CN208225506U - A kind of boiler exhaust muffler based on piezoelectricity magnetorheological fluid composite construction - Google Patents

Abstract

The utility model relates to exhaust noise silencing apparatus fields, and in particular to a kind of boiler exhaust muffler based on piezoelectricity magnetorheological fluid composite construction.Including cylinder, air inlet pipe and an air outlet pipe is equipped with along cylinder both ends；Cylinder includes shell, mineral wool and perforated plate, and several stomatas are provided on perforated plate；Cylinder is divided into the first cavity, the second cavity and third cavity along vertical tubular axis direction by left clapboard and right clapboard in cylinder；It is equipped with the input shaft coaxial with cylinder in second cavity, damping unit is installed on input shaft；Input shaft left end extend into the first cavity and is equipped with sound-absorbing blade in uniform way on the shaft shoulder, and sound-absorbing blade is bonded by piezoelectric chip and metal substrate.Advantage and characteristic: the kinetic energy of air-flow is transformed into mechanical energy using sound-absorbing blade, reduces the acoustical power of various frequency bands, acoustical absorptivity is strong；Low-frequency sound wave is absorbed by piezoelectric effect, absorbs medium-high frequency sound wave in conjunction with mineral wool using perforated plate, absorption band is wide.

Description

A kind of boiler exhaust muffler based on piezoelectricity magnetorheological fluid composite construction

Technical field

The utility model relates to exhaust noise silencing apparatus fields, and in particular to a kind of based on piezoelectricity magnetorheological fluid composite construction Boiler exhaust muffler.

Background technique

Boiler exhaust silencer is to be made an uproar by gradually decreasing the pulsation of pressure at expulsion and the pressure at expulsion that decays to cut down exhaust Sound is typically mounted in the boiler steam discharge system of the industry such as electric power, petroleum, chemical industry, metallurgy, weaving, is to eliminate steam row Put the important noise-reducing equipment of Aerodynamic Noise of A.There are many type of boiler exhaust silencer, are according to anti-, spray, resistance composite sound damping Principle is developed, and mainly has micropore jet and dilatation sound absorption.Micropore jet refers to since the general flow velocity of boiler steam discharge is fast, gas Flow noise is high, needs first to expand with through-hole and flow, and the steam after multiple through-hole obtains decompression drop stream in resistance expansion chambers, and air-flow passes through again Aperture sprays, and the acoustical power of its frequency band has reduced after ejection.

Dilatation sound absorption refers to that noise greatly weakens when the frequency of sound pressure level is raised to 20000Hz range above, but The secondary noise of component frequency also needs further to eliminate the noise.Therefore installing resistive sound absorption cotton structure additional outside expansion chambers, it is according to drop Designed by the spectral characteristic for the residual noise that laminate is issued, to effectively absorb residual noise.

In the prior art, the exhaust noise silencing effect of boiler exhaust silencer is not ideal enough, and reason is: 1. are sprayed based on aperture The noise reduction method of note has the intrinsic frequency of oneself due to each hole, certain frequencies only near mesh intrinsic frequency Sound wave could be by mesh, therefore acoustic absorptivity is low, and absorption band is narrow, and not easy to control；2. the sound-absorbing method based on impedance matching It is good to the effect of low frequency and high-frequency effect is poor.

Summary of the invention

The problems of in terms of for existing boiler exhaust muffler noise reduction, the utility model proposes one kind to be based on piezoelectricity The boiler exhaust muffler of magnetorheological fluid composite construction, the embodiment that the utility model uses is: including hollow cylinder, edge The position of cylinder one end off-axis is equipped with air inlet pipe, is equipped with escape pipe along the position of cylinder other end axis；Cylinder includes shell Body, mineral wool and perforated plate are provided with several stomatas on perforated plate；By left clapboard and right clapboard along vertical tubular axis side in cylinder The first cavity, the second cavity and third cavity are divided by cylinder, and air inlet pipe is communicated with the first cavity, escape pipe and third chamber Body communicates；Be provided with left recirculation hole and right recirculation hole on left clapboard and right clapboard in uniform way, the sum of left recirculation hole sectional area be greater than or Equal to the sum of air inlet pipe sectional area, the sum of the sum of right recirculation hole sectional area more than or equal to left recirculation hole sectional area；Second cavity Interior to be equipped with the input shaft coaxial with cylinder, input shaft both ends are mounted on left clapboard and right clapboard by rolling bearing, left clapboard It is equipped with the end cap for sealing bearing with right clapboard both ends of the surface, damping unit is installed on input shaft；Input shaft left end extend into Sound-absorbing blade is installed in uniform way in one cavity and by screw on the shaft shoulder, sound-absorbing blade is glued by piezoelectric chip and metal substrate It connects；Cavity is set in damping unit, left portion of the input shaft in cavity is laid with radially projecting left raised line, input Middle right part of the axis in cavity is laid with radially projecting right raised line, left raised line and right raised line and staggeredly sets along input shaft outer circle It sets, it is all semicircle that left raised line is consistent with right raised line cross section；Damping unit include be disposed in parallel in left clapboard and right clapboard it Between left pole and right pole, left piston, right piston, coil, magnetorheological fluid；Left pole and right extremely circular ring shape, left clapboard, Zuo Ji, the right side Pole and right clapboard are fixed as one, and the annular groove of setting coil is provided between left pole and right pole；It is left extremely on to be provided at least one transversal Face is L-shaped left slot, is equipped with left piston contact with middle left part of the input shaft in cavity in each left slot, it is right extremely on be provided with and Left slot number is equal and cross section is the right slot of backward L-shaped, is equipped in each right slot and contacts with middle right part of the input shaft in cavity Right piston, left slot is connected to form U-type groove with right slot, and magnetorheological fluid is equipped in the U-type groove between left piston and right piston.

In the utility model, for the absorbing sound and lowering noise ability for improving sound-absorbing blade, sound-absorbing blade is set in the axial plane of input shaft, And it is connected by screw to the shaft shoulder, and with axial direction at certain angle of inclination beta (similar blade of electric fan inclination angle), sound-absorbing blade inclines Oblique angle is β=110 °, and sound-absorbing blade is curved iridescent type structure, and the radius of curvature of piezoelectric chip is less than the curvature of metal substrate Radius, for piezoelectric chip with a thickness of the PZT4 of 0.15~0.3mm, metal substrate is beryllium-bronze, the thickness of metal substrate and piezoelectric chip The ratio between degree is 1~2.5, and the absorbing sound and lowering noise ability of sound-absorbing blade is stronger at this time.

After air-flow enters the first cavity by air inlet pipe, air-flow generates pneumatic power drive input shaft when blowing to sound-absorbing blade Rotation；When coil is in the case where no be powered i.e. without magnetic field, input shaft rotation causes left raised line to contact with left piston, left piston The magnetorheological fluid in U-type groove is pushed under the action of left raised line, magnetorheological fluid is liquid at this time, right because of liquid Incoercibility Piston extends downwardly under the action of magnetorheological fluid；Working as right piston on the contrary moves downward left piston under the effect of right raised line, week And renew, the kinetic energy of air-flow is transformed into mechanical energy；Magnetic field is generated after coil energization, the magnetorheological fluid in U-type groove is in magnetic field Acting on lower moment from liquid becomes class solid-state, and the motion damping force of left piston and right piston increases, and noise energy consume is caused to increase Greatly；When high-speed flow enters, magnetic field size can be changed by regulating winding size of current, the change in magnetic field is so that magnetorheological fluid Mechanical property change so that damping unit damping force is also changed, adjust noise consume size to reach Purpose.

While air-flow is blown on sound-absorbing blade, the vibration of sound wave causes the piezoelectric effect of piezoelectric chip, piezoelectric chip Surface forms charge, which is stored such that the sound of sound wave can be converted into electric energy by storage circuit, actively inhales to reach The purpose of sound.

Fast into the general flow velocity of air-flow in boiler exhaust muffler, noise is high, first passes through sound-absorbing blade for the dynamic of air-flow The acoustical power that various frequency bands in noise after mechanical energy can be transformed into has reduced, therefore noise greatly weakens, while passing through piezoelectric chip Piezoelectric effect, by sound can be converted into electric energy can active absorption low-frequency sound wave, then by perforated plate and mineral wool collective effect Can Passive intake medium-high frequency sound wave, effectively absorb residual noise.

Advantage and characteristic: 1) being transformed into mechanical energy for the kinetic energy of air-flow using sound-absorbing blade, reduces the sound function of various frequency bands Rate weakens noise, and acoustical absorptivity is strong, high reliablity；2) big by adjusting coil current size change damping unit X damping force It is small, and then noise energy consumption size is controlled, controllability is strong；3) by piezoelectric effect active absorption low-frequency sound wave, using perforated plate with Mineral wool combination Passive intake medium-high frequency sound wave, absorption band are wide.

Detailed description of the invention

Fig. 1 is a kind of boiler exhaust based on piezoelectricity magnetorheological fluid composite construction in one preferred embodiment of the utility model The structural schematic diagram of muffler；

Fig. 2 is in schematic diagram when off working state for A-A cross-sectional view muffler in Fig. 1；

Fig. 3 is schematic diagram when A-A cross-sectional view muffler is in running order in Fig. 1.

Fig. 4 is sound-absorbing blade and input shaft assembling structure schematic diagram in one preferred embodiment of the utility model；

Specific embodiment

A kind of boiler exhaust muffler based on piezoelectricity magnetorheological fluid composite construction, including hollow cylinder V, along cylinder V The position of one end off-axis is equipped with air inlet pipe a, is equipped with escape pipe p along the position of cylinder V other end axis；Cylinder V includes shell Body b, mineral wool c and perforated plate d are provided with several stomata d1 on perforated plate d；By left clapboard g and right clapboard m along vertical in cylinder V Cylinder V is divided into the first cavity A, the second cavity B and third cavity C, air inlet pipe a and the first cavity A phase by cylinder V axis direction Logical, escape pipe p is communicated with third cavity C；Left recirculation hole g1 and right recirculation hole m1 are provided on left clapboard g and right clapboard m in uniform way, The sum of left recirculation hole g1 sectional area right recirculation hole m1 sectional area and is greater than or equal to more than or equal to the sum of air inlet pipe a sectional area The sum of left recirculation hole g1 sectional area；The input shaft t coaxial with cylinder V is equipped in second cavity B, the both ends input shaft t pass through rolling Bearing is mounted on left clapboard g and right clapboard m, and left clapboard g and right clapboard m both ends of the surface are equipped with the end cap for sealing bearing, input Damping unit X is installed on axis t；The left end input shaft t extend into the first cavity A and pacifies in uniform way by screw on shaft shoulder t1 It is bonded equipped with sound-absorbing blade E, sound-absorbing blade E by piezoelectric chip e1 and metal substrate e2；Cavity D is set in damping unit X, it is defeated Enter left portion of the axis t in cavity D and be laid with radially projecting left raised line t2, middle right part of the input shaft t in cavity D is equal Be laid with radially projecting right raised line t3, left raised line t2 and right raised line t3 are staggered along input shaft t outer circle, left raised line t2 and The cross section right raised line t3 is consistent, is all semicircle；Damping unit X includes the left side being disposed in parallel between left clapboard g and right clapboard m Pole h and right pole k, left piston i, right piston f, coil q, magnetorheological fluid n；Left pole h and right pole k is circular ring shape, left clapboard g, Zuo Ji H, right pole k and right clapboard m are fixed as one, and the annular groove r of setting coil q is provided between left pole h and right pole k；Be provided on left pole h to A few cross section is L-shaped left slot h1, is equipped with the left side contacted with middle left part of the input shaft t in cavity D in each left slot h1 The right slot k1 that and cross section equal with left slot h1 quantity is backward L-shaped is provided on piston i, right pole k, be equipped in each right slot k1 with it is defeated Enter the right piston f of middle right part contact of the axis t in cavity D, left slot h1 is connected to form U-type groove J with right slot k1, left piston i and the right side Magnetorheological fluid n is equipped in U-type groove J between piston f.

In the utility model, for the absorbing sound and lowering noise ability for improving sound-absorbing blade, sound-absorbing blade E is set in the axis of input shaft t Face t4, and be connected by screw to shaft shoulder t1, and inhaled with axial direction at certain angle of inclination beta (similar blade of electric fan inclination angle) The sound inclination angle blade E is β=110 °, and sound-absorbing blade E is curved iridescent type structure, and the radius of curvature of piezoelectric chip e1 is less than gold Belong to the radius of curvature of substrate e2, for piezoelectric chip e1 with a thickness of the PZT4 of 0.15~0.3mm, metal substrate e2 is beryllium-bronze, metal The ratio between thickness of substrate e2 and piezoelectric chip e1 is 1~2.5, and the absorbing sound and lowering noise ability of sound-absorbing blade E is stronger at this time.

After air-flow enters the first cavity A by air inlet pipe a, it is defeated that air-flow generates pneumatic power drive when blowing to sound-absorbing blade E Enter axis t rotation；When coil q is in the case where no be powered i.e. without magnetic field, input shaft t rotation causes left raised line t2 and left piston i Contact, left piston i push the magnetorheological fluid n in U-type groove J under the action of left raised line t2, and magnetorheological fluid n is liquid at this time, because Liquid Incoercibility, right piston f are extended downwardly under the action of magnetorheological fluid n；On the contrary when right piston f is acted in right raised line t3 Under move downward left piston i, in cycles, the kinetic energy of air-flow is transformed into mechanical energy；Magnetic field, U are generated after coil q energization Magnetorheological fluid n in the type groove J moment under magnetic fields from liquid becomes class solid-state, the kinetic damping of left piston i and right piston f Power increases, and noise energy consume is caused to increase；When high-speed flow enters, magnetic can be changed by regulating winding q size of current Field size, the change in magnetic field is so that the mechanical property of magnetorheological fluid n changes, so that damping unit X damping force also obtains To change, to achieve the purpose that adjust noise consume size.

While air-flow is blown on sound-absorbing blade E, the vibration of sound wave causes the piezoelectric effect of piezoelectric chip e1, piezo crystals The surface piece e1 forms charge, which is stored such that the sound of sound wave can be converted into electric energy by storage circuit, to reach main The purpose of dynamic sound absorption.

Fast into the general flow velocity of air-flow in boiler exhaust muffler, noise is high, first passes through sound-absorbing blade E for the dynamic of air-flow The acoustical power that various frequency bands in noise after mechanical energy can be transformed into has reduced, therefore noise greatly weakens, while passing through piezoelectric chip The piezoelectric effect of e1, by sound can be converted into electric energy can active absorption low-frequency sound wave, then by perforated plate d and mineral wool c it is common Effect can Passive intake medium-high frequency sound wave, effectively absorb residual noise.

Claims (1)

1. a kind of boiler exhaust muffler based on piezoelectricity magnetorheological fluid composite construction, it is characterised in that: including hollow cylinder, It is equipped with air inlet pipe along the position of cylinder one end off-axis, is equipped with escape pipe along the position of cylinder other end axis；Cylinder includes Shell, mineral wool and perforated plate are provided with several stomatas on perforated plate；By left clapboard and right clapboard along vertical tubular axis in cylinder Cylinder is divided into the first cavity, the second cavity and third cavity by direction, and air inlet pipe is communicated with the first cavity, escape pipe and third Cavity communicates；Left recirculation hole and right recirculation hole are provided on left clapboard and right clapboard in uniform way, the sum of left recirculation hole sectional area is greater than Or the sum equal to air inlet pipe sectional area, the sum of the sum of right recirculation hole sectional area more than or equal to left recirculation hole sectional area；Second chamber Be equipped with the input shaft coaxial with cylinder in vivo, input shaft both ends are mounted on left clapboard and right clapboard by rolling bearing, a left side every Plate and right clapboard both ends of the surface are equipped with the end cap for sealing bearing, are equipped with damping unit on input shaft；Input shaft left end is extend into Sound-absorbing blade is installed in uniform way in first cavity and by screw on the shaft shoulder, sound-absorbing blade is by piezoelectric chip and metal substrate It is bonded；Cavity is set in damping unit, left portion of the input shaft in cavity is laid with radially projecting left raised line, defeated Enter middle right part of the axis in cavity and be laid with radially projecting right raised line, left raised line and right raised line interlock along input shaft outer circle Setting, it is all semicircle that left raised line is consistent with right raised line cross section；Damping unit includes being disposed in parallel in left clapboard and right clapboard Between left pole and right pole, left piston, right piston, coil, magnetorheological fluid；Left pole and right extremely circular ring shape, left clapboard, Zuo Ji, Right pole and right clapboard are fixed as one, and the annular groove of setting coil is provided between left pole and right pole；It is left extremely on be provided at least one cross Section is L-shaped left slot, is equipped with the left piston contacted with middle left part of the input shaft in cavity in each left slot, it is right extremely on be provided with Equal and cross section is the right slot of backward L-shaped with left slot number, is equipped in each right slot and middle right part of the input shaft in cavity connects The right piston of touching, left slot are connected to form U-type groove with right slot, and magnetorheological fluid is equipped in the U-type groove between left piston and right piston.