A novel dual-electrode arrangement for corrosion protection in converter valves

Abstract

The present invention discloses a novel dual-electrode arrangement structure for anti-corrosion deposition in a converter valve, comprising a voltage-equalizing electrode 1, a voltage-equalizing electrode 2, a collector, a branch tube, an aluminum alloy radiator, a thyristor assembly and a wire, wherein the voltage-equalizing electrode 1 and the voltage-equalizing electrode 2 are installed together on both sides of the collector, the branch tube is connected to the collector, the aluminum alloy radiator is arranged on the branch tube, the thyristor assembly is connected to the aluminum alloy radiator, and the wire is connected to the voltage-equalizing electrode 1, the voltage-equalizing electrode 2 and the aluminum alloy radiator. The present invention belongs to the technical field of converter valves, and specifically refers to a novel dual-electrode arrangement structure for anti-corrosion deposition in a converter valve, which avoids leakage current from flowing through a radiator, solves the problem of electrochemical corrosion and deposition inside a cooling system from the root, and ensures the safe operation of a power transmission system.

Description

Technical Field

[0001] The present invention belongs to the technical field of converter valves, and specifically refers to a novel dual-electrode arrangement structure for anti-corrosion deposition in converter valves. Background Art

[0002] The converter valve is the core equipment of the high-voltage direct current transmission system, which is composed of the basic unit - valve sections in series. Taking the ±500kV converter valve as an example, the flow capacity of the converter valve in the operating converter station is as high as 5.5kA or more. The heat generated by the valve loss must be effectively dissipated to ensure the normal operation of the converter valve. In engineering, a water cooling system is used to dissipate heat for the key components in the converter valve. The water cooling system structure is divided into series type, parallel type and series-parallel mixed type. Thanks to the symmetrical structure and superior heat dissipation performance of the parallel cooling system, most ±500kV converter stations are equipped with a parallel water cooling system. When the converter valve is operating normally, the metal components in direct contact with the cooling water have different high potentials, which will inevitably generate leakage current in the water. Once the leakage current flows through the metal components, it will inevitably bring a series of problems such as electrochemical corrosion and deposition. In the parallel single valve section cooling system, there are still electrochemical corrosion and deposition problems after the converter valve has been in operation for a long time, which will cause a series of problems such as cooling water blockage, water leakage, and heat dissipation failure. In severe cases, the entire transmission system will be locked and shut down. Existing studies have shown that the content of aluminum oxide in the scale deposited on the surface of the equalizing electrode exceeds 96%, and the aluminum element all comes from the aluminum alloy radiator, which means that under the existing technical conditions, the leakage current will still flow through the aluminum alloy radiator, causing electrochemical corrosion, and causing the scale-forming ions containing aluminum elements to enter the cooling water, and a deposition reaction occurs on the surface of the equalizing electrode. Studies have shown that due to the needle-shaped design of the equalizing electrode and the low conductivity of the cooling water, the electric field distribution near the equalizing electrode is more concentrated, causing the potential distribution in the confluence tube to differ from the ideal potential distribution, resulting in a potential difference at both ends of each branch tube, causing the leakage current in the water channel to flow into the branch tube, and then causing electrochemical corrosion on the surface of the radiator that is in direct contact with the cooling water.

[0003] In summary, the traditional voltage-equalizing electrodes adopt a single-electrode arrangement scheme, which is installed perpendicular to the plane at the center of the collector corresponding to the outermost branch pipe of the valve section. This cannot completely suppress the leakage current flowing through the radiator. Based on existing research, a new dual-electrode arrangement structure for anti-corrosion deposition in the converter valve is proposed. Summary of the invention

[0004] In order to solve the above-mentioned problems, the present invention provides a new dual-electrode arrangement structure for anti-corrosion deposition in a converter valve, which avoids leakage current from flowing through the radiator, fundamentally solves the electrochemical corrosion and deposition problems inside the cooling system, and ensures the safe operation of the power transmission system.

[0005] In order to achieve the above functions, the technical solution adopted by the present invention is as follows: a new dual-electrode arrangement structure for anti-corrosion deposition in a converter valve, including an equalizing electrode 1, an equalizing electrode 2, a busbar, a branch tube, an aluminum alloy radiator, a thyristor assembly and a wire, wherein the equalizing electrode 1 and the equalizing electrode 2 are installed together on both sides of the busbar, the branch tube is connected to the busbar, the aluminum alloy radiator is arranged on the branch tube, the thyristor assembly is connected to the aluminum alloy radiator, and the wire is connected to the equalizing electrode 1, the equalizing electrode 2 and the aluminum alloy radiator.

[0006] Preferably, the voltage-equalizing electrode 1 and the voltage-equalizing electrode 2 include a stainless steel electrode, a stainless steel base, a thread, a hexagonal nut structure and an annular groove. The stainless steel electrode is welded to the stainless steel base. The thread is arranged on the side of the stainless steel base close to the stainless steel electrode to enhance the airtightness and stability of the water cooling system during normal operation. The hexagonal nut structure is arranged in the middle of the stainless steel base to improve the convenience during installation. The annular groove is arranged at the top of the stainless steel base, and the top of the stainless steel base is rounded.

[0007] Preferably, the voltage-equalizing electrode 1 is installed perpendicular to the plane direction and is located at 17.6 mm in the X direction of the traditional voltage-equalizing electrode. The length of its stainless steel electrode is equal to the radius of the manifold. The voltage-equalizing electrode 2 is installed parallel to the Y direction of the plane and is inserted from the outside of the manifold to the outlet of the outermost branch pipe of the valve section. The voltage-equalizing electrode 2 is in the same straight line as the branch pipe. The length of its stainless steel electrode is equal to the diameter of the manifold. The positions of the voltage-equalizing electrodes installed at both ends of the two manifolds of the valve section are symmetrically distributed with the voltage-equalizing electrode 1 and the voltage-equalizing electrode 2.

[0008] Preferably, the stainless steel electrode is made of stainless steel and is a solid cylindrical needle-shaped structure as a whole. The tip of the electrode is rounded to make it hemispherical to prevent the electric field near the tip of the stainless steel electrode from being distorted and to weaken the electric field strength. The length is divided into two types: 1. Equal to the radius of the collector, 2. Equal to the diameter of the collector. The radius of the stainless steel electrode is 1 mm.

[0009] Preferably, the stainless steel base is made of stainless steel.

[0010] The present invention adopts the above structure to achieve the following beneficial effects: a new dual-electrode arrangement structure for anti-corrosion deposition in a converter valve provided by the present invention has two electrodes arranged on both sides. This design structure can greatly enhance the role of the equalizing electrode in clamping the potential in the water. Compared with the traditional single-electrode arrangement scheme, the total leakage current flowing through 14 radiators is reduced by 95.7%, and the total leakage current is less than 1μA, thereby reducing the corrosion rate of the aluminum alloy radiator by 95.7%, so that the cooling water contains almost no scaling ions, thereby preventing the deposition reaction of other metal components such as the surface of the equalizing electrode, solving the electrochemical corrosion and deposition problems inside the cooling system from the root, and ensuring the stable and safe operation of the power transmission system; thanks to the superiority of the dual-electrode arrangement scheme in terms of corrosion resistance and deposition, the material used for the equalizing electrode is stainless steel, which is cheaper than the traditional platinum electrode, and the tip of the electrode is designed to be hemispherical, which prevents the electric field around the electrode from being distorted, making it safer; the installation position and direction of the second equalizing electrode are more stable in structure and more resistant to the impact of water flow than directly inserting it into the branch pipe orifice in the vertical plane direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is an overall structural diagram of a new dual-electrode arrangement structure for anti-corrosion deposition in a converter valve proposed by the present invention;

[0012] Figure 2 A three-dimensional structural diagram of a new dual-electrode arrangement structure for anti-corrosion deposition in a converter valve proposed by the present invention.

[0013] Figure 3 This is an overall structural diagram of a voltage-equalizing electrode 1 and a voltage-equalizing electrode 2 of a new dual-electrode arrangement structure for anti-corrosion deposition in a converter valve proposed by the present invention.

[0014] Among them, 1-1, equalizing electrode 1, 1-2, equalizing electrode 2, 2, collector, 3, branch tube, 4, aluminum alloy heat sink, 5, thyristor assembly, 6, wire, 7, stainless steel electrode, 8, stainless steel base, 9, thread, 10, hexagonal nut structure, 11, annular groove. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. The present invention is further described in detail below in conjunction with the accompanying drawings.

[0017] like Figure 1-3 As shown, the present invention proposes a new dual-electrode arrangement structure for anti-corrosion deposition in a converter valve, comprising an equalizing electrode 1-1, an equalizing electrode 2 1-2, a collector 2, a branch tube 3, an aluminum alloy radiator 4, a thyristor assembly 5 and a wire 6. The equalizing electrode 1-1 and the equalizing electrode 2 1-2 are installed together on both sides of the collector 2, the branch tube 3 is connected to the collector 2, the aluminum alloy radiator 4 is arranged on the branch tube 3, the thyristor assembly 5 is connected to the aluminum alloy radiator 4, and the wire 6 is connected to the equalizing electrode 1-1, the equalizing electrode 2 1-2 and the aluminum alloy radiator 4.

[0018] like Figure 3 As shown, the voltage-equalizing electrode 1-1 and the voltage-equalizing electrode 2 1-2 include a stainless steel electrode 7, a stainless steel base 8, a thread 9, a hexagonal nut structure 10 and an annular groove 11. The stainless steel electrode 7 is welded to the stainless steel base 8. The thread 9 is arranged on the side of the stainless steel base 8 close to the stainless steel electrode 7. The hexagonal nut structure 10 is arranged in the middle of the stainless steel base 8. The annular groove 11 is arranged at the top of the stainless steel base 8. The stainless steel electrode 7 is made of stainless steel and is a solid cylindrical needle-shaped structure as a whole. The stainless steel base 8 is made of stainless steel.

[0019] like Figure 2 As shown, the equalizing electrode 1-1 is installed perpendicular to the plane direction and is located 17.6 mm in the X direction of the traditional equalizing electrode. The length of its stainless steel electrode 7 is equal to the radius of the manifold 2. The equalizing electrode 1-2 is installed parallel to the Y direction of the plane and is inserted from the outside of the manifold 2 to the mouth of the outermost branch pipe 3 of the valve section. The equalizing electrode 1-2 and the branch pipe 3 are in the same straight line. The length of its stainless steel electrode 7 is equal to the diameter of the manifold 2. The positions of the equalizing electrodes installed at both ends of the two manifolds 2 of the valve section are symmetrically distributed with the equalizing electrode 1-1 and the equalizing electrode 1-2.

[0020] When used specifically, two electrodes are set on both sides. This design structure can greatly enhance the role of the equalizing electrode in clamping the potential in the water. Compared with the traditional single-electrode arrangement, the total leakage current flowing through the 14 radiators is reduced by 95.7%, and the total leakage current is less than 1μA, thereby reducing the corrosion rate of the aluminum alloy radiator 4 by 95.7%, so that the cooling water contains almost no scaling ions, thereby preventing the deposition reaction of other metal components such as the surface of the equalizing electrode, and solving the electrochemical corrosion and deposition problems inside the cooling system from the root, ensuring the stable and safe operation of the power transmission system. Compared with the installation position and direction of the equalizing electrode 1-2 directly inserted into the branch pipe 3 in the vertical plane direction, the structure is more stable and more resistant to the impact of water flow.

[0021] The present invention and its embodiments are described above, and such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.

Claims

1. A novel dual-electrode arrangement structure for anti-corrosion deposition in a converter valve, characterized in that: It includes a voltage-equalizing electrode 1, a voltage-equalizing electrode 2, a busbar, a branch tube, an aluminum alloy heat sink, a thyristor assembly and a wire, wherein the voltage-equalizing electrode 1 and the voltage-equalizing electrode 2 are installed together on both sides of the busbar, the branch tube is connected to the busbar, the aluminum alloy heat sink is arranged on the branch tube, the thyristor assembly is connected to the aluminum alloy heat sink, and the wire is connected to the voltage-equalizing electrode 1, the voltage-equalizing electrode 2 and the aluminum alloy heat sink; The voltage-equalizing electrode 1 and the voltage-equalizing electrode 2 include a stainless steel electrode, a stainless steel base, a thread, a hexagonal nut structure and an annular groove. The stainless steel electrode is welded to the stainless steel base, the thread is arranged on the stainless steel base close to the stainless steel electrode, the hexagonal nut structure is arranged in the middle of the stainless steel base, and the annular groove is arranged at the top of the stainless steel base; The voltage-equalizing electrode 1 is installed perpendicular to the plane direction and is located at 17.6 mm in the X direction of the traditional voltage-equalizing electrode. The length of its stainless steel electrode is equal to the radius of the manifold. The voltage-equalizing electrode 2 is installed parallel to the Y direction of the plane and is inserted from the outside of the manifold to the outlet of the outermost branch pipe of the valve section. The voltage-equalizing electrode 2 is in the same straight line as the branch pipe. The length of its stainless steel electrode is equal to the diameter of the manifold. The voltage-equalizing electrodes installed at both ends of the two manifolds of the valve section are symmetrically distributed with the voltage-equalizing electrode 1 and the voltage-equalizing electrode 2. The stainless steel electrode is made of stainless steel and is a solid cylindrical needle-shaped structure as a whole; The stainless steel base is made of stainless steel.

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