SIMULATION AND MONITORING OF FOULING AND SLAGGING IN COAL-FIRED STEAM BOILERS

The mathematical model of a steam boiler has been developed, showing the influence of water-wall slagging and superheater fouling on the boiler performance. With traditional methods, operators often are not able to detect the critical build-up of deposits on the specific heating surfaces of the boiler. The mathematical model can be used as a boiler slagging and fouling simulator to monitor the boiler operation when the boiler heating surfaces become covered with ash deposits. In addition, the computer-based boiler performance system, presented in reference [9], has been implemented to provide a quantitative assessment of cleanliness of the surfaces in the furnace and the convective pass. Measurements of temperatures, pressures, flows, and gas composition are used to perform heat transfer analysis in the boiler furnace and evaporator. The on-line measurements of ash deposit loadings can be used to guide sootblower operations for the: combustion chamber and steam superheaters. This contributes to the lowering of the medium usage in the sootblowers and an increase of the water-wall lifetime.