An electrical device and method for soil electro-osmotic dewatering comprising series-parallel electrical power sources

Abstract

The application relates to the technical field of soil electro-osmotic dewatering, and particularly discloses a soil electro-osmotic dewatering power supply device and method comprising series-parallel power supplies, the device comprising a power supply, a plurality of current distributors and a plurality of electrode groups, wherein the power supply comprises a plurality of power supply modules with adjustable series-parallel states; the method comprises the following steps: device preparation; single-round power supply: starting voltage is applied to each electrode group through the current distributors, and the current of each group is detected; according to the size of the detected current of each group, the current of the group is controlled to be turned on or turned off or the size of the voltage of the group is adjusted through the current distributors; step-by-step voltage boosting and multi-round power supply. According to the application, the on-off of the current and the voltage adjustment are controlled according to the change of the current with time in the electro-osmosis process, the electro-osmosis is kept to be carried out under suitable voltage conditions, the electro-osmosis efficiency is improved, and the waste of electric energy is reduced; by adjusting the series-parallel states of the plurality of power supply modules, different current and voltage requirements in different power supply stages are met, and the design power of the power supply is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil electro-osmotic dewatering, in particular to a soil electro-osmotic dewatering power supply device and method comprising a series-parallel power supply. BACKGROUND

[0002] There are five main electrical phenomena in soil, namely: flow potential, migration potential, electro-osmosis, ion electromigration and electrophoresis. Soil electrokinetic technology is developed by utilizing soil electrical phenomena, which is a platform technology. Through the input of direct current into the soil, water migration, ion migration, electrochemical reaction, etc. in the soil can be achieved. This technology can be applied in many fields, such as sludge dewatering, soft foundation treatment, contaminated soil remediation, mud-water co-management, saline-alkali land management, rare earth green mining, etc.

[0003] For special soil such as mud pond, beach and river, due to small soil particles and low permeability coefficient, it is difficult for pore water to seep out naturally. Electro-osmosis is an effective dewatering method. Electro-osmotic dewatering technology is to place the water-containing soil in an electric field. In the system where the solid movement is limited, the counter ions in the diffusion layer move along the slip interface to the electrode, and at the same time, the water molecules move to the negative electrode. The water is discharged from the negative electrode by suction or gravity drainage, realizing soil dewatering.

[0004] In the initial stage of power supply, the soil has high water content and small resistance, so the current is large. As the power supply proceeds, the water content of the soil decreases, the ion content in the pore water decreases, and the polarization of the soil near the electrode increases, so the current increases. Most of the current soil electro-osmotic dewatering technology uses ordinary variable voltage and rectifier power supply. The main problems are: (1) Due to the non-uniformity of the soil properties on site, the current changes differently over time. If the same power supply method is used in each region, it is difficult to produce the expected effect with inappropriate current and voltage in the invalid power supply area, and it wastes a lot of electric energy; (2) When used on a large scale, the power and energy consumption are too large, which restricts the large-scale application of soil electro-osmotic dewatering technology.

[0005] On the other hand, the design power of the power supply is usually designed according to the maximum current and maximum voltage. However, in the application of soil electrokinetic technology, in the initial stage of power supply, the soil resistance is small, and high current corresponds to low voltage. As the power supply proceeds, the soil resistance increases, and high voltage corresponds to low current. If different current and voltage requirements are needed at different stages of power supply, the power supply needs a larger design power, which increases the cost of the power supply. SUMMARY

[0006] In order to improve the electro-osmotic efficiency, reduce the power consumption, and reduce the design power of the power supply, the present application provides a soil electro-osmotic dewatering power supply device and method comprising a series-parallel power supply.

[0007] The application provides a soil electro-osmotic dehydration method by using a series-parallel power supply.

[0008] The application provides a soil electro-osmotic dehydration method by using a series-parallel power supply.

[0009] Device preparation: the site to be treated is divided into several areas, and an electrode group is buried in the soil of each area, each electrode group comprising a plurality of positive electrode columns and a plurality of negative electrode columns; a current distributor is arranged in each area, and the positive electrode columns and the negative electrode columns in each electrode group are connected to the positive electrode and the negative electrode of the current distributor in the area, respectively; the current distributor is connected to a power supply, and the power supply comprises a plurality of power supply modules, and the series-parallel state of the plurality of power supply modules can be adjusted.

[0010] Single round of power supply: the starting voltage is applied to each electrode group by the current distributor, and the current of each group is detected; according to the size of the detected current of each group, the current of the group is controlled to be turned on or off or the size of the voltage of the group is adjusted by the current distributor;

[0011] Step 2: During the single round of power supply, the change of the current in each group with time is fitted to obtain a fitting curve I=Ae -at +B, wherein I is the current, t is the power-on time, A is a coefficient, a is a time index, B is a current residual constant, and e is a natural constant; when the detected current approaches B, the round of power supply of the group is ended, and the next round of power supply is then performed, and the starting voltage of the next round of power supply is higher than that of the previous round of power supply; before each round of power supply, the series-parallel state of the plurality of power supply modules in the power supply is changed, so that the output voltage of the power supply is increased round by round.

[0012] Further, the single round of power supply step comprises:

[0013] If the detected current is greater than the set upper limit value of the single-group current, the power supply of the group is stopped.

[0014] If the detected current is not greater than the set upper limit value of the single-group current, it is judged whether the detected current is less than the set lower limit value of the single-group current, and the voltage of the group is further adjusted.

[0015] Further, the single round of power supply step further comprises:

[0016] If the detected current is less than the set lower limit value of the single-group current, the voltage of the group is increased by a gradient until the current reaches the set lower limit value of the single-group current, and the current power supply is continued at the current voltage.

[0017] If the detected current is not less than the set lower limit value of the single-group current, it is judged whether the voltage is in an upward trend, and the voltage of the group is further adjusted.

[0018] Further, the single round of energization step further comprises:

[0019] If the detected current is not less than the set single group current lower limit value, and the voltage is in an upward trend, the voltage of the group is lowered, and the energization is continued.

[0020] If the detected current is not less than the set single group current lower limit value, and the voltage is not in an upward trend, the current voltage is maintained and the energization is continued.

[0021] Further, the single round of energization step further comprises: every time interval, applying a starting voltage to the unconnected group and detecting the current, and according to the size of the detected current, controlling the group to be connected or not connected by the current distributor.

[0022] Further, the single round of energization step further comprises: when the total current of all groups is less than the set total current upper limit value, applying a starting voltage to the unconnected group and detecting the current, and according to the size of the detected current, controlling the group to be connected or not connected by the current distributor.

[0023] Further, after each round of energization, the positive and negative poles of the current distributor are short-circuited to release the electric charge; during the release of electric charge of one or more groups, the other groups are kept energized.

[0024] Further, after each short-circuiting, the polarity of the electrode is reversed, and the next round of energization is performed.

[0025] Further, in the first round of energization, all the power supply modules are connected in parallel, so that the power supply outputs low voltage and high current; as the number of rounds of energization increases, the number of parallel power supply modules is reduced and the number of series power supply modules is increased, so that the output voltage of the power supply is increased round by round.

[0026] The application also discloses a soil electro-osmotic dewatering energization device comprising series-parallel power supply, which is used to implement the above-mentioned soil electro-osmotic dewatering energization method comprising series-parallel power supply, and the device comprises:

[0027] A power supply comprising a plurality of power supply modules, and the series-parallel state between the plurality of power supply modules can be adjusted;

[0028] A plurality of electrode groups are respectively buried in the soil of different areas of the site to be treated, each electrode group comprising a plurality of positive electrode columns and a plurality of negative electrode columns, the positive electrode column comprising a plurality of positive electrode rods arranged in a column, the negative electrode column comprising a plurality of negative electrode rods arranged in a column, and the positive electrode column and the negative electrode column in each electrode group being alternately and spacedly arranged;

[0029] A plurality of current distributors, each corresponding to an electrode group, in each electrode group, the positive electrode column and the negative electrode column are connected to the positive electrode and the negative electrode of the current distributor respectively; the current distributor is connected to the power supply, used to adjust the voltage applied to the corresponding electrode group; the current distributor also has the functions of current parameter reading back, polarity conversion, short circuit and disconnection;

[0030] A controller, used to control the on-off and voltage adjustment of the corresponding current distributor according to the current situation of each area, and used to change the series-parallel state between the plurality of power modules to adjust the output voltage and current of the power supply.

[0031] In summary, the present application includes at least one of the following beneficial technical effects:

[0032] 1. The present application controls the on-off and voltage adjustment of the current according to the change of the current with time in the electro-osmosis process, keeps the electro-osmosis always under suitable voltage conditions, improves the electro-osmosis efficiency, reduces the waste of electric energy, and is conducive to reducing energy consumption;

[0033] 2. The present application divides the site to be treated into several areas for separate control, which is conducive to overcoming the regional difference caused by the non-uniformity of the soil properties, ensuring that each area can implement electro-osmosis under suitable voltage conditions, thereby improving the electro-osmosis efficiency and reducing the waste of electric energy;

[0034] 3. Through the short-circuit discharging process, the electrode polarization in the soil is eliminated, thereby enhancing the electro-osmosis effect and reducing energy consumption; at the same time, the short-circuit discharging time is fully utilized to power other areas, thereby reducing the demand for power supply power;

[0035] 4. Through the series-parallel combination of the plurality of power modules, in the initial stage of power-on, the parallel mode is adopted to meet the demand for high current; in the later stage of power-on, as the soil resistance gradually increases, the series mode is adopted to meet the demand for high voltage, and the power module with lower designed power can meet the different current and voltage demands in different stages of power-on. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is the overall structure schematic diagram of a soil electro-osmosis dewatering power-on device containing a series-parallel power supply according to an embodiment of the present application;

[0037] Figure 2 is the flowchart of a single round of power-on in a soil electro-osmosis dewatering power-on method containing a series-parallel power supply according to an embodiment of the present application;

[0038] Figure 3 is one of the flowcharts of connecting the unconnected groups during the single round of power-on in a soil electro-osmosis dewatering power-on method containing a series-parallel power supply according to an embodiment of the present application;

[0039] Figure 4is a flowchart of a process of connecting a group not connected in a single round of power-on in a power-on method for soil electro-osmotic dewatering comprising a series-parallel power supply.

[0040] Fig. 1 is a power supply; 1-1, a power supply module; 2, a current distributor; 3, an electrode group; 3-1, a positive electrode column; 3-2, a negative electrode column. DETAILED DESCRIPTION

[0041] The following will be described in detail with reference to the accompanying drawings Figures 1-4 The present application will be further described in detail.

[0042] The present application discloses a power-on device for soil electro-osmotic dewatering comprising a series-parallel power supply. Referring to Figure 1 , the power-on device for soil electro-osmotic dewatering comprising a series-parallel power supply comprises 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. Wherein, the power supply 1 comprises a plurality of power supply modules 1-1, and the series-parallel state between the plurality of power supply modules 1-1 can be adjusted.

[0043] Referring to Figure 1 , the site to be treated is divided into three areas, and three electrode groups 3 are buried in the three areas respectively. Each electrode group 3 comprises a plurality of positive electrode columns 3-1 and a plurality of negative electrode columns 3-2. Each positive electrode column 3-1 is formed by a plurality of positive electrode rods arranged in a column at intervals and connected by wires, and the distance between adjacent two positive electrode rods is 1m; each negative electrode column 3-2 is formed by a plurality of negative electrode rods arranged in a column at intervals and connected by wires, and the distance between adjacent two negative electrode rods is 1m. The positive electrode columns 3-1 and the negative electrode columns 3-2 in each electrode group 3 are arranged alternately and at intervals, and the distance is set to 1m.

[0044] Referring to Figure 1 , in each electrode group 3, the positive electrode column 3-1 and the negative electrode column 3-2 are connected to the positive and negative poles of the current distributor 2 through the wire connector respectively; the current distributor 2 is connected to the power supply 1, and is used to adjust the voltage applied to the corresponding electrode group 3. The current distributor 2 also has the functions of reading back the power-on parameters (current, voltage, etc.), polarity conversion, short circuit and disconnection.

[0045] The device further comprises a controller for controlling the on-off and voltage adjustment of the corresponding current distributor 2 according to the current situation of each area, and for changing the series-parallel state between the plurality of power supply modules 1-1 to adjust the output voltage and current of the power supply 1.

[0046] A power-on method for soil electro-osmotic dewatering is implemented by using the above-mentioned power-on device for soil electro-osmotic dewatering comprising a series-parallel power supply, comprising the following steps:

[0047] Step 1, device preparation:

[0048] The site to be treated is divided into three areas. An electrode group 3 is buried in the soil of each area. Each electrode group 3 includes several positive electrode columns 3-1 and several negative electrode columns 3-2. A current distributor 2 is set in each area. The positive electrode columns 3-1 and negative electrode columns 3-2 in each electrode group 3 are connected to the positive and negative terminals of the current distributor 2 in this area, respectively. The current distributor 2 is connected to the power supply 1.

[0049] Step 2, Powering on a single wheel:

[0050] A starting voltage (e.g., 2V) is applied to each electrode group 3 via current distributor 2, and the current in each group is detected. Based on the magnitude of the detected current in each group, current distributor 2 controls the current flow of that group or adjusts the voltage of that group. Figure 2 Specifically, it includes the following steps:

[0051] Step 2.1: After applying the starting voltage, if the detected current is greater than the set upper limit of the single group current (e.g., 60A), then stop energizing that group.

[0052] Step 2.2: After applying the initial voltage, 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 group voltage accordingly. This includes the following steps:

[0053] Step 2.2.1: If the detected current is less than the set lower limit of the single group current (50A), then the voltage of the group is increased in a gradient (e.g., in 2V increments) until the current reaches the set lower limit of the single group current (50A), and then the current voltage is maintained and the power is continued.

[0054] Step 2.2.2: If the detected current is not less than the set lower limit of the single group current (50A), determine whether the voltage is trending upward, and then further adjust the group voltage, specifically including the following steps:

[0055] Step 2.2.2.1: If the detected current is not less than the set lower limit of the single group current (50A) and the voltage is rising, then reduce the voltage of that group and continue to power on.

[0056] Step 2.2.2.2: If the detected current is not less than the set single-group current lower limit (50A) and the voltage does not show an upward trend, then maintain the current voltage and continue to power on.

[0057] Step 2.3: Refer to Figure 3 At regular intervals (e.g., every hour), an initial voltage is applied to the unconnected packets and the current is detected. Based on the magnitude of the detected current, the current distributor 2 controls whether the packet is connected or kept unconnected. Specifically, the following steps are included:

[0058] Step 2.3.1: If the 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.

[0059] Step 2.3.2: If the current of the unconnected group is not less than the set single group current lower limit (50A), then keep the group unconnected.

[0060] Step 2.4: Refer to Figure 4 The system reads the total current of all groups in real time. When the total current of all groups is less than the set upper limit of the total current (400A), an initial voltage is applied to the unconnected group and the current is detected. Based on the magnitude of the detected current, the current distributor controls whether the group is connected or kept unconnected. The specific steps include:

[0061] Step 2.4.1: If the 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.

[0062] Step 2.4.2: If the current of the unconnected group is not less than the set single group current lower limit (50A), then keep the group unconnected.

[0063] Step 3: Staged voltage boosting and multiple rounds of power application:

[0064] During a single-cycle energization process, the data on 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.

[0065] When the current detection value approaches B, the energization of that region ends, and the positive and negative terminals of current distributor 2 are short-circuited to release the charge. During the discharge of charge by one or more groups, other groups remain energized, thereby distributing the power available from the discharged groups to other regions to maximize the utilization of power supply.

[0066] When the current generated by the released charge approaches zero, the polarity of the current distributor 2 is switched, converting the original positive electrode column 3-1 to the negative electrode column 3-2, and vice versa. The purpose of this polarity switch is that as electroosmosis proceeds, the positive electrode area becomes drier, while the negative electrode area becomes wetter. Switching the electrode polarity makes the previously dry areas wetter, thereby reducing resistance, increasing the effective electric field strength of the soil, and improving electroosmosis efficiency.

[0067] After the polarity reversal is complete, the area is energized for the next round. The starting voltage of each subsequent round of energization is higher than that of the previous round, and the starting voltages for multiple rounds of energization are set sequentially to 2V, 10V, 20V, 40V, 60V, 80V, etc. The method for each round of energization is the same as step 2.

[0068] As the number of power-on cycles increases, the number of parallel power modules decreases while the number of series power modules increases. For example, power supply 1 includes four power modules 1-1, each with a maximum design voltage / current of 20V / 100A. Initially, when the starting voltage is no higher than 20V, all four power modules 1-1 are connected in parallel to meet the low voltage and high current (400A) requirements. As the number of power-on cycles increases, the starting voltage increases. When the starting voltage is 40V, the four power modules 1-1 are connected in series in pairs and then in parallel to meet the medium current (200A) requirements during the middle power-on cycle. When the starting voltage is 60V, three of the power modules 1-1 are connected in series. When the starting voltage is 80V, all four power modules 1-1 are connected in series to provide high voltage and low current (100A). It is important to note that during each power-on cycle, the current flowing through each power module 1-1 must not exceed its maximum design current value.

[0069] If a conventional power supply meeting the requirements of high current (400A) and high voltage (80V) is used, the power supply power is 400A × 80V = 32kW. In this embodiment, four power supply modules are combined, and the total power supply power is 4 × 20V × 100A = 8kW, which is only 1 / 4 of the power of a conventional power supply.

[0070] This embodiment 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 electroosmosis can be carried out in each area under suitable voltage conditions. Specifically, the on / off state of the current and the voltage are controlled according to the change of current over time during the electroosmosis process, keeping the electroosmosis under suitable voltage conditions at all times, improving electroosmosis efficiency, reducing energy waste, and thus reducing energy consumption. Using the energizing method provided in this application, the energy consumption per unit volume is approximately 0.5 kWh / m². 3 In contrast, the traditional method of powering a unit volume using ordinary transformers and rectifiers consumes approximately 10 kWh / m² of electrical energy. 3 , or even higher.

[0071] It should be noted that the energizing method and energizing device provided in this application can be applied not only to soil electro-osmotic dehydration, but also to other soil electro-energizing technologies, such as saline-alkali land treatment, contaminated soil remediation, and rare earth electro-energizing mining, in order to achieve the effect of reducing energy consumption.

[0072] The above are all preferred embodiments of the present application, and do not limit the protection scope of the present application, so that: all equivalent changes made according to the structure, shape, principle of the present application should be covered in the protection scope of the present application.

Claims

1. An energized method for soil electro-osmosis dewatering including series and parallel power supplies, characterized in that: Includes the following steps: Equipment preparation: The site to be treated is divided into several areas. An electrode group is buried in the soil of each area. Each electrode group includes several positive electrode columns and several negative electrode columns. A current distributor is set up in each area. The positive electrode columns and negative electrode columns of each electrode group are connected to the positive and negative terminals of the current distributor in this area, respectively. The current distributor is connected to a power supply, which includes multiple power modules. The series and parallel connection status between the multiple power modules can be adjusted. Single-wheel energization: The current distributor applies an initial voltage to each electrode group and detects the current of each group. Based on the magnitude of the detected current of each group, the current distributor controls the current on / off of that group or adjusts the voltage of that group. Staged voltage boosting and multi-round energization: During a single-round energization process, data fitting is performed on the current change over time in each group 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 current detection value approaches B, the energizing of this group in this round ends, and then the positive and negative terminals of the current distributor are short-circuited to release the charge; during the discharge of one or more groups, other groups are kept energized, so that the power freed up by the discharged group is distributed to other areas to maximize the utilization of power supply power; when the current generated by the discharge charge approaches zero, the polarity of the current distributor is reversed, and the next round of energizing is carried out. The starting voltage of the next round of energizing is higher than the starting voltage of the previous round of energizing; before each round of energizing, the series and parallel connection state of multiple power supply modules in the power supply is changed, so that the output voltage of the power supply increases round by round.

2. The method for soil electro-osmosis dewatering including a series and parallel power supply according to claim 1, characterized in that: The single-wheel power-on steps include: If the detected current exceeds the set upper limit of the single group current, then the power supply to that group will be stopped. If the detected current is not greater than the set upper limit of the single group current, then determine whether the detected current is less than the set lower limit of the single group current, and then adjust the voltage of that group.

3. The method for soil electro-osmosis dewatering including a series and parallel power supply according to claim 2, characterized in that: The single-wheel power-on process also includes: If the detected current is less than the set lower limit of the single group current, the voltage of the group is gradually increased until the current reaches the set lower limit of the single group current, and the current voltage is maintained to continue to power on. If the detected current is not less than the set lower limit of the single group current, then determine whether the voltage is trending upward, and further adjust the voltage of that group.

4. The method for soil electro-osmosis dewatering including a series and parallel power supply according to claim 3, characterized in that: The single-wheel power-on process also includes: If the detected current is not less than the set lower limit of the single group current and the voltage shows an upward trend, then reduce the voltage of that group and continue to power on. If the detected current is not less than the set lower limit of the single current and the voltage does not show an upward trend, maintain the current voltage and continue to supply power.

5. The method for soil electro-osmosis dewatering including a series and parallel power supply according to claim 2, characterized in that: The single-round power-on step also includes: applying an initial voltage to the unconnected group and detecting the current at regular intervals, and controlling the group to connect or keep the group unconnected based on the magnitude of the detected current through a current distributor.

6. The method for soil electro-osmosis dewatering including a series and parallel power supply according to claim 2, characterized in that: The single-round power-on step also includes: when the sum of the currents of all groups is less than the set upper limit of the total current, applying an initial voltage to the unconnected group and detecting the current, and controlling the group to connect or keep the group unconnected according to the magnitude of the detected current through the current distributor.

7. The method for soil electro-osmosis dewatering including a series and parallel power supply according to claim 6, characterized in that: After each short circuit ends, the polarity of the electrodes is reversed before the next round of energization is performed.

8. The method for soil electro-osmosis dewatering including a series and parallel power supply according to claim 1, characterized in that: During the first power-on cycle, all power modules are connected in parallel, resulting in a low voltage and high current output. As the number of power-on cycles increases, the number of parallel power modules is reduced, while the number of series power modules is increased, causing the power output voltage to increase gradually.

9. An energized device for soil electro-osmosis dewatering including a series and parallel power supply, characterized in that: An apparatus for implementing the method of soil electro-osmotic dewatering comprising a series-parallel power supply as described in any one of claims 1-8, comprising: The power supply includes multiple power modules, and the series and parallel connection status between the multiple power modules can be adjusted; Multiple electrode groups are buried in the soil in different areas of the site to be treated. Each electrode group includes several positive electrode columns and several negative electrode columns. The positive electrode columns include several positive electrode rods arranged in rows, and the negative electrode columns include several negative electrode rods arranged in rows. The positive electrode columns and negative electrode columns in each electrode group are arranged alternately. Multiple current distributors correspond one-to-one with multiple electrode groups. In each electrode group, the positive electrode column and the negative electrode column are connected to the positive and negative terminals of the current distributor, respectively. The current distributor is connected to a power supply and is used to adjust the voltage applied to the corresponding electrode group. The current distributor also has a power-on parameter readback function, a polarity reversal function, a short-circuit function, and a disconnect function. The controller is used to control the on / off state of the corresponding current distributor and voltage regulation according to the current conditions of each area, and to change the series and parallel connection state between multiple power modules to regulate the output voltage and current of the power supply.

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