Power-on method and power-on device for soil desalination

Abstract

The invention 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, and the method comprises the following steps: preparing the device; single-wheel electrifying: adjusting the distance between the electrified positive and negative electrodes according to the magnitude of each group of detection current; and the interval between the initial energization positive electrode and the initial energization negative electrode of the later-round energization is smaller than the interval between the initial energization positive electrode and the initial energization negative electrode of the previous-round energization. According to the change of the current along with time in the electric desalting process, the current is adjusted by adjusting the distance between the electrodes, so that the electric desalting process is always carried out under a proper current condition, the desalting efficiency is improved, the desalting time is shortened, the electric energy waste is reduced, and the energy consumption is reduced; compared with a mode of adjusting the voltage by adopting a variable-voltage power supply, the power-on method provided by the invention adopts a constant-voltage direct-current power supply, does not need to use a power supply with continuously adjustable voltage, and is beneficial to reducing the cost of the power supply.

Description

Technical Field

[0001] The present application relates to the field of soil desalination, and in particular to an electrification method and an electrification device for soil desalination. Background Art

[0002] Electric desalination is a technology that uses electric field to promote the migration and removal of salt in soil. It can be applied to saline-alkali land improvement and other fields. The principle of electric desalination of soil is: under the action of electric field, cations (such as Na + , K + etc.) will move to the cathode for enrichment, while anions (such as Cl - 、SO 4 2- The ions in the soil will move toward the anode and accumulate. The enriched ions will be discharged from the soil through drainage at the electrode, thus achieving soil desalination.

[0003] In the initial stage of power-on, due to the high salt content of the soil, the resistance is small and the current is large; as the power-on progresses, the salt content of the soil decreases, the ion content in the pore water also decreases accordingly, and the soil near the electrode polarizes, causing the current to decrease. Most of the current electric desalination technologies use transformers and rectifiers. The main problems are: (1) Due to the uneven nature of the soil on site, the current changes differently over time. If the same power-on method is used for each area, it is difficult to produce the expected effect when the inappropriate current and voltage are used in the invalid power-on area, and electric energy is wasted; (2) When applied on a large scale, the power and energy consumption are too large, which restricts the large-scale application of soil electric desalination technology; (3) The cost of a continuously adjustable power supply is high. Summary of the invention

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

[0005] The present application provides an electrification method for soil desalination using the following technical solution: An electrification method for soil desalination comprises the following steps: Device preparation: Divide the site to be treated 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 two adjacent electrodes is L; set a current distributor in each area, connect each electrode in the electrode group to the positive and negative electrodes of the current distributor in this area respectively, and use a connector to control the connection and disconnection of the electrode and the positive or negative electrode 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 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. Multi-round power-on: During each round of power-on, the current decreases exponentially with time. When the current approaches zero or the current margin constant, end the power-on of this round for this group and then proceed to the next round of power-on. The initial distance between the positive and negative electrodes under power-on in the latter round is smaller than that in the previous round.

[0006] Further, the single-round power-on step includes: If the detected current in some groups is greater than the set upper limit of the current for a single group, stop the power-on of this group, and continue the power-on for other groups; If the detected current in all groups is greater than the set upper limit of the current for a single group, increase the distance between the positive and negative electrodes under power-on in all groups in steps of L until the current in at least one group is not greater than the set upper limit of the current for a single group, and then continue the power-on while maintaining the current distance between the positive and negative electrodes under power-on for this group, and stop the power-on for other groups.

[0007] Further, the single-round power-on step includes: If the detected current is not greater than the set upper limit of the current for a single group, then determine whether the detected current is less than the set lower limit of the current for a single group, and further adjust the distance between the positive and negative electrodes under power-on for this group.

[0008] Further, the single-round power-on step also includes: If the detected current is less than the set lower limit of the current for a single group, decrease the distance between the positive and negative electrodes under power-on in steps of L until the current is not less than the lower limit of the current for a single group and not greater than the upper limit of the current for a single group, and then maintain the current distance between the positive and negative electrodes under power-on and continue the power-on; If the detected current is not less than the set lower limit of the current for a single group, maintain the current distance between the positive and negative electrodes under power-on and continue the power-on.

[0009] 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.

[0010] Further, the single-round power-on step also includes: When the total current sum of all groups is less than the set upper limit of the total current, 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.

[0011] Furthermore, if the detected current of the non-connected group is not less than the set single-group current lower limit, the group is kept disconnected; if the detected current of the non-connected group is less than the set single-group current lower limit, it is determined whether the total current of all groups is less than the set total current upper limit. If so, the group is connected; if not, the group is kept disconnected.

[0012] Furthermore, the multiple rounds of power-on steps are as follows: in each round of power-on, the data of the change of the current in each group over time is fitted to obtain a fitting curve I=Ae -at +B, where I is the current, t is the power-on time, A is the coefficient, a is the time index, B is the current margin constant, and e is the natural constant; when the current detection value approaches B, the polarity of the electrode is converted and the power is continued. After several polarity conversions, when the current is close to zero or B, the power-on of this group is ended, and then the next round of power-on of this group is carried out. The initial positive and negative electrode spacing of the next round of power-on is smaller than the initial positive and negative electrode spacing of the previous round of power-on.

[0013] The present application also provides an electrification device for soil desalination, which is used to implement an electrification method for soil desalination, and the device comprises: power supply; Multiple electrode groups are buried in soil at different areas of the site to be treated, each electrode group includes a number of electrodes arranged at equal intervals; Multiple current distributors correspond to 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 independent connectors, and the connection and disconnection of the electrode and the positive or negative electrode of the current distributor are controlled by the connectors. Multiple current distributors are connected to a power supply, and the current distributor has a power-on parameter reading back function, a polarity conversion function, a short-circuit function, and a disconnection function.

[0014] Furthermore, it also includes a controller for controlling the on and off of the corresponding current distributor and the on and off of the corresponding connector according to the current conditions of each area.

[0015] In summary, the present application includes at least one of the following beneficial technical effects: 1. This application adjusts the current by adjusting the distance between electrodes according to the change of current over time during the electric desalination process, so as to keep the electric desalination process always under appropriate current conditions, improve desalination efficiency, shorten desalination time, reduce energy waste, and help reduce energy consumption; 2. Compared with the method of using a transformer power supply to adjust the voltage, the power-on method provided in the present application uses a constant voltage DC power supply, which does not require a power supply with continuously adjustable voltage, and is conducive to reducing the cost of the power supply; 3. The connection and disconnection between the electrode and the positive or negative electrode of the power supply are controlled by the connector and the current distributor, so as to realize the convenient control of the electrode power-on state and adjust the electrode spacing without rewiring; 4. This application divides the site to be treated into several areas for separate control, which is conducive to overcoming the regional differences caused by the uneven properties of the soil and ensuring that each area can implement desalination under appropriate current conditions, thereby improving desalination efficiency and reducing energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of an electric device for soil desalination according to an embodiment of the present application; Figure 2 This is a flow chart of a single round of electrification in an electrification method for soil desalination according to an embodiment of the present application; Figure 3 It is one of the flow charts of accessing a non-accessed group during a single round of power-on in an power-on method for soil desalination in an embodiment of the present application; Figure 4 This is the second flow chart of accessing the non-accessed groups during a single round of power-on in an electrification method for soil desalination in an embodiment of the present application.

[0017] Figure numerals: 1, power supply; 2, current distributor; 3, electrode group; 3-1, electrode; 4, connector. DETAILED DESCRIPTION

[0018] The following is combined with Figure 1-4 This application is described in further detail.

[0019] The present application embodiment discloses an electric device for soil desalination. Figure 1 The power supply device for soil desalination includes a power supply 1, a plurality of electrode groups 3, and a plurality of current distributors 2 corresponding to the plurality of electrode groups 3. The power supply 1 is a 36V or 24V DC power supply 1.

[0020] Reference Figure 1 The site to be treated is divided into two areas (area 1 and area 2), 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, and the distance between two adjacent electrodes 3-1 is L. In this embodiment, N=6, L=5m. The length of the electrode 3-1 is 10m, arranged in the horizontal direction, and the burial depth is 30cm. For the convenience of explanation, the electrodes 3-1 in the two areas are numbered as (1)-(6) and (7)-(12) respectively.

[0021] Reference Figure 1In each electrode group 3, each electrode 3-1 is connected to the positive electrode and the negative electrode of the current distributor 2 through an independent connector 4, and the connection and disconnection of the electrode 3-1 and the positive electrode or the negative electrode of the current distributor 2 are controlled by the connector 4. A plurality of current distributors 2 are connected to a power supply 1, and the current distributor 2 has a power-on parameter reading function, a polarity conversion function, a short-circuit function, and a disconnection function.

[0022] The device also includes a controller for controlling the on and off of the corresponding current distributor 2 and the on and off of the corresponding connector 4 according to the current conditions of each area.

[0023] An electrification method for soil desalination is implemented by using an electrification device for soil desalination, comprising the following steps: Step 1: Device preparation: The site to be treated is divided into two areas, and an electrode group 3 is buried in the soil of each area. Each electrode group 3 includes 6 electrodes 3-1 arranged at equal intervals, and the interval between two adjacent electrodes 3-1 is 5m. A current distributor 2 is set in each area, and the electrodes 3-1 in the electrode group 3 are respectively connected to the positive and negative electrodes of the current distributor 2 through independent connectors 4. The connector 4 is used to control the connection and disconnection of the electrode 3-1 with the positive or negative electrode of the current distributor 2. All current distributors 2 are connected to a power source 1.

[0024] Step 2: Single wheel power on: Generally, the initial electrode spacing for the first round of power-on is moderate. The electrodes (1) and (4) in region 1 are connected to the positive and negative electrodes of the current distributor 2 in this region, respectively, and the electrodes (7) and (10) in region 2 are connected to the positive and negative electrodes of the current distributor 2 in this region, respectively, and power is applied and the current is detected. Except for the connector 4 between the connected electrode 3-1 and the current distributor 2, all other connectors 4 are disconnected.

[0025] According to the size of each group of detection current, the connection and disconnection of the electrode and the positive or negative electrode of the current distributor 2 are controlled by the connector 4, so as to adjust the distance between the positive and negative electrodes that are energized; Figure 2 , specifically including the following steps: Step 2.1: If the detected current of some groups is greater than the set upper limit of the current of a single group (for example, 60A), the power supply of the group is stopped, and the other groups continue to be powered.

[0026] Step 2.2: If the detected current of all groups is greater than the set single group current upper limit (60A), increase the distance between the positive and negative electrodes in all groups by 5m. For example, connect electrodes (1) and (5) in area 1 to the positive and negative electrodes of the current distributor 2 in this area, respectively, and connect electrodes (7) and (11) in area 2 to the positive and negative electrodes of the current distributor 2 in this area, respectively; until the current of at least one group is not greater than the set single group current upper limit (60A), then keep the distance between the positive and negative electrodes of the group currently powered on and continue to power on, and stop powering on other groups.

[0027] Step 2.3: For the group being powered on, if the detected current is not greater than the set single group current upper limit (60A), it is determined whether the detected current is less than the set single group current lower limit (e.g. 50A), and then the distance between the positive and negative electrodes of the group being powered on is adjusted, which specifically includes the following steps: Step 2.3.1: If the detected current is less than the set single-group current lower limit (50A), reduce the distance between the energized positive and negative electrodes in steps of 5m until the current is not less than the single-group current lower limit (50A) and not greater than the single-group current upper limit (60A), then maintain the current distance between the energized positive and negative electrodes and continue to energize.

[0028] Step 2.3.2: If the detected current is not less than the set single group current lower limit (50A), the current positive and negative electrode spacing is maintained and the power is continued.

[0029] Step 2.4: Reference Figure 3 At regular intervals (e.g., 1 hour), two electrodes in the group that are not connected and are 15 m apart are connected to the positive and negative electrodes of the current distributor 2 and energized. According to the magnitude of the detected current, the group is controlled to be connected or kept disconnected, specifically including the following steps: Step 2.4.1: If the detection current of the non-connected group is not less than the set single group current lower limit (50A), keep the group disconnected.

[0030] Step 2.4.2: If the detection current of the non-connected group is less than the set single group current lower limit (50A), determine whether the total current of all groups is less than the set total current upper limit (e.g. 400A). If so, connect the group; if not, keep the group disconnected.

[0031] Step 2.5: Reference Figure 4 When the total current of all groups is less than the set upper limit of the total current (400A), the two electrodes with a distance of 15m in the unconnected group are connected to the positive and negative electrodes of the current distributor 2 respectively and energized. According to the magnitude of the detected current, the group is controlled to be connected or kept disconnected, which specifically includes the following steps: Step 2.5.1: If the detection current of the non-connected group is not less than the set single group current lower limit (50A), keep the group disconnected; Step 2.5.2: If the detection current of the non-connected group is less than the set single group current lower limit (50A), determine whether the total current of all groups is less than the set total current upper limit (400A). If so, connect the group; if not, keep the group disconnected.

[0032] Step 3: Multiple rounds of power-on: During each round of power-on, the data of the change of current over time in each group is fitted to obtain the fitting curve I=Ae -at +B, where I is the current, t is the power-on time, A is the coefficient, a is the time index, B is the current margin constant, and e is the natural constant.

[0033] When the current detection value approaches B, the polarity of the current distributor 2 is changed, the original positive electrode is changed to the negative electrode, and the original negative electrode is changed to the positive electrode, and then the power is continued. The purpose of changing the polarity is that as the electromigration and electroosmosis proceed, the positive and negative electrodes become polarized, and precipitation may be generated at the cathode, resulting in a decrease in desalination efficiency. Changing the polarity of the electrode eliminates polarization, dissolves precipitation, thereby reducing resistance, and increasing the effective electric field strength of the soil, which is beneficial to improving electromigration and electroosmosis efficiency.

[0034] After several polarity conversions, when the current is close to zero or B, the current round of power-on for the group is ended, and then the next round of power-on for the group is carried out. The initial positive and negative electrode spacing of the latter round of power-on is smaller than the initial positive and negative electrode spacing of the previous round of power-on.

[0035] For example, the initial state of the first round of power-on is: electrodes (1) and (4) in region 1 are respectively positive and negative electrodes, and electrodes (7) and (10) in region 2 are respectively positive and negative electrodes; the initial state of the second round of power-on is: electrodes (1) and (3) in region 1 are respectively positive and negative electrodes, and electrodes (7) and (9) in region 2 are respectively positive and negative electrodes.

[0036] Repeat the above steps until all areas are desalted.

[0037] The present application divides the site to be treated into several areas for separate control, which is conducive to overcoming the regional differences caused by the uneven properties of the soil, ensuring that each area can implement desalination under appropriate current conditions, thereby improving the desalination efficiency and reducing the waste of electric energy. Specifically, according to the change of current over time during the electric desalination process, the current is adjusted by adjusting the distance between the electrodes 3-1, and the electric desalination process is always carried out under appropriate current conditions, thereby improving the desalination efficiency, shortening the desalination time, reducing the waste of electric energy, and helping to reduce energy consumption. Specifically, for a desalination site that normally takes 1-3 months, it only takes 1-2 weeks to implement desalination using the power-on method provided in the present application. In addition, compared to the method of adjusting the voltage using a transformer power supply, the power-on method provided in the present application uses a constant voltage DC power supply, which does not require a power supply with continuously adjustable voltage, and is conducive to reducing the cost of the power supply.

[0038] It should be noted that the power-on method and power-on device provided in the present application can be applied not only to soil desalination, but also to other soil electric technologies, such as soil electro-osmosis dehydration, contaminated soil remediation, rare earth electric mining, etc., to achieve the effect of improving processing efficiency and reducing energy consumption.

[0039] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An electrification 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 between the electrode and 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 group to the positive and negative poles of the current distributor respectively and apply power, and detect the current; According to the magnitude of the detected current in each group, control the connection and disconnection between the electrode and the positive or negative pole of the current distributor through the connector, so as to adjust the distance between the positive and negative electrodes during power-on; Multi-round power-on: During each round of power-on, the current decreases exponentially with time. When the current approaches zero or the current margin constant, end this round of power-on for this group and then proceed to the next round of power-on. The initial power-on positive and negative electrode distance in the next round of power-on is less than that in the previous round of power-on.

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

3. The method for applying electricity to 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 single-group current upper limit value, then judge whether the detected current is less than the set single-group current lower limit value, and further adjust the distance between the positive and negative electrodes during power-on of this group.

4. The method for applying electricity to 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 single-group current lower limit value, decrease the distance between the positive and negative electrodes during power-on with a step of L until the current is not less than the single-group current lower limit value and not greater than the single-group current upper limit value, and then maintain the current positive and negative electrode distance and continue the power-on; If the detected current is not less than the set single-group current lower limit value, maintain the current positive and negative electrode distance and continue the power-on.

5. The method for applying electricity to 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 groups to the positive and negative poles 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.

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

7. The method for applying electricity to soil desalination according to claim 5 or 6, characterized in that: If the detection current of the non-connected group is not less than the set single-group current lower limit, the group remains disconnected; if the detection current of the non-connected group is less than the set single-group current lower limit, it is determined whether the total current of all groups is less than the set total current upper limit. If so, the group is connected; if not, the group remains disconnected.

8. The method for applying electricity to soil desalination according to claim 1, characterized in that: The specific steps of multiple rounds of power-on are as follows: During each round of power-on, the data of the change of current in each group over time is fitted to obtain the fitting curve I=Ae -at +B, where I is the current, t is the power-on time, A is the coefficient, a is the time index, B is the current margin constant, and e is the natural constant; When the current detection value approaches B, the polarity of the electrode is converted and power is continued. After several polarity conversions, when the current is close to zero or B, the current round of power-on for the group is ended, and then the next round of power-on for the group is carried out. The initial positive and negative electrode spacing in the latter round of power-on is smaller than the initial positive and negative electrode spacing in the previous round of power-on.

9. An energizing device for soil desalination, used to implement an energizing method for soil desalination according to any one of claims 1 to 8, characterized in that: include: power supply; Multiple electrode groups are buried in soil at different areas of the site to be treated, each electrode group includes a number of electrodes arranged at equal intervals; A plurality of current distributors corresponding to a plurality of electrode groups one by one, in each electrode group, each electrode is respectively connected to the positive electrode and the negative electrode of the current distributor through an independent connector, and the connection and disconnection of the electrode and the positive electrode or the negative electrode of the current distributor are controlled by the connector; A plurality of current distributors are connected to a power supply, and the current distributors have a power-on parameter reading back function, a polarity conversion function, a short-circuit function, and a disconnection function.

10. The energizing device for soil desalination according to claim 9, characterized in that: It also includes a controller for controlling the on and off of the corresponding current distributor and the on and off of the corresponding connector according to the current conditions of each area.

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