Device and method for reducing the hardness of cooling water of a unit

Abstract

The present invention provides a device and method for reducing the hardness of cooling water of a unit, comprising a water replenishment device, a water reservoir, a water treatment device and a flow-increasing pump; the water replenishment device is used to automatically replenish water to the water reservoir through a water replenishment pipe; the water reservoir is used to store cooling water and send the cooling water into a cooling water supply pipe for external circulation of a rectifier unit; the water treatment device is used to reduce the hardness of the cooling water in the water reservoir; by being embedded in the water-to-water cooling system of an electrolytic aluminum rectifier unit, the scaling rate of the water-to-water cooling system of the rectifier unit is reduced, and the heat exchange efficiency of the water-to-water cooling system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum electrolysis rectification, and in particular to a device and method for reducing the hardness of cooling water of a unit. Background Art

[0002] In aluminum electrolysis rectifier systems, water-to-water coolers serve as crucial auxiliary cooling elements. Water-to-water cooling involves cooling pure water with externally circulating water. During this process, the externally circulating water continuously evaporates, removing heat and completing heat exchange. However, this process presents several challenges: Calcium and magnesium ions gradually accumulate in the water, causing scaling and severely impacting the efficiency of the heat exchanger. Extensive scaling of the heat exchanger occurs. After the externally circulating water evaporates, calcium and magnesium ions gradually accumulate, leading to extensive scaling of the heat exchanger and reduced heat exchange efficiency. This requires shutting down the rectifier unit for manual descaling, severely impacting production in the aluminum electrolysis line. The water storage capacity of the water distribution tank is limited, capable of sustaining only 12 hours of evaporation. Prolonged unplanned water outages, coupled with inability to replenish the externally circulating water in a timely manner, can easily lead to a complete shutdown of the aluminum electrolysis line.

[0003] In view of the above-mentioned problems existing in the prior art, the present invention provides a device and method for reducing the hardness of the cooling water of the unit. By being embedded in the water-water cooling system of the electrolytic aluminum rectifier unit, the scaling rate of the water-water cooling system of the rectifier unit is reduced and the heat exchange efficiency of the water-water cooling system is improved. Summary of the Invention

[0004] The object of the present invention is to provide a device for reducing the hardness of the cooling water of a unit, comprising a water replenishment device, a water reservoir, a water treatment device and a flow-increasing pump; the water replenishment device is used to automatically replenish the water reservoir with water through a water replenishment pipe; the water reservoir is used to store cooling water and send the cooling water into a cooling water supply pipe for external circulation of the rectifier unit; the water treatment device is used to reduce the water hardness of the cooling water in the water reservoir.

[0005] Furthermore, it also includes a plurality of separate water tanks, which are used to store water in the cooling water supply pipeline for standby use when water is cut off.

[0006] Furthermore, the water treatment device includes a cooling water inlet pipe, a dosing device, a parallel water treatment device and a treated water outlet pipe; the dosing device is used to add drugs to the cooling water in the cooling water inlet pipe; the parallel water treatment device is used to reduce the hardness of the cooling water and discharge the treated water into the water reservoir through the treated water outlet pipe.

[0007] Furthermore, the water reservoir includes a first water reservoir and a second water reservoir, the first water reservoir is connected to the cooling water inlet pipe; the second water reservoir is connected to the treated water outlet pipe.

[0008] Furthermore, the water treatment device also includes a PLC controller, which controls the dosing device to add chemicals and the parallel water treatment device to treat cooling water.

[0009] Furthermore, the PLC controller controls the water replenishing device to replenish water through the liquid level information of the water reservoir.

[0010] The object of the present invention is to provide a method for reducing the hardness of the cooling water of a unit, comprising: obtaining liquid level information of a water reservoir; based on the liquid level information, controlling a water replenishment device to replenish production water to the water reservoir; inputting the cooling water in the water reservoir into a water treatment device to reduce the water hardness, and discharging the treated water obtained after the hardness is reduced back to the water reservoir; inputting the cooling water in the water reservoir into a cooling water supply pipeline to supply external circulation water and multiple separate water tanks of a rectifier unit.

[0011] Furthermore, the operation of reducing water hardness includes: adding drugs into the water treatment device and circulating water to circulate the cooling water; backwashing the water treatment device and discharging the sediment after backwashing; and repeating the circulation treatment of the cooling water.

[0012] Furthermore, the method further includes increasing the gap between the impeller of the flow-increasing pump and the pump casing when the water consumption increases.

[0013] Furthermore, when there is a water outage, the separate water tank is activated to supply external circulating water to the rectifier unit.

[0014] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0015] The calcium and magnesium ions in the water are fully removed, and the water hardness is reduced to about 30 mg / L, which minimizes the scaling risk of the cooler and improves the heat exchange rate.

[0016] The flow-boosting pump uses a pipeline pump with a larger gap between the impeller and the pump casing, which ensures water supply while also reducing pipeline pressure, killing two birds with one stone.

[0017] The PLC program automatically controls the parallel water treatment device, dosing device, and water replenishment device, achieving 24-hour circulation of water in the reservoir.

[0018] The setting of separate water pools serves the purpose of emergency water supply and ensures the supply of cooling water. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 An exemplary schematic diagram of a device for reducing the hardness of cooling water in a unit provided in some embodiments of the present invention;

[0020] Figure 2 An exemplary schematic diagram of another device for reducing the hardness of cooling water in a unit provided in some embodiments of the present invention;

[0021] Figure 3 An exemplary flow chart of a method for reducing the hardness of cooling water in a unit provided in some embodiments of the present invention. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0023] Figure 1 This is an exemplary schematic diagram of a device for reducing the hardness of cooling water in a unit according to some embodiments of the present invention. Figure 1 As shown, the device for reducing the hardness of the unit's cooling water includes a water make-up device, a water reservoir, a water treatment device and a flow-increasing pump.

[0024] The water replenishment device is used to automatically replenish the water reservoir through the water replenishment pipe; the water reservoir is used to store cooling water and send the cooling water into the cooling water supply pipe for external circulation of the rectifier unit; the water treatment device is used to reduce the water hardness of the cooling water in the water reservoir.

[0025] In some embodiments, the water treatment device includes a cooling water inlet pipe, a dosing device, a parallel water treatment device, and a treated water outlet pipe.

[0026] The dosing device is used to add medicine to the cooling water in the cooling water inlet pipe; the parallel water treatment device is used to reduce the hardness of the cooling water and discharge the treated water into the water reservoir through the treated water outlet pipe.

[0027] In some embodiments, the water treatment device further includes a PLC controller, which controls the dosing device to add chemicals and the parallel water treatment device to treat cooling water.

[0028] In some embodiments, the PLC controller also controls the water replenishment device to replenish water through the liquid level information of the water reservoir.

[0029] Liquid level information can be obtained by installing a liquid level sensor in the water reservoir and connecting it to the PLC control communication. The PLC's input and output (I / O) modules automatically control the parallel water treatment device, dosing device, and water replenishment device. The PLC controller controls the parallel water treatment device to continuously circulate and filter the water in the water reservoir. At the same time, the PLC controls the dosing device to add flocculants to the water. The flocculants form calcium and magnesium ions in the water into flocs, which are then removed when passing through the parallel water treatment device's filters.

[0030] In some embodiments, a plurality of separate water tanks are further included, and the plurality of separate water tanks are used to store water in the cooling water supply pipeline for standby use when water is cut off.

[0031] In some embodiments of the present invention, the cooling water in the water reservoir is continuously treated by a water treatment device, so that the water in the main water reservoir is filtered 24 hours a day, which can fully remove calcium and magnesium ions in the water and reduce the water hardness to about 30 mg / L.

[0032] Figure 2 This is an exemplary schematic diagram of another device for reducing the hardness of cooling water in a unit provided in some embodiments of the present invention. Figure 2 As shown, another device for reducing the hardness of cooling water for a unit includes a first reservoir and a second reservoir. The first reservoir is connected to the cooling water inlet pipe; the second reservoir is connected to the treated water outlet pipe. The first and second reservoirs can separate the produced water from the treated water in the cooling water, preventing the treated water from mixing with the produced water.

[0033] Figure 3 This is an exemplary flow chart of a method for reducing the hardness of cooling water in a unit according to some embodiments of the present invention. Figure 3 As shown in the figure, the methods to reduce the hardness of the cooling water of the unit include:

[0034] Step 110: Obtain the liquid level information of the water reservoir.

[0035] Liquid level information can be obtained through the liquid level sensor in the water reservoir.

[0036] Step 120: Based on the liquid level information, control the water replenishment device to replenish production water to the water reservoir.

[0037] For example, liquid level sensors include low and high level sensors. When a signal from the low level sensor is received, the PLC controller controls the water replenishment device to add water to the reservoir. When a signal from the high level sensor is received, the PLC controller stops the water replenishment device from adding water to the reservoir. The low level sensor monitors whether the water level in the reservoir has reached its minimum level. The high level sensor monitors whether the water level in the reservoir has reached its maximum level.

[0038] In some embodiments, for the first water reservoir and the second water reservoir, a first liquid level sensor is provided in the first water reservoir, and a second liquid level sensor is provided in the second water reservoir, respectively for obtaining liquid level information x of the first water reservoir. 1t And the liquid level information x of the second water tank 2t Then controlling the water replenishment device to replenish the produced water to the water reservoir includes:

[0039] Obtain the first liquid level information x of the first water reservoir and the second liquid level information y of the second water reservoir at the current time.

[0040] Predict the remaining water volume y1 in the second reservoir after time period t.

[0041] Predict the remaining water volume y2 in the second reservoir after a period of 2t.

[0042] In some embodiments, the amount of treated water required for the first preset period t and the amount of treated water described in the second preset period 2t can be predicted based on the operating status of the rectifier unit's external circulating water. The remaining water volume in the second water reservoir after periods t and 2t can then be predicted based on the treated water volume. Where t is the total time required for each cycle of treatment by the water treatment device, including production water input time, water treatment time, backwash time, and treated water output time. In some embodiments, the amount of treated water required for the first preset period t and the amount of treated water described in the second preset period 2t can be predicted based on the historical cooling water demand of the unit's external circulating water.

[0043] Obtain the amount of water Q processed by the water treatment device in time period t.

[0044] The minimum and maximum water levels of the first water reservoir are determined based on the remaining water volume y1 of the second water reservoir after time period t, the remaining water volume y2 of the second water reservoir after time period 2t, and the water volume Q processed by the water treatment device during time period t.

[0045] In some embodiments, the expression for the lowest water level is:

[0046]

[0047] Among them, Q min1 Indicates the lowest water level of the first reservoir; Q min2 represents the lowest water level of the second water reservoir; y2 represents the remaining water volume in the second water reservoir after a period of 2t; Q represents the amount of water treated by the water treatment device in a period of t.

[0048] In some embodiments, the expression for the highest water level is:

[0049]

[0050] Among them, Q max1 Indicates the highest water level of the first reservoir; Q max2 represents the highest water level of the second water reservoir; y1 represents the remaining water volume in the second water reservoir after time period t; s2 represents the bottom area of ​​the second water reservoir; s1 represents the bottom area of ​​the first water reservoir.

[0051] Determine whether the first liquid level information x is between the minimum water level and the maximum water level. If the first liquid level information x is lower than the minimum water level, the PLC controller controls the water replenishing device to replenish water to the first water reservoir; if the first liquid level information x is higher than the maximum water level, the PLC controller controls the water replenishing device to stop replenishing water to the first water reservoir.

[0052] In step 130, the cooling water in the water reservoir is input into a water treatment device to reduce the hardness of the water, and the treated water obtained after the hardness is reduced is discharged back to the water reservoir.

[0053] In some embodiments, the operation of reducing water hardness includes: adding drugs into the water treatment device and circulating water to circulate the cooling water; backwashing the water treatment device and discharging the sediment after backwashing; and repeating the circulation treatment of the cooling water.

[0054] Step 140: The cooling water in the water reservoir is input into the cooling water supply pipe to supply the external circulating water of the rectifier unit and the multiple separate water tanks.

[0055] In some embodiments, the method further includes increasing the gap between the impeller of the booster pump and the pump casing when the water consumption increases.

[0056] In some embodiments, the method further includes activating the separate water tank to supply external circulating water to the rectifier unit when there is a water outage.

[0057] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A device for reducing the hardness of cooling water of a unit, characterized in that: It includes water replenishment device, water reservoir, water treatment device and flow booster pump; The water replenishing device is used to automatically replenish water to the water reservoir through the water replenishing pipe; The water reservoir is used to store cooling water and send the cooling water into the cooling water supply pipe for external circulation of the rectifier unit; The water treatment device is used to reduce the water hardness of the cooling water in the water reservoir; The water treatment device includes a cooling water inlet pipe, a dosing device, a parallel water treatment device and a treated water outlet pipe; The dosing device is used to add medicine to the cooling water in the cooling water inlet pipe; The parallel water treatment device is used to reduce the hardness of the cooling water and discharge the treated water into the water reservoir through the treated water outlet pipe; The water treatment device further comprises a PLC controller, which controls the dosing device to add chemicals and the parallel water treatment device to treat cooling water; The PLC controller also controls the water replenishing device to replenish water based on the liquid level information of the water reservoir; the water reservoir includes a first water reservoir and a second water reservoir, the first water reservoir is connected to the cooling water inlet pipe; the second water reservoir is connected to the treated water outlet pipe; controlling the water replenishing device to replenish water includes: Obtaining first liquid level information of the first water reservoir and second liquid level information of the second water reservoir at the current time; Predict the remaining water volume in the second reservoir after time period t; Predict the remaining water volume in the second reservoir after a 2t period; Obtain the amount of water processed by the water treatment device in time period t; Based on the remaining water volume of the second water reservoir after time period t, the remaining water volume of the second water reservoir after time period 2t, and the amount of water treated by the water treatment device during time period t, the minimum water level and the maximum water level of the first water reservoir are determined; the expressions for the minimum water level and the maximum water level are: ； in, Indicates the lowest water level of the first reservoir; Indicates the lowest water level of the second reservoir; Indicates the remaining water volume in the second reservoir after a period of 2t; represents the amount of water treated by the water treatment device during period t; ； in, Indicates the highest water level of the first reservoir; Indicates the highest water level of the second reservoir; represents the remaining water volume in the second reservoir after time period t; represents the bottom area of ​​the second water reservoir; represents the bottom area of ​​the first water reservoir; Determine whether the first liquid level information is between the minimum water level and the maximum water level. If the first liquid level information is lower than the minimum water level, the PLC controller controls the water replenishing device to replenish water to the first water reservoir; if the first liquid level information is higher than the maximum water level, the PLC controller controls the water replenishing device to stop replenishing water to the first water reservoir.

2. The device for reducing the hardness of cooling water of a unit according to claim 1, characterized in that: It also includes a plurality of separate water tanks, which are used to store water in the cooling water supply pipeline for standby use when the water supply is cut off.

3. A method for reducing the hardness of cooling water of a unit, characterized in that: include: Get the liquid level information of the water tank; Based on the liquid level information, controlling the water replenishment device to replenish production water to the water reservoir, the water reservoir comprising a first water reservoir and a second water reservoir, the first water reservoir being connected to a cooling water inlet pipe of a water treatment device; and the second water reservoir being connected to a treated water outlet pipe of the water treatment device, comprising: Obtaining first liquid level information of the first water reservoir and second liquid level information of the second water reservoir at the current time; Predict the remaining water volume in the second reservoir after time period t; Predict the remaining water volume in the second reservoir after a 2t period; Obtain the amount of water processed by the water treatment device in time period t; Based on the remaining water volume of the second water reservoir after time period t, the remaining water volume of the second water reservoir after time period 2t, and the amount of water treated by the water treatment device during time period t, the minimum water level and the maximum water level of the first water reservoir are determined; the expressions for the minimum water level and the maximum water level are: ; in, Indicates the lowest water level of the first reservoir; Indicates the lowest water level of the second reservoir; Indicates the remaining water volume in the second reservoir after a period of 2t; represents the amount of water treated by the water treatment device during period t; ； in, Indicates the highest water level of the first reservoir; Indicates the highest water level of the second reservoir; represents the remaining water volume in the second reservoir after time period t; represents the bottom area of ​​the second water reservoir; represents the bottom area of ​​the first water reservoir; Determine whether the first liquid level information is between the minimum water level and the maximum water level. If the first liquid level information is lower than the minimum water level, the PLC controller controls the water replenishing device to replenish water into the first water reservoir; if the first liquid level information is higher than the maximum water level, the PLC controller controls the water replenishing device to stop replenishing water into the first water reservoir; The cooling water in the water reservoir is input into the water treatment device to reduce the water hardness, and the treated water obtained after the hardness reduction is discharged back to the water reservoir; The cooling water in the water reservoir is input into the cooling water supply pipeline to supply the external circulation water of the rectifier unit and a plurality of separate water tanks.

4. The method for reducing the hardness of cooling water of a unit according to claim 3, characterized in that: The operation of reducing water hardness comprises: Adding medicine into the water treatment device and performing water circulation to circulate the cooling water; Backwashing the water treatment device and discharging the sediment after backwashing; Repeat the cooling water circulation process.

5. The method for reducing the hardness of cooling water of a unit according to claim 3, characterized in that: The method also includes increasing the gap between the impeller of the booster pump and the pump casing when the water consumption increases.

6. The method for reducing the hardness of cooling water of a unit according to claim 3, characterized in that: It also includes, when there is a water outage, activating the separate water tank to supply external circulating water to the rectifier unit.

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