Cable tunnel fan noise suppression method, apparatus, and system

Abstract

This application relates to a method, device, and system for suppressing noise from a cable tunnel fan. The method includes: acquiring operating parameters of the fan within the cable tunnel and environmental parameters of the fan's duct; determining the fan's noise frequency and total noise power based on the operating parameters; determining the structural parameters of a silencer device based on the noise frequency, total noise power, and environmental parameters; and installing the silencer device within the duct based on the structural parameters. The silencer device is used to suppress the noise generated by the fan. This method can both reduce fan noise within the cable tunnel and meet the ventilation requirements of the cable tunnel.

Description

Technical Field

[0001] This application relates to the field of noise reduction technology, and in particular to a method, device and system for suppressing noise from cable tunnel fans. Background Technology

[0002] Cable tunnels are typically enclosed or semi-enclosed spaces. The heat generated by the cables operating within these tunnels can accumulate and cause the ambient temperature to rise, leading to accelerated aging of the cable insulation and increasing the risk of insulation breakdown. Fans are usually installed inside cable tunnels to force airflow and create air convection, quickly dissipating the heat generated by the cables or other equipment.

[0003] However, the operation of the wind turbine generates a lot of noise, which affects the normal work of the operators. In addition, the high noise can mask the alarm sounds indicating equipment abnormalities and the voices of personnel, making it impossible for the operators to take timely countermeasures and increasing the risk of safety accidents. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, device, and system for suppressing fan noise in cable tunnels that can reduce fan noise, in order to address the aforementioned technical problems.

[0005] In a first aspect, this application provides a method for suppressing noise from a cable tunnel ventilation fan, the method comprising:

[0006] Obtain the operating parameters of the fan inside the cable tunnel and the environmental parameters of the fan duct.

[0007] The noise frequency and total noise power of the fan are determined based on the operating parameters.

[0008] The structural parameters of the noise reduction device are determined based on the noise frequency, the total noise power, and the environmental parameters.

[0009] Based on the structural parameters, a noise reduction device is installed inside the air duct; the noise reduction device is used to suppress the noise generated by the fan.

[0010] In one embodiment, the silencing device includes an airflow channel and a sound-absorbing baffle; the structural parameters include the cross-sectional perimeter and cross-sectional area of ​​the airflow channel, the sound-absorbing material of the sound-absorbing baffle, the baffle properties, and the baffle length;

[0011] Determining the structural parameters of the noise reduction device based on the noise frequency, the total noise power, and the environmental parameters includes:

[0012] The dimensional constraints of the noise reduction device are determined based on the environmental parameters.

[0013] Based on the noise frequency, determine the sound-absorbing material and the properties of the sound-absorbing partition.

[0014] Based on the sound-absorbing material, the properties of the partition, the total noise power, the dimensional constraints, and the preset ventilation conditions of the airflow channel, the length of the partition, the perimeter of the airflow channel, and the cross-sectional area are determined.

[0015] In one embodiment, determining the length of the partition, the cross-sectional perimeter, and the cross-sectional area of ​​the airflow channel based on the sound-absorbing material, the properties of the partition, the total noise power, the dimensional constraints, and the preset ventilation conditions of the airflow channel includes:

[0016] The initial noise reduction of the silencing device is determined based on the sound-absorbing material, properties, and initial length of the sound-absorbing partition, as well as the initial cross-sectional perimeter and cross-sectional area of ​​the airflow channel.

[0017] Based on the initial noise reduction amount and the total noise power, adjust at least one of the initial baffle length, the initial cross-sectional perimeter, and the initial cross-sectional area, and return to the step of determining the noise reduction amount of the noise reduction device until the preset stop condition is met;

[0018] The preset stopping conditions include that the difference between the noise reduction of the silencer and the total noise power is within a preset difference range, and that the structural parameters of the silencer meet the size constraints, and that the cross-sectional perimeter and cross-sectional area of ​​the airflow channel meet the preset ventilation conditions.

[0019] In one embodiment, determining the initial noise reduction of the silencing device based on the sound-absorbing material of the sound-absorbing partition, the partition properties, the initial partition length, the initial cross-sectional perimeter, and the initial cross-sectional area of ​​the airflow channel includes:

[0020] The normal sound absorption coefficient of the sound-absorbing partition is determined based on the sound-absorbing material of the partition and the properties of the partition.

[0021] The sound absorption coefficient of the sound-absorbing partition is determined based on the normal sound absorption coefficient.

[0022] The initial noise reduction is determined by the product of the noise reduction coefficient, the initial partition length, and the initial cross-sectional perimeter, and the quotient of the initial cross-sectional area.

[0023] In one embodiment, determining the sound-absorbing material and properties of the sound-absorbing partition based on the noise frequency includes:

[0024] Based on the noise frequency, the normal absorption coefficient is determined from a pre-built frequency-normal absorption coefficient correlation library;

[0025] Based on the normal sound absorption coefficient, the properties of the sound-absorbing material and the partition are determined from a pre-built library of normal sound absorption coefficients and materials.

[0026] In one embodiment, the operating parameters include the fan impeller speed, the number of fan blades, the fan blade thickness, and the relative velocity of the air blades; the noise power includes the fundamental frequency of rotational noise and the fundamental frequency of eddy current noise.

[0027] Determining the fan noise frequency based on the aforementioned operating parameters includes:

[0028] The fundamental frequency of the rotational noise is determined by the product of the impeller speed and the number of blades; the fundamental frequency of the rotational noise is positively correlated with the product.

[0029] The fundamental frequency of the eddy current noise is determined by the quotient of the relative velocity of the air blades and the thickness of the wind turbine blades; the fundamental frequency of the eddy current noise is positively correlated with the quotient.

[0030] In one embodiment, the cable tunnel is equipped with multiple fans; the operating parameters include fan operating air volume, fan operating air pressure, noise reference power, fan reference air volume, and fan reference air pressure;

[0031] Determining the total noise power based on the operating parameters includes:

[0032] The first calculated value is determined by multiplying the square of the operating wind pressure of the fan by the operating air volume of the fan.

[0033] The second calculated value is determined by multiplying the square of the reference wind pressure of the fan by the reference air volume of the fan;

[0034] The quotient of the first and second calculated values ​​is converted into a third calculated value for the sound power level;

[0035] The fan noise power of a single fan is determined by summing the third calculated value with the fan noise reference power.

[0036] The total noise power of the fans is determined by summing the noise power of each fan.

[0037] In the above-mentioned method for suppressing noise from cable tunnel fans, the operating parameters of the fans in the cable tunnel and the environmental parameters of the fan duct are obtained. The noise frequency and total noise power of the fans are determined based on the operating parameters. The structural parameters of the silencer are determined based on the noise frequency, total noise power and environmental parameters, taking into account both the noise reduction amount and size constraints. Based on the structural parameters, a silencer is installed in the duct to suppress the noise generated by the fans, which can reduce auditory interference to workers and avoid safety hazards.

[0038] Secondly, this application provides a noise suppression device for cable tunnel fans, including at least one of a first silencing device and a second silencing device;

[0039] The first silencing device is installed inside the air intake duct of the cable tunnel; the structural parameters of the first silencing device are obtained according to the cable tunnel fan noise suppression method provided in any of the above embodiments;

[0040] The second silencing device is located at the air outlet of the cable tunnel; the structural parameters of the second silencing device are obtained according to the cable tunnel fan noise suppression method provided in any of the above embodiments.

[0041] In one embodiment, the first silencing device and the second silencing device each include a plurality of sound-absorbing partitions and an airflow channel; wherein the plurality of sound-absorbing partitions are spaced apart, and the airflow channel is located between adjacent sound-absorbing partitions.

[0042] Thirdly, this application also provides a cable tunnel fan noise suppression system, including a fan installed in a cable tunnel, and the cable tunnel fan noise suppression device provided in any of the above embodiments.

[0043] In the aforementioned cable tunnel fan noise suppression equipment and system, by installing a first silencing device in the air inlet duct of the cable tunnel that meets both silencing and ventilation requirements, the noise inside the cable tunnel can be reduced, providing a relatively quiet working environment for workers; by installing a second silencing device in the air outlet of the cable tunnel that meets both silencing and ventilation requirements, the noise at the air outlet of the cable tunnel can be reduced, ensuring that the noise at the air outlet meets noise emission standards. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a flowchart illustrating a method for suppressing noise from a cable tunnel ventilation fan in one embodiment.

[0046] Figure 2 This is a schematic diagram of the structure of a noise reduction device in one embodiment;

[0047] Figure 3 This is a schematic diagram showing the installation positions of the first and second noise-reducing devices in a cable tunnel in one embodiment.

[0048] Figure 4 for Figure 3 Top view. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0050] In one embodiment, this application provides a method for suppressing noise from a cable tunnel ventilation fan, such as... Figure 1 As shown, it includes the following S102-S108.

[0051] S102, obtain the operating parameters of the fan in the cable tunnel and the environmental parameters of the fan duct.

[0052] Operating parameters may include the fan impeller speed, number of fan blades, fan blade thickness, relative velocity of the air and blades, fan operating air volume, and fan operating air pressure. The number of fan blades and fan blade thickness can be obtained from the fan's equipment manual, cable tunnel engineering design drawings, etc. The fan impeller speed can be obtained from a speed sensor deployed near the fan. The fan operating air volume can be obtained from an air volume sensor deployed near the fan. The fan operating air pressure can be obtained from an air pressure sensor deployed near the fan. The relative velocity of the air and blades can be calculated based on the fan impeller speed, number of fan blades, and fan blade thickness.

[0053] The air duct of a fan may include at least one of an inlet air duct and an outlet air duct. Environmental parameters include the cross-sectional area of ​​the air duct, the inner diameter of the air duct wall, and the length of the air duct. Environmental parameters can be obtained from the engineering design drawings of the cable tunnel or through measurement.

[0054] S104, determine the noise frequency and total noise power of the fan based on the operating parameters.

[0055] Fan noise mainly consists of rotational noise and eddy current noise. Rotational noise is caused by the periodic mechanical disturbance and smooth pressure pulses of the air caused by the rotation of the fan impeller. The frequency of rotational noise is related to the fan impeller speed and the number of fan blades. Eddy current noise is caused by turbulence, eddy current shedding, and turbulent flow pulsations generated when air flows around the fan components. The frequency of eddy current noise is related to the fan blade thickness and the relative velocity of the air blades.

[0056] The total noise power is the sum of the noise power of multiple fans within the cable tunnel. The noise power of each fan can be calculated separately based on operating parameters, and then the total noise power can be calculated from the noise power of each fan. Alternatively, acoustic sensors can be used to directly measure the fan noise, and the total noise power can be determined based on the measured noise signals.

[0057] S106. Determine the structural parameters of the noise reduction device based on the noise frequency, total noise power, and environmental parameters.

[0058] The silencer device needs to effectively reduce fan noise while ensuring that airflow can pass through normally. For example... Figure 2 As shown, the silencing device includes sound-absorbing partitions and airflow channels. The sound-absorbing partitions are made of porous sound-absorbing material. When sound waves enter the silencing device, some of the sound energy is dissipated as heat energy through friction within the pores of the porous material, thus weakening the sound waves. The space between adjacent sound-absorbing partitions forms the airflow channel, which ensures that the ventilation function of the fan is not impaired. The structural parameters of the silencing device may include the thickness, density, and length of the sound-absorbing partitions, as well as the cross-sectional area and perimeter of the airflow channel.

[0059] The structural parameters of a noise reduction device are closely related to its noise reduction capacity. The noise reduction capacity of the noise reduction device can be determined based on the noise frequency and the total noise power. The noise reduction capacity can be used as a noise reduction constraint, and the environmental parameters can be used as dimensional constraints to determine the structural parameters of the noise reduction device.

[0060] S108, based on structural parameters, a silencing device is installed inside the air duct; the silencing device is used to suppress the noise generated by the fan.

[0061] The silencer can be installed in at least one of the air inlet duct or air outlet duct.

[0062] In this embodiment, by acquiring the operating parameters of the fan in the cable tunnel and the environmental parameters of the fan duct, the noise frequency and total noise power of the fan are determined based on the operating parameters. The structural parameters of the silencer are then determined based on the noise frequency, total noise power, and environmental parameters, taking into account both noise reduction and size constraints. Based on the structural parameters, a silencer is installed in the duct to suppress the noise generated by the fan, which can reduce auditory interference to workers and avoid safety hazards.

[0063] In one embodiment, the silencing device includes an airflow channel and a sound-absorbing baffle; the structural parameters include the cross-sectional perimeter and cross-sectional area of ​​the airflow channel, the sound-absorbing material of the sound-absorbing baffle, the baffle properties, and the baffle length.

[0064] The structural parameters of the silencer are determined based on the noise frequency, total noise power, and environmental parameters, including the following S202-S206.

[0065] S202, Determine the size constraints of the silencer based on environmental parameters.

[0066] Size constraints are used to constrain the structural parameters of airflow channels and baffle structures. For example, they may include that the cross-sectional area of ​​the airflow channel is smaller than that of the duct, the diameter of the airflow channel is smaller than that of the duct, the length of the baffle is smaller than that of the duct, and so on.

[0067] S204, Determine the sound-absorbing material and partition properties of the sound-absorbing partition based on the noise frequency.

[0068] The properties of a partition can include its thickness and its density.

[0069] First, the normal sound absorption coefficient can be determined from a pre-built frequency-normal sound absorption coefficient association library based on the noise frequency. Then, the sound-absorbing material and partition properties can be determined from a pre-built normal sound absorption coefficient-material association library based on the normal sound absorption coefficient.

[0070] The noise frequency can be the frequency in the fan noise spectrum where the noise power exceeds a preset value, or it can be the fundamental frequency of rotational noise or eddy current noise. The normal absorption coefficient is a core indicator for evaluating the acoustic performance of sound-absorbing materials. It refers to the ratio of the sound energy absorbed by the material to the total sound energy incident on the material surface when a sound wave is incident perpendicularly (normally) to the surface. Its value ranges from 0 to 1. The normal absorption coefficient is a function of frequency; materials with different normal absorption coefficients have varying suppression effects on different noise frequencies. The frequency-normal absorption coefficient correlation library shows the relationship between frequency and normal absorption coefficient. The normal absorption coefficient-material correlation library shows the relationship between sound-absorbing materials, material thickness, and / or material density, and the material's normal absorption coefficient.

[0071] It is understandable that we can first determine the normal absorption coefficient that matches the noise frequency from the frequency-normal absorption coefficient association library, and then determine the sound-absorbing material and corresponding partition properties that match the normal absorption coefficient from the normal absorption coefficient-material association library.

[0072] S206. Based on the sound-absorbing material, the properties of the partition, the total noise power, the dimensional constraints, and the preset ventilation conditions of the airflow channel, determine the length of the partition, the perimeter of the airflow channel, and the cross-sectional area.

[0073] The initial noise reduction of the silencer can be determined based on the sound-absorbing material of the sound-absorbing partition, the properties of the partition, the initial length of the partition, the initial cross-sectional perimeter and the initial cross-sectional area of ​​the airflow channel.

[0074] Specifically, the normal sound absorption coefficient of the sound-absorbing partition can be determined based on the sound-absorbing material and partition properties. The sound attenuation coefficient of the sound-absorbing partition can then be determined based on the normal sound absorption coefficient. Then, based on equation (1), the initial sound attenuation amount can be determined by the quotient of the product of the sound attenuation coefficient, the initial partition length, and the initial cross-sectional perimeter, and the initial cross-sectional area. The initial partition length, the initial interface perimeter, and the initial cross-sectional area can be set based on empirical rules.

[0075]

[0076]

[0077] in, This indicates the noise reduction amount, measured in decibels. The normal sound absorption coefficient of the sound-absorbing material can be matched according to the properties of the partition (at least one of the partition thickness and the partition density); The sound absorption coefficient of the sound-absorbing material can be calculated based on equation (2); L represents the perimeter of the airflow channel; S represents the cross-sectional area of ​​the airflow channel; Indicates the length of the partition.

[0078] Then, based on the initial noise reduction and total noise power, at least one of the initial baffle length, initial cross-sectional perimeter, and initial cross-sectional area can be adjusted, and the process can return to the step of determining the noise reduction of the noise reduction device until the preset stop condition is met.

[0079] The preset stopping conditions include that the difference between the noise reduction of the silencer and the total noise power is within a preset difference range, the structural parameters of the silencer meet dimensional constraints, and the cross-sectional perimeter and cross-sectional area of ​​the airflow channel meet preset ventilation conditions. The preset difference range can be reasonably set according to actual needs. The preset ventilation conditions are used to constrain the ventilation performance of the airflow channel. For example, preset ventilation conditions can include that the cross-sectional area of ​​the airflow channel is greater than or equal to a preset cross-sectional area value, the flow cross-section of the airflow channel meets the requirement that the friction coefficient is less than or equal to a preset resistance coefficient, and the ratio of the cross-sectional area to the perimeter of the airflow channel meets the requirement that the fluid cross-sectional velocity deviation is less than or equal to a preset deviation value, etc.

[0080] It is understandable that by comparing the initial noise reduction amount with the total noise power, at least one of the following can be adjusted: the length of the partition, the perimeter of the cross section, the cross-sectional area, etc., and this process can be repeated cyclically until the preset stopping conditions are met. The structural parameters that meet the preset stopping conditions are then determined as the final structural parameters of the silencer, so that the final silencer can meet both the noise reduction requirements and the ventilation requirements.

[0081] In one embodiment, the noise power includes the fundamental frequency of rotational noise and the fundamental frequency of eddy current noise. Determining the fan noise frequency based on operating parameters includes determining the fundamental frequency of rotational noise based on the product of the fan impeller speed and the number of fan blades, and determining the fundamental frequency of eddy current noise based on the quotient of the relative velocity of the air blades and the thickness of the fan blades. The fundamental frequency of rotational noise is positively correlated with the product; the fundamental frequency of eddy current noise is positively correlated with the quotient.

[0082] For example, the fundamental frequency of rotational noise The following relationship exists between the fan impeller speed n and the number of fan blades z:

[0083]

[0084] Eddy current noise fundamental frequency The following relationship exists between the relative velocity V of the air blades and the thickness D of the fan blades:

[0085]

[0086] Where K is the Strauhall number.

[0087] In one embodiment, multiple fans are installed within the cable tunnel. Operating parameters include fan operating airflow, fan operating air pressure, noise reference power, fan reference airflow, and fan reference air pressure. The noise reference power, fan reference component, and fan reference air pressure can be the noise power, fan operating airflow, and fan operating air pressure of any single fan. The noise power of the fans under different operating conditions has the following relationship:

[0088]

[0089] in, and These represent the noise power of the fan under operating conditions 1 and 2, respectively. and These represent the air volume for fan operating condition 1 and fan operating condition 2, respectively. and These represent the air pressure under fan operating conditions 1 and 2, respectively.

[0090] Thus, a first calculated value can be determined by multiplying the square of the fan's operating air pressure by its operating air volume. A second calculated value can be determined by multiplying the square of the fan's reference air pressure by its reference air volume. The quotient of the first and second calculated values ​​is converted into a third calculated value for the sound power level. The sum of the third calculated value and the fan noise reference power is used to determine the noise power of a single fan. Finally, the total fan noise power is determined by summing the noise power of all fans. This method can accurately obtain the total noise power in scenarios where multiple fans operate collaboratively within a cable tunnel, with varying operating conditions.

[0091] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0092] In one embodiment, this application also provides a cable tunnel fan noise suppression device, which may include at least one of a first silencing device and a second silencing device.

[0093] like Figure 3 and Figure 4 As shown, the first silencing device is installed inside the air intake duct of the cable tunnel, and the structural parameters of the first silencing device are obtained according to the cable tunnel fan noise suppression method provided in any of the above embodiments. The overall cross-sectional shape of the first silencing device can be circular or rectangular.

[0094] like Figure 3 and Figure 4 As shown, the second silencing device is located at the air outlet of the cable tunnel, and the structural parameters of the second silencing device are obtained according to the cable tunnel fan noise suppression method provided in any of the above embodiments. The second silencing device can be a sound-absorbing louver.

[0095] In this embodiment, by installing a first silencing device in the air intake duct of the cable tunnel that meets both silencing and ventilation requirements, the noise inside the cable tunnel can be reduced, providing a relatively quiet working environment for workers; by installing a second silencing device in the air outlet of the cable tunnel that meets both silencing and ventilation requirements, the noise at the air outlet of the cable tunnel can be reduced, so that the noise at the air outlet meets the noise emission standards.

[0096] In one embodiment, such as Figure 2 As shown, the first and second silencing devices each include multiple sound-absorbing baffles and airflow channels. The airflow channels are arranged parallel to the air inlet duct or parallel to the air outlet. The multiple sound-absorbing baffles are located on the inner wall of the airflow channels.

[0097] In one embodiment, this application also provides a cable tunnel fan noise suppression system, which includes a fan installed in a cable tunnel and the cable tunnel fan noise suppression device provided in any of the above embodiments.

[0098] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0099] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for suppressing noise from a cable tunnel ventilation fan, characterized in that, The method includes: Obtain the operating parameters of the fan inside the cable tunnel and the environmental parameters of the fan duct. The noise frequency and total noise power of the fan are determined based on the operating parameters. The structural parameters of the noise reduction device are determined based on the noise frequency, the total noise power, and the environmental parameters. Based on the structural parameters, a noise reduction device is installed inside the air duct; the noise reduction device is used to suppress the noise generated by the fan.

2. The method according to claim 1, characterized in that, The silencing device includes an airflow channel and a sound-absorbing partition; the structural parameters include the cross-sectional perimeter and cross-sectional area of ​​the airflow channel, the sound-absorbing material of the sound-absorbing partition, the partition properties, and the partition length; Determining the structural parameters of the noise reduction device based on the noise frequency, the total noise power, and the environmental parameters includes: The dimensional constraints of the noise reduction device are determined based on the environmental parameters. Based on the noise frequency, determine the sound-absorbing material and the properties of the sound-absorbing partition. Based on the sound-absorbing material, the properties of the partition, the total noise power, the dimensional constraints, and the preset ventilation conditions of the airflow channel, the length of the partition, the perimeter of the airflow channel, and the cross-sectional area are determined.

3. The method according to claim 2, characterized in that, The step of determining the length of the partition, the cross-sectional perimeter and cross-sectional area of ​​the airflow channel based on the sound-absorbing material, the properties of the partition, the total noise power, the dimensional constraints, and the preset ventilation conditions of the airflow channel includes: The initial noise reduction of the silencing device is determined based on the sound-absorbing material, properties, and initial length of the sound-absorbing partition, as well as the initial cross-sectional perimeter and cross-sectional area of ​​the airflow channel. Based on the initial noise reduction amount and the total noise power, adjust at least one of the initial baffle length, the initial cross-sectional perimeter, and the initial cross-sectional area, and return to the step of determining the noise reduction amount of the noise reduction device until the preset stop condition is met; The preset stopping conditions include that the difference between the noise reduction of the silencer and the total noise power is within a preset difference range, and that the structural parameters of the silencer meet the size constraints, and that the cross-sectional perimeter and cross-sectional area of ​​the airflow channel meet the preset ventilation conditions.

4. The method according to claim 3, characterized in that, The determination of the initial noise reduction of the silencing device based on the sound-absorbing material, properties, and initial length of the sound-absorbing partition, as well as the initial cross-sectional perimeter and cross-sectional area of ​​the airflow channel, includes: The normal sound absorption coefficient of the sound-absorbing partition is determined based on the sound-absorbing material of the partition and the properties of the partition. The sound absorption coefficient of the sound-absorbing partition is determined based on the normal sound absorption coefficient. The initial noise reduction is determined by the product of the noise reduction coefficient, the initial partition length, and the initial cross-sectional perimeter, and the quotient of the initial cross-sectional area.

5. The method according to claim 2, characterized in that, Based on the noise frequency, determine the sound-absorbing material and the properties of the sound-absorbing partition, including: Based on the noise frequency, the normal absorption coefficient is determined from a pre-built frequency-normal absorption coefficient correlation library; Based on the normal sound absorption coefficient, the properties of the sound-absorbing material and the partition are determined from a pre-built library of normal sound absorption coefficients and materials.

6. The method according to any one of claims 1-5, characterized in that, The operating parameters include the fan impeller speed, the number of fan blades, the fan blade thickness, and the relative velocity of the air blades; The noise frequencies include the fundamental frequency of rotational noise and the fundamental frequency of eddy current noise; Determining the fan noise frequency based on the aforementioned operating parameters includes: The fundamental frequency of the rotational noise is determined by the product of the impeller speed and the number of blades; the fundamental frequency of the rotational noise is positively correlated with the product. The fundamental frequency of the eddy current noise is determined by the quotient of the relative velocity of the air blades and the thickness of the wind turbine blades; the fundamental frequency of the eddy current noise is positively correlated with the quotient.

7. The method according to any one of claims 1-5, characterized in that, The cable tunnel is equipped with multiple fans; the operating parameters include fan operating air volume, fan operating air pressure, noise reference power, fan reference air volume, and fan reference air pressure; Determining the total noise power based on the operating parameters includes: The first calculated value is determined by multiplying the square of the operating wind pressure of the fan by the operating air volume of the fan. The second calculated value is determined by multiplying the square of the reference wind pressure of the fan by the reference air volume of the fan; The quotient of the first and second calculated values ​​is converted into a third calculated value for the sound power level; The fan noise power of a single fan is determined by summing the third calculated value with the fan noise reference power. The total noise power of the fans is determined by summing the noise power of each fan.

8. A noise suppression device for cable tunnel fans, characterized in that, Includes at least one of the first silencing device and the second silencing device; The first silencing device is installed inside the air intake duct of the cable tunnel; the structural parameters of the first silencing device are obtained according to the cable tunnel fan noise suppression method as described in any one of claims 1-7; The second silencing device is located at the air outlet of the cable tunnel; the structural parameters of the second silencing device are obtained according to the cable tunnel fan noise suppression method as described in any one of claims 1-7.

9. The cable tunnel fan noise suppression device according to claim 8, characterized in that, The first silencing device and the second silencing device each include multiple sound-absorbing baffles and airflow channels; The airflow channel is arranged parallel to the air inlet duct, or parallel to the air outlet; The plurality of sound-absorbing baffles are located on the inner wall of the airflow channel.

10. A noise suppression system for cable tunnel fans, characterized in that, Includes a fan installed in a cable tunnel, and a cable tunnel fan noise suppression device as described in claim 8 or 9.

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