Gas turbine combustion device

Abstract

Gas turbine combustion device (3) comprising a combustion lining (7) forming a combustion chamber (8) for generating combustion gas (9), a combustion housing (11) arranged on an outer circumferential side of the combustion lining (7), and a burner (20, 30) for supplying air flowing between the combustion lining (7) and the combustion housing (11), and fuel to be supplied to the combustion chamber (8) by a fuel supply system (21, 31), wherein the gas turbine combustion device (3) is characterized in that it comprises the following: a guide vane (40) arranged in an annular channel (13) between the outer circumferential side of the combustion lining (7) and an inner circumferential side of the combustion housing (11), wherein the guide vane (40) has a predetermined width in the axial direction of the combustion lining (7); several supports (41) arranged circumferentially on an inner side of the combustion housing (11) and extending towards a center of the combustion chamber (8) to fix the guide vane (40); and a pressure dynamic damping hole (42) formed in the combustion lining (7) at a position corresponding to the guide vane (40) for communication with the combustion chamber (8) and the annular channel (13), wherein a pressure wave generated by combustion vibrations in the combustion chamber (8) which propagates into the annular channel (13) is reflected by the guide vane (40) and then damped to suppress an increase in the amplitude value of the combustion vibrations.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a gas turbine combustion apparatus.

[0002] Gas turbine combustion engines of any type use liquefied natural gas as fuel. With a view to global environmental protection, a premixed combustion mode is used to burn premixed air and fuel to suppress the emission of nitrogen oxides (NOx), a cause of air pollution.

[0003] In the premixed combustion mode, the air-fuel premixing can suppress the generation of a local high-temperature combustion region during combustion. Therefore, it is possible to suppress the generation of nitrogen oxides from the high-temperature combustion region.

[0004] In general, the premixed combustion mode succeeds in suppressing the amount of nitrogen oxides produced. However, in certain cases, the mode fails to stabilize the combustion state, resulting in combustion oscillations in which the pressure in the combustion chamber fluctuates periodically. Therefore, the premixed combustion mode is combined with the diffusion combustion mode, which is excellent for stabilizing the combustion state.

[0005] When both diffusion combustion and premixed combustion modes are used to suppress the amount of nitrogen oxides generated, the ratio of premixed combustion to diffusion combustion may be increased, or premixed combustion may be performed entirely. In the above-described case, an acoustic liner is mounted on an outer peripheral surface of the combustion liner forming the combustion chamber to dampen pressure fluctuations due to combustion vibrations.

[0006] An example of background of the technology described above is contained in WO 2013 / 077394 A1.

[0007] The disclosed gas turbine combustion device includes a combustion cylinder and an acoustic liner mounted on an outer side of the combustion cylinder to form a space from the outer peripheral surface of the combustion cylinder. The combustion cylinder has a group of through holes. The through holes are formed at intervals in the circumferential direction in a plurality of rows and arranged at intervals in axial rows (see description in SUMMARY OF THE INVENTION of WO 2013 / 077394 A1). SUMMARY OF THE INVENTION

[0008] WO 2013 / 077394 A1 discloses the gas turbine combustion device having the acoustic lining. The disclosed acoustic lining is attached to the combustion cylinder (the combustion lining). Furthermore, CN 104 296 160 A discloses a guide bushing for a gas turbine combustion chamber with a cooling function, proposing an improvement in the structural strength of the guide bushing, so that the guide bushing has a longer service life during the operation of the gas turbine.US 4,872,312 A discloses a gas turbine combustor apparatus wherein a cooling air introduction device comprises a group of small holes formed in a first region of a flow sleeve proximate a turbine section, the flow sleeve having a second region closer to a combustor liner than a frost region of the small holes, wherein through holes for introducing the cooling air are formed in the second region. US 2015 226 122 A1 discloses a sequential burner assembly wherein a mixer includes a plurality of injection tubes extending inwardly from side walls of the mixer for admixing a diluent gas to cool hot exhaust gases exiting a first combustion chamber.US 2011 220 433 A1 discloses a combustion chamber having a cylindrical body, wherein an acoustic section is provided along the cylindrical body so as to extend in a direction intersecting an axial direction of the cylindrical body. Finally, DE 10 2009 026 056 A1 discloses a combustion chamber wherein a combustion chamber liner and a combustion chamber sleeve define a flow channel therebetween.

[0009] When the disclosed acoustic liner is attached to the combustion liner as a high-temperature component, a cooling process in which purge air is introduced into the space between the acoustic liner and the combustion liner is required to ensure mechanical reliability.

[0010] It is an object of the present invention to provide a gas turbine combustion apparatus having a relatively simple structure for damping pressure fluctuations due to combustion vibrations while ensuring mechanical reliability.

[0011] The above-mentioned object is solved by the features of claims 1 and 6. Particular embodiments are described in the dependent claims.

[0012] The present invention provides a gas turbine combustion apparatus having a relatively simple structure for damping the pressure fluctuations due to combustion vibrations while ensuring mechanical reliability.

[0013] Other problems, structures, and beneficial effects than those described above are clarified by descriptions of the following examples. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 conceptually illustrates a gas turbine power generation plant provided with a gas turbine combustion device 3 to be described in a first example; Fig. 2 is a schematic, partially enlarged sectional view of a main part of the gas turbine combustion apparatus 3 to be described in the first example; Fig. 3 is a schematic, partially enlarged sectional view of a main part of the gas turbine combustion apparatus 3 to be described in a second example; Fig. 4 is a schematic, partially enlarged sectional view of a main part of the gas turbine combustion apparatus 3 to be described in a third example; Fig. Fig. 5 is a schematic view of the gas turbine combustion apparatus 3 to be described in the third example, as viewed from a combustion chamber; and Fig. 6 schematically illustrates a method for operating the gas turbine combustion device 3 to be described in the third example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An explanation will be given below with reference to the drawings regarding examples according to the present invention. Substantially the same or similar structures are denoted by the same codes, and repeated explanations thereof are thus omitted. First example

[0015] A conceptual explanation will be given with respect to the gas turbine power generation plant provided with a gas turbine combustor 3 (hereinafter referred to as combustor) according to a first example.

[0016] Fig. 1 conceptually illustrates the gas turbine power generation plant provided with the combustion device 3 according to the first example.

[0017] The gas turbine power generation plant (gas turbine power plant) provided with the combustion device 3 according to the first example includes a turbine 2, a compressor 1 connected to the turbine 2 for generating compressed air 5 for combustion, a plurality of gas turbine combustion devices 3, and a generator 4 connected to the turbine 2 for generating power in conjunction with driving the turbine 2. Fig. 1 shows a unit of the combustion device 3 for ease of explanation.

[0018] The compressed air 5 discharged from the compressor 1 is supplied to the combustion device 3 via a compressed air duct 6. In a combustion chamber 8, which is formed within a combustion liner 7 for the combustion device (hereinafter referred to as the combustion liner), combustion gas 9 is generated by burning the compressed air 5 and the fuel. The combustion gas 9 is supplied to the turbine 2 for driving via a transition piece 10.

[0019] The combustion device 3 includes a diffusion burner 20, a premix burner 30, the combustion liner 7, the transition piece 10, a housing 11 for the combustion device (hereinafter referred to as combustion housing), and an end cover 12. The diffusion burner 20 receives fuel supplied by a diffusion fuel supply system 21, and the premix burner 30 receives fuel supplied by a premix fuel supply system 31.

[0020] The diffusion burner 20 has a fuel jet hole 25 through which the diffusion fuel exits via a fuel channel (fuel nozzle) 22. The diffusion burner 20 is provided with a swirler 23 to impart a swirl component to the combustion air (compressed air 5). The diffusion burner 20 mixes the diffusion fuel with combustion air, to which the swirl component is imparted by the swirler 23, to generate a diffusion flame downstream of the diffusion burner 20.

[0021] The premix burner 30 enables a premixer 34 to premix the premix fuel exiting through a fuel channel (fuel nozzle) 32 with the combustion air (compressed air 5). A premix flame is generated by a mixture of the premix fuel and the compressed air 5 downstream of a flame stabilizer 35.

[0022] The combustion device 3 includes a guide vane 40 and a plurality of supports 41 in an annular channel 13 formed between the combustion liner 7, which forms the combustion chamber 8 for generating the combustion gas 9, and the combustion casing 11 surrounding the combustion liner 7 (located on the outer peripheral side of the combustion liner 7). The guide vane 40 is located on the outer peripheral side of the combustion liner 7 in the annular channel 13. The support 41 is attached to an inner side of the combustion casing 11 in the annular channel 13 to fix the guide vane 40.

[0023] The combustion device 3 has a pressure dynamic damping hole 42 in the combustion liner 7 at a position corresponding to the guide vane 40 for communication with the combustion chamber 8.

[0024] A main part of the combustion apparatus 3 according to the first example will be briefly described.

[0025] Fig. 2 is a schematic, partially enlarged sectional view of the main part of the combustion apparatus 3 according to the first example.

[0026] In the diffusion burner 20, diffusion fuel 24, flowing through the fuel passage (fuel nozzle) 22, exits through the fuel jet hole 25. The diffusion fuel 24 is mixed with combustion air 5a (compressed air 5), which is provided with the swirl component by the swirler 23, so that a diffusion flame is generated downstream of the diffusion burner 20. In other words, the diffusion burner 20 supplies the combustion air 5a and the diffusion fuel 24 into the combustion chamber 8.

[0027] The premix burner 30 enables the premixer 34 to mix the premix fuel 33 exiting through the fuel passage 32 with combustion air 5b (compressed air 5). The sufficiently mixed mixture of the premix fuel 33 and the compressed air 5b generates the premix flame downstream of the flame stabilizer 35. In other words, the premix burner 30 is arranged on an outer peripheral side of the diffusion burner 20 to supply the combustion air 5b and the premix fuel 33 into the combustion chamber 8.

[0028] Upon receiving heat energy from the diffusion flame, the premixed flame burns stably in combustion chamber 8 (suppressing the generation of the local high-temperature combustion zone during combustion). This makes it possible to suppress the amount of nitrogen oxides generated.

[0029] The combustion device 3 includes the guide vane 40 and the supports 41 in the annular channel 13 formed between the combustion liner 7 forming the combustion chamber 8 and the combustion casing 11 surrounding the combustion liner 7. The guide vane 40 is arranged in the annular channel 13 on the outer peripheral side of the combustion liner 7. The support 41 is attached to the inside of the combustion casing 11 in the annular channel 13 to fix the guide vane 40. The combustion device 3 further includes the pressure dynamic damping hole 42 in the combustion liner 7 at the position corresponding to the guide vane 40 (combustion liner 7 at the position corresponding to the part where the guide vane 40 is formed) for communication with the combustion chamber 8.

[0030] The guide vane 40 and the supports 41 are arranged in the annular channel 13 formed on an outer peripheral side of the combustion chamber 8. In particular, it is preferable to arrange the guide vane and the supports downstream (around an outer peripheral side of the flame stabilizer 35) in the flow direction of the compressed air 5 flowing through the annular channel 13.

[0031] The supports 41 are mounted circumferentially on the inside of the combustion casing 11, extending toward the center to fix the guide vane 40 to the combustion casing 11. For example, four supports 41 may be mounted circumferentially. Preferably, the support 41 has a streamlined cross-section to suppress turbulence in the compressed air 5.

[0032] The guide vane 40 is an annular member (formed by continuously enclosing the outer peripheral side of the combustion liner 7) attached to the support 41 in the annular channel 13 and having a predetermined width in the axial direction of the combustion liner 7. In other words, the guide vane 40 is arranged between the inner peripheral side of the combustion casing 11 and the outer peripheral side of the combustion liner 7 (annular channel 13) and fixed to the combustion casing 11 via the support 41. The guide vane 40 is arranged substantially parallel to the combustion liner 7 in the radial direction of the annular channel 13.In other words, the guide vane 40 is arranged in the annular channel 13 formed between the combustion liner 7 and the combustion casing 11, at a position around the outer peripheral side of the flame stabilizer 35 (downstream in the flow direction of the compressed air 5 flowing through the annular channel 13).

[0033] The pressure dynamic damping hole 42 is formed in the combustion liner 7 at a position corresponding to a part where the guide vane 40 is arranged (the combustion liner 7 faces the guide vane 40 in the radial direction, in other words, at the position corresponding to the guide vane 40) for communication between the combustion chamber 8 and the annular channel 13.

[0034] A plurality of pressure dynamic damping holes 42 are formed in the circumferential row of the combustion liner 7. The circumferential rows are arranged in the axial direction. Each interval between the pressure dynamic damping holes 42 in the circumferential direction can be set to a fixed value or an irregular value. Preferably, the pressure dynamic damping holes 42 in one of the rows are formed at predetermined intervals, and those in the next row are formed in a zigzag arrangement.

[0035] Namely, the combustion device 3 according to the first example includes the combustion liner 7 forming the combustion chamber 8 for generating the combustion gas 9, the combustion casing 11 enclosing the combustion liner 7 on its outer peripheral side, burners (diffusion burner 20 for supplying the combustion air 5a and the diffusion fuel 24 into the combustion chamber 8 and premix burner 30 arranged on an outer peripheral side of the diffusion burner 20 for supplying the combustion air 5b and the premix fuel 33 into the combustion chamber 8) for supplying the combustion air flowing through the annular channel 13 formed between the combustion liner 7 and the combustion casing 11 and the fuel (the diffusion fuel 24 and the premix fuel 33) supplied from the fuel supply system (the diffusion fuel supply system 21 and the premix fuel supply system 31).

[0036] The combustion device 3 includes the guide vane 40, the supports 41, and the pressure dynamic damping hole 42. The guide vane 40 is arranged in the annular channel 13 formed between the combustion liner 7 and the combustion casing 11 (the outer peripheral side of the combustion liner 7 and the inner peripheral side of the combustion casing 11), downstream in the flow direction of the compressed air 5 flowing through the annular channel 13. The supports 41 are arranged on the inside of the combustion casing 11 to fix the guide vanes 40. The pressure dynamic damping hole 42 is formed in the combustion liner 7 at the position corresponding to the part where the guide vane 40 is formed, for communication with the combustion chamber 8.

[0037] The combustion device 3, with its relatively simple structure, dampens pressure fluctuations due to combustion vibrations while ensuring mechanical reliability. The guide vanes 40 and supports 41 allow the compressed air 5 flowing through the annular channel 13 to flow smoothly while suppressing pressure loss.

[0038] Preferably, the position where the pressure dynamic damping hole 42 is formed (the position where the guide vane 40 is arranged) corresponds to the position as the base point where the flame stabilizer 35 begins to generate the premixed flame. This allows the compressed air 5 to be introduced through the pressure dynamic damping hole 42 into the base point of the premixed flame.

[0039] In particular, when the pressure dynamic damping holes 42 are irregularly formed in the circumferential direction, the characteristics of the premixed flame (flame shape and flame temperature) can be made uneven in the circumferential direction of the annular premixed flame. This makes it possible to suppress the increase in the amplitude value of the combustion oscillations.

[0040] The pressure wave generated by the combustion vibrations in the combustion chamber 8 propagates into the annular channel 13 through the pressure dynamic damping hole 42 formed in the combustion liner 7 and is reflected by the guide vane 40. In other words, the pressure wave propagating into the annular channel 13 is reflected by the guide vane 40 and then damped to suppress an increase in the amplitude of the combustion vibrations. The pressure wave is damped as a result of the damping of the energy of the combustion vibrations.

[0041] It is preferable to design a gap g1 between the outer periphery (outer peripheral surface) of the combustion liner 7 and the inner periphery (inner peripheral surface) of the guide vane 40 based on the frequency of the pressure wave generated by the combustion vibrations. It is preferable to design the gap g1 taking into account the phase of the pressure wave propagating into the annular channel 13 and the phase of the reflected wave reflected by the guide vane 40. This makes it possible to attenuate the pressure wave propagating into the annular channel 13 and suppress the increase in the amplitude value of the combustion vibrations.

[0042] Since the frequency of the damping pressure wave varies under the combustion conditions (load of the turbine 2, ie, fuel flow rate, flow rate of the compressed air 5), it is preferable to use the frequency of the pressure wave generated under the combustion conditions at the rated load of the turbine 2, assuming a long operating time.

[0043] The combustion apparatus according to the first example keeps the amount of nitrogen oxides generated low to maintain the stable combustion state (stable flame burning) and suppresses the combustion oscillations that cause the pressure in the combustion chamber 8 to fluctuate periodically (keeping the amplitude value of the combustion oscillations at a predetermined level or lower).

[0044] The combustion device according to the first example has a relatively simple structure and is capable of suppressing an increase in the amplitude value of combustion vibrations generated during combustion. The combustion device ensures the mechanical reliability of the element (guide vane 40) that dampens pressure fluctuations due to combustion vibrations. Second example

[0045] A main part of the combustion apparatus 3 according to a second example will be briefly described.

[0046] Fig. 3 is a schematic, partially enlarged sectional view of the main part of the combustion apparatus 3 according to the second example.

[0047] The combustion device 3 according to the second example differs from the combustion device 3 according to the first example by using a flow sleeve 50 instead of the supports 41 and the guide vane 40.

[0048] The flow sleeve 50 is an annular element arranged in the annular channel 13 substantially parallel to the combustion liner 7 in the radial direction of the annular channel 13 to narrow its cross-sectional area through which the compressed air 5 flows.

[0049] The flow sleeve 50 is arranged such that it expands toward the outer peripheral side downstream in the flow direction of the compressed air 5 flowing through the annular channel 13 (around the outer peripheral side of the flame stabilizer 35). The flow sleeve 50 is fixed to the inner peripheral side of the combustion housing 11.

[0050] The flow sleeve 50 has a part that extends substantially parallel to the combustion liner 7 and the other part that extends toward the outer periphery.

[0051] The flow sleeve 50 reflects the pressure wave, which propagates into an annular channel 130 (narrowed annular channel 13) via the pressure dynamic damping hole 42 formed in the combustion liner 7. The pressure dynamic damping hole 42 is formed in the combustion liner 7 substantially parallel thereto at the position corresponding to the flow sleeve 50.

[0052] Specifically, the combustion device 3 according to the second example includes the combustion liner 7 constituting the combustion chamber 8 for generating the combustion gas 9, the combustion casing 11 disposed on the outer peripheral side of the combustion liner 7, and the burners (the diffusion burner 20 and the premix burner 30) for supplying the compressed air 5 flowing between the combustion liner 7 and the combustion casing 11 and the fuel (the diffusion fuel 24 and the premix fuel 33) supplied from the fuel supply system (the diffusion fuel supply system 21 and the premix fuel supply system 31).

[0053] The combustion device 3 includes the flow sleeve 50 arranged on the outer peripheral side of the combustion liner 7, and the pressure dynamic damping hole 42 formed in the combustion liner 7 at the position corresponding to the flow sleeve 50 for communication with the combustion chamber 8.

[0054] The pressure wave generated by the combustion vibrations in the combustion chamber 8 propagates into the annular channel 130 through the pressure dynamic damping hole 42 formed in the combustion liner 7 and is reflected by the flow sleeve 50. The pressure wave propagating into the annular channel 130 is reflected by the flow sleeve 50 and then damped, thus suppressing an increase in the amplitude of the combustion vibrations. The flow sleeve 50 dampens the pressure fluctuations due to the combustion vibrations and improves the cooling effect of the combustion liner 7, the flow velocity of the compressed air 5, and the rectification effect of the compressed air 5.

[0055] When the flow sleeve 50 is provided in the combustion device 3, the gap g1 between the outer periphery (outer peripheral surface) of the combustion liner 7 and the inner periphery (inner peripheral surface) of the flow sleeve 50 is designed based on the frequency of the pressure wave generated by the combustion vibrations. In other words, the gap g1 is adjusted according to the combustion device 3 by adjusting the cross-sectional area of ​​the annular channel 13. The flow sleeve 50 is designed taking into account the predetermined performance of the combustion device 3 (cooling of the combustion liner 7), the flow velocity, and the rectification of the compressed air 5.

[0056] As described above, the gap g1 is designed based on the frequency of the pressure wave generated by the combustion vibrations and the predetermined performance of the combustion device 3.

[0057] Preferably, the position where the pressure dynamic damping hole 42 is formed corresponds to the position as the base point where the flame stabilizer 35 begins to generate the premixed flame. This allows the compressed air 5 to be introduced through the pressure dynamic damping hole 42 into the position as the base point of the premixed flame.

[0058] In particular, if the pressure dynamic damping holes 42 are irregularly formed in the circumferential direction, the premixed flame characteristics may become uneven in the circumferential direction of the annular premixed flame. Making the premixed flame characteristics uneven in the circumferential direction can suppress an increase in the amplitude value of combustion oscillations.

[0059] The pressure dynamic damping holes 42 are formed downstream (around the outer periphery of the flame stabilizer 35) in the flow direction of the compressed air 5 flowing through the annular channel 13, for communication between the combustion chamber 8 and the annular channel 13. The pressure dynamic damping holes 42 are arranged in a row in the circumferential direction of the combustion liner 7. Multiple rows (two rows in the second example) in the circumferential direction are arranged in the axial direction. The pressure dynamic damping holes 42, either in a single row or in three or more rows, can suppress an increase in the amplitude value of combustion vibrations.

[0060] When the pressure damping holes 42 are formed in multiple rows in the axial direction, the flow rate of the compressed air 5 to be introduced into the combustion chamber 8 through the pressure damping holes 42 is increased. As a result, the effect of suppressing the increase in the amplitude value of combustion vibrations is enhanced. However, the flow rate of the combustion air is reduced to increase the amount of nitrogen oxides generated. The pressure damping holes 42 are designed taking into account the balance between the flow rate of the compressed air 5 introduced into the combustion chamber 8 through the pressure damping holes 42 and the flow rate of the combustion air.

[0061] Preferably, the combustion device 3 includes a rib 51 comprising an annular element disposed on the outer peripheral side of the combustion liner 7 downstream of the pressure dynamic damping holes 42 (downstream in the flow direction of the compressed air 5 flowing through the annular channel 13). The rib 51 is capable of adjusting the flow velocity of the compressed air 5 flowing through an annular channel 130 formed between the outer periphery of the combustion liner 7 and the inner periphery of the flow sleeve 50 according to the specification (size, configuration) and mounting position.

[0062] The pressure wave generated by the combustion vibrations in the combustion chamber 8 propagates through the pressure dynamic damping holes 42 into the annular channel 130 and is reflected by the flow sleeve 50. The flow velocity of the compressed air 5 flowing through the annular channel 130 can impair the pressure wave damping capacity. The rib 51 serves to adjust the flow velocity of the compressed air 5 flowing through the annular channel 130 in order to maintain the pressure wave damping capacity.

[0063] In the second example, the rib 51 is attached to the outer periphery of the combustion liner 7 downstream of the pressure dynamic damping holes 42. The rib 51 can also be attached to the outer periphery of the combustion liner 7 upstream of the pressure dynamic damping holes 42. Alternatively, each of the ribs 51 can be attached to the outer periphery of the combustion liner 7 upstream or downstream of the pressure dynamic damping holes 42. In each of the cases described above, the rib can adjust the flow velocity of the compressed air 5 flowing through the annular channel 130.

[0064] The rib 51 may be formed in the combustion device 3 according to the first example. The rib 51 does not necessarily have to be formed in the combustion device 3 according to the second example.

[0065] The combustion device according to the second example suppresses the amount of nitrogen oxides generated to maintain the stable combustion state (stable flame burning) and ensures that the combustion oscillations that cause the pressure in the combustion chamber 8 to fluctuate periodically are suppressed (keeping the amplitude value of the combustion oscillations at a uniform level or lower).

[0066] The combustion device according to the second example has a relatively simple structure and is capable of suppressing an increase in the amplitude value of combustion vibrations during combustion. The combustion device ensures the mechanical reliability of the element (the flow sleeve 50) for damping pressure fluctuations due to combustion vibrations. Third example

[0067] A main part of the combustion apparatus 3 according to a third example will be briefly described.

[0068] Fig. 4 is a schematic, partially enlarged sectional view of the main part of the combustion apparatus 3 according to the third example.

[0069] The combustion device 3 according to the third examples differs from the combustion device 3 according to the first example in the state in which the supports 41 and the guide vane 40 are arranged in the circumferential direction.

[0070] The combustion device 3 according to the first example is configured to adjust the uniform gap g1 between the outer periphery (outer peripheral surface) of the combustion liner 7 and the inner periphery (inner peripheral surface) of the guide vane 40 in the circumferential direction. Meanwhile, the combustion device 3 according to the third example is configured to adjust the uneven gap between the outer periphery (outer peripheral surface) of the combustion liner 7 and the inner periphery (circumferential surface) of the guide vane 40 in the circumferential direction.

[0071] Specifically, in the third example, the gap between the outer periphery of the combustion liner 7 and the inner periphery of the guide vane 40 is made variable in the circumferential direction of the combustion liner 7. At a position A of the combustion liner 7 in the circumferential direction, the distance between the outer peripheral surface of the combustion liner 7 and the inner peripheral surface of a guide vane 40a is set to the gap g1. At a position B of the combustion liner 7 in the circumferential direction, the distance between the outer peripheral surface of the combustion liner 7 and the inner peripheral surface of a guide vane 40d is set to a gap g2.

[0072] In the third example, the gap formed between the outer peripheral surface of the combustion liner 7 and the inner peripheral surface of the guide vane 40 becomes different in the circumferential direction of the combustion liner 7.

[0073] An explanation will be given with respect to the combustion device 3 according to the third examples when viewed from the combustion chamber.

[0074] Fig. 5 is a schematic view of the gas turbine combustion apparatus 3 according to the third example as viewed from the combustion chamber.

[0075] In the combustion device 3 according to the third example, the premix burner 30 is divided by four premix burner partitions 36a, 36b, 36c, and 36d. The premixer 34 is divided into four premixers 34a, 34b, 34c, and 34d. The premix fuel supply system 31 for supplying the premix fuel to the premix burner 30 is correspondingly divided into four premix fuel supply systems 31a, 31b, 31c, and 31d. Each of the premix fuel supply systems supplies the premix fuel individually to the premixers 34a, 34b, 34c, and 34d.

[0076] Four supports 41a, 41b, 41c, and 41d are arranged at positions corresponding to the four pre-mixers 34a, 34b, 34c, and 34d, respectively, at the centers of each of the pre-mixers on the outer peripheral side. The four supports 41a, 41b, 41c, and 41d extend from the inside of the combustion casing 11 toward the center and are arranged at equal intervals along the circumference of the combustion casing 11.

[0077] The guide vanes 40a, 40b, 40c, and 40d are fixed to the four supports 41a, 41b, 41c, and 41d, respectively. Specifically, the guide vane 40b extends between the supports 41a and 41b, the guide vane 40c extends between the supports 41b and 41c, the guide vane 40d extends between the supports 41c and 41d, and the guide vane 40a extends between the supports 41d and 41a.

[0078] The gap between the outer periphery of the combustion liner 7 and the inner periphery of the guide vane 40a, and the gap between the outer periphery of the combustion liner 7 and the inner periphery of the guide vane 40c are each set to the gap g1. The gap between the outer periphery of the combustion liner 7 and the inner periphery of the guide vane 40b, and the gap between the outer periphery of the combustion liner 7 and the inner periphery of the guide vane 40d are each set to the gap g2.

[0079] The position A of the combustion lining 7 in the circumferential direction, as shown in Fig. 4 corresponds to position A as shown in Fig. 5. The position B of the combustion lining 7 in the circumferential direction, as shown in Fig. 4 corresponds to position B as shown in Fig. 5 is shown.

[0080] A cone 26 carries the diffusion burner 20 and has air holes 27 formed therein.

[0081] In the combustion device 3 according to the third example, two types of gaps (g1 and g2) can be formed. This makes it possible to suppress an increase in the amplitude value of the combustion vibrations to respective frequencies of two types of pressure waves generated by the combustion vibrations. In other words, two types of phases (phase of the wave reflected by the guide vane 40) can be considered to cancel the phases of the two types of pressure waves.

[0082] An explanation will be given regarding a method of operating the gas turbine combustion apparatus 3 according to the third example.

[0083] Fig. 6 schematically shows the method of operating the gas turbine combustion device 3 according to the third example, where an x-axis represents the load of the turbine 2 and a y-axis represents the flow rate of the fuel supplied to each burner (the diffusion burner 20 and the premix burner 30).

[0084] The flow rate of fuel to the diffusion burner 20 is designated as fuel F-21. The premix fuel supplied to the premixer 34a is designated as fuel F-34a. The premix fuel supplied to the premixer 34b is designated as fuel F-34b. The premix fuel supplied to the premixer 34c is designated as fuel F-34c. The premix fuel supplied to the premixer 34d is designated as fuel F-34d. Point a denotes an idle condition at a rated speed, and point f denotes a rated load.

[0085] In a load range from point a to point b, the fuel F-21 is supplied to the diffusion burner 20.

[0086] When the load reaches point b, the supply of fuel F-21 is reduced and fuel F-34a is supplied to the premixer 34a to start the premix combustion.

[0087] When the load is increased, the respective supply of fuel F-21 and F-34a is increased in the load range from point b to point c.

[0088] When the load reaches point c, the respective supply of fuel F-21 and F-34a is reduced and fuel F-34b is supplied to premixer 34b.

[0089] When the load is increased, the respective supply of fuel F-21, F-34a and F-34b is increased in the load range from point c to point d.

[0090] When the load reaches point d, the respective supply of fuel F-21, F-34a and F-34b is reduced and fuel F-34d is supplied to the premixer 34d.

[0091] When the load is increased, the respective supply of fuel F-21, F-34a, F-34b and F-34d is increased in the load range from point d to point e.

[0092] When the load reaches point e, the respective supply of fuel F-21, F-34a, F-34b and F-34d is reduced and fuel F-34c is supplied to the premixer 34c.

[0093] When the load is increased, full burner combustion is started in the load range from point e to point f.

[0094] Under the load at point f (rated load), the supply of fuel F-21 to the diffusion burner 20 is reduced to suppress the amount of nitrogen oxides generated. Then, the respective proportion of premixed fuel (F-34a, F-34b, F-34c, and F-34d) supplied to the premixers 34a, 34b, 34c, and 34d to the F-21 is increased.

[0095] With reference to Fig. 6, the combustion device 3 reaches the rated load under different combustion conditions. In the process of increasing the load of the turbine 2, it is preferable to suppress an increase in the amplitude value of the combustion vibrations at frequencies of the pressure waves generated by the combustion vibrations. In the third example, the combustion device is capable of suppressing an increase in the amplitude value of the combustion vibrations at a respective frequency of two types of pressure waves generated by the combustion vibrations. In other words, respective combustion vibrations at two different frequencies can be suppressed.

[0096] Preferably, the gap is formed according to the frequency (frequency of combustion vibrations occurring at the rated load) of the pressure wave under the combustion conditions at the rated load of the turbine 2. Even at the rated load, combustion vibrations may occur at multiple frequencies in response to changes in fuel properties, fuel conditions, and fuel calorific values. Even in the case where combustion vibrations are generated at different frequencies, the combustion device according to the third example ensures that the combustion vibrations are suppressed.

[0097] Like it Fig. As shown in Figure 5, in the third example, the support 41a is disposed at the outer peripheral center of the pre-mixer 34a. The guide vane 40a is attached to the support 41a on the side of the pre-mixer 34d, and the guide vane 40b is attached to the support 41a on the side of the pre-mixer 34b.

[0098] Specifically, in the circumferential direction of the premixer 34a, the gap between the outer peripheral surface of the combustion liner 7 and the inner peripheral surface of the guide vane 40 on one side of the support 41a is different from the gap on the other side of the support 41a. This structure changes the flow phase of the combustion air introduced into the premixer 34a along its circumferential direction.

[0099] The premixed flame characteristics can be made non-uniform in the circumferential direction of the annular premixed flame. The non-uniform premixed flame characteristics can suppress an increase in the amplitude value of combustion oscillations.

[0100] Preferably, the combustion device 3 according to the third example includes the ribs 51 arranged upstream and downstream of the pressure dynamic damping holes 42, respectively. This makes it possible to maintain the pressure wave damping capability.

[0101] The combustion device according to the third example is capable of suppressing the amount of nitrogen oxides generated, maintaining the stable combustion state (stable flame combustion), and suppressing the combustion oscillations that cause the pressure in the combustion chamber 8 to fluctuate periodically (keeping the amplitude value of the combustion oscillations at a predetermined level or lower).

[0102] The combustion device according to the third example has a relatively simple structure and is capable of suppressing an increase in the amplitude value of the combustion vibrations generated during combustion, thereby ensuring the mechanical reliability of the element (the guide vane 40) for damping the pressure fluctuations due to the combustion vibration.

[0103] The operating procedure as it is in Fig.6 can be applied to the first and second examples.

[0104] The present invention is not limited to the examples described above, but includes various modifications. In particular, the examples have been described in detail for easier understanding of the present invention. The present invention is not necessarily limited to the one provided with all the structures as described above. It is possible to partially replace a structure of one of the examples with a structure of another example, or to partially add the structure of one of the examples to the structure of another example. It is also possible to add, remove, and replace part of the structure of one of the examples with part of the structure of another example. LIST OF REFERENCE SYMBOLS 1 compressor, 2 turbines, 3 combustion device, 4 generators, 5 compressed air, 6 compressed air duct, 7 combustion lining, 8 combustion chamber, 9 combustion gas, 10 transition piece, 11 combustion casing, 12 end cover, 13 Annular canal, 20 diffusion burners, 21 Diffusion fuel supply system, 22 fuel nozzle, 23 swirlers, 24 Diffusion fuel 25 fuel jet hole, 26 pins, 27 air hole, 30 premix burners, 31 Premixed fuel supply system, 32 fuel nozzle, 33 Premix fuel, 34 premixers, 35 Flame stabilizer, 36 premix burner separating element, 40 guide vanes, 41 carriers, 42 pressure dynamic damping hole, 50 flow sleeve, 51 rib

Claims

[1] A gas turbine combustion device (3) comprising a combustion liner (7) forming a combustion chamber (8) for generating combustion gas (9), a combustion casing (11) arranged on an outer peripheral side of the combustion liner (7), and a burner (20, 30) for supplying air flowing between the combustion liner (7) and the combustion casing (11) and fuel to be supplied from a fuel supply system (21, 31) into the combustion chamber (8), the gas turbine combustion device (3) characterized by is that it includes the following: a guide vane (40) arranged in an annular channel (13) between the outer peripheral side of the combustion liner (7) and an inner peripheral side of the combustion casing (11), the guide vane (40) having a predetermined width in the axial direction of the combustion liner (7); a plurality of supports (41) arranged on an inner side of the combustion casing (11) in the circumferential direction and extending toward a center of the combustion chamber (8) to fix the guide vane (40); and a pressure dynamic damping hole (42) formed in the combustion liner (7) at a position corresponding to the guide vane (40) for communication with the combustion chamber (8) and the annular channel (13), wherein a pressure wave generated by combustion vibrations in the combustion chamber (8) and propagating into the annular channel (13) is reflected by the guide vane (40) and then damped to suppress an increase in an amplitude value of the combustion vibrations. [2] Gas turbine combustion device (3) according to claim 1, wherein the support (41) has a streamlined cross-section. [3] The gas turbine combustion device (3) according to claim 1, wherein gaps formed between the outer peripheral surface of the combustion liner (7) and the inner peripheral surface of the guide vane (40) are made different from each other in a circumferential direction of the combustion liner (7). [4] The gas turbine combustion device (3) according to claim 1, wherein a gap formed between the outer peripheral surface of the combustion liner (7) and the inner peripheral surface of the guide vane (40) on one side of the support (41) is different from a gap formed between the outer peripheral surface of the combustion liner (7) and the inner peripheral surface of the guide vane (40) on the other side of the support (41). [5] A gas turbine combustion device (3) according to claim 4, wherein four pieces of the supports (41) are arranged at equal intervals on the inside of the combustion casing (11). [6] A gas turbine combustion device (3) comprising a combustion liner (7) forming a combustion chamber (8) for generating combustion gas (9), a combustion casing (11) arranged on an outer peripheral side of the combustion liner (7), and a burner (20, 30) for supplying air flowing between the combustion liner (7) and the combustion shell and fuel to be supplied from a fuel supply system (21, 31) into the combustion chamber (8), the gas turbine combustion device (3) characterized by is that it includes the following: a flow sleeve (50) formed as an annular element, which is arranged in an annular channel (13) parallel to the combustion lining (7) in order to narrow a cross-sectional area of the flow sleeve (50) through which a compressed air flows; and a pressure dynamic damping hole (42) formed in the combustion liner (7) at a position corresponding to the flow sleeve (50) for communication with the combustion chamber (8) and the annular channel (13), wherein a pressure wave generated by combustion vibrations in the combustion chamber (8) is reflected by the flow sleeve (50) and then damped to suppress an increase in an amplitude value of the combustion vibrations. [7] The gas turbine combustion device (3) according to claim 6, further comprising a rib (51) formed as an annular member on the outer peripheral side of the combustion liner (7) downstream of the pressure dynamic damping hole (42).

Images