An integrated adaptive impressed current cathodic protection device and method of use thereof

Abstract

The application belongs to the technical field of corrosion protection, and particularly relates to an integrated self-adaptive impressed current cathodic protection device and a use method thereof. The main structure comprises a self-adaptive control module, a power supply communication interface arranged at the top end of the self-adaptive control module, a metal structural part interface arranged at the bottom end of the self-adaptive control module, mounting parts arranged at both ends, and auxiliary electrodes and reference electrodes arranged on the surface. The integrated assembly of an in-situ single-point cathodic protection power supply and auxiliary anodes is adopted to avoid the use of large-section cable transmission of low-voltage large current, so that the driving power supply can be accessed nearby. The self-adaptive testing and calculation method is used to determine the cathodic protection potential, and preset adjustment is not needed. When the cathodic protection is performed on a complex structure, rapid deployment can be realized through simple calculation, and the design calculation time is greatly reduced. Different protection strategies are implemented on different parts of the structural parts made of various metal materials through the separate setting of the cathodic protection potential, and the overall cathodic protection effect is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of corrosion protection, and particularly relates to an integrated self-adaptive impressed current cathodic protection device and a use method thereof, which is suitable for corrosion protection of metal structural members. BACKGROUND

[0002] In a corrosive liquid medium environment, impressed current cathodic protection is an important means of corrosion protection for metal structural members, has advantages of long service life and simple maintenance, and has been widely applied to buried industrial pipelines, marine structures and various marine vessels. The existing impressed current cathodic protection system mainly consists of a cathodic protection power supply, an auxiliary anode and a reference electrode. The basic working principle is to provide direct current by the cathodic protection power supply, the current passes through the auxiliary anode into the corrosive medium, and returns to the metal structural member, so that the metal structural member is cathodically polarized and is effectively inhibited from corrosion when polarized to a certain potential.

[0003] With the rapid increase in the size of metal structures applied in corrosive environments and the dramatic increase in the degree of material diversification of metal structures, different metal structures have diversified needs for impressed current cathodic protection. When offshore platforms, ocean-going ships and other structures are being built, a large amount of time and effort needs to be spent on detailed design and demonstration of impressed current cathodic protection schemes to improve the protection effect of the cathodic protection system. In the shipbuilding industry, as the tonnage of ships gradually increases, larger cathodic protection current is required for large and medium-sized ships, and cathodic protection power supplies with larger output current and higher voltage need to be configured. At the same time, the length of the auxiliary electrode cable also increases greatly. In view of this situation, a distributed ship impressed current cathodic protection system disclosed in Chinese patent 202210287920.0 includes a host computer, a slave computer, an auxiliary electrode and a reference electrode. The host computer is connected to a plurality of slave computers through communication cables. Each slave computer is connected to N auxiliary electrodes and one reference electrode through output cables, where N is a positive integer greater than or equal to 1. The communication cable between the host computer and the slave computer is used for communication between the host computer and the slave computer. The output cable between the slave computer and the auxiliary anode is used for transmitting output current. The output cable between the slave computer and the reference electrode is used for transmitting potential signals. The host computer is an electronic computer capable of intelligent upgrading and is arranged in a general cabin. The control logic of the slave computer adopts open-loop control, i.e., only sending instructions to the slave computer to command the slave computer to work, while receiving the monitoring signals uploaded by the slave computer, real-time summarizing and displaying the operating parameters and monitoring parameters of each slave computer to reflect the working condition and the ship body potential protection condition, and realizing the centralized management function. The slave computer is an electrical device composed of a control unit based on a PID algorithm and a power output unit. The control logic of the control unit includes DSP and PLC. The main components of the power output unit include MOSFET and IGBT. The slave computer adopts integrated and modular design and has potential regulation and DC output functions. The slave computer is arranged in the cabin at the bottom of the ship cabin and receives the instructions of the host computer to work and control the near-end auxiliary anode and reference electrode. The control logic of the slave computer adopts closed-loop control, i.e., executing the commands of the host computer to perform DC output on the auxiliary anode and performing negative feedback through the monitoring potential of the reference electrode to real-time adjust and control the output current. The operation of each slave computer is independent and does not interfere with each other, and the slave computer has a cathodic protection partition control function. The number of auxiliary anodes is selected according to the size of the required protection current of the protected area. The reference electrode has the functions of protection potential monitoring and control signal feedback. The communication protocol used by the external interface of the host computer communication unit includes 485, CAN and Ethernet. The host computer communication unit exchanges information with the upper control platform of the ship power system, real-time monitors the cathodic protection state of the whole ship through the user terminal platform, and realizes the functions of remote control, one-key start and stop and one-key switching. The system has been optimized and improved, but it still needs to set the parameters of the cathodic protection through a total control device, resulting in a large initial investment and complicated operation and maintenance.Therefore, the application discloses an integrated adaptive impressed current cathodic protection device and a use method thereof, so that the impressed current cathodic protection reaches a more optimal application effect and provides technical support for expanding the application range of the impressed current cathodic protection. SUMMARY

[0004] The application aims at overcoming the defects in the prior art, and seeks to design an integrated adaptive impressed current cathodic protection device and a use method thereof, so as to realize intelligent control and operation of the impressed current cathodic protection and reduce the technical threshold of the impressed current cathodic protection in actual working conditions.

[0005] In order to achieve the above-mentioned purpose, the main body structure of the integrated adaptive impressed current cathodic protection device comprises an adaptive control module, a power supply communication interface arranged at the top end of the adaptive control module, a metal structural part interface arranged at the bottom end of the adaptive control module, mounting parts arranged at both ends of the adaptive control module, and auxiliary electrodes and reference electrodes arranged on the surface of the adaptive control module, wherein the reference electrodes can be externally connected through the interface and arranged near the metal structural part.

[0006] The adaptive control module is integrated with a CPU control and storage unit, an input power supply conversion unit, a communication circuit, a high-frequency conversion output unit, a potential current test unit and a rectifier filter unit; the power supply communication interface and the metal structural part interface are watertight interfaces; the auxiliary anode is a non-consumable anode capable of bearing a large current density (parameter value), such as a noble metal oxide or platinum niobium, platinum titanium; the reference electrode comprises a solid silver / silver chloride, silver / halide silver, copper / copper sulfate reference electrode.

[0007] The adaptive control module is an electrical circuit with voltage resistance and waterproof performance, which can work normally in a corrosive medium and has the following functions:

[0008] 1) bidirectional current output capability;

[0009] 2) executing a preset program, controlling current output, carrying out an electrochemical characteristic test based on an open circuit potential, and automatically determining a cathodic protection potential of a current metal structural part to be protected;

[0010] 3) communicating with an upper computer or other modules and executing an issued instruction, and issuing an instruction to other modules;

[0011] 4) storing and recording working states and test measurement data during work, and transmitting the working states and the test measurement data to the upper computer when connected to the upper computer.

[0012] The integrated adaptive impressed current cathodic protection device is used as follows:

[0013] First, according to the area of the metal structure to be protected and the maximum output current of the integrated adaptive impressed current cathodic protection device, the number of integrated adaptive impressed current cathodic protection devices is calculated;

[0014] Then, one or more integrated adaptive impressed current cathodic protection devices are connected in series, and are connected to the power supply or the upper computer and the metal structure through cables respectively;

[0015] Finally, the integrated adaptive impressed current cathodic protection device is arranged near the metal structure to be protected, and the reference electrode is arranged together with the integrated adaptive impressed current cathodic protection device or is arranged at the most critical protection position;

[0016] Among them, the cable is a power or signal cable with water tightness; the power supply provides direct current or alternating current for the integrated adaptive impressed current cathodic protection device; the upper computer is a comprehensive control instrument with a power supply and a control system.

[0017] Compared with the prior art, the integrated adaptive impressed current cathodic protection device is assembled with an in-situ single-point cathodic protection power supply and an auxiliary anode, avoiding the use of large-section cables to transmit low-voltage large current, so that the driving power supply can be accessed nearby, reducing the overall wiring difficulty; then, the self-adaptive test and calculation method is used to determine the cathodic protection potential, without the need for adjustment and presetting, and when cathodic protection is performed on complex structures, rapid deployment can be achieved through simple calculation, greatly reducing the design calculation time, reducing the dependence on the technical ability of maintenance personnel, and reducing the cost; finally, by separately setting the cathodic protection potential, different protection strategies are implemented at different positions of the structure made of multiple metal materials, improving the overall cathodic protection effect, avoiding under-protection or over-protection phenomenon, and having a wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the main structure of the integrated adaptive impressed current cathodic protection device.

[0019] Figure 2 It is a circuit logic schematic diagram of the integrated adaptive impressed current cathodic protection device.

[0020] Figure 3 It is a schematic diagram of the use state of the integrated adaptive impressed current cathodic protection device according to embodiment 1 of the application.

[0021] Figure 4 It is a schematic diagram of the use state of the integrated adaptive impressed current cathodic protection device according to embodiment 2 of the application. PREFERRED EMBODIMENT

[0022] The application will be further described in connection with the accompanying drawings and by way of working examples.

[0023] Example 1

[0024] The main structure of the integrated adaptive impressed current cathodic protection device involved in the present example is shown in Figure 1 Fig. 1, which comprises an adaptive control module 1, equal potential power communication interfaces 2 and 3, a metal structural part interface 4, a mounting part 5, an auxiliary electrode 6 and a reference electrode 7. The adaptive control module 1 is provided at the top end with the equal potential power communication interfaces 2 and 3, at the bottom end with the metal structural part interface 4, at both ends with the mounting part 5, and on the surface with the auxiliary electrode 6 and the reference electrode 7.

[0025] The adaptive control module 1 involved in the present example is shown in Figure 2 Fig. 2, which is integrated with a central processing unit, a direct current carrier communication module, an output control module, a current output module, a potential acquisition module and a power supply module. The central processing unit is bidirectionally connected with the direct current carrier communication module and unidirectionally connected with the output control module. The output control module is unidirectionally connected with the current output module. The current output module is unidirectionally connected with the cathodic protection interface (i.e. the metal structural part interface 4), the auxiliary anode (the auxiliary electrode 6) and the current and voltage acquisition module. The cathodic protection interface is unidirectionally connected with the potential acquisition module. The potential acquisition module is unidirectionally connected with the reference electrode 7 and the central processing unit. The current and voltage acquisition module is unidirectionally connected with the central processing unit. Among them, the central processing unit, the direct current carrier communication module and the power supply module are connected with the equal potential power communication interfaces 2.

[0026] The integrated adaptive impressed current cathodic protection device involved in the present example is used as shown in Figure 3 Fig. 3.

[0027] The equal potential power communication interfaces 2 and 3 are connected with the output interface of the power supply or the upper computer 12 or the equal potential power communication interfaces 2 and 3 of other parallel devices through the cable 11. The metal structural part interface 4 is connected with the protected metal structural part 13.

[0028] After the adaptive control module 1 is started, it first judges whether the environment in which it is located is a medium environment. When it is in a medium environment, it enters a working state. When it is not in a medium environment, it enters a standby state. In the standby state, the adaptive control module 1 judges the environment in which it is located once a minute. If the environment changes to a medium environment, it enters the working state. When it is in the working state, if the output current decreases to 0, it stops outputting and judges the working state.

[0029] In working state: adaptive control module 1 actively sends out broadcast networking request through equal potential power communication interface 2 and 3, judges whether there is host computer 12 connected; if host computer 12 responds, enters controlled working state; if host computer 12 does not respond, enters adaptive working state; when other adaptive control modules 1 respond, according to set rules, one adaptive control module 1 is determined as master control adaptive control module 1, and other adaptive control modules 1 automatically become auxiliary adaptive control modules 1; in adaptive working state, after adaptive control module 1 receives control signal of host computer 12, it enters controlled working state.

[0030] In adaptive working state, adaptive control module 1 automatically determines cathodic protection potential according to the following working sequence:

[0031] 1) In-network adaptive control module 1 performs cyclic linear polarization test according to preset program in sequence, determines self-corrosion potential E0 of metal structural member 13 in current adaptive control module 1 range, sets E1=E0-XmV, wherein E1 is cathodic protection potential, X is potential offset value, and according to material system selection of metal structural member 13, it is specifically 100-300 (unit: mV);

[0032] 2) Dynamic potential polarization is performed with E0-5mV and E0-15mV as potential boundary respectively, polarization rate is 1mV / min, real-time polarization potential E and corresponding polarization current I are recorded, E-I data is linearly fitted with E as variable, and fitting slope R0 is obtained;

[0033] 3) Dynamic potential polarization is performed with E1 and E1-10mV as potential boundary respectively, polarization rate is 1mV / min, real-time polarization potential E and corresponding polarization current I are recorded, E-I is linearly fitted with E as variable, and fitting slope R1 is obtained;

[0034] 4) If current adaptive control module 1 cannot polarize potential of metal structural member 13 to E1, potential +10mV after set time period of full load current output is set as E1, and alarm warning signal is generated and sent to host computer 12 or sent after host computer 12 is connected;

[0035] 5) R0 and R1 are compared, when R0>R1, E1 is set as cathodic protection potential; otherwise, E1=E1+10mV, 3) step and this step are repeated until R0>R1;

[0036] After determining cathodic protection potential, each adaptive control module 1 outputs current according to set cathodic protection potential to perform impressed current cathodic protection;

[0037] When the adaptive control module 1 cannot reach the preset cathodic protection potential in the maximum output state, or the net adaptive control module 1 is damaged and unresponsive, each adaptive control module 1 generates an alarm signal and sends it to the upper computer 12 after being connected.

[0038] Embodiment 2:

[0039] The main structure of the integrated adaptive impressed current cathodic protection device involved in this embodiment is the same as that of embodiment 1, which is used in the liquid tank instead of a sacrificial anode. The maximum demand for cathodic protection current under different coating damage rates is calculated according to the cathodic protection specification, without the need for cathodic protection simulation design and optimization and verification work, greatly reducing the design difficulty. When used, as shown in Figure 4

[0040] 9 integrated adaptive impressed current cathodic protection devices are connected to 1 upper computer 12, which provides 24V 10A DC power and is responsible for receiving cathodic protection data and alarm information. The adaptive control module 1 operates in the adaptive state and is not controlled by the upper computer 12, which improves the poor uniformity of the cathodic protection potential distribution on the surface of the high-strength steel liquid tank wall and the over-protection phenomenon of the cathodic protection potential caused by the good coating of the liquid tank in the early stage of service, greatly reducing the risk of hydrogen embrittlement caused by local over-protection of high-strength steel.

[0041] Among them, the equal potential power communication interface 2 is an equal potential carrier power interface, the metal structural part 13 is a liquid tank, the liquid tank is made of high-strength steel material, and the cathodic protection potential offset value X is 200;

[0042] Due to the complete coating protection of the main structure of the liquid tank in the early stage, the demand for cathodic protection current is very small, and the output is automatically adjusted in steps, with the minimum output current as low as 1 microampere;

[0043] Due to the uniformity of the main structure of the liquid tank and the limited space, the reference electrode 7 is integrated and installed on the adaptive control module 1;

[0044] To reduce the cables 11 and interfaces, 24V DC power supply is used for communication through DC carrier technology, so that the communication signal is transmitted on the power line;

[0045] To reduce the assembly process difficulty, the connection line and the steel mounting foot of the liquid tank are electrically connected in advance;

[0046] To improve the reliability of the adaptive control module 1 in the submerged environment, after debugging, the adaptive control module 1 is sealed and packaged with electronic potting compound.​

Claims

1. An integrated adaptive impressed current cathodic protection device, the main structure comprising an adaptive control module and a power supply communication interface arranged at the top end thereof, a metal structural component interface arranged at the bottom end thereof, mounting components arranged at both ends thereof, and an auxiliary electrode and a reference electrode arranged on the surface thereof, characterized in that, The reference electrode is externally connected through an interface and is arranged near the metal structural member, and the adaptive control module is an electrical circuit with pressure resistance and waterproof performance, which is integrated with a CPU control and storage unit, an input power conversion unit, a communication circuit, a high-frequency conversion output unit, a potential and current test unit and a rectifier filter unit, and the adaptive control module is integrated with a central processor, a direct current carrier communication module, an output control module, a current output module, a potential acquisition module and a power supply module; after the adaptive control module is started, it is firstly determined whether the environment in which the adaptive control module is located is a medium environment; when the adaptive control module is located in the medium environment, the adaptive control module enters a working state, and when the adaptive control module is not located in the medium environment, the adaptive control module enters a standby state; in the standby state, the adaptive control module determines the environment in which the adaptive control module is located once per minute, and when the environment changes to the medium environment, the adaptive control module enters the working state; when the adaptive control module is in the working state, the adaptive control module stops outputting and determines the working state when the output current decreases to 0; when the adaptive control module is in the working state: the adaptive control module actively sends a broadcast networking request through the equal potential power supply communication interface, and determines whether a host computer is connected; when the host computer responds, the adaptive control module enters a controlled working state; when the host computer does not respond, the adaptive control module enters an adaptive working state; when other adaptive control modules respond, one adaptive control module is determined as a master adaptive control module among the online adaptive control modules according to a set rule, and other adaptive control modules automatically become auxiliary adaptive control modules; when the adaptive control module is in the adaptive working state, the adaptive control module enters the controlled working state after receiving a control signal of the host computer.

2. An integrated self-adapting impressed current cathodic protection device according to claim 1, characterized in that, The power supply communication interface and the metal structural member interface are watertight interfaces; the auxiliary electrode is a non-consumable anode; and the reference electrode includes a solid silver / silver chloride electrode, a silver / halide silver electrode and a copper / copper sulfate electrode.

3. An integrated self-adapting impressed current cathodic protection device according to claim 1 or 2, characterized in that, In use: Firstly, the number of the integrated adaptive impressed current cathodic protection devices is calculated according to the area of the metal structural member to be protected and the maximum output current of the integrated adaptive impressed current cathodic protection device; Then, one or more integrated adaptive impressed current cathodic protection devices are connected in series and connected with a power supply or a host computer and a metal structural member through cables; Finally, the integrated adaptive impressed current cathodic protection device is arranged near the metal structural member to be protected, and the reference electrode is arranged together with the integrated adaptive impressed current cathodic protection device or arranged at the most critical protection position.

4. An integrated self-adapting impressed current cathodic protection device according to claim 3, characterized in that, The adaptive control module has the following functions: 1) bidirectional current output capability; 2) executing a preset program, controlling current output, carrying out an electrochemical characteristic test based on an open circuit potential, and automatically determining a cathodic protection potential of the metal structural member to be protected; 3) communicating with a host computer or other modules and executing an issued instruction, and issuing an instruction to other modules; 4) storing and recording working states and test and measurement data during work, and transmitting the working states and the test and measurement data to the host computer when connected to the host computer.

5. An integrated self-adapting impressed current cathodic protection device according to claim 4, characterized in that, The central processor is bidirectionally connected with the direct current carrier communication module, unidirectionally connected with the output control module, the output control module is unidirectionally connected with the current output module, the current output module is unidirectionally connected with the cathodic protection interface, auxiliary electrode and current voltage collection module respectively, the cathodic protection interface is unidirectionally connected with the potential collection module, the potential collection module is unidirectionally connected with the reference electrode and the central processor respectively, and the current voltage collection module is unidirectionally connected with the central processor; the central processor, the direct current carrier communication module and the power supply module are connected with the power supply interface.

6. An integrated self-adapting impressed current cathodic protection device according to claim 3, wherein, The cable is a water-tight power cable or signal cable; the power supply is a direct current or alternating current for the integrated adaptive impressed current cathodic protection device; and the upper computer is a comprehensive control instrument with a power supply and a control system.

7. The integrated adaptive impressed current cathodic protection device according to claim 3, characterized in that, The adaptive control module in the adaptive working state automatically determines the cathodic protection potential according to the following working sequence: 1) The in-net adaptive control module performs cyclic linear polarization test in sequence according to a preset program to determine the self-corrosion potential E0 of the metal structural member in the current adaptive control module range, and sets E1 = E0-XmV, wherein E1 is the cathodic protection potential, X is the potential offset value, and is 100-300 according to the material system of the metal structural member; 2) The potentiodynamic polarization is performed with E0-5mV and E0-15mV as the potential boundary, the polarization rate is 1mV / min, the real-time polarization potential E and the corresponding polarization current I are recorded, and the E-I data is linearly fitted with E as the variable to obtain the fitting slope R0; 3) The potentiodynamic polarization is performed with E1 and E1-10mV as the potential boundary, the polarization rate is 1mV / min, the real-time polarization potential E and the corresponding polarization current I are recorded, and the E-I is linearly fitted with E as the variable to obtain the fitting slope R1; 4) If the current adaptive control module cannot polarize the potential of the metal structural member to E1, the potential +10mV after the set time period of the full load current output is set as E1, and an alarm warning signal is generated and sent to the upper computer or sent after the upper computer is connected; 5) R0 and R1 are compared, when R0>R1, E1 is set as the cathodic protection potential; otherwise, E1=E1+10mV, the step 3) and the step are repeated until R0>R1; After the cathodic protection potential is determined, each adaptive control module outputs current according to the set cathodic protection potential for impressed current cathodic protection; When the adaptive control module cannot reach the preset cathodic protection potential in the maximum output state, or the in-net adaptive control module is damaged and fails to respond, each adaptive control module generates an alarm signal and sends it to the upper computer after being connected.

8. An integrated self-adapting impressed current cathodic protection device according to claim 7, characterized in that, The sacrificial anode is replaced by the cathodic protection in the liquid tank, the maximum demand for the cathodic protection current under different coating damage rates is calculated according to the cathodic protection specification, and the cathodic protection simulation design and optimization and verification are not needed, specifically: Several integrated adaptive impressed current cathodic protection devices are connected with the host computer, the host computer provides DC power and is responsible for receiving cathodic protection data and alarm information, and the adaptive control module operates in the adaptive working state.

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