Patent ID: 8713946
Filing Date: 2014-05-06
Classification: F02C,F05D

Abstract:
1. A method for controlling an operating point of a gas turbine that includes a compressor, a combustor and at least a turbine, the method comprising: determining an exhaust pressure drop at an exhaust of the turbine; measuring a compressor pressure discharge at the compressor; determining a turbine pressure ratio based on the exhaust pressure drop and the compressor pressure discharge; calculating an exhaust temperature reference curve of the turbine as a function of the turbine pressure ratio; determining whether both conditions (1) and (2) are true, wherein condition (1) is IGV changing, if both conditions (1) and (2) are true, a split fuel quantity from a first value to a second value or otherwise maintaining the first value, the first value characterizing a lean-lean steady state mode and the second value characterizing a premixed secondary mode of a premixed mode, wherein the premixed mode is defined as providing fuel to primary burners and to a second burner of the combustor and igniting the provided fuel in a secondary region of the combustor while primary regions are free of flames, the primary regions being adjacent to the secondary region, the lean-lean mode is defined as providing fuel to both the primary burners and the secondary burner and igniting the provided fuel both in the primary regions and the secondary region, and the split fuel quantity describes in percentages a first amount of the total fuel that is received by the primary burners and a second amount of the total fuel that is received by the secondary burner.