Converter valve voltage-sharing electrode scale layer detection method and device

Abstract

The invention belongs to the technical field of converter valve cooling control, and particularly relates to a converter valve voltage-sharing electrode scale layer detection method and device. Scale layer resistance enabling leakage current between a metal pipeline and deionized water to reach the leakage current allowable maximum value serves as a scale layer resistance threshold value, voltage-sharing electrodes symmetrically arranged in a converter valve tower are selected, when only one voltage-sharing electrode is arranged on the same section of a water pipe of the converter valve tower, one voltage-sharing electrode serves as a measuring electrode, and the other voltage-sharing electrode serves as a measuring electrode. The other uniform electrode is a reference electrode; respectively testing the loop resistance of the measuring electrode and the loop resistance of the reference electrode, respectively taking down the jumpers corresponding to the voltage-sharing electrodes during testing, calculating the difference value between the loop resistance of the measuring electrode and the loop resistance of the reference electrode, taking the difference value as the scale layer resistance and comparing the scale layer resistance with a scale layer resistance threshold value; the scaling condition of the voltage-sharing electrode of the converter valve is determined, the voltage-sharing electrode does not need to be disassembled, the structure of the voltage-sharing electrode is not damaged, and the obtained scale layer condition is more accurate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cooling control of converter valve, and particularly relates to a converter valve equalizing electrode scale layer detection method and device. BACKGROUND

[0002] The converter valve is a key equipment of the high-voltage direct current transmission system, and each component will generate a large amount of heat during operation, so that a valve cooling system needs to be used to cool the converter valve. The valve cooling system takes away the heat in the converter valve assembly through circulating cooling water, and exchanges the heat in the aluminum alloy radiator to the environment, so as to make the converter valve work normally. The cooling water generally uses deionized water, and the conductivity of the deionized water is usually 0.1-0.5 μS / cm. Since the cooling water of the valve cooling system flows through metal pieces (including metal pipelines, radiators and other metal components) of different potentials, the water path between the metal pieces of different potentials under the high-voltage and complex electromagnetic field environment will generate a leakage current, so that the metal pieces will be subjected to electrolytic corrosion. Therefore, in the prior art, an equalizing electrode is generally arranged in the water path of the converter valve cooling system, so that the leakage current is transferred from the metal to the inert equalizing electrode, and the metal pieces have the same potential through the equipotential line of the equalizing electrode, so as to avoid the corrosion of the metal equipment.

[0003] The equalizing electrode is continuously scaled during work, and the scale layer falling off will cause the electrode to fail, resulting in corrosion of the metal water pipe, and may also block the internal cooling water pipeline, and further damage the valve tower equipment, so that the scaling condition of the equalizing electrode needs to be grasped in time, and the scaling needs to be removed in time. The prior art is to periodically check the equalizing electrode, and the checking method is to disassemble the equalizing electrode after draining water, measure the thickness of the equalizing electrode, judge whether the electrode is failed through the thickness, and remove the scale by a mechanical method. The process of disassembling the equalizing electrode is relatively cumbersome, and the accuracy of detecting the scaling condition of the equalizing electrode according to the thickness is low, and repeatedly disassembling the equalizing electrode is easy to make the sealing washer loose, so that the scaling detection efficiency of the equalizing electrode is low and the equalizing electrode is damaged. SUMMARY

[0004] The purpose of the present application is to provide a converter valve equalizing electrode scale layer detection method and device, which solves the problems of low detection efficiency, low accuracy and easy damage to the equalizing electrode when the equalizing electrode is disassembled and the equalizing electrode scale layer is detected according to the thickness of the equalizing electrode.

[0005] The application provides a method for detecting scale layers of voltage-sharing electrodes of a converter valve to solve the above technical problems, and the method comprises the following steps: selecting voltage-sharing electrodes symmetrically arranged in a water pipe of a converter valve tower; when there is only one voltage-sharing electrode arranged in the same section of the water pipe of the converter valve tower, one of the voltage-sharing electrodes is a measurement electrode, and the other voltage-sharing electrode is a reference electrode; respectively testing the loop resistance of the measurement electrode and the loop resistance of the reference electrode, and taking out the jumpers corresponding to the voltage-sharing electrodes respectively during the testing; wherein one end of the loop is the corresponding voltage-sharing electrode, and the other end of the loop is the metal component closest to the water pipe in terms of distance; calculating the difference between the loop resistance of the measurement electrode and the loop resistance of the reference electrode, taking the difference as the scale layer resistance, comparing the scale layer resistance with a scale layer resistance threshold value, and determining the scale formation condition of the voltage-sharing electrodes of the converter valve; and the scale layer resistance threshold value is the scale layer resistance that makes the leakage current between the metal pipe and the deionized water reach the maximum allowable value of the leakage current.

[0006] Further, the scale layer resistance threshold value is calculated according to the following formula:

[0007]

[0008] wherein R0 is the scale layer resistance threshold value, I0 is the maximum allowable value of the leakage current, R1 is the water pipe resistance between the voltage-sharing electrode and the metal pipe, I 总 is the total current, U is the voltage difference between the symmetrically arranged voltage-sharing electrodes, and R2 is the water pipe resistance between the symmetrically arranged voltage-sharing electrodes.

[0009] Further, if the voltage-sharing electrode is arranged in an S-shaped water pipe or an interlayer water pipe, the metal component closest to the water pipe in terms of distance is a metal flange; and if the voltage-sharing electrode is arranged in a water pipe in a valve layer of the valve tower, the metal component closest to the water pipe in terms of distance is a heat sink made of metal.

[0010] Further, the method further comprises the following step: after the testing of the loop resistance of the measurement electrode and the loop resistance of the reference electrode is completed, the jumpers corresponding to the voltage-sharing electrodes are restored.

[0011] To solve the above technical problems, the application further provides a device for detecting scale layers of voltage-sharing electrodes of a converter valve, which comprises a data acquisition module and a judgment module; the data acquisition module is used for acquiring the loop resistance of a measurement electrode and the loop resistance of a reference electrode; the measurement electrode and the reference electrode are two voltage-sharing electrodes symmetrically arranged in a water pipe of a converter valve tower when there is only one voltage-sharing electrode arranged in the same section of the water pipe of the converter valve tower; during the testing, the jumpers corresponding to the voltage-sharing electrodes are taken out, one end of the data acquisition module is connected to the corresponding voltage-sharing electrode, and the other end of the data acquisition module is connected to the metal component closest to the water pipe in terms of distance; and the judgment module is used for calculating the difference between the loop resistance of the measurement electrode and the loop resistance of the reference electrode, taking the difference as the scale layer resistance, comparing the scale layer resistance with a scale layer resistance threshold value, and determining the scale formation condition of the voltage-sharing electrodes of the converter valve; and the scale layer resistance threshold value is the scale layer resistance that makes the leakage current between the metal pipe and the deionized water reach the maximum allowable value of the leakage current.

[0012] Further, the scale layer resistance threshold is calculated according to the following formula:

[0013]

[0014] Wherein, R0 is the scale layer resistance threshold, I0 is the maximum allowable leakage current, R1 is the water path resistance between the grading electrode and the metal pipeline, I 总 is the total current, U is the voltage difference between the symmetrically arranged grading electrodes, R2 is the water path resistance between the symmetrically arranged grading electrodes.

[0015] The beneficial effects of the above technical solution are: the present application is an open-ended invention, the arrangement position of the grading electrode in the converter valve tower has symmetry, through historical inspection data statistics, the specific rule that "the symmetrically arranged grading electrode has one end scaling and the other end not scaling" is obtained, therefore, when the water pipe of the converter valve tower is arranged with only one grading electrode in the same section, two symmetrically arranged grading electrodes in the converter valve tower are selected for detection, one as a measurement electrode and the other as a reference electrode, since the water path resistances of the measurement electrode and the reference electrode are consistent, the wire resistance can be ignored, a measurement loop is designed to connect the grading electrode at one end and the metal part closest to the water path at the other end, the grading electrode-deionized water-metal part in the measurement loop constitutes a conductive loop, the difference of the loop resistances of the measurement electrode and the reference electrode is tested to determine the extra scale layer resistance, and the scale layer resistance that makes the leakage current between the metal pipeline and the deionized water reach the maximum allowable leakage current is taken as a standard to evaluate the calculated scale layer resistance, to judge the scaling condition of the grading electrode and whether it is invalid, the measurement principle is more in line with the function of the grading electrode itself, compared with the measurement thickness, the scale layer condition obtained by the present application is more accurate, and the grading electrode does not need to be disassembled, the structure of the grading electrode is not damaged, the inspection efficiency of the on-site maintenance personnel is greatly improved, thereby ensuring the safe operation of the converter valve, and the present application has high application value in the fields of electrical test and converter valve maintenance.

[0016] To solve the above technical problems, the application further provides a method for detecting scale layers of equalizing electrodes of a converter valve, comprising: when three equalizing electrodes are arranged on the same section of a water pipe of a converter valve tower, the symmetrically arranged equalizing electrodes are scale-forming electrodes and non-scale-forming electrodes, wherein three scale-forming electrodes are arranged on one section, and three non-scale-forming electrodes are arranged on one section; three equalizing electrodes of each section form a measuring loop in pairs, and the loop resistance between scale-forming electrodes and the loop resistance between non-scale-forming electrodes are tested respectively, and the corresponding equalizing electrode jumpers are removed during the testing; the loop resistance between scale-forming electrodes comprises scale layer resistances of two scale-forming electrodes and water path resistances, and the loop resistance between non-scale-forming electrodes comprises water path resistances between two non-scale-forming electrodes; the scale layer resistances of the three scale-forming electrodes are calculated based on the loop resistance between scale-forming electrodes and the loop resistance between non-scale-forming electrodes, and compared with a scale layer resistance threshold value to determine the scale-forming condition of the corresponding scale-forming electrode; the scale layer resistance threshold value is a scale layer resistance that makes the leakage current between a metal pipe and deionized water reach a maximum allowed value of leakage current.

[0017] Further, the scale layer resistance is calculated according to the following formula:

[0018]

[0019] wherein R 垢1 is the scale layer resistance of the first scale-forming electrode, R 垢2 is the scale layer resistance of the second scale-forming electrode, R 垢3 is the scale layer resistance of the third scale-forming electrode, R 结垢A is the loop resistance between the first scale-forming electrode and the second scale-forming electrode, R 结垢B is the loop resistance between the second scale-forming electrode and the third scale-forming electrode, R 结垢C is the loop resistance between the first scale-forming electrode and the third scale-forming electrode, R 不结垢A is the loop resistance between the first non-scale-forming electrode and the second non-scale-forming electrode, R 不结垢B is the loop resistance between the second non-scale-forming electrode and the third non-scale-forming electrode, and R 不结垢C is the loop resistance between the first non-scale-forming electrode and the third non-scale-forming electrode.

[0020] To solve the above technical problems, the application further provides a detection device for scale layers of equalizing electrodes of a converter valve, comprising a data acquisition module and a judgment module; the data acquisition module is used for acquiring loop resistances between scale electrodes and loop resistances between non-scale electrodes, the loop resistances between scale electrodes comprise scale layer resistances and waterway resistances of two scale electrodes, the loop resistances between non-scale electrodes comprise waterway resistances between two non-scale electrodes, the scale electrodes and the non-scale electrodes refer to symmetrically arranged equalizing electrodes in a converter valve tower; during testing, jumpers corresponding to the equalizing electrodes are taken down respectively, when three equalizing electrodes are arranged on one section in a water pipe of the converter valve tower, three scale electrodes are arranged on one section, three non-scale electrodes are arranged on one section, three equalizing electrodes of each section form a measuring loop in pairs, and the data acquisition module is connected to each measuring loop; the judgment module is used for calculating scale layer resistances of the three scale electrodes based on the loop resistances between the scale electrodes and the loop resistances between the non-scale electrodes, and comparing the scale layer resistances with a scale layer resistance threshold value to determine scale conditions of the corresponding scale electrodes; the scale layer resistance threshold value is a scale layer resistance that makes a leakage current between a metal pipe and deionized water reach a maximum allowed value of the leakage current.

[0021] Further, the scale layer resistance is calculated according to the following formula:

[0022]

[0023] wherein, R 垢1 is the scale layer resistance of the first scale electrode, R 垢2 is the scale layer resistance of the second scale electrode, R 垢3 is the scale layer resistance of the third scale electrode, R 结垢A is the loop resistance between the first scale electrode and the second scale electrode, R 结垢B is the loop resistance between the second scale electrode and the third scale electrode, R 结垢C is the loop resistance between the first scale electrode and the third scale electrode, R 不结垢A is the loop resistance between the first non-scale electrode and the second non-scale electrode, R 不结垢B is the loop resistance between the second non-scale electrode and the third non-scale electrode, and R 不结垢C is the loop resistance between the first non-scale electrode and the third non-scale electrode.

[0024] The beneficial effects of the above technical solutions are: the application is an opening-type invention, the arrangement position of the grading electrode in the converter valve tower has symmetry, and a specific rule that "the symmetrically arranged grading electrode has one end scaling and the other end not scaling" is obtained through historical inspection data statistics, so that the grading electrode arranged in one section of the water pipe scales, and the grading electrode arranged in the other section does not scale, for the case that three grading electrodes are arranged in one section, each two grading electrodes form a measurement loop, since the loop resistance between the scaling electrodes includes the scale layer resistance of the two scaling electrodes and the water resistance, and the loop resistance between the non-scaling electrodes includes the water resistance between the two non-scaling electrodes, therefore, only by testing the loop resistances, the scale layer resistance of the three scaling electrodes can be calculated, and the scale layer resistance that makes the leakage current between the metal pipe and the deionized water reach the maximum allowable value of the leakage current is taken as a standard to evaluate the calculated scale layer resistance, to judge the scaling condition of the grading electrode and whether the grading electrode is invalid, the measurement principle is more in line with the function of the grading electrode itself, compared with the measurement thickness, the scale layer condition obtained by the application is more accurate, and the grading electrode does not need to be disassembled, the structure of the grading electrode is not damaged, the inspection efficiency of the on-site maintenance personnel is greatly improved, thereby ensuring the safe operation of the converter valve, and the application has high application value in the fields of electrical test and converter valve maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a converter valve grading electrode scale layer detection flowchart of the method embodiment one of the application;

[0026] Figure 2 is a grading electrode absorption leakage current model diagram of the method embodiment one of the application;

[0027] Figure 3 is a grading electrode-metal water pipe flange test loop wiring diagram of the method embodiment one of the application;

[0028] Figure 4 is a grading electrode-radiator test loop wiring diagram of the method embodiment one of the application;

[0029] Figure 5 is a grading electrode test loop wiring diagram of the method embodiment two of the application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the application more clear and explicit, the specific embodiments of the application are further described below with reference to the drawings.

[0031] The present application utilizes the symmetrical arrangement of the equalizing electrodes in the valve tower, and obtains the rule that "the symmetrically arranged equalizing electrodes have one end scaling and the other end not scaling" through the historical inspection data statistics, detects the symmetrically arranged equalizing electrodes in the valve tower, determines the scale layer resistance of the scaling electrode by using the difference method, and determines the scale layer condition of the equalizing electrode based on the scale layer resistance.

[0032] Method embodiment one

[0033] A scaling layer detection method for equalizing electrodes of a valve, as shown in Figure 1 , comprises the following steps:

[0034] 1. Formulate the evaluation index R0 of the scale layer resistance of the equalizing electrode.

[0035] The equalizing electrode is arranged to suppress the leakage current flowing through the metal pipe joint in the water path. Therefore, the present application takes the scale layer resistance of the leakage current between the metal pipe and the deionized water reaching the maximum value of the allowed leakage current as the scale layer resistance threshold, and takes the scale layer resistance threshold R0 as the evaluation index to evaluate the scale layer resistance of the equalizing electrode obtained by testing, so as to determine whether the equalizing electrode is failed.

[0036] The equalizing electrode absorption leakage current model is as shown in Figure 2 , the maximum value of the leakage current flowing through the metal pipe joint (i.e. the leakage current between the metal pipe and the deionized water, the current flowing through the water path resistance between the equalizing electrode and the metal pipe in the model) depends on the scale layer resistance and the water path resistance, and the water path resistance includes the water path resistance R1 between the equalizing electrode and the metal pipe and the water path resistance R2 between the symmetrically arranged equalizing electrodes. The maximum value of the allowed leakage current is I0 when the valve manufacturer designs. Taking the equalizing electrode arranged on the water distribution pipe and the water collection pipe as an example, I0 is the maximum value of the allowed leakage current flowing through the flange when the valve manufacturer designs, and the current value flowing through the metal flange should be less than I0. According to the equalizing electrode absorption leakage current model, the scale layer resistance threshold is calculated according to the following formula:

[0037]

[0038] Wherein, I 总 is the total current, and U is the voltage difference between the symmetrically arranged equalizing electrodes.

[0039] The water path resistance R1 between the equalizing electrode and the metal pipe and the water path resistance R2 between the equalizing electrodes are calculated according to the following formula:

[0040]

[0041] Wherein, R is the calculated water path resistance (water path resistance between the equalizing electrode and the metal pipeline, or water path resistance between the equalizing electrodes), l is the length of the water pipeline of the water path, s is the cross-sectional area of the water path, p is the resistivity of deionized water, and s is the conductivity of deionized water. Generally, s is 0.5 pS / cm.

[0042] 2. Select the measurement circuit corresponding to the equalizing electrode.

[0043] During measurement, the symmetrically arranged equalizing electrodes in the water pipeline of the converter valve tower are selected. When there is only one equalizing electrode arranged in the same cross section of the water pipeline of the converter valve tower, one of the equalizing electrodes is the measurement electrode, and the other equalizing electrode is the reference electrode. When measuring the scale layer resistance of the equalizing electrode, an electrically conductive circuit must be formed. One end of the circuit is the equalizing electrode, and the other end is the metal component closest to the water path.

[0044] As shown in Figure 3 , if the equalizing electrode is arranged in the S-shaped water pipeline or the interlayer water pipeline, the metal flange is the metal component closest to the water path. As shown in Figure 4 , if the equalizing electrode is arranged in the valve layer water pipeline of the valve tower, the heat sink made of metal (such as an aluminum alloy heat sink) is the metal component closest to the water path.

[0045] 3. Determine the measurement electrode and the reference electrode.

[0046] Through years of maintenance statistics, the structure rule of the equalizing electrode is that "the electrode surface where the leakage current flows from the electrode to the deionized water will scale, and vice versa". Therefore, according to this rule, the electrode where the leakage current flows from the equalizing electrode to the deionized water is used as the measurement electrode, that is, the measurement electrode is the scaling electrode, and the reference electrode is the non-scaling electrode. At this time, the positions corresponding to the measurement electrode and the reference electrode in the converter valve tower are shown in Table 1.

[0047] Table 1

[0048] Serial number Measurement electrode position Reference electrode position 1 Pole 2-S pipe-valve hall ceiling side Pole 2-S pipe-valve tower top shielding side 2 Pole 1-S pipe-valve tower top shielding side Pole 1-S pipe-valve hall ceiling side 3 Rectifier station-interfloor water pipe-valve module cathode Rectifier station-interfloor water pipe-valve module anode 4 Inverter station-interfloor water pipe-valve module anode Inverter station-interfloor water pipe-valve module cathode 5 Rectifier station-infloor water pipe-valve module cathode Rectifier station-infloor water pipe-valve module anode 6 Inverter station-infloor water pipe-valve module anode Inverter station-infloor water pipe-valve module cathode

[0049] 4. Test the loop resistance of the measurement electrode and the loop resistance of the reference electrode, respectively.

[0050] During testing, the jumper wire corresponding to the equalizing electrode needs to be removed, the detector is connected to both ends of the loop, and after testing, the jumper wire needs to be restored and the continuity of the metal component (such as a steel beam) connected to the jumper wire of the equalizing electrode is measured using a multimeter. The detector can be an insulation resistance tester, and the detector is selected according to the resistance and current of the equalizing electrode loop. For example, a 500V insulation resistance tester can be selected to measure the loop resistance.

[0051] Specifically, when testing the loop resistance of the measuring electrode, remove the jumper wire of the measuring electrode and connect the tester to both ends of the measuring electrode loop. One end of the measuring electrode loop is the measuring electrode, and the other end is the metal component closest to the water path. When testing the loop resistance of the reference electrode, remove the jumper wire of the reference electrode and connect the tester to both ends of the reference electrode loop. One end of the reference electrode loop is the reference electrode, and the other end is the metal component closest to the water path.

[0052] 5. Calculate the difference between the loop resistance of the measuring electrode and the loop resistance of the reference electrode. Use this difference as the scale resistance of the equalizing electrode and compare it with the scale resistance threshold to determine the scaling condition of the equalizing electrode of the converter valve.

[0053] In a converter valve tower, the symmetrically arranged equalizing electrodes at both ends will inevitably have scale buildup at one end and remain scale-free at the other. The loop resistance of the scaled electrode includes scale resistance, water circuit resistance, and wire resistance. The loop resistance of the non-scaled electrode includes water circuit resistance and wire resistance, with the wire resistance being negligible. Since the water circuit resistances of both the scaled and non-scaled electrodes are the same, the equalizing electrode with the larger loop resistance is the scaled equalizing electrode. The difference between the loop resistance of the measuring electrode and the reference electrode is the scale resistance of the scaled equalizing electrode. When the measuring electrode refers to the electrode from which leakage current flows from the equalizing electrode to deionized water, scale will form on the surface of the measuring electrode, while the reference electrode will not. The loop resistance of the measuring electrode includes scale resistance, water circuit resistance, and wire resistance, while the loop resistance of the reference electrode includes water circuit resistance and wire resistance. The difference between the loop resistance of the measuring electrode and the loop resistance of the reference electrode is the scale resistance of the measuring electrode. In other words:

[0054]

[0055] Among them, R 结垢 To test the loop resistance of the obtained scaled electrode, R 不结垢 To test the loop resistance of the obtained non-scaling electrode, R 水 R is the resistance of the water circuit. 垢0 This refers to the scale resistance. If the scale resistance is greater than the scale resistance threshold, it indicates that the equalizing electrode has failed and needs to be descaled. If the scale resistance is greater than 0 and less than or equal to the scale resistance threshold, it indicates that the equalizing electrode has minimal scale buildup, and descaling can be determined based on requirements. If the scale resistance is 0, the surface equalizing electrode has no scale buildup.

[0056] Device Implementation Method 1

[0057] The present invention provides a device for detecting scale on the equalizing electrode of a converter valve, comprising a data acquisition module and a judgment module.

[0058] The data acquisition module is used to collect the loop resistance of the measuring electrode and the loop resistance of the reference electrode. The reference electrode and the measuring electrode are two symmetrical electrodes arranged in the water pipe of the converter valve tower when only one equalizing electrode is arranged in the same section of the water pipe of the converter valve tower. Through years of maintenance statistics, the structure rule of the equalizing electrode is that the electrode surface where the leakage current flows from the electrode to the deionized water will scale, and vice versa. Therefore, according to the rule, the scaling electrode where the leakage current flows from the equalizing electrode to the deionized water is taken as the measuring electrode, and the corresponding reference electrode is the non-scaling electrode.

[0059] When the loop resistance of the measuring electrode and the loop resistance of the reference electrode are collected, the jumpers of the corresponding equalizing electrodes are taken off, one end of the data acquisition module is connected to the corresponding equalizing electrode, and the other end is connected to the metal part closest to the waterway. If the equalizing electrode is arranged in the S-shaped water pipe or the interlayer water pipe, the metal part closest to the waterway is the metal flange. If the equalizing electrode is arranged in the water pipe in the valve layer of the valve tower, the metal part closest to the waterway is the radiator made of metal.

[0060] The determination module is used to calculate the difference between the loop resistance of the measuring electrode and the loop resistance of the reference electrode, take the difference as the scale layer resistance, and compare the scale layer resistance with the scale layer resistance threshold value to determine the scale layer of the equalizing electrode of the converter valve. The scale layer resistance threshold value is the scale layer resistance that makes the leakage current between the metal pipe and the deionized water reach the maximum allowable value of the leakage current, and the calculation formula is:

[0061]

[0062] Wherein, R0 is the scale layer resistance threshold value, I0 is the maximum allowable value of the leakage current, R1 is the waterway resistance between the equalizing electrode and the metal pipe, I 总 is the total current, U is the voltage difference between the symmetrical equalizing electrodes, and R2 is the waterway resistance between the symmetrical equalizing electrodes. The waterway resistance R1 between the equalizing electrode and the metal pipe and the waterway resistance R2 between the symmetrical equalizing electrodes are calculated according to the following formula:

[0063]

[0064] Wherein, R is the calculated waterway resistance, l is the length of the water pipe of the waterway, s is the cross-sectional area of the waterway, p is the resistivity of deionized water, and sigma is the conductivity of deionized water, which is generally taken as 0.5 mu S / cm.

[0065] Method implementation two

[0066] The method for detecting the scale layer of the equalizing electrode of the converter valve comprises the following steps:

[0067] S1: When three equalizing electrodes are arranged on the same section of the water pipe of the converter valve tower, the symmetrically arranged equalizing electrodes are scaling electrodes and non-scaling electrodes respectively, wherein three scaling electrodes are on one section and three non-scaling electrodes are on one section.

[0068] Through the maintenance statistics in previous years, the equalizing electrode structure rule is that the electrode surface where the leakage current flows from the electrode to the deionized water will scale, and vice versa. Therefore, according to the rule, the three electrodes on the section where the leakage current flows from the equalizing electrode to the deionized water are scaling electrodes, and the three equalizing electrodes symmetrically arranged on the other section are non-scaling electrodes.

[0069] When measuring, the equalizing electrodes symmetrically arranged in the converter valve tower are selected. Since the scale layer resistance of the equalizing electrode must form a conductive loop when measuring, when three equalizing electrodes are arranged on the same section of the water pipe of the converter valve tower, the three equalizing electrodes on each section form a measurement loop.

[0070] S2: The loop resistance between the scaling electrodes and the loop resistance between the non-scaling electrodes are tested respectively. When testing, the jumpers of the corresponding equalizing electrodes are removed, and after testing is completed, the jumpers of the corresponding equalizing electrodes are restored.

[0071] The loop resistance between the scaling electrodes includes the scale layer resistance and the water resistance of two scaling electrodes, and the loop resistance between the non-scaling electrodes includes the water resistance between two non-scaling electrodes. As shown in Figure 5 , taking the section where the scaling electrodes are located as an example, the three scaling electrodes form three measurement loops, i.e., the first scaling electrode-second scaling electrode, the second scaling electrode-third scaling electrode, and the first scaling electrode-third scaling electrode. The loop resistance between the scaling electrodes corresponding to the three measurement loops is obtained by using an insulation resistance meter, and the loop resistance between the scaling electrodes satisfies the following formula:

[0072] R 结垢A = R 垢1 + R 垢2 + R 水1

[0073] R 结垢B = R 垢2 + R 垢3 + R 水2

[0074] R 结垢C = R 垢1 + R 垢3 + R 水2

[0075] wherein R 垢1 is the scale layer resistance of the first scaling electrode, R 垢2 is the scale layer resistance of the second scaling electrode, and R 垢3R is the scale resistance of the third scaling electrode. 结垢A R is the loop resistance between the first and second scaling electrodes. 结垢B R is the circuit resistance between the second and third scaling electrodes. 结垢C R is the loop resistance between the first and third scaling electrodes. 水1 R 水2 R 水3 These are the water circuit resistances between the first and second scaling electrodes, the water circuit resistances between the second and third scaling electrodes, and the water circuit resistances between the first and third scaling electrodes, respectively. The loop resistances between the three non-scaling electrodes are obtained using an insulation resistance meter. The loop resistances between the non-scaling electrodes satisfy the following formula:

[0076] R 不结垢A =R 水1

[0077] R 不结垢B =R 水2

[0078] R 不结垢C =R 水2

[0079] Among them, R 不结垢A R is the loop resistance between the first non-scaling electrode and the second non-scaling and scaling electrode. 不结垢B R is the loop resistance between the second and third non-scaling electrodes. 不结垢C The circuit resistance is between the first non-scaling electrode and the third non-scaling and scaling electrode. The first scaling resistor and the first non-scaling resistor are arranged symmetrically, the second scaling resistor and the second non-scaling resistor are arranged symmetrically, and the third scaling resistor and the third non-scaling resistor are arranged symmetrically.

[0080] S3: Calculate the scale resistance of the three scaled electrodes based on the loop resistance between scaled electrodes and the loop resistance between non-scaled electrodes, and compare it with the scale resistance threshold to determine the scaling status of the corresponding scaled electrodes.

[0081] The scale resistance is calculated using the following formula:

[0082]

[0083] The scale resistance threshold is the scale resistance required to cause the leakage current between the metal pipe and deionized water to reach the maximum allowable leakage current. The calculation method for the scale resistance threshold has been described in detail in one embodiment of the method, and will not be repeated here.

[0084] If the scale layer resistance is greater than the scale layer resistance threshold value, it indicates that the equalizing electrode is invalid and needs to be descaled. If the scale layer resistance is greater than 0 and less than or equal to the scale layer resistance threshold value, it indicates that the equalizing electrode is less scaled, and whether descaling is needed can be determined according to the requirement. If the scale layer resistance is 0, it indicates that the surface equalizing electrode is not scaled.

[0085] Device implementation two

[0086] The scale layer detection device of the converter valve equalizing electrode provided by the application comprises a data acquisition module and a determination module. The data acquisition module is used to acquire the loop resistance between the scaled electrodes and the loop resistance between the non-scaled electrodes. The loop resistance between the scaled electrodes comprises the scale layer resistance and the waterway resistance of the two scaled electrodes, and the loop resistance between the non-scaled electrodes comprises the waterway resistance between the two non-scaled electrodes. The scaled electrodes and the non-scaled electrodes refer to the symmetrically arranged equalizing electrodes in the converter valve tower. When testing, the jumpers corresponding to the equalizing electrodes are removed respectively. When three equalizing electrodes are arranged in the same section of the water pipe of the converter valve tower, three scaled electrodes are arranged in one section, and three non-scaled electrodes are arranged in one section. The three equalizing electrodes in each section form a measurement loop in pairs, and the data acquisition module is connected to each measurement loop, so as to acquire the loop resistance between the scaled electrodes and the loop resistance between the non-scaled electrodes.

[0087] The determination module is used to calculate the scale layer resistance of the three scaled electrodes based on the loop resistance between the scaled electrodes and the loop resistance between the non-scaled electrodes, and compare the scale layer resistance with a scale layer resistance threshold value, so as to determine the scaling condition of the corresponding scaled electrode.

[0088] The calculation process of the scale layer resistance has been described in detail in the method implementation two, and will not be repeated here. If the scale layer resistance is greater than the scale layer resistance threshold value, it indicates that the equalizing electrode is invalid and needs to be descaled. If the scale layer resistance is greater than 0 and less than or equal to the scale layer resistance threshold value, it indicates that the equalizing electrode is less scaled, and whether descaling is needed can be determined according to the requirement. If the scale layer resistance is 0, it indicates that the surface equalizing electrode is not scaled. The scale layer resistance threshold value is the scale layer resistance that makes the leakage current between the metal pipeline and the deionized water reach the maximum allowable value of the leakage current.

[0089] The present application utilizes the symmetrical arrangement of the grading electrodes in the converter valve tower, and obtains the rule that "the symmetrically arranged grading electrodes must have one end scaling and the other end not scaling" through historical inspection data statistics. By measuring the resistance of the loop in which the symmetrically arranged grading electrodes are located in the converter valve tower, the loop resistance of the scaling electrode and the non-scaling electrode is obtained. Based on the loop resistance of the scaling electrode and the non-scaling electrode, the scale layer resistance of the scaling electrode is calculated, without considering the influence of the conductivity change of the deionized water on the measurement, thereby improving the accuracy of the scale layer resistance measurement. According to the evaluation index of the scale layer resistance formulated according to the model of the grading electrode absorbing the leakage current, the actual scaling condition of the measured scale layer resistance is evaluated. When the measured scale layer resistance is greater than the evaluation index, it indicates that the grading electrode has failed, which is more in line with the working principle of the grading electrode, and the evaluation accuracy is higher. Moreover, the grading electrode does not need to be disassembled, which greatly accelerates the maintenance efficiency of the on-site maintenance personnel on the scale layer of the grading electrode, thereby ensuring the safe operation of the converter valve, and having high application value in the fields of electrical test and converter valve maintenance.

Claims

1. A method for detecting a layer of electrode dirt of a voltage-sharing electrode of a converter valve, characterized in that The method comprises the following steps: selecting the symmetrical voltage-sharing electrodes in the water pipe of the converter valve tower, when there is only one voltage-sharing electrode in the same section of the water pipe of the converter valve tower, one of the voltage-sharing electrodes is a measurement electrode, and the other is a reference electrode; respectively testing the loop resistance of the measurement electrode and the loop resistance of the reference electrode, and respectively removing the jumpers of the corresponding voltage-sharing electrodes during the testing; wherein one end of the loop is the corresponding voltage-sharing electrode, and the other end is the metal component closest to the water pipe in distance; calculating the difference between the loop resistance of the measurement electrode and the loop resistance of the reference electrode, taking the difference as the scale resistance, and comparing the scale resistance with a scale resistance threshold to determine the fouling condition of the voltage-sharing electrode of the converter valve; the scale resistance threshold is the scale resistance that makes the leakage current between the metal pipe and the deionized water reach the maximum allowable value of the leakage current.

2. The method according to claim 1, characterized in that, The scale resistance threshold is calculated according to the following formula: wherein R0 is the scale layer resistance threshold, I0 is the maximum allowable leakage current, R1 is the water path resistance between the grading electrode and the metal pipe, I 总 is the total current, U is the voltage difference between the symmetrically arranged grading electrodes, and R2 is the water path resistance between the symmetrically arranged grading electrodes.

3. The method according to claim 1 or 2, characterized in that If the voltage-sharing electrode is arranged in the S-shaped water pipe or the interlayer water pipe, the metal component closest to the water pipe in distance is the metal flange; if the voltage-sharing electrode is arranged in the valve layer water pipe of the valve tower, the metal component closest to the water pipe in distance is the heat sink made of metal.

4. The method according to claim 1 or 2, characterized in that The method further comprises the following step: after the testing of the loop resistance of the measurement electrode and the loop resistance of the reference electrode is completed, the jumpers of the corresponding voltage-sharing electrodes are restored.

5. A method of detecting a layer of electrode dirt of a voltage sharing electrode of a converter valve, characterized in that The method comprises the following steps: when there are three voltage-sharing electrodes in the same section of the water pipe of the converter valve tower, the symmetrical voltage-sharing electrodes are respectively fouling electrodes and non-fouling electrodes, wherein the three fouling electrodes are in one section, and the three non-fouling electrodes are in one section; the three voltage-sharing electrodes in each section form a measurement loop, and the loop resistance between the fouling electrodes and the loop resistance between the non-fouling electrodes are respectively tested, and the jumpers of the corresponding voltage-sharing electrodes are respectively removed during the testing; the loop resistance between the fouling electrodes includes the scale resistance and the water resistance of the two fouling electrodes, and the loop resistance between the non-fouling electrodes includes the water resistance between the two non-fouling electrodes; based on the loop resistance between the fouling electrodes and the loop resistance between the non-fouling electrodes, the scale resistance of the three fouling electrodes is calculated and compared with a scale resistance threshold to determine the fouling condition of the corresponding fouling electrode; the scale resistance threshold is the scale resistance that makes the leakage current between the metal pipe and the deionized water reach the maximum allowable value of the leakage current.

6. The method according to claim 5, wherein The scale resistance is calculated according to the following formula: wherein R 垢1 is the scale layer resistance of the first scale-forming electrode, R 垢2 is the scale layer resistance of the second scale-forming electrode, R 垢3 is the scale layer resistance of the third scale-forming electrode, R 结垢A is the loop resistance between the first scale-forming electrode and the second scale-forming electrode, R 结垢B is the loop resistance between the second scale-forming electrode and the third scale-forming electrode, R 结垢C is the loop resistance between the first scale-forming electrode and the third scale-forming electrode, R 不结垢A is the loop resistance between the first scale-forming electrode and the second non-scale-forming scale-forming electrode, R 不结垢B is the loop resistance between the second non-scale-forming electrode and the third non-scale-forming electrode, R 不结垢C is the loop resistance between the first non-scale-forming electrode and the third non-scale-forming scale-forming electrode.

7. A device for detecting a layer of electrode dirt of a voltage sharing electrode of a converter valve, characterized in that The method comprises a data acquisition module and a determination module; the data acquisition module is used to acquire the loop resistance of the measurement electrode and the loop resistance of the reference electrode; the measurement electrode and the reference electrode are two symmetrical voltage-sharing electrodes in the water pipe of the converter valve tower when there is only one voltage-sharing electrode in the same section of the water pipe of the converter valve tower; during the testing, the jumpers of the corresponding voltage-sharing electrodes are respectively removed, one end of the data acquisition module is connected to the corresponding voltage-sharing electrode, and the other end is connected to the metal component closest to the water pipe in distance; the determination module is used to calculate the difference between the loop resistance of the measurement electrode and the loop resistance of the reference electrode, take the difference as the scale resistance, and compare the scale resistance with a scale resistance threshold to determine the fouling condition of the voltage-sharing electrode of the converter valve; the scale resistance threshold is the scale resistance that makes the leakage current between the metal pipe and the deionized water reach the maximum allowable value of the leakage current.

8. The device according to claim 7, characterized in that The scale resistance threshold is calculated according to the following formula: Wherein, R0 is the scale layer resistance threshold, I0 is the maximum value of the leakage current, R1 is the waterway resistance between the equalizing electrode and the metal pipeline, I 总 is the total current, U is the voltage difference between the symmetrically arranged equalizing electrodes, and R2 is the waterway resistance between the symmetrically arranged equalizing electrodes.

9. A device for detecting a layer of electrode dirt of a voltage sharing electrode of a converter valve, characterized in that The device comprises a data collection module and a determination module; the data collection module is used to collect the loop resistance between scaling electrodes and the loop resistance between non-scaling electrodes; the loop resistance between scaling electrodes comprises the scale layer resistance of two scaling electrodes and the water path resistance; the loop resistance between non-scaling electrodes comprises the water path resistance between two non-scaling electrodes; the scaling electrodes and the non-scaling electrodes refer to the symmetrically arranged grading electrodes in the converter valve tower; during the test, the jumpers corresponding to the grading electrodes are taken down respectively; when three grading electrodes are arranged on one section and three non-scaling electrodes are arranged on one section in the water pipe of the converter valve tower, the three grading electrodes on each section form a measuring loop with each other, and the data collection module is connected to each measuring loop; the determination module is used to calculate the scale layer resistance of the three scaling electrodes based on the loop resistance between scaling electrodes and the loop resistance between non-scaling electrodes, compare the scale layer resistance with a scale layer resistance threshold value, and determine the scaling condition of the corresponding scaling electrode; the scale layer resistance threshold value is the scale layer resistance that makes the leakage current between the metal pipeline and the deionized water reach the maximum allowable value of the leakage current.

10. The device according to claim 9, characterized in that The scale layer resistance is calculated according to the following formula: wherein R 垢1 is the scale layer resistance of the first scale electrode, R 垢2 is the scale layer resistance of the second scale electrode, R 垢3 is the scale layer resistance of the third scale electrode, R 结垢A is the loop resistance between the first scale electrode and the second scale electrode, R 结垢B is the loop resistance between the second scale electrode and the third scale electrode, R 结垢C is the loop resistance between the first scale electrode and the third scale electrode, R 不结垢A is the loop resistance between the first non-scale electrode and the second non-scale electrode, R 不结垢B is the loop resistance between the second non-scale electrode and the third non-scale electrode, R 不结垢C is the loop resistance between the first non-scale electrode and the third non-scale electrode.

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