LARGE SCALE CFB FOR WASTE-TO-ENERGY

摘要

Valmet Power has a long experience in fluidized bed combustion.Since 1980's both Bubbling Fluidized Bed (BFB) and Circulating Fluidized Bed (CFB) boilers have been used in combustion for various types of solid fuels, from fossil fuels to biomass and nowadays more and more for recovered fuels like demolition wood and SRF.Design features for large scale CFB boiler concept for Waste-to-Energy is presented.Main design parameters of fuel mixtures, chemical as well as physical properties are described.Fuel based challenges in boiler operation, eg.bed agglomeration, fouling, corrosion and flue gas emissions, and related process design and constructional features to tackle these challenges are discussed.Reference data for full SRF combustion is gathered from 75 MWth E.ON H(a)ndel(o)verket, Norrk(o)ping, Sweden and from 125 MWth Stora-Enso Langerbrugge, Belgium.This data includes typical combustion efficiency, ash and flue gas emission figures and findings related to fouling and corrosion.Availability history of the boilers show that higher than 97％ reliability figures are typical for Waste-to-Energy CFB boilers.Regarding full SRF boiler concept, the design of new 155 MWth Waste-to-Energy CFB boiler for M(a)larenergi, V(a)ter(a)s, Sweden is presented.This boiler is designed to burn household waste up to 70％ and industrial waste up to 100％ of heat input.Also some sludge, recovered wood, peat and biomass are part of the design fuel palette.Finally, the next generation Waste-to-Energy CFB concept of 250 MWth utilizing the latest knowledge available, eg superheating steam temperature capability up to 520 °C is highlighted.