DYNAMIC MODELLING OF FOSSIL POWER PLANTS – INCREASING FLEXIBILITY TO BALANCE FLUCTUATIONS FROM...
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Transcript of DYNAMIC MODELLING OF FOSSIL POWER PLANTS – INCREASING FLEXIBILITY TO BALANCE FLUCTUATIONS FROM...
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. Hassel
University of Rostock
Institute of Technical Thermodynamics
2
Overview
1. Motivation 2. Reference PowerPlant3. Simulation and Validation4. Example Results5. Outlook
Institute of Technical Thermodynamics – Dynamic Power Plant Simulation
3
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
4
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
5
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
Dec
reas
ing
Min
imum
Loa
d
Incr
easi
ng
Load
Gra
dien
ts
METHODE: Dynamic Modeling
• Identify restrictions• Develop optimization strategies• Comparison of scenarios
7Lehrstuhl für Technische Thermodynamik – Dynamische Modellierung des Kraftwerks “Jänschwalde”
Block D
Block 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
8
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
dm
1
t
n
iii WQmh
dt
dU 1
i
n
iiiii
n
iiifiii
n
iii ngzAnApAnccA
dt
mcd
11
01
)()(
2
2
dr
Tda
dt
dT TAQ
Inlet massflow
Outlet massflow
heat flux
Inlet enthalpy flux
Outlet enthalpy flux
Inlet p
Outlet p
Δ p
Toutside Tinside
TFluid
Fundamental equations
10
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
16
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
17
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