WO2022089456A1

WO2022089456A1 - Liquid flow cavitation apparatus

Info

Publication number: WO2022089456A1
Application number: PCT/CN2021/126552
Authority: WO
Inventors: 刘杰
Original assignee: 刘杰
Priority date: 2020-10-29
Filing date: 2021-10-27
Publication date: 2022-05-05
Also published as: CN112282715A

Abstract

A liquid flow cavitation apparatus, comprising: a housing (1) having a top opening (11) and a bottom opening (12); a freely movable working medium (2) limited in an inner cavity of the housing (1), wherein a flow channel (3) for a liquid flow to flow through is comprised between the working medium (2) and the wall of the inner cavity of the housing (1); and resonant tails (4) which are located on the housing (1) and extend out of the end face of the bottom opening (12) of the housing along the axial direction of the cavitation apparatus. The liquid flow cavitation apparatus can further enhance a cavitation effect of a cavitator, improve a reconstruction effect on an underground rock stratum, and improve the seepage capacity and the recovery rate of a reservoir.

Description

A liquid flow cavitation device

technical field

The invention relates to the fields of oil, natural gas, coalbed methane and uranium mining, in particular to a liquid flow cavitation device.

Background technique

At present, two technologies are mainly used in oil exploitation, one is hydraulic fracturing technology, and the other is ultrasonic cavitation technology.

Hydraulic fracturing is an oil-increasing technology that injects fracturing fluid into the oil layer to create a main fracture in order to change the oil flow. The 1980s was an important stage in the development history of hydraulic fracturing, and it gradually became an important technical means in the field of oil and gas, especially low-permeability oil and gas exploration and development. The mechanism of hydraulic fracturing stimulation: when the high-viscosity liquid is injected into the well by the high-pressure pump group on the ground at a displacement that exceeds the absorption capacity of the formation, the pressure generated at the bottom of the well exceeds the pressure of the in-situ stress near the well wall and the tensile strength of the rock, that is, in the formation. cracks formed in it. As the proppant-laden liquid is injected into the formation, the fractures gradually extend forward to form sand-packed fractures with a certain length, width and height. The fracture has high conductivity and changes the flow state of oil and gas seepage.

However, hydraulic fracturing has the following disadvantages: (1) The process is complicated and the operating cost is high. Hydraulic fracturing is a rigorous systematic project. If there is insufficient understanding of reservoir geology, improper well selection, improper selection of fracturing fluid, improper proppant selection, unreasonable fracturing operation parameter design, improper construction scale, Improper post-drainage measures may lead to fracturing construction failure or reduce the stimulation effect, and may even have a serious impact on the later development and adjustment of oil and gas fields. Reservoir stimulation technology is also a high-investment and high-risk technology. The operating cost of a single well is generally between hundreds of thousands and millions of yuan, and the operating cost of a deep well is even more than ten million yuan. (2) Serious pollution to oil wells and formations. If the fracturing fluid is improperly selected, it will cause the expansion of clay minerals in the formation, the emulsification of crude oil, the introduction of mechanical impurities into the formation, and the formation of precipitation due to incompatibility with formation water. The poor corrosion inhibition performance of acid solution will also cause serious corrosion to construction equipment and pipe strings. Fracturing is a high-pressure operation, and various chemicals used in construction will also pose serious threats to human life, property and the ecological environment. (3) Great damage to oil wells and formations. Improper fracturing can cause serious consequences of oil well flooding and reactive water injection, or fracturing adjacent aquifers or the upper part of reservoirs containing gas caps. In addition, improper drainage can cause increased damage to the reservoir, possibly causing proppant backflow, which can lead to permanent damage to the formation and the well. (4) The introduction of artificial trunk fractures aggravates the heterogeneity of the reservoir, which may bring adverse effects on the development of oil and gas reservoirs.

Ultrasonic oil recovery technology is one of the tertiary oil recovery technologies developed in recent decades. Ultrasonic cavitation plugging removal technology is high-power ultrasonic plugging removal technology. The new ultrasonic oil filling system is mainly composed of a magnetic positioning system, a special transmission cable, a high-power ultrasonic electrical signal transmitter and an ultrasonic electro-acoustic converter. It uses the high-power pulsed electrical oscillation signal generated by the ground-mounted high-power ultrasonic transmitter to transmit the pulsed electrical oscillation signal to the piezoelectric ceramic electro-acoustic converter of the oil layer through a special transmission cable, and is converted into ultrasonic waves by the electro-acoustic converter. injection into oil-bearing formations. By ultrasonically treating the near-well oil layers of production oil wells and water injection wells, the physical properties and flow patterns of the fluids in the oil layers are changed, the circulation conditions and permeability of the bottom hole near the wellbore are improved, the blockage of oil production wells and water injection wells is relieved, and the fluid production is improved. volume, crude oil production and water injection to achieve the purpose of increasing production.

However, ultrasonic cavitation has the following disadvantages: (1) Ultrasonic cavitation can only be used for plugging removal near wellbore. The liquid medium produces cavitation bubbles, and the ultrasonic wave is required to have a certain intensity. The greater the ultrasonic power, the better the blocking effect. However, the attenuation speed of ultrasonic waves is extremely fast. Some studies have shown that the sound intensity at the borehole wall is attenuated to 45% of that at the sound source, and the sound intensity at a radius of 1 meter of the pore medium geometric model attenuates to 10% of the sound intensity at the borehole wall. Therefore, the cavitation effect produced by ultrasonic waves can only act in the area near the wellbore, and the maximum acting radius is only 15 meters, so the effect is limited. (2) The cavitation area is in a non-flowing state, and the cavitation area (or cavitation) formed around the cavitation device has a limited range. Interruption of liquid flow creates air pockets. According to the numerical requirements of cavitation, in order to create a gap in the liquid flow, the liquid must be pumped at a very high speed, but this very high speed cannot be obtained in all cases, especially in deep wells or extended pipelines; Under high external hydrostatic pressure, such as in deep wells, the cavitation effect cannot be obtained using ultrasonic waves. (3) Limited by the processing time, the operation effect is limited. The cumulative ultrasonic treatment time has a great influence on the plugging effect, but after the treatment time exceeds 60 minutes, the plugging effect does not increase significantly; the higher the ultrasonic frequency, the greater the attenuation during the propagation process, and the worse the plugging effect. (4) The technical supporting equipment is complex, the operating cost is high, and the operating environment requirements are relatively high. (5) Not suitable for oil wells with inclination greater than 45 degrees.

Today, natural gas and coalbed methane extraction mainly adopts hydraulic fracturing technology as mentioned above, of course, there are also the problems mentioned above. In addition, hydraulic fracturing is used in coalbed methane wells to cause coal powder drift and blockage, which cannot be solved at present.

At present, uranium mining mainly adopts the solution leaching method, but there are significant differences in the permeability of each layer of the ore-bearing layer profile, and the solution seepage is not uniform. The difference in the permeability of the ore-bearing layer and the uneven distribution of the leaching solution will seriously affect the balance of leaching and directly affect the uranium concentration and leaching rate of the leaching solution. And during the leaching period, with the operation of the in-situ leaching and pumping system, the physical blockage of the ore-bearing layer caused by the migration of the solution and the fine particles in the ore layer and the chemical blockage of the ore-bearing layer caused by the interaction of the solution and the mineral will cause the ore-bearing layer to be blocked. The permeability of the ore layer changes again, changing the structure of the reservoir, reducing the permeability coefficient of the ore-bearing layer, reducing the flow rate of the pumping fluid, and even causing some of the pumping fluid holes to lose their productivity, which seriously affects the production operation. Such problems have always plagued in-situ leaching mines, and so far, there is no effective method to solve the inhomogeneity of leaching of heterogeneous ore-bearing layers. .

In order to solve the above-mentioned problems, the Chinese patent "liquid flow cavitation, liquid flow cavitation system and liquid flow cavitation method", publication number CN105201482A, provides a liquid flow cavitation, through which air is generated in the liquid. The resulting shock waves are transmitted through a large number of micro-fractures in the reservoir, thereby increasing the pore-throat channels of the reservoir, effectively improving the seepage capacity of the reservoir, greatly improving the homogeneity of the reservoir, and improving the production rate. yield. On this basis, the designer found that the structure of the cavitation can be further improved on the basis of the above-mentioned cavitation, so as to further enhance the cavitation effect of the cavitation, increase the transformation effect of the underground rock formation, improve the seepage capacity of the reservoir and the mining capacity. yield.

SUMMARY OF THE INVENTION

In view of the above problems, the purpose of the present invention is to provide a liquid flow cavitation device to further enhance the cavitation effect of the cavitation device, increase the transformation effect of the underground rock formation, and improve the seepage capacity and recovery rate of the reservoir.

To achieve the above object, the present invention adopts the following technical solutions:

The present invention provides a liquid flow cavitation device comprising:

A casing with an opening at the top and an opening at the bottom;

a freely movable working medium confined in the inner cavity of the shell, and a flow channel for the liquid to flow through is included between the working medium and the cavity wall of the shell;

The cavitation device further includes a resonance tail on the casing, which extends out of the open end face of the bottom of the casing along the axial direction of the cavitation device.

In addition, a preferred solution is that the cavitation device includes a plurality of resonant fins uniformly arranged along the circumferential direction of the casing; and an interval is left between the side walls of two adjacent resonant fins.

In addition, a preferred solution is that the resonant fin and the casing have an integral structure, and the resonant fin extends from the edge of the bottom opening of the casing along the axial direction of the cavitation device.

In addition, a preferred solution is that the resonant tail and the housing are of separate structures; the cavitation device includes a resonance member, and the resonance member includes:

an annular fixing portion connected to the bottom of the housing, and

the vibrating parts on the fixing part are evenly arranged along the circumferential direction of the fixing part, and the vibrating parts extend along the axial direction of the fixing part;

The vibrating part of the resonance member forms the resonance tail of the cavitation device.

In addition, a preferred solution is that the cavitation device includes a plurality of resonant fins uniformly arranged along the circumferential direction of the casing; the distance between the side walls of two adjacent resonant fins is not less than one third of the width of the resonant fin, and Not more than twice the width of the resonant tail.

In addition, a preferred solution is that the inner wall surface of the resonance tail is an arc surface or a plane surface, and the outer wall surface of the resonance tail is an arc surface.

In addition, a preferred solution is that the inner wall surface of the resonance tail and its corresponding shell inner cavity wall surface are arc surfaces with the same curvature;

In the axial direction of the cavitation device, the projection of the inner wall surface of the resonance tail and its corresponding shell inner cavity wall surface on the horizontal plane is located on the same arc.

In addition, a preferred solution is that the thickness of the resonant fin in the radial direction decreases from the end of the resonant fin close to the opening at the bottom of the casing to the end away from the opening at the bottom of the casing.

In addition, a preferred solution is that, in the axial direction of the cavitation device, the length of the resonance tail is not greater than 45% of the length of the casing.

In addition, a preferred solution is that the cavitation device includes a plurality of upper partitions adjacent to the opening at the top of the casing, and a lower partition adjacent to the opening at the bottom of the casing;

A plurality of the upper partitions are formed by protruding inward from the inner cavity wall of the casing, and are used to prevent the working medium from leaving the casing from the top opening of the casing;

The lower partition protrudes inward from the inner cavity wall of the shell, and is used to prevent the working medium from leaving the shell from the bottom opening of the shell;

The bottom surface of the upper partition is flat, the axis of the upper partition and the axis of the cavitation device form an angle, and two adjacent upper partitions are arranged in parallel.

The beneficial effects of the present invention are as follows:

1. Compared with the existing cavitation structure, when the liquid flow of the liquid cavitation device provided by the present invention flows out from the opening at the bottom of the casing, the eddy currents around the high-speed fluid alternately generate lateral vibration of a certain frequency, and when the frequency of the vibration is close to resonance At the resonant frequency of the fin, the resonant fin is excited to vibrate, radiating sound waves to the surrounding liquid, and cavitation near the fin.

The cavitation bubbles in the cavitation area flow with the liquid, forming a cavitation field in the flow field. The lateral vibration of the resonant fin along with the effect of sound wave radiation makes the cavitation bubbles in the cavitation field unable to merge, increasing the number of cavitation bubbles. , and further strengthen the cavitation strength. In addition, due to the transferability of the sound wave energy, the flowing cavitation continues to generate cavitation under the effect of transfer, forming a multi-level cavitation effect.

The vibration of the resonant tail excites the large-scale vibration of the bubble, making the bubble a good energy storage device. Under the action of the sound field, the energy-gathering effect is generated, which greatly improves the energy density in the bubble, which can be increased by more than ten orders of magnitude.

2. The resonance tail vibrates left and right under the action of cavitation, squeezing the water flow, that is, under the influence of the pressure difference between the internal and external water, the resonance tail vibrates left and right, and the resonance tail provides new vibration waves and sound waves that vibrate and sound, and the sound waves are conducted along the radial direction of the device. The two form new vibration energy, further enhance the cavitation effect, and increase the transformation effect of the underground rock formation.

3. The vibration waves and sound waves generated by the vibration of the resonant tail have a resonance effect with the self-excited oscillation and cavitation energy of the device, and the resonance effect acts on the device to further enhance the self-excited oscillation of the device and the energy waves generated by cavitation.

4. The effect of the pulsed liquid flow on the resonance tail can make the frequency of the sound wave generated by the resonance tail not fixed, and change with the change of the pulsed water flow, which can form a resonance effect with the self-excited oscillation of the device, increase the impact on the underground rock formation, and improve the Cavitation effect.

Description of drawings

The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

Fig. 1 shows a schematic diagram of the external structure of the liquid flow cavitation device provided by the present invention.

FIG. 2 shows a structural cross-sectional view of a specific embodiment of the liquid flow cavitation device provided by the present invention.

FIG. 3 shows a structural cross-sectional view of another specific embodiment of the liquid flow cavitation device provided by the present invention.

FIG. 4 shows a schematic structural diagram of a resonance member in the structure of the liquid flow cavitation device shown in FIG. 3 .

Detailed ways

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques and devices should be considered part of the specification.

In all examples shown and discussed herein, any specific values should be construed as illustrative only and not limiting. Accordingly, other instances of the exemplary embodiment may have different values.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further discussion in subsequent figures.

In order to further enhance the cavitation effect of the cavitation device, increase the transformation effect on the underground rock formation, and improve the seepage capacity and recovery rate of the reservoir, the present invention provides a liquid flow cavitation device as shown in FIG. 1 to FIG. 4 ; First, as shown in FIG. 1 and FIG. 2 , in a specific embodiment, the cavitation device includes:

Housing 1 with top opening 11 and bottom opening 12;

The freely movable working medium 2 confined in the inner cavity of the shell 1 includes a flow channel 3 for the liquid flow to flow through between the working medium 2 and the cavity wall of the shell 1; There is no mechanical connection between the mass and the shell.

The cavitation device further includes a resonance tail 4 located on the casing 1 and extending out of the end face of the bottom opening 12 of the casing 1 along the axial direction of the cavitation device.

Compared with the existing liquid flow cavitation device, in the working process of the liquid flow cavitation device provided by the present invention, the liquid flow (water) enters from the top of the device and passes through the working medium, and flows out from the bottom of the device, and the working medium oscillates to generate a pulsed water flow, The device itself produces self-excited oscillation, and the water at the bottom of the device forms a liquid cavitation field containing a large number of cavitations, and the cavitation bubbles are rapidly squeezed in the liquid and burst continuously.

In addition, the alternating eddy currents around the high-speed fluid cause lateral vibration of a certain frequency. When the frequency of the vibration is close to the resonant frequency of the resonant fin, the resonant fin is excited to vibrate, radiate sound waves to the surrounding liquid, and generate cavitation near the fin.

The cavitation bubbles in the cavitation area flow with the liquid, forming a cavitation field in the flow field. The lateral vibration of the tail is accompanied by the effect of sound wave radiation, so that the cavitation bubbles in the cavitation field cannot be merged, increasing the number of cavitation bubbles. And further strengthen the cavitation strength. And due to the transferability of the sound wave energy, the flowing cavitation continues to generate cavitation under the transfer effect, forming a multi-level cavitation effect.

Further, the vibration of the tail fin excites the large-scale vibration of the bubble, making the bubble a good energy storage device, which can generate energy-gathering effect under the action of the sound field, and greatly increase the energy density in the bubble, which can be increased by more than ten orders of magnitude.

The liquid flow cavitation device provided by the present invention utilizes the resonance tail to vibrate left and right under the action of cavitation to squeeze the water flow, that is, under the influence of the pressure difference between the internal and external water flow, the resonance tail vibrates left and right, and the resonance tail provides new vibration waves and sound waves that vibrate and produce sound. The sound wave is conducted in the radial direction of the device, and the two form new vibration energy, which further enhances the cavitation effect and increases the transformation effect of the underground rock formation.

In addition, the vibration waves and sound waves generated by the vibration of the resonant tail fin have a resonance effect with the self-excited oscillation of the device and the cavitation energy, and the resonance effect acts on the liquid cavitation device to further enhance the self-excited oscillation of the liquid cavitation device. and energy waves generated by cavitation.

The effect of the pulsed liquid flow on the resonance tail in the present invention can make the frequency of the sound wave generated by the resonance tail not fixed, and change with the change of the pulsed water flow. Improve cavitation effect.

Optionally, the cavitation device provided by the present invention includes a plurality of resonant fins 4 evenly arranged along the circumferential direction of the casing 1; no less than three resonant fins 4 are arranged along the circumferential direction of the casing 1, and the sides of two adjacent resonant fins are Spaces are left between the walls. Further, the distance between the side walls of two adjacent resonant fins 4 is not less than one third of the width of the resonant fin 4 and not more than twice the width of the resonant fin 4 . In order to ensure that the vibration conduction influence angle of the vibration tail 4 does not appear blind.

In this embodiment, the resonant fin 4 and the casing 1 have an integral structure, and the resonant fin 4 extends from the edge of the bottom opening 12 of the casing 1 along the axial direction of the cavitation device. Optionally, the shell 1 is integrally processed with a high-strength metal material, and when the resonant tail 4 vibrates laterally under the action of high-speed fluid cavitation, the overall structure is beneficial to form resonance with the self-excited vibration of the equipment.

3 and 4, in another embodiment, the resonant tail and the housing are separate structures; specifically, the cavitation device includes a resonator 5, and the resonator 5 includes :

an annular fixing portion 51 connected to the bottom of the housing 1 and fixed, and

The vibrating parts 52 located on the fixing part 51 are evenly arranged along the circumferential direction of the fixing part, and the vibrating parts 52 extend along the axial direction of the fixing part 51; the vibrating parts 52 of the resonator 5 form the resonance tail 4 of the cavitation device .

The connection and fixing method between the annular fixing portion 51 of the resonance member 5 and the housing 1 may adopt a connection method well known in the art, including but not limited to screw connection, snap connection, welding, and plug connection. The advantage is that the design of the resonant tail and the shell as a separate structure can facilitate the separate processing and production of the resonance parts and the shell, and facilitate disassembly and assembly. In different application scenarios and under different conditions, a resonance tail with a different number of resonance tails can be selected. It expands the scope of application of the cavitation device. And for the resonant tail material selected on the resonator, a metal material with high elasticity and strength different from the shell can be selected, such as high carbon alloy or copper alloy and stainless steel. Referring to FIG. 4 , in this embodiment, the annular fixing portion 51 includes a reinforcing rib 53 to increase the structural strength of the annular fixing portion 51 . Optionally, the reinforcing rib can also be used as a lower partition for limiting the freely movable working medium in the inner cavity of the housing.

In an optional embodiment, the inner wall surface of the resonance tail 4 is an arc surface or a plane surface, and the outer wall surface of the resonance tail 4 is an arc surface. It should be noted that, in an optional embodiment, when the inner surface of the resonant fin is a plane structure, the lateral vibration effect of the resonant fin can be improved.

In another optional embodiment, in order to ensure that the cavitation bubbles will not be broken ahead of time due to changes in flow pressure during the process of moving out of the cavity with the flowing liquid. The inner wall surface of the resonance tail 4 and its corresponding inner cavity wall surface of the shell 1 are arc surfaces with the same curvature; in the axial direction of the cavitation device, the inner wall surface of the resonance tail 5 and its corresponding inner cavity cavity of the shell 1 The projection of the wall surface on the horizontal plane lies on the same arc.

Combined with the structure shown in the figure, the thickness of the resonance tail 4 in the radial direction decreases gradually from the end of the resonance tail 4 close to the bottom opening 12 of the casing 1 to the end away from the bottom opening 12 of the casing 1 . In order to improve the new vibration wave provided by the resonant tail and the sound wave effect of the vibration sound, the vibration wave and sound wave generated by the vibration of the improved resonance tail will have a resonance effect with the self-excited oscillation of the device and the cavitation energy, and the resonance effect will act on the liquid. The flow cavitation device can further enhance the self-excited oscillation of the liquid flow cavitation device and the energy waves generated by cavitation.

Since the length of the resonance tail affects its amplitude frequency and sound wave intensity, in the axial direction of the cavitation device, the length of the resonance tail is not easy to be too long or too short. Considering the material strength of the resonance tail and its effect on the cavitation device The strength of the vibration wave and the sound wave effect, and then preferably in the axial direction of the cavitation device, the length of the resonant tail is not more than 45% of the length of the shell.

In the present invention, the cavitation device includes a plurality of upper partitions 111 adjacent to the top opening 11 of the casing 1 and a lower partition 121 adjacent to the bottom opening 12 of the casing 1; The inner cavity wall is formed to protrude inward to prevent the working medium 2 from leaving the shell 1 from the top opening 11 of the shell 1; the lower partition 121 can be protruded inward from the inner cavity wall of the shell 1 to prevent the working medium 2 from The bottom opening 12 of the housing 1 is separated from the housing 1; the bottom surface of the upper partition 111 is flat, the axis of the upper partition 111 and the axis of the cavitation device form an angle, and two adjacent upper partitions 111 are arranged in parallel.

The upper baffle 111 can be integrally processed with the casing, or can be formed on the casing 1 by processing other metal materials or high-strength engineering plastic materials. The similar lower baffle 121 can be integrally processed with the casing 1 , and its structure can be inline or cross-shaped, or adopt other structural patterns that can be used to prevent the working medium 2 from leaving the casing from the bottom opening 12 of the casing 1 . The working medium 2 can be a perfect circle or an eccentric sphere. In addition to metal materials, the working medium can also be made of other materials such as high-strength engineering plastics, rubber, etc. Block the impact and prolong the service life of the device.

The present invention utilizes the inclined arrangement of several upper partitions relative to the casing, and the liquid flow passes through the diversion of the upper partitions after entering the inner cavity of the casing, so that the liquid flow can be rotated in a clockwise or counterclockwise direction to act on the workpiece. The rotation of the working medium can be used to reduce the impact force between the working medium and the inner cavity wall of the shell, and at the same time, the cavitation effect can be enhanced.

Different working fluid structures are suitable for different product structures and have different advantages. For the structural form of the working fluid, the present invention provides the following several optional embodiments.

In one embodiment, the working medium is a spherical structure, the spherical working medium is confined in the inner cavity of the shell and can move freely, and a flow channel through which the liquid flows is included between the working medium and the cavity wall of the shell .

In an alternative example, the working medium is a cylindrical structure, preferably, the working medium of the cylindrical structure is a cylindrical shape along the liquid flow direction. Alternatively, the working medium can also be a conical structure, preferably, the working medium of the conical structure is tapered along the liquid flow direction. Alternatively, the working medium is an annular structure, preferably, the working medium of the annular structure is an annular shape on a plane perpendicular to the liquid flow direction, similar to the shape of a doughnut. Optionally, the working fluid of the above-mentioned various structures may include through holes, or may be solid.

In an optional implementation manner, a freely movable spacer and/or a washer spring may also be provided at a position below the working medium, and the spacer and/or the spacer spring are also limited in the inner cavity of the housing, and also That is, spacers and/or springs are arranged in the housing cavity below the working medium and above the lower baffle. In the present invention, when the liquid flow is cavitated, the working fluid vibrates together with the gasket and/or the washer spring, which can enhance the cavitation effect of the liquid flow cavitation device provided by the present invention.

In a preferred embodiment, a single or a plurality of working fluids can be limited and constrained in the inner cavity of the casing. When the liquid flow cavitation operation is performed, multiple working fluids interact to enhance the cavitation effect. The plurality of working fluids may be spherical, cylindrical, conical and annular working fluids or combinations thereof.

In addition, the inner cavity of the casing of the liquid flow cavitation device provided by the present invention may include a plurality of compartments, and the plurality of compartments may be separated along the direction of liquid flow by a middle through partition wall formed by the inward protrusion of the inner wall of the casing, wherein Each compartment contains a plurality of working fluids in groups. In this way, only the working fluids in the same group are made to collide with each other, and the cavitation effect along the liquid flow direction is accelerated.

In the actual use process of the liquid flow cavitation device provided by the present invention, the vibration wave generated by the excitation of the resonant tail and the sound wave radiated to the surrounding liquid can be used to increase the cavitation effect of the cavitation device and further utilize the resonance. The vibration waves and sound waves generated by the tail wing have a resonance effect with the self-excited oscillation of the device and the cavitation energy, which in turn acts on the cavitation device, further enhancing the self-excited oscillation of the cavitation device and the energy waves generated by cavitation. In order to make better use of the cavitation device to transform the underground rock formation, improve the seepage capacity and recovery rate of the reservoir.

Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Changes or changes in other different forms cannot be exhausted here, and all obvious changes or changes derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

A liquid flow cavitation device, characterized in that the cavitation device comprises:

A casing with an opening at the top and an opening at the bottom;

a freely movable working medium confined in the inner cavity of the shell, and a flow channel for the liquid to flow through is included between the working medium and the cavity wall of the shell;

The cavitation device further includes a resonance tail on the casing, which extends out of the open end face of the bottom of the casing along the axial direction of the cavitation device.
The liquid flow cavitation device according to claim 1, characterized in that, the cavitation device comprises a plurality of resonance fins uniformly arranged along the circumferential direction of the casing; a space is left between the side walls of two adjacent resonance fins .
The liquid flow cavitation device according to claim 1, wherein the resonant fin and the casing are integral structures, and the resonant fin extends from the bottom opening edge of the casing along the axial direction of the cavitation device out.
The liquid flow cavitation device according to claim 1, wherein the resonant tail and the shell are of separate structures; the cavitation device comprises a resonator, and the resonator comprises:

an annular fixing portion connected to the bottom of the housing, and

the vibrating parts on the fixing part are evenly arranged along the circumferential direction of the fixing part, and the vibrating parts extend along the axial direction of the fixing part;

The vibrating part of the resonance member forms the resonance tail of the cavitation device.
The liquid flow cavitation device according to claim 1, wherein the cavitation device comprises a plurality of resonance fins uniformly arranged along the circumferential direction of the casing; the distance between the side walls of two adjacent resonance fins is not less than One third of the width of the resonant fin and not more than twice the width of the resonant fin.
The liquid flow cavitation device according to claim 1, wherein the inner wall surface of the resonance tail is an arc surface or a flat surface, and the outer wall surface of the resonance tail is an arc surface.
The liquid flow cavitation device according to claim 1, wherein the inner wall surface of the resonance tail and its corresponding shell inner cavity wall surface are arc surfaces with the same curvature;

In the axial direction of the cavitation device, the projection of the inner wall surface of the resonance tail and its corresponding shell inner cavity wall surface on the horizontal plane is located on the same arc.
The liquid flow cavitation device according to claim 1, wherein the thickness of the resonance fin in the radial direction decreases gradually from the end of the resonance fin close to the opening at the bottom of the casing to the end away from the opening at the bottom of the casing.
The liquid flow cavitation device according to claim 1, characterized in that, in the axial direction of the cavitation device, the length of the resonant tail is not more than 45% of the length of the shell.
The liquid flow cavitation device according to claim 1, wherein the cavitation device comprises a plurality of upper partitions adjacent to the top opening of the casing, and a lower partition adjacent to the bottom opening of the casing;

A plurality of the upper partitions are formed by protruding inward from the inner cavity wall of the casing, and are used to prevent the working medium from leaving the casing from the top opening of the casing;

The lower partition protrudes inward from the inner cavity wall of the shell, and is used to prevent the working medium from leaving the shell from the bottom opening of the shell;

The bottom surface of the upper partition is flat, the axis of the upper partition and the axis of the cavitation device form an angle, and two adjacent upper partitions are arranged in parallel.