Experiences with Coal fired USC Boilers
in Denmark.

Presented by Knud Bendixen, BWE, at Power-Gen Europe
May 6-8 2003, Düsseldorf, Germany

Abstract

Coal firing for utility boilers is an old tradition in Denmark based on imported bituminous coal. The development of the boiler units has been going on continuously in the second half of the 20th century. Within that period the power cycle has changed from subcritical pressures to super - and ultra super critical ranges to reach still higher efficiencies.

For the boiler designers it has been an essential challenge to meet the increasing requirements from this development. This paper describes this process as it has taken place by BWE - one of the leading Benson boiler designers- . BWE has brought its boiler design all the way up to the present day's pressure level of 300 bar and corresponding steam temperatures in the range 580 - 600°C leading to a world record of 47% overall efficiency for power production.

The steam data are now close to the maximum possible while using steel based materials in the boiler. The future development which is under way will be requiring the so called super alloys to be used for the critical components like exit headers and superheater tubes.