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Temperature, Species and Heat Transfer Characteristics of A 250 MWe Utility Boiler

ABSTRACT This paper presents and discusses measurements of local flame temperature, local gas species concentrations and incident wall heat fluxes obtained in a 250 MWe residual fuel-oil front fired utility boiler. The work is aimed at improving knowledge of the efficiency of the thermal processes involved in large industrial boilers and covers three different operating conditions, which include load and air-fuel ratio variations. The measurements were made using special design probes through the ports available for inspection of the boiler. Local gas temperatures varied between 1650°C in the centre of the flames attached to the burners to around 1100°C close to the boiler nose, with maximum variations in the plane of the burners between the front and rear walls of about 200°C. The levels of CO were as high as 2% close to the ash pit and reach 1% near the boiler nose, suggesting some limitations in the process of fuel burnout and CO oxidation. Wall incident total heat fluxes varied between 200 k W/m2 and ...