A gas turbine engine with a structure for reducing a thermal stress

Abstract

The present invention relates to a gas turbine engine having an improved thermal stress reduction structure so that thermal stress is not concentrated in a specific area. A gas turbine engine according to one embodiment of the present invention includes an exhaust case comprising a plurality of struts that partition an area where exhaust gas is discharged and a gas pass seat having a first connecting portion that extends in the direction of the drive shaft and protrudes radially; a vane assembly that supports a plurality of vanes disposed in a low-pressure turbine section and includes a second connecting portion that is connected to the gas pass seat and contacts a portion of the front of the first connecting portion; and a rotor blade that rotates together with the drive shaft.

Description

Technology Field

[0001] The present invention relates to a gas turbine engine having a thermal stress reduction structure, and more specifically, to a gas turbine engine capable of mitigating thermal stress by improving the contact structure between a vane assembly and an exhaust duct assembly. Background Technology

[0002] In gas turbine engines (especially turbo shaft engines), the vane assembly supporting the vanes of the low-pressure turbine is positioned adjacent to the main passage of the gas turbine engine and is therefore exposed to a high-temperature environment during the operation of the gas turbine engine. Furthermore, the front gaspath sheet of the exhaust duct assembly, which is in direct contact with the vane assembly, is thin and receives heat from the relatively high-temperature vane assembly, resulting in a large thermal gradient. This causes thermal stress to be locally concentrated on the front gaspath sheet, which shortens the lifespan of the exhaust duct assembly and the gas turbine engine containing it.

[0003] The aforementioned background technology is technical information that the inventor possessed for the derivation of the present invention or acquired during the process of deriving the present invention, and it cannot be considered as publicly known technology disclosed to the general public prior to the filing of the present invention. Prior art literature

[0004] U.S. Patent Publication 2004 / 0018081 The problem to be solved

[0005] The present invention aims to solve the aforementioned problems and provides a gas turbine engine capable of improving lifespan by improving the contact structure between the vane ring and the gas pass sheet, thereby reducing the heat transferred from the vane ring to the gas pass sheet and preventing the concentration of thermal stress.

[0006] However, these problems are exemplary, and the problems to be solved by the present invention are not limited thereto. means of solving the problem

[0007] A gas turbine engine according to one embodiment of the present invention includes an exhaust case comprising a plurality of struts that partition an area where exhaust gas is discharged and a gas pass seat having a first connecting portion that extends in the direction of the drive shaft and protrudes radially, a vane assembly that supports a plurality of vanes disposed in a low-pressure turbine section and includes a second connecting portion that is connected to the gas pass seat and contacts a portion of the front of the first connecting portion, and a rotor blade that rotates together with the drive shaft.

[0008] In a gas turbine engine according to one embodiment of the present invention, the second connecting member has a ring shape extending radially inward from one end of the vane assembly and may be arranged radially spaced inward relative to the upper end of the first connecting member.

[0009] In a gas turbine engine according to one embodiment of the present invention, the area of ​​the second connection part may be smaller than the area of ​​the first connection part.

[0010] In a gas turbine engine according to one embodiment of the present invention, the second connecting portion may include a plurality of first connecting protrusions that extend radially outward along the outer surface and are spaced apart from each other in the circumferential direction.

[0011] In a gas turbine engine according to one embodiment of the present invention, the second connecting portion may include a plurality of second connecting protrusions that extend radially inward along the inner surface and are spaced apart from each other in the circumferential direction.

[0012] Other aspects, features, and advantages other than those described above will become clear from the specific details, claims, and drawings for implementing the invention below. Effects of the invention

[0013] A gas turbine engine according to one embodiment of the present invention can prevent localized concentration of thermal stress on the gas pass sheet, thereby mitigating the temperature gradient of the gas pass sheet and improving the lifespan of the gas turbine engine. Brief explanation of the drawing

[0014] FIG. 1 shows a gas turbine engine according to one embodiment of the present invention. FIG. 2 shows a part of a gas turbine engine according to one embodiment of the present invention. FIG. 3 shows an enlarged view of the combined area of ​​the exhaust case and vane assembly of a gas turbine engine according to one embodiment of the present invention. FIG. 4 shows a second connecting part in one embodiment of the present invention. FIG. 5 shows an enlarged view of the combined area of ​​the exhaust case and vane assembly of a gas turbine engine according to another embodiment of the present invention. FIG. 6 shows a second connecting part according to another embodiment of the present invention. Specific details for implementing the invention

[0015] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the description of the invention. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. In describing the present invention, the same identification numerals are used for identical components, even if they are illustrated in different embodiments.

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.

[0017] In the following embodiments, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component.

[0018] In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0019] In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0020] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.

[0021] In the following embodiments, the x-axis, y-axis, and z-axis are not limited to three axes in an orthogonal coordinate system and can be interpreted in a broader sense that includes them. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but they may also refer to different directions that are not orthogonal to each other.

[0022] Where an embodiment can be implemented differently, a specific process sequence may be performed differently from the order described. For example, two processes described consecutively may be performed substantially simultaneously or proceed in the reverse order of the description.

[0023] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. In this application, terms such as “comprising” or “having” are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0025] FIG. 1 shows a gas turbine engine (1) according to one embodiment of the present invention, FIG. 2 shows a part of a gas turbine engine (1) according to one embodiment of the present invention, FIG. 3 shows an enlarged view of the combined area of ​​the exhaust case (100) and the vane assembly (200) of the gas turbine engine (1) according to one embodiment of the present invention, and FIG. 4 shows a second connecting part (211) in one embodiment of the present invention.

[0026] Referring to FIG. 1, a gas turbine engine (1) according to one embodiment of the present invention can be installed in an aircraft or a power plant to produce power. For example, the gas turbine engine (1) may be a turbo shaft engine for an aircraft. However, the type of gas turbine engine (1) is not particularly limited and may include various fluid machines.

[0027] For example, the gas turbine engine (1) may be a turbojet engine, a turbofan engine, a turboprop engine, a pulse-jet engine, or a ramjet engine. However, for the convenience of explanation, the following description will focus on the case where the gas turbine engine (1) is a turboshaft engine installed in an aircraft.

[0028] As shown in FIG. 1, a gas turbine engine (1) according to one embodiment of the present invention has a central axis Ax and may include an inlet section (2), a compressor (3), a combustion chamber (4), an exhaust section (5), a drive shaft (6), and a turbine (10). Additionally, the components of the gas turbine engine (1) may be placed inside a housing, a case, or a nacelle.

[0029] The inlet section (2) is positioned at the tip of the gas turbine engine (1) and introduces external air into the interior of the gas turbine engine (1). The external air introduced through the inlet section (2) is introduced into the compressor (3) and compressed to a predetermined temperature and pressure. In one embodiment, the compressor (3) may be a multi-stage compressor having a plurality of low-pressure compression sections and high-pressure compression sections.

[0030] External air passing through the compressor (3) flows into the combustion chamber (4) and is combusted, and rotates the drive shaft (6) as it passes through the turbine (10). In one embodiment, the turbine (10) may be a multi-stage turbine having a low-pressure turbine section and a high-pressure turbine section. The drive shaft (6) may be connected to other engines not shown, and accordingly, the gas turbine engine (1) according to one embodiment of the present invention can transmit work to the outside.

[0031] The external air passing through the turbine (10) is discharged to the outside of the nacelle through the exhaust section (5).

[0032] In one embodiment, the inlet section (2), compressor (3), combustion chamber (4), exhaust section (5), drive shaft (6), and turbine (10) may be arranged coaxially on the central axis Ax.

[0033] Referring to FIGS. 2 and FIGS. 3, a gas turbine engine (1) according to one embodiment of the present invention may include an exhaust case (100), a vane assembly (200), and a rotor blade (300). More specifically, FIG. 2 shows an enlarged view of the low-pressure turbine section and the exhaust section (5) of the turbine (10) of the gas turbine engine (1) according to one embodiment of the present invention. FIG. 3 also shows a frontal view of the second connecting section (211).

[0034] The exhaust case (100) is a passage through which exhaust gas passing through the turbine (10) is discharged to the outside. The exhaust case (100) may be positioned at the front end of the exhaust section (5) so as to be adjacent to the turbine (10). In one embodiment, the exhaust case (100) may be provided with a bearing housing (not shown) into which a drive shaft (6) is inserted radially inward.

[0035] In one embodiment, the exhaust case (100) may include a strut (110), a gas pass seat (120), and a hairpin (130).

[0036] The strut (110) extends radially inward from the inner circumference of the exhaust case (100) and can be connected to the bearing housing. A plurality of struts (110) are spaced apart from each other along the circumferential direction of the exhaust case (100) to partition the area where exhaust gas passing through the turbine (10) is exhausted.

[0037] In one embodiment, a tube (not shown) connected to an oil supply unit (not shown) may be disposed inside the strut (110) to supply oil, etc. to the bearing housing.

[0038] The gas pass sheet (120) is a member that guides exhaust gas discharged from a turbine (10), more specifically a low-pressure turbine, to an exhaust case (100), and may have a thin cylindrical shape extending in the direction of the drive shaft (6) from one end of the exhaust case (100).

[0039] Referring to FIG. 3, the gas pass sheet (120) may include a first connecting portion (121) that protrudes radially at one end. The first connecting portion (121) is a part that connects to a second connecting portion (211) of a vane assembly (200) described later, and the first connecting portion (121) and the second connecting portion (211) are supported by an axial load generated by a pressure difference passing through the gas passage.

[0040] As described above, since the exhaust case (100) is positioned at the rear end of the turbine (10), it comes into direct contact with high-temperature exhaust gas. In particular, the gas pass sheet (120) is the part that comes into contact with the exhaust gas first and has a relatively thin thickness, so it is prone to becoming hot when the gas turbine engine (1) is operating. As a result, large thermal stress is concentrated locally in the part of the gas pass sheet (120) that contacts the vane assembly (200), which can shorten the lifespan of not only the gas pass sheet (120) but also the exhaust case (100) and the entire gas turbine engine (1).

[0041] A gas turbine engine (1) according to one embodiment of the present invention can extend the lifespan of the gas turbine engine (1) by alleviating thermal stress concentrated on the gas pass sheet (120) by changing the shape of the vane assembly (200) that contacts the exhaust case (100).

[0042] The hairpin (130) is configured to fasten the exhaust case (100) to another member (e.g., a turbine support case of a gas turbine engine (1)), extends from the outer surface of the exhaust case (100), and may have a fastening hole (not shown in the drawing) at one end for fastening to another member.

[0043] As shown in FIGS. 2 and 3, the vane assembly (200) can be placed in the turbine (10) of the gas turbine engine (1), more specifically in the low-pressure turbine section. For example, the vane assembly (200) can serve to guide exhaust gas that has passed through the high-pressure turbine section to the low-pressure turbine section. In one embodiment, the vane assembly (200) may include a vane ring (210) and a vane (220).

[0044] The vane ring (210) supports a plurality of vanes (220) and can be connected to the gas pass sheet (120). More specifically, the vane ring (210) is positioned radially outward of the plurality of vanes (220) arranged in the low-pressure turbine section to support them, and can be extended toward the exhaust case (100) to be connected to the gas pass sheet (120).

[0045] In one embodiment, the vane ring (210) may have a shape in which the cross-sectional area increases toward the exhaust case (100), that is, toward the wake of the gas turbine engine (1).

[0046] In one embodiment, the vane ring (210) may include a second connecting portion (211). For example, as shown in FIG. 3, the second connecting portion (211) is positioned at the end of the vane ring (210) and may come into contact with a portion of the front surface of the first connecting portion (121). That is, the second connecting portion (211) may cover only a portion of the first connecting portion (121) instead of covering the entire first connecting portion (121).

[0047] More specifically, the vane ring (210) is a part directly connected to the gas pass sheet (120) and is relatively high in temperature because it is directly exposed to the high-temperature oiling environment. And when heat from the vane ring (210) is transferred to the gas pass sheet (120), thermal stress is locally concentrated in the gas pass sheet (120).

[0048] In order to prevent this, a gas turbine engine (1) according to one embodiment of the present invention can reduce the area of ​​the second connecting portion (211) of the vane ring (210) that contacts the first connecting portion (121) of the gas pass sheet (120), thereby reducing the amount of heat transferred to the gas pass sheet (120).

[0049] For example, as shown in FIG. 3, in a conventional gas turbine engine, the second connection part protrudes up to the part indicated by the dotted line and covers the entire upper portion of the first connection part. Here, the distance between the upper portion of the first connection part and the upper portion of the dotted line is h1. Therefore, the contact area between the second connection part and the first connection part is relatively large, so a large amount of heat is transferred from the vane ring to the gas pass sheet, and thermal stress is concentrated in the gas pass sheet.

[0050] On the other hand, in a gas turbine engine (1) according to one embodiment of the present invention, the area of ​​the second connecting part (211) is smaller than the area of ​​the first connecting part (121), as shown in FIG. 3. In particular, the contact surface of the second connecting part (211) with the first connecting part (121) may be arranged so as to be spaced inwardly with respect to the top of the first connecting part (121) in the radial direction. Here, the distance between the top of the first connecting part (121) and the top of the second connecting part (211) is h2. Through this configuration, the gas turbine engine (1) according to one embodiment of the present invention can reduce the total amount of heat transferred from the vane ring (210) to the gas pass sheet (120).

[0051] In one embodiment, on the surface where the first connecting part (121) and the second connecting part (211) come into contact with each other, the area of ​​the second connecting part (211) may be less than or equal to half the area of ​​the first connecting part (121).

[0052] In one embodiment, the second connecting portion (211) may further include a first connecting projection (212). For example, as shown in FIG. 3, the first connecting projection (212) extends radially outward along the inner circumference of the second connecting portion (211) and may be arranged in multiple numbers spaced apart from each other in the circumferential direction. Accordingly, the area of ​​contact between the second connecting portion (211) and the first connecting portion (121) can be further reduced, thereby further reducing the total amount of heat transferred from the vane ring (210) to the gas pass sheet (120).

[0053] More specifically, as described above, the second connection of the conventional gas turbine engine extends radially outward to cover up to the top of the first connection, which is indicated by the dotted line in FIG. 4. Accordingly, the area where the conventional second connection contacts the first connection is the entire area between the innermost solid circle and the outermost dotted circle.

[0054] On the other hand, the second connecting part (211) of the gas turbine engine (1) according to one embodiment of the present invention is spaced inwardly relative to the upper end of the first connecting part (121) in the radial direction, and a plurality of first connecting protrusions (212) are spaced apart from each other in the circumferential direction. Here, h1+h2 represents the distance between the first connecting protrusion (212) and the dotted line in FIG. 4. Accordingly, the area indicated by hatching in FIG. 4 becomes an area where the first connecting part (121) and the second connecting part (211) do not come into contact with each other in the gas turbine engine (1) according to one embodiment of the present invention.

[0055] Accordingly, the space between the first connecting protrusions (212) in the circumferential direction becomes an empty space, so that the second connecting part (211) does not come into contact with the first connecting part (121). That is, the gas turbine engine (1) according to one embodiment of the present invention can more effectively reduce the heat transferred from the vane ring (210) to the gas pass sheet (120) by having a scallop shape in which the outer surface of the second connecting part (211) is partially cut in the circumferential direction.

[0056] As shown in FIGS. 1 to 3, the rotor blade (300) is a blade disposed in the turbine (10), more specifically in the low-pressure turbine section, and can be disposed between the exhaust case (100) and the vane assembly (200). External air introduced through the vane assembly (200) rotates the rotor blade (300), and power can be generated as the drive shaft (6) connected to the rotor blade (300) rotates.

[0057] FIG. 5 shows an enlarged view of the combined area of ​​the exhaust case (100) and vane assembly (200) of a gas turbine engine (1) according to another embodiment of the present invention, and FIG. 6 shows a second connecting part (211A) according to another embodiment of the present invention.

[0058] The second connecting part (211A) of the vane assembly (200) according to the present embodiment has a different specific configuration from the second connecting part (211) of the vane assembly (200) according to the previously described embodiment. The remaining configuration may be the same as that of the previously described embodiment, and a detailed description thereof is omitted.

[0059] In one embodiment, the second connecting part (211A) may form a smaller contact surface than the second connecting part (211) according to the previously described embodiment by cutting a portion of the inner surface as shown in FIG. 5. Here, the dotted line indicates the lower end of the contact portion of the second connecting part of a conventional gas turbine engine, and h3 indicates the distance between the dotted line and the lower end of the contact portion of the second connecting part (211A) according to the present embodiment.

[0060] In one embodiment, the portion of the inner surface of the second connecting part (211A) that is cut may be formed so that it does not completely penetrate the second connecting part (211A), but rather a portion protrudes radially inward from the second connecting part (211A). More specifically, as shown in FIG. 5, a protrusion (not shown in the drawing) is formed radially inward as a portion of the inner surface of the second connecting part (211A) is cut, and the protrusion does not come into contact with the first connecting part (121). Accordingly, the contact area of ​​the second connecting part (211A) that contacts the first connecting part (121) is reduced, and a portion of the heat flowing into the second connecting part (211A) is dissipated through the protrusion, thereby preventing excessive heat from concentrating in the second connecting part (211A).

[0061] As shown in FIG. 6 in one embodiment, the second connecting portion (211A) may further include a second connecting projection (213A). For example, the second connecting projection (213A) may extend radially inward along the inner circumference of the second connecting portion (211A) and may be arranged in multiple numbers spaced apart from each other in the circumferential direction. Accordingly, the area of ​​contact between the second connecting portion (211A) and the first connecting portion (121) can be further reduced, thereby further reducing the total amount of heat transferred from the vane ring (210) to the gas pass sheet (120).

[0062] That is, the second connecting portion (211A) of the gas turbine engine (1) according to one embodiment of the present invention includes, in addition to a plurality of first connecting protrusions (212A) arranged on the outer surface spaced apart from each other in the circumferential direction, a plurality of second connecting protrusions (213A) arranged on the inner surface spaced apart from each other in the circumferential direction. Here, h1+h2 represents the distance between the first connecting protrusion (212A) and the dotted line in FIG. 6. Also, h3 represents the distance between the second connecting protrusion (213A) and the dotted line in FIG. 6.

[0063] Through this configuration, the area indicated by hatching in FIG. 6 becomes an area where the first connecting part (121) and the second connecting part (211A) do not come into contact with each other in the gas turbine engine (1) according to one embodiment of the present invention.

[0064] Accordingly, the space between the first connecting protrusion (212A) and the space between the second connecting protrusion (213A) in the circumferential direction becomes an empty space, so that the second connecting part (211A) does not come into contact with the first connecting part (121). That is, in the gas turbine engine (1) according to one embodiment of the present invention, the inner and outer surfaces of the second connecting part (211A) both have a scallop shape, thereby more effectively reducing the heat transferred from the vane ring (210) to the gas pass sheet (120).

[0065] FIG. 6 shows the first connecting projection (212A) and the second connecting projection (213A) arranged to face each other, but is not limited thereto. For example, the second connecting projection (213A) may be arranged between the first connecting projection (212A) in the circumferential direction. That is, the first connecting projection (212A) and the second connecting projection (213A) may be arranged to be staggered from each other in the circumferential direction. Accordingly, heat transmitted through the first connecting projection (212A) and the second connecting projection (213A) can be dispersed from each other in the circumferential direction, and the first connecting part (121) and the second connecting part (211A) can be connected more firmly.

[0066] A gas turbine engine (1) according to one embodiment of the present invention can prevent localized concentration of thermal stress on the gas pass sheet (120), thereby mitigating the temperature gradient of the gas pass sheet (120) and improving the lifespan of the gas turbine engine (1).

[0067] Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely illustrative. Those skilled in the art will fully understand that various modifications and equivalent alternative embodiments are possible from the embodiments. Accordingly, the true technical scope of protection of the present invention should be determined based on the appended claims.

[0068] The specific technical details described in the embodiments are merely examples and do not limit the technical scope of the embodiments. To make the description of the invention concise and clear, descriptions of general prior art and configurations may be omitted. Furthermore, the connections of lines or connecting members between components depicted in the drawings are illustrative of functional connections and / or physical or circuit connections, and may be replaced or represented by various additional functional, physical, or circuit connections in actual devices. Additionally, unless specifically stated with terms such as "essential" or "importantly," a component may not be strictly necessary for the application of the present invention.

[0069] The term "the above" or similar designations in the description of the invention and claims may refer to both singular and plural forms unless specifically limited otherwise. Furthermore, where a range is described in the embodiments, it is considered to include the invention with respect to individual values ​​within said range (unless otherwise stated), and is equivalent to describing each individual value constituting said range in the description of the invention. Additionally, regarding the steps constituting the method according to the embodiments, the steps may be performed in a suitable order unless explicitly stated or otherwise stated. The embodiments are not necessarily limited by the order in which the steps are described. The use of all examples or exemplary terms (e.g., etc.) in the embodiments is merely for the purpose of describing the embodiments in detail, and the scope of the embodiments is not limited by said examples or exemplary terms unless otherwise limited by the claims. Furthermore, a person skilled in the art will understand that various modifications, combinations, and changes may be made according to design conditions and factors within the scope of the claims or equivalents to which they are added. Explanation of the symbols

[0070] 1: Gas turbine engine 10: Turbine 100: Exhaust case 200: Vane Assembly 300: Rotor blade

Claims

Claim 1 An exhaust case comprising a plurality of struts partitioning an area where exhaust gas is discharged and a gas pass seat having a first connecting portion extending in the direction of the drive shaft and protruding radially; a vane assembly supporting a plurality of vanes disposed in a low-pressure turbine section, connected to the gas pass seat, and including a second connecting portion contacting a portion of the front of the first connecting portion; A gas turbine engine comprising: a rotor blade that rotates together with the drive shaft; wherein, in the radial direction, the second connecting portion is in a non-contact state with the first connecting portion; in the axial direction, the area of ​​the second connecting portion is smaller than the area of ​​the first connecting portion; the second connecting portion has a ring shape extending radially inward from one end of the vane assembly and is spaced inwardly from the upper end of the first connecting portion in the radial direction; the second connecting portion includes a plurality of first connecting protrusions that extend radially outward along the outer surface and are spaced apart from each other in the circumferential direction; the second connecting portion includes a plurality of second connecting protrusions that extend radially inward along the inner surface and are spaced apart from each other in the circumferential direction; the plurality of second connecting protrusions are spaced between the plurality of first connecting protrusions in the circumferential direction; and the inner surface and outer surface of the second connecting portion have a scallop shape that is cut circumferentially between the plurality of first connecting protrusions and the plurality of second connecting protrusions. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete

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