A tail nozzle noise reduction device with adjustable ejection quantity

Abstract

The application discloses an ejecting quantity adjustable tail nozzle noise reduction device, and relates to the technical field of tail nozzle noise reduction of a test bench combustion engine, which comprises a shell, one end of which is connectable with an exhaust pipe, wherein the shell comprises an inner ring and an outer ring, and the inner ring and the outer ring divide the shell into a jet flow area and an ejecting flow area; a noise reduction sheet is annularly arranged between the inner ring and the outer ring and used for reducing the noise of the ejecting flow area; a sound insulation ring is annularly arranged at one end of the inner ring, the inner diameter of the sound insulation ring is changeable, and the sound insulation ring is attached to the outer wall surface of a tail nozzle with different diameters, so that the sound insulation ring is used for blocking the noise of the jet flow area; and a throttle sheet is arranged at the end of the shell far from the exhaust pipe, and the throttle sheet can realize the adjustment of the ejecting quantity by changing the opening angle. The ejecting quantity adjustable tail nozzle noise reduction device provided by the application can make the escape noise of the tail nozzle lower, simultaneously match multiple models of combustion engines, and reduce the disassembly and assembly workload.

Description

Technical Field

[0001] This invention relates to the field of noise reduction technology for gas turbine exhaust nozzles on test benches, and in particular to a noise reduction device for exhaust nozzles with adjustable ejector volume. Background Technology

[0002] The jet noise from the tail nozzle is the main noise source of the gas turbine test stand. The conventional ejector tube is mainly used to extract the jet. Its open structure does not have the ability to adjust the ejection volume or reduce the noise of the tail nozzle, which causes great noise pollution to the working environment of the test stand. Conventional ejector tubes can only be matched with the tail nozzle of a single type of gas turbine, and most of them are mechanical disassembly and assembly structures. When testing different types of gas turbines, the corresponding ejector tubes need to be replaced, which involves a large amount of disassembly and assembly work. Summary of the Invention

[0003] The purpose of this invention is to provide a tail nozzle noise reduction device with adjustable ejector volume to solve the problems existing in the prior art, so as to reduce the exhaust noise of the tail nozzle and match multiple gas turbine models, thereby reducing the amount of disassembly and assembly work.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] This invention provides a tail nozzle noise reduction device with adjustable ejector volume, comprising a housing, one end of which can be connected to an exhaust pipe. The housing includes an inner ring and an outer ring, which divide the housing into a jet flow zone and an ejector flow zone. A silencer is disposed between the inner and outer rings to reduce noise in the ejector flow zone. A sound insulation ring is disposed at one end of the inner ring, the inner diameter of which can be changed and fits against the outer wall surface of tail nozzles of different diameters, thereby blocking noise in the jet flow zone. A throttling vane is disposed at the end of the housing away from the exhaust pipe, and the ejector volume can be adjusted by changing the opening angle of the throttling vane.

[0006] Optionally, the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring are both made of micro-perforated plates. The micro-perforated plates are made of heat-resistant steel. The thickness, aperture, and perforation rate of the micro-perforated plates are designed according to the noise spectrum of the tail nozzle. Both the inner and outer rings are provided with resonant cavities. The thickness of the resonant cavities is designed according to the noise spectrum of the tail nozzle. The resonant cavities are located on the side where the micro-perforated plates are connected to the inner or outer ring. The resonant cavity of the outer ring is provided with a heat insulation layer on the side away from the inner ring.

[0007] Optionally, one end of the outer ring is provided with a mounting boss, the tapered surface of which can be inserted into the exhaust pipe for installation.

[0008] Optionally, a plurality of sound-absorbing plates are provided in the annular space between the inner ring and the outer ring. The sound-absorbing plates are connected to the shell by a thermal compensation structure. The surface of the sound-absorbing plates is provided with a sound-absorbing surface in the shape of a cylindrical helical surface. The helical angle of the sound-absorbing surface is greater than 25°. The sound-absorbing surface is made of micro-perforated plate by stamping. The sound-absorbing surface is provided with a sound-absorbing cavity inside. The sound-absorbing cavity is provided with a partition plate inside. The partition plate is made of heat-resistant steel plate by stamping.

[0009] Optionally, the throttling plate is hinged to the outer end of the muffler, and a driving device is provided on the housing. The driving device can control the throttling plate to rotate around the hinge point by a set angle.

[0010] Optionally, the driving device includes an annular connecting rod that sequentially passes through multiple throttling vanes and is fixedly connected to the throttling vanes; multiple slide rails are fixedly provided at the end of the outer ring away from the exhaust pipe, the annular connecting rod is slidably disposed in the slide rails, and a cylinder is provided on the slide rails; the telescopic rod of the cylinder is hinged to the annular connecting rod, and the cylinder can drive the annular connecting rod to rotate along the slide rails.

[0011] Optionally, the sound insulation ring includes a fixed ring and a rotating ring coaxially arranged with the same inner diameter. The fixed ring is mounted on the end face of one end of the inner ring, and the rotating ring is located on the side of the fixed ring away from the inner ring. Multiple blades are rotatably arranged between the fixed ring and the rotating ring. A cylindrical pin is provided on one side of each blade, passing through a sliding groove on the fixed ring. A sliding shoe is provided on the other side of each blade, passing through a sliding groove in the rotating ring. The rotating ring is connected to a driving cylinder, which can drive the rotating ring. The ring rotates, causing the blades to rotate and open / close. The inner edge of the blades is always tangent to the outer diameter of a virtual circle. This virtual circle is concentrically set with the fixed ring, and its diameter is the same as the outer diameter of the tail nozzle. When the rotating ring is pushed to rotate by the driving cylinder, it causes the blades to rotate and open / close. The variable diameter inscribed circle enclosed by the edge of the blade is the outer diameter of the tail nozzle. The sound insulation ring can adapt to tail nozzles with a certain diameter range. The blades are made of heat-resistant steel and stamped. The internal cavity of the blades is filled with aerogel. The sound insulation ring has high sound insulation performance.

[0012] Optionally, a support mechanism is also included. The support mechanism includes an ear seat, which is hinged to the connecting shafts on both sides of the housing via a spherical bearing. Both ends of the ear seat are slidably mounted on guide rods. A slider is fixedly connected to the bottom of the guide rod. A hydraulic oil damping device is provided in the cavity of the guide rod. A lifting rod is provided between the two guide rods. One end of the lifting rod is connected to the bottom of the ear seat, and the other end is connected to the slider. The lifting rod adopts a screw lifting mechanism, which is driven by an electric motor.

[0013] Optionally, it also includes a mounting base, which can be connected to the civil engineering ground or the platform rail; a horizontal rail is fixedly provided on the mounting base, and a longitudinal rail is provided above the horizontal rail. The longitudinal rail is slidably disposed on the horizontal rail through a guide block. The guide block and the top of the horizontal rail form a sliding pair that can move horizontally along the radial direction of the nozzle. The slider is slidably disposed on the longitudinal rail. The top of the longitudinal rail and the slider form a sliding pair that can move axially along the nozzle. The present invention uses an electric drive to control the reciprocating movement of the sliding pair.

[0014] The present invention achieves the following technical effects compared to the prior art:

[0015] The tail nozzle noise reduction device with adjustable ejector volume of the present invention has the advantages of adjustable ejector volume, strong noise reduction capability, strong adaptability and automatic control; the inner ring and outer ring divide the shell into the jet flow area and the ejector flow area. The noise of the jet flow area, which accounts for the largest proportion of the sound source noise, is blocked by the sound insulation ring, while the noise of the ejector flow area, which accounts for a smaller proportion, is reduced by the open sound-absorbing plate. The flow ratio design of the sound-absorbing plate has a large margin and has minimal impact on the flow field of the tail nozzle.

[0016] The present invention has a throttling plate at the front end of the airflow channel of the housing. By adjusting the opening angle of the throttling plate on the end face of the housing, the ejection volume can be adjusted to meet the requirements of the tail nozzle for different ejection volumes. There is no need to install throttling accessories. The rotatable sound insulation ring can fit well with tail nozzles within a certain outer diameter range. Automatic control can be achieved by cylinder drive.

[0017] The present invention supports the housing to achieve lifting and lowering movement, and the guide rails can drive the support to achieve two degrees of freedom of horizontal movement. During the installation and debugging of the tail nozzle, the housing can be moved outside the working space. After the tail nozzle is debugged, the guide rails and supports are controlled to move the housing back to the installation position. The mounting boss at the rear end of the housing is connected and sealed with the exhaust pipe of the test bench. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an isometric view of the overall structure of the present invention;

[0020] Figure 2 This is a cross-sectional view of the housing of the present invention;

[0021] Figure 3 This is an isometric view of the sound-absorbing plate of the present invention;

[0022] Figure 4 This is a cross-sectional view of the sound-absorbing sheet of the present invention;

[0023] Figure 5 This is a schematic diagram of the throttling plate of the present invention;

[0024] Figure 6 This is a schematic diagram of the sound insulation ring of the present invention;

[0025] Figure 7 This is an isometric drawing of the sound insulation ring of the present invention;

[0026] Figure 8 This is a schematic diagram of the support mechanism and guide rail of the present invention;

[0027] Explanation of reference numerals in the attached drawings: 10-Noise reduction device for adjustable ejection volume at the tail nozzle; 100-Housing, 101-Inner ring, 102-Outer ring, 103-Resonance cavity, 104-Mounting boss; 200-Silence absorbing plate, 201-Sound absorbing surface, 202-Silence absorbing cavity, 203-Baffle plate; 300-Throttle plate, 301-Hinge, 302-Annular connecting rod, 303-Cylinder, 304-Slide rail; 400 - Sound insulation ring, 401- Blade, 402- Cylindrical pin, 403- Fixing ring, 404- Slipper, 405- Rotating ring, 406- Drive cylinder; 500- Support mechanism, 501- Ear seat, 502- Lifting rod, 503- Guide rod, 504- Slider; 600- Guide rail, 601- Longitudinal rail, 602- Transverse rail, 603- Guide block, 604- Mounting base; 20- Tail nozzle. Detailed Implementation

[0028] 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, and 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.

[0029] The purpose of this invention is to provide a tail nozzle noise reduction device with adjustable ejector volume to solve the problems existing in the prior art, so as to reduce the exhaust noise of the tail nozzle and match multiple gas turbine models, thereby reducing the amount of disassembly and assembly work.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Reference Appendix Figure 1 ~Attached Figure 8This invention provides a tail nozzle noise reduction device 10 with adjustable ejection volume. The main structure is a cylindrical shell 100, which includes two concentric hollow cylinders, an inner ring 101 and an outer ring 102. The outlet end of the outer ring 102 is provided with a mounting boss 104 that can be connected to the exhaust pipe. The inner ring 101 and the outer ring 102 divide the shell 100 into a jet flow area and an ejection flow area. A sound-absorbing plate 200 is provided between the inner ring 101 and the outer ring 102 to reduce noise in the ejection flow area. A sound-insulating ring 400 is provided at the outer end of the inner ring 101. Its inner diameter can be changed and it fits against the outer wall surface of the tail nozzle 20 with different diameters, thereby blocking noise in the jet flow area. A throttling plate 300 is provided at the end of the shell 100 away from the exhaust pipe. The ejection volume can be adjusted by changing the opening angle of the throttling plate 300.

[0032] Further preferably, the outer circumferential surface of the inner ring 101 and the inner circumferential surface of the outer ring 102 are made of micro-perforated plates with perforation parameters set as plate thickness 1.2mm, hole diameter φ0.8mm, and perforation rate 1%. The acoustic impedance of the small holes themselves will reduce airflow noise. A 50mm thick resonant cavity 103 is provided on the back of the micro-perforated plate. The sound waves of the corresponding frequency band resonate with the air in the cavity, thereby reducing the sound wave energy by using friction damping. A heat insulation layer is provided outside the outer ring resonant cavity 103, filled with a heat-resistant aluminum silicate layer to reduce the heat diffusion of the tail nozzle to the surroundings.

[0033] Based on the aforementioned shell 100, 15 hollow silencing plates 200 are non-rigidly installed inside the annular space between the inner ring 101 and the outer ring 102 of the shell 100 to reduce noise in the ejector flow area. The sound-absorbing surfaces 201 on both sides of the silencing plates 200 are made of 310s micro-perforated plates, with a thickness of 1.2mm, a perforation diameter of φ0.8mm, and a perforation rate of 1%. The acoustic resistance of the small holes themselves will reduce airflow noise. Based on the characteristics of the tail nozzle noise spectrum, micro-perforated plates with different acoustic parameters can be designed to improve the noise reduction in specific frequency bands. The silencing cavity 202 is thick... The sound-absorbing surface 201 has a diameter of 50 mm and a thickness of 0.8 mm made of 310s material. The middle part of the sound-absorbing cavity 202 is equipped with a partition 203. The partition 203 divides the sound-absorbing cavity 202 into two independent and sealed cavities to prevent airflow from passing through and causing the sound-absorbing plate 200 to become unstable. In particular, the sound-absorbing surface 201 can be divided into multiple regions with different perforation parameters along the airflow direction, which will make the sound-absorbing effect of the sound-absorbing plate 200 cover a wider frequency band. In particular, the sound-absorbing plate 200 is designed as a cylindrical helical surface with a helical angle greater than 25°. This means that when noise is transmitted, it must pass through the sound-absorbing surface 201 or the transmission partition 203 and cannot be directly transmitted outward, which effectively improves the noise reduction capability of the present invention.

[0034] To achieve remote online adjustment of the jet volume from the tail nozzle, this invention, based on the aforementioned housing 100 and muffler 200, adds a hinge 301 at the front end of the muffler 200. The movable end of the hinge connects to a throttling vane 300. A spherical bearing of the annular connecting rod 302 is used to connect the various throttling vanes 300 in series. Three slide rails 304 are arranged around the outer ring 102 to assist the mechanical movement of the annular connecting rod 302. A cylinder 303 pushes the annular connecting rod 302 to rotate around its center, while simultaneously sliding back and forth along the slide rails 304. The throttling vanes 300 hinged on the annular connecting rod 302 can then open and close synchronously, thereby achieving remote online adjustment of the jet volume from the tail nozzle 20 without needing to stop the tail nozzle 20 or install other throttling accessories.

[0035] To block the noise from the jet stream, which constitutes the largest proportion of the noise source, this invention installs a rotatable sound-insulating ring 400 on the front end face of the inner ring to block the noise transmission from the jet stream area of ​​the tail nozzle 20. The sound-insulating ring includes blades 401, cylindrical pins 402, fixed rings 403, sliding shoes 404, rotating rings 405, and a drive cylinder 406. The sound-insulating ring 400 is composed of eight rotatable blades 401. Each blade 401 is a hollow structure filled with aerogel, and its inner edge is always tangent to a certain diameter during opening and closing, thus allowing it to fit well with the outer wall of the tail nozzle within a certain diameter range. One side of the blade 401... A cylindrical pin 402 is provided that can reciprocate along the sliding groove of the fixed ring 403, and a sliding shoe 404 is provided on the other side that can reciprocate along the sliding groove of the rotating ring 405. The rotating ring 405 is driven to rotate around the center by the driving cylinder 406, thereby driving eight blades 401 to rotate along the cylindrical pin 402 and move radially along the tail nozzle 20. Finally, its inner edge line fits with the outer circle of the tail nozzle 20. The sound insulation ring 400 of the present invention can be adapted to tail nozzles 20 with an outer diameter of 500mm to 900mm, but by adjusting the number and shape of the blades 401, it can be adapted to tail nozzles 20 with other outer diameter ranges.

[0036] To facilitate the fixing of the housing 100, the present invention hinges the lug 501 of the support mechanism 500 to the small shafts on both sides of the housing 100 via a spherical bearing. The multiple degrees of freedom of the spherical bearing allows the mounting boss 104 at the rear end of the housing 100 to present various postures, reducing the installation difficulty of the mounting boss 104 and the exhaust pipe. The lifting rod 502 and the guide rod 503 are installed on the bottom surface of the lug 501. The lifting rod 502 adopts an electric screw lifting device, or a hand-cranked screw, cylinder or hydraulic cylinder lifting device can also be used. The guide rod 503 adopts a hydraulic cylinder with hydraulic damping to reduce the vibration from the housing 100. The slider 504 is set at the lower part of the support mechanism 500 and is used to drive the support mechanism 500 to move along the longitudinal rail 601. The slider 504 is a linear bearing with a self-locking device.

[0037] Based on the support mechanism 500, the present invention provides a guide rail 600 for the housing 100 that can move in two directions, including a longitudinal rail 601, a transverse rail 602, a guide block 603, and a mounting base 604. The guide block 603 is installed on the bottom surface of the longitudinal rail 601, so that the longitudinal rail 601 can reciprocate along the transverse rail 602. The guide block 603 uses a linear bearing, or it can use a machined smooth surface as a sliding pair. More preferably, the guide block 603 is provided with a set screw locking device, which can lock the position of the longitudinal rail 601. The mounting base 604 is used to fix to the foundation, and is not limited to a T-shaped ground rail or the bottom surface of the civil engineering.

[0038] In the description of this invention, it should be noted that the terms "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A tail nozzle noise reduction device with adjustable ejector quantity, characterized in that: The device includes a housing, one end of which can be connected to an exhaust pipe. The housing includes an inner ring and an outer ring, which divide the housing into a jet flow area and an ejector flow area. A noise-reducing plate is arranged in a ring between the inner and outer rings to reduce noise in the jet flow area; A sound-insulating ring is provided at one end of the inner ring. Its inner diameter can be changed and it can fit against the outer wall surface of the tail nozzle with different diameters, thereby blocking the noise in the jet flow area. A throttling vane is located at the end of the housing away from the exhaust pipe. The throttling vane can adjust the injection volume by changing the opening angle.

2. The tail nozzle noise reduction device with adjustable ejection volume according to claim 1, characterized in that: The outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring are both made of micro-perforated plates. Both the inner and outer rings are provided with resonant cavities, which are located on the side where the micro-perforated plate connects to the inner or outer ring. The resonant cavity of the outer ring is provided with a heat insulation layer on the side away from the inner ring.

3. The tail nozzle noise reduction device with adjustable ejection volume according to claim 1, characterized in that: One end of the outer ring is provided with a mounting boss, which can be inserted and installed with the exhaust pipe.

4. The tail nozzle noise reduction device with adjustable ejection volume according to claim 1, characterized in that: Multiple sound-absorbing plates are provided in the annular space between the inner ring and the outer ring. The surface of the sound-absorbing plate is provided with a sound-absorbing surface in the shape of a cylindrical helical surface. The helical angle of the sound-absorbing surface is greater than 25°. The sound-absorbing surface is made by stamping a micro-perforated plate. A sound-absorbing cavity is provided inside the sound-absorbing surface. A partition is provided inside the sound-absorbing cavity.

5. The tail nozzle noise reduction device with adjustable ejection volume according to claim 4, characterized in that: The throttling plate is hinged to the outer end of the silencing plate, and a driving device is provided on the housing. The driving device can control the throttling plate to rotate around the hinge point by a set angle.

6. The tail nozzle noise reduction device with adjustable ejection volume according to claim 5, characterized in that: The driving device includes an annular connecting rod that passes through multiple throttling vanes in sequence and is fixedly connected to the throttling vanes; multiple slide rails are fixedly provided at the end of the outer ring away from the exhaust pipe, and the annular connecting rod is slidably disposed in the slide rails, with a cylinder provided on the slide rails; the telescopic rod of the cylinder is hinged to the annular connecting rod, and the cylinder can drive the annular connecting rod to rotate along the slide rails.

7. The tail nozzle noise reduction device with adjustable ejection volume according to claim 1, characterized in that: The sound insulation ring includes a fixed ring and a rotating ring coaxially arranged with the same inner diameter. The fixed ring is installed on the end face of one end of the inner ring, and the rotating ring is located on the side of the fixed ring away from the inner ring. Multiple blades are rotatably arranged between the fixed ring and the rotating ring. A cylindrical pin is provided on one side of the blade and passes through a sliding groove on the fixed ring. A sliding shoe is provided on the other side of the blade and passes through a sliding groove on the rotating ring. The rotating ring is connected to a driving cylinder, which can drive the rotating ring to rotate and drive the blades to rotate and open. The inner edge of the blade is always tangent to the outer diameter of a virtual circle. The virtual circle is concentric with the fixed ring, and the diameter of the virtual circle is the same as the outer diameter of the tail nozzle.

8. The tail nozzle noise reduction device with adjustable ejection volume according to claim 1, characterized in that: It also includes a support mechanism, which includes an ear seat. The ear seat is hinged to the connecting shafts on both sides of the housing via a spherical bearing. Both ends of the ear seat are slidably mounted on guide rods. A slider is fixedly connected to the bottom of the guide rod. A lifting rod is provided between the two guide rods. One end of the lifting rod is connected to the bottom of the ear seat, and the other end is connected to the slider.

9. The tail nozzle noise reduction device with adjustable ejection volume according to claim 8, characterized in that: It also includes a mounting base, on which a horizontal rail is fixedly mounted, and a vertical rail is mounted above the horizontal rail. The vertical rail is slidably mounted on the horizontal rail via a guide block, and the slider is slidably mounted on the vertical rail.

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