Ventilation silencing window for medium-high frequency noise

Abstract

The ventilation silencing window comprises an upper window frame and a lower window frame, the inner side and the outer side between the upper window frame and the lower window frame are each provided with a row of multiple concave blades distributed at intervals, and the two sides of any blade on any side are embedded into grooves of two adjacent blades on the other side correspondingly; the upper window frame, the lower window frame and the blades on the two sides define a plurality of channels used for communicating the inner side and the outer side, the top of the lower window frame is provided with a slope gradually lowered from the inner side to the outer side along the channel. The silencing window can realize noise reduction without reducing ventilation and heat exchange efficiency and is small in size.

Description

Technical Field

[0001] The invention relates to a ventilation window, in particular to a ventilation and sound-absorbing window for medium and high frequency noise. Background Art

[0002] The chilled water, steam, compressed air, etc. provided by power stations and air compressor stations play an important role in the production of industrial plants. However, the power equipment such as refrigeration machines, air compressors, water pumps, etc. in power stations and air compressor stations will generate large medium and high-frequency noise during actual operation.

[0003] For ventilation and heat dissipation considerations of power equipment, ventilation windows need to be reserved on the exterior walls of air compressor stations and power station buildings. However, this also allows the medium and high-frequency noise generated by internal air compressors, refrigeration machines, etc. to be transmitted to the outdoors through these ventilation windows with almost no loss, seriously interfering with the work of nearby personnel.

[0004] Conventional ventilation and sound-absorbing shutters require the shutters to be hollow (filled with a sound-absorbing porous material) or have sound-absorbing material attached to their surfaces. However, since power stations and air compressor stations are located outdoors, the sound-absorbing shutters on their exterior walls are susceptible to reduced sound absorption due to rain and dust (rainwater and dust adhere to the shutter surfaces and the sound-absorbing material in the cavities, reducing the original sound absorption capacity). Furthermore, the design of conventional shutters means that in some cases, rainwater can enter the room through the shutters' ventilation channels, causing water to accumulate inside the power station or air compressor station, posing a safety hazard.

[0005] Chinese invention patent publication number CN112347594B discloses a folded-duct broadband noise reduction structure and its design method. This structure is installed on the ventilation path sidewalls of naturally ventilated staggered soundproof windows. Each folded-duct unit is composed of two coupled rectangular ducts with different cross-sectional areas. Multiple folded-duct units designed for different frequencies can achieve broadband noise reduction for noise entering the window. This structure effectively improves the low-frequency noise reduction of staggered soundproof windows. Compared to traditional active control technologies for low-frequency noise reduction, this structure is easy to install, has a simple system, and operates stably. It also reduces noise at mid- and high-frequency levels.

[0006] Although the above-mentioned device achieves the effect of sound insulation and noise reduction through multiple folded pipe units with sudden changes in cross-section, its structure requires the use of multiple folded pipe units in conjunction with each other, which is bulky and increases the total length of the internal and external gas exchange flow, hindering the rapid exchange of internal and external gases and reducing ventilation and heat exchange efficiency. Summary of the Invention

[0007] Purpose of the invention: The purpose of the present invention is to provide a ventilation and sound-absorbing window for medium and high frequency noise that can achieve noise reduction without reducing ventilation and heat exchange efficiency and has a small size.

[0008] Technical solution: The ventilation and sound-absorbing window for medium and high-frequency noise described in the present invention includes an upper window frame and a lower window frame. A row of multiple concave blades are provided on the inner and outer sides between the upper and lower window frames. The two sides of any blade on either side are respectively embedded in the grooves of two adjacent blades on the other side. The upper and lower window frames and the blades on both sides form a plurality of channels for connecting the inside and outside and with scalable cross-sectional areas.

[0009] The present application arranges a row of multiple concave blades at intervals on both the inside and outside. These blades are relatively staggered and embedded in each channel connecting the inside and outside, which is surrounded by the upper and lower window frames. Theoretically, there can be a design with five cross-sectional mutations. These five cross-sectional mutations can be specifically achieved by changing the spacing between the adjacent sides of two adjacent outer blades, the spacing between the side ends of the outer blades and the bottom of the inner blade groove, the side spacing between the inner and outer adjacent blades, the spacing between the side ends of the inner blades and the bottom of the outer blade groove, and the spacing between the adjacent sides of two adjacent inner blades. According to the principle of the resistive silencer, "noise will be reflected and attenuated when passing through the cross-sectional mutation channel during propagation, thereby weakening the noise propagating outward", it can be seen that the channel designed in the present application can achieve effective noise reduction. Moreover, thanks to the relatively staggered embedding structure of multiple concave blades on the inside and outside, the present application can achieve more cross-sectional mutations in a shorter length, thereby achieving effective noise reduction in a smaller volume, greatly saving installation space. At the same time, there can be multiple inlets and outlets on the inside and outside, which can maintain efficient ventilation and heat exchange inside and outside while reducing noise.

[0010] Preferably, the length W2 between the inner and outer blades is the same, the adjacent side spacing between two adjacent outer blades is the same as the adjacent side spacing d1 between two adjacent inner blades, and the value range of d1 is

[0011] The zigzag channel formed by the staggered arrangement of the inner and outer concave structure blades can effectively weaken the noise propagating outward. Considering the air flow resistance of the silencer window, if d1, that is, the width of the air inlet or exhaust channel, is too large, the flow cross-section of the air inlet or exhaust will be too small, which will greatly increase the flow resistance. Considering the balancing of the silencer and ventilation functions of the silencer window, the value range of the channel width d1 is limited to Through simulation test calculation, it is verified that when d1 changes within this range, when the weighted sound attenuation (Rw) of the anechoic window changes within ±1dB, the increase in flow resistance is within 20%; but when When d2=W2, the flow resistance will increase by 2 to 3 times compared with the silencer window structure within the specified range, because 2*d2+d1=W2. It can be directly seen from the formula that when it is greater than the threshold, the corresponding d2 is less than 1 / 4*W2. If d2 is too small, the flow velocity will surge accordingly, which will increase the resistance.

[0012] Preferably, the distance d2 between the adjacent sides of the inner blade and the outer blade satisfies

[0013] This arrangement is equivalent to symmetrically arranging two outflow channels of the same width on both sides of the channel formed by two adjacent inner blades, so that the gas can flow evenly to both sides to achieve uniform heat dissipation.

[0014] Preferably, the distance d3 between the side end of the inner blade and the bottom of the outer blade groove into which it is embedded is in the range of

[0015] The width d3 of the flow section is within the range of the width d1 of the air inlet or exhaust channel. On the one hand, a sudden change in the flow cross-section can be formed, thereby increasing the reflection and attenuation of noise and strengthening the noise reduction ability of the designed silencer window; on the other hand, considering the flow resistance, the width d3 of the contracted flow cross-section cannot be too small to avoid excessive flow resistance of the silencer window, which affects the ventilation capacity of the silencer window. Simulation verification shows that when d3 is within this range, a relative balance between noise reduction and flow resistance can be achieved.

[0016] Preferably, the top of the lower window frame is provided with a slope gradually decreasing from the inside to the outside along the channel.

[0017] Through the above design, rainwater splashing on the inside can be drained to the outside during rainfall, preventing rainwater from accumulating on the inside and causing safety hazards.

[0018] Preferably, the lower window frame is provided with a slope gradually decreasing from the inside to the outside on the inner side of the inner blade and the outer side of the outer blade.

[0019] This design can further guide the rainwater on the inside to the outside, preventing rainwater from remaining inside.

[0020] Preferably, the bottom of the upper window frame is provided with a slope that gradually decreases from the inside to the outside.

[0021] The upper window frame is provided with a slope that gradually decreases from the inside to the outside, which can also guide the rainwater on the inside to the outside.

[0022] Beneficial effect: By installing multiple relatively staggered and embedded concave blades on the inside and outside and forming multiple channels connecting the inside and outside with the upper and lower window frames, multiple cross-sectional mutations can be achieved in a shorter length to achieve limited noise reduction, while reducing the size of the device and retaining multiple air inlets and outlets, maintaining high ventilation and heat dissipation efficiency while reducing noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 for Figure 1 Cross-sectional view in the AA direction;

[0025] Figure 3 This is a schematic diagram of the local structure of the lower window frame;

[0026] Figure 4 This is a side view of the upper window frame. DETAILED DESCRIPTION

[0027] As shown in the figure, the ventilation and sound-absorbing window for medium and high-frequency noise described in the present invention includes an upper window frame 1 and a lower window frame 2. A row of multiple concave blades 3 are provided on the inner and outer sides between the upper and lower window frames. The two sides of any blade 3 on either side are respectively embedded in the grooves of two adjacent blades 3 on the other side. The upper and lower window frames and the blades 3 on both sides form a plurality of channels for connecting the inside and outside and with scalable cross-sectional areas.

[0028] The upper window frame 1 and the lower window frame 2 can be made of rectangular plates, and the bottom of the upper window frame 1 is provided with a slope that gradually decreases from the inside to the outside.

[0029] The blades 3 are arranged in a row on the inner and outer sides, and the inner and outer blades 3 are distributed at equal intervals. The inner and outer blades 3 are relatively staggered and embedded. Specifically, the two sides of any blade 3 on any side are respectively embedded in the grooves of the two adjacent blades 3 on the other side (see Figure 2 ); The two adjacent side edges of the two adjacent inner blades 3 form an air outlet, which can be used as an air inlet for the inner airflow to be discharged outward, or as an air outlet for the outer airflow to enter the inner side. For the airflow discharged from the inside to the outside, after passing through the air outlet, it enters the groove of the outer blades 3 embedded in the two side edges and flows out in the left and right directions, and is discharged from the two air outlets formed by the side edges of the outer blades 3 on the left and right sides of the groove.

[0030] Better noise reduction and ventilation effects can be achieved when the sizes of the inner and outer blades 3 and the distances between them meet the following conditions:

[0031] The side length W1 of the outer blade 3 and its middle length W2 meet The length W2 between the inner and outer blades 3 is the same, the adjacent side spacing between two adjacent outer blades 3 is the same as the adjacent side spacing d1 between two adjacent inner blades 3 (if these two spacings are not equal, there will be two cross-sectional mutations), and the value range of d1 is The distance d2 between the adjacent sides of the inner blade 3 and the outer blade 3 satisfies The range of the distance d3 between the side end of the inner blade 3 and the bottom of the groove of the outer blade 3 into which it is embedded is Through simulation experiments, when the inlet flow rate is 0.3m / s, d3=0.4*d1, flow resistance is 20Pa, and the weighted sound attenuation and sound insulation is 15.2dB; d3=0.8*d1, flow resistance is 0.56Pa, and the weighted sound attenuation and sound insulation is 4.5dB, it can be seen that when d3 is within the range set in this application, a relative balance between sound attenuation and flow resistance can be achieved.

[0032] The side length W3 of the inner blade 3 satisfies W3=W1+d1-d3, where W1 is the side length of the outer blade 3;

[0033] Combining all the above restrictions, if According to the value range of d1 and d2, we can get However, the blades of this muffler window are many, so the value of W2 will not be very large, which will result in the width d2 of the flow channel formed by the adjacent sides of the inner blades and the outer blades being too small, and it is impossible to form an effective muffler tortuous muffler channel, so it is necessary to limit

[0034] According to the above definition, it can be determined that the distance d4 between the side end of the outer blade 3 and the bottom of the groove of the inner blade 3 satisfies d4=d1. According to d1-d4, it can be seen that theoretically there are four opportunities for cross-sectional mutation in the noise wave transmission path (that is, in the channel connecting the inside and the outside). However, the design of this embodiment has three cross-sectional mutations to take into account both sound absorption and ventilation.

[0035] In actual use, only half of the outer blades 3 at the leftmost and rightmost ends can be retained, and then a vertical board is set at the leftmost and rightmost ends to form a channel with the inner blades 3. This can maintain the uniformity of the channel and also close the left and right ends of the soundproof window to block rain.

[0036] The blade 3 can be made of a metal plate with a thickness of ≥0.5 mm, which is strong enough to be not easily damaged, and can achieve effective noise reduction and silencing without the need to attach any porous sound-absorbing material to its surface.

[0037] The top of the lower window frame 2 is provided with a slope gradually decreasing from the inside to the outside along the channel; the lower window frame 2 is provided with a slope gradually decreasing from the inside to the outside on the inner side of the inner blade 3 and the outer side of the outer blade 3. Note that the slopes at these two places must be connected with the slopes in the channel, and no faults should appear to hinder the flow of rainwater. In short, the slope designed for the window frame 2 is used to divert the rainwater from the inside to the outside to prevent rainwater from accumulating inside.

[0038] The slope angles of the upper and lower window frames can both be designed to be 1° to 3°.

[0039] In order to better illustrate the effect of this sound-absorbing window, the following is further explained through specific experimental data.

[0040] The 1 / 1OCT sound insulation data of the anechoic window calculated by numerical simulation is shown in Table 1:

[0041] Table 1 Noise reduction results

[0042]

[0043] As can be seen from Table 1 above, the weighted sound insulation of the soundproof window of the present invention is 14.5 dB, and the sound insulation effect of the medium and high frequencies is ≥12 dB. According to the standard GB / T 50121-2005 "Building Sound Insulation Evaluation Standard", the sound insulation of the present invention is calculated to be RW+Ctr=34.6 dB, reaching the level 3 standard for airborne sound insulation performance; at the same time, according to the standard T / CAEPI 38-2021 "Technical Requirements for Ventilated Soundproof Windows", the design of the present invention reaches the level 5 standard for sound insulation of ventilated soundproof windows in the ventilated state.

[0044] Numerical simulation is also used to calculate the pressure drop of the present invention under different inlet gas flow rates. During the simulation calculation process, the inlet gas flow rate is uniform, and the inlet gas flow rate ranges from 0.1m / s to 1.0m / s with a step size of 0.1m / s. The pressure drop variation of the silencer window is shown in Table 2 below:

[0045] Table 2 Pressure drop change table

[0046]

[0047] According to the standard T / CAEPI 38-2021 "Technical Requirements for Ventilated Soundproof Windows", the ventilation rate of the soundproof window of the present invention under natural ventilation state (pressure difference between the inside and outside of the ventilated soundproof window is 3Pa) is calculated from Table 2 above to be 820m3 / h. The design of the present invention meets the standard ventilation rate level 6 of the natural ventilation soundproof window.

[0048] The soundproofing window of this invention is simple to manufacture and maintain, has a long service life, and is suitable for outdoor weather conditions such as high temperatures, rain, and dust. The zigzag, converging and expanding channels formed by the concave inner and outer blades provide high sound insulation against medium and high-frequency noise, resulting in excellent sound insulation performance. The upper and lower window frames of this design also feature sloped structures to drain rainwater that adheres to the blades to the outside, preventing it from entering the room and causing water accumulation.

Claims

1. A ventilation and sound-absorbing window for medium and high frequency noise, comprising an upper window frame (1) and a lower window frame (2), characterized in that: A row of multiple concave blades (3) are arranged at intervals on the inner and outer sides between the upper and lower window frames, and the two sides of any blade (3) on either side are respectively embedded in the grooves of two adjacent blades (3) on the other side. The upper and lower window frames and the blades (3) on both sides form multiple channels for connecting the inner and outer sides and with scalable cross-sectional areas.

2. The ventilation and sound-absorbing window according to claim 1, characterized in that: The side length W1 of the outer blade (3) and its middle length W2 satisfy 3. The ventilation and sound-absorbing window according to claim 1, characterized in that: The length W2 between the inner and outer blades (3) is the same, the adjacent side spacing between two adjacent outer blades (3) is the same as the adjacent side spacing d1 between two adjacent inner blades (3), and the value range of d1 is 4. The ventilation and sound-absorbing window according to claim 3, characterized in that: The distance d2 between the adjacent sides of the inner blade (3) and the outer blade (3) satisfies 5. The ventilation and sound-absorbing window according to claim 3, characterized in that: The range of the distance d3 between the side end of the inner blade (3) and the bottom of the groove of the outer blade (3) into which it is embedded is 6. The ventilation and sound-absorbing window according to claim 5, characterized in that: The side length W3 of the inner blade (3) satisfies W3=W1+d1-d3, wherein W1 is the side length of the outer blade (3).

7. The ventilation and sound-absorbing window according to claim 1, characterized in that: The top of the lower window frame (2) is provided with a slope that gradually decreases from the inside to the outside along the channel.

8. The ventilation and sound-absorbing window according to claim 7, characterized in that: The lower window frame (2) is provided with a slope surface gradually decreasing from the inside to the outside on the inside of the inner blade (3) and the outside of the outer blade (3).

9. The ventilation and sound-absorbing window according to claim 1, characterized in that: The bottom of the upper window frame (1) is provided with a slope that gradually decreases from the inside to the outside.

10. The ventilation and sound-absorbing window according to claim 9, characterized in that: The slope angle of the slope is 1° to 3°.

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