Autonomously seeking cross-type aeration reoxygenation system and aeration reoxygenation method

Abstract

The application discloses an autonomous tracking cross type aeration reoxygenation system, which comprises a moving ship body, the moving ship body is uniformly distributed with dissolved oxygen detection units in the circumferential direction, a solar panel and a storage battery are arranged on the ship body, a lifting device is arranged on the ship body, a cross type aeration system is arranged at the end of the lifting device, a controller and a dissolved oxygen probe are arranged on the moving ship body, and the controller is in signal connection with the ship body dissolved oxygen probe, the ship body periphery dissolved oxygen detection unit, the lifting device and the cross type aeration system. The autonomous tracking cross type aeration reoxygenation system and the aeration reoxygenation method can avoid the impact disturbance of aeration on the bottom mud, reduce the aeration bubble particle size, increase the bubble specific surface area, accelerate the oxygen dissolution mass transfer speed and effectively improve the reoxygenation efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to an autonomous tracking cross-type aeration reoxygenation system and aeration reoxygenation method, and belongs to the field of water treatment. BACKGROUND

[0002] There are a large number of closed and semi-closed water bodies such as gate-controlled rivers, broken streams, lakes and ponds in urban and rural areas in China. The water flow is slow or even static, and the exchange capacity with the outside world is weak. Pollutants are often enriched in these water bodies, leading to low dissolved oxygen (DO) content in the middle and lower layers of the water body, resulting in the death of aquatic organisms, deterioration of environmental quality, and even black and odorous ecological environment problems.

[0003] For such weakly dynamic and low-DO water bodies, artificial aeration can be used to reoxygenate the middle and lower layers of the water body. However, traditional aeration is mostly fixed-point aeration, which has a limited reoxygenation range. For a certain area of water, multiple aeration points need to be set up for reoxygenation, which is relatively low in efficiency, and causes a large amount of scouring of the sediment, resuspension of particles in the sediment, release of pollutants into the overlying water, and internal source pollution. Current patents (such as CN106915419A) propose artificial control of mobile aeration, which improves aeration efficiency but requires artificial control, increasing labor costs. Patents (such as CN114030568A) propose cruise-type mobile aeration, but cruise-type mobile aeration can only be used for aeration along a specific route designed in advance, and cannot be flexibly moved in a larger water body or autonomously seek the best reoxygenation point. Moreover, these existing aeration methods cannot effectively inhibit the disturbance of aeration to the sediment, inevitably causing internal source pollution.

[0004] Therefore, the present application proposes an autonomous tracking cross-type aeration reoxygenation system and method that avoids disturbance of the sediment. The system can autonomously determine the optimal reoxygenation point based on the anoxic condition of the water area and automatically move to the point for cross-jet aeration reoxygenation, achieving completely autonomous reoxygenation path identification and optimization without human intervention and high-efficiency aeration, while minimizing disturbance of the aeration process to the sediment. SUMMARY

[0005] The present application provides an autonomous tracking cross-type aeration reoxygenation system and aeration reoxygenation method that avoids disturbance of the sediment by aeration during the reoxygenation process, while reducing the particle size of the aeration bubbles, increasing the specific surface area of the bubbles, accelerating the DO mass transfer speed, and effectively improving the reoxygenation efficiency.

[0006] Technical solution: To solve the above technical problems, the self-tracking cross aeration and reoxygenation system comprises a moving ship body, the moving ship body is uniformly distributed with dissolved oxygen detection units in the circumferential direction, a solar panel and a storage battery are arranged on the ship body; a lifting device is arranged on the moving ship body, a cross aeration system is arranged at the end of the lifting device, the aeration system is retracted when the ship body moves, so as to avoid being entangled by foreign matters such as waterweeds and to block the effective movement of the ship body, the aeration system is opened to perform aeration when the ship body reaches the aeration point; a controller and a ship body dissolved oxygen probe are arranged on the moving ship body, and the controller is signal-connected with the dissolved oxygen detection units, the ship body dissolved oxygen probe, the lifting device and the cross aeration system.

[0007] As a preferred, the dissolved oxygen detection unit comprises a telescopic rod and a dissolved oxygen probe, and the dissolved oxygen probe is located at the end of the telescopic rod.

[0008] As a preferred, the cross aeration system comprises a body, three uniformly distributed support units are arranged on the body, an aeration pipe is arranged at the top of the support unit, the included angle between the aeration pipe and the horizontal plane is 30°, and a cross jet flow aeration is formed; the inner wall edge of the aeration port ring is uniformly distributed with isosceles triangle sawteeth with a top angle of 30°, the ratio of the height of the sawteeth to the radius of the aeration port is 1:10, the ratio of the thickness of the sawteeth to the height is 1:4, and the interval of the sawteeth is π / 36 times of the radius of the aeration port. By adopting the preferred design, the turbulent dissipation rate of the aeration airflow can be significantly improved, the kinetic energy of the aeration airflow and the induced environmental water flow movement can be reduced, the mutual collision and mixing between the multiple aeration airflows and the induced water flows can be caused, the energy dissipation can be effectively realized, the disturbance impact on the bottom mud can be avoided, the aeration bubble particle size can be reduced, the bubble specific surface area can be increased, the oxygen dissolution mass transfer speed can be accelerated, and the reoxygenation efficiency can be effectively improved.

[0009] An aeration and reoxygenation method of a self-tracking cross aeration and reoxygenation system, comprising the following steps:

[0010] (1) Place the system device in water, control the 8-direction DO probe to extend, the ship body dissolved oxygen probe to extend, detect the ship body DO concentration, set as c0, and the DO value measured by the 8-direction DO probe is c i， i=1, 2, …, 8;

[0011] (2) If c0 is lower than the set starting aeration threshold value, the threshold value is the standard value of the water body, the controller controls the cross aeration system to descend to a certain height, and starts the cross jet flow aeration, while the 9 probes continuously monitor the DO value of the point where the probe is located, after the DO values monitored by all the probes are stable above the set stop aeration threshold value for 1 h, the aeration is stopped, and the control system controls the motor to retract the aeration system; if c0 is higher than the set threshold value, step (3) is entered;

[0012] (3) Eight direction dissolved oxygen probe to the point probe distance is equal to L, define c i The corresponding direction of the dissolved oxygen concentration gradient is G i i = (c0-c i ) / L (i = 1, 2, …, 8), G i The maximum direction is the maximum gradient direction, which is selected as the best reoxygenation direction; if multiple G values are equal and maximum, the dissolved oxygen concentration of each maximum G value corresponding direction and the projection of the dissolved oxygen concentration of the probe on both sides in the direction are added to calculate the comprehensive dissolved oxygen concentration index I of the direction Where c l , c r are the DO concentrations measured by the probes on the left and right sides of c i . Then compare the size of the I value of each G maximum direction, where the minimum I direction is the best reoxygenation direction, and if multiple I values are minimum and equal, any one of the directions corresponding to the minimum I value is selected as the best reoxygenation direction;

[0013] (4) The 8 direction DO probe is retracted, the control system controls the motor to change the turbine power, so that the two side turbines produce a speed difference, the ship body turns direction, and after the ship body front direction is the same as the best reoxygenation direction, the control system controls the turbine to make the ship body move in the direction, at this time the ship body DO probe works continuously, and the value is continuously fed back to the control system;

[0014] (5) When the ship body dissolved oxygen probe detects that the DO concentration is lower than the set starting aeration threshold, the turbine stops running, the aeration system is controlled to descend to a certain height and start working, and the 9 probes continuously monitor the DO value of the point where the probe is located, and enter steps (2) and (3).

[0015] Since the application scenario of the present application is closed, semi-closed and weakly dynamic water bodies such as lakes, ponds, broken streams and gate-controlled rivers in urban and rural areas, the water flow speed is slow, so the size of the dissolved oxygen concentration gradient in these directions can be represented by the size of the dissolved oxygen concentration measured by the 8 direction dissolved oxygen probe. The direction with the lowest dissolved oxygen concentration in the 8 directions is the best reoxygenation direction, and if two or more maximum gradients are equal, the best direction can be selected by the following process: the dissolved oxygen concentration of each maximum gradient corresponding direction and the projection of the dissolved oxygen concentration of the probe on both sides in the direction are added to calculate the comprehensive dissolved oxygen concentration index I of the direction Where c l , c r are the DO concentrations measured by the probes on the left and right sides of c iThe DO concentration measured by the probes on the left and right sides of the direction. Then compare the size of the I value of the maximum direction of each gradient, where the minimum I direction is the best direction of reoxygenation, if multiple I values are minimum and equal, then select one from the minimum I value corresponding direction as the best reoxygenation direction.

[0016] The cross aeration system is connected with the ship body through the lifting rod, the movement of the aeration system is controlled by the control system, the ship body is lowered into the lower layer of the water body to implement aeration when working, and is automatically raised after aeration is completed, so that the ship body is not entangled by foreign matters such as waterweeds when sailing, and the movement of the ship body is hindered. The inner wall edge of the ring of the aeration port is uniformly distributed with a circle of isosceles triangle sawteeth with a top angle of 30°, the ratio of the height of the sawteeth to the radius of the aeration port is 1:10, the ratio of the thickness to the height of the sawteeth is 1:4, and the interval of the sawteeth is π / 36 times of the radius of the aeration port, so that the turbulent dissipation rate of the aeration airflow is improved, and the kinetic energy of the aeration airflow and the induced environmental water flow movement is reduced. Considering the water and air mixing effect and energy consumption, three cross-flow jet aeration is adopted, the distance between the aeration ports is the same, and the three aeration airflows cross on the vertical line where the center of the equilateral triangle formed by the three aeration ports is located. Through cross aeration, mutual collision and mixing between the aeration airflow and the induced water flow are formed, the energy of the aeration jet is dissipated, the bubble particle size is reduced, the specific surface area of the bubbles is increased, and the reoxygenation efficiency of the aeration system is improved.

[0017] To determine the optimal angle to achieve efficient reoxygenation and avoid bottom sediment disturbance, we constructed a cross-aeration water tank model system and conducted aeration experiments. The model water tank is a rectangular tank with a length of 50 cm, a width of 38 cm, and a height of 48 cm. The experimental water sample was collected from the center line of the tank near the bottom using a siphon method. The specific experimental design and experimental process are described as follows. In the cross-jet aeration experiment, the outlets of the three aeration pipes are on the same horizontal plane and have the same distance, so that the three aeration airflows intersect at the vertical line of the centroid of the equilateral triangle formed by the three aeration ports. Seven groups of aeration devices with different aeration pipe intersection angles of 0°, 15°, 30°, 45°, 60°, 75°, and 90° were designed and placed in seven water tanks of the same size for aeration experiments. Tap water was used as the experimental overlying water. Before the experiment, the treated sediment sample was spread on the bottom of the experimental water tank with a thickness of 15 cm. After the surface of the sediment was treated evenly, tap water with a depth of 30 cm was slowly injected using a siphon tube, and it was left for two weeks. Then, the cross-aeration system was floated on the water surface, and continuous aeration was started for 60 minutes, during which the experimental aeration jet velocity followed the Froude similarity principle. After the aeration was completed, the dissolved oxygen (DO) concentration at the sampling point was measured every 1 minute using a Hach LDO TM HQ30d dissolved oxygen meter, and water samples were collected at the sampling point. The suspended solids (SS) concentration in the water tank was measured using the weighing method, and the detection was continued for 10 minutes. The DO and SS concentrations measured in the seven groups of working conditions were averaged, and the results of each angle condition were normalized based on the DO and SS average values of the 90° condition. The relative concentrations of DO and SS under different angle conditions were obtained. The results showed that the DO concentration in the experimental water body changed with the change of the angle between the airflow outlet and the horizontal plane, which could be divided into two stages. First, it increased with the decrease of the angle, and when the angle between the airflow outlet and the horizontal plane was 30°, the DO concentration reached the highest value, and then it decreased steadily. The SS concentration in the experimental water body decreased non-linearly and monotonically with the decrease of the angle between the airflow outlet and the horizontal plane. When the angle between the airflow outlet and the horizontal plane was 30°, the SS concentration tended to 0, indicating that the aeration had little disturbance to the sediment.

[0018] Through experimental research, we determined that the optimal angle between the three aeration pipe outlets of the cross-aeration system and the horizontal plane is 30°. At this angle, the aeration can reduce the bubble size, increase the specific surface area of the bubbles, and achieve the highest oxygen dissolution efficiency. At the same time, through airflow collision and water-air mixing, the aeration jet can be effectively dissipated, and the impact and disturbance to the sediment can be avoided.

[0019] Beneficial Effects: The autonomous tracking cross-type aeration and reoxygenation system of this invention enables the autonomous search for anoxic locations in weakly kinetic water bodies and its navigation to these areas for aeration and reoxygenation without any human intervention. The serrated edge design of the aeration port improves the turbulence dissipation rate of the aeration airflow, reducing the kinetic energy of the aeration airflow and its induced ambient water flow. The cross-type aeration method causes multiple aeration airflows and their induced water flows to collide and mix, effectively dissipating energy and avoiding impact on the bottom sediment. Simultaneously, it reduces bubble particle size, increases bubble specific surface area, accelerates mass transfer, and effectively improves dissolved reoxygenation efficiency. Compared to micro-nano bubble aeration, it is more energy-efficient, has a longer service life, effectively reduces operating and maintenance costs, and maintains a relatively high reoxygenation efficiency. In summary, this invention features autonomous tracking, automated operation, high aeration efficiency, low cost, and environmental friendliness, enabling autonomous tracking and undisturbed mobile aeration without bottom sediment disturbance in a completely unattended manner. Attached Figure Description

[0020] Fig. 1 This is a schematic diagram of the specific structure of the present invention.

[0021] Fig. 2 This is a top view of the present invention.

[0022] Fig. 3 This is a schematic diagram of a cross-aeration system.

[0023] Fig. 4 This is a cross-sectional view of the aeration outlet.

[0024] In the diagram: 1-Solar panel; 2-Warning light; 3-Control system; 4-Lifting motor; 5-Battery; 6-Turbine; 7-Infrared obstacle detector; 8-Retractable connecting rod; 9-Cross-aeration system; 10-Dissolved oxygen probe; 11-Serrated structure. Detailed Implementation

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] like Figs. 1 to 4 As shown, the autonomous tracking cross-aeration reoxygenation system and method for avoiding sediment disturbance provided by this invention includes a mobile hull. At the bottom of the mobile hull are DO probes 10 extending in eight directions and a hull DO probe. A liftable cross-aeration system 9 is located at the center point of the bottom. A tracking module and a control system 3 are located inside the hull. Turbines 6 are located on both sides of the stern to propel the hull. Solar panels 1 are installed on the hull to convert solar energy into electrical energy, which is stored in a battery 5. The battery powers the entire hull, including the turbines, lifting motor, control system, and tracking module.

[0027] Eight directional probes at the bottom of the hull are connected to the hull via retractable connecting rods 8, and are automatically extended and retracted by the control system. The lifting and lowering cross-type aeration system is controlled by a lifting motor 4 located inside the hull. In the cross-aeration system, the aerators use jet aeration. The angle between the three aeration pipes and the horizontal plane is set at 30°. The aeration ports are evenly spaced, and the three aeration airflows intersect on the vertical line where the centroid of the equilateral triangle formed by the three aeration ports is located. At the aeration ports, a ring of evenly distributed isosceles triangular sawtooth structures 11 with a vertex angle of 30° is set around the inner wall edge. The ratio of sawtooth height to aeration outlet radius is set at 1:10, the ratio of sawtooth thickness to height is set at 1:4, and the sawtooth spacing is set at π / 36 times the aeration outlet radius. The hull is equipped with an obstacle avoidance system, including infrared detectors at the bow, sides, and dissolved oxygen probes on the hull, which are connected to the control system. When an obstacle is detected, the forward angle is adjusted to achieve autonomous obstacle avoidance. A red flashing warning light is installed on the top of the hull to prevent collisions with other vessels.

[0028] The implementation of this autonomous tracking cross-aeration reoxygenation system and method to avoid sediment disturbance includes the following steps:

[0029] (1) Place the system device in the water, and use the connecting rod to control the DO probes in 8 directions to extend and the dissolved oxygen probe on the hull to extend and detect the DO concentration. If it is lower than the water body function standard (which is used as the stop aeration threshold), control the aeration system to descend to 1 / 3 of the water depth from the bottom and start working. At the same time, the 9 probes continuously monitor the DO value at the probe location. If it is higher than the set threshold, proceed to step (3).

[0030] (2) After the DO value detected by all probes stabilizes above the set stop aeration threshold for 1 hour, stop aeration and control the motor to retract the aeration system.

[0031] (3) The DO values ​​c measured by the DO probes in 8 directions at this moment i (i = 1, 2, ..., 8) are transmitted to the tracking module. The tracking module selects the direction with the maximum gradient as the optimal direction for reoxygenation and transmits it to the control system. If two or more equal maximum gradients occur, the optimal direction can be selected using the following process: the DO concentration in the direction corresponding to each maximum gradient is summed with the projections of the DO concentrations from the two probes on either side in that direction, and the comprehensive DO concentration index in that direction is calculated. Where c l c r c i The DO concentration is measured by the probes on the left and right sides of the direction. Then, the I value of each direction with the largest G is compared. The direction with the smallest I is the best direction for reoxygenation. If multiple I values ​​are the smallest and equal, then one of the directions corresponding to the smallest I value is selected as the best direction for reoxygenation.

[0032] (4) 8 direction DO probe retracted, the control system control motor change turbine power, so that both sides of the turbine speed difference, the hull steering direction;

[0033] (5) after the hull is in the same direction as the optimal oxygenation direction, the control system controls the turbine to move the hull in that direction. At this time, the hull DO probe continues to work, and the value is continuously fed back to the control system;

[0034] (6) when the hull DO probe detects that the DO concentration is lower than the set starting aeration threshold, the turbine stops running, the aeration system is controlled to descend to a position 1 / 3 of the water depth from the bottom bed and starts to work, while the 9 probes continuously monitor the DO value at the probe point, and steps (2) and (3) are entered.

[0035] The above is only the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. An autonomous, self-tracking, cross-aerated reoxygenation system, characterized by: The utility model discloses a mobile ship body is evenly distributed with dissolved oxygen detection unit, is equipped with solar panel and battery on the ship body, is installed with liftable device on the mobile ship body, is equipped with cross type aeration system on the end of liftable device, is equipped with control system and dissolved oxygen probe on the mobile ship body, and control system is signal connected with dissolved oxygen detection unit, ship body dissolved oxygen probe, liftable device and cross type aeration system.

2. The self-tracking, cross-aerated reoxygenation system of claim 1, wherein: The dissolved oxygen detection unit comprises a telescopic rod and a dissolved oxygen probe, and the dissolved oxygen probe is located at the end of the telescopic rod.

3. The method of aeration and reoxygenation of the self-tracking cross aeration and reoxygenation system according to claim 2, characterized in that, The method comprises the following steps: (1) The system device is placed in water, the connecting rod controls the extension of the 8-direction DO probe, the ship body dissolved oxygen probe is extended, the DO concentration is detected, and is set as c0, and the DO values measured by the 8-direction DO probe are respectively c i， i=1, 2, …, 8; (2) if c0 is lower than the set starting aeration threshold value, the control system controls the cross type aeration system to descend to a certain height, and starting cross type jet flow aeration, the angle between the three aeration pipes and the horizontal plane is controlled to be 30°, and meanwhile, the nine probes continuously monitor the DO value of the point where the probes are located, after the DO value monitored by all the probes is stable above the set aeration stopping threshold value for 1h, the aeration is stopped, and the control system controls the motor to make the aeration system retract; if c0 is higher than the set threshold value, step (3) is entered; (3) The distances from the DO probes in eight directions to the dissolved oxygen probes on the ship are equal and denoted as L. Define c i The dissolved oxygen concentration gradient in the corresponding direction is G. i =(c0-c i ) / L, i=1,2,…,8,G i The direction corresponding to the largest value is the direction of the maximum gradient, which is selected as the optimal direction for reoxygenation. If multiple G values ​​are equal and the largest, the dissolved oxygen concentration in the direction corresponding to each maximum G value is summed with the projections of the dissolved oxygen concentrations from the two probes on either side in that direction, and the comprehensive dissolved oxygen concentration index in that direction is calculated. , where c l c r c i The DO concentration is measured by probes on both sides of the direction; then the comprehensive dissolved oxygen concentration index I value of each direction with the largest G is compared. The direction with the smallest I value is the best direction for reoxygenation. If multiple I values ​​are the smallest and equal, then one of the directions corresponding to the smallest I value is selected as the best direction for reoxygenation. (4) the eight direction dissolved oxygen probes are retracted, the control system controls the motor to change the turbine power, so that the two side turbines generate a speed difference, the ship body is turned, after the front direction of the ship body is the same as the best oxygen recovery direction, the control system controls the turbine to make the ship body move in the direction, at this time, the ship body has the probes continuously working, and the values are continuously fed back to the control system; (5) when the ship body dissolved oxygen probe detects that the DO concentration is lower than the set starting aeration threshold value, the turbine stops running, the aeration system is controlled to descend to a certain height and start working, and meanwhile, the nine probes continuously monitor the DO value of the point where the probes are located, steps (2) and (3) are entered.

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