gas turbine diffuser

Abstract

In gas turbines, this enables the stable placement of the diffuser at a relatively low cost, even in environments where the heat generated during operation affects the diffuser. [Solution] The gas turbine diffuser comprises a main diffuser member and a sub-diffuser member, which is a separate component from the main diffuser member and connects the main diffuser member to the combustor. The main diffuser member includes a diffuser body portion having an air inlet and arranged circumferentially around the rotating shaft, and an extended portion extending radially inward from the diffuser body portion. The sub-diffuser member has a first fixed portion fixed to the extended portion and a second fixed portion connected to the combustor or turbine nozzle.

Description

Technical Field

[0001] The present disclosure relates to a diffuser for circulating air introduced into a combustor of a gas turbine.

Background Art

[0002] Patent Document 1 discloses a support structure for supporting a diffuser pipe for guiding air to a combustion section in a gas turbine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a gas turbine, it is required to stably arrange the diffuser even in an environment where heat generated during driving reaches the diffuser. However, if the diffuser is simply composed of a high-functional material that can withstand such an environment, the manufacturing cost of the gas turbine increases.

[0005] Therefore, an object of the present disclosure is to enable the diffuser to be stably arranged at a relatively low cost even in an environment where heat generated during driving reaches the diffuser in a gas turbine.

Means for Solving the Problems

[0006] One aspect of the present disclosure relates to a gas turbine in which a compressor, a combustor and a turbine are arranged along a rotating shaft, and combustion gas from the combustor is guided to the turbine through a turbine nozzle, and the diffuser is used to circulate air from the compressor toward the combustor, comprising: a main diffuser member and a sub-diffuser member which is a separate component from the main diffuser member and connects the main diffuser member to the combustor, wherein the main diffuser member includes a diffuser body portion which has an inlet for introducing air from the compressor and is arranged around the rotating shaft in the circumferential direction, and an extending portion which extends radially inward from the diffuser body portion toward the rotating shaft, and the sub-diffuser member which has a first fixing portion which is fixed to the extending portion which is fixed to the main diffuser member, and a second fixing portion which is connected to the combustor or the turbine nozzle. [Effects of the Invention]

[0007] According to one aspect of this disclosure, in a gas turbine, the diffuser can be stably positioned at a relatively low cost, even in an environment where heat generated during operation affects the diffuser. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view of a gas turbine according to an embodiment. [Figure 2] Figure 2 is an enlarged cross-sectional view of the diffuser in Figure 1. [Figure 3] Figure 3 is an enlarged cross-sectional view of the main diffuser member and the sub-diffuser member shown in Figure 2. [Figure 4] Figure 4 is a view of the fixing member and its surrounding configuration of the diffuser shown in Figure 3, as seen from the axial direction. [Figure 5] Figure 5 is a schematic diagram of the unmanned aerial vehicle equipped with the gas turbine shown in Figure 1. [Modes for carrying out the invention]

[0009] [Embodiment] Embodiments will be described below with reference to the drawings. In the following description, axial direction X0 means the direction in which the axis X of the rotating shaft 2 extends. The front side means the upstream side in the direction in which air flows in the compressor 4 and turbine 6. The rear side means the downstream side in the direction in which air flows in the compressor 4 and turbine 6. That is, the front side means the side in axial direction X0 where the fan 3 is located. The rear side means the side in axial direction X0 opposite to the side where the fan 3 is located. Radial direction R means the radial direction of axis X, in other words, the direction perpendicular to axis X. Circumferential direction C means the direction around axis X.

[0010] Figure 1 is a cross-sectional view of a gas turbine 1 according to an embodiment. The gas turbine 1 is used, for example, as an engine for an aircraft such as an unmanned aerial vehicle, but the applications of the gas turbine 1 are not limited. As shown in Figure 1, the gas turbine 1 comprises a rotating shaft 2, a fan 3, a compressor 4, a combustor 5, a turbine 6, a gas turbine casing 7, and a diffuser 8.

[0011] As shown below, in the diffuser 8, the sub-diffuser member 21 is made of a separate component from the main diffuser member 20. Therefore, the sub-diffuser member 21 can be made of a high-performance material that can withstand the heat generated when the gas turbine 1 is in operation, separately from the main diffuser member 20. Consequently, even if heat is generated in the gas turbine 1 when it is in operation, the diffuser 8 can be stably positioned at a relatively low cost.

[0012] The rotating shaft 2 extends in the front-to-back direction of the gas turbine 1. The fan 3 is connected to the front of the rotating shaft 2 and rotates together with the rotating shaft 2. The compressor 4, combustor 5, and turbine 6 are arranged in this order from front to rear along the rotating shaft 2. The gas turbine casing 7 is a cylindrical object whose axis coincides with axis X. The gas turbine casing 7 houses the rotating shaft 2, fan 3, compressor 4, and turbine 6.

[0013] The gas turbine 1 is, for example, a twin-shaft gas turbine. The rotating shaft 2 includes a low-pressure shaft 11 and a high-pressure shaft 12 which is arranged on the same axis as the low-pressure shaft 11 and is rotatable relative to the low-pressure shaft 11. The high-pressure shaft 12 is a tubular hollow shaft. The low-pressure shaft 11 is inserted through the hollow space of the high-pressure shaft 12. The low-pressure shaft 11 is longer than the high-pressure shaft 12 in the front-rear direction. The front and rear ends of the low-pressure shaft 11 are exposed to the outside of the high-pressure shaft 12. The low-pressure shaft 11 is connected to a fan 3.

[0014] The compressor 4 includes a low-pressure compressor 13 and a high-pressure compressor 14. The low-pressure compressor 13 is positioned forward of the high-pressure compressor 14 in the axial direction X0. For example, the low-pressure compressor 13 is an axial-flow compressor, and the high-pressure compressor 14 is a centrifugal compressor.

[0015] The turbine 6 includes a high-pressure turbine 15 and a low-pressure turbine 16 positioned behind the high-pressure turbine 15. The low-pressure shaft 11 mechanically connects the low-pressure compressor 13 to the low-pressure turbine 16. The high-pressure shaft 12 mechanically connects the high-pressure compressor 14 to the high-pressure turbine 15.

[0016] The gas turbine casing 7 includes an inner shell 17 and an outer shell 18. The inner shell 17 and the outer shell 18 have a cylindrical shape and are arranged concentrically with respect to each other. The inner shell 17 houses the compressor 4, the combustor 5, and the turbine 6. A cylindrical bypass passage 25 is located between the inner shell 17 and the outer shell 18.

[0017] A portion of the air drawn in by fan 3 flows through bypass path 25 and is discharged to the rear. The remaining air drawn in by fan 3 flows into low-pressure compressor 13. The air that has passed through low-pressure compressor 13 and high-pressure compressor 14 is introduced into combustor 5 via diffuser 8. The combustion gas discharged from combustor 5 passes through turbine nozzle 9 and is introduced into high-pressure turbine 15.

[0018] The combustor 5 of this embodiment is, as an example, a counterflow type. Further, the combustor 5 is, for example, an annular type having an annular shape extending in the circumferential direction C. The combustor 5 includes an inner liner 5a, an outer liner 5b, an end liner 5c, a first turn guide 5d, and a second turn guide 5e. The liners 5a to 5c define a combustion chamber S inside the combustor 5. The axial direction of the combustor 5 coincides with the axial direction X0 of the rotation axis 2.

[0019] The inner liner 5a and the outer liner 5b have a cylindrical shape extending in the axial direction X0. The outer liner 5b is arranged outside the inner liner 5a in the radial direction R. The end liner 5c connects one end portion in the axial direction X0 of the inner liner 5a and the outer liner 5b. The end liner 5c has an annular shape extending in the radial direction R. A fuel nozzle N through which fuel is supplied from a pipe 10 extending in the axial direction X0 is attached to the end liner 5c.

[0020] The first turn guide 5d curves so as to change the direction by 180° from the tip of the outer liner 5b on the front side in the axial direction X0 and extends to the rear side in the axial direction X0. The second turn guide 5e curves so as to change the direction by 180° from the tip of the inner liner 5a on the front side in the axial direction X0 and extends to the rear side in the axial direction X0. The turn guides 5d and 5e define an exhaust passage T continuous with the combustion chamber S. The exhaust port of the exhaust passage T is directed toward a turbine nozzle 9 including a plurality of nozzle guide vanes 9a.

[0021] As an example, the diffuser 8 circulates the air from the compressor 4 toward the combustor 5. Air flowing out from the high-pressure compressor 14 may flow through the diffuser 8. The diffuser 8 may be a cylindrical object extending in the axial direction X0. The diffuser 8 may be arranged so as to surround the outer circumference of the rear end of the high-pressure compressor 14. The combustor 5 may be arranged behind the diffuser 8.

[0022] Figure 2 is an enlarged cross-sectional view of the diffuser 8 in Figure 1. As shown in Figure 2, the diffuser 8 comprises a main diffuser member 20 and a sub-diffuser member 21, which is a separate component from the main diffuser member 20 and connects the main diffuser member 20 to the combustor 5.

[0023] The sub-diffuser member 21 has higher heat resistance or higher strength than the main diffuser member 20. For example, the sub-diffuser member 21 may contain a nickel alloy. In this case, the sub-diffuser member 21 may contain, as an example, a nickel-chromium-iron alloy. The main diffuser member 20 may contain stainless steel.

[0024] The main diffuser member 20 includes a diffuser body portion 20a and an extended portion 20b. The diffuser body portion 20a is arranged to surround the rotation axis 2 in the circumferential direction C. The diffuser body portion 20a guides the air discharged from the high-pressure compressor 14, which is a centrifugal compressor, to the outer circumference of the combustor 5. The diffuser body portion 20a has an inlet 20c into which air is introduced from the compressor 4 and an outlet 20d into which the air that has passed through the diffuser body portion 20a is discharged into the combustor casing 19. The diffuser body portion 20a has a cylindrical shape extending around an axis X. The diffuser body portion 20a overlaps, for example, the outer liner 5b and the first turn guide 5d of the combustor 5 in the radial direction R.

[0025] The extended portion 20b is connected to the sub-diffuser member 21. The extended portion 20b extends inward in the radial direction R from the diffuser body portion 20a. For example, the extended portion 20b extends inward in the radial direction R from the portion of the diffuser body portion 20a facing the combustor 5, along the rear surface of the high-pressure compressor 14. The inward side of the extended portion 20b in the radial direction R may be connected to the sub-diffuser member 21.

[0026] The sub-diffuser member 21 is connected to the main diffuser member 20 and supports the combustor 5 or the turbine nozzle 9. The sub-diffuser member 21 has a cylindrical shape extending in the circumferential direction C about the axis X. The sub-diffuser member 21 has a first fixing portion 21a fixed to the extended portion 20b and a second fixing portion 21b connected to the combustor 5 or the turbine nozzle 9. In this embodiment, the second fixing portion 21b is connected to both the combustor 5 and the turbine nozzle 9.

[0027] The connection structure between the main diffuser member 20 and the sub-diffuser member 21 is not particularly limited, but in this embodiment, the main diffuser member 20 and the sub-diffuser member 21 are fixed to each other by a screw structure. As an example, the extended portion 20b of the main diffuser member 20 and the first fixing portion 21a of the sub-diffuser member 21 have circumferential surfaces that extend in the circumferential direction C and are in contact with each other, and the circumferential surface of the sub-diffuser member 21 and the circumferential surface of the main diffuser member 20 have a screw structure 22 that screws into each other.

[0028] For example, the extended portion 20b of the main diffuser member 20 has a disc portion 20e extending radially R and circumferentially C from the diffuser body portion 20a, and a cylindrical portion 20f extending axially X0 from the inner end of the disc portion 20e in the radial direction R. The disc portion 20e may be inclined with respect to the radial direction R. Alternatively, for example, the disc portion 20e may be inclined inward and rearward with respect to the radial direction R. The cylindrical portion 20f has a circumferential surface extending in the circumferential direction C. In this case, the cylindrical portion 20f has a first screw structure 20g arranged on its inner circumferential surface with screw threads extending in the circumferential direction C. The cylindrical portion 20f is located radially R inward from the exhaust passage T of the combustor 5.

[0029] For example, the first fixing portion 21a of the sub-diffuser member 21 is a cylindrical portion having a circumferential surface extending in the circumferential direction C. In this case, the first fixing portion 21a has a second screw structure 21c arranged on the outer circumferential surface and having screw threads extending in the circumferential direction C. The screw structure 22 of this embodiment, as an example, has this first screw structure 20g and the second screw structure 21c. The sub-diffuser member 21 is fixed to the main diffuser member 20 by screwing the first screw structure 20g and the second screw structure 21c together.

[0030] The extending portion 20b may have a projection 20h that protrudes radially inward from the disc portion 20e in the radial direction R. The projection 20h may have an end face 20i that extends in the circumferential direction C and radial direction R and is oriented towards the rear. In contrast, the first fixing portion 21a may have an end face 21d that extends in the circumferential direction C and radial direction R and is oriented towards the front, and is facing the end face 20i. In this case, the end face 20i of the projection 20h may face the end face 21d of the first fixing portion 21a in the axial direction X0, thereby restricting the relative movement of the main diffuser member 20 and the sub-diffuser member 21 in the axial direction X0.

[0031] The connection structure of the sub-diffuser member 21 to the combustor 5 or turbine nozzle 9 is not particularly limited, but in this embodiment, the sub-diffuser member 21, combustor 5, and turbine nozzle 9 are fixed to each other by bolts B. As an example, in the sub-diffuser member 21, the second fixing portion 21b has a flange portion 21e that protrudes radially outward from the first fixing portion 21a in the radial direction R and extends in the circumferential direction C. The flange portion 21e is provided with a plurality of bolt shaft housing recesses 21f arranged at intervals in the circumferential direction C. The bolt shaft housing recesses 21f have bolt holes 21g with female threads formed therein. Alternatively, the flange portion 21e may simply be provided with a plurality of bolt holes arranged at intervals in the circumferential direction C.

[0032] The combustor 5 has a combustor body 5g including a combustion chamber S, and a flange portion 5h that protrudes radially R inward from the combustor body 5g and extends circumferentially C. The flange portion 5h has a plurality of through holes 5f. The turbine nozzle 9 has a nozzle body 9c that guides the combustion gas from the combustor 5 to the turbine 6, and a flange portion 9d that protrudes radially R inward from the nozzle body 9c and extends circumferentially C. The flange portion 9d has a plurality of through holes 9b.

[0033] In the gas turbine 1, the flange portions 21e, 5h, and 9d are stacked so that the multiple bolt holes 21g and the multiple insertion holes 5f and 9b align, and the bolt shafts of bolts B are inserted through the multiple bolt holes 21g and the multiple insertion holes 5f and 9b. In this case, the male threads on the outer circumference of the bolt shaft are screwed into the female threads on the inner circumference of the bolt holes 21g. As a result, the second fixing portion 21b is connected to the combustor 5 and the turbine nozzle 9.

[0034] The turbine nozzle 9 has a plurality of nozzle guide vanes 9a arranged spaced apart in the circumferential direction C. Each nozzle guide vane 9a has a plate surface that is inclined with respect to the axial direction X0. As a result, when combustion gas passes through the turbine nozzle 9, the load of the combustion gas acts on each nozzle guide vane 9a of the turbine nozzle 9 in one of the circumferential directions C1. For example, the screw structure 22 is arranged so that the screwing progresses in the direction C1 in the circumferential direction C where the load of combustion gas from the combustor 5 acts on the turbine nozzle 9. Direction C1 is, for example, counterclockwise when viewed from the front, but is not limited to this.

[0035] Figure 3 is an enlarged cross-sectional view of the main diffuser member 20 and the sub-diffuser member 21 in Figure 2. As shown in Figure 3, the diffuser 8 may include at least one fixing member 23 that fixes the relative position of the main diffuser member 20 and the sub-diffuser member 21 in the circumferential direction C. The configuration of the fixing member 23 is not limited. For example, the fixing member 23 may be positioned to penetrate the main diffuser member 20 and the sub-diffuser member 21 with the screw structures 22 of the main diffuser member 20 and the sub-diffuser member 21 screwed into each other.

[0036] The fixing member 23 includes, for example, a pin P1 extending in the axial direction X0. In this case, the diffuser 8 has an insertion hole 8a defined by the main diffuser member 20 and the sub-diffuser member 21 when the screw structure 22 is fully screwed in. The inner circumferential surface 8b of the insertion hole 8a is defined by the inner circumferential surfaces of a groove 20j located on the inner circumferential surface side of the cylindrical portion 20f of the main diffuser member 20 and a groove 21h located on the outer circumferential surface of the first fixing portion 21a of the sub-diffuser member 21.

[0037] The pin P1 is inserted into the through hole 8a. By positioning the pin P1 within the through hole 8a, the sub-diffuser member 21 is prevented from being angularly displaced in the circumferential direction C relative to the main diffuser member 20, thereby preventing the screw structure 22 from loosening. In this way, the pin P1 acts as an anti-rotation device that restricts the relative angular displacement of the main diffuser member 20 and the sub-diffuser member 21 in the circumferential direction C.

[0038] The diffuser 8 may include a fall prevention structure 24 to prevent the pin P1 from falling out of the main diffuser member 20 and the sub-diffuser member 21. Figure 4 is a view of the fixing member 23 and its surrounding configuration of the diffuser 8 of Figure 3, as seen from the axial direction X0. As shown in Figure 4, the fall prevention structure 24 has, for example, at least one crimping structure P2. The front end face of the pin P1 is located behind the front opening of the insertion hole 8a in the axial direction X0.

[0039] The front surface of the main diffuser member 20 around the insertion hole 8a is partially recessed towards the rear in the axial direction X0, and the modified portion of the main diffuser member 20 partially blocks the front opening of the insertion hole 8a, thereby forming a crimping structure P2 that prevents the pin P1 from coming out of the insertion hole 8a. The fall prevention structure 24 has, for example, a pair of crimping structures P2 arranged on both sides of the pin P1 when viewed from the axial direction X0. The fall prevention structure 24 may also be a snap pin that penetrates the main diffuser member 20 and the pin P1 in the radial direction R.

[0040] Figure 5 is a schematic diagram of an unmanned aerial vehicle 40 equipped with the gas turbine 1 shown in Figure 1. As shown in Figure 5, the gas turbine 1 is located, for example, inside a through-hole 41a that extends in the longitudinal direction and is positioned in the fuselage 41 of the unmanned aerial vehicle 40. The configuration of the unmanned aerial vehicle 40 and the arrangement of the gas turbine 1 in the unmanned aerial vehicle 40 are not limited to this.

[0041] When the gas turbine 1 is running, air introduced from the high-pressure compressor 14 through the inlet 20c to the diffuser 8 is sent into the combustor casing 19 through the outlet 20d. A portion of the air in the combustor casing 19 is introduced into the combustion chamber S of the combustor 5. The fuel nozzle N also injects liquid fuel into the combustion chamber S. In the combustion chamber S, the fuel mixed with air is burned to produce combustion gases.

[0042] After being discharged from the combustor 5, the combustion gas is guided by multiple nozzle guide vanes 9a of the turbine nozzle 9 and flows into the high-pressure turbine 15 and the low-pressure turbine 16. In this way, the combustion gas from the combustor 5 is guided to the turbine 6 through the turbine nozzle 9 in the gas turbine 1. The rotational driving force of the turbine 6 is transmitted to the rotating shaft 2, causing the rotating shaft 2 to rotate in the circumferential direction C.

[0043] As described above, in the diffuser 8 of this embodiment, the sub-diffuser member 21 is made of a separate component from the main diffuser member 20. Therefore, the sub-diffuser member 21, which receives high heat from the combustor 5 or turbine nozzle 9, can be made of a high-performance material that can withstand such heat, separately from the main diffuser member 20. This eliminates the need to make both the main diffuser member 20 and the sub-diffuser member 21 from expensive high-performance materials. Furthermore, the main diffuser member 20 and the sub-diffuser member 21 can be manufactured efficiently and individually. Consequently, even when heat is generated in the gas turbine 1 during operation, the diffuser 8 can be stably positioned at a relatively low cost.

[0044] Furthermore, if the sub-diffuser member 21 is configured to have higher heat resistance or higher strength than the main diffuser member 20, the diffuser 8 can be stably positioned at a relatively lower cost compared to the case where both the main diffuser member and the sub-diffuser member are configured to have high heat resistance or high strength. In this case, for example, it is preferable that the main diffuser member 20 is made of stainless steel and the sub-diffuser member 21 is made of a nickel alloy.

[0045] As another example, the extended portion 20b of the main diffuser member 20 has a circumferential surface extending in the circumferential direction C, and the first fixing portion 21a of the sub-diffuser member 21 extends in the circumferential direction C and has a circumferential surface facing the circumferential surface of the main diffuser member 20 in the radial direction R. In this case, the circumferential surface of the sub-diffuser member 21 and the circumferential surface of the main diffuser member 20 have a screw structure 22 that screws into each other. With this configuration, the main diffuser member 20 and the sub-diffuser member 21 can be easily connected by the screw structure 22.

[0046] Furthermore, the screw structure 22 is arranged, as an example, in a direction such that the screwing progresses in the direction C1 of the circumferential direction C, where the load of combustion gas from the combustor 5 acts on the turbine nozzle 9. With this configuration, the screwing of the screw structure 22 between the main diffuser member 20 and the sub-diffuser member 21 can be maintained by the load acting on the turbine nozzle 9.

[0047] Furthermore, the diffuser 8 may, as an example, further include at least one fixing member 23 positioned through the main diffuser member 20 and the sub-diffuser member 21 while the screw structure 22 of the main diffuser member 20 and the sub-diffuser member 21 are screwed together. With this configuration, the screwing of the screw structure 22 of the main diffuser member 20 and the sub-diffuser member 21 can be maintained by the fixing member 23.

[0048] Furthermore, the combustor 5, as an example, has a combustor body 5g including a combustion chamber S and a flange portion 5h. In contrast, the turbine nozzle 9, as an example, has a nozzle body 9c that guides the combustion gas from the combustor 5 to the turbine 6 and a flange portion 9d that protrudes radially inward from the nozzle body 9c in the direction R. The second fixing portion 21b of the sub-diffuser member 21 is fastened to the flange portion 9d of the combustor 5 and the flange portion 9d of the turbine nozzle 9 by a fastener, which is a bolt B.

[0049] With the above configuration, the combustor 5 and turbine nozzle 9 can be easily connected to the second fixing portion 21b of the sub-diffuser member 21 by fastening. Furthermore, the combustor 5 and turbine nozzle 9 can be stably supported by the main diffuser member 20 via the sub-diffuser member 21. Therefore, in the gas turbine 1, even if high heat from the combustor 5 and turbine nozzle 9 is transferred to the diffuser 8, the diffuser 8 can be stably positioned at a relatively low cost.

[0050] As another example, the combustor 5 is of the reverse flow type. This allows the size of the combustor 5 in the axial direction X0 to be shortened, enabling a more compact arrangement of the combustor 5.

[0051] As described above, the embodiments have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these embodiments and can be applied to embodiments that have been modified, replaced, added, or omitted as appropriate. It is also possible to combine the components described in the embodiments to create new embodiments. For example, some components or methods in one embodiment may be applied to other embodiments, and some components in an embodiment can be separated from other components in that embodiment and extracted as appropriate. Furthermore, the components described in the attached drawings and detailed description include not only components essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the technology.

[0052] At least one of the connection structure between the main diffuser member 20 and the sub-diffuser member 21, and the connection structure of the second fixing part 21b to the combustor 5 or turbine nozzle 9, may include a welded portion. Furthermore, the first thread structure 20g of the cylindrical part 20f may be located on the outer circumferential surface of the cylindrical part 20f, and the second thread structure 21c of the first fixing part 21a may be located on the inner circumferential surface of the first fixing part 21a. Either the first thread structure 20g or the second thread structure 21c may be a male thread.

[0053] Furthermore, screws are not required to be placed in the second fixing portion 21b. In this case, the bolt shafts of the bolts B inserted into the multiple bolt holes and multiple insertion holes 5f and 9b located in the flange portion 21e of the sub-diffuser member 21 may be fastened with fastening components such as nuts.

[0054] Furthermore, the fixing member 23 may include a threadlocker to secure the screw connection between the first screw structure 20g and the second screw structure 21c. Also, the fixing member 23 is not essential. For example, the fixing member 23 may be omitted when the connection between the main diffuser member 20 and the sub-diffuser member 21 is maintained.

[0055] Furthermore, the position in which the crimping structure P2 is positioned is not limited. For example, the crimping structure P2 may be positioned in a position that overlaps with the protrusion 20h. In this case, the protrusion 20h is positioned in a position that overlaps with the first fixing part 21a from front to rear. Therefore, for example, when the crimping structure P2 is formed by pressing the surface of the main diffuser member 20 from the front with a tool during the manufacture of the diffuser 8, the protrusion 20h is stably supported by the first fixing part 21a. Also, if the main diffuser member 20 has a protrusion 20h, the insertion hole 8a may be positioned at a distance from the screw structure 22 and overlapping with the protrusion 20h.

[0056] [Pattern] The embodiments described above are specific examples of the following embodiments. [Aspect 1] In a gas turbine in which a compressor, a combustor, and a turbine are arranged along a rotating shaft, and combustion gas from the combustor is guided to the turbine through a turbine nozzle, a diffuser is provided for circulating air from the compressor toward the combustor, Main diffuser component, The system includes a sub-diffuser member, which is a separate component from the main diffuser member, and which connects the main diffuser member to the combustor. The main diffuser member is, A diffuser body having an inlet through which air is introduced from the compressor, and arranged to surround the rotating shaft in the circumferential direction, The diffuser body includes an extended portion that extends radially inward from the rotating shaft, A gas turbine diffuser, wherein the sub-diffuser member has a first fixing portion fixed to the extended portion of the main diffuser member and a second fixing portion connected to the combustor or the turbine nozzle.

[0057] According to the above configuration, the sub-diffuser member can be made as a separate component from the main diffuser member. Therefore, the sub-diffuser member, which receives high heat from the combustor or turbine nozzle, can be made of a high-performance material capable of withstanding that heat, separately from the main diffuser member. This eliminates the need to make both the main and sub-diffuser members from expensive high-performance materials. Furthermore, the sub-diffuser member and the main diffuser member can be manufactured efficiently and individually. Consequently, even when heat is generated during operation in a gas turbine, the diffuser can be stably positioned at a relatively low cost.

[0058] [Aspect 2] The diffuser for a gas turbine according to embodiment 1, wherein the sub-diffuser member has higher heat resistance or higher strength than the main diffuser member.

[0059] With the above configuration, the diffuser can be stably positioned at a relatively low cost compared to cases where both the main diffuser member and the sub-diffuser member are configured to have high heat resistance or high strength.

[0060] [Aspect 3] The extended portion of the main diffuser member has a circumferential surface that extends in the circumferential direction, The first fixing portion of the sub-diffuser member extends in the circumferential direction and has a circumferential surface facing the circumferential surface of the main diffuser member in the radial direction. A gas turbine diffuser according to embodiment 1 or 2, wherein the circumferential surface of the sub-diffuser member and the circumferential surface of the main diffuser member have a screw structure that allows them to be screwed together.

[0061] With the above configuration, the main diffuser member and the sub-diffuser member can be easily connected by the screw structure.

[0062] [Aspect 4] The diffuser for a gas turbine according to embodiment 3, wherein the screw structure is arranged in a direction such that the screwing progresses in the circumferential direction in which the load of combustion gas from the combustor acts on the turbine nozzle.

[0063] According to the above configuration, the threaded connection between the main diffuser member and the sub-diffuser member can be maintained by the load acting on the turbine nozzle.

[0064] [Aspect 5] A gas turbine diffuser according to embodiment 3 or 4, further comprising at least one fixing member disposed through the main diffuser member and the sub-diffuser member, with the screw structures of the main diffuser member and the sub-diffuser member screwed together.

[0065] According to the above configuration, the screw connection between the main diffuser member and the sub-diffuser member can be maintained by the fixing member.

[0066] [Aspect 6] A diffuser according to any one of embodiments 1 to 5, The compressor and, A combustor having a combustor body portion including a combustion chamber, and a flange portion projecting radially inward from the combustor body portion, The aforementioned turbine, The rotating shaft that connects the compressor to the turbine, The turbine nozzle comprises a nozzle body portion that guides the combustion gas from the combustor to the turbine, and a flange portion that protrudes radially inward from the nozzle body portion. A gas turbine in which the second fixing portion of the sub-diffuser member of the diffuser is fastened to the flange portion of the combustor and the flange portion of the turbine nozzle by fasteners.

[0067] With the above configuration, the combustor and turbine nozzle can be easily connected to the second fixing part of the sub-diffuser member by fastening. Furthermore, the combustor and turbine nozzle can be stably supported by the main diffuser member via the sub-diffuser member. Therefore, in a gas turbine, even if high heat from the combustor and turbine nozzle is transferred to the diffuser, the diffuser can be stably positioned at a relatively low cost.

[0068] [Aspect 7] The gas turbine according to embodiment 6, wherein the combustor is of the reverse flow type.

[0069] According to the above configuration, the size of the combustor in the axial direction of the rotating shaft is shortened, resulting in a gas turbine with a compactly arranged combustor.

[0070] [Aspect 8] An unmanned aerial vehicle equipped with a gas turbine according to embodiment 6 or 7.

[0071] According to the above configuration, even if high heat from the combustor and turbine nozzle is transferred to the diffuser, an unmanned aerial vehicle equipped with a gas turbine that can stably position the diffuser can be obtained at a relatively low cost. [Explanation of symbols]

[0072] C circumferential direction 1 Gas Turbine 4. Compressor 5 Combustor 5g combustion device 5h Flange section of the combustion chamber 6 Turbines 8 Diffusers 9. Turbine nozzle 9d Flange section of turbine nozzle 20 Main diffuser component 20a Diffuser main body 20c inlet 21 Sub-diffuser member 21a 1st fixed part 21b Second fixed part 22 Screw structure 23 Fixing member 40 Unmanned aerial vehicle

Claims

1. In a gas turbine in which a compressor, a combustor, and a turbine are arranged along a rotating shaft, and combustion gas from the combustor is guided to the turbine through a turbine nozzle, a diffuser is provided for circulating air from the compressor toward the combustor, Main diffuser component, The system includes a sub-diffuser member, which is a separate component from the main diffuser member, and which connects the main diffuser member to the combustor. The main diffuser member is, A diffuser body having an inlet through which air is introduced from the compressor, and arranged to surround the rotating shaft in the circumferential direction, The diffuser body includes an extended portion that extends radially inward from the rotating shaft, The sub-diffuser member has a first fixing portion fixed to the extended portion of the main diffuser member, and a second fixing portion connected to the combustor or the turbine nozzle. A gas turbine diffuser, wherein the extending portion and the first fixed portion have circumferential surfaces extending in the axial direction of the rotation shaft and the circumferential direction, and their circumferential surfaces are joined together with their surfaces overlapping in the radial direction.

2. The gas turbine diffuser according to claim 1, wherein the sub-diffuser member has higher heat resistance or higher strength than the main diffuser member.

3. A gas turbine in which a compressor, a combustor and a turbine are arranged along a rotating shaft, and combustion gas from the combustor is guided to the turbine through a turbine nozzle, wherein a diffuser is provided for circulating air from the compressor toward the combustor, Main diffuser component, The system includes a sub-diffuser member, which is a separate component from the main diffuser member, and which connects the main diffuser member to the combustor. The main diffuser member is, A diffuser body having an inlet through which air is introduced from the compressor, and arranged to surround the rotating shaft in the circumferential direction, The diffuser body includes an extended portion that extends radially inward from the rotating shaft, The sub-diffuser member has a first fixing portion fixed to the extended portion of the main diffuser member, and a second fixing portion connected to the combustor or the turbine nozzle. The extended portion of the main diffuser member has a circumferential surface that extends in the circumferential direction, The first fixing portion of the sub-diffuser member extends in the circumferential direction and has a circumferential surface facing the circumferential surface of the main diffuser member in the radial direction. A gas turbine diffuser in which the circumferential surface of the sub-diffuser member and the circumferential surface of the main diffuser member have a screw structure that allows them to be screwed together.

4. The diffuser for a gas turbine according to claim 3, wherein the screw structure is arranged in a direction such that the screwing progresses in the direction in which the load of combustion gas from the combustor acts on the turbine nozzle in the circumferential direction.

5. The gas turbine diffuser according to claim 3, further comprising at least one fixing member disposed through the main diffuser member and the sub-diffuser member, with the screw structures of the main diffuser member and the sub-diffuser member screwed together.

6. A diffuser according to any one of claims 1 to 5, The compressor and, A combustor having a combustor body portion including a combustion chamber, and a flange portion projecting radially inward from the combustor body portion, The aforementioned turbine, The rotating shaft that connects the compressor to the turbine, The turbine nozzle comprises a nozzle body portion that guides the combustion gas from the combustor to the turbine, and a flange portion that protrudes radially inward from the nozzle body portion. A gas turbine in which the second fixing portion of the sub-diffuser member of the diffuser is fastened to the flange portion of the combustor and the flange portion of the turbine nozzle by fasteners.

7. The gas turbine according to claim 6, wherein the combustor is of the reverse flow type.

8. An unmanned aerial vehicle comprising the gas turbine described in claim 6.

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