Ventilation silencer and energy storage thermal management system

Abstract

The utility model discloses a ventilation sound -absorbing device and energy storage heat management system belongs to the technical field of silencer, and is designed for solving the inconvenient of existing silencer dismounting, transportation etc. The utility model discloses a ventilation sound -absorbing device includes: frame, including the two end plates and two side plates for surrounding ventilation pipeline, and each end plate is detachably connected between two side plates, and sound -absorbing piece is located in ventilation pipeline and is detachably connected to the side plate, and sound -absorbing piece includes shell and the composite sound -absorbing inner core of setting in the shell, and the composite sound -absorbing inner core includes at least three layers of sound -absorbing layer of sequentially adhering settings, and the material density of outside sound -absorbing layer is lower than the material density of internal sound -absorbing layer. The utility model discloses a ventilation sound -absorbing device and energy storage heat management system, and the dismounting is convenient, and the transportation difficulty is low, and the composite sound -absorbing inner core can simultaneously absorb the noise of medium -high frequency and low frequency, solves the problem that the existing silencer can only handle medium -high frequency noise, and the noise reduction effect is good.

Description

Technical Field

[0001] This utility model relates to the field of silencer technology, and in particular to a ventilation silencer device and an energy storage thermal management system. Background Technology

[0002] Many devices, including energy storage thermal management systems, generate heat during operation. To avoid affecting the normal operation of these devices, ventilation systems are needed for air cooling. However, the movement of cold air through these ventilation systems generates noise. To improve the user experience, silencers can be installed on the ventilation systems.

[0003] Some existing silencers consist of a housing with multiple air outlets spaced apart at the outlet end, and sound-absorbing material is attached to the walls of the air outlets. The drawbacks of this silencer include: the housing and the partitions separating the air outlets are a single unit, resulting in a large size and weight, making disassembly, assembly, and transportation inconvenient; furthermore, it can only handle mid-to-high frequency noise and cannot effectively handle broadband frequency noise from low to high frequencies (63Hz to 8000Hz), nor can it effectively address sound sources where low-frequency noise dominates the frequency spectrum. Utility Model Content

[0004] The purpose of this utility model is to propose a ventilation and silencing device and an energy storage thermal management system, which solves the problem that existing silencers are inconvenient to disassemble, install, and transport, and has a good silencing and noise reduction effect.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A ventilation and noise reduction device includes: a frame including two end plates and two side plates for forming a ventilation duct, each of the end plates being detachably connected between the two side plates; and a sound-absorbing element located in the ventilation duct and detachably connected to the side plates, the sound-absorbing element including a housing and a composite sound-absorbing core disposed within the housing, the composite sound-absorbing core including at least three sequentially bonded sound-absorbing layers, the material density of the outer sound-absorbing layer being lower than the material density of the inner sound-absorbing layer.

[0007] In one preferred embodiment, the end plate includes an end plate body and an end plate cover, which, when fastened together, form a cavity for filling with sound-absorbing material. A through hole is provided on the side of the end plate body facing the ventilation duct. And / or, the side plate includes a side plate body and a side plate cover, which, when fastened together, form a cavity for filling with sound-absorbing material. A through hole is provided on the side of the side plate body facing the ventilation duct.

[0008] In one preferred embodiment, the sound-absorbing component includes an air outlet end near the air outlet of the ventilation duct and an air inlet end near the air inlet of the ventilation duct. The air outlet end is bent relative to the air inlet end, and the bending direction of the air outlet end is perpendicular to the direction of gas flow.

[0009] In one preferred embodiment, the included angle α between the air outlet and the air inlet is between 0° and 30°.

[0010] In one preferred embodiment, the sound-absorbing component further includes a resonant silencing cavity, which is located on the side of the outer shell near the air inlet of the ventilation duct. The cross-section of the resonant silencing cavity along the airflow direction is triangular, and the resonant silencing cavity and the space where the composite sound-absorbing inner core is located are isolated from each other by a partition.

[0011] In one preferred embodiment, the windward side of the resonant silencing cavity includes two resonant silencing side surfaces, one of which has a circular hole. The area of ​​the circular hole satisfies the following formula:

[0012]

[0013] Where f is the frequency to be eliminated, in Hz; c is the speed of sound, in m / s; and A is the area of ​​the circular hole, in m². 2 V represents the volume of the resonant silencing cavity, in meters (m³). 3 t represents the thickness of the sheet metal plate used to prepare the resonant silencing cavity, in meters (m).

[0014] In one preferred embodiment, a compression pad made of flexible material is provided between any two connected structures of the end plate, the side plate, and all the sound-absorbing components.

[0015] In one preferred embodiment, the material density of the outer sound-absorbing layer is 32 kg / m³. 3 Up to 48Kg / m 3 Between these values, the material density of the internal sound-absorbing layer is 60 kg / m³. 3 Up to 80kg / m 3 between.

[0016] In one preferred embodiment, the two side panels are arranged parallel and spaced apart, the sound-absorbing element is vertically connected between the two side panels, and the sound-absorbing element is interference-fitted with the frame.

[0017] On the other hand, the present invention adopts the following technical solution:

[0018] An energy storage thermal management system includes an energy storage thermal management box, and the energy storage thermal management system also includes the aforementioned ventilation and noise reduction device, which is installed on the top or side of the energy storage thermal management box.

[0019] The ventilation and noise reduction device disclosed in this utility model includes multiple independent structures. These structures are transported to the work site and then assembled together, making disassembly and assembly convenient and reducing transportation difficulty. The sound-absorbing component includes a composite sound-absorbing core, which is formed by using a low-density material on the outer layer and a high-density material in the middle. It can absorb both mid-to-high frequency and low-frequency noise simultaneously, solving the problem that existing silencers can only handle mid-to-high frequency noise. The material density of the composite sound-absorbing core gradually increases from the outside to the inside, and the acoustic impedance gradually increases, which is conducive to the entry and absorption of sound waves, achieving enhanced absorption of low frequencies and good noise reduction effect.

[0020] The energy storage thermal management system disclosed in this utility model includes the above-mentioned ventilation and silencing device, which can absorb medium-high frequency and low-frequency noise at the same time, and has a good noise reduction effect. The ventilation and silencing device can be divided into multiple independent small structures, which are then assembled into a ventilation and silencing device after arriving at the work site, making transportation convenient. The ventilation and silencing device can be installed on the side or top of the energy storage thermal management box, which can adapt to various site environments, avoid collisions with surrounding objects, and make it more convenient to use. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an energy storage thermal management system provided in a specific embodiment of this utility model;

[0022] Figure 2 This is a schematic diagram of another energy storage thermal management system provided in a specific embodiment of this utility model;

[0023] Figure 3 This is one of the structural schematic diagrams of the ventilation and noise reduction device provided in a specific embodiment of this utility model;

[0024] Figure 4 This is the second structural schematic diagram of the ventilation and noise reduction device provided in a specific embodiment of this utility model;

[0025] Figure 5 This is an exploded view of the ventilation and silencing device provided in a specific embodiment of this utility model;

[0026] Figure 6 This is a structural schematic diagram of the sound-absorbing component provided in a specific embodiment of this utility model;

[0027] Figure 7 This is a schematic diagram of the composite sound-absorbing core provided in a specific embodiment of this utility model;

[0028] Figure 8 These are working distance comparison diagrams of single sound-absorbing layer and double sound-absorbing layer provided in specific embodiments of this utility model;

[0029] Figure 9This is a schematic diagram of the structure of the outer shell, the resonant silencing cavity, and the partition provided in a specific embodiment of this utility model;

[0030] Figure 10 This is a side view of the sound-absorbing component provided in a specific embodiment of this utility model;

[0031] Figure 11 This is a schematic diagram of pressure loss calculation provided by a specific embodiment of this utility model;

[0032] Figure 12 This is a schematic diagram of the structure of the second shell provided in a specific embodiment of this utility model;

[0033] Figure 13 This is a schematic diagram of the structure of the first housing provided in a specific embodiment of the present utility model;

[0034] Figure 14 This is a schematic diagram of Helmholtz resonator noise attenuation provided in a specific embodiment of this utility model;

[0035] Figure 15 This is a schematic diagram of the structure of the resonance silencing cavity provided in a specific embodiment of this utility model.

[0036] In the picture:

[0037] 1. Frame; 2. Sound-absorbing component; 3. Energy storage thermal management box; 11. End plate; 12. Side plate; 13. Ventilation duct; 14. Waist-shaped perforated plate; 21. Outer shell; 22. Composite sound-absorbing core; 23. Air outlet; 24. Air inlet; 25. Resonance silencing cavity; 26. Partition; 111. End plate body; 112. End plate cover; 121. Side plate body; 122. Side plate cover; 211. First shell; 212. Second shell; 213. Connecting folded edge; 221. Outer sound-absorbing layer; 222. Inner sound-absorbing layer; 251. Resonance silencing side; 252. Circular hole. Detailed Implementation

[0038] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0039] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0042] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0044] This embodiment discloses a ventilation and silencing device and an energy storage thermal management system, such as Figure 1 and Figure 2 As shown, the energy storage thermal management system includes an energy storage thermal management box 3, and a ventilation and noise reduction device is installed on the side of the energy storage thermal management box 3 (e.g., Figure 1 (as shown) and top surface (as shown) Figure 2 As shown in the image, it can adapt to various environments, avoid collisions with surrounding objects, and is more convenient to use.

[0045] like Figures 1 to 8 As shown, the ventilation and noise reduction device includes a frame 1 and a sound-absorbing component 2. The frame 1 includes two end plates 11 and two side plates 12. Each end plate 11 is detachably connected between two side plates 12. That is, one end plate 11, one side plate 12, one end plate 11 and one side plate 12 are connected in sequence to form a ventilation duct 13. The sound-absorbing component 2 is located in the ventilation duct 13 and is detachably connected to the side plate 12.

[0046] The ventilation and silencing device is disassembled into multiple independent structures, transported to the work site, and then reassembled. This method is convenient for disassembly and assembly and reduces transportation difficulty. The frame 1 is connected to the energy storage thermal management box 3. The specific connection structure between the frame 1 and the energy storage thermal management box 3 is not limited and can be, but is not limited to, a fixed connection achieved through bending plates and bolts.

[0047] The sound-absorbing component 2 includes a housing 21 and a composite sound-absorbing core 22 disposed within the housing 21. The housing 21 has through holes through which sound waves can reach the composite sound-absorbing core 22. The composite sound-absorbing core comprises at least three sequentially bonded sound-absorbing layers, with the outer sound-absorbing layer 221 having a lower material density than the inner sound-absorbing layer 222. The composite sound-absorbing core 22, formed by using a low-density outer layer and a high-density middle layer, can simultaneously absorb mid-to-high frequency and low-frequency noise, solving the problem that existing silencers can only handle mid-to-high frequency noise. The material density of the composite sound-absorbing core 22 gradually increases from the outside to the inside, resulting in a gradual increase in acoustic impedance, which is beneficial for the absorption of sound waves, achieving enhanced absorption of low frequencies and providing good noise reduction.

[0048] Figure 8The diagram shows a comparison of the working principles of a single-density sound-absorbing layer and two sound-absorbing layers formed by composite sound-absorbing materials. Specifically, Figure 8 a represents a sound-absorbing layer formed by a single-density sound-absorbing material. Figure 8 b represents two sound-absorbing layers formed by composite sound-absorbing materials.

[0049] When sound waves travel from the air to a sound-absorbing material, some are reflected and some are incident. The incident portion of the sound waves is dissipated as heat energy by the sound-absorbing material. Therefore, a higher proportion of incident sound waves is desirable. The smaller the difference between the impedance of the air and the impedance of the sound-absorbing material, the easier it is for sound waves to enter. The impedance can be calculated using the following formula:

[0050] Z0=ρ×c

[0051] Where Z0: acoustic impedance kg / (m) 2 ×s), ρ: density of medium (kg / m³) 3 c: speed of sound in m / s.

[0052] To more effectively handle noise over a wide frequency range, especially low-frequency noise, the selection of materials for the sound-absorbing layer needs to consider impedance matching to facilitate sound wave incidence. The appropriate density value for different density ranges generally needs to be evaluated based on the weight limitations of the ventilation and silencing device. In this embodiment, the material density of the outer sound-absorbing layer 221 is 32 kg / m³. 3 Up to 48Kg / m 3 Between these layers, the material density of the internal sound-absorbing layer 222 is 60 kg / m³. 3 Up to 80kg / m 3 between.

[0053] The specific thickness of each sound-absorbing layer is not limited. In this embodiment, the overall thickness of the sound-absorbing layer is 150mm, the thickness of the two outer sound-absorbing layers 221 is 50mm, and the thickness of the inner sound-absorbing layer 222 is also 50mm. It is easy to process and has a good absorption effect on both mid-high frequency noise and low frequency noise.

[0054] The specific shape and size of the frame 1 are not limited, as long as the cross-sectional area of ​​the ventilation duct 13 meets the ventilation requirements of the energy storage thermal management system. The specific connection method between the end plate 11 and the side plate 12 is not limited. In this embodiment, the end plate 11 and the side plate 12 are fixedly connected by a waist-shaped perforated plate 14 and self-tapping screws.

[0055] The specific connection structure between the frame 1 and the sound-absorbing component 2 is not limited. In this embodiment, the two side plates 12 are arranged parallel and spaced apart, and the sound-absorbing component 2 is vertically connected between the two side plates 12. The sound-absorbing component 2 and the frame 1 are interference-fitted, making the connection more stable. In order to make the overall structure of the ventilation and noise reduction device more robust, a bendable waist-shaped perforated plate can be provided between the sound-absorbing component 2 and the side plate 12. The two ends of the bendable waist-shaped perforated plate are fixed to the sound-absorbing component 2 and the side plate 12 respectively using self-tapping screws.

[0056] like Figure 5 As shown, the end plate 11 includes an end plate body 111 and an end plate cover 112. After the end plate cover 112 and the end plate body 111 are fastened together, they form a cavity for filling with sound-absorbing material to reduce noise. Correspondingly, the side plate 12 includes a side plate body 121 and a side plate cover 122. After the side plate body 121 and the side plate cover 122 are fastened together, they form a cavity for filling with sound-absorbing material.

[0057] The end plate body 111 has a through hole on the side facing the ventilation duct 13, and the side plate body 121 has a through hole on the side facing the ventilation duct 13. Sound can be absorbed by the sound-absorbing material through the through hole, resulting in good noise reduction effect. The airflow will not turn and enter the through hole, so it will not affect the normal air outlet.

[0058] like Figure 9 and Figure 10 As shown, the sound-absorbing component 2 includes an air outlet 23 near the air outlet of the ventilation duct 13 and an air inlet 24 near the air inlet of the ventilation duct 13. The air outlet 23 is bent relative to the air inlet 24, and the bending direction of the air outlet 23 is perpendicular to the direction of gas flow.

[0059] The sound-absorbing component 2, with a certain degree of bending, increases the contact area between the sound source and the composite sound-absorbing core 22, resulting in better sound absorption and noise reduction. The larger the angle α between the air outlet 23 and the air inlet 24, the larger the contact area between the sound source and the composite sound-absorbing core 22, and the better the noise reduction effect. However, the bending structure increases wind resistance, and the larger the angle α between the air outlet 23 and the air inlet 24, the greater the pressure loss. In this embodiment, the angle α between the air outlet 23 and the air inlet 24 is between 0° and 30°, preferably 1°, 5°, 10°, 15°, 20°, 25°, and 30°. When α is 15°, the pressure loss is 16 Pa, which is a relatively suitable pressure loss value. Figure 11 This diagram illustrates the calculation of pressure loss, using simulation software for assessment. It is understood that the specific simulation software used is not limited; any existing software capable of calculating pressure loss can be employed.

[0060] like Figures 9 to 15As shown, the sound-absorbing component 2 also includes a resonant silencing cavity 25, which is located on the side of the outer shell 21 near the air inlet of the ventilation duct 13. The cross-section of the resonant silencing cavity 25 along the airflow direction is triangular. When the sound-absorbing material in the sound-absorbing component 2 can eliminate low-frequency noise, the space where the resonant silencing cavity 25 and the composite sound-absorbing inner core 22 are located is isolated from each other by a partition 26.

[0061] The resonant silencing cavity 25 includes two resonant silencing side surfaces 251 on its windward side. A circular hole 252 is formed on one of the resonant silencing side surfaces 251, creating a low-frequency resonant cavity. The size of the circular hole 252 can adjust the frequency of noise it can attenuate. In this embodiment, the area of ​​the circular hole 252 satisfies the following formula:

[0062]

[0063] Where f is the frequency to be eliminated, in Hz; c is the speed of sound, in m / s; and A is the area of ​​the circular hole 252, in m². 2 V represents the volume of the resonant silencing cavity 25, in meters. 3 t represents the thickness of the sheet metal plate used to prepare the resonant silencing cavity 25, in meters (m).

[0064] In this embodiment, the volume of the triangular resonant anechoic cavity 25 is V = 4.19E-4m. 3 The sheet metal thickness t = 1.5E-3m is used to attenuate 250Hz noise. According to the formula, the diameter of the circular hole 252 is calculated to be 4.2mm.

[0065] A triangular wedge-shaped resonant silencing cavity 25 is positioned at the air inlet to reduce airflow resistance. A circular hole 252 is formed on the resonant silencing side 251, which utilizes the Helmholtz resonant cavity principle to process specific low-frequency noise that is difficult for sound-absorbing materials to absorb, causing sound energy attenuation and thus reducing low-frequency noise. The principle is that when the external noise frequency matches the resonant frequency, the air column at the neck of the circular hole 252 vibrates violently, forming a low-frequency resonant cavity. Sound energy is dissipated as heat energy through viscous friction and thermal conduction, thereby eliminating low-frequency noise.

[0066] By treating specific low-frequency noise through the resonant anechoic cavity 25, the overall target value is effectively reduced, resulting in good noise reduction. The size of the resonant anechoic cavity 25 is not limited; it is designed according to the structural dimensions of the sound-absorbing component 2, and the resonance attenuation of noise can be disregarded initially. When the sound-absorbing component 2 is bent to a certain extent, the triangular wedge-shaped resonant anechoic cavity 25 remains vertically downward and does not bend with the sound-absorbing component 2.

[0067] Based on the above structure, the outer shell 21 of the sound-absorbing component 2 includes a first shell 211 and a second shell 212, which together form an accommodating cavity for filling the composite sound-absorbing inner core 22. A connecting flange 213 is formed by bending on the second shell 212. During assembly, the connecting flange 213 is attached and fixed to the first shell 211, which is a separate process with high processing efficiency.

[0068] Compression pads made of flexible material (e.g., rubber) are provided at the joints between any two connected structures of end plate 11, side plate 12 and all sound-absorbing components 2 to reduce gaps and make the connection tighter.

[0069] The following data compares the noise reduction effects of various noise reduction devices.

[0070] Table 1 below shows the original noise measurements taken at a distance of 1m from the air outlet:

[0071]

[0072] The goal of designing a ventilation and noise reduction device is to achieve a total noise reduction of no less than 10 dB(A) at the same measuring point. The design formula is:

[0073] ΔL=Φ(a)×L×P / S(dB)

[0074] Wherein, ΔL: the sound attenuation dB of the ventilation silencer at a certain flow rate; Φ(a): the static silencing coefficient obtained from the sound-absorbing material a0; a0: the sound absorption coefficient measured by the standing wave tube method, Φ(a) = 1.6a0; L: the height of the ventilation silencer protruding from the surface of the energy storage thermal management box 3, which is the height of the side plate 12 along the airflow direction, in units of (m); P is the perimeter of the cross-section of the single channel formed between two adjacent sound-absorbing components 2; S is the area of ​​the cross-section of the single channel formed between two adjacent sound-absorbing components 2.

[0075] The length of the single channel formed between two adjacent sound-absorbing elements 2 is D1, and the width is D2. Therefore, P = 2 × (D1 + D2), in meters (m); S = D1 × D2, in meters (m). 2 In this embodiment, L = 600mm, D1 = 110mm, and D2 = 800mm.

[0076] The sound absorption coefficient a0 can be determined based on the sound absorption material used. When polyester fiber is used as the sound absorption material, the sound absorption coefficient of polyester fiber is taken as 0.7.

[0077] The thickness of the protective plate surrounding the outer shell 21 also needs to be determined, based on 1 / 8 of the wavelength of the lower limit frequency of the noise spectrum. Theoretically, a thicker plate will provide better coverage, but the actual thickness will be limited by engineering space. In engineering, it is generally taken to be around 100mm. In this embodiment, the low-frequency noise energy of the sound source accounts for a prominent proportion, so a plate thickness of 150mm is chosen.

[0078] Based on the above data, calculations show that the total noise attenuation can reach 13.9 dB(A).

[0079] Table 2 below shows the statistical values ​​of noise reduction measured by conventionally designed mufflers:

[0080]

[0081] The actual total attenuation was 4.4 dB(A), which falls short of the requirement of 10 dB(A) and differs significantly from the theoretical calculation. Spectrum analysis revealed that in the low-frequency range below 500 Hz, there was only a 6 dB(A) attenuation at 500 Hz, and almost no attenuation at 63 Hz, 125 Hz, and 250 Hz. Furthermore, the energy proportion in the low-frequency range was relatively large, especially at 250 Hz.

[0082] Further analysis shows that the high-frequency band of the entire spectrum can be attenuated to 10dB(A). The simplest solution is to continue increasing the thickness of the sheet, but due to practical engineering applications, it is obviously impossible to continue increasing the thickness. Therefore, we need to further analyze and optimize the characteristics of the sound-absorbing material.

[0083] The conventional design in existing technology is to fill with a single-density sound-absorbing material, typically a low-density material of 32 kg / m³. 3 Up to 48Kg / m 3 This allows for coverage of a certain wide frequency range and enables sound waves to penetrate the sound-absorbing material as much as possible. This is because the acoustic impedance of the air must be matched as closely as possible with the acoustic impedance of the sound-absorbing material, with the impedance difference between the two being as small as possible, so that sound waves can easily penetrate.

[0084] The characteristics of sound waves are that the higher the frequency, the shorter the wavelength, and the lower the frequency, the longer the wavelength. Shorter wavelengths are more likely to penetrate low-density sound-absorbing materials. Because sound-absorbing materials have low density, their impedance is closer to that of air, making it easier for sound waves to enter. Therefore, low-density sound-absorbing materials are usually used when filling sound-absorbing materials. However, this also results in poor attenuation of low-frequency noise by the silencer, because low-frequency wavelengths have long wavelengths and strong diffraction capabilities, requiring high-density sound-absorbing materials to absorb them.

[0085] Table 3 below shows the statistical data of the measured values ​​of the composite sound-absorbing material silencer:

[0086]

[0087] The actual attenuation was 8.9 dB(A), which is 4.5 dB(A) higher than the attenuation of 4.4 dB(A) of the conventionally designed muffler. This shows that the composite material has a significant effect on improving the performance of the muffler.

[0088] However, the target value of no less than 10dB(A) has not yet been met. Analyzing the spectrum, after using composite sound-absorbing materials, the attenuation at 500Hz and 250Hz has increased significantly, reaching 11.7dB(A) at 500Hz and 5.5dB(A) at 250Hz. From the perspective of the energy ratio of the spectrum, the energy attenuation of high frequencies is already sufficient. Further attenuation of high frequencies will not have any effect on reducing the total value. Only by further attenuating the energy of low frequencies can the total value be reduced.

[0089] Table 4 below shows the statistical data of measurements taken using composite materials and resonant cavity silencers:

[0090]

[0091] The total attenuation reached 11.4 dB(A), meeting the design requirements. From the test spectrum, in the low frequency range, especially at 250 Hz, there was an attenuation of 3.8 dB(A) compared to the previous maximum, which further verified the feasibility of the theory through experiments.

[0092] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A ventilation and noise reduction device, characterized in that, include: The frame (1) includes two end plates (11) and two side plates (12) for forming a ventilation duct (13), each of the end plates (11) being detachably connected between the two side plates (12); and, The sound-absorbing component (2) is located in the ventilation duct (13) and detachably connected to the side plate (12). The sound-absorbing component (2) includes a housing (21) and a composite sound-absorbing core (22) disposed in the housing (21). The composite sound-absorbing core includes at least three layers of sound-absorbing layers that are sequentially bonded together. The material density of the outer sound-absorbing layer (221) is lower than that of the inner sound-absorbing layer (222).

2. The ventilation and noise reduction device according to claim 1, characterized in that, The end plate (11) includes an end plate body (111) and an end plate cover (112). The end plate cover (112) and the end plate body (111) are fastened together to form a cavity for filling with sound-absorbing material. The end plate body (111) has a through hole on its side facing the ventilation duct (13); and / or, The side panel (12) includes a side panel body (121) and a side panel cover (122). The side panel body (121) and the side panel cover (122) are fastened together to form a cavity for filling sound-absorbing material. The side panel body (121) has a through hole on its side facing the ventilation duct (13).

3. The ventilation and noise reduction device according to claim 1, characterized in that, The sound-absorbing component (2) includes an air outlet (23) near the air outlet of the ventilation duct (13) and an air inlet (24) near the air inlet of the ventilation duct (13). The air outlet (23) is bent relative to the air inlet (24), and the bending direction of the air outlet (23) is perpendicular to the direction of gas flow.

4. The ventilation and noise reduction device according to claim 3, characterized in that, The angle α between the air outlet (23) and the air inlet (24) is between 0° and 30°.

5. The ventilation and noise reduction device according to claim 1, characterized in that, The sound-absorbing component (2) also includes a resonant silencing cavity (25), which is located on the side of the outer shell (21) near the air inlet of the ventilation duct (13). The cross-section of the resonant silencing cavity (25) along the airflow direction is triangular. The space where the resonant silencing cavity (25) and the composite sound-absorbing inner core (22) are located is isolated from each other by a partition (26).

6. The ventilation and noise reduction device according to claim 5, characterized in that, The resonant silencing cavity (25) includes two resonant silencing side surfaces (251) on its windward side. A circular hole (252) is provided on one of the resonant silencing side surfaces (251), and the area of ​​the circular hole (252) satisfies the following formula: Where f is the frequency to be eliminated, in Hz; c is the speed of sound, in m / s; and A is the area of ​​the circular hole (252), in m². 2 V represents the volume of the resonant silencing cavity (25), in meters. 3 t is the thickness of the sheet metal plate used to prepare the resonant silencing cavity (25), in meters.

7. The ventilation and silencing device according to any one of claims 1 to 6, characterized in that, A compression pad made of flexible material is provided between any two connected structures of the end plate (11), the side plate (12), and all the sound-absorbing components (2).

8. The ventilation and silencing device according to any one of claims 1 to 6, characterized in that, The material density of the outer sound-absorbing layer (221) is 32 kg / m³. 3 Up to 48Kg / m 3 Between these points, the material density of the internal sound-absorbing layer (222) is 60 kg / m³. 3 Up to 80kg / m 3 between.

9. The ventilation and silencing device according to any one of claims 1 to 6, characterized in that, The two side panels (12) are arranged parallel and spaced apart, and the sound-absorbing component (2) is vertically connected between the two side panels (12). The sound-absorbing component (2) is interference-fitted with the frame (1).

10. An energy storage thermal management system, comprising an energy storage thermal management enclosure (3), characterized in that, The energy storage thermal management system further includes a ventilation and noise reduction device as described in any one of claims 1 to 9, wherein the ventilation and noise reduction device is disposed on the top or side of the energy storage thermal management box (3).

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