WO2020244107A1

WO2020244107A1 - Cathode protection test probe

Info

Publication number: WO2020244107A1
Application number: PCT/CN2019/110374
Authority: WO
Inventors: 李龙; 张石超; 孙磊峰; 苗松
Original assignee: 西安英柯迈信息技术有限公司
Priority date: 2019-06-05
Filing date: 2019-10-10
Publication date: 2020-12-10
Also published as: CN210367917U; WO2020244107A9

Abstract

Disclosed is a cathode protection test probe, comprising an outer cavity, a polarized test piece, an inner cavity, an alternating-current test piece, a copper electrode and a test cable, wherein the polarized test piece is of a hollow cylinder shape; the polarized test piece wraps an outer wall of the outer cavity; the polarized test piece, the outer cavity and the inner cavity are coaxially arranged; the polarized test piece is fixed on the outer wall of the outer cavity; the alternating-current test piece is embedded into an inner side of the top of the outer cavity; the copper electrode is inserted into a lumen of the inner cavity from the center of the bottom of the outer cavity and is fixed to the outer cavity and the inner cavity in a sealed manner; a copper sulfate crystal is filled between the copper electrode and an inner wall of the inner cavity; and three wires of a three-core test cable are respectively connected to the polarized test piece, the alternating-current test piece and the copper electrode. The cathode protection test probe uses the polarized test piece of a hollow cylinder shape to surround a test electrode so as to eliminate impurity current interference, and uses an all-solid-state structure involving no leakage and no pollution of the test piece for a test, making a test result more reliable.

Description

Cathodic protection test probe

Technical field

The invention belongs to the technical field of cathodic protection detection, and specifically relates to a cathodic protection test probe.

Background technique

At present, the commonly used methods for measuring polarization potential (cathodic protection potential) include instantaneous power off method and test piece power off method. The instantaneous power off method is often difficult to implement in actual engineering due to many inconveniences. The test piece power-off method is to bury a test piece at the test point, whose material and burying state requirements are the same or similar to those of the pipeline. The test piece and the metal buried object to be tested are electrically connected with a wire, and the metal component provides protection current to the test piece Polarize the test piece. When measuring, it is only necessary to disconnect the connecting wire between the test piece and the buried metal object, and then the power-off potential of the test piece can be measured. The power-off potential of the test piece represents the potential of the metal buried object, thereby avoiding cutting off the main protection Trouble with current and other electrical connections.

However, in the presence of stray current interference, since the stray current will flow on the test path between the test strip and the reference electrode, it will cause errors in the measurement results, that is, it is still impossible to obtain an accurate polarization potential. At present, the environmental conditions around some metal components such as buried steel pipelines are more complicated, especially AC and DC stray current interference is very common. Under such interference conditions, how to measure the true cathodic protection polarization potential of the pipeline appears Particularly important.

In addition, because the detection of cathodic protection potential needs to be carried out for a long time and continuously, and multiple installations of cathodic protection potential detection devices will consume a lot of manpower and material resources, increase maintenance costs, and the polarization of the detection device also takes a long time, so The cathodic protection potential detection device needs to be buried in the soil near the metal buried object to be tested for a long time to facilitate long-term monitoring and multiple measurements; the internal filling material of the prior art phase detection device is generally copper sulfate solution, which requires Place the test piece and the reference electrode at the bottom of the detection device. As a result, with the passage of landfilling time, the ground surface will naturally settle, and rain erosion will cause the soil at the bottom of the detection device Loss, and then make the contact effect between the reference electrode, cathodic protection test piece, etc. and the soil worse, or even no longer contact, not only can not measure the true cathodic protection potential, but also need to be re-filled continuously, increasing Maintenance cost; at the same time, due to the rapid loss of electrolyte, the service life of the detection device is affected.

Therefore, portable cathodic protection test probes are becoming more and more popular. However, the polarization potential of the buried cathodic protection structure will be affected by the cathodic protection current of the protected body itself, the geomagnetic current, and the current flowing through or flowing into the protected body from other external structures to the ground. However, the existing portable cathodic protection test The probe cannot effectively resist the interference of electric and magnetic fields, and the copper sulfate solution filled inside is easy to penetrate outwards, which not only contaminates the test piece, but also when the copper sulfate solution is replaced/added, the copper electrode is exposed to air and oxidizes. The potential shifts and the measurement data error increases.

Summary of the invention

In order to solve the problems of easy interference, copper sulfate solution penetration and copper electrode oxidation in the existing portable cathodic protection test probes, the present invention provides a cathodic protection test probe which adopts hollow cylindrical polarization. The test piece surrounds the test electrode, eliminating the interference of impurity current, and adopts an all solid structure, no leakage, no pollution to the test piece, copper electrode is not oxidized, and the test result is more reliable. The technical problem to be solved by the present invention is realized through the following technical solutions:

A cathodic protection test probe, including an outer cavity, a polarization test piece, an inner cavity, an AC test piece, a copper electrode and a test cable;

The polarization test piece is hollow cylindrical, the polarization test piece is embedded on the outer wall of the outer cavity, and the polarization test piece is fixedly connected to the outer wall of the outer cavity, and the polarization test piece is connected to The outer cavity and the inner cavity are arranged coaxially;

The AC test piece is embedded on the top wall of the outer cavity;

The copper electrode is inserted into the inner cavity of the inner cavity from the center of the bottom of the outer cavity, and the copper electrode and the outer cavity are sealed and fixed;

Copper sulfate crystals are filled between the copper electrode and the inner wall of the inner cavity;

The three wires in the test cable are respectively connected with the copper electrode, the polarization test piece and the AC test piece.

Further, a cavity filled with micro-permeable filler is provided between the top of the inner cavity and the top of the outer cavity, and the cavity is in communication with the inner cavity.

Further, the top of the AC test strip is flush with the outer side of the top wall of the outer cavity.

Further, the material of the outer cavity is polyvinyl chloride or polymethyl methacrylate.

Further, the outer wall of the polarized test piece is flush with the outer wall of the outer cavity.

The beneficial effects of the present invention:

1. The cathodic protection test probe of the present invention uses a hollow cylindrical polarized test piece to surround the test electrode, which eliminates the voltage drop between the electrode and the test piece caused by the stray current in the soil, and has the advantage of eliminating the interference of impurity current ；

2. The cathodic protection test probe of the present invention adopts an all-solid structure, has no leakage, does not pollute the test piece, and the test result is more reliable;

3. The cathodic protection test probe of the present invention adopts an all-solid sealed structure, no need to replace the copper sulfate solution, and the copper electrode does not need to be cleaned and rusted, and maintenance-free; 4. The cathodic protection test probe of the present invention adopts a sealed structure, and the copper electrode is not oxidized. More stable, higher test accuracy;

5. The cathodic protection test probe of the present invention adopts a standard bare area of 1 square centimeter AC test piece and cylindrical polarization test piece, and with the test instrument, it can simultaneously test the DC power-on potential, power-off potential, DC current, AC voltage, and AC Current measurement, DC current density and AC current density can be obtained by calculation, and the cathodic protection effect, DC interference state, and AC interference state of the protected structure can be evaluated. The structure is small and easy to carry;

6. The cathodic protection test probe of the present invention can obtain different exposed areas of the polarization test piece by changing the length of the cylinder, and has a wide application range.

The present invention will be further described in detail below in conjunction with the drawings and embodiments.

Description of the drawings

Figure 1 is a schematic diagram of the structure of the cathodic protection test probe of this embodiment.

Figure 2 is a bottom view of the cathodic protection test probe of this embodiment.

Figure 3 is a top view of the cathodic protection test probe of this embodiment.

In the figure: 1. Outer cavity; 2. Polarized test piece; 3. Inner cavity; 5. Cavity; 6. AC test piece; 8. Copper sulfate crystal; 9. Copper electrode; 10. Test cable.

Detailed ways

In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose, the specific implementation, structural features and effects of the present invention will be described in detail below with reference to the accompanying drawings and examples.

In order to solve the problems of easy interference and penetration of copper sulfate solution existing in the existing portable cathodic protection test probes, this embodiment provides a cathodic protection test probe. 1, 2 and 3, the cathodic protection test probe includes an outer cavity 1, a polarization test piece 2, an inner cavity 3, an AC test piece 6, a copper electrode 9 and a test cable 10. AC test strips and cylindrical polarization test strips, together with the test instrument, can simultaneously test DC power-on potential, power-off potential, DC current, AC voltage, and AC current measurement. The DC current density and AC current density can be obtained by calculation, and the evaluation is Protection structure cathodic protection effect, DC interference state, AC interference state.

The polarization test strip 2 of this embodiment is a hollow cylinder. The polarization test strip 2 is embedded on the outer wall of the outer cavity. The inner cavity 3 is located inside the outer cavity 1. The polarization test strip 2 and the outer cavity 1 and the inner cavity 3 are arranged coaxially, and the polarized test piece 2 is fixedly connected with the outer wall of the outer cavity 1, and the outer wall of the polarized test piece 2 is arranged flush with the outer wall of the outer cavity 1. The hollow cylindrical polarized test piece is used to surround the test electrode, which eliminates the voltage drop caused by the distance between the electrode and the test piece caused by the stray current in the soil, and has the advantage of eliminating the interference of impurity current. Due to the different coating materials and coating quality of the protected pipeline, test strips of different areas should be selected. The probe of this embodiment can obtain different exposed areas of the polarized test strip by changing the length of the cavity, which has a wide range of applications.

The three wires of the 10 types of test cables are respectively connected to the copper electrode 9, the polarization test piece 2 and the AC test piece 6. The AC test piece 6 is embedded in the top inner side of the outer cavity 1, and the AC test piece 6 and the polarization test piece 2 are respectively led to the bottom of the outer cavity through wires, and three copper electrode wires are connected to the test cable, leading to the outside Cavity for testing.

The copper electrode 9 is inserted into the inner cavity of the inner cavity 3 from the center of the bottom of the outer cavity 1, and the copper electrode 9 is sealed and fixed to the outer cavity 1 and the inner cavity 3, and this embodiment is sealed by a sealant. The copper electrode 9 and the inner wall of the cavity 3 are filled with copper sulfate crystals 8. The cathodic protection test probe adopts a solid-state sealed structure, which avoids the problem of replacing the copper sulfate solution with the existing probe without leakage and pollution. The test specimen will not pollute the copper electrode, and there is no need to clean and remove the rust on the copper electrode, and the test result is more reliable.

A cavity 5 for filling the micro-permeable filler is provided between the top of the inner cavity 3 and the top of the outer cavity 1, and the lower part of the cavity is in communication with the inner cavity 3. The upper part of the cavity is provided with a top cover, which can be opened or closed. The copper sulfate crystals in the inner cavity dissolve to form a copper sulfate solution, and the micro-permeable filler restricts the leakage of the copper sulfate solution to the outside to prevent the leakage of the solution from contaminating the test piece. At the same time, it also slows down the penetration of the external solution into the probe and pollutes the copper sulfate in the probe .

The top of the AC test strip 6 in this embodiment is flush with the outer side of the top wall of the outer cavity 1, and the material of the outer cavity 1 is polyvinyl chloride or polymethyl methacrylate.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention.

Claims

A cathodic protection test probe, which is characterized by comprising an outer cavity (1), a polarization test piece (2), an inner cavity (3), an AC test piece (6), a copper electrode (9) and a test cable ( 10);

The polarization test piece (2) is hollow cylindrical, the polarization test piece (2) is embedded on the outer wall of the outer cavity (1), and the polarization test piece (2) and the outer cavity The outer wall of (1) is fixedly connected, and the polarization test piece (2) is arranged coaxially with the outer cavity (1) and the inner cavity (3);

The AC test piece (6) is embedded in the top inner side of the outer cavity (1);

The copper electrode (9) is inserted into the inner cavity of the inner cavity (3) from the center of the bottom of the outer cavity (1), and the copper electrode (9) is connected to the outer cavity (1) and the inner cavity (3) All sealed and fixed;

Copper sulfate crystals (8) are filled between the copper electrode (9) and the inner wall of the inner cavity (3);

The three wires in the test cable (10) are respectively connected with the copper electrode (9), the polarization test piece (2) and the AC test piece (6).
The cathodic protection test probe according to claim 1, wherein a cavity (5) for filling micro-permeable filler is provided between the top of the inner cavity (3) and the top of the outer cavity (1) , The cavity (5) is in communication with the inner cavity (3).
The cathodic protection test probe according to claim 1, wherein the top of the AC test strip (6) is flush with the outer side of the top wall of the outer cavity (1).
The cathodic protection test probe according to claim 1, wherein the material of the outer cavity (1) is polyvinyl chloride or polymethyl methacrylate.
The cathodic protection test probe according to claim 1, wherein the outer wall of the polarized test piece (2) is flush with the outer wall of the outer cavity (1).