Mathematical Modelling for Coal Fired Supercritical Power Plants and Model Parameter Identification Using Genetic Algorithms
Abstract
The paper presents the progress of our study of the whole process mathematical model for a supercritical coal-fired power plant. The modelling procedure is rooted from thermodynamic and engineering principles with reference to the previously published literatures. Model unknown parameters are identified using Genetic Algorithms (GAs) with 600MW supercritical power plant on-site measurement data. The identified parameters are verified with different sets of measured plant data. Although some assumptions are made in the modelling process to simplify the model structure at a certain level, the supercritical coal-fired power plant model reported in the paper can represent the main features of the real plant once-through unit operation and the simulation results show that the main variation trends of the process have good agreement with the measured dynamic responses from the power plants.
Keywords
Coal-fired power generation Genetic algorithms Mathematical modeling Supercritical boilerNomenclature
- ff
Fitness function for genetic algorithms
- ffr
Pulverized fuel flow rate (kg/s)
- h
Enthalpy per unit mass (MJ/kg)
- K
Constant parameter
- k
Mass flow rate gain
- m
Mass (kg)
- \( \dot{m} \)
Mass flow rate (kg/s)
- P
Pressure of a heat exchanger (MPa)
- \( \dot{Q} \)
Heat transfer rate (MJ/s)
- R
Response
- T
Temperature (°C)
- t
Time (s)
- ?
Time constant (s)
- U
Internal energy (MJ)
- V
Volume of fluid (m3)
- \( \dot{W} \)
Work rate or power (MW)
- x
Generator reactance (p.u)
- y
Output vector
- ?
Density (kg/m3)
- ?
Valve opening
- ?
Rotor angle (rad)
- ?
Mechanical angle (rad)
- ?
Speed (p.u)
- ?
Torque (p.u)
Subscripts
- a
Accelerating
- air
Air
- e
Electrical
- d
Direct axis
- ec
Economizer
- hp
High pressure turbine
- hx
Heat exchanger
- i
Inlet
- ip
Intermediate pressure turbine
- me
Mechanical
- ms
Main steam
- m
Measured
- o
Outlet
- out
Output of the turbine
- q
Quadrature axis
- rh
Reheater
- sh
Superheater
- si
Simulated
- ww
Waterwall
Abbreviations
- BMCR
Boiler maximum continuous rate
- ECON
Economizer
- GA
Genetic algorithm
- HP
High pressure
- HX
Heat exchanger
- IP
Intermediate pressure
- MS
Main steam
- RH
Reheater
- SC
Supercritical
- SH
Superheater
- WW
Waterwall
Notes
Acknowledgments
The authors would like to give our thanks to E.ON Engineering for their support and engineering advices. The authors also want to thank EPSRC (RG/G062889/1) and ERD/AWM Birmingham Science City Energy Efficiency and Demand Reduction project for the research funding support.
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