belchatow-poland-supercritical-steam-coal-power-plant-editorial

LIGNITE POWER
Operating large coal and lignite plants in Poland
R Hard coal
4 Lignite
4 Elblag
Main features of the new
Belchatow 858 MWe
supercritical unit
Turów
• secure fuel costs by achieving constant lignite
demand;
• secure extended lifetimes for the upgraded
existing units; and
• meet all EU requirements relating to coal fired
plants.
The environmental performance of the new plant
can be summarised as follows:
• NO x emissions below 200 mg/Nm 3 ;
• particulate emissions below 30 mg/Nm 3 thanks
to ESP plus additional effect of wet
desulphurisation;
• reduction of SO x emissions to below 200 mg/Nm 3
with a removal efficiency of over 96 %, again
thanks to the wet desulphurisation system;
• limitation of CO 2 emissions thanks to high
plant efficiency;
• reduction of raw cooling water consumption
through measures such as reuse of cooling tower
blowdown water and reuse of water from the
nearby mine for ash slurry transport instead of
using surface water resources; and
• noise abatement though use of protection
systems and special attention to design of
sensitive systems, such as coal handling
equipment, boiler fans, and cooling tower.
Solid waste consisting of fly and bottom ash
will be transported as slurry to a new landfill in
the nearby lignite mine. Waste gypsum from the
new wet limestone FGD scrubbing system will
be used commercially, a practice well established
in Poland. In fact the use of power plant gypsum
for plasterboard in Poland was pioneered by the
existing Belchatow units.
Design features
The Alstom scope of supply includes: a tower type
supercritical once through pulverised coal boiler
(with low NO x combustion system); five-casing
steam turbine with three double flow exhausts
(STF100); hydrogen cooled generator
(GIGATOP); water cooled condenser;
feedheating system with seven heaters; milling
system; wet flue gas desulphurisation system; coal
Five-casing steam
turbine for Belchatow
R Dolna Odra
8 x 200 MW
Turów
3 x 238 MW
1 x 265 MW
4 6 x 200 MW
R Opole
4 x 360 MW
4 Patnow
7 x 120 MW
8 X 200 MW
4 Bełchatów
12 x 360 MW
Łayiska
2 x 120 MW
R 4 x 200 MW
R Rybnik R Jaworzno III
8 x 200 MW 6 x 200 MW
R Ostrolęka
3 x 200 MW
R Kozienice
8 x 200 MW
2 x 500 MW
R Połaniec
8 x 200 MW
Patnow
and ash handling systems; control system based
on Alstom ALSPA technology; and balance of
plant. An important feature of the project has been
careful integration of all these systems throughout
all phases, from development of the concept,
through the basic and detailed design up to erection
and commissioning.
The new 858 MW unit has been designed to
achieve an operating life of about 200 000 hours,
ie about 35 years.
It will use local lignite from the existing
Belchatow open cast mine, presently supplying fuel
to the existing units, as well as from a new open cast
lignite mine being constructed at Szczercow.
The design of the unit as well as the equipment
selected will allow the new plant to achieve an
availability above 88% over the first two years
of operation, with scheduled outages reduced to
about two weeks for the annual overhaul, with a
six week outage every three years.
Thanks to its compact and modular design the
new unit, with all auxiliary installations, will cover
the relatively small area of 300 m long and 350 m
wide, an extension to the area of the existing plant.
The total height of the new turbine building will
be 39 m and the boiler will be up to 150 m high.
In addition to the new power block (boiler, turbine
and generator) the project consists of: the new
desulphurisation plant with auxiliary installations;
recirculating cooling system with the cooling tower
also used as a chimney; the complete electrical
system with two unit transformers; new control
system; water treatment system; coal handling
system connecting the new unit with the lignite
transportation system from the open mine to the
existing units; hydraulic ash slurry transport
systems; electrostatic precipitator; auxiliary systems
and buildings, including administration building.
The majority of deliveries and almost all the onsite
work will be provided by Polish companies.
Main components
The main data for the plant are summarised in
the table, right.
Key features of the main systems include the
following:
Boiler
Supercritical once-through single pass boiler
with circulating pump for start up and turn down
capability to 40% of boiler load.
There is one 100% boiler feedwater pump driven
by an auxiliary steam turbine connected to steam
extraction from the main steam turbine and two
start up and reserve pumps (35% each) connected
to electrical motors via hydrokinetic couplings.
Fuel
Cooling system
Contract type
Boiler
Boiler type
Lignite (domestic)
Cooling tower
(natural draft)
Turnkey
Tower,
once through
Steam flow (t/h) 2400
Steam pressure (bar) 275
Steam temperature (°C) 554
Turbine (STF100)
Number of casings 5
Steam pressure (bar) 252
Steam temperature -
inlet/reheat (°C) 550/580
Speed (rpm) 3000
Generator (GIGATOP)
Rating (MVA) 1042
Power factor 0.85
Frequency (Hz) 50
Terminal voltage (kV) 27
Excitation system
Alstom
Static Excitation
System P320
Cooling system
Hydrogen
plus water
Condensing plant
Circulating water
temperature (°C) 17.5
Condenser pressure
(mbar) 43
Tube material
Stainless steel,
DIN 1.4439
Feedwater heating plant
Feedwater heaters 7
Feedwater deaerating tank 1
Feedwater temperature (°C) 275
Main pumps
Condensate extraction 3 x 50% (first stage
pumps
plus second stage)
Feedwater pump
1 x 100% main
turbine driven
feedwater pump
plus 2 x 35% start-up
motor driven
feedwater pumps
Circulating water pumps 2 x 50%
Polishing plant
yes
Main transformer
Rated output (MVA) 2 x 700
Primary/secondary (kV) 420/27
Unit transformers
Rated output (MVA) 80/40/40
Primary/secondary (kV) 27/10.5/10.5
Standby transformer
Rated output (MVA) 80/40/40
Primary/secondary (kV) 115/10.5/10.5
Instrumentation and control system
Logic control
Alstom ALSPA
Analog control
Alstom ALSPA
Data acquisition
Alstom ALSPA