Rotary impulse mixed flow centrifugal combined compressor and its application

Abstract

The application provides a rotary impingement oblique flow centrifugal combined compressor and application thereof, and belongs to the technical field of turbine engines, and comprises an outer casing structure, an inner casing structure, a working mechanism and a diffuser mechanism, the outer casing structure and the inner casing structure are rotary bodies, the inner casing structure is located inside the outer casing structure, the inner casing structure and the outer casing structure form a working cavity, the working mechanism is installed in the working cavity and is used for pressurizing airflow. Compared with the compression mode of a conventional combined compressor, the application draws lessons from the pressurization mode of a supersonic inlet, and the Mach number of airflow relative to a rotating impeller reaches 2 or more through high-speed rotation; at this time, a series of weak oblique shock waves are constructed through the contraction of a passage, and a high-efficiency compression system is obtained through the pressurization of the shock wave system, the single-stage pressure ratio of the high-efficiency compression system is much higher than that of a conventional compressor, and the application has the advantages of compact structure, simple processing and long service life.

Description

Technical Field

[0001] This invention belongs to the field of turbine engine technology, and specifically relates to a rotary ram-flow centrifugal combined compressor and its application. Background Technology

[0002] Centrifugal compressors are characterized by their compact structure, high stage pressure ratio, and wide stable operating range. Currently, the tangential velocity at the centrifugal impeller outlet has reached the level of 680 m / s, posing a significant challenge to the structural strength and lifespan design of compressors. For example... Figure 1 The image shows an existing combined compressor, which uses a three-stage axial compressor (a) connected to a single-stage centrifugal compressor (b). This design combines the advantages of axial stages (suitable for large inlet flow rates) and centrifugal stages (suitable for small flow rates), high single-stage pressure ratio, and a wide stable operating range, thus meeting both flow rate and pressure ratio requirements. Generally, the number of axial stages in a conventional combined compressor changes with the pressure ratio; a pressure ratio around 15 is achieved with three axial stages plus one centrifugal stage.

[0003] However, to further improve the pressure ratio of existing combined compressors, one approach is to increase the impeller outlet tangential velocity. However, due to material limitations, the tangential velocity cannot be increased indefinitely, limiting the potential for increasing the overall pressure ratio. Furthermore, high tangential velocities are detrimental to the structural strength and lifespan of the compressor. Another approach is to increase the number of stages in the axial compressor. However, increasing the number of compressor stages increases the size, weight, number of parts, and processing time of the compressor. Finally, current axial compressor design methods limit the airflow velocity, so the single-stage pressure ratio is generally no more than 2.2. Summary of the Invention

[0004] To address the above problems, this invention proposes a rotary ram-centrifugal combined compressor and its application.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A rotary ram-flow centrifugal combined compressor includes an outer casing structure, an inner casing structure, a working mechanism, and a diffuser mechanism;

[0007] The outer casing structure and the inner casing structure are rotating bodies;

[0008] The inner casing structure is located inside the outer casing structure, and the inner casing structure and the outer casing structure constitute the working cavity.

[0009] The working mechanism is installed inside the working chamber and is used to pressurize the airflow;

[0010] Both the outer casing structure and the inner casing structure are connected to one end of the diffuser mechanism.

[0011] The diffuser mechanism includes a first diffuser and a second diffuser. The first diffuser is used for radial diffusion along the outer casing structure, and the second diffuser is used for axial diffusion along the outer casing structure.

[0012] Preferably, the outer casing structure includes a first outer casing, a second outer casing, a third outer casing, a fourth outer casing, and a fifth outer casing connected in sequence;

[0013] The inner casing structure includes a first inner casing, a second inner casing, and a third inner casing;

[0014] The first inner casing is located inside the first outer casing and the second outer casing;

[0015] The second inner casing is located inside the fourth outer casing and is connected to the second inner casing;

[0016] The third inner casing is located inside the fifth outer casing.

[0017] Preferably, the working mechanism includes adjustable guide vanes, a stamped rotor, stator blades, and a centrifugal impeller;

[0018] The adjustable guide vane is installed between the second outer casing and the first inner casing;

[0019] The stamping rotor is located inside the third outer casing and between the first inner casing and the second inner casing;

[0020] The stator blades are installed between the fourth outer casing and the second inner casing;

[0021] The centrifugal impeller is installed between the fifth outer casing and the third inner casing.

[0022] Preferably, the surface of the third outer casing is provided with a drain hole, which faces the stamping rotor.

[0023] Preferably, an air collection chamber is also provided on the outside of the third outer casing, and a switch is provided on the surface of the air collection chamber for opening or closing the air collection chamber.

[0024] Preferably, the gas collecting chamber overlaps with both ends of the third outer casing.

[0025] Preferably, the diffuser mechanism includes a first housing and a second housing;

[0026] One end of the first housing is connected to the fifth outer casing;

[0027] The second housing is connected to the end of the first housing that is away from the fifth outer casing.

[0028] Preferably, the first housing overlaps with the second housing.

[0029] Preferably, the first housing is arranged radially along the fifth outer casing, and the second housing is arranged axially along the fifth outer casing.

[0030] Preferably, the first diffuser is installed inside the first housing, and the second diffuser is installed inside the second housing.

[0031] An application of a rotary ram-flow centrifugal combined compressor for a gas turbine engine;

[0032] The gas turbine engine includes a recirculation combustion chamber and a single-stage axial turbine.

[0033] One end of the recirculation combustion chamber is connected to the rotary ram-press centrifugal combined compressor, and the other end is connected to the single-stage axial turbine.

[0034] The beneficial effects of this invention are:

[0035] 1. Compared with the compression method of conventional combined compressors, this invention draws on the pressurization method of supersonic inlet. By rotating at high speed, the airflow reaches a Mach number of 2 or higher relative to the rotating impeller. At this time, by the contraction of the channel, a series of weak oblique shock waves are constructed. Through the pressurization of the shock wave system, a highly efficient compression system is obtained with a single-stage pressure ratio that is much higher than that of conventional compressors. Moreover, it has a compact structure, simple processing, and long service life.

[0036] 2. Add a mixed-flow or centrifugal compressor after the ram section to utilize centrifugal force to do further work and increase the total pressure ratio of the compressor;

[0037] 3. The single-stage pressure ratio of the rotary ram-flow centrifugal combined compressor of the present invention is much higher than that of conventional axial flow compressors. Furthermore, when the pressure ratio is further increased, the present invention can achieve this simply by increasing the relative Mach number of the airflow at the inlet of the ram section.

[0038] 4. By using a working mechanism, this invention achieves the flow rate and pressure ratio of the original three-stage axial flow plus one-stage centrifugal flow configuration with a single-stage ram compressor. This significantly reduces the axial length, weight, and number of parts of the compressor. At the same time, since the rotary ram compressor has fewer blades (generally around three), its processing time is also greatly reduced.

[0039] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic diagram of the structure of a conventional combined compressor according to the present invention is shown;

[0042] Figure 2 A schematic diagram of the structure of a rotary ramming mixed-flow centrifugal combined compressor according to the present invention is shown;

[0043] Figure 3 A model diagram of the working mechanism of the present invention is shown;

[0044] Figure 4 A schematic diagram of the Mach number cloud of the ram section in the combined compressor of the present invention is shown;

[0045] Figure 5 A schematic diagram of the Mach number of the centrifugal compressor in the combined compressor of the present invention is shown;

[0046] Figure 6 This paper presents a comparison of the calculated and experimental characteristic curves of the rotary ram-combined flow / centrifugal combined compressor of the present invention. Figure 1 ;

[0047] Figure 7 This paper presents a comparison of the calculated and experimental characteristic curves of the rotary ram-combined flow / centrifugal combined compressor of the present invention. Figure 2 ;

[0048] Figure 8 A model diagram of a rotary ram-flow centrifugal combined compressor according to the present invention is shown;

[0049] Figure 9 A physical diagram of the stamped rotor of the present invention is shown;

[0050] Figure 10 A structural diagram of a gas turbine engine is shown.

[0051] In the diagram: 1. First outer casing; 2. Second outer casing; 3. Third outer casing; 301. Drain hole; 4. Fourth outer casing; 5. Fifth outer casing; 6. First inner casing; 7. Second inner casing; 8. Third inner casing; 9. Adjustable guide vane; 10. Stamped rotor; 11. Stator blades; 12. Centrifugal impeller; 13. Gas collection chamber; 14. First shell; 15. Second shell; 16. First diffuser; 17. Second diffuser; 18. Recirculation combustion chamber; 19. Single-stage axial turbine. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] To achieve a new type of compressor with a compact structure, high efficiency (low entropy increase), and high pressure ratio, this invention proposes a rotary ram-centrifugal combined compressor, comprising an outer casing structure, an inner casing structure, a working mechanism, and a diffuser mechanism. Both the outer and inner casing structures are rotating bodies. The inner casing structure is located inside the outer casing structure, and the inner and outer casing structures together form a working chamber. The working mechanism is installed within the working chamber and is used to pressurize the airflow. Both the outer and inner casing structures are connected to one end of the diffuser mechanism.

[0054] It should be noted that the outer casing structure and the inner casing structure are generally composed of multiple shells, or they can be a one-piece structure. Moreover, since they are both rotating structures, the outer casing structure and the inner casing structure are generally coaxially arranged, and a duct for airflow can be formed between them. The rotary ram-flow centrifugal combined compressor of the present invention will be described in detail below with reference to the accompanying drawings.

[0055] like Figure 2 As shown, the outer casing structure includes a first outer casing 1, a second outer casing 2, a third outer casing 3, a fourth outer casing 4, and a fifth outer casing 5 connected sequentially; specifically, they can be fixedly connected by overlapping, welding, or other methods. The inner casing structure includes a first inner casing 6, a second inner casing 7, and a third inner casing 8; wherein, the first inner casing 6 is located inside the first outer casing 1 and the second outer casing 2, and both have a long strip-shaped cross-section, arranged along the axial direction. The second inner casing 7 is located inside the fourth outer casing 4 and is connected to the second inner casing 7, and both the second inner casing 7 and the fourth outer casing 4 have an arc-shaped cross-section, with an angle of 25° to 45° with the axial direction. The third inner casing 8 is located inside the fifth outer casing 5, and the fifth outer casing 5 and the third inner casing 8 form an arc-shaped duct, the structure of which is bent from the axial direction to the radial direction.

[0056] Furthermore, in Figure 2The working mechanism includes adjustable guide vanes 9, stamped rotor 10, stator blades 11, and centrifugal impeller 12; wherein, the adjustable guide vanes 9 are installed between the second outer casing 2 and the first inner casing 6; the stamped rotor 10 is located inside the third outer casing 3 and between the first inner casing 6 and the second inner casing 7; the stator blades 11 are installed between the fourth outer casing 4 and the second inner casing 7; and the centrifugal impeller 12 is installed between the fifth outer casing 5 and the third inner casing 8.

[0057] It should be noted that, as Figure 3 The figure shows a model of the working mechanism of the present invention. As can be seen from the figure, a shaft is set at the center of the working mechanism. The blades of the stamping rotor 10 and the centrifugal impeller 12 are arranged on the shaft in sequence. The adjustable guide vane 9 and the stator blade 11 are both plate-shaped and evenly distributed on the casing. The blades of the stamping rotor 10 are spiral blades and are spirally distributed along the axial direction. The centrifugal impeller 12 is composed of several plate-shaped blades and is truncated cone-shaped as a whole.

[0058] Furthermore, in Figure 2 In the middle, the surface of the third outer casing 3 is provided with a vent hole 301, which faces the stamping rotor 10. Moreover, the outer side of the third outer casing 3 is also provided with a gas collection chamber 13. A switch is provided on the surface of the gas collection chamber 13. The switch is used to open or close the gas collection chamber 13. The gas collection chamber 13 overlaps with both ends of the third outer casing 3.

[0059] It should be noted that the vent 301 can be opened or closed as needed. When the vent 301 is open, a portion of the airflow passing through the ram compressor rotor 10 can enter the gas collecting chamber 13, and the airflow in the gas collecting chamber 13 can be released through the opening. At low speeds, because the shock wave of the ram compressor has not yet fully established, it is prone to surge. Therefore, it is necessary to open the vent 301 to release some gas and prevent surge.

[0060] Furthermore, the diffuser mechanism includes a first housing 14 and a second housing 15, a first diffuser 16 and a second diffuser 17. The first diffuser 16 is used for radial diffusion along the outer casing structure, and the second diffuser 17 is used for axial diffusion along the outer casing structure. Specifically, one end of the first housing 14 is connected to the fifth outer casing 5, and the second housing 15 overlaps with the end of the first housing 14 away from the fifth outer casing 5. Moreover, the first housing 14 is arranged radially along the fifth outer casing 5, and the second housing 15 is arranged axially along the fifth outer casing 5. The first diffuser 16 is installed inside the first housing 14, and the second diffuser 17 is installed inside the second housing 15.

[0061] It should be noted that the airflow is decelerated and pressurized in the first diffuser 16, and then the second diffuser 17 in the axial direction turns the airflow into a near-axial direction to facilitate subsequent combustion in the combustion chamber.

[0062] It should be further explained that this invention utilizes adjustable guide vanes 9 to provide sufficient anti-pre-swirl for the rotary ram compressor, increasing the relative Mach number of the ram rotor 10 to above 2. When the supersonic airflow passes through the channel of the first half of the rotor, which is similar to a two-dimensional supersonic inlet, a series of shock waves will be generated. These shock waves are used to achieve the purpose of decelerating and pressurizing the airflow. In the ram section, the stator blades 11 with large rotation angles convert the rammed airflow into an axial direction to facilitate matching with the centrifugal mixed-flow / centrifugal compressor. After the stator, the mixed-flow / centrifugal compressor uses centrifugal force to further perform work, increasing the overall pressure ratio of the compressor. At the same time, the airflow is decelerated and diffused by radial diffusers and axial diffusers. The rotary ram and mixed-flow / centrifugal compressors can achieve the flow rate and pressure ratio of a conventional 3-stage axial-flow + 1-stage centrifugal combined compressor within a compact size, significantly reducing the number of parts, processing time, and cost, and exploring a feasible path for future high power-to-weight ratio engine compressor components.

[0063] like Figure 4 The figure shows the internal shock wave structure cloud diagram of the rotating ram section of the rotating ram-flow centrifugal compressor obtained from simulation. It can be seen from the figure that the Mach number at 50% of the height has reached 2.0, and the compressor is gradually pressurized after a series of weak shock wave decelerations.

[0064] like Figure 5 As shown, the simulation results of the internal Mach number cloud map of the centrifugal section of the rotating ram-flow centrifugal compressor are presented. It can be seen from the figure that the highest Mach number in the centrifugal compressor is 1.0, and it is gradually reduced to about 0.25 through the radial diffuser and axial diffuser deceleration diffusion.

[0065] like Figure 6 As shown, the comparison results of flow rate-pressure ratio between simulation and actual test are presented. The curve represented by CFD (Computational Fluid Dynamics) is the simulation result, and DP represents the test result of actual test. The simulation curve and the test surface are basically consistent.

[0066] Similarly, such as Figure 7 As shown, the comparison results of flow efficiency between simulation and physical test are presented, and the simulation curve and the test surface are basically consistent.

[0067] like Figure 8 As shown, the compressor assembly diagrams are given respectively, in which the vent hole 301 is inclined relative to the axial direction and the outlet faces the upper left of the diagram.

[0068] like Figure 9 The figure shown is a physical diagram of the rotor. As can be seen from the figure, the stamped rotor 10 and the centrifugal impeller 12 are driven by a shaft.

[0069] like Figure 10As shown, the rotary ram-centrifugal combined compressor is used in a gas turbine engine, which includes a recirculation combustion chamber 18 and a single-stage axial turbine 19; wherein one end of the recirculation combustion chamber 18 is connected to the rotary ram-centrifugal combined compressor, and the other end is connected to the single-stage axial turbine 19.

[0070] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rotary ram-centrifugal combined compressor, characterized in that, It includes the outer casing structure, the inner casing structure, the working mechanism, and the diffuser mechanism; The outer casing structure and the inner casing structure are rotating bodies; The inner casing structure is located inside the outer casing structure, and the inner casing structure and the outer casing structure constitute the working cavity. The working mechanism is installed inside the working chamber and is used to pressurize the airflow; Both the outer casing structure and the inner casing structure are connected to one end of the diffuser mechanism. The diffuser mechanism includes a first diffuser (16) and a second diffuser (17), wherein the first diffuser (16) is used for radial diffusion along the outer casing structure, and the second diffuser (17) is used for axial diffusion along the outer casing structure. The outer casing structure includes a first outer casing (1), a second outer casing (2), a third outer casing (3), a fourth outer casing (4), and a fifth outer casing (5) connected in sequence. The inner casing structure includes a first inner casing (6), a second inner casing (7), and a third inner casing (8). The first inner casing (6) is located inside the first outer casing (1) and the second outer casing (2); The second inner casing (7) is located inside the fourth outer casing (4); The third inner casing (8) is located inside the fifth outer casing (5); The working mechanism includes adjustable guide vanes (9), stamping rotor (10), stator blades (11) and centrifugal impeller (12). The adjustable guide vane (9) is installed between the second outer casing (2) and the first inner casing (6); The stamping rotor (10) is located inside the third outer casing (3) and between the first inner casing (6) and the second inner casing (7); The stator blade (11) is installed between the fourth outer casing (4) and the second inner casing (7); The centrifugal impeller (12) is installed between the fifth outer casing (5) and the third inner casing (8); The surface of the third outer casing (3) is provided with a drain hole (301), which faces the stamping rotor (10).

2. The rotary ram-press mixed-flow centrifugal combined compressor according to claim 1, characterized in that, The outer side of the third outer casing (3) is also provided with an air collection chamber (13), and a switch is provided on the surface of the air collection chamber (13) for opening or closing the air collection chamber (13).

3. A rotary ram-press mixed-flow centrifugal combined compressor according to claim 2, characterized in that, The gas collecting chamber (13) overlaps with both ends of the third outer casing (3).

4. A rotary ram-press mixed-flow centrifugal combined compressor according to claim 1, characterized in that, The diffuser mechanism includes a first housing (14) and a second housing (15); One end of the first housing (14) is connected to the fifth outer casing (5); The second housing (15) is connected to the end of the first housing (14) away from the fifth outer casing (5).

5. A rotary ram-press mixed-flow centrifugal combined compressor according to claim 4, characterized in that, The first housing (14) overlaps with the second housing (15).

6. A rotary ram-press mixed-flow centrifugal combined compressor according to claim 4, characterized in that, The first housing (14) is arranged radially along the fifth outer casing (5), and the second housing (15) is arranged axially along the fifth outer casing (5).

7. A rotary ram-press mixed-flow centrifugal combined compressor according to claim 4, characterized in that, The first diffuser (16) is installed inside the first housing (14), and the second diffuser (17) is installed inside the second housing (15).

8. The application of the rotary ram-centrifugal combined compressor as described in any one of claims 1-7, characterized in that, Used in gas turbine engines; The gas turbine engine includes a recirculation combustion chamber (18) and a single-stage axial turbine (19). One end of the recirculation combustion chamber (18) is connected to the rotary ram-flow centrifugal combined compressor, and the other end is connected to the single-stage axial turbine (19).

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