Rapid design method for parameters of marine impressed current cathodic protection system

Abstract

The invention relates to the technical field of ship electrical and anti-corrosion system design, in particular to a rapid design method for parameters of a ship impressed current cathodic protection system. Based on the electromagnetic field theory, the invention provides a method for quickly calculating the resistance of the auxiliary anode and the metal hull in the seawater medium, and based on the calculation method, a method for calculating the effective action boundary of the anti-corrosion current of the auxiliary anode is provided. Therefore, rapid calculation of impressed current cathodic protection system key parameters such as the number of auxiliary anodes, potentiostat voltage and power capacity is achieved, compared with a traditional finite element method, the parameter calculation time can be greatly shortened, and the design efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of ship electrical and anti-corrosion system design, and in particular to a method for quickly designing parameters of a ship impressed current cathodic protection system. Background Art

[0002] The hull and propeller of a ship sailing on the sea are usually made of different metals. For example, the hull is mostly made of steel, while the propeller is mostly made of copper. According to the principle of electrochemistry, when the two are immersed in seawater, a potential difference will be generated between the hull and the propeller. Under the action of this potential difference, the propeller, hull, seawater and shafting form a circuit and a current flows through it. This current is called corrosion current. Since the chemically active steel hull has a lower potential than the chemically stable propeller, the corrosion current flows from the propeller (cathode) to the hull (anode) through the shafting in the ship's metal structure; while in seawater, the corrosion current flows from the hull to the propeller to form a complete circuit. Since seawater is an electrolyte, both positive and negative ions in it can conduct electricity, while the hull, propeller and shafting are all metals, which can only conduct electricity by the movement of negatively charged electrons, and metal atoms with positrons cannot move. Therefore, in order to maintain the continuity of the corrosion current on a macro scale, the current caused by the simultaneous movement of one unit of positive ions and one unit of negative ions in seawater is compensated by the movement of two units of electrons in the metal structure of the hull. In this case, the speed at which the ship loses negative charge (electrons) through the metal conductive path is faster than the speed at which negative charge (negative ions) is replenished through the seawater path. On the one hand, the ship's hull (anode) forms positively charged metal ions due to the loss of electrons, which combine with negative ions (hydroxyl ions) in seawater. On a macro scale, the steel is corroded to form ferric hydroxide; at the propeller (cathode), electrons react with water molecules and oxygen molecules to form hydroxide: this is the principle of the corrosion of the ship's hull metal in seawater due to electrochemical reactions.

[0003] In order to prevent the electrochemical corrosion effect, the prior art usually adopts methods such as sacrificial anode method and impressed current cathodic protection (ICCP). The sacrificial anode method uses a metal that is more active than steel, such as a zinc block, and immerses it in seawater to form a lower potential than the protected hull, thereby replacing the hull and corroding it; the impressed current cathodic protection method connects the hull to the negative pole of the external power supply to form a cathode, and the positive pole of the external power supply is connected to an additionally installed metal auxiliary anode. The auxiliary anode is insulated from the hull and immersed in seawater. In the cathodic protection path thus formed, the positive pole of the power supply outputs current through the auxiliary anode, flows into the hull through the seawater conductor, and then returns to the negative pole of the power supply. Obviously, in this process, the anti-corrosion current output by the external power supply directly replenishes electrons for the hull, so the hull changes from the original anode to the protected cathode, achieving the purpose of protecting the hull from corrosion.

[0004] Obviously, the external power supply required for the impressed current cathodic protection method should have the ability to adjust the anti-corrosion current of the hull to adapt to the current fluctuations caused by factors such as changes in the hull draft depth and changes in seawater conductivity, so as to avoid under-protection due to too small anti-corrosion current, or over-protection due to too large anti-corrosion current. Therefore, this power supply needs to have the ability to dynamically adjust the output voltage in a closed loop. In engineering, the hull potential is usually monitored in real time through a reference electrode. The power supply adjusts its output voltage in real time based on the monitoring results to achieve the purpose of controlling the anti-corrosion current within a suitable range. Therefore, this power supply is called a constant potential instrument. The power capacity reserve of the constant potential instrument must be able to ensure the output of a sufficiently large anti-corrosion current so that the entire submerged part of the hull is effectively protected.

[0005] However, due to the complexity of the hull structure and the differences in the number and location of auxiliary anodes, the distribution of anti-corrosion current in the seawater near the hull is difficult to calculate accurately. It is usually necessary to perform a large number of simulation calculations in the design stage, and optimize the number and installation location of auxiliary anodes based on the simulation results to determine the anti-corrosion current output by the auxiliary anodes and the output voltage of the constant potential instrument. This process requires the use of professional electromagnetic field simulation software and finite element methods. When the hull size is large, the number of grids used for simulation calculations is large, the calculation time is long, and the efficiency is low.

[0006] The existing technology is based on theoretical calculation or electromagnetic field simulation methods. Although the accuracy is high, it has certain limitations. For example, the theoretical calculation method needs to perform integral operations based on electromagnetic field theory. When the hull structure is complex, it will be difficult to obtain an analytical solution. The use of electromagnetic field simulation calculation software, such as the finite element method, requires professionals to set reasonable boundary conditions, select the calculation area and perform reasonable mesh division. Otherwise, the calculation results will be inaccurate or the calculation amount will be large and time-consuming, which is not conducive to rapid design. Summary of the invention

[0007] The technical problem to be solved by the present invention is: to propose a rapid design method for the parameters of a ship-based impressed current cathodic protection system, which can quickly calculate the resistance of the auxiliary anode-local hull in the seawater medium, and quickly estimate the effective action boundary of the anti-corrosion current output by the anode, and can quickly estimate the number of auxiliary anodes, thereby realizing a rapid estimation of key electrical parameters such as the output voltage and power capacity of the constant potential instrument, greatly saving design time.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] A rapid design method for parameters of a marine impressed current cathodic protection system comprises the following steps:

[0010] S1, calculate the resistance of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium;

[0011] S2, based on the initial dimensions of the auxiliary anode, insulating bracket, and anode shielding layer, quantitatively estimate the effective action boundary of the anti-corrosion current output by the auxiliary anode;

[0012] S3, estimating the number of auxiliary anodes according to a preset hull design waterline length and the effective action boundary of the anti-corrosion current;

[0013] S4, calculate the rated output voltage and rated output power of the potentiostat according to the total anti-corrosion current required by the hull and the equivalent total resistance of the auxiliary anode;

[0014] S5, estimating the output voltage range and power capacity of the potentiostat using a linear estimation method according to the rated output voltage and the rated output power;

[0015] S6, adjusting the dimensions of the auxiliary anode, the insulating bracket, and the anode shielding layer, and repeating steps S1 to S5, until it is determined that the estimated output voltage range and power capacity of the constant potential instrument are feasible in engineering, and then outputting the design result.

[0016] Furthermore, in step S1, the calculation of the resistance of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium includes:

[0017] S11, establishing an electromagnetic coupling model between the auxiliary anode and the adjacent hull structure: in the model, the auxiliary anode is equivalent to a disc-shaped metal electrode p1 with negligible thickness, and the hull structure is equivalent to a ring-shaped metal electrode p2 with negligible thickness, and p1 and p2 are placed concentrically, and there is an annular insulating region with a width of d between the two ring-shaped metal electrodes to be equivalent to an insulating bracket and an anode shielding layer;

[0018] S12, based on the electromagnetic coupling model of the auxiliary anode and the adjacent hull structure, a calculation coordinate system is established, the origin of the coordinate system coincides with the center of the circle of p1 and p2, and p1 and p2 are located in the xoz plane of the coordinate system;

[0019] S13, in the calculation coordinate system, using a preset calculation formula to calculate the resistance of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium.

[0020] The preset calculation formula is as follows:

[0021]

[0022] in,

[0023]

[0024] R is the resistance value of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium, σ is the seawater conductivity, L1 is the radius of the disk-shaped metal electrode p1 equivalent to the auxiliary anode, and L2 is the width of the circular ring area of ​​the circular ring-shaped metal electrode p2 equivalent to the hull structure.

[0025] Furthermore, in step S2, the effective action boundary of the anti-corrosion current output by the auxiliary anode is quantitatively estimated, including:

[0026] S21, determining the initial L1, d, σ inputs according to the initial auxiliary anode, insulating bracket, and anode shielding layer sizes, and calculating the trend of the resistance R of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium as L2 changes;

[0027] S22, when the resistance value R no longer decreases significantly as L2 increases, it is considered that the effective action boundary of the anti-corrosion current has been reached.

[0028] The method for determining whether the resistance R no longer decreases significantly is as follows:

[0029] First, calculate the resistance value when L2 = L1, record it as R0, gradually increase the value of L2 and calculate the corresponding resistance value R 计 , when R 计 =a×R0, that is, the L2 value corresponding to the effective action boundary of the anti-corrosion current, is recorded as L2', and the corresponding resistance value is recorded as R', where a is the preset threshold value and 0.5<a<1.

[0030] Furthermore, in step S3, the number of auxiliary anodes is calculated as follows:

[0031]

[0032] Where n is the number of auxiliary anodes, L S Design the waterline length for a given hull.

[0033] Furthermore, in step S4, the equivalent total resistance R of the auxiliary anode n for:

[0034]

[0035] Then, the rated output voltage U of the potentiostat is:

[0036] U=IR n

[0037] The rated output power P is:

[0038] P=I2 R n

[0039] Where I is the total corrosion resistance current required by the hull.

[0040] Further, in step S5, the output voltage range and power capacity of the potentiostat are calculated as follows:

[0041] The minimum output voltage U of the potentiostat min for:

[0042]

[0043] Maximum output voltage U max for:

[0044] U max =U·β

[0045] Power capacity P of the potentiostat max for:

[0046] P max =P·γ

[0047] Wherein, β and γ are both preset coefficients, and β>1, γ>1.

[0048] Among them, the output current I0 of a single auxiliary anode is:

[0049] I0=I / n.

[0050] Furthermore, in step S6, the output voltage range and power capacity of the constant potentiostat are feasible in engineering, specifically, the calculation results of the voltage range and power capacity are within the preset standard range, and the design results include the adjusted dimensions of the auxiliary anode, insulating bracket, and anode shielding layer.

[0051] Compared with the prior art, the present invention has the following main advantages:

[0052] 1. Based on electromagnetic field theory, the present invention proposes a method for quickly calculating the resistance of the auxiliary anode and the metal hull in the seawater medium, and based on this calculation method, a method for calculating the effective action boundary of the auxiliary anode's anti-corrosion current is proposed, thereby realizing the rapid calculation of key parameters of the impressed current cathodic protection system such as the number of auxiliary anodes, constant potential instrument voltage and power capacity. Compared with the traditional finite element method, the parameter calculation time can be greatly compressed, greatly improving the design efficiency;

[0053] 2. The present invention can quickly calculate the resistance of the auxiliary anode-local hull in the seawater medium, and quickly estimate the effective action boundary of the anti-corrosion current output by the anode, and can quickly estimate the number of auxiliary anodes, thereby realizing a rapid estimation of key electrical parameters such as the output voltage and power capacity of the constant potential instrument, which can greatly save design time. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a side schematic diagram of the disk-shaped auxiliary anode outputting anti-corrosion current to the adjacent hull through seawater in the embodiment;

[0055] Figure 2 It is a bottom schematic diagram of the disk-shaped auxiliary anode outputting anti-corrosion current to the adjacent hull through seawater in the embodiment;

[0056] Figure 3 A schematic diagram of a disk-shaped auxiliary anode and an electrode model of a local area adjacent to the hull in the embodiment;

[0057] Figure 4 A schematic diagram of a coordinate system established based on the auxiliary anode and the electrode model of the adjacent hull in the embodiment;

[0058] Figure 5 Schematic diagram of the variation trend of the resistance R in the half-space seawater medium with L2 in the embodiment. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0060] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, and two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0061] Embodiment 1: This embodiment provides a method for quickly designing parameters of a marine impressed current cathodic protection system, which specifically includes:

[0062] Step 1: A method for calculating the resistance of the disk-shaped auxiliary anode and the adjacent hull structure in seawater

[0063] First, the electromagnetic coupling between the auxiliary anode and the adjacent hull structure is analyzed and modeled. Usually, the disk-shaped auxiliary anode installed below the waterline of the hull is installed in the hull (side view, bottom view) and the current path is as shown in the following figure. Figures 1-2 As shown. Figures 1-2 It can be seen that the circular auxiliary anode outputs anti-corrosion current to the metal hull through the conductive seawater. Since the insulating bracket and the anode shielding layer are not conductive, the anti-corrosion current output by the auxiliary anode crosses these two areas and flows back to the hull. The farther away from the center of the auxiliary anode, the smaller the current density. Therefore, in fact, the anti-corrosion current output by the auxiliary anode has a limited action area. When modeling, the hull part around the auxiliary anode can be based on the attached Figure 1 The effective action boundary of the anti-corrosion current shown in the bottom view (dashed line) is equivalent to a metal ring.

[0064] Furthermore, in the modeling, the ship auxiliary anode is equivalent to a disc-shaped metal electrode p1 with negligible thickness, and the hull is equivalent to a ring-shaped metal electrode p2 with negligible thickness. P1 and p2 are placed concentrically, and there is a ring-shaped insulating area with a width of d between the two electrodes to be equivalent to the insulating bracket and the anode shielding layer, as shown in the attached figure. Figure 3 shown.

[0065] For attachment Figure 3 The electrode structure shown in the attached Figure 4 The coordinate system shown in the figure has its origin and Figures 1-2 The centers of the electrodes p1 and p2 coincide, and p1 and p2 are located in the xoz plane. Below the xoz plane is seawater, where an electric field exists, thus forming a conductive path, while above the xoz plane there is no electric field. Figure 3 The models and attachments in Figure 4 In the coordinate system shown, the resistance of the electrode structure composed of a disk-shaped auxiliary anode and the adjacent hull in the seawater medium is:

[0066]

[0067] in,

[0068]

[0069]

[0070] R is the resistance between the disk-shaped auxiliary anode and the adjacent hull structure in the half-space seawater, σ is the conductivity of seawater, L1 is the radius of the disk-shaped auxiliary anode, L2 is the width of the hull ring area, and d is the width of the non-conductive area between the two electrodes after considering the insulating bracket and the anode shielding layer.

[0071] Step 2: A method for quantitatively estimating the effective action boundary of the anti-corrosion current output by the auxiliary anode when the dimensions of the auxiliary anode, the insulating bracket, and the anode shielding layer are known

[0072] With L1, d, and σ as known inputs, based on formula (1), the trend of the resistance R of the electrode structure in the half-space seawater medium changing with L2 is calculated. When the resistance R no longer decreases significantly with the increase of L2, it is considered that the effective action boundary of the anti-corrosion current has been found. The method for determining that the resistance R no longer decreases significantly in this example is to first calculate R when L2 = L1, recorded as R0, gradually increase L2 and calculate the corresponding R, and when R < αR0, the corresponding L2' is the desired value, and the R at this time is recorded as R'. Where α is the threshold value set by the user and 0.5 < α < 1, and the typical α value is 0.51.

[0073] Step 3: A method for estimating the number of auxiliary anodes based on the designed waterline length of the ship and the effective action boundary of the anti-corrosion current

[0074] According to L2' obtained in the previous step, the designed waterline length of the hull is known to be L s If auxiliary anodes are arranged on both sides, and at least one pair of anodes are arranged on the bow and stern, in order to ensure that the flooded part of the whole ship is protected more evenly, the number of auxiliary anodes can be estimated as follows:

[0075]

[0076] When the above formula cannot be divided evenly, n can be rounded up to the nearest even number.

[0077] Step 4: A method for estimating rated output parameters of a potentiostat

[0078] It is known that the total anti-corrosion current required by the hull is I (I can be obtained by consulting relevant standards such as GB / T3108-1999 through hull design parameters). According to the calculation steps proposed above, when n auxiliary anodes are configured, these n auxiliary anodes and the nearby hull form n disk-ring metal electrode structures, and these electrode structures are in parallel, then their equivalent total resistance is

[0079]

[0080] Where R' and n are calculated by the methods provided in step 2 and step 3 respectively. The driving impedance of the potentiostat is R n The load is , and the output anti-corrosion current is I, then the rated output voltage of the potentiostat is

[0081] U=IR n (6)

[0082] Rated output power is approximately

[0083] P=I 2 R n (7)

[0084] Step 5: A method for estimating the output voltage range and power capacity of a potentiostat

[0085] When the potentiostat is actually working, it usually uses automatic feedback control to make its output voltage and output power change with the external conditions such as the draft depth of the injected hull, the conductivity of seawater in the sea area, and the speed of the ship, so as to ensure that the total hull protection current is basically constant. Therefore, the rated output voltage and rated output power of the potentiostat calculated in step 4 reflect the nominal value rather than the limit value. Therefore, the output voltage range of the potentiostat needs to be estimated based on the calculated value. Specifically, the linear estimation method is used, that is, the minimum output voltage of the potentiostat

[0086]

[0087] Maximum output voltage

[0088] U max =U·β (9)

[0089] Where β>1.

[0090] Similarly, the power capacity of the potentiostat needs to have a margin, so the above nominal output power calculation value is corrected to obtain its power capacity:

[0091] P max =P·γ (10)

[0092] Where γ>1.

[0093] Step 6. Determine the feasibility of electrical parameters such as the power capacity and output voltage range of the potentiostat, and calculate the output current of a single auxiliary anode according to the following formula:

[0094] I0=I / n (11)

[0095] If the electrical parameters of the potentiostat are difficult to achieve in engineering (beyond the standard range of the actual project and relevant specifications), or the calculated auxiliary anode output current does not meet the technical specifications of the auxiliary anode, then without changing the overall design parameters of the ship such as waterline length, hull material and other parameters, reset the auxiliary anode, insulation bracket, anode shielding layer and other related parameters, and repeat the calculation process from step 1 to step 6 until a reasonable design result is obtained.

[0096] Embodiment 2: This embodiment provides a method for rapid design of parameters of a marine impressed current cathodic protection system, including: In this embodiment, according to GB / T 7388-1999, a CYQ-4 auxiliary anode (disc type) is selected, and its anode radius is about L1≈0.1m. The working current range of this type of anode is 2A-15A. The insulating bracket and the anode shielding layer form an annular insulating area with a width of d=1m. α=0.51 is taken, and the seawater conductivity is α=4.6S / m. L1, d, and σ are used as inputs to calculate the trend of the resistance R of the electrode structure in the half-space seawater medium as L2 changes, as shown in the attached figure. Figure 5 As shown, it can be seen that when L2>>L1, the resistance R gradually converges to a constant value, which is half of the resistance value corresponding to L2=L1. When L2=L1=0.1m, according to formulas (1) to (3), it can be seen that

[0097] R0=3.782Ω.

[0098] When L2=5.995m, the same method can be used to calculate:

[0099] R'=1.925Ω.

[0100] at this time,

[0101] R'<αR0=0.51×3.782=1.929Ω.

[0102] According to the criterion in Technical Point 2, when an auxiliary anode outputs anti-corrosion current to the metal hull, its effective anti-corrosion current action boundary is approximately

[0103] L2'=5.995m,

[0104] In actual engineering applications, rounding is required and the result is rounded to

[0105] L2'=6.00m.

[0106] Calculating R' again, the resistance of the electrode structure composed of the auxiliary anode and its adjacent hull in the seawater medium is approximately

[0107] R'=1.92Ω.

[0108] Assume the waterline length of the ship is L s =70m, then according to formula (4), the required number of auxiliary anodes is calculated as

[0109] n=12,

[0110] According to formula (5), the total resistance of 12 auxiliary anodes to the hull in seawater medium is approximately

[0111]

[0112] Assume that the ship's draft is T = 5m and its full load displacement is ▽ = 5000m 3 , according to the calculation formula of hull flooding area specified in GB / T 3108-1999

[0113] S1=1.7TL s +▽ / T (12)

[0114] get

[0115] S1=1595m 2 .

[0116] Furthermore, the reference value range of corrosion current density provided by GB / T 3108-1999 is 30~50mA / m 2 , take the upper limit value and get the corrosion current density

[0117] I1=50mA / m 2 ,

[0118] The calculated corrosion resistance current required for the entire ship is approximately

[0119] I=I1S1≈80A.

[0120] According to formula (6), the rated output voltage of the constant potential instrument is

[0121] U=IR n =12.8V.

[0122] According to formula (7), the rated output power of the potentiostat is

[0123] P=I 2 R n =1024W.

[0124] Furthermore, taking β = 1.5, according to formula (8), the minimum output voltage of the potentiostat is

[0125]

[0126] According to formula (9), the maximum output voltage of the potentiostat is

[0127]

[0128] Taking γ = 1.5, according to formula (10), the power capacity of the constant potential instrument is

[0129] P max =P·γ=1536VA.

[0130] Finally, check the feasibility of the parameters. To facilitate engineering implementation, the output voltage range and power capacity calculation results of the constant potential instrument can be rounded. For this embodiment, it can be seen that the output DC voltage range of the constant potential instrument is 8V~20V, and the power capacity is 2000VA. The output voltage range and power capacity of this type of power supply are common specifications in industrial products. Further, the anode output current is calibrated. According to formula (11), the current output by each anode is approximately

[0131] I0=I / n≈6.67A.

[0132] It can be seen that I0 is within the rated working current range of 2A to 15A for this type of anode, so the parameter design is reasonable. At this point, the preliminary estimation of the key parameters of the impressed current cathodic protection system is completed.

[0133] Furthermore, all parts involved in this application that are not described in detail are the same as the prior art or are implemented using the prior art.

[0134] In summary:

[0135] 1. Based on electromagnetic field theory, the present invention proposes a method for quickly calculating the resistance of the auxiliary anode and the metal hull in the seawater medium, and based on this calculation method, a method for calculating the effective action boundary of the auxiliary anode's anti-corrosion current is proposed, thereby realizing the rapid calculation of key parameters of the impressed current cathodic protection system such as the number of auxiliary anodes, constant potential instrument voltage and power capacity. Compared with the traditional finite element method, the parameter calculation time can be greatly compressed, greatly improving the design efficiency;

[0136] 2. The present invention can quickly calculate the resistance of the auxiliary anode-local hull in the seawater medium, and quickly estimate the effective action boundary of the anti-corrosion current output by the anode, and can quickly estimate the number of auxiliary anodes, thereby realizing a rapid estimation of key electrical parameters such as the output voltage and power capacity of the constant potential instrument, which can greatly save design time.

[0137] The above is a preferred embodiment of the present invention, which is intended to illustrate the typical implementation scheme and workflow of the present invention. However, due to the diversity of the shapes / sizes / materials of the auxiliary anodes, the number of constant potentiostats and the connection methods of the auxiliary anode circuits, the implementation method of the present invention also has great flexibility, so the present invention should not be limited to the contents disclosed in the embodiment and the accompanying drawings. Therefore, any equivalent or modification that does not deviate from the spirit disclosed by the present invention, such as changing the shape / size of the anode in the embodiment, using multiple constant potentiostats to drive the auxiliary anode, and changing the α, β, γ parameters proposed in the patent, etc., all fall within the scope of protection of the present invention.

Claims

1. A rapid design method for parameters of a marine impressed current cathodic protection system, characterized in that: The steps include: S1, calculate the resistance of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium; S2, based on the initial dimensions of the auxiliary anode, insulating bracket, and anode shielding layer, quantitatively estimate the effective action boundary of the anti-corrosion current output by the auxiliary anode; S3, estimating the number of auxiliary anodes according to a preset hull design waterline length and the effective action boundary of the anti-corrosion current; S4, calculate the rated output voltage and rated output power of the potentiostat according to the total anti-corrosion current required by the hull and the equivalent total resistance of the auxiliary anode; S5, estimating the output voltage range and power capacity of the potentiostat using a linear estimation method according to the rated output voltage and the rated output power; S6, adjusting the dimensions of the auxiliary anode, the insulating bracket, and the anode shielding layer, and repeating steps S1 to S5, until it is determined that the estimated output voltage range and power capacity of the constant potential instrument are feasible in engineering, and then outputting the design result.

2. A method for rapid design of parameters of a marine impressed current cathodic protection system according to claim 1, characterized in that In step S1, the calculation of the resistance of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium includes: S11, establishing an electromagnetic coupling model between the auxiliary anode and the adjacent hull structure: in the model, the auxiliary anode is equivalent to a disc-shaped metal electrode p1 with negligible thickness, and the hull structure is equivalent to a ring-shaped metal electrode p2 with negligible thickness, and p1 and p2 are placed concentrically, and there is an annular insulating region with a width of d between the two ring-shaped metal electrodes to be equivalent to an insulating bracket and an anode shielding layer; S12, based on the electromagnetic coupling model of the auxiliary anode and the adjacent hull structure, a calculation coordinate system is established, the origin of the coordinate system coincides with the center of the circle of p1 and p2, and p1 and p2 are located in the xoz plane of the coordinate system; S13, in the calculation coordinate system, using a preset calculation formula to calculate the resistance of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium.

3. A method for rapid design of parameters of a marine impressed current cathodic protection system according to claim 2, characterized in that: The preset calculation formula is as follows: in, R is the resistance value of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium, σ is the seawater conductivity, L1 is the radius of the disk-shaped metal electrode p1 equivalent to the auxiliary anode, and L2 is the width of the circular ring area of ​​the circular ring-shaped metal electrode p2 equivalent to the hull structure.

4. A method for rapid design of parameters of a marine impressed current cathodic protection system according to claim 3, characterized in that In step S2, the quantitative estimation of the effective action boundary of the anti-corrosion current output by the auxiliary anode includes: S21, determining the initial L1, d, σ inputs according to the initial auxiliary anode, insulating bracket, and anode shielding layer sizes, and calculating the trend of the resistance R of the electrode structure composed of the disk-shaped auxiliary anode and the adjacent hull in the seawater medium as L2 changes; S22, when the resistance value R no longer decreases significantly as L2 increases, it is considered that the effective action boundary of the anti-corrosion current has been reached.

5. A rapid design method for parameters of a marine impressed current cathodic protection system according to claim 4, characterized in that: The method for determining whether the resistance R no longer decreases significantly is as follows: First, calculate the resistance value when L2 = L1, record it as R0, gradually increase the value of L2 and calculate the corresponding resistance value R 计 , when R 计 =a×R0, that is, the L2 value corresponding to the effective action boundary of the anti-corrosion current, is recorded as L2', and the corresponding resistance value is recorded as R', where a is the preset threshold value and 0.5<a<1.

6. A method for rapid design of parameters of a marine impressed current cathodic protection system according to claim 5, characterized in that In step S3, the number of auxiliary anodes is calculated as follows: Where n is the number of auxiliary anodes, L S Design the waterline length for a given hull.

7. A method for rapid design of parameters of a marine impressed current cathodic protection system according to claim 6, characterized in that In step S4, the equivalent total resistance R of the auxiliary anode n for: Then, the rated output voltage U of the potentiostat is: U=IR n The rated output power P is: P=I 2 R n Where I is the total corrosion resistance current required by the hull.

8. A method for rapid design of parameters of a marine impressed current cathodic protection system according to claim 7, characterized in that In step S5, the output voltage range and power capacity of the potentiostat are calculated as follows: The minimum output voltage U of the potentiostat min for: Maximum output voltage U max for: IN max =U·β Power capacity P of the potentiostat max for: P max =P·γ Wherein, β and γ are both preset coefficients, and β>1, γ>1.

9. A method for rapid design of parameters of a marine impressed current cathodic protection system according to claim 6, characterized in that: The output current I0 of a single auxiliary anode is: I0=I / n.

10. A method for rapid design of parameters of a marine impressed current cathodic protection system according to claim 1, characterized in that In step S6, the output voltage range and power capacity of the constant potential instrument are feasible in engineering, specifically, the calculation results of the voltage range and power capacity are within the preset standard range, and the design results include the adjusted dimensions of the auxiliary anode, insulating bracket, and anode shielding layer.

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