GAS TURBINE, METHOD FOR OPERATING A GAS TURBINE AND METHOD FOR MODIFYING A GAS TURBINE

Description

[0001] The invention relates to a gas turbine with a cooling device and further methods.

[0002] Gas turbines draw in air and compress it in the compressor to feed the compressed air for combustion. The air is drawn in from the surroundings through an intake casing.

[0003] Gas turbines with a prior art cooling device are known from the documents US 2008 / 098891 and US 2004 / 163536.

[0004] To increase performance, the current technology involves spraying water into the intake housing after the filter to increase performance.

[0005] This is complex and particularly difficult to retrofit if water injection was not initially planned.

[0006] It is therefore an object of the invention to solve the above-mentioned problem.

[0007] The object is achieved by a gas turbine according to claim 1 and methods according to claims 7 and 10.

[0008] The subclaims list further advantageous measures which can be combined with one another as desired to achieve further advantages.

[0009] It shows Figure 1 schematically shows the arrangement of the invention with a part of the intake casing, Figures 2 to 5 further embodiments of the invention, Figure 6 a gas turbine.

[0010] The evaporation of the water being drawn in causes cooling and thus an increase in the volume-specific mass (density) of the intake air. This leads to greater combustion efficiency due to the increased oxygen mass flow and thus to an increase in the power of the gas turbine.

[0011] The advantage of the invention lies in the fact that the cooling device is located outside of a filter housing. This makes it possible to achieve a performance increase of up to 17% by activating the cooling system at the touch of a button, depending on the air intake temperature.

[0012] The cooling device can also be used with normal, clean water, i.e. drinking water, which does not need to be specially treated for use with the cooling device.

[0013] The cooling device or cooling process can also be operated in combination with the "wet compression" principle of the gas turbine.

[0014] In addition, the cooling device can be used for gas turbines from various manufacturers.

[0015] The figures and description represent only embodiments of the invention.

[0016] Figure 1shows schematically a cooling device 1 with an intake housing 4 for air.

[0017] The intake housing 4 is connected to a filter housing 2. The cooling device 1 is arranged in front of the filter housing 2, as is particularly the case for a gas turbine 100 ( Fig. 6 ) is used.

[0018] The filter housing 2 has air filters as known from the prior art.

[0019] The cooling device 1 consists in particular of several modules 7', 7", ..., but can also have only one module 7'.

[0020] The modules 7', 7" are constructed in particular as follows: In longitudinal cross-section, the module 7', ... is particularly triangular in shape.

[0021] The module 7', 7" has an upper cover 8', 8'', 8‴, ..., which is connected at one end to the filter housing 2 and extends downwards (foundation) at an angle <90° to the vertical.

[0022] At the other end of the upper cover 8', 8", ... a flat inflow area 9' is arranged, which in turn is connected to the filter housing 2 and thus forms the triangular shape.

[0023] Ambient air flows in via the inflow area 9'.

[0024] This is known from the state of the art.

[0025] In the inflow area 9', however, according to the invention, several nozzles 13 are provided as the outermost nozzles, which are distributed in particular over the inflow area 9" ( Fig. 3, 4 ).

[0026] A water supply 10 supplies water to the nozzles 13. The water supply 10 may also supply other modules (7" 7‴, ...).

[0027] The modules 7', 7", ... are preferably arranged one above the other.

[0028] According to the invention, a grid 19' is provided after several nozzles 13 in the inflow direction 16 of the air from outside into the filter housing 2.

[0029] The nozzles 13 spray finely distributed water onto the grille 19, while the air flows past the nozzles 13 and through the grille 19'.

[0030] This achieves the effects and benefits described above.

[0031] The grid 19' as for example in Figure 5 is preferably made of polypropylene (PP) and preferably has a cross-diagonal and vertical grid structure so that no drops form and are carried into the intake tract.

[0032] Figure 2 shows a modified cooling device 1'.

[0033] In Figure 1 the spray direction of the water from the nozzles 13 is given in the inflow direction 14. The Figure 2 However, shows an arrangement in which nozzles 23 are arranged in comparison to Figure 1 are virtually turned around and spray the water against the inflow direction 16, i.e. in direction 24.

[0034] Thus, the air that is sucked in flows in direction 16 opposite to the outflow direction 24 of the water from the nozzles 23 into and through the grille 19' and then into the intake housing 4 via the filter area 2.

[0035] The order according to Figure 1 or 2 As is easily apparent, it can be installed directly in new plants, but can also be retrofitted. This can be done during operation of an existing gas turbine without requiring extended shutdown.

[0036] In desert regions and locations with high dust levels, the cooling device also cleans the intake air and increases filter service life as a result of the dust particles being washed out by the injected water.

[0037] Figure 3 and Figure 4 show how the nozzles 13, 23 are distributed over the surface.

[0038] The nozzles 13, 23 can be arranged in rows vertically and horizontally and have the same distance to each other to the right or left and to the top or bottom ( Fig. 3 ).

[0039] The nozzles 13, 23 can also be arranged offset from one another ( Fig. 4 ).

[0040] The Figure 6 shows, by way of example, a gas turbine 100 in a longitudinal section, for which the invention can be used.

[0041] The gas turbine 100 has inside a rotor 103 with a shaft 101, which is rotatably mounted about a rotation axis 102 and is also referred to as a turbine rotor.

[0042] Along the rotor 103 there follow an intake housing 4, 104, a compressor 105, a combustion chamber 110, for example a toroidal one, in particular an annular combustion chamber, with several coaxially arranged burners 107, a turbine 108 and the exhaust housing 109.

[0043] The annular combustion chamber 110 communicates with an annular hot gas duct 111, for example. There, four turbine stages 112 connected in series form the turbine 108.

[0044] Each turbine stage 112 is formed, for example, from two blade rings. Viewed in the flow direction of a working medium 113, a row of guide vanes 115 is followed in the hot gas duct 111 by a row 125 formed from rotor blades 120.

[0045] The guide vanes 130 are attached to an inner housing 138 of a stator 143, whereas the rotor blades 120 of a row 125 are attached to the rotor 103, for example by means of a turbine disk 133.

[0046] A generator or a working machine (not shown) is coupled to the rotor 103.

[0047] During operation of the gas turbine 100, air 135 is drawn in by the compressor 105 through the intake casing 104 and compressed. The compressed air provided at the turbine end of the compressor 105 is fed to the burners 107, where it is mixed with a fuel. The mixture is then combusted in the combustion chamber 110 to form the working medium 113. From there, the working medium 113 flows along the hot gas duct 111 past the guide vanes 130 and the rotor blades 120. At the rotor blades 120, the working medium 113 expands, transmitting momentum, so that the rotor blades 120 drive the rotor 103, which drives the driven machine coupled to it.

[0048] The components exposed to the hot working medium 113 are subject to thermal loads during operation of the gas turbine 100. The guide vanes 130 and rotor blades 120 of the first turbine stage 112, as seen in the flow direction of the working medium 113, are subjected to the greatest thermal loads, along with the heat shield elements lining the annular combustion chamber 110.

[0049] In order to withstand the temperatures prevailing there, they can be cooled using a coolant.

[0050] Likewise, substrates of the components can have a directional structure, i.e. they are single-crystalline (SX structure) or have only longitudinally oriented grains (DS structure).

[0051] For example, iron-, nickel- or cobalt-based superalloys are used as materials for the components, in particular for the turbine blades 120, 130 and components of the combustion chamber 110.

[0052] Likewise, the blades 120, 130 can have coatings against corrosion (MCrAlX; M is at least one element from the group iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and / or silicon, scandium (Sc) and / or at least one element of the rare earths or hafnium).

[0053] A thermal insulation layer may be present on the MCrAlX, and may consist, for example, of ZrO 2 , Y 2 O 3 -ZrO 2 , ie it is not, partially or completely stabilized by yttrium oxide and / or calcium oxide and / or magnesium oxide.

[0054] The guide vane 130 has a guide vane root (not shown here) facing the inner casing 138 of the turbine 108 and a guide vane tip opposite the guide vane root. The guide vane tip faces the rotor 103 and is secured to a mounting ring 140 of the stator 143.

Claims

1. Gas turbine (100) having a filter housing (2) with air filters, and having a cooling device (1) for cooling the intake air of an intake housing (4), wherein the cooling device (1, 1') comprises at least: a plurality of nozzles (13, 23) and a grid (19'), which are arranged together in a module (7'), a water supply (10) for the nozzles (13, 23), wherein the nozzles (13, 23) are arranged first in terms of flow in a planned inflow direction (16) of air, wherein the nozzles (13, 23) can finely spray water in an ejection direction (14, 24) and the grid (19', ...) is then arranged in the inflow direction (16'), characterized in that the cooling device (1) is arranged in front of the filter housing (2).

2. Gas turbine according to Claim 1, in which there are nozzles (13) which can spray water in the inflow direction (16') of the air into the module (7', ...) in a first ejection direction (14).

3. Gas turbine according to Claim 1 or 2, in which there are nozzles (23) which can spray water counter to the inflow direction (16') of the air into the module (7', ...) in a second ejection direction (24).

4. Gas turbine according to one or more of Claims 1, 2 or 3, wherein the cooling device is constructed from a plurality of modules (7', 7'', ...), each of which comprises a plurality of nozzles and a grid, in particular one above the other.

5. Gas turbine according to one or more of Claims 1, 2, 3 or 4, in which a plurality of nozzles (13, 23) is distributed over the area of the grid (19').

6. Gas turbine according to one or more of Claims 1, 2, 3, 4 or 5, in which the three-dimensional grid (19') prevents droplet formation and has, in particular, a diagonally crossed and vertical structure.

7. Method for operating a gas turbine (100) according to Claims 1 to 6, in which use is made of nozzles (13, 23) which spray water while air flows through a grid (19') in the inflow direction (16).

8. Method according to Claim 7, in which wet compression is used when operating the gas turbine (100).

9. Method according to Claim 7 or 8, in which plain water is sprayed through the nozzles (13, 23).

10. Method for modifying a gas turbine, in which a cooling device (1) is retrofitted so as to obtain a gas turbine according to one or more of Claims 1, 2, 3, 4, 5 or 6.