An advanced model to assess fouling and slagging in coal fired boilers; Corrosion tests in combustion of recovered fuels in modem CFB boiler;Development of a novel and robust boiler design based on raining particles;Power Plant Boiler Expert System;USING COMPUTER TECHNOLOGIES FOR DESIGNING AND DIAGNOSTICS OF STEAM BOILERS AND HEAT-RECOVERY STEAM GENERATORS (HRSG) OF COMBINED-CYCLE UNITS