C1_CCPP
-
Upload
subrahmanyan-edamana -
Category
Documents
-
view
36 -
download
2
description
Transcript of C1_CCPP
HIPT
1. Introduction to Combined 1. Introduction to Combined Cycle Cycle Power Plants Power Plants
Combined Cycle Power Plants 1. Combined Cycle Power Plants 1 / 109
HIPT
Introduction to Combined Cycle Power Plants 21
Electricity Demand and Supply 222
Cost of Electricity 443
Electricity Demand and Supply 222
Characteristics of Combined Cycle Power Plants 534
Wide Use of Gas Turbine 1025
Characteristics of Combined Cycle Power Plants 534
Combined Cycle Power Plants 1. Combined Cycle Power Plants 2 / 109
HIPT
Gas Turbine In a gas turbine, the working fluid for transforming thermal energy into rotating mechanical energy is the hot
combustion gas, hence the term “gas turbine.”
The first power generation gas turbine was introduced by ABB in 1937 it was a standby unit with a thermal The first power generation gas turbine was introduced by ABB in 1937. it was a standby unit with a thermal efficiency of 17%.
The gas turbine technology has many applications. The original jet engine technology was first made into a h d t li ti f h i l d iheavy duty application for mechanical drive purposes.
Pipeline pumping stations, gas compressor plants, and various modes of transportation have successfully used gas turbines.
While the mechanical drive applications continue to have widespread use, the technology has advanced into larger gas turbine designs that are coupled to electric generators for power generation applications.
Gas turbine generators are self-contained packaged power plants.
Air compression, fuel delivery, combustion, expansion of combustion gas through a turbine, and electricity generation are all accomplished in a compact combination of equipment usually provided by a singlegeneration are all accomplished in a compact combination of equipment usually provided by a single supplier under a single contract.
The advantages of the heavy-duty gas turbines are their long life, high availability, and slightly higher overall
Combined Cycle Power Plants 1. Combined Cycle Power Plants 3 / 109
efficiencies. The noise level from the heavy-duty gas turbines is considerably less than gas turbines for aviation.
HIPT
Power Generation Requirement
CoalGas
Variety of Fuels Competitive Machine
GasOilWaterNuclearWind ci
ency
ilabi
lity
erat
ing
xibi
lity
Em
issioC
osts
WindSolarGeothermalBiomass
Effi
cAv
aO
peFl
ex
ns
Combined Cycle Power Plants 1. Combined Cycle Power Plants 4 / 109
HIPT
Type of Plant
Base Load Intermediate Load Peak Load
OperatingOperating Hours [hr/a] 5000 2000 to 5000 2000
• Nuclear plant • Gas turbine
Generating Units
• High-performance steam turbine plant
• High efficient combined cycle
• Simple steam turbine plant
• Old base-load plant
• Combined gas and steam
• Diesel engine
• Pumping-up power plantg yplant
• Hydropower plant
• Combined gas and steam plant • Old simple steam turbine
plant
Characteri-
• Operated at full load as long as possible during the year
• High efficiency and lowest cost
• Operated on weekdays andshutdown at night and on the weekend
• Low capital investment, buthighest operating costs
Characteri-stics
• High efficiency and lowest cost
• Poor load change capability (take more time to respond load demand)
• The efficiency is higher than that of peak-load plants, but lower than that of base-load plants
• Ease in startup
• Used as standby or emergency also
Combined Cycle Power Plants 1. Combined Cycle Power Plants 5 / 109
) plants
HIPT
Combined Cycle Power Plants
In simple cycle mode, the gas turbine is operated alone, without the benefit of recovering any of energy in the hot exhaust gases. The exhaust gases are sent directly to the atmosphere.Fuel
In combined cycle mode, the gas turbine exhaust gases are sent into HRSG. The HRSG generates steam that is normally used to power a steam turbine.
Combustor
Turbine G
Compressor
Inlet Air
Steam GHP LP
Exhaust GasAir Turbine G
Condenser
HP Drum
LP Drum
HRSGCondenser
DeaeratorHP Superheater
HP EvaporatorHP Economizer
LP Superheater
Condensate
LP Boiler Feed Pump
pLP Evaporator
LP Economizer
Combined Cycle Power Plants 1. Combined Cycle Power Plants 6 / 109
PumpHP Boiler Feed Pump
HIPT
Simple Cycle
Simple cycle gas turbines for electricity generation are typically used for standby or peaking capacity and are generally operated for a limited number of hours per year. Peaking operation is often defined as fewer than 2,000 hours of operation per year., p p y
In mechanical drive applications, and for some industrial power generation, simple cycle gas turbines are base load and operate more than 5 000 hours of operation per yearbase-load and operate more than 5,000 hours of operation per year.
Some plants are initially installed as simple cycle plants with provisions for future conversion to combined cycle.
Gas turbines typically have their own cooling, lubricating, and other service systems needed for simple yp y g g y pcycle operation. This can eliminate the need to tie service systems into the combined cycle addition and will allow continued operation of the gas turbine during the conversion process and, with proper provisions, during periods when the combined cycle equipment is out of service.
If future simple cycle is desired, a bypass stack may be included with the connection of the HRSG. A typical method for providing this connection is to procure a divert damper box at the outlet of the gas turbine.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 7 / 109
HIPT
Schematic of a CCPP
Combined Cycle Power Plants 1. Combined Cycle Power Plants 8 / 109
HIPT
3 P R h C l (F Cl G T bi )
Cycle Diagram3 Pressure Reheat Cycle (F-Class Gas Turbine)
Fuel
GHeat Recovery
Steam Generator
Air
Gas Turbine
IP Steam LP SteamCold ReheatHot Reheat Main
G
SteamCold Reheat Steam
Hot Reheat Steam
Main Steam
St
Condenser
G
Steam Turbine
Condensate Pump
SteamWaterFuelAir
Combined Cycle Power Plants 1. Combined Cycle Power Plants 9 / 109
HIPT
T-s Diagram for a Typical CCPP
T
Topping Cyclepp g y(Brayton Cycle)
Bottoming Cycle(Rankine Cycle)
s
Combined Cycle Power Plants 1. Combined Cycle Power Plants 10 / 109
HIPT
CHP; Combined Heat and Power
In the simplest arrangements, the gas turbine waste heat is used directly in an industrial process, such as for drying in a paper mill,such as for drying in a paper mill, or cement works.
Adding an HRSG converting t h t i t t iwaste heat into steam, gives
greater flexibilities in the process for chemical industries, or district heating
Combined Cycle Power Plants 1. Combined Cycle Power Plants 11 / 109
HIPT
Thermodynamic Consideration
THH
W
QH
Gas
TH
WTurbine
W
QH
에너지
HRSG
Q
W에너지변환
Q
WSteamTurbine
TL
QL
TL
QL
[ F il / N l ] [ C bi d C l ]
Combined Cycle Power Plants 1. Combined Cycle Power Plants 12 / 109
[ Fossil / Nuclear ] [ Combined Cycle]
HIPT
Gas Turbine Combined Cycle
구분 Topping Cycle Bottoming Cycle
Main Components GT ST/HRSG
Working Fluid Air Water/Steam
Temperature High Medium/Low
Thermodynamic Cycle Brayton Rankine
Coupling Two Cycles Heat Exchanger
Topping Cycle Bottoming Cycle
Combined Cycle Power Plants 1. Combined Cycle Power Plants 13 / 109
HIPT
Combined Cycle Power Plants
Combined cycle means the combination of two thermal cycles in one plant.
When two cycles are combined, the efficiency increases higher than that of one cycle alone.y y g y
Thermal cycles with the same or with different working fluid can be combined.
In general a combination of cycles with different working fluid has good characteristics because their In general, a combination of cycles with different working fluid has good characteristics because their advantages can complement one another.
Normally, when two cycles are combined, the cycle operating at the higher temperature level is called as t i l Th t h t i d f d th t i t d t th l t t l ltopping cycle. The waste heat is used for second process that is operated at the lower temperature level, and is called as bottoming cycle.
The combination used today for commercial power generation is that of a gas topping cycle with a water/steam bottoming cycle. In this case heat can be introduced at higher temperature and exhausted at very low temperature.
Temperature of the air used as a working fluid of gas turbines can be increased very high under lower Temperature of the air used as a working fluid of gas turbines can be increased very high under lower pressure. Water/steam used as a working fluid can contain very high level of energy at lower temperature because it has very high specific heat.
N ll th t i d b tt i l l d i h t h
Combined Cycle Power Plants 1. Combined Cycle Power Plants 14 / 109
Normally the topping and bottoming cycles are coupled in a heat exchanger.
HIPT
Combined Cycle Power Plants
Air is used as a working fluid in gas turbines having high turbine inlet temperatures because it is easy to get and has good properties for topping cycle.
Steam/water is an ideal material for bottoming cycle because it is inexpensive, easy to get, non-hazardous, and suitable for medium and low temperature ranges.
The initial breakthrough of gas-steam cycle onto the commercial power plant market was possible due to the development of the gas turbine.
In the late 1970s, EGT reached sufficiently high level that can be used for high efficiency combined cycles.
The breakthrough was made easier because gas turbines have been used for power generation as a simple cycle and steam turbines have been used widely.
For this reason, the combined cycle, which has high efficiency, low installation cost, fast delivery time, had been developed easily.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 15 / 109
HIPT
CCPP System Options
Items Options Remarks
• Single pressure / Two pressure /Three pressure *Steam Cycle • Reheat
• Non-reheatDependent on EGT
• Natural gas */ Distillate oil / Ash bearing oilFuel • Low BTU coal and oil-derived gas
• Multiple fuel systems
• Water injection / Steam injectionNOx Control • SCR (NOx and/or CO)
• Dry Low NOx combustion *
Condenser• Water cooled (once-through system) *
Condenser• Water cooled (cooling tower) /Air-cooled condenser
Deaeration• Deaerating condenser *• Deaerator/evaporator integral with HRSGg
HRSG Design
• Natural circulation evaporators *• Forced circulation evaporators• Unfired *
Combined Cycle Power Plants 1. Combined Cycle Power Plants 16 / 109
• Supplementary fired
HIPT
Base Configurations for CCPP
Unfired, 3-pressure steam cycle• Non-reheat for rated EGT less than 1000°F/538°C• Reheat for rated EGT higher than 1050°F/566°C and fuel heating• Heat recovery feedwater heating• Feedwater dearation on condenser• Feedwater dearation on condenser• Natural circulation HRSG evaporators
GT with DLN combustors
Once-through condenser cooling water system
Multi-shaft systems
Single-shaft systems• Integrated equipment and control system
Combined Cycle Power Plants 1. Combined Cycle Power Plants 17 / 109
HIPT
GT vs. ST
Gas Turbine Steam Turbine
Combustion Internal External
Thermodynamic cycle Brayton Rankine
Cycle type Open Closed
Working fluid Air Water/Steam
Max. pressure, bar 23 (40 for Aviation) 350 (5050 psig)
Max. temperature, C(F) 1350 (2462) 630 (1166)a te pe atu e, C( ) 350 ( 6 ) 630 ( 66)
Blade cooling Yes No
Shaft cooling No Yes (USC only)
Max. cycle efficiency, % 40 49 (USC only)
Max. number of reheat 1 2
Power density High Lowy g
Steam conditions of the steam turbines for combined cycle applications are lower than those for USC steam turbines.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 18 / 109
HIPT
CCPP
Major equipment of combined cycle power plant• Gas turbine, steam turbine, generator, HRSG
Main advantages of the combined cycle power plant• Higher thermal efficiency than the others (up to 60%)
- SC steam plants: 35~40%, USC steam plants: 49%p , p• Shorter construction period• Lower initial construction cost
- Capital costs of gas fired combined cycle are about 40% of coal fired steam plants• Lower emission (low NOx burners, SCR, CO catalysts are available)
Current situationC t ti f CCPP h i d d ti ll i 1970• Construction of CCPP has increased dramatically since 1970s
• Market is governed by GE and SIEMENS• It is hard to develop a new competitive model because it requires both advanced technologies and
high costhigh cost
Combined Cycle Power Plants 1. Combined Cycle Power Plants 19 / 109
HIPT
CCPP Concept
Electricity Demand Process-energy (steam/water) demand Operating Philosophy Financing
Customer Requirements
(steam/water) demand
Site Related FactorsSite conditions / Ambient conditions50 or 60Hz Site conditions / Ambient conditions
Legislation / Emission requirements
Resources
50 or 60Hz
Fuel Water Space
Plant Concept SolutionpCapital cost
US$/kWType / Number of GTs
Single shaft Multiple shaft
Cycle selection with parameter optimization
Final optimization Plant /Cycle
Combined Cycle Power Plants 1. Combined Cycle Power Plants 20 / 109
Plant /Cycle
HIPT
A Typical HRSG
StackHPSection
IPSection
LPSection
TransitionDuct
starting
DuctBurner
Air Inlet
Duct
AddtionalAir supply
startingMoter
GeneratorGasTurbine
GasTurbine
FlowCorrectionDevice
HRSG
Inlet duct
A-A section
Combined Cycle Power Plants 1. Combined Cycle Power Plants 21 / 109
Exhaust duct
HIPT
Introduction to Combined Cycle Power Plants1
Electricity Demand and Supply2
Cost of Electricity 3
Electricity Demand and Supply2
Characteristics of Combined Cycle Power Plants4
Wide Use of Gas Turbine 5
Characteristics of Combined Cycle Power Plants 4
Combined Cycle Power Plants 1. Combined Cycle Power Plants 22 / 109
HIPT
Demand and Supply
Electricity must be produced when the consumers need it because it cannot be stored in a practical manner on a large scale.
Electricity can be stored indirectly through water, but it is not economical.
Actually only storage of water pumped into lakes during off-peak time to be used during peak hours has been used practically.
Large fluctuation in demand during the day requires quick response from power plants to meet the balance between demand and supply.
Gas turbine combined cycle power plants have good characteristics in terms of fast start-up and shut-down.
In addition, they have low investment costs, short construction times compared to large coal-fired power stations and nuclear plants.
The other advantages of combined cycles are high efficiency and low emission.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 23 / 109
HIPT
Power Demand during a Day
Excellent start-up and shut down capabilities are essential for thisare essential for this
Combined Cycle Power Plants 1. Combined Cycle Power Plants 24 / 109
HIPT
발전전력량 분석
Combined Cycle Power Plants 1. Combined Cycle Power Plants 25 / 109
출처: 전력시장분석보고서, 전력거래소 (2012)
HIPT
연도별 전력수급 실적 및 전망
Combined Cycle Power Plants 1. Combined Cycle Power Plants 26 / 109
출처: 전력시장분석보고서, 전력거래소 (2012)
HIPT
발전연료별 설비용량 추이
Combined Cycle Power Plants 1. Combined Cycle Power Plants 27 / 109
출처: 전력시장분석보고서, 전력거래소 (2012)
HIPT
발전원별 연평균 가동시간 비율
Combined Cycle Power Plants 1. Combined Cycle Power Plants 28 / 109
출처: 전력시장분석보고서, 전력거래소 (2012)
HIPT
발전원별 발전기 이용률
Combined Cycle Power Plants 1. Combined Cycle Power Plants 29 / 109
출처: 전력시장분석보고서, 전력거래소 (2012)
HIPT
발전연료별 열량 단가
Combined Cycle Power Plants 1. Combined Cycle Power Plants 30 / 109
출처: 전력시장분석보고서, 전력거래소 (2012)
HIPT
향후 발전연료별 구성 전망
Combined Cycle Power Plants 1. Combined Cycle Power Plants 31 / 109
출처: 전력시장분석보고서, 전력거래소 (2012)
HIPT
주요 발전회사별 전력거래량 점유율
Combined Cycle Power Plants 1. Combined Cycle Power Plants 32 / 109
출처: 전력시장분석보고서, 전력거래소 (2012)
HIPT
국내 복합발전 설치 현황 - 민자
회사 위치 제작사 GT 대수 GT용량 ST용량 총용량 비고
GS EPS 당진 SiemensV84.3
SGT6-8000H41
710.0274 0
378.0136 0 2013/8 완공SGT6 8000H 1 274.0 136.0 2013/8 완공
GS 파워부천 WH 501D5 3 315.6 100.0 CHP안양 ABB GT11N 4 317.6 100.0 CHP
SK E&S광양 GE 7FA+e 4 686.8 340.0 K-Power평택 3 515 1 285 0 833 3 on 1 Conf평택 3 515.1 285.0 833 3-on-1 Conf.
POSCO광양 GE 7FA+ 2 337.6 165.0포항 GE 7FA+ 2 337.6 165.0
POSCO에너지 인천 WHW501D5 12 1,200.0 600.0
POSCO에너지 인천 WHV84.3A 4 812.0 440.0
MPC순천
Siemens W501F 2 340.0 160.0MHI M501J 2 640.0 280.0 920 2-on-1 Conf.
대산 WH W501D5 4 408.0 100.0 현대중공업 인수
한국지역난방기술 화성 2 340.0한국지역난방공사 7EA인천종합에너지 인천 GE 6F 2 154.0
여천NCC 여수 GE 6B 5 190 0여천NCC 여수 GE 6B 5 190.0포천파워 포천 2 1560S-Power 안산 Siemens SGT6-8000H 2 548.0 272.0 2014/10 완공예정
대륜발전(한진중) 양주 556 2013/12 열병합
Combined Cycle Power Plants 1. Combined Cycle Power Plants 33 / 109
소 계
HIPT
국내 복합발전 설치 현황 - 한전
발전소 Site 제작사 GT (용량) GT 대수 GT용량 ST용량 총용량 비고
신인천 GE 7FA+e (171.7) 8 1373.6 680.0부산 GE 7FA (170) 8 1360.0 680.0
남부발전 한림 GE 6B (38) 2 76.0 38.0영월 MHI M501F 3 550.0 310.5안동 Siemens SGT6-8000H 1 274.0 136.0 2014년 완공
보령 ABB GT24 (150) 6 900 0 450 0
중부발전
보령 ABB GT24 (150) 6 900.0 450.0
인천Siemens V84.3A
?22
320.0360.0
160180.0
세종 515.0 2013/11월 열병합
서부발전
서인천 GE 7FA+e (171.7) 8 1373.6 680.0
평택GE 7EA (87.9) 4 351.6 160.0MHI M501J 2 640.0 280.0
군산 MHI M501G 2 508.0 210.0군산 MHI M501G 2 508.0 210.0동두천 MHI M501J 4 1280.0 560.0
남동발전 분당 ABB GT11N (79.4) 8 635.2 300.0일산 WH 501D5 (105.2) 6 631.2 300.0
동서발전 울산
WH 501D5 (105.2) 2 210.4 100.0WH 501F (150) 4 600.0 300.0MHI M501J 2 640.0 280.0
춘천 500MW 열병합 340 0 160 0 2014 완공(열병합)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 34 / 109
춘천 500MW 열병합 340.0 160.0 2014 완공(열병합)
소 계
HIPT
신인천/서인천복합발전단지
복합화력 4,300 MW (7FA+e x 16 Units)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 35 / 109
HIPT
국내 복합화력발전소
부산복합 (2,000 MW) 분당복합 (960 MW) 일산복합 (900 MW)
보령복합 (1,800 MW) POSCO 광양복합 (500 MW) POSCO 포항복합 (500 MW)
POSCO파워 (3 000 MW) GS EPS (1 000 MW) 현대중 대산 (500 MW) 메이야율촌 (500 MW) K P (1 074 MW)POSCO파워 (3,000 MW) GS EPS (1,000 MW) 현대중 대산 (500 MW) 메이야율촌 (500 MW) K-Power(1,074 MW)
울산 (1,200 MW)
담수설비
GS 파워 (1,000 MW)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 36 / 109
담수설비
HIPT
국내 복합화력발전소
메이야율촌복합 (550 MW) 군산복합 (700 MW) 영월복합 (900 MW)( ) ( ) ( )
현대 대산복합 (507 MW)분당복합 (960 MW) GS EPS 부곡복합 (1020 MW)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 37 / 109
HIPT
Gas Turbine Production by SectorS D i F F I i l
18
Source: Davis Franus, Forecast International
7)
15Commercial Aviation
lars
(200
7
12
Electrical Generation
ons
of D
ol
6
9Electrical Generation
Billi
o
3
6Military Aviation
Mechanical Drive
2004 2006 2008 2010
Marine Propulsion
Combined Cycle Power Plants 1. Combined Cycle Power Plants 38 / 109
HIPT
세계 에너지원별 소비
구분 석유 천연가스 석탄 원자력 신재생 합계
(단위: QBtu, %)
구분 석유 천연가 석탄 원자력 신재생 합계
소비량 162.1 99.1 100.4 26.5 32.7 420.8
소비비중 38.5 23.6 23.9 6.2 7.8 100
기준년도: 2003년
원자력 ( )
신재생 (7.8%)
자료) 미국에너지정보국, International Energy Outlook, 2006
1 QBtu = 25.2Mtoe
1 QBtu 1 Qu d illi Btu {Qu d illi 1015
석유 (38.5%)석탄(23.9%)
원자력 (6.2%)
1 QBtu = 1 Quadrillion Btu {Quadrillion = 1015
(미국) or 1024 (유럽)}
toe = Tonnage of Oil Equivalent (1석유환산톤 = 석유 1톤을 연소시킬 때 발생되는 에너지)
천연가스 (23.6%)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 39 / 109
HIPT
World Primary Energy
Combined Cycle Power Plants 1. Combined Cycle Power Plants 40 / 109
HIPT
S IEO (2008)
World Power Generation by Fuel Type
Billion MW-h40
Source: IEO (2008)
40
30
Renewables
Nuclear
20
Renewables
Nat. Gas
10Coal
02005 2010 2015 2020 2025 2030
Hydro
Combined Cycle Power Plants 1. Combined Cycle Power Plants 41 / 109
2005 2010 2015 2020 2025 2030
HIPT
B d C li d G i
World Power Generation by Fuel TypeBased on Centralized Generation
Combined Cycle Power Plants 1. Combined Cycle Power Plants 42 / 109
HIPT
Market Share and Product
Combined Cycle Power Plants 1. Combined Cycle Power Plants 43 / 109
HIPT
Introduction to Combined Cycle Power Plants1
Electricity Demand and Supply2
Cost of Electricity 3
Electricity Demand and Supply2
Characteristics of Combined Cycle Power Plants4
Wide Use of Gas Turbine 5
Characteristics of Combined Cycle Power Plants4
Combined Cycle Power Plants 1. Combined Cycle Power Plants 44 / 109
HIPT
국내 발전원가 비교
2007년 기준
단위: 원/kWh 677 4단위: 원/kWh 677.4
117.0128.3
107.3
39.4 40.9
원자력
• 석탄의 경우 탄소배출권 비용을 감안하면 발전원가 27.2원 상승
원자력의 경우 핵폐기물 처리비용 미반영
원자력 석탄 중유 LNG 풍력 태양광
Combined Cycle Power Plants 1. Combined Cycle Power Plants 45 / 109
• 원자력의 경우 핵폐기물 처리비용 미반영
HIPT
S P Pl E i i (Bl k & V h)
발전원가 비교Source: Power Plant Engineering (Black & Veatch)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 46 / 109
HIPT
발전원가 비교
400
300W
-yea
r
Coal-Steam
Gas Turbine
200
l Cos
t, $/
kW
100
Ann
ua Combined Cycle
0 1,500 5,000 8,760
Operation Hours/year
0
Comparisons will depend on fuel costs, capital costs, and maintenance costs.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 47 / 109
HIPT
발전원가 비교
In contrast to steam turbine-generators, the manufacturers of gas turbines have a defined product line, allowing for substantial standardization and assembly line manufacturing.
The modular concept of the package power plants made gas turbines relatively quick and easy to install.
Standardization and modularization combine to provide the product benefits of relatively low capital cost and fast installation.
The benefits of low capital cost and fast installation were initially offset by higher operating costs when compared to other installed capacity. Therefore, early utility applications of gas turbine generator were strictly for peak load operation for a few hundred hours per year.
Improvements in efficiency and reliability and the application of combined cycles have added to the economic benefits of the technology and now give gas turbine based power plants a wider range of application on electric systems.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 48 / 109
HIPT
Cost of Electricity
< Inputs for the evaluation of the cost of electricity >
Type of Plant Output, MW
Description
Investment cost, US$/kW
Average efficiency (LHV), %
Fuel price, US$/MBTu
(LHV)감가상각
Combined Cycle Power Plant 800
2 x GT1 x ST
750 56.5 8.0 25
Gas Turbine Plant (gas) 250 1 x GT 413 37.5 8.0 25Plant (gas)
Steam Power Plant (coal) 800 1 x ST 1716 44.0 3.5 25
Nuclear Power 1250 1 x ST 3500 34 5 0 5 40Plant 1250 1 x ST 3500 34.5 0.5 40
No cost for CO2 emissions were included.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 49 / 109
HIPT
Cost of Electricity
100Capital
I t di t L dB L d
MW
h) 80
O&MFuel
Intermediate LoadBase Load
ricity
(US
$/M
60
ost o
f Ele
ctr
20
40
Co 20
800 MW CCPP (gas)
800 MW Steam (coal)
250 MW GT PP (gas)
1250 MW Nuclear PP
800 MW CCPP (gas)
800 MW Steam (coal)
250 MW GT PP (gas)
1250 MW Nuclear PP
Combined Cycle Power Plants 1. Combined Cycle Power Plants 50 / 109
HIPT
복합화력발전 가격
GE S109H: Dry Low NOxCombustors(H System™): Combined cycle: 14 Can-annular lean pre-mix DLN-2.5combustors : Output 480 MW (Gas turbine power 300 MW): Heat rate 6000 kJ/kWh: $153,500,000 ($320/kW) F15-K : $1억
Combined Cycle Power Plants 1. Combined Cycle Power Plants 51 / 109
HIPT
Turbine Blade Prices (1998년 기준)NOZZLE BUCKET
제작사 MODEL 출력(MW) TIT (C) 단
개수 가격($)/Set MATERIAL 개수 가격($)/Set MATERIAL1 48 1,180,000 FSX410 92 2,200,000 GTD1112 48 1,180,000 GTD222 92 1,500,000 GTD1117FA 175 1,2603 60 1 190 000 GTD222 92 1 450 000 GTD1113 60 1,190,000 GTD222 92 1,450,000 GTD1111 32 680,000 FSX414 92 670,000 GTD1112 48 690,000 FSX414 92 680,000 IN7387EA 88 1,1043 48 740,000 FSX414 92 600,000 U5001 36 390,000 FSX414 92 430,000 GTD111
GE
2 48 450,000 GTD222 92 330,000 IN7386B 39 1,1043 64 420,000 GTD222 92 310,000 U5001 42 240,000 IN738 115 400,000 IN738LC2 66 210,000 IN939 115 400,000 IN738LC3 84 280 000 IN730 97 210 000 IN738LCGT11N 80 1 027 3 84 280,000 IN730 97 210,000 IN738LC4 90 210,000 X45 105 390,000 IN738LC
GT11N 80 1,027
5 40 390,000 20/25/2 59 500,000 ST 16/25MD1 100 1,170,000 MAR M247LC 197 800,000 DS CM247LC2 44 656,000 MAR M247LC 88 950,000 DS CM247LC
ABB
3 80 948,000 MAR M247LC 86 1,170,000 DS CM247LC4 78 1,170,000 IN738LC 84 950,000 MAR M247LC
GT24 150 1,255
5 76 800,000 IN738LC 82 1,240,000 MAR M247LC1 48 810,000 ECY-768 81 340,000 U5202 48 700 000 X45 73 300 000 U5202 48 700,000 X45 73 300,000 U5203 56 720,000 ECY-768 55 340,000 U520
501D2 105 1,198
4 56 770,000 X45 51 340,000 IN GC-7501 32 560,000 ECY-768 72 1,400,000 IN7382 24 410,000 X45 66 1,000,000 IN738
WH
501F 150 1 293
Combined Cycle Power Plants 1. Combined Cycle Power Plants 52 / 109
3 16 380,000 ECY-768 112 1,400,000 IN738501F 150 1,293
4 14 430,000 X45 100 1,100,000 U520
HIPT
Introduction to Combined Cycle Power Plants1
Electricity Demand and Supply2
Cost of Electricity 3
Electricity Demand and Supply2
Characteristics of Combined Cycle Power Plants4
Wide Use of Gas Turbine 5
Characteristics of Combined Cycle Power Plants 4
Combined Cycle Power Plants 1. Combined Cycle Power Plants 53 / 109
HIPT
System Features of CCPP
Advantages Disadvantages
ff1. High thermal efficiency
2. Low initial investment
3. Short construction time
4. Fuel flexibility Wide range of gas and liquid fuels
5. High reliability and availability1. Higher fuel costs
g y y
6. Low operation and maintenance cost
7. High efficiency in small capacity increments Various gas turbine models
2. Uncertain long-term fuel supply
3. Output more dependent on ambient temperatures
Various gas turbine models
8. Operating flexibility Base, intermediate, peak load
9 E i t l f i dli9. Environmental friendliness
10. Reduced plant space
Combined Cycle Power Plants 1. Combined Cycle Power Plants 54 / 109
HIPT
1. High Thermal Efficiency [1/6]
The value of efficiency is very high because fuel spend may be about 70 percent of the total cost.
All major OEMs have developed air-cooled gas turbines for combined cycles with efficiencies around 61 percent.percent.
Siemens proved performance of 60.75% at the Irsching site outside Berlin.
The old paradigm that high performance meant advanced steam cooled gas turbines and slow started The old paradigm that high performance meant advanced steam cooled gas turbines and slow started bottoming cycles has definitely proven false.
Both GE and Siemens are able to do a hot-start within 30 minutes to full load.
Steam cooling will most likely only be used for 1,600C firing level since there will be an air shortage for both dry low emission and turbine cooling.
The key for 61% efficiency is high performance gas turbines having higher pressure ratio and firing The key for 61% efficiency is high performance gas turbines having higher pressure ratio and firing temperature.
In addition, the exhaust gas temperature has to be at a level for maximum bottoming cycle performance.
Currently, most OEMs have capability of steam turbine throttle temperature of 600C(1112F) and the optimum exhaust gas temperature should therefore be on the order of 25-30C higher.
B th GE d Si h t d d d th ttl diti f th i b tt i l 165
Combined Cycle Power Plants 1. Combined Cycle Power Plants 55 / 109
Both GE and Siemens have presented advanced throttle conditions for their bottoming cycles, 165 bar/600C and 170 bar/600C, respectively.
HIPT
1. High Thermal Efficiency [2/6]
Fuel EnergyThree Pressure
Combined cycle power plants have a higher thermal efficiency because of the application of two complementary thermodynamic cycles
Fuel Energy
100%
GT 37 6%L i HRSG
Three PressureReheat Cycle T
Topping CycleGT 37.6%Loss in HRSG0.3%
Loss
0 5%
pp g y(Brayton Cycle)
ST 21.7%
ense
r
0.5%
Loss
Con
deStack8.6%Loss
0.3% Bottoming Cycle(Rankine Cycle)
31.0%s
[ Heat balance in a typical combined cycle plant ]
Combined Cycle Power Plants 1. Combined Cycle Power Plants 56 / 109
HIPT
C i f Th l Effi i
1. High Thermal Efficiency [3/6]
발전 유형별 성능 비교
Comparison of Thermal Efficiency
60
5049 48
60발전 유형별 성능 비교
, %
50
4035
38 40
열효
율
30
35
10
20
원자력 IGCC가스터빈(SIMPLE)
화력(SC)
화력(USC)
가스터빈(복합)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 57 / 109
(SIMPLE)(SC) (USC) (복합)
HIPT
E l i f H D G T bi D i F
1. High Thermal Efficiency [4/6]
1967 1972 1979 1990 2000 2008 2012
Evolution of Heavy Duty Gas Turbine Design Features
TIT, C (F) 900 (1650) 1010 (1850) 1120 (2050) 1260 (2300) 1426 (2600)
1426 (2600) 1500
Press. Ratio 10.5 11 14 14.5 19-23 20-23 20-23
EGT, C (F) 427 (800) 482 (900) 530 (986) 582 (1080) 593 (1100) 623
Cooling 1 vane1&2 vane1 blade
1&2 vane1&2 blade
1,2,3 vane1,2,3 blade
1,2,3 vane1,2,3 bladeblade
SC Power, MW 50-60 60-80 70-105 165-240 165-280 400-480 (CC)
SC Heat RateSC Heat Rate, Btu/kWh 11,600 11,180 10,250 9,500 8,850
CC Heat Rate, Btu/kWh 8,000 7,350 7,000 6,400 5,880 5,690
SC Effi., % 29.4 30.5 33.3 35.9 38.6 40
CC Effi., % 42.7 46.4 48.7 53.3 58.0 60 61
Combined Cycle Power Plants 1. Combined Cycle Power Plants 58 / 109
HIPT
P L d Effi i
1. High Thermal Efficiency [5/6]
100 The gas turbine equipped with
Part Load Efficiency
95
90
The gas turbine equipped with VIGV or several rows of variable stator vanes keeps the efficiency of the combined cycle plant almost constant down to
85
80
almost constant down to approximately 80 to 85% load.
This is because a high exhaust
75
70
ggas temperature can be maintained as the air mass flow is reduced.
30 40 50 60 70 80 90 100
65
60
Below that level, the turbine inlet temperature must be reduced, leading to an increasingly fast
d i f ffi i iLoad, %
30 40 50 60 70 80 90 100reduction of efficiencies.
The steam turbine is operated with sliding pressure mode down to 50% load. Below that point, the live-steam pressure is held constant resulting in throttling losses
Combined Cycle Power Plants 1. Combined Cycle Power Plants 59 / 109
steam pressure is held constant, resulting in throttling losses.
HIPT
P L d Effi i
1. High Thermal Efficiency [6/6]
110
Part Load Efficiency
95
1004GTs3GTs2GTs1GT
85
90
75
80
Down to 75% parallel reduction in load on all 4 GTs
65
70
Down to 75%, parallel reduction in load on all 4 GTs.At 75%, one GT is shut down.Down to 50%, parallel reduction in load on 3 remaining GTs.At 50%, a second GT is shut down.
Combined Cycle Load, %30 40 50 60 70 80 90 100
6020
Combined Cycle Power Plants 1. Combined Cycle Power Plants 60 / 109
4 GTs + 1 ST Arrangement
HIPT
C i f I i i l C i C
2. Low Initial Construction Cost [1/4]
Capital costs of gas-fired combined cycle are about 45% of coal-fired steam plants
Comparison of Initial Construction Cost
Type of Plant Output (MW) Specific Price (US$/kW)
Combined Cycle Power Plant 800 550 650Combined Cycle Power Plant 800 550 - 650
Combined Cycle Power Plant 60 700 - 800
Gas Turbine Plant 250 300 - 400
Gas Turbine Plant 60 500 - 600
Steam Power Plant (coal) 800 1,200 – 1,400
Steam Power Plant (coal) 60 1,000 – 1,200
Nuclear Power Plant 1,250 2,000 – 3,000
Bi P Pl t 30 2 000 2 500Biomass Power Plant 30 2,000 – 2,500
These prices are valid for 2007.Interest during construction is not included.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 61 / 109
g
HIPT
C i f G T bi P i
2. Low Initial Construction Cost [2/4]
550
Source: Gas Turbine World (1999 Jan/Feb)
Comparison of Gas Turbine Price
500
550
1xV84.2
1xGT13D1x401
1x501D5A
1x701D
G.E.
SIEMENS
ABB
se)
450
500
W
1x7FA
1xV94.21xV84.3A
1xGT11N2 1xGT24
1x701DW.H.
urnk
ey B
as
400
450
US
Dpe
rkW
1x7EA
1 9FA
1xGT11N2 1xGT24
r CC
PP
(Tu
350
400U 1x9FA
1xV94.2A
1x501F
e Le
vel f
or
100 200 300 400300
350
1xV94.3A1xGT26
1x701F
Pric
e
Combined Cycle Power Plants 1. Combined Cycle Power Plants 62 / 109
100 200 300 400ISO Net Combined Cycle Plant Output (MW)
300
HIPT
C B kd f CCPP
2. Low Initial Construction Cost [3/4]
Items Portion % CCPP
Cost Breakdown for CCPP
Integrated Services 15%
4 Project management / Subcontracting
2 Plant and project engineering / Software
8 Plant erection / Commissions / TrainingServices 8 Plant erection / Commissions / Training
1 Transport / Insurance
15 Civil works
Lots 85%
32 Gas turbine / Steam turbine / Generator set
16 Balance of plants
7 Electrical systems7 Electrical systems
4 Instrumental and control
11 HRSG island
Basis: 350~700MW CC plant with a V94.3A Gas Turbine
As a rule of thumb, a 1% increase in the efficiency could mean that 3.3% more capital can be invested.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 63 / 109
, y p
HIPT
C B kd f 400 MW CCPP
2. Low Initial Construction Cost [4/4]
Site
Cost Breakdown for a 400 MW CCPP
Steam Turbine Set
Power Island Mechanical System
9%Civil, Arrangement, Building Facilities
18%
Site Infrastructure
3%
8%Heat Recovery
Steam Generator 10%
Mechanical Systems Outside
18%
Control 3%
yPower Island
8%
Electrical (without high
Control 3%
Gas Turbine Set 32%
Electrical (without high voltage switchyard)
9%
Combined Cycle Power Plants 1. Combined Cycle Power Plants 64 / 109
32%
HIPT
C i f C i Ti
3. Short Construction Time [1/2]
T pe of Plant Time [Months] Combined cycle plants are relatively quick
to design and erect because all major
Comparison of Construction Time
Type of Plant Time [Months]
Combined Cycle Power Plant 20 - 30
Gas Turbine Plant 12 - 24
to design and erect because all major equipment is shipped to the field as assembled and tested components.
The gas turbine is assembled at theSteam Power Plant (coal) 40 - 50
Nuclear Power Plant 60 - 80
The gas turbine is assembled at the factory and mounted on a structural base plate or skid, minimizing the need for field assembly of the turbine.
Biomass Power Plant 22 - 26 Other components and support systems such as cooling water and lubricating oil are modules that are easily erected and connected to the gas turbine skid
The gas turbine usually can be operated in simple cycle mode while the steam portion of the combined cycle is erected.
connected to the gas turbine skid.
The gas turbine from the 1960s to the late 1980s was used only as peaking power in the countries where the large steam turbines were used as base load power plants.
However gas turbine was used as base load mainly in the developing countries where the need of power
Combined Cycle Power Plants 1. Combined Cycle Power Plants 65 / 109
However, gas turbine was used as base load mainly in the developing countries where the need of power was increasing rapidly because the waiting period of three to six years for a steam plant was unacceptable.
HIPT
3. Short Construction Time [2/2]
Design Philosophy for Combined Cycle Plants
주문 / 제작 모델 / 표준화
Customizationstart from outside to inside
Standardizationstart from inside to outside
주문 / 제작 모델 / 표준화
1980’s 2000’s
Pre-engineered solution has the following benefits:• Time (shorter delivery time)• Quality (robust design)• Risk (exchangeable components in case of troubles)• Cost
Combined Cycle Power Plants 1. Combined Cycle Power Plants 66 / 109
HIPT
4. Fuel Flexibility
Most gas turbine applications rely on natural gas or No. 2 distillate oil.
Because of the availability and economics of natural gas, the [Table] GE heavy-duty GT shipped for fuels (by 1983)y g ,
majority of new power plants prefer natural gas as a fuel.
Fuel affects CC performance in a variety of ways.Fuel Units
Natural Gas 1408
shipped for fuels (by 1983)
Natural gas containing high hydrogen content has a higher heat content and therefore output and efficiency increase when the natural gas is used as a fuel.
Process GasDual GasDistillateNaphtha
1360
78314
Plant output and efficiency can be reduced when the ash bearing fuels (crude oil, residual oil, blends, or heavy distillate) are used because of fouling occurred in gas turbine and HRSG.
KeroseneDistillate or GasDistillate and GasCrudeCrude and Distillate
30964
825932
Plant output and efficiency can be reduced when the fuels containing higher sulfur content are used. This is because higher stack gas temperature is required to prevent condensation of corrosive sulfuric acid
Crude and DistillateResidualResidual or GasResidual/Distillate/Gas
32120
41
corrosive sulfuric acid.
Heavy fuels normally cannot be ignited for gas turbine startup; therefore a startup and shutdown fuel, usually light distillate, is needed with its own storage forwarding system and fuel
Total 3570
Combined Cycle Power Plants 1. Combined Cycle Power Plants 67 / 109
needed with its own storage, forwarding system, and fuel changeover equipment.
HIPT
D fi i i f R li bili d A il bili
5. High Reliability and Availability [1/4]
Reliability = Availability =P F P S F
Definition of Reliability and Availability
P = period hours (normally one year, 8,760h)F = total forced outage hours for unplanned outages and repairs
Reliability = Availability =P P
No of Successful Starts
S = scheduled maintenance hours
The probability that a unit, which is classified as available, and in ready service, can be started, and be brought to synchronization within a specific period time is defined as above An inability to start
Starting Reliability =No. of Successful StartsNo. of Attempted Starts
be brought to synchronization within a specific period time is defined as above. An inability to start within the specified period and synchronize is considered a failure to start. However, repeated attempts to start without attempting corrective action are not considered additional failures to start.
MTBF =Fired Hours
Trips from a state of operation
Combined Cycle Power Plants 1. Combined Cycle Power Plants 68 / 109
HIPT
C i f R li bili d A il bili
5. High Reliability and Availability [2/4]
Source A Source B
Comparison of Reliability and Availability
Type of Plant Availability (%)
Reliability (%)
Availability (%)
Reliability (%)
Combined Cycle Power Plant 90 - 94 95 - 98 86 - 93 95 - 98y
Advanced GT CCPP 84 - 90 94 - 96
Gas Turbine Plant (gas fired) 90 - 95 97 - 99 88 - 95 97 - 99
Steam Power Plant (coal fired) 88 - 92 94 - 98 82 - 89 94 - 97
Nuclear Power Plant 88 - 92 94 - 98 80 - 89 92 - 98
• SGT6-5000F (W501F): Reliability: 99%, Availability: 95%, Starting reliability: 93% (2010)
Many analyses show that a 1% drop in the availability needs about 2~3% increase in the efficiency to Many analyses show that a 1% drop in the availability needs about 2 3% increase in the efficiency to offset that loss.
The larger gas turbines, just due to their size, take more time to undergo any of the regular inspections, such as combustor, hot gas path, and major overall inspections, thus reducing the availability of these turbines
Combined Cycle Power Plants 1. Combined Cycle Power Plants 69 / 109
availability of these turbines.
HIPT
A il bili R d i i C l Fi d P Pl
5. High Reliability and Availability [3/4]
Source: EPRI CS-3344 pp.1-3
Stack S.H.R.H.
Availability Reduction in Coal-Fired Power Plant
Stack
HP Turbine IP Turbine
Econ
Gas
Water
LP Turbines
I.D. fan
Generator
Gas clean up
Condenser
AshAsh
Air heater
Coal
HP heater
LP heater
Water treatment
Fans (0 6%) Boiler tubes (4 2%) Fouling/slagging (2 8%) Pulverizers (0 6%) Bearings (2 0%)
Pulverizer
Coal prep Coal
F.D. fan
Combined Cycle Power Plants 1. Combined Cycle Power Plants 70 / 109
Fans (0.6%) Boiler tubes (4.2%) Fouling/slagging (2.8%) Pulverizers (0.6%) Bearings (2.0%) Pumps (1.7%) Condenser (3.8%) Turbine blades (2.7%) Generator (3.8%)
HIPT
5. High Reliability and Availability [4/4]
Reliability is the percentage of the time between planned overhauls where the plant is generating or is ready to generate electricity, whereas the availability is the percentage of the total time where power could be producedbe produced.
Availability and reliability are very important in terms of plant economy because the power station’s fixed costs are constant whether the plant is running or not.costs are constant whether the plant is running or not.
A high availability has a positive impact on the cost of electricity.
The major factors affecting plant availability and reliability are:
• Design of the major components
• Engineering of the plant as whole, especially of the interfaces between the systems
• Mode of operation (whether base, intermediate, or peak-load duty)
• Type of fuel• Type of fuel
• Qualifications and skill of the operating and maintenance staff
• Adherence to manufacturer’s operating and maintenance instructions (preventive maintenance)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 71 / 109
HIPT
C i f O i d M i C
6. Low O&M Cost [1/4]
Type of Plant Output (MW) Fixed (Million US$/ )
Variable(US$/MWh)
Comparison of Operating and Maintenance Cost
yp p ( ) US$/year) (US$/MWh)
Combined Cycle Power Plant 800 6~8 2~3
Combined Cycle Power Plant 60 3~4 3~4y
Gas Turbine Plant 250 2~2.5 3~4
Gas Turbine Plant 60 1~1.5 4~5
Steam Power Plant (coal) 800 12~15 2.5~3.5
Nuclear Power Plant 1250 40~60 2.0
Biomass Power Plant 30 3~4 5~8
Fixed O&M: personnel and insurance costs. Variable O&M: cost depending upon the operation regime of the plant. Included items are:Variable O&M: cost depending upon the operation regime of the plant. Included items are: • Inspection and overhauls, including labor, parts, and rentals• Water treatment expenses• Catalyst replacement• Major overhaul expences
Combined Cycle Power Plants 1. Combined Cycle Power Plants 72 / 109
Major overhaul expences• Air filter replacements
HIPT
C i f O i d M i C
6. Low O&M Cost [2/4]
Source: GE (1991)
Comparison of Operating and Maintenance Cost
Items Simple cycle
Combined cycle Steam coal IGCC
Fuel type NG NG Coal Coal
Fuel cost ($/MBtu) 2.65 2.65 1.5 1.5
Fixed O&M cost ($/kW/year) 0.7 3.7 28.1 38.8
Variable O&M cost ($/MWh) 7.3 3.3 2.7 3.7
Normalized plant cost 1.14 1 4.40 6.07
Some estimate that burning residual or crude oil will increase maintenance costs by a factor of 3, (summing a base of 1 for natural gas, and by a factor of 1.5 for distillate) and that those costs will ( g g , y )be three times higher for the same number of fired hours if the unit is started every fired hour, instead of once every 1000 fired hours.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 73 / 109
HIPT
6. Low O&M Cost [3/4]
O&M costs include operating labor, materials, and tools for plant maintenance on both a routine and emergency basis.
These expenses are neither a function of plant capital cost nor plant generating capacity.p p p p g g p y
They vary from year to year and generally become higher as the plant becomes older.
These costs also vary according to the size of plant type of fuel used loading schedule and operating These costs also vary according to the size of plant, type of fuel used, loading schedule, and operating characteristics (peaking or base load).
In general, O&M costs are approximately equal to one-fourth of the fuel costs.
A good rule of thumb is that the maintenance cost is twice the initial cost during the plant life (normally, 25 years).
The running profile has a profound impact on the O&M cost The running profile has a profound impact on the O&M cost.
Usually, the first maintenance is scheduled for either 24,000 hours or 1,200 starts (whichever occurs first).
Nowadays it is common to have a maintenance agreement at some level for risk mitigation Nowadays, it is common to have a maintenance agreement at some level for risk mitigation.
There are different levels of contractual services ranging from part agreement to full coverage LTSA services.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 74 / 109
One can choose to use either the OEM or another third party service provider.
HIPT
6. Low O&M Cost [4/4]
In many cases, financing organs or insurer requires and LTSA (or better) for risk mitigation to level the insurance cost at a reasonable level.
There are ways of potentially reducing the maintenance cost and one should always lumped methods with equivalent hours.
The word lumped is used in a sense that the two different ageing mechanisms, such as creep, oxidation, regular wear and tear and stresses related to thermal gradients during start and stop, are evaluated as equivalent time by e.g. assuming that a start consumes time rather being a low cycle.
The total number of gas turbine operated in the world is about 47,000 units and the total value of the gas turbine after market was 19.3 billion USD in 2009.
The after market is valuable greatly to the manufacturers since all 47,000 units requires maintenance on a regular basis.
Certain in-house produced parts may be offered with several hundred percent margin. In contrast, the margin of a complete new turn-key power plant is about 10 percent.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 75 / 109
The reward for the user, by having a LTSA, is discounted parts and prioritized treatment by the supplier.
HIPT
7. Operating Flexibility [1/11]
Mode Baseload Plant (1990s) SCC5-4000F cycling plant (Siemens)
Hot start (8 h) 90 min 45-55 min
Warm start (64 h) 200 min 120 min
C ld t t ( 120 h) 250 i 150 iCold start (>120 h) 250 min 150 min
Operational flexibility is essential in combined cycle power plants for frequency control.
Most OEMs are capable of 30 min hot-start and steep (35-50 MW/minute) ramp-rates.
The steam cooled gas turbine gas a longer start-up time. Thus, is has less flexibility in terms of DSS.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 76 / 109
HIPT
7. Operating Flexibility [2/11]
Gas turbines as well as combined cycle power plants have the unique potential to react quickly and with flexibility to changes in grid, because they have the following characteristics:
• Short startup time• High-loading gradients• Possibilities for frequency support
Operational flexibility becomes a major topic in modern power
k t• Good part load behavior• Additional system for power augmentation
B ilt f b th b l d d k l d ti
markets
Built for both base-load and peak-load operation
High efficiency to maximize generation opportunities
Lower start-up emissions
Lower demineralized water consumption
• Once-through HRSG
Combined Cycle Power Plants 1. Combined Cycle Power Plants 77 / 109
HIPT
7. Operating Flexibility [3/11]
[ Start-up procedure ]
Combined Cycle Power Plants 1. Combined Cycle Power Plants 78 / 109
HIPT
7. Operating Flexibility [4/11]
Hot start (start after an 8-hour shutdown) of a 400 MW CCPP with optimized steam turbine start-up technology (Siemens)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 79 / 109
HIPT
7. Operating Flexibility [5/11]
5 additional
30 min. to baseload
30 MW/min 5 additional minutes to 150 MW
5 minutes to accelerate
13.5 minutes to accelerate
Improved
accelerate to accelerate
Improvement of SGT6-5000F (W501F) Starting Capability
Combined Cycle Power Plants 1. Combined Cycle Power Plants 80 / 109
Improvement of SGT6-5000F (W501F) Starting Capability
HIPT
7. Operating Flexibility [6/11]
Combined Cycle Power Plants 1. Combined Cycle Power Plants 81 / 109
HIPT
7. Operating Flexibility [7/11]
Gas turbines are capable of relatively quick starts.
Heavy duty gas turbines can achieve starting times as low as 10 minutes but usually no higher than 30 minutes from cold start to 100% load.
Aeroderivative gas turbines can achieve 100% load in 3 minutes or less.
If equipped with bypass systems, the startup of the steam cycle portion of the combined cycle can be t d f th t biseparated from the gas turbine.
The gas turbine can be operated at full load while the steam turbine is warming up.
The HRSG can be warmed up nearly as quickly as the gas turbine with excess steam produced being The HRSG can be warmed up nearly as quickly as the gas turbine, with excess steam produced being bypassed to the condenser.
The startup time of the gas turbine and the combined cycle plant is significantly less than the time required for a comparably sized coal-fired power plantfor a comparably sized coal-fired power plant.
Supercritical plants require feedwater purity so that tube side deposition will not cause overheating damage.
Condensate polishing with oxygenated water treatment is required to achieve excellent water purity.p g yg q p y
Even many natural circulation (drum type) units now use oxygenated water treatment.
The deposition has been greatly reduced so that the requirement for frequent chemical cleaning is almost
Combined Cycle Power Plants 1. Combined Cycle Power Plants 82 / 109
eliminated.
HIPT
7. Operating Flexibility [8/11]
For rapid changes in gas temperature, the edges of the bucket or nozzle respond more quickly than the thicker bulk section.
These gradients, in turn, produce thermal stress that, when cycled, can eventually lead cracking.
Turbine start/stop cycle – firing temperature changes Transient temperature distribution (1st stage bucket)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 83 / 109
HIPT
B k L C l F i (LCF) T S i Hi
7. Operating Flexibility [9/11]
Key Parameters
Bucket Low Cycle Fatigue (LCF) – Temperature Strain History
FSNL
Fired Shutdown
Tens
ile (+
)Key Parameters• Total strain range• Max metal temperature
Tm
FSNL
rain
T
Metal Temperaturem
% S
tr
max Base Load
ress
ive
()
Light Off & Warm-up
Acceleration
Com
pr
Combined Cycle Power Plants 1. Combined Cycle Power Plants 84 / 109
HIPT
7. Operating Flexibility [10/11]
Currently, short start-up and shutdown times are emphasized by customers because of high fuel price.
Especially, fast start-up is important for intermediate load application.
The important parameters should be considered for fast start-up are as follows:
• HRSG ramp capability• Steam turbine ramp capabilityp p y• Piping warm up times• Steam chemistry• Steam turbine back-pressure limitations
Combined Cycle Power Plants 1. Combined Cycle Power Plants 85 / 109
HIPT
HRSG
7. Operating Flexibility [11/11]
HRSG
There has also been a debate over the years whether the once-through HRSG technology should be better off than drum boilers in terms of cyclingthan drum boilers in terms of cycling.
• Detailed transient analysis showed that the majority of fatigue life consumption occurs at the hottest high pressure superheater and reheater during fast gas turbine loading
GE
the hottest high pressure superheater and reheater during fast gas turbine loading, regardless of whether the HRSG uses high pressure drum or once through technology.
• The HRSG stack is equipped with an automatic damper that closes upon plant shutdown to reduce HRSG heat loss and the time required for next plant start-up as well as reduce thereduce HRSG heat loss and the time required for next plant start up, as well as reduce the cyclic stress of the start.
• Once through HRSG eliminates the thick wall HP drum and allows an unrestricted gas
Siemens
• Once-through HRSG eliminates the thick wall HP drum and allows an unrestricted gas turbine start-up.a. gas turbine start-up produces rapid boiling in the evaporatorb. if water level in the drum rises to the separators, water carry over into the superheaterp , y p
may occurc. the typical response to this is to either trip or slow gas turbine load ramp
Combined Cycle Power Plants 1. Combined Cycle Power Plants 86 / 109
It is hard to conclude that which one is better in terms of operating flexibility.
HIPT
8. Lower Emissions [1/6]
Pollutants characteristics
Smoke • Smoke is usually formed in small fuel rich regions especially during start-up.
Unburned hydrocarbons • The unburned hydrocarbons and CO are formed incomplete combustion and CO typically at idling conditions.
• CO2 production is a direct function of the CHx fuels burned it produces 3.14 times the fuel burned
CO2
times the fuel burned.
• The only way to reduce the production of CO2 is to use less fuel for the power produced.
• NOx have been major pollutant in modern gas turbines.
• New units under development have goals which would reduce NOx levels below 9 ppmNOx below 9 ppm.
• SCRs have also been used in conjunction with DLN combustors.
• New research of catalytic combustors will give 2 ppm in the future.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 87 / 109
HIPT
E i i [N 2 Oil]
8. Lower Emissions [2/6]
Emission [No. 2 Oil]
4000 300
High SmokeEmissions
High CO Emissions
3000F e, p
pmv
and
3000
me
Tem
p.,
200
NO
x R
ate
cond
ition
Opt
imum
B
2000Fla
100
chio
met
ric
O
1000
Sto
i
Combined Cycle Power Plants 1. Combined Cycle Power Plants 88 / 109
0.5 1.51.0Equivalence Ratio
Fuel richFuel lean
HIPT
W /S I j i
8. Lower Emissions [3/6]
Most gas turbines control NOx emission with diluent injection into the combustor until 1990.
The injected diluent used as a heat sink that lowers the combustion zone temperature which is the primary
Water/Steam Injection
The injected diluent used as a heat sink that lowers the combustion zone temperature, which is the primary parameter affecting NOx formation.
As the combustion zone temperature decreases, NOx production decreases exponentially.
In order to increase thermal efficiency, gas turbines having higher firing temperature has being developed by manufacturers.
H hi h fi i t t hi h b ti t t hi h d NO However, higher firing temperature mean higher combustion temperatures, which produce more NOx, resulting in more diluent injection to achieve the same emission levels of NOx.
The increased diluent injection lowers the thermal efficiency because some of the energy of combustion i d t h t th t tgases is used to heat the water or steam.
Furthermore, as injection increases, dynamic pressure oscillation activity (i.e., noise) in the combustor also increases, resulting in increased wear of internal parts.
Carbon monoxide, representing the measure of the inefficiency of the combustion process, also increases as the diluent injection increases.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 89 / 109
The lowest practical NOx levels achieved with diluent injection are generally 25 ppm and 42 ppm when firing natural gas and distillate oil, respectively.
HIPT
L NO E i i
8. Lower Emissions [4/6]
CCPP includes gas turbines with DLN combustors that can operate with stack gas NOx emission concentration as low as 9 ppmvd at 15% oxygen without steam or water injection, when the natural gas is
f
Lower NOx Emissions
used as a fuel.
Water or steam injection may be required to meet NOx emission requirements, when distillate is used as a fuel.
Water or steam injection can be used in the gas turbines with diffusion flame combustors to meet NOxemission limits.
NOx can be reduced to less than 9 ppmvd by the installation of SCR in the HRSG.
Lower CO Emissions
Carbon monoxide (CO) emissions are low at gas turbine loads above 50%, typically less than 5~25 ppmvd(9~43 g/GJ).
Low CO emissions are the result of highly-efficient combustion.
Catalytic CO emission abatement systems are also available, if required.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 90 / 109
The CO catalyst is installed in the exhaust gas path, typically upstream of the HRSG superheater.
HIPT
L CO E i i
8. Lower Emissions [5/6]
The role of gas turbine has changed from either a special application or stand-by mode to combined cycle plants in either intermediate or base load.
Lower CO2 Emissions
The high efficiency combined with natural gas high hydrogen content result in relatively low levels of specific CO2 emission.
Unfortunately, however, the relative lower CO2 content in the flue gas makes the separation process more difficult, and may render in high separation tower heights to provide for sufficient residence time.
Another issue is the flue gas flow which is on the order of 1.5 kg/MW, compared to 0.95 kg/MW for than advanced steam plants.
The cross section of the separation tower should provide for a velocity around 5 m/s Therefore a combined The cross section of the separation tower should provide for a velocity around 5 m/s. Therefore, a combined cycle plant requires a higher and wider tower for CO2 capture plant compared to a coal fired plant.
No commercial full-scale technology for CO2 capture exists today and the road-maps towards feasible solution are still not clear.
It has been expected that the efficiency of combined cycle power plant with CO2 capture plant will drop 8 percent for a GE 9FB.03 with a 3-pressure HRSG. This is because a lot of LP steam is required for solvent
Combined Cycle Power Plants 1. Combined Cycle Power Plants 91 / 109
percent for a GE 9FB.03 with a 3 pressure HRSG. This is because a lot of LP steam is required for solvent regeneration.
HIPT
CO E i i f Diff P Pl
8. Lower Emissions [6/6]
Lignite: 980~1,230
CO2 Emissions from Different Power Plants
Hard coal: 790~1,080
Oil: 890
NG: 640
NG Comb. cycle 410~430
Unit: g CO2/kWh
Solar 80~160
Nuclear: 16~23
Wind: 8~16
Hydro power: 4~13
Electricity generation with CCS
The CO2 emissions of the plant are having a more direct impact on the economics of a plant due to the effort to globally limitation.
The combined cycle plant emits about 40% of the CO of a coal fired plant This is driven by the higher
Combined Cycle Power Plants 1. Combined Cycle Power Plants 92 / 109
The combined cycle plant emits about 40% of the CO2 of a coal-fired plant. This is driven by the higher efficiency and the higher hydrogen content in natural gas.
HIPT
9. Options for Power Enhancements
O ti f P E h tTypical Performance Impact
Output = m h•
Options for Power Enhancements Output Heat Rate
Base configuration Base Base
Evaporative cooling GT inlet air (85% effective cooler) +5.2 % -
Chill GT inlet air to 45F +10.7 % +1.6 %
GT k l d i 2 % 1 0 %GT peak load operation +5.2 % 1.0 %
GT steam injection (5% of GT airflow) +3.4 % +4.2 %
GT water injection (2 9% of GT airflow) +5 9 % +4 8 %GT water injection (2.9% of GT airflow) +5.9 % +4.8 %
HRSG supplementary firing +28 % +9 %
Note: 1. Site conditions = 90F, 30% RH(Relative Humidity)2. Fuel = NG3. 3-pressure, reheat steam cycle
Combined Cycle Power Plants 1. Combined Cycle Power Plants 93 / 109
HIPT
C i i h C l Fi d P Pl
10. Compactness [1/8]
BoilerFeedwater
Steam Turbine
Comparison with Coal-Fired Power Plants
FeedwaterPump
Turbine
10 Meters
Combined Cycle Power Plants 1. Combined Cycle Power Plants 94 / 109
HIPT
A f Si l Sh f [GE]
10. Compactness [2/8]
Arrangement of Single-Shaft [GE]
[ Single-Shaft CCPP (107FA) ]
Combined Cycle Power Plants 1. Combined Cycle Power Plants 95 / 109
HIPT
A f M l i Sh f [207FA GE]
10. Compactness [3/8]
Arrangement of Multi-Shaft [207FA – GE]
Combined Cycle Power Plants 1. Combined Cycle Power Plants 96 / 109
HIPT
10. Compactness [4/8]
Single Shaft (1-on-1 configuration) Multiple Shaft (2-on-1 configuration)
ComponentsLess generator required One large ST instead of 2 smaller STs
ComponentsOne compact lube oil system Less auxiliaries (pumps etc) required
Civil Smaller plant area Higher flexibility in plant layout
L i l f l bCosts
Lower capital cost of plant because one generator and one step-up transformer is eliminated
St t bi h hi h ffi i bPerformance Same level in larger plants Steam turbine has higher efficiency because of larger steam volume flow
Operating Fl ibilit
Suitable for daily start and stop (DSS) ti Suitable for base load operationFlexibility operation p
Availability Higher (less complexity)
Operation limit
Operation is limited to concurrent operation of the gas turbine and steam turbine, unless the steam turbine can be decoupled from the generator through a clutch
The gas turbine can be decoupled from the operation of the steam turbine, allowing for steam turbine shutdown with continued gas turbine operation
Combined Cycle Power Plants 1. Combined Cycle Power Plants 97 / 109
generator through a clutch turbine operation
HIPT
A f Si l Sh f [Si ]
10. Compactness [5/8]
Arrangement of Single-Shaft [Siemens]
Combined Cycle Power Plants 1. Combined Cycle Power Plants 98 / 109
HIPT
Si l Sh f
10. Compactness [6/8]
Single-shaft with generator between gas turbine and steam turbine enables installation of a clutch between steam turbine and generator.
Single-Shaft
One problem of a Jaw clutch, which was used previously, is that it can only be engaged when the gas turbine is at rest. This means that in the event of a failed gas turbine start, the operator must wait until the gas turbine is stationary before engaging the jaw clutch to re-start.
Currently, SSS(Synchronous Self-Shifting) clutch has been employed popularly. The SSS clutch engages in that moment when the steam turbine speed tries to overrun the rigidly coupled gas turbine generator and disengages if the torque transmitted from the steam turbine to the generator becomes zero.
The clutch allows startup and operation of gas turbine without driving the steam turbine.
This results in a lower starting power and eliminates certain safety measures for the steam turbine, such as g ycooling steam or sealing steam.
The clutch also provides design opportunities for accommodating axial thermal expansion.
However, the clutch is an additional component with a potential impact on availability. Additionally, the generator located at the end of the line of shafting has advantages during generator overhaul.
Single-shaft units without a clutch definitely need auxiliary steam supply to cool the steam turbine during
Combined Cycle Power Plants 1. Combined Cycle Power Plants 99 / 109
Single shaft units without a clutch definitely need auxiliary steam supply to cool the steam turbine during startup. This is not necessary in units with a clutch.
HIPT
A f Si l Sh f [GE 6FA]
10. Compactness [7/8]
Arrangement of Single-Shaft [GE, 6FA]
A b i i li ti hA gearbox is necessary in applications where the manufacturer offers the package for both 60 and 50 cycle applications. The gearbox will use roughly 2 percent of the power produced b th t biby the turbine.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 100 / 109
HIPT
T i l Pl A [GE S207EA]
10. Compactness [8/8]
Typical Plant Arrangement [GE, S207EA]
Combined Cycle Power Plants 1. Combined Cycle Power Plants 101 / 109
HIPT
Introduction to Combined Cycle Power Plants1
Electricity Demand and Supply2
Cost of Electricity 3
Electricity Demand and Supply2
Characteristics of Combined Cycle Power Plants4
Wide Use of Gas Turbine 5
Characteristics of Combined Cycle Power Plants 4
Combined Cycle Power Plants 1. Combined Cycle Power Plants 102 / 109
HIPT
C i [1/2]
Wide Use of Gas Turbine
Cogeneration means the simultaneous production of electricity and thermal energy in the same plants.
Cogeneration [1/2]
The thermal energy is usually steam or hot water.
The types of cogeneration plants:
① Industrial power stations supplying heat to an industrial process
② District heating power plants
③ Power plants coupled to seawater desalination plants
The supplementary firing in the HRSG gives greater design and operating flexibility, but the cycle efficiency is normally lower if supplementary firing is used.y pp y g
Thermal energy in the form of steam can be extracted from HRSG, or from an extraction in the steam turbine.
The power coefficient (also called the alpha-value) is defined as the ratio between the electrical and the thermal output.
Fuel utilization is a measure of how much of the fuel supplied is usefully used in the plant It is equal to the
Combined Cycle Power Plants 1. Combined Cycle Power Plants 103 / 109
Fuel utilization is a measure of how much of the fuel supplied is usefully used in the plant. It is equal to the sum of electrical output and thermal output divided by the fuel input.
HIPT
C i [2/2]
Wide Use of Gas TurbineCogeneration [2/2]
Single PressureSupplementary FiringB k T bi
Heat Balance
Backpressure Turbine
Combined Cycle Power Plants 1. Combined Cycle Power Plants 104 / 109
HIPT
S D li i Pl
Wide Use of Gas TurbineSeawater Desalination Plant
Combined Cycle Power Plants 1. Combined Cycle Power Plants 105 / 109
HIPT
P ll l P i
Wide Use of Gas TurbineParallel Powering
Combined Cycle Power Plants 1. Combined Cycle Power Plants 106 / 109
Parallel powering: Gas turbine exhausts are used in the existing steam cycle.
HIPT
IGCC
Wide Use of Gas TurbineIGCC
Combined Cycle Power Plants 1. Combined Cycle Power Plants 107 / 109
HIPT
Load Control & Frequency Response
Combined cycle plants are very well suited to rapid load changes because gas turbine react extremely quickly to frequency variations.
As soon as fuel valve opens more added power becomes available on the shaft and gas turbine load jumps As soon as fuel valve opens, more added power becomes available on the shaft and gas turbine load jumps of up to 35% are possible, but this is detrimental to the life expectancy of the turbine blades.
To perform a plant load jump while the frequency is falling, it is essential that gas turbine is operating below the maximum output levelthe maximum output level.
For frequency support gas turbines are typically operated between 50 and 95% load.
The electrical output of the combined cycle power plants is controlled by means of gas turbine only This is The electrical output of the combined cycle power plants is controlled by means of gas turbine only. This is because the gas turbine generates two-thirds of the total power output, a solution without control for the steam turbine power output is generally preferred.
The gas turbine output is controlled by a combination of VIGV and TIT control The gas turbine output is controlled by a combination of VIGV and TIT control.
The TIT is controlled by a combination of the fuel flow into the combustor and VIGV setting.
VIGV ll hi h t bi h t t t d t i t l 40% GT l d B l thi l l VIGVs allows a high gas turbine exhaust temperature down to approximately 40% GT load. Below this level, TIT is further reduced because the airflow cannot be further reduced.
The steam turbine will always follow the gas turbine by generating power with whatever steam is available.
Combined Cycle Power Plants 1. Combined Cycle Power Plants 108 / 109
HIPT
질의 및 응답질의 및 응답
작성자: 이 병 은 (공학박사)작성일: 2014 03 03 (Ver 3)
Combined Cycle Power Plants 1. Combined Cycle Power Plants 109 / 109
작성일: 2014. 03. 03 (Ver.3)연락처: ebyeong @ naver.com
Mobile: 010-3122-2262저서: 실무 발전설비 열역학/증기터빈 열유체기술