(19)
(11)EP 2 821 706 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
26.06.2019 Bulletin 2019/26

(21)Application number: 12869701.8

(22)Date of filing:  30.11.2012
(51)International Patent Classification (IPC): 
F23R 3/32(2006.01)
F23R 3/14(2006.01)
F02C 7/232(2006.01)
F23R 3/28(2006.01)
(86)International application number:
PCT/JP2012/081106
(87)International publication number:
WO 2013/128739 (06.09.2013 Gazette  2013/36)

(54)

COMBUSTOR AND GAS TURBINE

BRENNKAMMER UND GASTURBINE

CHAMBRE DE COMBUSTION ET TURBINE À GAZ


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 28.02.2012 WO PCT/JP2012/054935

(43)Date of publication of application:
07.01.2015 Bulletin 2015/02

(73)Proprietor: Mitsubishi Hitachi Power Systems, Ltd.
Yokohama 220-8401 (JP)

(72)Inventors:
  • NAKAMURA Sosuke
    Tokyo 108-8215 (JP)
  • MATSUMURA Yoshikazu
    Tokyo 108-8215 (JP)
  • KATANO Hikaru
    Tokyo 108-8215 (JP)
  • TANIGUCHI Kenta
    Tokyo 108-8215 (JP)
  • YAMASAKI Hiroyuki
    Yokohama-shi Kanagawa 231-8715 (JP)

(74)Representative: Henkel, Breuer & Partner 
Patentanwälte Maximiliansplatz 21
80333 München
80333 München (DE)


(56)References cited: : 
EP-A1- 1 543 272
JP-A- 2000 055 367
JP-A- 2002 195 562
US-A1- 2009 031 728
EP-A1- 1 605 208
JP-A- 2001 254 947
JP-A- 2007 501 926
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Technical Field



    [0001] The present invention relates to a combustor and a gas turbine.

    Background Art



    [0002] In the past, in the field of gas turbines, there has been a gas turbine that uses a premixed combustion type combustor as a combustor that blows fuel into compressed air, thereby performing combustion. As the premixed combustion type combustor, there is a combustor that includes a combustor basket to which compressed air is supplied from a compressor, a plurality of main nozzles annularly disposed along the inner periphery of the combustor basket, and a pilot nozzle that is disposed on the center axis of the combustor basket and that holds a pilot flame. This type of combustor performs premixed combustion by supplying premixed gas of fuel and compressed air to the inside of the combustor basket by the main nozzles and igniting the premixed gas using the pilot flame.

    [0003] For example, in JP 2007-285572A, a premixed combustion burner is constituted of a fuel nozzle, a burner cylinder that surrounds the fuel nozzle so as to form an air pathway between the burner cylinder and the fuel nozzle, and a swirler that is disposed at plural places in the circumferential direction of the outer peripheral surface of the fuel nozzle and which swirls air flowing therethrough. In this combustor, a vortical air flow is generated on the downstream of the swirler by forming a cutout portion in a trailing edge portion on the inner periphery of the swirler, and thus the fuel concentration of the premixed gas is made uniform in the radial direction of the air pathway, whereby suppression of an increase in NOx and prevention of reversion (flashback) of a flame are attempted.

    Disclosure of the Invention


    Problems that the Invention is to Solve



    [0004] Incidentally, in the combustor as described above, usually, cooling of the combustor basket, a transition piece, and a peripheral member thereof is attained by making cooling air flow along the inner peripheral surface of the combustor basket or the transition piece or blowing cooling air thereon. Further, the combustor has a structure in which cooling air flows to a space that is formed between the burner cylinder of a plurality of main nozzles and a pilot cone that is disposed outside the pilot nozzle.

    [0005] However, in the combustor of the related art, even if the fuel concentration of the premixed gas in an outlet end portion of the burner cylinder is made uniform in the radial direction, since the cooling air is mixed therein before reaching a flame front, fuel concentration at the flame front does not become uniform, and thus there is a possibility that a section where fuel concentration becomes locally high may be created. Here, thermal NOx that depends on flame temperature in combustion increases exponentially with respect to a rise in the flame temperature. Therefore, if a section is created where the temperature of a flame becomes locally high due to a locally high fuel concentration, there is a problem in that NOx increases.

    [0006] The present invention has been made in consideration of such circumstances and has an object of suppressing the generation of NOx in a combustor and a gas turbine.

    [0007] EP 1605208A1 discloses a low-emission method for producing power using a gas turbine with a combustor having a plurality of fuel nozzles provided at intervals along an inner periphery of a combustor basket. The method includes premixing a plurality of fuel and air mixtures, injecting the fuel and air mixtures into a combustion chamber using the fuel nozzles, and adjusting a ratio of fuel and air injected by at least one of the nozzles to control a fuel/air concentration distribution within the combustion chamber.

    Means for Solving the Problems



    [0008] The present invention provides a combustor with the features of claim 1 or 2. The combustor according to the invention includes: a combustor basket to which air is supplied from the outside; a first nozzle that extends in an axial direction of the combustor basket, that is provided in a plurality at intervals along an inner periphery of the combustor basket, and that supplies premixed gas of the air and fuel to the inside of the combustor basket; and a transition piece in which the combustor basket is connected to a base end thereof and which burns the premixed gas supplied from the first nozzles, thereby forming a flame front; wherein each of the first nozzles supplies the premixed gas with fuel concentration changed around a center axis of the first nozzle such that the flame front has a uniform temperature in an axial direction.

    [0009] According to this configuration, since each of the first nozzles supplies the premixed gas with fuel concentration changed around the center axis thereof such that the flame front has a uniform temperature in the axial direction, even if cooling air is mixed in the premixed gas, it is possible to reduce the variance in the fuel concentration of the premixed gas over the axial direction. Thus, the flame front is formed by the premixed gas having a fuel concentration that is uniform over the axial direction, so it is possible to suppress combustion of the flame front at a non-uniform temperature in the axial direction and also suppress the generation of NOx.

    [0010] In one embodiment the first nozzles are configured such that, in a leading end outlet of the first nozzle, a fuel concentration of the premixed gas in a second area located radially inward of the inside of the combustor basket is higher than that in a first area located radially outward of the inside of the combustor basket.

    [0011] That is, for example, in a case where the fuel concentration of the premixed gas that is supplied from the first nozzle is affected by the cooling air that flows between the first nozzle and a second nozzle that is provided inside the first nozzle, since the fuel concentration of the premixed gas that is supplied from the first nozzle is relatively less likely to decrease in the first area and relatively more likely to decrease in the second area, the fuel concentration in the second area is set to be relatively higher than that in the first area. Thus, it is possible to make the fuel concentration of the premixed gas that reaches the flame front uniform in the axial direction with a relatively simple configuration.

    [0012] In this specification, the first area of the premixed gas located radially outward of the inside of the combustor basket indicates that, of the premixed gas generated by one first nozzle, a part of or the whole of the area located radially outward of the inside of the combustor basket constitutes the first area. The first area is not necessarily the whole of the area located radially outward of the inside of the combustor basket. Similarly, the second area of the premixed gas located radially inward of the inside of the combustor basket indicates that a part of or the whole of the area located radially inward of the inside of the combustor basket constitutes the second area.

    [0013] In another embodiment the first nozzles are configured such that, in a leading end outlet of the first nozzle, a fuel concentration of the premixed gas in a first area located radially outward of the inside of the combustor basket is relatively higher than that in a second area located radially inward of the inside of the combustor basket.

    [0014] That is, for example, in a case where the fuel concentration of the premixed gas that is supplied from the first nozzle is affected by the cooling air that flows on the inner peripheral surface of the combustor basket or a transition piece, since the fuel concentration of the premixed gas that is supplied from the first nozzle is relatively more likely to decrease in the first area and relatively less likely to decrease in the second area, the fuel concentration in the first area is set to be relatively higher than that in the second area. Thus, it is possible to make the fuel concentration of the premixed gas that reaches the flame front uniform in the axial direction with a relatively simple configuration.

    [0015] Further, the first nozzle may have a nozzle body provided on the center axis of the first nozzle, and a plurality of fuel discharge sections that is provided at an outer periphery of the nozzle body and discharges the fuel, and the plurality of fuel discharge sections may discharge the fuel with a discharge quantity changed around the center axis of the first nozzle.

    [0016] According to this configuration, since the plurality of fuel discharge sections discharges the fuel with a discharge quantity changed around the center axis of the first nozzle, the fuel concentration of the premixed gas can be easily changed around the center axis of the first nozzle.

    [0017] Further, each of the plurality of fuel discharge sections may have a fuel discharge hole, and a discharge quantity of the fuel may be changed by varying opening areas of the fuel discharge holes.

    [0018] According to this configuration, since the number of fuel discharge holes is different, it is possible to change the fuel concentration of the premixed gas by changing the discharge quantity of the fuel with a relatively simple configuration.

    [0019] Further, each of the plurality of fuel discharge sections may have a fuel discharge hole, and a discharge quantity of the fuel may be changed by varying the number of fuel discharge holes.

    [0020] According to this configuration, since the opening areas of the fuel discharge holes are different, it is possible to change the fuel concentration of the premixed gas by changing the discharge quantity of the fuel with a relatively simple configuration.

    [0021] Further, each of the plurality of fuel discharge sections may have a fuel discharge hole, the fuel discharge holes may be divided into a plurality of groups, and each group may be connected to an independent fuel supply path, thereby changing the discharge quantity of the fuel.

    [0022] According to this configuration, since the fuel discharge holes are divided into the plurality of groups and each group is connected to the independent fuel supply path, a fuel discharge quantity of each group is arbitrarily changed by controlling, for example, fuel supply pressure of each fuel supply path, and eventually, the fuel concentration of the premixed gas or the fuel concentration ratio between the respective groups can be changed. Further, even at the time of operation, it is possible to arbitrarily change the fuel discharge quantity of each group or the fuel concentration ratio between the respective groups.

    [0023] Further, the first nozzle may have a swirler blade that is provided in a plurality at an outer periphery of the nozzle body and forms a swirl flow of the premixed gas, and the plurality of fuel discharge sections may be formed at the swirler blade.

    [0024] According to this configuration, since the plurality of fuel discharge sections is formed at the swirler blade, a swirl flow is formed in the premixed gas and as a result, the fuel concentration of the premixed gas can be efficiently adjusted in the radial direction.

    [0025] Further, the swirler blade may have the fuel discharge sections at a plurality of positions in a radial direction of the nozzle body, and the plurality of fuel discharge sections may discharge the fuel with a discharge quantity changed in the radial direction of the nozzle body.

    [0026] According to this configuration, since the plurality of fuel discharge sections discharges the fuel with a discharge quantity changed in the radial direction of the nozzle body, the fuel concentration of the premixed gas can be adjusted in the radial direction.

    [0027] In addition, according to another aspect of the invention, there is provided a gas turbine including: a compressor, a combustor, and a turbine, wherein the combustor may be any of the above-described combustors.

    [0028] According to this configuration, since any of the above-described combustors is provided, a gas turbine can be configured in which the generation of NOx is suppressed.

    Effects of the Invention



    [0029] According to the combustor related to the invention, the generation of NOx can be suppressed.

    [0030] According to the gas turbine related to the invention, a gas turbine can be configured in which the generation of NOx is suppressed.

    Brief Description of the Drawings



    [0031] 

    FIG. 1 is is a schematic cross-sectional view showing the overall configuration of a gas turbine 1 related to a first embodiment of the invention.

    FIG. 2 is an enlarged cross-sectional view of a combustor 10 related to the first embodiment of the invention.

    FIG. 3 is an enlarged cross-sectional view of a main section of the combustor 10 related to the first embodiment of the invention.

    FIG. 4 is an enlarged view of a main section related to the first embodiment of the invention and is a view in the direction of arrow I in FIG. 3.

    FIG. 5 is a diagram showing the fuel concentration of premixed gas M in the cross-section of FIG. 3 related to the first embodiment of the invention converted into temperature, and flame temperature at a flame front F of the premixed gas M which corresponds to the cross-section of FIG. 3, wherein a vertical axis shows a position in a radial direction from a nozzle center axis P3 and a horizontal axis shows fuel concentration converted into temperature.

    FIG. 6 is a comparative example of the combustor 10 related to the first embodiment of the invention and is equivalent to FIG. 5 showing the combustor 10.

    FIG. 7 is a diagram showing the fuel concentration of the premixed gas M in the cross-section of FIG. 3 related to a second embodiment of the invention convereted into temperature, and flame temperature at the flame front F of the premixed gas M which corresponds to the cross-section of FIG. 3, wherein a vertical axis shows a position in a radial direction from the nozzle center axis P3 and a horizontal axis shows fuel concentration convereted into temperature.

    FIG. 8 is a comparative example of a combustor 10 related to the second embodiment of the invention and is equivalent to FIG. 7 showing the combustor 10.

    FIG. 9 is a diagram showing a main nozzle related to a modified example of the second embodiment of the invention and is a diagram as viewed from the direction of a center axis.

    FIG. 10 is a front view showing the schematic configuration of the main nozzle related to the modified example of the second embodiment of the invention.

    FIG. 11 is a diagram showing the main nozzle related to the modified example of the second embodiment of the invention and is a cross-sectional view along line X - X in FIG. 10.

    FIG. 12 is a diagram showing the main nozzle related to the modified example of the second embodiment of the invention and is a cross-sectional view along line Y - Y in FIG. 10.


    Best Mode for Carrying Out the Invention


    (First Embodiment)



    [0032] Hereinafter, a first embodiment of the invention will be described with reference to the drawings.

    [0033] FIG. 1 is a schematic cross-sectional view showing the overall configuration of a gas turbine 1 related to an embodiment of the invention.

    [0034] As shown in FIG. 1, the gas turbine 1 is schematically configured by a compressor 2, a plurality of combustors 10, and a turbine 3.

    [0035] The compressor 2 takes in air as working fluid and generates compressed air (air) A.

    [0036] The plurality of combustors 10 communicates with an outlet of the compressor 2, as shown in FIG. 1, and mixes fuel with the compressed air A supplied from the compressor 2 and also burns the mixture, thereby generating high-temperature and highpressure combustion gas B.

    [0037] The turbine 3 converts the thermal energy of the combustion gas B sent thereto from the combustor 10 into the rotational energy of a rotor 1a. Then, the rotational energy is transmitted to an electric generator (not shown) connected to the rotor 1a.

    [0038] In addition, the respective combustors 10 are radially disposed in a state where a combustor center axis P2 of each combustor is inclined such that the inlet side of the combustor 10 is on the radially farther side than the outlet side with respect to a center axis P1 of rotation of the rotor 1a in the gas turbine 1.

    [0039] FIG. 2 is an enlarged cross-sectional view of the combustor 10.

    [0040] As shown in FIG. 2, each combustor 10 includes an external cylinder 11, a combustor basket 12, a main nozzle (a first nozzle) 14, a pilot nozzle (a second nozzle) 13, and a transition piece 15.

    [0041] In the external cylinder 11, the center axis thereof overlaps the combustor center axis P2 and a flange 11f extending radially outward from the outer periphery on one end side in an axial direction is fixed to a casing 1b. A fuel feeder 10a that supplies fuel to the main nozzle 14 and a nozzle cylinder stand 20 supporting the main nozzle 14 are disposed on a base end portion 11a side on the other end side in the axial direction of the external cylinder 11.

    [0042] The combustor basket 12 is formed so as to have a smaller diameter than the external cylinder 11 and the center axis thereof overlaps the combustor center axis P2. The combustor basket 12 is fixed to the external cylinder 11 through a supporter 12f extending from a base end opening portion 12b side, and the like.

    [0043] The gap between the combustor basket 12 and the external cylinder 11 forms a flow path of the compressed air A, as shown in FIG. 2, and the compressed air A is introduced from the base end opening portion 12b on the base end portion 11a side of the external cylinder 11 into the inside of the combustor basket 12.

    [0044] The pilot nozzle 13 is formed in an elongated shape and disposed on the combustor center axis P2. A base end 13b side of the pilot nozzle 13 is supported on the nozzle cylinder stand 20 and the like, and a leading end 13a side of the pilot nozzle 13 is surrounded by the combustor basket 12. A pilot flame is formed on the leading end 13a side of the pilot nozzle 13 by the fuel supplied from the fuel feeder 10a to the base end 13b side. In addition, the fuel feeder 10a may be configured to include a fuel supply path 10b formed in the periphery on the base end 21b side of a main nozzle body 21 and a fuel supply path 10c formed in the bottom on the base end 21b side of the main nozzle body 21, as necessary.

    [0045] A plurality of (for example, eight) main nozzles 14 is annularly disposed at equal pitch along the inner periphery of the combustor basket 12. The plurality of main nozzles 14 is disposed such that the nozzle center axis P3 (refer to FIG. 3) of each nozzle is parallel to the combustor center axis P2 of the combustor 10.

    [0046] FIG. 3 is an enlarged cross-sectional view of a main section of the combustor 10 and FIG. 4 is a view in the direction of arrow I in FIG. 3.

    [0047] As shown in FIG. 3, each main nozzle 14 includes the main nozzle body 21, a plurality of main swirler blades 22, a main nozzle cylinder 23, and an extension pipe 24. Further, the pilot nozzle 13 includes a pilot nozzle body 25, a plurality of pilot swirler blades 26, a pilot nozzle cylinder 27, and a pilot cone 28.

    [0048] The main nozzle body 21 is formed in an elongated shape, as shown in FIG. 2, and is located on the nozzle center axis P3. The main nozzle body 21 is supported on the nozzle cylinder stand 20 at the base end 21b side, as shown in FIG. 2, and has, in the inside thereof, a fuel flow path connected to the fuel feeder 10a.

    [0049] A plurality of (in this embodiment, six) main swirler blades 22 is radially disposed on the outer periphery on the leading end 21a side of the main nozzle body 21, as shown in FIGS. 3 and 4, and forms a swirl flow of premixed gas M.

    [0050] Fuel discharge sections 22A and 22B are disposed at each main swirler blade 22, as shown in FIG. 4.

    [0051] Each of the fuel discharge sections 22A and 22B is constituted of a pair of fuel discharge holes 22c formed in a pressure surface 22a and a negative pressure surface 22b of the main swirler blade 22, and the fuel discharge section 22A is formed on the radially outward side of the main swirler blade 22 and the fuel discharge section 22B is formed on the radially inward side of the main swirler blade 22.

    [0052] Each of the fuel discharge holes 22c communicates with the fuel flow path of the main nozzle body 21. The fuel discharge holes 22c are formed such that with respect to each of the fuel discharge sections 22A and 22B, the fuel discharge hole 22c formed in the pressure surface 22a is located on the radially outward side of the main swirler blade 22 and the fuel discharge hole 22c formed in the negative pressure surface 22b is located on the radially inward side of the main swirler blade 22.

    [0053] Due to such a configuration, as shown in FIG. 3, the fuel discharge sections 22A and 22B discharge fuel f from the fuel discharge holes 22c, thereby generating the premixed gas M of the compressed air A and the fuel f.

    [0054] The main nozzle cylinder 23 is disposed such that the center axis thereof overlaps the nozzle center axis P3, and each of a cylinder leading end opening 23 a and a cylinder base end opening 23b faces in the axial direction. Then, the main nozzle cylinder 23 surrounds a leading end 21a of each main nozzle body 21 and the plurality of main swirler blades 22.

    [0055] In the extension pipe 24, a pipe base end opening 24b side in the axial direction is connected to the cylinder leading end opening 23a of the nozzle cylinder 23. In a pipe leading end opening portion (a leading end outlet) 24a of the extension pipe 24, the cross-section of a flow path is gradually reduced as it extends from the pipe base end opening 24b side to the pipe leading end opening portion 24a side.

    [0056] The extension pipe 24 makes cooling air a2 for a cooling film flow out from the radially outer peripheral wall side of the pipe leading end opening 24a.

    [0057] Similarly to the pilot nozzle 13, the main nozzle 14 is surrounded by the combustor basket 12 at a leading end side where the main nozzle cylinder 23, the extension pipe 24 and the like are located.

    [0058] The pilot nozzle 13 has the pilot nozzle cylinder 27 at the leading end 25a side of the pilot nozzle body 25 and an annular space is formed between the pilot nozzle cylinder 27 and the pilot nozzle body 25. Then, the pilot swirler blade 26 is disposed between the cylindrical pilot nozzle cylinder 27 and the pilot nozzle body 25, and the pilot swirler blade 26 forms a swirl flow of the compressed air A.

    [0059] A base end opening 28b of the pilot cone 28 is connected to a leading end opening 27a side of the pilot nozzle cylinder 27. In the pilot cone 28, a flow path area thereof is gradually increased as it extends from the base end opening 28b to a leading end opening 28a.

    [0060] Further, a flow path of cooling air a1 is formed in the gap between the extension pipe 24 and the pilot cone 28, and the extension pipe 24 or the pilot cone 28 is cooled by the cooling air a1 flowing out from the flow path.

    [0061] As shown in FIGS. 2 and 3, in the transition piece 15, a base end opening 15b is connected to a leading end opening portion 12a side of the combustor basket 12 and a leading end opening (a leading end in the axial direction) 15a communicates with the turbine 3. The transition piece 15 burns the premixed gas M supplied from the main nozzle 14, thereby forming the flame front F spreading to the radially outward toward the leading end opening 15a side.

    [0062] As shown in FIG. 3, a flow path of cooling air a3 is formed in the gap between the transition piece 15 and the combustor basket 12, and the cooling air a3 flowing in from the flow path flows along the inner peripheral surface of the transition piece 15, thereby forming a cooling film. Further, as shown in FIG. 3, cooling air a4 also flows in from the downstream of the leading end opening portion 12a of the combustor basket 12.

    [0063] In addition, in this embodiment, a case is described where, of the cooling air a1 to a4, the cooling air a1 flowing out from the gap between the extension pipe 24 and the pilot cone 28 is dominant in influence.

    [0064] As described above, the main nozzle 14 supplies the premixed gas M of the compressed air A and the fuel f to the inside of the combustor basket 12. At that time, the main nozzle 14 supplies the premixed gas M with fuel concentration changed around the nozzle center axis P3 of the main nozzle 14 such that the flame front F has a uniform temperature in the axial direction.

    [0065] In the pipe leading end opening 24a of the main nozzle 14, the fuel concentration in a second area S2 located radially inward of the inside of the combustor basket 12 is made relatively higher than in a first area S1 located radially outward of the inside of the combustor basket 12 (a side farther from the combustor center axis P2).

    [0066] As a specific configuration, as shown in FIG. 4, of the six fuel discharge sections 22A, the fuel discharge quantity of Group G1 where the discharged fuel f reaches the first area S1 is reduced, and the fuel discharge quantity of Group G2 where the discharged fuel f reaches the second area S2 is increased.

    [0067] More specifically, as shown in FIG. 4, the opening areas of the fuel discharge holes 22c are different between two fuel discharge sections 22A that are located on the radially inward of the combustor basket 12 and one fuel discharge section 22A adjacent to the two fuel discharge sections 22A in a turning direction (Group Gl), and the remaining three fuel discharge sections 22A (Group G2).

    [0068] In addition, the size of each fuel discharge holes 22c in the six fuel discharge sections 22B is the same.

    [0069] As for the opening area of the fuel discharge hole 22c, when the diameter of the fuel discharge hole 22c belonging to the fuel discharge section 22B is taken as 1, the diameter of the fuel discharge hole 22c belonging to Group G1 is set to 0.9 and the diameter of the fuel discharge hole 22c belonging to Group G2 is set to 1.1.

    [0070] In addition, the position, the number, and the size of the diameter of the fuel discharge holes 22c are determined according to the concentration distribution in the pipe leading end opening 24a.

    [0071] In this manner, the fuel discharge quantities of the six fuel discharge sections 22A are divided into two kinds around the nozzle center axis P3 of the main nozzle 14. Further, in the same main swirler blade 22, the fuel discharge quantity is different between the fuel discharge section 22A on the radially outward side of the main nozzle body 21 and the fuel discharge section 22B on the inward side thereof.

    [0072] Due to such a configuration, when pressure is applied to the fuel f in the fuel flow path of the main nozzle body 21, the amount of fuel f corresponding to the opening area is discharged from each fuel discharge hole 22c toward a flow of the compressed air A.

    [0073]  Next, an operation of the combustor 10 described above will be described.

    [0074] When an operation of the gas turbine 1 is started, the compressor 2 generates the compressed air A. The compressed air A flows from the base end opening portion 12b of the combustor basket 12 of each combustor 10 into the inside of the combustor basket 12, as shown in FIG. 2.

    [0075] The compressed air A flowing into the inside of the combustor basket 12 is partially used in the combustion of the pilot flame by the pilot nozzle 13 and partially flows into the main nozzle cylinder 23 of the main nozzle 14.

    [0076] Each fuel discharge hole 22c discharges the amount of fuel f corresponding to the opening area to the compressed air A flowing into the main swirler blade 22. Then, the fuel f discharged and the compressed air A are mixed by the main swirler blade 22, whereby the premixed gas M is generated and also a swirl flow of the premixed gas M is formed.

    [0077] When the premixed gas M has reached the pipe leading end opening 24a of the extension pipe 24, the concentration in the first area S1 is relatively low and the concentration in the second area S2 is relatively high.

    [0078] The premixed gas M flowing out from the pipe leading end opening 24a forms the flame front F, as shown in FIG. 3.

    [0079] More specifically, as the premixed gas M flows to the downstream in the direction of the combustor center axis P2 of the combustor 10, the premixed gas M on the inward side (the combustor center axis P2 side) of the combustor basket 12 burns more on the radially inward side in an upstream area. In other words, the premixed gas M on the radially outward side of the combustor basket 12, reaches a further downstream area and also burns further on the radially outward side.

    [0080] That is, the premixed gas M flowing out from the cylinder leading end opening 23a burns first in the second area S2 that is located inward of the combustor basket 12 and in which the fuel concentration is higher than that in the first area S1.

    [0081] On the other hand, when the premixed gas M flows to the downstream, the cooling air a1 is mixed in the second area S2 during a period until the premixed gas M flows to the downstream area, and thus the fuel concentration that was relatively high at the pipe leading end opening 24a is diluted and becomes almost the same as the premixed gas in the first area S1.

    [0082] In this way, an area in which the premixed gas M burns sequentially moves from the inward of the combustor basket 12 to the radially outward side, and the flame front F is formed by the premixed gas M having approximately the same fuel concentration in the axial direction. In the flame front F formed in this way, the flame temperature becomes uniform in the axial direction, and thus the generation of NOx becomes slight.

    [0083] As described above, according to the combustor 10, since each main nozzle 14 supplies the premixed gas M with the fuel concentration changed around the nozzle center axis P3 such that the flame front F has a uniform temperature in the axial direction, it is possible to reduce the variance in the fuel concentration of the premixed gas M over the axial direction. Thus, even if the cooling air a1 is mixed in the premixed gas M, the flame front F is formed by the premixed gas M having uniform fuel concentration over the axial direction, and thus it is possible to suppress the combustion of the flame front F at a non-uniform temperature in the axial direction and also suppress the generation of NOx.

    [0084] FIG. 5 is a diagram showing the fuel concentration of the premixed gas M in the pipe leading end opening 24a of the main nozzle 14 convereted into temperature, and flame temperature at the flame front F of the premixed gas M which corresponds to the cross-section of FIG. 3, wherein the vertical axis shows a position in the radial direction from the nozzle center axis P3 and the horizontal axis shows fuel concentration convereted into temperature. In addition, in FIG. 5, a solid line represents flame temperature at the flame front F of the premixed gas M and a dashed line represents a value obtained by converting the fuel concentration of the premixed gas M in the pipe leading end opening 24a into temperature.

    [0085] Further, FIG. 6 is a comparative example in a case where all the opening areas of the fuel discharge holes 22c are made to be the same around the nozzle center axis P3 (the fuel discharge hole 22c of the fuel discharge section 22A has the same diameter as that of the fuel discharge hole 22c of the fuel discharge section 22B).

    [0086] As in the comparative example, if the concentration distribution in the pipe leading end opening 24a is made to be substantially uniform by making all the opening areas of the fuel discharge holes 22c be the same around the nozzle center axis P3, a temperature peak R (the highest flame temperature) is generated in the flame front F on the radially outward of the combustor basket 12 as shown by a solid line in FIG. 6, and the flame temperature becomes locally high at this portion. On the other hand, the flame temperature is rapidly lowered toward the radially inward side from the temperature peak R.

    [0087] This is because the fuel concentration of the premixed gas M on the radially inward side is more likely to decrease due to the cooling air a1.

    [0088] On the other hand, in the combustor 10 according to the invention, in contrast with the comparative example, the concentration distribution in the pipe leading end opening 24a is not uniform, and the concentration in an area of the radially inward side of the combustor 10 is relatively higher than that of the radially outward side thereof as shown in FIG. 5. Further, in the combustor 10 according to the invention, in contrast with the comparative example, the flame temperature of the premixed gas in the flame front F becomes substantially uniform. In addition, in the combustor 10 according to the invention, compared to the comparative example, the temperature peak R becomes low, as shown by a solid line in FIG. 5. In this manner, in the combustor 10, since the combustion temperature becomes uniform on the whole and a local rise in flame temperature can be reduced, the generation of NOx is sufficiently suppressed.

    [0089] Further, in the pipe leading end opening 24a of the main nozzle 14, the fuel concentration in the second area S2 located radially inward of the inside of the combustor basket 12 is made relatively higher than that in the first area S1 located radially outward of the inside of the combustor basket 12. That is, the fuel concentration of the premixed gas in the first area S1 of which the fuel concentration is relatively less likely to decrease and which burns on the downstream side is set to be low, and the fuel concentration of the premixed gas in the second area S2 of which the fuel concentration is more likely to decrease and which burns on the upstream side is set to be high. In this way, it is possible to make the fuel concentration of the premixed gas M that reaches the flame front F uniform in the axial direction with a relatively simple configuration.

    [0090]  Further, since the fuel discharge quantities of the fuel discharge sections 22A respectively formed at the six main swirler blades 22 are divided into two kinds around the nozzle center axis P3, the fuel concentration of the premixed gas M can be easily changed around the nozzle center axis P3 so as to correspond to the second area S2 of which the premixed gas burns at an early stage after flowing out from the pipe leading end opening 24a, and the first area S1 of which the premixed gas flows to the downstream area and burns with a delay.

    [0091] Further, since the fuel discharge quantity is varied at the fuel discharge section 22A on the radially outward of the main nozzle 14 and the fuel discharge section 22B on the inward side in the same main swirler blade 22, the fuel concentration of the premixed gas M can be adjusted easily and appropriately in the radial direction.

    [0092] Further, since the opening areas of the fuel discharge holes 22c are different, it is possible to change the fuel concentration of the premixed gas M by changing a fuel discharge quantity with a relatively simple configuration.

    [0093] In addition, according to the gas turbine 1, since the combustor 10 is provided, a configuration can be obtained in which the generation of NOx is suppressed.

    (Second Embodiment)



    [0094] In the first embodiment, a case has been described where the influence of the cooling air a1 that flows out from the gap between the extension pipe 24 and the pilot cone 28 is dominant. However, in the second embodiment, a case will be described where the influence of cooling air on the radially outward of the combustor basket, such as the cooling air a2 for the cooling film from the radially outer peripheral wall side of the pipe leading end opening 24a of the extension pipe 24, the cooling air a3 flowing in from the flow path of the gap between the transition piece 15 and the combustor basket 12, and the cooling air a4 flowing in from the downstream of the leading end opening 12a of the combustor basket 12, is dominant. Therefore, with respect to the same configuration as that in the first embodiment, a description thereof is omitted here.

    [0095] In this embodiment, in the pipe leading end opening 24a of the main nozzle 14, the fuel concentration in the first area S1 located radially outward of the inside of the combustor basket 12 is made relatively higher than that of the premixed gas in the second area S2 located radially inward of the inside of the combustor basket 12 (a side coming closer to the combustor center axis P2).

    [0096] As a specific configuration, in FIG. 4, of the six fuel discharge sections 22A, the fuel discharge quantity of Group G 1 where the fuel f discharged reaches the first area S1 is increased, and the fuel discharge quantity of Group G2 where the fuel f discharged reaches the second area S2 is reduced.

    [0097] In addition, the position, the number, and the size of the diameter of the fuel discharge holes 22c are determined according to the concentration distribution in the pipe leading end opening 24a.

    [0098] Next, an operation of the combustor 10 described above will be described.

    [0099] When the premixed gas M has reached the pipe leading end opening 24a of the extension pipe 24, the concentration in the first area S1 is relatively high and the concentration in the second area S2 is relatively low.

    [0100] That is, the premixed gas M flowing out from the cylinder leading end opening 23a burns first in the second area S2 located inward of the combustor basket 12 in which the fuel concentration became low compared to that of the first area S1.

    [0101] On the other hand, when the premixed gas M flows to the downstream, the cooling air a2 to a4 is mixed in the first area S1 during the period until the premixed gas M flows to the downstream area, and thus the fuel concentration that was relatively high at the pipe leading end opening 24a is diluted and becomes almost the same as that of the second area S2.

    [0102] In this way, an area in which the premixed gas M burns sequentially moves from the inward of the combustor basket 12 to the radially outward side, and the flame front F is formed by the premixed gas M having approximately the same fuel concentration in the axial direction.

    [0103] In the flame front F formed in this way, the flame temperature becomes uniform in the axial direction, and thus the generation of NOx becomes slight.

    [0104] As described above, according to the combustor 10, since each main nozzle 14 supplies the premixed gas M with the fuel concentration changed around the nozzle center axis P3 such that the flame front F has a uniform temperature in the axial direction, it is possible to reduce the variance in the fuel concentration of the premixed gas M over the axial direction.

    [0105] Thus, even if the cooling air a2 to a4 is mixed in the premixed gas M, the flame front F is formed by the premixed gas M having uniform fuel concentration over the axial direction, and thus it is possible to suppress the combustion of the flame front F at a non-uniform temperature in the axial direction and also suppress the generation of NOx.

    [0106] FIG. 7 is a diagram showing the fuel concentration of the premixed gas M in the radial direction in the pipe leading end opening 24a convereted into temperature, and flame temperature at the flame front F of a corresponding premixed gas M, wherein a solid line represents flame temperature at the flame front F of the premixed gas M and a dashed line represents a value obtained by converting the fuel concentration of the premixed gas M in the pipe leading end opening 24a into temperature.

    [0107] Further, FIG. 8 is a comparative example in a case where all the opening areas of the fuel discharge holes 22c are made to be the same around the nozzle center axis P3 (the fuel discharge hole 22c of the fuel discharge section 22A has the same diameter as that of the fuel discharge hole 22c of the fuel discharge section 22B).

    [0108] As in the comparative example, if the fuel concentration in the pipe leading end opening 24a is made to be substantially uniform by making all the opening areas of the fuel discharge holes 22c be the same around the nozzle center axis P3, a temperature peak R (the highest flame temperature) is generated in the flame front F on the radially outward of the combustor basket 12 as shown by a solid line in FIG. 8, and the flame temperature becomes locally high at this portion. On the other hand, the flame temperature rapidly decreases toward the radially outward side from the temperature peak R.

    [0109] This is because the fuel concentration of the premixed gas M on the radially outward side is more likely to decrease due to the cooling air a2 to a4.

    [0110] On the other hand, in the combustor 10 according to the invention, in contrast with the comparative example, the concentration distribution in the pipe leading end opening 24a is not uniform and the concentration on the radially outward side is relatively higher than the radially inward side as shown in FIG. 7. Further, in the combustor 10 according to the invention, in contrast with the comparative example, the flame temperature of the premixed gas in the flame front F becomes substantially uniform. In addition, in the combustor 10 according to the invention, compared to the comparative example, the temperature peak R becomes low, as shown by a solid line in FIG. 7. In this manner, in the combustor 10, since the combustion temperature becomes uniform on the whole and a local rise in flame temperature can be reduced, the generation of NOx is sufficiently suppressed.

    [0111] Further, in the pipe leading end opening 24a of the main nozzle 14, the fuel concentration in the first area S1 located radially outward of the inside of the combustor basket 12 is made relatively higher than that of the premixed gas in the second area S2 located radially inward of the inside of the combustor basket 12. That is, the fuel concentration of the premixed gas in the first area S1 of which the fuel concentration is relatively more likely to decrease and which burns on the downstream side is set to be high, and the fuel concentration of the premixed gas in the second area S2 of which the fuel concentration is relatively less likely to decrease and which burns on the upstream side is set to be low.

    [0112] In this way, it is possible to make the fuel concentration of the premixed gas M that reaches the flame front F uniform in the axial direction with a relatively simple configuration.

    [0113] In addition, the operation procedure or the shapes, the combination, or the like of the respective constituent members shown in the embodiments described above are examples and can be variously changed based on design requirements or the like within a scope that does not depart from the gist of the invention.

    [0114] As an example, in the embodiments described above, the fuel concentration is changed by varying the fuel discharge quantities by varying the opening areas of the fuel discharge holes 22c. However, alternatively, the fuel concentration may also be changed by varying the fuel discharge quantities by changing, for example, the number of fuel discharge holes 22c or supply pressure to each fuel discharge hole 22c. Alternatively, the fuel concentration may also be changed by an appropriate combination of these.

    [0115] Hereinafter, a modified example of the first embodiment or the second embodiment of the invention will be described with reference to FIGS. 9 to 12.

    [0116] FIG. 9 is a diagram when the main nozzle 14 is viewed from the leading end side in the direction of the center axis. Further, FIG. 10 is a front view showing the schematic configuration of the main nozzle 14, and FIGS. 11 and 12 respectively show cross-sectional views along line X - X and line Y - Y of the main nozzle 14 in FIG. 10.

    [0117] In this modified example, as shown in FIG. 9, the main nozzle 14 includes a first fuel supply system and a second fuel supply system which are independent of each other, and the main nozzle body 21 has a fuel discharge hole 22c that communicates with the first fuel supply system and belongs to a first pressure section 30A (a shaded section) and a fuel discharge hole 22c that communicates with the second fuel supply system and belongs to a second pressure section 30B.

    [0118] The discharge quantity of the fuel f that is discharged from the fuel discharge holes 22c of the first pressure section 30A and the discharge quantity of the fuel f that is discharged from the fuel discharge holes 22c of the second pressure section 30B can be respectively adjusted by adjusting the supply pressure of the fuel f in the first fuel supply system and the second fuel supply system. Since other components are the same as those in the first embodiment or the second embodiment, the same signs are used and a description thereof is omitted here.

    [0119] Specifically, in the main nozzle body 21, as shown in FIGS. 9 and 10, among the plurality of (in this embodiment, six) main swirler blades 22 radially disposed at the outer periphery on the leading end 21a side of the main nozzle body 21, for example, three belong to the first pressure section 30A and the remaining three belong to the second pressure section 30B.

    [0120] Further, the first pressure section 30A is configured to include Group G1 corresponding to the first area S1 and the second pressure section 30B is configured to include Group G2 corresponding to the second area S2.

    [0121] In addition, the position, the number, and the size of the diameter of the fuel discharge holes 22c are determined according to the concentration distribution in the pipe leading end opening 24a.

    [0122] In each main swirler blade 22, as shown in FIGS. 9 and 10, for example, the two fuel discharge holes 22c are formed on each of the pressure surface 22a and the negative pressure surface 22b, and the fuel discharge holes 22c formed in the pressure surface 22a are disposed further on the relatively radially outward side than the fuel discharge holes 22c formed in the negative pressure surface 22b.

    [0123]  Here, a pair of fuel discharge holes 22c located on the radially outward side in each of the pressure surface 22a and the negative pressure surface 22b of each main swirler blade 22 forms the fuel discharge section 22A.

    [0124] Further, a pair of fuel discharge holes 22c located on the radially inward side in each of the pressure surface 22a and the negative pressure surface 22b of each main swirler blade 22 forms the fuel discharge section 22B.

    [0125] The main nozzle body 21 has, in the inside thereof, a first fuel supply path 31 constituting the first fuel supply system and a second fuel supply path 32 constituting the second fuel supply system, as shown in FIG. 10, and the first fuel supply system and the second fuel supply system are independent in terms of pressure and are connected to the fuel feeder 10a.

    [0126] The first fuel supply path 31 includes, for example, a first fuel supply port 31A, a first fuel flow path 31B, a fuel reservoir 31C, and a first branch path 31D. The first fuel supply port 31A is formed at a side portion of the main nozzle body 21 and the fuel reservoir 31C is branched to communicate with each fuel discharge hole 22c through the first branch path 31D.

    [0127] Further, the second fuel supply path 32 includes, for example, a second fuel supply port 32A, a second fuel flow path 32B, a fuel reservoir 32C, and a second branch path 32D. The second fuel supply port 32A is formed in the end face on the base end 21b side of the main nozzle body 21 and the fuel reservoir 32C is branched to communicate with each fuel discharge hole 22c through the second branch path 32D.

    [0128] The fuel reservoir 31C and the fuel reservoir 32C are adjacently disposed to be surrounded by a peripheral wall section 21F in the main nozzle body 21, as shown in FIGS. 10 and 12, and the fuel reservoir 31C and the fuel reservoir 32C are partitioned by a partition wall section 21G, and are thereby independent of each other in terms of pressure.

    [0129] Further, by providing the fuel reservoir 31C and the fuel reservoir 32C, it is possible to stabilize the flow rate of the fuel f that is supplied to the fuel discharge holes 22c belonging to the first pressure section 30A and the flow rate of the fuel f that is supplied to the fuel discharge holes 22c belonging to the second pressure section 30B, and also easily perform communication of the first fuel flow path 31B and the second fuel flow path 32B with the corresponding fuel discharge holes 22c.

    [0130] Further, in this modified example, as shown in FIG. 2, the first fuel supply port 31A is made such that the fuel f is supplied thereto from the fuel supply path 10b communicating with the fuel feeder 10a and formed in the periphery on the base end 21b side of the main nozzle body 21, and the second fuel supply port 32A is made such that the fuel f is supplied thereto from the fuel supply path 10c communicating with the fuel feeder 10a and formed in the bottom on the base end 21b side of the main nozzle body 21.

    [0131] In this embodiment, the fuel feeder 10a is made so as to adjust the flow rate of the fuel f that is supplied to the first fuel supply path 31 and the second fuel supply path 32 by, for example, adjusting the setting of a parameter such as the supply pressure of the fuel f in the first fuel supply system and the second fuel supply system.

    [0132] That is, in this modified example, a configuration is made such that the flow rate of the fuel f of the first fuel supply system and the second fuel supply system, and eventually, the discharge quantity of the fuel f from the fuel discharge holes 22c belonging to the first pressure section 30A and the second pressure section 30B are adjusted by supplying the fuel f by the first fuel supply system and the second fuel supply system independent of the first fuel supply system and individually controlling the supply pressure of the first fuel supply system and the second fuel supply system.

    [0133] For example, by making the supply pressure of the fuel discharge holes 22c belonging to the first pressure section 30A higher than that of the fuel discharge holes 22c belonging to the second pressure section 30B, the fuel discharge holes 22c belonging to Group G1 discharge a relatively larger amount of fuel f than the fuel discharge holes 22c belonging to Group G2, and thus, the fuel concentration of the premixed gas becomes higher in the first area S1 of the combustor basket 12 than the second area S2.

    [0134] In addition, operation procedure or the shapes, the combination, or the like of the respective constituent members shown in the embodiments described above is an example and can be variously changed based on design requirements or the like within a scope that does not depart from that of the appended claims.

    [0135] For example, in the above-described embodiments, a case has been described where the first area S1 is the radially inward of the inside of the combustor basket 12 and the second area S2 is the radially outward of the inside of the combustor basket 12. However, a configuration may be adopted in which, for example, the first area S1 is a portion of the radially outward of the inside of the combustor basket 12 and the second area S2 is a portion of the radially inward of the inside of the combustor basket 12, or the first area S1 and the second area S2 respectively constitute portions of the radially outward and inward of the inside of the combustor basket 12.

    [0136] Further, for example, in the above-described embodiments, a case has been described where the main nozzle 14 includes two kinds of fuel discharge holes 22c; one kind of the fuel discharge holes 22c belonging to the first pressure section 30A corresponding to the first area S1 and the other kind of the fuel discharge holes 22c belonging to the second pressure section 30B corresponding to the second area S2. However, the present invention is not limited thereto.

    [0137] For example, in such cases as where the premixed gas having a plurality of fuel concentrations is supplied to the radially outward of the inside of the combustor basket 12 by dividing an area on the radially outward of the inside of the combustor basket 12 of the premixed gas M generated in each main nozzle 14 into a plurality of areas that includes the first area S1, or by dividing the first area S1 into a plurality of areas having different fuel concentration, the fuel discharge hole 22c corresponding to the radially outward of the inside of the combustor basket 12 may be configured to communicate with an individual fuel supply system independent of the first pressure section 30A, in addition to the first pressure section 30A.

    [0138] Further, for example, in such cases as where the premixed gas having a plurality of fuel concentrations is supplied to the radially inward of the combustor basket 12 by dividing an area on the radially inward of the inside of the combustor basket 12 of the premixed gas M generated in each main nozzle 14 into a plurality of areas that includes the second area S2, or by dividing the second area S2 into a plurality of areas having different fuel concentration, the fuel discharge hole 22c corresponding to the radially inward of the inside of the combustor basket 12 may be configured to communicate with an individual fuel supply system independent of the second pressure section 30B, in addition to the second pressure section 30B.

    [0139] In addition, a plurality of independent fuel supply systems may also be provided at each of both the radially outward side and the radially inward of the inside of the combustor basket 12.

    [0140] Further, in the above-described embodiments, a case has been described where the main nozzle 14 is provided with three main swirler blades 22 belonging to Group G1 and the three main swirler blades 22 belonging to Group G2, and four fuel discharge holes 22c are formed in each of the main swirler blades 22 belonging to the first pressure section 30A and the second pressure section 30B. However, the present invention is not limited thereto.

    [0141] For example, the number of main swirler blades 22 that the main nozzle 14 has, the number of main swirler blades 22 corresponding to Group G1 and Group G2, or the number of main swirler blades 22 corresponding to the first pressure section 30A and the second pressure section 30B can be arbitrarily set.

    [0142] Further, the number of fuel discharge holes 22c that are formed in each main swirler blade 22 can also be arbitrarily set.

    [0143] Further, in the above-described embodiments, a case has been described where the main nozzle 14 has six main swirler blades 22. However, for example, a configuration may be adopted in which the main nozzle 14 is not provided with the main swirler blade 22.

    [0144] Further, in the above-described embodiments, a case has been described where there are an equal number of fuel discharge holes 22c belonging to the first pressure section 30A and fuel discharge holes 22c belonging to the second pressure section 30B which are disposed to correspond to each other and have equal respective opening areas. However, for example, any or all of the number, the disposition, and the opening areas of the fuel discharge holes 22c belonging to the first pressure section 30A and the fuel discharge holes 22c belonging to the second pressure section 30B may be set to be different.

    [0145] Further, in the above-described embodiments, a case has been described where the first pressure section 30A is connected to the first fuel supply system, the second pressure section 30B is connected to the second fuel supply system, and the discharge quantity of the fuel f that is discharged from each fuel discharge hole 22c belonging to the first pressure section 30A and the second pressure section 30B is adjusted by controlling a parameter such as the pressure of the first fuel supply system and the second fuel system. However, for example, a configuration may be adopted in which the flow rate of the fuel f that is supplied by each fuel supply system is adjusted by the setting of the flow path area, the flow path resistance, or the like of each fuel supply system such as the first fuel supply port 31A, the second fuel supply port 32A, the first fuel flow path 31B, or the second fuel flow path 32B.

    [0146]  Further, in the above-described embodiments, a case has been described where the first fuel supply path 31 includes the first fuel supply port 31A, the first fuel flow path 31B, the fuel reservoir 31C, and the first branch path 31D. However, it goes without saying that the present invention is not limited to the above configuration. The same applies to the second fuel supply path 32.

    [0147] Further, the supply quantity of the fuel f may also be adjusted by the setting of the number or the opening area of each fuel discharge hole 22c belonging to the first pressure section 30A and the second pressure section 30B.

    [0148] Further, the fuel concentration may also be changed by an appropriate combination of these.

    [0149] Further, in the embodiments described above, a configuration has been shown in which, in the combustor 10 where the main nozzles 14 are disposed at intervals along the inner peripheral surface of the combustor basket 12, the pilot flame is formed by the pilot nozzle 13 that is disposed on the combustor center axis P2, thereby igniting the premixed gas from the main nozzle 14 to perform premixed combustion. However, the present invention is not limited to this configuration. For example, it is also possible to apply the invention to a combustor which includes a plurality of first nozzles that is disposed at intervals along the inner peripheral surface of a combustor basket and a second nozzle that is disposed on a combustor center axis, and in which the first and second nozzles can independently perform the premixed combustion.

    Industrial Applicability



    [0150]  According to the combustor related to the invention, the generation of NOx can be suppressed.

    [0151] According to the gas turbine related to the invention, a gas turbine in which the generation of NOx is suppressed can be configured.

    [Reference Signs List]



    [0152] 

    1: gas turbine

    10: combustor

    12: combustor basket

    14: main nozzle (first nozzle)

    15: transition piece

    15a: leading end opening (leading end in an axial direction)

    15b: base end opening (base end)

    22: main swirler blade (swirler blade)

    22A, 22B: fuel discharge section

    22c: fuel discharge hole

    24a: pipe leading end opening (leading end outlet)

    P2: combustor center axis

    P3: nozzle center axis (center axis of a main nozzle)

    S1: first area

    S2: second area

    A: compressed air (air)

    F: flame front

    M: premixed gas

    f: fuel




    Claims

    1. A combustor (10) comprising:

    a combustor basket (12) to which air (A) can be supplied from the outside;

    a plurality of first nozzles (14) extending in an axial direction of the combustor basket (12), the first nozzles (14) being provided at intervals along an inner periphery of the combustor basket (12) surrounding a second nozzle (13) configured to form a pilot flame, and being adapted to supply premixed gas (M) of the air (A) and fuel (f) to the inside of the combustor basket (12); and

    a transition piece (15) in which the combustor basket (12) is connected to a base end (15b) thereof and which is adapted to burn the premixed gas (M) supplied from the first nozzles (14), thereby forming a flame front (F),

    wherein each of the first nozzles (14) is adapted to supply the premixed gas (M) with fuel concentration changed around its center axis (P3), and

    wherein each of the first nozzles (14) is configured such that, in a leading end outlet (24a) of an extension pipe (24) of the first nozzle (14), a fuel concentration of the premixed gas (M) in a second area (S2) located radially inward of the inside of the combustor basket (12) is relatively higher than that in a first area (S1) located radially outward of the inside of the combustor basket (12), such that the premixed gas (M) of the second area (S2) mixes downstream with cooling air (a1) that flows out from a gap between the extension pipes (24) and a pilot cone (28) of the second nozzle (13) so that the fuel concentration becomes almost the same as that of the premixed gas (M) in the first area (S1), and such that the flame front (F) has a uniform temperature in an axial direction.


     
    2. A combustor (10) comprising:

    a combustor basket (12) to which air (A) can be supplied from the outside;

    a plurality of first nozzles (14) extending in an axial direction of the combustor basket (12), the first nozzles (14) being provided at intervals along an inner periphery of the combustor basket (12) surrounding a second nozzle (13) configured to form a pilot flame, and being adapted to supply premixed gas (M) of the air (A) and fuel (f) to the inside of the combustor basket (12); and

    a transition piece (15) in which the combustor basket (12) is connected to a base end (15b) thereof and which is adapted to burn the premixed gas (M) supplied from the first nozzles (14), thereby forming a flame front (F),

    wherein each of the first nozzles (14) is adapted to supply the premixed gas (M) with fuel concentration changed around its center axis (P3), and

    wherein each of the first nozzles (14) is configured such that, in a leading end outlet (24a) of an extension pipe (24) of the first nozzle (14), a fuel concentration of the premixed gas (M) in a first area (S1) located radially outward of the inside of the combustor basket (12) is relatively higher than that in a second area (S2) located radially inward of the inside of the combustor basket (12), such that the premixed gas (M) of the first area (S1) mixes downstream with cooling air (a2) for a cooling film from the radially outer peripheral wall side of the leading end outlet (24a) of the extension pipe (24) so that the fuel concentration becomes almost the same as that of the premixed gas (M) in the second area (S2), and such that the flame front (F) has a uniform temperature in an axial direction.


     
    3. The combustor (10) according to Claim 1 or 2, wherein
    the first nozzle (14) has a nozzle body (21) provided on the center axis (P3) of the first nozzle (14), and
    a plurality of fuel discharge sections (22A,22B) that are provided at an outer periphery of the nozzle body (21) and are adapted to discharge the fuel (f) with a discharge quantity changed around the center axis (P3) of the first nozzle (14).
     
    4. The combustor (10) according to Claim 3, wherein
    each of the plurality of fuel discharge sections (22A,22B) has at least one fuel discharge hole (22c), and the discharge quantity of the fuel (f) is changed by varying opening areas of the fuel discharge holes (22c).
     
    5. The combustor (10) according to Claim 3 or 4, wherein
    each of the plurality of fuel discharge sections (22A,22B) has at least one fuel discharge hole (22c), and the discharge quantity of the fuel (f) is changed by varying the number of fuel discharge holes (22c).
     
    6. The combustor (10) according to anyone of Claims 3 to 5, wherein
    each of the plurality of fuel discharge sections (22A,22B) has at least one fuel discharge hole (22c), the fuel discharge holes (22c) are divided into a plurality of groups (G1G2), and each group (G1,G2) is connected to an independent fuel supply path (31,32), thereby allowing changing the discharge quantity of the fuel (f).
     
    7. The combustor (10) according to anyone of Claims 3 to 6, wherein
    each first nozzle (14) has a plurality of swirler blades (22) provided at an outer periphery of the nozzle body (21) and adapted to form a swirl flow of the premixed gas (M), and the plurality of fuel discharge sections (22A,22B) are formed at the swirler blades (22).
     
    8. The combustor (10) according to Claim 7, wherein
    the swirler blades (22) have the fuel discharge sections (22A,22B) at a plurality of positions in a radial direction of the nozzle body (21), and
    the plurality of fuel discharge sections (22A,22B) are adapted to discharge the fuel (f) with the discharge quantity changed in the radial direction of the nozzle body (21).
     
    9. A gas turbine (1) comprising:

    a compressor (2);

    a combustor (10) according to anyone of Claims 1 to 8; and

    a turbine (3).


     


    Ansprüche

    1. Eine Brennkammer (10) mit:

    einem Brennkammerkorb (12), dem Luft (A) von der Außenseite zugeführt werden kann,

    einer Vielzahl von ersten Düsen (14), die sich in einer axialen Richtung des Brennkammerkorbs (12) erstrecken, wobei die ersten Düsen (14) in Intervallen entlang einem Innenumfang des Brennkammerkorbs (12) so vorgesehen sind, dass sie eine zweite Düse (13) umgeben, die konfiguriert ist, um eine Pilotflamme zu bilden, und die eingerichtet sind, um ein Vormischgas (M) aus der Luft (A) und Brennstoff (f) zu der Innenseite des Brennkammerkorbs (12) zuzuführen, und

    einem Übergangsstück (15), in dem der Brennkammerkorb (12) mit einem Basisende (15b) davon verbunden ist und das eingerichtet ist, um das Vormischgas (M), das von den ersten Düsen (14) zugeführt wird, zu verbrennen, um dadurch eine Flammenfront (F) zu bilden,

    wobei jede der ersten Düsen (14) eingerichtet ist, um das Vormischgas (M) mit um deren Mittelachse (P3) herum veränderter Brennstoffkonzentration zuzuführen, und

    wobei jede der ersten Düsen (14) so konfiguriert ist, dass in einem Vorderendauslass (24a) eines Erweiterungsrohrs (24) der ersten Düse (14) eine Brennstoffkonzentration des Vormischgases (M) in einem zweiten Bereich (S2), der sich radial einwärts der Innenseite des Brennkammerkorbs (12) befindet, relativ höher ist als die in einem ersten Bereich (S1), der sich radial auswärts der Innenseite des Brennkammerkorbs (12) befindet, sodass das Vormischgas (M) des zweiten Bereichs (S2) sich stromab mit Kühlluft (a1) vermischt, die von einem Zwischenraum zwischen den Erweiterungsrohren (24) und einem Pilotkegel (28) der zweiten Düse (13) ausströmt, sodass die Brennstoffkonzentration annähernd die gleiche wird wie die des Vormischgases (M) in dem ersten Bereich (S1), und so, dass die Flammenfront (F) eine gleichmäßige Temperatur in einer Axialrichtung besitzt.


     
    2. Eine Brennkammer (10) mit:

    einem Brennkammerkorb (12), dem Luft (A) von der Außenseite zugeführt werden kann,

    einer Vielzahl von ersten Düsen (14), die sich in einer axialen Richtung des Brennkammerkorbs (12) erstrecken, wobei die ersten Düsen (14) in Intervallen entlang einem Innenumfang des Brennkammerkorbs (12) so vorgesehen sind, dass sie eine zweite Düse (13) umgeben, die konfiguriert ist, um eine Pilotflamme zu bilden, und die eingerichtet sind, um ein Vormischgas (M) aus der Luft (A) und Brennstoff (f) zu der Innenseite des Brennkammerkorbs (12) zuzuführen, und

    einem Übergangsstück (15), in dem der Brennkammerkorb (12) mit einem Basisende (15b) davon verbunden ist und das eingerichtet ist, um das Vormischgas (M), das von den ersten Düsen (14) zugeführt wird, zu verbrennen, um dadurch eine Flammenfront (F) zu bilden,

    wobei jede der ersten Düsen (14) eingerichtet ist, um das Vormischgas (M) mit um deren Mittelachse (P3) herum veränderter Brennstoffkonzentration zuzuführen, und

    wobei jede der ersten Düsen (14) so konfiguriert ist, dass in einem Vorderendauslass (24a) eines Erweiterungsrohrs (24) der ersten Düse (14) eine Brennstoffkonzentration des Vormischgases (M) in einem ersten Bereich (S1), der sich radial auswärts der Innenseite des Brennkammerkorbs (12) befindet, relativ höher ist als die in einem zweiten Bereich (S2), der sich radial einwärts der Innenseite des Brennkammerkorbs befindet, sodass das Vormischgas (M) des ersten Bereichs (S1) sich stromab mit Kühlluft (a2) für einen Kühlfilm von der radial äußeren Umfangswandseite des Vorderendauslasses (24a) des Erweiterungsrohrs (24) vermischt, sodass die Brennstoffkonzentration annähernd die gleiche wird wie die des Vormischgases (M) in dem zweiten Bereich (S2), und so, dass die Flammenfront (F) eine gleichmäßige Temperatur in einer Axialrichtung besitzt.


     
    3. Die Brennkammer (10) gemäß Anspruch 1 oder 2, wobei
    die erste Düse (14) einen Düsenkörper (21) hat, der an der Mittelachse (P3) der ersten Düse (14) vorgesehen ist, und
    eine Vielzahl von Brennstoffaustragabschnitten (22A,22B), die an einem Außenumfang des Düsenkörpers (21) vorgesehen sind und eingerichtet sind, um den Brennstoff (f) mit einer Austragmenge auszutragen, die um die Mittelachse (P3) der ersten Düse (14) herum verändert ist.
     
    4. Die Brennkammer (10) gemäß Anspruch 3, wobei
    jeder der Vielzahl von Brennstoffaustragabschnitten (22A,22B) zumindest ein Brennstoffaustragloch (22c) besitzt, und die Austragmenge des Brennstoffs (f) durch Variieren von Öffnungsbereichen der Brennstoffaustraglöcher (22c) verändert wird.
     
    5. Die Brennkammer (10) gemäß Anspruch 3 oder 4, wobei
    jeder der Vielzahl von Brennstoffaustragabschnitten (22A,22B) zumindest ein Brennstoffaustragloch (22c) besitzt, und die Austragmenge des Brennstoffs (f) durch Variieren der Anzahl von Brennstoffaustraglöchern (22c) verändert wird.
     
    6. Die Brennkammer (10) gemäß einem der Ansprüche 3 bis 5, wobei
    jeder der Vielzahl von Brennstoffaustragabschnitten (22A,22B) zumindest ein Brennstoffaustragloch (22c) besitzt, die Brennstoffaustraglöcher (22c) in eine Vielzahl von Gruppen (G1,G2) unterteilt sind, und jede Gruppe (G1,G2) mit einem unabhängigen Brennstoffzuführweg (31,32) verbunden ist, um dadurch eine Veränderung der Austragmenge des Brennstoffs (f) zu ermöglichen.
     
    7. Die Brennkammer (10) gemäß einem der Ansprüche 3 bis 6, wobei
    jede erste Düse (14) eine Vielzahl von Verwirbelungsschaufeln (22) besitzt, die an einem Außenumfang des Düsenkörpers (21) vorgesehen sind und eingerichtet sind, um eine Wirbelströmung des Vormischgases (M) zu bilden, und die Vielzahl von Brennstoffaustragabschnitten (22A,22B) an den Verwirbelungsschaufeln (22) ausgebildet sind.
     
    8. Die Brennkammer (10) gemäß Anspruch 7, wobei
    die Verwirbelungsschaufeln (22) die Brennstoffaustragabschnitte (22A,22B) an einer Vielzahl von Positionen in einer Radialrichtung des Düsenkörpers (21) hat, und
    die Vielzahl von Brennstoffaustragabschnitten (22A,22B) eingerichtet sind, um den Brennstoff (f) mit der in der Radialrichtung des Düsenkörpers (21) veränderten Austragmenge auszutragen.
     
    9. Eine Gasturbine (1) mit:

    einem Kompressor (2),

    einer Brennkammer (10) gemäß einem der Ansprüche 1 bis 8, und

    einer Turbine (3).


     


    Revendications

    1. Chambre de combustion (10), comprenant :

    un panier (12) de chambre de combustion, auquel de l'air (A) peut être envoyé de l'extérieur ;

    une pluralité de premières buses (14), s'étendant dans une direction axiale du panier (12) de la chambre de combustion, les premières buses (14) étant prévues à des intervalles le long d'une périphérie intérieure du panier (12) de la chambre de combustion entourant une deuxième buse (13), configurée pour former une flamme pilote, et étant conçues pour envoyer du gaz (M) prémélangé, de l'air (A) et du combustible (f) à l'intérieur du panier (12) de la chambre de combustion et

    une pièce (15) de transition, dans laquelle le panier (12) de la chambre de combustion est relié à son extrémité (15b) de base et qui est conçue pour brûler le gaz (M) prémélangé fourni par les premières buses (14), en formant ainsi un front (F) de flamme,

    dans laquelle chacune des premières buses (14) est conçue pour fournir le gaz (M) prémélangé à une concentration en combustible modifiée autour de son axe (P3) central et

    dans laquelle chacune des premières buses (14) est configurée de manière à ce que, dans une sortie (24a) d'extrémité menante d'un conduit (24) de prolongement de la première buse (14), une concentration en combustible du gaz (M) prémélangé, dans une deuxième zone (S2) située radialement vers l'intérieur de l'intérieur du panier (12) de la chambre de combustion, soit relativement plus grande que dans une première zone (S1) située radialement vers l'extérieur de l'intérieur du panier (12) de la chambre de combustion, de manière à ce que le gaz (M) prémélangé de la deuxième zone (S2) se mélange en aval avec de l'air (a1) de refroidissement, qui sort d'un intervalle entre les conduits (24) de prolongement et un cône (28) pilote de la deuxième buse (13), de manière à ce que la concentration en combustible devienne presque la même que celle du gaz (M) prémélangé dans la première zone (S1) et de manière à ce que le front (F) de flamme ait une température uniforme dans une direction axiale.


     
    2. Chambre (10) de combustion, comprenant :

    un panier (12) de chambre de combustion, auquel de l'air (A) peut être envoyé de l'extérieur ;

    une pluralité de premières buses (14), s'étendant dans une direction axiale du panier (12) de la chambre de combustion, les premières buses (14) étant prévues à des intervalles le long d'une périphérie intérieure du panier (12) de la chambre de combustion entourant une deuxième buse (13), configurée pour former une flamme pilote, et étant conçues pour envoyer du gaz (M) prémélangé, de l'air (A) et du combustible (f) à l'intérieur du panier (12) de la chambre de combustion et

    une pièce (15) de transition, dans laquelle le panier (12) de la chambre de combustion est relié à son extrémité (15b) de base et qui est conçue pour brûler le gaz (M) prémélangé fourni par les premières buses (14), en formant ainsi un front (F) de flamme,

    dans laquelle chacune des premières buses (14) est conçue pour fournir le gaz (M) prémélangé à une concentration de combustible modifiée autour de son axe (P3) central et

    dans laquelle chacune des premières buses (14) est configurée de manière à ce que, dans une sortie (24a) d'extrémité menante d'un conduit (24) de prolongement de la première buse (14), une concentration en combustible du gaz (M) prémélangé, dans une première zone (S1), située radialement vers l'extérieur de l'intérieur du panier (12) de la chambre de combustion, soit relativement plus grande que celle dans une deuxième zone (S2) située radialement vers l'intérieur de l'intérieur du panier (12) de la chambre de combustion, de manière à ce que le gaz (M) prémélangé de la première zone (S1) se mélange en aval avec de l'air (a2) de refroidissement, pour un film de refroidissement, à partir du côté de la paroi périphérique extérieure radialement de la sortie (24a) d'extrémité menante du conduit (24) de prolongement, de manière à ce que la concentration en combustible devienne presque la même que celle du gaz (M) prémélangé dans la deuxième zone (S2) et de manière à ce que le front (F) de flamme ait une température uniforme dans une direction axiale.


     
    3. Chambre (10) de combustion suivant la revendication 1 ou 2, dans laquelle
    la première buse (14) a un corps (21), prévu sur l'axe (P3) central de la première buse (14) et
    une pluralité de parties (22A, 22B) d'évacuation de combustible, qui sont prévues à une périphérie extérieure du corps (21) de la buse et qui sont conçues pour évacuer le combustible (f) en une quantité d'évacuation, qui varie autour de l'axe (P3) central de la première buse (14).
     
    4. Chambre (10) de combustion suivant la revendication 3, dans laquelle
    chacune de la pluralité de parties (22A, 22B) d'évacuation de combustible a au moins un trou (22c) d'évacuation de combustible et la quantité d'évacuation du combustible (f) est modifiée en faisant varier des surfaces d'ouverture des trous (22c) d'évacuation du combustible.
     
    5. Chambre (10) de combustion suivant la revendication 3 ou 4, dans laquelle
    chacune de la pluralité de parties (22A, 22B) d'évacuation de combustible a au moins un trou (22c) d'évacuation de combustible et la quantité d'évacuation du combustible (f) est modifiée en faisant varier le nombre de trous (22c) d'évacuation du combustible.
     
    6. Chambre (10) de combustion suivant l'une quelconque des revendications 3 à 5, dans laquelle
    chacune des parties (22A, 22B) d'évacuation du combustible a au moins un trou (22c) d'évacuation du combustible, les trous (22c) d'évacuation du combustible étant subdivisés en une pluralité de groupes (G1, G2) et chaque groupe (G1, G2) est relié à un trajet (31, 32) indépendant de l'alimentation en combustible, en permettant ainsi de changer la quantité d'évacuation du combustible (f).
     
    7. Chambre (10) de combustion suivant l'une quelconque des revendications 3 à 6, dans laquelle
    chaque première buse (14) a une pluralité de pales (22) de tourbillonnement, prévues à une périphérie extérieure du corps (2) de la buse et conçues pour former un écoulement turbulent du gaz (M) prémélangé et la pluralité de parties (22A, 22B) d'évacuation du combustible est formée aux pales (22) de tourbillonnement.
     
    8. Chambre (10) de combustion suivant la revendication 7, dans laquelle
    les pales (22) de tourbillonnement ont les parties (22A, 22B) d'évacuation de combustible, en une pluralité de positions dans une direction radiale du corps (21) de la buse et
    la pluralité de parties (22A, 22B) d'évacuation du combustible sont conçues pour évacuer le combustible (f), en ayant la quantité d'évacuation modifiée dans la direction radiale du corps (21) de la buse.
     
    9. Turbine (1) à gaz, comprenant :

    un compresseur (2) ;

    une chambre de combustion (10) suivant l'une quelconque des revendications 1 à 8 et

    une turbine (3).


     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description