A refrigerator with active noise reduction
By setting a heat dissipation gap between the refrigerator compressor compartment and the bottom wall, and combining a microphone and speaker system, the conflict between airtightness and heat dissipation in active noise reduction is resolved, achieving better noise suppression and energy efficiency improvement.
Patent Information
- Application Number
- CN202210958681.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-08-09
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2042-08-09
AI Technical Summary
In the active noise reduction technology of existing refrigerators, there is a conflict between airtightness and heat dissipation, resulting in limited noise suppression effect and increased energy consumption.
A heat dissipation gap is set between the compressor compartment and the bottom wall, and combined with a microphone and speaker system, active noise reduction is achieved through phase analysis and anti-phase noise cancellation, while the heat dissipation gap is used to dissipate the heat from the compressor.
It achieves better active noise reduction effect and lower energy consumption, takes into account the heat dissipation needs of the compressor, and avoids increased energy consumption and poor cooling effect caused by excessive sealing.
Smart Images
Figure CN115265074B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of refrigeration appliances, and in particular to a refrigerator with active noise reduction. Background Art
[0002] Refrigerators are household appliances that run 24 / 7, generating a certain amount of noise. Operating noise generally ranges from 35 to 42 decibels. Existing inverter refrigerators can achieve a minimum noise level of 35 decibels, but due to the variable speed, inverter refrigerators can still generate higher noise levels during certain periods of time. While this noise is largely imperceptible during the day, it can still disrupt users' rest at night when background noise is lower.
[0003] Traditional noise reduction technology relies on passive noise reduction, which reduces the amount of noise energy transmitted from the noise source by adding vibration-damping and sound-absorbing materials. However, this approach has limited effectiveness. Active noise reduction technology is used near the refrigerator's compressor. A microphone collects noise, a control module performs phase analysis on the noise's acoustic signal, and controls the speaker to produce noise with an opposite phase. When refrigerator noise overlaps with speaker noise, the noise is partially offset, effectively reducing refrigerator noise.
[0004] Effective active noise reduction requires a relatively sealed compressor compartment. However, a sealed compressor compartment can affect heat dissipation from the compressor and condenser. Therefore, a new compressor compartment layout is needed to address the conflict between airtightness and heat dissipation in active noise reduction. Summary of the Invention
[0005] In order to solve the conflict between airtightness and heat dissipation in dynamic noise reduction, the present application provides a refrigerator with active noise reduction, including a compressor compartment, a bottom wall, a compressor rear cover, a compressor, a microphone, a first speaker and a main control board; the compressor is arranged in the compressor compartment; the bottom wall is arranged at the bottom of the refrigerator, and a heat dissipation gap is arranged between the compressor compartment and the bottom wall, the compressor rear cover is provided with a compressor rear cover air outlet on the side where the compressor is arranged, the microphone is arranged on the top of the compressor, the first speaker is arranged on the side of the compressor close to the compressor rear cover air outlet, and the first speaker is facing the compressor.
[0006] When the compressor compartment is completely enclosed, active noise reduction is effective, but this affects the heat dissipation of the compressor, increasing refrigerator energy consumption, reducing cooling efficiency, and making the forced heat dissipation condenser unusable. This application provides a heat dissipation gap between the compressor compartment and the bottom wall. While ensuring a certain degree of sealing of the compressor compartment, it also allows heat generated by the compressor to be discharged from the compressor compartment through the heat dissipation gap. This ensures that the compressor compartment meets both airtightness and heat dissipation requirements, achieving better active noise reduction and greater energy efficiency.
[0007] The microphone and the first speaker are connected to the main control board, and the main control board is configured to: receive noise information collected by the microphone, and perform phase analysis on the noise information to obtain noise phase information; perform inversion processing on the noise phase information to obtain noise inversion phase information; and send a sound instruction to the speaker, wherein the sound instruction includes an instruction to start sounding and the noise inversion phase information to control the speaker to emit a sound with an opposite phase to the noise.
[0008] Optionally, the compressor compartment also includes a refrigerator door, a refrigerator rear wall, a first refrigerator wall, a second refrigerator wall, an upper wall, a front wall and a compressor base plate; the first refrigerator wall and the second refrigerator wall are vertically arranged on both sides of the refrigerator, one end of the upper wall, the front wall and the bottom wall are connected to the first refrigerator wall, and the other end is connected to the second refrigerator wall, the upper wall and the bottom wall are horizontally arranged, the bottom wall is arranged on the side close to the refrigerator door, and the upper wall is arranged on the side close to the refrigerator rear wall; one end of the front wall is connected to the upper wall, and the other end is connected to the bottom wall; the compressor rear cover is connected to the refrigerator rear wall, and the refrigerator rear wall is connected to the first refrigerator wall and the second refrigerator wall, the compressor base plate is connected to the compressor rear cover plate, the compressor base plate is horizontally arranged at the same level as the bottom wall, the compressor is arranged on the compressor base plate, and the heat dissipation gap is provided between the compressor base plate and the bottom wall.
[0009] Optionally, a gap with a width of 8-10 mm is set between the compressor base plate and the bottom wall.
[0010] Optionally, a first shock-absorbing strip and a second shock-absorbing strip are further included, wherein the first shock-absorbing strip and the second shock-absorbing strip are arranged between the compressor base plate and the bottom wall, and the heat dissipation gap is arranged between the first shock-absorbing strip and the second shock-absorbing strip, and the first shock-absorbing strip and the second shock-absorbing strip are butyl rubber strips with aluminum foil applied on one side.
[0011] Optionally, the invention further includes a first sound barrier strip, a second sound barrier strip, and a third sound barrier strip, wherein the first sound barrier strip, the second sound barrier strip, and the third sound barrier strip are arranged on the bottom wall surface, and the first sound barrier strip, the second sound barrier strip, and the third sound barrier strip and the compressor are arranged on both sides of the bottom wall surface, and the first sound barrier strip, the second sound barrier strip, and the third sound barrier strip are connected to form a U-shaped structure, and the opening of the U-shaped structure faces the heat dissipation gap.
[0012] Optionally, a second speaker is further included, the second speaker is arranged on the bottom wall, the second speaker and the first sound barrier are arranged on one surface of the bottom wall, the second speaker is connected to the main control board, and the second speaker faces the heat dissipation gap.
[0013] Optionally, a third speaker and a condenser fan are further included, wherein the condenser fan is arranged on one side of the compressor, the third speaker is connected to the main control board, and the third speaker faces the condenser fan.
[0014] Optionally, the compressor rear cover is provided with a compressor rear cover air inlet on a side where the condenser fan is provided, and the third speaker is provided at the position of the compressor rear cover air inlet.
[0015] Optionally, the main control board is connected to the compressor, and the main control board is further configured to: receive noise information collected by the microphone, compare the loudness of the noise information, and when the loudness of the noise exceeds a preset loudness value, control the compressor to increase or decrease the speed; if the reduction in the loudness of the sound after adjustment is greater than or equal to a reduction threshold, the main control board controls the compressor to operate at the adjusted speed; if the reduction in the loudness of the sound after adjustment is less than the reduction threshold, the main control board controls the compressor to operate at the speed before adjustment.
[0016] The refrigerator provided in the present application is provided with heat dissipation gaps on the compressor compartment, so that the compressor compartment satisfies both airtightness and heat dissipation capabilities, and the active noise reduction effect is better and more energy-efficient. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0018] Figure 1 A side view of a refrigerator with active noise reduction;
[0019] Figure 2 A bottom view of a refrigerator with active noise reduction;
[0020] Figure 3A schematic diagram of the locations of microphones and speakers in the compressor compartment of an active noise reduction refrigerator;
[0021] Figure 4 A cross-sectional view showing the locations of microphones and speakers in a compressor compartment of an active noise reduction refrigerator;
[0022] Figure 5 A schematic diagram of the opening on the rear cover of a natural heat dissipation condenser compressor in a refrigerator with active noise reduction.
[0023] Figure 6 A schematic diagram of the opening on the rear cover of a compressor of an active noise reduction refrigerator using forced convection heat dissipation condenser;
[0024] Figure 7 A schematic diagram of the electrical components of an active noise reduction system for an active noise reduction refrigerator;
[0025] Figure 8 Flowchart for refrigerator active noise cancellation when setting up the microphone and first speaker;
[0026] Figure 9 This is a flowchart of refrigerator active noise reduction when a microphone, first speaker, second speaker, and third speaker are set;
[0027] Figure 10 A flowchart for active noise reduction adjustment of refrigerators;
[0028] Legend:
[0029] 1-Microphone; 201-First speaker; 202-Second speaker; 3-Compressor base plate; 4-Compressor rear cover; 501-First sound barrier; 502-Second sound barrier; 503-Third sound barrier; 6-Compressor rear cover air outlet; 7-Compressor rear cover air inlet; 801-First shock-absorbing strip; 802-Second shock-absorbing strip; 901-Upper wall; 902-Front wall; 903-Bottom wall; 10-Refrigerator door; 11-Refrigerator rear wall; 12-First refrigerator wall; 13-Second refrigerator wall; 14-Compressor; 15-Heating gap. DETAILED DESCRIPTION
[0030] The following embodiments are described in detail, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numbers in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following embodiments are not intended to represent all possible implementations consistent with the present application. They are merely examples of systems and methods consistent with certain aspects of the present application, as detailed in the claims.
[0031] When applying active noise reduction technology to the compressor in a refrigerator, the more enclosed the compressor compartment, the better the effect. However, an overly enclosed compressor compartment can also lead to poor heat dissipation from the compressor, increasing energy consumption and reducing cooling efficiency. Furthermore, if a forced-cooling condenser is installed, it becomes unusable. Therefore, a new compressor compartment layout is needed to resolve the conflict between airtightness and heat dissipation in active noise reduction.
[0032] An embodiment of the present application provides a refrigerator with active noise reduction, comprising a compressor compartment, a bottom wall 903, a compressor rear cover 4, a compressor 14, a microphone 1, a first speaker 201 and a main control board; the compressor 14 is arranged in the compressor compartment; the bottom wall 903 is arranged at the bottom of the refrigerator, and a heat dissipation gap 15 is arranged between the compressor compartment and the bottom wall 903, the compressor rear cover 4 is provided with a compressor rear cover air outlet 6 on the side where the compressor 14 is arranged, the microphone 1 is arranged on the top of the compressor 14, the first speaker 201 is arranged on the side of the compressor 14 near the compressor rear cover air outlet 6, and the first speaker 201 is facing the compressor 14.
[0033] like Figures 1-6 As shown, the compressor 14 is arranged in the compressor compartment, and there is a heat dissipation gap 15 between the compressor compartment and the refrigerator body, and the heat dissipation gap 15 is arranged close to the compressor 14. When the compressor 14 is working, the heat generated can flow out from the heat dissipation gap 15. The heat dissipation gap 15 is not less than 150*10mm, and its width of 150mm is close to the width of the compressor 14. The compressor rear cover plate 4 is provided with a compressor rear cover air outlet 6 at a position slightly above the compressor 14, and a natural convection channel is formed with the gap retained on the front side of the compressor 14 to ensure good heat dissipation of the compressor 14.
[0034] like Figure 8 As shown, the microphone 1 and the first speaker 201 are connected to the main control board, and the main control board is configured to: receive the noise information collected by the microphone 1, and perform phase analysis on the noise information to obtain noise phase information; perform inverse phase processing on the noise phase information to obtain noise inverse phase information; and send a sound instruction to the first speaker 201, wherein the sound instruction includes an instruction to start sounding and the noise inverse phase information to control the first speaker 201 to emit a sound with an opposite phase to the noise.
[0035] like Figure 7As shown, the main control board in the refrigerator active noise reduction system is connected to microphone 1 and first speaker 201. Microphone 1 collects noise, and the main control board performs phase analysis on the noise's acoustic signal, controlling the speaker to produce noise with an opposite phase. When refrigerator noise overlaps with the noise generated by the speaker, they partially cancel each other out, effectively reducing refrigerator noise.
[0036] In some embodiments, the main control board in the active noise reduction system of the refrigerator can be connected not only to the microphone 1 and the first speaker 201, but also to multiple speakers. For example, the main control board can be connected to the microphone 1, the first speaker 201, the second speaker 202 and the third speaker at the same time.
[0037] In some embodiments, as Figures 1-6 As shown, the compressor compartment also includes a refrigerator door 10, a refrigerator rear wall 11, a first refrigerator wall 12, a second refrigerator wall 13, an upper wall 901, a front wall 902 and a compressor base plate 3; the first refrigerator wall 12 and the second refrigerator wall 13 are vertically arranged on both sides of the refrigerator, one end of the upper wall 901, the front wall 902 and the bottom wall 903 are connected to the first refrigerator wall 12, and the other end is connected to the second refrigerator wall 13, the upper wall 901 and the bottom wall 903 are horizontally arranged, the bottom wall 903 is arranged on the side close to the refrigerator door 10, and the upper wall 901 is arranged On the side close to the refrigerator rear wall 11; the front wall 902 is connected to the upper wall 901 at one end and to the bottom wall 903 at the other end; the compressor rear cover 4 is connected to the refrigerator rear wall 11, and the refrigerator rear wall 11 is connected to the first refrigerator wall 12 and the second refrigerator wall 13. The compressor base plate 3 is connected to the compressor rear cover 4. The compressor base plate 3 is horizontally arranged at the same level as the bottom wall 903. The compressor 14 is arranged on the compressor base plate 3. The heat dissipation gap 15 is provided between the compressor base plate 3 and the bottom wall 903. The side wall of the compressor compartment close to the interior of the refrigerator, i.e., the front wall 902, is inclined. This arrangement reduces the space occupied by the compressor compartment and saves space inside the refrigerator. In some embodiments, a first shock-absorbing strip 801 and a second shock-absorbing strip 802 are further included. A gap with a width of 8-10 mm is set between the compressor base plate 3 and the bottom wall 903. The first shock-absorbing strip 801 and the second shock-absorbing strip 802 are set between the compressor base plate 3 and the bottom wall 903. The heat dissipation gap 15 is set between the first shock-absorbing strip 801 and the second shock-absorbing strip 802. The first shock-absorbing strip 801 and the second shock-absorbing strip 802 are butyl rubber strips with aluminum foil on one side.
[0038] like Figure 2As shown, a gap is provided between the compressor baseplate 3 and the bottom wall 903. When the compressor 14 is operating, the compressor compartment vibrates along with the compressor 14. If the compressor compartment were directly connected to the refrigerator body, the vibration would be transmitted from the compressor compartment to the refrigerator, sometimes causing resonance and amplifying the sound. Therefore, by providing a gap between the compressor baseplate 3 and the bottom wall 903, the compressor compartment and the refrigerator body are isolated and the resonance phenomenon can be reduced.
[0039] In some embodiments, the system further includes a first sound barrier strip 501, a second sound barrier strip 502, and a third sound barrier strip 503. The first sound barrier strip 501, the second sound barrier strip 502, and the third sound barrier strip 503 are arranged on the bottom wall 903. The first sound barrier strip 501, the second sound barrier strip 502, and the third sound barrier strip 503 and the compressor 14 are arranged on both sides of the bottom wall 903. The first sound barrier strip 501, the second sound barrier strip 502, and the third sound barrier strip 503 are connected to form a U-shaped structure, and the opening of the U-shaped structure faces the heat dissipation gap 15.
[0040] like Figure 2 As shown, a U-shaped sound barrier structure is provided on the bottom wall 903, with the opening of the U-shaped structure facing the heat dissipation slot 15. When noise is transmitted from the heat dissipation slot 15, it is reflected back and forth between the U-shaped sound barrier structures. The phase differences between the reflected noises cancel each other out, thus achieving a certain degree of noise reduction.
[0041] In some embodiments, the first sound barrier strip 501, the second sound barrier strip 502, and the third sound barrier strip 503 are made of PVC material. PVC sound barrier strips are insulated, cheap, readily available, and durable.
[0042] In some embodiments, a second speaker 202 is further included. The second speaker 202 is arranged on the bottom wall 903. The second speaker 202 and the first sound barrier 501 are arranged on the same surface of the bottom wall 903. The second speaker 202 is connected to the main control board, and the second speaker 202 faces the heat dissipation gap 15.
[0043] like Figure 2 As shown, a second speaker 202 is positioned within the opening of the U-shaped sound barrier structure, with the opening of second speaker 202 facing the heat dissipation slot 15. Second speaker 202 is connected to the main control board, allowing it to emit sound with a phase opposite to the noise. When noise escapes from heat dissipation slot 15, it is not only attenuated by reflection back and forth within the U-shaped sound barrier structure, but also further reduces noise by emitting sound with a phase opposite to the noise, in conjunction with second speaker 202.
[0044] In some embodiments, a third speaker and a condenser fan are further included. The condenser fan is disposed on one side of the compressor 14. The compressor rear cover plate 4 is provided with a compressor rear cover air inlet 7 on the side where the condenser fan is disposed. The third speaker is connected to the main control board and is disposed at the position of the compressor rear cover air inlet 7, facing the condenser fan. The provision of the third speaker can effectively and actively reduce the noise of the condenser fan and the compressor, thereby reducing the noise radiated outward through the compressor rear cover air inlet 7.
[0045] like Figure 9 As shown, a microphone 1, a first speaker 201, a second speaker 202, a third speaker, a condenser fan and a condenser heat dissipation fan are provided at the same time. The microphone 1 transmits the collected noise information to the main control board. After analyzing the received noise information, the main control board transmits the sound information with the opposite phase to the noise information to the first speaker 201, the second speaker 202 and the third speaker, and controls the first speaker 201, the second speaker 202 and the third speaker to perform active noise reduction at the compressor 14, the heat dissipation gap 15 and the condenser air inlet 7 respectively.
[0046] In some embodiments, as Figure 10 As shown, the main control board is connected to the compressor 14, and the main control board is further configured to: receive the noise information collected by the microphone 1, compare the loudness of the noise information, and when the loudness of the noise exceeds a preset loudness value, control the compressor 14 to increase or decrease the speed; if the amount of reduction in the loudness of the sound after adjustment is greater than or equal to the reduction threshold, the main control board controls the compressor 14 to operate at the adjusted speed; if the amount of reduction in the loudness of the sound after adjustment is less than the reduction threshold, the main control board controls the compressor 14 to operate at the speed before adjustment.
[0047] The microphone 1 in the active noise reduction system is used to monitor the sound pressure level. When the noise in the compressor compartment exceeds the preset loudness value, the compressor 14 is adjusted to reduce or increase the speed. The speed change amplitude does not exceed 60rpm each time, and the maximum speed change does not exceed 300rpm. When the compressor 14 is adjusted to increase or decrease the speed within the speed range of 300rpm, if the sound intensity is detected to be reduced by more than the reduction threshold, it is considered that the compressor 14 is operating within the original target speed and there is resonance. At this time, the compressor 14 operates at a low-noise speed; on the contrary, if the compressor 14 is adjusted to increase or decrease the speed within the speed range of 300rpm, if the sound intensity is detected to be reduced by less than the reduction threshold, the compressor 14 continues to operate at the speed before adjustment.
[0048] Through the above scheme, this application provides a new compressor compartment layout, which solves the conflict between airtightness and heat dissipation in the active noise reduction of the refrigerator, improves the active noise reduction effect of the refrigerator, and also takes into account the heat dissipation of the refrigerator compressor, preventing the compressor from being unable to dissipate heat, resulting in increased energy consumption of the refrigerator and poor refrigeration effect.
[0049] Similar parts between the embodiments provided in this application can be referenced to each other. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without expending creative work shall fall within the scope of protection of this application.
Claims
1. A refrigerator with active noise reduction, characterized in that: It includes a compressor cabin, a bottom wall (903), a compressor rear cover (4), a compressor (14), a microphone (1), a first speaker (201) and a main control board; The compressor (14) is arranged in the compressor compartment; the bottom wall (903) is arranged at the bottom of the refrigerator, a heat dissipation gap (15) is arranged between the compressor compartment and the bottom wall (903), the compressor rear cover (4) is provided with a compressor rear cover air outlet (6) on the side where the compressor (14) is arranged, the microphone (1) is arranged on the top of the compressor (14), the first speaker (201) is arranged on the side of the compressor (14) near the compressor rear cover air outlet (6), and the first speaker (201) faces the compressor (14); The compressor compartment further comprises a refrigerator door (10), a refrigerator rear wall (11), a first refrigerator wall (12), a second refrigerator wall (13), an upper wall (901), a front wall (902) and a compressor bottom plate (3); The first refrigerator wall (12) and the second refrigerator wall (13) are vertically arranged on both sides of the refrigerator, one end of the upper wall (901), the front wall (902) and the bottom wall (903) are connected to the first refrigerator wall (12), and the other end is connected to the second refrigerator wall (13), the upper wall (901) and the bottom wall (903) are horizontally arranged, the bottom wall (903) is arranged on the side close to the refrigerator door (10), and the upper wall (901) is arranged on the side close to the refrigerator rear wall (11); one end of the front wall (902) is connected to the upper wall (901), The other end is connected to the bottom wall (903); the compressor rear cover (4) is connected to the refrigerator rear wall (11), the refrigerator rear wall (11) is connected to the first refrigerator wall (12) and the second refrigerator wall (13), the compressor bottom plate (3) is connected to the compressor rear cover (4), the compressor bottom plate (3) is horizontally arranged at the same level as the bottom wall (903), the compressor (14) is arranged on the compressor bottom plate (3), and the heat dissipation gap (15) is provided between the compressor bottom plate (3) and the bottom wall (903); It also includes a first shock-absorbing strip (801) and a second shock-absorbing strip (802), wherein the first shock-absorbing strip (801) and the second shock-absorbing strip (802) are arranged between the compressor base plate (3) and the bottom wall (903), and the heat dissipation gap (15) is arranged between the first shock-absorbing strip (801) and the second shock-absorbing strip (802), and the first shock-absorbing strip (801) and the second shock-absorbing strip (802) are butyl rubber strips with aluminum foil applied on one side; It also includes a first sound barrier strip (501), a second sound barrier strip (502) and a third sound barrier strip (503), wherein the first sound barrier strip (501), the second sound barrier strip (502) and the third sound barrier strip (503) are arranged on the lower side of the bottom wall (903), and the first sound barrier strip (501), the second sound barrier strip (502) and the third sound barrier strip (503) are connected to form a U-shaped structure, and the opening of the U-shaped structure faces the heat dissipation gap (15); The microphone (1) and the first speaker (201) are connected to the main control board, and the main control board is configured as follows: receiving noise information collected by the microphone (1), and performing phase analysis on the noise information to obtain noise phase information; Performing phase inversion processing on the noise phase information to obtain noise inverted phase information; A sounding instruction is sent to the first speaker (201), the sounding instruction including an instruction to start sounding and the noise anti-phase information, so as to control the first speaker (201) to emit a sound with a phase opposite to the noise.
2. The refrigerator according to claim 1, wherein: The width of the heat dissipation gap (15) is 8-10 mm.
3. The refrigerator according to claim 1, wherein: The device further comprises a second speaker (202), the second speaker (202) being arranged on the bottom wall (903), the second speaker (202) and the first sound barrier strip (501) being arranged on one side of the bottom wall (903), the second speaker (202) being connected to the main control board, and the second speaker (202) facing the heat dissipation gap (15).
4. The refrigerator according to claim 1, wherein It also includes a third speaker and a condenser fan, wherein the condenser fan is arranged on one side of the compressor, the third speaker is connected to the main control board, and the third speaker faces the condenser fan.
5. The refrigerator according to claim 4, characterized in that The compressor rear cover plate (4) is provided with a compressor rear cover air inlet (7) on a side where the condenser fan is provided, and the third speaker is provided at the position of the compressor rear cover air inlet (7).
6. The refrigerator according to claim 1, wherein: The main control board is connected to the compressor (14), and the main control board is further configured to: receiving noise information collected by the microphone (1), comparing the loudness of the noise information, and controlling the compressor to increase or decrease speed when the loudness of the noise exceeds a preset loudness value; If the amount of reduction in the loudness of the sound after adjustment is greater than or equal to the reduction threshold, the main control board controls the compressor to operate at the adjusted speed.
7. The refrigerator according to claim 6, characterized in that If the amount of reduction in the loudness of the sound after adjustment is less than the reduction threshold, the main control board controls the compressor to run at the speed before adjustment.