Method for operating a gas turbine group
View Patent ↗A gas turbine group comprises a device, arranged in a suction-intake duct, for cooling a suction-intake airflow. The device is, for example, a device for injecting a liquid mass flow. The cooling device is activated automatically when a first limit temperature of the ambient air is overshot and is deactivated automatically when a second limit temperature is undershot. Stability of the automatic algorithm can be improved in that the second limit temperature can lie by a specific amount below the first limit temperature. In one embodiment, the limit temperatures are predetermined as a function of the position of an adjustable initial guide blade cascade.
1. A method for operating a gas turbine group, comprising:
measuring a temperature of ambient air (T AMB ) and/or a temperature in an inflow duct of the gas turbine group to provide a temperature measurement value, upstream of a compressor of the gas turbine group, and
automatically activating means, arranged upstream of the compressor of the gas turbine group, for cooling the supply airflow of the compressor when a first limit temperature for this measurement value is overshot, wherein the means for cooling are activated for a partially closed position of an adjustable initial guide blade cascade, wherein the first limit temperature is a function of the position of an adjustable initial guide blade cascade of the compressor, where at least over a range of the position of the initial guide blade cascade, the first limit temperature is higher, the further the initial guide blade is closed.
2. The method as claimed in claim 1 , wherein a second limit temperature is a function of the position of an adjustable initial guide blade cascade of the compressor.
3. The method as claimed in claim 2 , wherein the second limit temperature is higher, at least over a range of the position of the initial guide blade cascade, the further the initial guide blade cascade is closed.
4. The method as claimed in claim 3 , wherein the first and/or second limit temperature is raised or at least kept constant as a function of a position of the initial guide blade cascade during closing of the initial guide blade cascade, and the first and/or second limit temperature is not lowered as a function of the position of the initial guide blade cascade during the closing of the initial guide blade cascade.
5. The method as claimed in claim 1 , wherein a fixed lower limit temperature is predetermined, below which the means for cooling are always deactivated.
6. The method as claimed in claim 1 , wherein the cooling is performed using an evaporation cooler.
7. The method as claimed in claim 1 , wherein a heat exchanger of the cooling means, in the activated state, discharges heat from the supply airflow.
8. The method as claimed in claim 1 , wherein a device of the cooling means for introducing a liquid mass flow into the supply airflow, such that with the means activated, a liquid mass flow is introduced into the supply airflow.
9. The method as claimed in claim 1 , wherein a first delay time is fixed and, after the overshooting of the first limit temperature, the means for cooling are activated only when the first limit temperature has been overshot at least for the entire delay time.
10. The method as claimed in claim 1 , wherein when a second limit temperature is undershot, the means for cooling the supply airflow are deactivated automatically.
11. The method as claimed in claim 10 , wherein the second limit temperature is selected to be lower than the first limit temperature.
12. The method as claimed in claim 11 , wherein a second delay time is fixed and, after the undershooting of the second limit temperature, the means for cooling are deactivated only when the second limit temperature has been undershot at least for the entire second delay time.
13. The method as claimed in claim 1 , wherein the ambient atmospheric moisture is measured and at least one limit temperature is a function of the measured atmospheric moisture.
14. The method as claimed in claim 1 , wherein a lower limit value of power of the gas turbine group is predetermined, below which the means for cooling are always deactivated.
15. The method as claimed in claim 14 , wherein the power limit value is predetermined as a relative power of the gas turbine group.
16. The method as claimed in claim 1 , wherein a limit value of the position of the initial guide blade cascade is predetermined, the means for cooling always being deactivated when the initial guide blade cascade is closed beyond the limit value.
17. The method as claimed in claim 1 , wherein a cooling power applied by the means for cooling is a function of the mass airflow sucked in by the compressor.
18. The method as claimed in claim 1 , wherein a liquid mass flow introduced into the supply airflow by a device for introducing a liquid mass flow is a function of the mass airflow sucked in by the compressor.