阅读说明：本技术 可使消声器入射噪声波长变短的装置 (Device capable of shortening incident noise wavelength of silencer ) 是由 谭志华 余多萍 于 2020-05-25 设计创作，主要内容包括：一种结构简单、通过降低气流温度来提高消声器降噪量的可使消声器入射噪声波长变短的装置。在消声器的气流入口端设有可对入射气流温度进行降温并随之使入射噪声波长变短的降温装置,入射气流穿过该降温装置进入消声器。通过降低入射气流的温度,使随入射气流传播至消声器内的入射噪声的声波波长也随之变短,大大降低了入射噪声的穿透能力,从而有效避免该入射噪声穿过消声器的外壳壳壁传播到环境中造成再次声污染,由于入射噪声的波长缩短,其可被设置于消声器内的吸声材料更好的吸收,因此也变相的提高了该消声器的降噪量。其采用两种降温装置,分别为喷水雾化和换热器,根据入射气流的温度的高低来选择上述两种降温装置。(A device which has a simple structure and can shorten the wavelength of incident noise of a silencer by reducing the temperature of air flow to increase the noise reduction amount of the silencer. The inlet end of the air flow of the silencer is provided with a cooling device which can cool the temperature of the incident air flow and then shorten the wavelength of the incident noise, and the incident air flow passes through the cooling device and enters the silencer. The temperature of the incident air flow is reduced, so that the wave length of the incident noise transmitted into the silencer along with the incident air flow is shortened, the penetrating power of the incident noise is greatly reduced, the incident noise is effectively prevented from being transmitted into the environment through the shell wall of the silencer to cause secondary sound pollution, and the incident noise can be better absorbed by a sound absorption material arranged in the silencer due to the shortened wave length of the incident noise, so that the noise reduction amount of the silencer is improved in a phase-changing manner. The two cooling devices are respectively a water spray atomizer and a heat exchanger and are selected according to the temperature of incident airflow.)

1. An apparatus for shortening the wavelength of the noise incident on a muffler, comprising: the temperature reducing device (2) capable of reducing the temperature of incident airflow and shortening the wavelength of incident noise is arranged at the airflow inlet end of the silencer (1), and the incident airflow passes through the temperature reducing device (2) and enters the silencer (1).

2. The apparatus for shortening the wavelength of the noise incident on the muffler according to claim 1, wherein: the cooling device (2) adopts a water mist cooling structure (3).

3. The apparatus for shortening the wavelength of the noise incident on the muffler according to claim 2, wherein: water smoke cooling structure (3) comprise casing (6), delivery pipe (31), grid formula air current passageway (32) and water smoke shower nozzle (33), casing (6) are the cylindric, and its inner links as an organic wholely with silencer (1) shell (11), is equipped with a plurality of baffle (34) that extend along the bobbin shaft direction in casing (6), and all baffle (34) constitute a plurality of grid formula air current passageway (32) through the cross arrangement, lay one in every grid formula air current passageway (32) and can make water atomizing shower nozzle (33), delivery pipe (31) pass casing (6) stretch into in a section of thick bamboo and communicate with all shower nozzles (33).

4. The apparatus for shortening the wavelength of the noise incident on the muffler according to claim 3, wherein: the section shape of the shell (6) is the same as that of the shell (11) of the silencer (1), and the section shape of the grid type airflow channel (32) is a quadrangle, a circle, a fan or a figure formed by intersection of two concentric circles and the fan.

5. The apparatus for shortening the wavelength of the noise incident on the muffler according to claim 4, wherein: the thickness of the clapboard (34) is 2mm-5mm, and the length of the clapboard (34) is 200mm-1000 mm.

6. The apparatus for shortening the wavelength of the noise incident on the muffler according to claim 1, wherein: the cooling device (2) is a heat exchanger (4) with fins (42), the heat exchanger (4) is fixedly connected in a hollow shell (6) with two open ends, and incident airflow enters the silencer (1) through gaps between the fins (42).

7. The device that can shorten the wavelength of the noise incident on the muffler according to any one of claims 1 to 6, characterized in that: a temperature sensor (5) is arranged between the airflow inlet end of the silencer (1) and the cooling device (2).

8. The apparatus for shortening the wavelength of the noise incident on the muffler according to claim 7, wherein: the shell (6) is made of stainless steel, titanium or carbon galvanized steel plate, and the length of the shell is 350-1150 mm.

9. The device capable of shortening the wavelength of an incident noise of a muffler according to any one of claims 3 to 5, wherein: the distance between two adjacent spray heads is 100-400 mm.

Technical Field

The invention relates to a large silencer, in particular to a temperature reducing device for reducing the wavelength of incident noise by reducing the temperature of incident airflow.

Background

The most basic performance evaluation indexes of the silencer are as follows: insertion loss (sound transmission loss) is colloquially referred to as "noise reduction amount". The silencer mainly plays a role in silencing and reducing noise, and the performance is better when the performance parameter is larger.

Disclosure of Invention

The invention aims to provide a device which has a simple structure, improves the noise reduction amount of a silencer by reducing the temperature of air flow and can shorten the incident noise wavelength of the silencer.

In order to solve the technical problems, the invention adopts the technical scheme that:

the invention provides a device capable of shortening incident noise wavelength of a silencer, which is characterized in that: the temperature reducing device capable of reducing the temperature of incident airflow and shortening the wavelength of incident noise is arranged at the airflow inlet end of the silencer, and the incident airflow penetrates through the temperature reducing device and enters the array silencer.

The cooling device adopts a water mist cooling structure.

The water mist cooling structure is composed of a shell, a water supply pipe, grid type airflow channels and water mist nozzles, wherein the shell is cylindrical, the inner end of the shell is connected with the shell of the silencer into a whole, a plurality of partition plates extending along the direction of a cylinder shaft are arranged in the shell, all the partition plates form a plurality of grid type airflow channels through cross arrangement, one nozzle capable of atomizing water is arranged in each grid type airflow channel, and the water supply pipe penetrates through the shell to extend into the cylinder and is communicated with all the nozzles.

The section shape of the shell is the same as that of the silencer shell, and the section shape of the grid type airflow channel is a quadrangle, a circle, a fan or a figure formed by intersection of two concentric circles and the fan.

The thickness of the partition board is 2mm-5mm, and the length of the partition board is 200mm-1000 mm.

The cooling device is a heat exchanger with fins, the heat exchanger is fixedly connected in a hollow shell with two open ends, and the incident airflow enters the silencer from gaps among the fins.

A temperature sensor is arranged between the airflow inlet end of the silencer and the cooling device.

The shell is made of stainless steel, titanium or carbon galvanized steel and the length of the shell is 350-1150 mm.

The distance between two adjacent spray heads is 100-400 mm.

The device capable of reducing the temperature of the incident airflow is arranged at the airflow inlet end of the silencer, so that the wavelength of the incident noise transmitted into the silencer along with the incident airflow is shortened along with the temperature of the incident airflow, the penetrating power of the incident noise is greatly reduced, the incident noise is effectively prevented from being transmitted into the environment through the shell wall of the silencer to cause secondary sound pollution, and the incident noise can be better absorbed by the sound absorption material arranged in the silencer due to the shortened wavelength of the incident noise, so that the noise reduction amount of the silencer is improved. The invention adopts two cooling devices, namely a water spray atomizer and a heat exchanger, which are selected according to the temperature of incident airflow.

Drawings

FIG. 1 is a schematic sectional view of a vertical muffler adopting a water mist cooling structure.

Fig. 2 is a schematic sectional view of a vertical muffler adopting a heat exchanger cooling structure.

Fig. 3 is a schematic sectional view of a water mist cooling structure adopted on the horizontal muffler.

Fig. 4 is a schematic plan view of several water mist cooling structures with different spray head layouts.

Fig. 5 is a schematic cross-sectional structure of several muffling segments.

The reference numbers are as follows:

the device comprises a silencer 1, a shell 11, a sound absorber or sound absorption layer 12, a temperature reduction device 2, a water mist temperature reduction structure 3, a water supply pipe 31, an air flow channel 32, a nozzle 33, a partition plate 34, a heat exchanger 4, a refrigerant circulating pipe 41, fins 42, a temperature sensor 5 and a shell 6.

Detailed Description

The device for shortening the wavelength of the incident noise of the silencer according to the invention is mounted at the air inlet end of the silencer 1, and can be of a separate construction from the prior art silencer (the separate construction has the advantage of being produced, transported and assembled after being transported to the site), or can be designed as an integral construction with the prior art silencer (the advantage of having stable silencing performance), the latter being preferred by the invention.

The silencer 1 with the device can be arranged vertically or horizontally (as shown in figures 1-3), and the silencer 1 matched with the device is basically a large silencer and is used for being installed in places with high noise, such as urban subway underground works, mine deep wells, tunnels, places where large central air-conditioning units are located, and the like. The types of mufflers involved may be of the square cross-sectional shape, the plate type, the array type, the honeycomb type, the return type, the circular pipe type, the circular core type, the plate type and the cross core type (see fig. 5).

The muffler 1 is composed mainly of an outer shell 11 and a sound absorber or sound absorbing layer 12 disposed inside the outer shell 11.

The noise entering the muffler 1 with the air flow is hereinafter referred to as incident noise.

The cooling device 2 used in the device capable of shortening the wavelength of the incident noise of the silencer 1 of the invention is composed of the following two types:

1. water mist cooling structure 3

Consists of a shell 6, a water supply pipe 31, a grid type airflow channel 32 and a water mist spray head 33.

1) Housing 6

The section profile wheel follows the shape of the shell 11 of the muffling segment and is connected with the shell 11 of the muffling segment into a whole.

The shell 6 is made of stainless steel, titanium material or carbon galvanized steel plate, the thickness of the shell is consistent with that of the shell 11 of the muffling segment, and the length is preferably 350mm-1150 mm. Mainly provides an internal space for installing the water supply pipe 31, the grid type airflow channel 32 and the water mist spray head 33 and provides a space environment for cooling incident airflow, thereby better achieving the cooling effect.

2) Water supply pipe 31

Preferably, stainless steel pipes are selected, the caliber of a main pipe of each water pipe is preferably DN25-DN50mm, the caliber of a branch pipe is preferably DN8-DN25mm, the caliber of the branch pipe is consistent with the caliber of the spray head 33, the wall thickness of the water pipe is 2-3mm, the water pipe penetrates through the shell 6, the water pipes are reasonably arranged according to the distribution of the spray head 33, and the water pipes mainly play a role in supplying water for the spray head 33.

3) Grille-type airflow passage 32

The structure is characterized in that a plurality of criss-cross partition plates 34 are arranged in a shell 6, a plurality of airflow channels 32 are arranged in the shell 6, each airflow channel 32 is formed by four partition plates 34 in a surrounding mode, the partition plates 34 extend from an inlet end to an outlet end of the shell 6, the length of each partition plate is 200mm-1000mm, the thickness of each partition plate 34 is 2mm-5mm, and each partition plate is made of stainless steel, copper or carbon galvanized steel plates.

In each air flow channel 32, a spray head 33 for atomizing water is arranged, the spray head 33 preferably being arranged in the center of the air flow channel 32 and close to the outer end of the housing 6, the water outlet direction of the spray head 33 being directed towards the muffler 1. The water supply pipe 31 passes through the housing 6 to communicate with the corresponding shower head 33 through the branched water supply pipe 31.

The incident airflow passes through the long and narrow airflow channel 32, and can be contacted with the water mist to exchange heat more fully, so that the cooling effect is improved, and meanwhile, the wavelength of the incident noise synchronously passing through the airflow channel 32 along with the incident airflow is shortened under the condition that the ambient temperature in the airflow channel 32 is reduced.

The cross-sectional shape of the gas flow passage 32 is a quadrangle, a circle, a fan, or a figure formed by the intersection of two concentric circles and a fan (see fig. 4).

4) Water mist head 33

The spray heads 33 are made of stainless steel, copper or carbon galvanized steel plates, can be solid cone spray heads, spiral spray heads, hollow cone spray heads and the like, the caliber is preferably DN8-DN25mm, the spray grain diameter is preferably 50-500 mu m, the spray angle is 60-150 ℃, and the distance between two adjacent spray heads 33 is 100-400 mm.

The arrangement of all the spray heads 33 is adjusted adaptively according to the sectional shape of the casing 6, as shown in fig. 4, which is a diagram of several arrangement structures.

5) Temperature sensor 5

In order to know the temperature of the incident airflow to be cooled down in time, a temperature sensor 5 is arranged between the airflow inlet end of the silencer 1 and the cooling device 2. And the temperature of the air flow after the water spraying and cooling is monitored in real time so as to ensure that the purpose of cooling is achieved.

The water mist cooling structure 3 is more suitable for the condition that the temperature of the incident airflow is higher than 100 ℃, and the generated water mist is easy to evaporate at the temperature, so that a better heat exchange effect can be achieved.

2. Finned heat exchanger 4

The heat exchanger is fixedly connected in a shell 6 with two open ends and a hollow end, the shape of the section of the shell 6 is the same as that of the section of the silencer 1, and the shell 6 is fixedly connected with a shell 11 of the silencer 1, and a separated structure or an integrated structure can be arranged between the shell 6 and the shell.

The heat exchanger 4 is a heat exchanger with fins 42, and the refrigerant circulation pipe 41 in the heat exchanger 4 may be a corrosion-resistant metal pipe such as a steel pipe, a stainless steel pipe, or a copper pipe.

The fins 42 may also be made of steel, stainless steel, copper or aluminum strips. The heat exchanger 4 is filled with low-temperature liquid to absorb heat so as to reduce the inlet air temperature of the silencer 1.

The fins 42 run parallel to the axis of the housing 6, i.e. the incident airflow can pass through the gaps between adjacent fins 42, thus effectively reducing the temperature of the incident airflow.

Also, a temperature sensor 5 is provided between the heat exchanger 4 and the airflow inlet end of the muffler 1.

The heat exchanger 4 with the fins 42 is suitable for use when the incident airflow is at normal temperature and normal pressure.

3. Principle of shortening incident noise wavelength by reducing air flow temperature

The longer the acoustic wave wavelength of the incident noise is, the stronger the incident acoustic wave penetrating power is, and the lower the noise reduction amount of the muffler is, whereas the shorter the acoustic wave wavelength of the incident noise is, the weaker the incident acoustic wave penetrating power is, and the higher the noise reduction amount of the muffler is.

The sound-deadening performance of the muffler is often lower in sound transmission loss at low sound wave frequencies (longer wavelengths) than at high frequencies, and the noise reduction effect is worse. For example, at normal temperature and pressure, a certain sheet type muffler has a wavelength of incident noise corresponding to a sound transmission loss of 11dB at a low frequency (for example, at a sound wave frequency of 63 Hz) of 5.4m, and a wavelength of incident noise corresponding to a sound transmission loss of 17dB at a higher frequency (for example, at a sound wave frequency of 125 Hz) of 2.72 m.

From the relationship of the speed of sound c to the temperature t: c 2.05(273+ t)^1/2And speed of sound c, frequency f, and wavelength λ: f is known as c/λ:

the higher the ambient temperature t, the greater the speed of sound through the environment, and the wavelength of the incident sound wave is proportional to the speed of the sound wave when the frequency of the sound wave is constant. The higher the temperature, the longer the incident acoustic wave wavelength.