Wärtsilä Biopower Oy has supplied a biomass-fired CHP power plant to Swedish municipal energy company Trollhättan Energi AB. The BioPower 5 DH plant, named Lextorp CHP, has a power output of 3.7 MWe and a thermal output of 17 MWth, the latter comprising 12.5 MWth generated by back-pressure steam from the turbine and 4.5 MWth by a flue gas condenser. The thermal output corresponds to 30% of Trollhättan's district heating needs. The fuel is a mixture of local sawmill and forest residuals. The moisture content of the fuel can be as high as 60%.
The boiler is a natural circulation water tube boiler that produces superheated steam for an efficient impulse-type district heating turbine. Additional heat for the district heat is recovered from the flue gases by the flue gas condenser. The thermal output of the flue gas condenser is increased by moistening the combustion air. Due to its high level of automation the plant can be run unmanned, based on periodical visits for supervision.
"This biomass-fuelled plant strengthens our aim to deliver positive environmental benefits. Approximately 95% of the district heating in Trollhättan now comes from biomass fuel in the form of wood chips, a renewable energy source. Trollhättan is a growing municipality, which emphasizes the importance of this change of fuel source for future district heating needs. The investment is also economically sound, both for us and our customers" says Mr Mats Johansson, Managing Director of Trollhättan Energi.
"In February 2005 the construction of the BioPower plant started", continues Mats Johansson "and the first delivery of heat was in December the same year which confirms that the project has proceeded well."
Wärtsilä BioPower plants are clean and efficient. They are a practical solution for renewable energy production with minimum environmental impact. They utilize patented Wärtsilä BioGrate combustion technology to burn biofuels with high efficiency and low NOX and CO emissions.
The BioPower plant operates on a closed steam-feed water system separate from the district heating water system. Steam is generated in an efficient water-tube boiler, and supplied to a back-pressure steam turbine driving an alternator. Turbine exhaust steam then heats the district heating water, and the condensate is returned as feed water to the boiler.
BioPower plants are highly modular, being based on well-proven technology and standardised components with a conservative design approach. The plants can thus be delivered and installed quickly. Their proven technology results in a reliable, durable plant.
Click here to see how the Lextorp CHP plant was built (text in Swedish)
| Main data |
| Name: |
Lextorp CHP |
| Type: |
Biopower 5 DH |
| Location: |
Trollhättan, Sweden |
| Owner: |
Trollhättan Energi AB |
| Delivered: |
2005 |
| Total electrical output: |
3.7 MW |
| Total thermal output: |
17 MW |
