Method for the operation of a gas turbine by active hydraulic gap adjustment

Abstract

A method for operating a stationary gas turbine at partial load, having at least one compressor, at least one expansion turbine and a combustion chamber provided with at least one burner, which gas turbine further includes a hydraulic gap adjuster, wherein the method has the following steps: operating the gas turbine at partial load; operating the a hydraulic gap adjuster; during the operation of the hydraulic gap adjuster, increasing the fuel supply to the burner while increasing the temperature of the combustion gases which are guided to the expansion turbine.

Claims

1. A method for operating a static gas turbine at partial load with at least one compressor, at least one expansion turbine and a combustion chamber that is provided with at least one burner, wherein the gas turbine further comprises a hydraulic gap adjuster, wherein the method comprises: operating the gas turbine at partial load; operating the hydraulic gap adjuster during partial load to shift a gas turbine rotor that connects the at least one compressor and the at least one expansion turbine in an axial direction, such that turbine blade tips of the at least one expansion turbine are displaced to have a smaller gap spacing with respect to an inner casing wall of the at least one expansion turbine; while operating the hydraulic gap adjuster, increasing a fuel supply to the at least one burner, raising a temperature of combustion gases supplied to the at least one expansion turbine, wherein the temperature of the combustion gases is below a predetermined upper temperature limit for rated load operation.

2. The method as claimed in claim 1, further comprising: adjusting a guide vane adjustment device of the gas turbine while or after increasing the fuel supply to additionally increase the temperature of the combustion gases.

3. The method as claimed in claim 1, further comprising: recording, by measurement, of a physical operating parameter which correlates with the temperature of the combustion gases in order to determine the temperature of the combustion gases, and initiating the increase in the fuel supply to the at least one burner when a recorded value of the physical operating parameter exceeds a predetermined limit value.

4. The method as claimed in claim 1, wherein increasing the fuel supply to the at least one burner takes place in dependence on an ambient temperature and/or on an ambient pressure.

5. The method as claimed in claim 2, wherein increasing the fuel supply to the at least one burner and/or the adjusting of the guide vane adjustment device takes place such that a turbine outlet temperature at partial load is below a turbine outlet temperature at rated load.

6. The method as claimed in claim 2, wherein increasing the fuel supply to the at least one burner takes place in dependence on a setting of the guide vane adjustment device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the figures:

(2) FIG. 1 shows a representationin the form of a flow chartof a first exemplary embodiment of the method according to the invention;

(3) FIG. 2 shows a schematic circuit view of one embodiment of a static gas turbine according to the invention.

DETAILED DESCRIPTION OF INVENTION

(4) FIG. 1 shows a representationin the form of a flow chartof an embodiment of the method according to the invention for operating a static gas turbine 1 at partial load, wherein the gas turbine 1 is for example designed as depicted in FIG. 2. In this context, the gas turbine 1 has a compressor 11, at least one expansion turbine 14 and a combustion chamber 12 that is provided with at least one burner 13, and further comprises means 20 for hydraulic gap adjustment. In this context, the method according to the embodiment comprises the following three steps:operating the gas turbine 1 at partial load (first method step 101);operating the means 20 for hydraulic gap adjustment (second method step 102);while operating the means 20 for hydraulic gap adjustment, increasing the fuel supply to the burner 13, raising the temperature of the combustion gases 15 that are supplied to the expansion turbine 14 (third method step 103).

(5) FIG. 2 shows an embodiment of the static gas turbine 1 according to the invention with a compressor 11, an expansion turbine 14, and at least one burner 13 that cooperates for combustion with a combustion chamber 12. The gas turbine 1 further comprises means 20 for hydraulic gap adjustment that are designed to shift the gas turbine rotor 10, that connects the compressor 11 and the expansion turbine 14, in the axial direction.

(6) As set out above, the gas turbine rotor 10 is shifted such that, in the process of the desired adjustment, the turbine blade tips (not shown here) have a smaller gap spacing with respect to the inner casing wall of the expansion turbine 14. The reduction in the gap spacing results in reduced fluid dynamic losses (the gas that flows along the internal surface would otherwise not contribute to the expansion work in the expansion turbine 14), such that the power output of the gas turbine 1 is improved.

(7) Therefore, if the gas turbine 1 is operated at partial load, with the means 20 for hydraulic gap adjustment being in operation at the same time, it is possible to increase the fuel supply to the burner 13 via the fuel line 16. According to the embodiment, this increase is taken in charge by a gas turbine closed-loop control unit 40 that cooperates with a fuel valve 17 which is connected into the fuel line 16.

(8) At the same time, the gas turbine closed-loop control unit 40 is in communication with the means 20 for hydraulic gap adjustment, and with a guide vane adjustment device 30 in the region of the inlet of the compressor 11, and with a temperature sensor 19 that interacts with the exhaust gas stream of the gas turbine 1 such that the exhaust gas temperature or the turbine outlet temperature can be recorded by measurement.

(9) According to the embodiment, the temperature sensor 19 is connected into an exhaust gas line 18 which conducts the exhaust gases issuing from the expansion turbine.

(10) If the gas turbine closed-loop control unit 40 now detects activation or operation of the means for hydraulic gap adjustment, or if the gas turbine closed-loop control unit 40 initiates operation of the means 20 for hydraulic gap adjustment, the fuel supply to the burner 13 is undertaken by suitable adjustment of the fuel valve in the fuel line 16. In particular, the fuel supply is increased.

(11) Initiation of the increase in the fuel supplied to the burner 13 takes place, according to the embodiment, in particular if a physical operating parameter is recorded that correlates with the temperature of the combustion gases 15 for determining the latter. In particular, this can be the setting of the guide vane adjustment device 30 or the exhaust gas temperature that is recorded by means of the temperature sensor 19 in the exhaust gas line 18.

(12) According to an alternative embodiment of the invention, it can also be provided that the guide vane adjustment device of the gas turbine 1 is additionally set during operation of the means 20 for hydraulic gap adjustment.

(13) This change can also for example be initiated, in terms of closed- or open-loop control, by the gas turbine closed-loop control unit 40.

(14) According to the embodiment, the gas turbine closed-loop control unit 40 can also be designed as a gas turbine open-loop control unit 40.

(15) Both forms of the adjustment are to be encompassed by the gas turbine closed-loop control unit 40.

(16) Further embodiments are to be found in the subclaims.