Intelligent aeration control system for realizing low-DO intermittent aeration regulation and control

Abstract

The invention relates to the technical field of aeration control, in particular to an intelligent aeration control system for realizing low-DO intermittent aeration regulation and control. According to the method, the effective ventilation flow coefficient at each moment is obtained according to the opening degree of the regulating valve and the pressure of the pipe network at each moment; according to the change trend of the effective ventilation flow coefficients and the biochemical potential values at different moments, the valve closing rate and the potential fluctuation rate at each moment are obtained; according to the distribution of the valve closing rate and the potential fluctuation rate at each moment, the relative closing intensity and the relative reaction activeness at each moment are obtained; obtaining a reaction endpoint characteristic coefficient of each moment according to the relative closing intensity and the relative reaction activeness of each moment; according to the time characteristics at different moments and the characteristic coefficient distribution of the reaction endpoint, obtaining the reaction stagnation significance at each moment, and regulating and controlling the aeration. According to the method, the reaction stagnation significance at each moment is accurately obtained, so that the accuracy of aeration regulation and control is improved.

Description

Technical Field

[0001] This invention relates to the field of aeration control technology, and more specifically to an intelligent aeration control system for achieving low DO intermittent aeration regulation. Background Technology

[0002] In intermittent aeration processes, in order to reduce energy consumption and optimize denitrification efficiency, a low dissolved oxygen (DO) operating mode is often used to identify the endpoint of the nitrification reaction, and the aeration stop time is determined based on the DO jump characteristics at the reaction endpoint. However, in the low DO constant control mode, the PID controller will automatically close the regulating valve to maintain DO at a low and constant level, which physically masks the abrupt change characteristics of DO concentration, causing the conventional judgment method based on DO threshold to fail.

[0003] In existing technologies, monitoring changes in the opening of regulating valves is used to assist in judgment. However, different regulating valve specifications and PID parameters result in varying closing rates, making it difficult to set a universal action judgment threshold. At the same time, fluctuations in pipeline pressure will change the pressure difference before and after the valve, causing the opening to be disproportionate to the actual air volume. Furthermore, fluctuations in influent load make it easy to misjudge fixed thresholds, resulting in poor accuracy in identifying the reaction endpoint and poor effectiveness of aeration control. Summary of the Invention

[0004] To address the technical problems of poor accuracy in identifying reaction endpoints and poor effectiveness of aeration control caused by differences in regulating valve response and interference from pipeline pressure and load fluctuations, the present invention aims to provide an intelligent aeration control system for achieving intermittent aeration regulation with low DO. The specific technical solution adopted is as follows: This invention proposes an intelligent aeration control system for achieving low-DO intermittent aeration regulation, the system comprising: The data acquisition module is used to acquire the valve opening, pipeline pressure, and biochemical potential value at any given moment. The rate characteristic analysis module is used to obtain the effective ventilation flow coefficient at each moment based on the valve opening and pipeline pressure at each moment; and to obtain the valve closing rate and potential fluctuation rate at each moment based on the changing trends of the effective ventilation flow coefficient and biochemical potential value at different moments. The reaction stagnation analysis module is used to obtain the relative closing strength and relative reactive activity at each moment based on the valve closing rate and potential fluctuation rate distribution at each moment; to obtain the reaction endpoint characteristic coefficient at each moment based on the relative closing strength and relative reactive activity at each moment; and to obtain the reaction stagnation significance at each moment based on the time characteristics at different moments and the distribution of the reaction endpoint characteristic coefficient. The aeration control module is used to adjust the aeration based on the degree of reaction stagnation at different times.

[0005] Furthermore, the method for obtaining the effective ventilation flow rate coefficient includes: Obtain the difference between the pipeline pressure and the preset back pressure at each moment. If the difference is greater than the preset difference threshold, calculate the root value of the difference result and use it as the driving differential pressure factor. The ratio of the regulating valve opening to the preset maximum opening value is obtained at each moment. The difference between the ratio result and the positive integer 1 is calculated as the regulating index. Based on the regulating index, a power operation is performed with the preset valve adjustable ratio as the base to obtain the relative flow coefficient. The product of the relative flow coefficient and the driving pressure difference factor is obtained as the effective ventilation flow coefficient at each moment. If the difference is less than or equal to the preset difference threshold, the effective ventilation flow rate coefficient at each moment is set to 0.

[0006] Furthermore, the method for obtaining the valve closing rate includes: Based on the changing trends of the effective ventilation flow rate coefficient and biochemical potential value at different times, the effective smoothed ventilation flow rate coefficient and biochemical smoothed potential value at each time are obtained. Obtain the difference between the effective ventilation smoothing flow coefficient between the first and last moments of the historical action range at each moment. If the difference is greater than the preset difference threshold, calculate the ratio between the difference result and the duration of the historical action range, and use it as the valve closing rate at each moment. If the difference is less than or equal to the preset difference threshold, the valve closing rate at each moment is set to 0.

[0007] Furthermore, the method for obtaining the potential fluctuation rate includes: Obtain the absolute value of the difference between the two ends of the historical response range at each moment, and calculate the ratio between the absolute value of the difference and the duration of the historical response range as the potential fluctuation rate at each moment.

[0008] Furthermore, the method for obtaining the effective ventilation smoothing flow coefficient and the biochemical smoothing potential value includes: For any data point in the effective ventilation flow rate coefficient or biochemical potential value, the average value of all data points within a preset time window prior to each time point is obtained as the smoothed data for each time point. The smoothed data includes the effective ventilation smoothed flow rate coefficient or biochemical smoothed potential value.

[0009] Furthermore, the method for obtaining the relative closure strength includes: The maximum adjustment rate is preset, and the ratio of the valve closing rate to the preset maximum adjustment rate at each moment is calculated as the relative closing strength at each moment.

[0010] Furthermore, the method for obtaining the relative reactivity includes: A preset baseline response rate is used to calculate the ratio of the potential fluctuation rate to the preset baseline response rate at each moment, which is taken as the relative response activity at each moment.

[0011] Furthermore, the method for obtaining the characteristic coefficients of the reaction endpoint includes: If the relative shut-off intensity at each moment is greater than the preset action dead zone threshold, the relative shut-off intensity at each moment and the relative responsiveness of the preset multiple are used to form a two-dimensional state vector. Obtain the cosine similarity between the two-dimensional state vector and the preset endpoint reference vector at each time step, and use it as the response endpoint feature coefficient at each time step; If the relative closing intensity at each moment is less than or equal to the preset action dead zone threshold, the reaction endpoint characteristic coefficient at each moment is set to 0.

[0012] Furthermore, the method for obtaining the significance of the reaction stagnation includes: If the time between each moment and the initial moment is less than the preset learning time, select the moment with the largest reaction endpoint feature coefficient among all moments in the neighborhood of each moment, and obtain the sum of the maximum reaction endpoint feature coefficient and the preset minimum safety margin as the local reaction endpoint feature observation value; select the maximum value between the local reaction endpoint feature observation value and the preset feature baseline as the reaction endpoint feature baseline value for each moment. If the duration between each moment and the initial moment is greater than or equal to the preset learning duration, the reaction endpoint feature benchmark value corresponding to the preset learning duration will be used as the reaction endpoint feature benchmark value for each moment. The ratio of the response endpoint characteristic coefficient to the response endpoint characteristic baseline value at each time step is obtained as the significance of response stagnation at each time step.

[0013] Furthermore, the regulation of aeration includes: If the duration between a given moment and the initial moment is greater than or equal to the preset learning duration, and the reaction stagnation at a given moment is significantly greater than the preset trigger threshold, the corresponding moment is taken as the trigger moment; the duration of the range of consecutive trigger moments is obtained, and if the duration is greater than the preset duration threshold, aeration is stopped.

[0014] The present invention has the following beneficial effects: This invention obtains the effective aeration flow coefficient at each moment based on the valve opening and pipeline pressure, reflecting the trend of the actual gas supply capacity after pressure differential compensation. Based on the changing trends of the effective aeration flow coefficient and biochemical potential value at different moments, it obtains the valve closing rate and potential fluctuation rate at each moment, quantifying the negative change rate of the gas supply flow and the absolute change rate of the potential reading. Based on the distribution of the valve closing rate and potential fluctuation rate at each moment, it obtains the relative closing intensity and relative reactive activity at each moment, reflecting the degree of abruptness of gas supply inhibition and the activity of the biochemical reaction. Based on the relative closing intensity and relative reactive activity at each moment, it obtains the reaction endpoint characteristic coefficient at each moment, reflecting the degree to which the biochemical reaction endpoint is met. Based on the time characteristics and the distribution of the reaction endpoint characteristic coefficient at different moments, it obtains the reaction stagnation significance at each moment, thus regulating aeration. This invention improves the accuracy of aeration regulation by accurately obtaining the reaction stagnation significance at each moment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a structural block diagram of an intelligent aeration control system for realizing low DO intermittent aeration regulation, provided in one embodiment of the present invention. Figure 2 A flowchart illustrating a method for obtaining the characteristic coefficients of a reaction endpoint according to an embodiment of the present invention; Figure 3 This is a flowchart illustrating a method for obtaining the significance of reaction stagnation according to an embodiment of the present invention. Detailed Implementation

[0017] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of an intelligent aeration control system for achieving low-DO intermittent aeration regulation according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0019] The following description, in conjunction with the accompanying drawings, details a specific scheme for an intelligent aeration control system provided by the present invention for achieving low DO intermittent aeration regulation.

[0020] Please see Figure 1 The diagram illustrates a structural block diagram of an intelligent aeration control system for implementing low-DO intermittent aeration regulation according to an embodiment of the present invention. The system specifically includes: a data acquisition module 101, a rate characteristic analysis module 102, a reaction stagnation analysis module 103, and an aeration control module 104. The data acquisition module 101 is used to acquire the opening degree of the regulating valve, the pipeline pressure, and the biochemical potential value at each moment.

[0021] In the embodiments of this invention, considering that different control valve specifications and PID parameters lead to varying closing rates, and that pipeline pressure fluctuations can alter the pressure difference before and after the valve, monitoring only the control valve opening change to assist in judgment is inaccurate. Therefore, the system collects and analyzes the original control valve opening, pipeline pressure, and biochemical potential values ​​via fieldbus. The control valve opening reflects the action command sent by the control system to the air control valve, expressed as a percentage. A pressure sensor is installed before the control valve to reflect the gas pressure in the main air pipe located on the inlet side of the control valve, i.e., the pressure before the valve, expressed in kilopascals. Biochemical potential value reflects the potential reading of the redox environment in the biochemical tank, and the unit is millivolts (mV).

[0022] It should be noted that, considering the potential time delays and jitter in data transmission from different sensors, to prevent false drastic actions calculated by the system due to momentary sensor packet loss or electrical faults, thus causing malfunctions, it is necessary to perform time-series alignment and validity verification on the data. This includes: if the pipeline pressure is negative at any given moment, or the valve opening exceeds the preset physical range, the data at that moment will be held at zero order, that is, the data from the previous moment will be assigned to the corresponding moment to ensure the continuity and safety of subsequent calculation inputs; whereby, based on existing knowledge, the preset physical range is 0 when the valve is fully closed. To full speed 100 .

[0023] It should be noted that in one embodiment of the present invention, the time interval is 1 second; in other embodiments of the present invention, the time interval may be set according to specific circumstances, and will not be limited or described in detail here.

[0024] Based on this, the valve opening, pipeline pressure, and biochemical potential value at each moment are obtained for subsequent processing.

[0025] The rate characteristic analysis module 102 is used to obtain the effective ventilation flow coefficient at each moment based on the opening degree of the regulating valve and the pipeline pressure at each moment; and to obtain the valve closing rate and potential fluctuation rate at each moment based on the changing trends of the effective ventilation flow coefficient and biochemical potential value at different moments.

[0026] Considering the interference of pipeline pressure fluctuations on flow rate judgment, the opening degree of the regulating valve mostly reflects the action sent to the regulating valve by the system. The larger the opening degree, the greater the flow. The preset back pressure reflects the total resistance under the valve. The greater the total resistance, the more the voltage fluctuation of the pipeline is affected, which is more helpful for quantifying the flow rate. Based on the opening degree of the regulating valve and the pipeline pressure at each moment, the effective ventilation flow coefficient at each moment is obtained.

[0027] Preferably, in one embodiment of the present invention, the method for obtaining the effective ventilation flow rate coefficient includes: Obtain the difference between the pipeline pressure and the preset back pressure at each moment. If the difference is greater than the preset difference threshold, calculate the root value of the difference result and use it as the driving differential pressure factor. It should be noted that, based on Bernoulli's principle, the flow rate is proportional to the square root of the pressure difference. Therefore, the root value of the difference between the pipeline pressure and the preset back pressure at each moment is calculated. In the embodiments of the present invention, the preset back pressure reflects the comprehensive resistance pressure at the end of the aeration system, and is obtained based on the static water pressure of the aeration system and the fixed value of the pipeline resistance set in advance. The static water pressure corresponding to the installation depth of the aeration head is obtained according to the empirical formula, as well as the empirical value of the sum of the opening resistance of the aeration head diaphragm and the pipeline resistance after the valve. The sum of the two is used as the preset back pressure. The empirical value range of the sum of the opening resistance of the aeration head diaphragm and the pipeline resistance after the valve is set to 5-10 kPa, which can be set according to specific circumstances.

[0028] Obtain the ratio of the regulating valve opening to the preset maximum opening at each moment, calculate the difference between the ratio result and the positive integer 1, and use it as the regulating index; based on the regulating index, perform a power operation with the preset valve adjustable ratio as the base, and use it as the relative flow coefficient; obtain the product of the relative flow coefficient and the driving pressure difference factor, and use it as the effective ventilation flow coefficient at each moment; if the difference is less than or equal to the preset difference threshold, set the effective ventilation flow coefficient at each moment to 0.

[0029] Based on this, the larger the opening of the regulating valve, the greater the flow rate, and therefore the larger the regulating index is relative to when it is fully closed, the larger the driving differential pressure factor, and the more flow rate is driven, resulting in a larger effective ventilation flow coefficient.

[0030] It should be noted that the difference reflects the effective pressure difference before and after the valve. The larger the positive value of the effective pressure difference, the better it reflects the greater the pipeline pressure and the greater the ventilation flow at each moment. Therefore, in the embodiments of the present invention, the preset difference threshold is 0 to avoid imaginary numbers in the square root calculation that could cause the program to crash. In an embodiment of the present invention, the preset maximum opening value is 100, which is obtained in advance based on the inherent mechanical characteristics of the regulating valve. The valve adjustability ratio determines the curvature of the curve. The larger the valve adjustability ratio, the more concave the curve, and the smaller the estimated flow rate at a small opening. The preset valve adjustability ratio setting range for general industrial valves is 30-50, which can be set according to specific circumstances, and will not be elaborated here.

[0031] In one embodiment of the present invention, the formula for the effective ventilation flow rate coefficient is expressed as: ;in, Indicates the first The effective ventilation flow rate coefficient at any given time; Indicates the first The valve opening at any given time; This indicates the maximum preset opening value; Indicates the adjustment index; Indicates the preset valve adjustment ratio; As the first The pipeline pressure at any given time; Indicates the preset back pressure; This represents the function that takes the maximum value. Indicates taking the first The difference between the pipeline pressure at any given time and the preset back pressure, and the maximum value of 0; This indicates the search for the root value.

[0032] The effective ventilation flow coefficient reflects the change trend of the actual gas's ability to enter the water body through the valve. The smaller the effective ventilation flow coefficient, the smaller the change trend of the gas's ability to enter the water body, and the greater the valve closing rate. The biochemical potential value reflects the potential reading of the redox environment in the biochemical tank. The greater the change in the biochemical potential value within the time range, the greater the fluctuation rate, which helps to quantify the potential fluctuation rate. Based on the change trends of the effective ventilation flow coefficient and the biochemical potential value at different times, the valve closing rate and potential fluctuation rate at each time moment can be obtained.

[0033] Preferably, in one embodiment of the present invention, the method for obtaining the valve closing rate includes: Based on the changing trends of the effective ventilation flow rate coefficient and biochemical potential value at different times, the effective smoothed ventilation flow rate coefficient and biochemical smoothed potential value at each time are obtained. Preferably, in one embodiment of the present invention, the method for obtaining the effective ventilation smoothing flow coefficient and the biochemical smoothing potential value includes: For any data point in the effective ventilation flow rate coefficient or biochemical potential value, the average value of all data points within a preset time window prior to each time point is obtained as the smoothed data for each time point. The smoothed data includes the effective ventilation smoothed flow rate coefficient or biochemical smoothed potential value.

[0034] It should be noted that the gas-liquid mixing during aeration generates fluid turbulence, resulting in high-frequency random noise in the sensor readings. Smoothing is necessary. If the time window is too short, it will exhibit drastic random jumps, making it impossible to discern the data's trend. If the time window is too long, it will lead to detection lag, resulting in poor smoothing. In one embodiment of the invention, based on relevant historical experience, the preset time window is set to smooth the range formed by each moment and the previous 60 historical moments. In other embodiments of the invention, the size of the preset time window can be set according to specific circumstances, and will not be limited or elaborated upon here.

[0035] Obtain the difference between the effective ventilation smoothing flow coefficient between the first and last moments within the historical action range at each moment. If the difference is greater than the preset difference threshold, calculate the ratio between the difference result and the duration within the historical action range, and use it as the valve closing rate at each moment. If the difference is less than or equal to the preset difference threshold, set the valve closing rate at each moment to 0.

[0036] It should be noted that, considering that the full stroke time of the regulating valve usually occurs within a few seconds, if the analysis range is too long, the calculated closing rate will be lowered, making it impossible to accurately capture the abrupt valve closing action. Therefore, the range setting needs to be small. In one embodiment of the present invention, the method for obtaining the historical action range based on relevant historical experience includes using each moment as a reference and a range consisting of 10 historical moments, including the reference moment. In other embodiments of the present invention, the size of the historical action range can be specifically set according to the specific situation, which will not be limited or elaborated here.

[0037] In one embodiment of the present invention, the formula for the valve closing rate is expressed as: ; Indicates the first The valve closing rate at any given time; Indicates the first Time span of historical actions The effective ventilation smoothing flow rate coefficient at the corresponding moment, i.e. the effective ventilation smoothing flow rate coefficient at the beginning moment within the historical action range; Indicates the first The effective ventilation smoothing flow rate coefficient at any given time, i.e., the effective ventilation smoothing flow rate coefficient at the end of the historical action range; Indicates the duration of the historical action range; This represents the function that takes the maximum value.

[0038] It should be noted that the duration of the historical action range can be obtained by calculating the range between the two ends of the historical action range. The range represents the difference between the maximum and minimum values.

[0039] It should be noted that, in order to evaluate the valve closing rate, the ventilation flow rate gradually decreases with time. The effective ventilation smoothing flow rate coefficient at each historical moment is greater than that at every moment, so that the effective ventilation smoothing flow rate coefficient at the beginning of the historical action range at each moment is greater than that at the end. The difference between the effective ventilation smoothing flow rate coefficients at the beginning and end moments is greater than 0, indicating that the flow rate is decreasing, thus quantifying the closing rate. Conversely, if the flow rate increases or remains unchanged, the valve does not close, and there is no closing rate. Therefore, in the embodiments of the present invention, the preset difference threshold is set to 0.

[0040] Preferably, in one embodiment of the present invention, the method for obtaining the potential fluctuation rate includes: Obtain the absolute value of the difference between the two ends of the historical response range at each moment, and calculate the ratio between the absolute value of the difference and the duration of the historical response range as the potential fluctuation rate at each moment.

[0041] In one embodiment of the present invention, the formula for the potential fluctuation rate is expressed as: ;in, Indicates the first The rate of potential fluctuation at any given moment; Indicates the first The biochemical smoothing potential value at time t, i.e., the biochemical smoothing potential value at the end of the historical action range; Indicates the first Time span of historical response range The biochemical smoothing potential value at the corresponding moment, that is, the biochemical smoothing potential value at the beginning of the historical action range; Indicates the duration of the historical response range; This indicates taking the absolute value.

[0042] It should be noted that the duration of the historical reaction range can be obtained by calculating the range between the two ends of the historical reaction range. The range represents the difference between the calculated maximum and minimum values. The absolute value of the difference between the two ends of the biochemical smoothing potential reflects the activity level of the biochemical reaction. The larger the absolute value of the difference, the more the biochemical smoothing potential will change. The greater the activity, the more likely it is that the microorganisms are consuming the substrate, and the greater the potential fluctuation rate. The smaller the absolute value of the difference, the more stable the biochemical smoothing potential is, the closer it is to the equilibrium state, the more the substrate is depleted, and the smaller the potential fluctuation rate.

[0043] It should be noted that the changes in potential within the biological treatment tank are caused by the metabolism of microorganisms in the water. Due to mass transfer limitations, these changes are very slow and smooth, and contain a large amount of high-frequency random noise. If the analysis range is small, it may be affected by noise, resulting in low reliability of potential fluctuations. Therefore, the range needs to be set large enough to reflect stable biochemical reaction trends. In one embodiment of the present invention, the method for obtaining the historical reaction range based on relevant historical experience includes using each moment as a baseline and a range consisting of 60 historical moments, including the baseline moment. In other embodiments of the present invention, the size of the historical reaction range can be set according to specific circumstances, and will not be limited or elaborated here.

[0044] The reaction stagnation analysis module 103 is used to obtain the relative closing strength and relative reactive activity at each moment based on the valve closing rate and potential fluctuation rate distribution at each moment; to obtain the reaction endpoint characteristic coefficient at each moment based on the relative closing strength and relative reactive activity at each moment; and to obtain the reaction stagnation significance at each moment based on the time characteristics at different moments and the distribution of the reaction endpoint characteristic coefficient.

[0045] The valve closing rate reflects the degree to which the regulating valve cuts off the oxygen source; the greater the valve closing rate, the greater the relative closing strength. The potential fluctuation rate reflects the activity of biochemical reaction kinetics; the greater the potential fluctuation rate, the greater the relative reaction activity. Based on the valve closing rate and potential fluctuation rate distribution at each moment, the relative closing strength and relative reaction activity at each moment can be obtained.

[0046] Preferably, in one embodiment of the present invention, the method for obtaining the relative shut-off strength includes: The maximum adjustment rate is preset, and the ratio of the valve closing rate to the preset maximum adjustment rate at each moment is calculated as the relative closing strength at each moment.

[0047] It should be noted that, in order to eliminate the influence of the full stroke time of the control valve on the rate magnitude, and to map the physical rate to a dimensionless relative intensity, in the embodiments of the present invention, the preset maximum control rate can be obtained from the valve manual by referring to the time required for the control valve to run at a constant speed from 100% fully open to 0% fully closed. The effective ventilation flow coefficients at 100% and 0% are calculated respectively, and the difference between the effective ventilation flow coefficients at 100% and 0% is divided by the required time. The ratio result is used as the preset maximum control rate; wherein, the time is calculated in seconds.

[0048] Preferably, in one embodiment of the present invention, the method for obtaining relative reactivity includes: A preset baseline response rate is used to calculate the ratio of the potential fluctuation rate to the preset baseline response rate at each moment, which is taken as the relative response activity at each moment.

[0049] It should be noted that, in order to eliminate the influence of different biochemical pool volumes on the rate magnitude, the physical rate is mapped to a dimensionless relative intensity; in the embodiments of the present invention, the preset reference reaction rate is represented by the typical rate of change of the potential during the vigorous phase of the biochemical reaction, and the preset reference reaction rate is set according to relative historical experience. In other embodiments of the present invention, the preset baseline reaction rate can be set according to specific circumstances, and will not be limited or described in detail here.

[0050] The relative shut-off strength reflects the degree of gas supply suppression. The greater the relative shut-off strength, the faster the valve operates and the closer it is to the reaction endpoint. The relative reactivity reflects the activity of the biochemical reaction. The greater the activity, the greater the relative biochemical reactivity, and the better it reflects the characteristics of the reaction endpoint at each moment. Based on the relative shut-off strength and relative reactivity at each moment, the reaction endpoint characteristic coefficient at each moment is obtained.

[0051] Preferably, in one embodiment of the present invention, the method for obtaining the reaction endpoint characteristic coefficients is described in [reference needed]. Figure 2 It shows a flowchart of a method for obtaining the characteristic coefficients of the reaction endpoint, including: Step S201: If the relative closing intensity at each moment is greater than the preset action dead zone threshold, construct a two-dimensional state vector by combining the relative closing intensity at each moment with the relative responsiveness of the preset multiple.

[0052] In one embodiment of the present invention, the two-dimensional state vector is represented as follows: ;in, Indicates the first The two-dimensional state vector at time t; Indicates the first The relative closure intensity at any given moment; Indicates the first Relative responsiveness at any given moment; Indicates the preset multiple; This represents the transpose symbol.

[0053] It should be noted that, in order to ensure that the reaction characteristics reach a high value when the biochemical reaction is extremely weak, the relative reactivity is weighted. The larger the weighting value, the more significant the change in the biochemical reaction. In the embodiments of the present invention, the preset multiple is set to 1.2 based on relevant historical experience. The smaller the relative reactivity, the larger the reaction endpoint characteristic coefficient. During aeration idle or steady-state operation, minute sensor noise, after normalization and amplification, may produce false non-zero exponents. Therefore, a small value is set for the preset dead zone threshold so that small changes reflect that the system is in a steady state or idle, avoiding judgment as the reaction endpoint. In one embodiment of the present invention, the preset dead zone threshold is set to 0.02 based on relevant historical experience. In other embodiments of the present invention, the preset multiple and the preset dead zone threshold can be set according to specific circumstances, and are not limited or elaborated here.

[0054] Step S202: Obtain the cosine similarity between the two-dimensional state vector and the preset endpoint reference vector at each time step, and use it as the response endpoint feature coefficient at each time step.

[0055] It should be noted that, under the low DO constant control mode, the ideal endpoint conditions for nitrification are as follows: due to ammonia nitrogen depletion, the oxygen consumption rate decreases, the DO concentration attempts to rise, and the PID controller performs a valve-closing action to maintain constant DO, resulting in a positive relative closing intensity; simultaneously, due to substrate depletion, the biochemical reaction kinetics tend to equilibrium, the ORP potential change rate is extremely low, resulting in the relative reaction activity approaching zero; in other embodiments of the present invention, the preset endpoint reference vector is set to .

[0056] It should be noted that cosine similarity reflects the consistency of the state direction between vectors. A higher similarity, approaching 1, indicates that the state direction is closer to the endpoint reference vector, and the corresponding endpoint characteristic coefficient is larger. Cosine similarity is calculated by dividing the dot product of the vectors by their magnitudes. Considering that relative closing strength and relative responsiveness may be zero, making the denominator zero and the formula meaningless, a manually set non-zero minimum positive number is added to the denominator. The value of this number is specifically set according to the range of values ​​in the denominator. The specific methods used are well-known to those skilled in the art and will not be elaborated upon here.

[0057] Step S203: If the relative closing intensity at each moment is less than or equal to the preset action dead zone threshold, set the reaction endpoint characteristic coefficient at each moment to 0.

[0058] Based on this, considering the dynamic dead zone, the response endpoint characteristic coefficients at each moment are analyzed to avoid misjudgment of the endpoint caused by the accumulation of small disturbances. The response endpoint characteristic coefficients are dimensionless parameters with a value range of 0-1.

[0059] The characteristic coefficient of the reaction endpoint reflects the degree to which it conforms to the characteristics of the biochemical reaction endpoint. The larger the characteristic coefficient of the reaction endpoint, the closer it is to the reaction endpoint, and the greater the significance of the reaction stagnation. The significance of the reaction stagnation at each time point is obtained based on the time characteristics at different times and the distribution of the characteristic coefficient of the reaction endpoint.

[0060] Preferably, in one embodiment of the present invention, the method for obtaining the significance of reaction stagnation is described in [reference needed]. Figure 3 It shows a flowchart of a method for obtaining the significance of response stagnation, including: Step S301: If the duration between each time point and the initial time point is less than the preset learning duration, select the time point with the largest reaction endpoint feature coefficient among all time points in the neighborhood of each time point, and obtain the sum of the maximum reaction endpoint feature coefficient and the preset minimum safety margin as the local reaction endpoint feature observation value; select the maximum value between the local reaction endpoint feature observation value and the preset feature baseline as the reaction endpoint feature baseline value for each time point.

[0061] It should be noted that, in the embodiments of the present invention, for each time interval between the initial time interval and the time interval less than the preset learning time interval, the neighborhood range of each time interval is the range formed by taking each time interval as the reference and all times between each time interval and the initial time interval, including the reference time interval.

[0062] It should be noted that the duration between each moment and the initial moment is the difference between each moment and the initial moment. The larger the difference, the longer the duration. The initial moment is the moment when aeration begins, and it is used as the zero point for timing. In one embodiment of the present invention, at the initial stage of each intermittent aeration cycle, the microorganisms are in a period of intense adsorption and degradation of newly introduced pollutants. In order to reflect the comparison benchmark of the load level at the initial stage of aeration, a learning time covering the typical initial adsorption and degradation period is preset based on relevant historical experience and set to 15 minutes. The difference between each moment and the initial moment is compared with the size of 15 minutes. The preset minimum safety margin is set to 0.05. The preset characteristic benchmark bottom limit is set to 0.15. In other embodiments of the present invention, the preset learning time, preset minimum safety margin, and preset characteristic benchmark bottom limit can be set according to specific circumstances, and are not limited or elaborated here.

[0063] Step S302: If the duration between each moment and the initial moment is greater than or equal to the preset learning duration, the reaction endpoint feature benchmark value corresponding to the moment with the preset learning duration is used as the reaction endpoint feature benchmark value for each moment.

[0064] At the initial stage of each intermittent aeration cycle, the microorganisms are in a period of intense adsorption and degradation of newly introduced pollutants, the biochemical reaction is most active, and the system background noise is the greatest. The baseline value of the reaction endpoint obtained during the learning stage quantifies the maximum intensity of the false endpoint caused by the influence of system background noise in the initial stage of aeration. Therefore, the maximum baseline value of the reaction endpoint obtained within the preset learning time is used as the baseline value for each subsequent moment in the calculation.

[0065] Step S303: Obtain the ratio of the response endpoint characteristic coefficient to the response endpoint characteristic benchmark value at each time point, as the significance of response stagnation at each time point.

[0066] After the initial aeration stage, as the nitrification reaction proceeds, ammonia nitrogen is gradually consumed. The PID controller begins to perform suppression actions, and the biochemical reaction tends to stagnate. This results in a larger reaction endpoint characteristic coefficient. If the reaction endpoint characteristic coefficient is larger relative to the reaction endpoint characteristic benchmark value, it indicates that the biochemical reaction endpoint characteristic has changed significantly relative to the reaction endpoint characteristic during the learning stage, and the reaction stagnation is more significant.

[0067] The aeration control module 104 is used to adjust the aeration according to the significance of reaction stagnation at different times.

[0068] The greater the significance of reaction stagnation, the more pronounced the stagnation characteristics, and the closer the biochemical reaction is to stagnation.

[0069] Preferably, in one embodiment of the present invention, the method for obtaining the aeration control includes: If the duration between a given moment and the initial moment is greater than or equal to the preset learning duration, and the reaction stagnation at a given moment is significantly greater than the preset trigger threshold, the corresponding moment is taken as the trigger moment; the duration of the range of consecutive trigger moments is obtained, and if the duration is greater than the preset duration threshold, aeration is stopped.

[0070] It should be noted that, considering that the system is in the initial stage of the reaction during the learning time and there is no reaction endpoint, if the judgment is made within the preset learning time range, the initial signal fluctuations may cause false exposure stoppage. Therefore, for the time between the moment and the initial moment that is greater than or equal to the preset learning time, the trigger threshold and continuous duration are analyzed to determine whether to stop the exposure.

[0071] It should be noted that in the initial stage of water influent, the pollutant concentration is high, microbial adsorption and degradation are active, the relative reaction activity is greater, DO is lower, and the PID is in the open or high-opening maintenance stage, without valve closing, which makes the reaction endpoint characteristic coefficient closer to 0 and the reaction endpoint characteristic benchmark value lower. After exceeding the preset learning time, as the nitrification reaction proceeds, the closer to the reaction endpoint, the more the reaction endpoint characteristic coefficient will increase significantly, getting closer to 1, while the reaction endpoint characteristic benchmark value remains at a low limit, causing the reaction stagnation significance to fluctuate between 0 and 6. The greater the reaction stagnation significance, the more the biochemical reaction tends to be in the later stage. In one embodiment of the present invention, the preset trigger threshold is set to 3 based on relevant historical experience, and the preset duration threshold is set to 3 minutes. In other embodiments of the present invention, the preset trigger threshold and preset duration threshold can be set according to specific circumstances, and are not limited or elaborated here.

[0072] It should be noted that if it is determined that aeration has been stopped and the nitrification reaction has completely ended, the opening of the regulating valve must be forcibly set to [value missing]. It sends an unloading or shutdown signal to the blower control system to cut off the oxygen supply; it resets the system status and prepares for the next round of aeration start signal, effectively overcoming the hidden characteristics of the reaction endpoint and the interference of operating condition fluctuations under low DO constant control.

[0073] In summary, this invention obtains the effective aeration flow rate coefficient at each moment based on the valve opening and pipeline pressure; it obtains the valve closing rate and potential fluctuation rate at each moment based on the changing trends of the effective aeration flow rate coefficient and biochemical potential value at different moments; it obtains the relative closing intensity and relative reactivity at each moment based on the distribution of the valve closing rate and potential fluctuation rate at each moment; it obtains the reaction endpoint characteristic coefficient at each moment based on the relative closing intensity and relative reactivity at each moment; and it obtains the reaction stagnation significance at each moment based on the time characteristics and the distribution of the reaction endpoint characteristic coefficient at different moments, thereby regulating aeration. This invention improves the accuracy of aeration regulation by accurately obtaining the reaction stagnation significance at each moment.

[0074] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0075] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. An intelligent aeration control system for achieving low-DO intermittent aeration regulation, the system comprising: The data acquisition module is used to acquire the valve opening, pipeline pressure, and biochemical potential value at any given moment. The rate characteristic analysis module is used to obtain the effective ventilation flow coefficient at each moment based on the valve opening and pipeline pressure at each moment; and to obtain the valve closing rate and potential fluctuation rate at each moment based on the changing trends of the effective ventilation flow coefficient and biochemical potential value at different moments. The reaction stagnation analysis module is used to obtain the relative closing strength and relative reactive activity at each moment based on the valve closing rate and potential fluctuation rate distribution at each moment; to obtain the reaction endpoint characteristic coefficient at each moment based on the relative closing strength and relative reactive activity at each moment; and to obtain the reaction stagnation significance at each moment based on the time characteristics at different moments and the distribution of the reaction endpoint characteristic coefficient. The aeration control module is used to adjust the aeration based on the degree of reaction stagnation at different times.

2. The intelligent aeration control system for achieving low DO intermittent aeration regulation according to claim 1, characterized in that, The method for obtaining the effective ventilation flow rate coefficient includes: Obtain the difference between the pipeline pressure and the preset back pressure at each moment. If the difference is greater than the preset difference threshold, calculate the root value of the difference result and use it as the driving differential pressure factor. The ratio of the regulating valve opening to the preset maximum opening value is obtained at each moment. The difference between the ratio result and the positive integer 1 is calculated as the regulating index. Based on the regulating index, a power operation is performed with the preset valve adjustable ratio as the base to obtain the relative flow coefficient. The product of the relative flow coefficient and the driving pressure difference factor is obtained as the effective ventilation flow coefficient at each moment. If the difference is less than or equal to the preset difference threshold, the effective ventilation flow rate coefficient at each moment is set to 0.

3. The intelligent aeration control system for achieving low DO intermittent aeration regulation according to claim 1, characterized in that, The method for obtaining the valve closing rate includes: Based on the changing trends of the effective ventilation flow rate coefficient and biochemical potential value at different times, the effective smoothed ventilation flow rate coefficient and biochemical smoothed potential value at each time are obtained. Obtain the difference between the effective ventilation smoothing flow coefficient between the first and last moments of the historical action range at each moment. If the difference is greater than the preset difference threshold, calculate the ratio between the difference result and the duration of the historical action range, and use it as the valve closing rate at each moment. If the difference is less than or equal to the preset difference threshold, the valve closing rate at each moment is set to 0.

4. The intelligent aeration control system for realizing low DO intermittent aeration regulation according to claim 3, characterized in that, The method for obtaining the potential fluctuation rate includes: Obtain the absolute value of the difference between the two ends of the historical response range at each moment, and calculate the ratio between the absolute value of the difference and the duration of the historical response range as the potential fluctuation rate at each moment.

5. The intelligent aeration control system for realizing low DO intermittent aeration regulation according to claim 3, characterized in that, The methods for obtaining the effective ventilation smoothing flow coefficient and biochemical smoothing potential value include: For any data point in the effective ventilation flow rate coefficient or biochemical potential value, the average value of all data points within a preset time window prior to each time point is obtained as the smoothed data for each time point. The smoothed data includes the effective ventilation smoothed flow rate coefficient or biochemical smoothed potential value.

6. The intelligent aeration control system for realizing low DO intermittent aeration regulation according to claim 1, characterized in that, The method for obtaining the relative closure strength includes: The maximum adjustment rate is preset, and the ratio of the valve closing rate to the preset maximum adjustment rate at each moment is calculated as the relative closing strength at each moment.

7. The intelligent aeration control system for realizing low DO intermittent aeration regulation according to claim 1, characterized in that, The method for obtaining the relative reactivity includes: A preset baseline response rate is used to calculate the ratio of the potential fluctuation rate to the preset baseline response rate at each moment, which is taken as the relative response activity at each moment.

8. The intelligent aeration control system for realizing low DO intermittent aeration regulation according to claim 1, characterized in that, The method for obtaining the characteristic coefficient of the reaction endpoint includes: If the relative shut-off intensity at each moment is greater than the preset action dead zone threshold, the relative shut-off intensity at each moment and the relative responsiveness of the preset multiple are used to form a two-dimensional state vector. Obtain the cosine similarity between the two-dimensional state vector and the preset endpoint reference vector at each time step, and use it as the response endpoint feature coefficient at each time step; If the relative closing intensity at each moment is less than or equal to the preset action dead zone threshold, the reaction endpoint characteristic coefficient at each moment is set to 0.

9. The intelligent aeration control system for realizing low DO intermittent aeration regulation according to claim 1, characterized in that, The method for obtaining the significance of the reaction stagnation includes: If the time between each moment and the initial moment is less than the preset learning time, select the moment with the largest reaction endpoint feature coefficient among all moments in the neighborhood of each moment, and obtain the sum of the maximum reaction endpoint feature coefficient and the preset minimum safety margin as the local reaction endpoint feature observation value; select the maximum value between the local reaction endpoint feature observation value and the preset feature baseline as the reaction endpoint feature baseline value for each moment. If the duration between each moment and the initial moment is greater than or equal to the preset learning duration, the reaction endpoint feature benchmark value corresponding to the preset learning duration will be used as the reaction endpoint feature benchmark value for each moment. The ratio of the response endpoint characteristic coefficient to the response endpoint characteristic baseline value at each time step is obtained as the significance of response stagnation at each time step.

10. The intelligent aeration control system for realizing low DO intermittent aeration regulation according to claim 1, characterized in that, The regulation of aeration includes: If the duration between a given moment and the initial moment is greater than or equal to the preset learning duration, and the reaction stagnation at a given moment is significantly greater than the preset trigger threshold, the corresponding moment is taken as the trigger moment; the duration of the range of consecutive trigger moments is obtained, and if the duration is greater than the preset duration threshold, aeration is stopped.

Images