Laboratory simulation device for alternating-current stray current interference of cathode protection pipeline

Abstract

The utility model belongs to the technical field of pipeline cathode protection, particularly relates to a laboratory simulation device for alternating-current stray current interference of a cathode protection pipeline, and aims to solve the problem of how to determine the influence degree of alternating-current stray current interference on the corrosion rate of a cathode protection system. One end of a branch where a cathode protection system is located is connected with an auxiliary electrode, the other end of the branch where the cathode protection system is located is connected with an interference system, and the connection point is connected with one end of a branch where a corrosion test piece is located; the other end of the branch where the interference system is located is connected with the other auxiliary electrode; the three branches can be connected with a data recorder connected with the reference electrode; the electrode and the test piece are arranged in the water tank system. The device can simulate the corrosion conditions of the cathode protection pipeline in different alternating current stray current interference environments under different cathode protection current magnitudes, is easy to erect and convenient to operate, and provides reference for alternating current stray current treatment of actual in-service pipelines.

Description

Technical Field

[0001] The utility model belongs to the technical field of pipeline cathodic protection, and particularly relates to a laboratory simulation device for alternating current stray current interference of a cathodically protected pipeline. Background Technique

[0002] With the development of the economic society, the mileage of long-distance oil and gas pipelines has gradually increased. However, due to their long distance, large transportation volume, and the fact that the transported media are flammable, explosive, and may pollute the environment, the requirements for the safety of long-distance oil and gas pipelines are getting higher and higher. Among oil and gas pipeline accidents, pipeline corrosion is one of the main causes of accidents. To solve the problem of pipeline corrosion, the method of combining an anticorrosive coating with cathodic protection is usually adopted to protect the pipeline against corrosion.

[0003] Currently, with the continuous construction of pipelines and the laying of power grids and electrified railways, there will inevitably be parallel and crossing phenomena between pipelines and transmission lines or electrified railways. At this time, high-voltage alternating current in power supply systems such as transmission lines and electrified railways may leak into the soil near the pipeline, and may have a relatively high voltage and current density, resulting in the pipeline being interfered by alternating current stray current. At the same time, many current studies and examples have shown that alternating current stray current interference is also an important cause of pipeline corrosion. Therefore, it is extremely necessary to explore alternating current interference and evaluate its impact on pipeline safety for the safe operation of pipelines.

[0004] To explore the influence of alternating current interference on pipelines under cathodic protection, this laboratory simulation device is designed to determine the influence degree of alternating current stray current interference on the corrosion rate of the system through small-scale laboratory tests, so as to provide reference opinions for the treatment of stray current on-site. Content of the Utility Model

[0005] To solve the above problems in the prior art, that is, the problem that the influence degree of alternating current stray current interference on the corrosion rate of the cathodic protection system cannot be determined in the prior art, the utility model provides a laboratory simulation device for alternating current stray current interference of a cathodically protected pipeline.

[0006] A laboratory simulation device for alternating current stray current interference of a cathodically protected pipeline provided by this application adopts the following technical scheme:

[0007] A laboratory simulation device for alternating current stray current interference of a cathodically protected pipeline includes a cathodic protection system, an interference system, a data recorder, and a water tank system;

[0008] Take the branch where the cathodic protection system is located as the first branch. The first end of the first branch is connected to the first auxiliary electrode, and the second end of the first branch is connected to the first end of the second branch. The second branch is the branch where the interference system is located. The second end of the second branch is connected to the second auxiliary electrode. The first end of the second branch is connected to the first end of the third branch, and the second end of the third branch is connected to the corrosion coupon.

[0009] The first branch, the second branch, and the third branch can all be connected to the first port and the second port of the data logger. The third port of the data logger is connected to the reference electrode.

[0010] The first auxiliary electrode, the second auxiliary electrode, the corrosion coupon, and the reference electrode are all arranged in the water tank system, and the water tank system is filled with soil solution.

[0011] Preferably, the cathodic protection system includes a constant current DC power supply and a low-frequency choke coil. The positive pole of the constant current DC power supply is connected to one low-frequency choke coil, and the negative pole of the constant current DC power supply is connected to another low-frequency choke coil.

[0012] Preferably, the interference system includes a waveform generator, a power amplifier, and a capacitor arranged on the second branch.

[0013] The waveform generator is connected to the power amplifier, and both ends of the power amplifier are connected to a capacitor.

[0014] Preferably, a fixed distance is maintained between the first auxiliary electrode and the second auxiliary electrode, and they do not come into direct contact.

[0015] Preferably, the soil solution is used to simulate the soil at the pipeline location.

[0016] Preferably, the capacitor is a non-polar capacitor.

[0017] Preferably, both the first auxiliary electrode and the second auxiliary electrode are anodes.

[0018] Preferably, an accessory switch is arranged on the first branch, and the first port and the second port of the data logger are connected on both sides of the accessory switch.

[0019] Preferably, an accessory switch is arranged on the second branch, and the first port and the second port of the data logger are connected on both sides of the accessory switch.

[0020] Preferably, an accessory switch is arranged on the third branch, and the first port and the second port of the data logger are connected on both sides of the accessory switch.

[0021] Advantages of the utility model:

[0022] (1) By designing a laboratory simulation device for AC stray current interference on cathodically protected pipelines, it is possible to simulate the corrosion conditions of cathodically protected pipelines under different AC stray current interference environments at different magnitudes of cathodic protection current in the laboratory, providing a reference for the treatment of AC stray current in actual in-service pipelines.

[0023] (2) The low-frequency choke coil and capacitor in this device can effectively suppress the mutual interference between the cathodic protection system and the AC stray current interference system, making the experimental data more reliable.

[0024] (3) This device can easily connect, disconnect, and reposition the data recorder, easily measure the cathodic protection current, interference current, and total current of the test piece, and reduce the time when the system is open-circuited due to wiring switching during the connection, removal, or repositioning of the data recorder, thereby reducing the impact on the device. The entire device is simple and easy to set up and operate. Description of the Drawings

[0025] Other features, objectives, and advantages of this application will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings:

[0026] Figure 1 It is a schematic connection structure diagram of a laboratory simulation device for AC stray current interference on cathodically protected pipelines in this embodiment. Detailed Embodiments

[0027] The following further elaborates on this application in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant utility model and do not limit the utility model. Additionally, it should be noted that for ease of description, only parts related to the relevant utility model are shown in the drawings.

[0028] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will elaborate on this application in detail with reference to the drawings and embodiments.

[0029] As Figure 1 shown, the present utility model provides a laboratory simulation device for AC stray current interference on cathodically protected pipelines, including a cathodic protection system 1, an interference system 2, a data recorder 3, and a water tank system 4;

[0030] Take the branch where the cathodic protection system 1 is located as the first branch. The first end of the first branch is connected to the first auxiliary electrode 5, and the second end of the first branch is connected to the first end of the second branch. The second branch is the branch where the interference system 2 is located;

[0031] The second end of the second branch is connected to the second auxiliary electrode 6; the first end of the second branch is connected to the first end of the third branch, and the second end of the third branch is connected to the corrosion coupon 7;

[0032] The first branch, the second branch, and the third branch can all be connected to the first port and the second port of the data recorder 3, and the third port of the data recorder 3 is connected to the reference electrode 8;

[0033] The first auxiliary electrode 5, the second auxiliary electrode 6, the corrosion coupon 7, and the reference electrode 8 are all arranged in the water tank system 4, and a soil solution is arranged in the water tank system 4.

[0034] In the present utility model, the cathodic protection system 1 includes a constant current DC power supply 11 and a low-frequency choke 12. The positive pole of the constant current DC power supply 11 is connected to one low-frequency choke 12, and the negative pole of the constant current DC power supply 11 is connected to the other low-frequency choke 12.

[0035] Specifically, the cathodic protection system 1 includes a high-precision constant current DC power supply 11 and two low-frequency chokes 12. The high-precision constant current DC power supply 11 applies a constant current cathodic protection current to the system, simulating the cathodic protection current applied by a cathodic protection station to a pipeline. The two low-frequency chokes 12 are respectively connected to the positive and negative poles of the constant current DC power supply 11 through wires, which can effectively suppress the mutual interference between the cathodic protection system 1 and the interference system 2 and make the experimental data more reliable. The other end of the low-frequency choke 12 connected to the positive pole is connected to the first auxiliary electrode 5 through a wire. The first auxiliary electrode 5 serves as an auxiliary anode and is made of the same or similar material as the corrosion coupon 7. The first auxiliary electrode 5 is arranged in the water tank system 4, and a soil solution is arranged in the water tank system 4. The soil solution is a simulated solution of the soil where the pipeline is located.

[0036] The other end of the low-frequency choke 12 connected to the negative pole is connected to the interference system 2 through a wire. A first accessory switch is arranged on this section of the wire, and connection points for the data recorder 3 are arranged at both ends of the accessory switch. The data recorder 3 can record the current on-off points and has an automatic on-off function. The data recorder 3 can be connected to the wire through the connection points of the data recorder 3. When the accessory switch is disconnected, the current passes through the wire where the data recorder 3 is located, facilitating the measurement of the cathodic protection current. The third end of the data recorder 3 is also connected to the reference electrode 8. The reference electrode 8 is arranged in the water tank system 4. The reference electrode 8 is a commonly used reference electrode, and a copper sulfate reference electrode or a calomel reference electrode can be selected.

[0037] In the present utility model, as Figure 1 shown, the interference system 2 includes a waveform generator 21, a power amplifier 22, and a capacitor 23 arranged on the second branch;

[0038] The waveform generator 21 is connected to the power amplifier 22, and both ends of the power amplifier 22 are connected to a capacitor 23.

[0039] Specifically, the interference system 2 includes a waveform generator 21, a power amplifier 22, and two capacitors 23. Both ends of the power amplifier 22 are connected to the two capacitors 23 through wires. The capacitance of each capacitor 23 reaches 470 microfarads and is a non-polar capacitor. The two non-polar capacitors can effectively suppress the mutual interference between the cathodic protection system 1 and the interference system 2, making the experimental data more reliable. The other end of one of the non-polar capacitors is connected to the second auxiliary electrode 6 as the anode through a wire, and the second auxiliary electrode 6 is placed in the water tank system 4. One end of the other non-polar capacitor is connected to the low-frequency choke 12 through a wire, specifically, it is connected to the low-frequency choke 12 connected to the negative pole of the constant current DC power supply 11. A second auxiliary switch is provided on this section of the wire, and data recorder 3 connection points are provided at both ends of the auxiliary switch. When the auxiliary switch is disconnected, it is convenient for the data recorder 3 to measure the interference current. The connection point where the cathodic protection system 1 and the interference system 2 are connected is connected to the corrosion coupon 7 through a wire, and the corrosion coupon 7 is placed in the water tank system 4. A third auxiliary switch is provided on this section of the wire, and data recorder 3 connection points are provided at both ends of the auxiliary switch. When the auxiliary switch is disconnected, it is convenient for the data recorder 3 to measure the total current of the corrosion coupon 7.

[0040] Among them, for the power amplifier 22, its maximum amplification voltage reaches 50 volts and the amplification factor reaches 10 times.

[0041] Among them, for the data recorder 3 connection points and the auxiliary switch, when connecting the data recorder 3, the switch is disconnected to allow current to pass through the data recorder 3, and when removing the data recorder 3, the switch is closed to directly provide a current path.

[0042] Among them, the first auxiliary electrode 5 and the second auxiliary electrode 6 are made of materials with a natural potential the same as or close to that of the coupon, and the coupon material can be selected.

[0043] Multiple auxiliary switches, the specific structure is as follows, as Figure 1 shown:

[0044] An auxiliary switch is provided on the first branch, and the first port and the second port of the data recorder 3 are connected to both sides of the auxiliary switch.

[0045] An auxiliary switch is provided on the second branch, and the first port and the second port of the data recorder 3 are connected to both sides of the auxiliary switch.

[0046] An auxiliary switch is provided on the third branch, and the first port and the second port of the data recorder 3 are connected to both sides of the auxiliary switch.

[0047] As a further explanation of the present utility model, a fixed distance is maintained between the first auxiliary electrode 5 and the second auxiliary electrode 6, and they do not come into direct contact.

[0048] In the description of the present utility model, terms indicating directions or positional relationships such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0049] In addition, it should be noted that in the description of the present utility model, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0050] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, so that a process, method, article, or device / equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent in these processes, methods, articles, or devices / equipment.

[0051] So far, the technical solution of the present utility model has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present utility model is obviously not limited to these specific embodiments. Without departing from the principle of the present utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present utility model.

Claims

1. A laboratory simulation device for AC stray current interference of cathodic protection pipeline, characterized in that: It includes a cathodic protection system (1), an interference system (2), a data recorder (3) and a water tank system (4); The branch where the cathode protection system (1) is located is used as a first branch, the first end of the first branch is connected to a first auxiliary electrode (5), the second end of the first branch is connected to a first end of a second branch, and the second branch is the branch where the interference system (2) is located; The second end of the second branch is connected to the second auxiliary electrode (6); the first end of the second branch is connected to the first end of the third branch, and the second end of the third branch is connected to the corrosion test piece (7); The first branch, the second branch and the third branch are all capable of connecting to a first port and a second port of a data recorder (3), and the third port of the data recorder (3) is connected to a reference electrode (8) (8); The first auxiliary electrode (5), the second auxiliary electrode (6), the corrosion test piece (7) and the reference electrode (8) are all arranged in a water tank system (4), and a soil solution is arranged in the water tank system (4).

2. The laboratory simulation device for AC stray current interference of cathodic protection pipeline according to claim 1 is characterized in that: The cathodic protection system (1) comprises a constant-current DC power supply (11) and a low-frequency choke (12), wherein the positive pole of the constant-current DC power supply (11) is connected to one low-frequency choke (12), and the negative pole of the constant-current DC power supply (11) is connected to another low-frequency choke (12).

3. The laboratory simulation device for AC stray current interference of cathodic protection pipeline according to claim 1 is characterized in that: The interference system (2) comprises a waveform generator (21) and a power amplifier (22) and a capacitor (23) arranged on the second branch; The waveform generator (21) is connected to the power amplifier (22), and both ends of the power amplifier (22) are connected to a capacitor (23).

4. The laboratory simulation device for AC stray current interference of cathodic protection pipeline according to claim 1 is characterized in that: The first auxiliary electrode (5) and the second auxiliary electrode (6) maintain a fixed distance between them and are not in direct contact.

5. The laboratory simulation device for AC stray current interference of cathodic protection pipeline according to claim 1 is characterized in that: The soil solution is used to simulate the soil where the pipeline is located.

6. The laboratory simulation device for AC stray current interference of cathodic protection pipeline according to claim 3 is characterized in that: The capacitor (23) is a non-polar capacitor.

7. The laboratory simulation device for AC stray current interference of cathodic protection pipeline according to claim 1 is characterized in that: The first auxiliary electrode (5) and the second auxiliary electrode (6) are both anodes.

8. The laboratory simulation device for AC stray current interference of cathodic protection pipeline according to claim 1 is characterized in that: The first branch is provided with an auxiliary switch, and the first port and the second port of the data recorder (3) are connected to both sides of the auxiliary switch.

9. The laboratory simulation device for AC stray current interference of cathodic protection pipeline according to claim 1, characterized in that: The second branch is provided with an auxiliary switch, and the first port and the second port of the data recorder (3) are connected to both sides of the auxiliary switch.

10. The laboratory simulation device for AC stray current interference of cathodic protection pipeline according to claim 1, characterized in that: The third branch is provided with an auxiliary switch, and the first port and the second port of the data recorder (3) are connected to both sides of the auxiliary switch.

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