Method for reducing shutdown cell voltage of 500kA electrolytic cell

Abstract

The invention discloses a method for reducing the cell stopping voltage of a 500kA electrolytic cell, and relates to the technical field of cell stopping of aluminum electrolytic cells. According to the actual data of the black voltage after the 500kA electrolytic cell is stopped, combining the actual voltage drop between the short-circuit peripheral buses of the upstream and downstream electrolytic cells; two points with the maximum voltage drop are selected from a bus at the periphery of the upper part of the electrolytic cell; the bus around the previous groove is directly connected to the bus around the next groove in a voltage soft connection short circuit mode; during installation, the number of a to-be-installed stop tank is determined firstly, and for a U-shaped voltage soft connection, the position is determined, and a grinding machine is used for grinding the crimping surface of the joint of a tank periphery bus and the head of the voltage soft connection at the position, needing to be short-circuited, of a previous electrolytic tank between a first stand column bus and a second stand column bus and between a fifth stand column bus and a sixth stand column bus and the stop tank periphery bus; and the U-shaped voltage soft connection is short-circuited by using the bow-shaped clamp. The invention provides a short-circuit technology which is simple and safe to install and can reduce the slot voltage of the upright bus short-circuit port during the overhaul period of the electrolytic cell.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum electrolytic cell stoppage, and in particular to a method for reducing the stoppage cell voltage of a 500kA electrolytic cell. Background Art

[0002] Our company's 500kA series aluminum electrolytic plant has conducted statistics on the voltage drop at the short-circuit junction of the idle cell. The average voltage drop for a single cell is 0.303v, which is relatively high. In order to reduce the voltage drop at the short-circuit junction, it is urgent to explore innovative short-circuiting technologies that can help Hualei Electrolytic Plant reduce the voltage drop at the short-circuit junction when the cell is stopped. Through practical exploration, we have developed the busbar short-circuiting technology around the idle cell of Hualei's 500kA series electrolytic cells, which optimizes and reduces the cell voltage at the short-circuit junction when the cell is stopped, improves economic benefits, and has important practical significance for saving electricity consumption during the overhaul period of 500kA large electrolytic cells.

[0003] Patent CN200510117420.9 discloses a method for reducing the voltage drop of aluminum electrolytic cells when the cells are stopped. First, the insulating plate in the short-circuit port is removed, the contact surface of the short-circuit busbar is polished and cleaned, conductive paste is applied, the short-circuit port is crimped, and a shunt is welded. A short circuit is implemented at the short-circuit port, and the cathode busbars of the two connected cells are connected below the ground cover. However, this scheme mainly reduces the short-circuit port resistance by polishing and cleaning the crimping surface of the short-circuit port, applying conductive paste, crimping the short-circuit port, and welding the shunt after the cell is stopped, thereby reducing the voltage of the stopped cell; at the same time, it brings environmental problems to the workplace. Summary of the invention

[0004] In view of the deficiencies in the above-mentioned prior art, the present invention provides a method for reducing the tank voltage of a 500kA electrolytic cell when the cell is stopped, and provides a short-circuiting technology that is simple to install, safe, and can reduce the tank voltage of the column bus short-circuit during the overhaul period of the electrolytic cell. The equipment required for this technology is similar to a soft connection, and the installation is very convenient. The operation can be performed after the electrolytic cell is stopped, and the production of other normal cells will not be affected. The cathode cell bus current short-circuiting technology for reducing the tank voltage when the cell is stopped is simple to operate - a technology for reducing the tank voltage of a 500kA electrolytic cell when the cell is stopped.

[0005] The specific technical solutions are as follows:

[0006] A method for reducing the stop tank voltage of a 500kA electrolytic cell, comprising:

[0007] According to the actual data of black voltage after the 500kA electrolytic cell is stopped, combined with the actual voltage drop between the upstream and downstream electrolytic cells, two points with the largest voltage drop are selected on the upper electrolytic cell busbar; the busbar of the previous cell is directly connected to the busbar of the next cell by voltage soft connection;

[0008] The two ends of the crimping surface of the voltage flexible connector are rectangular parallelepiped, and the voltage flexible connector includes U-shaped and L-shaped;

[0009] During installation, first confirm the number of the stop slot to be installed. For the U-shaped voltage flexible connection: confirm the position, between the first and second column busbars, between the fifth and sixth column busbars, the previous electrolytic cell and the stop slot busbar need to be short-circuited. Use a grinder to grind the crimping surface of the head connection between the busbar around the slot and the voltage flexible connection, and use a bow-shaped clamp to short-circuit the U-shaped voltage flexible connection; for the L-shaped voltage flexible connection: re-short-circuit the first and sixth non-conductive slot bottom through-slot busbars of the stop slot to re-conduct.

[0010] Furthermore, in the above scheme, the voltage soft connector includes a soft busbar bundle and an aluminum busbar block, the aluminum busbar blocks are arranged at both ends of the soft busbar bundle, and the soft busbar bundle is composed of three bundles of 10 1mm thick aluminum sheets; the width of the aluminum sheet is 240mm.

[0011] In the above solution, a handle is provided at the end of the aluminum busbar block.

[0012] In the above solution, the bow-shaped fixture is arranged between the two aluminum busbar blocks of the U-shaped voltage flexible connector.

[0013] Furthermore, in the above scheme, the bow-shaped fixture includes a bow-shaped steel plate, a bolt and a baffle, wherein the bolt is arranged at one end of the bow-shaped steel plate and is connected to and faces the other end of the bow-shaped steel plate, the bolt is threadedly connected to the bow-shaped steel plate, and the baffle is rotatably arranged at the end of the bolt.

[0014] Furthermore, in the above scheme, the bow-shaped clamp is made of stainless steel.

[0015] In the above solution, the size of the aluminum busbar block is 250mm×200mm×40mm.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention increases the cross-sectional area of ​​the conductive conductor of the cathode busbar of the electrolytic cell: (1) The 500kA electrolytic cell series has six slot-bottom through-the-groove busbars. For the electrolytic cell that has been stopped, the first and sixth through-the-groove busbars are not conductive when the cell is stopped. The present invention makes the first and sixth through-the-groove busbars that are not conductive conductive again by making an "L"-shaped soft connection in a soft connection short-circuiting manner, thereby increasing the cross-sectional area of ​​the conductive conductor of the cathode busbar of the electrolytic cell, reducing the cathode busbar resistance, and reducing the stopped cell voltage, thereby achieving the purpose of saving the stopped cell power consumption. The present invention directly short-circuits the cathode busbar of the electrolytic cell: For the electrolytic cell that has been stopped, a "U" soft connection is made, and the current is directly transferred from the upper slot busbar to the next slot busbar through a soft connection short-circuiting manner. By reducing the current at the short-circuit, the stopped cell voltage is reduced, thereby achieving the purpose of saving the stopped cell power consumption. The present invention combines to short-circuit the cathode busbar of the electrolytic cell: the "L"-shaped soft connection and the "U"-shaped soft connection are used in combination to short-circuit the cathode busbar of the electrolytic cell. The "L"-shaped soft connection can reduce 70mv, and the "U"-shaped soft connection can reduce 25mv. After short-circuiting, the stop cell voltage drop is reduced by an average of about 95mv.

[0018] 2. The 500kA electrolytic cell voltage reduction soft connection of the present invention is mainly made of existing materials in the electrolytic aluminum plant, has no special requirements on the materials, has a simple manufacturing process, and is low in cost. Due to the small current carried, it has a long service life and is safe, economical, and environmentally friendly.

[0019] 3. The installation of the soft connection in the present invention only requires fastening with a bow-shaped clamp, which is easy to operate. Operators can start operation after simple training, which reduces the labor intensity of operators and improves work efficiency. When short-circuiting the busbar around the upper trough, safety measures for high-altitude operations can be taken.

[0020] 4. The installation of the present invention is very simple and effective. Under the condition that the crimping surface is polished to a qualified standard and the fastening quality is good, the conduction is smooth and the risk is low.

[0021] 5. The present invention is operated after the electrolytic cell is stopped, and the installation is convenient and reliable. It can be used during major repairs, medium repairs, and minor repairs, and the cost is significantly saved. The industrial promotion has more practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of a U-shaped voltage soft connection;

[0023] Figure 2 It is a schematic diagram of the front structure of a U-shaped voltage soft connection;

[0024] Figure 3 It is a schematic diagram of the handle of the voltage soft connection;

[0025] Figure 4It is a schematic diagram of a U-shaped voltage soft connection structure;

[0026] Figure 5 It is a schematic diagram of the bow-type fixture structure.

[0027] In the attached drawings, 1-aluminum busbar block, 2-soft busbar bundle, 3-handle, 4-crimping surface, 5-bow-shaped clamp, 6-bow-shaped steel plate, 7-bolt, 8-baffle. DETAILED DESCRIPTION

[0028] The following is a further detailed description of the embodiments of the invention in conjunction with the accompanying drawings to make the objectives, technical solutions and technical effects of the invention more clearly presented.

[0029] The present invention discloses a method for reducing the stop tank voltage of a 500kA electrolytic cell, comprising:

[0030] According to the actual data of the black voltage after the 500kA electrolytic cell is stopped, combined with the actual voltage drop between the short-circuited busbars of the upstream and downstream electrolytic cells; two points with the largest voltage drop are selected on the busbars of the upper part of the electrolytic cell; the busbars of the upper cell are directly connected to the busbars of the next cell by short-circuiting the voltage soft connection. The two ends of the crimping surface 4 of the voltage soft connection are rectangular parallelepiped, and the voltage soft connection includes U-shaped and L-shaped.

[0031] During installation, first confirm the number of the stop slot to be installed. For the U-shaped voltage flexible connection: confirm the position, between the first and second column busbars, between the fifth and sixth column busbars, the previous electrolytic cell and the stop slot busbar need to be short-circuited. Use a grinder to grind the crimping surface 4 of the head connection between the busbar and the voltage flexible connection, and use the bow-shaped clamp 5 to short-circuit the U-shaped voltage flexible connection. For the L-shaped voltage flexible connection: re-short-circuit the first and sixth non-conductive bottom busbars of the stop slot, and re-conduct.

[0032] like Figure 1-2 It is a U-shaped voltage soft connection, such as Figure 4 It is an L-shaped voltage flexible connector. The voltage flexible connector includes a flexible busbar bundle 2 and an aluminum busbar block 1. The aluminum busbar block 1 is arranged at both ends of the flexible busbar bundle 2. The flexible busbar bundle 2 is composed of three bundles of 10 1mm thick aluminum sheets; the width of the aluminum sheet is 240mm. The size of the aluminum busbar block 1 is 250mm×200mm×40mm. A handle 3 is provided at the end of the aluminum busbar block 1 for easy mobile installation.

[0033] like Figure 5 Schematic diagram of the structure of the bow-shaped fixture 5, the bow-shaped fixture 5 includes a bow-shaped steel plate 6, a bolt 7 and a baffle 8, the bolt 7 is arranged at one end of the bow-shaped steel plate 6 and faces the other end of the bow-shaped steel plate 6, the bolt 7 is threadedly connected to the bow-shaped steel plate 6, and the baffle 8 is rotatably arranged at the end of the bolt 7. The bow-shaped fixture 5 is made of stainless steel.

[0034] During installation, the bow-shaped fixture 5 is arranged between the two aluminum busbar blocks 1 of the U-shaped voltage flexible connection, and the baffle 8 is located outside the bow-shaped steel plate 6, that is, the bolt 7 can be adjusted to achieve clamping. For the L-shaped voltage flexible connection, the bow-shaped fixture 5 presses the aluminum busbar block 1 of the L-shaped voltage flexible connection against the first and sixth non-conductive bottom through-slot busbars of the electrolytic cell in the idle slot, and the baffle 8 is located inside the bow-shaped steel plate 6.

[0035] The above scheme is specifically implemented as follows: according to the actual data of the black voltage of Hualei's 500kA electrolytic cell after the cell is stopped, combined with the actual voltage drop between the short-circuited busbars of the upstream and downstream electrolytic cells, and using the principle that the greater the voltage drop, the better the short-circuiting effect, two points with the largest voltage drop are selected on the busbars of the upper part of the cell; the current is directly transferred from the busbars of the upper cell to the busbars of the next cell through a soft connection short-circuit, thereby reducing the current at the short-circuit junction and thus reducing the stop voltage, thereby achieving the purpose of saving the stop voltage drop. The two ends of the designed soft connection crimping surface 4 for reducing the stop voltage are rectangular parallelepiped, and the soft connection for the stop voltage is made in two types of soft connection models, "U" and "L", which are conducive to installation. The present invention adopts a combined short-circuit method to reduce the stop voltage.

[0036] U-shaped voltage soft connection short-circuiting method: the current is directly transferred from the busbar around the previous slot to the busbar around the next slot through soft connection short-circuiting. By reducing the current at the short-circuit junction, the voltage of the stopped slot is reduced, thereby achieving the purpose of saving the power consumption of the stopped slot.

[0037] L-shaped voltage soft connection short-circuiting method: Through the soft connection short-circuiting method, the first and sixth non-conductive slotted busbars are made conductive again, reducing the current at the short-circuit junction and thus reducing the voltage of the idle slot, thereby achieving the purpose of saving the idle slot power consumption.

[0038] Voltage drop change: The current average voltage drop of Hualei electrolytic cells when they are not in use is about 303mv. By combining short-circuiting method 1 and short-circuiting method 2, the voltage drop can be reduced by about 95mv after short-circuiting.

[0039] Installation process: confirm the slot number to be installed, use a grinder to grind the busbar around the slot and the crimping surface 4 of the column, and use a bow-shaped clamp to tighten the polished soft connection one by one in the short-circuit position. At the same time, check to ensure that the crimping and tightening quality meets the operating requirements. The installation of the stop slot voltage soft connection is completed.

[0040] Working principle: For the electrolytic cells that have been stopped, the U-shaped voltage soft connection: the current is directly transferred from the busbar around the previous cell to the busbar around the next cell through a soft connection short circuit, and the voltage of the stopped cell is reduced by reducing the current at the short circuit, thereby saving the power consumption of the stopped cell. The L-shaped voltage soft connection: through the soft connection short circuit, the first and sixth non-conductive through-slot busbars are re-conductive, reducing the current at the short circuit and thus reducing the voltage of the stopped cell, thereby saving the power consumption of the stopped cell. But the overall operation is safe and controllable.

[0041] The present invention is applicable to large-scale aluminum electrolytic cells with a capacity of 500kA or above, in which the busbar passing through the bottom of the cell does not fully participate in the conduction. The principle of Ohm's law U=IR is used to increase the cross-sectional area of ​​the conductive cathode busbar of the electrolytic cell as a whole, thereby reducing the resistance, so as to achieve the purpose of reducing the cathode busbar resistance and lowering the stop cell voltage. Advantages of the present invention: (1) Good safety and conductive effect. The installation and operation of the present invention is simple, safe, environmentally friendly, and has a good conductive effect. The short-circuit tools manufactured by the present invention have good matching properties and can be reused, with good promotion prospects and social benefits. (2) No environmental problems. The installation of the present invention is clean, environmentally friendly, and efficient, and the equipment can be reused and recycled.

[0042] Benefit analysis of the present invention:

[0043] Economic benefits: (1) After Hualei's 500kA electrolytic cell voltage reduction soft connection is put into use, only 4 people are needed to complete the installation and removal, and the installation and removal operations are easy. (2) Hualei's 500kA electrolytic cell voltage reduction soft connection can reduce the voltage of the electrolytic cell by 0.095v through the combination of upper and lower composite short-circuit. According to the overhaul cycle of 28 days, the daily series of downtime voltage drop is 0.095v. According to the electricity price of 0.39 yuan and the current of 500kA, the current idle cost of each cell can be saved by about 12,448 yuan / month during the overhaul. According to the calculation of 60 cells per year, the annual electricity saving is about 747,000 yuan, and the electricity saving cost is obvious. Social benefits: After the technology of reducing the voltage of the 500kA electrolytic cell is put into practical use, it has greatly changed the current domestic power-on mode. The fuse is simple to operate, saving a lot of manpower and material resources, and greatly improving the work efficiency of the electrolytic cell power-on. If it is promoted to the electrolytic aluminum industry, the social benefits will be significant. Environmental benefits: The technical material soft connection for reducing the stop voltage of 500kA electrolytic cells is easy to obtain. After the electrolytic cell is stopped, it can be used during major repairs, medium repairs, and minor repairs. The cost savings are obvious, and industrial promotion has more practical significance. At the same time, no pollutants and harmful gases are generated during use, the environmental protection effect is obvious, and the use prospects are broad.

[0044] The above description is only a preferred feasible embodiment of the present invention and is not intended to limit the scope of the patent application of the present invention. All equivalent changes, equivalent substitutions or modified changes performed within the technical spirit and principles suggested by the present invention should be included in the scope of patent protection covered by the present invention.

Claims

1. A method for reducing the stop tank voltage of a 500kA electrolytic cell, characterized in that: include: According to the actual data of black voltage after the 500kA electrolytic cell is stopped, combined with the actual voltage drop between the busbars around the short-circuited cells of the upstream and downstream electrolytic cells; Select two points with the largest voltage drop on the busbar around the upper part of the electrolytic cell; directly connect the busbar around the upper cell to the busbar around the next cell by means of voltage soft connection and short-circuit; The two ends of the crimping surface of the voltage flexible connector are rectangular parallelepiped, and the voltage flexible connector includes U-shaped and L-shaped; During installation, first confirm the number of the stop slot to be installed. For the U-shaped voltage flexible connection: confirm the position, between the first and second column busbars, between the fifth and sixth column busbars, the previous electrolytic cell and the stop slot busbar need to be short-circuited. Use a grinder to grind the crimping surface of the head connection between the busbar around the slot and the voltage flexible connection, and use a bow-shaped clamp to short-circuit the U-shaped voltage flexible connection; for the L-shaped voltage flexible connection: re-short-circuit the first and sixth non-conductive slot bottom through-slot busbars of the stop slot to re-conduct.

2. A method for reducing the stop tank voltage of a 500kA electrolytic cell according to claim 1, characterized in that: The voltage soft connector includes a soft busbar bundle and an aluminum busbar block. The aluminum busbar blocks are arranged at both ends of the soft busbar bundle. The soft busbar bundle is composed of three bundles of 10 1mm thick aluminum sheets; the width of the aluminum sheet is 240mm.

3. A method for reducing the stop tank voltage of a 500kA electrolytic cell according to claim 2, characterized in that: A handle is provided at the end of the aluminum busbar block.

4. A method for reducing the stop tank voltage of a 500kA electrolytic cell according to claim 2, characterized in that: The bow-shaped fixture is arranged between two aluminum busbar blocks of the U-shaped voltage flexible connector.

5. A method for reducing the stop tank voltage of a 500kA electrolytic cell according to claim 2, characterized in that: The bow-shaped fixture includes a bow-shaped steel plate, a bolt and a baffle, wherein the bolt is arranged at one end of the bow-shaped steel plate and faces the other end of the bow-shaped steel plate, the bolt is threadedly connected to the bow-shaped steel plate, and the baffle is rotatably arranged at the end of the bolt.

6. A method for reducing the stop tank voltage of a 500kA electrolytic cell according to claim 5, characterized in that: The bow-shaped fixture is made of stainless steel.

7. A method for reducing the stop tank voltage of a 500kA electrolytic cell according to claim 2, characterized in that: The dimensions of the aluminum busbar block are 250mm×200mm×40mm.

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