Naturkraft - NTNU

NTNU TPG 4140
September 24, 2012
Naturkraft
Gas Fired Power Plant
Stein Espen Bøe
Operations Manager
s.e.boe@naturkraft.no

Contents
• Introduction
• Background
• Theory of the CCPP process
• Details of main components
• Performance and environment
• Experiences
• Market, Future, CCS and Politics
• Summarization

Naturkraft AS
• Established in 1994.
• 10 years on permits and regulations!
• Government resigned due to our concession.
• Owners: Statoil / Statkraft (50/50).
• Norway's first commercial gas power plant!
• 420 MW Single shaft, combined cycle.
• First fire 27th of July, first synchronization 9th of August.
• PAC 6th of December 2007

Norwegian power production
• Almost 100% hydro electric.
• In dry years /seasons, import of mainly coal- and nuclear
power.
• In wet years /seasons, export of hydropower.

Norwegian oil & gas production
• Norway is one of the
largest oil exporters in
the world.
• Approximately 0,5% of
the Norwegian gas
consumed domestically.
• A longlasting political
debate regarding
increased domestic use
of gas vs. increased
CO2-emissions.

Starting up
The power plant is ready
for commercial
production after two
years of construction.

CCPP: GT & Gen

CCPP: HRSG

CCPP: ST

CCPP: Combined Cycle

CCPP: the process
Simplification of the process
SCR NOx RENSING

The main components – virtual tour
• Fuel Gas intake
• Air intake
• Compressor
• Combustion chamber
• Gas Turbine
• Boiler
• SCR
• Steam Turbines
• Cooling water
• Generator and power transmission

Lager/verksted
Virtual tour at the powerplant
-Fuelgas
Fuel gas treatment
Fuel gas intake:
Natural gas from Europipe II
at aprox. 180 bars. The
HVAC-unit preheats the gas
before pressure reduction in
two steps to approx 30 bars.
Consumption approx 15 kg/s =
1,6 mill Sm
Transformator
Fuel gas pressure
reduction.
3 /d
HVAC

Virtual tour at the powerplant
-Fuelgas
Lager/verksted
Fuel gas treatment
Transformator
Fuel gas pressure
reduction.
HVAC

Virtual tour at the power plant
- Air intake
Lager/verksted
Air intake
Air intake:
The compressor supplies the
gas turbine with 600 m3 of air
pr sec, approx 3 x
stoichiometric air excess
compared to fuel gas.
The air is being filtered in
several steps before it enters
Transformator
the turbine.

Virtual tour at the power plant
- Air intake
Lager/verksted
Air intake
Transformator

Virtual tour at the powerplant
-Gas turbine
Air intake
Combustion camber:
24 low-NOX burners in tiled
combustion chamber converts
the chemical energy to thermal
energy.
Temperature approx 1230 °C
IGV Compressor
Combustion chamber Turbine
Gas turbine:
Output 280 MW, converts thermal
energy to mechanical energy.
Exhaust temperature 600 °C

Virtual tour at the power plant
- Steam system
Water treatment
Tank for
DeMin Water
Ammonia storage
Lager/verksted
Feed water pumps
Boiler (HRSG)
SCR
De-NOX
Water treatment plant:
Purification of water for the
boiler, and addition of
corrosion inhibitors.
Heat Recovery Steam Generator:
Waste heat used to produce heat on 3
pressure levels:
HP: 555 °C, 120 Bar
MP: 555 °C, 33 Bar
LP: 230 °C, 4 Bar
Transformator
Selective Catalytic Reduction:
Ammonia injected into the exhaust gas
reacts with NOX at the surface of a
catalyst. NOX concentration reduced
from 25 to 2 ppm.

SCR deNOX system
• Catalyst installed inside HRSG.
• Ammonia used as reducing
agent.
• Diluted and injected upfront
catalyst.

SCR deNOX system
4NO � 4NH
3 � 4N
2 � 6H
2O
6NO2 � 8NH
3 � 7N
2 �12H
2O
NO �
NO2
� 2NH 3 � N 2 � 3H
2O

Virtual tour at the powerplant
- Steam turbines
● Each steam pressure from the boiler goes to
separate steam turbines:
–HP steamturbine
– IP steam turbine
– LP steam turbine
● Steam turbines connected to the same shaft as
gas turbine and generator, however it is possible
to dissconnect the steam turbines by a clutch.

Virtual tour at the powerplant
-Colingwater
• Consession of emitting max 28.000 m3 cooling water pr hour, max additional
energyflux of 250 MW.
• Cooling water intake at 79 m depth, outlet at 18 m depth, temperature
increase approx 10 °C.
• Main use of cooling water is to condense the steam in the condensor after the
low pressure steam turbine.

Virtual tour at the powerplant
- From generator to grid
• The largest generator in Norway: 520MVA / 447MW
• Hydrogen cooled generator
• Generator current of 15kA
• Generator voltage of 20 kV
• Generator transformer transforms to 300 kV
• 3x1x1000 mm2 Cu ground cables á 1350m for connection to grid.

Performance
• Naturkraft CCPP was the most efficient gasfired powerplant ever built
(2007)
• Power output eficiency of 59,5% (based on LHV) without fuel gas pre
heater installed.
• Higher performance corresponds to lower emissions pr MWh

60
58
56
54
52
50
48
46
Combined Cycle Energy efficiency –
a continous improvement
Steam cycle
Single pressure Dual pressure Tripple pressure with reheat
Net efficiency
(%)
960°C
—
50 bar
460°C
1983/84
1000°C
—
60 bar
485°C
Source: Siemens Gas Turbines
1050°C
—
75 bar
510°C
1120°C
—
80 bar
520°C
1160°C
—
100 bar
520°C
1190°C
200°C
110 bar
540°C
1230°C
130°C
110 bar
550°C
Fuel gas firing
ISO ambient conditions
(15°C, 1013 mbar, 60% rel. humidity)
Condenser back pressure 0.04 bar
1230°C
130°C
125 bar
565°C
1250°C
200°C
160 bar
580°C
1987/88 1990/91 1992/93 1994/95 1996/97 1998/99 2001 2007/08
Year of commissioning
Turbine inlet
temp. (ISO)
Fuel preheating
Life steam
pressure
Life steam
temperature

Lignite-fired
steam power plant
43% 47%
Niederaußem,
965 MW
1992:
Efficiency
36 %
2006: 43 %
2020 target: >50 %*
* Using lignite pre-drying technology
PG’s fossil-based technology is setting efficiency
standards worldwide
CO 2 -
emissions
Basis
-16%
>-28%
Hard coal-fired
steam power plant
Reference STPP NRW,
600 MW
Efficiency
1992: 42 %
2006: 47 %
2020 target: > 50 %
CO 2 -
emissions
Basis
-11%
>-16%
58%
Karstoe
420 MW
Combined cycle
power plant
Development of efficiency and corresponding reduction of CO 2 emissions
Efficiency
1992: 52 %
2006: 58 %
2020 target: > 60 %
CO 2 -
emissions
Basis
-10%
>-13%

Performance
60 %
58 %
56 %
54 %
52 %
50 %
48 %
46 %
44 %
42 %
40 %
38 %
36 %
34 %
32 %
30 %
Corrected Performance (Net,
GCV=HHV) %
Corrected Performance (Net,
NCV=LHV) %
Corrected Performance (Gross,
GCV=HHV) %
Corrected Performance (Gross,
NCV=LHV) %
CO emission ppm
Performance at various loads
Performance at low load
CO emission limit by SFT
100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460
Net Power
100
90
80
70
60
50
40
30
20
10
0

Performance

Steam turbine
Gas turbine
Generator
Naturkrafts CCPP
SCR
HRSG Gas de-NOx supply

Operational experiences
• Mostly stable operation, some repeting or serious problems
– Fuel gas supply
– HP-bypass system
– ST hydraulic actuators
– Too small clearings in GT found during eHGPI

Revision autumn 2011 - EOH: 23191

Axial clearance between blades/vanes
Clerance to smaal!
Move casing 1mm

Axial clearance between blades/vanes
All 15 stages grinded

Move gasturbine casing 1 mm in counter flow direction
• 14 days delay
• 800 additional man-hours
• Compressor bearing mod.
• Grinding compressor blades
all stages
• Rotor out twice + cleaning
• Final assembly

Marked & avtaler
• Naturkraft sells the availability to convert NG to Power to our owners
• Commersially arrangement by a ”Tolling agreement”
• Produktion or not decided by each toller each day
• Operates in both Spot market and Balance market

Commersial model
Market dependent
gass el
Naturkraft owns, operates and maintain the plant
Gas supplied free of charge to Naturkraft
Power delivered free of charge back to owners/tollers

Availability
Availability
Availability

● Low production in 2008
– Expensive gas, cheap power, expensive quotas,
limited posibilities for export
● Full production Feb.2009 untill june 2011
– Cheap gas, cheap quotas.
– Dry years -> high power prices
– More profitable to convert gas to power than to
export gas directly
● Low production in 2008
– Expensive gas, wet year -> cheap power.

Todays prices:

Future?
• Energy consumption growth or energy saving?
• European finacial chrisis?
• Nuclear debate?
• Skifer gas in USA/Canada
• Increased subsidized renewables
• Several contradicting incetives

CO 2
Kvote
CO 2
• Regulated by Quota directive for the entire CO2 volume
• Naturkraft recieves free quotas according to 2125 production
hours for Kyotoperiod 2008-2012, or1/3 of comparable
industry in Norway
• Short of quotas, has to be purchased in the market
• New regime after 2012?
• Should have harminized legislations in the same market area
for gas and power!

CCS

CO 2 capture?

Gasskraftverket på Kårstø
• Naturkraft is owned by Statkraft 50% and Statoil 50%
• 430 MW capacity
• Annual production 3,5 TWh
• Prformance 58 – 60 % (electric)
• 0,6 BCM gas consumption
• Invesment approx. 2 BNOK
• Project period approx. 2,5 år,
PACdesember 2007
• NOX emissions below 5 ppm
• CO2 emissions 1,2 millions MT annually on continous
baseload operation. Part of CO2 quota directive
• 36 permanent employees

Thank you for your attention!

Naturkraft AS Gas Fired Power Plant
The entire content in this presentation is owned by Naturkraft
AS. Further distribution or use of the content or parts of the
content is illegal whithout written approval from Naturkraft
AS.
Stein Espen Bøe
Operations Manager
s.e.boe@naturkraft.no