Self-power-generation metal cathode protection system based on moisture power generation as well as construction method and application of self-power-generation metal cathode protection system

Abstract

The invention discloses a self-power-generation metal cathode protection system based on moisture power generation, which comprises engineering metal to be protected, a moisture power generator, a constant potential rectifier, an auxiliary anode and a reference electrode, and is characterized in that the engineering metal to be protected is electrically connected with a negative electrode of the moisture power generator, and the auxiliary anode is electrically connected with a positive electrode of the moisture power generator through the constant potential rectifier; the reference electrode is electrically connected with the constant potential rectifier and is used for detecting the current in the loop and the real-time electrode potential of the engineering metal to be protected; the moisture generator can generate electricity by itself or serve as electric energy supplement for traditional cathode protection, a large amount of moisture in the environment is converted into electric energy to provide direct current for metal, electrons flow into the metal from the negative electrode, the corrosion potential of the protected metal is reduced, and cathode protection is achieved; according to the mode, the output performance is highly adjustable, direct current is output, the current density is large, a rectifier is not needed, the structure is simple, the size is small, use of fossil energy in the cathode protection process is reduced, and the characteristic of environmental protection is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal corrosion and protection, and in particular to a self-generating metal cathode protection system based on moisture power generation, a construction method and an application thereof. Background Art

[0002] Among corrosion prevention and control measures, cathodic protection is an efficient, long-term and reliable technology, especially suitable for metal protection in harsh environments. It mainly includes two methods: impressed current protection and sacrificial anode protection.

[0003] Traditional impressed current protection requires the use of fossil energy conversion to provide electrical energy as an external power source to apply cathode current to the protected metal, which is not in line with the concept of green development; while triboelectric cathodic protection requires the use of rectifiers and other components to convert the generated AC into DC, resulting in a complex structure and troublesome assembly and maintenance. Therefore, the present invention proposes a self-generating metal cathode protection system based on wet gas power generation, as well as a construction method and application to solve the problems existing in the prior art. Summary of the Invention

[0004] In response to the above problems, the purpose of the present invention is to propose a self-generating metal cathodic protection system based on wet gas power generation, as well as a construction method and application. The wet gas generator can generate self-generated electricity or serve as a supplementary power source for existing external current cathodic protection. A large amount of moisture in the environment is converted into electrical energy to provide direct current to the metal. Electrons flow from the negative electrode into the metal, reducing the corrosion potential of the protected metal and realizing cathodic protection. This method directly outputs direct current with a high current density, does not require a rectifier, has a simple structure and a small size, reduces the use of fossil energy, and is green and environmentally friendly.

[0005] To achieve the purpose of the present invention, the present invention is implemented through the following technical scheme: a self-generating metal cathodic protection system based on wet gas power generation, including the engineering metal to be protected, a wet gas generator, a constant potential meter, an auxiliary anode and a reference electrode, the engineering metal to be protected is electrically connected to the negative pole of the wet gas generator, the auxiliary anode is electrically connected to the positive pole of the wet gas generator through the constant potential meter, and the reference electrode is electrically connected to the constant potential meter, which is used to detect the current in the circuit and the real-time electrode potential of the engineering metal to be protected.

[0006] A method for constructing a self-generating metal cathode protection system based on wet gas power generation comprises the following steps:

[0007] Step 1: Investigate and understand the basic parameters of the metal to be protected and the equipment information;

[0008] Step 2: Investigate the corrosion environment parameters of the protected metal and derive the density of the protection current based on the parameters;

[0009] Step 3: Design a corresponding wet gas generator based on the protection requirements of the metal being protected and the parameters obtained in Steps 1 and 2;

[0010] Step 4: Determine the layout of the auxiliary anode and reference electrode based on the protection requirements of the protected metal and the protection range of different auxiliary anodes;

[0011] Step 5: Connect the designed circuit. The wet gas generator will spontaneously absorb moisture to provide electrons for the protected metal, so that it can achieve cathodic polarization protection or serve as a supplementary power source for the existing cathodic protection system.

[0012] A further improvement is that the basic parameters in step 1 include the metal material, surface condition, protection area and volume of the protected metal; the surface condition specifically refers to whether there is a protective coating on the surface.

[0013] A further improvement is that the corrosion environment parameters in step 2 include ambient temperature, humidity change, seawater oxygen content, salinity and resistivity.

[0014] A self-generated metal cathodic protection system based on wet gas power generation is used in metal corrosion protection. It uses the wet gas power generation phenomenon to achieve self-generated impressed current cathodic protection, or as an energy supplement for traditional cathodic protection.

[0015] The beneficial effects of the present invention are: the present invention can generate electricity by itself through the wet gas generator, and utilizes a large amount of moisture in the environment to convert into electrical energy to provide direct current to the metal. Electrons flow from the negative electrode into the metal, thereby reducing the corrosion potential of the protected metal, realizing cathodic protection or serving as a supplementary power source for existing cathodic protection. This method directly outputs direct current with a high current density, does not require a rectifier, has a simple structure and a small size, reduces the use of fossil energy, is green and environmentally friendly, and can sustainably and effectively protect easily corroded metals, thereby reducing the electricity cost of traditional cathodic protection, and has considerable application prospects in self-powered corrosion protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention.

[0017] Figure 2 This is a diagram showing the open circuit potential measurement of 304 stainless steel in Example 1 of the present invention.

[0018] Figure 3 This is a Tafel curve measurement diagram of 304 stainless steel in Example 1 of the present invention.

[0019] Figure 4 This is a diagram showing the open circuit potential measurement of pure copper in Example 2 of the present invention.

[0020] Figure 5 This is a measurement diagram of the pure copper Tafel curve in Example 2 of the present invention. DETAILED DESCRIPTION

[0021] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0022] In a simulated seawater environment, the metal being protected is assembled in a three-electrode system, known as a cathodic protection system. First, the required protection conditions for the commonly corroded metals to be protected are determined, including protection potential, minimum protection current density, and other requirements. This is done to avoid insufficient protection under these conditions, power loss in power generation devices, and reduced protection effectiveness.

[0023] The negative electrode of the wet gas generator is connected to the protected metal, allowing the wet gas generator to provide electrons to the protected metal, shifting the electrode potential negatively to the cathode protection zone. The positive electrode of the wet gas generator is connected to a potentiostat, which is used to monitor the stability of the applied current in the circuit and the polarization potential of the protected metal in real time.

[0024] A 3.5 wt % sodium chloride solution is used to simulate the seawater corrosion environment. For the wet gas generator environment, an ambient temperature of 25° C. and a relative humidity of 20%-90% are proposed.

[0025] In order to meet the cathodic protection requirements of different metals, a single wet gas generator is designed to be integrated in series and parallel.

[0026] Example 1

[0027] according to Figure 2 and Figure 3 As shown, this embodiment provides a self-generating metal cathodic protection system based on moisture power generation to perform cathodic protection experiments on 304 stainless steel samples.

[0028] A moisture generator with an effective area of ​​1 x 2 cm was used to provide protection current to a 304 stainless steel sheet with an exposed surface area of ​​1 x 1 cm. The generator was operated at a temperature of 25°C and a relative humidity of 70%. A three-electrode system used a saturated calomel electrode as the reference electrode and a platinum electrode as the auxiliary anode. The negative electrode of the moisture generator was connected to the 304 stainless steel sheet, while the positive electrode was connected to the platinum electrode via a potentiostat.

[0029] As the instruction manual Figure 2 As shown in the figure, before the wet gas generator was connected, the open circuit potential remained at its initial state, approximately -0.1 V. When the sample was connected to the wet gas generator, the open circuit potential decreased by 260 mV compared to the initial state. When the sample was disconnected from the wet gas generator, the open circuit potential gradually returned to its initial value, verifying the effectiveness and repeatability of the power generation system.

[0030] As the instruction manual Figure 3As shown in the figure, the polarization curves with and without the wet gas generator connected. When the cathodic protection system is connected, the corrosion potential of the metal sample becomes more negative, which is consistent with the change trend of the open circuit potential. The results show that the wet gas generator can improve the corrosion resistance of 304 stainless steel as a power source. Figure 3 The self-corrosion potential, corrosion current density, anodic Tafel slope and cathodic Tafel slope calculated by fitting are summarized in Table 1 below.

[0031] The following table 1 shows that the self-corrosion potential of 304 stainless steel shifts from the original -0.45114 V to -0.5259 V. Due to the existence of the external current, the total current density increases from 0.6051 μA cm -2 Positive shift to 13.794 μAcm -2 .

[0032] Table 1

[0033]

[0034] Example 2

[0035] according to Figure 4 and Figure 5 As shown, this embodiment provides a self-generating metal cathodic protection system based on moisture power generation to conduct cathodic protection experiments on pure copper samples.

[0036] A moisture generator with an effective area of ​​2 x 4 cm was used to provide protection current for pure copper with an exposed area of ​​1 x 1 cm. The moisture generator was operated at a temperature of 25°C and a relative humidity of 70%. A three-electrode system used a saturated calomel electrode as the reference electrode and a platinum electrode as the auxiliary anode. The negative electrode of the moisture generator was connected to the copper, while the positive electrode was connected to the platinum electrode via a potentiostat.

[0037] As the instruction manual Figure 4 As shown in the figure, before the wet gas generator is connected, the open circuit potential remains at the initial state, about -0.26 V. When the sample is connected to the wet gas generator, the open circuit potential value drops by 500 mV, indicating that the self-generating system is effective and repeatable for the cathode polarization of copper.

[0038] As the instruction manual Figure 5 As shown in the figure, the trend of polarization curves with and without the wet gas generator connected is consistent with the trend of open circuit potential, that is, the corrosion potential decreases and the total current density increases. This shows that the wet gas generator, as an external power source, polarizes the copper sample cathode, reducing its surface potential. Figure 5 The self-corrosion potential, total current density, anodic Tafel slope and cathodic Tafel slope calculated by fitting are summarized in Table 2 below.

[0039] Table 2 shows that the self-corrosion potential of copper shifted from -0.33269 V to -0.36496 V. At the same time, due to the addition of external current, the total current density increased from 2.9702 μA cm -2 Positive shift to 36.599 μAcm -2 .

[0040] Table 2

[0041]

[0042] The method of the present invention can provide direct current to the protected metal without rectifier regulation, simplifying the cathodic protection equipment circuit and reducing equipment energy loss. By absorbing readily available moisture and converting it into electrical energy under environmentally friendly conditions, it replaces the use of traditional fossil fuels. The method also features a simple process, easy integration, environmental friendliness, and a wide response range, meeting the needs of metal cathodic protection in a variety of environments.

[0043] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-generating metal cathodic protection system based on wet gas power generation, characterized by: It includes the engineering metal to be protected, a wet gas generator, a constant potential meter, an auxiliary anode and a reference electrode. The engineering metal to be protected is electrically connected to the negative pole of the wet gas generator, the auxiliary anode is electrically connected to the positive pole of the wet gas generator through the constant potential meter, and the reference electrode is electrically connected to the constant potential meter, and is used to detect the current in the circuit and the real-time electrode potential of the engineering metal to be protected.

2. The method for constructing a self-generating metal cathode protection system based on wet gas power generation according to claim 1, characterized in that: The following steps are involved: Step 1: Investigate and understand the basic parameters, equipment information and environmental information of the metal to be protected; Step 2: Investigate the corrosion environment parameters of the protected metal and derive the density of the protection current based on the parameters; Step 3: Design a corresponding wet gas generator based on the protection requirements of the metal being protected and the parameters obtained in Steps 1 and 2; Step 4: Determine the layout of the auxiliary anode and reference electrode based on the protection requirements of the protected metal and the protection range of different auxiliary anodes; Step 5: Connect the designed circuit. The wet gas generator will spontaneously absorb moisture to provide electrons for the protected metal, thus achieving cathodic polarization protection or serving as a supplementary power source for the existing cathodic protection system. Step 6: Regularly inspect and replace the wet gas generator to keep the metal in a cathodic polarization state for a long time.

3. The method for constructing a self-generating metal cathodic protection system based on wet gas power generation according to claim 2, characterized in that: The basic parameters in step 1 include the metal material, surface condition, protection area and volume of the protected metal; the surface condition specifically refers to whether there are corrosion products, oxide layers, pitting and scratch defects on the surface.

4. The method for constructing a self-generating metal cathodic protection system based on wet gas power generation according to claim 2, characterized in that: The corrosion environment parameters in step 2 include ambient temperature, humidity change, seawater oxygen content, salinity and resistivity.

5. Application of the metal cathodic protection system according to claim 1 in metal corrosion protection, which utilizes the phenomenon of moisture power generation to achieve self-generated impressed current cathodic protection, or serves as an energy supplement for traditional cathodic protection.

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