Steam Boiler CHP Power Plant with 240 MW Pyroflow CFB Boiler and Siemens 88MVA Steam Turbine

10502025 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.

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

General Introduction video 

Walkaround Video of Siemens Steam Turbine Package