Circulating water multi-stage purification system and control method thereof

Abstract

The invention relates to the technical field of circulating water treatment, and provides a circulating water multi-stage purification system and a control method thereof.The control method comprises the steps that water quality parameters of each purification step of the circulating water multi-stage purification system and proportional parameters of a PID control algorithm are collected, and target water quality parameters are marked; acquiring a collection moment cluster, marking a target water quality parameter and a target collection moment, determining a dosing effect and a first reference value of a proportion parameter, and further determining a second reference value of the proportion parameter of each purification step; a water quality parameter cluster is obtained, the adjustment influence degree is calculated, and a third reference value of the proportion parameter of each purification step is determined; and determining the optimal value of the proportion parameter of each purification step by combining the second reference value and the third reference value of the proportion parameter, so as to realize circulating water multi-stage purification control. According to the invention, the proportional parameter value of the PID control algorithm can be adaptively determined, and accurate adjustment of the water quality of the water circulation system is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of circulating water treatment, and in particular to a circulating water multi-stage purification system and a control method thereof. Background Art

[0002] The multi-stage circulating water purification process utilizes a multi-stage combination model to treat circulating water, using a combination of processes such as physical and chemical synergistic purification, electrochemical and biological coupling technology, and membrane separation. During the operation of a circulating water system, water quality is affected by a variety of factors, such as hardness, alkalinity, pH, concentration ratio, temperature, and ambient humidity. To adapt to changes in water quality, dynamically adjust dosing, precisely control chemical dosage, and improve system stability and reliability, PID control equipment is generally used to control the dosage of related chemicals.

[0003] PID control equipment uses the PID control algorithm to achieve drug control. The proportional parameter is a parameter in the PID control algorithm used to control the system's response to errors. It generally takes a fixed constant value. However, the operating conditions of the circulating water system are complex and changeable. The fixed proportional parameter is often difficult to adapt to the dynamic changes in water quality, and cannot guarantee the stable operation of the water circulation system and the precise regulation of water quality. Summary of the Invention

[0004] The present invention provides a circulating water multi-stage purification system and a control method thereof to solve the problem that the operating conditions of the circulating water system are complex and changeable, the fixed proportional parameter values ​​cannot adapt to the dynamic changes of water quality, and cannot ensure the stable operation of the water circulation system and the precise regulation of water quality. The technical solutions adopted are as follows:

[0005] In a first aspect, an embodiment of the present invention provides a circulating water multi-stage purification control method, the method comprising the following steps:

[0006] Collect all types of water quality parameters at the current collection time and the historical collection time corresponding to the current collection time for each purification step of the circulating water multi-stage purification system, and the values ​​of the proportional parameters of the PID control algorithm corresponding to the water quality parameters, and mark the target water quality parameters of each purification step;

[0007] For the same purification step, all collection moments are clustered according to the differences in the same type of water quality parameters at all collection moments to obtain collection moment clusters, any type of water quality parameter is recorded as the target water quality parameter, and any collection moment is recorded as the target collection moment, and based on the differences between the target water quality parameters of all adjacent purification steps at the target collection moment and all historical collection moments of the target collection moment, the dosing effect of each purification step at the target water quality parameter at the target collection moment is determined, and the proportional parameters of the corresponding PID control algorithm are weighted and summed according to the dosing effect to obtain a first reference value of the proportional parameter of the same type of water quality parameter in the same purification step, and a second reference value of the proportional parameter of each purification step is determined based on all the first reference values ​​of the proportional parameters and the target water quality parameter;

[0008] Clustering water quality parameters of the same type at the same purification step at all sampling moments within the sampling moment cluster including the current sampling moment, obtaining water quality parameter clusters for the same purification step, calculating the adjustment influence of each purification step based on the differences between the dosing effects of the purification steps corresponding to the water quality parameter clusters and the number of water quality parameter clusters, and determining a third reference value of the proportional parameter for each purification step based on the adjustment influence;

[0009] According to the second reference value and the third reference value of the proportional parameter of each purification step, the optimal value of the proportional parameter of each purification step is determined to realize multi-stage purification control of circulating water.

[0010] Furthermore, the target water quality parameter of the purification step is specifically: the type of water quality parameter controlled by the purification step.

[0011] Furthermore, the method for obtaining the clustering cluster at the collection time is:

[0012] For the same purification step, the normalized value of the square of the difference between the same type of water quality parameters obtained at different collection times is recorded as the first normalized value of the same type of water quality parameters obtained at the different collection times. The arithmetic square root of the cumulative sum of all the first normalized values ​​of the same type of water quality parameters obtained at different collection times is recorded as the water quality parameter difference at the different collection times for the same purification step.

[0013] The difference in water quality parameters at different collection times in the same purification step is used as a distance metric for clustering, and the current collection time and all historical collection times are clustered to obtain a collection time cluster corresponding to the same purification step.

[0014] Furthermore, the method for determining the dosing effect of the purification step is:

[0015] For the same purification step, the variance of the target water quality parameter at the target collection time and all historical collection times is recorded as the first variance of the same purification step at the target collection time, and the ratio of the first variance of the purification step to the first adjacent purification step at the target collection time is recorded as the first ratio of the target water quality parameter at the target collection time of the purification step;

[0016] For the same purification step, the target water quality parameter at the target collection time and all historical collection times is summed up with the absolute value of the difference between the target water quality parameter and the standard value of the target water quality parameter, and the target water quality parameter at the target collection time is recorded as the first cumulative sum;

[0017] The normalized value of the ratio of the first ratio of the target water quality parameter at the target collection time in the same purification step to the first cumulative sum is recorded as the dosing effect of the target water quality parameter at the target collection time in the same purification step.

[0018] Furthermore, the method for obtaining the first reference value of the proportional parameter of the same type of water quality parameter in the same purification step is:

[0019] For two different collection moments within the same collection moment cluster, the mean of the dosing effect of the same type of water quality parameter at the two collection moments in the same purification step is recorded as the first mean of the same type of water quality parameter at the two collection moments in the same purification step, and the normalized value of the ratio of the first mean to the distance metric of the corresponding clusters at the two collection moments is recorded as the reference weight of the same type of water quality parameter at the two collection moments in the same purification step;

[0020] The reference weight is used as the weight of the mean value of the proportional parameter of the PID control algorithm of the corresponding purification step for the corresponding type of water quality parameter at the two acquisition moments. The weighted summation is performed on the mean value of the proportional parameter of the PID control algorithm of the same type of water quality parameter at all different acquisition moments in all clusters in the same purification step to obtain the first reference value of the proportional parameter of the same type of water quality parameter in the cluster at the same acquisition moment in the same purification step.

[0021] Furthermore, the method for determining the second reference value of the proportional parameter of each purification step is:

[0022] The first reference value of the proportion parameter of the collection moment cluster including the current collection moment of the target water quality parameter corresponding to the same purification step is used as the second reference value of the proportion parameter of the same purification step.

[0023] Furthermore, the method for obtaining the water quality parameter cluster is:

[0024] The absolute value of the difference between the water quality parameters is used as the distance metric for clustering. The water quality parameters of the same type at the same purification step in all the collection time clusters including the current sampling time are clustered to obtain the water quality parameter clusters of the same purification step.

[0025] Furthermore, the method of calculating the adjustment influence of each purification step based on the difference between the dosing effects of the purification steps corresponding to the water quality parameter clusters and the number of water quality parameter clusters, and determining the third reference value of the proportional parameter of each purification step based on the adjustment influence, includes the following specific steps:

[0026] The variance of the dosing effect of the purification step corresponding to the water quality parameter cluster at all historical collection moments corresponding to all water quality parameters in the water quality parameter cluster is recorded as the second variance of the water quality parameter cluster; the ratio of the number of water quality parameter clusters to the cumulative sum of the second variances of all water quality parameter clusters is recorded as the second ratio of the purification step and the corresponding type of water quality parameters corresponding to the water quality parameter cluster;

[0027] The variance of the dosing effect of all water quality parameters in all water quality parameter clusters at all historical collection moments in the purification step corresponding to the water quality parameter cluster is recorded as the third party variance of the water quality parameters of the corresponding types of the water quality parameter clusters in the purification step corresponding to the water quality parameter clusters;

[0028] The normalized value of the product of the third difference and the second ratio of the water quality parameters of the type corresponding to the water quality parameter cluster in the purification step corresponding to the water quality parameter cluster is recorded as the adjustment influence degree of the water quality parameters of the type corresponding to the water quality parameter cluster in the purification step corresponding to the water quality parameter cluster;

[0029] The water quality parameter corresponding to the adjustment influence greater than the influence threshold is recorded as the important water quality parameter of the purification step corresponding to the adjustment influence, the cumulative sum of the adjustment influence of all important water quality parameters of the same purification step is recorded as the important adjustment influence, the ratio of the adjustment influence of the important water quality parameter of the same purification step to the important adjustment influence is used as the weight, and the proportional parameters of the PID control algorithm of the important water quality parameters of the same purification step at the corresponding collection time are weighted and summed to obtain the third reference value of the proportional parameter of the same purification step.

[0030] Furthermore, the method of determining the optimal value of the proportional parameter of each purification step according to the second reference value and the third reference value of the proportional parameter of each purification step includes the following specific steps:

[0031] The average of the second reference value and the third reference value of the proportional parameter of the same purification step is used as the value of the proportional parameter of the PID algorithm in the same purification step at the current collection moment.

[0032] In a second aspect, an embodiment of the present invention further provides a circulating water multi-stage purification system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above methods when executing the computer program.

[0033] The beneficial effects of the present invention are:

[0034] The present application clusters the collection moments corresponding to the same type of water quality parameters in the same purification step, and divides water quality parameters with similar values ​​into clusters at the same collection moment. Based on the water quality parameters corresponding to all collection moments within the same collection moment cluster, the circulating water purification effect is evaluated and the dosing effect is obtained. The better the purification effect of the target water quality parameter in the purification step, the greater the dosing effect of the target water quality parameter in the purification step. According to the dosing effect, the proportional parameters of the corresponding PID control algorithm are weighted and summed to obtain a first reference value of the proportional parameter, and then a second reference value of the proportional parameter of each purification step is determined. The second reference value of the proportional parameter is an estimated value of the proportional parameter of the PID control algorithm determined according to the values ​​of the water quality parameters at each collection moment. Furthermore, the differences between the water quality parameters at historical collection moments and the corresponding differences in dosing effects are analyzed. Evaluate the degree of influence of the types of water quality parameters corresponding to the water quality parameter clusters on the treatment effect of the circulating water in the corresponding purification step, obtain the adjustment influence degree, and determine the third reference value of the proportional parameter of each purification step according to the adjustment influence degree. The third reference value of the proportional parameter is the estimated value of the proportional parameter of the PID control algorithm determined according to the influence of the water quality parameters on the dosing effect; finally, according to the second reference value and the third reference value of the proportional parameter of each purification step, determine the optimal value of the proportional parameter of each purification step, realize multi-stage purification control of circulating water, solve the problem that the operating conditions of the circulating water system are complex and changeable, the fixed proportional parameter value cannot adapt to the dynamic changes of water quality, and cannot guarantee the stable operation of the water circulation system and the precise adjustment of water quality, adaptively determine the optimal value of the proportional parameter of the PID control algorithm, and ensure the precise adjustment and stability of the water quality of the water circulation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic flow chart of a circulating water multi-stage purification control method provided by one embodiment of the present invention;

[0037] Figure 2 This is a flow chart of obtaining clusters by clustering at the collection moment provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] See also Figure 1 , which shows a flow chart of a circulating water multi-stage purification control method provided by one embodiment of the present invention, the method comprising the following steps:

[0040] Step S001, collect all types of water quality parameters of each purification step of the circulating water multi-stage purification system at the current collection time and the historical collection time corresponding to the current collection time, and the values ​​of the proportional parameters of the PID control algorithm corresponding to the water quality parameters, and mark the target water quality parameters of each purification step.

[0041] Each stage of the circulating water purification process of the circulating water multi-stage purification system is recorded as a purification step, and all types of water quality parameters are collected using a water quality sensor at the water inlet position of each purification step of the circulating water multi-stage purification system.

[0042] Among them, the types of water quality parameters selected in this embodiment include pH value, turbidity, total phosphorus, chromaticity, suspended solids, conductivity, dissolved oxygen, ammonia nitrogen, total nitrogen and hardness; in actual application, as other implementation methods, the implementer can decide the type of water quality parameters according to the specific needs of circulating water, and this application does not impose any special restrictions.

[0043] Specifically, water quality parameters are collected at the current collection moment and a collection moments before the current collection moment. In this embodiment, the water quality parameter collection interval is set to 1 minute, where a represents a first preset parameter, which is a preset parameter value. In this embodiment, the value of the first preset parameter is 30. The a collection moments before the current collection moment are all recorded as historical collection moments of the current collection moment. In actual application, as other implementation methods, implementers can determine the water quality parameter collection interval and the number of historical collection moments based on the specific needs of circulating water, and this application does not impose any special restrictions.

[0044] Furthermore, the values ​​of the proportional parameters of the PID control algorithm corresponding to all types of water quality parameters at the current collection moment and all historical collection moments are extracted.

[0045] It should be understood that for the circulating water multi-stage purification system, each purification step has only one purpose and only one agent is added. Therefore, it is only necessary to obtain the proportional parameter values ​​corresponding to the water quality parameters that need to be controlled in each purification step, and record the type of water quality parameters controlled by the purification step as the target water quality parameters of the purification step.

[0046] At this point, all types of water quality parameters of each purification step of the circulating water multi-stage purification system at the current collection moment and a preset number of historical collection moments, and the values ​​of the proportional parameters of the PID control algorithm corresponding to all types of water quality parameters at all historical collection moments are obtained, and the target water quality parameters of each purification step are obtained.

[0047] Step S002: For the same purification step, cluster all collection moments according to the differences in the same type of water quality parameters at all collection moments to obtain collection moment clusters, record any type of water quality parameter as the target water quality parameter, and record any collection moment as the target collection moment. Based on the differences between the target water quality parameters of all adjacent purification steps at the target collection moment and all historical collection moments of the target collection moment, determine the dosing effect of each purification step at the target water quality parameter at the target collection moment. Based on the dosing effect, weighted summation is performed on the proportional parameters of the corresponding PID control algorithm to obtain a first reference value of the proportional parameter of the same type of water quality parameter in the same purification step. Based on the first reference values ​​of all proportional parameters and the target water quality parameter, a second reference value of the proportional parameter of each purification step is determined.

[0048] For the same purification step, the normalized squared difference between the same type of water quality parameter acquired at different collection times is recorded as the first normalized value of the same type of water quality parameter acquired at the different collection times. The square root of the cumulative sum of all first normalized values ​​of the same type of water quality parameter acquired at different collection times is recorded as the water quality parameter difference for the same purification step at the different collection times. Using the water quality parameter difference for the same purification step at different collection times as the clustering distance metric, clustering is performed on the current collection time and all historical collection times to obtain a collection time cluster corresponding to the same purification step.

[0049] The flow chart of cluster acquisition at the time of collection is as follows: Figure 2 shown.

[0050] This embodiment uses the DBSCAN clustering algorithm to cluster all historical collection moments. In actual applications, while achieving clustering, implementers may use other existing methods such as the Mean Shift clustering algorithm, the OPTICS clustering algorithm, the Gaussian Mixture Models clustering algorithm, or the Spectral Clustering algorithm for clustering. This application does not impose any specific restrictions. This embodiment uses the Z-Score standard normalization method to calculate the normalized value. In actual applications, implementers may use other existing methods such as the maximum and minimum normalization method or the sigmoid function to calculate the normalized value. This is not limited here.

[0051] The values ​​of water quality parameters corresponding to all collection moments in the same collection moment cluster corresponding to the same purification step are similar. Based on the water quality parameters corresponding to all collection moments in the same collection moment cluster, the circulating water purification effect can be evaluated. Then, the optimal value of the proportional parameter at the current collection moment can be determined based on the proportional parameter value corresponding to the collection moment with better purification effect.

[0052] Any type of water quality parameter is recorded as the target water quality parameter, and the current collection time and any collection time among all historical collection times are recorded as the target collection time.

[0053] It can be understood that the a collection moments before the target collection moment are historical collection moments of the target collection moment.

[0054] According to the difference between the target water quality parameters of all adjacent purification steps at the target collection time and all historical collection times of the target collection time, the dosing effect of each purification step of the target water quality parameter at the target collection time is determined respectively.

[0055] For the same purification step, the variance of the target water quality parameter at the target collection time and all historical collection times is recorded as the first variance of the same purification step at the target collection time. The ratio of the first variance of the purification step to the first adjacent purification step at the target collection time is recorded as the first ratio of the target water quality parameter at the target collection time of the purification step. For the same purification step, the absolute value of the difference between the target water quality parameter at the target collection time and all historical collection times and the standard value of the target water quality parameter is recorded as the first cumulative sum of the target water quality parameter at the target collection time. The normalized value of the ratio of the first ratio of the target water quality parameter at the target collection time of the same purification step to the first cumulative sum is recorded as the dosing effect of the target water quality parameter at the target collection time for the same purification step.

[0056] It is understood that the final purification step does not have an adjacent purification step, and therefore the dosing effect of the final purification step is not analyzed. The purification effect of the final purification step can be determined by comparing the water quality parameters of the purified circulating water with the target water quality parameters. It should be noted that the standard values ​​of the target water quality parameters are determined by experts in the field based on the purification requirements of the circulating water.

[0057] If the difference between the target water quality parameters at the target collection moment and all historical collection moments is smaller than the difference corresponding to the target collection moment, and the difference between the target water quality parameters of the purification step and the next adjacent purification step is larger, then the purification effect of the target water quality parameter in the purification step is better, that is, the dosing effect of the target water quality parameter in the purification step is greater.

[0058] It should be noted that for the current collection moment and any of all historical collection moments, the target water quality parameter has a corresponding dosing effect in each purification step; at the same time, for each water quality parameter, at the current collection moment and any of all historical collection moments, each purification step has a corresponding dosing effect.

[0059] The same method can be used to obtain the dosing effect of any type of water quality parameter at the current collection time and any collection time among all historical collection times and at any purification step.

[0060] According to the dosing effect of the same type of water quality parameters at different collection times in the cluster at the same collection time in the same purification step, the proportional parameters of the corresponding PID control algorithm are weighted summed to obtain the first reference value of the proportional parameter of the same type of water quality parameters in the cluster at the same collection time in the same purification step.

[0061] For two different collection moments within the same collection moment cluster, the mean of the dosing effects of the same type of water quality parameters at the two collection moments in the same purification step is recorded as the first mean of the same type of water quality parameters at the two collection moments in the same purification step. The normalized value of the ratio of the first mean to the values ​​of the distance measurement of the clusters at the corresponding two collection moments is recorded as the reference weight of the same type of water quality parameters at the two collection moments in the same purification step. The reference weight is used as the weight of the mean of the proportional parameters of the PID control algorithm of the corresponding type of water quality parameters at the corresponding two collection moments in the corresponding purification step. The weighted sum of the mean of the proportional parameters of the PID control algorithm of the same type of water quality parameters at all different collection moments in all clusters is performed to obtain the first reference value of the proportional parameter of the same type of water quality parameters in the cluster at the same collection moment in the same purification step.

[0062] The first reference value of the proportion parameter of the collection moment cluster including the current collection moment of the target water quality parameter corresponding to the same purification step is used as the second reference value of the proportion parameter of the same purification step.

[0063] At this point, the second reference value of the ratio parameter of each purification step is obtained.

[0064] Step S003: Cluster the water quality parameters of the same type at the same purification step for all collection moments within the collection moment clustering cluster including the current sampling moment, obtain the water quality parameter clustering clusters for the same purification step, calculate the adjustment influence of each purification step according to the difference between the dosing effects of the purification steps corresponding to the water quality parameter clustering clusters and the number of water quality parameter clustering clusters, and determine the third reference value of the proportional parameter of each purification step according to the adjustment influence.

[0065] Each stage of a multi-stage circulating water purification system has different treatment objectives, and different treatment processes may interfere with each other. For example, when using activated carbon to adsorb organic matter, color, and odor in water, residual chlorine in the water may oxidize the activated carbon, reducing its adsorption capacity and resulting in poor adsorption performance. Therefore, it is necessary to analyze the differences in water quality parameters at historical collection times and the corresponding differences in dosing effects to determine the appropriate value for the proportional parameter of the PID control algorithm.

[0066] The absolute value of the difference between the water quality parameters is used as the distance metric for clustering. The water quality parameters of the same type at the same purification step in all the collection time clusters including the current sampling time are clustered to obtain the water quality parameter clusters of the same purification step.

[0067] Among them, this embodiment uses the DBSCAN clustering algorithm to cluster all water quality parameters. In actual application, on the basis of achieving the purpose of clustering, the implementer can use other existing methods such as Mean Shift clustering algorithm, OPTICS clustering algorithm, Gaussian Mixture Models clustering algorithm, Spectral Clustering spectral clustering for clustering, and this application does not impose any special restrictions.

[0068] It can be understood that the values ​​of water quality parameters within the same water quality parameter cluster are similar, and the dosing effects corresponding to the water quality parameters should also be similar, that is, the purification effects of the purification steps corresponding to the water quality parameters within the same water quality parameter cluster should be close. When the difference in the values ​​of water quality parameters within the same water quality parameter cluster is greater, the water quality parameters corresponding to the water quality parameter cluster have a greater impact on the circulating water purification effect.

[0069] According to the differences between the dosing effects of the purification steps corresponding to the water quality parameter clusters and the number of water quality parameter clusters, the regulation influence of each purification step is calculated respectively.

[0070] The variance of the dosing effect of all water quality parameters within a water quality parameter cluster at all historical collection moments in the purification step corresponding to the water quality parameter cluster is recorded as the second variance of the water quality parameter cluster. The ratio of the number of water quality parameter clusters to the cumulative sum of the second variances of all water quality parameter clusters is recorded as the second ratio of the purification step and the type of water quality parameter corresponding to the water quality parameter cluster. The variance of the dosing effect of all water quality parameters within a water quality parameter cluster at all historical collection moments in the purification step corresponding to the water quality parameter cluster is recorded as the third variance of the water quality parameter of the type of water quality parameter in the purification step corresponding to the water quality parameter cluster. The normalized value of the product of the third variance of the water quality parameter of the type of water quality parameter in the purification step corresponding to the water quality parameter cluster and the second ratio is recorded as the regulation influence of the water quality parameter of the type of water quality parameter in the purification step corresponding to the water quality parameter cluster.

[0071] The smaller the difference between all water quality parameters within a water quality parameter cluster, and the greater the difference between the dosing effects of all historical collection moments corresponding to all water quality parameters within a water quality parameter cluster in the purification step corresponding to the water quality parameter cluster, the greater the impact of the type of water quality parameters corresponding to the water quality parameter cluster on the treatment effect of the circulating water in the corresponding purification step.

[0072] The water quality parameter corresponding to the adjustment influence greater than the influence threshold is recorded as the important water quality parameter of the purification step corresponding to the adjustment influence, the cumulative sum of the adjustment influence of all important water quality parameters of the same purification step is recorded as the important adjustment influence, the ratio of the adjustment influence of the important water quality parameter of the same purification step to the important adjustment influence is used as the weight, and the proportional parameters of the PID control algorithm of the important water quality parameters of the same purification step at the corresponding collection time are weighted and summed to obtain the third reference value of the proportional parameter of the same purification step.

[0073] At this point, the third reference value of the ratio parameter of each purification step is obtained.

[0074] Step S004: determining the optimal value of the proportional parameter of each purification step according to the second reference value and the third reference value of the proportional parameter of each purification step, thereby realizing multi-stage purification control of circulating water.

[0075] The average of the second reference value and the third reference value of the proportional parameter of the same purification step is used as the value of the proportional parameter of the PID algorithm in the same purification step at the current collection moment, so as to realize the control of the multi-stage purification of the circulating water in the same purification step.

[0076] At this point, multi-stage purification control of circulating water is achieved.

[0077] Based on the same inventive concept as the above method, an embodiment of the present invention also provides a circulating water multi-stage purification system, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of any one of the above-mentioned circulating water multi-stage purification control methods are implemented.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A circulating water multi-stage purification control method, characterized in that: The method comprises the following steps: Collect all types of water quality parameters at the current collection time and the historical collection time corresponding to the current collection time for each purification step of the circulating water multi-stage purification system, and the values ​​of the proportional parameters of the PID control algorithm corresponding to the water quality parameters, and mark the target water quality parameters of each purification step; For the same purification step, all collection moments are clustered according to the differences in the same type of water quality parameters at all collection moments to obtain collection moment clusters, any type of water quality parameter is recorded as the target water quality parameter, and any collection moment is recorded as the target collection moment, and based on the differences between the target water quality parameters of all adjacent purification steps at the target collection moment and all historical collection moments of the target collection moment, the dosing effect of each purification step at the target water quality parameter at the target collection moment is determined, and the proportional parameters of the corresponding PID control algorithm are weighted and summed according to the dosing effect to obtain a first reference value of the proportional parameter of the same type of water quality parameter in the same purification step, and a second reference value of the proportional parameter of each purification step is determined based on all the first reference values ​​of the proportional parameters and the target water quality parameter; Clustering water quality parameters of the same type at the same purification step at all sampling moments within the sampling moment cluster including the current sampling moment, obtaining water quality parameter clusters for the same purification step, calculating the adjustment influence of each purification step based on the differences between the dosing effects of the purification steps corresponding to the water quality parameter clusters and the number of water quality parameter clusters, and determining a third reference value of the proportional parameter for each purification step based on the adjustment influence; According to the second reference value and the third reference value of the proportional parameter of each purification step, the optimal value of the proportional parameter of each purification step is determined to realize multi-stage purification control of circulating water.

2. A circulating water multi-stage purification control method according to claim 1, characterized in that: The target water quality parameter of the purification step is specifically: the type of water quality parameter controlled by the purification step.

3. A circulating water multi-stage purification control method according to claim 1, characterized in that: The method for obtaining the clustering cluster at the acquisition time is: For the same purification step, the normalized value of the square of the difference between the same type of water quality parameters obtained at different collection times is recorded as the first normalized value of the same type of water quality parameters obtained at the different collection times. The arithmetic square root of the cumulative sum of all the first normalized values ​​of the same type of water quality parameters obtained at different collection times is recorded as the water quality parameter difference at the different collection times for the same purification step. The difference in water quality parameters at different collection times in the same purification step is used as a distance metric for clustering, and the current collection time and all historical collection times are clustered to obtain a collection time cluster corresponding to the same purification step.

4. A circulating water multi-stage purification control method according to claim 1, characterized in that: The method for determining the dosing effect of the purification step is: For the same purification step, the variance of the target water quality parameter at the target collection time and all historical collection times is recorded as the first variance of the same purification step at the target collection time, and the ratio of the first variance of the purification step to the first adjacent purification step at the target collection time is recorded as the first ratio of the target water quality parameter at the target collection time of the purification step; For the same purification step, the target water quality parameter at the target collection time and all historical collection times is summed up with the absolute value of the difference between the target water quality parameter and the standard value of the target water quality parameter, and the target water quality parameter at the target collection time is recorded as the first cumulative sum; The normalized value of the ratio of the first ratio of the target water quality parameter at the target collection time in the same purification step to the first cumulative sum is recorded as the dosing effect of the target water quality parameter at the target collection time in the same purification step.

5. A circulating water multi-stage purification control method according to claim 1, characterized in that: The method for obtaining the first reference value of the proportional parameter of the same type of water quality parameter in the same purification step is: For two different collection moments within the same collection moment cluster, the mean of the dosing effect of the same type of water quality parameter at the two collection moments in the same purification step is recorded as the first mean of the same type of water quality parameter at the two collection moments in the same purification step, and the normalized value of the ratio of the first mean to the distance metric of the corresponding clusters at the two collection moments is recorded as the reference weight of the same type of water quality parameter at the two collection moments in the same purification step; The reference weight is used as the weight of the mean value of the proportional parameter of the PID control algorithm of the corresponding purification step for the corresponding type of water quality parameter at the two acquisition moments. The weighted summation is performed on the mean value of the proportional parameter of the PID control algorithm of the same type of water quality parameter at all different acquisition moments in all clusters in the same purification step to obtain the first reference value of the proportional parameter of the same type of water quality parameter in the cluster at the same acquisition moment in the same purification step.

6. A circulating water multi-stage purification control method according to claim 1, characterized in that: The method for determining the second reference value of the proportional parameter of each purification step is: The first reference value of the proportion parameter of the collection moment cluster including the current collection moment of the target water quality parameter corresponding to the same purification step is used as the second reference value of the proportion parameter of the same purification step.

7. A circulating water multi-stage purification control method according to claim 1, characterized in that: The method for obtaining the water quality parameter cluster is: The absolute value of the difference between the water quality parameters is used as the distance metric for clustering. The water quality parameters of the same type at the same purification step in all the collection time clusters including the current sampling time are clustered to obtain the water quality parameter clusters of the same purification step.

8. A circulating water multi-stage purification control method according to claim 1, characterized in that: The method of calculating the adjustment influence of each purification step according to the difference between the dosing effects of the purification steps corresponding to the water quality parameter clusters and the number of water quality parameter clusters, and determining the third reference value of the proportional parameter of each purification step according to the adjustment influence, includes the following specific steps: The variance of the dosing effect of the purification step corresponding to the water quality parameter cluster at all historical collection moments corresponding to all water quality parameters in the water quality parameter cluster is recorded as the second variance of the water quality parameter cluster; the ratio of the number of water quality parameter clusters to the cumulative sum of the second variances of all water quality parameter clusters is recorded as the second ratio of the purification step and the corresponding type of water quality parameters corresponding to the water quality parameter cluster; The variance of the dosing effect of all water quality parameters in all water quality parameter clusters at all historical collection moments in the purification step corresponding to the water quality parameter cluster is recorded as the third party variance of the water quality parameters of the corresponding types of the water quality parameter clusters in the purification step corresponding to the water quality parameter clusters; The normalized value of the product of the third difference and the second ratio of the water quality parameters of the type corresponding to the water quality parameter cluster in the purification step corresponding to the water quality parameter cluster is recorded as the adjustment influence degree of the water quality parameters of the type corresponding to the water quality parameter cluster in the purification step corresponding to the water quality parameter cluster; The water quality parameter corresponding to the adjustment influence greater than the influence threshold is recorded as the important water quality parameter of the purification step corresponding to the adjustment influence, the cumulative sum of the adjustment influence of all important water quality parameters of the same purification step is recorded as the important adjustment influence, the ratio of the adjustment influence of the important water quality parameter of the same purification step to the important adjustment influence is used as the weight, and the proportional parameters of the PID control algorithm of the important water quality parameters of the same purification step at the corresponding collection time are weighted and summed to obtain the third reference value of the proportional parameter of the same purification step.

9. A circulating water multi-stage purification control method according to claim 1, characterized in that: The method of determining the optimal value of the proportional parameter of each purification step according to the second reference value and the third reference value of the proportional parameter of each purification step comprises the following specific steps: The average of the second reference value and the third reference value of the proportional parameter of the same purification step is used as the value of the proportional parameter of the PID algorithm in the same purification step at the current collection moment.

10. A circulating water multi-stage purification system comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 9 are implemented.

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