阅读说明：本技术 一种分频组合压力脉动衰减装置及方法 (Frequency-division combined pressure pulsation attenuation device and method ) 是由 罗小辉 王家祥 李秋坪 尚搏宁 于 2020-06-24 设计创作，主要内容包括：本发明属于消声技术领域,并具体公开了一种分频组合压力脉动衰减装置及方法,其包括本体、蓄能器和衰减器,其中本体为中空结构,用于作为待衰减流体的输送通道；所述蓄能器设置在所述本体上,并与所述输送通道导通；所述衰减器环绕所述蓄能器设置,并且同样与所述输送通道导通；以此,通过蓄能器和衰减器的配合实现流体压力脉动的衰减。本发明可有效降低流体噪声和管路振动,适用于各种流体例如水、液压油、气体等的压力脉动的多级频率衰减。(The invention belongs to the technical field of noise elimination, and particularly discloses a frequency-division combined pressure pulsation attenuation device and a method, wherein the frequency-division combined pressure pulsation attenuation device comprises a body, an energy accumulator and an attenuator, wherein the body is of a hollow structure and is used as a conveying channel of fluid to be attenuated; the energy accumulator is arranged on the body and communicated with the conveying channel; the attenuator is arranged around the energy accumulator and is also communicated with the conveying channel; in this way, the fluid pressure pulsations are damped by the cooperation of the energy accumulator and the damper. The invention can effectively reduce fluid noise and pipeline vibration, and is suitable for multi-stage frequency attenuation of pressure pulsation of various fluids such as water, hydraulic oil, gas and the like.)

1. A frequency-division combined pressure pulsation damping device is characterized by comprising a body (1), an energy accumulator (3) and an attenuator (2), wherein the body (1) is of a hollow structure, and the hollow part of the body is used as a conveying channel (17) of fluid to be attenuated; the energy accumulator (3) is arranged outside the body (1) and communicated with the conveying channel (17); the attenuator (2) is arranged around the energy store (3) and is also in communication with the feed channel (17), in order to attenuate fluid pressure pulsations by means of the cooperation of the energy store and the attenuator.

2. The frequency division combined pressure pulsation damping device according to claim 1, wherein the energy accumulator (3) comprises an energy accumulator cavity (7), an energy accumulator cover plate (5) and a diaphragm (8), wherein the energy accumulator cavity (7) is directly opened on the body (1), the bottom of the energy accumulator cavity is opened with an energy accumulator hole (11) communicated with the delivery channel (17), and the top of the energy accumulator cavity is closed by the energy accumulator cover plate (5); the diaphragm (8) is arranged in the energy accumulator accommodating cavity (7) to divide the energy accumulator accommodating cavity (7) into two independent spaces which are defined as a gas accommodating space and a fluid accommodating space, and meanwhile, the diaphragm (8) is pressed on the body (1) through the energy accumulator cover plate (5); an inflation interface (10) is arranged on the energy accumulator cover plate (5), and the gas containing space is inflated through the inflation interface (10).

3. The frequency-division combined pressure pulsation damping device according to claim 1 or 2, wherein the attenuator (2) comprises an attenuator chamber (13) which is disposed around the accumulator chamber (7) and is directly opened on the body (1), and a damping hole (14) which is communicated with the delivery channel (17) is opened at the bottom of the attenuator chamber (13) and the top of the attenuator chamber is closed.

4. A divided-frequency combined pressure pulsation damping device according to claim 3, wherein the attenuator volume (13) is closed at the top by an accumulator cover plate (5).

5. The frequency division combined pressure pulsation damping device according to any one of claims 2 to 4, wherein a sealing ring (12) is embedded on the contact surface of the body (1) and the accumulator cover plate (5); preferably, a circular ring (4) is mounted on the energy accumulator cover plate (5), and the circular ring (4) is sleeved outside the energy accumulator cavity (7) and is in threaded connection with the energy accumulator cavity; preferably, a sealing ring is embedded on the contact surface of the circular ring (4) and the energy accumulator cover plate (5); preferably, an annular protruding structure matched with the energy storage container (7) is arranged on the energy storage cover plate (5), a groove is formed in the annular protruding structure, and the opening end of the diaphragm (8) is embedded in the groove.

6. A frequency-division combined pressure pulsation damping device according to any one of claims 1 to 5, wherein the body (1) is preferably square, the accumulators (3) and the attenuators (2) are preferably four, four accumulators are respectively arranged on four faces of the square body, four attenuators are respectively arranged around the corresponding accumulators, namely, one attenuator is arranged around the outside of one accumulator, and the attenuators are communicated with each other to form an attenuator large cavity.

7. A frequency division combined pressure pulsation damping device according to any one of claims 1 to 6, characterised in that preferably both ends of the body (1) are provided with flanges for connecting pipes; preferably, the bottom of the diaphragm (8) is designed to be a plane, and a convex structure is arranged at the bottom inside the diaphragm; preferably, the accumulator is preferably used to attenuate shaft frequency pulsations and the attenuator is preferably used to attenuate blade frequency pulsations.

8. The frequency division multiplexed pressure pulsation dampener of any of claims 1-7, wherein the accumulator is parametrically designed by:

(1) first, the effective volume V of the energy accumulator is determined_{Is effective}：

Wherein Δ V is the pulse volume of the object to be attenuated within one pulse cycle; is the initial pressure pulsation rate; k is an inflation gas polytropic index;

(2) then, according to the effective volume of the accumulatorV_{Is effective}Determining an initial volume V of an accumulator_Initial：

Wherein s is a pressure coefficient;

(3) then, according to the initial volume V of the accumulator_InitialDetermining the volume V of a diaphragm_DiaphragmAnd according to the volume V of the diaphragm_DiaphragmThe diaphragm is dimensioned such that the gas receiving space is equal in size to the diaphragm volume V_Diaphragm；

(4) And determining the depth l of the accumulator hole according to the following formula_AAnd total accumulator aperture area a_A：

Wherein f is_ANFor the frequency to be attenuated, K is the gas adiabatic coefficient, a_AIs the total area of the accumulator aperture, p₀Is the average pressure of the fluid, ρ is the density of the fluid, l_AThe depth of the accumulator bore; v_DiaphragmIs the diaphragm volume;

(5) finally, according to the total area a of the accumulator hole_ADetermining the opening number n of the energy accumulator holes by adopting the following formula:

wherein d is the diameter of the accumulator bore.

9. The frequency-division multiplexed pressure pulsation attenuation device according to any one of claims 1-8, wherein said attenuator is parametrically designed by:

(1) first, the effective volume V of the attenuator is determined_H；

(2) Then, the damping hole depth l is determined according to the following formula_HAnd total area a of the orifice_H：

In the formula (f)_HNFor the frequency to be attenuated, β_eIs the bulk modulus of the fluid, a_HRho is the density of the fluid, l is the total area of the damping orifice_HIs the depth of the damping hole, V_HIs the effective volume of the attenuator;

(3) finally, according to the total area a of the damping holes_HDetermining the opening number of the damping holes by adopting the following formula:

wherein d is₁Is the diameter of the damping hole which is preset.

10. A method of frequency-division combined pressure pulsation damping, implemented with a damping device according to any one of claims 1-9, comprising the steps of:

1) filling gas with set pressure into the energy accumulator;

2) the fluid to be attenuated enters the hollow part of the attenuating device and enters the attenuator through the hollow part, the fluid also enters the accumulator when the pressure of the fluid is higher than the gas pressure, and the fluid is discharged from the accumulator when the pressure of the fluid is lower than the gas pressure, so that the attenuation of the pressure pulsation of the fluid is realized through the matching of the attenuator and the accumulator.

Technical Field

The invention belongs to the technical field of noise elimination, and particularly relates to a frequency-division combined pressure pulsation attenuation device and method.

Background

In order to eliminate the pressure pulsation of the fluid power system and achieve the purpose of reducing noise and vibration, a pressure pulsation muffler, also called a pressure pulsation attenuator, is generally required to be arranged in a pipeline of the system. At present, a common pressure pulsation attenuator comprises an energy accumulator and a Helmholtz silencer, but the natural frequency of the traditional energy accumulator is lower, the effect of reducing low-frequency pressure pulsation is better, and the effect of reducing high-frequency pressure pulsation is poorer, so that the traditional energy accumulator can not be used alone to simultaneously eliminate the low-frequency pressure pulsation and the high-frequency pressure pulsation, namely the multi-frequency attenuation of the pressure pulsation can not be realized; in contrast, the helmholtz silencer, which is often used as a gas silencer, has a high natural frequency, and when the helmholtz silencer is used for other fluids such as water and hydraulic oil, the volume and mass of the helmholtz silencer need to be designed to be large.

Therefore, for the current fluid pressure pulsation noise elimination structure, further research is still needed to obtain an attenuation device which can realize attenuation of multiple frequencies and has a wider application range, so as to achieve the purpose of noise reduction and improve the stability of system operation.

Disclosure of Invention

Aiming at the defects or the improvement requirements of the prior art, the invention provides a frequency-division combined pressure pulsation attenuation device and a frequency-division combined pressure pulsation attenuation method, which can realize the multi-frequency attenuation of pressure pulsation, effectively reduce the fluid noise and the pipeline vibration, are suitable for the multi-frequency attenuation of the pressure pulsation of various fluids such as water, hydraulic oil, gas and the like and have wide application range by designing the specific structural components and the specific arrangement modes of the components of the attenuation device.

In order to achieve the above object, according to one aspect of the present invention, there is provided a frequency-division combined pressure pulsation damping device, comprising a body, an accumulator and a damper, wherein the body is a hollow structure, and a hollow portion is used as a conveying channel for a fluid to be damped; the energy accumulator is arranged outside the body and communicated with the conveying channel; the attenuator is arranged around the energy accumulator and is also in communication with the feed channel, so that the fluid pressure pulsations are attenuated by the cooperation of the energy accumulator and the attenuator.

Preferably, the energy accumulator comprises an energy accumulator cavity, an energy accumulator cover plate and a diaphragm, wherein the energy accumulator cavity is directly arranged on the body, the bottom of the energy accumulator cavity is provided with an energy accumulator hole communicated with the conveying channel, and the top of the energy accumulator cavity is sealed by the energy accumulator cover plate; the diaphragm is arranged in the energy accumulator cavity to divide the energy accumulator cavity into two independent spaces, namely a gas containing space and a fluid containing space, and is pressed on the body through the energy accumulator cover plate; an inflation interface is arranged on the energy accumulator cover plate, and the gas accommodating space is inflated through the inflation interface.

Preferably, the attenuator comprises an attenuator cavity which is arranged around the energy accumulator cavity and is directly arranged on the body, the bottom of the attenuator cavity is provided with a damping hole communicated with the conveying channel, and the top of the attenuator cavity is closed.

As a further preference, the attenuator chamber is closed at the top by an accumulator cover plate.

More preferably, a seal ring is fitted to a contact surface between the body and the accumulator cover plate.

Preferably, the energy accumulator cover plate is provided with a circular ring, and the circular ring is sleeved outside the energy accumulator accommodating cavity and is in threaded connection with the energy accumulator accommodating cavity.

Preferably, a sealing ring is embedded on a contact surface of the circular ring and the energy accumulator cover plate.

Preferably, the energy accumulator cover plate is provided with an annular protruding structure matched with the energy accumulator containing cavity, the annular protruding structure is provided with a groove, and the opening end of the diaphragm is embedded in the groove, so that reliable assembly and sealing of the diaphragm are realized.

As a further preferred, the body is preferably square, the energy accumulators and the attenuators are preferably four, the four energy accumulators are respectively arranged on four faces of the square body, the four attenuators are respectively arranged around the corresponding energy accumulators, that is, one attenuator is arranged around the outside of one energy accumulator, and the attenuators are mutually communicated to form a large attenuator cavity.

Further preferably, flanges for connecting pipelines are arranged at two ends of the body.

As a further preference, the bottom of the diaphragm is designed as a plane and the bottom of the interior of the diaphragm is provided with a raised structure.

As a further preference, the energy store is preferably used for damping axial frequency pulsations, and the attenuator is preferably used for damping blade frequency pulsations.

As a further preferred option, the energy accumulator is designed by the following steps:

(1) first, the effective volume V of the energy accumulator is determined_{Is effective}：

Wherein Δ V is the pulse volume of the object to be attenuated within one pulse cycle; is the initial pressure pulsation rate; k is an inflation gas polytropic index;

(2) then, according to the effective volume V of the accumulator_{Is effective}Determining an initial volume V of an accumulator_Initial：

Wherein s is a pressure coefficient;

(3) then, according to the initial volume V of the accumulator_InitialDetermining the volume V of a diaphragm_DiaphragmAnd according to the volume V of the diaphragm_DiaphragmThe diaphragm is dimensioned such that the gas receiving space is equal in size to the diaphragm volume V_Diaphragm；

(4) And determining the depth l of the accumulator hole according to the following formula_AAnd total accumulator aperture area a_A：

Wherein f is_ANFor the frequency to be attenuated, K is the gas adiabatic coefficient, a_AIs the total area of the accumulator aperture, p₀Is the average pressure of the fluid, ρ is the density of the fluid, l_AThe depth of the accumulator bore; v_DiaphragmIs the diaphragm volume;

(5) finally, according to the total area a of the accumulator hole_ADetermining the opening number n of the energy accumulator holes by adopting the following formula:

wherein d is the diameter of the accumulator bore.

Preferably, the attenuator is designed by the following steps:

(1) first, the effective volume V of the attenuator is determined_H；

(2) Then, the damping hole depth l is determined according to the following formula_HAnd total area a of the orifice_H：

In the formula (f)_HNFor the frequency to be attenuated, β_eIs the bulk modulus of the fluid, a_HRho is the density of the fluid, l is the total area of the damping orifice_HIs the depth of the damping hole, V_HIs the effective volume of the attenuator;

(3) finally, according to the total area a of the damping holes_HDetermining the opening number of the damping holes by adopting the following formula:

wherein d is₁Is the diameter of the damping hole which is preset.

According to another aspect of the present invention, there is provided a frequency-division combined pressure pulsation damping method, which is implemented by using the damping device, and comprises the following steps:

1) filling gas with set pressure into the energy accumulator;

2) the fluid to be attenuated enters the hollow part of the attenuating device and enters the attenuator through the hollow part, the fluid also enters the accumulator when the pressure of the fluid is higher than the gas pressure, and the fluid is discharged from the accumulator when the pressure of the fluid is lower than the gas pressure, so that the attenuation of the pressure pulsation of the fluid is realized through the matching of the attenuator and the accumulator.

Generally, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:

1. the invention designs the attenuation device comprising the body, the energy accumulator and the attenuator, the energy accumulator is arranged outside the body and is communicated with the middle part of the body, the attenuator is designed to be arranged around the energy accumulator and is communicated with the middle part of the body so as to integrate the energy accumulator and the attenuator, and the multi-frequency attenuation of fluid pressure pulsation is realized through the independent work and the cooperation of the energy accumulator and the attenuator, so that the fluid noise and the pipeline vibration are effectively reduced.

2. The cavity of the energy accumulator is directly arranged on the body, and the attenuator cavity is also directly arranged on the body, so that the body, the cavity of the energy accumulator and the attenuator cavity are integrated, and the structural stability of the attenuation device and the reliability of the attenuation effect are effectively improved.

3. The energy accumulator cover plate is preferably used for simultaneously sealing the energy accumulator cavity and the attenuator cavity, so that the overall structural stability of the attenuation device can be further improved, and the attenuation effect is ensured.

4. The invention can effectively improve the bearing strength of the cover plate of the energy accumulator by arranging the circular ring and prevent the cover plate of the energy accumulator from deforming when the pressure is overlarge.

5. The bottom of the diaphragm is designed to be a plane, so that the diaphragm can be conveniently processed and manufactured, and the bottom inside the diaphragm is provided with the protruding structure, so that the bottom of the diaphragm is thickened, the diaphragm is prevented from being pressed into an energy accumulator hole when the gas pressure is overlarge, the service life of the diaphragm is effectively prolonged, and the attenuation reliability of the diaphragm is effectively improved.

6. The body of the attenuation device is preferably designed to be square, the energy accumulators and the attenuators are preferably designed to be four, and the four energy accumulators are arranged on four surfaces of the square body, so that the attenuation device is of an axisymmetric structure, the attenuation effect can be effectively improved, and the processing difficulty of the device is reduced.

7. The attenuation device designed by the invention can realize the attenuation of the axial frequency and the leaf frequency of the object to be attenuated by designing the parameters of the energy accumulator and the attenuator.

8. The invention also pertinently provides specific operation steps for designing parameters of the energy accumulator and the attenuator, and can provide guidance for the practical application of the attenuation device.

Drawings

Fig. 1 is a schematic structural diagram of a frequency division combined pressure pulsation damping apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an accumulator according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an attenuator provided in an embodiment of the present invention;

FIG. 4 is a schematic diagram of an accumulator coupled to a ring according to an embodiment of the present invention;

FIG. 5 is a schematic view of a ring structure provided by an embodiment of the present invention;

FIG. 6 is a schematic diagram of a body structure provided in an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a square body according to an embodiment of the present invention;

FIG. 8 is a distribution plot of accumulator holes with an equivalent accumulator hole diameter of 13 mm;

FIG. 9 is a distribution plot of accumulator holes with an equivalent accumulator hole diameter of 9.5 mm;

FIG. 10 is a distribution plot of accumulator holes with an equivalent accumulator hole diameter of 8 mm;

FIG. 11 is a distribution plot of accumulator orifices for an equivalent accumulator orifice diameter of 40 mm;

FIG. 12 is a schematic view of an accumulator cover plate assembled with a diaphragm.

The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein:

1-body, 2-attenuator, 3-accumulator, 4-ring, 5-accumulator cover plate, 6-first hexagon socket screw, 7-accumulator chamber, 8-diaphragm, 9-combined sealing ring, 10-gas charging interface, 11-accumulator hole, 12-sealing ring, 13-attenuator chamber, 14-damping hole, 15-inlet, 16-inlet flange, 17-delivery channel, 18-sealing groove, 19-outlet, 20-outlet flange, 21-second hexagon socket screw, and 22-protective nut.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As shown in fig. 1, the embodiment of the present invention provides a frequency-division combined pressure pulsation damping device, which comprises a body 1, an accumulator 3 and an attenuator 2, wherein the body 1 is a hollow structure and is used as a conveying channel 17 for a fluid to be damped; the energy accumulator 3 is arranged outside the body 1 and communicated with the conveying channel 17; the attenuator 2 is arranged around the energy store 3 and is likewise in communication with the supply channel 17, whereby the attenuation of fluid pressure pulsations is achieved by the cooperation of the energy store and the attenuator.

As shown in fig. 2, the energy accumulator 3 includes an energy accumulator housing chamber 7, an energy accumulator cover plate 5 and a diaphragm 8, wherein the energy accumulator housing chamber 7 is directly provided on the body 1, an energy accumulator hole 11 communicated with the conveying passage 17 is provided at the bottom of the energy accumulator housing chamber 7, and the energy accumulator hole 11 is also provided on the body 1, that is, the energy accumulator hole 11 communicating the energy accumulator housing chamber 7 and the conveying passage 17 is provided on the body 1. The top of the energy storage cavity 7 is closed by an energy storage cover plate 5, so that the energy storage cavity is a closed cavity. The energy accumulator designed by the invention has the advantages of light weight, small deformation resistance of the thin diaphragm, no inertia, good pressure pulsation absorption performance and the like, and can be used for absorbing hydraulic pulsation in a hydraulic device with high action frequency and small volume.

Specifically, the energy accumulator cover plate 5 is connected with the body 1 through a first inner hexagon screw 6, so that the cavity is sealed. The membrane 8 is arranged in the accumulator volume 7 to divide the accumulator volume 7 into two separate spaces, defined as a gas receiving space and a fluid receiving space, while the membrane 8 is pressed against the body 1 by the accumulator cover 5. Specifically, a space between the diaphragm 8 and the energy accumulator cover plate 5 is a gas accommodating space, and a space between the diaphragm 8 and the inner wall and the bottom of the energy accumulator accommodating cavity 7 is a fluid accommodating space. The energy accumulator cover plate 5 is further provided with an air inflation interface 10, and the air accommodating space can be inflated through the air inflation interface 10. The energy accumulator designed by the invention has the advantages of light weight, small film deformation resistance, no inertia, good pressure pulsation absorption performance and the like, and can be used for absorbing hydraulic pulsation of fluid in a hydraulic device with high action frequency and small volume.

Specifically, an external thread is processed in the inflation connector 10 and used for being connected with an inflation tool to achieve inflation, and specific gas can be nitrogen. After inflation or no inflation, the inflation connector 10 compresses the combined sealing ring 9 through the socket head cap screws for sealing. Further, a protective nut 22 is sleeved outside the inflation port 10 for protection.

Further, as shown in fig. 12, an annular protruding structure which is matched with the energy storage cavity 7 is arranged on the energy storage cover plate 5, a groove is formed in the annular protruding structure, the opening end of the diaphragm 8 is embedded in the groove, so that reliable assembly and sealing of the diaphragm are achieved, and a sealed space formed between the diaphragm and the energy storage cover plate is a gas accommodating space.

When the gas storage device works, when the pressure of fluid is higher than the pressure of gas in the gas containing space, the fluid can enter a containing cavity (namely a fluid containing space) formed by the energy storage containing cavity 7 and the diaphragm 8 through the energy storage hole 11, and the diaphragm 8 contracts to enable the fluid to continuously enter the fluid containing space; when the pressure of the fluid is lower than the pressure of the gas in the gas-containing space, the diaphragm 8 expands and the fluid passes from the fluid-containing space through the accumulator orifice 11 into the delivery channel 17, thereby reducing the pressure pulsations. Considering the processing difficulty of the diaphragm 8, the bottom of the diaphragm is designed to be flat, and in order to prevent the diaphragm from entering the energy storage air hole after being expanded, a protruding structure is arranged at the bottom inside the diaphragm, and the area of the protruding structure is larger than the total area of all the energy storage holes.

As shown in fig. 1 and 3, the attenuator 2 includes an attenuator chamber 13 disposed around the energy storage chamber 7 and directly disposed on the body 1, a damping hole 14 communicated with the conveying channel 17 is disposed at the bottom of the attenuator chamber 13, and the damping hole 14 is also disposed on the body 1, that is, the damping hole 14 communicated with the attenuator chamber 13 and the conveying channel 17 is disposed on the body 1. The attenuator chamber 13 is closed at the top so that the attenuator chamber is a closed chamber. In order to ensure the sealing reliability of the attenuator containing cavity and the compactness and stability of the integral structure of the device, the top of the attenuator containing cavity 13 is preferably sealed by the energy accumulator cover plate 5, namely the energy accumulator containing cavity 7 and the attenuator containing cavity 13 are directly sealed by an integral component, namely the energy accumulator cover plate, so that the sealing reliability of the energy accumulator containing cavity 7 and the attenuator containing cavity 13 is improved, and the integral structure stability of the attenuator device is improved. In operation, fluid passes from the damping orifice 14 into the attenuator chamber 13, thereby attenuating pressure pulsations in the fluid.

As shown in fig. 4 and 5, since the energy storage cover plate 5 has a large area and is to bear the pressure of the fluid to be attenuated in the energy storage cavity 7 and the attenuator cavity 13, and when the pressure is too high, the energy storage cover plate 5 is easily deformed, a ring 4 is installed on the energy storage cover plate 5, and the ring 4 is sleeved outside the energy storage cavity 7 and is in threaded connection with the outside of the energy storage cavity 7. Specifically, the outer surface processing that the energy storage holds chamber 7 has the external screw thread, and the internal surface processing internal thread of ring 4 realizes the threaded connection that ring and energy storage held the chamber through the cooperation of this internal thread and energy storage appearance external screw thread on holding the chamber, and this ring 4 then links to each other with energy storage apron 5 through second hexagon socket head cap screw 21, can effectively improve the bearing strength of energy storage apron 5 through setting up this ring, prevents that the energy storage apron from taking place to warp when pressure is too big. Further, a sealing ring is embedded on a contact surface between the ring 4 and the energy storage cover plate 5, specifically, a sealing groove is formed on a contact surface between the ring 4 and the energy storage cover plate 5, and then the sealing ring is embedded in the sealing groove to realize effective sealing and prevent fluid in the energy storage accommodating cavity and the attenuator accommodating cavity from leaking, wherein the sealing ring is preferably an O-ring, and preferably two sealing rings are arranged.

In order to improve the tightness of the accumulator housing 7 and the attenuator housing 13, a sealing ring 12 is inserted on the contact surface of the body 1 and the accumulator cover 5. Specifically, a sealing groove 18 is formed in the contact surface of the body 1 and the energy accumulator cover plate 5, and then a sealing ring 12 is embedded in the sealing groove 18 to realize effective sealing and prevent fluid in the energy accumulator cavity and the attenuator cavity from leaking, wherein the sealing ring is preferably an O-shaped ring.

Specifically, the energy accumulator containing cavity and the attenuator containing cavity are directly arranged on the body and are integrally formed with the body, so that the stability of the whole structure of the attenuation device and the reliability of attenuation can be effectively improved. The body is preferably machined from aluminum bronze and has two ends for connection to a pipeline to effect damping of pressure pulsations in the fluid in the pipeline, wherein the fluid inlet end is the inlet 15 and the fluid outlet end is the outlet 19. In order to facilitate the connection of the damping device to the pipeline and to achieve damping of pressure pulsations of the fluid in the pipeline, it is preferred that flanges are provided at both ends of the body (i.e., both ends of the transfer channel). As shown in fig. 6, an inlet flange 16 is provided at one end of the inlet 15, and an outlet flange 20 is provided at one end of the outlet 19, so that the inlet flange 16 is connected to one section of the pipeline, and the outlet flange 20 is connected to the other section of the pipeline, so that the fluid in the pipeline is attenuated by the attenuation device and then discharged through the pipeline.

The energy accumulator can be provided with one or more energy accumulators, in order to ensure the attenuation effect, the energy accumulator is preferably provided with a plurality of energy accumulators, the number of the attenuators corresponds to that of the energy accumulators, and when the attenuators are arranged, the containing cavities of the attenuators are communicated to form a large attenuator containing cavity, so that the attenuation effect is improved. For the convenience of processing and the effect of attenuation, four accumulators are preferably provided in the present invention, and four attenuators are also preferably provided.

As shown in fig. 7, the body 1 is designed to be square, the number of the energy accumulators 3 and the number of the attenuators 2 are four, the four energy accumulators are respectively arranged on four surfaces of the square along the outer circumference of the square body, the four attenuators are respectively arranged around the corresponding energy accumulators, that is, one attenuator is arranged around the outer portion of one energy accumulator, and the attenuators are mutually communicated to form a large attenuator cavity. During specific processing, a cuboid material can be selected, a conveying channel 17 is firstly processed in the middle of the cuboid material, then energy storage device accommodating cavities 7 are respectively processed on four surfaces of the cuboid material, an attenuator accommodating cavity 13 is respectively processed around each energy storage device accommodating cavity 7 correspondingly, meanwhile, each attenuator accommodating cavity 13 is opened to form a large cavity, in addition, an energy storage device hole 11 communicated with the conveying channel 17 is processed at the bottom of each energy storage device accommodating cavity 7, and a damping hole 14 communicated with the conveying channel 17 is processed in each attenuator accommodating cavity 13. The energy accumulator containing cavity, the attenuator containing cavity and the body are integrally formed through the processing arrangement, and the overall stability and the attenuation effect of the device are greatly improved. In addition, flanges for connecting pipelines can be directly processed at two ends of the square body. The above steps can be completed by milling with a conventional numerical control milling machine.

After the machining is finished, the energy accumulator cover plates 5 are covered on the energy accumulator containing cavities 7 and the corresponding attenuator containing cavities 13 to seal the energy accumulator containing cavities 7 and the attenuator containing cavities 13, and therefore the frequency division combined pressure pulsation attenuation device can be obtained.

The attenuation device of the invention integrates the energy accumulator and the attenuator into a whole, and both the energy accumulator and the attenuator can be used as attenuation components to attenuate pressure pulsation, so that the attenuation device of the invention can realize the simultaneous attenuation of pressure pulsation with a plurality of frequencies. Preferably, the energy accumulator of the present invention is mainly used for attenuating shaft frequency pulsation, and the attenuator is mainly used for attenuating blade frequency pulsation. Specifically, the energy accumulator designed by the invention mainly realizes the attenuation of shaft frequency pulsation through parameter optimization design, and the attenuator realizes the attenuation of leaf frequency pulsation.

Specifically, the following procedure is used to design the accumulator parameters:

(1) first the effective volume of the accumulator is determined:

wherein Δ V is a pulsation volume of the object to be processed in one pulsation cycle, and the parameter can be obtained through numerical simulation after the object to be processed is determined, which is not described herein in detail for the prior art; the initial pressure pulsation rate can be actually measured; k is the polytropic index of the inflation gas, and the value of k is 1.4;

(2) the initial volume of the accumulator is then determined:

the method comprises the following steps that s is a pressure coefficient which is a multiple of the charging pressure of an energy accumulator relative to the pressure (working pressure) of fluid in a pipeline during working, and is determined according to the actual situation, wherein s is determined to be 0.6-0.9, preferably 0.9 through multiple tests;

(3) determining the volume V of the diaphragm according to the initial volume of the energy accumulator_DiaphragmSpecifically, the volume of the diaphragm is slightly larger than the initial volume, generally, the minimum integer larger than the initial volume is taken, and then the size of the diaphragm is designed according to the volume of the diaphragm, so that the volume of the gas containing space is equal to the volume of the diaphragm;

(4) determining the depth l of the accumulator bore according to equation (3)_AAnd total accumulator aperture area a_A：

Wherein f is_ANFor the frequency to be attenuated (in the present case the axial frequency of the object to be attenuated, which also represents the natural frequency of the energy store), K is the gas adiabatic coefficient, a_AIs the total area of the accumulator aperture, p₀Is the average pressure of the fluid (i.e. the pressure of the fluid in the pipeline during operation, i.e. the operating pressure), ρ is the density of the fluid, l_AFor accumulator hole depth, V_DiaphragmThe aim of the invention is to design the membrane volume such that the natural frequency of the energy store is close to the frequency to be damped, the damping effect being better as the frequency is closer. In the above formula f_AN、K、p₀Rho and V_DiaphragmFor a known parameter, a_AAnd l_AFor unknown parameters, five haveThe known parameters are substituted into the formula (3) to determine the proper a_AAnd l_AWherein groups a can be determined_AAnd l_AAnd selecting a proper group of data according to design requirements.

(5) Finally according to the total area a of the holes of the energy accumulator_ADetermining the number of the energy accumulator holes to complete the design of the energy accumulator, specifically, determining the number of the energy accumulator holes according to the following formula, wherein the diameter of a single energy accumulator hole is d:

the parameters of the attenuator are designed by adopting the following process:

(1) firstly, the effective volume V of the attenuator is determined_HThe effective volume V_HThe design method is determined according to actual design requirements, and the design method is preferably 5L;

(2) then determining the depth of the damping hole and the total area of the damping hole according to the formula (4):

in the formula (f)_HNFor the frequencies to be attenuated (the leaf frequencies of the object to be attenuated, which also represent the natural frequencies of the attenuator in the present invention), β_eIs the bulk modulus of the fluid, a_HIs the total area of the damping hole, /)_HIs the depth of the damping hole, V_HThe design aims to enable the natural frequency of the attenuator to be close to the frequency to be attenuated, and the attenuation effect is better when the natural frequency is close to the frequency to be attenuated;

(3) finally, according to the total area a of the damping holes_HDetermining the number of the damping holes to complete the design of the attenuator, wherein the diameter of each damping hole is d₁Determining the number n of the damping holes according to the following formula:

the damping device designed by the invention can be applied to any system with pressure pulsation, such as a centrifugal pump, a hydraulic pump and the like, namely, the object to be treated can be any system with pressure pulsation, the damping of the pressure pulsation of the corresponding system is realized by damping the pressure pulsation of the fluid (such as water, hydraulic oil, gas and the like) discharged by the object to be treated, after the object to be treated is determined, the frequency of the pressure pulsation needing to be damped, such as axial frequency (low frequency) pulsation, blade frequency (high frequency) pulsation and the like, can be determined, and then the corresponding attenuator and an accumulator are designed according to the frequency needing to be damped.

The design of the energy accumulator and the attenuator is explained in detail below by taking a centrifugal pump as an example, the centrifugal pump set has 8 blades and the output flow rate is 150m when the centrifugal pump set is in rated operation³The pressure pulsation is excited in the output pipeline of the engine, and is more prominent at an axial frequency (fz is 48.3Hz) and a blade frequency (fy is 387 Hz). The embodiment realizes the attenuation of the two frequencies by designing an energy accumulator and an attenuator, wherein four energy accumulators are arranged, the initial pressure pulsation rate is 3%, and the pulsation volume DeltaV is 8.62 × 10^-6m³(obtained by simulation), the fluid is water, and specific parameter design is carried out based on the design basis:

(1) designing the volume of the energy accumulator:

in order to effectively absorb the shaft frequency pulsation, the pressure coefficient s is 0.9, and the initial volume of the energy accumulator for absorbing the shaft frequency pulsation is as follows:

the volume V of the diaphragm_DiaphragmDesigned to be 0.5L>0.46L to meet the calculation requirement, designing the outline size of the diaphragm according to the capacity of the diaphragm of 0.5L, designing the diaphragm to be similar to a U shape, and designing the size of the diaphragm to be phi 130mm × 50mm so that the capacity of the gas containing space is approximately equal to 0.5L;

(2) design of accumulator bore:

determining the depth and total area of the accumulator hole according to the formula, wherein K is 1.4, f_ANAxial frequency of 48.3Hz, V_Diaphragm＝0.5L，p₀In this embodiment, the design of the accumulator holes under multiple environmental pressures is studied, where the environmental pressures are 1MPa, 2MPa, and 3MPa, and the working pressure is generally slightly greater than the environmental pressure, and in this embodiment, the working pressure is set to be 0.3MPa + the environmental pressure;

for an axial frequency of 48.3Hz, if the ambient pressure p₁1MPa, the working pressure p₀1.3MPa, according to the formula

Determine the appropriate a_A＝1.33×10^-4m²，l_AThe value is 0.005m (although there are other combinations of values, the value calculated by substituting the formula may be close to the axial frequency, the same applies hereinafter), and the parameters obtained as described above are substituted into the formula

And checking to calculate the frequency to be 49.4Hz, and the frequency is close to the axial frequency of 48.3Hz to meet the requirement.

For an axial frequency of 48.3Hz, if the ambient pressure p₁2MPa, the working pressure p₀When the pressure is 2.3MPa, a may be selected_A＝7.1×10^-5m²，l_AWhen the average value is 0.005m, the calculation is carried out

Equal to the shaft frequency of 48.3 Hz.

For an axial frequency of 48.3Hz, if the ambient pressure p₁Working pressure p of 3MPa₀When the pressure is 3.3MPa, a may be selected_A＝5.0×10^-5m²，l_AWhen the average value is 0.005m, the calculation is carried outThe axial frequency is close to 48.3Hz to meet the requirement.

For a leaf frequency of 387Hz, if the ambient pressure p₁1MPa, the working pressure p₀1.3MPa, take a_A＝1.26×10^{- 3}m²，l_AWhen the average grain size is 0.002m, the calculation is carried outThe difference with the leaf frequency of 387Hz is too much to meet the requirement.

The environmental pressure is the common environmental pressure, namely p, aiming at the leaf frequency of 387Hz₁Working pressure p of 3MPa₀When the pressure is 3.3MPa, a may be selected_A＝1.26×10^-3m²，l_AWhen the average grain size is 0.002m, the calculation is carried out

The frequency is close to 387Hz of the leaf frequency, and the requirement is met.

In the embodiment, the diameter of a single energy accumulator hole is designed to be d equal to 3mm, and the number n of the energy accumulator holes is set according to a formulaAnd (4) calculating. When a is_A＝1.33×10^-4m²Can be obtained by the formula a_A＝π/4×d₀ ²Calculating equivalent aperture d of accumulator hole₀13mm and can use the formulaCalculating n to be 19, namely opening 19 accumulator holes, as shown in FIG. 8; when a is_A＝7.1×10^-5m²Can be obtained by the formula a_A＝π/4×d₀ ²Calculating equivalent aperture d of accumulator hole₀9.5mm and using the formulaCalculating n as 11, i.e. on11 accumulator holes are provided, as shown in fig. 9; when a is_A＝5.0×10^-5m²Can be obtained by the formula a_A＝π/4×d₀ ²Calculating equivalent aperture d of accumulator hole₀8mm and using the formula

Calculating n to be 8, namely opening 8 accumulator holes, as shown in fig. 10; when a is_A＝1.26×10^-3m²Can be obtained by the formula a_A＝π/4×d₀ ²Calculating equivalent aperture d of accumulator hole₀40mm and using the formulaN is calculated to be 179, that is, 179 accumulator holes are opened, as shown in fig. 11.

The specific design parameters are shown in table 1:

TABLE 1 energy accumulator parameter design Table

Serial number

VDiaphragm

Operating pressure

Inflation pressure

d0

lA

n

Attenuating object

1

0.5L

1.3MPa

1.17MPa

13mm

5mm

19

Shaft frequency

2

0.5L

2.3MPa

2.07MPa

9.5mm

5mm

11

Shaft frequency

3

0.5L

3.3MPa

2.97MPa

8mm

5mm

8

Shaft frequency

4

0.5L

3.3MPa

2.97MPa

40mm

2mm

179

Leaf frequency

Therefore, through the optimization design of various parameters of the energy accumulator, the energy accumulator can be used for attenuating the shaft frequency pulsation under different environmental pressures, and can also be used for attenuating the leaf frequency pulsation under partial environmental pressure, for example, the energy accumulator can be designed to attenuate the leaf frequency pulsation under the environmental pressure of 3 MPa. Therefore, in the actual design, the four energy accumulators can be respectively designed to attenuate the axial frequency pulsation under the environmental pressure of 1MPa, the axial frequency pulsation under the environmental pressure of 2MPa, the axial frequency pulsation under the environmental pressure of 3MPa and the blade frequency pulsation under the environmental pressure of 3MPa, and the design can be specifically carried out according to the actual requirements, wherein the specific design parameters are carried out according to the table 1.

(3) Designing parameters of the attenuator:

according to the processing and design requirements, the total volume V of the chamber of the attenuator_HDesigned to be 5L, i.e. V_H＝0.005m³The attenuator is used for attenuating 387Hz β leaf frequency_e＝2.4×10⁹Pa, substituting the known parameters into the formula

Then determine the appropriate a_H＝1.23×10^-4m²，l_HThe value is 0.01m (of course, other combinations of values may be used, and the value calculated by substituting the formula may be close to the axial frequency), and each parameter is substituted into the formulaAnd (4) calculating to obtain the frequency of 386.7Hz which is close to the leaf frequency of 387Hz, and meeting the requirement.

The diameter of the single damping hole in the embodiment is designed to be d₁The number n of the damping holes is set to 4.4mm according to a formulaThe number of the damping holes is 8, so that 8 damping holes with the diameter of 4.4mm and the thickness of × 10mm can be designed, and the damping holes can effectively damp the blade frequency pulsation by the optimized design of the parameters of the attenuator.

The invention also provides a frequency division combined pressure pulsation attenuation method, which is realized by adopting the attenuation device designed by the invention and specifically comprises the following steps:

1) firstly, filling gas with set pressure into an energy accumulator, and specifically filling gas into a gas accommodating space through an inflation interface;

2) then, the fluid to be attenuated enters the hollow part of the attenuation device and enters the attenuator through the hollow part to realize the attenuation of the blade frequency pulsation, when the pressure of the fluid is higher than the gas pressure, the fluid also enters the energy accumulator, and when the pressure of the fluid is lower than the gas pressure, the fluid is discharged from the energy accumulator to realize the attenuation of the shaft frequency pulsation, so that the attenuation of the fluid pressure pulsation (including the shaft frequency and the blade frequency) is realized through the matching of the attenuator and the energy accumulator.

In practical use, parameters (including inflation pressure, volume of the containing cavity, depth, diameter and number of corresponding holes) of the energy accumulator and the attenuator are designed, so that the energy accumulator and the attenuator can correspondingly attenuate axial frequency and blade frequency pulsation respectively, and high-low pulsation can be attenuated simultaneously. When the damping device is used, the damping device is arranged in a corresponding pipeline, fluid in the pipeline enters the damping device through the inlet, pressure pulsation is damped after the fluid passes through the energy accumulator and the attenuator, and then the fluid is discharged from the outlet through the pipeline.

The invention integrates the energy accumulator and the attenuator into a whole, can effectively integrate the working frequency bands of the energy accumulator and the attenuator, and realizes the attenuation of pressure pulsation with a plurality of frequencies, thereby reducing the noise of fluid in a pipeline and the vibration of the pipeline and further improving the operation stability and the overall performance of a system connected with the pipeline.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.