Analysis of Deposit Formation in Coal Fired Boilers

摘要

The brown coal fired power plants of RWE are supplied from RWE’s own opencast mines. Thebrown coal used has a varying composition, with a trend towards increasing heating values. Inconsequence, texture and amount of fouling have changed especially in the superheater tubebanks.The rate of fouling and the interference with operating parameters were analyzed by softwaretools on basis of neural networks for a 600 MW brown coal fired boiler. Operating parameterswere developed, which grant an operation with less fouling and also maintain emission limits andincrease efficiency. Both the standard operation set points and the recommended set points wereput into operation during a full-scale test.The mechanism of deposit formation in superheater tube banks has as yet only been partly understood.To examine this mechanism, fly ash samples were taken and deposits collected from aheating surface and from a probe during the full-scale test periods. The results of the tests and theanalysis of the samples will be presented.