A natural gas long-distance pipeline anticorrosion cathode protection device and a use method thereof

Abstract

This invention discloses a cathodic protection device for corrosion prevention of long-distance natural gas pipelines and its usage method, relating to the technical field of pipeline protection equipment. It includes two parallel long-distance natural gas pipelines: the bottoms of the two pipelines are connected to a common bottom connecting pipeline via bottom delivery pipes. The beneficial effects of this invention are: the device includes long-distance natural gas pipelines, a protective cover, and a filter cylinder. The core of the device is the sacrificial anode method, where a metal block with a more negative potential is electrically connected to the protected steel pipeline via a wire, forming a galvanic cell in the soil electrolyte, thereby slowing down the corrosion of the pipeline's inner wall by the medium; a storage battery provides some power for the operation of electrical equipment; an infrared sensor assists in remote monitoring; a lighting lamp assists in on-site lighting; and two limiting blocks limit the movement of the guide rail on both sides to prevent the equipment from falling off.

Description

Technical Field

[0001] This invention relates to the field of pipeline protection equipment technology, specifically to a cathodic protection device for corrosion prevention of long-distance natural gas pipelines and its usage method. Background Technology

[0002] Natural gas long-distance pipelines are usually buried underground, and their outer walls are constantly exposed to complex corrosive environments such as soil and stray currents, making them highly susceptible to electrochemical corrosion. This can lead to thinning and perforation of the pipe wall, causing leaks and safety accidents. Cathodic protection is one of the most effective means of preventing this type of corrosion, with the sacrificial anode method being widely used due to its lack of external power supply and simple management.

[0003] Chinese Patent Publication No. CN 222503155 U discloses a pressure-resistant protection structure for water supply pipelines in water conservancy projects, comprising: a first support plate and a second support plate; and a first support platform fixedly installed on one side of the bottom of the first support plate. This utility model provides a pressure-resistant protection structure for water supply pipelines in water conservancy projects. By adjusting the distance between the first and second support plates through an embedded groove and an embedded block, the distance between the first and second clamping plates can be adjusted, facilitating the clamping of pipes of different diameters by the first and second clamping plates. This allows the first support plate, second support plate, first support platform, and second support platform to support the outer surface of the pipe, providing pressure protection. This device has a simple structure and strong practicality. Operators can quickly assemble the first and second support plates according to the pipe diameter to provide pressure protection, improving the practicality and flexibility of the device, reducing the pipe breakage rate, and alleviating the maintenance workload of operators.

[0004] However, the above solution still has the following problems:

[0005] Firstly, since the anode blocks, such as magnesium and zinc alloys, are fixedly buried, their consumption status cannot be detected in real time. They can only be inspected by periodic excavation, which is time-consuming, labor-intensive, and has a lag effect. There may be a protection failure window during the inspection interval.

[0006] Secondly, the distribution of the protection potential along the pipeline is not uniform, and the monitoring at fixed points cannot fully reflect the protection effect of the entire pipeline, resulting in monitoring blind spots.

[0007] Finally, the medium transported in the pipeline may contain corrosive impurities that can cause corrosion to the inner wall of the pipeline. Traditional external cathodic protection devices cannot handle this and cannot meet the requirements for normal use.

[0008] Therefore, the present invention needs to design a cathodic protection device for corrosion prevention of long-distance natural gas pipelines and its usage method to solve the above-mentioned problems. Summary of the Invention

[0009] The purpose of this invention is to provide an integrated device that can automatically inspect the cathodic protection status, monitor without blind spots, and has a certain internal corrosion protection capability, so as to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a cathodic protection device for corrosion prevention of long-distance natural gas pipelines, comprising two parallel long-distance natural gas pipelines:

[0011] The bottoms of the two natural gas long-distance pipelines are connected to a common bottom connection pipeline via bottom delivery pipelines;

[0012] The two natural gas long-distance pipelines are provided with a protective cover on the outside, and a metal block serving as a sacrificial anode is provided inside the protective cover;

[0013] Each side of the metal block is provided with a set of driving and moving mechanisms. Each set of driving and moving mechanisms includes a reciprocating lead screw driven by a drive motor. A movable slider that can reciprocate along the reciprocating lead screw is threadedly connected to the reciprocating lead screw. A field movable monitoring instrument for monitoring the status of the pipeline is installed on the movable slider.

[0014] The top of the protective cover is connected to a filter cylinder, which is connected to the inside of the long-distance natural gas pipeline through a top connecting pipe, and the filter cylinder is equipped with a filter element and an adsorption rod inside.

[0015] In a preferred embodiment of the present invention, symmetrically distributed fixing frames are installed at the bottom of both of the two natural gas long-distance pipelines. The bottom connecting pipe and the bottom conveying pipe are located between the two fixing frames. The top of the bottom conveying pipe is connected to the bottom of the corresponding natural gas long-distance pipeline. An intermediate pipe is installed at the other end of the two bottom connecting pipes. Input pipes are installed on both sides of the two natural gas long-distance pipelines. An access pipe extending to the outside of the protective cover and penetrating the metal block is installed at one end of each of the two input pipes.

[0016] A top connecting pipe is installed on one side of the filter cartridge, extending into the interior of the long-distance natural gas pipeline and connecting to the intermediate pipeline. An access pipe is installed on one side of the protective cover. One end of the access pipe passes through a metal block and is connected to a conductive conveying pipeline. Two symmetrically distributed protective sleeves are fitted on the outside of the access pipe and on one side of the long-distance natural gas pipeline.

[0017] Both sides of the two field mobile monitoring devices are fixedly connected to batteries. The outer sides of the multiple batteries are fixedly connected to equally spaced infrared sensors. The outer sides of the two field mobile monitoring devices are fixedly connected to lighting lamps. The batteries are used to provide some of the power resources for the operation of the electrical equipment, the infrared sensors are used to assist in remote monitoring and processing, and the lighting lamps are used to assist in field lighting.

[0018] In a preferred embodiment of the present invention, a second valve is fixedly connected to the outside of the input pipe, and a pressure relief pipe is installed at one end of another input pipe. A first valve is fixedly connected to the outside of the pressure relief pipe. The first valve is used to control the opening and closing of the pressure relief pipe, and the second valve is used to control the opening and closing of the corresponding input pipe. Equally spaced current conductors are installed inside the metal block and on the outside of the access pipe to ensure that the long-distance natural gas pipeline is in a current-connected state. The metal block, as an anode, will gradually be consumed and corroded. The primary protection of the long-distance natural gas pipeline can be completed by periodically replacing the metal block. The entire protective cover is used for secondary protection of the long-distance natural gas pipeline. Two protective jackets are used for protection of one end of the long-distance natural gas pipeline, and the filter cylinder is used for protection of the other end of the long-distance natural gas pipeline.

[0019] In a preferred embodiment of the present invention, a current conduction wire is installed on the outer side of the natural gas long-distance pipeline and above the input pipeline. In use, the protective cover on the outer side of the current conduction wire is removed, and it is directly connected to the precious metal base plate for subsequent current transmission. A third valve is fixedly connected to the outer side of the access pipeline. Fixing plates are installed on both sides of the two protective jackets. The top of the uppermost fixing plate is penetrated by a positioning bolt located on the lowermost fixing plate, thereby reinforcing the connection between the two protective jackets and the access pipeline. A sponge pad is installed on the side of the two protective jackets near the access pipeline to provide protection during positioning. The third valve is used to control the opening and closing of the access pipeline, thereby ensuring the transmission of subsequent natural gas into the natural gas long-distance pipeline.

[0020] In a preferred embodiment of the present invention, a maintenance cover is installed on the top of the filter cartridge, an external discharge pipe is installed on the side of the filter cartridge away from the top connecting pipe, a fourth valve is fixedly connected to the outside of the external discharge pipe, a fifth valve is fixedly connected to the outside of the top connecting pipe, the fifth valve is located on the side of the filter cartridge away from the external discharge pipe, a sedimentation chamber is installed at the bottom inside the filter cartridge, the fourth valve is used to control the opening and closing of the external discharge pipe, thereby treating the gas discharge inside the filter cartridge or connecting it to other pipes, and the fifth valve is used to control the opening and closing of the top connecting pipe.

[0021] In a preferred embodiment of the present invention, both ends of the reciprocating lead screw are equipped with fixing plates. A drive motor is fixedly connected to the outer side of one of the fixing plates. The output end of the drive motor is fixedly connected to one end of the corresponding reciprocating lead screw. When the output end of the drive motor rotates, it drives the corresponding reciprocating lead screw to rotate, thereby driving the outer movable slider to reciprocate. This facilitates the reciprocating detection of the on-site mobile monitoring instrument at the top and records various data of the long-distance natural gas pipeline in real time.

[0022] In a preferred embodiment of the present invention, a wireless transceiver is fixedly connected to the top of the protective cover and to the side away from the filter cylinder. A main control board is fixedly connected inside the wireless transceiver, and a control chip is fixedly connected to the outside of the main control board. The current conduction line, the first valve, the second valve, the third valve, the wireless transceiver, the fourth valve, the drive motor, the field motion monitor, the battery, the infrared sensor, and the lighting are all electrically connected to the control chip. The control chip is used to control the operation of the current conduction line, the first valve, the second valve, the third valve, the wireless transceiver, the fourth valve, the drive motor, the field motion monitor, the battery, the infrared sensor, and the lighting, thereby realizing unified management of power equipment.

[0023] In a preferred embodiment of the present invention, a limit guide rail is installed inside the protective cover on the side where the two reciprocating lead screws are close to each other. The movable slider is slidably connected to the corresponding limit guide rail. Limit blocks are installed on the outer sides of both ends of the limit guide rail. The two limit blocks are used to limit the two sides of the limit guide rail to prevent the equipment from falling off.

[0024] In a preferred embodiment of the present invention, the bottom of the lowest protective sleeve is equipped with a positioning screw that extends to the inner wall of the precious metal base plate.

[0025] A method for using a cathodic protection device for corrosion prevention in long-distance natural gas pipelines includes the following specific steps:

[0026] S1. Installation and connection of protective equipment: The metal block is electrically connected to the conductive pipeline of the natural gas long-distance pipeline through the access pipe and the internal current conductor to form a sacrificial anode cathodic protection circuit; at the same time, the current conductor is connected to the precious metal base plate to establish a monitoring reference potential;

[0027] S2. Dynamic monitoring start-up and data acquisition: The drive motor is turned on, driving the reciprocating screw to rotate, which in turn drives the moving slider and the on-site mobile monitoring instrument on it to move back and forth along the pipeline axis; the potential, corrosion status and environmental data of the pipeline outer wall are collected in real time through the on-site mobile monitoring instrument and infrared sensor, and uploaded through the wireless signal transceiver.

[0028] S3. Maintenance and Replacement: Based on monitoring data, when the metal blocks are exhausted or the filter element is saturated, close the relevant valves and replace the filter element and adsorption rod by opening the maintenance top cover, or replace the metal blocks that have been corroded and consumed inside the protective cover, in order to maintain continuous cathodic protection and filtration protection effects.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] This invention comprises a natural gas long-distance pipeline, a protective cover, and a filter cartridge. The core of the device is the sacrificial anode method, where a metal block with a more negative potential is electrically connected to the protected steel pipeline via a wire, forming a galvanic cell in the soil electrolyte. Electrons flow from the metal block (anode) to the pipeline (cathode), thus making the entire pipeline surface a cathode, inhibiting its tendency to lose electrons and corrode. The metal block is continuously consumed, protecting the pipeline. A drive motor rotates a reciprocating screw, causing a movable slider carrying a monitoring instrument to move automatically and reciprocally along the pipeline axis. The output of the drive motor rotates, driving the corresponding reciprocating screw to rotate, which in turn drives the outer movable slider to reciprocate. This facilitates the reciprocating detection of the on-site mobile monitoring instrument at the top, recording the real-time status of the natural gas long-distance pipeline. Each data point acts as a mobile reference electrode, continuously and seamlessly measuring the protection potential along the pipeline, generating real-time potential distribution maps, promptly identifying sections with insufficient or excessive protection, and assessing the remaining lifespan of the anode blocks. The internal protection principle involves a filter cartridge connected in series along the pipeline's connecting path. When a medium such as natural gas flows through, solid impurities, moisture, and some corrosive substances are intercepted or adsorbed by the filter element and adsorption rods. The purified medium then enters another section of the pipeline or equipment, thus mitigating corrosion of the pipeline's inner wall. A battery provides power to some of the electrical equipment, an infrared sensor assists in remote monitoring, lighting assists in on-site illumination, and two limit blocks limit the movement of equipment on both sides of the guide rail to prevent it from falling off. Attached Figure Description

[0031] Figure 1 This is an external schematic diagram of the overall structure of the cathodic protection device for corrosion prevention of natural gas long-distance pipelines and its usage method according to the present invention;

[0032] Figure 2 This is a schematic diagram of the overall structure of a cathodic protection device for corrosion prevention of long-distance natural gas pipelines and its usage method according to the present invention. Figure 1 ;

[0033] Figure 3 This is a schematic diagram of the overall structure of a cathodic protection device for corrosion prevention of long-distance natural gas pipelines and its usage method according to the present invention. Figure 2 ;

[0034] Figure 4 This is an enlarged schematic diagram of the internal structure of the filter cylinder of the cathodic protection device for corrosion prevention of natural gas long-distance pipelines and its usage method according to the present invention.

[0035] Figure 5 This is an enlarged schematic diagram of the driving and moving mechanism of a cathodic protection device for corrosion prevention of natural gas long-distance pipelines and its usage method according to the present invention.

[0036] Figure 6This invention relates to a cathodic protection device for corrosion prevention of long-distance natural gas pipelines and its usage method. Figure 1 Enlarged schematic diagram of the structure at point A in the diagram;

[0037] Figure 7 This invention relates to a cathodic protection device for corrosion prevention of long-distance natural gas pipelines and its usage method. Figure 5 Enlarged schematic diagram of the structure at point B in the diagram;

[0038] Figure 8 This invention relates to a cathodic protection device for corrosion prevention of long-distance natural gas pipelines and its usage method. Figure 3 A magnified schematic diagram of the structure at point C.

[0039] In the picture:

[0040] 1. Natural gas long-distance pipeline; 11. Current conduction line; 12. Bottom conveying pipeline; 13. Bottom connecting pipeline; 14. Fixing frame; 15. Input pipeline; 16. Pressure relief pipeline; 17. First valve; 18. Conductive conveying pipeline; 19. Second valve;

[0041] 2. Protective cover; 21. Precious metal base plate; 22. Access pipe; 23. Third valve; 24. Protective jacket; 25. Fixing plate; 26. Positioning bolt; 27. Positioning screw; 28. Metal block; 29. ​​Wireless transceiver;

[0042] 3. Filter cartridge; 31. Inspection top cover; 32. Filter element; 33. External discharge pipe; 34. Fourth valve; 35. Sedimentation tank; 36. Adsorption rod; 37. Top connecting pipe; 38. Fifth valve;

[0043] 4. Fixed plate; 41. Reciprocating lead screw; 42. Moving slider; 43. Drive motor; 44. Limit guide rail; 45. Limit block; 46. On-site movement monitoring instrument; 47. Storage battery; 48. Infrared sensor; 49. Lighting lamp. Detailed Implementation

[0044] 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, and 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.

[0045] Please see Figures 1-8The present invention provides a technical solution: a cathodic protection device for corrosion prevention of long-distance natural gas pipelines, comprising two long-distance natural gas pipelines 1, each of the two long-distance natural gas pipelines 1 having symmetrically distributed fixed frames 14 installed at the bottom, each of the two fixed frames 14 having a bottom connecting pipe 13 installed between them, each of the bottom connecting pipes 13 having a bottom conveying pipe 12 fixedly connected to the top of it, each of the bottom conveying pipes 12 having its top connected to the bottom of the corresponding long-distance natural gas pipeline 1, each of the two bottom connecting pipes 13 having an intermediate pipe installed at the other end, each of the two long-distance natural gas pipelines 1 having an input pipe 15 installed on both sides, each of the two input pipes 15 having an access pipe 22 extending to the outside of a protective cover 2, and a metal block 28 installed inside the protective cover 2 and outside the access pipe 22.

[0046] In this scheme, both sides of the metal block 28 are equipped with drive moving mechanisms for use with two long-distance natural gas pipelines 1. Each drive moving mechanism includes a fixed plate 4. Two fixed plates 4 are installed on both sides of the two metal blocks 28. A reciprocating screw 41 is rotatably connected between the two fixed plates 4 on the same side. A moving slider 42 is threadedly connected to the outside of the two reciprocating screws 41. A field movement monitoring instrument 46 is fixedly connected to the top of the two moving sliders 42.

[0047] The protective cover 2 is installed on the outside of the natural gas long-distance pipeline 1. A precious metal base plate 21 is fixedly connected to the bottom of the protective cover 2. A filter cylinder 3 connected to the natural gas long-distance pipeline 1 is installed on the top of the protective cover 2. A top connecting pipe 37 extending into the interior of the natural gas long-distance pipeline 1 and connected to the intermediate pipe is installed on one side of the filter cylinder 3. A filter element 32 is installed inside the filter cylinder 3. An adsorption rod 36 is installed inside the filter element 32. An access pipe 22 is installed on one side of the protective cover 2. One end of the access pipe 22 passes through a metal block 28 and is connected to the conductive conveying pipe 18. Two symmetrically distributed protective jackets 24 are fitted on the outside of the access pipe 22 and on one side of the natural gas long-distance pipeline 1.

[0048] Please see Figures 1-7 In this scheme, batteries 47 are fixedly connected to both sides of the two field mobile monitoring devices 46, and infrared sensors 48 are fixedly connected to the outside of the multiple batteries 47 at equal intervals. Lighting lamps 49 are fixedly connected to the outside of the two field mobile monitoring devices 46. The batteries 47 are used to provide some of the power resources for the operation of the power equipment, the infrared sensors 48 are used to assist in remote monitoring and processing, and the lighting lamps 49 are used to assist in field lighting.

[0049] In this scheme, a second valve 19 is fixedly connected to the outside of the input pipe 15, and a pressure relief pipe 16 is installed at one end of another input pipe 15. A first valve 17 is fixedly connected to the outside of the pressure relief pipe 16. The first valve 17 is used to control the opening and closing of the pressure relief pipe 16, and the second valve 19 is used to control the opening and closing of the corresponding input pipe 15. Equally spaced current conductors are installed inside the metal block 28 and outside the access pipe 22 to ensure that the natural gas long-distance pipeline 1 is in a current-connected state. The metal block 28, as an anode, will gradually be consumed and corroded. The primary protection of the natural gas long-distance pipeline 1 can be completed by periodically replacing the metal block 28. The protective cover 2 is used for the secondary protection of the natural gas long-distance pipeline 1. Two protective jackets 24 are used for the protection of one end of the natural gas long-distance pipeline 1, and the filter cylinder 3 is used for the protection of the other end of the natural gas long-distance pipeline 1.

[0050] Please see Figures 1-7 In this scheme, a current conduction line 11 is installed on the outside of the natural gas long-distance pipeline 1 and above the input pipeline 15. When in use, the protection on the outside of the current conduction line 11 is removed and it is directly connected to the precious metal base plate 21 for subsequent current transmission. A third valve 23 is fixedly connected to the outside of the access pipeline 22. Fixing plates 25 are installed on both sides of the two protective sleeves 24. The top of the uppermost fixing plate 25 is penetrated by the positioning bolt 26 of the lowermost fixing plate 25, thereby reinforcing the connection between the two protective sleeves 24 and the access pipeline 22. Sponge pads are installed on the side of the two protective sleeves 24 near the access pipeline 22 to provide protection during positioning. The third valve 23 is used to control the opening and closing of the access pipeline 22, thereby ensuring the transmission of subsequent natural gas into the natural gas long-distance pipeline 1.

[0051] In this design, a maintenance cover 31 is installed on the top of the filter cartridge 3. An external discharge pipe 33 is installed on the side of the filter cartridge 3 away from the top connecting pipe 37. A fourth valve 34 is fixedly connected to the outside of the external discharge pipe 33. A fifth valve 38 is fixedly connected to the outside of the top connecting pipe 37. The fifth valve 38 is located on the side of the filter cartridge 3 away from the external discharge pipe 33. A sedimentation chamber 35 is installed at the bottom inside the filter cartridge 3. The fourth valve 34 is used to control the opening and closing of the external discharge pipe 33, thereby treating the gas inside the filter cartridge 3 or connecting it to other pipes. The fifth valve 38 is used to control the opening and closing of the top connecting pipe 37.

[0052] Please see Figures 1-8 In this scheme, a drive motor 43 is fixedly connected to the outer side of one of the fixed plates 4. The output end of the drive motor 43 is fixedly connected to one end of the corresponding reciprocating screw 41. When the output end of the drive motor 43 rotates, it drives the corresponding reciprocating screw 41 to rotate, which drives the outer movable slider 42 to reciprocate, thereby facilitating the reciprocating detection of the on-site mobile monitoring instrument 46 at the top and recording various data of the natural gas long-distance pipeline 1 in real time.

[0053] In this solution, a wireless transceiver 29 is fixedly connected to the top of the protective cover 2 and the side away from the filter cartridge 3. A main control board is fixedly connected inside the wireless transceiver 29, and a control chip is fixedly connected to the outside of the main control board. The current conduction line 11, the first valve 17, the second valve 19, the third valve 23, the wireless transceiver 29, the fourth valve 34, the drive motor 43, the field motion monitor 46, the battery 47, the infrared sensor 48, and the lighting 49 are all electrically connected to the control chip. The control chip is used to control the operation of the current conduction line 11, the first valve 17, the second valve 19, the third valve 23, the wireless transceiver 29, the fourth valve 34, the drive motor 43, the field motion monitor 46, the battery 47, the infrared sensor 48, and the lighting 49, realizing unified management of power equipment. The infrared sensor 48 measures the corresponding environmental parameters, converts them into signals, and sends them to the control chip. The control chip receives the signals, processes them, and generates corresponding control signals according to the preset control algorithm.

[0054] Please see Figures 1-7 In this solution, the protective cover 2 is equipped with a limit guide rail 44 inside and on the side where the two reciprocating screws 41 are close to each other. The movable sliders 42 are slidably connected to the corresponding limit guide rails 44. Limit blocks 45 are installed on the outer sides of both ends of the limit guide rails 44. The two limit blocks 45 are used to limit the two sides of the limit guide rails 44 to prevent the equipment from falling off.

[0055] The bottom of the lowest protective sleeve 24 is equipped with positioning screws 27 that extend to the inner wall of the precious metal base plate 21.

[0056] A method for using a cathodic protection device for corrosion prevention in long-distance natural gas pipelines includes the following specific steps:

[0057] S1. Installation and connection of protective equipment: The metal block 28 is electrically connected to the conductive conveying pipe 18 of the natural gas long-distance pipeline 1 through the access pipe 22 and the internal current wire to form a sacrificial anode cathodic protection circuit; at the same time, the current conduction line 11 is connected to the precious metal base plate 21 to establish a monitoring reference potential.

[0058] S2. Dynamic monitoring start-up and data acquisition: Turn on the drive motor 43 to drive the reciprocating screw 41 to rotate, which drives the moving slider 42 and the on-site moving monitoring instrument 46 on it to move back and forth along the pipeline axis; the on-site moving monitoring instrument 46 and infrared sensor 48 collect the potential, corrosion status and environmental data of the pipeline outer wall in real time, and upload them through the wireless signal transceiver 29.

[0059] S3. Maintenance and Replacement: Based on monitoring data, when the metal block 28 is exhausted or the filter element 32 is saturated, close the relevant valves and replace the filter element 32 and adsorption rod 36 by opening the maintenance cover 31, or replace the metal block 28 that has been corroded and consumed inside the protective cover 2, in order to maintain continuous cathodic protection and filtration protection effects.

[0060] Please see Figures 1-8 The working principle of this invention is as follows:

[0061] It is equipped with a long-distance natural gas pipeline 1, a protective cover 2, and a filter cartridge 3. During use:

[0062] Cathodic protection and monitoring principles:

[0063] The core of the device is the sacrificial anode method, in which a metal block 28 with a more negative potential is electrically connected to the steel pipe 1 to be protected through a wire, forming a galvanic cell in the soil electrolyte. Electrons flow from the metal block 28, which acts as the anode, to the pipe, which acts as the cathode, thereby making the entire surface of the pipe a cathode, inhibiting its tendency to lose electrons and thus corrode. The metal block 28 is continuously consumed, while the pipe is protected.

[0064] Dynamic monitoring mechanism: The drive motor 43 drives the reciprocating screw 41 to rotate, causing the movable slider 42 equipped with the monitor 46 to move automatically and reciprocally along the pipeline axis. The output end of the drive motor 43 rotates, driving the corresponding reciprocating screw 41 to rotate, driving the outer movable slider 42 to move back and forth, thus facilitating the reciprocating detection of the on-site mobile monitor 46 at the top, recording various data of the natural gas long-distance pipeline 1 in real time. It is equivalent to a movable reference electrode, which can continuously and seamlessly measure the protection potential along the pipeline, draw the potential distribution map in real time, promptly detect sections with insufficient or over-protection, and assess the remaining life of the anode block.

[0065] Principles of auxiliary protection and intelligent management:

[0066] Internal protection principle: The filter cartridge 3 is connected in series in the pipeline. When the medium, such as natural gas, flows through, the solid impurities, moisture and some corrosive substances in it are intercepted or adsorbed by the filter element 32 and the adsorption rod 36. The purified medium then enters another section of pipeline or equipment, thereby slowing down the corrosion of the pipeline inner wall by the medium.

[0067] Centralized control principle:

[0068] The control chip is used to control the operation of the current conduction line 11, the first valve 17, the second valve 19, the third valve 23, the wireless signal transceiver 29, the fourth valve 34, the drive motor 43, the field mobile monitoring instrument 46, the storage battery 47, the infrared sensor 48, and the lighting 49, realizing unified management of power equipment. The infrared sensor 48 measures the corresponding environmental parameters, converts them into signals, and sends them to the control chip. The control chip receives the signals, processes them, and generates corresponding control signals according to the preset control algorithm.

[0069] All valves, motors, and sensors are managed by a unified control chip. Staff can remotely acquire monitoring data, control the start and stop of inspections, and receive fault or maintenance alarms via wireless transceiver 29, thus realizing the intelligent operation and remote management of the device.

[0070] The storage battery 47 is used to provide some of the power resources for the operation of the electrical equipment; the infrared sensor 48 is used to assist in remote monitoring and processing; the lighting lamp 49 is used to assist in on-site lighting; and the two limit blocks 45 are used to limit the two sides of the guide rail 44 to prevent the equipment from falling off.

[0071] The core monitoring parameter of the on-site mobile monitoring instrument 46 is the pipe-to-ground potential. By moving back and forth along the pipeline, a continuous potential distribution curve is plotted. The on-site mobile monitoring instrument 46 integrates a long-term reference electrode, a multi-channel data acquisition unit, and a positioning module. When it moves along the pipeline axis under the drive mechanism, the data acquisition unit synchronously records the pipe-to-ground potential value measured by the reference electrode and the precise position information provided by the positioning module at fixed time / distance intervals. The data is then transmitted in real time via the wireless transmission module. After receiving this data, the control chip 29 can automatically generate the protection potential distribution curve along the pipeline for that section. By analyzing whether the curve is lower than the minimum protection potential such as -0.85V CSE throughout, it can accurately determine whether the cathodic protection is effective, whether the anode block is consumed evenly, and locate abnormal pipe sections with insufficient or excessive protection.

[0072] One of the main causes of corrosion on the inner wall of pipelines is the presence of corrosive components such as water, hydrogen sulfide, and carbon dioxide in the transported medium. The adsorption rods 36 inside the filter cartridge 3 of this device can specifically adsorb the above-mentioned corrosive media, thereby forming a synergistic anti-corrosion system that combines internal and external cathodic protection from the perspective of internal media purification, thus extending the service life of the pipeline.

[0073] Infrared sensor 48 detects an abnormal increase in humidity inside protective cover 2, which may indicate a seal failure or water leakage. The control chip can automatically increase the potential inspection frequency of the mobile monitoring instrument 46 in this area and simultaneously report an early warning, reflecting the data linkage and intelligent response between the sensor and the actuator, rather than simple centralized control.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cathodic protection device for corrosion prevention of long-distance natural gas pipelines, comprising two parallel long-distance natural gas pipelines (1), characterized in that: The bottoms of the two natural gas long-distance pipelines (1) are connected to a common bottom connecting pipeline (13) via bottom delivery pipelines (12); A protective cover (2) is provided on the outside of the two natural gas long-distance pipelines (1), and a metal block (28) serving as a sacrificial anode is provided inside the protective cover (2). Each side of the metal block (28) is provided with a set of driving and moving mechanisms. Each set of driving and moving mechanisms includes a reciprocating screw (41) driven by a drive motor (43). A movable slider (42) that can reciprocate along the reciprocating screw (41) is threadedly connected to the reciprocating screw (41). A field movable monitoring instrument (46) for monitoring the status of the pipeline is installed on the movable slider (42). The top of the protective cover (2) is connected to a filter cylinder (3), which is connected to the inside of the natural gas long-distance pipeline (1) through a top connecting pipe (37), and is equipped with a filter element (32) and an adsorption rod (36) inside.

2. A corrosion protection cathodic protection device for long distance natural gas pipelines according to claim 1, characterized in that: The bottom of each of the two natural gas long-distance pipelines (1) is equipped with symmetrically distributed fixing frames (14). The bottom connecting pipe (13) and the bottom conveying pipe (12) are located between the two fixing frames (14). The top of the bottom conveying pipe (12) is connected to the bottom of the corresponding natural gas long-distance pipeline (1). The other end of the two bottom connecting pipes (13) is equipped with an intermediate pipe. The two natural gas long-distance pipelines (1) are equipped with input pipes (15) on both sides. One end of each of the two input pipes (15) is equipped with an access pipe (22) that extends to the outside of the protective cover (2) and penetrates the metal block (28). A top connecting pipe (37) is installed on one side of the filter cylinder (3) and extends into the interior of the natural gas long-distance pipeline (1) and is connected to the intermediate pipeline. An access pipe (22) is installed on one side of the protective cover (2). One end of the access pipe (22) passes through the metal block (28) and is connected to the conductive conveying pipeline (18). Two symmetrically distributed protective jackets (24) are fitted on the outside of the access pipe (22) and on one side of the natural gas long-distance pipeline (1). Both sides of the two field mobile monitoring instruments (46) are fixedly connected to batteries (47), and infrared sensors (48) are fixedly connected to the outside of the multiple batteries (47) at equal intervals. Lighting lamps (49) are fixedly connected to the outside of the two field mobile monitoring instruments (46). The batteries (47) are used to provide some of the power resources for the operation of the power equipment, the infrared sensors (48) are used to assist in remote monitoring and processing, and the lighting lamps (49) are used to assist in field lighting.

3. A corrosion protection cathodic protection device for long distance natural gas pipelines according to claim 2, characterized in that: A second valve (19) is fixedly connected to the outside of the input pipe (15). A pressure relief pipe (16) is installed at one end of another input pipe (15). A first valve (17) is fixedly connected to the outside of the pressure relief pipe (16). The first valve (17) is used to control the opening and closing of the pressure relief pipe (16). The second valve (19) is used to control the opening and closing of the corresponding input pipe (15). Equally spaced current wires are installed inside the metal block (28) and outside the access pipe (22). The metal block (28) can be replaced periodically to complete the primary protection of the natural gas long-distance pipeline (1). The protective cover (2) is used as a whole for the secondary protection of the natural gas long-distance pipeline (1). Two protective jackets (24) are used for the protection of one end of the natural gas long-distance pipeline (1). The filter cylinder (3) is used for the protection of the other end of the natural gas long-distance pipeline (1).

4. A corrosion protection cathodic protection device for long distance gas pipelines according to claim 3, characterized in that: A current conduction line (11) is installed on the outside of the natural gas long-distance pipeline (1) and above the input pipeline (15). A third valve (23) is fixedly connected to the outside of the access pipeline (22). Fixing plates (25) are installed on both sides of the two protective jackets (24). The top of the uppermost fixing plate (25) is penetrated by a positioning bolt (26) located on the lowermost fixing plate (25), thereby reinforcing the connection between the two protective jackets (24) and the access pipeline (22). A sponge pad is installed on the side of the two protective jackets (24) close to the access pipeline (22). The third valve (23) is used to control the opening and closing of the access pipeline (22).

5. A corrosion protection cathodic protection device for long distance natural gas pipelines according to claim 4, characterized in that: The filter cylinder (3) is equipped with an inspection cover (31) on its top. An external discharge pipe (33) is installed on the side of the filter cylinder (3) away from the top connecting pipe (37). A fourth valve (34) is fixedly connected to the outside of the external discharge pipe (33). A fifth valve (38) is fixedly connected to the outside of the top connecting pipe (37). The fifth valve (38) is located on the side of the filter cylinder (3) away from the external discharge pipe (33). A sedimentation chamber (35) is installed at the bottom inside the filter cylinder (3). The fourth valve (34) is used to control the opening and closing of the external discharge pipe (33), and the fifth valve (38) is used to control the opening and closing of the top connecting pipe (37).

6. A corrosion protection cathodic protection device for long distance gas pipelines according to claim 5, characterized in that: Both ends of the reciprocating lead screw (41) are equipped with fixing plates (4), and a drive motor (43) is fixedly connected to the outside of one of the fixing plates (4). The output end of the drive motor (43) is fixedly connected to one end of the corresponding reciprocating lead screw (41).

7. A corrosion protection cathodic protection device for long distance natural gas pipelines according to claim 6, characterized in that: A wireless transceiver (29) is fixedly connected to the top of the protective cover (2) and to the side away from the filter cartridge (3). A main control board is fixedly connected inside the wireless transceiver (29), and a control chip is fixedly connected to the outside of the main control board. The current conduction line (11), the first valve (17), the second valve (19), the third valve (23), the wireless transceiver (29), the fourth valve (34), the drive motor (43), the field motion monitoring instrument (46), the storage battery (47), the infrared sensor (48), and the lighting lamp (49) are all electrically connected to the control chip.

8. A corrosion protection cathodic protection device for long distance natural gas pipelines according to claim 6, characterized in that: Inside the protective cover (2) and on the side close to the two reciprocating screws (41), a limit guide rail (44) is installed. The movable slider (42) is slidably connected to the corresponding limit guide rail (44). Limit blocks (45) are installed on the outer sides of both ends of the limit guide rail (44). The two limit blocks (45) are used to limit the two sides of the limit guide rail (44).

9. The corrosion protection apparatus for long distance gas pipelines according to claim 2, characterized in that: The bottom of the lowest protective sleeve (24) is equipped with a positioning screw (27) that extends to the inner wall of the precious metal base plate (21).

10. A method of using a cathodic protection device for corrosion prevention of a long-distance natural gas pipeline, for implementing the cathodic protection device for corrosion prevention of a long-distance natural gas pipeline as described in any one of claims 1-9, characterized in that: The specific steps include the following: S1. Installation and connection of protective equipment: The metal block (28) is electrically connected to the conductive transmission pipeline (18) of the natural gas long-distance pipeline (1) through the access pipe (22) and the internal current wire to form a sacrificial anode cathodic protection circuit; at the same time, the current conduction line (11) is connected to the precious metal base plate (21) to establish a monitoring reference potential. S2. Dynamic monitoring start-up and data acquisition: Turn on the drive motor (43) to drive the reciprocating screw (41) to rotate, which in turn drives the moving slider (42) and the on-site moving monitoring instrument (46) on it to move back and forth along the pipeline axis; the on-site moving monitoring instrument (46) and infrared sensor (48) collect the potential, corrosion status and environmental data of the outer wall of the pipeline in real time, and upload them through the wireless signal transceiver (29); S3. Maintenance and Replacement: According to the monitoring data, when the metal block (28) is exhausted or the filter element (32) is saturated with adsorption, close the relevant valves and replace the filter element (32) and adsorption rod (36) by opening the maintenance cover (31), or replace the metal block (28) that has been corroded and consumed in the protective cover (2) to maintain the continuous cathodic protection and filtration protection effect.

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