WO2010097014A1 - 一种基于声线偏折理论的消声方法和消声器 - Google Patents
一种基于声线偏折理论的消声方法和消声器 Download PDFInfo
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- WO2010097014A1 WO2010097014A1 PCT/CN2010/000242 CN2010000242W WO2010097014A1 WO 2010097014 A1 WO2010097014 A1 WO 2010097014A1 CN 2010000242 W CN2010000242 W CN 2010000242W WO 2010097014 A1 WO2010097014 A1 WO 2010097014A1
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- Prior art keywords
- muffler
- sound
- wall
- temperature
- pipe
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENTS OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B64D33/00—Arrangements in aircraft of power plant parts or auxiliaries not otherwise provided for
- B64D33/04—Arrangements in aircraft of power plant parts or auxiliaries not otherwise provided for of exhaust outlets or jet pipes
- B64D33/06—Silencing exhaust or propulsion jets
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/18—Methods or devices for transmitting, conducting or directing sound
- G10K11/26—Sound-focusing or directing, e.g. scanning
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/24—Silencing apparatus characterised by method of silencing by using sound-absorbing materials
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
- F01N2240/02—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a heat exchanger
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
- F01N2240/04—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being an electric, e.g. electrostatic, device other than a heater
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2260/00—Exhaust treating devices having provisions not otherwise provided for
- F01N2260/02—Exhaust treating devices having provisions not otherwise provided for for cooling the device
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2510/00—Surface coverings
- F01N2510/04—Surface coverings for sound absorption
Definitions
- the invention relates to a muffler, in particular to a muffling method and a muffler based on the theory of sound line deflection. Background technique
- Aeronautical noise mainly comes from jet noise and fan noise of aero-engines.
- researchers have been trying to find a way to have good sound absorption in a wider frequency band, reduce jet noise and fan noise, and generally adopt the following methods and Design guidelines:
- the sound lining is laid on the pipe wall to reduce the radiation noise of the engine.
- the present invention provides a method for suppressing sound based on the theory of sound line deflection.
- a temperature is formed in the wall of the muffler cavity by installing a cryogenic refrigeration system on the outer wall of the muffler duct.
- the temperature gradient of the temperature outside the pipe wall is used to deflect the sound rays in the pipe wall toward the outer wall of the low-temperature muffler pipe, so that more sound rays enter the sound absorbing structure of the muffler lining in oblique incident form.
- the incident angle of the ignited incident sound wave is increased, the sound absorption coefficient of the sound absorbing structure is increased, the effective absorption of the noise in the pipeline is enhanced, the amplitude of the stimulated acoustic normal vibration mode in the pipeline is reduced, and the noise reduction amount of the muffler is increased.
- the radiation noise is reduced, wherein the cryogenic refrigeration system should cover at least 5% of the outer wall area of the muffler pipe.
- the invention also proposes a muffler based on the theory of sound line deflection, comprising a muffler housing, the muffler
- the sound absorbing structure 4 is disposed on the inner wall of the housing 1; wherein the outer wall of the muffler housing 1 is provided with a cryogenic refrigeration system 2 corresponding to the sound absorbing structure 4, and the low temperature refrigeration system 2 should at least cover the muffler housing 1 5% of the outer wall area; the muffler housing 1 has a circular, elliptical or rectangular cross section.
- cryogenic refrigeration system 2 is also coupled to a temperature control device 3 for quantitative control of the temperature gradient by the temperature control device 3.
- the quantitative control range of the temperature gradient is 1 to 2000, that is, the temperature inside the pipe of the muffler housing 1 is 1 to 2000 larger than the temperature of the cold end of the outer wall of the muffler housing 1.
- the sound absorbing structure 4 described in the above technical solution may be a porous sound absorbing material, a thin plate resonant sound absorbing structure, a thin film resonant sound absorbing structure, a perforated plate sound absorbing structure, a microperforated sound absorbing structure, a micro slit sound absorbing structure,
- the tube bundle perforated plate resonance sound absorbing structure or the tube bundle perforated plate composite resonance sound absorbing structure, and the sound absorbing structure 4 has a thickness of 1 to 1000 mm.
- the cryogenic refrigeration system 2 described in the above technical solution may employ compressor refrigeration, semiconductor refrigeration, liquid nitrogen refrigeration, dry ice refrigeration, acoustic refrigeration, chemical refrigeration, magnetic refrigeration, adsorption refrigeration, pulse tube refrigeration or solar refrigeration, or may be transported.
- the compressor refrigeration system comprises: a compressor 10, a condenser 1 1 , an evaporator 12 and a liquid storage dryer 5; wherein, the evaporator 12
- the pipe is wound on the outer wall of the muffler pipe, and the compressor refrigeration system is connected to the temperature control device 3.
- the temperature control device further comprises: an expansion valve 6 and a capillary temperature package 7:
- the semiconductor refrigeration system comprises: an insulating ceramic sheet 13, a metal conductor 14, an N-type and a P-type semiconductor 15 and a DC power source 16; after being connected, a cold end 17 and a hot end 18 are respectively formed, wherein the cold end 17 is attached to the muffler shell
- the temperature control device 3 uses heat sink heat dissipation, fan heat dissipation, air cooling or water cooling to control heat dissipation;
- the semiconductor refrigeration patch is attached to the outer wall of the muffler pipe, and the muffler is controlled by controlling the heat dissipation of the hot end of the semiconductor refrigeration chip.
- the liquid nitrogen refrigeration system comprises: a liquid nitrogen dewar 19, a normal temperature nitrogen bottle 39 and a pipe cooler 20; the liquid nitrogen is mixed with a normal temperature nitrogen gas into the pipe cooler 20; the pipe cooler 20 is covered in the muffler On the outer wall of the casing 1, the flow meter of the temperature control device 3 is electrically connected, and the temperature of the outer wall of the casing 1 is controlled by controlling the flow rate of the liquid nitrogen at normal temperature;
- the magnetic refrigeration system comprises: a magnetic medium 27, a magnetic N pole 25, a magnetic S pole 26, a heat sink 28 and a duct cooler 20; the magnetic medium 27 is isothermally magnetized in the high temperature region 23, and heat is released.
- the heat sink 28 conducts heat, depolarizes in the low temperature region 24, absorbs heat, places the pipe cooler 20 in the low temperature region of the magnetic medium 27, absorbs heat through the adiabatic demagnetization of the magnetic medium 27, forms a cold end and covers the muffler.
- thermoacoustic refrigeration system is a standing wave thermoacoustic refrigerator, a traveling wave thermoacoustic refrigerator, a Stirling refrigerator or a pulse tube refrigerator, and emits heat at the high temperature heat exchanger 30 according to the thermoacoustic principle, in the low temperature heat exchanger. 31, the heat is absorbed to form a cold end, the low temperature heat exchanger 31 is in communication with the pipe cooler 20, and the pipe cooler 20 covers the outer wall of the muffler casing 1.
- the standing wave thermoacoustic refrigerator comprises: sound waves a generator 29, a high temperature heat exchanger 30, a low temperature heat exchanger 31, a regenerator 32, a resonant cavity 33, and a duct cooler 20; the traveling wave thermoacoustic refrigerator comprises: a sound wave generator 29, a high temperature heat exchanger 30.
- the Stirling refrigerator includes: an acoustic wave generator 29, an acoustic wave absorber 35, a high temperature heat exchanger 30, and a low temperature heat
- the pulse tube refrigerator comprises: an acoustic wave generator 29, a high temperature heat exchanger 30, a low temperature heat exchanger 31, a regenerator 32, a gas reservoir 36, a valve 37, pulse tube 38 and tube Cooler 20.
- the gas or cooling liquid below the temperature in the pipe passes through the pipe cooler 20, which covers the outer wall of the muffler housing 1 to form a cold end.
- the ice layer is placed in a pipe cooler 20 which overlies the outer wall of the muffler housing 1 to provide a cold end using the physical properties of the dry ice itself.
- the invention installs a cryogenic refrigeration system on the outer wall of the existing muffler pipe, additionally generates a temperature gradient inside and outside the wall of the muffler, and the temperature inside the pipe wall is larger than the pipe wall. According to Fermat's theorem, the temperature gradient is used to generate the sound rays in the pipe wall.
- Deviation to the outer wall of the muffler pipe installed in the cryogenic refrigeration system so that more sound rays enter the sound absorbing structure of the muffler lining in oblique incidence instead of grazing incidence, so as to more fully and effectively exert the sound absorbing potential of the muffler , reducing the amplitude of the stimulated acoustic normal vibration mode inside the muffler, thereby providing a muffler based on the theory of sound line deflection.
- the muffler based on the sound line deflection theory of the invention adopts a pipe muffler, and a sound absorption structure with a certain thickness is laid on the inner wall of the muffler housing.
- a cryogenic refrigeration system is installed on the outer wall of the muffler housing.
- the cryogenic refrigeration system can use compressor refrigeration, semiconductor refrigeration, liquid nitrogen refrigeration, dry ice refrigeration, acoustic refrigeration, chemical refrigeration, magnetic refrigeration, adsorption refrigeration, solar refrigeration, etc., or the surrounding environment can be used to transport the refrigeration system below the pipeline.
- the temperature of the gas or cooling liquid, even the outer wall of the muffler housing is covered with ice to provide a cold end.
- the evaporator pipe can be wound around the outer wall of the muffler pipe; if semiconductor refrigeration is used, the semiconductor refrigeration chip can be attached to the outer wall of the muffler pipe; if liquid nitrogen and dry ice are used for cooling, Liquid nitrogen and dry ice are placed in a heat exchanger and then over the outer wall of the muffler tube.
- the temperature of the cryogenic refrigeration system is adjusted by the temperature control device to set the temperature gradient inside and outside the muffler. The temperature inside the wall of the muffler is greater than the outside of the pipe wall.
- a temperature gradient is generated inside and outside the wall of the muffler to bend and distort the sound ray to the sound absorbing structure on the inner wall of the muffler, effectively exerting the sound absorbing performance of the sound absorbing structure, increasing the sound absorption of the sound absorbing structure, and making the sound absorbing
- the structure changes from the "undersaturated” state to the "saturated, oversaturated” state.
- the incident angle of the grazing incident sound wave increases.
- the sound absorption coefficient of the sound absorbing structure is increased, and the sound absorption amount is increased.
- the present invention proposes a method of capturing noise and reducing noise using a "cold trap" - namely: a muffler having a cryogenic refrigeration system based on a temperature gradient and a sound line deflection.
- the novel muffler comprises a pipe muffler, a cryogenic refrigeration system and a temperature control device, a sound absorbing structure is arranged on the inner wall of the pipe muffler, and a low temperature refrigeration system is installed on the outer wall of the pipe muffler, and the refrigeration system reduces the temperature of the wall surface of the sound absorbing structure back surface, thereby being in the muffler
- the temperature inside the sound absorbing structure generates a temperature gradient from relatively high temperature to relatively low temperature, and the temperature gradient generated by the cold end of the cryogenic refrigeration system causes the bending of the sound line in the tube to bend, so that more acoustic components are obliquely incident into the sound absorbing structure.
- the sound absorbing structure can "capture" more noise through the cold end of the cryogenic refrigeration system, instead of letting the noise pass over its surface, so that the sound absorbing potential of the sound absorbing structure can be fully utilized, so that the sound absorbing ability is fully obtained.
- the performance of the sound absorption improves the sound absorption performance, so that the muffler's muffling ability changes from "undersaturated” to "saturated, supersaturated” state, which greatly improves the sound absorption effect of the sound absorbing structure, and gives the original muffler of the muffler. Based on the amount of excessive noise reduction.
- the muffler based on the sound line deflection theory of the present invention can be used for the nacelle noise reduction design of the aviation turbofan engine, and can also be used for the suction processing of the helicopter vortex shaft duct and the pipe noise reduction for the low temperature refrigeration system and the cold end.
- a muffler based on a sound-line deflection with a cryogenic refrigeration system is applied to the nacelle noise reduction design of an aviation turbofan engine, in order to save energy, it is also possible to start the cryogenic refrigeration system only during the take-off and landing phases of the aircraft (the cryogenic refrigeration system is turned off during the cruise phase). ), significantly increasing the noise reduction of the air-conditioning structure of the aviation turbofan engine, in order to more effectively control the ambient noise around the airport and better meet the noise airworthiness requirements.
- the advantages of the present invention are: to further improve the noise reduction of the existing pipe muffler based on the theory of sound line deflection.
- the present invention is an improvement on the existing pipe muffler, it is easy to install and promote only by installing a low temperature refrigeration system on the outer wall of the existing muffler pipe. That is, the invention only installs a cryogenic refrigeration system on the structure of the original muffler, and basically does not change the overall structure of the muffler, thereby reducing the difficulty and cost of the modification.
- FIG. 1 is a schematic view of a muffler having a cryogenic refrigeration system according to the present invention:
- Figure 2 is a schematic diagram showing the deflection of the sound line under the condition that the daytime temperature decreases with height
- Figure 3 is a schematic diagram of the deflection of the sound line at nighttime temperature with increasing height
- FIG. 4 is a schematic view showing a composite resonance sound absorbing structure of a muffler covered with 100 mm thick ice and using a tube bundle perforated plate;
- FIG. 5 is an insertion loss measurement result of the outer side of the muffler of the present invention covered with 100 mm thick ice and no ice;
- FIG. 6 is a high temperature flue gas inlet of the axial flow fan of the present invention, and the outer side of the muffler is covered with a thick ice of 100 tons and is inserted without ice. Loss measurement result;
- FIG. 7 is a schematic structural view of an embodiment of a muffler using a compressor as a refrigeration system according to the present invention
- 8 is a schematic structural view of an embodiment of a muffler fabricated by using a semiconductor refrigeration system according to the present invention
- FIG. 9 is a schematic structural view of an embodiment of a muffler having a liquid nitrogen refrigeration system according to the present invention.
- Figure 10 is a schematic diagram of the present invention for utilizing a surrounding refrigeration system to deliver a gas below the temperature of the pipe to the outer wall of the muffler housing;
- FIG. 1 is a schematic structural view of an embodiment of a muffler having a magnetic refrigeration system according to the present invention
- FIG. 12 is a schematic structural view of an embodiment of a muffler having a standing wave thermoacoustic refrigerator refrigeration system according to the present invention
- FIG. 13 is a schematic structural view of an embodiment of a muffler having a traveling wave thermoacoustic refrigerator refrigeration system according to the present invention
- FIG. 15 is a schematic structural view of an embodiment of a muffler having a pulse tube thermoacoustic refrigerator refrigeration system according to the present invention
- FIG. 16 is a schematic diagram of a micro-slot sound absorbing structure of the present invention. Schematic diagram of the ice structure
- FIG. 17 is a measurement result of the sound absorption characteristics of the standing wave tube in the case of the bottom frozen ice of the micro-slot sound absorbing structure of the present invention
- FIG. 18 is a schematic view showing the condition that the cooling system coverage area of the muffler having the refrigeration system of the present invention is 100%;
- Fig. 19 is a view showing the state in which the refrigeration system of the muffler having the refrigeration system has a coverage area of 5%.
- the muffler based on the theory of sound line deflection proposed by the present invention includes a muffler housing 1 and a cryogenic refrigeration system 2 and a temperature control device 3, and a certain thickness (1 - 1000 mm) is laid on the inner wall of the muffler housing 1.
- the sound absorbing structure 4 is provided with a cryogenic refrigeration system 2 on the outer wall of the muffler housing 1.
- the cryogenic refrigeration system can be compressor refrigeration, semiconductor refrigeration, acoustic refrigeration, liquid nitrogen refrigeration, dry ice refrigeration, chemical refrigeration, magnetic refrigeration, adsorption refrigeration, solar refrigeration, etc., and the surrounding environment can be used to transport the refrigeration system below the pipeline.
- the temperature of the gas even using the outer wall of the muffler housing to cover the ice layer to provide a cold end; the pipe of the cryogenic refrigeration system 2 covers at least 5% of the outer wall of the gas flow pipe.
- the cryogenic refrigeration system 2 of the present invention is mounted on a muffler to generate a large (1 to 200 (TC) temperature gradient with respect to the high temperature in the gas flow conduit. According to Fermat's theorem, the sound ray propagates along the slowest path with the least time.
- the line will be bent toward the cold end, that is, the sound absorption structure of the inner wall of the air flow duct, which reduces the sound wave component of the muffler duct that does not contact with the sound absorbing structure of the muffler, so that more acoustic components are obliquely incident into the sound absorbing structure. Therefore, the sound absorption potential of the sound absorbing structure can be more fully and effectively utilized, the effective absorption of the noise in the pipeline can be enhanced, the amplitude of the stimulated acoustic normal vibration mode in the pipeline can be reduced, the noise reduction of the muffler can be increased, and the radiation noise can be reduced.
- the temperature inside the pipeline can be normal temperature or high temperature. The higher the temperature, the larger the relative temperature gradient, and the more the components of the sound line are deflected, so that the more the sound absorption potential of the existing sound absorbing structure is fully utilized.
- a muffler having a cryogenic refrigeration system based on the theory of sound line deflection produced in this embodiment is composed of a muffler housing 1, a sound absorbing structure 4, and a cryogenic refrigeration system 2.
- the sound absorbing structure 4 adopts a tube bundle micro slit perforated plate resonance sound absorbing device which is laminated with a layer of sound absorbing cotton. Applying a layer of OOrnin thick ice layer 2' to the outer wall of the muffler housing 1 as a cryogenic refrigeration system 2, and then laying the above-mentioned tube bundle perforated plate composite resonant sound absorbing structure 4' on the inner wall of the muffler housing 1. . Based on the treatment of the housing 1 of the axial fan outlet muffler covered with a 100 mm thick ice layer 2', the actual insertion loss caused by the treatment of the 100 mm thick ice layer 2' was measured.
- the experimental parameters are as follows:
- the muffler 1 adopts a tube bundle perforated plate composite resonance sound absorbing structure, wherein: the sound absorbing cotton has a thickness of 100 mm, a bulk density of 32 Kg/m 3 , a tube bundle length of 10 mm, a tube diameter of 1.6 mm, a perforation rate of 3.6%, a slit length of 3.6 mm, and a slit width of 0.04 mm.
- the cavity depth is 100mm.
- the outer side of the muffler covers the insertion frequency (Hz) caused by the ice layer treatment.
- the flue gas temperature inside the muffler reaches 65 °C under the condition that the inlet of the axial fan produces flue gas.
- the outer wall of the muffler is covered with a 100 mm thick ice layer, which is caused by the treatment of covering 100 mm thick ice layer.
- the actual loss was measured by the insertion loss, and the ambient temperature was 12 ° C. The measurement results are shown in Figure 6 and Table 2.
- the muffler of the invention comprises a pipe muffler, a cryogenic refrigeration system and a temperature control device, the sound absorption structure is laid on the inner wall of the pipe muffler, and a low temperature refrigeration system is installed on the outer wall of the pipe muffler, and the refrigeration system reduces the temperature of the wall surface of the sound absorption structure back surface, thereby being in the muffler
- the temperature inside the sound absorbing structure generates a temperature gradient from relatively high temperature to relatively low temperature, and the temperature gradient generated by the cold end of the cryogenic refrigeration system causes the bending of the sound line in the tube to bend, so that more acoustic components are obliquely incident into the sound absorbing structure.
- the sound absorbing structure can "capture" more noise through the cold end of the cryogenic refrigeration system. Sound, instead of letting noise pass over its surface, can fully utilize the sound-absorbing potential of the sound-absorbing structure, so that its sound-absorbing ability can be fully exerted, and the sound-absorbing performance is improved, thereby making the muffler's sound-absorbing ability
- the saturation "becomes" a saturated, supersaturated state, which greatly improves the sound absorption effect of the sound absorbing structure, and produces an excessive amount of noise reduction based on the original muffler of the given muffler.
- the muffler based on the sound line deflection theory of the present embodiment having a cryogenic refrigeration system is composed of a muffler housing 1, a cryogenic refrigeration system 2, a temperature control device 3, and a sound absorbing structure 4, in the shell of the muffler.
- a cryogenic refrigeration system 2 is installed on the outer wall of the body 1, and the refrigeration system is cooled by a compressor.
- the refrigeration system is composed of a compressor 10, a condenser 11, an evaporator 12, a low pressure pipe 8, a high pressure pipe 9, and a liquid storage dryer 5.
- the temperature control device 3 is a temperature control device conventionally used in the art, that is, the temperature control device 3 is composed of an expansion valve 6 and a capillary temperature pack 7.
- the evaporator 12 is wound around the outer wall of the muffler tube to absorb heat, and the temperature gradient is quantitatively controlled by the refrigeration system 2 and the temperature control device 3.
- a sound absorbing structure 4 is placed on the inner wall of the casing 1 of the muffler.
- the sound absorbing structure of the inner wall of the muffler pipe in the embodiment may be a porous sound absorbing material, a thin plate resonance sound absorbing structure, a thin film resonant sound absorbing structure, a perforated plate sound absorbing structure, a micro perforated plate sound absorbing structure, and a micro
- the sound absorbing structure the Chinese patent number held by the inventor: ZL00100641.X, the tube bundle type perforated plate resonance sound absorbing device and the composite sound absorbing structure thereof.
- the temperature control device of the cryogenic refrigeration system is used to ensure that there is a temperature gradient of 1-200 between the inner and outer walls of the muffler pipe, and the temperature inside the pipe is greater than the temperature of the cold end of the outer wall of the pipe.
- the low temperature refrigeration system should at least cover the outer wall area of the muffler casing. 5%.
- a muffler having a cryogenic refrigeration system based on the theory of sound line deflection is composed of a muffler housing 1, a cryogenic refrigeration system 2", a temperature control device 3, and a sound absorbing structure 4, in the muffler.
- the cryogenic refrigeration system 2" is mounted on the outer wall of the casing 1.
- the cryogenic refrigeration system in this embodiment uses semiconductor refrigeration, wherein the semiconductor refrigeration system insulating ceramic sheet 13, the metal conductor 14, the N-type and P-type semiconductor 15, and the DC power source 16 are composed.
- the cold end 17 and the hot end 18 are respectively formed; the temperature control device 3 can use a conventional heat sink to dissipate heat, a fan to dissipate heat, or a method such as air cooling or water cooling to control heat dissipation.
- the semiconductor refrigerating patch is attached to the outer wall of the muffler pipe, and the temperature gradient is quantitatively controlled by the refrigeration system and the temperature control device.
- the sound absorbing structure 4 is laid on the inner wall of the casing 1 of the muffler.
- the cryogenic refrigeration system in this embodiment uses semiconductor refrigeration, and the semiconductor refrigeration chip, that is, the cold end 17, can be attached to the outer wall of the muffler pipe; Example 4
- a muffler having a cryogenic refrigeration system based on the theory of sound line deflection is composed of a muffler housing 1, a cryogenic refrigeration system 2, a temperature control device 3, and a sound absorbing structure 4, in the shell of the muffler.
- the cryogenic refrigeration system 2 is mounted on the outer wall of the body 1, and the refrigeration system in this embodiment is cooled by liquid nitrogen.
- the cryogenic refrigeration system consists of a liquid nitrogen dewar 19 and a pipe cooler 20, and the temperature control device is controlled by a valve, and the valve is used to control the nitrogen pressure in the liquid nitrogen dewar 19 and the nitrogen bottle 39 and to the pipe cooler. 20 liquid nitrogen and normal temperature nitrogen flow to achieve quantitative control of temperature.
- a sound absorbing structure 4 is placed on the inner wall of the casing 1 of the muffler.
- the refrigeration system in this embodiment is cooled by liquid nitrogen, and the liquid nitrogen and normal temperature nitrogen are introduced into the pipe cooler 20, mixed in the pipe cooler 20, and then the pipe cooler 20 is covered.
- the outer wall of the muffler housing 1 is described; the temperature control device 3 controls the temperature of the outer wall of the muffler housing 1 by controlling the flow rate of the liquid nitrogen dewar 19 and the nitrogen bottle 39 of normal temperature nitrogen.
- a muffler having a cryogenic refrigeration system based on the theory of sound line deflection is composed of a muffler housing 1, a cryogenic refrigeration system 2, a temperature control device 3, and a sound absorbing structure 4, in the shell of the muffler.
- the cryogenic refrigeration system 2 is installed on the outer wall of the body 1.
- the refrigeration system in the embodiment uses a refrigeration system existing in the surrounding environment to supply a gas or a cooling liquid lower than the temperature inside the pipeline to the outer wall of the muffler, and the temperature control device adopts a valve control. Quantitative control of temperature is achieved by using a valve to control the flow of temperature gas or cooling liquid into the cryogenic conduit of the conduit cooler 20.
- a muffler based on a sound line deflection theory having a cryogenic refrigeration system is composed of a muffler housing 1, a cryogenic refrigeration system 2, a temperature control device 3, and a sound absorbing structure 4, in the muffler.
- the cryogenic refrigeration system 2 is mounted on the outer wall of the casing 1.
- the refrigeration system in this embodiment is magnetically cooled, and is composed of a magnetic medium 27, a magnetic N pole 25, a magnetic S pole 26, a radiator 28, and a duct cooler 20, etc.
- the working medium 27 is isothermally magnetized in the high temperature zone 23, releasing heat, and the heat is led out through the heat sink 28, and the heat is demagnetized in the low temperature zone 24 to absorb heat, and the heat exchanger is placed in the low temperature region of the magnetic medium 27 through the magnetic medium 27
- the adiabatic demagnetization absorbs heat, forming a cold end, and lowering the temperature of the outer wall of the muffler through the duct cooler 20.
- the muffler based on the sound line deflection theory of the present embodiment has a muffler of a low temperature refrigeration system, a housing of a muffler 1, a cryogenic refrigeration system 2, a temperature control device 3, and a suction
- the sound structure 4 is composed, and the low temperature refrigeration system 2 is installed on the outer wall of the casing 1 of the muffler.
- the refrigeration system in this embodiment adopts thermoacoustic refrigeration, and uses a standing wave thermoacoustic refrigerator, a traveling wave thermoacoustic refrigerator, and a Stirling refrigerator. , pulse tube refrigerator. As shown in Fig.
- the standing wave thermoacoustic refrigerator is composed of a sound wave generator 29, a high temperature heat exchanger 30, a low temperature heat exchanger 31, a regenerator 32, a resonance chamber 33, and a duct cooler 20.
- the traveling wave thermoacoustic refrigerator is composed of a sound wave generator 29, a temperature heat exchanger 30, a low temperature heat exchanger 31, a regenerator 32, a traveling wave acoustic tube 34, and a pipe cooler 20.
- the Stirling refrigerator is composed of a sound wave generator 29, an acoustic wave absorber 35, a high temperature heat exchanger 30, a low temperature heat exchanger 31, a regenerator 32, and a duct cooler 20.
- the pulse tube refrigerator is composed of a sound wave generator 29, a high temperature heat exchanger 30, a low temperature heat exchanger 31, a regenerator 32, a gas reservoir 36, a valve 37, a pulse tube 38, and a pipe cooler 20. .
- the bottom of the micro-slot sound absorbing structure is subjected to freezing ice treatment.
- the micro-slot sound absorbing structure 21 having the ice block 22 at the bottom is frozen in the freezer for more than 10 hours, and the ice 22 is frozen and fixed at the bottom of the micro-slot sound absorbing structure 21 to form a micro-slot sound absorbing structure in the case of frozen ice. .
- the structural parameters of the micro-slot sound absorbing structure 21 are: slit length: 1.8tnm, slit width: 0.03 mm, slit spacing: 5tnm, thickness: 0.8mm, cavity depth 298mm, ice thickness 42mm.
- the ice cube is frozen and fixed at the bottom of the micro-slot sound absorbing structure, and the micro-slot sound absorbing structure of the bottom frozen ice is fixed on the test end of the standing wave tube.
- the micro-slot sound absorbing structure of the bottom frozen ice is prepared, and the sound absorption performance of the micro-slot sound absorbing structure is tested on the standing wave tube.
- the normal incidence sound absorption coefficient of the micro-slot sound absorption structure before and after the frozen ice treatment on the bottom of the micro-slot sound absorption structure is as shown in Fig. 17.
- the sound absorption coefficient of the micro-slot sound absorption structure after the bottom frozen ice treatment increased from 0.410, 0.400, 0.420 to 0.685, 0.720 and 0.620, respectively, and in the low frequency range of 125Hz ⁇ 400Hz, the bottom
- the sound absorption coefficient of the micro-slot sound absorption structure after frozen ice treatment is 0.1-0.3 higher than that of the unfrozen ice treatment, and the sound absorption coefficient at the bottom frozen ice is also compared with the unfrozen at the frequency of 800 Hz to 1600 Hz. The situation of ice has improved.
- the sound absorption coefficient of the micro-slot sound-absorbing structure before and after freezing ice is not difficult to see: after the bottom-frozen ice treatment of the micro-slot sound-absorbing structure, not only the low-frequency sound absorption coefficient is obviously improved, but also the intermediate frequency suction. The acoustic coefficient is also improved, effectively suppressing broadband noise and increasing the sound absorption of the entire frequency band.
- the muffler based on the theory of sound line deflection based on the theory of sound line deflection has a muffler installed on the outer wall of the muffler housing, which occupies 5% and 100% of the surface of the muffler, actually In the application, the coverage area can be selected within 5%-100% as needed.
- the muffler based on the theory of sound line deflection theory of the present invention essentially utilizes the deflection of the sound line caused by the "cold trap" generated by the temperature gradient to maximize the capture and reduce the noise, and at the same time fully exerts the existing
- the sound absorption potential of the muffler sound absorption structure is a noise reduction technology based on temperature gradient and sound line deflection with a low temperature refrigeration system.
- the characteristic is that the temperature gradient is artificially introduced into the structure design of the muffler as a design optimization parameter.
- the cryogenic refrigeration system is installed on the outer wall of the muffler, so that it becomes a cryogenic refrigeration system.
- the cold-end muffler additionally generates a temperature gradient, and uses the temperature gradient to make the sound line in the pipe wall face the cold end, that is, the bending and deflection of the sound-absorbing structure on the inner wall of the air-flow pipe, which reduces the contact between the muffler pipe and the sound-absorbing structure of the muffler.
- the sound wave component makes more acoustic components obliquely incident into the sound absorbing structure of the muffler inner lining, so that the sound absorbing potential of the sound absorbing structure of the muffler can be more fully and effectively utilized, the effective absorption of noise in the pipeline is enhanced, and the pipeline is reduced.
- the amplitude of the stimulated acoustic normal vibration mode increases the muffler of the muffler and reduces the external radiated noise inside the tube.
- the muffler realizes the quantitative control of the temperature gradient by adjusting the cold end temperature of the cryogenic refrigeration system, further improves the muffling amount of the muffler, and optimizes the sound absorption band.
- the method is an improvement to the existing pipe muffler, the method of installing the cryogenic refrigeration system on the outer wall of the existing muffler pipe is provided with an additional over-consumption method without substantially modifying the structure of the existing muffler.
- cryogenic refrigeration systems By optimizing the selection and changing the cold end generation mode of cryogenic refrigeration systems (low temperature refrigeration systems can use dedicated compressor refrigeration, semiconductor refrigeration, liquid nitrogen refrigeration, dry ice refrigeration, acoustic refrigeration, chemical refrigeration, magnetic refrigeration, adsorption refrigeration, pulse tube refrigeration, Solar cooling, etc., can also use the surrounding environment, the transport of the refrigeration system is lower than the temperature inside the pipeline. Gas or cooling liquid, even using the outer wall of the muffler housing to cover the ice layer to provide the cold end, etc.> and the installation method can generate the cold end temperature gradient that can meet the requirements of large noise reduction and application environment to meet the requirements of different noise control occasions. .
- the invention can be applied to aero-engine nacelle muffling, helicopter turboshaft engine muffling ducts, gas turbines and other intake and exhaust piping systems and other environmental conditions that facilitate and allow the provision of cold-end cryogenic refrigeration systems.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Aviation & Aerospace Engineering (AREA)
- Compressor (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
- Exhaust Silencers (AREA)
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/203,699 US8408359B2 (en) | 2009-02-27 | 2010-02-26 | Acoustic attenuation method based on acoustic ray deflection theory and a muffler |
EP10745798.8A EP2402568B1 (en) | 2009-02-27 | 2010-02-26 | Noise elimination method and muffler |
EA201171092A EA019238B1 (ru) | 2009-02-27 | 2010-02-26 | Способ шумопоглощения и шумоглушитель, основанный на теории преломления звуковых лучей |
JP2011551395A JP5291206B2 (ja) | 2009-02-27 | 2010-02-26 | 音線偏向理論に基づく消音方法及び消音器 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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CN200910119947.3 | 2009-02-27 | ||
CN200910119947 | 2009-02-27 |
Publications (1)
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WO2010097014A1 true WO2010097014A1 (zh) | 2010-09-02 |
Family
ID=42665018
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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PCT/CN2010/000242 WO2010097014A1 (zh) | 2009-02-27 | 2010-02-26 | 一种基于声线偏折理论的消声方法和消声器 |
Country Status (5)
Country | Link |
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US (1) | US8408359B2 (zh) |
EP (1) | EP2402568B1 (zh) |
JP (1) | JP5291206B2 (zh) |
EA (1) | EA019238B1 (zh) |
WO (1) | WO2010097014A1 (zh) |
Cited By (2)
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CN106448647A (zh) * | 2016-10-21 | 2017-02-22 | 武汉市发源发明推广有限公司 | 一种蒸汽或气体特效消声器 |
CN108615522A (zh) * | 2018-04-26 | 2018-10-02 | 重庆大学 | 一种单腔多个共振频率旁支型共振消声器 |
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JP5527125B2 (ja) * | 2010-09-14 | 2014-06-18 | 富士通株式会社 | 音量予測プログラム、音量予測装置及び音量予測方法 |
US9752494B2 (en) | 2013-03-15 | 2017-09-05 | Kohler Co. | Noise suppression systems |
US9388731B2 (en) | 2013-03-15 | 2016-07-12 | Kohler Co. | Noise suppression system |
GB2515277B (en) * | 2013-06-12 | 2019-04-17 | Airbus Operations Ltd | Distributing gas within an aircraft |
JP6075263B2 (ja) * | 2013-10-04 | 2017-02-08 | 株式会社デンソー | 車両用吸気装置 |
US9759447B1 (en) * | 2016-03-14 | 2017-09-12 | Acoustic Metameterials, Inc. | Acoustic metamaterial noise control method and apparatus for ducted systems |
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- 2010-02-26 JP JP2011551395A patent/JP5291206B2/ja not_active Expired - Fee Related
- 2010-02-26 EA EA201171092A patent/EA019238B1/ru not_active IP Right Cessation
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CN106448647A (zh) * | 2016-10-21 | 2017-02-22 | 武汉市发源发明推广有限公司 | 一种蒸汽或气体特效消声器 |
CN108615522A (zh) * | 2018-04-26 | 2018-10-02 | 重庆大学 | 一种单腔多个共振频率旁支型共振消声器 |
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Also Published As
Publication number | Publication date |
---|---|
JP2012518746A (ja) | 2012-08-16 |
US20120055735A1 (en) | 2012-03-08 |
EP2402568A4 (en) | 2013-12-18 |
EP2402568B1 (en) | 2016-11-23 |
US8408359B2 (en) | 2013-04-02 |
JP5291206B2 (ja) | 2013-09-18 |
EA019238B1 (ru) | 2014-02-28 |
EA201171092A1 (ru) | 2012-02-28 |
EP2402568A1 (en) | 2012-01-04 |
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