Noise reduction intake bypass recirculation structure for a compressor

Abstract

The application discloses a noise reduction intake bypass recirculation structure of a compressor and belongs to the technical field of an intake structure of a supercharger, which comprises an intake pipe and an intake bypass recirculation annular sleeve, the intake bypass recirculation annular sleeve is fixedly sleeved outside the intake pipe, the intake bypass recirculation annular sleeve comprises an inner ring and an outer ring, the outer ring is sleeved outside the inner ring, an annular sealing chamber is formed between the inner ring and the outer side wall of the intake pipe, an annular cavity is formed between the outer side wall of the intake pipe, the outer side wall of the inner ring and the inner side wall of the outer ring, the side wall of the intake pipe is provided with a bypass air inlet and a bypass air outlet which are both communicated with the annular cavity, the bypass air inlet is close to the air outlet of the intake pipe, the bypass air outlet is close to the air inlet of the intake pipe, the side wall of the end of the inner ring away from the intake pipe can be elastically deformed, and the annular sealing chamber is filled with a certain pressure gas. The application can reduce the noise of discrete single sound of the compressor under different rotating speeds and reduce potential hidden dangers in normal operation of equipment.

Description

Technical Field

[0001] This invention relates to the technical field of the intake structure of a turbocharger, and in particular to a noise-reducing intake bypass recirculation structure for a compressor. Background Technology

[0002] In recent years, to meet the requirements of modern internal combustion engines for high power and high economy, especially the requirement for turbocharged diesel engines used in transportation and construction machinery to maintain sufficient boost pressure over a wide range of speeds and loads to achieve satisfactory low-speed performance, the matching turbocharger compressor must possess both high efficiency and a wide stable operating range, particularly requiring a high pressure ratio at low flow rates. This necessitates a shift in the compressor's surge line towards lower flow rates. Employing a compressor intake bypass recirculation system is an effective technical measure to broaden the compressor's stable operating range at low flow rates and is currently widely used.

[0003] With advancements in design technology, turbochargers are continuously evolving towards higher flow rates and higher pressure ratios, making noise issues increasingly prominent. Numerous studies have confirmed that the high frequency of the compressor's aerodynamic noise sound pressure level is one of the main noise sources of turbochargers. Therefore, reducing the compressor's aerodynamic noise can effectively reduce the overall noise of the turbocharger. One of the main methods for noise reduction is to control noise along its propagation path. Currently, the most common approach is to install mufflers, with few measures addressing noise reduction through changes to the compressor's intake pipe structure. The main contributor to the aerodynamic noise of centrifugal compressors comes from discrete single-tone noise, the frequency of which is closely related to the compressor's rotational speed. In actual diesel engine operation, different conditions require the compressor to operate at different speeds, but current research rarely considers compressor intake pipe structures for noise reduction at different speeds. Summary of the Invention

[0004] The purpose of this invention is to provide a noise-reducing intake bypass recirculation structure for a compressor to solve the problems existing in the prior art. It can reduce the noise of discrete single tones of the compressor at different speeds, reduce potential hazards to the normal operation of the equipment, and benefit the normal work and life of the staff.

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

[0006] This invention provides a noise-reducing intake bypass recirculation structure for a compressor, comprising an intake pipe and an intake bypass recirculation annular sleeve. The intake bypass recirculation annular sleeve is fixedly fitted outside the intake pipe. The intake bypass recirculation annular sleeve includes an inner ring and an outer ring, with the outer ring fitted outside the inner ring. A hollow annular sealed chamber is formed between the inner ring and the outer wall of the intake pipe. A hollow annular chamber is formed between the outer wall of the intake pipe, the outer wall of the inner ring, and the inner wall of the outer ring. A bypass inlet and a bypass outlet are provided on the side wall of the intake pipe, both communicating with the annular chamber. The inner ring is located between the bypass inlet and the bypass outlet, with the bypass inlet close to the intake pipe outlet and the bypass outlet close to the intake pipe inlet. The side wall of the inner ring at the end away from the intake pipe is capable of elastic deformation. The annular sealed chamber is filled with gas at a certain pressure.

[0007] Preferably, it also includes an air inlet flange, which is fixedly connected to one end of the air inlet port.

[0008] Preferably, the axis of the intake pipe, the axis of the inner ring, and the axis of the outer ring are collinear.

[0009] Preferably, the gas is nitrogen.

[0010] Preferably, both the bypass air inlet and the bypass air outlet are annular openings.

[0011] Preferably, the opening width of the bypass air inlet is the same as the opening width of the bypass air outlet.

[0012] Preferably, the bypass outlet is provided with a plurality of connecting supports in the circumferential direction, the connecting supports being used to fix one end of the air inlet of the air inlet pipe to the middle part of the air inlet pipe.

[0013] Preferably, the plurality of connecting struts are evenly distributed along the circumference of the air intake pipe.

[0014] Preferably, the sidewall of the end of the inner ring away from the air intake pipe is an elastic circular film.

[0015] Preferably, the two sidewalls of the inner ring connected to the intake pipe are made of a rigid material.

[0016] The present invention achieves the following technical effects compared to the prior art:

[0017] This invention provides a noise-reducing intake bypass recirculation structure for a compressor. The aerodynamic noise generated by the compressor is transmitted into the annular chamber through the bypass intake port and then exits through the bypass outlet. At the bypass outlet, the sound waves from the annular chamber and the sound waves from the intake pipe undergo destructive interference. The path difference between the two sound waves is continuous within a certain range, thus achieving noise reduction for a wide frequency range including discrete single-tone noise frequencies. Furthermore, the centrifugal compressor operates at varying speeds in a diesel engine, with each speed corresponding to a different discrete single-tone noise frequency. The air pressure in the annular chamber varies at different speeds, while the air pressure inside the annular sealed chamber remains constant. This causes different deformations in the sidewall of the inner ring away from the intake pipe at different speeds, altering the path of the sound waves within the annular chamber. This achieves destructive interference of the discrete single-tone noise corresponding to different speeds, thus reducing the discrete single-tone noise of the compressor at different speeds. 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 a schematic diagram of the noise reduction intake bypass recirculation structure of a compressor under the following conditions;

[0020] Figure 2 The acoustic waveform diagram of the noise reduction intake bypass recirculation structure of the compressor under the following conditions;

[0021] Figure 3 This is a schematic diagram of the noise reduction intake bypass recirculation structure of the compressor under scenario two.

[0022] Figure 4 The acoustic path diagram of the noise reduction intake bypass recirculation structure of the compressor under case two;

[0023] Figure 5 This is a schematic diagram of the noise reduction intake bypass recirculation structure of the compressor under scenario three.

[0024] Figure 6 The acoustic path diagram is shown for the noise reduction intake bypass recirculation structure of the compressor under case three.

[0025] In the diagram: 1-Intake pipe; 2-Outer ring; 3-Inner ring; 4-Annular sealing chamber; 5-Annular chamber; 6-Bypass inlet; 7-Bypass outlet; 8-Intake pipe inlet; 9-Intake pipe outlet; 10-Intake pipe flange; 11-Connecting support. Detailed Implementation

[0026] 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.

[0027] The purpose of this invention is to provide a noise-reducing intake bypass recirculation structure for a compressor to solve the problems existing in the prior art. This structure can reduce the noise generated by the compressor, reduce potential hazards to the normal operation of the equipment, and benefit the normal work and life of the staff.

[0028] 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.

[0029] This invention provides a noise-reducing intake bypass recirculation structure for a compressor, such as... Figure 1-6As shown, it includes an intake pipe 1 and an intake bypass recirculation annular sleeve. The intake bypass recirculation annular sleeve is fixedly fitted outside the intake pipe 1. The intake bypass recirculation annular sleeve includes an inner ring 3 and an outer ring 2. The outer ring 2 is fitted outside the inner ring 3. A hollow annular sealed chamber 4 is formed between the inner ring 3 and the outer wall of the intake pipe 1. A hollow annular chamber 5 is formed between the outer wall of the intake pipe 1, the outer wall of the inner ring 3, and the inner wall of the outer ring 2. A bypass inlet 6 and a bypass outlet 7 are provided on the side wall of the intake pipe 1. Both the bypass inlet 6 and the bypass outlet 7 are connected to the annular chamber 5. The inner ring 3 is located between the bypass inlet 6 and the bypass outlet 7. The bypass inlet 6 is close to the intake pipe outlet 9, and the bypass outlet 7 is close to the intake pipe inlet 8. The side wall of the inner ring 3 at the end away from the intake pipe can undergo elastic deformation. The annular sealed chamber 4 is filled with gas at a certain pressure. One side of the intake pipe outlet 9 is a high-pressure environment, and the other side of the intake pipe inlet 8 is a low-pressure environment. Airflow flows from the high-pressure side to the low-pressure side. Therefore, a bypass inlet 6 is provided near the intake pipe outlet 9. The airflow generated by the compressor enters the annular chamber 5 through the bypass inlet 6, and after passing through the annular chamber 5, it flows out through the bypass outlet 7, then flows back to the impeller for further pressurization. At the bypass outlet 7, the sound waves from the annular chamber 5 and the sound waves from the intake pipe 1 will undergo destructive interference. The path difference between the two sound waves is continuous within a certain range, thus enabling the processing of discrete single-tone noise frequencies. The noise reduction effect is achieved across a wide frequency band, including the frequency of the centrifugal compressor. Furthermore, the operating speed of the centrifugal compressor in the diesel engine varies, with each speed corresponding to a different discrete single-tone noise frequency. The air pressure in the annular chamber 5 differs at different speeds, while the air pressure inside the annular sealed chamber 4 remains constant. This causes different deformations in the sidewall of the inner ring 3 at the end furthest from the intake pipe at different speeds, thereby altering the propagation path of the sound waves within the annular chamber 5. This achieves the purpose of destructive interference of the discrete single-tone noise corresponding to different speeds, thus realizing the noise reduction effect of the compressor's discrete single-tone noise at different speeds.

[0030] In a further preferred embodiment of the present invention, the compressor noise reduction intake bypass recirculation structure further includes an intake pipe flange 10, which is fixedly connected to one end of the intake pipe outlet 9.

[0031] In a further preferred embodiment of the present invention, the axis of the intake pipe 1, the axis of the inner ring 3, and the axis of the outer ring 2 are collinear.

[0032] In a further preferred embodiment of the present invention, the gas is nitrogen or other gases with a certain pressure and high acoustic impedance. Gases with high acoustic impedance can serve as effective acoustic barriers.

[0033] In a further preferred embodiment of the present invention, both the bypass air inlet 6 and the bypass air outlet 7 are annular openings, and the opening width of the bypass air inlet 6 and the opening width of the bypass air outlet 7 are the same.

[0034] In a further preferred embodiment of the present invention, a plurality of connecting supports 11 are provided circumferentially on the bypass outlet 7. The connecting supports 11 are used to fix one end of the air inlet of the air inlet pipe to the middle part of the air inlet pipe, and the plurality of connecting supports 11 are evenly distributed along the circumferential direction of the air inlet pipe.

[0035] In a further preferred embodiment of the present invention, the sidewall of the inner ring 3 at the end furthest from the intake pipe is an elastic annular membrane or other elastic element that can deform differently with different pressures. When the compressor speed changes, the pressure on the outer side of the annular membrane also changes. The annular membrane can produce different deformations with the gas pressure changes in the annular chamber 5, thereby affecting the sound propagation path inside the intake bypass recirculation chamber, so that the variable air chamber structure can achieve noise reduction at different speeds. Specifically, there are three typical cases: Case 1, the gas pressure in the annular chamber 5 is the same as the pressure in the annular sealed chamber 4, and the annular membrane does not deform; Case 2, the gas pressure in the annular chamber 5 is greater than the pressure in the annular sealed chamber 4, and the annular membrane bends inward; Case 3, the gas pressure in the annular chamber 5 is less than the pressure in the annular sealed chamber 4, and the annular membrane bends outward. The path of sound wave 2 in the annular chamber 5 is different in the three cases, while the path of sound wave 1 is constant. Therefore, the path difference between the two sound waves at the bypass outlet 7 changes with the compressor speed, which causes the suppressed noise frequency range to change with the compressor speed.

[0036] Assume the compressor has three speeds: speed 1, speed 2, and speed 3. At speed 1, the variable chamber structure corresponds to case 1; at speed 2, it corresponds to case 2; and at speed 3, it corresponds to case 3. The discrete single-tone noise frequency is λ1 at speed 1, λ2 at speed 2, and λ3 at speed 3. In cases 1, 2, and 3, the travel distance of sound wave 2 within the intake bypass recirculation structure cavity is d, respectively. 21 d 22 d 23 The travel distance of sound wave 1 in the intake manifold is d1.

[0037]

[0038] n takes integer values ​​(0, 1, 2, ...), which physically represent the frequency at which destructive interference occurs. Each integer corresponds to a specific travel difference condition, thus determining the frequency band at which sound waves cancel each other out in space. Reasonable pressure within the sealed cavity and the material of the annular diaphragm can be obtained through experiments or simulations. As long as the travel difference between the two sound waves at each rotational speed satisfies this formula, the two sound waves will undergo destructive interference, achieving noise reduction for discrete single-tone noise at different rotational speeds. This invention changes the sound wave travel (d2) in the intake bypass recirculation chamber by varying the compressor speed. The change in rotational speed itself causes a change in wavelength (λ), ultimately continuously satisfying this formula to achieve an adaptive passive control noise reduction effect.

[0039] In a further preferred embodiment of the present invention, the two sidewalls of the inner ring 3 connected to the intake pipe 1 are made of rigid material, so that when the gas pressure in the annular chamber 5 changes, the deformation of the two sidewalls of the inner ring 3 connected to the intake pipe 1 is small.

[0040] 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 noise-reducing intake bypass recirculation structure for a compressor, characterized in that: The device includes an intake pipe and an intake bypass recirculation annular sleeve. The intake bypass recirculation annular sleeve is fixedly fitted outside the intake pipe. The intake bypass recirculation annular sleeve includes an inner ring and an outer ring. The outer ring is fitted outside the inner ring. A hollow annular sealed chamber is formed between the inner ring and the outer wall of the intake pipe. A hollow annular chamber is formed between the outer wall of the intake pipe, the outer wall of the inner ring, and the inner wall of the outer ring. A bypass inlet and a bypass outlet are provided on the side wall of the intake pipe. Both the bypass inlet and the bypass outlet are connected to the annular chamber. The inner ring is located between the bypass inlet and the bypass outlet. The bypass inlet is close to the intake pipe outlet, and the bypass outlet is close to the intake pipe inlet. The side wall of the inner ring at the end away from the intake pipe can undergo elastic deformation. The annular sealed chamber is filled with gas at a certain pressure.

2. The noise-reducing intake bypass recirculation structure for the compressor according to claim 1, characterized in that: It also includes an intake pipe flange, which is fixedly connected to one end of the intake pipe outlet.

3. The noise-reducing intake bypass recirculation structure for the compressor according to claim 1, characterized in that: The axis of the intake pipe, the axis of the inner ring, and the axis of the outer ring are collinear.

4. The noise-reducing intake bypass recirculation structure of the compressor according to claim 1, characterized in that: The gas is nitrogen.

5. The noise-reducing intake bypass recirculation structure for the compressor according to claim 1, characterized in that: Both the bypass air inlet and the bypass air outlet are annular openings.

6. The noise-reducing intake bypass recirculation structure for the compressor according to claim 5, characterized in that: The opening width of the bypass air inlet is the same as the opening width of the bypass air outlet.

7. The noise-reducing intake bypass recirculation structure for the compressor according to claim 5, characterized in that: The bypass outlet is provided with multiple connecting supports in the circumferential direction. The connecting supports are used to fix one end of the air inlet of the air inlet pipe to the middle part of the air inlet pipe.

8. The noise-reducing intake bypass recirculation structure for the compressor according to claim 7, characterized in that: The multiple connecting struts are evenly distributed along the circumference of the air intake pipe.

9. The noise-reducing intake bypass recirculation structure for the compressor according to claim 1, characterized in that: The sidewall of the inner ring at the end away from the air intake pipe is an elastic circular film.

10. The noise-reducing intake bypass recirculation structure for a compressor according to claim 9, characterized in that: The two sidewalls of the inner ring that connect to the intake pipe are made of rigid material.

Images