Corrosion prevention and control method and system for seawater pipeline

Abstract

The invention discloses a corrosion prevention and control method and system for a seawater pipeline, and relates to the technical field of seawater corrosion prevention. The method comprises the following steps: acquiring basic parameters of an electronic transmission module of each seawater pipeline section, seawater temperature of each seawater pipeline section and basic parameters of each seawater pipeline section; determining a target protection potential of each seawater pipeline section according to the basic parameter of the electron transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, the basic parameter of each seawater pipeline section and a preset potential adjustment algorithm model; and adjusting the potential of each seawater pipeline section according to the target protection potential of each seawater pipeline section. According to the method, the protection potential of each seawater pipeline section of the seawater pipeline can be dynamically adjusted according to the seawater temperature of each seawater pipeline section of the seawater pipeline and the preset potential adjustment algorithm, intelligent anti-corrosion control is achieved, and the method is suitable for ship seawater pipeline application under the polar region environment condition and is wide in application range and high in flexibility.

Description

Technical Field

[0001] The present application relates to the technical field of seawater anti-corrosion, and in particular to a method and system for preventing and controlling corrosion of seawater pipelines. Background Art

[0002] For marine diesel engines, seawater pipelines are exposed to salty seawater, a highly corrosive medium, for a long time and are extremely susceptible to electrochemical corrosion. Therefore, the corrosion prevention and control design of seawater pipelines is the key to the design of diesel engine seawater systems and is of great significance to improving the reliability of diesel engines.

[0003] In seawater anti-corrosion design, cathodic protection is a common technical means of seawater pipeline corrosion prevention and control. Its implementation principle is: by providing a certain amount of electron flow to the protected metal for cathodic polarization, the metal's potential shifts negatively, making it in a thermodynamically stable zone, so as to inhibit the corrosion process of the inner wall of the seawater pipeline. At present, there are two main cathodic protection schemes for seawater pipelines: sacrificial anode scheme and impressed current scheme.

[0004] However, in the application scenario of electrochemical protection of seawater pipelines on ships under polar environmental conditions, the existing cathodic protection system has the following problems: Since the seawater pipelines on ships are long and relatively complex in layout, the sacrificial anode cathodic protection system requires regular replacement of sacrificial anode materials, resulting in a short protection time and high maintenance frequency and cost. When dealing with the above polar environmental conditions, the existing impressed current solution using a constant potentiostat may cause over-protection due to excessive local current density in a short period of time due to its working characteristics of maintaining a constant voltage, causing hydrogen embrittlement near the cathode and causing safety hazards of seawater pipeline leakage. Summary of the invention

[0005] Purpose of the invention: An embodiment of the present application provides a method for preventing and controlling corrosion of seawater pipelines, aiming to overcome the technical problem that existing corrosion prevention and control methods are not suitable for corrosion protection of seawater pipelines under polar environmental conditions; another purpose of an embodiment of the present application is to provide a method and system for preventing and controlling corrosion of seawater pipelines.

[0006] Technical solution: A method for preventing and controlling corrosion of a seawater pipeline described in an embodiment of the present application is applied to a potential regulating device, wherein the seawater pipeline comprises a plurality of seawater pipeline sections; each of the seawater pipeline sections is provided with an electronic transmission module and a temperature detection module;

[0007] The method comprises:

[0008] Acquire basic parameters of the electronic transmission module of each of the seawater pipeline sections, seawater temperature of each of the seawater pipeline sections, and basic parameters of each of the seawater pipeline sections;

[0009] Determine the target protection potential of each seawater pipeline section according to the basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, the basic parameters of each seawater pipeline section and a preset potential adjustment algorithm model;

[0010] And the potential of each seawater pipeline section is adjusted according to the target protection potential of each seawater pipeline section.

[0011] In some embodiments, the target protection potential of each seawater pipeline segment is determined according to the basic parameters of the electronic transmission module of each seawater pipeline segment, the seawater temperature of each seawater pipeline segment, the basic parameters of each seawater pipeline segment and a preset potential adjustment algorithm model, including:

[0012] Determining the current density of each of the seawater pipeline sections according to the seawater temperature of each of the seawater pipeline sections, the basic parameters of the electronic transmission modules of each of the seawater pipeline sections, the basic parameters of each of the seawater pipeline sections, and the first preset protection potential;

[0013] The target protection potential of each seawater pipeline section is determined according to the current density of each seawater pipeline section and the preset potential adjustment algorithm model.

[0014] In some embodiments, the current density of each seawater pipeline segment is determined according to the seawater temperature of each seawater pipeline segment, the basic parameters of the electronic transmission module of each seawater pipeline segment, the basic parameters of each seawater pipeline segment and the first preset protection potential, including:

[0015] Determine the equivalent resistance between the seawater medium and the electronic transmission module corresponding to each seawater pipeline section according to the seawater temperature of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section;

[0016] The current density of each seawater pipeline section is determined according to basic parameters of each seawater pipeline section, equivalent resistance of the seawater medium corresponding to each seawater pipeline section and the electronic transmission module, and the first preset protection potential.

[0017] In some embodiments, determining the equivalent resistance between the seawater medium and the electronic transmission module corresponding to each seawater pipeline segment according to the seawater temperature of each seawater pipeline segment and the basic parameters of the electronic transmission module of each seawater pipeline segment includes:

[0018] Determining the conductivity of the seawater medium of each of the seawater pipeline sections according to the seawater temperature of each of the seawater pipeline sections;

[0019] The equivalent resistance of the seawater medium corresponding to each seawater pipeline section and the electronic transmission module is determined according to the conductivity of the seawater medium of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section.

[0020] In some embodiments, determining the conductivity of the seawater medium of each of the seawater pipeline sections according to the seawater temperature of each of the seawater pipeline sections includes:

[0021] Determining the seawater salinity of each of the seawater pipeline sections according to the seawater temperature of each of the seawater pipeline sections;

[0022] The conductivity of the seawater medium of each of the seawater pipeline sections is determined according to the seawater temperature of each of the seawater pipeline sections and the seawater salinity of each of the seawater pipeline sections.

[0023] In some embodiments, determining the seawater salinity of each of the seawater pipeline sections according to the seawater temperature of each of the seawater pipeline sections includes:

[0024] Determining whether the seawater temperature of each of the seawater pipeline sections is greater than a preset temperature;

[0025] If there is a seawater temperature of the seawater pipeline section that is greater than the preset temperature, the seawater salinity of the seawater area where the seawater pipeline section corresponding to the seawater temperature greater than the preset temperature is currently located is used as the seawater salinity of the seawater pipeline section corresponding to the seawater temperature greater than the preset temperature;

[0026] If there is a seawater pipe section whose seawater temperature is less than or equal to the preset temperature, the seawater salinity of the seawater pipe section corresponding to the preset temperature is determined according to a preset salinity mathematical model.

[0027] In some embodiments, the calculation formula of the preset salinity mathematical model is:

[0028] S=a 0 + 1 T+a 2 T 2 +P

[0029] Wherein, S is the salinity of the seawater in each of the seawater pipeline sections; t is the seawater temperature in each of the seawater pipeline sections; a 0 、a 1 、a 2 , b are polynomial coefficients; P is the sea water pressure.

[0030] In some embodiments, the calculation formula for determining the conductivity of the seawater medium of each seawater pipeline section according to the seawater temperature of each seawater pipeline section and the seawater salinity of each seawater pipeline section is:

[0031]

[0032] Wherein, σ is the conductivity of the seawater medium of each of the seawater pipeline sections; S is the seawater salinity of each of the seawater pipeline sections; and T is the seawater temperature of each of the seawater pipeline sections.

[0033] In some embodiments, the basic parameters of the electron transmission module of each of the seawater pipeline segments include: the radius and length of the electron transmission module;

[0034] The calculation formula for determining the equivalent resistance between the seawater medium and the electronic transmission module corresponding to each seawater pipeline section according to the conductivity of the seawater medium of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section is:

[0035]

[0036] Wherein, R is the equivalent resistance between the seawater medium corresponding to each of the seawater pipeline sections and the electronic transmission module; σ is the conductivity of the seawater medium of each of the seawater pipeline sections; L a is the length of the electronic transmission module; d a is the radius of the electron transport module.

[0037] In some embodiments, the basic parameters of each of the seawater pipeline segments include: the inner diameter and length of the seawater pipeline segment;

[0038] The calculation formula for determining the current density of each seawater pipeline section according to the basic parameters of each seawater pipeline section, the equivalent resistance of the seawater medium corresponding to each seawater pipeline section and the electronic transmission module, and the first preset protection potential is:

[0039]

[0040] Among them, J 1 is the current density of each seawater pipeline segment; R is the equivalent resistance between the seawater medium corresponding to each seawater pipeline segment and the electronic transmission module; d is the inner diameter of each seawater pipeline segment; L is the length of each seawater pipeline segment; U 1 The first preset protection potential.

[0041] In some embodiments, the calculation formula for determining the target protection potential of each seawater pipeline segment according to the current density of each seawater pipeline segment and the preset potential adjustment algorithm model is:

[0042]

[0043] Wherein, U is the target protection potential of each seawater pipeline segment; R is the equivalent resistance between the seawater medium corresponding to each seawater pipeline segment and the electronic transmission module; J 1 is the current density of each seawater pipeline section; J 0 is the preset current density; d is the inner diameter of each of the seawater pipeline sections; and L is the length of each of the seawater pipeline sections.

[0044] Accordingly, in a corrosion prevention and control system for a seawater pipeline described in an embodiment of the present application, the seawater pipeline includes a plurality of seawater pipeline segments; the system includes: a potential regulating device, an electronic transmission module and a temperature detection module; wherein the potential regulating device is provided with a first connection end and a second connection end; the first connection end is electrically connected to the electronic transmission module; each of the seawater pipeline segments is provided with an electronic transmission module and a temperature detection module; each of the temperature detection modules is used to detect the seawater temperature in the corresponding seawater pipeline segment; the outer wall of each of the seawater pipeline segments is electrically connected to the second connection end; wherein each of the seawater pipeline segments is insulated from the corresponding electronic transmission module;

[0045] Wherein, each of the seawater pipeline segments, the corresponding electronic transmission module and the corresponding seawater medium, and the potential regulating device each form a corresponding closed loop;

[0046] The potential regulating device is electrically connected to the temperature detection module, and the potential regulating device is used to execute the corrosion prevention and control method for the seawater pipeline as described above.

[0047] In some embodiments, the corrosion prevention and control system for the seawater pipeline further includes a reference electrode; each of the seawater pipeline segments is further provided with a reference electrode; a first end of the reference electrode is electrically connected to the corresponding seawater pipeline segment, and a second end of the reference electrode is electrically connected to the potential regulating device, and each reference electrode is used to detect the actual potential of the corresponding seawater pipeline segment and send it to the potential regulating device;

[0048] The potential regulating device is configured to regulate the potential of each of the seawater pipeline sections according to the target protection potential and the actual potential of each of the seawater pipeline sections.

[0049] In some embodiments, the potential regulating device further includes: a control module, a communication module and a power supply module; wherein the communication module and the power supply module are both electrically connected to the control module; and the control module is electrically connected to each of the temperature detection modules.

[0050] Beneficial effect: Compared with the prior art, the corrosion prevention and control method and system of the seawater pipeline of the embodiment of the present application comprises: obtaining the basic parameters of the electronic transmission module of each of the seawater pipeline sections, the seawater temperature of each of the seawater pipeline sections and the basic parameters of each of the seawater pipeline sections; determining the target protection potential of each of the seawater pipeline sections according to the basic parameters of the electronic transmission module of each of the seawater pipeline sections, the seawater temperature of each of the seawater pipeline sections, the basic parameters of each of the seawater pipeline sections and the preset potential adjustment algorithm model; and adjusting the potential of each of the seawater pipeline sections according to the target protection potential of each of the seawater pipeline sections. The corrosion prevention and control method of the seawater pipeline provided by the present application can dynamically adjust the protection potential of each of the seawater pipeline sections of the seawater pipeline according to the seawater temperature of each of the seawater pipeline sections of the seawater pipeline and the preset potential adjustment algorithm, thereby realizing intelligent anti-corrosion control of the seawater pipeline, so that the seawater pipeline can be applied to ship seawater pipeline applications under polar environmental conditions. The method can be applied to seawater application scenarios in different regions and different flow states, and has a wide range of application and strong flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0052] Figure 1 It is a principle structure diagram of a corrosion prevention and control system for seawater pipelines provided in an embodiment of the present application;

[0053] Figure 2 It is a principle structure diagram of another corrosion prevention and control system for seawater pipelines provided in an embodiment of the present application;

[0054] Figure 3 It is a structural schematic diagram of a corrosion prevention and control system for seawater pipelines provided in an embodiment of the present application;

[0055] Figure 4 It is a flow chart of a method for preventing and controlling corrosion of seawater pipelines provided in an embodiment of the present application;

[0056] Figure 5 It is an overall outflow schematic diagram of a corrosion prevention and control method for a seawater pipeline provided in an embodiment of the present application;

[0057] Figure 6 It is a schematic diagram of the installation of a corrosion prevention and control system for a seawater pipeline provided in an embodiment of the present application.

[0058] Reference numerals:

[0059] 11-first seawater pipeline section; 12-first electron transmission module; 13-first seawater medium; 14-first temperature detection module; 15-first reference electrode; 21-second seawater pipeline section; 22-second electron transmission module; 23-second seawater medium; 24-second temperature detection module; 25-second reference electrode; 100-potential adjustment device. DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0061] It should be understood that although the terms first, second, etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another component. Therefore, the first component discussed below can be referred to as the second component without departing from the teachings of the concepts of the present application. As used herein, the term "and / or" includes any one of the associated listed items and all combinations of one or more.

[0062] Those skilled in the art will appreciate that the drawings are only schematic diagrams of example embodiments and may not be to scale. The modules or processes in the drawings are not necessarily required to implement the present application and therefore cannot be used to limit the scope of protection of the present application.

[0063] For marine diesel engines, seawater pipelines are exposed to salty seawater, a highly corrosive medium, for a long time and are extremely susceptible to electrochemical corrosion. Therefore, the corrosion prevention and control design of seawater pipelines is the key to the design of diesel engine seawater systems and is of great significance to improving the reliability of diesel engines.

[0064] In seawater corrosion protection design, cathodic protection is a common technical means of seawater pipeline corrosion prevention and control. Its implementation principle is: by providing a certain amount of electron flow to the protected metal for cathodic polarization, the metal's potential shifts negatively, making it in a thermodynamically stable zone, so as to inhibit the corrosion process of the inner wall of the seawater pipeline. At present, there are two main cathodic protection schemes for seawater pipelines: sacrificial anode scheme and impressed current scheme. However, in the application scenario of electrochemical protection of ship seawater pipelines in polar environmental conditions, the existing cathodic protection system has the following problems:

[0065] 1) For the sacrificial anode cathodic protection system, which is the most widely used at present, the corrosion of metal materials can be effectively suppressed by connecting sacrificial anode materials, and it has the advantages of easy installation and maintenance. However, the ship's seawater pipeline is long and the layout is relatively complex. The use of the sacrificial anode cathodic protection system requires regular replacement of the sacrificial anode material, the protection time is short, and the maintenance frequency and cost are high. The existing patented technical solutions mainly improve the protection effect of the cathodic protection system by improving the structural design and layout of the sacrificial anode on the protected metal pipe, and improve the intuitiveness and convenience of the sacrificial anode maintenance (such as patent CN113913831A / B, patent CN108728851A, etc.). However, it cannot solve the maintenance cycle and cost problems of long pipelines, and is not suitable for electrochemical protection of polar ship seawater pipelines.

[0066] 2) For the impressed current cathodic protection system, the existing scheme mainly monitors and maintains the low potential of the seawater pipeline through a constant potential instrument. However, relevant data show that in the case of polar winter navigation, the seawater temperature is between -2 and 4 ° C, which has reached the freezing point of seawater (about -1.8 ° C). If the seabed gate does not have a special heating and deicing device or the device fails, the seawater entering the seawater system will present a seawater-ice crystal two-phase flow state. At this time, the salt precipitated from the ice crystal phase will increase the salinity of the seawater, thereby increasing the local conductivity of the seawater pipeline (for example: when the ice content IPF increases from 0% (single-phase flow) to 10%, the seawater salinity increases by about 11%, and the current density increases by about 9.97%). When dealing with the above situation, the existing impressed current scheme using a constant potential instrument may form over-protection due to excessive local current density in a short period of time due to its working characteristics of maintaining a constant voltage, causing hydrogen embrittlement near the cathode, causing a safety hazard of leakage in the seawater pipeline. For example, in patent CN117364087A, a metal pipe network anti-corrosion system is formed by setting a number of cathode contacts and a constant potential meter paired with it to solve the problem of seawater pipeline corrosion. However, the number of equipment required is large, the sampling accuracy requirement is high, and the overall use and maintenance cost of the system is huge. In patent CN111254443A, on the basis of the original external current protection system, a seawater pipeline stray current detection device is added to further improve the pipeline anti-corrosion performance. In patent CN106086900A, for structures such as hulls and rudders, a protection voltage control scheme combining a constant potential meter device with a fuzzy PID control method is proposed based on actual marine environmental factors, but it is limited to adjustment within the preset voltage value range, and cannot consider the seawater-ice crystal two-phase flow state under polar environmental conditions.

[0067] In view of this, the embodiments of the present application provide a corrosion prevention and control method and system for seawater pipelines, which can realize intelligent anti-corrosion control of seawater pipelines, so that seawater pipelines can be suitable for ship seawater pipeline applications under polar environmental conditions.

[0068] Figure 1This is a principle structure diagram of a corrosion prevention and control system for seawater pipelines provided in an embodiment of the present application. Figure 1 , the seawater pipeline includes several seawater pipeline sections; the system includes: a potential regulating device 100, an electronic transmission module and a temperature detection module; wherein the potential regulating device 100 is provided with a first connection end A1 and a second connection end A2; the first connection end A1 is electrically connected to the electronic transmission module; an electronic transmission module and a temperature detection module are provided in each seawater pipeline section; each temperature detection module is used to detect the seawater temperature in the corresponding seawater pipeline section; the outer wall of each seawater pipeline section is electrically connected to the second connection end A2; wherein each seawater pipeline section is insulated from the corresponding electronic transmission module; wherein each seawater pipeline section, and its corresponding electronic transmission module The transmission module and the corresponding seawater medium, as well as the potential regulating device 100 each form a corresponding closed loop; the potential regulating device is electrically connected to the temperature detection module, and the potential regulating device is used to obtain the basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, and the basic parameters of each seawater pipeline section; determine the target protection potential of each seawater pipeline section according to the basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, the basic parameters of each seawater pipeline section, and a preset potential regulation algorithm model; and adjust the potential of each seawater pipeline section according to the target protection potential of each seawater pipeline section.

[0069] Among them, the first connection terminal A1 and the second connection terminal A2 are electrodes of the potential adjustment device. Exemplarily, the first connection terminal A1 is the positive electrode of the device (electrons flow in), and the second connection terminal A2 is the negative electrode of the device (electrons flow out). Conversely, it is also possible, and it can be specifically set according to actual conditions, and no specific limitation is made here. Exemplarily, in the technical solution of the embodiment of the present application, the first connection terminal A1 is the positive electrode of the device, and the second connection terminal A2 is the negative electrode of the device for illustration (the same below, no further description).

[0070] Among them, the seawater pipeline is usually relatively long. In order to achieve comprehensive and reliable anti-corrosion control of the seawater pipeline, the seawater pipeline is provided with several seawater pipeline sections. Figure 1 , Figure 1 It is shown that the seawater pipeline comprises a first seawater pipeline section 11 and a second seawater pipeline section 21 .

[0071] Each seawater pipeline segment is provided with an electronic transmission module and a temperature detection module. Each temperature detection module is electrically connected to the potential adjustment device 100. Each temperature detection module is used to detect the seawater temperature in the corresponding seawater pipeline segment and send it to the potential adjustment device 100. For example, see Figure 1, a first electronic transmission module 12 is arranged in the first seawater pipeline section 11, and a second electronic transmission module 22 is arranged in the second seawater pipeline section 21. Among them, the first electronic transmission module 12 is insulated from the first seawater pipeline section 11, and the first electronic transmission module 12 is in contact with the first seawater medium 13 in the first seawater pipeline section 11, and is electrically connected to the first connection end A1. The first seawater medium 13 is stored in the first seawater pipeline section 11, and the outer wall of the first seawater pipeline section 11 is electrically connected to the second connection end A2, thereby forming a first closed loop L1 between the first seawater pipeline section 11, the first seawater medium 13, the first electronic transmission module 12 and the potential regulating device 100. Therefore, a current is applied to the first seawater pipeline section 11 through the first closed loop L1, making it a cathode, thereby reducing or preventing the occurrence of corrosion reaction in the first seawater pipeline section 11, thereby achieving corrosion prevention and control of the first seawater pipeline section 11.

[0072] Similarly, the second electronic transmission module 22 is insulated from the second seawater pipeline section 21, and the second electronic transmission module 22 is in contact with the second seawater medium 23 in the second seawater pipeline section 21, and is electrically connected to the first connection end A1. The second seawater medium 23 is stored in the second seawater pipeline section 21, and the outer wall of the second seawater pipeline section 21 is electrically connected to the second connection end A2, thereby forming a second closed loop L2 between the second seawater pipeline section 21, the second seawater medium 23, the second electronic transmission module 22 and the potential regulating device 100. Thus, current is applied to the second seawater pipeline section 21 through the second closed loop L2, making it a cathode, thereby reducing or preventing the occurrence of corrosion reaction in the second seawater pipeline section 21, thereby achieving corrosion prevention and control of the second seawater pipeline section 21.

[0073] Among them, a first temperature detection module 14 is provided in the first seawater pipeline section 11, and the first temperature detection module 14 is used to detect the temperature of the first seawater medium in the first seawater pipeline section 11 and send it to the potential adjustment device 100. A second temperature detection module 24 is provided in the second seawater pipeline section 21, and the second temperature detection module 24 is used to detect the temperature of the second seawater medium in the second seawater pipeline section 21 and send it to the potential adjustment device 100. The potential adjustment device 100 is used to calculate the target protection potential of the first seawater pipeline section 11 according to the seawater temperature of the first seawater medium 13, the basic parameters of the first seawater pipeline section 11, the basic parameters of the first electronic transmission module 12 and the preset potential adjustment algorithm model, thereby dynamically adjusting the protection potential of the first seawater pipeline section 11 according to the real-time seawater temperature of the first seawater pipeline section 11, so that the protection potential of the first seawater pipeline section 11 is controlled at a reasonable potential, and the current of the first closed loop L1 is controlled within a reasonable range, so as to realize intelligent anti-corrosion control of the first seawater pipeline section 11.

[0074] Similarly, the potential regulating device 100 is also used to calculate the target protection potential of the second seawater pipeline section 21 according to the seawater temperature of the second seawater medium 23, the basic parameters of the second seawater pipeline section 21, the basic parameters of the second electronic transmission module 22, and the preset potential regulation algorithm model, thereby dynamically adjusting the protection potential of the second seawater pipeline section 21 according to the real-time temperature of the seawater in the second seawater pipeline section 21, so that the protection potential of the second seawater pipeline section 21 is controlled at a reasonable potential, so that the current of the second closed loop L2 is controlled within a reasonable range, and the intelligent anti-corrosion control of the second seawater pipeline section 21 is realized. Thus, the protection potential of each seawater pipeline section in the seawater pipeline can be intelligently controlled to control it at a reasonable potential, and the intelligent anti-corrosion control of each customs pipeline can be realized, so that the seawater pipeline can be applied to the ship seawater pipeline application under polar environmental conditions, and its application range is wide, and it can be applied to seawater application scenarios in different regions and different flow states. Compared with the prior art, there is no need for complex layout, the implementation method is simple and reliable, easy to maintain, and low cost.

[0075] The seawater pipeline may be a metal water pipe, etc., which may be specifically configured according to actual conditions and is not specifically limited here.

[0076] The basic parameters of the seawater pipeline section include basic dimensions of the seawater pipeline section, such as the length and radius of the seawater pipeline section, which can be set according to actual conditions and are not specifically limited here.

[0077] Exemplarily, the electron transport module may be an auxiliary anode, wherein the material of the auxiliary anode may be a titanium-based metal oxide anode material.

[0078] Exemplarily, the basic parameters of the electronic transmission module include the shape and size of the electronic transmission module, such as length and radius, etc., which can be set according to actual conditions and are not specifically limited here.

[0079] Exemplarily, the temperature detection module may be a temperature sensor, which may be specifically configured according to actual conditions and is not specifically limited herein.

[0080] The technical solution of the embodiment of the present application provides a corrosion prevention and control system for seawater pipelines. The corrosion prevention and control system of the seawater pipeline comprises: a potential regulating device, an electronic transmission module and a temperature detection module; wherein the potential regulating device is provided with a first connection end and a second connection end; the first connection end is electrically connected to the electronic transmission module; an electronic transmission module and a temperature detection module are provided in each seawater pipeline section; each temperature detection module is used to detect the seawater temperature in the corresponding seawater pipeline section; the outer wall of each seawater pipeline section is electrically connected to the second connection end; wherein each seawater pipeline section is insulated from the corresponding electronic transmission module; wherein each seawater pipeline section, its corresponding electronic transmission module and the corresponding seawater medium, and the potential regulating device each form a corresponding closed loop; the potential regulating device is electrically connected to the temperature detection module, and the potential regulating device is used to obtain the basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section and the basic parameters of each seawater pipeline section; according to the basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, the basic parameters of each seawater pipeline section and the preset potential regulation algorithm model, the target protection potential of each seawater pipeline section is determined; and the potential of each seawater pipeline section is adjusted according to the target protection potential of each seawater pipeline section. Therefore, the system can achieve the following: by setting a potential regulating device and setting an electronic transmission module in each seawater pipeline segment, a corresponding closed loop is formed in each seawater pipeline segment, and thus a current can be applied to each corresponding seawater pipeline segment through the closed loop corresponding to each seawater pipeline segment, making it a cathode, thereby reducing or preventing the occurrence of corrosion reactions in each seawater pipeline segment, and achieving corrosion prevention and control of each seawater pipeline segment. In addition, by setting a temperature detection module in each seawater pipeline segment, it is possible to dynamically adjust the protection potential of each seawater pipeline segment according to the real-time temperature of each seawater pipeline segment, so that its potential is controlled at a reasonable potential, so that the current of each closed loop is controlled within a reasonable range, and then realize intelligent anti-corrosion control of each seawater pipeline segment. Therefore, it is possible to realize intelligent control of the protection potential of each seawater pipeline segment in the seawater pipeline, so that it is controlled at a reasonable potential, and realize intelligent anti-corrosion control of each customs pipeline, so that the seawater pipeline can be suitable for ship seawater pipeline applications under polar environmental conditions.

[0081] It has a wide range of applications and can be applied to seawater application scenarios in different regions and under different flow states. Compared with the existing technology, it does not require complicated layout, and the implementation method is simple and reliable, easy to maintain, and low in cost.

[0082] Figure 2 This is a schematic diagram of another corrosion prevention and control system for seawater pipelines provided in the embodiments of the present application. Figure 2The corrosion prevention and control system for the seawater pipeline also includes a reference electrode; each seawater pipeline segment is also provided with a reference electrode; the first end of the reference electrode is electrically connected to the corresponding seawater pipeline segment, and the second end of the reference electrode is electrically connected to the potential regulating device, and each reference electrode is used to detect the actual potential of the corresponding seawater pipeline segment and send it to the potential regulating device; the potential regulating device is configured to: adjust the potential of each seawater pipeline segment according to the target protection potential and the actual potential of each seawater pipeline segment.

[0083] Each seawater pipeline segment is also provided with a reference electrode. Figure 2 , the first seawater pipeline section 11 is provided with a first reference electrode 15, and the second seawater pipeline section 21 is provided with a second reference electrode 25. The first end of the first reference electrode 15 is electrically connected to the first seawater pipeline section 11, and the second end of the first reference electrode 15 is electrically connected to the potential regulating device 100. The first reference electrode 15 is used to detect the actual potential of the first seawater pipeline section 11, so that the potential regulating device 100 regulates the potential of the first seawater pipeline section 11 to the target protection potential according to the target protection potential and the actual potential of the first seawater pipeline section 11. The first end of the second reference electrode 25 is electrically connected to the second seawater pipeline section 21, and the second end of the second reference electrode 25 is electrically connected to the potential regulating device 100. The second reference electrode 25 is used to detect the actual potential of the second seawater pipeline section 21, so that the potential regulating device 100 regulates the potential of the second seawater pipeline section 21 to the target protection potential according to the target protection potential and the actual potential of the second seawater pipeline section 21.

[0084] Exemplarily, the reference electrode may be a silver / silver chloride electrode, which can measure a potential in the range of about -1.05 to -0.80 V.

[0085] In some embodiments, please refer to Figure 2 The potential regulating device 100 further includes: a control module 101, a communication module 102 and a power supply module 103; wherein the communication module 102 and the power supply module 103 are both electrically connected to the control module 101; and the control module 101 is electrically connected to each temperature detection module.

[0086] The control module 101 is a cathode protection control module. For example, the control module 101 can be a control chip such as a single chip microcomputer, which can be specifically configured according to actual conditions and is not specifically limited here.

[0087] Among them, the communication module 102 is a seawater system communication module, which is used to receive real-time data from the seawater system of the polar ship, including the rotation speed of the seawater pump, the flow rate of each section of the seawater pipeline, the inlet temperature of the seawater gate and the central cooler, and transmit it to the cathodic protection control module (i.e., the control module 101).

[0088] The power supply module 103 is used to supply power to various components in the potential adjustment device 100. Exemplarily, the power supply module 103 is a direct current power supply.

[0089] It should be noted that in the technical solution of the embodiment of the present application, the seawater pipeline of the ship diesel engine is provided with several seawater pipeline sections, and accordingly, a temperature detection module and an electronic transmission module can be provided at each seawater pipeline section. Moreover, the electronic transmission module at each seawater pipeline section forms a closed loop with the corresponding seawater medium, the corresponding seawater pipeline section and the potential regulating device. Each seawater pipeline section can achieve its own corrosion protection through its own closed loop. And the temperature detection module at each seawater pipeline section is used to detect the seawater temperature of the corresponding seawater pipeline section and send it to the potential regulating device 100. The potential regulating device 100 can dynamically adjust the protection potential of the corresponding seawater pipeline section according to the seawater temperature of each seawater pipeline section, thereby realizing intelligent adjustment of the potential of each seawater pipeline section.

[0090] Figure 3 Schematic diagram of the structure of a corrosion prevention and control system for a seawater pipeline provided in an embodiment of the present application. For example, in the technical solution of the embodiment of the present application, the potential adjustment of one of the seawater pipeline sections is used as an example for explanation (the same below, no further description). Figure 3 The corrosion prevention and control system of the seawater pipeline is composed of a potential regulating device, an auxiliary anode (i.e., an electronic transmission module), a protected metal pipe section (i.e., a seawater pipeline section), a seawater medium, and a reference electrode. The positive electrode of the potential regulating device is connected to the auxiliary anode through a cable, and the negative electrode of the potential regulating device is connected to the protected metal pipe section through a cable; the auxiliary anode is in contact with the seawater medium in the protected metal pipe section and is insulated from the protected metal pipe section. Among them, the potential regulating device, the auxiliary anode, the seawater medium, and the protected metal pipe section form a closed loop. In addition, the protected metal pipe section is in contact with the reference electrode, and the reference electrode is connected to the potential detection end of the cathodic protection control module. Among them, the potential regulating device is composed of a DC power supply, a cathodic protection control module, a seawater system communication module, and a seawater pipeline temperature sensor group (i.e., a temperature detection module). Among them, the DC power supply is connected to the cathodic protection control module to supply DC power to the potential regulating device. The seawater system communication module is connected to the cathodic protection control module and the sensor network of the polar ship seawater system to receive the monitoring data of the seawater cooling system and transmit it to the cathodic protection control module. The seawater temperature sensor group is connected to the cathodic protection control module to monitor the local temperature of the seawater in each section of the seawater pipeline to be protected and transmit it to the cathodic protection control module. The cathodic protection control module calculates the required protection potential of each section of the protected metal pipe and controls the potential adjustment device to output the protection potential to each reference electrode and each auxiliary anode.

[0091] Among them, the functions of each component are: a DC power supply, which supplies power to each component of the potential regulating device. A seawater pipeline temperature sensor group, which is used to monitor the seawater temperature of each protected metal pipe section of the seawater pipeline and transmit it to the cathodic protection control module. A seawater system communication module, which receives real-time data from the seawater system of polar ships, including the rotation speed of the seawater pump, the flow rate of each section of the seawater pipeline, the inlet temperature of the seawater gate and the central cooler, and transmits it to the cathodic protection control module. The cathodic protection control module adopts the corrosion prevention and control method of the seawater pipeline proposed in this application, and through the temperature, pressure and other data of each section of the protected metal pipe section, the intelligent regulating device outputs the voltage between each section of the protected metal pipe section and the auxiliary anode to realize the control of the protection potential and current density. The auxiliary anode is used as a conductor medium for the current from the protection potential regulating device to the seawater medium and the protected metal pipe section. The reference electrode monitors the potential of the protected metal pipe section, and directly outputs the potential signal to the cathodic protection control module to assist the cathodic protection control module in realizing the control of the protection potential.

[0092] For example, see Figure 3 The working principle of the corrosion prevention and control system of the seawater pipeline is as follows: when seawater flows through the protected metal pipe section, due to the presence of chloride ions, dissolved oxygen and microorganisms in the seawater, the metal on the pipe wall is prone to lose electrons and undergo oxidation reactions, forming electrochemical corrosion of the seawater pipeline and destroying the pipeline structure. This system uses a closed loop composed of a potential regulating device, an auxiliary anode, a seawater medium and a protected metal pipe section, wherein the negative electrode of the potential regulating device directly provides electrons to the protected metal pipe section, thereby enriching the electrons on the metal surface, and by controlling the potential and current density of the seawater pipeline, the pipeline is cathodically polarized, reversing the oxidation trend of the metal on the inner wall of the pipeline, thereby achieving the purpose of reducing or even completely inhibiting the electrochemical corrosion of the seawater pipeline. In addition, the system collects existing seawater system sensor data, identifies the state of the seawater medium (such as temperature, flow state, pressure, flow rate, etc.), and calculates the resistance of the seawater medium based on different electrochemical models in the control method, and realizes intelligent adjustment of the protection potential and current density by calculating the corresponding current density under the maximum protection potential and comparing and judging with the safe current density (preset value). When the seawater conductivity is low and the flow rate is high, the system outputs a preset protection potential to each protected metal pipe section; when the seawater conductivity is high and the flow rate is low, maintaining the preset protection potential will lead to over-protection problems. The control module lowers the protection potential according to the resistance calculation results and limits the current density to a safe range.

[0093] Figure 4 Flow chart of a method for preventing and controlling corrosion of seawater pipelines provided in the embodiment of the present application. Correspondingly, the embodiment of the present application also provides a method for preventing and controlling corrosion of seawater pipelines, please refer to Figure 4 , the corrosion prevention and control method of the seawater pipeline includes the following steps:

[0094] Step 110: Obtain basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, and basic parameters of each seawater pipeline section.

[0095] The electron transmission module is an auxiliary anode. The basic parameters of the electron transmission module of each seawater pipeline section are the size parameters such as the length and radius of the electron transmission module, which can be set according to actual conditions and are not specifically limited here.

[0096] The seawater temperature of each seawater pipeline section can be detected by a temperature sensor or the like.

[0097] The basic parameters of each seawater pipeline section are the size parameters of each seawater pipeline section, etc., which can be set according to actual conditions and are not specifically limited here.

[0098] Step 120, determining the target protection potential of each seawater pipeline section according to the basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, the basic parameters of each seawater pipeline section and a preset potential adjustment algorithm model.

[0099] Among them, the preset potential adjustment algorithm model is used to determine the protection potential of each seawater pipeline section.

[0100] Specifically, when the basic parameters of the electronic transmission module of each seawater pipeline section are obtained, the target protection potential of each corresponding seawater pipeline section can be calculated according to the basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, and the basic parameters of each seawater pipeline section, combined with the preset potential adjustment algorithm model.

[0101] Step 130: adjusting the potential of each seawater pipeline section according to the target protection potential of each seawater pipeline section.

[0102] Specifically, after the target protection potential of each seawater pipeline section is calculated, the potential of each seawater pipeline section is adjusted accordingly according to the target protection potential of each seawater pipeline section, so that the potential of each seawater pipeline section is adjusted to the calculated target protection potential, thereby controlling the potential of each seawater pipeline section at a reasonable potential, realizing intelligent control of the potential, avoiding the problems of under-protection and over-protection, and further realizing intelligent anti-corrosion control of each seawater pipeline section.

[0103] In the technical solution of the embodiment of the present application, the working principle of the corrosion prevention and control method of the seawater pipeline is as follows: Figure 4First, the basic parameters of the electronic transmission module of each of the seawater pipeline sections, the seawater temperature of each of the seawater pipeline sections, and the basic parameters of each of the seawater pipeline sections are obtained. Then, the target protection potential of each of the seawater pipeline sections is determined according to the basic parameters of the electronic transmission module of each of the seawater pipeline sections, the seawater temperature of each of the seawater pipeline sections, the basic parameters of each of the seawater pipeline sections, and the preset potential adjustment algorithm model. Finally, the potential of each of the seawater pipeline sections is adjusted according to the target protection potential of each of the seawater pipeline sections. It can be seen that this method can dynamically adjust the protection potential of each of the seawater pipeline sections of the seawater pipeline according to the seawater temperature of each of the seawater pipeline sections and the preset potential adjustment algorithm, thereby realizing intelligent anti-corrosion control of the seawater pipeline, so that the seawater pipeline can be applied to ship seawater pipeline applications under polar environmental conditions. This method can be applied to seawater application scenarios in different regions and different flow states, and has a wide range of applications and strong flexibility.

[0104] In some embodiments, the target protection potential of each seawater pipeline segment is determined based on the basic parameters of the electronic transmission module of each seawater pipeline segment, the seawater temperature of each seawater pipeline segment, the basic parameters of each seawater pipeline segment and a preset potential adjustment algorithm model, including: determining the current density of each seawater pipeline segment based on the seawater temperature of each seawater pipeline segment, the basic parameters of the electronic transmission module of each seawater pipeline segment, the basic parameters of each seawater pipeline segment and a first preset protection potential; determining the target protection potential of each seawater pipeline segment based on the current density of each seawater pipeline segment and a preset potential adjustment algorithm model.

[0105] Among them, in the closed loop corresponding to each seawater pipeline section, the negative electrode of the potential regulating device directly provides electrons to each seawater pipeline section, thereby enriching the electrons on the metal surface, and by controlling the potential and current density of each seawater pipeline section, the pipeline is cathodically polarized, reversing the oxidation trend of the metal on the inner wall of the pipeline, and achieving the purpose of reducing or even completely inhibiting the electrochemical corrosion of the seawater pipeline. Therefore, by collecting the seawater temperature of each seawater pipeline section, and based on the seawater temperature of each seawater pipeline section, the basic parameters of the electronic transmission module of each seawater pipeline section, and the basic parameters of each seawater pipeline section, by calculating the current density of each seawater pipeline section corresponding to the maximum protection potential, and determining the target protection potential of each seawater pipeline section according to the current density of each seawater pipeline section and the preset potential regulation algorithm model, it is possible to realize intelligent control of the potential of each seawater pipeline section, thereby realizing intelligent anti-corrosion control of each seawater pipeline section.

[0106] The first preset protection potential is the maximum protection potential. The setting of the maximum protection potential is related to the material of the seawater pipeline section, the flow rate range of the seawater pipeline section, and the protection effect requirements. For example, the maximum protection potential (i.e., the first preset protection potential) is U 1 , maximum protection potential U 1 It is related to the selection of the metal tube material. The specific data can be obtained through a large number of experimental verifications and modified and adjusted in actual applications. For example, the maximum protection potential (i.e., the first preset protection potential) is U 1 Please refer to Table 1 for parameter selection.

[0107] Table 1 Maximum protection potential reference table

[0108] Material Maximum protection potential range (V) Carbon Steel -0.85--1.1 Stainless steel -0.5--0.8 Copper / Copper Alloy -0.2--0.5 Aluminum / Aluminum Alloy -0.75--1.0

[0109] In some embodiments, the current density of each seawater pipeline section is determined based on the seawater temperature of each seawater pipeline section, the basic parameters of the electronic transmission module of each seawater pipeline section, the basic parameters of each seawater pipeline section and the first preset protection potential, including: determining the equivalent resistance of the seawater medium and the electronic transmission module corresponding to each seawater pipeline section according to the seawater temperature of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section; determining the current density of each seawater pipeline section according to the basic parameters of each seawater pipeline section, the equivalent resistance of the seawater medium and the electronic transmission module corresponding to each seawater pipeline section and the first preset protection potential.

[0110] Among them, the seawater medium and the electron transmission module corresponding to each seawater pipeline section can be regarded as equivalent resistance. By calculating the equivalent resistance corresponding to each seawater pipeline section, and according to the equivalent resistance of each seawater pipeline section and the basic parameters of each seawater pipeline section, the current density of each seawater pipeline section corresponding to the maximum protection potential can be calculated.

[0111] In some embodiments, the equivalent resistance of the seawater medium and the electronic transmission module corresponding to each seawater pipeline section is determined according to the seawater temperature of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section, including: determining the conductivity of the seawater medium of each seawater pipeline section according to the seawater temperature of each seawater pipeline section; determining the equivalent resistance of the seawater medium and the electronic transmission module corresponding to each seawater pipeline section according to the conductivity of the seawater medium of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section.

[0112] Among them, the size of the equivalent resistance of the seawater medium and the electronic transmission module corresponding to each seawater pipeline section is related to the conductivity of the seawater medium of each seawater pipeline section and the integrated parameters of the electronic transmission module. Therefore, firstly, the conductivity of the seawater medium of each seawater pipeline section is calculated, and then the equivalent resistance of the seawater medium and the electronic transmission module corresponding to each seawater pipeline section can be calculated according to the conductivity of the seawater medium of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section.

[0113] In some embodiments, the conductivity of the seawater medium of each seawater pipeline section is determined according to the seawater temperature of each seawater pipeline section, including: determining the seawater salinity of each seawater pipeline section according to the seawater temperature of each seawater pipeline section; determining the conductivity of the seawater medium of each seawater pipeline section according to the seawater temperature of each seawater pipeline section and the seawater salinity of each seawater pipeline section.

[0114] Among them, the seawater salinity and seawater temperature of each seawater pipeline section will affect the conductivity of the seawater medium of each seawater pipeline section. Therefore, it is necessary to calculate the seawater salinity and detect the seawater temperature of each seawater pipeline section in real time.

[0115] Furthermore, the conductivity σ of the seawater medium in each seawater pipeline section is positively correlated with the seawater salinity S and the seawater temperature T. That is, the higher the seawater salinity S and the higher the seawater temperature T, the greater the conductivity σ of the seawater medium. Its mathematical formula can be obtained by fitting experimental data or citing relevant empirical formulas.

[0116] In some embodiments, the seawater salinity of each seawater pipeline section is determined according to the seawater temperature of each seawater pipeline section, including: judging whether the seawater temperature of each seawater pipeline section is greater than a preset temperature; if there is a seawater pipeline section whose seawater temperature is greater than the preset temperature, taking the seawater salinity of the sea area where the seawater pipeline section corresponding to the seawater temperature greater than the preset temperature is currently located as the seawater salinity of the seawater pipeline section corresponding to the seawater temperature greater than the preset temperature; if there is a seawater pipeline section whose seawater temperature is less than or equal to the preset temperature, determining the seawater salinity of the seawater pipeline section corresponding to the seawater temperature less than or equal to the preset temperature according to a preset salinity mathematical model.

[0117] The preset temperature is a safe temperature value. For example, the safe temperature T 0 It can be -0.2° C. In addition, the safety temperature can also be other values, which can be set according to actual conditions and are not specifically limited here.

[0118] The salinity of the seawater in the sea area where each seawater pipeline section is currently located can be determined based on the empirical data of the shallow sea salinity in the current sea area of ​​the ship, and can be specifically set according to the actual situation, and no specific limitation is made here.

[0119] Specifically, when the seawater temperature of the seawater pipeline section is greater than the preset temperature, the seawater salinity of the corresponding seawater pipeline section (i.e., the seawater pipeline section corresponding to the corresponding seawater temperature greater than the preset temperature) adopts the empirical data of the shallow sea salinity of the current sea area of ​​the ship. When the seawater temperature of the seawater pipeline section is less than or equal to the preset temperature, since the seawater medium of the corresponding seawater pipeline section (i.e., the seawater pipeline section corresponding to the corresponding seawater temperature less than or equal to the preset temperature) begins to form a two-phase flow, the salt precipitated from the ice crystal phase will increase the salinity of the seawater phase, thereby increasing the conductivity σ of the seawater medium. At this time, the salinity S of the seawater phase in the two-phase flow is negatively correlated with the seawater temperature (the water-ice crystal two-phase flow temperature at this time) and the seawater pressure P. That is, the lower the seawater temperature T and the seawater pressure P, the higher the salinity S of the seawater phase in the two-phase flow. Therefore, at this time, the seawater salinity of the corresponding seawater pipeline section (i.e., the seawater pipeline section corresponding to the corresponding seawater temperature less than or equal to the preset temperature) is calculated according to the preset salinity mathematical model.

[0120] In some embodiments, the calculation formula of the preset salinity mathematical model is:

[0121] S=a 0 + 1 T+a 2 T 2 +P

[0122] Where S is the salinity of the seawater in each seawater pipeline section, in ‰; T is the seawater temperature in each seawater pipeline section, in °C; a 0 、a 1 、a 2 , b are polynomial coefficients; P is sea water pressure, the unit is bar.

[0123] Among them, the polynomial coefficient a 0 、a 1 、a 2 , b, can be obtained by fitting the test data of seawater freezing point temperature under different salinities and pressures.

[0124] In some embodiments, the calculation formula for determining the conductivity of the seawater medium of each seawater pipeline section according to the seawater temperature of each seawater pipeline section and the seawater salinity of each seawater pipeline section is:

[0125]

[0126] Among them, σ is the conductivity of the seawater medium in each seawater pipeline section, and the unit is S / m; S is the seawater salinity in each seawater pipeline section, and the unit is ‰; T is the seawater temperature in each seawater pipeline section.

[0127] The conductivity of the seawater medium in each seawater pipeline section is the inverse of the resistivity, S = Ω -1 .

[0128] In some embodiments, the basic parameters of the electronic transmission module of each seawater pipeline section include: the radius and length of the electronic transmission module; the calculation formula for determining the equivalent resistance between the seawater medium and the electronic transmission module corresponding to each seawater pipeline section according to the conductivity of the seawater medium of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section is:

[0129]

[0130] Wherein, R is the equivalent resistance between the seawater medium corresponding to each seawater pipeline section and the electronic transmission module; σ is the conductivity of the seawater medium in each seawater pipeline section; L a is the length of the electronic transmission module; d a is the radius of the electron transport module.

[0131] In some embodiments, the basic parameters of each seawater pipeline segment include: the inner diameter and length of the seawater pipeline segment; the calculation formula for determining the current density of each seawater pipeline segment according to the basic parameters of each seawater pipeline segment, the equivalent resistance of the seawater medium and the electronic transmission module corresponding to each seawater pipeline segment, and the first preset protection potential is:

[0132]

[0133] Among them, J 1 is the current density of each seawater pipeline section; R is the equivalent resistance of the seawater medium and the electron transmission module corresponding to each seawater pipeline section; d is the inner diameter of each seawater pipeline section, in m; L is the length of each seawater pipeline section, in m; U 1 It is the first preset protection potential (safety protection potential).

[0134] In some embodiments, the calculation formula for determining the target protection potential of each seawater pipeline segment according to the current density of each seawater pipeline segment and the preset potential adjustment algorithm model is:

[0135]

[0136] Wherein, U is the target protection potential of each seawater pipeline section; R is the equivalent resistance of the seawater medium and the electron transmission module corresponding to each seawater pipeline section; J 1 is the current density of each seawater pipeline section; J 0 is the preset current density; d is the inner diameter of each seawater pipeline section; L is the length of each seawater pipeline section.

[0137] The preset current density is the safe current density. 0 It is closely related to the seawater flow rate. The specific data can be obtained through a large number of experimental verifications and corrected and adjusted in actual applications.

[0138] For example, taking the material of the seawater pipeline as a steel pipeline as an example, the safe current density J 0 Please refer to Table 2 for parameter selection.

[0139] Table 2 Safety current density reference table

[0140] Seawater flow rate (m / s) <![CDATA[Protection current density (mA / m 2 )]]> 2 2500 4 4000 8 7000 12 11000

[0141] Specifically, when the current density J required to maintain the maximum protection potential 1 When the current density is lower than the safe current density, the system outputs the intelligent adjustment protection potential U (i.e. the target protection potential) and the maximum protection potential U 1 Keep consistent and maximize the electrochemical protection performance of the system; when the maximum protection potential requires a current density J 1 When the current density is higher than the safe current density, the intelligent regulation protection potential U output by the system depends on the safe current density J 0 , to avoid over-protection problems in the cathodic protection system.

[0142] Figure 5 Schematic diagram of the overall flow of a method for preventing and controlling corrosion of a seawater pipeline provided in an embodiment of the present application. For example, taking the electron transmission module as an auxiliary anode and the corrosion prevention and control of a certain section of the seawater pipeline to be protected in the seawater pipeline as an example, refer to Figure 5 The overall implementation process of the corrosion prevention and control method for seawater pipelines is as follows: First, the seawater temperature sensor group receives the seawater temperature data and returns it to the cathodic protection control module to realize real-time monitoring of the seawater temperature; the seawater system communication module receives the seawater pressure P and other data and transmits it to the cathodic protection control module. Then, the cathodic protection control module first determines whether the seawater temperature T is higher than the set safety temperature value T according to the above sensor data. 0 (T 0 The value should be slightly higher than the freezing point of seawater, such as the freezing point of seawater at 5‰ salinity and 1 standard atmospheric pressure -0.2℃). 0 , then directly combine the normal temperature seawater conductivity model to calculate the local conductivity σ of the seawater medium; if T <T 0 , the seawater salinity S (i.e., corrected salinity) is first calculated according to the preset salinity mathematical model, and then the seawater medium conductivity σ in the current seawater pipeline section is calculated. Finally, based on the conductivity (or equivalent resistance), the maximum protection potential U is calculated. 1 (Preset value based on different pipe materials and seawater flow rate) The corresponding current density J 1 and the safe current density J 0 The optimal protection potential is determined by comparison with the preset limit value (to prevent the current density from being too high), and is applied to the seawater and the metal pipe of the protected seawater pipeline section through the auxiliary anode and the reference electrode respectively.

[0143] It can be seen that the corrosion prevention and control method of the seawater pipeline of the present application can realize the intelligent adjustment of the cathodic protection potential of the seawater pipeline, reduce the layout and maintenance costs of the cathodic protection system, and improve the safety of the cathodic protection system in polar low temperature environments. And compared with the prior art, on the one hand, by using the seawater system sensor measurement points to replace a number of constant potential instrument groups, a "one-end to multiple points" impressed current cathodic protection scheme is proposed, which has low layout cost and good maintainability. On the other hand, in view of the changes in seawater salinity and conductivity in different regions and different flow states, a potential control strategy and intelligent adjustment method are proposed, which improves the polar adaptability of the system and effectively avoids the hydrogen embrittlement of seawater pipelines caused by excessive short-term local current density.

[0144] The implementation scheme of this application also needs to consider many factors, such as the size structure and external connectors of the seawater pipeline section, the anti-corrosion coating on the inner wall of the pipeline, the selection of pipeline and flange materials, whether to combine sacrificial anodes for joint protection, etc. The actual final parameters need to be measured and calibrated for the protected seawater pipeline section. Therefore, in the implementation scheme of this application, a section of metal straight pipe is used as the electrochemical protection object, and a layout including auxiliary anodes and reference electrodes, a mathematical model of seawater conductivity, and a mathematical model of protection potential are provided as design references.

[0145] Figure 6 Schematic diagram of the installation of a corrosion prevention and control system for a seawater pipeline provided in an embodiment of the present application. For example, the arrangement of the seawater pipeline section, auxiliary anode, reference electrode, etc., please refer to Figure 6 Exemplarily, the overall implementation process of the corrosion prevention and control system of the seawater pipeline is as follows:

[0146] First, the layout of the auxiliary prototype and the reference electrode. Referring to GB / T 17005-2019 and other relevant standards, the auxiliary anode is selected as a titanium-based metal oxide anode material with a maximum working current density of about 1000A / m2 and a size of diameter d a Length L a The cylinder is insulated from the seawater pipe during installation; the reference electrode is a silver / silver chloride electrode, which can measure the potential range of about -1.05 to -0.80V.

[0147] Second, the mathematical model of seawater conductivity. The conductivity σ of the seawater medium is positively correlated with the seawater salinity S and the seawater temperature T: the higher the seawater salinity S and the higher the seawater temperature T, the greater the conductivity σ of the seawater medium. Its mathematical formula can be obtained by fitting experimental data or citing relevant empirical formulas.

[0148] With reference to the Practical Salt Standard (PSS-78) and the Seawater State Equation (EOS-80), the following empirical formula is used for calculation in the embodiments of the present application:

[0149]

[0150] Among them, S is the salinity of seawater, in ‰; T is the temperature of seawater, in ℃; σ is the conductivity of the seawater medium, in S / m (Note: conductivity is the reciprocal of resistivity, S = Ω-1).

[0151] When the seawater temperature is higher than the set safety temperature value T 0 (For example, take T 0 When the seawater temperature is lower than the set safety temperature value T 0 (-0.2℃), the seawater medium begins to form a two-phase flow, and the salt precipitated from the ice crystal phase will increase the salinity of the seawater phase, thereby increasing the conductivity σ of the seawater medium. At this time, the salinity of the seawater phase in the two-phase flow is negatively correlated with the seawater-ice crystal two-phase flow temperature and the seawater pressure P: the lower the seawater temperature T and the seawater pressure P, the higher the salinity of the seawater phase in the two-phase flow. In the embodiment of the present application, a polynomial fitting method is used to establish a mathematical model S=f(T, P):

[0152] S=a 0 + 1 T+a 2 T 2 +P

[0153] Wherein, T is the temperature of seawater-ice crystal two-phase flow, in °C; P is the seawater pressure, in bar.

[0154] Among them, the polynomial coefficient a 0 、a 1 、a 2 , b, can be obtained by fitting the test data of seawater freezing point temperature under different salinities and pressures. For example, the parameters of the above polynomial are obtained based on the test data of a certain sea area as follows: a 0 =-0.2432; a 1 =-19.1646; a 2 =-0.4348; b =-0.1443.

[0155] Third, the mathematical model of the protection potential. First, calculate the equivalent resistance R between the auxiliary anode and the seawater medium in the closed loop. The lower the conductivity of the seawater medium, the larger the radius of the auxiliary anode, and the longer the length, the lower the equivalent resistance.

[0156] For example, referring to GB / T 17005-2019 and other relevant standards, the cylindrical pipe is used in the embodiment of the present application and the following empirical formula is used for calculation:

[0157]

[0158] Among them, d a is the radius of the auxiliary anode; L a is the auxiliary anode length.

[0159] Then calculate the maximum protection potential U 1 The current density J 1 :

[0160]

[0161] Wherein, d is the inner diameter of the protected seawater pipeline section, in m; L is the length of the protected seawater pipeline section, in m.

[0162] Among them, the mathematical model of intelligently adjusting the protection potential U (i.e., the preset potential adjustment algorithm model) is:

[0163]

[0164] Specifically, when the current density J required to maintain the maximum protection potential 1 When the current density is lower than the safe current density, the target protection potential U output by the system is different from the maximum protection potential U 1 Keep consistent and maximize the electrochemical protection performance of the system; when the maximum protection potential requires a current density J 1 When the current density is higher than the safe current density, the target protection potential U output by the system depends on the safe current density J 0 , to avoid over-protection problems in the cathodic protection system.

[0165] In addition, the actual output voltage of the potential regulating device also needs to take into account the resistance of the cable and the seawater pipeline, and be adjusted in real time according to the inner wall potential of the pipeline fed back by the reference electrode until the potential measured by the reference electrode is equal to the target protection potential U calculated by the mathematical model, thereby achieving accurate adjustment of each target protection potential.

[0166] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0167] The above is a detailed introduction to the corrosion prevention and control method and system for seawater pipelines provided in the embodiments of the present application, and specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A method for preventing and controlling corrosion of seawater pipelines, characterized in that: Applied to a potential regulating device, the seawater pipeline comprises a plurality of seawater pipeline sections; each of the seawater pipeline sections is provided with an electronic transmission module and a temperature detection module; The method comprises: Acquire basic parameters of the electronic transmission module of each of the seawater pipeline sections, seawater temperature of each of the seawater pipeline sections, and basic parameters of each of the seawater pipeline sections; Determine the target protection potential of each seawater pipeline section according to the basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, the basic parameters of each seawater pipeline section and a preset potential adjustment algorithm model; And the potential of each seawater pipeline section is adjusted according to the target protection potential of each seawater pipeline section.

2. The method for preventing and controlling corrosion of seawater pipelines according to claim 1, characterized in that: Determining the target protection potential of each seawater pipeline section according to the basic parameters of the electronic transmission module of each seawater pipeline section, the seawater temperature of each seawater pipeline section, the basic parameters of each seawater pipeline section and a preset potential adjustment algorithm model includes: Determine the current density of each seawater pipeline segment according to the seawater temperature of each seawater pipeline segment, the basic parameters of the electronic transmission module of each seawater pipeline segment, the basic parameters of each seawater pipeline segment and the first preset protection potential; The target protection potential of each seawater pipeline section is determined according to the current density of each seawater pipeline section and the preset potential adjustment algorithm model.

3. The method for preventing and controlling corrosion of seawater pipelines according to claim 2, characterized in that: Determining the current density of each seawater pipeline section according to the seawater temperature of each seawater pipeline section, the basic parameters of the electronic transmission module of each seawater pipeline section, the basic parameters of each seawater pipeline section and the first preset protection potential includes: Determine the equivalent resistance between the seawater medium and the electronic transmission module corresponding to each seawater pipeline section according to the seawater temperature of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section; The current density of each seawater pipeline section is determined according to basic parameters of each seawater pipeline section, equivalent resistance of the seawater medium corresponding to each seawater pipeline section and the electronic transmission module, and the first preset protection potential.

4. The method for preventing and controlling corrosion of seawater pipelines according to claim 3, characterized in that: The determining of the equivalent resistance between the seawater medium corresponding to each seawater pipeline section and the electronic transmission module according to the seawater temperature of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section includes: Determining the conductivity of the seawater medium of each of the seawater pipeline sections according to the seawater temperature of each of the seawater pipeline sections; The equivalent resistance of the seawater medium corresponding to each seawater pipeline section and the electronic transmission module is determined according to the conductivity of the seawater medium of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section.

5. The method for preventing and controlling corrosion of seawater pipelines according to claim 4, characterized in that: Determining the conductivity of the seawater medium of each seawater pipeline section according to the seawater temperature of each seawater pipeline section includes: Determining the seawater salinity of each of the seawater pipeline sections according to the seawater temperature of each of the seawater pipeline sections; The electrical conductivity of the seawater medium of each of the seawater pipeline sections is determined according to the seawater temperature of each of the seawater pipeline sections and the seawater salinity of each of the seawater pipeline sections.

6. The method for preventing and controlling corrosion of seawater pipelines according to claim 5, characterized in that: Determining the seawater salinity of each of the seawater pipeline sections according to the seawater temperature of each of the seawater pipeline sections includes: Determining whether the seawater temperature of each of the seawater pipeline sections is greater than a preset temperature; If there is a seawater temperature of the seawater pipeline section that is greater than the preset temperature, the seawater salinity of the seawater area where the seawater pipeline section corresponding to the seawater temperature greater than the preset temperature is currently located is used as the seawater salinity of the seawater pipeline section corresponding to the seawater temperature greater than the preset temperature; If there is a seawater pipe section whose seawater temperature is less than or equal to the preset temperature, the seawater salinity of the seawater pipe section corresponding to the preset temperature is determined according to a preset salinity mathematical model.

7. The method for preventing and controlling corrosion of seawater pipelines according to claim 6, characterized in that: The calculation formula of the preset salinity mathematical model is: S=a0+a1T+a2T 2 +bP Wherein, S is the seawater salinity of each of the seawater pipeline sections; T is the seawater temperature of each of the seawater pipeline sections; a0, a1, a2, and b are polynomial coefficients; and P is the seawater pressure.

8. The method for preventing and controlling corrosion of seawater pipelines according to claim 5, characterized in that: The calculation formula for determining the conductivity of the seawater medium of each seawater pipeline section according to the seawater temperature of each seawater pipeline section and the seawater salinity of each seawater pipeline section is: Wherein, σ is the conductivity of the seawater medium of each of the seawater pipeline sections; S is the seawater salinity of each of the seawater pipeline sections; and T is the seawater temperature of each of the seawater pipeline sections.

9. The method for preventing and controlling corrosion of seawater pipelines according to claim 4, characterized in that: The basic parameters of the electron transmission module of each of the seawater pipeline sections include: the radius and length of the electron transmission module; The calculation formula for determining the equivalent resistance between the seawater medium and the electronic transmission module corresponding to each seawater pipeline section according to the conductivity of the seawater medium of each seawater pipeline section and the basic parameters of the electronic transmission module of each seawater pipeline section is: Wherein, R is the equivalent resistance between the seawater medium corresponding to each of the seawater pipeline sections and the electronic transmission module; σ is the conductivity of the seawater medium of each of the seawater pipeline sections; L a is the length of the electronic transmission module; d a is the radius of the electron transport module.

10. The method for preventing and controlling corrosion of seawater pipelines according to claim 3, characterized in that: The basic parameters of each of the seawater pipeline sections include: the inner diameter and length of the seawater pipeline section; The calculation formula for determining the current density of each seawater pipeline section according to the basic parameters of each seawater pipeline section, the equivalent resistance of the seawater medium corresponding to each seawater pipeline section and the electronic transmission module, and the first preset protection potential is: Among them, J1 is the current density of each seawater pipeline segment; R is the equivalent resistance between the seawater medium corresponding to each seawater pipeline segment and the electronic transmission module; d is the inner diameter of each seawater pipeline segment; L is the length of each seawater pipeline segment; U1 is the first preset protection potential.

11. The method for preventing and controlling corrosion of seawater pipelines according to claim 2, characterized in that: The calculation formula for determining the target protection potential of each seawater pipeline section according to the current density of each seawater pipeline section and the preset potential adjustment algorithm model is: Among them, U is the target protection potential of each seawater pipeline segment; R is the equivalent resistance between the seawater medium corresponding to each seawater pipeline segment and the electronic transmission module; J1 is the current density of each seawater pipeline segment; J0 is the preset current density; d is the inner diameter of each seawater pipeline segment; L is the length of each seawater pipeline segment.

12. A corrosion prevention and control system for seawater pipelines, characterized in that: The seawater pipeline includes several seawater pipeline sections; the system includes: a potential regulating device, an electronic transmission module and a temperature detection module; wherein the potential regulating device is provided with a first connection end and a second connection end; the first connection end is electrically connected to the electronic transmission module; each of the seawater pipeline sections is provided with an electronic transmission module and a temperature detection module; each of the temperature detection modules is used to detect the seawater temperature in the corresponding seawater pipeline section; the outer wall of each of the seawater pipeline sections is electrically connected to the second connection end; wherein each of the seawater pipeline sections is insulated from the corresponding electronic transmission module; Wherein, each of the seawater pipeline segments, the corresponding electronic transmission module and the corresponding seawater medium, and the potential regulating device each form a corresponding closed loop; The potential regulating device is electrically connected to the temperature detection module, and the potential regulating device is used to execute the corrosion prevention and control method for the seawater pipeline according to any one of claims 1 to 11.

13. The corrosion prevention and control system for seawater pipeline according to claim 12, characterized in that: It also includes a reference electrode; each of the seawater pipeline segments is also provided with a reference electrode; a first end of the reference electrode is electrically connected to the corresponding seawater pipeline segment, and a second end of the reference electrode is electrically connected to the potential regulating device, and each reference electrode is used to detect the actual potential of the corresponding seawater pipeline segment and send it to the potential regulating device; The potential regulating device is configured to regulate the potential of each of the seawater pipeline sections according to the target protection potential and the actual potential of each of the seawater pipeline sections.

14. The corrosion prevention and control system for seawater pipeline according to claim 12, characterized in that: The potential regulating device further comprises: a control module, a communication module and a power supply module; wherein the communication module and the power supply module are both electrically connected to the control module; and the control module is electrically connected to each of the temperature detection modules.

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