DYNAMIC MODELLING OF FOSSIL POWER PLANTS – INCREASING FLEXIBILITY TO BALANCE FLUCTUATIONS FROM RENEWABLE ENERGY SOURES

Baku, 23.05.2013

M. Hübel, Dr. J. Nocke, Prof. E. HasselUniversity of RostockInstitute of Technical Thermodynamics

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Overview

1. Motivation 2. Reference PowerPlant3. Simulation and Validation4. Example Results5. Outlook

Institute of Technical Thermodynamics – Dynamic Power Plant Simulation

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MotivationGerman Electric Energy System 2020

Institute of Technical Thermodynamics – Dynamic Power Plant Simulation

http://meltblog.de/wp-content/uploads/2013/02/Fotolia_45848443_XS.jpg

Installed CapacitiesPhotovoltaic: ~ 50 GWWind:~ 55 GW

GRID FREQUENCY

indicats deviations in the energy balance

Consumer LoadMaximum: ~ 80 GWAverage: ~ 60 GW

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MotivationGerman Electric Energy System 2020

Institute of Technical Thermodynamics – Dynamic Power Plant Simulation

http://meltblog.de/wp-content/uploads/2013/02/Fotolia_45848443_XS.jpg

Annual ProductionPhotovoltaic: ~ 50 TWhWind: ~ 120 TWh

GRID FREQUENCY

indicats deviations in the energy balance

Annual Consumption~ 600 TWh/a

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MotivationGerman Electric Energy System 2020

Institute of Technical Thermodynamics – Dynamic Power Plant Simulation

http://meltblog.de/wp-content/uploads/2013/02/Fotolia_45848443_XS.jpg

Annual ProductionPhotovoltaic: ~ 50 TWhWind: ~ 120 TWh

GRID FREQUENCY

indicats deviations in the energy balance

Annual Consumption~ 600 TWh/a

Fossil: >300 TWh

6Institute of Technical Thermodynamics – Dynamic Power Plant Simulation

MotivationRole of Fossil Power Plants in the German Electric Energy System

• Most of our consumed electric energy is from thermal power plants – today and in the next decades

• Some grid services, e.g. Primary Control can currently be done only by thermal power plants

• (too) little investments for modernization and optimization within this sector – high potential for optimization

Operating Schedule

GOAL: Flexible power plants

Pmin

Gradmax

t

P

Decr

easin

g M

inim

um L

oad

Incr

easin

g Lo

ad G

radi

ents

METHODE: Dynamic Modeling

• Identify restrictions• Develop optimization strategies• Comparison of scenarios

7Lehrstuhl für Technische Thermodynamik – Dynamische Modellierung des Kraftwerks “Jänschwalde”

Block DBlock C

Werk Y2

D2D1

C2C1

Reference Power PlantJänschwalde Block D

• Year of commissioning: 1985• combustible:

lignite• generator output:

530 MW• Efficiency:

36%• live steam

- mass flow rate: 2x230 kg/s- pressure: 162 bar

- temperature: 535 °C

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Overview on Power Plant / Model Structure

Lehrstuhl für Technische Thermodynamik – Dynamische Modellierung des Kraftwerks “Jänschwalde”

Boiler

Turbine

Condensator

LP-Preheaters

Feedwater System

HP-Preheaters

Mass balance

Energy balance

Momentum balance

Heat transfer

Inside wall at boundary layer

according Fouriers α determined by Dittus-Boelterheat transfer equation (1-phase flow) or Chen-correlation (2-phase flow)

n

iimdt

dm1

t

n

iii WQmh

dtdU

1

i

n

iiiii

n

iiifiii

n

iii ngzAnApAnccA

dtmcd

----11

01

)()(

2

2

drTda

dtdT

TAQ

Inlet massflow

Outlet massflow

heat flux

Inlet enthalpy flux

Outlet enthalpy flux

Inlet p

Outlet p

Δ p

Toutside Tinside

TFluid

Fundamental equations

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Results

Institute of Technical Thermodynamics – Transient Modeling of the Lignite Power Plant “Jänschwalde”

Simulation and ValidationInput Data

11Institute of Technical Thermodynamics – Transient Modeling of the Lignite Power Plant “Jänschwalde”

P GeneratorP Generator Simulated

Simulation and ValidationPower Output

12Institute of Technical Thermodynamics – Transient Modeling of the Lignite Power Plant “Jänschwalde”

Simulation and ValidationBoiler Temperatures

13Institute of Technical Thermodynamics – Transient Modeling of the Lignite Power Plant “Jänschwalde”

Simulation and ValidationPreheater Temperatures

14Institute of Technical Thermodynamics – Transient Modeling of the Lignite Power Plant “Jänschwalde”

Simulation and ValidationPreheater Temperatures

Fartigue of Headers

Result

• Fartigue for the components varies between 0,0008 and 0,0051 % for the reference scenario

• Evaporator and Superheater 2 are critical components in dynamic operation

Conclusion

• Same input scenario dones not lead to same fatigue because of different temperatues and different geometries

Example ResultsFatigue in components for the reference scenario

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different operation modes

Simulation of critical load and wind scenarios under

variation of load gradient, min load of PP

Jänschwalde or operation of the power plant

in special mode

operation parameters

Pmin

Gradmax

Load gradient Scenarios2.5%, 4%, 6%

special operation modes„shut down & restart“„reduce to circulation mode“

Stillstand

Lastgradient

Mindestlast

Min load scenarios50%, 37.5%, 33%, 20 %

Outlook

Institute of Technical Thermodynamics – Effects of fluctuating Wind Power on Power plant operation

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Thank you for your attention!

Dipl.-Ing. M. HübelDr.-Ing. J. Nocke

Prof. Dr.-Ing. E. Hassel

Institute of Technical Thermodynamics – Dynamic Power Plant Simulation

And thanks to our sponsors for financial support