A ventilation noise reduction mechanism and a ventilation noise reduction device including the ventilation noise reduction mechanism

Abstract

The present application discloses a ventilation and noise reduction mechanism and a ventilation and noise reduction device including the ventilation and noise reduction mechanism. The ventilation and noise reduction mechanism includes a first shell, a second shell and a noise reduction structure. The first shell has at least one first through hole. The second shell and the first shell together define a cavity, and the second shell has at least one second through hole. The noise reduction structure includes at least one, each noise reduction structure is located in the cavity, each noise reduction structure has an airflow channel, and the two ports of the airflow channel of each noise reduction structure are respectively connected to each first through hole and each second through hole. The noise reduction structure also has at least two resonance cavities. The noise reduction structure is also provided with an opening connecting the resonance cavity and the airflow channel, and the number of openings is the same as that of the resonance cavity and the positions correspond one to one. The ventilation and noise reduction mechanism of the present application is used for power capacitors and reactors, and the noise reduction effect can reach more than 15dB, and the impact on the temperature rise of the equipment is less than 5°C.

Description

Technical Field

[0001] The present application relates to the technical field of electric power equipment, and in particular to a ventilation and noise reduction mechanism and a ventilation and noise reduction device including the ventilation and noise reduction mechanism. Background Art

[0002] Many power equipment will radiate audible noise into the air during operation. In places where the acoustic environment requirements are high, the audible noise radiation of power equipment needs to be strictly controlled. For example, high-voltage power capacitors and reactors are important equipment for efficiently transmitting electric energy or improving the quality of electric energy in substations. However, the large amount of sound generated by capacitors and reactors during operation may affect the surrounding environment and even interfere with the normal operation of surrounding electronic equipment. As people's environmental awareness gradually increases, the noise pollution problem of converter substations has become increasingly prominent. Research on noise control technology for power capacitors and reactors is very important. How to effectively control the noise of the equipment while ensuring ventilation and heat dissipation has become the key to noise reduction. Summary of the invention

[0003] The present application provides a ventilation and noise reduction mechanism and a ventilation and noise reduction device including the ventilation and noise reduction mechanism, which can ensure the noise reduction effect of capacitors and reactors while taking into account the ventilation and heat dissipation functions.

[0004] An embodiment of the present application provides a ventilation noise reduction mechanism, comprising a first shell, a second shell and a noise reduction structure. The first shell has at least one first through hole. The second shell and the first shell together define a cavity, and the second shell has at least one second through hole. The noise reduction structure includes at least one, each noise reduction structure is located in the cavity, each noise reduction structure has an airflow channel, and the two ports of the airflow channel of each noise reduction structure are respectively connected to each first through hole and each second through hole. The noise reduction structure also has at least two resonance cavities. The noise reduction structure is also provided with an opening connecting the resonance cavity and the airflow channel, and the number of the openings is the same as that of the resonance cavity and the positions correspond one to one.

[0005] In some of the embodiments, each resonance cavity is arranged along the length direction of the air flow channel.

[0006] In some embodiments, each resonant cavity includes a first resonant cavity and a second resonant cavity, and the first resonant cavity and the second resonant cavity are respectively located on both sides of the width direction of the airflow channel. Each opening includes a first opening and a second opening, the first opening connects the first resonant cavity with the airflow channel, the number of the first openings is the same as that of the first resonant cavity and the positions correspond one to one, and the second opening connects the second resonant cavity with the airflow channel, the number of the second openings is the same as that of the first resonant cavity and the positions correspond one to one.

[0007] In some of the embodiments, the first opening and the second opening are staggered in the length direction of the air flow channel.

[0008] In some of the embodiments, the first opening and the second opening are staggered in the width direction of the air flow channel.

[0009] In some embodiments, the noise reduction structure further has at least one sound absorption cavity. The noise reduction structure further has openings connecting the sound absorption cavity and the air flow channel, and the number of the openings is the same as the number of the sound absorption cavities and the positions correspond to each other. The inner wall of each sound absorption cavity is covered with sound absorption material.

[0010] In some of the embodiments, each sound absorbing cavity is arranged downstream of each resonance cavity in the gas flow direction of the gas flow channel.

[0011] An embodiment of the present application further provides a ventilation and noise reduction device, comprising a plurality of ventilation and noise reduction mechanisms in any of the above embodiments, wherein the ventilation and noise reduction mechanisms jointly define a receiving space.

[0012] In some embodiments, the receiving space is a hollow cylindrical cavity.

[0013] In some embodiments, the receiving space is a rectangular cavity.

[0014] According to an embodiment of the present application, a ventilation and noise reduction mechanism is provided, comprising a first shell, a second shell and a noise reduction structure. The first shell has at least one first through hole. The second shell and the first shell together define a cavity, and the second shell has at least one second through hole. The noise reduction structure includes at least one, each noise reduction structure is located in the cavity, each noise reduction structure has an airflow channel, and the two ports of the airflow channel of each noise reduction structure are connected to each first through hole and each second through hole respectively. The noise reduction structure also has at least two resonance cavities. The noise reduction structure is also provided with an opening connecting the resonance cavity and the airflow channel, and the number of openings is the same as that of the resonance cavity and the position corresponds one to one. The ventilation and noise reduction mechanism of the present application is used for power capacitors and reactors. After the noise test of capacitors and reactor equipment, the design of internal noise reduction structure and the matching of ventilation and heat dissipation are carried out in a specific noise reduction frequency band, so as to achieve targeted noise reduction, and the noise reduction effect can reach more than 15dB, and the temperature rise of the equipment is less than 5°C, so as to ensure the noise reduction effect of capacitors and reactors, and take into account the ventilation and heat dissipation function. In addition, the ventilation and noise reduction mechanism of the present application can effectively replace the sound insulation cover structure commonly used in power equipment, achieving the comprehensive effect of suppressing noise and enhancing ventilation, while improving the operating life of the power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 A cross-sectional view showing the connection between the first shell and the second shell in the ventilation and noise reduction mechanism in the embodiment of the present application;

[0017] Figure 2 A cross-sectional view of a noise reduction structure in an embodiment of the present application;

[0018] Figure 3 This is a front view of a noise reduction structure in another embodiment of the present application;

[0019] Figure 4 A top view of a noise reduction structure in another embodiment of the present application;

[0020] Figure 5 A top view of a noise reduction structure in another embodiment of the present application;

[0021] Figure 6 This is a schematic diagram of the structure of a ventilation and noise reduction device in an embodiment of the present application;

[0022] Figure 7 This is a schematic diagram of the structure of a ventilation and noise reduction device in an embodiment of the present application;

[0023] Figure 8 This is a schematic diagram of the structure of a ventilation and noise reduction device in another embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0025] At present, due to the large number of capacitors in operation, the radiation noise is high. Therefore, the noise control of a single capacitor or multiple capacitors at the same time has become one of the main means of noise reduction. At present, the production process of power capacitors has been basically mature. If the noise of power capacitors is to be reduced by improving the structural process, the technical and cost requirements are high and the effect is minimal. If the noise of power capacitors is controlled from the noise propagation path, it can be used at a lower cost and have a significant effect. At present, the commonly used noise control methods for capacitors include: (1) soundproof cover / soundproof baffle. A soundproof cover or soundproof baffle is installed on the bottom surface and casing surface of the capacitor unit. The inner side of the soundproof cover is equipped with sound-absorbing material to absorb and isolate noise, thereby achieving the purpose of noise reduction. (2) Resonance silencing structure. Resonance silencing structure is a common noise reduction measure. Commonly used ones include Helmholtz resonator and perforated silencer. It first installs the resonance silencer at the bottom of the conventional capacitor box, and then installs the capacitor core into the capacitor box, evacuates the vacuum, and injects insulating oil. (3) Spring shock absorber, damping element, etc. The capacitor is equipped with a mass block, damping element, elastic element, etc. to reduce mechanical vibration and thus achieve noise reduction. Commonly used sound-absorbing materials are porous sound-absorbing materials, such as glass fiber, high-density sponge, etc. The main technical problems of this method are:

[0026] (1) Soundproof cover / soundproof baffle. It does not affect the heat dissipation of the capacitor, but its noise reduction is limited and may cause the noise in certain directions to be amplified. (2) Resonance silencing structure. Due to the incompressibility of the liquid impregnation agent inside the capacitor, the role of this resonance silencing device is limited. From the design principle, this microporous silencing device is only effective for a single frequency. This limits the application of this method to a certain extent. At the same time, the clogging of the micropores should be avoided during use to avoid silencing failure. (3) Spring shock absorbers, damping elements, etc. Since the vibration of power capacitors is mainly medium and high frequency vibration and contains rich harmonic frequency components, and dynamic shock absorbers are mainly suitable for medium and low frequency vibration, the vibration reduction effect is not obvious under high frequency conditions. In addition, dynamic shock absorbers can often only be designed for vibrations of a single frequency, and have limited vibration suppression effects on other frequencies.

[0027] Due to the limitation of its specific structure, the radiated noise of the reactor comes from the vibration of the reactor shell and the shell inside. The noise suppression method of the reactor equipment is mainly to add a closed soundproof cover. Conventional soundproof covers have large openings due to the requirements of heat dissipation, which reduces its noise shielding effect on the reactor.

[0028] Other power equipment also has different degrees of noise pollution. The noise reduction measures for transformer equipment mostly adopt BOX-IN technology. The problems of this technology are: 1) Fully enclosed state: affecting the heat dissipation of equipment, causing power equipment failure; 2) Semi-enclosed state: unable to effectively suppress noise, resulting in more serious noise leakage problems.

[0029] To solve the above problems, see Figure 1-8 The embodiment of the present application provides a ventilation and noise reduction mechanism 1, specifically a ventilation and noise reduction mechanism 1 for the outside of power capacitors, reactors and other power equipment. The ventilation and noise reduction mechanism 1 includes a first shell 10, a second shell 11 and a noise reduction structure 12.

[0030] See also Figure 1 The first shell 10 and the second shell 11 located on the periphery of the first shell 10 are used together for the inlet and outlet of airflow and for supporting the noise reduction structure 12 located between the first shell 10 and the second shell 11 .

[0031] See also Figure 1 The first shell 10 can be specifically an inner shell, which can be a semi-annular structure. The first shell 10 has at least one first through hole 100, such as one, two, or three. The first through holes 100 can be evenly arranged to form an array. The first through holes 100 can all be circular holes. The aperture of each first through hole 100 is relatively small, which is generally related to the matching noise reduction amount and the noise reduction frequency band. The center line of each first through hole 100 can be perpendicular to the first shell 10.

[0032] See also Figure 1 , the second shell 11 can be specifically an outer shell, can be a semi-annular structure, and can be located on the periphery of the first shell 10. The second shell 11 is connected to the first shell 10, and the connection method can be a snap connection, and they jointly define a cavity 110. The second shell 11 has at least one second through hole 111, such as one, two, or three, and can correspond one to one with the first through hole 100. Each second through hole 111 can be a circular hole. The second through holes 111 can be evenly arranged and form an array. The aperture of each first through hole 100 is relatively small, which is generally related to the matching noise reduction amount and the noise reduction frequency band, and can be the same as the aperture of the first through hole 100. The center line of each second through hole 111 can be perpendicular to the second shell 11, and can coincide with the center line of the first through hole 100.

[0033] See also Figure 2-5 The noise reduction structure 12 is used to achieve a noise suppression effect when sound waves pass through the air path of the noise reduction structure 12 .

[0034] The noise reduction structure 12 includes at least one, such as one, two, or three. Moreover, one noise reduction structure 12 may correspond to one first through hole 100 and one second through hole 111, and constitute a ventilation noise reduction unit. Each noise reduction structure 12 is fixed in the cavity 110, and the fixing method may be various mechanical connection methods such as welding and bolt connection.

[0035] See also Figure 2-5, each noise reduction structure 12 has an airflow channel 120. The two ports of the airflow channel 120 of each noise reduction structure 12 are respectively connected to the corresponding first through holes 100 and the second through holes 111. At this time, the airflow can flow through the airflow channel 120, the first through holes 100 and the second through holes 111. Each airflow channel 120 can be a rectangular channel. The center line of each airflow channel 120 can be perpendicular to the first shell 10 and the second shell 11, and can coincide with the center line of the first through hole 100 and the second through hole 111.

[0036] See also Figure 2-3 The noise reduction structure 12 also has at least two resonance cavities 121, such as two, three, or four, the number of which can be determined by comprehensive conditions such as the noise reduction amount and weight of the device. Each resonance cavity is arranged along the length direction of the air flow channel. Each resonance cavity 121 can be a rectangular cavity or a cube cavity.

[0037] Further, see Figure 3 Each resonance cavity 121 may include a first resonance cavity 1210 and a second resonance cavity 1211, which is equivalent to the resonance cavity 121 being specifically a resonance cavity group, and the resonance cavity group includes the first resonance cavity 1210 and the second resonance cavity 1211. The first resonance cavity 1210 and the second resonance cavity 1211 may be located at both sides of the airflow channel 120 in the width direction.

[0038] See also Figure 2-4 The noise reduction structure 12 is also provided with openings 122 connecting the resonance cavity 121 and the airflow channel 120. The number of the openings 122 and the resonance cavity 121 are the same and the positions correspond to each other. The openings 122 can all be circular holes. The center lines of the openings 122 can all be perpendicular to the center line of the airflow channel 120.

[0039] Further, see Figure 3-4 Each opening 122 may include a first opening 1220 and a second opening 1221, which is equivalent to the opening 122 being specifically an opening group, which includes the first opening 1220 and the second opening 1221. The first opening 1220 connects the first resonance cavity 1210 with the airflow channel, and the number of the first openings 1220 and the first resonance cavity 1210 are the same and the positions correspond one to one. The second opening 1221 connects the second resonance cavity 1211 with the airflow channel, and the number of the second openings 1221 and the first resonance cavity 1210 are the same and the positions correspond one to one.

[0040] For further information, see Figure 4 The first opening 1220 and the second opening 1221 may be staggered in both the length direction and the width direction of the airflow channel 120. That is, the first opening 1220 and the second opening 1221 are not arranged opposite to each other in the length direction of the airflow channel 120, but are arranged as follows. Figure 4As shown in FIG. 1 , the first opening 1220 and the second opening 1221 are arranged respectively at the bottom and at the top, and the first opening 1220 and the second opening 1221 are not arranged flush in the width direction of the air flow channel 120, but are arranged as shown in FIG. Figure 4 The settings shown are right and left respectively.

[0041] See also Figure 5 The noise reduction structure 12 also has at least one sound absorption cavity 123, such as one, two, or three, and the number can be determined by comprehensive conditions such as the noise reduction amount and weight of the equipment. Each sound absorption cavity 123 can be arranged along the length direction of the air flow channel. Each sound absorption cavity 123 can be arranged downstream of each resonance cavity in the gas flow direction of the air flow channel. Each sound absorption cavity 123 can be a rectangular cavity or a cube cavity, and the shape can be the same as the resonance cavity 121. The inner wall of each sound absorption cavity 123 can be attached with a sound absorption material 125, such as a porous sound absorption material 125: glass fiber, high-density sponge, etc.

[0042] The noise reduction structure 12 may also be provided with openings 124 connecting the sound absorption cavity 123 and the air flow channel, and the number of the openings 124 and the sound absorption cavity 123 are the same and the positions correspond one to one. The openings 124 may all be circular holes. The center lines of the openings 124 may all be perpendicular to the center line of the air flow channel. Through the above arrangement, after the sound waves flow into the sound absorption cavity 123, the sound energy is absorbed by the sound absorption material 125, thereby achieving a higher noise reduction effect.

[0043] The above-mentioned noise reduction structure 12 forms an acoustic bandgap between the ventilation noise reduction unit composed of the first through hole 100, the noise reduction structure 12 and the second through hole 111 and the sound source 3 by adopting the Bragg scattering principle of the acoustic superstructure. Based on the acoustic bandgap effect, the sound source 3 is subjected to noise suppression. Moreover, after the sound wave enters the ventilation noise reduction unit, it achieves the purpose of noise reduction through multi-path diffraction and resonance (specifically, multi-stage Helmholtz configuration resonance). At the same time, the above-mentioned ventilation noise reduction unit does not affect the flow of air, thereby achieving the purpose of heat dissipation. In addition, the ventilation noise reduction mechanism 1 in the present application has a flexible installation method, does not affect the heat dissipation characteristics of the equipment itself, and adopts a modular design, which can be flexibly applied to equipment of different external dimensions, facilitating cost control. In addition, considering that the frequency spectrum of the sound source 3 of capacitors, reactors and other power equipment is quite different, the internal noise reduction structure 12 can be changed and replaced, and can be flexibly designed and matched.

[0044] See also Figure 6, the embodiment of the present application further provides a ventilation and noise reduction device 2, comprising a plurality of ventilation and noise reduction mechanisms 1 in any of the above embodiments, each ventilation and noise reduction mechanism 1 is connected and jointly defines a receiving space, the receiving space is used to accommodate a sound source 3, the receiving space can be a hollow enclosure-like structure, can also be a cover-like structure with one side open, or can be a completely closed box-like structure. The ventilation and noise reduction device 2 can be directly used as the outer shell of the power equipment, or the ventilation and noise reduction device 2 can be used to surround the power equipment on all sides. In other words, the ventilation and noise reduction device 2 is used on the outside of the sound source 3, and the sound source 3 is placed inside it by wrapping. For this reason, its implementation is similar to the sound insulation cover method, and the installation method can be a mechanical connection method. The structure and quantity of the ventilation and noise reduction mechanism 1 can be designed and customized according to the noise spectrum of the equipment.

[0045] See also Figure 7 The receiving space can be a hollow cylindrical cavity. In this case, the receiving space is used to accommodate the reactor body 4. The ventilation and noise reduction device 2 is used as the reactor housing. The effect diagram after it is installed on the reactor is as shown in FIG. Figure 7 As shown. In the ventilation and noise reduction device 2, the structure and quantity of the ventilation and noise reduction mechanism 1 can be designed and customized according to the noise spectrum of the equipment. It should be noted that although Figure 7 Only the top and part of the side of the ventilation and noise reduction device 2 show the ventilation and noise reduction unit composed of the first through hole 100, the noise reduction structure 12 and the second through hole 111, but in fact the ventilation and noise reduction unit is arranged on the top, surrounding wall and bottom of the ventilation and noise reduction device 2.

[0046] See also Figure 8 The receiving space can be a rectangular cavity. In this case, the receiving space is used to accommodate the capacitor body 5. The ventilation and noise reduction device 2 is used as a capacitor shell. The effect diagram after it is installed on the capacitor is as shown in FIG. Figure 8 As shown. In the ventilation and noise reduction device 2, the structure and quantity of the ventilation and noise reduction mechanism 1 can be designed and customized according to the noise spectrum of the equipment. It should be noted that although Figure 8 In the figure, only the top of the ventilation and noise reduction device 2 shows the ventilation and noise reduction unit composed of the first through hole 100, the noise reduction structure 12 and the second through hole 111, but in fact the ventilation and noise reduction unit is arranged on the top, around and bottom of the ventilation and noise reduction device 2.

[0047] In summary, it can be seen that the ventilation and noise reduction mechanism 1 of the present application is used for power capacitors and reactors. After the noise test on the capacitor and reactor equipment, the design of the internal noise reduction structure 12 and the matching of ventilation and heat dissipation are carried out in a specific noise reduction frequency band, which can achieve targeted noise reduction. The noise reduction effect can reach more than 15dB, and the impact on the temperature rise of the equipment is less than 5°C. Therefore, while ensuring the noise reduction effect of the capacitor and the reactor, the ventilation and heat dissipation function is taken into account, and the heat generated by the equipment is effectively dissipated, thereby reducing the risk of equipment damage, and further suppressing the low-frequency noise of the equipment, which is beneficial to noise environmental protection.

[0048] In addition, the ventilation and noise reduction mechanism 1 of the present application can effectively replace the sound insulation cover structure commonly used in power equipment, thereby achieving the comprehensive effect of suppressing noise and enhancing ventilation, while improving the operating life of the power equipment.

[0049] In addition, the ventilation and noise reduction mechanism 1 in the present application is applied to the outside of the power equipment. After the structural design is determined, it is processed according to the external material of the power equipment itself, without changing the original electrical, thermal, and mechanical operating performance of the equipment, and has good practicality. Its modular design enables it to have good scalability, which is convenient for promotion and application in noise reduction of other power equipment. The material of the ventilation and noise reduction mechanism 1 of the present application can be selected according to the requirements of the power equipment, and there is a large space for material selection.

[0050] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0051] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A ventilation and noise reduction mechanism, characterized in that: include: A first housing having at least one first through hole; A second shell, defining a cavity together with the first shell, the second shell having at least one second through hole; and A noise reduction structure, comprising at least one, each of the noise reduction structures is located in the cavity, each of the noise reduction structures has an airflow channel, and two ports of the airflow channel of each of the noise reduction structures are respectively connected to each of the first through holes and each of the second through holes; the noise reduction structure also has at least two resonance cavities; the noise reduction structure is also provided with openings connecting the resonance cavities and the airflow channel, and the number of the openings is the same as that of the resonance cavities and the positions correspond one to one; Wherein, each of the resonance cavities comprises a first resonance cavity and a second resonance cavity, and the first resonance cavity and the second resonance cavity are respectively located on two sides of the width direction of the airflow channel; Each of the openings includes a first opening and a second opening, the first opening connecting the first resonant cavity and the airflow channel, the first openings are the same in number and the positions are in one-to-one correspondence with the first resonant cavity, the second openings connect the second resonant cavity and the airflow channel, the second openings are the same in number and the positions are in one-to-one correspondence with the first resonant cavity.

2. The ventilation and noise reduction mechanism according to claim 1, characterized in that: Each of the resonance cavities is arranged along the length direction of the air flow channel.

3. The ventilation and noise reduction mechanism according to claim 1, characterized in that: The first opening and the second opening are staggered in the length direction of the air flow channel.

4. The ventilation and noise reduction mechanism according to claim 1, characterized in that: The first opening and the second opening are staggered in a width direction of the air flow channel.

5. The ventilation and noise reduction mechanism according to claim 1, characterized in that: The noise reduction structure further has at least one sound absorption cavity; the noise reduction structure further has openings connecting the sound absorption cavity and the air flow channel, and the number of the openings is the same as that of the sound absorption cavity and the positions correspond one to one; The inner wall of each sound absorbing cavity is covered with sound absorbing material.

6. The ventilation and noise reduction mechanism according to claim 1, characterized in that: Each sound absorbing cavity is arranged downstream of each resonance cavity in the gas flow direction of the gas flow channel.

7. A ventilation and noise reduction device, characterized in that: It comprises the ventilation and noise reduction mechanism as described in any one of claims 1 to 6, and each of the ventilation and noise reduction mechanisms jointly defines a receiving space.

8. The ventilation and noise reduction device according to claim 7, characterized in that: The receiving space is a hollow cylindrical cavity.

9. The ventilation and noise reduction device according to claim 7, characterized in that: The receiving space is a rectangular cavity.

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