Oxidation ditch optimization method and system based on computational fluid mechanics simulation and medium

Abstract

The invention discloses an oxidation ditch optimization method and system based on computational fluid mechanics simulation and a medium, mainly relates to the technical field of oxidation ditch optimization, and aims to solve the problems that an existing process of searching and solving unsmooth backflow, high energy consumption and sludge deposition and an adjustment process of an oxidation ditch operation state highly depends on artificial experience and needs to be repeatedly tested and verified, and the working efficiency is high. And the problems of long adjustment period and low efficiency are solved. Comprising the steps of establishing an oxidation ditch three-dimensional model; obtaining distribution data, a velocity field and sludge concentration distribution data; presetting operation parameters, returned by the expert terminal, of the stirrer and the water impeller; using the oxidation ditch three-dimensional model to simulate angles and rotating speeds of a flow impeller and a stirrer meeting a preset flow field flow state under different sewage, mixed liquid and return sludge flow data, and storing the angles and rotating speeds in a simulated flow field flow state database; actual water flow data are collected, and corresponding angle and rotating speed data of the water impeller and the stirrer are obtained from the simulated flow field flow state database to be automatically adjusted.

Description

Technical Field

[0001] The present application relates to the technical field of oxidation ditch optimization in the field of sewage treatment, and in particular to an oxidation ditch optimization method, system and medium based on computational fluid dynamics simulation. Background Art

[0002] The oxidation ditch is an activated sludge treatment process, the core of which is to circulate the sewage and activated sludge mixture in the ditch through a closed ditch-shaped aeration tank. The oxidation ditch process combines the characteristics of plug flow and complete mixing. It not only effectively overcomes the short-circuit phenomenon, but also improves the buffering capacity of the system. It has a strong ability to withstand shock loads and also shows a good removal effect on difficult-to-degrade organic matter. However, in actual applications, the oxidation ditch process still faces some technical difficulties, such as poor internal recirculation, high energy consumption, and sludge deposition. These problems lead to low treatment efficiency of the oxidation ditch process and increase its operating costs.

[0003] In order to solve the above problems, the existing technology mainly involves: simulating the current state of water and sludge in the oxidation ditch (whether the reflux is poor, energy consumption is high, sludge deposition, etc.) through an oxidation ditch sludge simulation model (for example, the Realizable k-ε turbulence model and the Eulerian multiphase flow model). In the specific implementation process, it is necessary to constantly manually adjust the specific operating data of the oxidation ditch in the oxidation ditch sludge simulation model (for example, the angle and speed of the flow promoter and the agitator), and obtain the optimal data that can solve the problems of poor reflux, high energy consumption, and sludge deposition by constantly adjusting the operating data of the oxidation ditch. Specifically, although the optimal oxidation ditch data that can solve problems such as poor reflux, high energy consumption, and sludge deposition can be obtained through continuous adjustment, this process is highly dependent on manual experience and requires repeated experiments and verifications, resulting in a long adjustment cycle and low efficiency. ‌ Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present application provides an oxidation ditch optimization method, system and medium based on computational fluid dynamics simulation to solve the problem that the existing solutions for finding oxidation ditch data to solve poor reflux, high energy consumption and sludge deposition are highly dependent on manual experience and require repeated experiments and verifications, resulting in long adjustment cycles and low efficiency.

[0005] In a first aspect, the present application provides an oxidation ditch optimization method based on computational fluid dynamics simulation, the method comprising: Obtain the structural parameters of the oxidation ditch, and then establish the corresponding three-dimensional model of the oxidation ditch; wherein the structural parameters of the oxidation ditch include at least: the geometric parameters of the middle partition wall, the guide wall, the aerator, the stirrer and the flow promoter; obtain the meshing data and boundary conditions of the three-dimensional model of the oxidation ditch through the CFD software ANSYSfluent, and update the three-dimensional model of the oxidation ditch; wherein the boundary conditions include: the simulation operation parameters of the water inlet, the water outlet weir and the return port in the three-dimensional model; set the initial mixed liquid suspended solids concentration of the water inlet and the return port corresponding to the turbulent condition, and then use Realizable The k-ε turbulence model and the Eulerian multiphase flow model are used to obtain the distribution data, velocity field and sludge concentration distribution data of the sludge in the three-dimensional model of the oxidation ditch; the current distribution data, velocity field and sludge concentration distribution data of the sludge in the three-dimensional model of the oxidation ditch are sent to the preset expert terminal to obtain the returned operating parameters of the agitator and the flowmaker; wherein the operating parameters at least include the impeller diameter, angle, speed and installation position of the agitator and the flowmaker; the three-dimensional model of the oxidation ditch is used to simulate the angle and speed of the flowmaker and the agitator that meet the preset flow field flow state under different water flow data, and save them in the simulated flow field flow state database; the water flow data detected by the front flow meter in the actual oxidation ditch corresponding to the three-dimensional model of the oxidation ditch is collected, and according to the actual water flow data, the corresponding angle and speed of the flowmaker and the agitator are obtained from the simulated flow field flow state database, and returned to the oxidation ditch operation equipment control terminal.

[0006] In one implementation of the present application, the meshing data and boundary conditions of the three-dimensional model of the oxidation ditch are obtained by using the CFD software ANSYS fluent, and the three-dimensional model of the oxidation ditch is updated, specifically including: Import the 3D model of the oxidation ditch into ANSYS fluent software; Based on a preset read address, read the mesh data of the three-dimensional model of the oxidation ditch, and configure the mesh data into the current ANSYS fluent software; wherein the mesh data of the three-dimensional model of the oxidation ditch at least includes the mesh type, mesh size, mesh density and mesh distribution of each area in the three-dimensional model; Based on the preset read address, read the boundary conditions and configure the boundary conditions into the current ANSYS fluent software.

[0007] In one implementation of the present application, the current sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch three-dimensional model are sent to a preset expert terminal to obtain the returned operating parameters of the agitator and the flow generator, including: S1. Send the current sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch three-dimensional model to all preset expert terminals; S2, broadcasting the operating parameters of the first returned agitator and flow generator to all preset expert terminals; S3, obtaining an operating parameter evaluation result; when the operating parameter evaluation result exceeding a preset ratio is reasonable, determining the current operating parameters of the agitator and the flowmaker as the final operating parameters of the agitator and the flowmaker; S4. When the evaluation results of the operating parameters that do not exceed the preset ratio are reasonable, the operating parameters uploaded by the expert terminal whose evaluation results of the operating parameters are unreasonable are obtained; S5. Based on the preset weights of the unreasonable expert terminals, broadcast the operating parameters of the expert terminal with the largest preset weight to all preset expert terminals to obtain the operating parameter evaluation results; S6, looping S3-S5, until the evaluation results of the operating parameters exceeding the preset ratio are reasonable, determining the current operating parameters of the agitator and the flowmaker as the final operating parameters of the agitator and the flowmaker; S7. Increase the preset first weight value by the preset weight of the uploaded expert terminal corresponding to the final operating parameters of the agitator and the flowmaker; increase the preset second weight value by the preset weight of the expert terminal that returns the final operating parameters of the agitator and the flowmaker as reasonable; wherein the preset first weight value>the preset second weight value.

[0008] In one implementation of the present application, the initial mixed liquor suspended solids concentration of the water inlet and the return flow corresponding to the turbulent condition is set, and then the Realizable k-ε turbulence model and the Eulerian multiphase flow model are used to obtain the distribution data, velocity field and sludge concentration distribution data of the sludge in the three-dimensional model of the oxidation ditch, specifically including: In ANSYS fluent, the initial mixed liquor suspended solids concentration of the water inlet and the return flow is set; in the model selection of ANSYS fluent, the Realizable k-ε turbulence model is selected; at the same time, the Eulerian multiphase flow model is selected to simulate the interaction between sludge and water; the solver of ANSYS fluent is started to perform simulation calculations based on the set initial mixed liquor suspended solids concentration, the Realizable k-ε turbulence model and the Eulerian multiphase flow model; after the simulation calculations are completed, the distribution data of sludge in the three-dimensional model of the oxidation ditch, the velocity field and the sludge concentration distribution data are extracted from ANSYS fluent.

[0009] In one implementation of the present application, a three-dimensional model of an oxidation ditch is used to simulate the angle and rotation speed of a flow promoter and a stirrer that meet a preset flow field flow pattern under different water flow data, and save the simulation flow field flow pattern database, specifically including: In ANSYS fluent, the water flow rate is set as a variable; for each set water flow value, the angle and speed of the flowmaker and the agitator are adjusted, and simulation calculations are performed until an angle and speed combination that satisfies the preset flow field and flow pattern is found; the angle and speed combination of the flowmaker and the agitator corresponding to each water flow rate is recorded; the recorded data is organized into a simulated flow field and flow pattern database; the simulated flow field and flow pattern database includes water flow data, flowmaker angle, flowmaker speed, agitator angle, and agitator speed.

[0010] In one implementation of the present application, after returning to the oxidation ditch operation equipment control terminal, the method further includes: The adjustment result of the adjusted oxidation ditch returned by the oxidation ditch operation equipment control terminal is obtained; wherein the adjustment result at least includes whether the sludge concentration decreases after a preset waiting time period; when the sludge concentration does not decrease after the preset waiting time period, a maintenance task is generated to the preset model maintenance terminal to correct the oxidation ditch three-dimensional model and the corresponding simulated flow field flow state database.

[0011] In a second aspect, the present application provides an oxidation ditch optimization system based on computational fluid dynamics simulation, the system comprising: The establishment module is used to obtain the structural parameters of the oxidation ditch, and then establish the corresponding three-dimensional model of the oxidation ditch; wherein the structural parameters of the oxidation ditch include at least: the geometric parameters of the intermediate partition wall, the guide wall, the aerator, the stirrer and the flow pusher; the update module is used to obtain the meshing data and boundary conditions of the three-dimensional model of the oxidation ditch through the CFD software ANSYS fluent, and update the three-dimensional model of the oxidation ditch; wherein the boundary conditions include: the simulation operation parameters of the water inlet, the water outlet weir and the return port in the three-dimensional model; the acquisition module is used to set the initial mixed liquid suspended solid concentration of the water inlet and the return port corresponding to the turbulent condition, and then use Realizable The k-ε turbulence model and the Eulerian multiphase flow model are used to obtain the distribution data, velocity field and sludge concentration distribution data of the sludge in the three-dimensional model of the oxidation ditch; the current distribution data, velocity field and sludge concentration distribution data of the sludge in the three-dimensional model of the oxidation ditch are sent to the preset expert terminal to obtain the returned operating parameters of the agitator and the flowmaker; wherein the operating parameters at least include the impeller diameter, angle, speed and installation position of the agitator and the flowmaker; the three-dimensional model of the oxidation ditch is used to simulate the angle and speed of the flowmaker and the agitator that meet the preset flow field flow state under different water flow data, and save them in the simulated flow field flow state database; the operation module is used to collect the water flow data detected by the front flow meter in the actual oxidation ditch corresponding to the three-dimensional model of the oxidation ditch, and obtain the corresponding angle and speed of the flowmaker and the agitator from the simulated flow field flow state database according to the actual water flow data, and return them to the oxidation ditch operation equipment control terminal.

[0012] In one implementation of the present application, the update module includes an update unit, which is used to import the three-dimensional model of the oxidation ditch into the ANSYS fluent software; based on a preset read address, read the mesh division data of the three-dimensional model of the oxidation ditch, and configure the mesh division data into the current ANSYS fluent software; wherein the mesh division data of the three-dimensional model of the oxidation ditch includes at least the mesh type, mesh size, mesh density and mesh distribution of each area in the three-dimensional model; based on the preset read address, read the boundary conditions, and configure the boundary conditions into the current ANSYS fluent software.

[0013] In one implementation of the present application, the acquisition module includes an acquisition unit, which is used to set the initial mixed liquor suspended solids concentration of the water inlet and the reflow in ANSYS fluent; in the model selection of ANSYS fluent, select the Realizable k-ε turbulence model; and select the Eulerian multiphase flow model to simulate the interaction between sludge and water; start the solver of ANSYS fluent to perform simulation calculations based on the set initial mixed liquor suspended solids concentration, the Realizable k-ε turbulence model and the Eulerian multiphase flow model; after the simulation calculations are completed, extract the sludge distribution data, velocity field and sludge concentration distribution data in the three-dimensional model of the oxidation ditch from ANSYS fluent.

[0014] In a third aspect, the present application provides a non-volatile computer storage medium having computer instructions stored thereon, which when executed implement an oxidation ditch optimization method based on computational fluid dynamics simulation as described above.

[0015] Those skilled in the art can understand that the present application has at least the following beneficial effects: The three-dimensional model is obtained by automatically acquiring the structural parameters of the oxidation ditch and establishing a three-dimensional model, and using the CFD software ANSYS Fluent to perform meshing and boundary condition setting. The three-dimensional model contains all the structural data of the current oxidation ditch and can simulate the scene data of the current oxidation ditch according to the specific structural parameters.

[0016] The simulated sludge distribution data, velocity field and sludge concentration distribution data are sent to the preset expert terminal. Through the analysis of the expert system, the optimal operating parameters of the agitator and flowmaker can be quickly given. In the implementation process, the impeller diameter, angle (initial), speed (initial), and installation position of the agitator and flowmaker are obtained by sending them to the expert terminal. After the impeller diameter and installation position of the agitator and flowmaker are fixed, the three-dimensional model is built.

[0017] Through the built three-dimensional model, the angle and speed of the flowmaker and agitator that meet the preset flow field flow pattern (no backflow, high energy consumption, sludge deposition and other problems) under different water flow data are automatically simulated, and a database (simulated flow field flow pattern database) is established, which solves the problem that the existing solution needs to constantly manually adjust the specific operation data of the oxidation ditch in the oxidation ditch sludge simulation model (for example, the angle and speed of the flowmaker and agitator). According to the simulated flow field flow pattern database, when the actual water flow changes, the corresponding existing parameters can be obtained from the database through the actual water flow, and the controller can be instructed by the control system to automatically adjust the agitator and flowmaker.

[0018] By using the simulated flow field and flow state database, we can find the angles and speeds of the flowmakers and agitators that meet the preset flow field and flow state (without problems such as poor backflow, high energy consumption, and sludge deposition) under the water flow data, thereby reducing operating costs and maintenance difficulties. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0020] Figure 1 It is a flow chart of an oxidation ditch optimization method based on computational fluid dynamics simulation provided in an embodiment of the present application.

[0021] Figure 2 It is a schematic diagram of the three-dimensional model structure of an oxidation ditch provided in an embodiment of the present application.

[0022] Figure 3 It is a structural schematic diagram of a whole aeration device in a three-dimensional model structure of an oxidation ditch provided in an embodiment of the present application.

[0023] Figure 4 The embodiment of the present application provides a sludge distribution map before optimization.

[0024] Figure 5 An optimized sludge distribution map is provided in an embodiment of the present application.

[0025] Figure 6 It is a schematic diagram of the internal structure of an oxidation ditch optimization system based on computational fluid dynamics simulation provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] It should be understood by those skilled in the art that the embodiments described below are only preferred embodiments of the present disclosure, and do not mean that the present disclosure can only be implemented through the preferred embodiments. The preferred embodiments are only used to explain the technical principles of the present disclosure, and are not used to limit the protection scope of the present disclosure. Based on the preferred embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work should still fall within the protection scope of the present disclosure.

[0027] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0028] The technical solution proposed in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0029] The embodiment provides an oxidation ditch optimization method based on computational fluid dynamics simulation, such as Figure 1 As shown, the method provided in the embodiment of the present application mainly includes the following steps: Step 110: Obtain oxidation ditch structural parameters, and then establish a corresponding oxidation ditch three-dimensional model.

[0030] It should be noted that the structural parameters of the oxidation ditch include at least the geometric parameters of the middle partition wall, guide wall, aerator, agitator and flow promoter.

[0031] Furthermore, the three-dimensional model of the oxidation ditch involved in the present application can be as follows Figure 2 As shown, it can be composed of the main body of the oxidation ditch, sewage inlet, sewage outlet, return sludge inlet, agitator, pusher, diversion wall, etc. Among them, the function of the agitator is to mix the sludge and push the flow, and the main function of the flow pusher is to push the flow.

[0032] In addition, those skilled in the art can add or delete the data in the above oxidation ditch structural parameters according to actual needs. As an example, simplifying non-essential structures such as walkways, railings, etc. is equivalent to simplifying important and complex structures, for example, Figure 3 As shown, the present application can transform an aerator composed of a plurality of aeration plates into plates with the same aeration volume and bubbles of the same size in strict accordance with the aeration positions.

[0033] Step 120: Obtain meshing data and boundary conditions of the three-dimensional model of the oxidation ditch through the CFD software ANSYS fluent, and update the three-dimensional model of the oxidation ditch.

[0034] It should be noted that the boundary conditions include: simulation operation parameters of the water inlet, water outlet weir and return outlet in the three-dimensional model.

[0035] This step can be specifically as follows: Import the three-dimensional model of the oxidation ditch into the ANSYS fluent software; based on a preset read address, read the mesh data of the three-dimensional model of the oxidation ditch, and configure the mesh data into the current ANSYS fluent software; wherein the mesh data of the three-dimensional model of the oxidation ditch includes at least the mesh type, mesh size, mesh density and mesh distribution of each area in the three-dimensional model; based on a preset read address, read the boundary conditions, and configure the boundary conditions into the current ANSYS fluent software.

[0036] It should be noted that, taking the A / A / O oxidation ditch of a sewage treatment plant with a treatment scale of 40,000 m³ / d as an example, the pool size is 110m×35m×6m, and the grid division data and boundary conditions can also be specific as follows: a hybrid grid form is adopted, with a total 3D grid number of 1.9-2.3 million, and then migrated to the CFD simulation of other equipment; the near-wall, aeration area, agitator and flowmaker are locally encrypted, and 3 layers of boundary layer grids are set; the water inlet is set as the velocity inlet (v=0.5-0.8 m / s); the outlet weir is set as the pressure outlet; the return port is set as the velocity inlet (return ratio 40-80%).

[0037] Step 130, setting the initial mixed liquor suspended solids concentration of the water inlet and the return flow corresponding to the turbulent conditions, and then using the Realizable k-ε turbulence model and the Eulerian multiphase flow model to obtain the sludge distribution data, velocity field and sludge concentration distribution data in the three-dimensional model of the oxidation ditch.

[0038] As an example, this step may be specifically as follows: Set the initial mixed liquor suspended solids concentration of the inlet and return in ANSYS fluent; In the model selection of ANSYS fluent, select the Realizable k-ε turbulence model; At the same time, the Eulerian multiphase flow model was selected to simulate the interaction between sludge and water; Start the ANSYS fluent solver and perform simulation calculations based on the set initial mixed liquid suspended solid concentration, Realizablek-ε turbulence model and Eulerian multiphase flow model; After the simulation calculation is completed, the sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch three-dimensional model are extracted from ANSYS fluent.

[0039] It should be noted that, taking the A / A / O oxidation ditch of a sewage treatment plant with a treatment scale of 40,000 m³ / d as an example, the pool size is 110m×35m×6m, and the initial mixed liquor suspended solids concentration can be specifically as follows: using the Realizable k-ε turbulence model and the Eulerian multiphase flow model, the sewage inlet and return flow are set to MLSS (initial mixed liquor suspended solids concentration) concentrations of 50-300 mg / L and 10,000-15,000 mg / L respectively; the coupled pressure-velocity coupling algorithm is used; and the convergence residual of Fluent is less than 1×10⁻³.

[0040] Step 140: Send the current sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch three-dimensional model to the preset expert terminal, and obtain the returned operating parameters of the agitator and the flowmaker.

[0041] It should be noted that the operating parameters include at least the impeller diameter, angle, rotation speed and installation position of the agitator and flowmaker.

[0042] In some embodiments, this step may specifically include: S1. Send the current sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch three-dimensional model to all preset expert terminals.

[0043] S2. Broadcast the operating parameters of the first returned agitator and flowmaker to all preset expert terminals.

[0044] S3, obtaining an evaluation result of the operating parameters; when the evaluation results of the operating parameters exceeding the preset ratio are reasonable, determining the current operating parameters of the agitator and the flowmaker as the final operating parameters of the agitator and the flowmaker.

[0045] S4. When the evaluation results of the operating parameters that do not exceed the preset ratio are reasonable, the operating parameters uploaded by the expert terminal whose evaluation results of the operating parameters are unreasonable are obtained.

[0046] S5. Based on the preset weights of the unreasonable expert terminals, the operating parameters of the expert terminal with the largest preset weight are selected and broadcasted to all preset expert terminals; and the operating parameter evaluation results are obtained.

[0047] S6, looping S3-S5 until the evaluation results of the operating parameters exceeding the preset ratio are reasonable, and determining the current operating parameters of the agitator and the flowmaker as the final operating parameters of the agitator and the flowmaker.

[0048] S7, increasing the preset first weight value by the preset weight of the expert terminal corresponding to the final operating parameters of the agitator and the flowmaker; increasing the preset second weight value by the preset weight of the expert terminal returning the final operating parameters of the agitator and the flowmaker as reasonable.

[0049] Among them, the preset first weight value>the preset second weight value.

[0050] It should be noted that the initial weight can be 1.

[0051] Step 150, using the three-dimensional model of the oxidation ditch, simulate the angles and rotation speeds of the flow promoter and the agitator that meet the preset flow field and flow pattern under different water flow data, and save them in the simulated flow field and flow pattern database.

[0052] As an example, this step may be specifically as follows: In ANSYS fluent, the water flow rate is set as a variable. For each set water flow rate value, the angle and speed of the flowmaker and agitator are adjusted, and simulation calculations are performed until an angle and speed combination that satisfies the preset flow field and flow pattern is found. The angle and speed combination of the flowmaker and agitator corresponding to each water flow rate is recorded. The recorded data is organized into a simulated flow field and flow pattern database.

[0053] Among them, the simulated flow field flow state database includes water flow data, flowmaker angle, flowmaker speed, agitator angle, and agitator speed.

[0054] Step 160, collect the water flow data detected by the front flow meter in the actual oxidation ditch corresponding to the three-dimensional model of the oxidation ditch, obtain the corresponding angle and rotation speed of the flow promoter and agitator from the simulated flow field flow state database according to the actual water flow data, and return it to the oxidation ditch operation equipment control terminal.

[0055] In addition, in order to avoid the changes in the oxidation ditch in the later stage that make the three-dimensional model no longer fit, the present application can obtain feedback returned by the terminal and determine the timing of adjustment based on the feedback.

[0056] The specific implementation process can be: After returning to the oxidation ditch operation equipment control terminal, the adjustment result of the adjusted oxidation ditch returned by the oxidation ditch operation equipment control terminal is obtained; wherein the adjustment result at least includes whether the sludge concentration decreases after a preset waiting time period; when the sludge concentration does not decrease after the preset waiting time period, a maintenance task is generated to the preset model maintenance terminal to correct the oxidation ditch three-dimensional model and the corresponding simulated flow field flow state database.

[0057] In summary, taking the A / A / O oxidation ditch of a sewage treatment plant with a treatment scale of 40,000 m³ / d as an example, the pool size is 110m×35m×6m, and the grid division data and boundary conditions can also be specific as follows: a hybrid grid form is adopted, with a total 3D grid number of 1.9-2.3 million, and then migrated to the CFD simulation of other equipment; the near wall, aeration area, agitator and flowmaker are locally encrypted, and 3 layers of boundary layer grids are set; the water inlet is set as the velocity inlet (v=0.5-0.8 m / s); the outlet weir is set as the pressure outlet; the return port is set as the velocity inlet (return ratio 40-80%). The initial mixed liquor suspended solids concentration can be specifically as follows: using the Realizable k-ε turbulence model and the Eulerian multiphase flow model, the sewage inlet and return flow are set to MLSS (initial mixed liquor suspended solids concentration) concentrations of 50-300 mg / L and 10,000-15,000 mg / L respectively; using the coupled pressure-velocity coupling algorithm; the convergence residual of Fluent is less than 1×10⁻³. The optimization effect is verified by the operation data of the past year: the sludge outlet concentration and the measured concentration of the effluent; the comparison of sludge concentration or dissolved oxygen in specific areas. The sludge distribution before optimization is shown in Figure 4 , the sludge distribution after optimization is shown in Figure 5 It can be seen that after optimization, the volume proportion of sludge concentration in the 4500-5000 mg / L segment increased from 75.28% to 90.89%, an increase of about 20% over the former; the sludge concentration in the 4900-5000 mg / L segment increased from the original 37.22% to 57.08%, an increase of about 53% over the former.

[0058] In addition, this application Figure 6 An oxidation ditch optimization system based on computational fluid dynamics simulation is provided in the embodiment of the present application. Figure 6 As shown, the system provided in the embodiment of the present application mainly includes: The module 210 is established to obtain the structural parameters of the oxidation ditch and then establish a corresponding three-dimensional model of the oxidation ditch; wherein the structural parameters of the oxidation ditch include at least: geometric parameters of the intermediate partition wall, the guide wall, the aerator, the stirrer and the flow promoter.

[0059] The updating module 220 is used to obtain the meshing data and boundary conditions of the three-dimensional model of the oxidation ditch through the CFD software ANSYS fluent, and update the three-dimensional model of the oxidation ditch; wherein the boundary conditions include: simulation operation parameters of the water inlet, water outlet weir and reflow port in the three-dimensional model.

[0060] The update module 220 includes an update unit, which is used to import the three-dimensional model of the oxidation ditch into the ANSYS fluent software; based on a preset read address, read the mesh division data of the three-dimensional model of the oxidation ditch, and configure the mesh division data into the current ANSYS fluent software; wherein the mesh division data of the three-dimensional model of the oxidation ditch at least includes the mesh type, mesh size, mesh density and mesh distribution of each area in the three-dimensional model; based on a preset read address, read the boundary conditions, and configure the boundary conditions into the current ANSYS fluent software.

[0061] The acquisition module 230 is used to set the initial mixed liquor suspended solids concentration of the water inlet and the return flow corresponding to the turbulent condition, and then use the Realizable k-ε turbulence model and the Eulerian multiphase flow model to obtain the sludge distribution data, velocity field and sludge concentration distribution data in the three-dimensional model of the oxidation ditch; the current sludge distribution data, velocity field and sludge concentration distribution data in the three-dimensional model of the oxidation ditch are sent to the preset expert terminal to obtain the returned operating parameters of the agitator and the flowmaker; wherein the operating parameters include at least the impeller diameter, angle, speed and installation position of the agitator and the flowmaker; the three-dimensional model of the oxidation ditch is used to simulate the angle and speed of the flowmaker and the agitator that meet the preset flow field flow state under different water flow data, and save them in the simulated flow field flow state database.

[0062] The acquisition module 230 includes an acquisition unit, which is used to set the initial mixed liquor suspended solids concentration of the water inlet and the reflow in ANSYS fluent; in the model selection of ANSYS fluent, select the Realizable k-ε turbulence model; and select the Eulerian multiphase flow model to simulate the interaction between sludge and water; start the solver of ANSYS fluent to perform simulation calculations based on the set initial mixed liquor suspended solids concentration, the Realizable k-ε turbulence model and the Eulerian multiphase flow model; after the simulation calculations are completed, extract the sludge distribution data, velocity field and sludge concentration distribution data in the three-dimensional model of the oxidation ditch from ANSYS fluent.

[0063] Operation module 240 is used to collect water flow data detected by the front flow meter in the actual oxidation ditch corresponding to the three-dimensional model of the oxidation ditch, and obtain the corresponding angles and rotation speeds of the flow promoter and agitator from the simulated flow field flow state database based on the actual water flow data, and return them to the oxidation ditch operation equipment control terminal.

[0064] In addition, an embodiment of the present application further provides a non-volatile computer storage medium on which executable instructions are stored. When the executable instructions are executed, an oxidation ditch optimization method based on computational fluid dynamics simulation as described above is implemented.

[0065] So far, the technical solutions of the present disclosure have been described in combination with the above multiple embodiments, but it is easy for those skilled in the art to understand that the protection scope of the present disclosure is not limited to these specific embodiments. Without departing from the technical principles of the present disclosure, those skilled in the art can split and combine the technical solutions in the above-mentioned various embodiments, and can also make equivalent changes or replacements to the relevant technical features. Any changes, equivalent replacements, improvements, etc. made within the technical concept and / or technical principle of the present disclosure will fall within the protection scope of the present disclosure.

Claims

1. A method for optimizing an oxidation ditch based on computational fluid dynamics simulation, characterized in that: The method comprises: Obtaining oxidation ditch structural parameters, and then establishing a corresponding oxidation ditch three-dimensional model; wherein the oxidation ditch structural parameters at least include: geometric parameters of the middle partition wall, the guide wall, the aerator, the stirrer and the flow promoter; The CFD software ANSYS fluent is used to obtain the meshing data and boundary conditions of the three-dimensional model of the oxidation ditch, and update the three-dimensional model of the oxidation ditch; wherein the boundary conditions include: the simulation operation parameters of the water inlet, water outlet weir and return port in the three-dimensional model; The initial mixed liquor suspended solids concentrations at the inlet and return flow corresponding to the turbulent conditions were set, and then the Realizable k-ε turbulence model and the Eulerian multiphase flow model were used to obtain the sludge distribution data, velocity field, and sludge concentration distribution data in the three-dimensional model of the oxidation ditch. The current sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch three-dimensional model are sent to the preset expert terminal to obtain the returned operating parameters of the agitator and the flowmaker; wherein the operating parameters at least include the impeller diameter, angle, speed and installation position of the agitator and the flowmaker; Using the three-dimensional model of the oxidation ditch, the angles and rotation speeds of the flow propeller and agitator that meet the preset flow field and flow pattern are simulated under different water flow data, and saved in the simulated flow field and flow pattern database; The water flow data detected by the front flow meter in the actual oxidation ditch corresponding to the three-dimensional model of the oxidation ditch is collected. According to the actual water flow data, the corresponding angles and rotation speeds of the flow promoter and agitator are obtained from the simulated flow field flow state database and returned to the oxidation ditch operation equipment control terminal.

2. The oxidation ditch optimization method based on computational fluid dynamics simulation according to claim 1, characterized in that: Through the CFD software ANSYS fluent, the meshing data and boundary conditions of the 3D model of the oxidation ditch are obtained, and the 3D model of the oxidation ditch is updated, including: Import the 3D model of the oxidation ditch into ANSYS fluent software; Based on a preset read address, read the mesh data of the three-dimensional model of the oxidation ditch, and configure the mesh data into the current ANSYS fluent software; wherein the mesh data of the three-dimensional model of the oxidation ditch at least includes the mesh type, mesh size, mesh density and mesh distribution of each area in the three-dimensional model; Based on the preset read address, read the boundary conditions and configure the boundary conditions into the current ANSYS fluent software.

3. The oxidation ditch optimization method based on computational fluid dynamics simulation according to claim 1, characterized in that: The current sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch 3D model are sent to the preset expert terminal to obtain the returned operating parameters of the agitator and flow generator, including: S1. Send the current sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch three-dimensional model to all preset expert terminals; S2, broadcasting the operating parameters of the first returned agitator and flow generator to all preset expert terminals; S3, obtaining an operating parameter evaluation result; when the operating parameter evaluation result exceeding a preset ratio is reasonable, determining the current operating parameters of the agitator and the flowmaker as the final operating parameters of the agitator and the flowmaker; S4. When the evaluation results of the operating parameters that do not exceed the preset ratio are reasonable, the operating parameters uploaded by the expert terminal whose evaluation results of the operating parameters are unreasonable are obtained; S5. Based on the preset weights of the unreasonable expert terminals, broadcast the operating parameters of the expert terminal with the largest preset weight to all preset expert terminals to obtain the operating parameter evaluation results; S6, looping S3-S5, until the evaluation results of the operating parameters exceeding the preset ratio are reasonable, determining the current operating parameters of the agitator and the flowmaker as the final operating parameters of the agitator and the flowmaker; S7. Increase the preset first weight value by the preset weight of the uploaded expert terminal corresponding to the final operating parameters of the agitator and the flowmaker; increase the preset second weight value by the preset weight of the expert terminal that returns the final operating parameters of the agitator and the flowmaker as reasonable; wherein the preset first weight value>the preset second weight value.

4. The oxidation ditch optimization method based on computational fluid dynamics simulation according to claim 1, characterized in that: The initial mixed liquor suspended solids concentrations at the inlet and return corresponding to the turbulent conditions are set, and then the Realizable k-ε turbulence model and the Eulerian multiphase flow model are used to obtain the sludge distribution data, velocity field and sludge concentration distribution data in the three-dimensional model of the oxidation ditch, including: Set the initial mixed liquor suspended solids concentration of the inlet and return in ANSYS fluent; In the model selection of ANSYS fluent, select the Realizable k-ε turbulence model; At the same time, the Eulerian multiphase flow model was selected to simulate the interaction between sludge and water; Start the ANSYS fluent solver and perform simulation calculations based on the set initial mixed liquid suspended solid concentration, Realizable k-ε turbulence model and Eulerian multiphase flow model; After the simulation calculation is completed, the sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch three-dimensional model are extracted from ANSYS fluent.

5. The oxidation ditch optimization method based on computational fluid dynamics simulation according to claim 1, characterized in that: The three-dimensional model of the oxidation ditch is used to simulate the angle and speed of the flow propeller and agitator that meet the preset flow field and flow pattern under different water flow data, and save them in the simulated flow field and flow pattern database, including: In ANSYS fluent, set the water flow rate as a variable; For each set water flow value, adjust the angle and speed of the flow generator and the agitator, and perform simulation calculations until a combination of angle and speed that satisfies the preset flow field and flow pattern is found; Record the angle and speed combination of the flowmaker and agitator corresponding to each water flow rate; The recorded data are organized into a simulated flow field flow state database; wherein the simulated flow field flow state database includes water flow data, flowmaker angle, flowmaker speed, agitator angle, and agitator speed.

6. The oxidation ditch optimization method based on computational fluid dynamics simulation according to claim 1, characterized in that: After returning to the oxidation ditch operation equipment control terminal, the method further comprises: Obtaining the adjusted result of the oxidation ditch returned by the oxidation ditch operation equipment control terminal; wherein the adjustment result at least includes whether the sludge concentration decreases after a preset waiting time period; When the sludge concentration does not decrease after the preset waiting time period, a maintenance task is generated to the preset model maintenance terminal to correct the oxidation ditch three-dimensional model and the corresponding simulated flow field flow state database.

7. An oxidation ditch optimization system based on computational fluid dynamics simulation, characterized in that: The system comprises: Establish a module for obtaining oxidation ditch structural parameters, and then establish a corresponding oxidation ditch three-dimensional model; wherein the oxidation ditch structural parameters at least include: geometric parameters of the middle partition wall, the guide wall, the aerator, the stirrer and the flow pusher; The updating module is used to obtain the meshing data and boundary conditions of the three-dimensional model of the oxidation ditch through the CFD software ANSYS fluent, and update the three-dimensional model of the oxidation ditch; wherein the boundary conditions include: simulation operation parameters of the water inlet, water outlet weir and return port in the three-dimensional model; An acquisition module is used to set the initial mixed liquor suspended solids concentration of the water inlet and the return flow corresponding to the turbulent condition, and then use the Realizable k-ε turbulence model and the Eulerian multiphase flow model to obtain the sludge distribution data, velocity field and sludge concentration distribution data in the three-dimensional model of the oxidation ditch; the current sludge distribution data, velocity field and sludge concentration distribution data in the three-dimensional model of the oxidation ditch are sent to the preset expert terminal to obtain the returned operating parameters of the agitator and the flowmaker; wherein the operating parameters include at least the impeller diameter, angle, speed and installation position of the agitator and the flowmaker; the three-dimensional model of the oxidation ditch is used to simulate the angle and speed of the flowmaker and the agitator that meet the preset flow field flow state under different water flow data, and save them in the simulated flow field flow state database; The operation module is used to collect the water flow data detected by the front flow meter in the actual oxidation ditch corresponding to the three-dimensional model of the oxidation ditch. According to the actual water flow data, the corresponding angles and rotation speeds of the flow promoter and agitator are obtained from the simulated flow field flow state database, and returned to the oxidation ditch operation equipment control terminal.

8. The oxidation ditch optimization system based on computational fluid dynamics simulation according to claim 7, characterized in that: The update module includes an update unit, Used to import the 3D model of the oxidation ditch into ANSYS fluent software; Based on a preset read address, read the mesh data of the three-dimensional model of the oxidation ditch, and configure the mesh data into the current ANSYS fluent software; wherein the mesh data of the three-dimensional model of the oxidation ditch at least includes the mesh type, mesh size, mesh density and mesh distribution of each area in the three-dimensional model; Based on the preset read address, read the boundary conditions and configure the boundary conditions into the current ANSYS fluent software.

9. The oxidation ditch optimization system based on computational fluid dynamics simulation according to claim 7, characterized in that: The acquisition module includes an acquisition unit, Used to set the initial mixed liquor suspended solids concentration for the inlet and return in ANSYS fluent; In the model selection of ANSYS fluent, select the Realizable k-ε turbulence model; At the same time, the Eulerian multiphase flow model was selected to simulate the interaction between sludge and water; Start the ANSYS fluent solver and perform simulation calculations based on the set initial mixed liquid suspended solid concentration, Realizable k-ε turbulence model and Eulerian multiphase flow model; After the simulation calculation is completed, the sludge distribution data, velocity field and sludge concentration distribution data in the oxidation ditch three-dimensional model are extracted from ANSYS fluent.

10. A non-volatile computer storage medium, characterized in that: Computer instructions are stored thereon, and when the computer instructions are executed, the method for optimizing an oxidation ditch based on computational fluid dynamics simulation as described in any one of claims 1 to 6 is implemented.

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