Steam Boiler CHP Power Plant with 240 MW Pyroflow CFB Boiler
A combined heat and power (CHP) plant in very good condition, with an
electrical capacity of 88 MVA and a thermal capacity of 240 MW. The
plant is designed to operate primarily on wood-based biomass, with
coal as a backup fuel. This is a complete power plant, still in full
operation, and includes all technical systems from fuel feeding to the
dispatch of electricity and live steam. The equipment has been
exceptionally well maintained and extensively upgraded throughout its
lifetime, meeting the most stringent modern quality standards.
The steam boiler utilises Circulating Fluidised Bed (CFB) technology
with the commercial-type PYROFLOW, manufactured in Finland by
Ahlström in 1989. This CFB boiler delivers a steam flow of 100
kg/second at a pressure of 137 bar and a temperature of 535ºC. The
primary fuel has been wood-based biomass with a moisture content of
35–55%, although it can also operate solely on coal.
The complete steam turbine plant was manufactured by Siemens. It
comprises an extraction back-pressure turbine (maximum operational
steam: 74 kg/s at 137 bar, total throughput: max. 100 kg/s) with a
dedicated district heating section, and a condensing turbine
(operational steam: max. 30 kg/s at 3.5 bar), as well as an 88 MVA /
10.5 kV / 50 Hz generator with auxiliaries. The 3.5 bar steam
extracted from the back-pressure turbine is used by a nearby
industrial facility and for district heating. In condensing mode, the
3.5 bar exhaust steam from the back-pressure turbine is routed into
the condensing turbine for maximum electricity generation. The
low-pressure steam is then condensed in a tubular condenser.
This boiler plant has been meticulously maintained and substantially
upgraded over the years. Both steam turbines were factory-refurbished
to zero-hour condition by Siemens Germany in 2023 and are therefore in
excellent condition. The alternator was found to be in perfect
condition during inspection. The power plant’s operation and control
system was completely rebuilt in 2016 and is currently based on the
Siemens T-3000 system with Siemens Simatic S7-series PLCs.
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Technical Characteristics – Steam Boiler Plant
Manufacturer: Ahlström (Foster Wheeler / Andritz)
Boiler Type: Circulating Fluidised Bed – PYROFLOW
Thermal Capacity: 240 MW
Steam Output: 100 kg/s, 137 bar, 535ºC
Year of Manufacture: 1989
Fuel: Wood-based biomass, peat, coal
Technical Characteristics – Turbine Plant
Back-Pressure Steam Turbine: Siemens Extraction EHNKS 90/80-4 with
district heating section
Live Steam Input (Back-Pressure): Max. 84 kg/s at 137 bar, 535ºC
Live Steam Input with DH Section: Max. 100 kg/s
Year of Manufacture: 1989
Condensing Turbine: Siemens WK 63/81/32-3
Live Steam Input (Condensing Turbine): 30 kg/s at 3.5 bar
Rotational Speed: 3,000 rpm
Generator: Siemens 88,000 kVA / 50 Hz
Voltage: 10,500 V