Combustor and gas turbine

Abstract

This combustor is for a gas turbine and comprises: an inner cylinder provided so as to surround a fuel nozzle; an outer cylinder provided on the outer side in the radial direction of the combustor with respect to the inner cylinder; and a porous plate section that is provided in an air passage formed between the inner cylinder and the outer cylinder and serves to rectify the air flow in the air passage. The porous plate section includes a rotor-side region and a vehicle interior-side region that is positioned outside of the rotor-side region in the radial direction of the rotor of the gas turbine and in which the porous plate section has an actual opening ratio or an effective opening ratio smaller than that of the rotor-side region. The actual opening ratio is the ratio of the area of the pores in the porous plate section to the area of the air passage. The effective opening ratio is the ratio of the product of the area of the pores in the porous plate section and the flow coefficient of the porous plate section to the area of the air passage.

Description

Combustors and Gas Turbines

[0001] This application claims priority to Japanese Patent Application No. 2024-009668, filed with the Japan Patent Office on January 25, 2024, the contents of which are incorporated herein by reference.

[0002] A combustor of a gas turbine may be provided with a mechanism for rectifying the flow of air flowing into the combustor.

[0003] Patent Document 1 describes a combustor that includes an inner cylinder that is arranged to surround a fuel nozzle and an outer cylinder that is arranged radially outward of the combustor relative to the inner cylinder, and in which a perforated plate (flow straightening plate) is provided as an air flow rate adjustment means in a compressed air flow path formed between the inner cylinder and the outer cylinder.

[0004] JP 2009-192175 A

[0005] In the air passage formed between the inner and outer cylinders of the combustor, if the airflow rate becomes uneven in the circumferential direction of the combustor due to the influence of the shape of the upstream side of the combustor, it is thought that this could be a factor in increasing the amount of nitrogen oxides (NOx) generated and causing combustion oscillations. Although it is thought that the unevenness in the airflow rate in the circumferential direction of the combustor can be suppressed by reducing the diameter of the holes provided in the straightening vanes, in this case, the pressure loss in the straightening vanes increases, which may degrade the performance of the gas turbine.

[0006] In view of the above circumstances, at least one embodiment of the present invention has an object to provide a combustor and a gas turbine that are capable of suppressing bias in the air flow rate in the circumferential direction of the combustor while suppressing an increase in pressure loss.

[0007] A combustor according to at least one embodiment of the present invention is a combustor for a gas turbine, the combustor comprising: an inner cylinder provided to surround a fuel nozzle; an outer cylinder provided radially outward of the combustor with respect to the inner cylinder; and a porous plate portion provided in an air passage formed between the inner cylinder and the outer cylinder for rectifying an air flow in the air passage, wherein the porous plate portion includes: a rotor-side region; and a casing-side region located radially outward of a rotor of the gas turbine than the rotor-side region and having an actual opening ratio or an effective opening ratio of the porous plate portion smaller than that of the rotor-side region, wherein the actual opening ratio is a ratio of an area of ​​holes in the porous plate portion to an area of ​​the air passage, and the effective opening ratio is a ratio of a product of an area of ​​holes in the porous plate portion and a flow coefficient of the porous plate portion to an area of ​​the air passage.

[0008] A combustor according to at least one embodiment of the present invention is a combustor for a gas turbine, comprising: an inner cylinder provided to surround a fuel nozzle; an outer cylinder provided radially outward of the combustor with respect to the inner cylinder; and a porous plate portion provided in an air passage formed between the inner cylinder and the outer cylinder and rectifying an air flow in the air passage, wherein the porous plate portion includes: a rotor-side region in which chamfered portions are formed at ends of holes provided in the porous plate portion; and a casing-side region located radially outward of the rotor of the gas turbine than the rotor-side region, in which chamfered portions are not formed at ends of holes provided in the porous plate portion.

[0009] Also, according to at least one embodiment of the present invention, there is provided a gas turbine comprising: the aforementioned combustor configured to combust fuel; and a turbine configured to be driven by combustion gases from the combustor.

[0010] According to at least one embodiment of the present invention, there is provided a combustor and a gas turbine that are capable of suppressing an increase in pressure loss while suppressing an imbalance in the air flow rate in the circumferential direction of the combustor.

[0011] FIG. 1 is a schematic configuration diagram of a gas turbine according to an embodiment; FIG. 2 is a schematic cross-sectional view of a combustor of the gas turbine shown in FIG. 1; FIG. 3 is a schematic cross-sectional view perpendicular to the axial direction of the combustor shown in FIG. 2; FIG. 4 is a schematic view of a segment including a porous plate portion according to an embodiment, viewed from the axial direction of the combustor; FIG. 5 is a schematic view of a segment including a porous plate portion according to an embodiment, viewed from the axial direction of the combustor; FIG. 6 is a schematic view of a segment including a porous plate portion according to an embodiment, viewed from the axial direction of the combustor; FIG. 7 is a schematic view of a segment including a porous plate portion according to an embodiment, viewed from the axial direction of the combustor;

[0012] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0013] (Configuration of Gas Turbine) Fig. 1 is a schematic configuration diagram of a gas turbine according to one embodiment. As shown in Fig. 1, the gas turbine 1 includes a compressor 2 for generating compressed air, a combustor 4 for generating combustion gas using the compressed air and fuel, and a turbine 6 configured to be rotationally driven by the combustion gas from the combustor 4. In the case of the gas turbine 1 for power generation, a generator (not shown) is connected to the turbine 6.

[0014] The compressor 2 includes a plurality of stator vanes 16 fixed to the compressor casing 10 side, and a plurality of moving blades 18 implanted in the rotor 8 so as to be arranged alternately with respect to the stator vanes 16. Air taken in from an air intake 12 is sent to the compressor 2, and this air is compressed as it passes through the plurality of stator vanes 16 and the plurality of moving blades 18, thereby becoming high-temperature, high-pressure compressed air.

[0015] The combustor 4 is supplied with fuel and compressed air generated by the compressor 2, and the fuel is combusted in the combustor 4 to generate combustion gas, which is a working fluid for the turbine 6. As shown in Fig. 1 , the gas turbine 1 has a combustor casing 20 and a plurality of combustors 4 arranged in the circumferential direction around a rotor 8 (rotor central axis O).

[0016] The turbine 6 has a combustion gas passage 28 formed by the turbine casing 22 and includes a plurality of stator vanes 24 and rotor blades 26 provided in the combustion gas passage 28. The stator vanes 24 and rotor blades 26 of the turbine 6 are provided downstream of the combustor 4 with respect to the flow of combustion gas. The stator vanes 24 are fixed to the turbine casing 22 side, and a plurality of the stator vanes 24 arranged along the circumferential direction of the rotor 8 constitute a stator vane row. The rotor blades 26 are implanted in the rotor 8, and a plurality of the rotor blades 26 arranged along the circumferential direction of the rotor 8 constitute a rotor blade row. The stator vane rows and rotor blade rows are arranged alternately in the axial direction of the rotor 8.

[0017] In the turbine 6, the combustion gas from the combustor 4 flows into a combustion gas passage 28 and passes through the plurality of stator vanes 24 and the plurality of rotor blades 26, thereby driving the rotor 8 to rotate, which in turn drives a generator connected to the rotor 8 to generate electricity. After driving the turbine 6, the combustion gas is discharged to the outside via an exhaust chamber 30.

[0018] Fig. 2 is a schematic cross-sectional view of the combustor 4 of the gas turbine 1 shown in Fig. 1. As shown in Fig. 2, each of the plurality of combustors 4 (see Fig. 1) arranged in the circumferential direction around the rotor 8 includes an inner cylinder 50 provided inside a combustor casing 20, a combustion cylinder 52 connected to the inner cylinder 50, a first combustion burner 38, and a plurality of second combustion burners 44 arranged to surround the first combustion burner 38.

[0019] The first combustion burner 38 is disposed so as to extend along the central axis Q of the inner cylinder 50, and has a first fuel nozzle 40 for injecting fuel and a first burner cylinder 41 disposed so as to surround the first fuel nozzle 40. Fuel is supplied to the first fuel nozzle 40 via a first fuel port 42.

[0020] The second combustion burner 44 has a second fuel nozzle 46 for injecting fuel and a second burner cylinder 47 arranged to surround the second fuel nozzle 46. Fuel is supplied to the second fuel nozzle 46 via the second fuel port 43.

[0021] The inner cylinder 50 is provided to surround the first combustion burner 38 including the first fuel nozzle 40 and the second combustion burner 44 including the second fuel nozzle 46 .

[0022] The combustor 4 further includes an outer casing 54 provided inside the combustor casing 20 on the outer circumferential side of the inner casing 50 (radially outward of the combustor 4). An annular air passage 56 through which compressed air flows is formed between the inner casing 50 and the outer casing 54 in the radial direction of the combustor 4. In this specification, the central axis of the combustor 4 refers to the central axis (central axis Q) of the inner casing 50. In addition, in this specification, the radial direction, circumferential direction, and axial direction of the combustor 4 are synonymous with the radial direction, circumferential direction, and axial direction of the inner casing 50, respectively.

[0023] Swirlers 45 and 49 are provided around the first fuel nozzle 40 and the second fuel nozzle 46, respectively, and compressed air from the compressor 2 (see FIG. 1) is supplied into the combustion liner 52 through the swirlers 45 and 49. In FIG. 2, arrows indicate compressed air flowing into the burners (first combustion burner 38 and second combustion burner 44) of the combustor 4 through an air passage 56.

[0024] In the combustor 4 configured as described above, a fuel-air mixture is formed in the combustion liner 52 by the fuel ejected from the first fuel nozzle 40 and the second fuel nozzle 46 and the compressed air supplied via the air passage 56 and the swirlers 45, 49. The mixture that flows into the combustion liner 52 is ignited by an ignition device (not shown) or a pilot flame and burns, thereby generating combustion gas. The combustion gas flows through the combustion liner 52 and is guided to the turbine 6 (see FIG. 1).

[0025] The first combustion burner 38 may be configured to form a pilot flame. That is, the first fuel nozzle 40 of the first combustion burner 38 may be a pilot nozzle for ejecting pilot fuel for forming the pilot flame.

[0026] FIG. 3 is a schematic cross-sectional view perpendicular to the axial direction (the direction of the central axis Q of the inner cylinder 50) of the combustor 4 shown in FIG.

[0027] 2 and 3 , the combustor 4 includes a perforated plate portion 60 that is provided in an air passage 56 formed between the inner cylinder 50 and the outer cylinder 54 in the radial direction of the combustor 4 and that rectifies the air flow in the air passage 56. The perforated plate portion 60 is provided with a plurality of holes 62, and these holes 62 rectify the flow of compressed air passing through the perforated plate portion 60.

[0028] As will be described in detail later, the porous plate portion 60 includes a rotor-side region R1 and a casing-side region R2 that is located radially outward of the rotor 8 of the gas turbine 1 relative to the rotor-side region R1 and has a smaller actual opening ratio or effective opening ratio of the porous plate portion 60 than the rotor-side region R1 (see FIG. 3 ). That is, the rotor-side region R1 is located radially inward of the rotor 8 of the gas turbine 1 (on the rotor 8 side) relative to the casing-side region R2. Alternatively, the casing-side region R2 is located radially outward of the rotor 8 of the gas turbine 1 (on the combustor casing 20 side) relative to the rotor-side region R1. Note that in FIG. 3 , a straight line L1 is a straight line in the radial direction of the rotor 8.

[0029] As a result of studies by the present inventors, it was found that in the annular air passage 56 (a passage of combustion air toward the combustor 4) formed between the inner casing 50 and the outer casing 54 of the combustor 4, the air flow velocity tends to be lower in a region radially inner of the rotor 8 of the gas turbine 1 than in a region radially outer of the rotor 8 of the gas turbine 1. According to the above-described configuration, the porous plate section 60 provided in the air passage 56 includes the rotor-side region R1 and the casing-side region R2 in which the actual opening ratio or effective opening ratio of the porous plate section 60 is smaller than that of the rotor-side region R1. Therefore, it is possible to suppress unevenness in the air flow rate in the circumferential direction of the combustor 4 while appropriately rectifying the air flow, without reducing the hole diameter of the porous plate section 60. In other words, it is possible to suppress unevenness in the air flow rate in the circumferential direction of the combustor 4 while suppressing an increase in pressure loss. Therefore, it is possible to rectify the combustion air while suppressing a deterioration in the performance of the gas turbine 1.

[0030] The porous plate portion 60 may be provided so as to extend along a plane perpendicular to the axial direction of the combustor 4. Each of the plurality of holes 62 provided in the porous plate portion 60 may be provided so that the central axis of the hole 62 is aligned with the axial direction of the combustor 4.

[0031] In some embodiments, the porous plate portion 60 may include a plurality of porous plates 61 that extend along the axial direction of the combustor 4 and are arranged along the circumferential direction of the combustor 4. Furthermore, the combustor 4 may include ribs 58 that extend along the radial direction of the combustor 4 and support the porous plates 61.

[0032] 2 and 3 , the porous plate section 60 includes eight porous plates 61 (61A to 61H) that extend along the axial direction of the combustor 4 and are arranged along the circumferential direction of the combustor 4. The porous plates 61A to 61H are respectively arranged in eight segments that are separated every 45 degrees in the circumferential direction of the combustor 4. The porous plates 61A to 61H are supported by a plurality of ribs 58 that extend along the radial direction of the combustor 4 between the inner cylinder 50 and the outer cylinder 54.

[0033] In some embodiments, the actual opening ratio is smaller in the cabin-side region R2 of the porous plate portion 60 than in the rotor-side region R1 of the porous plate portion 60. Here, the actual opening ratio is the ratio of the area of ​​the holes (flow path cross-sectional area) of the porous plate portion 60 to the area of ​​the air passage 56 (flow path cross-sectional area). For example, as shown in the figure, in an example in which the porous plate portion 60 is made up of eight porous plates 61 arranged in eight segments each at 45 degrees, the actual opening ratio Aa of the segment in which each porous plate 61 is arranged is expressed by the following formula (A), where Sa is the total area of ​​the air passage 56 (the area of ​​the entire circumference around the central axis Q of the combustor 4) and Sb is the total area of ​​the holes 62 in that segment (i.e., the total area of ​​the holes 62 in the porous plates 61). Aa = Sb / (Sa / 8) (A)

[0034] In some embodiments, the perforated plate portion 60 includes a rotor-side region R1 including segments with a relatively large actual opening ratio, and segments with a relatively small actual opening ratio (i.e., compared to the rotor-side region R1).

[0035] The actual opening ratio of the perforated plate portion 60 can be changed by changing the size (hole diameter), number, shape, etc. of the holes 62 of the perforated plate portion 60 .

[0036] 4 to 7 are schematic diagrams of a segment including a porous plate 61 (porous plate portion 60) according to one embodiment, viewed from the axial direction of the combustor 4. Note that, although Figs. 4 to 7 are schematic diagrams for illustrating a comparison of the actual opening ratio of the porous plate portion 60, the opening pattern of the holes 62 in the porous plate portion 60 is not limited thereto.

[0037] In each example shown in FIGS. 4 to 7 , the porous plate 61 is provided with the same number of holes 62 a (seven in the figures). In the examples shown in FIGS. 5 and 6 , the porous plate 61 is further provided with relatively small-diameter holes 62 b (holes in the radially central region of the combustor 4). Therefore, the actual aperture ratio of the porous plate portion 60 in the segment shown in FIGS. 5 and 6 is greater than the actual aperture ratio of the porous plate portion 60 in the segment shown in FIG. 4 . In the example shown in FIG. 6 , the porous plate 61 is further provided with relatively small-diameter holes 62 c (holes in the radially inner region of the combustor 4) and 62 d (holes in the radially outer region of the combustor 4). Therefore, the actual aperture ratio of the porous plate portion 60 in the segment shown in FIG. 6 is greater than the actual aperture ratio of the porous plate portion 60 in the segment shown in FIG. 5 . In the example shown in FIG. 7 , the elongated hole 62 e provided in the porous plate 61 has a shape in which two of the small-diameter holes 62 b shown in FIG. 5 are connected. That is, the area of ​​the elongated hole 62e in Fig. 7 is larger than the total area of ​​the two holes 62b in Fig. 5. Therefore, the actual opening rate of the porous plate portion 60 in the segment shown in Fig. 7 is larger than the actual opening rate of the porous plate portion 60 in the segments shown in Figs.

[0038] In the exemplary embodiment shown in Figure 3, the rotor-side region R1 of the porous plate section 60 includes first porous plates 64 (porous plates 61D to 61F) having a relatively large actual opening rate, and the casing-side region R2 of the porous plate section 60 includes second porous plates 66 (porous plates 61A, 61B, and 61H) having a smaller actual opening rate than the first porous plate 64. Note that in the exemplary embodiment shown in Figure 3, the porous plate section 60 includes a third porous plate 68 (porous plate 61G) that is provided between the first porous plate 64 (rotor-side region R1) and the second porous plate 66 (casing-side region R2) in the circumferential direction of the combustor 4 and has an actual opening rate smaller than that of the first porous plate 64 and larger than that of the second porous plate 66. In the exemplary embodiment shown in FIG. 3 , the porous plate portion 60 is provided between the first porous plate 64 (rotor side region R1) and the second porous plate 66 (cabin side region R2) in the circumferential direction of the combustor 4, and includes a porous plate 61C having an actual opening rate equivalent to that of the first porous plate 64.

[0039] In some embodiments, the actual opening ratio of the perforated plate portion 60 in the rotor side region R1 is 75% or less, and the actual opening ratio of the perforated plate portion 60 in the cabin side region R2 is 55% or more.

[0040] In the above-described configuration, the actual opening ratio of the porous plate portion 60 in the rotor-side region R1 is 75% or less, so that the air flow toward the combustor 4 can be appropriately rectified in the rotor-side region R1 where the actual opening ratio of the porous plate portion 60 is relatively large. Furthermore, the actual opening ratio of the porous plate portion 60 in the cabin-side region R2 is 55% or more, so that an increase in pressure loss in the porous plate portion 60 is suppressed in the cabin-side region R2 where the actual opening ratio of the porous plate portion 60 is relatively small. Therefore, with the above-described configuration, it is possible to appropriately rectify the air flow toward the combustor 4 while suppressing an increase in pressure loss, and to suppress bias in the air flow rate in the circumferential direction of the combustor 4.

[0041] In some embodiments, the actual opening ratio of the perforated plate portion 60 in the rotor side region R1 may be greater than 65% and less than 75%, and the actual opening ratio of the perforated plate portion 60 in the cabin side region R2 may be greater than 55% and less than 65%.

[0042] In some embodiments, the difference between the actual opening rate of the porous plate portion 60 in the rotor-side region R1 and the actual opening rate of the porous plate portion 60 in the cabin-side region R2 may be 5% or more.

[0043] According to the above-described configuration, the actual opening ratio of the porous plate portion 60 provided in the air passage 56 of the combustor 4 is larger in the rotor-side region R1 by 5% or more than that in the casing-side region R2. This makes it easier to obtain the effect of suppressing an increase in pressure loss while suppressing bias in the air flow rate in the circumferential direction of the combustor 4.

[0044] In some embodiments, the effective opening ratio is smaller in the cabin-side region R2 of the porous plate portion 60 than in the rotor-side region R1 of the porous plate portion 60. Here, the effective opening ratio is the ratio of the product of the area of ​​the holes in the porous plate portion 60 (flow path cross-sectional area) and the flow coefficient (Cd value) of the porous plate portion 60 to the area of ​​the air passage 56 (flow path cross-sectional area). For example, as shown in the figure, in an example in which the porous plate portion 60 is made up of eight porous plates 61 arranged in eight segments each at 45 degrees, the effective opening ratio Ae of the segment in which each porous plate 61 is arranged is expressed by the following formula (B), where Sa is the total area of ​​the air passage 56 (the area of ​​the entire circumference around the central axis Q of the combustor 4), Sb is the total area of ​​the holes in that segment (i.e., the total area of ​​the holes in the porous plates 61), and Cd is the flow coefficient of that segment. Ae=(Sb×Cd) / (Sa / 8) (B) The product (Sb×Cd) of the total area Sb of the holes in a certain region (for example, a segment) and the flow coefficient Cd is called the effective hole area in that region.

[0045] The flow coefficient Cd is a correction coefficient used to express the actual flow velocity of a fluid, taking into account losses due to contraction and friction with respect to the theoretical flow velocity. If the theoretical flow velocity of a fluid is VL, the actual flow velocity is VA, and the flow coefficient is Cd, the relationship shown in equation (C) below holds: VA = Cd x VL ... (C) Furthermore, if the differential pressure between the upstream and downstream of the pressure loss body is ΔP, the density of the fluid is ρ, and the acceleration of gravity is g, the theoretical flow velocity (average) VL of the fluid can be expressed by equation (D) below.

[0046] For holes in a perforated plate or the like, even if the holes have the same diameter, the flow coefficient Cd may vary depending on the shape and properties of the hole. For example, even for holes of the same diameter, the smaller the ratio (L / D) of the hole diameter D to the axial length L, the larger the flow coefficient Cd; the smaller the surface roughness of the hole inner surface, the larger the flow coefficient Cd; the smoother the shape of the hole inlet or outlet (by providing a chamfer or bell mouth, for example), the larger the flow coefficient; and the more restrictor portions are present near the hole outlet or inlet, the smaller the flow coefficient Cd.

[0047] In some embodiments, the porous plate portion 60 includes a rotor side region R1 including segments with a relatively large effective opening rate, and a cabin side region R2 including segments with a relatively small effective opening rate (i.e., compared to the rotor side region R1).

[0048] The effective opening ratio of the perforated plate portion 60 basically increases or decreases in accordance with the increase or decrease in the actual opening ratio, and can be changed by the size (hole diameter), number, or shape of the holes 62 of the perforated plate portion 60. The effective opening ratio of the perforated plate portion 60 can also be changed, for example, by whether or not the inlets of the holes 62 are chamfered.

[0049] 8 and 9 are schematic cross-sectional views of a segment including a porous plate 61 (porous plate portion 60) according to one embodiment, taken along the axial direction of the combustor 4. Note that, although FIGS. 8 and 9 are schematic views for illustrating a comparison of the effective opening ratios of the porous plate portion 60, the shape of the holes 62 in the porous plate portion 60 is not limited thereto.

[0050] In the example shown in Figure 8, a chamfered portion 63 is formed at the end of the perforated plate 60 on the inlet side of the hole 62 (i.e., the upstream side in the air flow). The chamfered portion 63 is a tapered portion that increases in diameter toward the open end of the hole 62 (the end surface 61a of the perforated plate 60). In contrast, in the example shown in Figure 9, the perforated plate 60 does not have a chamfered portion 63 at the end of the perforated plate 60 on the inlet side of the hole 62 (i.e., the upstream side in the air flow). If the diameters of the holes 62 shown in Figures 8 and 9 are the same, the effective hole area when the perforated plate 60 has the chamfered portion 63 formed as shown in Figure 8 is larger than the effective hole area when the perforated plate 60 does not have the chamfered portion 63 formed as shown in Figure 9.

[0051] That is, in some embodiments, the porous plate portion 60 may include a rotor-side region R1 in which chamfered portions 63 are formed at the ends of the holes 62 provided in the porous plate portion 60, and a cabin-side region R2 in which no chamfered portions are formed at the ends of the holes 62 provided in the porous plate portion 60. In this case, the effective opening ratio of the porous plate portion 60 in the cabin-side region R2 is smaller than the effective opening ratio of the porous plate portion 60 in the rotor-side region R1.

[0052] For example, in one embodiment, the rotor side region R1 of the perforated plate portion 60 may include a perforated plate 61 having a chamfered portion 63 at the hole 62, and the cabin side region R2 of the perforated plate portion 60 may include a perforated plate 61 having no chamfered portion 63 at the hole 62.

[0053] In some embodiments, the effective opening ratio of the perforated plate portion 60 in the rotor side region R1 is 115% or less, and the effective opening ratio of the perforated plate portion 60 in the cabin side region R2 is 75% or more.

[0054] In the above-described configuration, since the effective opening ratio of the porous plate portion 60 in the rotor-side region R1 is 115% or less, the air flow toward the combustor 4 can be appropriately rectified in the rotor-side region R1, where the effective opening ratio of the porous plate portion 60 is relatively large. Furthermore, since the effective opening ratio of the porous plate portion 60 in the casing-side region R2 is 75% or more, an increase in pressure loss in the porous plate portion 60 is suppressed in the casing-side region R2, where the effective opening ratio of the porous plate portion 60 is relatively small. Therefore, with the above-described configuration, it is possible to appropriately rectify the air flow toward the combustor 4 while suppressing an increase in pressure loss, and to suppress bias in the air flow rate in the circumferential direction of the combustor 4.

[0055] In some embodiments, the effective opening ratio of the perforated plate portion 60 in the rotor side region R1 may be greater than 95% and less than 115%, and the effective opening ratio of the perforated plate portion 60 in the cabin side region R2 may be greater than 75% and less than 95%.

[0056] In some embodiments, the difference between the effective opening ratio of the porous plate portion 60 in the rotor-side region R1 and the effective opening ratio of the porous plate portion 60 in the cabin-side region R2 may be 10% or more.

[0057] According to the above-described configuration, the effective opening ratio of the porous plate portion 60 provided in the air passage 56 of the combustor 4 is greater in the rotor-side region R1 by 10% or more than that in the casing-side region R2. This makes it easier to obtain the effect of suppressing an increase in pressure loss while suppressing bias in the air flow rate in the circumferential direction of the combustor 4.

[0058] 3, the first perforated plate 64 (perforated plates 61D, 61E, 61F) may have the chamfered portions 63 formed at the ends of the holes 62, and the second perforated plate 66 (perforated plates 61A, 61B, 61H) may not have the chamfered portions 63 formed at the ends of the holes 62. In this case, the effective opening ratio of the first perforated plate 64 can be increased compared to when the first perforated plate 64 does not have the chamfered portions 63, and the difference in the effective opening ratio between the first perforated plate 64 and the second perforated plate 66 can be increased.

[0059] In some embodiments, the porous plate portion 60 includes a plurality of porous plates 61, and the plurality of porous plates 61 may include at least one first porous plate (e.g., the first porous plate 64 described above) provided in the rotor side region R1 and at least one second porous plate (e.g., the second porous plate 66 described above) provided in the cabin side region R2 and having an actual opening rate or effective opening rate smaller than each of the at least one first porous plate.

[0060] According to the above-described configuration, the first porous plate and the second porous plate having different actual opening ratios or effective opening ratios can be used to realize the porous plate portion 60. This makes it possible to suppress an increase in pressure loss while suppressing bias in the air flow rate in the circumferential direction of the combustor 4.

[0061] In some embodiments, the porous plate portion 60 may include, in addition to the at least one first porous plate and at least one second porous plate described above, a third porous plate (e.g., the third porous plate 68 described above) that is arranged circumferentially between the first porous plate and the second porous plate (or between the rotor side region R1 and the cabin side region R2) and has an actual opening rate or effective opening rate that is smaller than that of the first porous plate and larger than that of the second porous plate.

[0062] According to the above-described configuration, the porous plate section 60 includes the first porous plate and the second porous plate having different actual opening ratios or effective opening ratios, and the third porous plate having an actual opening ratio or effective opening ratio smaller than that of the first porous plate and larger than that of the second porous plate, so that it is possible to more finely adjust the air flow rate in the circumferential direction of the combustor 4. Therefore, it is possible to more effectively suppress bias in the air flow rate in the circumferential direction of the combustor 4 while suppressing an increase in pressure loss.

[0063] As shown in FIG. 3 , the third porous plate (third porous plate 68 in FIG. 3 ) may be disposed in a region including a position shifted by 90 degrees from the radial direction of the rotor 8 (straight line L1 in FIG. 3 ) around the central axis Q of the combustor 4.

[0064] In some embodiments, the rotor side region R1 and the casing side region R2 may each extend in the circumferential direction of the combustor 4 over an angular range of 45 degrees or more around the central axis Q of the combustor 4.

[0065] In some embodiments, the rotor-side region R1 and the casing-side region R2 may each extend in the circumferential direction of the combustor 4 over an angular range of 90 degrees or more around the central axis Q of the combustor 4. In some embodiments, the rotor-side region R1 and the casing-side region R2 may each extend in the circumferential direction of the combustor 4 over an angular range of 120 degrees or more around the central axis Q of the combustor 4.

[0066] According to the above-described embodiment, even when a region where the air flow velocity is relatively high or low exists over a wide range of 90 degrees or more or 120 degrees or more around the central axis of the combustor 4, by providing the porous plate portion 60 including the rotor-side region R1 and the casing-side region R2, it is possible to suppress an increase in pressure loss and to suppress bias in the air flow rate in the circumferential direction of the combustor.

[0067] The contents described in each of the above embodiments can be understood, for example, as follows.

[0068] [1] A combustor (4) according to at least one embodiment of the present invention is a combustor for a gas turbine (1), comprising: an inner cylinder (50) provided to surround fuel nozzles (e.g., a first fuel nozzle 40 and a second fuel nozzle 46); an outer cylinder (54) provided radially outward of the combustor with respect to the inner cylinder; and a perforated plate portion (60) provided in an air passage (56) formed between the inner cylinder and the outer cylinder, for rectifying an air flow in the air passage, wherein the perforated plate portion includes: a rotor-side region (R1); and a casing-side region (R2) located radially outward of a rotor (8) of the gas turbine than the rotor-side region, the perforated plate portion having an actual opening ratio or an effective opening ratio smaller than that of the rotor-side region, wherein the actual opening ratio is a ratio of an area of ​​holes (62) in the perforated plate portion to an area of ​​the air passage, The effective opening ratio is the ratio of the product of the area of ​​the holes in the perforated plate portion and the flow coefficient of the perforated plate portion to the area of ​​the air passage.

[0069] As a result of investigations by the present inventors, it was found that in an annular air passage (a passage of combustion air toward the combustor) formed between the inner and outer cylinders of a combustor, the air flow velocity tends to be lower in a region radially inner of the gas turbine rotor than in a region radially outer of the gas turbine rotor. According to the configuration [1] above, the perforated plate portion provided in the air passage includes a rotor-side region and a casing-side region in which the actual opening ratio or effective opening ratio of the perforated plate portion is smaller than that of the rotor-side region. Therefore, it is possible to appropriately rectify the air flow and suppress unevenness in the air flow rate in the circumferential direction of the combustor without reducing the hole diameter of the perforated plate portion. In other words, it is possible to suppress unevenness in the air flow rate in the circumferential direction of the combustor while suppressing an increase in pressure loss. Therefore, it is possible to rectify the combustion air while suppressing a deterioration in the performance of the gas turbine 1.

[0070] [2] In some embodiments, in the configuration of [1] above, the actual opening ratio of the perforated plate portion in the rotor side region is 75% or less, and the actual opening ratio of the perforated plate portion in the cabin side region is 55% or more.

[0071] In the configuration [2], since the actual opening ratio of the perforated plate portion in the rotor-side region is 75% or less, the air flow toward the combustor can be appropriately rectified in the rotor-side region where the actual opening ratio of the perforated plate portion is relatively large. Furthermore, since the actual opening ratio of the perforated plate portion in the casing-side region is 55% or more, an increase in pressure loss in the perforated plate portion is suppressed in the casing-side region where the actual opening ratio of the perforated plate portion is relatively small. Therefore, according to the configuration [2], the air flow toward the combustor can be appropriately rectified while suppressing an increase in pressure loss, and an imbalance in the air flow rate in the circumferential direction of the combustor can be suppressed.

[0072] [3] In some embodiments, in the configuration of [1] or [2] above, the difference between the actual opening rate of the perforated plate portion in the rotor side region and the actual opening rate of the perforated plate portion in the cabin side region is 5% or more.

[0073] According to the configuration [3], the actual opening ratio of the porous plate section provided in the air passage of the combustor is 5% or more larger in the rotor side region than in the casing side region, which makes it easier to obtain the effect of suppressing an increase in pressure loss while suppressing bias in the air flow rate in the circumferential direction of the combustor.

[0074] [4] In some embodiments, in any of the configurations [1] to [3] above, the effective opening ratio of the perforated plate portion in the rotor side region is 115% or less, and the effective opening ratio of the perforated plate portion in the cabin side region is 75% or more.

[0075] In the configuration [4], since the effective opening ratio of the porous plate portion in the rotor-side region is 115% or less, the air flow toward the combustor can be appropriately rectified in the rotor-side region where the effective opening ratio of the porous plate portion is relatively large. Furthermore, since the effective opening ratio of the porous plate portion in the casing-side region is 75% or more, an increase in pressure loss in the porous plate portion is suppressed in the casing-side region where the effective opening ratio of the porous plate portion is relatively small. Therefore, according to the configuration [4], the air flow toward the combustor can be appropriately rectified while suppressing an increase in pressure loss, and an imbalance in the air flow rate in the circumferential direction of the combustor can be suppressed.

[0076] [5] In some embodiments, in any of the configurations [1] to [4] above, the difference between the effective opening ratio of the perforated plate portion in the rotor side region and the effective opening ratio of the perforated plate portion in the cabin side region is 10% or more.

[0077] According to the configuration [5], the effective opening ratio of the porous plate section provided in the air passage of the combustor is 10% or more higher in the rotor side region than in the casing side region, which makes it easier to obtain the effect of suppressing the bias of the air flow rate in the circumferential direction of the combustor while suppressing an increase in pressure loss.

[0078] [6] In some embodiments, in the configuration of any one of [1] to [5] above, the porous plate portion includes a plurality of porous plates (61) extending along a plane perpendicular to the axial direction of the combustor and arranged along the circumferential direction of the combustor, and the combustor includes a plurality of ribs (58) extending along the radial direction of the combustor and supporting the plurality of porous plates.

[0079] According to the configuration [6] above, the above-mentioned porous plate portion can be realized with a relatively simple configuration using a plurality of porous plates and a plurality of ribs, which makes it possible to suppress the unevenness of the air flow rate in the circumferential direction of the combustor while suppressing an increase in pressure loss, as described in [1] above.

[0080] [7] In some embodiments, in the configuration of [6] above, the plurality of perforated plates include at least one first perforated plate (64) provided in the rotor side region and at least one second perforated plate (66) provided in the cabin side region, and the actual aperture ratio of each of the at least one second perforated plate is smaller than the actual aperture ratio of each of the at least one first perforated plate, or the effective aperture ratio of each of the at least one second perforated plate is smaller than the effective aperture ratio of each of the at least one first perforated plate.

[0081] According to the configuration of the above [7], the above-mentioned porous plate portion can be realized by using the first porous plate and the second porous plate having different actual opening ratios or effective opening ratios, which makes it possible to suppress the bias of the air flow rate in the circumferential direction of the combustor while suppressing an increase in pressure loss, as described in the above [1].

[0082] [8] In some embodiments, in the configuration of [7] above, the plurality of perforated plates include at least three of the first perforated plates provided in the rotor side region, at least three of the second perforated plates provided in the cabin side region, and a third perforated plate (68) provided in the circumferential direction between the at least three first perforated plates and the at least three second perforated plates, the actual opening rate or the effective opening rate being smaller than that of the first perforated plates and larger than that of the second perforated plates.

[0083] According to the configuration [8], the porous plate portion includes the first porous plate and the second porous plate having different actual opening ratios or effective opening ratios, and the third porous plate having an actual opening ratio or effective opening ratio smaller than that of the first porous plate and larger than that of the second porous plate, so that the air flow rate in the circumferential direction of the combustor can be adjusted more finely. Therefore, it is possible to more effectively suppress bias in the air flow rate in the circumferential direction of the combustor while suppressing an increase in pressure loss.

[0084] [9] A combustor (4) according to at least one embodiment of the present invention is a combustor for a gas turbine (1), comprising: an inner cylinder (50) provided to surround fuel nozzles (e.g., a first fuel nozzle 40 and a second fuel nozzle 46); an outer cylinder (54) provided radially outward of the combustor with respect to the inner cylinder; and a porous plate portion (60) provided in an air passage (56) formed between the inner cylinder and the outer cylinder and for rectifying an air flow in the air passage, wherein the porous plate portion includes: a rotor-side region (R1) in which chamfered portions (63) are formed at ends of holes (62) provided in the porous plate portion; and a casing-side region (R2) located radially outward of the rotor of the gas turbine relative to the rotor-side region, in which chamfered portions are not formed at ends of holes provided in the porous plate portion.

[0085] According to the configuration [9] above, the porous plate portion provided in the air passage includes a rotor-side region in which chamfered portions are formed at the ends of the holes provided in the porous plate portion and a casing-side region located radially outward of the rotor of the gas turbine than the rotor-side region and in which chamfered portions are not formed at the ends of the holes provided in the porous plate portion. Therefore, even without reducing the hole diameter of the porous plate portion, it is possible to appropriately rectify the air flow and suppress unevenness in the air flow rate in the circumferential direction of the combustor. In other words, it is possible to suppress unevenness in the air flow rate in the circumferential direction of the combustor while suppressing an increase in pressure loss. Therefore, it is possible to rectify the combustion air while suppressing a deterioration in the performance of the gas turbine 1.

[0086]

[10] A gas turbine (1) according to at least one embodiment of the present invention comprises: a combustor (4) according to any one of [1] to [9] above, configured to combust fuel; and a turbine (6) configured to be driven by combustion gas from the combustor.

[0087] As a result of investigations by the present inventors, it was found that in the annular air passage (a passage of combustion air toward the combustor) formed between the inner and outer cylinders of the combustor, the air flow velocity tends to be lower in a region radially inner of the gas turbine rotor than in a region radially outer of the gas turbine rotor. According to the configuration of the above

[10] , the perforated plate portion provided in the air passage includes a rotor-side region and a casing-side region in which the actual opening ratio or effective opening ratio of the perforated plate portion is smaller than that of the rotor-side region. Therefore, it is possible to appropriately rectify the air flow and suppress unevenness in the air flow rate in the circumferential direction of the combustor without reducing the hole diameter of the perforated plate portion. In other words, it is possible to suppress unevenness in the air flow rate in the circumferential direction of the combustor while suppressing an increase in pressure loss. Therefore, it is possible to rectify the combustion air while suppressing a deterioration in the performance of the gas turbine 1. Alternatively, according to the configuration

[10] described above, the porous plate portion provided in the air passage includes a rotor-side region in which chamfered portions are formed at the ends of the holes provided in the porous plate portion and a casing-side region located radially outward of the rotor of the gas turbine than the rotor-side region and in which the chamfered portions are not formed at the ends of the holes provided in the porous plate portion. Therefore, even without reducing the hole diameter of the porous plate portion, it is possible to appropriately rectify the air flow and suppress unevenness in the air flow rate in the circumferential direction of the combustor. In other words, it is possible to suppress unevenness in the air flow rate in the circumferential direction of the combustor while suppressing an increase in pressure loss. Therefore, it is possible to rectify the combustion air while suppressing a deterioration in the performance of the gas turbine 1.

[0088] The above describes an embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and also includes forms in which the above-described embodiment is modified, or forms in which these forms are appropriately combined.

[0089] In this specification, expressions expressing relative or absolute arrangements, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such arrangements, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions expressing that things are in an equal state, such as "identical," "equal," and "homogeneous," not only express a state in which there is a strict equivalence, but also express a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions expressing shapes such as a rectangular shape or a cylindrical shape not only express shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also express shapes including concave and convex portions, chamfered portions, etc., to the extent that the same effect is obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components.

[0090] REFERENCE SIGNS LIST 1 gas turbine 2 compressor 4 combustor 6 turbine 8 rotor 10 compressor casing 12 air intake 16 stator vane 18 moving blade 20 combustor casing 22 turbine casing 24 stator vane 26 moving blade 28 combustion gas passage 30 exhaust chamber 38 first combustion burner 40 first fuel nozzle 41 first burner casing 42 first fuel port 43 second fuel port 44 second combustion burner 45 swirler 46 second fuel nozzle 47 second burner casing 49 swirler 50 inner casing 52 combustion casing 54 outer casing 56 air passage 58 rib 60 perforated plate portion 61, 61Z to 61H perforated plate 61a end face 62 hole 62a hole 62b hole 62c hole 62e: Slot 63: Chamfered portion 64: First porous plate 66: Second porous plate 68: Third porous plate O: Rotor central axis Q: Combustor central axis R1: Rotor side region R2: Cassette side region

Claims

1. A combustor for a gas turbine, comprising: an inner cylinder provided so as to surround a fuel nozzle; an outer cylinder provided on the radially outer side of the combustor with respect to the inner cylinder; and a perforated plate portion provided in an air passage formed between the inner cylinder and the outer cylinder for rectifying an air flow in the air passage, wherein the perforated plate portion includes a rotor-side region and a cabin-side region located radially outside the rotor of the gas turbine with respect to the rotor-side region and having a smaller actual opening ratio or effective opening ratio than the rotor-side region, the actual opening ratio being the ratio of the area of the holes of the perforated plate portion to the area of the air passage, and the effective opening ratio being the ratio of the product of the area of the holes of the perforated plate portion and the flow coefficient of the perforated plate portion to the area of the air passage.

2. The combustor according to claim 1, wherein the actual opening ratio of the perforated plate portion in the rotor-side region is 75% or less, and the actual opening ratio of the perforated plate portion in the cabin-side region is 55% or more.

3. The combustor according to claim 1 or 2, wherein the difference between the actual opening ratio of the perforated plate portion in the rotor-side region and the actual opening ratio of the perforated plate portion in the cabin-side region is 5% or more.

4. The combustor according to claim 1 or 2, wherein the effective opening ratio of the perforated plate portion in the rotor-side region is 115% or less, and the effective opening ratio of the perforated plate portion in the cabin-side region is 75% or more.

5. The combustor according to claim 1 or 2, wherein the difference between the effective opening ratio of the perforated plate portion in the rotor-side region and the effective opening ratio of the perforated plate portion in the cabin-side region is 10% or more.

6. The combustor according to claim 1 or 2, wherein the perforated plate portion includes a plurality of perforated plates extending along a plane orthogonal to the axial direction of the combustor and arranged along the circumferential direction of the combustor, and includes a plurality of ribs extending along the radial direction of the combustor for supporting the plurality of perforated plates.

7. The plurality of perforated plates includes at least one first perforated plate provided in the rotor side region and at least one second perforated plate provided in the passenger compartment side region, and the actual opening ratio of each of the at least one second perforated plate is smaller than the actual opening ratio of each of the at least one first perforated plate, or the effective opening ratio of each of the at least one second perforated plate is smaller than the effective opening ratio of each of the at least one first perforated plate. The combustor according to claim 6.

8. The plurality of perforated plates includes at least three first perforated plates provided in the rotor side region, at least three second perforated plates provided in the passenger compartment side region, and a third perforated plate provided between the at least three first perforated plates and the at least three second perforated plates in the circumferential direction, and having an actual opening ratio or an effective opening ratio smaller than that of the first perforated plate and larger than that of the second perforated plate. The combustor according to claim 7.

9. A combustor for a gas turbine, comprising an inner cylinder provided so as to surround a fuel nozzle, an outer cylinder provided on the radially outer side of the combustor with respect to the inner cylinder, and a perforated plate portion provided in an air passage formed between the inner cylinder and the outer cylinder for rectifying an air flow in the air passage. The perforated plate portion includes a rotor side region in which a chamfered portion is formed at an end of a hole provided in the perforated plate portion, and a passenger compartment side region located radially outside the rotor of the gas turbine with respect to the rotor side region and in which no chamfered portion is formed at an end of a hole provided in the perforated plate portion.

10. A gas turbine comprising the combustor according to claim 1 or 9 configured to burn fuel, and a turbine configured to be driven by combustion gas from the combustor.

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