfor the partners in the project and for future model work. The result of this isan integration between the DTU simulation code DNA and Matlab. Other possibletools are suggested.The modelling work in the project has resulted in preliminary studies of timeconstants of evaporator tubes, an analysis that shows that Ledinegg-instabilities donot occur in modern boilers even at low load, development of a validated evaporatormodel that can be coupled to tools for control system development, and an analysisof two different configurations af the low load system of Benson boilers.Based in a validated power plant model different control strategies have beenstudied. Because constraints on control signals and temperature gradients are dominating,it is recommended to use model predictive control. It is demonstrated, howsuch a simulator can handle large low gradients without violating the constraints.By switching between different linearized models the whole load range may becovered.The project indicates that Model predictive control can improve the control inlow low significantly. This should be studied further in future projects by realistictests. At first these should be done with a simulator based on first principlesand after this on a real boiler. The model work in MOBE has made the basis foran applicable model but this should be developed further to better understand theevaporator process and its coupling to the rest of the plant, particularly reheat.The models developed in the project are based on several simplified assumptions.These assumptions will have to be evaluated in future work by more focus on thereal operation of Benson boilers with different fuels.",

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N2 - The present report is the documentation of the work in the PSO-project MOBE,“Modelling and Optimization of biomass-based Energy production”. The aim ofthe project is to develop better control methods for boilers in central power plantunits, so the plant will achieve better controllability with respect to load changes.in particular focus is on the low load operation near and below the Benson point.The introduction of the report includes a description of the challenges the centralpower stations see in the modern electricity market where wind power deliversa signigicant prioritized production, and thus, in connection with consumptionvariations, contributes to the load requirements of the central units.The report documents the work on development of a common simulation platformfor the partners in the project and for future model work. The result of this isan integration between the DTU simulation code DNA and Matlab. Other possibletools are suggested.The modelling work in the project has resulted in preliminary studies of timeconstants of evaporator tubes, an analysis that shows that Ledinegg-instabilities donot occur in modern boilers even at low load, development of a validated evaporatormodel that can be coupled to tools for control system development, and an analysisof two different configurations af the low load system of Benson boilers.Based in a validated power plant model different control strategies have beenstudied. Because constraints on control signals and temperature gradients are dominating,it is recommended to use model predictive control. It is demonstrated, howsuch a simulator can handle large low gradients without violating the constraints.By switching between different linearized models the whole load range may becovered.The project indicates that Model predictive control can improve the control inlow low significantly. This should be studied further in future projects by realistictests. At first these should be done with a simulator based on first principlesand after this on a real boiler. The model work in MOBE has made the basis foran applicable model but this should be developed further to better understand theevaporator process and its coupling to the rest of the plant, particularly reheat.The models developed in the project are based on several simplified assumptions.These assumptions will have to be evaluated in future work by more focus on thereal operation of Benson boilers with different fuels.

AB - The present report is the documentation of the work in the PSO-project MOBE,“Modelling and Optimization of biomass-based Energy production”. The aim ofthe project is to develop better control methods for boilers in central power plantunits, so the plant will achieve better controllability with respect to load changes.in particular focus is on the low load operation near and below the Benson point.The introduction of the report includes a description of the challenges the centralpower stations see in the modern electricity market where wind power deliversa signigicant prioritized production, and thus, in connection with consumptionvariations, contributes to the load requirements of the central units.The report documents the work on development of a common simulation platformfor the partners in the project and for future model work. The result of this isan integration between the DTU simulation code DNA and Matlab. Other possibletools are suggested.The modelling work in the project has resulted in preliminary studies of timeconstants of evaporator tubes, an analysis that shows that Ledinegg-instabilities donot occur in modern boilers even at low load, development of a validated evaporatormodel that can be coupled to tools for control system development, and an analysisof two different configurations af the low load system of Benson boilers.Based in a validated power plant model different control strategies have beenstudied. Because constraints on control signals and temperature gradients are dominating,it is recommended to use model predictive control. It is demonstrated, howsuch a simulator can handle large low gradients without violating the constraints.By switching between different linearized models the whole load range may becovered.The project indicates that Model predictive control can improve the control inlow low significantly. This should be studied further in future projects by realistictests. At first these should be done with a simulator based on first principlesand after this on a real boiler. The model work in MOBE has made the basis foran applicable model but this should be developed further to better understand theevaporator process and its coupling to the rest of the plant, particularly reheat.The models developed in the project are based on several simplified assumptions.These assumptions will have to be evaluated in future work by more focus on thereal operation of Benson boilers with different fuels.

M3 - Report

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PB - DONG Energy

ER -

MOBE: Final Report: Modelling and Optimization of biomass-based Energy production

Abstract

Bibliografisk note

AUB Link

Fingeraftryk

Citationsformater