Fan cavity noise reduction device, control method and air conditioner

Abstract

The invention discloses a fan cavity noise reduction device, a control method and an air conditioner, the fan cavity noise reduction device is applied to a fan cavity, and the fan cavity noise reduction device comprises a micro-perforated plate arranged in the fan cavity, and the micro-perforated plate comprises a back cavity. The micro-perforated plate can be regarded as an acoustic element with acoustic resistance and acoustic quality, the micro-perforated plate is installed in front of the back cavity, a certain cavity is reserved behind the back cavity, in this way, a resonance sound absorber can be formed, and noise reduction is conducted on the fan cavity through the resonance sound absorption effect. In addition, different micro-perforated plate specification parameters such as the thickness, the hole diameter and the back cavity depth of the micro-perforated plate can be set based on the actual situation, the specification parameters can influence the sound absorption coefficient of the structure, and therefore the micro-perforated plate specification parameter most conforming to the actual scene is selected, and the fan noise control effect is improved.

Description

Technical Field

[0001] This invention relates to the field of air conditioner technology, and in particular to a fan cavity noise reduction device, control method, and air conditioner. Background Technology

[0002] During air conditioner use, although the outdoor unit is installed outdoors, the noise it generates still significantly disrupts people's daily lives, seriously affecting living comfort and quality of life. As air conditioning technology moves towards miniaturization and lightweight design, the diameter of the fan blades and the fan speed have increased accordingly to ensure heat dissipation and cooling performance. This trend makes noise issues in the outdoor unit development stage increasingly difficult to resolve; the noise composition of the fan cavity is becoming more complex, making it not only difficult to control the noise intensity but also accompanied by poor sound quality, further exacerbating the noise's impact on the surrounding environment.

[0003] To alleviate the aforementioned noise problems, numerous technological research and development efforts have been undertaken in related fields, but significant limitations remain. For example, patent document CN206207692U discloses a perforated air guide ring, an outdoor air conditioning unit, and an air conditioner. Its technical approach involves designing circular perforations in the air guide ring structure. Utilizing the relatively enclosed cavity formed by the air guide ring body, surrounding side plates, and top cover, the rotational noise of the axial fan blades is reduced through the principle of resonant silencing via the perforated plate. However, the silencing performance of this device is highly dependent on fixed structural parameters. Once the structural parameters are determined, its effective silencing frequency is also fixed. In practical applications, the fan speed of the outdoor air conditioning unit changes according to operating conditions, and multiple noise peaks are generated during operation. A fixed silencing frequency design cannot match dynamically changing noise characteristics, thus failing to achieve the desired noise reduction effect. For example, patent CN213775825U discloses a noise-reducing air guide ring and a fan using it. This air guide ring innovatively integrates a silencing component and a noise-reducing component: the silencing component is arranged circumferentially along the rear end of the air guide surface, while perforations are set on the air guide ring body to form a noise-reducing component, attempting to suppress noise at multiple frequencies through the combination of the two components. However, this technical solution also has a key drawback: its component structure and silencing parameters cannot be dynamically adjusted after installation and fixation. When the fan speed changes due to changes in operating conditions, the corresponding noise frequency characteristics will also change. The fixed structure of the silencing and noise-reducing components is difficult to adapt to noise changes over a wide frequency range, and ultimately cannot achieve effective broadband noise reduction, making it difficult to meet the comprehensive noise control requirements in actual use.

[0004] Therefore, how to control the fan noise of the outdoor unit of an air conditioner is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a fan cavity noise reduction device, control method, and air conditioner, aiming to improve the fan noise control effect.

[0006] In a first aspect, embodiments of the present invention provide a fan cavity noise reduction device, applied to a fan cavity, the device comprising:

[0007] A micro-perforated plate is disposed in the fan cavity, and the micro-perforated plate includes a back cavity.

[0008] Furthermore, the micro-perforated plate is provided with multiple layers, and the multiple layers of the micro-perforated plate are arranged in parallel within the fan cavity.

[0009] Furthermore, it also includes:

[0010] A driving mechanism is connected to one or more of the micro-perforated plates in the multilayer micro-perforated plates to drive the connected micro-perforated plates away from or closer to other micro-perforated plates.

[0011] Furthermore, the driving mechanism includes a drive motor and a drive rack disposed on the fan cavity, and the drive rack is fixedly connected to one or more micro-perforated plates.

[0012] Furthermore, the cavity of the micro-perforated plate is filled with sound-insulating material.

[0013] In a second aspect, embodiments of the present invention provide a fan cavity noise reduction control method, applied to the fan cavity noise reduction device as described in any of the preceding claims, the method comprising:

[0014] Obtain the specifications and target noise reduction frequency band of the fan cavity;

[0015] Set the parameter range of the micro-perforated plate based on the aforementioned specifications;

[0016] The target noise reduction frequency band is discretized to obtain multiple discrete frequency points;

[0017] Obtain the frequency absorption coefficient at each discrete frequency point, and set the sum of all frequency absorption coefficients as the objective function;

[0018] Based on the parameter range, a genetic algorithm is used to obtain the maximum value of the objective function, and the maximum value is set as the optimal parameter of the micro-perforated plate;

[0019] The optimal micro-perforated plate is constructed based on the optimal parameters, and the optimal micro-perforated plate is used to control the noise reduction of the fan cavity.

[0020] Furthermore, the micro-perforated plate includes a first micro-perforated plate and a second micro-perforated plate, and the second micro-perforated plate is connected to the driving mechanism;

[0021] The construction of the optimal micro-perforated plate based on the optimal parameters, and the use of the optimal micro-perforated plate to control noise reduction in the fan cavity, includes:

[0022] Construct the optimal first layer micro-perforated plate and the optimal second layer micro-perforated plate based on the aforementioned optimal parameters;

[0023] The first layer of micro-perforated plate and the optimal second layer of micro-perforated plate are installed in the fan cavity, and the corresponding fan is controlled to operate to obtain the fan speed. Then, the optimal second layer of micro-perforated plate is driven and adjusted according to the fan speed.

[0024] Furthermore, the step of installing the first layer of micro-perforated plate and the optimal second layer of micro-perforated plate into the fan cavity, controlling the corresponding fan operation to obtain the fan speed, and then adjusting the drive of the optimal second layer of micro-perforated plate according to the fan speed includes:

[0025] Noise octave band diagrams for different fan speeds are pre-established, and the target frequency band with the most significant noise is determined based on the noise octave band diagrams.

[0026] The maximum sound absorption coefficient of the target frequency band is taken as the optimization objective, and the position of the optimal second layer micro-perforated plate is set as a variable. Then, the optimal position of the optimal second layer micro-perforated plate under different fan speeds is determined by a genetic algorithm.

[0027] The optimal second layer micro-perforated plate is driven and adjusted according to the optimal position.

[0028] Furthermore, the step of using the maximum sound absorption coefficient of the target frequency band as the optimization objective, and setting the position of the optimal second layer micro-perforated plate as a variable, and then using a genetic algorithm to determine the optimal position of the optimal second layer micro-perforated plate at different fan speeds, includes:

[0029] The optimal position of the second layer micro-perforated plate at different fan speeds is obtained according to the following formula:

[0030]

[0031] Where Q represents the optimization objective, f1 and f2 represent the endpoint values ​​of the target frequency band, α represents the sound absorption coefficient, and f represents the position of the optimal second layer of micro-perforated plate.

[0032] Thirdly, embodiments of the present invention provide an air conditioner, including a fan cavity noise reduction device as described in any of the preceding claims or employing a fan cavity noise reduction control method as described in any of the preceding claims.

[0033] This invention provides a fan cavity noise reduction device, control method, and air conditioner. The device, applied to a fan cavity, includes a micro-perforated plate disposed within the fan cavity, and the micro-perforated plate includes a back cavity. The micro-perforated plate described in this invention can be considered an acoustic element with acoustic impedance and acoustic mass. Installed in front of the back cavity with a certain cavity behind it, it forms a resonant sound absorber, thereby reducing noise in the fan cavity through resonant sound absorption. Furthermore, this invention allows for setting different micro-perforated plate specifications, such as thickness, aperture, and back cavity depth, based on actual conditions. These specifications affect the sound absorption coefficient of the structure, allowing for the selection of the most suitable micro-perforated plate specifications for the specific scenario, thereby improving the fan noise control effect. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the installation of a fan cavity noise reduction device provided in an embodiment of the present invention;

[0036] Figure 2 This is an assembly diagram of a fan cavity noise reduction device provided in an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of a fan cavity noise reduction device provided in an embodiment of the present invention;

[0038] Figure 4 for Figure 3 An enlarged schematic diagram of part A in the middle;

[0039] Figure 5 This is a cross-sectional schematic diagram of a fan cavity noise reduction device provided in an embodiment of the present invention;

[0040] Figure 6 for Figure 5 Enlarged schematic diagram of part B;

[0041] Figure 7 This is an exploded view of a fan cavity noise reduction device provided in an embodiment of the present invention;

[0042] Figure 8 This is a flowchart illustrating a fan cavity noise reduction control method provided in an embodiment of the present invention;

[0043] Figure 9 This is a schematic diagram of a sub-process in a fan cavity noise reduction control method provided in an embodiment of the present invention;

[0044] Figure 10 This is a schematic diagram of another sub-process in a fan cavity noise reduction control method provided in an embodiment of the present invention;

[0045] Figure 11 A comparative schematic diagram of a fan cavity noise reduction control method provided in an embodiment of the present invention;

[0046] Figure 12 This is a schematic block diagram of an air conditioner provided in an embodiment of the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0049] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0050] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0051] Please see below. Figure 1 This invention provides a fan cavity noise reduction device, applied to a fan cavity 100, the device comprising:

[0052] A micro-perforated plate 200 is disposed within the fan cavity 100, and the micro-perforated plate 200 includes a back cavity.

[0053] The micro-perforated plate 200 described in this embodiment can be considered as an acoustic element with acoustic impedance and acoustic mass. Installed in front of the back cavity with a certain cavity behind it, it forms a resonant sound absorber, thereby reducing noise in the fan cavity 100 through resonant sound absorption. Furthermore, this embodiment allows for setting different specifications for the micro-perforated plate 200, such as thickness, pore size, and back cavity depth, based on actual conditions. These specifications affect the sound absorption coefficient of the structure, allowing for the selection of the most suitable specifications for the actual scenario, thus improving the fan noise control effect.

[0054] In one embodiment, the micro-perforated plate 200 is provided with multiple layers, and the multiple layers of the micro-perforated plate 200 are arranged in parallel within the fan cavity 100.

[0055] This embodiment, by setting up multiple layers of micro-perforated plates 200, can further expand the sound absorption frequency band and improve the adaptability of the noise reduction device to noise of different frequencies. The multiple layers of micro-perforated plates 200 are arranged in parallel within the fan cavity 100, forming a multi-level resonant sound absorption structure. Each layer of micro-perforated plates 200 absorbs noise within a specific frequency range. By rationally designing the specifications of each layer of micro-perforated plates 200, such as aperture, plate thickness, perforation rate, and back cavity depth, the entire noise reduction device can achieve efficient sound absorption over a wider frequency range. For example, when the fan operates at low speed, the main noise is concentrated in the low-frequency range. At this time, the first layer of micro-perforated plates 210 near the fan side can be designed to be optimized for low-frequency noise, and its larger aperture and deeper back cavity can enhance the absorption of low-frequency sound waves. When the fan operates at high speed, the high-frequency noise component increases, and subsequent layers of micro-perforated plates 200 can improve the absorption effect of high-frequency noise through smaller apertures and shallower back cavities. Compared to a single-layer micro-perforated plate 200, this multi-layer structure design can more comprehensively cover the complex noise spectrum generated by the fan under different operating conditions, effectively solving the problem that traditional noise reduction devices are difficult to adapt to dynamic noise characteristics due to fixed silencing frequencies, thereby significantly improving the overall noise reduction performance of the fan cavity 100.

[0056] In a specific embodiment, the double-layer micro-perforated plate 200 comprises a first layer micro-perforated plate 210 and a second layer micro-perforated plate 220. The first layer micro-perforated plate 210 is positioned close to the back plate of the fan cavity 100, while the second layer micro-perforated plate 220 is positioned away from the back plate. Furthermore, the first layer micro-perforated plate 210 can be positioned above the guide ring within the fan cavity 100. Additionally, the apertures of the first layer micro-perforated plate 210 and the second layer micro-perforated plate 220 can be the same or different, allowing for flexible adjustment based on different noise frequency characteristics. When the fan operates at a specific speed, if the main noise is concentrated in a certain frequency band, the aperture combination of the two layers of micro-perforated plates 200 can be changed. This allows the first layer micro-perforated plate 210 to efficiently absorb the dominant frequency noise in that band, while the second layer micro-perforated plate 220 supplements the absorption of noise in the remaining frequency bands, thereby achieving precise noise control under specific operating conditions. For example, under low-speed conditions, the aperture of the first layer of micro-perforated plate 210 can be set to a larger value (e.g., 2mm), and the back cavity depth can be set to a deeper value (e.g., 50mm) to enhance the absorption of low-frequency noise; simultaneously, the aperture of the second layer of micro-perforated plate 220 can be set to a smaller value (e.g., 1mm), and the back cavity depth can be set to a shallower value (e.g., 30mm) to cover mid- and high-frequency noise. Under high-speed conditions, the relative position of the two layers of micro-perforated plates 200 can be adjusted by the drive mechanism 300 to change their resonant frequency characteristics, so that the first layer of micro-perforated plate 210 focuses on absorbing mid-frequency noise, and the second layer of micro-perforated plate 220 focuses on absorbing high-frequency noise. This adjustable multi-layer micro-perforated plate 200, combined with the dynamic adjustment function of the drive mechanism 300, enables the noise reduction device to adapt to the changes in noise characteristics of the fan under different speeds and operating conditions, achieving continuous and efficient noise reduction over a wide frequency range.

[0057] In one embodiment, the fan cavity noise reduction device further includes:

[0058] A driving mechanism 300 is connected to one or more of the multi-layer micro-perforated plates 200 to drive the connected micro-perforated plates 200 away from or closer to other micro-perforated plates 200.

[0059] Considering the diverse operating conditions of wind turbines leading to constantly changing noise frequency characteristics, traditional fixed-structure noise reduction devices are ill-suited to these dynamic demands. Therefore, this embodiment utilizes the linkage between the drive mechanism 300 and the micro-perforated plate 200 to precisely adjust the spacing between each layer of the micro-perforated plate 200 based on the wind turbine's real-time speed and noise characteristics. This adjusts the back cavity depth of the double-layer micro-perforated plate, thus solving the problem of the unadjustable effective noise reduction frequency range of the micro-perforated plate 200 and broadening the structure's effective noise reduction frequency band. For example, with two layers of micro-perforated plates 200, when the wind turbine is at low speed, the noise is predominantly low-frequency. In this case, the drive mechanism 300 can increase the spacing between the two layers of micro-perforated plates 200, increasing the back cavity volume, thereby reducing the resonant frequency and enhancing the absorption effect of low-frequency noise. Conversely, when the wind turbine is running at high speed, the proportion of high-frequency noise increases, and the drive mechanism 300 reduces the spacing between the two layers of micro-perforated plates 200, improving the structure's acoustic quality and enhancing its ability to suppress high-frequency noise. This dynamic adjustment mechanism based on changes in operating conditions not only breaks through the limitation of the single frequency response of traditional noise reduction devices, but also achieves effective control of noise across the entire speed range of the fan by optimizing the sound absorption structure in real time.

[0060] In practical applications, the drive mechanism 300 can be powered and controlled by the outdoor unit's main board.

[0061] Specifically, the drive mechanism 300 includes a drive motor 310 and a drive rack 320 disposed on the fan cavity 100, and the drive rack 320 is fixedly connected to one or more micro-perforated plates 200.

[0062] By configuring the drive motor 310 and drive rack 320, precise and stable adjustment of the position of the micro-perforated plate 200 can be achieved. The drive motor 310, as a power source, outputs corresponding rotational power according to control commands. The drive rack 320 converts this rotational motion into linear motion, causing the micro-perforated plate 200, which is fixedly connected to it, to move closer to or away from other micro-perforated plates 200. In practical applications, the drive motor 310 can be a stepper motor or a servo motor. A stepper motor can rotate precisely according to a set step angle, thereby controlling the movement distance of the drive rack 320 and achieving precise positioning of the micro-perforated plate 200. A servo motor has higher control precision and response speed, and can quickly adjust its output based on real-time feedback signals, ensuring the stability and accuracy of the micro-perforated plate 200 during dynamic adjustment. Simultaneously, the design of the drive rack 320 must consider its installation and fixing method with the fan cavity 100 to ensure that it does not loosen or shift during operation, thus affecting the adjustment effect of the micro-perforated plate 200. For example, a special mounting groove or guide rail can be set on the fan cavity 100 to firmly fix the drive rack 320 in it, so that it can only move in a straight line along the preset trajectory, thereby ensuring that the micro-perforated plate 200 connected to the drive rack 320 can be adjusted in the expected way to adapt to the noise control requirements under different working conditions.

[0063] In one embodiment, the cavity of the microperforated plate 200 is filled with a sound-insulating material 400.

[0064] This embodiment addresses the problem of poor high-frequency sound absorption in the micro-perforated plate 200 by filling its back cavity with sound-insulating material 400, thereby further enhancing the sound absorption effect of the noise reduction device. The sound-insulating material 400 described in this embodiment can be a material with good sound absorption properties, such as glass wool or polyester fiber cotton. When sound waves enter the back cavity, this sound-insulating material 400 absorbs some of the sound energy, converting it into heat energy and dissipating it, thus reducing sound wave reflection and propagation. Simultaneously, filling with sound-insulating material 400 can also alter the acoustic characteristics of the back cavity, adjusting the resonant frequency and enabling the noise reduction device to achieve efficient sound absorption over a wider frequency range. For example, in the low-frequency range, the sound-insulating material 400 can increase the acoustic impedance of the back cavity, improving its absorption capacity for low-frequency sound waves; in the high-frequency range, the sound-insulating material 400 can work together with the micro-perforated plate 200 to form a more complex sound-absorbing structure, enhancing the suppression effect on high-frequency noise. In addition, the filling of sound insulation material 400 can also play a certain role in heat insulation and moisture protection, protecting the micro-perforated plate 200 from environmental factors and extending the service life of the noise reduction device. In practical applications, the appropriate sound insulation material 400 and its filling amount can be selected according to the specific size and noise characteristics of the fan cavity 100 to achieve the best noise reduction effect.

[0065] like Figure 8 As shown, this embodiment of the invention also provides a fan cavity noise reduction control method, applied to the fan cavity noise reduction device as described above, the method including: steps S101 to S106.

[0066] Step S101: Obtain the specifications and target noise reduction frequency band of the fan cavity 100;

[0067] Step S102: Set the parameter range of the micro-perforated plate 200 in accordance with the specifications;

[0068] Step S103: Discretize the target noise reduction frequency band to obtain multiple frequency discrete points;

[0069] Step S104: Obtain the frequency absorption coefficient of each frequency discrete point, and set the sum of all frequency absorption coefficients as the objective function;

[0070] Step S105: Based on the parameter range, use a genetic algorithm to obtain the maximum value of the objective function, and set the maximum value as the optimal parameter of the micro-perforated plate 200;

[0071] Step S106: Construct an optimal micro-perforated plate 200 based on the optimal parameters, and use the optimal micro-perforated plate 200 to control the noise reduction of the fan cavity 100.

[0072] In this embodiment, the specifications and target noise reduction frequency range of the fan cavity 100 are first obtained. The specifications may include the size and shape of the fan cavity 100, as well as the airflow characteristics during fan operation. These parameters directly affect the sound absorption effect of the micro-perforated plate 200. The target noise reduction frequency range is determined based on the noise frequency characteristics generated by the fan under different operating conditions, clearly defining the frequency range requiring focused noise reduction. The parameter range of the micro-perforated plate 200 is set in conjunction with the specifications, covering key parameters such as aperture, plate thickness, perforation rate, and back cavity depth. Reasonable setting of these parameters is crucial to ensuring efficient sound absorption of the micro-perforated plate 200 in different frequency ranges. Subsequently, the target noise reduction frequency range is discretized to obtain multiple discrete frequency points. For example, an initial value of 1Hz is set, resulting in a series of discrete points with a step size of 1Hz. The frequency absorption coefficient of each discrete frequency point is then obtained, and the sum of all frequency absorption coefficients is set as the objective function. By optimizing the objective function, the optimal combination of micro-perforated plate 200 parameters within a given parameter range can be found. Based on the parameter range, a genetic algorithm is used to obtain the maximum value of the objective function, and this maximum value is set as the optimal parameter of the micro-perforated plate 200. This ensures that the selected parameters enable the noise reduction device to achieve the optimal sound absorption effect within the target noise reduction frequency range. Finally, an optimal micro-perforated plate 200 is constructed based on the optimal parameters, and this optimal micro-perforated plate 200 is used to control the noise reduction of the fan cavity 100.

[0073] In this embodiment, the structural parameters of the micro-perforated plate 200 are designed based on the target noise reduction frequency using a genetic algorithm. This solves the problem of the difficulty in determining the parameters of the micro-perforated plate 200, enabling the micro-perforated plate 200 to effectively reduce noise in the target frequency range.

[0074] In one embodiment, the micro-perforated plate 200 includes a first micro-perforated plate 210 and a second micro-perforated plate 220, and the second micro-perforated plate 220 is connected to the driving mechanism 300.

[0075] like Figure 9 As shown, step S106 includes steps S201 to S202.

[0076] Step S201: Construct the optimal first layer micro-perforated plate and the optimal second layer micro-perforated plate based on the optimal parameters;

[0077] Step S202: Install the first layer micro-perforated plate 210 and the optimal second layer micro-perforated plate in the fan cavity 100, and control the corresponding fan to operate to obtain the fan speed. Then, adjust the drive of the optimal second layer micro-perforated plate according to the fan speed.

[0078] In this embodiment, firstly, based on the optimal parameters obtained in the aforementioned steps, optimal first-layer micro-perforated plate 210 and optimal second-layer micro-perforated plate 220 are constructed, respectively. Both layers of micro-perforated plates 200 achieve optimal settings in terms of specifications for the target noise reduction frequency range. Next, these two layers of micro-perforated plates 200 are installed inside the fan cavity 100. At this time, the fan starts running, and the real-time speed of the fan is acquired through corresponding sensors or a control system. Subsequently, based on the acquired fan speed information, the optimal second-layer micro-perforated plate 220 is driven and adjusted, thereby changing the distance between it and the first-layer micro-perforated plate 210, and thus adjusting the back cavity depth of the double-layer micro-perforated plates. This dynamic adjustment mechanism enables the noise reduction device to optimize the sound absorption structure in real time according to the noise frequency characteristics under the actual operating conditions of the fan, ensuring continuous and efficient noise reduction over a wide frequency range under various fan speeds and operating conditions. This effectively solves the problem that traditional noise reduction devices, due to their fixed silencing frequency, are difficult to adapt to dynamic noise characteristics.

[0079] In a specific embodiment, such as Figure 10 As shown, step S202 includes steps S301 to S303.

[0080] Step S301: Pre-establish noise octave band diagrams for different fan speeds, and determine the target frequency band with the most significant noise based on the noise octave band diagrams;

[0081] Step S302: Taking the maximum sound absorption coefficient of the target frequency band as the optimization target, and setting the position of the optimal second layer micro-perforated plate as a variable, the optimal position of the optimal second layer micro-perforated plate under different fan speeds is determined by using a genetic algorithm.

[0082] Specifically, step S302 includes:

[0083] The optimal position of the second layer micro-perforated plate at different fan speeds is obtained according to the following formula:

[0084]

[0085] Where Q represents the optimization objective, f1 and f2 represent the endpoint values ​​of the target frequency band, α represents the sound absorption coefficient, and f represents the position of the optimal second layer of micro-perforated plate.

[0086] Step S303: Drive and adjust the optimal second layer micro-perforated plate according to the optimal position.

[0087] This embodiment first determines the frequency range [f1, f2] where noise is most significant at different fan speeds by experimentally testing noise octave band diagrams (e.g., 1 / 3 octave band diagrams). Then, with the goal of maximizing the sound absorption coefficient of the frequency range [f1, f2], and setting the position of the second layer micro-perforated plate 220 as a variable, the optimal position of the second layer micro-perforated plate 220 at each fan speed is determined based on a genetic algorithm.

[0088] In practical applications, a noise reduction device based on the optimal first layer micro-perforated plate and the second layer micro-perforated plate 220 can be installed on the outdoor unit. The fan speed is identified by the outdoor unit main board, and the optimal second layer micro-perforated plate is adjusted to the optimal position by the drive mechanism 300. It is also determined whether the fan speed has changed. If it has changed, the second layer micro-perforated plate 220 is adjusted from the current position to the optimal position corresponding to the speed by the drive mechanism 300.

[0089] In a specific embodiment, taking a double-layer micro-perforated plate as an example, based on the sound absorption theory of the micro-perforated plate 200, the relative acoustic impedance and relative acoustic mass of the first layer micro-perforated plate 210 are as follows:

[0090]

[0091] Where r1 is the relative acoustic impedance of the first layer of microperforated plate 210, m1 is the relative acoustic mass of the first layer of microperforated plate 210, η is the air viscosity coefficient, f is the frequency of the incident sound, ρ is the air density, c is the sound velocity, d1 is the diameter of the first layer of micropores, p1 is the perforation rate of the first layer of micropore structure, t1 is the thickness of the first layer of microperforated plate 210, and k1 is the perforation parameter of the first layer of microperforated plate 210.

[0092] The relative acoustic impedance and relative acoustic mass of the second layer micro-perforated plate 220 are:

[0093]

[0094] Where r2 is the relative acoustic impedance of the second layer microperforated plate 220, m2 is the relative acoustic mass of the second layer microperforated plate 220, η is the air viscosity coefficient, f is the frequency of the incident sound, ρ is the air density, c is the sound velocity, d2 is the diameter of the second layer micropores, p2 is the perforation rate of the second layer micropore structure, t2 is the thickness of the second layer microperforated plate 220, and k2 is the perforation parameter of the second layer microperforated plate 220.

[0095] The relative acoustic impedance and relative acoustic mass of a double-layer microperforated plate can be expressed as:

[0096]

[0097] Where, r 12 The relative acoustic impedance of the double-layer microperforated plate is m. 12 D1 represents the relative acoustic mass of the double-layer micro-perforated plate, D2 represents the back cavity depth of the first layer micro-perforated plate 210, D2 represents the back cavity depth of the second layer micro-perforated plate 220, and ω represents the angular frequency ω=2πf.

[0098] The sound absorption coefficient of the double-layer micro-perforated plate is:

[0099]

[0100] For example, if the distance from the air guide ring to the panel is 70mm, then the overall thickness of the noise reduction in this embodiment can be determined to be 70mm. The noise spectrum at the outdoor unit fan's maximum operating speed is used as the noise reduction spectrum. For example, noise reduction is performed on a series of discrete points within the 0-1600Hz range with a step size of 1Hz. The sum of the sound absorption coefficients Q at each frequency is used as the objective function.

[0101]

[0102] The parameter ranges for the first layer micro-perforated plate 210 are: d1 between [0, 1.5 mm], p1 between [0, 0.1], t1 between [0, 2 mm], and D1 between [0, 68 mm]. The parameter ranges for the second layer micro-perforated plate 220 are: d2 between [0, 1.5 mm], p2 between [0, 0.1], t2 between [0, 2 mm], and D2 between [0, 68 mm]. After removing the shell structure thickness, the sum of the cavity depths is 68 mm, so D1 + D2 = 68 mm is limited. Based on the genetic algorithm, optimization was performed with Q taking the maximum value. The structural parameters of the device in this embodiment were determined as follows: the first layer micro-perforated plate 210 parameters were d1 = 0.72 mm, p1 = 0.021, t1 = 0.571 mm, and D1 = 23.7 mm; the second layer micro-perforated plate 220 parameters were d2 = 0.325 mm, p2 = 0.012, t2 = 0.767, and D2 = 44.3 mm. A comparison of the sound absorption coefficient of this embodiment with that of a simple perforated plate is provided. Figure 11 As shown, from Figure 11 As can be seen from the data, the double-layer micro-perforated plate structure used in this embodiment has a significantly higher sound absorption coefficient than the simple perforated plate in the target noise reduction frequency range.

[0103] For example, when the outdoor unit fan needs to operate at speeds of 450 r / min, 520 r / min, 680 r / min, and 750 r / min under different operating conditions or compressor frequencies, the corresponding peak noise frequency ranges [f1, f2] in the 1 / 3 octave band are [357 Hz, 450 Hz], [562 Hz, 708 Hz], [891 Hz, 1122 Hz], and [1410 Hz, 1778 Hz], respectively. Based on the genetic algorithm, the location of the second layer micro-perforated plate 220 with the highest sound absorption coefficient [f1, f2] is determined. The location of the second layer micro-perforated plate 220 is calibrated using the depth D2 of the second layer micro-perforated plate 220. After optimization, D2 can be taken as 25 mm, 28 mm, 34 mm, and 42 mm, respectively.

[0104]

[0105] When the air conditioner actually runs at the above speed, the outdoor unit main board controls the drive device to make the second layer of micro-perforated plate 220 reach the designated position.

[0106] The present invention also provides an air conditioner, including the fan cavity noise reduction device as described above or the fan cavity noise reduction control method as described above.

[0107] Please see Figure 12 The air conditioner 1200 provided in this embodiment of the invention is a device with both wireless and wired communication capabilities.

[0108] See Figure 12The air conditioner 1200 includes a processor 1202, a memory, and a network interface 1205 connected via a system bus 1201. The memory may include a non-volatile storage medium 1203 and internal memory 1204.

[0109] The non-volatile storage medium 1203 can store an operating system 12031 and a computer program 12032. When the computer program 12032 is executed, it causes the processor 1202 to execute a fan cavity noise reduction control method.

[0110] The processor 1202 provides computing and control capabilities to support the operation of the entire air conditioner 1200.

[0111] The internal memory 1204 provides an environment for the operation of the computer program 12032 in the non-volatile storage medium 1203. When the computer program 12032 is executed by the processor 1202, the processor 1202 can execute a fan cavity noise reduction control method.

[0112] This network interface 1205 is used for network communication with other devices. Those skilled in the art will understand that... Figure 12 The structure shown is merely a block diagram of a portion of the structure related to the present invention and does not constitute a limitation on the air conditioner 1200 to which the present invention is applied. The specific air conditioner 1200 may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0113] The processor 1202 is used to run a computer program 12032 stored in a memory to implement any embodiment of the above-described method for controlling noise reduction in the steam fan cavity.

[0114] It should be understood that, in this embodiment of the invention, the processor 1202 may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0115] It will be understood by those skilled in the art that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program may be stored in a storage medium, which is a computer-readable storage medium. The computer program is executed by at least one processor in the computer system to implement the process steps of the embodiments of the above methods.

[0116] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed, can perform the steps provided in the above embodiments. The storage medium may include various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0117] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section. It should be noted that those skilled in the art can make various improvements and modifications to these embodiments without departing from the principles thereof, and these improvements and modifications also fall within the protection scope of the claims of these embodiments.

[0118] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A fan cavity noise reduction device, applied to the fan cavity, characterized in that, The device includes: A micro-perforated plate is disposed in the fan cavity, and the micro-perforated plate includes a back cavity.

2. The fan cavity noise reduction device according to claim 1, characterized in that, The micro-perforated plate is provided in multiple layers, and the multiple layers of micro-perforated plates are arranged in parallel within the fan cavity.

3. The fan cavity noise reduction device according to claim 2, characterized in that, Also includes: A driving mechanism is connected to one or more of the micro-perforated plates in the multilayer micro-perforated plates to drive the connected micro-perforated plates away from or closer to other micro-perforated plates.

4. The fan cavity noise reduction device according to claim 3, characterized in that, The drive mechanism includes a drive motor and a drive rack disposed on the fan cavity, and the drive rack is fixedly connected to one or more micro-perforated plates.

5. The fan cavity noise reduction device according to claim 1, characterized in that, The cavity of the micro-perforated plate is filled with sound-insulating material.

6. A method for controlling noise reduction in a fan cavity, applied to the fan cavity noise reduction device as described in any one of claims 1-5, characterized in that, The method includes: Obtain the specifications and target noise reduction frequency band of the fan cavity; Set the parameter range of the micro-perforated plate based on the aforementioned specifications; The target noise reduction frequency band is discretized to obtain multiple discrete frequency points; Obtain the frequency absorption coefficient at each discrete frequency point, and set the sum of all frequency absorption coefficients as the objective function; Based on the parameter range, a genetic algorithm is used to obtain the maximum value of the objective function, and the maximum value is set as the optimal parameter of the micro-perforated plate; The optimal micro-perforated plate is constructed based on the optimal parameters, and the optimal micro-perforated plate is used to control the noise reduction of the fan cavity.

7. The fan cavity noise reduction control method according to claim 6, applied to the fan cavity noise reduction device according to claim 3, characterized in that, The micro-perforated plate includes a first layer of micro-perforated plate and a second layer of micro-perforated plate, and the second layer of micro-perforated plate is connected to the driving mechanism; The construction of the optimal micro-perforated plate based on the optimal parameters, and the use of the optimal micro-perforated plate to control noise reduction in the fan cavity, includes: Construct the optimal first layer micro-perforated plate and the optimal second layer micro-perforated plate based on the aforementioned optimal parameters; The first layer of micro-perforated plate and the optimal second layer of micro-perforated plate are installed in the fan cavity, and the corresponding fan is controlled to operate to obtain the fan speed. Then, the optimal second layer of micro-perforated plate is driven and adjusted according to the fan speed.

8. The fan cavity noise reduction control method according to claim 1, characterized in that, The step of installing the first layer of micro-perforated plate and the optimal second layer of micro-perforated plate into the fan cavity, controlling the corresponding fan operation to obtain the fan speed, and then adjusting the drive of the optimal second layer of micro-perforated plate according to the fan speed includes: Noise octave band diagrams are pre-established for different fan speeds, and the target frequency band with the most significant noise is determined based on the noise octave band diagrams; The maximum sound absorption coefficient of the target frequency band is taken as the optimization objective, and the position of the optimal second layer micro-perforated plate is set as a variable. Then, the optimal position of the optimal second layer micro-perforated plate under different fan speeds is determined by a genetic algorithm. The optimal second layer micro-perforated plate is driven and adjusted according to the optimal position.

9. The fan cavity noise reduction control method according to claim 8, characterized in that, The optimization objective is to use the maximum sound absorption coefficient of the target frequency band as the optimization target, and the position of the optimal second layer micro-perforated plate is set as a variable. Then, a genetic algorithm is used to determine the optimal position of the optimal second layer micro-perforated plate at different fan speeds, including: The optimal position of the second layer micro-perforated plate at different fan speeds is obtained according to the following formula: Where Q represents the optimization objective, f1 and f2 represent the endpoint values ​​of the target frequency band, α represents the sound absorption coefficient, and f represents the position of the optimal second layer of micro-perforated plate.

10. An air conditioner, characterized in that, This includes the fan cavity noise reduction device as described in any one of claims 1-5 or the fan cavity noise reduction control method as described in any one of claims 6-9.

Images