Type of CHP system: BFB boiler

Plant owner: Plant is owned by Jämsänkosken Voima Oy

Commissioned: (reconstructed):1969 (2002)

Status of plant: Commercial

Contractor details:

The new boiler of Jämsänkoski  plant was commissioned by Foster Wheeler Oy. Fuel handling systems were delivered by BMH Wood Technology Oy. Automation and control system was delivered by Honeywell Oy, steam turbine by Alstom Power.

Power generation: Steam turbine

The new boiler is a fluidised bed boiler with a maximum thermal output of 185 MW. Boiler was the biggest BFB boiler built by Foster Wheeler so far.

Main fuel: Multifuel (more biofuels and/or peat)

Power plant was designed for wood and peat fuels. The main fuels are by-products from papermill, wood chips and peat. The boiler can burn all the combustible waste from mill site, bark from fuel handling and sludge from from the effluent treatment plant, which has reduced the total amount of the landfill waste. In year 2002 the use of fuels was 931 GWh in total. The main fuel was peat, 475 GWh, also 354 GWh of wood fuels and 102 GWh of oil was used.The new boiler started in May 2002, so fuel data given above does not correspond to a typical year.

Nominal capacities & efficiencies:

Thermal input, biomass & waste: 205 MW

Total thermal input, incl. fossil fuels: 205 MW

Gross electrical output: 46 MWe

Heat output: 138 MJ/s

Electrical efficiency, gross: 22 %

Overall efficiency, gross: 90 %

Power to heat ratio: 0,33

With the commissioning of the new boiler plant also heat recovery inside the pulp and paper mill has been emphasized. Heat recovered from thermo mechanical pulp production process is used for heating the combustion air, excess water, buildings and district heat grid. Also heat recovery from cooling systems intensified and cooling waters are circulated more efficiently.

How is plant controlled: Power plant is controlled by the process heat demand.

Heat backup: Old fluidised bed boilers is retrofitted to oil-fired boilers and kept as standby boilers Also there are two existing oil-fired boilers for the backup.

Heat usage: Process steam

Energy usage:

Process steam is used in paper mill and district heat is used in the town of Jämsänkoski. In 2002 district heat generation was about 29 GWh. A total of 630 GWh of process steam and 205 GWh of electricity was generated. District heat consumption will increase in near future as the city of Jamsa will also start to use heat energy produced in Jamsankoski.

DH inlet temperature: 80 – 110 °C

DH return temperature: 45 – 50°C

Heat storage size:Two steam accumulator tanks, (300 m3, 10 bar and 250 m3, 20 bar) m3

Hours of full load that the heat storage can meet: 0,25

Fuel storage:

Peat fuels are handled using the existing fuel receiving and handling station and storage silo (2000 m3). A new fuel receiving station has been built for biofuels. Biofuels are screened and crushed and conveyed either to intermediate fuel storage or directly to the boiler. Fuel storage capacity is 2000 m3. In addition there is bark storage (5000 m3) in the field.Fuel storage capacity corresponds to about 24 – 48 hours depending on boiler output.

Ash discharge:

Ash is partly used for landscaping and grounding roads. UPM has developed a new ash recycling /fertilizing system. The spereading of wet ash has been tested in UPM’s own forests. The analysis show, that the plant’s ash can be used for fertilizing.

Plant description:

The 185 MWth steam boiler used is a multifuel-fired boiler, able to fire all indigenous fuels. New power plant replaces two old boilers.  In old power plant two old grate fired boilers were retrofitted to fluidised bed boilers in 1980’s. Also new steam turbine replaced an old one and made it possible to double the back pressure electricity generation.

The commissioning of the new plant has brought significant environmental benefits. The power plant’s airborne sulphur dioxide and nitrogen emissions have decreased substantially, 30% and 50% respectively. The particulate emissions have decreased 55%. Also the goal has been to reduce CO2-emissions and use of oil.The boiler can burn all the combustible waste from the mill site, bark from wood handling and sludge from the effluent treatment plant, which reduces the total amount of landfill waste. High availability is essential to this type of a plant. Plant can be shut-down for annual revisions no more than 7-10 days.

Also requirements set for control range are very hard. As the energy consumption varies a lot in the paper mill using TMP (Thermo mechanical pulp), plant has to be able to produce steam efficienty in range of 15 – 70 kg/s.

Fuel feeding system:

As the plant receives very heterogenous assortment of fuels, fuel receiving, handling and feeding systems are diversified and flexible. Plant receives and crushed loose forest residue, baled forest residue, stumps, and different type of residues from the mills, such as paper, construction residue etc. Peat and wood based fuels are blended before feeding to the boiler. Wood fuels can be fed to the boiler from a storage silo or directly from receiving station.

Boiler: 185 MWth BFB boiler by Foster Wheeler.

Turbine: Back pressure turbine. Steam extractions 20 and 10 bars, backpressure of the steam turbine is 3.5 bar

Steam data: 70  kg/s, 533°C, 107 bar

Flue gas cleaning:

The flue gases are cleaned with one box and a three-field electric precipatator delivered by Alstom Finland Oy. The efficiency of the electrostatic precipatator is more than 99.7% (particles separated).

Staff: There are four men in five shift and five men in  day shift. Total of 25 men.

Electricity sale info: Electricity is used in the UPM-Kymmene paper mill.

Total capital cost: € 70,000,000

Data collected and quality assured by: VTT Processes.

Contact person: Kati Veijonen