First test results of Oxyfuel combustion with Hitachi’s DST-burner at Vattenfall’s 30 MWth Pilot Plant at Schwarze Pumpe

AbstractSituated in the near of Schwarze Pumpe power station southeast of Berlin, Germany, Vattenfall operates a 30 MWth pilot plant in order to investigate the Oxyfuel process. Hitachi Power Europe delivered a DST-burner (DST-Brenner®) for the indirect firing system of the plant which was installed without modifications to the pressure part of the boiler. The combustion behavior during Oxyfuel operation was investigated and optimal burner settings for different operation points were established. The results show that the burner can be operated in a wide range of oxygen concentrations in the oxidant gas flow. The burner is characterized by low emissions of carbon monoxide and nitrogen oxides. The high flame stability was found to be unaffected by operational influences such as fluctuations in the coal mass flow, coal quality or soot blowing. Due to the high flame stability the change-over from air blown to Oxyfuel combustion can be realized very easily and is automated. During Oxyfuel operation measurements of temperatures and flue gas species in the flame were performed. The measurement values were compared with the values of the combustion modeling by computational fluid dynamics. The good agreement between both measurement and modeling shows the suitability of the applied models to predict the combustion behavior under Oxyfuel conditions