Abstract: In a method of operating a gas-turbine group having sequential combustion, action is taken first of all on the inlet temperatures (A, B) at the two turbines (6, 10) in order to provide a partial-load operation. The subsequent lowering of the load takes place by adjustment of the compressor guide blades (C), that is, by reducing the mass flow (E) to below 50% of the rated load (X). During this lowering, the inlet temperature (A) at the first turbine (6) is kept constant, while the other inlet temperature (B) at the second turbine (10) is continuously lowered; the outlet temperature (D) of the second turbine (10) is in contrast kept constant. After the lowering of the load is complete by adjusting the compressor guide blades, the inlet temperatures (A, B) are reduced directly or in a phase-displaced manner (Y).

Abstract: A method of establishing part-load operation is proposed for a turbine group. This gas turbine group consists essentially of a compressor unit (1), of an HP combustion chamber (4) downstream of the compressor unit (1), of an HP turbine (5) downstream of this HP combustion chamber (4), of an LP combustion chamber (8) operating by self-ignition and arranged downstream of the HP turbine (5), the hot gases (10) of which LP combustion chamber (8) being admitted to an LP turbine (11). The temperature at outlet from the HP turbine (5) remains essentially the same due to the reduction of the fuel quantity in the LP combustion chamber (8) to zero. Furthermore, the fuel quantity of the HP combustion chamber (4) remains approximately constant during the reduction of the fuel quantity in the LP combustion chamber (8) so that the temperature at inlet to the HP turbine (5) likewise remains constant.