A full-band noise reduction system and noise reduction method thereof

Abstract

The present invention discloses a full-band silencer system and a silencer method thereof, comprising: a silencer outer shell connected to a pipeline, the silencer outer shell comprising an air inlet pipe and an air outlet pipe; an inner guide seat, the guide seat being fixedly mounted inside the silencer outer shell; a silencer structure, the silencer structure comprising a plurality of reference sensors, a secondary sound source located on the right side of the reference sensor and connected to the inner guide seat, an error sensor arranged on the side of the inner guide seat close to the air outlet pipe, an active control system is adopted to reduce the noise value in the pipeline, and the active noise control algorithm for suppressing secondary sound feedback proposed in this case adopts a dual-reference microphone array method to indirectly estimate the actual reference signal after suppressing the feedback sound signal, thereby providing more accurate noise information for the active noise control system, and stimulating the secondary sound source arranged in the pipeline to achieve a more superior noise reduction effect at the error point.

Description

Technical Field

[0001] The present invention relates to the field of pipeline silencing, in particular to a full-band silencing system and a silencing method thereof. Background Art

[0002] The fresh air system is a ventilation method that is continuous and can control the ventilation path. Through a high-performance fan and airflow control system, the replacement of fresh air is completely controlled. This technology has little impact on the indoor temperature and is very popular in many factories and homes. The fresh air system is an independent air treatment system consisting of an air supply system and an exhaust system. It will generate noise during its operation. The noise generated will have a greater impact on the installation environment and also have higher requirements for the installation structure.

[0003] There are two traditional ways to deal with fresh air equipment pipe noise on the market: pipe sound insulation wrapping and installation of resistive silencers. Pipe sound insulation wrapping has limited effect on noise reduction and is relatively difficult to construct. Common pipe wrapping only has a significant effect on reducing high-frequency noise. Resistive silencers use porous sound-absorbing materials (often called resistive materials) with different structural forms in the air flow duct to absorb sound energy and reduce noise. However, aerodynamic noise in the duct, such as radiation noise from the air inlet, flow noise in the pipe, and radiation noise from the exhaust port, is usually low-frequency noise. Due to the limitations of material size and volume, pipe sound insulation wrapping has poor control effect on low-frequency noise. Resistive silencers have a wider sound reduction frequency range, and their sound reduction performance is particularly significant in the medium and high frequency bands. The above two methods have poor suppression effects on low-frequency duct noise.

[0004] Therefore, this case aims to provide a full-band noise reduction system that can use a secondary sound source or actuator to offset primary noise or vibration, and can weaken the impact of secondary sound feedback on the active noise control algorithm. At the same time, combined with a proposed dual-channel active noise reduction method, it provides a more superior noise reduction effect. Summary of the Invention

[0005] The present invention provides a full-band silencing system and a silencing method thereof, which can effectively solve the above problems.

[0006] The present invention is achieved in that:

[0007] A full-band silencing system, comprising:

[0008] A muffler outer shell connected to the pipeline, the muffler outer shell including an air inlet pipe and an air outlet pipe;

[0009] an inner guide seat, the guide seat being fixedly mounted inside the outer shell of the muffler;

[0010] A silencer structure includes a plurality of reference sensors installed on the side of the inner guide seat close to the air inlet pipe, a secondary sound source located on the right side of the reference sensor and connected to the inner guide seat, and an error sensor arranged on the side of the inner guide seat close to the air outlet pipe.

[0011] As a further improvement, the reference sensor, the secondary sound source, the error sensor and a line perpendicular to the axis of the intake pipe are arranged on the same straight line.

[0012] As a further improvement, the outer shell of the muffler has a thick galvanized steel plate, a thick damping layer, aluminum silicate sound-absorbing cotton, non-woven fabric, and a galvanized perforated plate arranged in sequence from the outside to the inside.

[0013] As a further improvement, the inner guide seat includes a guide air duct located inside the outer shell of the muffler, and the cross-sectional area of the guide air duct gradually decreases from the middle to both sides. The reference sensor is installed at the air inlet end of the guide air duct, and the error sensor is installed on the air outlet side of the guide air duct. The error sensor points to the secondary sound source, and the secondary sound source is arranged at the rear end of the vertical line of the center of the guide air duct.

[0014] As a further improvement, the reference sensor and the error sensor are both connected to a wind-breaking cone head at one end close to the gas intake direction, and the wind-breaking cone head has a pointed cone head at the end pointing to the gas intake direction, and a plurality of flow holes are provided on the outer side surface of the wind-breaking cone head, and the flow holes are facing the gas intake direction.

[0015] As a further improvement, the wind-breaking cone head and the guide air duct are spaced apart and form a guide groove, and the gas entering the wind-breaking cone head through the flow hole is then discharged through the guide groove.

[0016] As a further improvement, the outer side of the guide air duct is fixedly mounted on the inner wall of the muffler outer shell by a number of fixing plates, the fixing plates are of an inverted cone-shaped structure, the fixing plates have an air intake portion arranged on one side facing the gas intake direction and a guide portion integrally formed with the air intake portion, the air intake portion and the guide portion form a cavity.

[0017] The present invention also provides a full-band silencing method, which uses the above-mentioned full-band silencing system, and the specific steps include:

[0018] S1; collecting the signals x1(n) and x2(n) on the two reference sensors, and using the NLMS algorithm to offline model the feedback transfer functions h1(n) and h2(n) from the secondary sound source to the two reference sensors;

[0019] S2; Based on the feedback transfer functions h1(n) and h2(n) of the reference sensor, construct a cost function J = |h1(n)-A×h2(nt)| 2 , where the parameters A and t correspond to the delay of the amplitude and phase response respectively;

[0020] S3; using differential evolution algorithm to adaptively optimize and generate parameters A and t;

[0021] S4; Based on the obtained A and t, the expression x(n) = x1(n) - A×x2(nt) is derived to obtain the actual reference signal x(n) after suppressing the feedback sound signal.

[0022] The beneficial effects of the present invention are:

[0023] The present invention adopts an active control system to reduce the noise value in the pipeline. First, the passive sound-absorbing material of the small-volume muffler outer shell is used to control the medium and high-frequency noise in the pipeline. Then, by setting a secondary sound source in the muffler outer shell, the low-frequency noise in the pipeline is controlled in an active control manner, thereby achieving a full-band noise control effect.

[0024] In order to improve the accuracy of active noise reduction of the secondary sound source, so that the amplitude of the sound waves it emits can significantly offset the noise source and emit sound waves closer to the noise source, a reference sensor is set at the front end of the secondary sound source. The reference sensor is used to obtain the specific sound wave pattern of the noise source and feed it back to the position of the secondary sound source, so that the secondary sound source can adjust the output sound waves in time according to the data obtained by the reference sensor, so that the output anti-sound wave cancellation effect is better.

[0025] Although the anti-sound wave output by the secondary sound source after feedback from the reference sensor is equal to the amplitude and opposite to the noise sound wave, due to the errors in the structure and installation in the pipeline, the signal received by the reference sensor may deviate, or the anti-sound wave emitted by the secondary sound source may not be so accurate. To this end, an error sensor is set at the back end of the secondary sound source. The error sensor can obtain the sound wave after the noise wave and the anti-sound wave are offset, identify the sound wave band after the offset, and thus judge the error amount of the emitted anti-sound wave, and then feed it back to the secondary sound source for fine-tuning. The back-end feedback method is used to improve the accuracy of the anti-sound wave.

[0026] Although secondary sound sources are also set on other devices, the sound waves generated by the placement of the secondary sound source of the existing active silencer and the original noise sound waves are not on the same horizontal plane to cancel each other out. As the airflow moves in the pipe, the friction between the airflow and the pipe wall boundary will cause secondary noise problems, affecting the signal quality of the sensor test collection, resulting in the sound waves generated by the secondary sound source and the original noise sound waves unable to reach equal amplitude and opposite phase, and unable to completely cancel each other out. In this regard, the present invention further sets the reference sensor, secondary sound source, error sensor and the axis vertical line of the intake pipe on the same straight line, and installs the sensor and secondary sound source in the middle position of the pipe, so that the sensor and secondary sound source are away from the turbulence caused by the contact between the gas and the side wall of the muffler.

[0027] In the present invention, the geometric shape of the front-end structure of the installation position of the reference sensor and the error sensor is changed, that is, a wind-breaking cone head is set at the front end of the reference sensor and the error sensor, and the air flow state is changed by the pointed cone head on the wind-breaking cone head, thereby reducing the resistance. That is, the front half of the object is pointed, and there is no obvious turning point during the change of the object shape. The gas is dispersed due to the impact of the pointed cone head, and the pointed cone head part will destroy the surface tension of the air, thereby reducing the resistance of the external structure of the sensor in the pipeline, and avoiding the direct contact between the gas and the sensor to affect the detection result.

[0028] On the basis of the above, a flow hole is also opened on the surface of the wind-breaking cone head. At the same time, the wind-breaking cone head and the guide air duct are spaced apart to form a guide groove. After the air flows into the sensor to collect noise data through the flow hole, it flows out from the guide groove between the wind-breaking cone head and the guide air duct, avoiding the air flow from accumulating inside the structure, causing turbulence and local air pressure increase, and affecting the sensor collection results.

[0029] Although the above method avoids air noise, its performance for low-frequency noise is still limited. Therefore, the present invention also proposes a full-band noise cancellation method. First, for the signals x1(n) and x2(n) at the two reference microphones, it is necessary to use the NLMS algorithm to offline model the feedback transfer functions h1(n) and h2(n) from the secondary source to the two reference microphones. Then, based on the characteristics of microphone array signal processing, a cost function J = |h1(n)-A×h2(nt)| is constructed. 2, to minimize the estimation error between the estimated h1(n) and h2(n), where the parameters A and t correspond to the delay of the amplitude and phase response, respectively; then, the differential evolution algorithm is used to adaptively optimize and generate the parameters A and t; finally, based on the above modeling and estimation results, the expression of the actual reference signal can be derived as x(n) = x1(n) - A × x2(nt). This signal x(n) avoids the influence of secondary acoustic feedback and can be directly used for active noise control. The proposed method takes advantage of the dual-microphone array and uses the differences in the offline designed acoustic feedback paths to indirectly estimate and suppress the influence of secondary acoustic feedback, thereby improving the suppression performance of broadband low-frequency noise.

[0030] Through the coordination of structure and algorithm, noise processing is performed across the entire frequency band, greatly alleviating the noise in the fresh air system ducts, making its installation structure and installation environment more diversified, with a wider range of applications and less impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 It is a schematic diagram of the three-dimensional structure of a full-band noise reduction system of the present invention.

[0033] Figure 2 It is a left-view structural schematic diagram of a full-band silencing system of the present invention.

[0034] Figure 3 It is a schematic diagram of the top structure of a full-band silencing system of the present invention.

[0035] Figure 4 This invention Figure 3 Cross-section view at AA in the middle.

[0036] Figure 5 This invention Figure 3 Isometric section view at center AA.

[0037] Figure 6 It is a schematic diagram of the three-dimensional structure of a fixing plate of the present invention.

[0038] Figure 7 It is a schematic diagram of the internal structure of an inner guide seat of the present invention.

[0039] Figure 8 It is a sound wave diagram of the secondary sound source installed on the side of the muffler shell in the prior art.

[0040] Figure 9 It is a sound wave diagram of a full-band silencing system of the present invention. DETAILED DESCRIPTION

[0041] All embodiments of the present invention are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0042] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as referring to the purpose, technical solutions and advantages of the methods. To be clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work indicate or imply relative importance or implicitly indicate the number of indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0043] Reference Figures 1 to 7 As shown, a full-band silencer system comprises: a silencer outer shell 10 connected to a pipe, the silencer outer shell 10 comprising an air inlet pipe 11 and an air outlet pipe 12; an inner guide seat 20, the guide seat 20 being fixedly mounted inside the silencer outer shell 10; a silencer structure comprising a plurality of reference sensors 30 mounted on the side of the inner guide seat 20 close to the air inlet pipe 11, a secondary sound source 40 located on the right side of the reference sensor 30 and connected to the inner guide seat 20, and an error sensor 50 arranged on the side of the inner guide seat 20 close to the air outlet pipe 12.

[0044] In this embodiment, the air inlet pipe 11 and the air outlet pipe 12 of the muffler outer shell 10 are both connected to the pipeline, thereby reducing the noise of the air flowing in the pipeline.

[0045] The outer shell 10 of the muffler is not simply made of metal, but is divided into a multi-layer structure. Specifically, the outer shell 10 of the muffler has thick galvanized steel plate, thick damping layer, aluminum silicate sound-absorbing cotton, non-woven fabric, and galvanized perforated plate arranged in sequence from the outside to the inside. It can structurally reduce the noise source through the material itself. At the same time, its volume is smaller than that of the existing structure, and it occupies less installation space.

[0046] On the basis of setting up the muffler outer shell 10, an active control machine system is introduced in this embodiment to control the noise, and an active control system is used to reduce the noise value in the pipeline. First, the passive sound-absorbing material of the small-volume muffler outer shell 10 is used to control the medium and high-frequency noise in the pipeline, and then by setting a secondary sound source 40 in the muffler outer shell 10, the low-frequency noise in the pipeline is controlled in an active control manner, thereby achieving a full-band noise control effect.

[0047] The noise generated in different pipeline environments and under different working conditions has different frequencies. It is obviously unreasonable to simply set a secondary sound source 40 with a fixed frequency. Therefore, in this embodiment, in order to improve the accuracy of active noise reduction of the secondary sound source 40, so that the amplitude of the sound waves it emits can greatly offset the noise source and emit sound waves closer to the noise source, a reference sensor 30 is set at the front end of the secondary sound source 40, and the reference sensor 30 is used to obtain the specific sound wave pattern of the noise source and feed it back to the position of the secondary sound source 40, so that the secondary sound source 40 can adjust the output sound wave in time according to the data obtained by the reference sensor 30, so that the output anti-sound wave cancellation effect is better.

[0048] However, although the anti-sound wave output by the secondary sound source 40 after feedback from the reference sensor 30 is equal to the amplitude and opposite to the phase of the noise sound wave, due to the errors in the structure and installation in the pipeline, the signal received by the reference sensor 30 may deviate, or the anti-sound wave emitted by the secondary sound source 40 may not be so accurate. To this end, an error sensor 50 is set at the rear end of the secondary sound source 40. The error sensor 50 can obtain the sound wave after the noise sound wave and the anti-sound wave are offset, identify the sound wave band after the offset, and thus judge the error amount of the emitted anti-sound wave, and then feed it back to the secondary sound source 40 for fine-tuning. The rear-end feedback method is used to improve the accuracy of the anti-sound wave.

[0049] In the actual application stage, some existing technologies have thought of applying the secondary sound source 40 in the pipeline. Usually, for the convenience of installation, the secondary sound source 40 is directly installed on the outside of the muffler, and part of it is embedded in the inside of the muffler, that is, the sound wave is canceled. However, with this setting method, Figure 8As shown, since the secondary noise source of the new active muffler is placed longitudinally, the secondary sound source is reflected multiple times by the pipe wall, interfering with the primary noise, affecting the noise reduction effect of the new active muffler. Therefore, in this embodiment, the secondary sound source 40 is placed on the same straight line as the axis perpendicular to the intake pipe 11, generating a sound wave with equal amplitude and opposite phase to the primary noise, and realizing noise reduction at the error sensor based on the principle of destructive interference. For specific diagrams, refer to Figure 9 .

[0050] When the secondary sound source emits sound waves downstream in the pipe, it also transmits sound waves upstream. When the reference microphone picks up the reference signal, it also picks up the sound waves radiated by the secondary sound source, causing system instability. This phenomenon is called secondary acoustic feedback. As the airflow moves through the pipe, the friction between the airflow and the pipe wall generates secondary acoustic feedback. At the same time, the gas flow rate on the inner wall of the pipe also affects data acquisition. Therefore, the data collected by the reference sensor 30 is not the true reference signal of the system. Inaccurate reference signals will greatly affect the noise reduction performance of the system. Therefore, in this embodiment, the reference sensor 30, secondary sound source 40, error sensor 50 are arranged on the same straight line as the axis perpendicular to the center of the intake pipe 11, so that the sensor and secondary sound source 40 are away from the turbulence caused by the contact between the gas and the side wall of the muffler.

[0051] Since the reference sensor 30, the secondary sound source 40, and the error sensor 50 need to be installed in the middle position of the entire muffler, it is impossible to set them in a suspended manner. Therefore, the inner guide seat 20 includes a guide air duct 21 located in the outer shell 10 of the muffler. The reference sensor 30, the secondary sound source 40, and the error sensor 50 are all installed in the guide air duct 21. In order to achieve the best setting effect of entering the secondary sound source 40, the cross-sectional area of the guide air duct 21 gradually decreases from the middle to both sides. The reference sensor 30 is installed at the air inlet end of the guide air duct 21, and the error sensor 50 is installed on the air outlet side of the guide air duct 21. The error sensor 50 points to the secondary sound source 40. The secondary sound source 40 is set at the rear end of the vertical line of the center of the guide air duct 21. The sound waves emitted by the secondary sound source 40 converge with the airflow from the surrounding areas, which can achieve a better noise reduction effect. The reference sensor 30 can accurately obtain the sound wave signal, and the error sensor 50 can accurately obtain the error signal.

[0052] After the fresh air enters the silencer from the pipeline, due to the obstruction of the guide air duct 21, the air flow configuration of the pipeline itself will inevitably be changed, the gas resistance in the pipeline will be increased, and unnecessary aerodynamic noise will be caused. To this end, the reference sensor 30 and the error sensor 50 are both connected with a wind-breaking cone head 60 at one end close to the gas intake direction. The wind-breaking cone head 60 has a pointed cone head 61 at one end pointing to the gas intake direction, and a plurality of flow holes 62 are provided on the outer side of the wind-breaking cone head 60. The flow holes 62 face the gas intake direction. By changing the reference sensor 30, The geometric shape of the front-end structure of the error sensor 50 installation position, that is, a wind-breaking cone head 60 is set at the front end of the reference sensor 30 and the error sensor 50, and the air flow state is changed by the pointed cone head 61 on the wind-breaking cone head 60, thereby reducing the resistance, that is, the front half of the object is pointed, and there is no obvious turning point during the change of the object shape. The gas is dispersed due to the impact of the pointed cone head 61, and the pointed cone head 61 part will destroy the surface tension of the air, thereby reducing the resistance of the external structure of the sensor in the pipeline, and avoiding the direct contact between the gas and the sensor to affect the detection result.

[0053] In order to avoid the accumulation of airflow inside the structure, the flow hole 62 is a small hole with a diameter of 3 mm. The wind-breaking cone head 60 and the guide air duct 21 are spaced apart and form a guide groove 70. The gas in the wind-breaking cone head 60 entering through the flow hole 62 is then output through the guide groove 70. After the airflow flows into the sensor through the flow hole 62 to collect noise data, it flows out from the guide groove 70 between the wind-breaking cone head 60 and the guide air duct 21, avoiding the accumulation of airflow inside the structure, causing turbulence and increased local air pressure, and affecting the sensor collection results.

[0054] The guide air duct 21 needs to be firmly fixed in the muffler outer shell 10. Specifically, the outer side of the guide air duct 21 is fixedly mounted on the inner wall of the muffler outer shell 10 by a number of fixing plates 80. Although a fixed structure is provided to maintain stability, the fixing plate 80 can easily become a factor that hinders the airflow dynamics. Therefore, the fixing plate 80 is an inverted cone-shaped structure. The fixing plate 80 has an air intake portion 81 arranged on one side facing the gas intake direction and a guide portion 82 integrally formed with the air intake portion 81. The air intake portion 81 and the guide portion 82 form a cavity 83, and the air intake portion 81 and the guide portion 82 gradually narrow along the airflow direction, reducing friction with the air and avoiding the generation of air noise. The setting of the cavity 83 can reserve space for installing the wires of the secondary sound source 40 and the sensor.

[0055] In the above, the mid- and high-frequency noise reduction effect of the muffler outer shell 10 is fully utilized. At the same time, the cancellation effect of the secondary sound source 40 is also utilized to reduce the low-frequency part of the noise, thereby achieving the effect of full-band noise reduction. However, in reality, the performance of the secondary sound source 40 for low-frequency noise is limited. Therefore, it is necessary to suppress the secondary sound feedback through other noise reduction methods. Common secondary sound feedback methods usually require modeling the transfer function between the secondary source and the reference microphone, and subtracting the estimated feedback sound signal from the reference signal. The algorithm complexity of the traditional method is relatively high. Therefore, in the present invention, a dual reference microphone array method is considered to indirectly estimate the actual reference signal x(n) after suppressing the feedback sound signal. In another embodiment of the present invention, a full-band noise reduction method is provided, including the above-mentioned frequency band noise reduction system, and the specific steps include:

[0056] S1; collecting the signals x1(n) and x2(n) on the two reference sensors 30, and using the NLMS algorithm to offline model the feedback transfer functions h1(n) and h2(n) from the secondary sound source 40 to the two reference sensors 30;

[0057] S2; Based on the feedback transfer functions h1(n) and h2(n) of the reference sensor 30, construct a cost function J = |h1(n)-A×h2(nt)| 2 , where the parameters A and t correspond to the delay of the amplitude and phase response respectively;

[0058] S3; using differential evolution algorithm to adaptively optimize and generate parameters A and t;

[0059] S4; Based on the obtained A and t, the expression x(n) = x1(n) - A×x2(nt) is derived to obtain the actual reference signal x(n) after suppressing the feedback sound signal.

[0060] The obtained signal x(n) avoids the influence of secondary acoustic feedback and can be directly used for active noise control to improve the suppression performance of broadband noise. The reference signal is obtained by combining the weighted dual microphones, and the weighting coefficient is solved using the differential evolution algorithm to obtain a pure reference signal after suppressing the acoustic feedback signal, effectively weakening the influence of secondary acoustic feedback on system performance. The designed method takes advantage of the advantages of the dual-microphone array and uses the differences in the offline designed acoustic feedback paths to indirectly estimate and suppress the influence of secondary acoustic feedback, thereby improving the suppression performance of broadband low-frequency noise.

[0061] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A full-band silencing system, installed on a pipe, characterized in that: include: A muffler outer shell (10) connected to the pipeline, the muffler outer shell (10) comprising an air inlet pipe (11) and an air outlet pipe (12); an inner guide seat (20), the guide seat (20) being fixedly mounted inside the muffler outer shell (10); A muffler structure comprising a plurality of reference sensors (30) mounted on a side of the inner guide seat (20) close to the air inlet pipe (11), a secondary sound source (40) located on the right side of the reference sensors (30) and connected to the inner guide seat (20), and an error sensor (50) disposed on a side of the inner guide seat (20) close to the air outlet pipe (12); The reference sensor (30) and the error sensor (50) are both connected and sleeved with a wind-breaking cone head (60) at one end close to the gas inlet direction, and the wind-breaking cone head (60) has a pointed cone head (61) at one end pointing to the gas inlet direction, and a plurality of flow holes (62) are formed on the outer side surface of the wind-breaking cone head (60), and the flow holes (62) face the gas inlet direction; The wind-breaking cone head (60) and the guide air duct (21) are spaced apart to form a guide groove (70), and the gas entering the wind-breaking cone head (60) through the flow hole (62) is then discharged through the guide groove (70).

2. A full-band silencing system according to claim 1, characterized in that: The reference sensor (30), the secondary sound source (40), the error sensor (50) and a vertical line of the axis of the intake pipe (11) are arranged on the same straight line.

3. A full-band silencing system according to claim 1, characterized in that: The muffler outer shell (10) comprises a thick galvanized steel plate, a thick damping layer, aluminum silicate sound-absorbing cotton, non-woven fabric, and a galvanized perforated plate, which are arranged in sequence from the outside to the inside.

4. A full-band silencing system according to claim 1, characterized in that: The inner guide seat (20) includes a guide air duct (21) located in the muffler outer shell (10), wherein the cross-sectional area of the guide air duct (21) gradually decreases from the middle to both sides, the reference sensor (30) is installed at the air inlet end of the guide air duct (21), and the error sensor (50) is installed at the air outlet side of the guide air duct (21). The error sensor (50) points to the secondary sound source (40), and the secondary sound source (40) is arranged at the rear end of the vertical center line of the guide air duct (21).

5. The full-band silencing system according to claim 1, characterized in that: The outer side of the guide air duct (21) is fixedly mounted on the inner side wall of the muffler outer shell (10) via a plurality of fixing plates (80), wherein the fixing plates (80) are of an inverted cone-shaped structure, and the fixing plates (80) have an air inlet portion (81) arranged on one side facing the gas inlet direction and a flow guide portion (82) integrally formed with the air inlet portion (81), wherein the air inlet portion (81) and the flow guide portion (82) form a cavity (83).

6. A full-band silencing method, using a full-band silencing system according to any one of claims 1 to 5, characterized in that: The specific steps include: S1; Collect the signals on the two reference sensors (30) and , using the NLMS algorithm to offline model the feedback transfer function from the secondary sound source (40) to the two reference sensors (30) and ; S2; Based on the feedback transfer function of the reference sensor (30) and , construct the cost function , where the parameters and These correspond to the delays in the amplitude and phase responses, respectively; S3; Use differential evolution algorithm to adaptively optimize and generate parameters and ; S4; According to the obtained and The derived expression is , get the actual reference signal after suppressing the feedback sound signal .

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