Low-pressure turbine cooling air supply structure

Abstract

The invention provides a low-pressure turbine cooling air supply structure, and belongs to the field of aero-engines. The low-pressure turbine disc is connected with the low-pressure turbine blades through mortise structures; the low-pressure turbine shaft is connected with the low-pressure turbine disc through a connecting piece; the disc rear baffle is clamped on the low-pressure turbine disc on the rear side of the low-pressure turbine blade through an elastic ring, and vent holes distributed in the circumferential direction are formed in the disc rear baffle; the air guiding pipe is arranged on the rear side of the low-pressure turbine blade and used for guiding cooling air from the air compressor; the disc rear air entraining ring is fixed to the engine stator part, an air entraining cavity and a nozzle are arranged on the disc rear air entraining ring, one side of the air entraining cavity communicates with the air entraining pipe, the other side of the air entraining cavity communicates with the nozzle, and a first honeycomb and a second honeycomb are arranged on the upper side and the lower side, facing the low-pressure turbine blades, of the disc rear air entraining ring correspondingly; and the first honeycomb and the second honeycomb respectively form a sealing structure with comb teeth on the disc rear baffle and the low-pressure turbine shaft.

Description

Technical Field

[0001] The present application belongs to the field of aero-engine technology, and in particular relates to a low-pressure turbine cooling air supply structure. Background Art

[0002] Turbine components are crucial components in aircraft engines. Traditionally, turbines consist of a high-pressure turbine and a low-pressure turbine, with guide vanes positioned between them. Turbine components operate in a high-temperature environment and require bleed air from the compressor to cool the turbine. Cooling air for the low-pressure turbine is typically drawn from the guide vane assembly.

[0003] However, in order to achieve a lightweight and compact design, the turbine components of some aircraft engines have begun to adopt a guide vaneless design, that is, the guide vanes have been eliminated.

[0004] The structure of turbine components without guide blades undergoes significant changes, especially to the air supply structure of the low-pressure turbine. The existing low-pressure turbine air supply structure is no longer suitable. Therefore, a new low-pressure turbine cooling air supply structure is needed to achieve air supply to the low-pressure turbine. Summary of the Invention

[0005] The purpose of the present application is to provide a low-pressure turbine cooling air supply structure to solve or alleviate at least one problem in the background technology.

[0006] The technical solution of this application is: a low-pressure turbine cooling air supply structure, comprising:

[0007] Air-cooled low-pressure turbine blades;

[0008] A low-pressure turbine disc, which is connected to the low-pressure turbine blades through a tongue-and-groove structure;

[0009] A low-pressure turbine shaft connected to the low-pressure turbine disc via a connecting piece;

[0010] A rear baffle is clamped onto the low-pressure turbine disk at the rear side of the low-pressure turbine blades via an elastic ring, and the rear baffle is provided with circumferentially distributed vents;

[0011] an air bleed duct, which is provided on the rear side of the low-pressure turbine blade and is used to introduce cooling gas from the compressor;

[0012] An air induction ring behind the disk is fixed to the engine stator. The air induction ring behind the disk is provided with an air induction cavity and a nozzle. One side of the air induction cavity is connected to the air induction pipe, and the other side of the air induction cavity is connected to the nozzle. The upper and lower sides of the air induction ring behind the disk facing the low-pressure turbine blades are respectively provided with a first honeycomb and a second honeycomb. The first honeycomb and the second honeycomb respectively form a sealing structure with the rear baffle and the grate teeth on the low-pressure turbine shaft.

[0013] The cooling gas introduced from the bleed air duct can flow into the vent hole from the bleed air cavity and the nozzle, and finally flow to the low-pressure turbine blades.

[0014] In at least one embodiment of the present application, the air-cooled low-pressure turbine blade has a radially extending cooling channel, and the blade surface of the low-pressure turbine blade is provided with air film holes, and the air film holes are connected to the cooling channel.

[0015] In at least one embodiment of the present application, the tongue and groove structure includes a dovetail tongue and groove and a circumferential fir-tree tongue and groove.

[0016] In at least one embodiment of the present application, the radial upper end of the rear baffle of the disk is provided with an axial protrusion, the axial protrusion is elastically supported on the low-pressure turbine blades, and the lower end of the rear baffle of the disk is clamped on the low-pressure turbine disk through an elastic ring.

[0017] In at least one embodiment of the present application, the elastic ring is a C-shaped open ring.

[0018] In at least one embodiment of the present application, the radial height of the vent hole on the rear baffle is lower than the nozzle on the rear air inlet ring, and the radial height of the vent hole is made consistent with the radial height of the nozzle by centrifugal force during operation.

[0019] In at least one embodiment of the present application, the low-pressure turbine blades, low-pressure turbine disc, low-pressure turbine shaft, disc rear baffle and elastic ring constitute a low-pressure turbine rotor assembly, and the low-pressure turbine rotor assembly is supported on the engine stator component through bearings.

[0020] The low-pressure turbine cooling air supply structure provided in this application is a feasible solution for cooling and supplying air to the low-pressure turbine after eliminating the guide vane assembly. It can effectively ensure that cold air enters the low-pressure turbine blades for cooling. The structure of this application is simple and reliable and has great engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0022] Figure 1 Schematic diagram of a typical turbine component.

[0023] Figure 2 This is a schematic diagram of the turbine cooling and air supply structure of this application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0025] like Figure 1 The figure shows a schematic diagram of a typical turbine component. A typical turbine component 100 includes a high-pressure turbine 101, a low-pressure turbine 102 and a guide vane 103 arranged between the high-pressure and low-pressure turbines. The guide vane 103 is a stator component. After a stream of low-temperature gas is introduced from the compressor, it passes through the guide vane 103 radially, is drawn out from the rear side of the turbine disk of the guide vane 103, and passes into the low-pressure turbine 102, thereby cooling the low-pressure turbine 2.

[0026] However, after the guide vanes 103 are removed, the low-pressure turbine cooling and air supply solution of the prior art is no longer applicable. Therefore, the present application provides a new low-pressure turbine cooling and air supply structure.

[0027] like Figure 2 As shown, the high-pressure turbine cooling air supply structure 200 provided in this application includes: low-pressure turbine blades 201, a low-pressure turbine disk 202, a low-pressure turbine shaft 203, a rear baffle 204, an elastic ring 205, a rear air bleed ring 206 and an air bleed pipe 207.

[0028] Among them, the low-pressure turbine blade 201 is an air-cooled blade, that is, a radially extending cooling channel is provided inside the low-pressure turbine blade 201, and an air film hole is provided on the surface of the blade body. The cooling gas can flow into the cooling channel and then flow out from the air film hole, thereby protecting the low-pressure turbine blade 201.

[0029] The low-pressure turbine blade 201 is mounted on the low-pressure turbine disc 202 via a tongue-and-groove structure. In some embodiments of the present application, the tongue-and-groove structure can be a dovetail tongue-and-groove or a circumferential fir-tree tongue-and-groove, depending on the use environment of the low-pressure turbine blade 201.

[0030] The low-pressure turbine disk 202 is connected to the low-pressure turbine shaft 203 by bolts.

[0031] Bleed air duct 207 is used to bleed air from the compressor and connects to the rear side of the low-pressure turbine blades 201. Bleed air duct 207 is located inside other engine components to avoid direct contact with high-temperature combustion gases. For example, bleed air duct 207 can be located inside a support plate. The support plate can have a double-layer hollow structure, with the air passing through the innermost hollow core, thereby reducing the temperature of the cooling gas within bleed air duct 207.

[0032] The disc-behind air ring 206 is a stator component, located behind the low-pressure turbine blades 201 and fixedly connected to the engine stator. The disc-behind air ring 206 is equipped with an air bleed cavity 2061 on its rear side and a nozzle 2062 on its front side. The air bleed cavity 2061 communicates with the air bleed duct 207 on one side and the nozzle 2062 on the other side, cooling the low-pressure turbine blades 207 with cold air introduced by the air bleed duct 207. In a preferred embodiment of the present application, the radial height of the nozzle 2062 is approximately between the low-pressure turbine blades 201 and the low-pressure turbine disc 202, allowing the gas ejected from the nozzle 2062 to smoothly enter the cooling channel of the low-pressure turbine blades 201.

[0033] In addition, the first honeycomb 2063 and the second honeycomb 2064 are respectively provided on the upper and lower sides of the rear air induction ring 206 facing the low-pressure turbine blades 201. The first honeycomb 2063 and the second honeycomb 2064 form a sealing structure with the rear baffle 204 and the grate teeth on the low-pressure turbine shaft 203, respectively, thereby forming a sealing cavity between the low-pressure turbine blades 201 and the rear air induction ring 206 to prevent cold air leakage.

[0034] The rear baffle 204 is mounted on the low-pressure turbine disk 202 behind the low-pressure turbine blades 201 via an elastic ring 205. Its radial upper end is typically provided with an axial protrusion that elastically abuts and supports the low-pressure turbine blades 201. The rear baffle 204 is provided with a plurality of circumferentially distributed air vents 2041. These air vents 2041 are positioned slightly lower in radial height than the nozzles 2062, allowing for the circulation of cool air. In this application, by setting the radial height of the air vents 2041 on the rear baffle 204 slightly lower than the nozzles 2062, the radial height of the air vents 2041 increases slightly during operation due to centrifugal deformation, reaching a position approximately aligned with the radial height of the nozzles 2062. This further facilitates the flow of cool air from the nozzles 2062 into the air vents 2041.

[0035] The elastic ring 205 has an open C-shaped structure with an L-shaped cross-section. The snap-fitting portion of the elastic ring 205 connects to the rear baffle 204, and its end face engages the low-pressure turbine disk 202, thereby securing the rear baffle 204. Furthermore, the elastic ring 205 can be made of a resilient metal material, such as 50CrVA chrome-vanadium alloy spring steel or Inconel 718 high-temperature spring steel.

[0036] The low-pressure turbine blades 201 , the low-pressure turbine disk 202 , the low-pressure turbine shaft 203 , the disk rear baffle 204 and the elastic ring 205 constitute a low-pressure turbine rotor assembly, which is supported on the engine stator component through a bearing 208 .

[0037] During operation, cold air is introduced into the air inlet cavity 2061 of the air inlet ring 206 behind the disk through the air inlet pipe 207, and then flows into the air vent 2041 of the baffle 204 behind the disk through the nozzle 2062 of the air inlet ring 206 behind the disk, and then flows into the internal cooling channel of the low-pressure turbine blade 201, and finally flows out from the air film holes on the surface of the low-pressure turbine blade 201, forming air model cooling on the surface of the low-pressure turbine blade 201, and the cooling gas flowing out from the air film holes enters the main channel, thereby completing the cooling air supply to the low-pressure turbine blade 201.

[0038] The low-pressure turbine cooling air supply structure provided in this application is a feasible solution for cooling and supplying air to the low-pressure turbine after eliminating the guide vane assembly. It can effectively ensure that cold air enters the low-pressure turbine blades for cooling. The structure of this application is simple and reliable and has great engineering application value.

[0039] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A low-pressure turbine cooling air supply structure, characterized in that: include: Air-cooled low-pressure turbine blades; A low-pressure turbine disc, which is connected to the low-pressure turbine blades through a tongue-and-groove structure; A low-pressure turbine shaft connected to the low-pressure turbine disc via a connecting piece; A rear baffle is clamped onto the low-pressure turbine disk at the rear side of the low-pressure turbine blades via an elastic ring, and the rear baffle is provided with circumferentially distributed vents; an air bleed duct, which is provided on the rear side of the low-pressure turbine blade and is used to introduce cooling gas from the compressor; An air induction ring behind the disk is fixed to the engine stator. The air induction ring behind the disk is provided with an air induction cavity and a nozzle. One side of the air induction cavity is connected to the air induction pipe, and the other side of the air induction cavity is connected to the nozzle. The upper and lower sides of the air induction ring behind the disk facing the low-pressure turbine blades are respectively provided with a first honeycomb and a second honeycomb. The first honeycomb and the second honeycomb respectively form a sealing structure with the rear baffle and the grate teeth on the low-pressure turbine shaft. The cooling gas introduced from the bleed air duct can flow into the vent hole from the bleed air cavity and the nozzle, and finally flow to the low-pressure turbine blades.

2. The low-pressure turbine cooling air supply structure according to claim 1, characterized in that: The air-cooled low-pressure turbine blade has a radially extending cooling channel. The blade surface of the low-pressure turbine blade is provided with air film holes, and the air film holes are connected to the cooling channel.

3. The low-pressure turbine cooling air supply structure according to claim 1, characterized in that: The mortise and tenon structure includes a dovetail mortise and a circumferential fir-tree mortise and tenon.

4. The low-pressure turbine cooling air supply structure according to claim 1, characterized in that: The radial upper end of the disc rear baffle is provided with an axial protrusion, which is elastically supported on the low-pressure turbine blades. The lower end of the disc rear baffle is clamped on the low-pressure turbine disc through an elastic ring.

5. The low-pressure turbine cooling air supply structure according to claim 4, characterized in that: The elastic ring is a C-shaped open ring.

6. The low-pressure turbine cooling air supply structure according to claim 1, characterized in that: The radial height of the vent hole on the rear baffle is lower than the nozzle on the rear air inlet ring. During operation, the radial height of the vent hole is made consistent with the radial height of the nozzle by centrifugal force.

7. The low-pressure turbine cooling air supply structure according to any one of claims 1 to 6, characterized in that: The low-pressure turbine blades, low-pressure turbine disc, low-pressure turbine shaft, disc rear baffle and elastic ring constitute a low-pressure turbine rotor assembly, and the low-pressure turbine rotor assembly is supported on the engine stator component through bearings.

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