A directional hydraulic jet acid fracturing device

Abstract

The application discloses a directional hydraulic jet acid fracturing device, and improves the technical problems of insufficient jet speed or pump blocking. The device comprises a tubing, a connector, an upper centralizer, a jet and a lower centralizer which are sequentially connected from top to bottom, and is characterized in that the jet comprises a support shell, a top end of which is connected with the upper centralizer and a bottom end of which is connected with the lower centralizer; a plurality of jet holes are arranged on the support shell; a damping ball is vertically and slidingly connected in the support shell; and a reset spring is arranged in the support shell. The damping ball can move downward under the pressure of the acid liquid fluid and sequentially open the plurality of jet holes, and the reset spring is used for pushing the damping ball to move upward and sequentially close the plurality of jet holes. The application can adjust the opening number of the jet holes according to the actual input flow and pressure of the acid liquid fluid, effectively improves the problems of insufficient jet speed or pump blocking, and prolongs the service life.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas extraction technology, and specifically relates to a directional hydraulic jet acid fracturing device. Background Technology

[0002] Currently, after years of exploration and development, some oilfields are starting with acidizing, progressing to large-scale acid fracturing and deep-to-ultra-deep well fracturing and acidizing. Reservoir stimulation has become an indispensable means for increasing oilfield reserves and production.

[0003] Chinese patent CN202832464U discloses a coiled tubing hydraulic jetting multi-stage acid fracturing tool string, including coiled tubing, a screw connector, a double-valve check valve, a release connector, an upper centralizer, a hydraulic jetting tool, a lower centralizer, and a guide shoe. The screw connector is threaded to the lower end of the coiled tubing, and the double-valve check valve is connected to the lower end of the screw connector. The release connector is connected to the lower end of the double-valve check valve. The upper centralizer is connected to the lower end of the safety release connector. The hydraulic jetting tool is connected to the lower end of the upper centralizer. The lower centralizer is connected to the lower centralizer. The guide shoe is connected to the lower end of the lower centralizer.

[0004] However, the aforementioned hydraulic jetting tools struggle to adjust the number of perforations opened based on the actual flow rate and pressure of the input fluid. In other words, if the input fluid flow rate and pressure are relatively low, opening too many perforations results in lower fluid pressure and velocity, compromising downhole acidizing effectiveness. Conversely, if the input fluid flow rate and pressure are relatively high, opening too few perforations can lead to pump stalling, reducing service life and requiring improvement. Summary of the Invention

[0005] To address all or some of the aforementioned problems, the present invention aims to provide a directional hydraulic jet acid pressure device that can adjust the number of injection holes opened according to the actual flow rate and pressure of the input acid fluid, effectively improving the problems of insufficient injection speed or pump stalling, and extending service life.

[0006] This invention provides a directional hydraulic jet acid fracturing device, comprising, from top to bottom, an oil pipe, a connector, an upper stabilizer, an injector, and a lower stabilizer, wherein the injector includes:

[0007] The support shell is connected at its top to the upper stabilizer and at its bottom to the lower stabilizer.

[0008] Multiple injection holes are provided on the support shell.

[0009] A damping ball is vertically and slidably connected within the support shell;

[0010] A reset spring is disposed within the support shell;

[0011] The damping ball can move downward under the pressure of the acid fluid, causing the plurality of injection holes to open sequentially. The return spring is used to push the damping ball upward, causing the plurality of injection holes to close sequentially.

[0012] Optionally, a sealing ring is fixedly connected to the top of the inner wall of the support shell along its circumference, and the inner sidewall of the sealing ring is provided with a sealing surface that matches the damping ball.

[0013] Optionally, the damping ball includes an upper spherical shell, a connecting ring, and a lower spherical shell connected sequentially from top to bottom. The connecting ring is made of a flexible material. The upper spherical shell can squeeze the connecting ring under the pressure of the acid fluid, so that the connecting ring expands outward and fits more tightly against the inner wall of the support shell.

[0014] Optionally, a guide cylinder is vertically fixedly connected inside the upper spherical shell, and a guide rod is vertically fixedly connected inside the lower spherical shell, with the guide rod and the guide cylinder being vertically slidably connected.

[0015] Optionally, an installation platform is fixedly connected to the inner wall of the upper spherical shell. An integrated circuit board is provided on the installation platform. The integrated circuit board integrates a power storage module, a gas pressure detection module, a data processing module, and a wireless transmission module. The wireless transmission module is wirelessly connected to the external monitoring equipment.

[0016] Optionally, a pressure sensor, a piezoelectric ceramic chip, and a pressure piston are arranged sequentially from top to bottom inside the guide cylinder. The top end of the piezoelectric ceramic chip is fixedly connected to the pressure sensing end of the pressure sensor, and the bottom end abuts against the pressure piston. The output terminal of the piezoelectric ceramic chip is connected to the charging terminal of the power storage module.

[0017] Optionally, a cooling pipe is horizontally arranged on the upper spherical shell above the mounting platform, and an inlet pipe is vertically connected to the cooling pipe, allowing acid fluid to enter the cooling pipe through the inlet pipe and flow out through both ends of the cooling pipe.

[0018] Optionally, the top end of the inlet pipe is flared.

[0019] Optionally, each of the spray holes is provided with a nozzle assembly.

[0020] Optionally, the nozzle assembly includes a receiving shell disposed within the spray hole, a nozzle shell movably disposed on the inner side of the receiving shell, a spray hole being opened at the center of the nozzle shell, a support ring being fixedly sleeved on the nozzle shell, a stepped groove being provided on the inner wall of the receiving shell, and the support ring being horizontally slidably connected to the stepped groove.

[0021] A sealing pin is horizontally fixedly connected to the receiving shell, and the sealing pin can be inserted into the spray hole. The receiving shell is provided with multiple water inlets, which are arranged along the circumference of the support ring and aligned with the support ring. A return spring is provided in the stepped groove.

[0022] The acid fluid can drive the support ring to move the nozzle housing and separate the sealing pin from the spray hole. The return spring can drive the support ring to move the nozzle housing and cover the multiple water inlets with the support ring, and the sealing pin is inserted into the spray hole.

[0023] As can be seen from the above technical solution, the directional hydraulic jet acid fracturing device provided by the present invention has the following advantages:

[0024] This device can adjust the number of injection orifices opened based on the actual flow rate and pressure of the input acid fluid, effectively improving problems such as insufficient injection speed or pump stalling, and extending service life. Simultaneously, a specially designed damping ball ensures a tighter fit between the damping ball and the inner wall of the support shell, resulting in a better seal and preventing acid fluid pressure loss and waste.

[0025] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0026] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0027] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0028] Figure 2 This is a cross-sectional view of the injector in Embodiment 1 of the present invention;

[0029] Figure 3 This is an exploded view of the damping sphere in Embodiment 1 of the present invention;

[0030] Figure 4 This is a schematic diagram of the upper spherical shell in Embodiment 1 of the present invention;

[0031] Figure 5 This is a schematic diagram of the integrated circuit board in Embodiment 1 of the present invention;

[0032] Figure 6 This is a cross-sectional view of the damping ball in Embodiment 1 of the present invention;

[0033] Figure 7 This is a cross-sectional view of the upper spherical shell in Embodiment 1 of the present invention;

[0034] Figure 8 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention;

[0035] Figure 9 This is a cross-sectional view of the injector in Embodiment 2 of the present invention;

[0036] Figure 10 This is a schematic diagram of the nozzle assembly in Embodiment 2 of the present invention;

[0037] Figure 11 This is a cross-sectional view of the nozzle assembly in Embodiment 2 of the present invention.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Oil pipe; 2. Connector; 3. Upper centralizer; 4. Injector; 41. Support shell; 42. Injection hole; 5. Lower centralizer; 6. Damping ball; 61. Upper spherical shell; 62. Connecting ring; 63. Lower spherical shell; 64. Guide cylinder; 65. Guide rod; 7. Return spring; 8. Sealing ring; 9. Sealing surface; 10. Mounting platform; 11. Integrated circuit board; 12. Piston ring; 13. Pressure sensor; 14. Piezoelectric ceramic chip; 15. Pressure piston; 16. Cooling pipe; 17. Liquid inlet pipe; 18. Nozzle assembly; 181. Receiving shell; 182. Nozzle shell; 183. Inlet; 184. Support ring; 185. Step groove; 186. Sealing pin; 187. Water inlet; 188. Return spring. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be arbitrarily combined with each other.

[0041] Example 1

[0042] like Figures 1-7 The following is an embodiment of the present invention. This embodiment discloses a directional hydraulic jet acid fracturing device, which includes an oil pipe 1, a connector 2, an upper stabilizer 3, an injector 4 and a lower stabilizer 5 connected in sequence from top to bottom. The injector 4 includes a vertically arranged support shell 41. The top end of the support shell 41 is connected to the upper stabilizer 3 and the bottom end is connected to the lower stabilizer 5. At the same time, a plurality of injection holes 42 are opened on the support shell 41.

[0043] In one embodiment, such as Figure 1 , Figure 2As shown, a damping ball 6 is vertically slidably connected inside the support shell 41, and the damping ball 6 is in contact with the inner wall of the support shell 41 so that the damping ball 6 can move downward under the pressure of the acid fluid. A return spring 7 is provided inside the support shell 41, located below the damping ball 6. One end of the return spring 7 is fixedly connected to the bottom wall of the support shell 41, and the other end is fixedly connected to the damping ball 6. The return spring 7 is used to push the damping ball 6 upward.

[0044] Acid fluid is injected through oil pipe 1. The acid fluid enters the injector 4 through connector 2 and upper stabilizer 3. At this time, the pressure of the acid fluid is applied above the damping ball 6, which causes the damping ball 6 to overcome the elastic force of the return spring 7 and move down until the injection hole 42 is leaked out, and the acid fluid can be sprayed out from the corresponding injection hole 42.

[0045] The damping ball 6 moves downward under the pressure of the acid fluid, causing multiple injection holes 42 to open sequentially. The return spring 7 pushes the damping ball 6 upward, causing the injection holes 42 to close sequentially. Simply put, the greater the flow rate and pressure of the acid fluid, the greater the displacement of the damping ball 6, and the more injection holes 42 open; conversely, the smaller the flow rate and pressure of the acid fluid, the smaller the displacement of the damping ball 6, and the fewer injection holes 42 open.

[0046] The directional hydraulic jet acid pressure device in this embodiment can adjust the number of opening nozzles 42 according to the actual flow rate and pressure of the input acid fluid. The number of opening nozzles 42 is positively correlated with the flow rate and pressure of the acid fluid and is adaptively adjusted, which effectively prevents insufficient jetting speed or pump blockage, and improves the stability and service life of use.

[0047] In this embodiment, the injection holes 42 are arranged in three rows, with four holes in each row. The three rows of injection holes 42 are arranged at equal intervals along the circumference of the support shell 41, and the four injection holes 42 in each row are arranged at equal intervals along the axial direction of the support shell 41. Of course, in other embodiments, the number of injection holes 42 can be other than that of other types, and the injection holes 42 can also be arranged in a spiral pattern.

[0048] In one embodiment, such as Figure 1 , Figure 2 As shown, a sealing ring 8 is fixedly connected to the top of the inner wall of the support shell 41 along its circumference. The inner sidewall of the sealing ring 8 is integrally formed with a sealing surface 9, which matches the damping ball 6. When the damping ball 6 moves upward under the action of the return spring 7 and closes all the injection holes 42 respectively, the damping ball 6 and the sealing surface 9 form an abutment seal to prevent backflow. Compared with a one-way valve, this structure is simpler.

[0049] In one embodiment, such as Figure 2 , Figure 3As shown, the damping ball 6 includes an upper spherical shell 61, a connecting ring 62, and a lower spherical shell 63 connected sequentially from top to bottom, and the connecting ring 62 is made of a flexible material. When the top of the upper spherical shell 61 is compressed, the pressure between the lower spherical shell 63 and the upper spherical shell 61 increases, causing the connecting ring 62 to expand outward. At this time, the connecting ring 62 fits more tightly against the inner wall of the support shell 41, resulting in a better sealing effect and preventing acid fluid from passing through the damping ball 6 to its bottom, thus preventing the problem of acid fluid pressure loss and waste.

[0050] In one embodiment, such as Figure 2 , Figure 3 As shown, a guide cylinder 64 is vertically fixedly connected to the inner wall of the upper spherical shell 61, and a guide rod 65 is vertically fixedly connected to the inner wall of the lower spherical shell 63. The guide rod 65 and the guide cylinder 64 are vertically slidably connected, thereby realizing the guidance and limiting of the upper spherical shell 61.

[0051] In one embodiment, such as Figure 4 , Figure 5 As shown, an installation platform 10 is welded and fixed to the inner wall of the upper spherical shell 61. An integrated circuit board 11 is connected to the installation platform 10 by bolts. The integrated circuit board 11 integrates a power storage module, a gas pressure detection module, a data processing module, and a wireless transmission module. The wireless transmission module is wirelessly connected to the external monitoring equipment.

[0052] When the directional hydraulic jet acid fracturing device is in use, communication can be established between the external monitoring equipment and the device's wireless transmission module. The device is then lowered into the well, followed by initial high-flow-rate water injection until the fluid level reaches the wellhead, at which point injection is stopped. The maximum data P from the air pressure detection module after water injection stops is then acquired. Next, by combining the product of fluid density ρ, gravitational acceleration g, and height h, the value of h can be obtained using the formula P = ρgh, thus determining the depth information of the jetting device 4.

[0053] Meanwhile, by setting the damping ball 6 as an upper spherical shell 61, a connecting ring 62, and a lower spherical shell 63, the inner cavity of the entire damping ball 6 is a "flexible cavity" with variable volume. When the top of the damping ball 6 is subjected to force, the volume of its inner cavity changes, and the pressure also changes accordingly. The depth information is obtained through the air pressure data of the air pressure detection module, thereby achieving the directional effect of directional acid pressure.

[0054] In one embodiment, such as Figure 5 , Figure 6As shown, a piston ring 12 is fixedly connected to the top of the guide rod 65, and the piston ring 12 is vertically slidingly engaged with the guide cylinder 64. Inside the guide cylinder 64, from top to bottom, are arranged a pressure sensor 13, a piezoelectric ceramic chip 14, and a pressure piston 15. The pressure sensor 13 and the piezoelectric ceramic chip 14 are fixedly connected to the guide cylinder 64, and the pressure piston 15 is vertically slidingly disposed within the guide cylinder 64. The top of the piezoelectric ceramic chip 14 is fixedly connected to the pressure sensing end of the pressure sensor 13, and its bottom end abuts against the pressure piston 15. Furthermore, the output terminal of the piezoelectric ceramic chip 14 is connected to the charging terminal of the power storage module via a guide.

[0055] Because the acid fluid does not flow in a perfectly stable state, but rather experiences pressure fluctuations within a certain pressure range, the pressure on the top of the upper spherical shell 61 also fluctuates. This causes pressure fluctuations in the closed cavity formed by the guide cylinder 64, pressure piston 15, and piston ring 12, resulting in pressure fluctuations on the piezoelectric ceramic chip 14 by the pressure piston 15. Utilizing the piezoelectric properties of the piezoelectric ceramic chip 14, the power storage module can be continuously charged, thus providing continuous power to the pressure sensor 13 and the entire integrated circuit board 11.

[0056] Meanwhile, by incorporating the piezoelectric ceramic chip 14, the piezoelectric effect can be used to power downhole electrical components, thus overcoming the inconvenience of external wires and the limitations of limited built-in power capacity. Furthermore, by utilizing the variable volume of the damping ball 6's inner cavity, combined with the fact that water pressure is not entirely stable during jetting, the pressure piston 15 can continuously and repeatedly press the piezoelectric ceramic chip 14. This ingenious design demonstrates strong inter-component coordination and improves design compactness.

[0057] In one embodiment, such as Figure 1 , Figure 2 As shown, a cooling pipe 16 is horizontally fixedly connected to the upper spherical shell 61, located above the mounting platform 10, and a liquid inlet pipe 17 is vertically connected to the cooling pipe 16. When the acid fluid flows downward, it can enter the cooling pipe 16 through the liquid inlet pipe 17 and flow out through both ends of the cooling pipe 16, thereby achieving a "water cooling" effect on the integrated circuit board to reduce its temperature. Simultaneously, the top of the liquid inlet pipe 17 is flared, i.e., the top of the liquid inlet pipe 17 is a "flare," to improve the guiding effect and allow the acid fluid to smoothly enter the liquid inlet pipe 17.

[0058] Example 2

[0059] like Figures 8-11 The following is an embodiment 2 of the present invention. The difference between this embodiment and embodiment 1 is that each injection hole 42 is provided with a nozzle assembly 18, which can realize the increase of fluid and directional injection.

[0060] In one embodiment, such as Figure 9 , Figure 10 , Figure 11 As shown, the nozzle assembly 18 includes a receiving shell 181 fixedly connected within the spray hole 42. One side of the receiving shell 181 is open, and the opening faces the outside of the supporting shell 41. A nozzle shell 182 is movably disposed inside the receiving shell 181. One side of the nozzle shell 182 is open, and the opening faces the inside of the supporting shell 41. Meanwhile, a spray hole 183 is provided at the center of the nozzle shell 182 so that acid fluid can be sprayed out through the spray hole 183.

[0061] In one embodiment, such as Figure 10 , Figure 11 As shown, a support ring 184 is fixedly sleeved on the nozzle housing 182, and a stepped groove 185 is formed on the inner wall of the receiving housing 181 along its circumferential direction. The support ring 184 and the stepped groove 185 are horizontally slidably connected to each other, so that the nozzle housing 182 can move laterally. At the same time, a sealing pin 186 is horizontally fixedly connected to the receiving housing 181, and the sealing pin 186 can be inserted into the spray hole 183.

[0062] In one embodiment, such as Figure 10 , Figure 11 As shown, the receiving shell 181 is provided with a plurality of water inlet holes 187, which are arranged at equal intervals along the circumference of the support ring 184 and are respectively aligned with the support ring 184. Meanwhile, a return spring 188 is provided in the stepped groove 185, one end of which is fixedly connected to the inner wall of the stepped groove 185 and the other end is fixedly connected to the support ring 184.

[0063] When the acid fluid enters the support shell 41, the force of the acid fluid is applied to the side of the support ring 184 through the water inlet 187, thereby pushing the support ring 184 outward and causing the sealing pin 186 to separate from the nozzle 183. At this time, the acid fluid enters the interior of the nozzle shell 182 through the water inlet 187 and is sprayed out through the nozzle 183. When the water pressure disappears, the support ring 184 moves in the opposite direction under the elastic force of the return spring 188. When the support ring 184 abuts against the inner wall of the receiving shell 181 and the support ring 184 covers multiple water inlets 187, the sealing pin 186 is inserted into the nozzle 183.

[0064] This design utilizes water pressure, combined with the lateral movement of the support ring 184, to achieve a secondary unidirectional flow path and prevent backflow. Simultaneously, by incorporating a sealing pin 186, after operation, the pin penetrates the nozzle 183, preventing blockage. Furthermore, this design eliminates the need for an additional drive source for the opening and closing of the nozzle assembly 18, improving both the coordination between components and resource utilization efficiency.

[0065] It should be noted that, unless otherwise stated, the technical or scientific terms used in this invention should have the ordinary meaning as understood by one of ordinary skill in the art.

[0066] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A directional hydraulic jet acid fracturing device, comprising an oil pipe (1), a connector (2), an upper centralizer (3), an injector (4), and a lower centralizer (5) connected sequentially from top to bottom, characterized in that, The injector (4) includes: The support shell (41) is connected at its top end to the upper stabilizer (3) and at its bottom end to the lower stabilizer (5); Multiple injection holes (42) are provided on the support shell (41); The damping ball (6) is vertically slidably connected inside the support shell (41); A return spring (7) is disposed inside the support shell (41); The damping ball (6) can move downward under the pressure of the acid fluid and open the plurality of injection holes (42) in sequence. The return spring (7) is used to push the damping ball (6) upward and close the plurality of injection holes (42) in sequence. The damping ball (6) includes an upper spherical shell (61), a connecting ring (62) and a lower spherical shell (63) connected from top to bottom. The connecting ring (62) is made of a flexible material. The upper spherical shell (61) can squeeze the connecting ring (62) under the pressure of the acid fluid, so that the connecting ring (62) expands outward and fits more tightly against the inner wall of the support shell (41). The inner wall of the upper spherical shell (61) is fixedly connected to an installation platform (10), and an integrated circuit board (11) is provided on the installation platform (10). The integrated circuit board (11) integrates a power storage module, a gas pressure detection module, a data processing module and a wireless transmission module, and the wireless transmission module is wirelessly connected to the external monitoring equipment.

2. The directional hydraulic jet acid fracturing device according to claim 1, characterized in that, A sealing ring (8) is fixedly connected to the top of the inner wall of the support shell (41) along its circumference, and the inner side wall of the sealing ring (8) is provided with a sealing surface (9) that matches the damping ball (6).

3. The directional hydraulic jet acid fracturing device according to claim 1, characterized in that, A guide cylinder (64) is vertically fixed inside the upper spherical shell (61), and a guide rod (65) is vertically fixed inside the lower spherical shell (63), with the guide rod (65) and the guide cylinder (64) being vertically slidably connected.

4. The directional hydraulic jet acid fracturing device according to claim 3, characterized in that, A piston ring (12) is fixedly connected to the top end of the guide rod (65). A pressure sensor (13), a piezoelectric ceramic chip (14) and a pressure piston (15) are arranged sequentially from top to bottom inside the guide cylinder (64). The top end of the piezoelectric ceramic chip (14) is fixedly connected to the pressure sensing end of the pressure sensor (13), and the bottom end abuts against the pressure piston (15). The output terminal of the piezoelectric ceramic chip (14) is connected to the charging terminal of the power storage module.

5. The directional hydraulic jet acid fracturing device according to claim 1, characterized in that, A cooling pipe (16) is horizontally arranged on the upper spherical shell (61) above the mounting platform (10). A liquid inlet pipe (17) is vertically connected to the cooling pipe (16). Acid fluid can enter the cooling pipe (16) through the liquid inlet pipe (17) and flow out through the two ports of the cooling pipe (16).

6. The directional hydraulic jet acid fracturing device according to claim 5, characterized in that, The top end of the liquid inlet pipe (17) is flared.

7. The directional hydraulic jet acid fracturing device according to any one of claims 1-6, characterized in that, Each of the spray holes (42) is provided with a nozzle assembly (18).

8. The directional hydraulic jet acid fracturing device according to claim 7, characterized in that, The nozzle assembly (18) includes a receiving shell (181) disposed within the spray hole (42), a nozzle shell (182) is movably disposed on the inner side of the receiving shell (181), a spray hole (183) is opened at the center of the nozzle shell (182), a support ring (184) is fixedly sleeved on the nozzle shell (182), a stepped groove (185) is provided on the inner wall of the receiving shell (181), and the support ring (184) is horizontally slidably connected to the stepped groove (185); A sealing pin (186) is horizontally fixedly connected to the receiving shell (181), and the sealing pin (186) can be inserted into the spray hole (183). The receiving shell (181) is provided with a plurality of water inlet holes (187), which are arranged along the circumferential direction of the support ring (184) and aligned with the support ring (184). A return spring (188) is provided in the stepped groove (185). The acid fluid can drive the support ring (184) to move the nozzle housing (182) and separate the sealing pin (186) from the nozzle (183). The return spring (188) can drive the support ring (184) to move the nozzle housing (182) and cover the multiple water inlets (187) with the support ring (184), and the sealing pin (186) is inserted into the nozzle (183).

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