A multi-layer switchable pressurized recharge device

Abstract

This invention belongs to the field of geothermal well reinjection technology and proposes a multi-layer switchable pressurized reinjection device, including a first water pump, a desander, a first water tank, a second water pump, a first filter, and a second filter connected in sequence. The outlet of the second filter is connected to the inlet of the first booster pump, and the outlet of the first booster pump is connected to the inlet of the injection pipe. A third one-way valve is installed on the pipeline connecting the first booster pump and the injection pipe. The pressurized reinjection device also includes a second water tank connected in parallel with the first water tank, with the inlet of the second water tank connected to the inlet of the first water tank and the outlet of the second water tank connected to the outlet of the first water tank. By setting up a second water tank in parallel with the first water tank, with the inlet of the second water tank connected to the inlet of the first water tank and the outlet of the second water tank connected to the outlet of the first water tank, this invention achieves dual-tank water supply, increasing the water supply and improving reinjection efficiency.

Description

Technical Field

[0001] This invention belongs to the field of geothermal well reinjection technology, and specifically relates to a pressurized reinjection device with multi-layer switching capability. Background Technology

[0002] In the fields of groundwater reinjection and geothermal system tailwater reinjection, pressurized reinjection technology is a key technical means to solve the problems of water resource recycling, groundwater level maintenance, and geological environment stability. Its core principle is to mechanically pressurize the fluid to be reinjected (groundwater, treated reclaimed water, and geothermal tailwater, etc.) and inject it into the aquifer or reservoir at a pressure higher than the hydrostatic pressure of the target formation, thereby overcoming the natural seepage resistance of the formation and achieving efficient reinjection. However, in practical engineering applications, due to the complexity of geological conditions, limitations in equipment performance, and the rationality of system design, the reinjection efficiency (the amount of fluid effectively injected into the formation per unit time) of existing pressurized reinjection devices often falls short of expectations.

[0003] Therefore, a pressurized recharge device that can improve recharge efficiency is needed. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a multi-layer switchable pressurized reinjection device, comprising a first water pump, a desander, a first water tank, a second water pump, a first filter, and a second filter connected in sequence. The inlet of the first water pump is connected to an underground well via a pipe, the outlet of the second filter is connected to the inlet of the first booster pump, and the outlet of the first booster pump is connected to the inlet of the injection pipe. A third check valve is installed on the pipe connecting the first booster pump and the injection pipe. The pressurized reinjection device also includes a second water tank connected in parallel with the first water tank. The inlet of the second water tank is connected to the inlet of the first water tank, and the outlet of the second water tank is connected to the outlet of the first water tank.

[0005] Furthermore, the pressurized reinjection device also includes a third water tank. The outlet of the first water tank and the outlet of the second water tank are both connected to the inlet of the third water tank. The outlet of the third water tank is connected to the inlet of the second water pump through a third branch. A third valve and a fifth check valve are provided on the third branch. The third valve is located on the side of the fifth check valve closer to the third water tank.

[0006] Furthermore, the outlet of the third water tank is connected to the inlet of the first booster pump via a first branch, and a fifth valve is installed on the first branch.

[0007] Furthermore, the pressurized reinjection device also includes a third filter and a fourth filter connected in series. The inlet of the third filter is connected to the outlet of the second water pump through a pipe, and the outlet of the third filter is connected to the inlet of the first booster pump.

[0008] Furthermore, a sixth valve and a second booster pump are sequentially installed on the pipeline between the first booster pump and the third check valve; the inlet of the sixth valve is connected to the inlet of the third check valve through a second branch, and a seventh valve is installed on the second branch.

[0009] Furthermore, the injection pipe includes a pipe wall, with a plurality of branch pipes arranged on the inner side of the pipe wall, and a plurality of solenoid valves and interface pipes arranged on the outer surface of the pipe wall. The number of branch pipes is the same as the number of solenoid valves. The solenoid valves are located on the side of the interface pipe closer to the first water pump. A nozzle unit is installed on the outer side of the interface pipe.

[0010] Furthermore, the outer surface of the pipe wall is provided with a plurality of mounting holes, which are connected to the corresponding branch pipes, and an interface pipe is installed in the mounting holes.

[0011] Furthermore, the interface tube includes an interface tube body, in which a cavity is provided. The cavity penetrates the interface tube body and communicates with the branch pipe. A ball and a second spring are installed in the cavity. One end of the second spring abuts against the ball, and the other end abuts against the bottom of the cavity. The end of the ball away from the second spring contacts and seals against the inner wall of the cavity.

[0012] Furthermore, a sealing sheet is rotatably installed in the cavity, and a rotating shaft is fixedly installed on the sealing sheet; an installation groove is provided in the side wall of the interface tube, and the rotating shaft is rotatably installed in the installation groove. A first magnet and a first spring are sequentially installed in the installation groove. One end of the first spring is fixedly connected to the first magnet, and the other end is fixedly connected to the inner wall of the installation groove. One end of a rope is wound on the rotating shaft, and the other end of the rope passes through the first spring and is fixedly connected to the first magnet.

[0013] Furthermore, the nozzle unit includes a nozzle, a pressure structure is provided in the internal cavity of the nozzle, a second magnet is provided at the lower end of the nozzle, the nozzle is snapped into the interface tube body, and the pressure structure abuts against the ball.

[0014] Beneficial effects: 1. The present invention achieves dual-tank water supply by setting up a second water tank in parallel with the first water tank, with the inlet of the second water tank connected to the inlet of the first water tank and the outlet of the second water tank connected to the outlet of the first water tank. This parallel connection of the first and second water tanks increases the water supply and improves the reinjection efficiency.

[0015] 2. This invention incorporates a third water tank. The outlets of both the first and second water tanks are connected to the inlet of the third water tank. The outlet of the third water tank is connected to the inlet of the second water pump via a third branch. When the first and / or second water tanks are full, the third water tank is filled with water for standby by opening the first and / or second valves. In other words, the third water tank serves to store water. When the water output from the injection pipe is low, water is stored in the third water tank. When the injection pipe requires a large water output, water is supplied through the third water tank, thus improving the reinjection efficiency.

[0016] 3. According to different water demand, the present invention sets different numbers of nozzles on the outside of the branch pipes, and at the same time utilizes all branch pipes to increase water output and improve reinjection efficiency.

[0017] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the pressurized reinjection device in an embodiment of the present invention is shown.

[0020] Figure 2 A schematic diagram of the injection pipe of the pressurized reinjection device in an embodiment of the present invention is shown.

[0021] Figure 3 An exploded view of the interface pipe and nozzle structure of the pressurized recharge device in an embodiment of the present invention is shown.

[0022] Figure 4 A schematic diagram of the interface pipe of the pressurized recharge device in an embodiment of the present invention is shown.

[0023] Figure 5 A schematic diagram of the nozzle structure of the pressurized recharge device in an embodiment of the present invention is shown.

[0024] In the diagram, 1 is the underground well; 21 is the first water pump; 22 is the second water pump; 31 is the first water tank; 32 is the second water tank; 33 is the third water tank; 41 is the first filter; 42 is the second filter; 43 is the third filter; 44 is the fourth filter; 51 is the first valve; 52 is the second valve; 53 is the third valve; 54 is the fourth valve; 55 is the fifth valve; 56 is the sixth valve; 57 is the seventh valve; 58 is the eighth valve; 61 is the first check valve; 62 is the second check valve; 63 is the third check valve; 64 is the fourth check valve; 65 is the fifth check valve; 71 is the first booster pump; 72 is the second booster pump; 81 is the sand separator; 101 is the first branch; 102 is the second branch; 103 is the third branch. 9. Injection pipe; 91. Solenoid valve; 92. Interface pipe; 921. Interface pipe body; 922. Sealing plate; 923. Rotating shaft; 924. Rope; 925. First spring; 926. First magnet; 927. Second spring; 928. Ball; 929. Mounting groove; 93. Nozzle unit; 931. Nozzle; 932. Top pressure structure; 933. Second magnet; 94. Pipe wall; 941. Branch pipe; 9411. First branch pipe; 9412. Second branch pipe; 9413. Third branch pipe; 9414. Fourth branch pipe; 945. Mounting hole. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] refer to Figure 1A multi-layer switchable pressurized reinjection device includes a first water pump 21, a desander 81, a first water tank 31, a second water pump 22, a first filter 41, and a second filter 42 connected in sequence. The inlet of the first water pump 21 is connected to an underground well 1 via a pipe. The outlet of the second filter 42 is connected to the inlet of a first booster pump 71, and the outlet of the first booster pump 71 is connected to the inlet of a pressure injection pipe 9. A third one-way valve 63 is installed on the pipe connecting the first booster pump 71 and the pressure injection pipe 9. The pressurized reinjection device also includes a second water tank 32 connected in parallel with the first water tank 31. The inlet of the second water tank 32 is connected to the inlet of the first water tank 31, and the outlet of the second water tank 32 is connected to the outlet of the first water tank 31. The outlet pipes of the first water tank 31 and the second water tank 32 are connected to the second water pump 22 via a fourth one-way valve 64 to prevent water from the third water tank 33 from entering the first water tank 31 and the second water tank 32, thereby improving the working efficiency of the device. By setting up a first water tank 31 and a second water tank 32 in parallel, a dual-tank water supply is achieved, increasing the water supply and improving the recharge efficiency.

[0027] Furthermore, the pressurized reinjection device also includes a third water tank 33. The outlet end of the first water tank 31 and the outlet end of the second water tank 32 are both connected to the inlet of the third water tank 33. The outlet of the third water tank 33 is connected to the inlet of the second water pump 22 through a third branch 103. A third valve 53 and a fifth check valve 65 are provided on the third branch 103. The third valve 53 is located at the end of the fifth check valve 65 near the third water tank 33. The fifth check valve 65 is used to prevent water backflow from causing a decrease in reinjection pressure. Specifically, a first valve 51 is installed on the pipe connecting the outlet of the first water tank 31 and the inlet of the third water tank 33, and a second valve 52 is installed on the pipe connecting the outlet of the second water tank 32 and the inlet of the third water tank 33. When the first water tank 31 and / or the second water tank 32 are full, the third water tank 33 is filled with water by opening the first valve 51 and / or the second valve 52; that is, the third water tank 33 serves to store water. When the water output from the pressure injection pipe 9 is low, the third water tank 33 stores water, and when the pressure injection pipe 9 requires a large water output, water is supplied through the third water tank 33.

[0028] Furthermore, the outlet of the third water tank 33 is connected to the inlet of the first booster pump 71 via the first branch 101, and a fifth valve 55 is installed on the first branch 101. Specifically, the third water tank 33 is directly connected to the inlet of the first booster pump 71 via the first branch 101. When a large amount of recharge water is needed, water is directly supplied to the first booster pump 71 through the third water tank 33. The fifth valve 55 serves to open and close the first branch 101.

[0029] refer to Figure 1The pressurized reinjection device also includes a third filter 43 and a fourth filter 44 connected in series. The inlet of the third filter 43 is connected to the outlet of the second water pump 22 via a pipe, and the outlet of the third filter 43 is connected to the inlet of the first booster pump 71. Specifically, an eighth valve 58 is installed on the pipe between the first filter 41 and the second water pump 22, and a fourth valve 54 is installed on the pipe between the third filter 43 and the second water pump 22. By opening and closing the third valve 53 and the fourth valve 54, the first filter 41 and the second filter 42 can work simultaneously with the third filter 43 and the fourth filter 44, or any one of them can work. A first check valve 61 is installed on the pipe connecting the second filter 42 and the first booster pump 71, and a second check valve 62 is installed on the pipe connecting the fourth filter 44 and the first booster pump 71. The first check valve 61 and the second check valve 62 serve to cut off the flow of water in the reverse direction and prevent backflow. The first filter 41 and the second filter 42 form one set of filters, and the third filter 43 and the fourth filter 44 form another set of filters. When the first filter 41 and the second filter 42 cannot achieve the required water output of the injection pipe 9, the water output is increased by opening the third filter 43 and the fourth filter 44. The first filter 41 and the third filter 43 are coarse filters, and the second filter 42 and the fourth filter 44 are fine filters.

[0030] In another optional implementation, a sixth valve 56 and a second booster pump 72 are sequentially installed on the pipeline between the first booster pump 71 and the third check valve 63. The inlet of the sixth valve 56 is connected to the inlet of the third check valve 63 through a second branch 102, and a seventh valve 57 is installed on the second branch 102. Specifically, closing the seventh valve 57 and opening the sixth valve 56 allows the water to undergo two pressurization processes (pressurization by the first booster pump 71 and the second booster pump 72), thus achieving a greater pressurization, suitable for formations requiring higher pressurization. Opening the seventh valve 57 and closing the sixth valve 56 allows the water to undergo only one pressurization process, suitable for formations requiring lower pressurization.

[0031] refer to Figure 2 The injection pipe 9 includes a pipe wall 94, with several branch pipes 941 arranged on the inner side of the pipe wall 94. Several solenoid valves 91 and interface pipes 92 are arranged on the outer surface of the pipe wall 94. The number of branch pipes 941 is the same as the number of solenoid valves 91, and they are installed in a one-to-one correspondence. The solenoid valves 91 are located on the side of the interface pipe 92 closest to the first water pump 21. A nozzle unit 93 (see reference) is installed on the outer side of the interface pipe 92. Figure 3 ).

[0032] Specifically, the cross-sectional reference of the pipe wall 94 Figure 2The system is divided into four sub-pipes 941 (which can be further divided into several as needed). Each sub-pipe 941 is equipped with a solenoid valve 91 and several interface pipes 92. The interface pipes 92 are normally closed and only open when the nozzle unit 93 is installed. The solenoid valve 91 controls the water flow and thus the pressure on the corresponding pipe wall 94. Different pressures can be applied to different formation depths. For example, pressure gradients can be set according to the reinjection depth (e.g., 0.5~1MPa for shallow layers, 1~3MPa for middle layers, and 3~5MPa for deep layers). This avoids excessive compression of shallow formations or waste of energy in deep formations due to a single high pressure, thereby improving reinjection efficiency (the saved energy is convenient for reinjection into deeper formations).

[0033] Furthermore, by installing nozzle units 93 on the interface pipes 92 at different positions outside the injection pipe 9, different formations can be reinjected through the same injection pipe 9, thereby improving the reinjection efficiency. When it is necessary to improve the reinjection efficiency of a certain formation, it is only necessary to install all nozzle units 93 on the interface pipes 92 at this formation location to improve the reinjection efficiency.

[0034] refer to Figure 2 The outer surface of the pipe wall 94 is provided with several mounting holes 945, which are connected to the corresponding branch pipes 941. An interface pipe 92 is installed in the mounting hole 945. Specifically, the mounting hole 945 is used to install the interface pipe 92.

[0035] refer to Figure 4 The interface pipe 92 includes an interface pipe body 921, in which a cavity is provided. The cavity extends through the interface pipe body 921 and communicates with the branch pipe 941. A ball 928 and a second spring 927 are installed in the cavity. One end of the second spring 927 abuts against the ball 928, and the other end abuts against the bottom of the cavity. The end of the ball 928 away from the second spring 927 contacts and seals against the inner wall of the cavity. Specifically, when the nozzle unit 93 is not installed, the ball 928, under the elastic force of the second spring 927, seals against the inside of the cavity of the interface pipe body 921, preventing water leakage and pressure loss in the branch pipe 941.

[0036] Furthermore, a sealing plate 922 is rotatably installed in the cavity, and a rotating shaft 923 is fixedly installed on the sealing plate 922. An installation groove 929 is provided in the side wall of the interface tube 921, and the rotating shaft 923 is rotatably installed in the installation groove 929. A first magnet 926 and a first spring 925 are sequentially installed in the installation groove 929. One end of the first spring 925 is fixedly connected to the first magnet 926, and the other end of the first spring 925 is fixedly connected to the inner wall of the installation groove 929. One end of a rope 924 is wound around the rotating shaft 923, and the other end of the rope 924 passes through the first spring 925 and is fixedly connected to the first magnet 926. Specifically, the sealing plate 922 achieves secondary sealing of the cavity, thereby achieving a double seal, preventing pressure and water leakage from the interface tube 921, and improving the sealing effect.

[0037] refer to Figure 5 The nozzle unit 93 includes a nozzle 931. A top-pressure structure 932 is provided in the internal cavity of the nozzle 931. The top-pressure structure 932 is a hollow structure to facilitate water flow. A second magnet 933 is provided at the lower end of the nozzle 931. The nozzle 931 is snapped into the interface tube 921. The top-pressure structure 932 abuts against the ball 928. Specifically, when a nozzle unit 93 is installed on the interface tube 92 (which can be connected to the interface tube body 921 by snap-fit ​​or thread), the top pressure structure 932 pushes the ball 928 to overcome the elastic force of the second spring 927, thereby opening the cavity. At the same time, the second magnet 933 is located above the first magnet 926, and an attraction is generated between the second magnet 933 and the first magnet 926 (opposite magnets generate attraction). The first magnet 926 overcomes the tension of the first spring 925 and moves towards the second magnet 933, thereby pulling the rope 924 and causing the rotating shaft 923 to rotate. The rotation of the rotating shaft 923 drives the sealing plate 922 to rotate, connecting the cavity. Then, the cavity of the water bucket interface tube body 921 enters the nozzle 931 and is sprayed out.

[0038] The present invention prevents backflow and improves recharge efficiency by setting up a number of first one-way valves 61, second one-way valves 62, third one-way valves 63, fourth one-way valves 64 and fifth one-way valves 65.

[0039] This invention has the following operating modes: In Mode 1, the recharge volume is small. Groundwater enters the first water tank 31 and the second water tank 32 through the first water pump 21 and the desander 81. Since the required recharge volume is small, the excess water enters the third water tank 33 for storage (first valve 51 and second valve 52 are open, third valve 53 and fifth valve 55 are closed). Water from the first water tank 31 and the second water tank 32 enters a set of filters (first filter 41 and second filter 42 or third filter 43 and fourth filter 44; that is, eighth valve 58 is opened and fourth valve 54 is closed or fourth valve 54 is opened and eighth valve 58 is closed). Water exiting the filter set enters the first booster pump 71. The pressure determines whether secondary boosting is needed. (If secondary pressurization is required, water enters the injection pipe 9 sequentially through the first booster pump 71 and the second booster pump 72, i.e., the sixth valve 56 is opened and the seventh valve 57 is closed; if secondary pressurization is not required, water enters the injection pipe 9 directly through the second branch 102 after passing through the first booster pump 71, i.e., the seventh valve 57 is opened and the sixth valve 56 is closed); According to different pressure layers and different water demand, nozzle units 93 of different numbers and positions are set on the outside of the pipe wall 94 (for example, when shallow and middle layer reinjection is required, different branch pipes 941 are selected, such as the first branch pipe 9411 and the second branch pipe 9412, and nozzle units 93 are set in the shallow layer of the first branch pipe 9411 and in the middle layer of the first branch pipe 9411).

[0040] Mode 2, moderate recharge volume mode: Groundwater enters the first water tank 31 and the second water tank 32 through the first water pump 21 and the desander 81. Since the required recharge volume is moderate, no excess water enters the third water tank 33 for storage (first valve 51 and second valve 52 are closed, third valve 53 and fifth valve 55 are closed). Water enters two sets of filters from the first water tank 31 and the second water tank 32 (first filter 41, second filter 42, third filter 43, and fourth filter 44 are all open, i.e., eighth valve 58 and fourth valve 54 are open). Water exits the filter set and enters the first booster pump 71. The pressure determines whether secondary pressurization is needed (if secondary pressurization is needed...). Water enters the injection pipe 9 sequentially through the first booster pump 71 and the second booster pump 72, i.e., the sixth valve 56 is opened and the seventh valve 57 is closed; if secondary pressurization is not required, water enters the injection pipe 9 directly through the second branch 102 after passing through the first booster pump 71, i.e., the seventh valve 57 is opened and the sixth valve 56 is closed); according to different pressure layers and different water demand, nozzle units 93 of different numbers and positions are set on the outside of the pipe wall 94 (for example, when shallow and middle layer reinjection is required, different branch pipes 941 are selected, such as the first branch pipe 9411 and the second branch pipe 9412, and nozzle units 93 are set in the shallow layer of the first branch pipe 9411 and in the middle layer of the first branch pipe 9411).

[0041] Mode 3, the mode with a large recharge volume: Groundwater enters the first water tank 31 and the second water tank 32 through the first water pump 21 and the desander 81. Due to the large recharge volume demand, water enters two sets of filters from the first and second water tanks 31 and 32 (the first filter 41, the second filter 42, the third filter 43, and the fourth filter 44 are all open; that is, the eighth valve 58 and the fourth valve 54 are opened). Water exits the filter sets and enters the first booster pump 71. Simultaneously, the third water tank 33 discharges water (the third valve 53 is opened and the fifth valve is closed). If the water demand is still insufficient, the water in the third water tank 33 directly enters the first booster pump 71 (opening the fifth valve 55 and closing the third valve 53); depending on the pressure requirement, it is determined whether secondary pressurization is needed (if secondary pressurization is needed, the water sequentially enters the injection pipe 9 through the first booster pump 71 and the second booster pump 72, that is, opening the sixth valve 56 and closing the seventh valve 57; if secondary pressurization is not needed, the water enters the injection pipe 9 directly through the second branch 102 after passing through the first booster pump 71, that is, opening the seventh valve 57 and closing the sixth valve 56). Depending on the pressure level, nozzle units 93 are installed at different positions on different branch pipes 941. For example, nozzle units 93 are installed on the first branch pipe 9411 (the nozzle unit 93 is located in the shallow layer), on the second branch pipe 9412 (the nozzle unit 93 is located in the middle layer), and on the third branch pipe 9413 (the nozzle unit 93 is located in the deep layer). At the same time, the opening degree of the solenoid valves 91 corresponding to the first branch pipe 9411, the second branch pipe 9412, and the third branch pipe 9413 is adjusted to meet the control of different pressures.

[0042] Depending on the different water demand, a different number of nozzle units 93 are installed on the outside of the branch pipe 941, and all branch pipes 941 are utilized to increase the water output and improve the reinjection efficiency. For example, when the middle layer requires a large amount of water and the deep layer requires a small amount of water, the fourth branch pipe 9414 is set as the deep layer, and nozzle units 93 are installed on the interface pipe 92 corresponding to the deep layer above it. The first branch pipe 9411, the second branch pipe 9412 and the third branch pipe 9413 are set as the shallow layer, and nozzle units 93 are installed on the interface pipe 92 corresponding to the shallow layer above them. Therefore, there are more nozzle units 93 corresponding to the shallow layer, which increases the water output and improves the reinjection efficiency.

[0043] 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pressurized rechargeable device capable of multilayer switching, characterized in that, The system includes a first water pump (21), a sand remover (81), a first water tank (31), a second water pump (22), a first filter (41), and a second filter (42) connected in sequence. The inlet of the first water pump (21) is connected to the underground well (1) through a pipe. The outlet of the second filter (42) is connected to the inlet of the first booster pump (71). The outlet of the first booster pump (71) is connected to the inlet of the injection pipe (9). A third check valve (63) is installed on the pipe connecting the first booster pump (71) and the injection pipe (9). The pressurized recharge device also includes a second water tank (32) connected in parallel with the first water tank (31). The inlet of the second water tank (32) is connected to the inlet of the first water tank (31), and the outlet of the second water tank (32) is connected to the outlet of the first water tank (31).

2. The pressurized reinjection device with multi-layer switching capability according to claim 1, characterized in that, The pressurized reinjection device also includes a third water tank (33). The outlet end of the first water tank (31) and the outlet end of the second water tank (32) are both connected to the inlet of the third water tank (33). The outlet of the third water tank (33) is connected to the inlet of the second water pump (22) through a third branch (103). A third valve (53) and a fifth check valve (65) are provided on the third branch (103). The third valve (53) is located on the side of the fifth check valve (65) close to the third water tank (33).

3. The pressurized reinjection device with multi-layer switching capability according to claim 2, characterized in that, The outlet of the third water tank (33) is connected to the inlet of the first booster pump (71) through the first branch (101), and the first branch (101) is equipped with a fifth valve (55).

4. The pressurized reinjection device with multi-layer switching capability according to claim 1, characterized in that, The pressurized reinjection device also includes a third filter (43) and a fourth filter (44) connected in series. The inlet of the third filter (43) is connected to the outlet of the second water pump (22) through a pipe, and the outlet of the third filter (43) is connected to the inlet of the first booster pump (71).

5. The pressurized reinjection device with multi-layer switching capability according to claim 1, characterized in that, A sixth valve (56) and a second booster pump (72) are sequentially installed on the pipeline between the first booster pump (71) and the third check valve (63); the inlet of the sixth valve (56) is connected to the inlet of the third check valve (63) through the second branch (102), and a seventh valve (57) is installed on the second branch (102).

6. A pressurized reinjection device with multi-layer switching according to any one of claims 1-5, characterized in that, The injection pipe (9) includes a pipe wall (94), and a number of branch pipes (941) are provided on the inner side of the pipe wall (94). A number of solenoid valves (91) and interface pipes (92) are provided on the outer surface of the pipe wall (94). The number of branch pipes (941) is the same as the number of solenoid valves (91). The solenoid valves (91) are located on the side of the interface pipe (92) close to the first water pump (21). A nozzle unit (93) is installed on the outer side of the interface pipe (92).

7. A pressurized reinjection device with multi-layer switching capability according to claim 6, characterized in that, The outer surface of the pipe wall (94) is provided with a plurality of mounting holes (945), the mounting holes (945) are connected to the corresponding branch pipes (941), and an interface pipe (92) is installed in the mounting holes (945).

8. A pressurized reinjection device with multi-layer switching capability according to claim 7, characterized in that, The interface tube (92) includes an interface tube body (921), in which a cavity is provided. The cavity penetrates the interface tube body (921) and is connected to the branch pipe (941). A ball (928) and a second spring (927) are installed in the cavity. One end of the second spring (927) abuts against the ball (928), and the other end abuts against the bottom of the cavity. The end of the ball (928) away from the second spring (927) contacts and seals against the inner wall of the cavity.

9. A pressurized reinjection device with multi-layer switching capability according to claim 8, characterized in that, A sealing plate (922) is rotatably installed in the cavity, and a rotating shaft (923) is fixedly installed on the sealing plate (922); an installation groove (929) is provided in the side wall of the interface tube (921), and the rotating shaft (923) is rotatably installed in the installation groove (929). A first magnet (926) and a first spring (925) are installed in the installation groove (929) in sequence. One end of the first spring (925) is fixedly connected to the first magnet (926), and the other end is fixedly connected to the inner wall of the installation groove (929). One end of a rope (924) is wound on the rotating shaft (923), and the other end of the rope (924) passes through the first spring (925) and is fixedly connected to the first magnet (926).

10. A pressurized reinjection device with multi-layer switching capability according to claim 9, characterized in that, The nozzle unit (93) includes a nozzle (931), a top-pressure structure (932) is provided in the internal cavity of the nozzle (931), a second magnet (933) is provided at the lower end of the nozzle (931), the nozzle (931) is engaged with the interface tube (921), and the top-pressure structure (932) abuts against the ball (928).

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