Turbine blades and gas turbines

Abstract

To provide a turbine blade capable of improving cooling performance while securing castability.SOLUTION: A turbine blade according to at least one embodiment of this disclosure includes: a pin fin flow passage formed in a rear edge of an airfoil, extending toward the rear edge of the airfoil, and opened to the outside of the airfoil at the rear edge; and a plurality of pin fins connecting a pair of confronting inner walls constituting the pin fin flow passage. The pin fin flow passage includes a first region, and a second region closer to the rear edge than the first region. The pin fins include a plurality of first pins provided in the first region and a plurality of second pin fins provided in the second region. A first diameter of the plurality of first pin fins is larger than a second diameter of the plurality of second pin fins. A first pin pitch between the first pin fins is larger than a second pin pitch between the second pin fins. A value obtained by dividing the first pin pitch by the first diameter is smaller than a value obtained by dividing the second pin pitch by the second diameter.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] This disclosure relates to turbine blades and gas turbines.

Background Art

[0002] As a turbine blade of a gas turbine, one known type cools the trailing edge of the blade through pin fins (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in the turbine blade described in Patent Document 1, a leading edge passage and a trailing edge passage are formed inside the airfoil portion (blade body), and a pin fin passage composed of a flow path between pin fins is formed on the trailing edge side of the blade body. Then, the cooling air after cooling the leading edge passage and the trailing edge passage flows through the pin fin passage to perform pin fin cooling.

[0005] For example, in a turbine blade having a flow path configuration of cooling air such as that of the turbine blade described in Patent Document 1, the metal temperature is relatively high in the region where the leading edge passage and the trailing edge passage are provided, and overcooling may occur in the region on the trailing edge side of the blade body where the pin fin passage is provided. In such a case, it is conceivable to suppress the metal temperature by expanding the region of the pin fin passage toward the leading edge side. However, in the region expanded toward the leading edge side in the pin fin passage, the distance between a pair of opposing inner walls构成 the pin fin passage becomes large, so the length of the pin fins in this region also becomes long. Therefore, when casting the turbine blade, it becomes difficult to cast, such as the pin fins in this region being easily broken.

[0006] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a turbine blade that can improve cooling performance while ensuring castability, and a gas turbine equipped with the turbine blade. [Means for solving the problem]

[0007] (1) A turbine blade according to at least one embodiment of the present disclosure is Wing section and, A pin fin channel is formed within the trailing edge of the airfoil portion, extends toward the trailing edge of the airfoil portion, and opens to the outside of the airfoil portion at the trailing edge; Multiple pin fins connecting a pair of opposing inner walls that constitute the pin fin channel, Equipped with, The pin fin channel includes a first region and a second region located on the trailing edge side of the first region. The plurality of pin fins include a plurality of first pin fins provided in the first region and a plurality of second pin fins provided in the second region. The first diameter of the plurality of first pin fins is greater than the second diameter of the plurality of second pin fins. The first pin pitch between the plurality of first pin fins is greater than the second pin pitch between the plurality of second pin fins. The value obtained by dividing the first pin pitch by the first diameter is smaller than the value obtained by dividing the second pin pitch by the second diameter.

[0008] (2) A gas turbine according to at least one embodiment of the present disclosure is The turbine blade is provided with any of the configurations described in (1) through (8) above. [Effects of the Invention]

[0009] According to at least one embodiment of this disclosure, it is possible to provide a turbine blade that can improve cooling performance while ensuring castability, and a gas turbine equipped with this turbine blade. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the configuration of a gas turbine equipped with turbine blades according to several embodiments. [Figure 2] This is a cross-sectional view of a turbine blade according to several embodiments. [Figure 3] This is a perspective view of the inner shroud of a turbine blade according to several embodiments, seen from the bottom side. [Figure 4] This is a perspective view of the outer shroud of a turbine blade according to several embodiments, as seen from the top. [Figure 5] The diagram shows the trailing edge of a turbine blade according to several embodiments, the upper panel is a cross-sectional view taken from a plane substantially perpendicular to the vertical axis of the turbine blade, and the lower panel is a cross-sectional view taken from a plane substantially parallel to the vertical axis of the turbine blade. [Figure 6] This is a table to explain the dimensions of pin fins. [Figure 7] This diagram illustrates the relationship between the dimensions of the pin fins and the cooling performance in the pin fin flow path. [Modes for carrying out the invention]

[0011] Hereinafter, several embodiments of this disclosure will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described or shown in the drawings as embodiments are not intended to limit the scope of this disclosure, but are merely illustrative examples. For example, expressions describing relative or absolute arrangements such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" should not only strictly describe such arrangements, but also describe states of relative displacement with tolerances or angles or distances that allow for the same function to be achieved. For example, expressions such as "identical," "equal," and "homogeneous" that describe things being in an equal state not only describe a state of being strictly equal, but also describe a state in which there is a tolerance or a difference that is sufficient to achieve the same function. For example, expressions representing shapes such as a rectangular shape or a cylindrical shape shall not only represent the shapes of a rectangular shape or a cylindrical shape in a geometrically exact sense, but also represent shapes including concave and convex portions, chamfered portions, etc. within the range where the same effects can be obtained. On the other hand, expressions such as "comprising", "having", "including", or "possessing" one component are not exclusive expressions that exclude the existence of other components.

[0012] Hereinafter, the turbine blades according to several embodiments will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a gas turbine including turbine blades according to several embodiments. FIG. 2 is a cross-sectional view of turbine blades according to several embodiments. FIG. 3 is a perspective view of the inner shroud of turbine blades according to several embodiments as viewed from the bottom side. FIG. 4 is a perspective view of the outer shroud of turbine blades according to several embodiments as viewed from the upper side. FIG. 5 is a view showing the trailing edge portion of turbine blades according to several embodiments, where the upper part is a cross-sectional view taken by a plane substantially orthogonal to the standing direction axis of the turbine blades, and the lower part is a cross-sectional view taken by a plane substantially parallel to the standing direction axis of the turbine blades. FIG. 6 is a table for explaining the dimensions of pin fins. FIG. 7 is a diagram for explaining the relationship between the dimensions of pin fins and the cooling performance in the pin fin flow path.

[0013] (Gas turbine 100) As shown in FIG. 1, a gas turbine 100 according to several embodiments includes a compressor 1 that compresses outside air to generate compressed air, a plurality of combustors 2 that mix fuel supplied from a fuel supply source (not shown) with the compressed air and burn the mixture to generate combustion gas, and a turbine  3 that is driven by the combustion gas FG.

[0014] As shown in FIG. 2, the turbine 3 includes a rotor 4 that rotates about an axis Ar. For example, a generator 5 (see FIG. 1) that generates electricity by the rotation of the rotor 4 is connected to the rotor 4.

[0015] Some embodiments of the turbine blade 10 can be applied, for example, to a stator blade in a turbine 3.

[0016] (Turbine blade 10) As shown in Figure 2, the turbine blade 10 comprises a blade body (airfoil section) 11 and an inner shroud 12 and an outer shroud 13 provided on the inside and outside of the blade body 11, respectively. The wing body 11 has a leading edge passage 42 and a trailing edge passage 44 formed inside by ribs 40, and bottomed cylindrical inserts 46 and 47, each having multiple cooling air holes 70 and 71 on their circumferential and bottom surfaces, are inserted into these leading edge passages 42 and trailing edge passages 44 from the outer shroud 13 side. The wing body 11 is equipped with a pin fin passageway 16 on its trailing edge 11b side, which is a passage with multiple pin fins 26. The pin fin passageway 16 will be described in detail later. When cooling air CA is supplied to these inserts 46 and 47 from a manifold (not shown), this cooling air CA is ejected from the cooling air holes 70 and 71, collides with the inner walls of the leading edge passage 42 and trailing edge passage 44, and so-called impingement cooling occurs. It also flows through the pin fin passage 16 on the trailing edge side of the wing body 11, and pin fin cooling occurs. Furthermore, the rib 40 has through-holes (not shown) that penetrate the rib 40 between the end face on the leading edge 11a side and the end face on the trailing edge 11b side, allowing cooling air CA to flow from the leading edge passage 42 to the trailing edge passage 44 through these through-holes.

[0017] The inner shroud 12 has a front flange 81 and a rear flange 82 formed on its front edge 11a and rear edge 11b sides, respectively, and is connected to a seal support portion 66 that supports a seal 14 that seals the space between the inner shroud 12 and the arm portion 48 of the rotor 4. A cavity 45 is formed between this seal support portion 66 and the inner shroud 12, and cooling air CA that has flowed out from the open end 84 of the insert 46 is supplied to this cavity 45. A passage 85 is formed in the seal support portion 66 on the front side (upstream side in the direction of the axis Ar). Through this passage 85, air is supplied from the cavity 45 to the front rotor blade 18 side and through the gap in the seal 14 to the rear rotor blade 19 side, maintaining a higher pressure inside than the passage for the high-temperature combustion gas FG, thereby preventing the high-temperature combustion gas FG from entering the interior.

[0018] (Inner shroud 12) As shown in Figure 3, the inner shroud 12 has a leading edge channel 88 with numerous needle-shaped fins 89 formed on its leading edge 11a side. Rails 96 are also formed along both sides of the inner shroud 12, and these rails 96 have side channels 93 formed on them, one end of which communicates with the leading edge channel 88 and the other end which opens into the combustion gas FG at the trailing edge of the inner shroud 12. On the bottom surface of the inner shroud 12, there are impact plates 84 having a plurality of small holes 101 spaced apart from the bottom surface, and these impact plates 84 form a chamber 83 (see Figure 2) on the bottom side of the inner shroud 12. Furthermore, multiple trailing edge passages 92 are formed on the trailing edge side of the inner shroud 12, one end of which communicates with the side passage 93 and the other end of which discharges into the combustion gas FG.

[0019] Furthermore, the cooling air CA sent into the cavity 45 also flows into the chamber 83 through the small holes 101 in the impact plate 84. When the cooling air CA flows into the chamber 83 through the small holes 101 in the impact plate 84, it collides with the bottom surface of the inner shroud 12, causing impingement cooling. The cooling air CA sent into the chamber 83 is then directed to the leading edge passage 88 of the inner shroud 12, where it passes between the needle-shaped fins 89, cooling the leading edge side of the inner shroud 12. After that, it passes through the side passage 93 and is released into the combustion gas FG from the trailing edge of the inner shroud 12 via the trailing edge passage 92.

[0020] (Outer shroud 13) As shown in Figure 4, the outer shroud 13 has impact plates 102 having a plurality of small holes 107 spaced apart from its upper surface, and these impact plates 102 form a chamber 104 (see Figure 2) on the upper side of the outer shroud 13. Furthermore, a leading edge channel 105 is formed in the outer shroud 13, and side channels 106 are formed on both sides that communicate with the leading edge channel 105 on the front side and open at the rear edge of the outer shroud 13, with the leading edge channel 105 communicating with one of the chambers 104.

[0021] The cooling air CA, which is sent into the manifold (not shown), flows into the chamber 104 through the small holes 107 in the impact plate 102 and is discharged from the trailing edge of the side passage 106. When the cooling air CA flows into the chamber 104 through the small holes 107 in the impact plate 102, it collides with the upper surface of the outer shroud 13, thereby performing impingement cooling. Furthermore, the cooling air CA that flows into the chamber 104 also flows into the leading edge channel 105, and by passing through this leading edge channel 105 and the side channel 106, it cools the leading edge and both sides of the outer shroud 13, and is then discharged from the trailing edge of the outer shroud 13.

[0022] (Regarding the pin fin channel 16) As shown in Figures 2 and 5, the turbine blade 10 according to some embodiments includes a pin fin channel 16 formed within the trailing edge 15 of the blade body 11, extending toward the trailing edge 11b of the blade body 11, and opening to the outside of the blade body 11 at the trailing edge 11b. The turbine blade 10 according to some embodiments includes a plurality of pin fins 26 connecting a pair of opposing inner walls 17 that constitute the pin fin channel 16. The pair of opposing inner walls 17 that constitute the pin fin channel 16 are the dorsal wall portion 21a and the ventral wall portion 21b of the blade body 11. Note that the dorsal wall portion 21a and the ventral wall portion 21b shown in the upper part of Figure 5 are actually curved along the dorsal wall surface 22a and the ventral wall surface 22b, but in Figure 5, for the sake of simplification, the dorsal wall portion 21a and the ventral wall portion 21b are shown in a simplified form without curvature.

[0023] As shown in the upper part of FIG. 5, the passage width W of the pin fin flow path 16, that is, the distance between a pair of opposing inner walls 17, is formed so as to gradually narrow (become tapered) from the leading edge 11a side toward the trailing edge 11b side. Also, as shown in the upper and lower parts of FIG. 5, the pin fin flow path 16 includes, for example, a first region 161, a second region 162, and a third region 163 from the leading edge 11a side toward the trailing edge 11b side. The plurality of pin fins 26 provided in the pin fin flow path 16 includes a plurality of first pin fins 261 provided in the first region 161, a plurality of second pin fins 262 provided in the second region 162, and a plurality of third pin fins 263 provided in the third region 163.

[0024] In the turbine blade 10 according to some embodiments, the diameter d of the plurality of pin fins 26 is set, for example, as follows. For example, the value of the diameter d of the first pin fin 261 is the first diameter d1, the value of the diameter d of the second pin fin 262 is the second diameter d2, and the value of the diameter d of the third pin fin 263 is the third diameter d3. In the turbine blade 10 according to some embodiments, the first diameter d1 is larger than the second diameter d2 (d2 < d1), and the third diameter d3 is equal to the second diameter d2 (d2 = d3).

[0025] In the turbine blade 10 according to some embodiments, the pin fins 26 are such that the first pin pitch p1, which is the pin pitch of the first pin fin 261 (the arrangement pitch in a direction substantially parallel to the standing axis AX of the blade body 11, that is, the center-to-center distance of the pin fins 26 in the direction along the standing axis AX, and the arrangement pitch in the direction Dx substantially orthogonal to the standing axis AX of the blade body 11, that is, the pitch between rows of the pin fin rows (a plurality of pin fins 26 arranged along the standing axis AX)), is larger than the second pin pitch p2, which is the pin pitch of the second pin fin 262 (p2 < p1), and the second pin pitch p2 of the second pin fin 262 is smaller than the third pin pitch p3, which is the pin pitch of the third pin fin 263 (p2 < p3). In this example, the pin pitch p of the pin fins 26 within the same region is set to be the same for the arrangement pitch in the direction approximately parallel to the vertical axis AX of the wing body 11 and the arrangement pitch in the direction approximately perpendicular to the vertical axis AX of the wing body 11 (first pin pitch p1 in the first region 161). However, the arrangement pitches in the direction approximately parallel and the direction approximately perpendicular do not have to be the same and may be different. However, it is preferable that the rate of change in the arrangement pitch when comparing each region is the same for the arrangement pitch in the direction approximately parallel to the vertical axis AX and the arrangement pitch in the direction approximately perpendicular to the vertical axis AX.

[0026] In some embodiments of the turbine blade 10, the cooling performance in the pin fin flow path 16 changes depending on the value p / d obtained by dividing the pin pitch p by the diameter d of the pin fin 26. In the following description, the value p / d obtained by dividing the pin pitch p by the diameter d of the pin fin 26 will also be referred to as the diameter-pitch ratio p / d. For example, as shown in Figure 7, in some embodiments of the turbine blade 10, the cooling performance in the pin fin flow path 16 is maximized when the diameter-pitch ratio p / d is between 1.0 and 2.0, more specifically between 1.5 and 2.0. Note that when the diameter-pitch ratio p / d is 1.0, there is no gap between adjacent pin fins, so the cooling air CA cannot flow through the pin fin flow path 16.

[0027] As shown in Figure 7, a smaller diameter-pitch ratio p / d results in higher cooling performance in the pin fin channel 16. However, as mentioned above, the cooling performance in the pin fin channel 16 is maximized when the diameter-pitch ratio p / d is between 1.5 and 2.0. Therefore, if the diameter-pitch ratio p / d is too small, the cooling performance in the pin fin channel 16 decreases as the diameter-pitch ratio p / d decreases. In other words, the cooling performance in the pin fin channel 16 is higher when the diameter-pitch ratio p / d is small, as long as it is not too small.

[0028] In the region on the leading edge 11a side of the pin fin channel 16, the distance between the pair of opposing inner walls 17 constituting the pin fin channel 16 (passage width W) is larger than in the region on the trailing edge 11b side of the pin fin channel 16. As a result, the length of the pin fins 26 in the region on the leading edge 11a side of the pin fin channel 16 is longer, making it more difficult to cast the turbine blade 10, such as by making the pin fins 26 in that region more prone to breaking. To improve castability, it is conceivable to increase the diameter d of the pin fins 26 in that region. However, simply increasing the diameter d of the pin fins 26 without changing the pin pitch p of the pin fins 26 may result in the diameter-pitch ratio p / d becoming too small, potentially reducing the cooling performance in that region.

[0029] Therefore, in some embodiments of the turbine blade 10, the first diameter d1 is made larger than the second diameter d2 (d2 <d1)。 By making the first diameter d1 larger than the second diameter d2, castability can be ensured even if the length of the first pin fin 261 is increased.

[0030] In some embodiments of the turbine blade 10, the diameter-pitch ratio p / d(p1 / d1) of the first pin fin 261 is made smaller than the diameter-pitch ratio p / d(p2 / d2) of the second pin fin 262. By making the diameter-pitch ratio p / d(p1 / d1) of the first pin fin 261 smaller than the diameter-pitch ratio p / d(p2 / d2) of the second pin fin 262, the cooling performance in the first region 161 can be made greater than the cooling performance in the second region 162.

[0031] In some embodiments of the turbine blade 10, the first pin pitch p1 is made larger than the second pin pitch p2 (p2 <p1)。 By making the first pin pitch p1 larger than the second pin pitch p2, the diameter-pitch ratio p / d can be made too small, which would reduce the cooling performance in the first region 161. Therefore, according to some embodiments of the turbine blade 10, it is possible to improve cooling performance while ensuring castability in the first region 161. Furthermore, according to some embodiments of the turbine blade 10, by improving cooling performance, it is possible to reduce the flow rate of the cooling air CA.

[0032] In some embodiments of the gas turbine 100, the turbine blades 10 are provided according to some embodiments, which allows the flow rate of cooling air CA in the turbine blades 10 to be suppressed and improves the performance of the gas turbine 100.

[0033] In some embodiments of the turbine blade 10, the first region 161 is preferably the region in the pin fin flow path 16 that is closest to the leading edge 11a of the blade body 11. In the pin fin channel 16, the region closest to the leading edge 11a of the blade body 11 has a larger distance (passage width W) between the pair of opposing inner walls 17 that make up the pin fin channel 16 compared to other regions. As a result, the length of the pin fin 26 is longer in this region, making it difficult to cast. According to several embodiments of the turbine blade 10, in the first region 161, where the length of the pin fins 26 is longer compared to other regions and therefore difficult to cast, it is possible to improve cooling performance while ensuring castability in the first region 161.

[0034] In some embodiments of the turbine blade 10, the second region 162 may be adjacent to the first region 161. This makes it possible to improve cooling performance while ensuring castability in the region adjacent to the second region 162 on the leading edge 11a side (first region 161).

[0035] In some embodiments of the turbine blade 10, the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263 may be greater than the diameter-pitch ratio p / d(p2 / d2) of the second pin fin 262. In the third region 163, which is located on the trailing edge 11b side of the second region 162, the cooling performance may be suppressed compared to the second region 162. Therefore, the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263 may be greater than the diameter-pitch ratio p / d(p2 / d2) of the second pin fin 262. This increases the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263, which in turn increases the size of the third pin pitch p3 relative to the third diameter d3. As a result, the proportion of the third pin fin 263 within the third region 163 decreases, thereby suppressing pressure loss of the cooling air CA in the third region 163.

[0036] In some embodiments of the turbine blade 10, the third diameter d3 may be equal to the second diameter d2 (d3=d2). In the third region 163, which is on the trailing edge 11b side of the second region 162, the distance between the pair of opposing inner walls 17 constituting the pin fin flow path 16 (passage width W) is smaller compared to the second region 162. Therefore, it is not necessary to make the third diameter d3 of the third pin fin 263 larger than the second diameter d2 of the second pin fin 262, as is the case in the first region 161. As mentioned above, the diameter-pitch ratio p / d has a significant impact on cooling performance. Furthermore, the relationship between the diameter-pitch ratio p / d(p2 / d2) of the second pin fin 262 and the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263 can be determined solely by the relationship between the second pin pitch p2 and the third pin pitch p3, provided that the third diameter d3 and the second diameter d2 are equal. Therefore, by making the third diameter d3 and the second diameter d2 equal, it becomes easier to set the cooling performance of the third region 163 during the design phase of the turbine blade 10.

[0037] In some embodiments of the turbine blade 10, the third pin pitch p3 may be larger than the second pin pitch p2 (p2 <p3)。 As described above, the cooling performance in the third region 163, which is on the trailing edge 11b side of the second region 162, may be suppressed compared to the second region. Therefore, the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263 may be greater than the diameter-pitch ratio p / d(p2 / d2) of the second pin fin 262. To increase the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263, the third pin pitch p3 may be increased, or the third diameter d3 may be decreased. However, decreasing the third diameter d3 may reduce the castability of the third pin fin 263. Therefore, by making the third pin pitch p3 larger than the second pin pitch p2, the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263 can be increased, thereby ensuring the castability of the third pin fin 263.

[0038] In some embodiments of the turbine blade 10, the third pin pitch p3 may be greater than or equal to the first pin pitch p1 (p1 ≤ p3). As described above, the diameter-pitch ratio p / d(p1 / d1) of the first pin fin 261 is smaller than the diameter-pitch ratio p / d(p2 / d2) of the second pin fin 262. Also, the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263 may be larger than the diameter-pitch ratio p / d(p2 / d2) of the second pin fin 262. Therefore, the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263 may be larger than the diameter-pitch ratio p / d(p1 / d1) of the first pin fin 261. Consequently, the third pin pitch p3 may be greater than or equal to the first pin pitch p1.

[0039] In some embodiments of the turbine blade 10, the third pin pitch p3 may be smaller than the first pin pitch p1 (p3 <p1)。 In other words, if the diameter-pitch ratio p / d(p3 / d3) of the third pin fin 263 is greater than the diameter-pitch ratio p / d(p1 / d1) of the first pin fin 261, then the third pin pitch p3 may be smaller than the first pin pitch p1.

[0040] This disclosure is not limited to the embodiments described above, but also includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate. For example, the cross-sectional shape of the pin fin 26 in some of the embodiments described above is not limited to a circle, but may be any shape such as an airfoil, streamlined, polygonal, or elliptical. If the cross-sectional shape of the pin fin 26 is not circular, the diameter d of the pin fin 26 may be the equivalent diameter of the circle of the cross-sectional shape. Also, the pin pitch p may be the distance between the centroids of the cross-sectional shapes of two adjacent pin fins 26.

[0041] While some of the turbine blades 10 according to the embodiments described above can be applied to stationary blades in a turbine 3, they may also be applied to rotor blades.

[0042] The contents described in each of the above embodiments can be understood, for example, as follows: (1) A turbine blade according to at least one embodiment of the present disclosure comprises an airfoil (blade body 11), a pin fin channel 16 formed within the trailing edge 15 of the airfoil (blade body 11) and extending toward the trailing edge 11b of the airfoil (blade body 11), and opening to the outside of the airfoil (blade body 11) at the trailing edge 11b, and a plurality of pin fins 26 connecting a pair of opposing inner walls 17 constituting the pin fin channel 16. The pin fin channel 16 includes a first region 161 and a second region 162 located on the trailing edge 11b side of the first region 161. The plurality of pin fins 26 includes a plurality of first pin fins 261 provided in the first region 161 and a plurality of second pin fins 262 provided in the second region 162. The first diameter d1 of the plurality of first pin fins 261 is greater than the second diameter d2 of the plurality of second pin fins 262. The first pin pitch p1 between multiple first pin fins 261 is greater than the second pin pitch p2 between multiple second pin fins 262. The value obtained by dividing the first pin pitch p1 by the first diameter d1 (p1 / d1) is less than the value obtained by dividing the second pin pitch p2 by the second diameter d2 (p2 / d2).

[0043] According to the configuration of (1) above, by making the first diameter d1 of the multiple first pin fins 261 larger than the second diameter d2 of the multiple second pin fins 262, castability can be ensured even if the length of the multiple first pin fins 261 is increased. According to the configuration of (1) above, by making the value obtained by dividing the first pin pitch p1 by the first diameter d1 (p1 / d1) smaller than the value obtained by dividing the second pin pitch p2 by the second diameter d2 (p2 / d2), the cooling performance in the first region 161 can be made greater than the cooling performance in the second region 162. Furthermore, according to the configuration of (1) above, by making the first pin pitch p1 between the multiple first pin fins 261 larger than the second pin pitch p2 between the multiple second pin fins 262, it is possible to avoid a decrease in cooling performance in the first region 161 due to the diameter-pitch ratio p / d becoming too small. Therefore, according to the configuration of (1) above, it is possible to improve cooling performance while ensuring castability in the first region 161. Furthermore, according to the configuration described in (1) above, the cooling performance can be improved, thereby reducing the flow rate of the cooling air CA.

[0044] (2) In some embodiments, in the configuration of (1) above, the first region 161 is the region in the pin fin channel 16 that is closest to the leading edge 11a of the airfoil (wing body 11).

[0045] In the pin fin channel 16, the region closest to the leading edge 11a of the airfoil section (wing body 11) has a larger distance (passage width W) between the pair of opposing inner walls 17 that make up the pin fin channel 16 compared to other regions. As a result, the length of the pin fin 26 is longer in this region, making it difficult to cast. According to the configuration of (2) above, in the first region 161, where the length of the pin fins 26 is longer compared to other regions and therefore difficult to cast, it is possible to improve cooling performance while ensuring castability in the first region 161.

[0046] (3) In some embodiments, in the configuration of (1) or (2) above, the second region 162 may be adjacent to the first region 161.

[0047] According to the configuration described in (3) above, in the region adjacent to the second region 162 on the leading edge 11a side (first region 161), casting properties can be ensured while improving cooling performance.

[0048] (4) In some embodiments, in any of the configurations (1) to (3) above, the pin fin channel 16 may include a third region 163 located on the trailing edge 11b side of the second region 162. The plurality of pin fins 26 may include a plurality of third pin fins 263 provided in the third region 163. The value obtained by dividing the third pin pitch p3 between the plurality of third pin fins 263 by the third diameter d3 of the plurality of third pin fins 263 (p3 / d3) may be greater than the value obtained by dividing the second pin pitch p2 by the second diameter d2 (p2 / d2).

[0049] In the third region 163, which is on the trailing edge 11b side of the second region 162, the cooling performance may be suppressed compared to the second region 162. Therefore, the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3) may be greater than the value obtained by dividing the second pin pitch p2 by the second diameter d2 (p2 / d2). According to the configuration described in (4) above, by increasing the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3), the size of the third pin pitch p3 relative to the third diameter d3 becomes larger. As a result, the proportion occupied by the third pin fin 263 within the pin fin flow path 16 decreases, and the pressure loss of the cooling air in the third region 163 can be suppressed.

[0050] (5) In some embodiments, in the configuration of (4) above, the third diameter d3 may be equal to the second diameter d2.

[0051] In the third region 163, which is on the trailing edge 11b side of the second region 162, the distance between the pair of opposing inner walls 17 constituting the pin fin flow path 16 (passage width W) is smaller compared to the second region 162. Therefore, as in the first region 161, it is not necessary to make the third diameter d3 of the multiple third pin fins 263 larger than the second diameter d2 of the multiple second pin fins 262. According to the configuration in (5) above, since the third diameter d3 and the second diameter d2 are equal, the diameter-pitch ratio p / d, which greatly affects the cooling performance, can be set solely by the relationship between the second pin pitch p2 and the third pin pitch p3. This makes it easier to set the cooling performance of the third region 163 during the design stage of the turbine blade 10.

[0052] (6) In some embodiments, in the configuration of (4) or (5) above, the third pin pitch p3 may be greater than the second pin pitch p2.

[0053] In the third region 163, which is on the trailing edge 11b side of the second region 162, the cooling performance may be suppressed compared to the second region 162. Therefore, the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3) may be greater than the value obtained by dividing the second pin pitch p2 by the second diameter d2 (p2 / d2). To increase the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3), the third pin pitch p3 may be increased, or the third diameter d3 may be decreased. However, decreasing the third diameter d3 may reduce the castability of the third pin fin 263. According to the configuration described in (6) above, by making the third pin pitch p3 larger than the second pin pitch p2, the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3) can be increased, thereby ensuring the castability of the third pin fin 263 even when the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3) is increased.

[0054] (7) In some embodiments, in any of the configurations (4) to (6) above, the third pin pitch p3 may be greater than or equal to the first pin pitch p1.

[0055] As described above, the value obtained by dividing the first pin pitch p1 by the first diameter d1 (p1 / d1) is smaller than the value obtained by dividing the second pin pitch p2 by the second diameter d2 (p2 / d2). Also, the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3) may be larger than the value obtained by dividing the second pin pitch p2 by the second diameter d2 (p2 / d2). Therefore, the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3) may be larger than the value obtained by dividing the first pin pitch p1 by the first diameter d1 (p1 / d1). Consequently, as in the configuration of (7) above, the third pin pitch p3 may be greater than or equal to the first pin pitch p1.

[0056] (8) In some embodiments, in any of the configurations (4) to (6) above, the third pin pitch p3 may be smaller than the first pin pitch p1.

[0057] As described above, the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3) may be greater than the value obtained by dividing the first pin pitch p1 by the first diameter d1 (p1 / d1). However, if the value obtained by dividing the third pin pitch p3 by the third diameter d3 (p3 / d3) is greater than the value obtained by dividing the first pin pitch p1 by the first diameter d1 (p1 / d1), then the third pin pitch p3 may be smaller than the first pin pitch p1, as in the configuration of (8) above.

[0058] (9) A gas turbine 100 according to at least one embodiment of the present disclosure comprises a turbine blade 10 having any of the configurations (1) to (8) above.

[0059] According to the configuration described in (9) above, the flow rate of cooling air CA in the turbine blade 10 can be suppressed, thereby improving the performance of the gas turbine 100. [Explanation of Symbols]

[0060] 3 Turbines 10 Turbine blades 11. Wing body (wing-shaped section) 11a Leading edge 11b Trailing edge 15 Trailing edge 16 Pin-fin channel 17 Inner wall 26 Pinfin 100 Gas Turbine 161 1st area 162 Second area 163 Third area 261 First Pinfin 262 Second Pinfin 263 Third Pinfin

Claims

1. Wing section and, A pin fin channel is formed within the trailing edge of the airfoil portion, extends toward the trailing edge of the airfoil portion, and opens to the outside of the airfoil portion at the trailing edge; Multiple pin fins connecting a pair of opposing inner walls that constitute the pin fin channel, Equipped with, The pin fin channel includes a first region and a second region located on the trailing edge side of the first region. The distance between the pair of opposing inner walls of the pin fin channel is greater in the first region than in the second region. The plurality of pin fins include a plurality of first pin fins provided in the first region and a plurality of second pin fins provided in the second region. The first diameter of the plurality of first pin fins is greater than the second diameter of the plurality of second pin fins. The first pin pitch between the plurality of first pin fins is greater than the second pin pitch between the plurality of second pin fins. The value obtained by dividing the first pin pitch by the first diameter is smaller than the value obtained by dividing the second pin pitch by the second diameter. Turbine blades.

2. The first region is the region in the pin fin flow path that is closest to the leading edge of the airfoil. The turbine blade according to claim 1.

3. The second region is adjacent to the first region. A turbine blade according to claim 1 or 2.

4. The pin fin channel includes a third region on the trailing edge side of the second region, The plurality of pin fins include a plurality of third pin fins provided in the third region, The value obtained by dividing the third pin pitch between the plurality of third pin fins by the third diameter of the plurality of third pin fins is greater than the value obtained by dividing the second pin pitch by the second diameter. A turbine blade according to claim 1 or 2.

5. The third diameter is equal to the second diameter. The turbine blade according to claim 4.

6. The aforementioned third pin pitch is larger than the aforementioned second pin pitch. The turbine blade according to claim 4.

7. The third pin pitch is greater than or equal to the first pin pitch. The turbine blade according to claim 4.

8. The third pin pitch is smaller than the first pin pitch. The turbine blade according to claim 4.

9. A gas turbine comprising the turbine blades described in claim 1.

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