Device and method for measuring protection potential of inner wall of seawater pipeline based on zinc plug anode

Abstract

The invention belongs to the technical field of seawater pipeline cathode protection potential measurement, and relates to a seawater pipeline inner wall protection potential measurement device and method based on a zinc plug anode, a main body structure comprises a seawater pipeline to be measured, a zinc plug anode arranged on the seawater pipeline, and a measurement module respectively connected with the seawater pipeline to be measured and the zinc plug anode, a trigger, an anode protection loop, a potential measurement loop and a controller are arranged in the measurement module, the trigger is connected with the anode protection loop or the potential measurement loop through an anode terminal, during normal work, a seawater pipeline to be measured is directly connected with a zinc plug anode, the zinc plug anode performs cathode protection on the seawater pipeline to be measured, and the controller is connected with the controller. When a potential measurement signal is manually or automatically triggered, the measurement module disconnects the electric connection between the zinc plug anode and the seawater pipeline to be measured, immediately takes the zinc plug anode as a reference electrode and the seawater pipeline to be measured as a working electrode, accesses a potential measurement loop, reads a protection potential value of the seawater pipeline to be measured at a set time point after delayed depolarization, and finally determines the potential value of the seawater pipeline to be measured according to the protection potential value of the seawater pipeline to be measured. And resetting after the test is finished.

Description

Technical field:

[0001] The present invention belongs to the technical field of seawater pipeline cathodic protection potential measurement, and specifically relates to a seawater pipeline inner wall protection potential measurement device and method based on a zinc plug anode. The invention does not require a hole to be opened on the seawater pipeline to install a reference electrode, and the seawater pipeline protection potential is measured using a zinc plug anode. Background technology:

[0002] Seawater pipelines are an important part of engineering facilities such as ships, offshore platforms, and coastal power plants, and they play an important role in ensuring the normal operation of ship power units, auxiliary machinery, and equipment. Seawater pipeline systems are widely distributed, of many types, difficult to repair and maintain, and most of them are in harsh environments. Therefore, corrosion and leakage problems often occur, seriously affecting the service safety and performance of ships. At present, copper alloys are generally used in seawater pipeline systems and equipment to improve their resistance to seawater corrosion. Even so, corrosion problems of equipment and pipe fittings still often occur in actual applications, affecting the safety of ships and marine engineering facilities. In response to this problem, existing seawater pipeline systems of large ships and marine engineering are generally equipped with sacrificial anodes (such as anti-corrosion zinc plugs) for corrosion protection. For example, Chinese Patent 202410651156.X discloses a quick-installation sacrificial anode device for marine metal corrosion protection, including a sacrificial anode, a mounting base, a signal transmission mechanism, and a centering positioning component arranged on the mounting base; a groove for installing the sacrificial anode is provided on the mounting base; the sacrificial anode is fixed in the groove; the centering positioning component includes a driving push rod, a first limit rod, a transmission connection and two limit clamping assemblies; the first limit rod and the transmission connection can move in the vertical direction under the drive of the driving push rod; the two limit clamping assemblies are respectively arranged at the two end portions of the transmission connection; the clamping ends of the two limit clamping assemblies can move toward each other in the horizontal direction under the drive of the transmission connection; a clamping space for clamping the protected cathode is formed between the first limit rod and the clamping ends of the two limit clamping assemblies; the signal transmission mechanism is arranged in the sacrificial anode for real-time long-distance feedback The installation base is provided with an installation groove; an inner nested tube is embedded in the installation groove; two ends of the inner nested tube are respectively fixed to two ends of the fixed base; the inner nested tube is spaced apart from the inner wall of the installation groove, and the spaced apart space constitutes an installation area for installing a centering positioning component; a clearance groove matching with the clamping end of the centering positioning component is provided on the inner nested tube; the clamping end extends into the inner cavity of the inner nested tube from the clearance groove, and the positioning clamping mechanism also includes a plurality of positioning and fastening structures arranged on the installation base; the positioning and fastening structure includes a rotating handle, a connecting rod and an anti-slip sleeve; the connecting rod is threadedly connected to the corresponding connecting sleeve, and the bottom thereof passes through the outer wall of the connecting sleeve and extends into the inner cavity of the connecting sleeve; the anti-slip sleeve is arranged at the inner end of the connecting rod, and the signal transmission mechanism includes a signal circuit, an information processing module, and a signal transmission module; the information processing module is used to analyze the current change in the signal circuit and obtain the remaining amount of the sacrificial anode; the signal transmission module transmits the information on the remaining amount of the sacrificial anode in the information processing module to the onshore monitoring device.Chinese Patent No. 202420014336.2 discloses an aluminum alloy sacrificial anode protection device for a hull, comprising a hull; two side plates are fixed on the hull, each of the side plates is provided with a slide groove, a first slider is arranged inside the slide groove, the first slider is slidably connected to the slide groove, a bottom plate is arranged between the side plates, one side of the bottom plate is connected to the hull, an anode body is arranged on the side of the bottom plate away from the hull, both ends of the anode body are connected with screws, the screws all pass through the first slider, a nut is arranged at one end of the screw away from the anode body, and one side of the nut is fitted with the first slider; two clamping plates are fixed on the side of the bottom plate away from the hull, one side of the clamping plates is fitted with the anode body, and the side of the side plate away from the hull is rotatably connected with A screw rod is connected to a pressure plate, and the side of the pressure plate away from the screw rod is fitted with the splint, a plurality of elastic components are arranged on the side of the hull close to the bottom plate, and the two ends of the elastic components are respectively connected to the hull and the bottom plate, a second slider is fixed on both sides of the first slider, T-shaped grooves are processed on both sides of the slide groove, the second slider is slidably connected to the T-shaped groove, a notch is processed on the side of the splint away from the bottom plate, the notch is fitted with the screw rod, the cross-section of the pressure plate is an inverted "L" shape, a damper is arranged inside the elastic component, and the two ends of the damper are respectively connected to the hull and the bottom plate, a guide rod is arranged on one side of the screw rod, a turntable is fixed to the guide rod and the end of the screw rod away from the side plate, the pressure plate is slidably connected to the guide rod, and one end of the guide rod is fixed to the pressure plate. Chinese Patent No. 202323537324.2 discloses an embedded sacrificial anode for a ship hull, comprising a hull; a groove is provided on the hull, two ear plates are fixed on one side of the hull, the side of the ear plate away from the hull is rotatably connected with an electric rotating plate, the electric rotating plate corresponds to the groove, an electric telescopic rod is installed inside the groove, a support is fixed at one end of the electric telescopic rod, an anode body is provided on the side of the support away from the electric telescopic rod, and a plurality of bottom plates are fixed on the side of the support away from the anode body; a first elastic component is fixedly connected to the side of the bottom plate close to the anode body, the first elastic component penetrates the support, and the end of the first elastic component away from the bottom plate is fixed to the anode body ; Slide grooves are provided on both sides of the inner wall of the groove, and guide rods are fixed inside the slide grooves. Slide blocks are provided on the guide rods. A second elastic component is fixed on the side of the slide block close to the anode body. The end of the second elastic component away from the slide block is fixed to the anode body. The side of the anode body away from the groove is processed into an arc surface. One side of the electric turntable is fitted with the anode body. The rotation angle of the electric turntable is 90°. Notches are processed on both sides of the anode body. The notches are fixed to the second elastic component. Dampers are provided inside the first elastic component and the second elastic component. One end of the damper is fixed to the anode body. The slide block is slidably connected to the guide rod, and the slide block corresponds to the side of the anode body. It has a good inhibitory effect on the corrosion of the seawater pipeline system. However, due to the small internal space of the seawater pipeline and the limited specifications of the installed anodes, the service life of the zinc plug anode is relatively short. At the end of the service life of the zinc plug anode, the seawater pipeline still has the problem of insufficient protection and the risk of corrosion and leakage.Since the seawater pipeline system is a closed structure, it is impossible to directly check the consumption and service status of the zinc plug anode. In order to evaluate the protection effect of the inner wall of the seawater pipeline, it is often necessary to drill holes in the seawater pipeline to install reference electrodes and measure the protection potential of the seawater pipeline. Commonly used reference electrodes include Ag / AgCl reference electrodes, Cu / CuSO4 reference electrodes and high-purity zinc reference electrodes. Considering that the seawater pipeline is a slender structure with a length of up to hundreds of meters, a large number of reference electrodes need to be installed when testing the potential of the seawater pipeline, which greatly increases the amount of engineering work, and increasing the number of holes will also increase the safety risks of the seawater pipeline. Therefore, at present, no reference electrodes are installed in the seawater pipeline for protection potential monitoring, making it difficult to accurately obtain the actual protection effect of the inner wall of the seawater pipeline. Therefore, a device and method for measuring the inner wall protection potential of a seawater pipeline are developed and designed, and the zinc plug anode is used to measure the protection potential of the seawater pipeline, so that the zinc plug anode can not only play the role of cathodic protection, but also measure the protection potential, so as to solve the structural and safety risks caused by drilling holes and installing reference electrodes in the seawater pipeline. Summary of the invention:

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art, develop and design a seawater pipeline inner wall protection potential measuring device and method based on zinc plug anode, utilize the reference electrode properties of high-purity zinc, and adopt a triggered instantaneous circuit breaking and delayed recording method to measure the protection potential of the seawater pipeline.

[0004] In order to achieve the above-mentioned purpose, the main structure of a seawater pipeline inner wall protection potential measuring device based on a zinc plug anode according to the present invention comprises a seawater pipeline to be measured and a zinc plug anode arranged thereon, and a measuring module connected to the two respectively, wherein the measuring module is built with a trigger, an anode protection circuit, a potential measuring circuit and a controller, and the trigger is connected to the anode protection circuit or the potential measuring circuit through an anode terminal;

[0005] The seawater pipeline to be tested is connected to the measuring module via a pipeline cable, and the zinc plug anode is connected to the measuring module via an anode cable;

[0006] A potentiometer is also provided in the measuring module. The pipeline cable is connected to the anode protection circuit and the potential measurement circuit. The anode cable controls the anode terminal to be connected to the anode protection circuit or the potential measurement circuit through a trigger. The controller communicates with the trigger and the potentiometer provided on the potential measurement circuit to control the potential measurement operation.

[0007] The zinc plug anode of the present invention is made of high-purity zinc material that meets the standard requirements of zinc alloy sacrificial anodes, and the specifications are selected according to the diameter of the seawater pipeline to be tested and with reference to the zinc plug anode design standards;

[0008] Both pipeline cables and anode cables are single-core or multi-core shielded cables with insulating sleeves, with specifications not less than 1mm 2 ;

[0009] The measuring module is packaged as a whole, wherein the trigger is used to control the on / off connection between the anode terminal and the cathode protection circuit and the potential measurement circuit. It is disconnected and connected according to the instructions issued by the controller or manually input, and the switching time point is fed back to the controller; the potentiometer is used to test the potential value between the seawater pipeline to be tested and the zinc plug anode, with an input impedance of not less than 10MΩ, a response time of not more than 1ms, and a potential measurement accuracy of not more than ±1uV; the controller has the functions of setting the measurement timing, timing, storage and display, and records the potential data measured by the potentiometer in real time, and displays and stores it.

[0010] The present invention relates to a method for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode. The method uses the reference electrode properties of high-purity zinc and adopts a triggered instantaneous circuit breaking and delayed recording method to measure the protection potential of the seawater pipeline. The zinc plug anode 2 is automatically or manually triggered to switch between cathodic protection and potential measurement. The specific implementation steps of the measurement method are as follows:

[0011] (I) Installation

[0012] The zinc plug anode is installed on the seawater pipeline to be tested by means of insulation installation, and the seawater pipeline to be tested and the zinc plug anode are connected to the measurement module by pipeline cables and anode cables respectively;

[0013] Among them, the zinc plug anode is installed through an insulating screw sleeve, or is encapsulated with insulating materials and then installed on the seawater pipeline to be tested. After installation, the dry insulation resistance between the seawater pipeline to be tested and the zinc plug anode should not be less than 1MΩ;

[0014] The pipeline cable and anode cable are connected by welding or screw connection to ensure good contact, and the connection points are sealed with insulating resin;

[0015] The measuring module is directly fixed on the seawater pipeline to be tested, or arranged near the seawater pipeline to be tested;

[0016] (ii) Cathodic protection

[0017] When working, the pipeline cable and anode cable are connected to the cathodic protection circuit, the seawater pipeline to be tested is directly electrically connected to the zinc plug anode, and the zinc plug anode plays a cathodic protection role;

[0018] Among them, the main function of the zinc plug anode in normal service is to provide cathodic protection for the seawater pipeline to be tested. In order to achieve a stable protection state for the seawater pipeline to be tested, the zinc plug anode should be operated continuously for more than 24 hours after the initial installation, because the protection potential value measured within 24 hours is not enough to accurately reflect the actual protection effect of the seawater pipeline to be tested;

[0019] (III) Potential measurement

[0020] During measurement, a signal is manually triggered or the controller automatically sends a signal regularly / irregularly according to the test requirements to disconnect the seawater pipeline to be tested from the zinc plug anode, that is, disconnect the connection between the anode terminal and the cathodic protection circuit, and connect the anode terminal to the potential measurement circuit;

[0021] When the signal is manually triggered, the trigger feeds back the triggering time point to the controller, and immediately disconnects the electrical connection between the zinc plug anode and the seawater pipeline to be tested, and switches the anode terminal of the zinc plug anode to the potential measurement circuit;

[0022] When the signal is automatically triggered, the controller automatically records the trigger time point and controls the trigger to switch the wiring;

[0023] (IV) Depolarization

[0024] According to the depolarization behavior of the seawater pipeline to be tested and the zinc plug anode under service conditions, the depolarization time is determined, and the protection potential value of the seawater pipeline to be tested is read and recorded at this time point;

[0025] Among them, for the seawater pipeline to be tested under specific working conditions, a depolarization test is used to determine the appropriate delayed test timing point, and the depolarization behavior of the seawater pipeline to be tested and the zinc plug anode is tested synchronously. When the residual polarization degree (the difference between the polarization potential and the natural potential) of the zinc plug anode is equivalent to the depolarization degree (the difference between the polarization potential and the protection potential before depolarization) of the seawater pipeline to be tested, the potential value of the seawater pipeline to be tested measured by the zinc plug anode is consistent with the actual protection potential value of the seawater pipeline to be tested before depolarization (relative to the zinc reference electrode). This time point is used as the potential measurement timing of the seawater pipeline to be tested, and the controller collects the reading of the potentiometer at this moment as the protection potential value of the seawater pipeline to be tested;

[0026] For different seawater pipeline systems to be tested, the depolarization behavior of the seawater pipeline to be tested and the zinc plug anode is related to the seawater flow rate, temperature, pipe diameter, etc. In addition, the material and surface state (presence or absence of sediment, etc.) of the seawater pipeline to be tested have an impact on the depolarization effect: under the condition of static seawater, the depolarization time point is 1-4s. Under the condition of flowing seawater, the depolarization time tends to decrease with the increase of flow rate. When the flow rate is 1-3m / s, the depolarization time is 0.5-2s.

[0027] (V) Reset

[0028] After the measurement is completed, the seawater pipeline to be tested is electrically reconnected to the zinc plug anode, and the zinc plug anode continues to provide cathodic protection for the seawater pipeline to be tested;

[0029] After the potential test of the seawater pipeline to be tested is completed, the controller re-issues an instruction to control the trigger to disconnect the anode terminal of the zinc plug anode from the potential measurement circuit and reconnect it to the cathodic protection circuit to continue to perform cathodic protection on the seawater pipeline 1 to be tested until the next potential test instruction is triggered;

[0030] In order to keep the seawater pipeline to be tested in a fully protected state, the interval between two adjacent potential measurements of the seawater pipeline to be tested is more than 1 hour.

[0031] Compared with the prior art, the present invention is that during normal operation, the seawater pipeline to be tested is directly connected to the zinc plug anode, and the zinc plug anode performs cathodic protection on the seawater pipeline to be tested. When the potential measurement signal is manually or automatically triggered, the measurement module disconnects the electrical connection between the zinc plug anode and the seawater pipeline to be tested, immediately uses the zinc plug anode as a reference electrode, uses the seawater pipeline to be tested as a working electrode, and connects to a potential measurement circuit. After delayed depolarization, the protection potential value of the seawater pipeline to be tested is read at a set timing point. After the test is completed, the zinc plug anode is directly electrically connected to the seawater pipeline to be tested, and the zinc plug anode plays a cathodic protection role again until the potential measurement signal is triggered next time. The present invention has a simple structure, can utilize the cathodic protection effect of the zinc plug anode, and can directly use the zinc plug anode to accurately measure the protection potential of the inner wall of the seawater pipeline to be tested, thereby avoiding structural damage and safety risks caused by drilling holes in the seawater pipeline to be tested to install reference electrodes. Description of the drawings:

[0032] Figure 1 The present invention is a schematic diagram of the main structure principle of a seawater pipeline inner wall protection potential measuring device based on a zinc plug anode.

[0033] Figure 2 It is a schematic diagram of the potential change of the seawater pipeline 1 to be tested and the zinc plug anode 2 involved in the present invention. Specific implementation method:

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0035] Embodiment 1:

[0036] The main structure of a seawater pipeline inner wall protection potential measuring device based on a zinc plug anode according to this embodiment is as follows: Figure 1 As shown, it includes a seawater pipeline 1 to be tested, a zinc plug anode 2, a pipeline cable 3, an anode cable 4 and a measuring module 5. The zinc plug anode 2 is arranged on the seawater pipeline 1 to be tested, and the seawater pipeline 1 to be tested and the zinc plug anode 2 are connected to the measuring module 5 through the pipeline cable 3 and the anode cable 4 respectively;

[0037] The measuring module 5 has a built-in trigger 6, an anode terminal 7, an anode protection circuit 8, a potential measurement circuit 9, a potentiometer 10 and a controller 11: the trigger 6 is connected to the anode protection circuit 8 or the potential measurement circuit 9 through the anode terminal 7, and the potential measurement circuit 9 is provided with a potentiometer 10;

[0038] The pipeline cable 3 is connected to the anode protection circuit 8 and the potential measurement circuit 9;

[0039] The anode cable 4 connects the trigger 6 , the controller 11 and the potentiometer 10 in series.

[0040] The specific process of the method for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode involved in this embodiment is as follows:

[0041] The seawater pipeline 1 to be tested and the zinc plug anode 2 are installed together by means of insulation installation to ensure complete insulation between the two;

[0042] The seawater pipeline 1 to be tested is connected to the cathodic protection circuit 8 and the potential measurement circuit 9 provided in the measurement module 5 through the pipeline cable 3, and the zinc plug anode 2 is connected to the trigger 6 in the measurement module 5 through the anode cable 4;

[0043] During normal operation, the anode terminal 7 is connected to the cathode protection circuit 8. At this time, the seawater pipeline 1 to be tested is directly connected to the zinc plug anode 2, and the zinc plug anode 2 performs cathodic protection on the seawater pipeline 1 to be tested.

[0044] When measuring the protection potential, the controller 11 sends a signal to control the trigger 6 to disconnect the connection between the anode terminal 7 and the cathode protection circuit 8, and immediately switch to the connection between the anode terminal 7 and the potential measurement circuit 9. This time point is recorded as the trigger point t0;

[0045] After the potential measurement loop 9 is connected, the zinc plug anode 2 acts as a reference electrode, and the potentiometer 10 measures the potential difference between the seawater pipeline 1 to be tested and the zinc plug anode 2. The controller 11 reads the measured value of the potentiometer 10 at a preset time point t' according to the depolarization effect of the seawater pipeline 1 to be tested and the zinc plug anode 2, and records it as the protection potential value of the seawater pipeline 1 to be tested;

[0046] After the measurement is completed, the controller 11 sends a signal again to control the trigger 6 to disconnect the anode terminal 7 from the potential measurement circuit 9, and switch the anode terminal 7 back to the cathode protection circuit 8, so that the zinc plug anode 2 continues to play the role of cathode protection;

[0047] Among them, when measuring the protection potential, according to the trigger signal, the electrical connection between the seawater pipeline 1 to be tested and the zinc plug anode 2 is disconnected, and the potential measurement circuit 9 is immediately connected. However, since the zinc plug anode 2 is polarized when performing cathodic protection, the potential of the zinc plug anode 2 deviates from the natural potential. At this time, it cannot be directly used as a reference electrode for protection potential measurement, and it is necessary to wait for the zinc plug anode 2 to be depolarized; and the time required for the zinc plug anode 2 to reach complete depolarization and restore the potential to the natural potential is relatively long. During this period of time, the seawater pipeline 1 to be tested loses the protection effect of the zinc plug anode 2 and depolarizes synchronously, causing the potential of the seawater pipeline 1 to be tested to deviate from the original protection potential. The potential of the seawater pipeline 1 to be tested measured by the zinc plug anode 2 does not match the actual protection potential. Therefore, it is necessary to select a suitable measurement time according to the depolarization effect of the seawater pipeline 1 to be tested and the zinc plug anode 2, so that both the seawater pipeline 1 to be tested and the zinc plug anode 2 are depolarized. When the residual polarization degree of the zinc plug anode 2 is equivalent to the depolarization degree of the seawater pipeline 1 to be tested, the potential of the seawater pipeline 1 to be tested measured by the zinc plug anode 2 is consistent with the actual protection potential. Selecting this time point can accurately measure the potential of the seawater pipeline 1 to be tested.

[0048] Embodiment 2:

[0049] When the seawater pipeline inner wall protection potential measuring device based on zinc plug anode involved in this embodiment is actually used:

[0050] First, a copper alloy seawater pipeline with a diameter of DN50 and a length of 3m is used as the seawater pipeline 1 to be tested, and the flow rate of normal temperature seawater in the seawater pipeline 1 to be tested is 1m / s;

[0051] Secondly, a zinc plug anode 2 with a specification of Φ16×24mm is insulated and installed in the middle of the seawater pipeline 1 to be tested through a nylon screw sleeve, a pipeline cable 3 is connected to the seawater pipeline 1 to be tested near the zinc plug anode 2, and an anode cable 4 is connected to the top of the zinc plug anode 2;

[0052] In order to test the depolarization effect of the tested seawater pipeline 1 and the zinc plug anode 2 and verify the potential measurement result of the tested seawater pipeline 1, a high-purity zinc reference electrode is installed by drilling a hole opposite to the zinc plug anode 2;

[0053] The zinc plug anode 2 performs cathodic protection on the seawater pipeline 1 to be tested, and operates continuously for more than 24 hours, so that the seawater pipeline 1 to be tested and the zinc plug anode 2 reach a stable polarization state;

[0054] Then, the depolarization test is performed on the seawater pipeline 1 and the zinc plug anode 2. At a certain time point (t0), the connection between the seawater pipeline 1 and the zinc plug anode 2 is disconnected, and the potential changes of the seawater pipeline 1 and the zinc plug anode 2 are immediately recorded synchronously and continuously using a dual-channel electrochemical test system. The results are as follows: Figure 2As shown, before the seawater pipeline 1 to be tested is disconnected from the zinc plug anode 2, the protection potential of the seawater pipeline 1 to be tested is 0.44V (vs. Zn, the same below). After the disconnection, the seawater pipeline 1 to be tested and the zinc plug anode 2 are depolarized, the potential of the seawater pipeline 1 to be tested shifts positively, and the potential of the zinc plug anode 2 shifts negatively. Since the size of the zinc plug anode 2 is relatively small and the polarization degree is large, the depolarization process is fast, while the area of ​​the seawater pipeline 1 to be tested is large, and the depolarization is relatively slow. After about 1.4s, the seawater pipeline 1 to be tested and the zinc plug anode 2 are both depolarized to a certain extent. At this time, the zinc plug anode 2 is used as a reference electrode, and the potential of the seawater pipeline 1 to be tested is measured to be equivalent to the actual protection potential (0.44V) of the seawater pipeline 1 to be tested before depolarization. Therefore, t'=1.4s is selected as the measurement timing of the protection potential of the seawater pipeline 1 to be tested;

[0055] Finally, the seawater pipeline 1 to be tested and the zinc plug anode 2 are connected to the measuring module 5 respectively, and the measuring timing of the measuring module 5 is set to record the potential value 1.4s after being triggered. When measuring the potential, the measuring module 5 automatically triggers the measurement signal at a fixed time or manually triggers the measurement signal. 1.4s after each measurement signal is triggered, the measuring module 5 automatically records the protection potential value of the seawater pipeline 1 to be tested. At the same time, the protection potential of the seawater pipeline 1 to be tested is synchronously measured using a high-purity zinc reference electrode. The measurement results are shown in Table 1:

[0056]

[0057]

[0058] It can be seen that the potential of the seawater pipeline 1 to be tested measured by the zinc plug anode 2 is basically consistent with the potential value of the seawater pipeline 1 to be tested measured by the high-purity zinc reference electrode, and the relative error does not exceed 5%, indicating that the zinc plug anode 2 can accurately evaluate the protection effect of the seawater pipeline 1 to be tested.

Claims

1. A device for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode, characterized in that: The main structure includes a seawater pipeline to be tested, a zinc plug anode arranged thereon, and a measuring module connected to the two respectively. The measuring module is equipped with a trigger, an anode protection circuit, a potential measurement circuit and a controller. The trigger is connected to the anode protection circuit or the potential measurement circuit through the anode terminal. A potentiometer is also arranged in the measuring module. The pipeline cable is connected to the anode protection circuit and the potential measurement circuit. The anode cable is connected to the anode protection circuit or the potential measurement circuit respectively through the trigger to control the anode terminal. The controller communicates with the trigger and the potentiometer arranged on the potential measurement circuit.

2. A seawater pipeline inner wall protection potential measuring device based on zinc plug anode according to claim 1, characterized in that: Utilizing the reference electrode properties of high-purity zinc, the protective potential of the seawater pipeline is measured by using a triggered instantaneous circuit break and delayed recording method. The zinc plug anode is switched between cathodic protection and potential measurement by automatic or manual triggering.

3. A seawater pipeline inner wall protection potential measuring device based on zinc plug anode according to claim 1 or 2, characterized in that: The specific measurement steps are as follows: (I) Installation The zinc plug anode is installed on the seawater pipeline to be tested, and the seawater pipeline to be tested and the zinc plug anode are connected to the measuring module through the pipeline cable and the anode cable respectively; (ii) Cathodic protection During operation, the pipeline cable and anode cable are connected to the cathodic protection circuit, the seawater pipeline to be tested is directly electrically connected to the zinc plug anode, and the zinc plug anode performs cathodic protection; (III) Potential measurement During measurement, a signal is manually triggered or the controller automatically sends a signal regularly / irregularly according to the test requirements to disconnect the seawater pipeline to be tested from the zinc plug anode, and connect the anode terminal to the potential measurement circuit; (IV) Depolarization According to the depolarization behavior of the seawater pipeline to be tested and the zinc plug anode under service conditions, the depolarization time is determined, and the protection potential value of the seawater pipeline to be tested is read and recorded at this time point.

4. The device for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode according to claim 3 is characterized in that: Both pipeline cables and anode cables are single-core or multi-core shielded cables with insulating sleeves, with specifications not less than 1mm 2 .

5. The device for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode according to claim 3 is characterized in that: The measuring module is packaged as a whole, wherein the trigger is used to control the on / off connection between the anode terminal and the cathode protection circuit and the potential measurement circuit. It is disconnected and connected according to the instructions issued by the controller or manually input, and the switching time point is fed back to the controller; the potentiometer tests the potential value between the seawater pipeline to be tested and the zinc plug anode, with an input impedance of not less than 10MΩ, a response time of not more than 1ms, and a potential measurement accuracy of not more than ±1uV; the controller has the functions of setting the measurement timing, timing, storage and display, and records the potential data measured by the potentiometer in real time, and displays and stores it.

6. The device for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode according to claim 3 is characterized in that: In step (i), the zinc plug anode is installed through an insulating screw sleeve, or is encapsulated with an insulating material and then installed on the seawater pipeline to be tested. After installation, the dry insulation resistance between the seawater pipeline to be tested and the zinc plug anode should not be less than 1MΩ; Pipeline cables and anode cables are connected by welding or screws, and the connection points are sealed with insulating resin; The measuring module is directly fixed on the seawater pipeline to be tested, or arranged near the seawater pipeline to be tested.

7. The device for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode according to claim 3 is characterized in that: In step (ii), the main function of the zinc plug anode during normal service is to provide cathodic protection for the seawater pipeline to be tested. The zinc plug anode operates continuously for more than 24 hours after initial installation.

8. The device for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode according to claim 3 is characterized in that: In step (iii), when the signal is manually triggered, the trigger 6 feeds back the triggering time point to the controller, and immediately disconnects the electrical connection between the zinc plug anode and the seawater pipeline to be tested, and switches the anode terminal of the zinc plug anode to the potential measurement circuit; When the signal is automatically triggered, the controller automatically records the trigger time point and controls the trigger to switch the wiring.

9. The device for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode according to claim 3 is characterized in that: In step (iv), a depolarization test is used to determine a suitable delayed test timing point, and the depolarization behaviors of the seawater pipeline to be tested and the zinc plug anode are tested synchronously. When the residual polarization degree of the zinc plug anode is equivalent to the depolarization degree of the seawater pipeline to be tested, the potential value of the seawater pipeline to be tested measured by the zinc plug anode is consistent with the actual protection potential value of the seawater pipeline to be tested before depolarization. This time point is used as the potential measurement timing of the seawater pipeline to be tested, and the controller collects the reading of the potentiometer at this moment as the protection potential value of the seawater pipeline to be tested.

10. The device for measuring the inner wall protection potential of a seawater pipeline based on a zinc plug anode according to claim 3, characterized in that: After the measurement is completed, the seawater pipeline to be tested is electrically reconnected to the zinc plug anode, and the zinc plug anode continues to provide cathodic protection for the seawater pipeline to be tested; the interval between two adjacent potential measurements of the seawater pipeline to be tested is more than 1 hour.

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