A structure for simulating turbine bleed air in a full-annulus test piece of a combustion chamber

Abstract

This application belongs to the field of aeroengines, and particularly relates to a structure for simulating turbine bleed air in a full-annulus combustor test piece. The present invention simulates the outlet conditions under the real operating conditions of the combustor by adding high-guide vanes at the outlet of the full-annulus combustor test piece, and leads out the turbine bleed air by designing a bleed orifice plate at the combustor outlet, which not only ensures that the inlet Mach number of the full-annulus combustor test piece at the design point is the same as the actual situation, but also avoids the disturbance of the secondary annulus flow caused by simulating the turbine bleed air.

Description

Technical Field

[0001] This application belongs to the field of aero-engines, and particularly relates to a structure for simulating turbine bleed air in a full-ring test piece of a combustion chamber. Background Art

[0002] As one of the three major components of the core engine of an aero-gas turbine, the main combustion chamber mainly converts the chemical energy of aviation fuel into heat energy through combustion to provide high-temperature and high-pressure gas for the turbine to do work. A large number of performance optimization and performance recording tests need to be carried out on component test pieces during the entire research and development cycle. According to the structural form, the combustion chamber component test pieces can be divided into single-head test pieces, multi-head test pieces (usually fan-shaped), and full-ring test pieces. Among them, the performance results obtained from the full-ring test piece tests are usually used as one of the important bases for measuring whether the design of a main combustion chamber meets the overall design requirements. Therefore, during the design process of the full-ring test piece, its structure needs to simulate the real working state of the core engine as much as possible. Since a part of the air inlet at the main combustion chamber inlet of the core engine is used for turbine blade cooling and does not participate in combustion, the design process of the full-ring test piece of the combustion chamber needs to consider the influence of this part of the air on the performance of the combustion chamber. The existing design schemes for the full-ring test piece of the main combustion chamber can usually be divided into two types. One scheme is to directly ignore this part of the air at the combustion chamber inlet (abbreviated as the inlet removal method), and the other scheme is to lead out this part of the air by opening holes on the inner and outer walls of the casing (abbreviated as the casing bleed air method). Both schemes only consider the aerodynamic influence of the air used for turbine blade cooling on the combustion characteristics, but ignore the influence of the structure of the high-pressure guide vane at the combustion chamber outlet on the performance of the combustion chamber.

[0003] The inlet removal method is a method of directly removing the turbine bleed air volume from the combustion chamber inlet. At the design point, the air intake of the flame tube head and the secondary air annulus of the full-ring test piece of the combustion chamber in this scheme is the same as the actual situation, but it cannot simulate the Mach number at the combustion chamber inlet under actual conditions;

[0004] The casing bleed air method is a turbine bleed air simulation method that leads out the turbine bleed air by designing bleed holes on the inner and outer casings of the combustion chamber. At the design point, this scheme can simulate the Mach number at the combustion chamber inlet and the air intake of the flame tube head and the secondary air annulus under actual conditions. However, due to the presence of bleed holes on the inner and outer walls of the casing, the flow in the secondary air annulus has turbulence, which will weaken the penetration ability of the large holes in the flame tube and deteriorate the quality of the outlet temperature field. Summary of the Invention

[0005] To solve the above problems, this application provides a structure for simulating turbine bleed air in a full-ring test piece of a combustion chamber, including:

[0006] The casing that houses the combustion chamber liner; the diffuser that introduces air flow into the casing; the combustion chamber liner divides the inner cavity of the casing into an outer ring cavity and an inner ring cavity; high guide vanes are installed at the tail of the combustion chamber liner, and the gases in the outer ring cavity, inner ring cavity, and combustion chamber liner flow into the high guide vanes; the inner wall of the casing has an air guiding channel; an air guiding orifice plate is installed at the corresponding position of the air guiding channel, and the air guiding orifice plate is installed at the rear end of the inner wall of the casing through bolts. The air guiding orifice plate has a plurality of air guiding small holes at the outlet of the air guiding channel; the outer edge of the rear end of the inner wall of the casing has a stepped surface, and the air guiding orifice plate axially extends at the corresponding position of the stepped surface to form a convex platform that mates with the stepped surface stop.

[0007] Preferably, on the side of the outlet end face of the air guiding channel away from the outer ring cavity, there is a U-shaped groove, and at the corresponding position of the air guiding orifice plate, there is a convex block that mates with the U-shaped groove, and the convex block falls into the U-shaped groove.

[0008] Preferably, the end face of the air guiding orifice plate close to the outer ring cavity is coated with a high-temperature coating.

[0009] Preferably, the air guiding small holes include two small holes distributed radially along the combustion chamber liner.

[0010] Preferably, the aperture of the air guiding small holes is not greater than 0.3 of the radial length of the air guiding channel along the combustion chamber liner.

[0011] Preferably, at the outlet of the air guiding small holes, there is a platform extending in the air flow direction, and the platform is used to install a measuring device.

[0012] Preferably, the bolts are located on the side of the outlet end face of the air guiding channel close to the outer ring cavity.

[0013] Preferably, the axis of the air guiding small holes is parallel to the center line of the combustion chamber.

[0014] The advantages of this application include: The present invention simulates the outlet conditions under the real working state of the combustion chamber by adding high guide vanes at the outlet of the full-ring test piece of the combustion chamber, and leads out the turbine air extraction by designing an air guiding orifice plate at the outlet of the combustion chamber. The position of the air guiding orifice plate and the air guiding channel is at the inner ring of the casing. With the help of the profile at the rear end of the inner ring of the casing, the profile bends towards the central axis of the combustion chamber liner, and air is extracted through the opening here, and the axis of the air hole is the same as the direction of the outlet of the combustion chamber liner, ensuring that the gas flows out smoothly, rather than forming a cyclone or pressure difference through the inclined small holes in the traditional way, which causes interference to the surrounding of the air extraction and disrupts the test. Through the position of the air guiding small holes, the axis direction of the small holes, and the limitation of the aperture, this application fully simulates the real environment during the test, and at the same time solves the problem of air flow disturbance caused by the air guiding small holes in the real environment. It not only ensures that the inlet Mach number of the full-ring test piece of the combustion chamber at the design point is the same as the real situation, but also avoids the local pressure pulsation in the secondary ring cavity caused by the traditional method of simulating turbine air extraction by opening holes in the combustion chamber casing, which has an adverse impact on the temperature quality at the outlet of the combustion chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic installation diagram of the air intake orifice plate (6) and the casing (8) in a preferred embodiment of the present application;

[0016] Figure 2 is a diagram of the combustion chamber air flow with the air intake orifice plate (6) installed;

[0017] Figure 3 is a diagram of the combustion chamber structure and the air flow with the air intake orifice plate (6) installed;

[0018] Among them, 1 - diffuser; 2 - nozzle; 3 - flame tube; 4 - outer ring cavity; 5 - high - conductivity vane; 6 - air intake orifice plate; 7 - inner ring cavity; 8 - casing; 9 - high - temperature coating; 61 - bump; 62 - air intake small hole; 63 - bolt; 81 - air intake flow channel; 82 - step surface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] To make the purpose, technical solutions, and advantages of the implementation of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The described embodiments are some, but not all, of the embodiments of the present application. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0020] The present application provides a structure for simulating turbine air extraction in a combustion chamber full - ring test piece, as shown, including: a casing 8 that houses the flame tube 3; a diffuser 1 that introduces air into the casing 3; the flame tube 3 divides the inner cavity of the casing 8 into an outer ring cavity 4 and an inner ring cavity 7; high - conductivity vanes 5 are installed at the tail of the flame tube 3, and the gases in the outer ring cavity 4, inner ring cavity 7, and flame tube 3 flow into the high - conductivity vanes 5 as Figure 3 shown; the inner wall of the casing 8 has an air intake flow channel 81; an air intake orifice plate 6 is installed at the corresponding position of the air intake flow channel 81, the air intake orifice plate 6 is installed at the rear end of the inner wall of the casing 8 through bolts 63, and the air intake orifice plate 6 has a plurality of air intake small holes 62 at the outlet of the air intake flow channel 81; the outer edge of the rear end of the inner wall of the casing 8 has a step surface 82, and the air intake orifice plate 6 axially extends at the corresponding position of the step surface 82 to form a boss that is in mating with the step surface 82 of the stop. The air intake orifice plate is fixed to the step surface 82 by means of stop mating and bolt connection. Its structural design also considers sealing by adding a sealing gasket, safety with a local high - temperature coating, and monitoring by arranging static pressure measuring points as Figure 1as shown

[0021] In the laboratory, the gas flow of this device is as Figure 2 shown. The air entering the combustion chamber from the front air intake section passes through the diffuser for deceleration and pressurization, and is divided into three streams, which flow into the outer ring cavity, the flame tube, and the inner ring cavity respectively. The air entering the outer ring is divided into two streams. One stream enters the flame tube to participate in combustion, and the other stream enters the high-conductivity cooling cavity to cool the high-conductivity blades. The air entering the inner ring cavity is divided into three streams. One stream enters the flame tube to participate in combustion, one stream enters the high-conductivity cooling cavity to cool the high-conductivity blades, and the other stream flows into the rear measurement section through the air intake orifice plate to simulate the air extraction of the turbine pre-whirl nozzle.

[0022] Preferably, the outlet end face of the air extraction flow channel 81 on the side away from the outer ring cavity 4 has a U-shaped groove, and at the corresponding position of the U-shaped groove, the air intake orifice plate 6 has a convex block that cooperates with the U-shaped groove. The convex block falls into the U-shaped groove. The cooperation of the U-shaped groove and the convex block can not only achieve the gas sealing effect, but also position and install the air intake orifice plate 6.

[0023] Preferably, the air intake orifice plate 6 near the outer ring cavity 4 is coated with a high-temperature coating 9. The end face of the air intake orifice plate 6 near the outer ring cavity 4 is directly in contact with the gas after combustion in the flame tube 3 and has a relatively high temperature. The high-temperature coating 9 can prevent the ablation of the air intake orifice plate 6.

[0024] Preferably, the air intake small holes 62 include two small holes distributed radially along the flame tube 3. The radially distributed small holes can achieve the rectification of the gas on the premise of meeting the ventilation requirements, avoid the generation of turbulent flow when the air flow in the air extraction flow channel 81 flows out, and affect the measurement at the rear end.

[0025] Preferably, the aperture of the air intake small holes 62 is not greater than 0.3 of the radial length of the air extraction flow channel 81 along the flame tube 3, which has been verified through multiple tests.

[0026] Preferably, at the outlet of the air intake small holes 62, there is a platform extending in the air flow direction, and the platform is used to install the measuring device.

[0027] Preferably, the bolt 63 is located on the side of the outlet end face of the air extraction flow channel 81 near the outer ring cavity 4. The bolt, the U-shaped groove, and the convex block are respectively located on both sides of the outlet of the air intake small holes 62, which can better achieve the sealing and installation firmness.

[0028] Preferably, the axis of the air intake small holes 62 is parallel to the center line of the combustion chamber, which can further smooth the air flow and further avoid the disturbance of the flow in the secondary ring cavity caused by the simulated turbine air extraction.

[0029] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims described above.

Claims

1. A structure for simulating turbine air extraction of a full-ring test piece of a combustion chamber, comprising: a casing (8) accommodating a flame tube (3); a diffuser (1) for introducing air flow into the casing (3); the flame tube (3) divides the inner cavity of the casing (8) into an outer ring cavity (4) and an inner ring cavity (7); characterized in that, a high-guide vane (5) is installed at the tail of the flame tube (3), and the gas in the outer ring cavity (4), the inner ring cavity (7) and the flame tube (3) flows into the high-guide vane (5); the inner wall of the casing (8) has an air extraction flow channel (81); an air extraction orifice plate (6) is installed at the corresponding position of the air extraction flow channel (81), the air extraction orifice plate (6) is installed at the rear end of the inner wall of the casing (8) through bolts (63), and the air extraction orifice plate (6) has a plurality of air extraction small holes (62) at the outlet of the air extraction flow channel (81); the outer edge of the rear end of the inner wall of the casing (8) has a step surface (82), and the air extraction orifice plate (6) axially extends at the corresponding position of the step surface (82) to form a boss that is in interference fit with the step surface (82).

2. The structure for simulating turbine air extraction of a full-ring test piece of a combustion chamber according to claim 1, characterized in that, a U-shaped groove is provided on the side of the outlet end face of the air extraction flow channel (81) away from the outer ring cavity (4), and the air extraction orifice plate (6) at the corresponding position has a convex block (61) that cooperates with the U-shaped groove, and the convex block (61) falls into the U-shaped groove.

3. The structure for simulating turbine air extraction of a full-ring test piece of a combustion chamber according to claim 1, characterized in that, the end face of the air extraction orifice plate (6) close to the outer ring cavity (4) is coated with a high-temperature coating (9).

4. The structure for simulating turbine air extraction of a full-ring test piece of a combustion chamber according to claim 1, characterized in that, the air extraction small holes (62) include two small holes radially distributed along the flame tube (3).

5. The structure for simulating turbine air extraction of a full-ring test piece of a combustion chamber according to claim 1, characterized in that, the aperture of the air extraction small holes (62) is not greater than 0.3 of the radial length of the air extraction flow channel (81) along the flame tube (3).

6. The structure for simulating turbine air extraction of a full-ring test piece of a combustion chamber according to claim 1, characterized in that, a platform extending in the air flow direction is provided at the outlet of the air extraction small holes (62), and the platform is used for installing a measuring device.

7. The structure for simulating turbine air extraction of a full-ring test piece of a combustion chamber according to claim 1, characterized in that, the bolts (63) are located on the side of the outlet end face of the air extraction flow channel (81) close to the outer ring cavity (4).

8. The structure for simulating turbine air extraction of a full-ring test piece of a combustion chamber according to claim 1, characterized in that, the axis of the air extraction small holes (62) is parallel to the center line of the combustion chamber.

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