CN108853855A - A kind of air-operated drive sound extinguishing device having cooling effect - Google Patents
A kind of air-operated drive sound extinguishing device having cooling effect Download PDFInfo
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- CN108853855A CN108853855A CN201810486187.9A CN201810486187A CN108853855A CN 108853855 A CN108853855 A CN 108853855A CN 201810486187 A CN201810486187 A CN 201810486187A CN 108853855 A CN108853855 A CN 108853855A
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- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62C—FIRE-FIGHTING
- A62C31/00—Delivery of fire-extinguishing material
- A62C31/02—Nozzles specially adapted for fire-extinguishing
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Abstract
A kind of air-operated drive sound extinguishing device having cooling effect, including air intake duct and the nozzle being connected at air intake port.The inlet port of air intake duct is provided with propeller, and propeller obtains high pressure draught by rotation；It is provided with disturbance device in air intake duct, low-frequency sound wave disturbance is carried out to high pressure draught, generates the high pressure draught with disturbance, the high pressure draught with disturbance enters in nozzle from air intake port.The nozzle has contraction section, so that the high pressure draught into nozzle is obtained bigger speed by way of contraction and sprays, to reduce the gas flow temperature sprayed from jet expansion.It is used using the acoustic perturbation cooling fire extinguishing for realizing sound synchronous with cooling, can effectively avoid the generation of re-ignition.
Description
Technical field
The present invention relates to acoustic applications technical fields, go out more particularly, to a kind of air-operated drive sound for having cooling effect
Fiery device.
Background technique
Fire is always to threaten one of people's public security and the major casualty of social development.Traditional fire-fighting mode is a variety of
Multiplicity, but as the expansion of userbase, intensity of a fire type increase, conventional fire extinguisher encounters many problems in the application.
(1) traditional gas fire extinguishing system is as breathed out dragon series, using carbon-dioxide fire engine, is usually used in for electrical equipment etc.
Some column Code in Hazardous Special Locations.However, the malfunction of gas extinguishing system can threaten the life security of personnel in the scene of a fire in confined space.
(2) conventional fire extinguisher is mostly high-pressure bottle, therefore higher to the condition of storage, not can extrude, cannot collide,
Explosion is easily expanded under high temperature.
(3) conventional fire extinguisher is not used to aerospace system.Extinguishing chemical used in conventional fire extinguisher will be to the in-orbit system of space flight
System is polluted and is destroyed.In addition, extinguishing chemical belongs to floating state under space microgravity environment, flame, Bu Nengshi can not be adhered to
Existing extinguishing effect.
In view of the above-mentioned problems, researcher has carried out the research work of sound fire extinguishing.Earliest work is put out a fire using shock wave.
This method is digested fuel by way of conflagration and makes burning cannot be from maintenance.Similar to explosive snuffing, this method is lacked
Point is that shock wave also seriously affects surrounding objects while fire extinguishing.
Related researcher proposes ultrasonic wave extinguishing method, and this method does not need extinguishing chemical, do not generate fire extinguishing residue, together
When do not bring ambient noise.High frequency sound wave causes flame front high-frequency vibration, and high vibration amplitude is needed to can be only achieved extinguishing effect.
Correlative study shows flame such as low-pass filter, and influence of the high frequency pumping to its performance is smaller, hands over referring to Xi'an
A kind of logical ultrasonic fire extinguisher (application number of university application patent：2016102822245.Inventor：Wei Yanju, Yang Yajing, Liu Sheng
China, Li Donghua).
Experiment shows that influence of the low-frequency sound wave to flame front is significant with theoretical research.In fact, for air, oxygen
The resonant frequency of gas is 60Hz, and the resonant frequency of nitrogen is lower than 60Hz.Pertinent literature shows the resonant frequency 20-50Hz model of air
In enclosing.When low-frequency sound wave acts on flame, resonance characteristics reinforces air vibration, increases the motion range of air, makes
The sparse and dense distribution for obtaining oxygen is reinforced, and flame will extinguish in sparse part because oxygen content is insufficient.On the other hand, sound
Pressure disturbance will break up the oxygen molecule of flame periphery, the oxygen supply channel of flame combustion be blocked, so that fray-out of flame.
Chen Yong team of the National University of Defense technology passes through analysis shows low-frequency sound wave is flame front pair the reason of can effectively putting out a fire
For example same low-pass filter of the response of disturbance.Low-frequency sound wave reinforces rough burning, and flame front forms large-scale pleat
Wrinkle stretches, and when reaching a certain level, flame front collapses, and leads to fray-out of flame.The flame front drawn high makees heat transfer
Cause burning can not be from maintenance to reduce flame front temperature with reinforcement.On the other hand, compared to high frequency sound wave, all-bottom sound
The longer wavelength of wave makes the low-pressure area duration longer, in the case where density is certain, according to The Ideal-Gas Equation p=
ρR0T(R0For gas constant) it can be seen that, in the case that density p is certain, the temperature T of low-pressure area also changes.
For low frequency fire-fighting mode, 2012 US Department of Defense Advanced Research Projects Agency (DARPA) it is successfully huge with two
Sound wave launching tube gone out fire, but equip it is heavy, it is complicated for operation.
2012, several students of George Mason University of the U.S. created one " hand-held fire-extinguisher ".This method utilizes
Low-frequency sound wave mode is put out a fire, research shows that influence of the sound wave to flame is very big as frequency of sound wave 30-60Hz, fire extinguishing
Effect is good.Chinese Donghua University Guan Hongyun team the research shows that sound wave of frequency of sound wave 20-80Hz can effectively realize fire extinguishing
Effect.Guan Hongyun team applies for a kind of low-frequency sound wave fire extinguisher (application number of patent of invention according to research achievement：
2016102840597.Inventor：Lu Hao, official's flood fortune, Zhao Dongyu, Wang Xuechun, Lu Xuechun, Lu Boxin, Yu Rongzheng).Shang Hai Zhao Peng
Intelligent development in science and technology Co., Ltd has also applied for a kind of intelligent portable sound wave fire extinguishing of the utility model patent based on the principle of similitude
Device (application number：201620176718.0.Inventor：Liu Yu, Wu Minghua).University Of Science and Technology Of Shandong has applied for that utility model patent is low
Frequency sound wave fire extinguisher (application number：2015206801107.Inventor：Han Baokun, Yan Chengwen, Cui Wenjie, Su Wei).
Above-mentioned patent all utilizes low-frequency sound wave to influence flame front structure, to reach extinguishing effect.However the above method is only
It can be directed to small scale flame, be difficult to avoid re-ignition.For biggish flame, there are problems for the above method.Biggish flame makes
It obtains ambient air temperature to increase, even if the possibility for still having flame re-ignition due to reaching ignition point after fray-out of flame.Therefore, exist
While fire extinguishing using low-frequency sound wave, need to reduce temperature simultaneously.
On the other hand, since sound fire extinguishing frequency used is 100Hz hereinafter, obtaining sound for current electric drive loudspeaker
For mode, energy conversion efficiency is lower, and the volume of loudspeaker is often more huge with weight, is unfavorable for portable fire suppression applications field
It closes.
Summary of the invention
In view of the defects existing in the prior art, the invention proposes a kind of air-operated drive sound fire extinguishings for having cooling effect
Device.
To realize the above-mentioned technical purpose, the specific technical solution that the present invention uses is as follows：
The present invention is a kind of using pneumatic method acquisition low-frequency sound wave, and passes through the method that nozzle obtains low temperature.
Specifically, the present invention provide a kind of air-operated drive sound extinguishing device for having cooling effect, including air intake duct with
And it is connected to the nozzle at air intake port, nozzle and air intake duct are to be tightly connected and communicating together.The air inlet of air intake duct
End is provided with propeller, and propeller obtains high pressure draught by rotation.Be provided with disturbance device in air intake duct, disturbance device into
High pressure draught in air flue carries out low-frequency sound wave disturbance, generates the high pressure draught of band disturbance, with the high pressure draught disturbed by into
Air passage outlet enters in nozzle；The nozzle has contraction section, and the high pressure draught into nozzle is made by way of contraction
It obtains bigger speed and is sprayed after reducing its gas flow temperature from jet expansion.The nozzle can select as the case may be
Shape nozzle or Laval supersonic nozzle are shunk with subsonic speed.
Heretofore described propeller can be using conventional electrically driven (operated) propeller comprising 2 or more blades, 2
Above blade is evenly distributed on its central rotating shaft of propeller, is driven on central rotating shaft by motor driven central rotating shaft
All blade synchronous rotaries, if the revolving speed of propeller be n.
Disturbance device of the present invention includes that multiple disturbance blades of radially circle distribution (are not limited only to shown in figure b 4
Disturb blade), the shape for disturbing blade is unlimited.Each disturbance blade is respectively connected with power, and each disturbance blade can be in power
It is revolved around its respective rotary shaft (such as each blade is around its respective center axis rotation) according to the π f angular speed of ω=2 under driving
Turn, to obtain the frequency disturbance that frequency is f, realizes and low-frequency sound wave disturbance is carried out to the high pressure draught in air intake duct, generate band
The high pressure draught of disturbance.
Aforementioned schemes are separately to be independently arranged propeller and disturbance device.It in the present invention can also be by the propeller
And disturbance device becomes one, propeller includes multi-disc blade, and multi-disc blade is distributed on its central rotating shaft of propeller, is led to
It crosses motor driven central rotating shaft and then drives all blade synchronous rotaries on central rotating shaft, to obtain high pressure draught；Each paddle
Self-powered i.e. each blade is connected separately with independent power to Ye Jun respectively, and each blade can be under the driving of each ultromotivity
Rotary shaft on its own is rotated with the angular speed of the π of ω=2 f, to obtain the frequency disturbance that frequency is f, is realized
Low-frequency sound wave disturbance to high pressure draught, generates the high pressure draught with disturbance.
It should be pointed out that the length of air intake duct is unfettered with shape, configured according to application scenarios.Its air inlet of air intake duct
The radius of mouth is bigger, its blade length of corresponding propeller is bigger, passes through the pressure p for the high pressure draught that propeller rotation obtainsa
It is bigger.Its length for disturbing blade of disturbance device and width are bigger, and the pressure of acquisition disturbs p 'aIt is bigger.
Pass through the pressure p for the high pressure draught that propeller rotation obtainsaIt can be obtained by following formula
pa=Cpρ0n2D4. (1)
In above formula, CpFor tension coefficient, determined by propeller geometric parameter；N is the revolving speed of propeller rotation；ρ0For air inlet
The current density of road inlet；D is the diameter of propeller.
The disturbance device, which is realized, disturbs the low-frequency sound wave of high pressure draught, so that flow through the high pressure draught of disturbance device
Airflow volume and pressure generating period change, and form low-frequency noise, the pressure disturbance of generation is p 'a。
If radius is R at nozzle entranceA, RCFor nozzle exit radius, nozzle adds high pressure draught by way of contraction
Speed, and then obtain the high pressure draught of bigger speed.In the inlet of nozzle, its pressure and temperature are expressed as pA(=pa+
p′a) and TA, air-flow velocity VA.The then energy enthalpy h of the inlet of nozzleAFor：
Wherein γ indicates specific heat ratio；cpIndicate heat capacity at constant pressure；ρAIndicate density at nozzle entrance；cAIt indicates at nozzle entrance
The velocity of sound.
Since air-flow flowing is equal entropy flux, then energy will not dissipate in nozzle, then energy enthalpy does not change,
For this purpose, total enthalpy can be defined
h0=hA (3)
Gas is perfect gas in nozzle, then system stagnation pressure (p can be obtained under the concept of total enthalpy0), total moisture content (T0) with
The stagnation velocity of sound (c0)
Wherein ρ0Represent corresponding density under system stagnation pressure；
According to constant entropy The Ideal-Gas Equation, the pressure p, temperature T and Mach number M of any position can be with tables in nozzle
Sign is
The temperature of any position can be characterized as in nozzle
It is found that corresponding temperature reduces when Flow in Nozzle Mach number increases；According to formula (6) it is found that at nozzle entrance
It can be characterized as with the temperature proportional of nozzle exit
Wherein, in the pressure of nozzle exit and outside pressure PEnvironmentUnanimously, i.e. PC=PEnvironment, available according to formula (5)
The Mach number M of nozzle exitCFor
As the Mach number M that nozzle exit is calculated by formula (8)CWhen less than 1, nozzle exit air-flow is subsonic speed
Flowing, at this point, nozzle shrinks shape nozzle using subsonic speed, the exit radius of inlet radius to the nozzle of the nozzle gradually subtracts
It is small, it, can with constantly reducing at nozzle entrance to the cross-sectional area for being gradually reduced i.e. nozzle of spout radius between nozzle exit
To bring the increase of nozzle interior air-flow speed, the reduction of nozzle interior air-flow pressure and temperature.
Formula (8) brings that formula (7) can obtain at nozzle entrance and the temperature of nozzle exit ratio is into
As the Mach number M for the nozzle exit being calculated by formula (8)CWhen greater than 1, then in a certain cross section of nozzle
Place's flowing Mach 2 ship 1, defining the cross section is critical cross-section；Used nozzle is Laval supersonic nozzle at this time,
The middle section of Laval supersonic nozzle is shunk, and the radius at nozzle entrance is RA, the radius of nozzle exit is RC, critical cross-section
Minimum cross-section position i.e. in the middle part of nozzle, corresponding cross sectional radius are RB, RAGreater than RB, RCGreater than RB.Laval ultrasound
Radius in the middle part of radius to nozzle at its nozzle entrance of fast nozzle at minimum cross-section is gradually reduced, minimum transversal in the middle part of nozzle
The radius of radius to nozzle exit at face is gradually increased.The changing rule of spout radius is unfettered in nozzle arrangements.Such as
The radius in the middle part of nozzle entrance to nozzle between minimum cross-section be can be in linear reduction, nozzle middle part is minimum transversal
It is without being limited thereto in practical applications to the radius of nozzle exit in linear increase at face.
For Laval supersonic nozzle, according to the conservation of mass in flow process, then radius R at its nozzle entranceAWith nozzle
Any cross-section radius R at there are following conservation of mass formula
Wherein, VA、ρAFlowing velocity and density respectively at nozzle entrance；V, ρ is respectively any cross-section of nozzle
Flowing velocity and density
It defines at nozzle entrance and the acoustic wave propagation velocity of any cross-section of nozzle is cAWith c, then exist
At critical cross-section, corresponding Mach 2 ship MB=1, then the radius R of critical cross-sectionBWith RARelationship can
To be characterized as：
Formula (5) brings the available following formula of formula (12) into
Nozzle exit radius RCRelative to critical cross-section radius RBRelational expression it is as follows
At this point, nozzle exit temperature TCWith temperature T at nozzle entranceARelationship such as formula (7) shown in.
It should be noted that the case where being compared to subsonic flow, supersonic flows middle outlet gasflow mach number breaks through 1
Limitation, better low temperature can be obtained.
Beneficial effects of the present invention are as follows：
Technical solution of the present invention is able to solve two technical problems that current sound fire extinguishing faces：
(1) electrodynamic transducer be converted into low-frequency sound wave (100Hz or less) transfer efficiency it is lower, equipment volume and weight are not
Meet portable use.
(2) do not have cooling effect in conventional acoustic fire-extinguishing apparatus, the generation of inevitable re-ignition constrains practical model
It encloses.
Structure of the invention is light, easy to carry, and has good cooling effect, can effectively avoid the hair of re-ignition
It is raw.
Detailed description of the invention
Fig. 1 is structural schematic diagram of the invention；
In Fig. 1：1, air intake duct；2, nozzle；A, propeller；B, disturbance device；
Fig. 2 is the structural schematic diagram of propeller and disturbance device；Wherein (a) is the structure and motion mode of propeller
Schematic diagram；(b) be disturbance device structure and motion mode schematic diagram.
Fig. 3 is the structure and motion mode schematic diagram of propeller and the integrated setting of disturbance device；
Fig. 4 is the structural schematic diagram that subsonic speed shrinks shape nozzle；
Fig. 5 is the structure principle chart of extinguishing device provided by the present invention in the case of subsonic flow；
Fig. 6 is the structural schematic diagram of Laval supersonic nozzle；
Fig. 7 is the structure principle chart of extinguishing device provided by the present invention in the case of supersonic flows.
Specific embodiment
In order to which technical solution of the present invention and advantage is more clearly understood, with reference to the accompanying drawings and embodiments, to this hair
It is bright to be further elaborated.It should be appreciated that described herein, the specific embodiments are only for explaining the present invention, is not used to
Limit the present invention.
The present invention is a kind of using pneumatic method acquisition low-frequency sound wave, and passes through the method that nozzle obtains low temperature.
Referring to Fig.1, it is the structural schematic diagram of an of the invention specific embodiment, including air intake duct 1 and is connected to air intake duct
The nozzle 2 in exit, nozzle 2 and air intake duct 1 are to be tightly connected and communicating together.The inlet port of air intake duct 1 is provided with spiral shell
Paddle a is revolved, propeller a obtains high pressure draught by rotation.Disturbance device b is provided in air intake duct 1, disturbance device b is to air intake duct
Interior high pressure draught carries out low-frequency sound wave disturbance, generates the high pressure draught with disturbance, and the high pressure draught with disturbance passes through air intake duct
Outlet enters in nozzle 2；The nozzle 2 has contraction section, obtains the high pressure draught into nozzle 2 by way of contraction
It obtains bigger speed and is sprayed after reducing its gas flow temperature from jet expansion.Entire air intake duct and propeller set in it
And disturbance device constitutes the pneumatic audible segment that the present invention has the air-operated drive sound extinguishing device of cooling effect.It is described
Nozzle 2 can select subsonic speed to shrink shape nozzle or Laval supersonic nozzle as the case may be.
Heretofore described propeller can be using conventional electrically driven (operated) propeller comprising 2 or more blades, 2
Above blade is evenly distributed on its central rotating shaft of propeller, is driven on central rotating shaft by motor driven central rotating shaft
All blade synchronous rotaries, if the revolving speed of propeller be n.
Disturbance device of the present invention includes that multiple disturbance blades of radially circle distribution (are not limited only to shown in figure b 4
Disturb blade), the shape for disturbing blade is unlimited.Each disturbance blade is respectively connected with power, and each disturbance blade can be in power
It is revolved around its respective rotary shaft (such as each blade is around its respective center axis rotation) according to the π f angular speed of ω=2 under driving
Turn, to obtain the frequency disturbance that frequency is f, realizes and low-frequency sound wave disturbance is carried out to the high pressure draught in air intake duct, generate band
The high pressure draught of disturbance.
It should be pointed out that the length of air intake duct is unfettered with shape, configured according to application scenarios.Its air inlet of air intake duct
The radius of mouth is bigger, and the length of corresponding its blade of propeller is bigger, passes through the pressure for the high pressure draught that propeller rotation obtains
It is bigger.
In Fig. 2 (a), the design of its structure of propeller will affect the air flow pressure in air intake duct, so that air velocity is influenced, spiral shell
Rotation its structure of paddle can be designed that (propeller lift formula is more perfect, referring to formula by propeller lift formula
(1)), designed pressure is determined according to specific application background.
Its each disturbance blade of disturbance device is rotated around own rotation axis in Fig. 2 (b), to obtain stronger pressure disturbance, is disturbed
Movable vane leaf length and width are larger, and forcing frequency is determined by the π of ω=2 f.
The pressure of the high pressure draught obtained by propeller rotation can be obtained by following formula
pa=Cpρ0n2D4. (1)
In above formula, CpFor tension coefficient, determined by propeller geometric parameter；N is the revolving speed of propeller rotation；ρ0For air inlet
The current density of road inlet；D is the diameter of propeller.
In Fig. 2 (b), the disturbance device includes multiple disturbance blades of radially circle distribution, and each blade that disturbs connects
Be connected to power, it is each disturb blade can around its respective rotary shaft, (such as each blade be around its respective central axis under power drive
Rotation) it is rotated according to the π f angular speed of ω=2, so that flowing through the airflow volume and pressure generation of the high pressure draught of disturbance device
Cyclically-varying forms low-frequency noise, i.e. pressure disturbance is p 'a。
The rotation of its blade of the rotation and disturbance device of propeller can be driven by motor mode, thus directly
It connects and electric energy is converted into mechanical energy.
Aforementioned schemes are separately to be independently arranged propeller and disturbance device, further can also using propeller and
Disturbance device integrates, referring to Fig. 3.Propeller includes multi-disc blade, and multi-disc blade is distributed in its central rotating shaft of propeller
On, drive all blades on central rotating shaft using n as revolving speed synchronous rotary by motor driven central rotating shaft, to obtain height
Pressure gas stream.Self-powered i.e. each blade is connected separately with independent power to each blade respectively, and each blade can be each
The rotary shaft on its own is surrounded under the driving of ultromotivity, (i.e. rotation) is rotated with the angular speed of the π of ω=2 f, to obtain
Frequency is the frequency disturbance of f, realizes and disturbs to the low-frequency sound wave of high pressure draught, generates the high pressure draught with disturbance.
If radius is R at nozzle entranceA, RCFor nozzle exit radius, nozzle adds high pressure draught by way of contraction
Speed, and then obtain the high pressure draught of bigger speed.In the inlet of nozzle, its pressure and temperature are expressed as pA(=pa+
p′a) and TA, air-flow velocity VA.The then energy enthalpy h of the inlet of nozzleAFor：
Wherein γ indicates specific heat ratio；cpIndicate heat capacity at constant pressure；ρAIndicate density at nozzle entrance？cAIt indicates at nozzle entrance
The velocity of sound.
Since air-flow flowing is equal entropy flux, then energy will not dissipate in nozzle, then energy enthalpy does not change,
For this purpose, total enthalpy can be defined
h0=hA (3)
Gas is perfect gas in nozzle, then system stagnation pressure (p can be obtained under the concept of total enthalpy0), total moisture content (T0) with
The stagnation velocity of sound (c0)
Wherein ρ0Corresponding density under system stagnation pressure.
According to constant entropy The Ideal-Gas Equation, the pressure p, temperature T and Mach number M of any position can be with tables in nozzle
Sign is
Further, the temperature of any position can be characterized as in nozzle
It is not difficult to find out that corresponding temperature reduces when Flow in Nozzle Mach number increases.According to above-mentioned formula, nozzle entrance
The temperature proportional of place (at A) and nozzle exit (at C) can be characterized as
It then can use the Mach number M for increasing nozzle exitCMethod realize nozzle exit gas flow temperature TCDrop
It is low.For the Mach number M for realizing nozzle exitCIncrease, can by using change cross section mode obtain.
The Mach number M of nozzle exit (at C) is considered firstC.In the pressure and outside pressure one of nozzle exit (at C)
Cause (outside pressure PEnvironmentIt is defined as PEnvironment), i.e. PC=PEnvironment.In the case, according to formula (5) available nozzle exit
Mach number MCFor
As the Mach number M of nozzle exitCWhen less than 1, nozzle exit air-flow is subsonic flow, at this point, nozzle is adopted
Shape nozzle is shunk with subsonic speed, the exit radius of inlet radius to the nozzle of the nozzle is gradually reduced, as shown in Figure 4.
Formula (8) is brought formula (7) into and can be obtained at nozzle entrance (at A)
Fig. 5 is the structure principle chart of fire extinguisher in the case of subsonic speed.
In subsonic speed, the exit radius of inlet radius to the nozzle of the nozzle is gradually reduced, with radius
Reducing is that cross-sectional area constantly reduces, and can bring the reduction of the increase of air velocity, pressure and temperature.When arrival critical value
When, that is, nozzle a certain cross-section its flow Mach 2 ship 1 when, air velocity is up to the velocity of sound, define the cross section be it is critical
Cross section.Supersonic flows will be entered by critical cross-section, during supersonic flows, to obtain bigger speed, this
When nozzle need to increase expansion line, i.e., the cross-sectional area for increasing nozzle after critical cross-section will cause the increasing of air velocity
Greatly, the reduction of pressure and the reduction of temperature.
As the Mach number M for the nozzle exit being calculated by formula (8)CWhen greater than 1, then in a certain cross section of nozzle
Place's flowing Mach 2 ship 1, defining the cross section is critical cross-section.At this point, nozzle uses Laval supersonic nozzle, such as Fig. 6 institute
Show, the middle section of Laval supersonic nozzle is shunk, and the radius at nozzle entrance is RA, the radius of nozzle exit is RC, critical cross
The position minimum cross-section B in the middle part of nozzle in section, that is, Fig. 6, corresponding cross sectional radius are RB。RAGreater than RB, RCIt is greater than
RB.Radius in the middle part of radius to nozzle at its nozzle entrance of Laval supersonic nozzle at minimum cross-section is gradually reduced, nozzle
The radius of radius to nozzle exit at the minimum cross-section of middle part is gradually increased.The changing rule of spout radius in nozzle arrangements
It is unfettered.The radius in the middle part of nozzle entrance to nozzle between minimum cross-section such as be can be in linear reduction, nozzle
It is without being limited thereto in practical applications to the radius of nozzle exit in linear increase at the minimum cross-section of middle part.
For Laval supersonic nozzle, according to the conservation of mass in flow process, then radius R (at A) at its nozzle entranceA
With there are following conservation of mass formula at any cross-section radius R of nozzle
Wherein, VA、ρAFlowing velocity and density at respectively nozzle entrance A；V, ρ is respectively any cross-section of nozzle
Flowing velocity and density.
Define nozzle entrance at (A at) with the acoustic wave propagation velocity of any cross-section of nozzle be cAWith c, then exist
At critical cross-section B, Mach 2 ship MB=1, then the radius R of critical cross-section BBWith RARelationship can be with table
Sign is：
Formula (5) brings the available following formula of formula (12) into
Nozzle exit radius RCRelative to critical cross-section radius RBRelational expression it is as follows
At this point, nozzle exit temperature TCWith temperature T at nozzle entranceARelationship as shown by：
It should be noted that the case where being compared to subsonic flow, supersonic flows middle outlet gasflow mach number breaks through 1
Limitation, better low temperature can be obtained.For the aerodynamic sound extinguishing device under supersonic flows, structure is as shown in Figure 7.
Although in conclusion the present invention has been disclosed as a preferred embodiment, however, it is not to limit the invention, any
Those of ordinary skill in the art, without departing from the spirit and scope of the present invention, when can make it is various change and retouch, therefore this hair
Bright protection scope is subject to the range defined depending on claims.
Claims (10)
1. a kind of air-operated drive sound extinguishing device for having cooling effect, it is characterised in that：Including air intake duct and it is connected to
Nozzle at air intake port, nozzle and air intake duct are to be tightly connected and communicating together.The inlet port of air intake duct is provided with
Propeller, propeller obtain high pressure draught by rotation.Disturbance device is provided in air intake duct, disturbance device is in air intake duct
High pressure draught carries out low-frequency sound wave disturbance, generates the high pressure draught with disturbance, and the high pressure draught with disturbance passes through air intake port
It enters in nozzle；The nozzle has contraction section, obtains the high pressure draught into nozzle by way of contraction bigger
Speed and reducing sprayed from jet expansion after its gas flow temperature.
2. the air-operated drive sound extinguishing device according to claim 1 for having cooling effect, it is characterised in that：Propeller
Including 2 or more blades, 2 or more blades are evenly distributed on its central rotating shaft of propeller, pass through motor driven center
All blade synchronous rotaries in shaft and then drive central rotating shaft, if the revolving speed of propeller is n.
3. the air-operated drive sound extinguishing device according to claim 2 for having cooling effect, it is characterised in that：It is described to disturb
Dynamic device includes multiple disturbance blades of radially circle distribution, and each blade that disturbs is respectively connected with power, and each disturbance blade is equal
It can be rotated around its respective rotary shaft according to the π f angular speed of ω=2 under the driving of power, to obtain the frequency that frequency is f
Rate disturbance, realizes and carries out low-frequency sound wave disturbance to the high pressure draught in air intake duct, generates the high pressure draught with disturbance.
4. the air-operated drive sound extinguishing device according to claim 1 for having cooling effect, it is characterised in that：The spiral shell
Rotation paddle and disturbance device become one, and propeller includes multi-disc blade, and multi-disc blade is distributed in its central rotating shaft of propeller
On, all blade synchronous rotaries on central rotating shaft are driven by motor driven central rotating shaft, to obtain high pressure draught；Respectively
Self-powered i.e. each blade is connected separately with independent power to piece blade respectively, and each blade can be in the drive of each ultromotivity
The dynamic lower rotary shaft on its own is rotated with the angular speed of the π of ω=2 f, so that the frequency disturbance that frequency is f is obtained,
It realizes and the low-frequency sound wave of high pressure draught is disturbed, generate the high pressure draught with disturbance.
5. the air-operated drive sound extinguishing device according to claim 3 or 4 for having cooling effect, it is characterised in that：Into
The radius of its air inlet of air flue is bigger, its blade length of corresponding propeller is bigger, the high pressure gas obtained by propeller rotation
The pressure p of streamaIt is bigger；
Its length for disturbing blade of disturbance device and width are bigger, and the pressure of acquisition disturbs pa' bigger.
6. the air-operated drive sound extinguishing device according to claim 5 for having cooling effect, it is characterised in that：Pass through spiral shell
Revolve the pressure p for the high pressure draught that paddle rotation obtainsaIt can be obtained by following formula
pa=Cpρ0n2D4. (1)
In above formula, CpFor tension coefficient, determined by propeller geometric parameter；N is the revolving speed of propeller rotation；ρ0Enter for air intake duct
Current density at mouthful；D is the diameter of propeller；
The disturbance device, which is realized, disturbs the low-frequency sound wave of high pressure draught, so that flowing through the air-flow of the high pressure draught of disturbance device
Volume and pressure generating period change, and form low-frequency noise, the pressure disturbance of generation is p 'a；
If radius is R at nozzle entranceA, RCFor nozzle exit radius, nozzle accelerates high pressure draught by way of contraction,
And then obtain the high pressure draught of bigger speed；In the inlet of nozzle, its pressure and temperature are expressed as pA(=pa+p′a)
And TA, air-flow velocity VA；The then energy enthalpy h of the inlet of nozzleAFor：
Wherein γ indicates specific heat ratio；cpIndicate heat capacity at constant pressure；ρAIndicate density at nozzle entrance；cAIndicate the velocity of sound at nozzle entrance；
Since air-flow flowing is equal entropy flux, then energy will not dissipate in nozzle, then energy enthalpy does not change, and be
This, can define total enthalpy
h0=hA (3)
Gas is perfect gas in nozzle, then system stagnation pressure p can be obtained under the concept of total enthalpy0, total moisture content T0With the stagnation velocity of sound
c0
Wherein ρ0Represent corresponding density under system stagnation pressure；
According to constant entropy The Ideal-Gas Equation, the pressure p of any position, temperature T can be characterized as with Mach number M in nozzle
The temperature of any position can be characterized as in nozzle
It is found that corresponding temperature reduces when Flow in Nozzle Mach number increases；According to formula (6) it is found that at nozzle entrance and spraying
The temperature proportional in mouth exit can be characterized as
Wherein, in the pressure of nozzle exit and outside pressure PEnvironmentUnanimously, i.e. PC=PEnvironment, nozzle can be obtained according to formula (5) and go out
Mach number M at mouthfulCFor
7. the air-operated drive sound extinguishing device according to claim 6 for having cooling effect, it is characterised in that：When passing through
The Mach number M of nozzle exit is calculated in formula (8)CWhen less than 1, nozzle exit air-flow is subsonic flow, at this point, nozzle
Shape nozzle is shunk using subsonic speed, the exit radius of inlet radius to the nozzle of the nozzle is gradually reduced, with nozzle entrance
The cross-sectional area for being gradually reduced i.e. nozzle of place to spout radius between nozzle exit constantly reduces, and brings nozzle interior air-flow speed
Increase, the reduction of nozzle interior air-flow pressure and temperature；
Formula (8) brings that formula (7) can obtain at nozzle entrance and the temperature of nozzle exit ratio is into
8. the air-operated drive sound extinguishing device according to claim 6 for having cooling effect, it is characterised in that：When passing through
The Mach number M for the nozzle exit that formula (8) is calculatedCWhen greater than 1, then Mach 2 ship is flowed in a certain cross-section of nozzle
1, defining the cross section is critical cross-section；Used nozzle is Laval supersonic nozzle, Laval supersonic nozzle at this time
Middle section shrink, the radius at nozzle entrance is RA, the radius of nozzle exit is RC, critical cross-section, that is, nozzle middle part minimum
Cross section position, corresponding cross sectional radius are RB, RAGreater than RB, RCGreater than RB；Its nozzle of Laval supersonic nozzle enters
Radius in the middle part of radius to nozzle at mouthful at minimum cross-section is gradually reduced, the radius in the middle part of nozzle at minimum cross-section to spray
The radius in mouth exit is gradually increased.
9. the air-operated drive sound extinguishing device according to claim 8 for having cooling effect, it is characterised in that：For
Laval supersonic nozzle, according to the conservation of mass in flow process, then radius R at its nozzle entranceAWith any cross section of nozzle
There are following conservation of mass formula at place radius R
Wherein, VA、ρAFlowing velocity and density respectively at nozzle entrance；V, ρ is respectively the flowing of any cross-section of nozzle
Speed and density；
It defines at nozzle entrance and the acoustic wave propagation velocity of any cross-section of nozzle is cAWith c, then exist
At critical cross-section, corresponding Mach 2 ship MB=1, then the radius R of critical cross-sectionBWith RARelationship can be with table
Sign is：
Formula (5) brings the available following formula of formula (12) into
Nozzle exit radius RCRelative to critical cross-section radius RBRelational expression it is as follows
At this point, nozzle exit temperature TCWith temperature T at nozzle entranceARelationship such as formula (7) shown in.
10. it is a kind of using have cooling effect described in any of the above-described claim air-operated drive sound extinguishing device fire extinguishing
Method.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114260571A (en) * | 2022-03-03 | 2022-04-01 | 深圳市艾贝特电子科技有限公司 | Liquid spray welding method, equipment and use method thereof |
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| CN205460603U (en) * | 2016-03-11 | 2016-08-17 | 中国空气动力研究与发展中心高速空气动力研究所 | Even stable supersonic extinguishing device in flow field |
| CN105903137A (en) * | 2016-04-29 | 2016-08-31 | 东华大学 | Low-frequency sound wave fire extinguisher |
| WO2016176345A1 (en) * | 2015-04-30 | 2016-11-03 | Task Force Tips, Inc. | Firefighting nozzle with trigger operated slide valve |
| KR20180002453A (en) * | 2016-06-29 | 2018-01-08 | 배병채 | wave fire subjugation |
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|---|---|---|---|---|
| WO2016176345A1 (en) * | 2015-04-30 | 2016-11-03 | Task Force Tips, Inc. | Firefighting nozzle with trigger operated slide valve |
| CN205460603U (en) * | 2016-03-11 | 2016-08-17 | 中国空气动力研究与发展中心高速空气动力研究所 | Even stable supersonic extinguishing device in flow field |
| CN105903137A (en) * | 2016-04-29 | 2016-08-31 | 东华大学 | Low-frequency sound wave fire extinguisher |
| KR20180002453A (en) * | 2016-06-29 | 2018-01-08 | 배병채 | wave fire subjugation |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114260571A (en) * | 2022-03-03 | 2022-04-01 | 深圳市艾贝特电子科技有限公司 | Liquid spray welding method, equipment and use method thereof |
| US11724326B1 (en) | 2022-03-03 | 2023-08-15 | Shenzhen Anewbest Electronic Technology Co., Ltd. | Method and device for liquid spray soldering and the application method thereof |
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Address after: 411228 South of Tianyi Avenue, Yiguhe Town, Xiangtan County, Xiangtan City, Hunan Province (Building 12, Phase 2 of Xiangtan Baiyi Independent Innovation Park) Patentee after: Hunan Fosi Fluid Technology Co.,Ltd. Address before: 410000 room 124, building 2, area D, hardware and electrical market, Yuhua District, Changsha City, Hunan Province Patentee before: HUNAN RUIZHONG TECHNOLOGY Co.,Ltd. |