Bus configuration method for improving magnetic fluid stability of aluminum electrolysis cell

Abstract

The invention provides a bus configuration method for improving magnetic fluid stability of an aluminum electrolysis cell, and relates to the technical field of aluminum electrolysis. The method comprises the following steps: firstly, connecting a bus of the aluminum electrolysis cell, and carrying out networked configuration on cathode buses around the aluminum electrolysis cell; secondly, correspondingly adjusting the section and length of a cathode soft belt of each group of cathode steel bar heads by adjusting the section and direction of each group of cathode buses around the cell, and adjusting the layout and configuration of the cathode buses around the cell connected with each group of upright post buses and short-circuit buses at the same time; ensuring that the value of current flowing out of each group of cathodes of cathode buses around the networked aluminum electrolysis cell and the value of current flowing into each column bus of the next aluminum electrolysis cell are the same as theoretical set values; and finally, an equivalent resistance method and a finite element method are combined for electric field calculation, the reasonability of current distribution of the aluminum electrolysis cell is verified, production fluctuation caused by uneven current is reduced, and therefore the stability and efficiency of the whole aluminum electrolysis production process are improved.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum electrolysis, and in particular to a busbar configuration method for improving the stability of magnetic fluid in an aluminum electrolysis cell. Background Art

[0002] In industrial production, electrolytic aluminum production adopts molten salt electrolysis. The raw materials required for production are aluminum oxide and fluoride salt. The direct current required for electrolysis is supplied by the rectifier. Under the action of direct current, the aluminum oxide dissolved in the electrolyte undergoes oxidation-reduction reaction with the carbon anode to produce liquid raw aluminum. As the main equipment for producing electrolytic aluminum, the aluminum electrolytic cell is mainly composed of anodes, cathodes and steel structures made of carbon materials. The magnetic fluid in the melt zone of the aluminum electrolytic cell is a molten electrolyte or aluminum liquid. After the current participates in the chemical reaction in the electrolytic cell, it is introduced into the cathode busbar around the cell through the cathode soft belt connected to the cathode steel rod. Several groups of cathode soft belts on the power-inlet side are connected to a group of cathode busbars on the power-inlet side, and the current is introduced into the column busbar of the next electrolytic cell.

[0003] In the traditional busbar configuration of aluminum electrolytic cells, the busbars on the power input side and the power output side are often independent of each other, and there are no crimping points or welding points between them, which may lead to uneven current distribution. Taking a 200kA electrolytic cell as an example, the electrolytic cell has 5 sets of column busbars, and the current introduced by each set of column busbars may be different, which will cause the stability problem of magnetic fluid in the electrolytic cell. The horizontal current in the aluminum liquid and the vertical magnetic field will cause the fluctuation of the electrolyte-aluminum liquid interface, which will affect the current efficiency of aluminum electrolysis and increase the power loss.

[0004] Aluminum electrolytic cells will inevitably experience fluctuations during the production process, such as loss of control of alumina concentration, instability of thermal balance regulation, human operation or accidental factors, etc. The essence of these fluctuations can be attributed to electrical imbalance. Electrical imbalance further leads to magnetic fluid fluctuations, which may cause adverse fluctuations such as anode effect or large swings of aluminum liquid, which not only affects the production of this cell, but also may have adverse effects on multiple adjacent electrolytic cells, such as increased noise and swings in adjacent cells, and increased energy consumption of the electrolytic series. Compared with general fluctuations, it is more difficult to eliminate such adverse fluctuations, which takes longer and causes greater harm. Therefore, the problem of adverse fluctuations in aluminum electrolytic cells affecting the production of adjacent electrolytic cells needs to be taken seriously and studied and solved. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a busbar configuration method for improving the stability of magnetic fluid in an aluminum electrolytic cell in view of the above-mentioned deficiencies in the prior art, so as to reduce the impact of adverse fluctuations such as anode effect or large swings of aluminum liquid on the normal production of the electrolytic cell and its adjacent aluminum electrolytic cells.

[0006] In order to achieve the above object, the main technical solutions adopted by the present invention are:

[0007] A busbar configuration method for improving the stability of magnetic fluid in an aluminum electrolysis cell specifically comprises the following steps:

[0008] Step 1, a plurality of groups of cathode busbars around the cell are arranged on the power input side and the power output side of the aluminum electrolytic cell, a group of cathode busbars around the cell are connected with a plurality of groups of cathode soft belts to form a current conduction path, and the column busbars and the short-circuit busbars are connected through the cathode busbars around the cell;

[0009] Furthermore, the working current of the aluminum electrolysis cell is 100-800 kA;

[0010] Step 2: Use aluminum busbars, aluminum soft tapes or aluminum welding sheets to interconnect the cathode busbars around several groups of slots on the power-in side to form a network, and then use aluminum busbars, aluminum soft tapes or aluminum welding sheets to interconnect the cathode busbars around several groups of slots on the power-out side to form another network;

[0011] Furthermore, the cross-section of the aluminum busbar, aluminum soft strip or aluminum welding sheet is adjusted as needed, and the adjustment range is (30-550) mm×(30-550) mm;

[0012] Furthermore, the types of aluminum electrolysis cells include ordinary aluminum electrolysis cells, three-layer liquid high-purity aluminum electrolysis cells, and any other molten salt electrolysis cells that use electrolysis to produce raw materials;

[0013] Furthermore, the number of cathode busbars around the slots on the power input side and the power output side is one group or several groups;

[0014] Step 3, by adjusting the cross-section and direction of the cathode busbars around each group of slots, the cross-section and length of the cathode soft belt of each group of cathode steel rod heads, and the layout and configuration of the cathode busbars around each group of slots connected to the column busbars and the short-circuit busbars, ensure that the current value flowing out of the cathode busbars around each group of slots of the networked aluminum electrolytic cells is the same;

[0015] Step 4: By adjusting the cross-section and direction of the cathode busbars around each group of cells, the cross-section and length of the cathode soft belt of each group of cathode steel rod heads are adjusted accordingly, and at the same time, the layout and configuration of the cathode busbars around the cells connected to each group of column busbars and short-circuit busbars are adjusted to ensure that the current value flowing into each column busbar of the next aluminum electrolytic cell is the same as the theoretical set value;

[0016] Step 5: Use a method combining equivalent resistance method and finite element method to calculate the electric field to verify the rationality of the current distribution of the aluminum reduction cell. The electric field is the distribution of current and voltage, which specifically includes the following steps:

[0017] Step 5.1, establish a busbar current calculation model, and calculate the current flowing through the busbar system, anode guide rods and anode steel claws according to Kirchhoff's law;

[0018] Step 5.2, using the finite element method, iteratively solve each point in the anode, melt and cathode current fields determined by coordinates x, y, z to obtain the current distribution in the entire aluminum electrolysis cell, wherein the melt is the electrolyte and the aluminum liquid, and the conductive differential equation of the conductive part in the aluminum electrolysis cell can be expressed as the Laplace equation;

[0019] Step 5.3, solve by computer and repeatedly adjust the calculation model until the ideal aluminum electrolysis cell current distribution is obtained.

[0020] The present invention has the following beneficial effects and advantages:

[0021] 1. The networked cathode busbar around the slot improves the interconnection capability of the busbar system;

[0022] 2. When severe fluctuations such as anode effect or large swings of aluminum liquid occur, the network configuration method of the aluminum electrolytic cell busbar in the present invention can effectively conduct and eliminate the abnormally large current caused by the severe fluctuations in the aluminum electrolytic cell, thereby significantly reducing the "infection" of the abnormally large current in the electrolytic series, and then eliminating the impact on the upstream electrolytic cells in adjacent areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of a 200kA electrolytic cell in which the busbars around the cell have not yet been networked according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of a busbar network around a 200kA electrolytic cell according to an embodiment of the present invention.

[0025] Among them, 1. The first column bus and the first short-circuit bus Ⅰ~Ⅴ; 2. The first incoming bus Ⅰ; 3. The first incoming bus Ⅱ; 4. The first incoming bus Ⅲ; 5. The first incoming bus Ⅳ; 6. The first incoming bus Ⅴ; 7. The first outgoing bus Ⅰ; 8. The first outgoing bus Ⅱ; 9. The first outgoing bus Ⅲ; 10. The first outgoing bus Ⅳ; 11. The first outgoing bus Ⅴ; 1', the first Two-column busbars and second short-circuit busbars Ⅰ~V; 2', second incoming busbar Ⅰ; 3', second incoming busbar Ⅱ; 4', second incoming busbar Ⅲ; 5', second incoming busbar Ⅳ; 6', second incoming busbar Ⅴ; 7', second outgoing busbar Ⅰ; 8', second outgoing busbar Ⅱ; 9', second outgoing busbar Ⅲ; 10', second outgoing busbar Ⅳ; 11', second outgoing busbar Ⅴ. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings.

[0027] The aluminum electrolytic cell busbar of the present invention is composed of a power-input side busbar, a power-output side busbar, a column busbar, a short-circuit busbar and the like.

[0028] The present invention provides a busbar configuration method for improving the stability of magnetic fluid in an aluminum electrolysis cell, which specifically comprises the following steps:

[0029] Step 1, a plurality of groups of cathode busbars around the cell are arranged on the power input side and the power output side of the aluminum electrolytic cell, a group of cathode busbars around the cell are connected with a plurality of groups of cathode soft belts to form a current conduction path, and the column busbars and the short-circuit busbars are connected through the cathode busbars around the cell;

[0030] The working current of the aluminum electrolysis cell is 100-800 kA;

[0031] Step 2: Use aluminum busbars, aluminum soft strips or aluminum welding sheets to interconnect several groups of cathode busbars around the slots on the power-input side to form a network, so that the several groups of busbars around the slots on the power-input side are no longer independent and current flows between them. Then use aluminum busbars, aluminum soft strips or aluminum welding sheets to interconnect several groups of cathode busbars around the slots on the power-output side to form another network, so that the several groups of busbars around the slots on the power-input side are no longer independent and current flows between them.

[0032] The cross-section of the aluminum busbar, aluminum soft strip or aluminum welding sheet can be adjusted as needed, and the adjustment range is (30-550) mm×(30-550) mm;

[0033] The types of aluminum electrolysis cells include ordinary aluminum electrolysis cells, three-layer liquid high-purity aluminum electrolysis cells, and any other molten salt electrolysis cells that use electrolysis to produce raw materials;

[0034] The number of cathode busbars around the slots on the power input side and the power output side is one group or several groups;

[0035] Step 3, by adjusting the cross-section and direction of the cathode busbars around each group of slots, the cross-section and length of the cathode soft belt of each group of cathode steel rod heads, and the layout and configuration of the cathode busbars around each group of slots connected to the column busbars and the short-circuit busbars, ensure that the current value flowing out of the cathode busbars around each group of slots of the networked aluminum electrolytic cells is the same;

[0036] In essence, this is done by adjusting the resistance of each branch, thereby adjusting the current passing through each branch, to achieve a uniform distribution of current;

[0037] Step 4: By adjusting the cross-section and direction of the cathode busbars around each group of cells, the cross-section and length of the cathode soft belt of each group of cathode steel rod heads are adjusted accordingly, and at the same time, the layout and configuration of the cathode busbars around the cells connected to each group of column busbars and short-circuit busbars are adjusted to ensure that the current value flowing into each column busbar of the next aluminum electrolytic cell is the same as the theoretical set value;

[0038] Step 5: The current in the aluminum electrolytic cell is introduced from the anode, passes through the electrolyte and the aluminum liquid to the cathode carbon block, and then is conducted out by the cathode steel rod. The electric field is the energy basis for the operation of the aluminum electrolytic cell and the root of the formation of other physical fields. Therefore, the current distribution of the aluminum electrolytic cell has an important impact on the aluminum electrolysis production;

[0039] The electric field calculation is performed by combining the equivalent resistance method with the finite element method to verify the rationality of the current distribution of the aluminum reduction cell. The electric field is the distribution of current and voltage, which specifically includes the following steps:

[0040] Step 5.1: Establish a busbar current calculation model, and calculate the current flowing through the busbar system, anode guide rod and anode steel claw according to Kirchhoff's law. The calculation formula is as follows:

[0041] ∑E=∑I·R (1)

[0042] Among them, E represents voltage V, I represents current A, and R represents resistance Ω;

[0043]

[0044] in, j Represents a node, I j represents the current A at each node;

[0045] Step 5.2, using the finite element method, iteratively solve each point determined by coordinates x, y, z in the anode, melt and cathode current fields to obtain the current distribution in the entire aluminum electrolysis cell. The melt is the electrolyte and aluminum liquid. The conductive differential equation of the conductive part in the aluminum electrolysis cell can be expressed as the Laplace equation, and the calculation formula is as follows:

[0046]

[0047] ∑V=∑I·R (4)

[0048] Among them, σ x represents the conductivity of a point in the x-axis direction determined by coordinates x, y, and z, σ y Represents the conductivity of a point in the y-axis direction determined by coordinates x, y, and z, σ z represents the conductivity of the point determined by the coordinates x, y, z in the z-axis direction, x represents the x-axis coordinate of the point determined by the coordinates x, y, z in the space rectangular coordinate system, y represents the y-axis coordinate of the point determined by the coordinates x, y, z in the space rectangular coordinate system, z represents the z-axis coordinate of the point determined by the coordinates x, y, z in the space rectangular coordinate system, V represents the scalar potential of the point determined by the coordinates x, y, z;

[0049] Step 5.3, solve by computer and repeatedly adjust the calculation model until the ideal aluminum electrolysis cell current distribution is obtained.

[0050] Example:

[0051] Taking a 200kA electrolyzer as an example, Figure 1 This is a schematic diagram of an embodiment of the present invention in which the busbars around the slot have not yet been networked. Figure 1 In the embodiment, the first incoming busbars Ⅰ2, Ⅱ3, Ⅲ4, Ⅳ5 and Ⅴ6 are not connected to each other; the first outgoing busbars Ⅰ7, Ⅱ8, Ⅲ9, Ⅳ10 and Ⅴ11 are not connected to each other. Each group of incoming busbars and each group of outgoing busbars are connected to the first column busbar and the first short-circuit busbar (1) of the next electrolytic cell, and then introduced into the anode busbar, and then introduced into the anode group. The anode busbars are connected with the balancing busbar.

[0052] Figure 2 It is a schematic diagram of the networking of busbars around the slot according to an embodiment of the present invention. Figure 2 In the figure, the second incoming bus I2', the second incoming bus II3', the second incoming bus III4', the second incoming bus IV5', and the second incoming bus V6' are all interconnected, and the busbars on the second incoming side are connected by a through-length busbar; the second outgoing bus I7', the second outgoing bus II8', the second outgoing bus III9', the second outgoing bus IV10', and the second outgoing bus V11' are all interconnected. Figure 1 The busbar configuration, the cross-section and direction of each group of busbars on the power-in and power-out sides, and the cross-section and length of the cathode soft band of each group of cathode steel rod heads are adjusted based on theoretical calculations.

[0053] As mentioned above, the busbars on the incoming and outgoing sides after networking need to be adjusted in terms of the cross-section and direction of the busbars around each group of slots, and the cross-section and length of the cathode soft strip of each group of cathode steel rod heads compared to the original configuration. Figure 1 and Figure 2 From the busbar direction, it can be seen that the layout and direction of each group of power-input side busbars have been adjusted. The current of each column of the next electrolyzer introduced by the networked cathode busbar around the tank is pre-configured according to the magnetic field calculation results. That is, the networked busbar around the tank optimizes the busbar structure of the electrolyzer while ensuring the stability of the electrolytic cell magnetic fluid.

[0054] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A busbar configuration method for improving the stability of magnetic fluid in an aluminum electrolysis cell, characterized in that: The following steps are involved: Step 1, a plurality of groups of cathode busbars around the cell are arranged on the power input side and the power output side of the aluminum electrolytic cell, a group of cathode busbars around the cell are connected with a plurality of groups of cathode soft belts to form a current conduction path, and the column busbars and the short-circuit busbars are connected through the cathode busbars around the cell; Step 2: Use aluminum busbars, aluminum soft tapes or aluminum welding sheets to interconnect the cathode busbars around several groups of slots on the power-in side to form a network, and then use aluminum busbars, aluminum soft tapes or aluminum welding sheets to interconnect the cathode busbars around several groups of slots on the power-out side to form another network; Step 3, by adjusting the cross-section and direction of the cathode busbars around each group of slots, the cross-section and length of the cathode soft belt of each group of cathode steel rod heads, and the layout and configuration of the cathode busbars around each group of slots connected to the column busbars and the short-circuit busbars, ensure that the current value flowing out of the cathode busbars around each group of slots of the networked aluminum electrolytic cells is the same; Step 4: By adjusting the cross-section and direction of the cathode busbars around each group of cells, the cross-section and length of the cathode soft belt of each group of cathode steel rod heads are adjusted accordingly, and at the same time, the layout and configuration of the cathode busbars around the cells connected to each group of column busbars and short-circuit busbars are adjusted to ensure that the current value flowing into each column busbar of the next aluminum electrolytic cell is the same as the theoretical set value; Step 5: Use a method combining equivalent resistance method and finite element method to calculate the electric field to verify the rationality of the current distribution of the aluminum reduction cell, where the electric field is the distribution of current and voltage.

2. A busbar configuration method for improving the stability of magnetic fluid in aluminum electrolysis cell according to claim 1, characterized in that: In the step 1, the operating current of the aluminum electrolysis cell is 100 to 800 kA.

3. A busbar configuration method for improving the stability of magnetic fluid in aluminum electrolysis cell according to claim 1, characterized in that: In step 2, the cross-section of the aluminum busbar, the aluminum soft strip or the aluminum welding sheet is adjusted as needed, and the adjustment range is (30 to 550) mm×(30 to 550) mm.

4. A busbar configuration method for improving the stability of magnetic fluid in aluminum electrolysis cell according to claim 1, characterized in that: In step 2, the types of aluminum electrolysis cells include ordinary aluminum electrolysis cells, three-layer liquid high-purity aluminum electrolysis cells, and any other molten salt electrolysis cells that use electrolysis methods to produce raw materials.

5. A busbar configuration method for improving the stability of magnetic fluid in aluminum electrolysis cell according to claim 1, characterized in that: In the step 2, the number of cathode busbars around the slots on the power input side and the power output side is one group or several groups.

6. A busbar configuration method for improving the stability of magnetic fluid in aluminum electrolysis cell according to claim 1, characterized in that: The step 5 specifically comprises the following steps: Step 5.1, establish a busbar current calculation model, and calculate the current flowing through the busbar system, anode guide rods and anode steel claws according to Kirchhoff's law; Step 5.2, using the finite element method, iteratively solve each point in the anode, melt and cathode current fields determined by coordinates x, y, z to obtain the current distribution in the entire aluminum electrolysis cell, wherein the melt is the electrolyte and the aluminum liquid, and the conductive differential equation of the conductive part in the aluminum electrolysis cell can be expressed as the Laplace equation; Step 5.3, solve by computer and repeatedly adjust the calculation model until the ideal aluminum electrolysis cell current distribution is obtained.

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