CN101782008B - Muffler based on sound ray deflection theory - Google Patents
Muffler based on sound ray deflection theory Download PDFInfo
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- CN101782008B CN101782008B CN2010101197979A CN201010119797A CN101782008B CN 101782008 B CN101782008 B CN 101782008B CN 2010101197979 A CN2010101197979 A CN 2010101197979A CN 201010119797 A CN201010119797 A CN 201010119797A CN 101782008 B CN101782008 B CN 101782008B
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Abstract
The invention relates to a muffler based on a sound ray deflection theory, which comprises a muffler shell, a low-temperature refrigerating system and a temperature controller. The inner wall of the muffler shell is coated with a sound-absorbing material or structure, and the low-temperature refrigerating system is installed on the outer wall of the muffler shell. A low-temperature refrigerating system pipeline covers at least 5% of the area of an airflow pipeline outer wall. In the invention, the low-temperature refrigerating system is installed on the muffler, a greater (1-2,000 DEG C) temperature gradient is generated corresponding to the high temperature in the airflow pipeline, the sound rays are bent and deflected towards a cool end which refers to the sound-absorbing material and structure at the inner wall of the airflow pipeline so as to reduce the passed sound wave components not contacted with the sound-absorbing material or structure of the muffler in a muffler pipeline, increase the efficient absorption of noises in the pipeline and reduce the radiated noise. The invention can be applied to the muffler design of an aviation turbofan engine nacelle and an air charging/discharging pipeline system, such as a helicopter shaft turbine noise-elimination duct, a gas turbine and the like, and other environmental conditions where are convenient to and allow to provide the low-temperature refrigerating system at the cool end.
Description
Technical field
The present invention relates to a kind of silencing apparatus, particularly a kind of silencing apparatus based on sound ray deflection theory.
Background technique
In recent decades, air transportation has brought great trip convenient to people, but pollutes also for simultaneously the severe noise of bringing around the airport, and according to investigations, the noise of aircraft is mainly reflected in and takes off and when landing, and is the most remarkable when taking off especially.Because the airport is generally not far from the city, and the course line is also partly through the sky, city, aircraft noise has become the important component part of city noise at present, have a strong impact on people's normal life, so, reduce the aircraft flight noise to greatest extent, particularly take off, the noise when landing, become extremely urgent, anxious to be solved problem.
As everyone knows, aircraft noise mainly comes from the jet noise and the fan noise of aeroengine.In broad frequency band, have the good sound absorption effect so the researcher is striving to find always, reduce the method for jet noise and fan noise, following method and the design criterion generally taked at present:
1, adopts high bypass ratio motor and orifice design, reduce jet noise.
2, adjust fan propeller/stator blade design and speed, reduce fan noise.
3, tube wall lays the sound lining, reduces the engine radiation noise.
Lining has had effect preferably aspect noise reduction although the aeroengine tube wall lays sound, still can't satisfy the actual demand of present aircraft noise control, the control of peripheral region, airport ambient noise and noise seaworthiness.It is reported that Airbus SAS just drops into a large amount of funds, participate in the aircraft noise project that European 9 states initiate, emphasis is captured the aircraft noise reduction technology, and target is in the time in 8 years the aircraft of its production just to be reduced by 6 decibels on existing effective noise floor.In fact, from the average noise reduction amplitude of aircraft noise, per 10 annual mean noise reductions are also less than 8dB.
And present aspect the research of muffler design, only considered Temperature Influence, and do not considered that silencing apparatus inside exists temperature gradient to cause the influence for raising silencing apparatus sound deadening capacity of sound ray deviation, such as document: the numerical analysis of perforated tube silencer, Zhu Helin, Liu Zhengshi, noise and vibration control journal, in June, 2008, the 3rd phase, the test of muffler for motor static properties and analysis and research, Wang Xiaojun, Li Zhiyuan, Wei Haozheng, noise and vibration control journal, in August, 2007, the 4th phase.
Use existing ways and means want to realize airplane engine significantly noise reduction seemed that some is unable to do what one wishes, because under the high sound intensity environment, the medium and low frequency noise often can not get effective control, strengthen its absorption, just must significantly increase the sound absorption structure cavity depth, and this can't accomplish in actual noise reduction often.Therefore, be necessary existing aeroengine tube wall sound lining acoustical absorptivity is deeply taped the latent power, strive under the situation of existing acoustic wave filter structure not being changed substantially, exploring the method and the measure that further improve the existing tube wall sound lining of aeroengine sound absorbing capabilities.
Below the influence that just atmospheric sound propagation produced from the natural temperature gradient obtain the present invention's enlightenment.By day, the environment around we can feel seems noisy, noisy, but at night, it is special quiet that environment on every side then can seem.That is that the velocity of sound and temperature are closely related because temperature gradient is very big to the influence of acoustic wave propagation, and temperature gradient makes the above velocity of sound in ground occur changing.By day, particularly at fine day, afternoon under the solar radiation, from ground significant negative temperature gradient is arranged upwards, make surface temperature be higher than atmospheric temperature, the ground velocity of sound is big, the overhead velocity of sound is little, and according to the optics Fermat's theorem, sound can be along the shortest time-consuming steepest propagated.Like this, by day, sound ray can be to " cold junction "--the crooked refraction of sky, although can occur " sound shadow zone " simultaneously, but upwards the sound ray of refraction contacts with ground hardly, the earth can not get performance as one " sound absorption structure " effect, thereby daytime, we can feel the clamour of surrounding environment and noisy.Situation at night is then different, the positive temperature gradient that makes progress from ground, make surface temperature be lower than atmospheric temperature, the ground velocity of sound is little, the overhead velocity of sound is big, according to the optics Fermat's theorem, sound ray can be to " cold junction "--the crooked deviation in ground, when airborne sound wave incides this porosity ground only in some reflected back atmosphere, most of energy absorbs by the hole propagation of soil and by the earth soil and decays, under the temperature gradient effect of the earth at night as cold junction, the effect of the earth " sound absorption structure " is fully played just, and let us is felt the quietness of surrounding environment.In addition, descend in a snow day situation, under the temperature gradient effect of the earth as cold junction, we also can experience quiet that the earth " snowberg cold junction sound absorption structure " brings.Day temperature with highly successively decrease and nocturnal temperature with highly increase progressively under the condition sound ray deviation situation as shown in Figures 2 and 3.
From the example that the natural temperature gradient exerts an influence to atmospheric sound propagation, we can draw: sound ray can be towards " cold junction " direction deviation under the temperature gradient effect.This just catches for utilization of the present invention " cold trap " and reduces noise, that is: utilize the acoustical absorptivity that causes the silencing apparatus with cryogenic refrigerating system of sound ray deflection theory further to improve existing silencing apparatus based on temperature gradient to bring enlightenment and Gospel.
Summary of the invention
The objective of the invention is to: be intended to improve existing airplane engine silencing apparatus acoustical absorptivity, by existing silencing apparatus pipeline outer wall is installed cryogenic refrigerating system, silencing apparatus tube wall temperature gradient inside or outside of extra generation, temperature is greater than outside the tube wall in the tube wall, utilize temperature gradient that the sound ray in the tube wall is produced to the silencing apparatus pipeline outer wall direction deviation that cryogenic refrigerating system is installed, allow more sound ray with oblique incidence but not the Grazing incidence form entered in the sound absorption structure of silencing apparatus liner, reduce silencing apparatus inside and be excited the amplitude of acoustics normal mode vibration pattern, increase the sound deadening capacity of aviation turbofan engine nacelle noise elimination structure, in the hope of more effectively controlling the airport ambient noise, satisfy the noise airworthiness requirement better; Thereby provide a kind of silencing apparatus based on sound ray deflection theory.
To achieve these goals, the invention provides a kind of silencing apparatus, comprise the housing 1 of a silencing apparatus, lay sound-absorbing material or sound absorption structure device 4 at described housing 1 inwall based on sound ray deflection theory; It is characterized in that: cryogenic refrigerating system 2 is installed on described housing 1 outer wall, and described cryogenic refrigerating system is to make to have 1 ℃-2000 ℃ temperature gradient between the silencing apparatus inner and outer walls of pipeline, and the temperature in the pipeline is greater than the temperature of pipeline outer wall cold junction;
Described cryogenic refrigerating system 2 should cover at least silencing apparatus housing outer wall area 5%.
The invention provides a kind of silencing apparatus, comprise the housing 1 of a silencing apparatus, lay sound-absorbing material or sound absorption structure device 4 at described housing 1 inwall based on sound ray deflection theory; It is characterized in that: also comprise a temperature control apparatus, cryogenic refrigerating system 2 is installed on described housing 1 outer wall, described cryogenic refrigerating system 2 connects with temperature control apparatus 3; The temperature control apparatus of described cryogenic refrigerating system should ensure and have 1-2000 ℃ temperature gradient between the silencing apparatus inner and outer walls of pipeline, and the temperature in the pipeline is greater than the temperature of pipeline outer wall cold junction.
In the technique scheme, the sound-absorbing material and the structure of described housing 1 inwall, can be porous sound-absorbing material, also can be resonance sound-absorbing structure for sheet, film resonance sound-absorbing structure, sound absorbent perforated structure, microperforated panel soundabsorbing construction, slit sound absorption structure, the patent No. held by the inventor is: tube bundle type perforated-plate resonance sound-absorbing device and compound sound-absorption structural thereof among the ZL00100641.X.
In the technique scheme, the thickness that described suppressor case 1 inwall lays sound-absorbing material or sound absorption structure device 4 is 1-1000mm.
In the technique scheme, described cryogenic refrigerating system 2 adopts compressor cooling, semiconductor refrigeration, liquid nitrogen refrigerating, dry ice refrigeration, acoustic refrigeration, chemical refrigeration, magnetic refrigeration, solar refrigeration, utilizes the conveying of the existing refrigeration system of surrounding environment to be lower than the gas of temperature in the pipeline, or adopts the mode that covers ice sheet on housing 1 outer wall of silencing apparatus.
In the technique scheme, the cryogenic refrigerating system of installing on the described housing outer wall adopts compressor cooling, and the evaporator pipeline of described compressor is wrapped on the silencing apparatus pipeline outer wall.
In the technique scheme, described cryogenic refrigerating system adopts semiconductor paster refrigeration, described semiconductor refrigeration paster is attached on housing (pipeline) outer wall of silencing apparatus.
In the technique scheme, the cryogenic refrigerating system of installing on described housing 1 outer wall adopts liquid nitrogen refrigerating, described liquid nitrogen and normal temperature nitrogen are fed in the pipeline cooler, and in the tube-cooled device, mix and then described tube-cooled device is covered on the housing outer wall of described silencing apparatus; Temperature control apparatus is controlled the temperature of suppressor case outer wall by the flow of control liquid nitrogen normal temperature nitrogen.
In the technique scheme, the cryogenic refrigerating system of installing on the described housing outer wall adopts dry ice refrigeration, dry ice is placed the tube-cooled device, then described tube-cooled device is covered on the housing outer wall of described silencing apparatus, utilize the physical property of dry ice self to provide a cold junction to reduce the temperature of suppressor case outer wall.
In the technique scheme, the cryogenic refrigerating system of installing on the described housing outer wall is to adopt the housing outer wall at silencing apparatus to cover an ice sheet.
In the technique scheme, the cryogenic refrigerating system of installing on described housing 1 outer wall is to utilize the existing refrigeration system of surrounding environment to carry gas or the cooling liquid that is lower than temperature in the pipeline to the housing outer wall of silencing apparatus.
In the technique scheme, the cryogenic refrigerating system of installing on described housing 1 outer wall adopts the magnetic refrigeration, then heat exchanger can be placed the adiabatic demagnetization district of magnetic working medium, simultaneously heat exchanger is covered on the silencing apparatus pipeline outer wall.
In the technique scheme, the cryogenic refrigerating system of installing on described housing 1 outer wall is to adopt thermoacoustic refrigeration, forms the temperature that cold junction reduces the silencing apparatus outer wall by the thermoacoustic refrigeration principle.
Silencing apparatus based on sound ray deflection theory of the present invention adopts the duct attenuation device, and the suppressor case inwall lays certain thickness sound-absorbing material and structure.On the suppressor case outer wall, install cryogenic refrigerating system.By the temperature that temperature control apparatus is regulated cryogenic refrigerating system, set the internal and external temperature gradient of silencing apparatus.Silencing apparatus tube wall temperature inside is greater than the tube wall outside.Inside and outside the silencing apparatus tube wall, produce a temperature gradient, make sound-absorbing material and the structure place crooked deviation of sound ray to silencer internal wall, brought into play the sound absorbing capabilities of sound-absorbing material effectively, increased the absorption of sound-absorbing material and structure, made sound-absorbing material and structure become " saturated, supersaturation " state from original " undersaturation " state.Simultaneously, because the deviation of sound ray makes the sound wave reference angle of Grazing incidence increase, the acoustic absorptivity of sound-absorbing material and structure improves, and has increased absorption.Therefore, technological scheme of the present invention has the following advantages with respect to prior art:
Silencing apparatus based on sound ray deflection theory of the present invention passes through the adjusting to the cryogenic refrigerating system cold junction temperature, improves temperature gradient, further improves the sound deadening capacity of silencing apparatus with this.Simultaneously again owing to the present invention is to having a kind of improvement of duct attenuation device now, under the situation of existing acoustic wave filter structure itself not being changed substantially, only by method, for it provides the amount of exceeding sound deadening capacity to existing silencing apparatus pipeline outer wall installation cryogenic refrigerating system.
Silencing apparatus based on sound ray deflection theory provided by the invention, because cryogenic refrigerating system is installed on the silencing apparatus, produce temperature gradient of big (1-2000 ℃) with respect to the high temperature in the airflow line, according to Fermat's theorem, sound ray is along time-consuming minimum steepest propagated, sound ray can be the crooked deviation in airflow line inwall sound-absorbing material and structure place towards cold junction, reduced the sound wave composition that does not contact with structure in the silencing apparatus pipeline and skim over the silencing apparatus sound-absorbing material, make that more sound wave composition is oblique to be mapped in sound-absorbing material and the structure, thereby can more fully bring into play the sound absorption potential of sound-absorbing material and structure effectively, enhancing is to effective absorption of noise in the pipeline, reduce and to be excited the amplitude of acoustics normal mode vibration pattern in the pipeline, increase the sound deadening capacity of silencing apparatus, reduce radiated noise.Temperature can be normal temperature or high temperature in the airflow line, and temperature is high more, and the relative temperature gradient is big more, and the composition of the crooked deviation of sound ray is also just many more, so just helps giving full play to the sound absorption potential of existing sound-absorbing material and structure more.And the present invention only installs a cover cryogenic refrigerating system on original acoustic wave filter structure, and therefore the overall structure of not changing silencing apparatus has substantially reduced difficulty and the cost transformed.
Silencing apparatus based on sound ray deflection theory of the present invention can be used for aviation turbofan engine nacelle noise elimination design, also can be used for the duct attenuation that the sound absorption of helicopter turbine engine duct is handled and cryogenic refrigerating system and cold junction conveniently are provided.When the silencing apparatus that has cryogenic refrigerating system based on the sound ray deviation is applied to aviation turbofan engine nacelle noise elimination design, for saving the energy, also can be only take off, the landing stage starts cryogenic refrigerating system (cruising phase is then closed cryogenic refrigerating system), enlarge markedly the sound deadening capacity of aviation turbofan engine nacelle noise elimination structure, in the hope of more effectively controlling the airport ambient noise, satisfy the noise airworthiness requirement better.
Description of drawings
Fig. 1 is that the silencing apparatus that the present invention is based on sound ray deflection theory is formed schematic representation;
Fig. 2 is that day temperature is with the sound ray deviation schematic representation under the height lapse conditions;
Fig. 3 is that nocturnal temperature is with the sound ray deviation schematic representation that highly increases progressively under the condition;
Fig. 4 covers the thick ice of 100mm on the suppressor case outer wall of the present invention, the schematic representation of one deck tube bundle perforated plate composite resonance sound absorption structure is installed on the inner walls;
Fig. 5 does not have insertion loss measurement result under the ice condition condition for covering thick ice of 100mm and silencing apparatus on the silencing apparatus outer wall of Fig. 4 of the present invention;
Fig. 6 is that axial-flow blower import of the present invention feeds high-temperature flue gas, and covering thick ice of 100mm and silencing apparatus on the silencing apparatus outer wall does not have insertion loss measurement result under the ice condition condition;
Fig. 7 is the present invention's example structure schematic representation of compressor as a kind of silencing apparatus of refrigeration system making;
Fig. 8 utilizes the example structure schematic representation of the silencing apparatus of semiconductor refrigeration system making for the present invention;
Fig. 9 has the example structure schematic representation of the silencing apparatus of liquid nitrogen refrigerating system for the present invention;
Figure 10 carries the gas that is lower than temperature in the pipeline for the present invention utilizes the existing refrigeration system of surrounding environment to the housing outer wall of silencing apparatus.
Figure 11 has the example structure schematic representation of the silencing apparatus of magnetic refrigerating system for the present invention;
Figure 12 has the example structure schematic representation of the silencing apparatus of standing wave thermoacoustic refrigeration machine cooling system for the present invention;
The example structure schematic representation of Figure 13 silencing apparatus of capable ripple thermoacoustic refrigeration machine cooling system for the present invention has;
Figure 14 has the example structure schematic representation of the silencing apparatus of Stirling (Stirling) thermoacoustic refrigeration machine cooling system for the present invention;
Figure 15 has the example structure schematic representation of the silencing apparatus of pulsed tube thermoacoustic refrigeration machine cooling system for the present invention;
Figure 16 freezes the schematic representation of structure for slit sound absorption structure of the present invention bottom;
Figure 17 freezes standing wave tube sound absorption characteristics measurement result under the situation for slit sound absorption structure of the present invention bottom;
The schematic representation that Figure 18 is 100% situation for its refrigeration system area coverage of silencing apparatus with refrigeration system of the present invention;
The schematic representation that Figure 19 is 5% situation for its refrigeration system area coverage of silencing apparatus with refrigeration system of the present invention;
Marginal data:
1-suppressor case 2-cryogenic refrigerating system 2 '-the thick ice sheet of 100mm
3-temperature control apparatus 4-sound-absorbing material or sound absorption structure device
4 '-tube bundle perforated plate composite resonance sound absorption constructional device
5-liquid storage exsiccator 6-expansion valve 7-capillary tube thermometer bulb
8-low-voltage tube 9-high-voltage tube 10-compressor
11-condenser 12-vaporizer 13-insulating ceramic film
14-metallic conductor 15-N type and P-type semiconductor 16-DC electrical source
17-cold junction 18-hot junction 19-Dewar container for liquefied nitrogen bottle
20-tube-cooled device 21-slit sound absorption structure 22-ice
The 23-high-temperature zone 24-low temperature area 25-magnetic N utmost point
26-magnetic S utmost point 27-magnetic working medium 2 8-radiator
29-sound generator 30-high-temperature heat exchanger 31-low temperature heat exchanger
The capable wave sound conduit of 32-regenerator 33-resonant cavity 34-
35-wave absorption device 36-air reservoir 37-valve
38-pulsed tube 39-nitrogen bottle
Embodiment
The present invention is described in detail below in conjunction with the drawings and specific embodiments.
With reference to figure 4, what present embodiment was made has the silencing apparatus of cryogenic refrigerating system based on sound ray deflection theory, utilize an existing silencing apparatus, with form fixedly cryogenic refrigerating system 2 being set on one deck sound-absorbing material and constructional device 4 and housing 1 outer wall on housing 1 inwall of this silencing apparatus at this silencing apparatus.The ice sheet 2 that coating one deck 100mm is thick on housing 1 outer wall of this silencing apparatus ', as cryogenic refrigerating system 2, on housing 1 inwall of silencing apparatus, lay one deck compound sound-absorption structural again, for example with the cotton tube bank slit perforated plate resonance sound-absorbing device of surface recombination one deck sound absorption, the thickness of this sound-absorbing material or sound absorption structure device 4 is 1000mm, and this is that those skilled in the art can implement.Cover on the thick ice sheet 2 of 100mm ' processing basis at housing 1, to having carried out actual measurement by covering the 100mm insertion that thick ice sheet 2 ' processing causes loss to axial-flow blower outlet silencing apparatus.Experiment parameter is as follows:
Experiment parameter: 12 ℃ of ambient temperatures, fan delivery 8000m
3/ h, blast 200Pa, wind speed 12.7m/s, silencing apparatus inner passage size 0.7m x 0.25m, long 1m.Silencing apparatus 1 adopts tube bundle perforated plate composite resonance sound absorption structure, wherein: the cotton thick 100mm that absorbs sound, unit weight 32Kg/m
3, restrain long 10mm, caliber 1.6mm, punching rate 3.6% is stitched long 3.6mm, stitches wide 0.04mm, the dark 100mm in chamber.
Measurement result is shown in Fig. 5 and table 1.
Table 1. covers the thick ice sheet of 100mm by the silencing apparatus outer wall and handles the insertion loss measurement result that causes
From Fig. 5 and table 1 as can be seen: because the temperature gradient that cold junction produces, the insertion loss that causes the crooked deviation of sound ray to cause reaches 1.5-6.7dB in the 315Hz-20KHz frequency range, at 100Hz-200Hz frequency range 0.5-2.2dB.Therefrom as can be seen, handling caused insertion loss by the thick ice sheet of covering 100mm is 3.1dBA.
In addition, produce under the smoke condition in the axial-flow blower import, the inner flue-gas temperature of silencing apparatus has reached 65 ℃, in the case, the silencing apparatus outer wall is covered the thick ice sheet of 100mm to be handled, carried out actual measurement to handling the insertion loss that causes by the thick ice sheet of covering 100mm, 12 ℃ of ambient temperatures, measurement result is shown in Fig. 6 and table 2.
Table 2. covers the thick ice sheet of 100mm by the silencing apparatus outer wall and handles the insertion loss measurement result that causes
From Fig. 6 and table 2 as can be seen: the axial-flow blower import produces under the smoke condition, because the temperature gradient that the thick ice sheet cold junction of 100mm produces, the insertion loss that causes the crooked deviation of sound ray to cause, reach 7.1-18.3dB in the 20Hz-400Hz frequency range, at 500Hz-800Hz frequency range 2.4-6.7dB, then existence-2.4-0.4dB increase in various degree more than the 1KHz frequency range.Therefrom as can be seen, handling caused insertion loss by the thick ice sheet of covering 100mm under the axial-flow blower import generation smoke condition is 5.2dBA.As seen, because the temperature gradient between silencing apparatus center and the outer wall raises, more sound ray has further been brought into play the noise elimination potential of silencing apparatus towards the crooked deviation in the sound-absorbing material place of silencer internal wall, has improved sound deadening capacity.
Handle the temperature gradient of cold junction generation (0-12 ℃ and 0-65 ℃) and little although cover the thick ice sheet of 100mm, the additional sound deadening capacity that brings has thus reached 3.1-5.2dBA.Can draw by theory analysis: temperature gradient is big more, and the crooked deviation degree of sound ray is high more, and the sound wave composition that oblique incidence enters the silencing apparatus sound absorption structure is also just many more, so just helps bringing into play the sound absorption potential of existing silencing apparatus more.Therefore, silencing apparatus of the present invention comprises the duct attenuation device, cryogenic refrigerating system and temperature control apparatus, duct attenuation device inwall lays sound-absorbing material and structure, on duct attenuation device outer wall, cryogenic refrigerating system is installed, refrigeration system has reduced the temperature of sound absorption structure backboard wall, thereby one of the generation of silencing apparatus sound absorption structure inside by the temperature gradient of relatively-high temperature to relative low temperature, the temperature gradient of utilizing the cryogenic refrigerating system cold junction to produce, the crooked deviation of sound ray in causing managing, make that more sound wave composition is oblique to be mapped in sound-absorbing material and the structure, therefore sound absorption structure just can " be caught " more noise by the cryogenic refrigerating system cold junction, rather than allow noise skim over from its surface, can utilize the sound absorption potential quality of sound absorption structure so fully, its acoustical absorptivity is fully played, improved sound absorbing capabilities, thereby make the silencing apparatus acoustical absorptivity become " saturated; supersaturation " state by " undersaturation ", improve the acoustically effective of sound-absorbing material and structure greatly, on the basis of the original sound deadening capacity of given silencing apparatus, produced the amount of exceeding sound deadening capacity.When being applied in temperature gradient, this technology can reach in the aeroengine noise elimination nacelle design more than thousands of degree, the noise reduction of the only 3-5 decibel that will bring, and the aeroengine noise reduction technology will reach a brand-new height when the time comes.
With reference to figure 7, what present embodiment was made has the silencing apparatus of cryogenic refrigerating system based on sound ray deflection theory, housing 1, cryogenic refrigerating system 2, temperature control apparatus 3 and sound-absorbing material or sound absorption structure device 4 by a silencing apparatus are formed, cryogenic refrigerating system 2 is installed on housing 1 outer wall of silencing apparatus, this refrigeration system adopts compressor cooling, and wherein refrigeration system is made up of compressor 10, condenser 11, vaporizer 12, liquid storage exsiccator 5..Temperature control apparatus 3 is the conventional temperature control apparatuss that use of this specialty, and promptly temperature control apparatus 3 is made up of expansion valve 6, capillary tube thermometer bulb 7, refrigeration piping.Vaporizer is wrapped on the silencing apparatus pipeline outer wall and absorbs heat, realizes the quantitative control of temperature gradient by refrigeration system 2 and temperature control apparatus 3.Housing 1 inwall at silencing apparatus lays sound-absorbing material or sound absorption structure device 4, and the thickness of its sound-absorbing material or sound absorption structure device 4 is 10mm, 100mm or 500mm.The sound-absorbing material or the sound absorption structure of the silencing apparatus inner-walls of duct in the present embodiment, can be porous sound-absorbing material, also can be resonance sound-absorbing structure for sheet, film resonance sound-absorbing structure, sound absorbent perforated structure, microperforated panel soundabsorbing construction, slit sound absorption structure or be: tube bundle type perforated-plate resonance sound-absorbing device and compound sound-absorption structural thereof among the 00100641.X by the patent No. that the inventor holds.
The temperature control apparatus of cryogenic refrigerating system should ensure and have 1-2000 ℃ temperature gradient between the silencing apparatus inner and outer walls of pipeline, and the temperature in the pipeline is greater than the temperature of pipeline outer wall cold junction.Cryogenic refrigerating system should cover 5% of suppressor case outer wall area at least.
With reference to figure 8, what present embodiment was made has the silencing apparatus of cryogenic refrigerating system based on sound ray deflection theory, housing 1 by a silencing apparatus, cryogenic refrigerating system 2, temperature control apparatus 3 and sound-absorbing material or sound absorption structure device 4 are formed, cryogenic refrigerating system 2 is installed on housing 1 outer wall of silencing apparatus, cryogenic refrigerating system in the present embodiment adopts semiconductor refrigeration, wherein the semiconductor refrigeration system insulating ceramic film 13, metallic conductor 14, N type and P-type semiconductor 15, DC electrical source 16 is formed, temperature control apparatus 3 can adopt conventional radiating fin heat radiation, the fan heat radiation also can be adopted air-cooled, methods such as water-cooled are controlled heat radiation.The semiconductor refrigeration paster is attached on the silencing apparatus pipeline outer wall, realizes the quantitative control of temperature gradient by refrigeration system and temperature control apparatus.Housing 1 inwall of silencing apparatus lays sound-absorbing material or sound absorption structure device 4, and the thickness of its sound-absorbing material or sound absorption structure device 4 is 1mm or 60mm.The sound-absorbing material or the sound absorption structure of housing 1 inwall of the silencing apparatus in the present embodiment, can be porous sound-absorbing material, also can be resonance sound-absorbing structure for sheet, film resonance sound-absorbing structure, sound absorbent perforated structure, microperforated panel soundabsorbing construction, slit sound absorption structure, the patent No. held by the inventor is: tube bundle type perforated-plate resonance sound-absorbing device and compound sound-absorption structural thereof among the 00100641.X.
Cryogenic refrigerating system adopts semiconductor refrigeration, then the semiconductor refrigeration paster can be attached on the silencing apparatus pipeline outer wall; The temperature control apparatus of cryogenic refrigerating system should ensure and have 1-2000 ℃ temperature gradient between the silencing apparatus inner and outer walls of pipeline, and the temperature in the pipeline is greater than the temperature of pipeline outer wall cold junction.Cryogenic refrigerating system should cover 5% of suppressor case outer wall area at least.
The cryogenic refrigerating system 2 of present embodiment adopts semiconductor refrigeration sheet mode refrigeration, wherein, semiconductor refrigeration system is made up of insulating ceramic film 13, metallic conductor 14, N type and P-type semiconductor 15 and DC electrical source 16, and temperature control apparatus 3 adopts radiating fin heat radiation, fan heat radiation, air-cooled or water-cooling method to control heat radiation; The semiconductor refrigeration paster is attached on the silencing apparatus pipeline outer wall, controls the temperature of suppressor case 1 outer wall by the heat radiation situation in control semiconductor refrigerating sheet hot junction, this can implement for those skilled in the art.
With reference to figure 9, what present embodiment was made has the silencing apparatus of cryogenic refrigerating system based on sound ray deflection theory, housing 1, cryogenic refrigerating system 2, temperature control apparatus 3 and sound-absorbing material or sound absorption structure device 4 by a silencing apparatus are formed, cryogenic refrigerating system 2 is installed on housing 1 outer wall of silencing apparatus, and the refrigeration system in the present embodiment adopts liquid nitrogen refrigerating.Wherein cryogenic refrigerating system is made up of Dewar container for liquefied nitrogen bottle 19 and tube-cooled device 20, temperature control apparatus is electrically connected with electromagnetic valve, employing valve control utilizes valve to control the nitrogen pressure in the Dewar container for liquefied nitrogen bottle 19 and the liquid nitrogen flow that leads to tube-cooled device 20 is realized the quantitative control of temperature.Housing 1 inwall at silencing apparatus lays sound-absorbing material and constructional device 4, and the thickness of its sound-absorbing material or sound absorption structure device 4 is 200mm.The sound-absorbing material or the sound absorption structure of the silencing apparatus inner-walls of duct in the present embodiment, can be porous sound-absorbing material, also can be resonance sound-absorbing structure for sheet, film resonance sound-absorbing structure, sound absorbent perforated structure, microperforated panel soundabsorbing construction, slit sound absorption structure, the patent No. held by the inventor is: tube bundle type perforated-plate resonance sound-absorbing device and compound sound-absorption structural thereof among the 00100641.X.
Refrigeration system in the present embodiment adopts liquid nitrogen refrigerating, described liquid nitrogen and normal temperature nitrogen are fed in the pipeline cooler 20, and mixing covers described tube-cooled device 20 on described suppressor case 1 outer wall then in tube-cooled device 20; Temperature control apparatus 3 is controlled the temperature of suppressor case 1 outer wall by the flow of control liquid nitrogen normal temperature nitrogen.
The temperature control apparatus of cryogenic refrigerating system should ensure and have 1 ℃-2000 ℃ temperature gradient between the silencing apparatus inner and outer walls of pipeline, and the temperature in the pipeline is greater than the temperature of pipeline outer wall cold junction.Cryogenic refrigerating system should cover 5% of suppressor case outer wall area at least.
Embodiment 5
With reference to Figure 10, what present embodiment was made has the silencing apparatus of cryogenic refrigerating system based on sound ray deflection theory, housing 1 by a silencing apparatus, cryogenic refrigerating system 2, temperature control apparatus 3 and sound-absorbing material or sound absorption structure device 4 are formed, cryogenic refrigerating system 2 is installed on housing 1 outer wall of silencing apparatus, refrigeration system in the present embodiment utilizes the existing refrigeration system of surrounding environment to carry gas or the cooling liquid that is lower than temperature in the pipeline to the housing outer wall of silencing apparatus, temperature control apparatus adopts valve control, utilizes valve to control to lead to the flow of temperature gas in the cryogenic piping of tube-cooled device 20 or cooling liquid to realize the quantitative control of temperature.Housing 1 inwall at silencing apparatus lays sound-absorbing material and constructional device 4.The sound-absorbing material or the sound absorption structure of the silencing apparatus inner-walls of duct in the present embodiment, can be porous sound-absorbing material, also can be resonance sound-absorbing structure for sheet, film resonance sound-absorbing structure, sound absorbent perforated structure, microperforated panel soundabsorbing construction, slit sound absorption structure, the patent No. held by the inventor is: tube bundle type perforated-plate resonance sound-absorbing device and compound sound-absorption structural thereof among the 00100641.X.
The temperature control apparatus of cryogenic refrigerating system should ensure and have 1-2000 ℃ temperature gradient between the silencing apparatus inner and outer walls of pipeline, and the temperature in the pipeline is greater than the temperature of pipeline outer wall cold junction.Cryogenic refrigerating system should cover 5% of suppressor case outer wall area at least.
With reference to Figure 11, what present embodiment was made has the silencing apparatus of cryogenic refrigerating system based on sound ray deflection theory, housing 1 by a silencing apparatus, cryogenic refrigerating system 2, temperature control apparatus 3 and sound-absorbing material or sound absorption structure device 4 are formed, cryogenic refrigerating system 2 is installed on housing 1 outer wall of silencing apparatus, refrigeration system in the present embodiment adopts conventional magnetic refrigerating system, for example by magnetic working medium 27, the magnetic N utmost point 25, the magnetic S utmost point 26, compositions such as radiator 28 and tube-cooled device 20, magnetic working medium 27 is 23 isothermal magnetizations in the high-temperature zone, emit heat, by radiator 28 heat is derived, in low temperature area 24 adiabatic demagnetizations, absorb heat, heat exchanger is placed the low temperature area of magnetic working medium 27, the adiabatic demagnetization by magnetic working medium 27 absorbs heat, form cold junction, reduce the temperature of silencing apparatus outer wall by tube-cooled device 20.Housing 1 inwall at silencing apparatus lays sound-absorbing material and constructional device 4.The sound-absorbing material or the sound absorption structure of the silencing apparatus inner-walls of duct in the present embodiment, can be porous sound-absorbing material, also can be resonance sound-absorbing structure for sheet, film resonance sound-absorbing structure, sound absorbent perforated structure, microperforated panel soundabsorbing construction, slit sound absorption structure, the patent No. held by the inventor is: tube bundle type perforated-plate resonance sound-absorbing device and compound sound-absorption structural thereof among the 00100641.X.
The temperature control apparatus of cryogenic refrigerating system should ensure and have 1-2000 ℃ temperature gradient between the silencing apparatus inner and outer walls of pipeline, and the temperature in the pipeline is greater than the temperature of pipeline outer wall cold junction.Cryogenic refrigerating system should cover 5% of suppressor case outer wall area at least.
With reference to Figure 12, Figure 13, Figure 14, Figure 15, what present embodiment was made has the silencing apparatus of cryogenic refrigerating system based on sound ray deflection theory, housing 1, cryogenic refrigerating system 2, temperature control apparatus 3 and sound-absorbing material or sound absorption structure device 4 by a silencing apparatus are formed, cryogenic refrigerating system 2 is installed on housing 1 outer wall of silencing apparatus, refrigeration system in the present embodiment adopts conventional thermoacoustic refrigeration system, and this conventional thermoacoustic refrigeration system comprises standing wave hot sound refrigerating machine, row ripple hot sound refrigerating machine, Stirling (Stirling) refrigerator and pulse tube refrigerating machine composition.Standing wave hot sound refrigerating machine (Figure 12) is made up of sound generator 29, high-temperature heat exchanger 30, low temperature heat exchanger 31, regenerator 32, resonant cavity 33 and tube-cooled device 20.Row ripple hot sound refrigerating machine (Figure 13) is made up of sound generator 29, high-temperature heat exchanger 30, low temperature heat exchanger 31, regenerator 32, row wave sound conduit 34 and tube-cooled device 20.Stirling refrigerator (Figure 14) is made up of sound generator 29, wave absorption device 35, high-temperature heat exchanger 30, low temperature heat exchanger 31, regenerator 32 and tube-cooled device 20.Pulse tube refrigerating machine (Figure 15) is made up of sound generator 29, high-temperature heat exchanger 30, low temperature heat exchanger 31, regenerator 32, air reservoir 36, valve 37, pulsed tube 38 and tube-cooled device 20.
Emit heat according to heat sound principle at high-temperature heat exchanger 30 places, 31 absorb heat at the low temperature heat exchanger place, form cold junction, reduce the temperature of silencing apparatus outer wall by tube-cooled device 20.Housing 1 inwall at silencing apparatus lays sound-absorbing material and constructional device 4.The sound-absorbing material or the sound absorption structure of the silencing apparatus inner-walls of duct in the present embodiment, can be porous sound-absorbing material, also can be resonance sound-absorbing structure for sheet, film resonance sound-absorbing structure, sound absorbent perforated structure, microperforated panel soundabsorbing construction, slit sound absorption structure, the patent No. held by the inventor is: tube bundle type perforated-plate resonance sound-absorbing device and compound sound-absorption structural thereof among the 00100641.X.
The temperature control apparatus of cryogenic refrigerating system should ensure and have 1-2000 ℃ temperature gradient between the silencing apparatus inner and outer walls of pipeline, and the temperature in the pipeline is greater than the temperature of pipeline outer wall cold junction.Cryogenic refrigerating system should cover 5% of suppressor case outer wall area at least.
With reference to Figure 16, by processing is frozen in slit sound absorption structure bottom.Have the slit sound absorption structure of ice cube to place refrigerating chamber freezing more than 10 hours the bottom, ice cube freezes and is fixed on slit sound absorption structure bottom, makes the slit sound absorption structure under the situation of freezing.
The structural parameter of slit sound absorption structure are: seam is long: 1.8mm, stitch wide: 0.03mm, kerf spacing: 5mm, thickness of slab: 0.8mm, cavity depth are 298mm, the thickness of ice is 42mm.Ice cube freezes and is fixed in slit sound absorption structure bottom, and the slit sound absorption structure that the bottom is frozen is fixed on the test lead of standing wave tube.
Present embodiment is made the slit sound absorption structure that freeze the bottom, on standing wave tube the slit sound absorption structure has been carried out the normal incidence testing sound absorption performance.The processing front and back are frozen in slit sound absorption structure bottom, and the normal incident absorption coefficient of slit sound absorption structure as shown in figure 17.At 125Hz, 160Hz and 200Hz, the acoustic absorptivity that the slit sound absorption structure after handling is frozen in the bottom rises to 0.685,0.720 and 0.620 by original 0.410,0.400,0.420 respectively, and in the low-frequency range of 125Hz～400Hz, the acoustic absorptivity that the slit sound absorption structure after the processing is frozen in the bottom exceeds 0.1～0.3 than what do not freeze processing respectively, and in 800Hz～1600Hz frequency, the bottom is frozen acoustic absorptivity under the situation and is also compared with the situation of not freezing and increase.
Present embodiment is not difficult to find out by acoustic absorptivity contrast before and after slit sound absorption structure bottom is frozen: carry out the bottom for the slit sound absorption structure and freeze after the processing, not only the acoustic absorptivity of low frequency is improved significantly, and the acoustic absorptivity of intermediate frequency also increases, suppress broadband noise effectively, improved the absorption of whole frequency band.
With reference to Figure 18,19, what embodiment made has the silencing apparatus of cryogenic refrigerating system based on sound ray deflection theory, housing 1 by a silencing apparatus, cryogenic refrigerating system 2, temperature control apparatus 3 and sound-absorbing material or sound absorption structure device 4 are formed, cryogenic refrigerating system 2 is installed on housing 1 outer wall of silencing apparatus, the refrigeration system that adopts in the present embodiment, it can be compressor cooling, semiconductor refrigeration, liquid nitrogen refrigerating, dry ice refrigeration, the magnetic refrigeration, thermoacoustic refrigeration, carry gas or the cooling water be lower than temperature in the pipeline to the suppressor case outer wall, or even cover the mode that ice sheet etc. provides cold junction at the silencing apparatus outer wall.
The cryogenic refrigerating system of installing on the suppressor case outer wall, its area that occupies the silencing apparatus surface can be 5%-100%.
Generally, silencing apparatus based on sound ray deflection theory of the present invention, its essence is that sound ray deviation bending that " the cold trap " that utilize temperature gradient to produce causes catches to greatest extent and reduce noise, having given full play to the sound absorption potential of existing silencing apparatus sound-absorbing material and structure simultaneously, is a kind of noise reduction technology that has cryogenic refrigerating system based on temperature gradient, sound ray deviation.Its characteristics are that a temperature gradient has been incorporated in the acoustic wave filter structure design artificially as a design optimization parameter, having now under the saturated already situation of silencing apparatus acoustical absorptivity, by the silencing apparatus outer wall is installed cryogenic refrigerating system, make it become cold junction silencing apparatus with cryogenic refrigerating system, the extra temperature gradient that produces, utilize temperature gradient to make the interior sound ray of tube wall towards cold junction, it is the crooked deviation in airflow line inwall sound-absorbing material and structure place, reduced the sound wave composition that does not contact with structure in the silencing apparatus pipeline and skim over the silencing apparatus sound-absorbing material, make in the oblique sound-absorbing material and structure that is mapped to the silencing apparatus liner of more sound wave composition, thereby can more fully bring into play the sound absorption potential of silencing apparatus sound-absorbing material and structure effectively, enhancing is to effective absorption of noise in the pipeline, reduce and to be excited the amplitude of acoustics normal mode vibration pattern in the pipeline, increase the sound deadening capacity of silencing apparatus, reduce external radiated noise in the pipe.Temperature is high more in the airflow line, and the relative temperature gradient is big more, and the composition of the crooked deviation of sound ray is also just many more, so just helps giving full play to the sound absorption potential of existing sound-absorbing material and structure more.This silencing apparatus is realized the quantitative control to temperature gradient by the adjusting to the cryogenic refrigerating system cold junction temperature, further improves the sound deadening capacity of silencing apparatus, optimizes sound sucting band.Simultaneously again because this method is a kind of improvement to existing duct attenuation device, under the situation of existing acoustic wave filter structure not being changed substantially, by the method that existing silencing apparatus pipeline outer wall is installed cryogenic refrigerating system, for it additionally provides the amount of exceeding sound deadening capacity.
(cryogenic refrigerating system can adopt the dedicated compressor refrigeration with the cold junction producing method that changes cryogenic refrigerating system by optimized choice, semiconductor refrigeration, liquid nitrogen refrigerating, dry ice refrigeration, acoustic refrigeration, chemical refrigeration, the magnetic refrigeration, absorption refrigeration, pulse tube refrigeration, solar refrigeration etc., also can utilize the conveying of the existing refrigeration system of surrounding environment to be lower than the gas of temperature in the pipeline, even adopt the suppressor case outer wall to cover the mode etc. that ice sheet provides cold junction) and mounting type produce and can satisfy the cold junction temperature gradient that noise reduction demand and applied environment significantly allow, control the requirement of occasions to satisfy different noises.
It is convenient and allow to provide the environmental conditions of cold junction cryogenic refrigerating system that the present invention can be applicable to intake and exhaust pipeline system such as the noise elimination of aeroengine nacelle, helicopter turbine engine noise elimination duct, gas turbine and other.
Claims (12)
1. silencing apparatus based on sound ray deflection theory comprises and the housing of a silencing apparatus lays sound-absorbing material or sound absorption structure device (4) at described housing (1) inwall; It is characterized in that: also comprise cryogenic refrigerating system (2), described cryogenic refrigerating system (2) is installed on described housing (1) outer wall; Described cryogenic refrigerating system (2) is can provide to have 1 ℃-2000 ℃ temperature gradient between the housing inside and outside wall of silencing apparatus, and the temperature in the housing is greater than the refrigeration system of housing outer wall cold junction temperature;
Described cryogenic refrigerating system (2) should cover 5% of suppressor case outer wall area at least.
2. by the described silencing apparatus based on sound ray deflection theory of claim 1, it is characterized in that: also comprise a temperature control apparatus, described cryogenic refrigerating system (2) connects with temperature control apparatus (3).
3. by claim 1 or 2 described silencing apparatuss based on sound ray deflection theory, it is characterized in that: described sound-absorbing material is a porous sound-absorbing material, and described sound absorption structure device (4) is resonance sound-absorbing structure for sheet, film resonance sound-absorbing structure sound absorbent perforated structure, microperforated panel soundabsorbing construction, slit sound absorption structure or tube bundle type perforated-plate resonance sound-absorbing device.
4. by claim 1 or 2 described silencing apparatuss based on sound ray deflection theory, it is characterized in that: described suppressor case (1) is circular cylinder, oval tube or the tube with rectangular cross-section.
5. by claim 1 or 2 described silencing apparatuss based on sound ray deflection theory, it is characterized in that: the thickness that described suppressor case (1) inwall lays sound absorption structure device (4) is 1-1000mm.
6. by claim 1 or 2 described silencing apparatuss based on sound ray deflection theory, it is characterized in that: described cryogenic refrigerating system (2) adopts compressor cooling, semiconductor refrigeration, liquid nitrogen refrigerating, dry ice refrigeration, acoustic refrigeration, chemical refrigeration, magnetic refrigeration, solar refrigeration, utilize the conveying of the existing refrigeration system of surrounding environment to be lower than the gas or the cooling liquid of temperature in the pipeline, perhaps adopts the mode that covers ice sheet on housing (1) outer wall at silencing apparatus to freeze.
7. by the described silencing apparatus of claim 6 based on sound ray deflection theory, it is characterized in that: described cryogenic refrigerating system (2) adopts compressor cooling, the evaporator pipeline of described compressor is wrapped in described silencing apparatus pipeline outer wall, and compressor refrigeration system is electrically connected with temperature control apparatus (3).
8. by the described silencing apparatus of claim 6 based on sound ray deflection theory, it is characterized in that: described cryogenic refrigerating system (2) adopts semiconductor refrigeration sheet mode refrigeration, wherein, semiconductor refrigeration system is made up of insulating ceramic film (13), metallic conductor (14), N type and P-type semiconductor (15) and DC electrical source (16), and temperature control apparatus (3) adopts radiating fin heat radiation, fan heat radiation, air-cooled or water-cooling method to control heat radiation; The semiconductor refrigeration paster is attached on the silencing apparatus pipeline outer wall, controls the temperature of suppressor case (1) outer wall by the heat radiation situation in control semiconductor refrigerating sheet hot junction.
9. by the described silencing apparatus of claim 6 based on sound ray deflection theory, it is characterized in that: described cryogenic refrigerating system (2) adopts liquid nitrogen refrigerating, and the tube-cooled device (20) that feeds liquid nitrogen and normal temperature nitrogen is covered on housing (1) outer wall of described silencing apparatus; The flowmeter of temperature control apparatus (3) is electrically connected, and controls the temperature of housing (1) outer wall by the flow of control liquid nitrogen normal temperature nitrogen.
10. by the described silencing apparatus of claim 6 based on sound ray deflection theory, it is characterized in that: described cryogenic refrigerating system (2) adopts dry ice refrigeration, described dry ice is placed tube-cooled device (20), then described tube-cooled device (20) is covered on the described silencing apparatus pipeline outer wall, temperature control apparatus (3) is controlled the temperature of suppressor case (1) outer wall by the flow of the low-temperature carbon dioxide gas of control dry ice generation.
11. by the described silencing apparatus based on sound ray deflection theory of claim 6, it is characterized in that: described cryogenic refrigerating system (2) adopts the magnetic refrigerating system of being made up of magnetic working medium (27), the magnetic N utmost point (25), the magnetic S utmost point (26), radiator (28) and tube-cooled device (20).
12., it is characterized in that: the thermoacoustic refrigeration system that described cryogenic refrigerating system (2) is made up of standing wave hot sound refrigerating machine, row ripple hot sound refrigerating machine, sterlin refrigerator and pulse tube refrigerating machine by the described silencing apparatus of claim 6 based on sound ray deflection theory.
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| CN107327650A (en) * | 2017-08-01 | 2017-11-07 | 北京市劳动保护科学研究所 | A kind of pipeline silencer and the pipe-line system with the silencer |
| CN107329553A (en) * | 2017-09-08 | 2017-11-07 | 合肥宗平计算机科技有限公司 | Display card cooling device |
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