JP2012255440A5 - - Google Patents

Description

Axial-flow turbo compressor

The present invention relates to an axial-flow turbocompressor having an annular compressor flow path concentrically arranged around a rotation axis, wherein the outer boundary of the compressor flow path is radial by a flow path wall. In the axial-flow turbocompressor, in which the rotor blades that are formed in a direction and that can be assembled to form an annulus are arranged so as to be rotatable around a rotation axis, the free ends of the rotor blades Each of the side tips are opposed to the flow channel wall in a state of forming a gap, and the flow channel wall has at least an in-wall structure (also known as casing treatment) in the axial section of the tip. The present invention relates to an axial-flow turbocompressor that is partly provided and has a bleed opening of a bleed channel provided to allow a medium flowing in the compressor channel to flow out.

  The above-described configuration is disclosed in Patent Document 1, for example. The casing process is disposed on the flow path wall on the casing side above the rotor blade row disposed on the upstream side. Extraction points for the outflowed air are arranged in the rotor blade row which is arranged downstream of the upstream rotor blade row. Further, in the blade flow path, a valve is provided for letting out various volumes of compressor air depending on the operating conditions. By both measures, the compressor operation can be controlled to some extent at a high compression ratio without undesirable phenomena such as surge phenomena and separation phenomena occurring in the process flow, for example. However, it has been found that the above configuration cannot be satisfied in the partial load operation of the gas turbine.

German Patent Application No. 2158879

  Accordingly, it is an object of the present invention to provide an axial-flow turbocompressor that further improves the operating range by more effectively preventing undesirable phenomena from occurring in the compressor.

  A further object of the present invention is to provide a gas turbine equipped with an axial flow turbocompressor according to the present invention that can prevent unacceptably high emissions, especially during partial load operation.

  The object which forms the basis of the present invention is achieved by an axial flow turbocompressor according to the features of claim 1. Advantageous developments and embodiments are disclosed in the respective dependent claims.

  The present invention is configured to place a bleed opening in the intrawall structure. Therefore, not only the use of casing processing and the outflow of compressor air are simultaneously used inside the proposed turbo compressor, but also the use of casing processing and outflow of compressor air are used in particular for axial-flow turbo compressors. Combining in the region of a single rotor blade row is locally effective. Accordingly, the backflow of compressed air and the associated high aerodynamically unfavorable pressure ratio in the subsequent compressor stage are prevented, so that the occurrence of undesirable phenomena mainly in the compressor can be prevented. . As a result of the combination according to the invention, the surge limit of the compressor stage can be adjusted according to operating conditions in a particularly simple manner. This allows particularly low partial load operation without exceeding the emission limit in the process when the axial turbo compressor is utilized in a stationary gas turbine. The corresponding small air volume for part-load operation is directed into the combustion chamber, especially by letting the compressor air out, when an axial turbo compressor is utilized in a gas turbine, Carbon monoxide emissions are minimized. Thus, air is exhausted from the compressor so that undesirable fluid effects do not occur. This may occur in the case of blow-off valves based on the prior art. Furthermore, since the outflow of air in the casing process also assists the effect of the in-wall structure itself, the casing process can be formed in a manner that takes less space than the casing process in which the bleed opening is not provided.

In a first advantageous development, the intra-wall structure can be changed in size and / or shape, so that the bleed opening is at least partially opened. According to this embodiment, three operating states of the axial-flow turbomachine are possible even with a simple configuration.
1. The axial-flow turbocompressor is preferably operated at full load in a state where the casing process is not utilized and the compressor air is not extracted.
2. The axial flow turbocompressor is preferably operated at a high partial load in the absence of compressor air flow by utilizing only casing treatment.
3. Axial turbocompressors are preferably operated at low partial loads by utilizing casing treatment and compressor air outflow simultaneously.

  In conclusion, the casing treatment, adjustable for its size or shape, is not simply used to adjust the wall structure, but at the same time to enable or disable the extraction of compressor air. Used. Thereby, especially a structure can be reduced in size.

  In the above-described embodiment, by utilizing a movable insert, the intra-wall structure can be changed in size and / or shape, and the bleed opening is disposed on the side wall of the recess that houses the insert. In this case, the structure is realized in a particularly simple manner. The insert may be formed as a plug that is movable along the recess. Depending on the position of the plug, the recess is completely closed (first operating state), the recess is only partially closed, but the bleed opening is still closed ( 2nd operation state), or a state in which the recess and the bleed opening are open (third operation state). In this respect, it is possible to simply and reliably switch between the three operating states described above simply by moving the plug along a recess that houses the plug.

  Advantageously, the bleed channel is connected to the air ejection system and / or the air cooling system on the fluid discharge side.

  Advantageously, a plurality of bleed openings are arranged for each rotor blade ring. In this case, the medium flowing in the compressor flow path is air in most cases, but is uniformly blown out of the compressor flow path over the entire circumference of the axial-flow turbo compressor. In particular, the gas turbine has an axial-flow turbocompressor configured in the above-described manner, so that the gas turbine can be operated at low partial loads with particularly low emissions. The

  Further advantages, functions and features of the invention are explained in detail on the basis of preferred exemplary embodiments represented in the drawings. The advantageous embodiment results in a corresponding advantageous combination of the functions of the device according to the invention shown.

1 is a partial longitudinal sectional view of a stationary gas turbine with an axial flow turbocompressor. FIG. It is detailed sectional drawing of the casing of the axial flow type turbo compressor in which the casing process based on the 1st Example was performed. It is detailed sectional drawing of the casing of the axial flow type turbo compressor in which the casing process based on the 1st Example was performed. It is a detailed perspective view of the casing of the axial flow type turbo compressor in which the casing process based on the 2nd Example was performed. FIG. 6 is a perspective view of an apparatus according to a third embodiment of the present invention. Fig. 6 represents a casing process and bleed opening according to a fourth embodiment of the invention.

FIG. 1 is a partial longitudinal cross-sectional view of a stationary gas turbine 10. The gas turbine 10 includes a rotor 14 that is rotatably mounted around the rotation axis 12 inside the gas turbine 10. The rotor 14 is referred to as a turbine rotor assembly. An inlet duct 16, an axial-flow turbocompressor 18, a toroidal annular combustion chamber 20 comprising a plurality of burners 22 arranged rotatably and symmetrically to each other, a turbine unit 24, an exhaust A gas duct 26 is arranged in series along the rotor 14. The gas turbine may include a silo type combustion chamber or a tubular combustion chamber instead of the annular combustion chamber.

  The axial-flow turbo compressor 18 includes a compressor flow path 25 configured in an annular shape, and the compressor flow path 25 is a rotor blade ring arranged in series in a cascade manner in the compressor flow path. And a compressor stage composed of a stator blade ring. The rotor blade 27 is disposed in the rotor 14 and faces the flow path wall 42 outside the compressor flow path 25 in the vicinity of the blade blade tip 29 which is a free end. The compressor flow path 25 is opened toward the inside of the plenum 38 through the diffuser 36 on the compressor outlet side. The annular combustion chamber 20 includes a combustion space 28 that is in communication with the annular hot gas flow path 30 of the turbine unit 24 inside the plenum 38. In the exemplary embodiment shown, four turbine stages 32 connected in series are arranged in the turbine unit 24. A generator or driven machine (both not shown) is connected to the rotor 14.

  During operation of the gas turbine 10, the axial flow turbo compressor 18 introduces ambient air 34 as a medium to be compressed through the inlet duct 16 and compresses this ambient air 34. The compressed ambient air is directed toward the inside of the plenum 38 through the diffuser 36 on the compressor outlet side, and flows into the burner 22 from the plenum. Further, the fuel travels into the combustion space 28 through the burner 22. In the combustion space, the fuel is burned by adding compressed air, and a hot gas M is generated. Thereafter, the hot gas M flows into the hot gas flow path 30 for expanding the hot gas M and functions in the turbine blades of the turbine unit 24. The energy released in the meantime is absorbed by the rotor 14 and used to drive the axial turbocompressor 18 while being used to drive the driven machine or generator.

  However, aerodynamic constraints and aerodynamic phenomena may occur during the operation of the gas turbine 10 and thus during the operation of the axial-flow turbocompressor 18. Is partially limited. In order to prevent the occurrence of these aerodynamic constraints and aerodynamic phenomena, at least one in-wall structure is provided in the flow path wall 42. In FIG. 1, this in-wall structure is omitted for clarity. This intra-wall structure is also known as a so-called “casing treatment”, for example, an annular endless groove extending in the circumferential direction, or arranged over the entire circumference and in the axial direction. Is formed as a casing groove extending at. The in-wall structure is usually provided in the axial direction section of the compressor flow path 25, and in the compressor flow path 25, each of the distal end portions on the free end side of the rotor blade 27 is connected to the flow path wall 42. They are arranged to face each other and form a gap with the flow path wall 42.

  2 and 3 are detailed views of a cross section passing through the flow path wall 42 of the compressor flow path 25 in the region of the in-wall structure 44. In the first embodiment, the in-wall structure 44 includes a plurality of recesses 46 extending through the flow path wall 42 in the radial direction. The insert 48 that is displaceable in the radial direction has a T-shaped cross section and is seated in each of the recesses 46. Two flow paths open toward the recess 46 at the sides. These flow paths are formed as bleed flow paths 50. The opening 52 of the bleed channel 50 is located in the in-wall structure 44, that is, formed in the side wall 54 of the recess 46. In a state where the insert 48 is pushed inward, the recess 46 and the opening 52 are simultaneously completely closed (not shown).

  In the position of the insert 48 shown in FIG. 2, in order to actuate the intra-wall structure 44 that exerts an aerodynamic effect by displacing the insert 48 outward from a closed position that adversely affects the recess 46. The recess 46 is partially open. At the illustrated position of the insert 48, the first opening 52 of the bleed channel 50 is open, so that the compressor air can be extracted from the compressor channel 25 through the recess 46, that is, discharged. The In the position of the insert 48 shown in FIG. 3, both openings 52 of the bleed channel 50 are open. In this regard, the intra-wall structure 44 is variable in size and / or configuration, and as a result, the opening 52 of the bleed channel 50 can be at least partially opened.

  FIG. 4 is a perspective view of a second embodiment of the apparatus according to the present invention. In the second embodiment, an annular endless groove 60 extending in the circumferential direction is provided on the surface of the flow path wall 42 facing toward the compressor flow path 25. Although not shown, the tip of the rotor blade moves in the circumferential direction along the annular groove 60. The plurality of bleed flow paths 62 are only shown around the periphery, but are distributed at regular intervals along the circumference, and are directed toward the inside of the side wall 61 of one of the annular endless grooves 60. Open. However, in the case of this embodiment, the valve system for opening and closing the bleed air of the compressor air is not formed by the movable insert, but is configured as a downstream system. Needless to say, the bleed channel 62 may be distributed at non-constant intervals.

  In the third embodiment shown in FIG. 5, the in-wall structure 44 is configured as a groove 64 that extends in the axial direction and is distributed in the same shape over the entire circumference of the flow path wall 42. Has been. The groove 64 is formed in the insert 45 that is disposed in the recess 47 that is disposed in the flow path wall 42 and that corresponds to the insert 45 and that is rotatable in the circumferential direction. The opening 52 of the bleed channel 50 is provided at the bottom of the recess 47. Depending on the position of the insert 45, the web 49 of the insert 45 disposed between the grooves 64 closes, partially opens, or is completely open, depending on the position of the insert 45. .

  FIGS. 6 and 7 are partial perspective views of a fourth embodiment of an adjustable casing process with a bleed opening 52 disposed therein, respectively. FIG. 6 shows the flow path wall 42 in which a circumferential annular endless groove 66 is formed. In the annular endless groove 66, a radially displaceable insert 68 is arranged to open and close the intra-wall structure 44 and the bleed opening 52 disposed in the side wall 70 of the annular groove. . In FIG. 6, the bleed opening 52 is closed by an insert 68. In FIG. 7, the bleed opening 52 is open.

In conclusion, the present invention is an axial-flow turbocompressor 18 or a gas turbine 10 having an annular compressor flow path 25 concentrically arranged around the rotation axis 12, the compressor flow path. Is formed in a radial direction by the flow path wall 42 on the outer side, and the rotor blade 27 assembled so as to form a ring is rotatably mounted around the rotation axis 12 in the compressor flow path. An axial-flow turbocompressor 18 or a gas turbine 10 is proposed that is arranged in a fixed state. In this case, each free end 29 of the rotor blade 27 is opposed to the flow path wall 42 and forms a gap with the flow path wall 42. An in-wall structure 44 is provided at least partially in the axial direction section of the free end 29 on the flow path wall 42 itself. In order to further improve the operation performance of the axial-flow turbocompressor 18, the bleed opening 52 of the bleed flow path 50 disposed in the in-wall structure 44 in the present invention is disposed in the compressor flow path 25. It is provided to drain and exhaust the flowing air.

DESCRIPTION OF SYMBOLS 10 Gas turbine 12 Rotating axis 14 Rotor 16 Inlet duct 18 Turbo compressor 20 Annular combustion chamber 22 Burner 24 Turbine unit 25 Compressor flow path 26 Exhaust gas duct 27 Rotor blade 28 Combustion space 29 Blade blade tip 30 High temperature gas flow path 32 Turbine stage 34 Ambient air 36 Compressor outlet side diffuser 38 Plenum 42 Flow channel outer wall 44 In-wall structure 45 Insert 46 Recess 47 Recess 48 Insert 50 Bleed flow channel 52 Opening portion 54 (Recess 46) Side wall 60 annular endless groove 62 bleed flow path 64 groove 66 annular endless groove 68 insert

Claims (6)

An axial-flow turbocompressor (18) having an annular compressor flow path (25) disposed concentrically around a rotation axis (12), outside the compressor flow path (25) Is formed by a flow path wall (42) in the radial direction, and a rotor blade (27) that can be assembled to form a ring is formed in the flow path wall (42). 12) In the axial-flow turbocompressor (18), arranged so as to be rotatable around ,
Each tip (29) on the free end side of the rotor blade (27) faces the flow path wall (42), forms a gap with the flow path wall (42), and the flow path wall ( 42 ) at least partially has an intra-wall structure (44) in the axial section of the tip (29);
A bleed opening (52) of the bleed flow path (50) is provided in the flow path wall (42) for allowing the medium flowing in the compressor flow path (25) to flow out,
The axial flow turbocompressor (18), wherein the bleed opening (52) is disposed in the intra-wall structure (44).   The inner wall structure (44) is changeable in size and / or shape, whereby the bleed opening (52) is at least partially open. An axial flow type turbo compressor as described in 1. The intra-wall structure (44) can be changed in size and / or shape by a movable insert (45, 48, 68);
The bleed opening (52) is disposed in a side wall (54, 70 ) of a recess (46, 4 7 ) for receiving the movable insert (45, 48, 68). Item 3. The axial-flow turbocompressor (18) according to item 2.   The axial flow turbocharger according to any one of claims 1 to 3, wherein the bleed channel (50) is connected to an air ejection system and / or an air cooling system on the flow outflow side. Compressor (18).   The axial flow type turbo compressor (18) according to any one of claims 1 to 4, wherein a plurality of said bleed openings (52) are arranged for every rotor blade ring.   A gas turbine (10) comprising the axial flow turbo compressor (18) according to any one of claims 1 to 5.