A dual fuel burner has been developed to meet stringent NOx goals without the use of water or steam injection. This combustion system is based on the proven ABB EV burner dry low NOx technology and uses the same type of aerodynamic vortex breakdown flame stabilization. A more advanced aerodynamic design improves the quality of the fuel air mixture for both gaseous and liquid fuels. The design of the liquid fuel injection and the fuel-air-mixture preparation is described in this paper. Fuel air mixture homogeneity was improved with the help of experimental and numerical tools. This way an optimization in fuel atomizer design was possible. Distinct differences in fuel distribution were observed for different designs of pressure atomizers. Combustion tests of the burner were performed at pressures up to 20 bars. The NOx levels measured under gas turbine full load conditions are <25 vppm using oil no. 2 and <10 vppm using natural gas. These results highlight the potential for achieving similar combustion low emission performance for gaseous and liquid fuels near perfect lean premix conditions.

Operating parameters and test results at part load conditions are discussed as well in this paper. The wide operating range of the burner in the full premix mode restricts the need for pilot application or burner staging to low load (<50 %) conditions. This allows for low emissions on NOx, CO and UHC in the entire load range.

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