The impact of different lignite mass share in the hard and lignite coal blend on co-firing behavior and parameters of PC boiler

摘要

The paper presents the experimental and numerical study on the boiler's behaviour and performance during combustion of pulverized bituminous coal with various fractions of pre-dried lignite. The experimental measurements were carried out on a WP120 boiler located in Opole Heating Plant, Poland. The boiler's loads that were tested varied between 100% and 50% and the lignite mass fraction reached up to 36%m. The pre-dried lignite, kept in dedicated separate bunkers, was mixed with bituminous coal just before the coal mills. Site measurements and numerical simulations, carried out to describe the boiler operation in details, show operational advantages (e.g. efficiency and performance improvement, emission reduction, boiler's flexibility) and hazards (e.g. increase of Carbon-In-Ash and physical enthalpy loss) resulting from the use of pre-dried lignite cofiring.