An energization method and an energization device for soil desalination

Abstract

The application relates to the field of soil desalination, and particularly discloses a power-on method and a power-on device for soil desalination. The device comprises a power supply, a plurality of current distributors and a plurality of electrode groups. The method comprises the following steps: device preparation; single round power-on: according to the size of the detection current of each group, the distance between the positive and negative electrodes of power-on is adjusted; multiple rounds of power-on: the initial power-on positive and negative electrode spacing of the next round of power-on is smaller than that of the previous round of power-on. According to the change of the current with time in the electric desalination process, the distance between the electrodes is adjusted to realize the adjustment of the current, the electric desalination process is kept under suitable current conditions at all times, the desalination efficiency is improved, the desalination time is shortened, the waste of electric energy is reduced, and the energy consumption is reduced. Compared with the mode of adjusting the voltage by using a variable voltage power supply, the power-on method provided by the application adopts a constant voltage direct current power supply, and a power supply with continuously adjustable voltage is not needed, so that the cost of the power supply is reduced.

Description

Technical Field

[0001] This application relates to the field of soil desalination, and in particular to an electric method and device for soil desalination. Background Technology

[0002] Electrostatic desalination is a technology that utilizes an electric field to promote the migration and removal of salts in soil, and can be applied to fields such as saline-alkali land improvement. The principle of electrostatic soil desalination is as follows: under the influence of an electric field, cations in the soil (such as Na+) migrate and remove salts. + K + (e.g., ions) will migrate and accumulate towards the cathode, while anions (e.g., Cl-) will... - SO4 2- (e.g., ions) will move towards the anode and accumulate; by draining water at the electrode, the accumulated ions are discharged from the soil, thereby achieving soil desalination.

[0003] In the initial stage of energization, due to the high salt content of the soil, the resistance is small and the current is large; as the energization proceeds, the salt content of the soil decreases, the ion content in the pore water also decreases accordingly, and the soil near the electrode becomes polarized, resulting in a decrease in current. Most of the current soil electric desalination technologies use transformer and rectifier power supplies. The main problems are: (1) Due to the uneven properties of the soil on site, the current changes differently over time. If the same energization method is used for each area, it is difficult to produce the expected effect when energizing ineffective energized areas with inappropriate current and voltage, and energy is wasted; (2) When applied on a large scale, the power and energy consumption are too high, which restricts the large-scale application of soil electric desalination technology; (3) The cost of continuously adjustable power supplies is high. Summary of the Invention

[0004] In order to improve desalination efficiency, reduce power consumption, and lower power supply costs, this application provides an energizing method and energizing device for soil desalination.

[0005] The electrostatic method for soil desalination provided in this application adopts the following technical solution:

[0006] An electrostatic method for soil desalination includes the following steps:

[0007] Equipment preparation: Divide the site to be treated into several areas, and bury an electrode group in the soil of each area. Each electrode group includes N (N>3) electrodes arranged at equal intervals, with a distance of L between two adjacent electrodes. Set up a current distributor in each area, and connect each electrode in the electrode group to the positive and negative terminals of the current distributor in this area. Use a connector to control the connection and disconnection of the electrodes with the positive or negative terminals of the current distributor. Connect all current distributors to the power supply.

[0008] Single-round power-on: Connect two electrodes with a distance of nL (1 < n < N - 1) in each group to the positive and negative electrodes of the current distributor respectively and apply power, then detect the current; according to the magnitude of the detected current in each group, control the connection and disconnection of the electrodes to the positive or negative electrode of the current distributor through the connector, so as to adjust the distance between the positive and negative electrodes under power-on.

[0009] Multi-round power-on: During each round of power-on, the current decreases exponentially with time. When the current is close to zero or the current margin constant, end the power-on of this round for this group and then perform the next round of power-on. The initial distance between the positive and negative electrodes under power-on in the next round is smaller than that in the previous round.

[0010] Further, the single-round power-on step includes:

[0011] If the detected current in some groups is greater than the set upper limit value of the current for a single group, stop the power-on of this group, and continue the power-on for other groups;

[0012] If the detected currents in all groups are greater than the set upper limit value of the current for a single group, increase the distance between the positive and negative electrodes under power-on in all groups with a step size of L until the current in at least one group is not greater than the set upper limit value of the current for a single group, then keep the distance between the positive and negative electrodes under power-on in this group and continue the power-on, and stop the power-on for other groups.

[0013] Further, the single-round power-on step includes: If the detected current is not greater than the set upper limit value of the current for a single group, then judge whether the detected current is less than the set lower limit value of the current for a single group, and further adjust the distance between the positive and negative electrodes under power-on in this group.

[0014] Further, the single-round power-on step also includes:

[0015] If the detected current is less than the set lower limit value of the current for a single group, decrease the distance between the positive and negative electrodes under power-on with a step size of L until the current is not less than the lower limit value of the current for a single group and not greater than the upper limit value of the current for a single group, then keep the distance between the positive and negative electrodes under power-on and continue the power-on;

[0016] If the detected current is not less than the set lower limit value of the current for a single group, keep the distance between the positive and negative electrodes under power-on and continue the power-on.

[0017] Further, the single-round power-on step also includes: Every once in a while, connect two electrodes with a distance of nL (1 < n < N - 1) in the unconnected groups to the positive and negative electrodes of the current distributor respectively and apply power, and control the connection or non-connection of this group according to the magnitude of the detected current.

[0018] Further, the single-round power-on step further includes: when the sum of the currents of all groups is less than the set upper limit value of the total current, two electrodes with a distance of nL (1 < n < N - 1) in the unconnected group are respectively connected to the positive and negative electrodes of the current distributor and powered on. According to the magnitude of the detected current, control the connection or non-connection of this group.

[0019] Further, if the detected current of the unconnected group is not less than the set lower limit value of the single-group current, then keep this group unconnected; if the detected current of the unconnected group is less than the set lower limit value of the single-group current, then judge whether the sum of the currents of all groups is less than the set upper limit value of the total current. If so, then connect this group; if not, then keep this group unconnected.

[0020] Further, the multi-round power-on step is specifically as follows: in each round of power-on process, perform data fitting on the change of current with time in each group to obtain a fitting curve I = Ae -at + B, where I is the current, t is the power-on time, A is a coefficient, a is the time exponent, B is the current margin constant, and e is the natural constant; when the current detection value approaches B, change the polarity of the electrode and then continue to power on. After several polarity conversions, when the current is close to zero or B, end the power-on of this group in this round, and then perform the next round of power-on for this group. The initial positive and negative electrode distances in the next round of power-on are smaller than those in the previous round of power-on.

[0021] The present application also provides a power-on device for soil desalination, which is used to implement a power-on method for soil desalination. The device includes:

[0022] A power supply;

[0023] Multiple electrode groups, which are respectively buried in the soil bodies in different areas of the treatment site. Each electrode group includes several electrodes arranged at equal intervals;

[0024] Multiple current distributors, corresponding to the multiple electrode groups one by one. In each electrode group, each electrode is respectively connected to the positive and negative electrodes of the current distributor through an independent connector, and the connection and disconnection of the electrode to the positive or negative electrode of the current distributor are controlled through the connector; the multiple current distributors are connected to the power supply, and the current distributor has functions of reading back power-on parameters, polarity conversion, short-circuiting, and disconnection.

[0025] Further, it further includes a controller, which is used to control the on-off of the corresponding current distributor and the on-off of the corresponding connector according to the current conditions in each area.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: <T

[0027] 1. This application adjusts the current by regulating the distance between electrodes based on the change of current over time during the electric desalination process, thereby maintaining the electric desalination process under suitable current conditions, improving desalination efficiency, shortening desalination time, reducing energy waste, and helping to reduce energy consumption;

[0028] 2. Compared with the method of regulating voltage using a transformer power supply, the power supply method provided in this application uses a constant voltage DC power supply, which does not require the use of a power supply with continuously adjustable voltage, thus helping to reduce the cost of the power supply;

[0029] 3. By controlling the connection and disconnection of the electrodes with the positive or negative terminal of the power supply through the connector and current distributor, the energization status of the electrodes can be conveniently controlled, and the electrode spacing can be adjusted without rewiring.

[0030] 4. This application divides the site to be treated into several areas for separate control, which helps to overcome the regional differences caused by the uneven soil properties, and ensures that each area can carry out desalination under appropriate current conditions, thereby improving desalination efficiency and reducing energy waste. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of an energized device for soil desalination according to an embodiment of this application;

[0032] Figure 2 This is a flowchart of a single-cycle energization process in an energization method for soil desalination according to an embodiment of this application;

[0033] Figure 3 This is one of the flowcharts for connecting unconnected groups during a single-round energization process in an energization method for soil desalination according to an embodiment of this application;

[0034] Figure 4 This is the second flowchart of a method for connecting unconnected groups during a single-round power-on process in an embodiment of this application for soil desalination.

[0035] Reference numerals: 1. Power supply; 2. Current distributor; 3. Electrode group; 3-1. Electrode; 4. Connector. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0037] This application discloses an electrified device for soil desalination. (Refer to...) Figure 1 The power supply device for soil desalination includes a power source 1, multiple electrode groups 3, and multiple current distributors 2 corresponding to the multiple electrode groups 3. The power source 1 is a 36V or 24V DC power source 1.

[0038] Reference Figure 1 The site to be treated is divided into two areas (area one and area two), and two electrode groups 3 are buried in the two areas respectively. In other embodiments, the site to be treated can also be divided into more areas. Each electrode group 3 includes N electrodes 3-1 arranged at equal intervals. The distance between two adjacent electrodes 3-1 is L. In this embodiment, N=6 and L=5m. The length of the electrode 3-1 is 10m, it is set in the horizontal direction, and the burial depth is 30cm. For ease of explanation, the electrodes 3-1 in the two areas are numbered as (1)-(6) and (7)-(12) respectively.

[0039] Reference Figure 1 In each electrode group 3, each electrode 3-1 is connected to the positive and negative terminals of the current distributor 2 via an independent connector 4. The connector 4 controls the connection and disconnection of electrode 3-1 with the positive or negative terminal of the current distributor 2. Multiple current distributors 2 are connected to the power supply 1. The current distributor 2 has functions such as power-on parameter readback, polarity reversal, short-circuiting, and disconnection.

[0040] The device also includes a controller for controlling the on / off state of the corresponding current distributor 2 and the corresponding connector 4 according to the current conditions of each area.

[0041] An electrostatic method for soil desalination is implemented using an electrostatic device, comprising the following steps:

[0042] Step 1, Equipment Preparation:

[0043] The site to be treated is divided into two areas. In each area, an electrode group 3 is buried in the soil. Each electrode group 3 consists of six equally spaced electrodes 3-1, with a spacing of 5m between adjacent electrodes 3-1. A current distributor 2 is installed in each area. The electrodes 3-1 in the electrode group 3 are connected to the positive and negative terminals of the current distributor 2 via independent connectors 4. The connectors 4 control the connection and disconnection of the electrodes 3-1 with the positive or negative terminals of the current distributor 2. All current distributors 2 are connected to a power supply 1.

[0044] Step 2, Powering on a single wheel:

[0045] Normally, the initial electrode spacing is moderate during the first round of energization. Connect electrodes (1) and (4) in region one to the positive and negative terminals of the current distributor 2 in this region, respectively. Connect electrodes (7) and (10) in region two to the positive and negative terminals of the current distributor 2 in this region, respectively. Energize and detect the current. Except for the connector 4 between the connected electrode 3-1 and the current distributor 2, all other connectors 4 are disconnected.

[0046] Based on the magnitude of the current detected in each group, the connection and disconnection between the electrodes and the positive or negative terminals of the current distributor 2 are controlled via connector 4, thereby adjusting the distance between the energized positive and negative electrodes; (Refer to...) Figure 2 Specifically, it includes the following steps:

[0047] Step 2.1: If the detection current of some groups exceeds the set upper limit of the single group current (e.g., 60A), then stop energizing that group, and continue energizing the other groups.

[0048] Step 2.2: If the detection current of all groups is greater than the set single-group current limit (60A), then increase the spacing between the energized positive and negative electrodes in all groups in increments of 5m. For example, connect electrodes (1) and (5) in region 1 to the positive and negative terminals of the current distributor 2 in this region, respectively, and connect electrodes (7) and (11) in region 2 to the positive and negative terminals of the current distributor 2 in this region, respectively; until the current of at least one group is not greater than the set single-group current limit (60A), then maintain the current spacing between the energized positive and negative electrodes of that group and continue to energize, while stopping the energization of other groups.

[0049] Step 2.3: For the energized group, if the detected current is not greater than the set upper limit of the single group current (60A), then determine whether the detected current is less than the set lower limit of the single group current (e.g., 50A), and then adjust the distance between the positive and negative electrodes of the energized group. This specifically includes the following steps:

[0050] Step 2.3.1: If the detected current is less than the set lower limit of the single current (50A), the distance between the energized positive and negative electrodes is reduced in steps of 5m until the current is not less than the lower limit of the single current (50A) and not greater than the upper limit of the single current (60A). Then, the current distance between the energized positive and negative electrodes is maintained and energization continues.

[0051] Step 2.3.2: If the detected current is not less than the set single-group current lower limit (50A), then maintain the current positive and negative electrode spacing and continue to energize.

[0052] Step 2.4: Refer to Figure 3 Every so often (e.g., every hour), two electrodes 15m apart in the unconnected group are connected to the positive and negative terminals of current distributor 2 respectively and energized. Based on the magnitude of the detected current, the group is controlled to connect or remain disconnected. The specific steps include:

[0053] Step 2.4.1: If the detection current of the unconnected group is not less than the set single group current lower limit (50A), then keep the group unconnected.

[0054] Step 2.4.2: If the detected current of the unconnected group is less than the set lower limit of the single group current (50A), then determine whether the sum of the currents of all groups is less than the set upper limit of the total current (e.g., 400A). If yes, then connect the group; otherwise, keep the group unconnected.

[0055] Step 2.5: Refer to Figure 4 When the sum of the currents of all groups is less than the set upper limit of the total current (400A), the two electrodes of the unconnected group, spaced 15m apart, are connected to the positive and negative terminals of the current distributor 2 respectively and energized. Based on the magnitude of the detected current, the group is controlled to be connected or kept unconnected. The specific steps include:

[0056] Step 2.5.1: If the detection current of the unconnected group is not less than the set single group current lower limit (50A), then keep the group unconnected;

[0057] Step 2.5.2: If the detected current of the unconnected group is less than the set lower limit of the single group current (50A), then determine whether the sum of the currents of all groups is less than the set upper limit of the total current (400A). If yes, then connect the group; otherwise, keep the group unconnected.

[0058] Step 3, Multiple rounds of power-on:

[0059] During each round of energization, the change of current over time in each group is fitted to obtain the fitted curve I=Ae. -at +B, where I is the current, t is the energizing time, A is the coefficient, a is the time exponent, B is the current margin constant, and e is the natural constant.

[0060] When the current detection value approaches B, the polarity of current distributor 2 is switched, converting the original positive electrode to a negative electrode and vice versa, and then the current continues to flow. The purpose of switching polarity is that as electromigration and electroosmosis proceed, the positive and negative electrodes become polarized, and precipitation may form at the cathode, leading to a decrease in desalination efficiency. Switching the electrode polarity eliminates polarization, dissolves precipitates, thereby reducing resistance, increasing the effective electric field strength of the soil, and thus improving electromigration and electroosmosis efficiency.

[0061] After several polarity reversals, when the current approaches zero or B, the current cycle of energizing this group ends, and then the next cycle of energizing this group begins. The initial positive and negative electrode spacing of the next cycle of energizing is smaller than that of the previous cycle.

[0062] For example, the initial state of the first round of energization is: electrodes (1) and (4) in region 1 are positive electrodes and negative electrodes respectively, and electrodes (7) and (10) in region 2 are positive electrodes and negative electrodes respectively; the initial state of the second round of energization is: electrodes (1) and (3) in region 1 are positive electrodes and negative electrodes respectively, and electrodes (7) and (9) in region 2 are positive electrodes and negative electrodes respectively.

[0063] Repeat the above steps until all areas have been desalinated.

[0064] This application divides the site to be treated into several areas for separate control, which helps overcome regional differences caused by the heterogeneity of soil properties and ensures that desalination can be carried out in each area under suitable current conditions, thereby improving desalination efficiency and reducing energy waste. Specifically, based on the change of current over time during the electric desalination process, the current is adjusted by regulating the distance between electrodes 3-1, keeping the electric desalination process under suitable current conditions at all times, improving desalination efficiency, shortening desalination time, reducing energy waste, and thus reducing energy consumption. Specifically, for desalination sites that normally take 1-3 months to complete, the electric desalination method provided in this application only takes 1-2 weeks. In addition, compared with the method of adjusting voltage using a transformer power supply, the electric desalination method provided in this application uses a constant voltage DC power supply, eliminating the need for a continuously adjustable voltage power supply, which helps reduce power supply costs.

[0065] It should be noted that the energizing method and energizing device provided in this application can be applied not only to soil desalination, but also to other soil electro-electric technologies, such as soil electro-osmotic dehydration, contaminated soil remediation, and rare earth electro-electric mining, in order to improve processing efficiency and reduce energy consumption.

[0066] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An electrostatic method for soil desalination, characterized in that: It includes the following steps: Device preparation: Divide the site to be processed into several areas, bury an electrode group in the soil of each area. Each electrode group includes N (N>3) electrodes arranged at equal intervals, and the distance between adjacent two electrodes is L; Set a current distributor in each area, connect each electrode in the electrode group to the positive and negative poles of the current distributor in this area respectively, and use a connector to control the connection and disconnection of the electrode with the positive or negative pole of the current distributor; Connect all current distributors to the power supply; Single-round power-on: Connect two electrodes with a distance of nL (1 < n < N - 1) in each electrode group to the positive and negative poles of the current distributor respectively and power on, and detect the current; According to the magnitude of the detected current in each electrode group, control the connection and disconnection of the electrode with the positive or negative pole of the current distributor through the connector, so as to adjust the distance between the positive and negative electrodes for power-on; Multiple energizing cycles: During each energizing cycle, the change of current in each electrode group over time is fitted to obtain the fitted curve I=Ae. -at +B, where I is the current, t is the energizing time, A is the coefficient, a is the time exponent, B is the current margin constant, and e is the natural constant; When the detected current value approaches B, reverse the polarity of the electrode and continue to power on. After several polarity reversals, when the current is close to zero or B, end the power-on of this round of this electrode group, and then perform the next round of power-on of this electrode group. The initial distance between the positive and negative electrodes in the next round of power-on is less than the initial distance between the positive and negative electrodes in the previous round of power-on.

2. The method for soil desalination according to claim 1, characterized in that: The single-round power-on step includes: If the detected current of some electrode groups is greater than the set upper limit value of the current for a single group, stop the power-on of this electrode group, and continue to power on other electrode groups; If the detected currents of all electrode groups are greater than the set upper limit value of the current for a single group, increase the distance between the positive and negative electrodes for power-on in all electrode groups in steps of L until the current of at least one electrode group is not greater than the set upper limit value of the current for a single group, and then continue to power on while maintaining the current distance between the positive and negative electrodes for power-on of this electrode group, and stop the power-on of other electrode groups.

3. The method for soil desalination according to claim 2, characterized in that: The single-round power-on step includes: If the detected current is not greater than the set upper limit value of the current for a single group, judge whether the detected current is less than the set lower limit value of the current for a single group, and then adjust the distance between the positive and negative electrodes for power-on of this electrode group.

4. The method for soil desalination according to claim 3, characterized in that: The single-round power-on step also includes: If the detected current is less than the set lower limit value of the current for a single group, decrease the distance between the positive and negative electrodes for power-on in steps of L until the current is not less than the lower limit value of the current for a single group and not greater than the upper limit value of the current for a single group, and then maintain the current distance between the positive and negative electrodes for power-on and continue to power on; If the detected current is not less than the set lower limit value of the current for a single group, maintain the current distance between the positive and negative electrodes for power-on and continue to power on.

5. The method for soil desalination according to claim 3, characterized in that: The single-round power-on step also includes: Every once in a while, connect two electrodes with a distance of nL (1 < n < N - 1) in the unconnected electrode group to the positive and negative poles of the current distributor respectively and power on, and control the connection or non-connection of this electrode group according to the magnitude of the detected current.

6. The method for soil desalination according to claim 3, characterized in that: The single-round power-on step also includes: When the sum of the currents of all electrode groups is less than the set upper limit value of the total current, connect two electrodes with a distance of nL (1 < n < N - 1) in the unconnected electrode group to the positive and negative poles of the current distributor respectively and power on, and control the connection or non-connection of this electrode group according to the magnitude of the detected current.

7. An electrostatic method for soil desalination according to claim 5 or 6, characterized in that: If the detected current of an unconnected electrode group is not less than the set lower limit of the single-group current, then the electrode group remains unconnected; if the detected current of an unconnected electrode group is less than the set lower limit of the single-group current, then it is determined whether the sum of the currents of all electrode groups is less than the set upper limit of the total current. If yes, then the electrode group is connected; otherwise, the electrode group remains unconnected.

8. An energizing device for soil desalination, used to implement the energizing method for soil desalination as described in any one of claims 1-7, characterized in that: include: power supply; Multiple electrode groups are buried in the soil in different areas of the site to be treated. Each electrode group includes several electrodes arranged at equal intervals. Multiple current distributors correspond one-to-one with multiple electrode groups. In each electrode group, each electrode is connected to the positive and negative terminals of the current distributor through an independent connector. The connection and disconnection of the electrode to the positive or negative terminal of the current distributor are controlled by the connector. Multiple current distributors are connected to the power supply. The current distributors have functions such as power-on parameter readback, polarity reversal, short-circuiting, and disconnection.

9. An energized device for soil desalination according to claim 8, characterized in that: It also includes a controller, which controls the on / off state of the corresponding current distributor and the corresponding wiring device according to the current conditions of each area.

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