Abstract: In a method of operating a gas turbine during shut down, the gas turbine is decelerated and closure of compressor inlet guide vanes (1) is initiated at a shaft speed at least 5% above the shaft speed where a vibration peak occurs. The compressor inlet guide vanes (1) are closed by an angle in the range from 15°-35°, preferably at a rate between 5° and 10° per second. The method effects a reduction of the risk of rotational stall.

Abstract: In a method of operating a gas turbine during shut down, the gas turbine is decelerated and closure of compressor inlet guide vanes (1) is initiated at a shaft speed at least 5% above the shaft speed where a vibration peak occurs. The compressor inlet guide vanes (1) are closed by an angle in the range from 15°-35°, preferably at a rate between 5° and 10° per second. The method effects a reduction of the risk of rotational stall.

Abstract: In a method of operating a compressor of a gas turbine, where compressor air sucked in from the environment is cooled down by evaporation cooling before entering the compressor, before starting operation of the compressor, maximum possible temperature drops which could be achieved by evaporation cooling are determined dependent on different ambient conditions and/or are provided as a data set. These temperature drops are correlated with a compressor map containing maximum temperature distortions at different ambient conditions and different rotation frequencies of the compressor which have to be met in order to avoid pumping. The evaporation cooling is then only operated when current ambient condition result in a maximum possible temperature drop from which a predetermined fraction of between 50% and 100% does not exceed the maximum distortion which can be taken from the compressor map for these ambient conditions and the current rotation frequency of the compressor.

Abstract: In a method of operating a compressor of a gas turbine, where compressor air sucked in from the environment is cooled down by evaporation cooling before entering the compressor, before starting operation of the compressor, maximum possible temperature drops which could be achieved by evaporation cooling are determined dependent on different ambient conditions and/or are provided as a data set. These temperature drops are correlated with a compressor map containing maximum temperature distortions at different ambient conditions and different rotation frequencies of the compressor which have to be met in order to avoid pumping. The evaporation cooling is then only operated when current ambient condition result in a maximum possible temperature drop from which a predetermined fraction of between 50% and 100% does not exceed the maximum distortion which can be taken from the compressor map for these ambient conditions and the current rotation frequency of the compressor.

Abstract: The injection of finely atomized liquid-droplets into the intake air flow of a compressor is used, for example, to improve the output of a gas turbine. If the atomization is effected via pressure atomizer nozzles, it is advantageous, when the injection device is operated with a portion of the design mass flow, to admit liquid to only some of the atomizer nozzles of the injection device. The atomizer nozzles may be arranged on nozzle tubes, liquid being jointly admitted to all the atomizer nozzles arranged on a respective nozzle tube, operated in such a way that the same mass flow is injected on each side of a symmetry line. To this end, nozzle tubes may be combined to form groups, to which liquid is jointly admitted, and the tubes of a group may be arranged in mirror image to one another relative to the symmetry line.

Abstract: In an axial compressor (10), in particular for a gas turbine, with a plurality of stages (ST1, . . . , ST5) which are arranged one behind the other between a compressor inlet (14) and a compressor outlet (15) and include in each case at least one ring of rotor blades (R) and one ring of stator blades (S), a substantial improvement is achieved in that, to minimize the losses in the individual stages (ST1, . . . , ST5), during operation of the axial compressor (10) in which water is injected into the compressor inlet (15) and evaporates on its way through the compressor (10) (what is known as “wet compression”), the variations, caused by the injected water, in the flow velocities (c1, cm1, w1) of the medium flowing through the compressor (10) are largely compensated by a controlled change in the geometry of the blades (R, S).