DYNAMIC MODELLING AND SIMULATION OF SUPERCRITICAL COAL-FIRED POWER PLANT

(SCPP) WITH CO2 CAPTURE

• Dynamic Modelling of System Components• Dynamic Modelling of Whole SCPP

•Steady State Validation

Akeem OlaleyeProcess\Energy Systems Engineering GroupDepartment of Chemical EngineeringSchool of EngineeringUniversity of Hull

Supervisors:

Dr. Meihong Wang (University of Hull)

Dr. Muhammad Abubakar (BF2RA)

BF2RA-CRF SEMINAR

1

CONTENTS 2

PROJECT BACKGROUND 3

Critical point of water-steam: 22.115 MPa, 374.150C

Water Phase Diagram

PROJECT BACKGROUND

What is Supercritical?

4

PROJECT BACKGROUND

Typical Primary and Secondary frequency responseTypical Primary and Secondary frequency response

UK Grid Code Requirement

5

• Project Background• Literature Review• 1ST Technical Report• Steady State Model• 2nd Technical Report

• Dynamic Component model

• 3rd Technical Report• Whole plant dynamic model

• Steady state validation

2012 2013 2014 2015

• Dynamic validation• Analysis of validated

model for grid code compliance studies

• Dynamic model of CO2 capture

• Integration of the dynamic model of SCPP and CO2capture

• Analysis of integrated model for grid compliance

PROJECT BACKGROUND 6

Review of Past WPs : WP1, WP2, WP3

WP1: Literature Review

WP2: Simplified flow Diagram WP3: Steady State Simulation

PROJECT BACKGROUND 7

• Deaerator• Feedwater heaters• Economiser• Boiler Feed Pump (BFP)

• HP, IP, LP Turbines• BFP Turbine• Condenser• Condenser Hotwell

• Steam Generation (Waterwalls)• Superheaters (Pry & Sec)• Reheaters

• Pulverised coal Flow

• Air Pre-Heaters• FD and ID Fans• Furnace• Superheaters

DEVELOPMENT OF DYNAMIC MODELS OF SCPP

CURRENT PROGRESS 8

CURRENT PROGRESS

SCPP COMPONENT S MODEL in gPROMS: General Model Equation

Global mass balance,

)..(

..............

..),(,

),(,

dtdPn

dtdTnVmm

nP

nT

dtdP

PdtdT

TdtTPd

HenceTPf

ButdtdVmm

iiiout in

iii

out in

)(

,

)()()(,

)(),(,,

dtdP

dtdh

dtdhVQhmhm

HencedtdP

dtdh

dtdhV

dtdPV

dthdV

dtPhdV

dtdUHence

PhVUPvhMUVMPVHU

dtdUQhmhm

ooii

ooii

Global energy balance, (Fluid)

Momentum balance, msgmm

pm QQdt

dTCM

Energy balance,(Metal)

2

. mfPP outin

Steam Property Relations Steam properties are estimated using Multiflash, a commercial property package.

Obtained by regression analysis on the steam table from IAPWS IFP-97 formulation

9

CURRENT PROGRESS

Heat Transfer Equations

Convection

)( coldhotcc TTAhQ

Radiation

g

gfR

TVKQ

4...

Heat transfer coefficient at supercritical condition

• The outside and inside tube heat transfer coefficients are simplified to be proportional to m0.6 and m0.8

)(6.0

6.0

mggkggm

gkc

TTmUQ

mUAhU

(Ordys et al, 1994)

(Masada, 1979)

SCPP COMPONENTS MODEL in gPROMS: General Model Equation

6.0

6.0

gk

g

mUU

mU

8.0

8.0

sk

s

mUU

mU

)(8.0

6.0

smsksms

gkc

TTmUQ

mUAhU

Outside tube (gas side) Inside tube (steam/water side)

10

CURRENT PROGRESS

Coal Mill Model

mcoal

ma

Var,f

mpf

Var,f out

mcoal = As received coal flowma = Air flowVar,f= Inlet T & P of air, coal

mpf = Pulverised coal flowma = Air flowVar,f out = outlet T & P of air, coal

SCPP COMPONENT MODELS in gPROMS : Coal Mill Model

11

CURRENT PROGRESS

Furnace Model

mpf

ma

Var,f

mg

Tgas, Tad

QR

mpf = Pulverised coal flowma = Air flowVar,f = Inlet T & P of air,

pulverised coal

mg = flue gas mass flowVar,f out = outlet P of air, coal

Tgas = Temperature of flue gasTad = Adiabatic flame TemperatureQR = Radiation heat transfer

SCPP COMPONENT MODEL in gPROMS : Furnace Model

12

CURRENT PROGRESS

Tg

Tm

Ts

P, Ps

Var,b

mgHEX

mw

QoQch

mw = Feedwater flowmg = flue gas flowVar,b = Inlet T & P of gas & feedwaterQch = heat flow in

P, Ps = gas and steam Pressure out , Ts = steam TemperatureTm = metal TemperatureQo = heat flow outms = steam flow

ms

SCPP COMPONENT MODEL in gPROMS : Heat Exchangers Model

(Waterwall, Economiser, Superheaters, Reheaters)

13

CURRENT PROGRESS

FeedwaterHeating

Train

mfwin

mstmin

Var,f

mstmout

mfwout

Var,f out

mfwinl = feedwater flow inmstmin = extracted steam flowmatt = attemperator mass flowVar,f= Inlet T & P of water, steam

mfwout = feedwater flow outmstmout = steam flow outVar,f out = outlet T & P of water, steam

SCPP COMPONENT MODEL in gPROMS : Feedwater Heaters Model

(HP and LP Feedwater heaters)

14

CURRENT PROGRESS

WHOLE PLANT MODEL in gPROMS

Data Value Unit

Net Power Output 491 MWe

Fuel flow 42.03 kg/s

Excess air 20 %

Steam flow at superheater outlet 372.03 kg/s

Superheater exit temperature 565.56 oC

Superheater exit pressure 279.07 bar

Steam flow at reheater inlet 313.69 kg/s

Reheater inlet temperature 377.89 oC

Reheater exit temperature 565.26 oC

Reheater exit pressure 66.09 bar

Mass flow of condensing steam 229.46 kg/s

• Reference Plant:500MWe supercritical coal-fired power plant using a once-through

boiler to power a double-reheat steam turbine.

(Halsbeck, J.L., 2002)

15

CURRENT PROGRESS

Primary Superheater

Secondary Superheater

ConvectionPass

Furnace Waterwalls

(multiple loop)

Economizer

HP Feedwater Heater Feed PumpStorage Tank

Deaerator

LP Feedwater Heater

CondensatePump

Hotwell

Condenser

LP TurbineIP Turbine

HP Turbine

Reheaters

Attemperator

Attemperator

Generator

Interceptvalve

WHOLE PLANT MODEL

Structure of the Dynamic Model of the Water-steam circuit of the SCPP in gPROMS®

16

CURRENT PROGRESS

WHOLE PLANT MODEL

Structure of the Dynamic Model of the Air-flue gas flow path of the SCPP in gPROMS®

PERFORMANCE DATA

Unit REFERENCE PLANT

gPROMS®MODEL

RELATIVE ERROR (%)

Net Power output MWe 491 489.44 -0.32

Fuel Flow kg/s 42.03 42.03 -

Excess air % 20.0 19.61 -1.95

Steam flow at superheater outlet kg/s 372.03 381.3 2.50

Superheater exit temperature oC 565.56 575.13 1.69

Superheater exit pressure bar 279.07 282.64 1.28

Reheater inlet temperature oC 377.89 383.42 1.46

Reheater exit temperature oC 565.26 561.72 -0.61

Reheater exit pressure bar 66.09 64.08 -3.04

Mass flow of condensing steam kg/s 229.46 226.65 -1.22

STEADY STATE VALIDATION

17

CURRENT PROGRESS

Dynamic Model of CO2 Capture in gPROMS ® (reduced Model 3)

Biliyok et al., 2012 Detailed Capture Model: Validated with good prediction Physical property calculations obtained from Aspen Plus® and Multiflash®

18

• Lumped Parameter Approximation (sections)

• Distributed Parameter Model

• Linking the individual components model

• Steady state Validation of the whole plant

• Dynamic validation of the whole plant model

• Analysis of the model for UK Grid Compliance studies

• Linking the Dynamic Model with CO2 Capture model

• Analysis of the Integrated Model for grid studies

FUTURE WORK 19

PROJECT PLAN 20

• Haslbeck, John L. Evaluation of Fossil Fuel Power Plants with CO2 Recovery. NETL Report 40465, 2002.

• Berry JE, Holland MR, Watkiss PR, Boyd R, Stephenson W. Power Generation and the Environment – a UK Perspective. Report number AEAT3776, ExternE Project, AEA Technology Environment, Abingdon, Oxfordshire; 1998.

• Paranjape, R. D., Modelling and control of a supercritical coal-fired boiler, PhD thesis, Texas Technical University, Lubbock, USA. 1996

• Masada, Y., Wormley, D.N. (1982),”Dynamic model of a 1400MW supercritical pressure steam plant”, ASME Papers.

• Zindler, H., Walter, H., Hauschke, A., and Leithner, R (2008), "Dynamic simulation of a 800MWe hard coal once-through supercritical power plant to fulfill the Great Britain grid code", 6th IASME/WSEAS International Conference on Heat Transfer, Thermal Engineering and Environment, 20-22 August, 2008, Rhodes, Greece, pp. 184-192

• Wagner, W., Kretzschmar, H.J. (2008), “International Steam Table – Properties of Water and Steam – Based on the Industrial Formulation IAPWS-IFP97”, 2nd Edition, Springer-Verlag, Berlin.

REFERENCES 21

QUESTIONS 22