CFB Status in Europe: Repowering in Eastern Europe and Large Biofuel Plants in Scandinavia

摘要

While economic growth is creating new demand for power generation in Eastern Europe, the world’s ecological concerns are simultaneously creating a demand for cleaner power generation. The replacement of older utility boilers in Eastern Europe with CFB boilers can be a very attractive option in many cases, providing the opportunity to update power generation facilities with state-of-the-art equipment while significantly reducing the emission of pollutants. An example, described in this paper, is the CYMIC CFB boiler project. In October 1997, the EPC contract was signed with a consortium, which included Kvaerner Pulping Oy as the supplier of the CYMIC boiler with auxiliaries. The boiler size is 110 MW{sub}th burning local coal, and the commercial operation in Tychy, Poland, started in February 2000. The CYMIC boiler is a new and innovative CFB technology, in which the cyclone is located inside of the furnace; among the benefits of the CYMIC design is that the design footprint is much smaller than with conventional CFB technology. This allowed the installation of the Tychy boiler within an existing steel structure, which reduces costs in repowering projects. The unit is burning coal, and the choice of re-powering with CFB technology decreased the SO{sub}x emissions by 50% and the NO{sub}x emissions by 40%, compared with the plant's previous performance. While economic and ecological power generation demands also exist in Scandinavia, biomass is the dominant fuel resource, and new power generation equipment is being installed to meet the needs of industry and utilities. The world's largest biofuel fired CFB boiler will be built at the new Alholmens Kraft power plant in Pietarsaari on the west coast of Finland. The Alholmens Kraft power plant will supply process steam to the nearby UPM-Kymmene Wisaforest pulp and paper mill, and will also supply steam for district heating in Pietarsaari. Of the plant's 550 MW{sub}th capacity, 240 MW{sub}e will go to electric power generation, which will be used by power companies in Finland and Sweden. Thus, the plant concept is rather unique, since it is a combination of industrial, heating, and utility plant. The Alholmens Kraft CFB boiler is a multi-fuel unit; the main fuels are bark, wood residues, and peat, and coal will also be used as a back-up fuel. The fuel selection is therefore consistent with the world's CO{sub}2 reduction mission. Reliability was the key design criterion for this plant and special measures have been taken to ensure this; the unit includes water-cooled cyclones and a fuel feeding system that will deliver 1000 m{sup} 3 /hr to the boiler. Kvaerner Pulping has delivered over 100 BFB boilers and over 50 CFB boilers; this paper describes the EC Tychy and Alholmens Kraft projects.