A method and system for controlling drug delivery based on floc fractal dimension

Abstract

The present application relates to tap water production technical field, disclose a kind of dosing control method and system based on floc fractal dimension, its basic concept is: the one-dimensional fractal dimension and two-dimensional fractal dimension of floc in flocculation sedimentation tank are collected;When two-dimensional fractal dimension falls in the second threshold range, maintain current dosing amount;When one-dimensional fractal dimension is greater than the maximum of first threshold range and two-dimensional fractal dimension falls outside the second threshold range, reduce current dosing amount;When one-dimensional fractal dimension falls less than the minimum of first threshold range and two-dimensional fractal dimension falls outside the second threshold range, increase current dosing amount.The dosing control method based on floc fractal dimension provided in the present application, with two-dimensional fractal dimension of floc as benchmark and combining one-dimensional fractal dimension to adjust dosing amount, break through the limitation that conventional dosing optimization method must detect numerous external influencing factors and narrow medicament application range, shorten lag time, enhance the dynamic characteristics of control system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tap water production, and particularly relates to a flocculation control method and system based on fractal dimension of flocculation. BACKGROUND

[0002] The water purification process of a water plant is mainly to add flocculants to make fine suspended particles and colloidal particles flocculate into larger particles to settle down to purify water. Common flocculants mainly include iron salts and aluminum salts, such as ferric chloride, polyaluminum chloride, and sometimes a coagulant such as silicic acid is also needed.

[0003] For a standard modern water supply system, intelligent control of the water supply system is crucial. In the water purification process of a water plant, the flocculation dosing link is the core process in the purification process, and the flocculation and sedimentation effect directly affects the water quality of the finished water, so the automatic control of the flocculant dosage becomes a key link in the modern water supply system. Although many flocculant dosing control schemes have been proposed in the prior art, they are not mature, and many water plants still use fixed dosing rate to add flocculants in daily operation. However, when the flocculants are added in the fixed dosing rate, the dosing rate is often too high, which will cause waste; in addition, when the water quality parameters of the raw water change suddenly, the water quality of the finished water cannot be guaranteed to meet the standard when the flocculants are added in the fixed dosing rate.

[0004] A Chinese patent application with the publication number CN111966053A discloses an intelligent flocculant decision system, which is applied to a water purification subsystem of a water supply system of a water plant. The water purification subsystem includes a raw water pool, a flocculation and sedimentation pool, and a flocculant dosing pump. The flocculation and sedimentation pool is connected to the raw water pool for flocculation and sedimentation of raw water to complete water purification operation. The intelligent flocculant decision system specifically includes: a water quality acquisition module for continuously monitoring the water quality of the raw water pool at a first preset frequency and outputting a water quality parameter set; a feedforward control module connected to the water quality acquisition module, which processes the water quality parameter set and a preset dosing model to output a feedforward dosing amount; the flocculant dosing pump adds flocculants to the flocculation and sedimentation pool according to the feedforward dosing amount; an image acquisition module for continuously acquiring flocculation images of the flocculation and sedimentation pool at a second preset frequency and preprocessing to output a flocculation feature set; a feedback control module connected to the image acquisition module, which processes the flocculation feature set and a preset correction model to output a feedback dosing correction amount; and the flocculant dosing pump corrects the amount of flocculants added to the flocculation and sedimentation pool according to the feedback dosing correction amount.

[0005] The existing patent can correct the dosing amount according to the flocculation characteristics, but the flocs are randomly distributed under the influence of water flow disturbance, and the influence of floc adhesion and uneven distribution cannot be excluded when the image is sampled, which is easy to cause errors in the image judgment effect. In addition, the flocculation characteristics include micro features such as floc size and density, and the density directly affects the sedimentation effect and the later filtration, so it is easy to cause the flocs to be difficult to settle and the operation cost of the water plant to rise only by correcting the dosing according to the alum flower number and distribution density. SUMMARY

[0006] The purpose of the present application is to provide a tap water production method based on floc fractal dimension for dosing control, to solve one or more technical problems in the prior art, and at least to provide a beneficial choice or create conditions.

[0007] To achieve the above purpose, the technical scheme is as follows.

[0008] A dosing control method based on floc fractal dimension is used for flocculation dosing control in tap water production, and the basic concept is as follows: collecting one-dimensional fractal dimension and two-dimensional fractal dimension of flocs in a flocculation sedimentation tank; when the two-dimensional fractal dimension falls within the second threshold range, the current dosing amount is maintained; when the one-dimensional fractal dimension is greater than the maximum value of the first threshold range and the two-dimensional fractal dimension falls outside the second threshold range, the current dosing amount is reduced; when the one-dimensional fractal dimension falls below the minimum value of the first threshold range and the two-dimensional fractal dimension falls outside the second threshold range, the current dosing amount is increased.

[0009] Compared with the prior art, the dosing control method based on floc fractal dimension provided by the present application adjusts the dosing amount based on the two-dimensional fractal dimension of the flocs and combines the one-dimensional fractal dimension, breaks through the limitations of the conventional dosing optimization method that must detect numerous external influencing factors (apparent parameters) and the narrow range of the medicament, shortens the lag time, enhances the dynamic characteristics of the control system; at the same time, it also effectively reduces the judgment errors caused by floc adhesion and uneven distribution, and ensures that the micro features such as floc size and density fall within the optimal range, thereby ensuring the sedimentation effect, reducing the filtration pressure in the later stage, and reducing the operation cost of the water plant.

[0010] More preferably, the one-dimensional fractal dimension and the two-dimensional fractal dimension of the flocs are realized by an image acquisition module, and the increase and decrease of the dosing amount are realized by a dosing module. The specific generation method of the one-dimensional fractal dimension and the two-dimensional fractal dimension is ordinary technical knowledge mastered by those skilled in the art.

[0011] More preferably, the flocculation sedimentation tank is divided into at least three flocculation stages connected in series, and corresponding image acquisition modules for acquiring the fractal dimension of the flocculation are arranged in each flocculation stage; during operation, the dosage is controlled according to the fractal dimension of the flocculation in each flocculation stage. In this way, the water quality of the effluent during continuous operation of the water plant can be ensured to be stable, and the error caused by the adhesion and overlap of the flocculation and uneven distribution can be minimized.

[0012] More preferably, a corresponding micro-interface generator is arranged in each coagulation stage, and the micro-interface generator is connected with an air compressor to generate micro-bubbles. During operation, when the one-dimensional fractal dimension is greater than the maximum value of the first threshold range and the two-dimensional fractal dimension is greater than the maximum value of the second threshold range, the micro-interface generator is started to improve the flocculation effect. The specific structure of the micro-interface generator is ordinary technical knowledge mastered by those skilled in the art.

[0013] More preferably, the first threshold range is 1.0-1.2, and the second threshold range is 1.6-1.8.

[0014] A dosage control system based on the fractal dimension of flocculation is used to implement the dosage control method described above.

[0015] More preferably, the dosage control system comprises an image acquisition module, a feedback control module and a dosing module, the image acquisition module is used for acquiring flocculation images of the flocculation sedimentation tank and pre-processing, and outputs one-dimensional fractal dimension and two-dimensional fractal dimension; the feedback control module is used for receiving the one-dimensional fractal dimension and the two-dimensional fractal dimension output by the image acquisition module, and controlling the dosing module to complete dosing according to the one-dimensional fractal dimension and the two-dimensional fractal dimension; the dosing module comprises a reagent storage tank, a frequency converter and a mechanical diaphragm metering pump, the reagent storage tank is used for storing reagents, and the feedback control module controls the mechanical diaphragm metering pump to dose through the frequency converter.

[0016] More preferably, the dosage control system further comprises a raw water quality acquisition module and a feedforward control module, the raw water quality acquisition module is used for monitoring the raw water quality, and the feedforward control module is connected with the raw water quality acquisition module and controls the dosing module to perform feedforward dosing according to the monitored raw water quality.

[0017] The present application has at least the following beneficial effects by adopting the above technical solutions.

[0018] I. Breakthrough the limitations of conventional dosage optimization methods, which must detect numerous external influencing factors (apparent parameters) and narrow the application range of reagents, shorten the lag time, and enhance the dynamic characteristics of the control system.

[0019] II. The morphological characteristics of individual flocs are easily affected by floc distribution, floc adhesion and uneven distribution on the image, which further leads to errors in the image-based discrimination results. DETAILED DESCRIPTION

[0020] To better enable those skilled in the art to better understand the essence of the present application, the specific embodiments of the present application are described in detail below.

[0021] A floc fractal dimension-based drug dosage control method is used for flocculation drug dosage control in tap water production, and the basic concept is as follows: one-dimensional and two-dimensional fractal dimensions of flocs in a flocculation sedimentation tank are collected; when the two-dimensional fractal dimension falls within a second threshold range, the current drug dosage is maintained; when the one-dimensional fractal dimension is greater than the maximum value of a first threshold range and the two-dimensional fractal dimension falls outside the second threshold range, the current drug dosage is reduced; and when the one-dimensional fractal dimension falls below the minimum value of the first threshold range and the two-dimensional fractal dimension falls outside the second threshold range, the current drug dosage is increased.

[0022] Compared with the prior art, the floc fractal dimension-based drug dosage control method provided by the present application uses the two-dimensional fractal dimension of flocs as a reference and combines the one-dimensional fractal dimension to adjust the drug dosage, breaks through the limitations of conventional drug dosage optimization methods that must detect numerous external influencing factors (apparent parameters) and narrow drug application ranges, shortens the lag time, enhances the dynamic characteristics of the control system, effectively reduces the discrimination errors caused by floc adhesion and uneven distribution, and ensures that the microscopic characteristics such as floc size and compactness fall within the optimal range, thereby ensuring the sedimentation effect, reducing the filtration pressure in the later stage, and reducing the operation cost of the water plant.

[0023] The one-dimensional and two-dimensional fractal dimensions of flocs are achieved by the image collection module, and the increase and decrease of the drug dosage are achieved by the drug feeding module. The specific generation method of the one-dimensional and two-dimensional fractal dimensions is common technical knowledge mastered by those skilled in the art.

[0024] In some embodiments, the flocculation sedimentation tank is divided into at least three flocculation stages connected in series, and corresponding image collection modules for collecting floc fractal dimensions are arranged corresponding to each flocculation stage; during operation, the drug dosage is controlled according to the floc fractal dimensions in each flocculation stage. In this way, the water quality during continuous operation of the water plant can be ensured to be stable, and the discrimination errors caused by floc adhesion and uneven distribution can be minimized.

[0025] In some embodiments, a micro-interface generator is arranged in each of the coagulation grids, and the micro-interface generator is connected to an air compressor to generate micro-bubbles. When the one-dimensional fractal dimension is greater than the maximum value of the first threshold range and the two-dimensional fractal dimension is greater than the maximum value of the second threshold range, the micro-interface generator is started to improve the flocculation effect. The specific structure of the micro-interface generator is common technical knowledge for those skilled in the art.

[0026] Running test 1.

[0027] The source water quality is selected from the Beijiang Puntang waterway, and the source water quality parameters are as follows: turbidity is 20-60 NTU, pH value is 7-7.6, water temperature is 24-35℃, CODMn is 1.5-2.1 mg / L, ammonia nitrogen is 0.011-0.021 mg / L, and nitrate nitrogen is 1.1-1.4 mg / L.

[0028] Running process: The flocculation tank is divided into three flocculation grids, and the first threshold range of each flocculation grid is 1.0-1.2, and the second threshold range is 1.6-1.8. Continuous operation for 30 days.

[0029] Output tap water quality: During continuous operation, the filter tank was not backwashed, and the water quality indicators met the "Drinking Water Health Standards" (GB5749-2022).

[0030] Running test 2.

[0031] The source water quality is selected from the Beijiang Puntang waterway, and the source water quality parameters are as follows: turbidity is 20-60 NTU, pH value is 7-7.6, water temperature is 24-35℃, CODMn is 1.5-2.1 mg / L, ammonia nitrogen is 0.011-0.021 mg / L, and nitrate nitrogen is 1.1-1.4 mg / L.

[0032] Running process: The flocculation tank is divided into three flocculation grids, and the first threshold range of each flocculation grid is 1.0-1.2, and the second threshold range is 1.6-1.8. Continuous operation for 30 days.

[0033] Output tap water quality: During continuous operation, the filter tank was not backwashed, and the water quality indicators met the "Drinking Water Health Standards" (GB5749-2022).

[0034] Running test 3.

[0035] The source water is selected from the Beijiang Puntang waterway, and the source water quality parameters are as follows: turbidity is 10-25 NTU, pH is 7.3-7.6, water temperature is 17-25 DEG C, dissolved oxygen is 7.4-10.3 mg / L, ammonia nitrogen is 1.5-2.5 mg / L, nitrite nitrogen is 0.1-0.3 mg / L, and CODMn is 2-3 mg / L.

[0036] Operation process: The flocculation tank is divided into three flocculation stages, the first threshold range of each flocculation stage is 1.0-1.2, and the second threshold range is 1.6-1.8. Continuous operation for 30 days.

[0037] Output tap water quality: During the continuous operation, the filter tank is not backwashed, and the water quality indicators meet the "Drinking Water Health Standards" (GB5749-2022).

[0038] It should be noted that the specific range of the first threshold range and the second threshold range can be an empirical value or an experimental value, and is not limited to the examples in the above running tests.

[0039] In some embodiments, the present application also provides a dosing control system based on the fractal dimension of flocs, which is used to implement the dosing control method as described above.

[0040] The dosing control system includes an image acquisition module, a feedback control module and a dosing module. The image acquisition module is used to acquire flocculation images of the flocculation and sedimentation tank and perform preprocessing, output one-dimensional fractal dimension and two-dimensional fractal dimension; the feedback control module is used to receive the one-dimensional fractal dimension and two-dimensional fractal dimension output by the image acquisition module, and control the dosing module to complete dosing according to the one-dimensional fractal dimension and two-dimensional fractal dimension; the dosing module includes a reagent storage tank, a frequency converter and a mechanical diaphragm metering pump. The reagent storage tank is used to store reagents, and the feedback control module controls the mechanical diaphragm metering pump to dose through the frequency converter.

[0041] Further, the dosing control system also includes a raw water quality acquisition module and a feedforward control module. The raw water quality acquisition module is used to monitor the raw water quality, and the feedforward control module is connected to the raw water quality acquisition module and controls the dosing module to perform feedforward dosing according to the monitored raw water quality.

[0042] It should be understood that various parts of the present application can be implemented in hardware, software, firmware or a combination thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or their combinations, can be used to implement the hardware: discrete logic circuitry having logic gates for implementing logic functions upon data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0043] Those skilled in the art can understand that all or part of the steps carried out by the above-mentioned embodiment method can be completed by a program instructing relevant hardware, and the program can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0044] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and modified by those skilled in the art without contradiction.

[0045] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for controlling the dosage of flocculants in water treatment, based on the fractal dimension of the flocs, characterized in that, The one-dimensional fractal dimension and the two-dimensional fractal dimension of the floc in the flocculation sedimentation tank are collected; when the two-dimensional fractal dimension falls within the second threshold range, the current dosage is maintained; When the one-dimensional fractal dimension is greater than the maximum value of the first threshold range and the two-dimensional fractal dimension falls outside the second threshold range, the current dosage is reduced; When the one-dimensional fractal dimension is less than the minimum value of the first threshold range and the two-dimensional fractal dimension falls outside the second threshold range, the current dosage is increased; the one-dimensional fractal dimension and the two-dimensional fractal dimension of the floc are obtained by the image collection module, and the increase or decrease of the dosage is realized by the dosing module; the value of the first threshold range is 1.0-1.2, and the value of the second threshold range is 1.6-1.

8.

2. The method according to claim 1, wherein The flocculation sedimentation tank is divided into at least three flocculation stages connected in series, and corresponding image collection modules for collecting the fractal dimension of the floc are arranged in each flocculation stage; during operation, the dosage is controlled according to the fractal dimension of the floc in each flocculation stage.

3. The method according to claim 2, wherein the method is characterized by, A corresponding micro-interface generator is arranged in each flocculation stage, and the micro-interface generator is connected with an air compressor to generate micro-bubbles; during operation, when the one-dimensional fractal dimension is greater than the maximum value of the first threshold range and the two-dimensional fractal dimension is greater than the maximum value of the second threshold range, the micro-interface generator is started to improve the flocculation effect.

4. A medicine administration control system based on a fractal dimension of a floc, characterized by A dosage control method based on the fractal dimension of the floc is realized, and the dosage control system comprises an image collection module, a feedback control module and a dosing module; the image collection module is used for acquiring flocculation images of the flocculation sedimentation tank and pre-processing, and outputs one-dimensional fractal dimension and two-dimensional fractal dimension; the feedback control module is used for receiving the one-dimensional fractal dimension and the two-dimensional fractal dimension output by the image collection module, and controlling the dosing module to complete dosing according to the one-dimensional fractal dimension and the two-dimensional fractal dimension; and the dosing module is used for realizing dosing operation.

5. The drug delivery control system based on fractal dimension of floc according to claim 4, wherein The dosing module comprises a medicament storage tank, a frequency converter and a mechanical diaphragm metering pump; the medicament storage tank is used for storing medicaments, and the feedback control module controls the mechanical diaphragm metering pump to dose through the frequency converter.

6. The drug delivery control system based on fractal dimension of floc according to claim 4, wherein The dosage control system further comprises a raw water quality collection module and a feedforward control module; the raw water quality collection module is used for monitoring the quality of raw water, and the feedforward control module is connected with the raw water quality collection module and controls the dosing module to dose in a feedforward manner according to the monitored quality of raw water.