Method for preventing corrosion of aluminum heat sink of cooling water system in converter valve
By combining ion exchange resin and aluminum corrosion inhibitor, the corrosion problem of aluminum radiators in the cooling water system of the converter valve was solved, achieving precise water quality control and equipment reliability, and extending the maintenance cycle.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- STATE GRID HUNAN ELECTRIC POWER COMPANY LIMITED
- Filing Date
- 2023-12-08
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technology cannot accurately control the water quality of the cooling water system inside the converter valve, resulting in severe corrosion of aluminum radiators, frequent scaling of the equalizing electrodes, and short replacement cycles of ion exchange resins, making it difficult to meet maintenance requirements.
A mixed bed composed of mixed ion exchange resins and an aluminum corrosion inhibitor were used to precisely control the conductivity of the internal cooling water between 0.08 μs/cm and 0.095 μs/cm. The internal cooling water was treated with a mixed bed composed of hydrogen-form, hydroxyl-form, and aluminum-removing ion exchange resins, and an aqueous siloxane ketone aluminum corrosion inhibitor was added.
It effectively slows down the corrosion of aluminum heat sinks, extends the service life of ion exchange resin by more than 3 years, reduces the amount of scale on the equalizing electrode, and meets the needs of long-term maintenance.
Abstract
Description
Technical Field
[0001] This invention belongs to the field of corrosion and protection technology, and relates to a corrosion prevention method for aluminum radiators in the cooling water system of a converter valve. Background Technology
[0002] With the continuous development of the power system and the construction of new power systems, a large number of ultra-high voltage (UHV) and high voltage (HVDC) transmission projects are under construction and put into operation. Converter stations are the parts in UHV and HVDC transmission systems that realize the energy conversion between AC and DC, and are also the central link in DC transmission. The converter valve is the most core and critical component of the converter station for AC-DC conversion. During normal operation, it withstands large currents and high voltages, generating a large amount of heat that needs to be dissipated by the internal cooling water system. Currently, corrosion of the internal cooling water system of converter valves is a common problem in converter stations in China, and typical failures of the internal cooling water system occur frequently. According to incomplete statistics, from 2015 to 2021, failures caused by the internal cooling water system accounted for more than 45% of converter station failures. Research shows that the aluminum radiator of the thyristor is the main site of corrosion in the internal cooling water system, and is also the source of problems such as scaling on the equalizing electrode and leakage of the equalizing electrode sealing ring. Preventing corrosion of the aluminum radiator in the internal cooling water system of the converter valve is key to reducing the failure rate of the internal cooling water system of the converter valve.
[0003] Currently, deionized water is used as the cooling medium in the internal cooling water system of the converter valve. Strict requirements are placed on the quality of the internal cooling water to prevent corrosion and scaling that could cause equipment failure. A bypass ion exchange resin method is typically used to purify the internal cooling water and control its conductivity. However, bypass ion exchange resins have the following problems: First, they cannot precisely control the quality of the internal cooling water in the converter valve; the conductivity cannot always be maintained within the optimal corrosion-resistant range for aluminum radiators, i.e., 0.08 μs / cm to 0.10 μs / cm. Second, conventional ion exchange resins cannot effectively remove Al metal ions from the internal cooling water. 3+ Complete removal, Al 3+ The presence of these factors leads to scaling on the equalizing electrodes, and thirdly, the ion exchange resin needs to be replaced annually. According to an investigation of the existing cooling water system operation within the converter valve, due to the presence of leakage current and the high solubility of low-conductivity pure water, the aluminum radiator has a high corrosion rate, resulting in severe scaling on the equalizing electrodes. Simultaneously, the short replacement cycle of the ion exchange resin makes it difficult to meet the requirements of lean maintenance in converter stations. Therefore, a new method for preventing corrosion of aluminum radiators in the cooling water system within the converter valve is needed to reduce scaling on the equalizing electrodes. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a corrosion prevention method for aluminum radiators in the internal cooling water system of the converter valve that can slow down the corrosion of aluminum radiators, has high reliability and long maintenance cycle.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.
[0006] A method for preventing corrosion of aluminum radiators in a converter valve internal cooling water system involves passing the internal cooling water of the converter valve through a mixed bed composed of mixed ion exchange resins. The conductivity of the internal cooling water is controlled to be 0.08 μs / cm to 0.095 μs / cm. The mixed ion exchange resins consist of hydrogen-form ion exchange resins, hydroxide-form ion exchange resins, and aluminum-removing ion exchange resins, with an exchange capacity ratio of 1:1:2 to 2.5. An aluminum corrosion inhibitor is added to the internal cooling water after passing through the mixed bed, and the system continues to operate within the converter valve internal cooling water system to achieve corrosion prevention of the aluminum radiators.
[0007] In the above-mentioned corrosion prevention method for aluminum radiators in the cooling water system of the converter valve, preferably, the mixed bed composed of the mixed ion exchange resin treats 100% flow rate of the cooling water inside the converter valve.
[0008] In the above-mentioned corrosion prevention method for aluminum radiators in the cooling water system of the converter valve, preferably, the hydrogen-form ion exchange resin is Rohm and Hach IRN 97 hydrogen-form ion exchange resin, the hydroxyl-form ion exchange resin is Rohm and Hach IRN 78 hydroxyl-form ion exchange resin, and the aluminum removal ion exchange resin is Dusheng T-62MP aluminum removal ion exchange resin.
[0009] In the above-mentioned corrosion prevention method for aluminum radiators in the cooling water system of the converter valve, preferably, the number of mixed beds is two or more.
[0010] In the above-mentioned corrosion prevention method for aluminum radiators in the cooling water system of the converter valve, preferably, the hydrogen-type ion exchange resin, the hydroxide-type ion exchange resin, and the aluminum removal ion exchange resin are pretreated and mixed before use.
[0011] In the above-mentioned corrosion prevention method for aluminum radiators in the cooling water system of the converter valve, preferably, the aluminum corrosion inhibitor is a water-based siloxane ketone aluminum corrosion inhibitor, which must meet the following conditions: completely soluble in water and does not ionize in water.
[0012] In the above-mentioned corrosion prevention method for aluminum radiators in the cooling water system of the converter valve, preferably, the aluminum corrosion inhibitor is AC-5S aluminum corrosion inhibitor from Shanghai Miling Chemical Co., Ltd.
[0013] In the above-mentioned corrosion prevention method for aluminum radiators in the cooling water system of the converter valve, preferably, the mass fraction of the aluminum corrosion inhibitor in the cooling water of the converter valve is 0.01% to 0.05%.
[0014] In the above-mentioned corrosion prevention method for aluminum radiators in the cooling water system of the converter valve, preferably, the aluminum corrosion inhibitor is automatically and quantitatively added using a metering pump.
[0015] In this invention, the mixed bed composed of mixed ion exchange resins can be set as a water treatment unit after the cold water pump and before the converter valve, but is not limited thereto.
[0016] Compared with the prior art, the advantages of the present invention are as follows:
[0017] This invention employs a mixed bed of ion exchange resins consisting of hydrogen-form ion exchange resin, hydroxide-form ion exchange resin, and aluminum-removing ion exchange resin, along with the synergistic effect of adding an aluminum corrosion inhibitor. This allows for precise control of the internal cooling water conductivity of the converter valve within the range of 0.08 μs / cm to 0.095 μs / cm, ensuring the internal cooling water quality remains within the low-corrosion zone for aluminum radiators. Furthermore, the ion exchange resins have a long operating cycle, exceeding three years, resulting in extended equipment maintenance intervals. The invention also utilizes a water-based siloxane ketone aluminum corrosion inhibitor with a mass fraction of 0.01% to 0.05%, which not only ensures unaffected water quality but also effectively slows down the corrosion of aluminum radiators. Detailed Implementation
[0018] The present invention will be further described below with reference to specific preferred embodiments, but this does not limit the scope of protection of the present invention. All materials and instruments used in the following embodiments are commercially available.
[0019] Example 1
[0020] A corrosion prevention method for aluminum radiators in a converter valve internal cooling water system according to the present invention includes the following steps: In the converter valve internal cooling water system, the internal cooling water is passed through a mixed bed composed of mixed ion exchange resins to make the conductivity of the internal cooling water 0.09 μs / cm. The mixed ion exchange resins are composed of Rohm and Hach IRN 97 hydrogen-type ion exchange resin, Rohm and Hach IRN 78 hydroxide-type ion exchange resin, and Dusheng T-62MP aluminum removal ion exchange resin with an exchange capacity ratio of 1:1:2. The mixed bed of mixed ion exchange resins is used to 100% purify the internal cooling water quality of the converter valve. The mixed bed is set up with one bed for standby use. An aluminum corrosion inhibitor, specifically AC-5S aluminum corrosion inhibitor from Shanghai Miling Chemical Co., Ltd., is added to the cooling water inside the converter valve after passing through a mixed bed. The aluminum corrosion inhibitor can be automatically and quantitatively added using a metering pump, so that the mass fraction of the aluminum corrosion inhibitor in the cooling water inside the converter valve is 0.03%. The treated cooling water inside the converter valve continues to run in the cooling water system inside the converter valve, thereby achieving corrosion protection for the aluminum radiator.
[0021] In the above embodiments, the method of the present invention can effectively prevent corrosion of aluminum radiators. In simulation tests, after treatment by the method of the present invention, the corrosion of aluminum radiators in the cooling water system inside the converter valve was significantly reduced. 3+ The content was 0, and the scale buildup on the equalizing electrodes was less than 0.2 mg. Meanwhile, the internal cooling water system using Dow MB20 mixed ion exchange resin in a 1:1 ratio without added aluminum corrosion inhibitors...3+ With a content ranging from 1.5 μg / L to 3.2 μg / L and a scaling amount of 45 mg to 500 mg on the equalizing electrode, it can be seen that the present invention effectively prevents corrosion of aluminum radiators.
[0022] Example 2
[0023] A corrosion prevention method for aluminum radiators in a converter valve cooling water system according to the present invention includes the following steps: using a mixed ion exchange resin bed composed of Rohm and Hach IRN 97 hydrogen-type ion exchange resin, Rohm and Hach IRN 78 hydroxyl-type ion exchange resin, and Dusheng T-62MP aluminum-removing ion exchange resin with an exchange capacity ratio of 1:1:2.5 to 100% purify the cooling water quality inside the converter valve, and setting one bed for standby use. The conductivity of the cooling water inside the converter valve is controlled to be 0.08 μs / cm. An aluminum corrosion inhibitor, specifically Shanghai Miling Chemical Co., Ltd.'s AC-5S aluminum corrosion inhibitor, is added to the cooling water inside the converter valve after passing through the mixed bed. The aluminum corrosion inhibitor can be automatically and quantitatively added using a metering pump to make the mass fraction of the aluminum corrosion inhibitor in the cooling water inside the converter valve 0.05%, thereby achieving corrosion prevention for the aluminum radiator.
[0024] The method in this embodiment can effectively prevent corrosion of aluminum radiators. In simulation tests, after treatment by the method of this invention, the corrosion of Al in the cooling water system inside the converter valve was significantly reduced. 3+ The content was 0, and the scaling amount on the equalizing electrode was less than 0.2 mg. Meanwhile, the internal cooling water system using a 1:1 ratio of Dow Rohm and Hach IRN160 mixed ion exchange resin without added aluminum corrosion inhibitors... 3+ With a content of 1.0 μg / L to 1.9 μg / L and a scaling amount of 38 mg to 300 mg on the equalizing electrode, it can be seen that the present invention effectively prevents corrosion of aluminum radiators.
[0025] Comparative Example 1
[0026] A corrosion prevention method for aluminum radiators in a converter valve internal cooling water system differs from Example 1 in that the mixed-bed ion exchange resin is different. Instead, a mixed-bed ion exchange resin composed of Rohm and Hach IRN 97 hydrogen-type ion exchange resin and Rohm and Hach IRN 78 hydroxyl-type ion exchange resin with an exchange capacity ratio of 1:1 is used to 100% purify the cooling water quality inside the converter valve, achieving a conductivity of 0.06 μS / cm. Additionally, 0.03% of Shanghai Milin Chemical Co., Ltd.'s AC-5S aluminum corrosion inhibitor is added to the internal cooling water system.
[0027] In the simulation test, after processing with this comparative method, the Al in the cooling water system inside the converter valve... 3+ The content was 1.2 μg / L, and the scale buildup on the equalizing electrode was 50 mg to 200 mg, which was significantly worse than that of Example 1.
[0028] Comparative Example 2
[0029] A corrosion prevention method for aluminum radiators in a converter valve internal cooling water system differs from Example 2 in that the internal cooling water flow rate is different. A mixed bed of mixed ion exchange resins consisting of Rohm and Hach IRN 97 hydrogen-type ion exchange resin, Rohm and Hach IRN 78 hydroxyl-type ion exchange resin, and Dusheng T-62MP aluminum-removing ion exchange resin with an exchange capacity ratio of 1:1:2.5 is used to purify 50% of the internal cooling water quality of the converter valve. The conductivity of the internal cooling water of the converter valve is 0.07 μs / cm. 0.05 wt% of Shanghai Milin Chemical Co., Ltd.'s AC-5S aluminum corrosion inhibitor is added to the internal cooling water of the converter valve after passing through the mixed bed.
[0030] In the simulation test, after processing with this comparative method, the Al in the cooling water system inside the converter valve... 3+ The content was 2.0 μg / L, and the scale buildup on the equalizing electrode was 100 mg to 700 mg, which was significantly worse than that of Example 2.
[0031] Comparative Example 3
[0032] A corrosion prevention method for aluminum radiators in a converter valve cooling water system differs from Example 1 in that the ion exchange resin ratio is different. A mixed ion exchange resin bed composed of Rohm and Hach IRN 97 hydrogen-type ion exchange resin, Rohm and Hach IRN 78 hydroxide-type ion exchange resin, and Dusheng T-62MP aluminum removal ion exchange resin with an exchange capacity ratio of 1:1:3 is used to 100% purify the cooling water quality inside the converter valve. It is set up with one bed for backup and one bed for use. The conductivity of the cooling water inside the converter valve is 0.12 μs / cm. 0.03 wt% of Shanghai Milin Chemical Co., Ltd.'s AC-5S aluminum corrosion inhibitor is added to the cooling water inside the converter valve after passing through the mixed bed.
[0033] In the simulation test, after processing with this comparative method, the Al in the cooling water system inside the converter valve... 3+ The content was 0.5 μg / L, and the scale buildup on the equalizing electrode was 150 mg to 400 mg, which was significantly worse than that of Example 1.
[0034] Comparative Example 4
[0035] A corrosion prevention method for aluminum radiators in a converter valve cooling water system differs from Example 1 in that the ion exchange resin ratio is different. A mixed bed of mixed ion exchange resins consisting of Rohm and Hach IRN 97 hydrogen-type ion exchange resin, Rohm and Hach IRN 78 hydroxide-type ion exchange resin, and Dusheng T-62MP aluminum removal ion exchange resin with an exchange capacity ratio of 1:2:3 is used to 100% purify the cooling water quality inside the converter valve. The bed is set to be used in a standby configuration. The conductivity of the cooling water inside the converter valve is 0.05 μs / cm. 0.03 wt% of Shanghai Milin Chemical Co., Ltd.'s AC-5S aluminum corrosion inhibitor is added to the cooling water inside the converter valve after it passes through the mixed bed.
[0036] In the simulation test, after processing with this comparative method, the Al in the cooling water system inside the converter valve... 3+ The content was 1.5 μg / L, and the scale buildup on the equalizing electrode was 200 mg to 400 mg, which was significantly worse than that of Example 1.
[0037] Comparative Example 5
[0038] A corrosion prevention method for aluminum radiators in a converter valve cooling water system differs from Example 1 in that: no corrosion inhibitor is added; instead, a mixed bed of ion exchange resins consisting of Rohm and Hach IRN 97 hydrogen-type ion exchange resin, Rohm and Hach IRN 78 hydroxide-type ion exchange resin, and Dusheng T-62MP aluminum-removing ion exchange resin with an exchange capacity ratio of 1:1:2 is used to 100% purify the cooling water quality inside the converter valve, and is set to one for standby use. The conductivity of the cooling water inside the converter valve is 0.09 μs / cm, and no further corrosion inhibitor is added.
[0039] In the simulation test, after processing with this comparative method, the Al in the cooling water system inside the converter valve... 3+ The content was 2.5 μg / L, and the scale buildup on the equalizing electrode was 500 mg to 600 mg, which was significantly worse than that of Example 1.
[0040] Comparative Example 6
[0041] A corrosion prevention method for aluminum radiators in a converter valve cooling water system differs from Example 1 in that the corrosion inhibitor concentration is different. A mixed bed of ion exchange resins consisting of Rohm and Hach IRN 97 hydrogen-type ion exchange resin, Rohm and Hach IRN 78 hydroxide-type ion exchange resin, and Dusheng T-62MP aluminum-removing ion exchange resin with an exchange capacity ratio of 1:1:2 is used to 100% purify the cooling water quality inside the converter valve. The bed is set up with one in reserve and one in use. The conductivity of the cooling water inside the converter valve is 0.09 μs / cm. 0.1 wt% of Shanghai Milin Chemical Co., Ltd.'s AC-5S aluminum corrosion inhibitor is added to the cooling water inside the converter valve after it passes through the mixed bed.
[0042] In the simulation test, after processing with this comparative method, the Al in the cooling water system inside the converter valve... 3+ The content was 1.4 μg / L, and the scale buildup on the equalizing electrode was 100 mg to 300 mg, which was significantly worse than that of Example 1.
[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.
Claims
1. A method for preventing corrosion of aluminum radiators in a cooling water system within a converter valve, characterized in that, In the cooling water system of the converter valve, the cooling water inside the converter valve is passed through a mixed bed composed of mixed ion exchange resins. The conductivity of the cooling water inside the converter valve is controlled to be 0.08 μs / cm to 0.095 μs / cm. The mixed ion exchange resins are composed of hydrogen-form ion exchange resins, hydroxide-form ion exchange resins, and aluminum removal ion exchange resins. The exchange capacity ratio of the hydrogen-form ion exchange resins, hydroxide-form ion exchange resins, and aluminum removal ion exchange resins is 1:1:2 to 2.
5. An aluminum corrosion inhibitor is added to the cooling water inside the converter valve after it passes through the mixed bed, and then the system continues to operate to prevent corrosion of the aluminum radiator. The mixed bed composed of mixed ion exchange resins treats 100% of the flow rate of the cooling water inside the converter valve. The hydrogen-form ion exchange resin is Rohm and Hach IRN 97 hydrogen-form ion exchange resin, the hydroxide-form ion exchange resin is Rohm and Hach IRN 78 hydroxide-form ion exchange resin, and the aluminum removal ion exchange resin is Dusheng T-62MP aluminum removal ion exchange resin. The number of mixed beds is two or more; The hydrogen-form ion exchange resin, hydroxide-form ion exchange resin, and aluminum-removing ion exchange resin are pretreated for impurity removal and mixed before use. The aluminum corrosion inhibitor is a water-based siloxane ketone aluminum corrosion inhibitor, which must meet the following conditions: it is completely soluble in water and does not ionize in water.
2. The corrosion prevention method for aluminum radiators in the cooling water system of the converter valve according to claim 1, characterized in that, The aluminum corrosion inhibitor is AC-5S aluminum corrosion inhibitor from Shanghai Miling Chemical Co., Ltd.
3. The corrosion prevention method for aluminum radiators in the cooling water system of the converter valve according to claim 1, characterized in that, The mass fraction of the aluminum corrosion inhibitor in the cold water inside the converter valve is 0.01% to 0.05%.
4. The corrosion prevention method for aluminum radiators in the cooling water system of the converter valve according to claim 3, characterized in that, The aluminum corrosion inhibitor is added automatically and quantitatively using a metering pump.