Corrosion, operation experience and improvements in process engineering to increase the availability and lifetime of the Timelkam biomass-fired power plant

摘要

Since 2005 Energie AG Oberosterreich Kraftwerke GmbH has been operating its biomass-fired power plant in Timelkam producing combined electricity and heat. The fuel thermal input of the stationary fluidised bed combustion plant used for this purpose is 49.7 MW_(therm). Approximately 150,000 tonnes_(air dry) of biogenic fuel per year of different material categories (quality category Q1 to Q4 or A1 to A3) is used. The high standard of fuel flexibility required for this) operational task represents a major challenge to the plant in terms of continuous operation time and reliability of the plant. The targets set for the past operational years were continuous reduction of corrosion on the heating surfaces arid avoidance of ash accumulations, wear and tear, boiler and fluidised bed fouling. Based on the plant layout and dimensions and the continuing operational experience gained, numerous improvements to process engineering were tested and implemented. Damage which has occurred to the economiser, superheater heating surfaces and air distributor plate particularly led to primary measures for optimising the upstream processes. Less foreign matter was introduced through improved fuel preparation. In addition to these steps, modifications of process engineering of the boiler plant and the assembly of new cleaning facilities were implemented as secondary measures. As a result of the deliberate implementation of separate measures and continuous improvements, plant availability increased significantly and considerably prolonged the boiler operating times. The paper at hand reports on the faults and problems that have happened since start-up of the plant and examines their background. The experience gained in the course of this work and the improvements made to design and process engineering are presented.