Water supply network independent metering partition secondary chlorine addition optimization method and system

Abstract

The present application relates to the technical field of water quality safety of water supply network, and proposes a kind of water supply network independent metering partition secondary chlorination optimization method and system, comprising the following steps: obtaining water supply network hydraulic model data;According to the scale of water supply network hydraulic model and the influence degree of residual chlorine decay on water quality, residual chlorine decay model is constructed and residual chlorine decay coefficient is configured, and chlorine dosing simulation mode is set;According to the water supply network hydraulic model, set DMA partition scheme, and evaluate the water quality change of water supply network after DMA partition;If the residual chlorine concentration of node meets the preset limit value, then output the original network secondary chlorination scheme;If the residual chlorine concentration of node does not meet the preset limit value, then construct a multi-objective optimization model of secondary chlorination, and perform secondary chlorination optimization calculation on the water supply network system after DMA partition, to generate a set of secondary chlorination optimization schemes after DMA partition;Comprehensive benefit evaluation is carried out on the set of secondary chlorination optimization schemes, and the scheme with higher comprehensive benefit is output as the alternative scheme.

Description

Technical Field

[0001] This invention relates to the field of water quality safety technology in water supply networks, and more specifically, to a method and system for optimizing secondary chlorination in independent metering zones of water supply networks. Background Technology

[0002] As water supply networks expand and become increasingly complex, simply adding chlorine to the water source is insufficient to guarantee water quality safety at the network's end. Secondary chlorination involves installing intermediate chlorination stations at one or more key nodes in the water supply network's transmission and distribution chain. The water plant and these chlorination stations work together to disinfect the network, ensuring water quality while reducing the total amount of chlorine added. On the other hand, District Metered Area (DMA) technology, as an effective method for controlling network leakage, is being implemented nationwide.

[0003] However, since establishing DMA zoning inevitably changes the original interconnection of the water supply network, the existing secondary chlorination method cannot meet the minimum chlorination amount required for at least a certain qualified water volume when the water supply network is directly applied after DMA zoning. This results in the water quality deteriorating in some areas of the water supply network or making it difficult to guarantee the safety of the water quality. Summary of the Invention

[0004] To overcome the shortcomings of the prior art's secondary chlorination method, which results in deterioration of water quality in some areas or difficulty in ensuring water quality safety when applied to water supply networks after DMA zoning, this invention provides an optimized method and system for secondary chlorination in independent metering zones of water supply networks.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] An optimized method for secondary chlorination in independent metering zones of a water supply network includes the following steps:

[0007] S1. Obtain hydraulic model data of water supply network;

[0008] S2. Based on the scale of the water supply network hydraulic model and the degree of impact of residual chlorine decay on water quality, construct a residual chlorine decay model and configure the residual chlorine decay coefficient, and set the chlorine dosing simulation method.

[0009] S3. Set up a DMA zoning scheme based on the hydraulic model of the water supply network, and evaluate the water quality changes of the water supply network after DMA zoning.

[0010] S4. Based on the assessment results of the water quality changes in the water supply network, make a judgment: if the residual chlorine concentration of the network nodes after DMA partitioning meets the preset limit, then output the original secondary chlorination scheme of the network; if the residual chlorine concentration of some network nodes after DMA partitioning does not meet the preset limit, then construct a secondary chlorination multi-objective optimization model, and perform secondary chlorination multi-objective optimization calculation on the hydraulic model of the water supply network after DMA partitioning through the secondary chlorination multi-objective optimization model to generate a set of secondary chlorination optimization schemes after DMA partitioning.

[0011] S5. Conduct a comprehensive benefit evaluation on the set of secondary chlorination optimization schemes after DMA partitioning, and output the secondary chlorination optimization scheme with higher comprehensive benefit in the set as the alternative scheme.

[0012] As a preferred option, in the optimized secondary chlorination scheme, a non-constant chlorination method is adopted for the water source point in the hydraulic model of the water supply network and other nodes as alternative secondary chlorination stations, and the chlorine dosage changes with time.

[0013] As a preferred embodiment, in step S4, the secondary chlorination multi-objective optimization model includes an objective function, decision variables, and constraints; the objective function aims to minimize the chlorination amount, chlorination complexity, and the number of chlorination stations.

[0014] The chlorination amount in the secondary chlorination multi-objective optimization model includes the sum of the chlorination amount at the water source point and the dosage of all secondary chlorination station nodes within a simulation cycle; the chlorination complexity in the secondary chlorination multi-objective optimization model represents the degree to which the non-constant chlorination concentration at the water source point and the secondary chlorination station nodes changes over time within a simulation cycle.

[0015] The decision variables include whether each node in the water supply network hydraulic model is selected as a secondary chlorination site, and the chlorination concentration at each hydraulic step when it is selected as a secondary chlorination site; the constraints include the residual chlorine concentration limits for all nodes and the residual chlorine concentration limits for the treated water.

[0016] As a preferred embodiment, the expression of the secondary chlorination multi-objective optimization model is as follows:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023] In the formula, OF 1. OF 2. OF 3 represents the objective function for minimizing the chlorination amount, chlorination complexity, and number of chlorination stations, respectively; M This refers to the amount of chlorine added. express i Water source at all times j The chlorination concentration; express i Secondary chlorination station k Chlorination strength, express i real-time water source flow rate This indicates the chlorination time at each water source point. Indicates the duration for which a certain chlorination intensity is maintained at a secondary chlorination site; J The total number of water sources. T To simulate the total duration; C This indicates the total complexity of chlorination disinfection measures; express i Water source at all times j Chlorination complexity, express i Chlorination stations k Chlorination complexity, K This represents the total number of secondary chlorination sites; B Indicates the number of chlorination stations. Represents a node n Whether it is used as a secondary chlorination site, if the node n If selected as a chlorination site, then ,otherwise ; N The total number of nodes requiring water; Boolean(·) represents the Boolean conversion function; express i Time Node n Residual chlorine concentration; express i Water source at all times j The residual chlorine concentration.

[0024] As a preferred embodiment, the constraints include the following: according to the "Standards for Drinking Water Quality (GB 5749-2022)," the residual chlorine concentration limit range for all nodes is 0.05 mg / L to 2 mg / L; the residual chlorine concentration of the treated water is not less than 0.3 mg / L.

[0025] As a preferred option, step S5, which involves a comprehensive benefit evaluation of the set of optimized secondary chlorination schemes after DMA partitioning, includes: calculating the total daily chlorine dosage, the number of secondary chlorination station nodes, and the complexity of the chlorination operation based on the set of optimized secondary chlorination schemes after DMA partitioning.

[0026] Furthermore, this invention also proposes a secondary chlorination optimization system for independent metering zones of a water supply network, applicable to the secondary chlorination optimization method for independent metering zones of a water supply network proposed in any of the above technical solutions. The system includes:

[0027] The data acquisition module is used to acquire hydraulic model data of the water supply network;

[0028] The water quality simulation setting module is used to construct a residual chlorine decay model and configure the residual chlorine decay coefficient, and set the chlorine addition simulation method, based on the scale of the water supply network hydraulic model and the degree of impact of residual chlorine decay on water quality.

[0029] The water quality change assessment module is used to set up a DMA zoning scheme based on the hydraulic model of the water supply network and to assess the water quality changes of the water supply network after DMA zoning.

[0030] The secondary chlorination optimization module includes a secondary chlorination multi-objective optimization model, which is used to perform secondary chlorination multi-objective optimization calculations on the hydraulic model of the water supply network after DMA partitioning, and generate a set of secondary chlorination optimization schemes after DMA partitioning.

[0031] The comprehensive benefit evaluation module is used to evaluate the comprehensive benefits of the set of secondary chlorination optimization schemes after DMA partitioning, and output the secondary chlorination optimization schemes with higher comprehensive benefits in the set as alternative schemes.

[0032] As a preferred embodiment, the secondary chlorination optimization module includes a secondary chlorination multi-objective optimization model comprising an objective function, decision variables, and constraints, wherein the objective function aims to minimize the amount of chlorination, the chlorination complexity, and the number of secondary chlorination stations.

[0033] The chlorination amount in the secondary chlorination multi-objective optimization model includes the sum of the chlorination amount at the water source point and the dosage of all secondary chlorination station nodes within a simulation cycle; the chlorination complexity in the secondary chlorination multi-objective optimization model represents the degree to which the non-constant chlorination concentration at the water source point and the secondary chlorination station nodes changes over time within a simulation cycle.

[0034] The decision variables include whether each node in the water supply network hydraulic model is selected as a secondary chlorination site, and the chlorination concentration at each hydraulic step when it is selected as a secondary chlorination site; the constraints include the residual chlorine concentration limits for all nodes and the residual chlorine concentration limits for the treated water.

[0035] Furthermore, the present invention also proposes a computer device comprising one or more processors; a memory; and one or more application programs; wherein the one or more application programs are stored in the memory and configured to be executed by the processor to perform the operation of the secondary chlorination optimization method for independent metering zones of water supply networks proposed in the present invention.

[0036] Furthermore, the present invention also proposes a storage medium storing a computer program, which is loaded by a processor to execute the operation of the secondary chlorination optimization method for independent metering zones of water supply networks proposed in this invention.

[0037] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows: The present invention is based on the assessment of water quality changes after the water supply network is divided into DMA zones. Furthermore, it uses a secondary chlorination multi-objective optimization model to perform secondary chlorination multi-objective optimization calculations on the hydraulic model of the water supply network after DMA zones, generating a set of secondary chlorination optimization schemes after DMA zones. This ensures that the secondary chlorination optimization schemes of the water supply network hydraulic model after DMA zones meet the requirements of the "Standards for Drinking Water Quality (GB 5749-2022)" for the range of residual chlorine concentration at the end of the network, thereby ensuring the safety of water quality.

[0038] This invention conducts a comprehensive benefit evaluation of a set of optimized secondary chlorination schemes, and outputs the optimized secondary chlorination schemes with higher comprehensive benefits as alternative schemes. This can further provide cost-benefit analysis for decision-making departments that weigh the control of water supply network leakage and the protection of water quality in the water supply network, and help generate reasonable decision-making schemes. Attached Figure Description

[0039] Figure 1 This is a flowchart of the optimized secondary chlorination method for independent metering zones in the water supply network in Example 1.

[0040] Figure 2 This is a schematic diagram of the water supply network and a schematic diagram of the water demand distribution at the nodes in Example 2.

[0041] Figure 3 This is a schematic diagram of the DMA zoning scheme for the water supply network in Example 2.

[0042] Figure 4 This is a schematic diagram of the distribution of the secondary chlorination stations before the DMA partition in Example 2.

[0043] Figure 5 This is a comparison chart of residual chlorine concentrations at key nodes of the water supply network before and after DMA partitioning in Example 2.

[0044] Figure 6 This is a schematic diagram of the optimal secondary chlorination scheme selected after considering the influence of DMA partitioning in Example 2.

[0045] Figure 7 This is an architecture diagram of the secondary chlorination optimization system for the independent metering zone of the water supply network in Example 3. Detailed Implementation

[0046] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0047] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

[0048] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0049] Example 1

[0050] This embodiment proposes an optimized method for secondary chlorination in independently metered zones of a water supply network, such as... Figure 1 The diagram shown is a flowchart of the secondary chlorination optimization method for independent metering zones in the water supply network in this embodiment.

[0051] The optimized secondary chlorination method for independent metering zones in the water supply network proposed in this embodiment includes the following steps:

[0052] S1. Obtain hydraulic model data of water supply network;

[0053] S2. Based on the scale of the water supply network hydraulic model and the degree of impact of residual chlorine decay on water quality, construct a residual chlorine decay model and configure the residual chlorine decay coefficient, and set the chlorine dosing simulation method.

[0054] S3. Set up a DMA zoning scheme based on the hydraulic model of the water supply network, and evaluate the water quality changes of the water supply network after DMA zoning.

[0055] S4. Based on the assessment results of the water quality changes in the water supply network, make a judgment: if the residual chlorine concentration of the network nodes after DMA partitioning meets the preset limit, then output the original secondary chlorination scheme of the network; if the residual chlorine concentration of some network nodes after DMA partitioning does not meet the preset limit, then construct a secondary chlorination multi-objective optimization model, and perform secondary chlorination multi-objective optimization calculation on the hydraulic model of the water supply network after DMA partitioning through the secondary chlorination multi-objective optimization model to generate a set of secondary chlorination optimization schemes after DMA partitioning.

[0056] S5. Conduct a comprehensive benefit evaluation on the set of secondary chlorination optimization schemes after DMA partitioning, and output the secondary chlorination optimization scheme with higher comprehensive benefit in the set as the alternative scheme.

[0057] In this embodiment, the residual chlorine decay model is set according to the actual situation of the water supply network hydraulic model, and a first-order decay model is generally selected. The residual chlorine decay coefficient can be determined experimentally or a reference value can be selected from literature, mainly for water quality simulation using EPANET software. The chlorine addition simulation method is selected in EPANET software, which determines the method of chlorine injection into the network and the chlorine dosage calculation formula. EPANET software provides four methods for simulating the chlorination process of the water supply network, including: fixed concentration source chlorination, fixed mass secondary chlorination, fixed superimposed concentration secondary chlorination, and fixed outflow concentration secondary chlorination. This embodiment sets the fixed mass secondary chlorination method.

[0058] In one specific embodiment, for the residual chlorine decay model using a first-order decay model, the value of kb ranges from -0.004 to -3.72, and kw is selected according to the pipe material. For example, when polyethylene pipe is selected in the hydraulic model of the water supply network, kw = -0.8.

[0059] Furthermore, using the original secondary chlorination scheme of the case pipeline network, hydraulic and water quality simulations were performed on the water supply network model. Then, the changes in water quality before and after the DMA zoning of the water supply network were compared, and the impact of DMA zoning on water quality was analyzed.

[0060] For cases where the original secondary chlorination scheme of the pipeline network is used, the judgment is made based on the assessment results of the water quality changes in the water supply network: if the residual chlorine concentration of some pipeline nodes does not meet the preset limit after DMA partitioning, the secondary chlorination multi-objective optimization model is used to perform secondary chlorination multi-objective optimization calculation on the hydraulic model of the water supply network after DMA partitioning, generating a set of secondary chlorination optimization schemes after DMA partitioning, ensuring that the hydraulic model of the water supply network after DMA partitioning meets the requirements of the "Standards for Drinking Water Quality (GB 5749-2022)" for the range of residual chlorine concentration at the end of the pipeline network after applying the secondary chlorination optimization scheme, so as to ensure the safety of water quality.

[0061] In an optional embodiment, the preset limit is set according to the "Standards for Drinking Water Quality (GB 5749-2022)", with the residual chlorine concentration at each node as the water quality assessment indicator, and the limit for residual chlorine concentration at each node is 0.05~2 mg / L.

[0062] In an optional embodiment, the secondary chlorination optimization scheme adopts a non-constant chlorination method for the water source point in the water supply network hydraulic model and other nodes as alternative secondary chlorination stations, and the chlorine dosage changes over time.

[0063] This embodiment uses the above-mentioned secondary chlorine dosing method, which can minimize the total amount of chlorine added and suppress the generation of disinfection byproducts.

[0064] Furthermore, in an optional embodiment, the secondary chlorination multi-objective optimization model includes an objective function, decision variables, and constraints.

[0065] The objective function aims to minimize the amount of chlorination, the complexity of chlorination, and the number of secondary chlorination stations.

[0066] The chlorination amount in the secondary chlorination multi-objective optimization model includes the sum of the chlorination amount at the water source point and the dosage of all secondary chlorination station nodes within a simulation cycle; the chlorination complexity in the secondary chlorination multi-objective optimization model represents the degree to which the non-constant chlorination concentration at the water source point and the secondary chlorination station nodes changes over time within a simulation cycle.

[0067] In addition, the decision variables include whether each node in the water supply network hydraulic model is selected as a secondary chlorination site, and the chlorination concentration at each hydraulic step when it is selected as a secondary chlorination site.

[0068] The constraints include the residual chlorine concentration limits for all nodes and the residual chlorine concentration limits for the treated water.

[0069] The expression for the multi-objective optimization model for secondary chlorination is as follows:

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076] In the formula, OF 1. OF 2. OF 3 represents the objective function for minimizing the chlorination amount, chlorination complexity, and number of chlorination stations, respectively; M This refers to the amount of chlorine added. express i Water source at all times j The chlorination concentration; express i Secondary chlorination station k Chlorination strength, express i real-time water source flow rate This indicates the chlorination time at each water source point. Indicates the duration for which a certain chlorination intensity is maintained at a secondary chlorination site; JThe total number of water sources. T To simulate the total duration; C This indicates the total complexity of chlorination disinfection measures; express i Water source at all times j Chlorination complexity, express i Chlorination stations k Chlorination complexity, K This represents the total number of secondary chlorination sites; B Indicates the number of chlorination stations. Represents a node n Whether it is used as a secondary chlorination site, if the node n If selected as a chlorination site, then ,otherwise ; N The total number of nodes requiring water; Boolean(·) represents the Boolean conversion function; express i Time Node n Residual chlorine concentration; express i Water source at all times j The residual chlorine concentration.

[0077] Furthermore, in an optional embodiment, the constraints include, according to the "Standards for Drinking Water Quality (GB5749-2022)," the residual chlorine concentration limit range for all nodes is 0.05 mg / L to 2 mg / L; and the residual chlorine concentration of the treated water is not less than 0.3 mg / L.

[0078] Furthermore, in an optional embodiment, the step of comprehensively evaluating the benefits of the set of optimized secondary chlorination schemes after DMA partitioning includes: calculating the total daily chlorine dosage, the number of secondary chlorination sites, and the complexity of chlorination operations after DMA partitioning, based on the set of optimized secondary chlorination schemes after DMA partitioning.

[0079] This embodiment conducts a comprehensive benefit assessment of the set of optimized secondary chlorination schemes, which can further provide decision-making departments with a cost-benefit analysis that can balance the control of water supply network leakage and the guarantee of water quality safety, thus contributing to the generation of reasonable decision-making schemes.

[0080] Example 2

[0081] This embodiment applies the secondary chlorination optimization method for independent metering zones in water supply networks proposed in Embodiment 1, specifically to a water supply network in a small town.

[0082] In this embodiment, the target area is flat, and the water supply network includes one water source, 27 water usage nodes, and 34 water supply pipes. In the northern part of the water supply network, there is a 50m elevated water tank that uses gravity water supply with a daily water supply capacity of 2.52 × 10⁴ m³. All water usage nodes have the same elevation of 25m, ensuring a normal water pressure of 15m for all nodes.

[0083] like Figure 2 The diagram shown is a schematic diagram of the water supply network and the water demand results of the nodes in this embodiment. It shows the nodes with large water demand and the nodes where the water quality is difficult to meet the standards.

[0084] This embodiment proposes a DMA zoning scheme for the hydraulic model of the water supply network, dividing the network into two zones. To meet the requirement that the water pressure at the nodes is higher than 15m, the network is modified by appropriately increasing the diameter of some pipes.

[0085] Based on the hydraulic model of the water supply network, a DMA partitioning scheme is set, such as... Figures 3-5 As shown, where Figure 3 This is a schematic diagram of a DMA partitioning scheme. Figure 4 This shows the distribution of the two chlorination stations before the DMA partitioning. Figure 5 A comparison chart of residual chlorine concentrations at key nodes of the water supply network before and after applying the preset chlorination scheme to the DMA zone.

[0086] In this embodiment, the secondary chlorination scheme shown in Table 1 below is first applied before and after the DMA partitioning scheme.

[0087] Table 1. Secondary chlorination scheme before DMA partitioning

[0088]

[0089] Please see Figure 5 This embodiment takes into account the scale of the water supply network and uses a grayscale image to present the difference in residual chlorine concentration at key nodes before and after DMA partitioning of the water supply network. Then, a program for optimizing secondary chlorination of the water supply network was written in C language using the Visual Studio platform. This program sets the chlorination methods for the water source and secondary chlorination station, calls the built-in functions of the EPANET2.0 Toolkit to perform hydraulic and water quality calculations on the hydraulic models before and after DMA partitioning, and uses a multi-objective optimization algorithm to solve the above-mentioned secondary chlorination multi-objective optimization model to obtain the corresponding set of secondary chlorination schemes. Finally, the comprehensive benefits of the set of secondary chlorination schemes are compared, and the secondary chlorination scheme with the best comprehensive benefits is selected, resulting in the following... Figure 6 The diagram shows the optimal secondary chlorination scheme selected after considering the impact of DMA partitioning.

[0090] Depend on Figure 5It can be seen that after the water supply network hydraulic model of this embodiment is partitioned by DMA, the residual chlorine concentration of the four key nodes is reduced to varying degrees, indicating that there is a risk of water quality deterioration at these locations after DMA partitioning.

[0091] The comparative analysis results of the comprehensive benefits of the secondary chlorination scheme before and after DMA zoning of the water supply network in this embodiment are shown in Table 2 below.

[0092] Table 2. Overall Benefits of the Two-Stage Chlorination Scheme Before and After DMA Partitioning

[0093]

[0094] As shown in the table above, both the total dosage and the total operational complexity increase to varying degrees after DMA partitioning. The secondary chlorination optimization method for independent metering partitions of the water supply network proposed in this embodiment can optimize the secondary chlorination scheme of the water supply network after partitioning, thus taking into account the water quality safety requirements of the network.

[0095] Example 3

[0096] This embodiment proposes an optimized secondary chlorination system for independent metering zones in a water supply network, applying the optimized secondary chlorination method for independent metering zones in a water supply network proposed in Embodiment 1. For example... Figure 7 The diagram shown is an architecture diagram of the secondary chlorination optimization system for independent metering zones of the water supply network in this embodiment.

[0097] The independent metering zone secondary chlorination optimization system for the water supply network proposed in this embodiment includes:

[0098] The data acquisition module is used to acquire hydraulic model data of the water supply network;

[0099] The water quality simulation setting module is used to construct a residual chlorine decay model and configure the residual chlorine decay coefficient, and set the chlorine addition simulation method, based on the scale of the water supply network hydraulic model and the degree of impact of residual chlorine decay on water quality.

[0100] The water quality change assessment module is used to set up a DMA zoning scheme based on the hydraulic model of the water supply network and to assess the water quality changes of the water supply network after DMA zoning.

[0101] The secondary chlorination optimization module includes a secondary chlorination multi-objective optimization model, which is used to perform secondary chlorination multi-objective optimization calculations on the hydraulic model of the water supply network after DMA partitioning, and generate a set of secondary chlorination optimization schemes after DMA partitioning.

[0102] The comprehensive benefit evaluation module is used to evaluate the comprehensive benefits of the set of secondary chlorination optimization schemes after DMA partitioning, and output the secondary chlorination optimization schemes with higher comprehensive benefits in the set as alternative schemes.

[0103] In an optional embodiment, the residual chlorine decay model is set according to the actual situation of the water supply network hydraulic model, and a first-order decay model is generally selected. The residual chlorine decay coefficient can be determined experimentally or a reference value can be selected from the literature. In the first-order decay model, the value range of kb is -0.004 to -3.72, and kw is selected according to the pipe material. For example, when polyethylene pipe is selected in the water supply network hydraulic model, kw=-0.8.

[0104] Optionally, before performing DMA partitioning, a suitable secondary chlorination simulation method is selected based on the actual operation of the water supply network hydraulic model. The original secondary chlorination scheme of the water supply network is used to simulate the hydraulic and water quality of the water supply network system. Then, the water quality change assessment module compares the changes in water quality before and after DMA partitioning of the water supply network and analyzes the impact of DMA partitioning on water quality. When the residual chlorine concentration at the network nodes after DMA partitioning meets the preset limit, the water quality change assessment module outputs the assessment results and the original secondary chlorination scheme of the network. When the residual chlorine concentration at some network nodes after DMA partitioning does not meet the preset limit, the water quality change assessment module sends a working signal to the secondary chlorination optimization module, which performs multi-objective optimization calculations for secondary chlorination and generates a set of optimized secondary chlorination schemes after DMA partitioning.

[0105] In an optional embodiment, the secondary chlorination optimization scheme adopts a non-constant chlorination method for the water source point in the water supply network hydraulic model and other nodes as alternative secondary chlorination stations, and the chlorine dosage changes over time.

[0106] In an optional embodiment, the secondary chlorination optimization module includes a multi-objective optimization model for secondary chlorination, comprising an objective function, decision variables, and constraints. The objective function aims to minimize the chlorination dosage, chlorination complexity, and the number of chlorination stations. The chlorination dosage in the multi-objective optimization model includes the sum of the chlorination dosage at the water source and the dosage at all secondary chlorination stations within a simulation period. The chlorination complexity in the multi-objective optimization model represents the degree to which the non-constant chlorination concentrations at the water source and secondary chlorination stations change over time within a simulation period.

[0107] The decision variables include whether each node in the water supply network hydraulic model is selected as a secondary chlorination site, and the chlorination concentration at each hydraulic step when it is selected as a secondary chlorination site; the constraints include the residual chlorine concentration limits for all nodes and the residual chlorine concentration limits for the treated water.

[0108] The expression for the multi-objective optimization model for secondary chlorination is as follows:

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] In the formula, OF 1. OF 2. OF 3 represents the objective function for minimizing the chlorination amount, chlorination complexity, and number of chlorination stations, respectively; M This refers to the amount of chlorine added. express i Water source at all times j The chlorination concentration; express i Secondary chlorination station k Chlorination strength, express i real-time water source flow rate This indicates the chlorination time at each water source point. Indicates the duration for which a certain chlorination intensity is maintained at a secondary chlorination site; J The total number of water sources. T To simulate the total duration; C This indicates the total complexity of chlorination disinfection measures; express i Water source at all times j Chlorination complexity, express i Chlorination stations k Chlorination complexity, K This represents the total number of secondary chlorination sites; B Indicates the number of chlorination stations. Represents a node n Whether it is used as a secondary chlorination site, if the node n If selected as a chlorination site, then ,otherwise ; N The total number of nodes requiring water; Boolean(·) represents the Boolean conversion function; express i Time Node n Residual chlorine concentration; express i Water source at all times j The residual chlorine concentration.

[0116] Furthermore, the chlorination amount in the secondary chlorination multi-objective optimization model includes the chlorination amount at the water source point and the sum of the dosage at all secondary chlorination stations within a simulation cycle.

[0117] In an optional embodiment, the constraints include the following: according to the "Standards for Drinking Water Quality (GB 5749-2022)," the residual chlorine concentration limit for all nodes is 0.05 mg / L to 2 mg / L; the residual chlorine concentration of the treated water is not less than 0.3 mg / L.

[0118] In an optional embodiment, the step of comprehensively evaluating the benefits of the set of optimized secondary chlorination schemes after DMA partitioning includes: calculating the total daily chlorine dosage, the number of secondary chlorination station nodes, and the complexity of chlorination operations after DMA partitioning based on the set of optimized secondary chlorination schemes after DMA partitioning.

[0119] In this embodiment, a multi-objective optimization calculation for secondary chlorination is performed based on the water quality changes in the water supply network after DMA partitioning, generating a set of optimized secondary chlorination schemes after DMA partitioning. Then, a comprehensive benefit evaluation is conducted on the set of optimized secondary chlorination schemes, and the optimized secondary chlorination schemes with higher comprehensive benefits are output as candidate schemes. This ensures that the optimized secondary chlorination schemes in the water supply network hydraulic model after DMA partitioning meet the minimum chlorination amount required for at least a specific qualified water volume, thereby guaranteeing water quality safety.

[0120] Example 4

[0121] This embodiment proposes a computer device, including one or more processors; a memory; and one or more application programs; wherein the one or more application programs are stored in the memory and configured to be executed by the processor to perform the operation of the secondary chlorination optimization method for independent metering zones of water supply networks proposed in this invention.

[0122] Example 5

[0123] This embodiment proposes a storage medium storing a computer program, which is loaded by a processor to execute the operation of the secondary chlorination optimization method for independent metering zones of water supply networks proposed in this invention.

[0124] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for optimizing secondary chlorination of a water distribution network independently metered partition, characterized in that, The method comprises the following steps: S1, obtaining water supply network hydraulic model data; S2, constructing a residual chlorine decay model and configuring a residual chlorine decay coefficient according to the size of the water supply network hydraulic model and the influence degree of residual chlorine decay on water quality, and setting a chlorine dosage simulation mode; S3, setting a DMA zoning scheme according to the water supply network hydraulic model, and evaluating the water quality change of the water supply network after DMA zoning; S4, judging according to the evaluation result of the water quality change of the water supply network: if the residual chlorine concentration of the pipe network node after DMA zoning meets the preset limit value, output the original pipe network secondary chlorine addition scheme; if there is part of the pipe network node after DMA zoning whose residual chlorine concentration does not meet the preset limit value, construct a secondary chlorine addition multi-objective optimization model, and perform secondary chlorine addition multi-objective optimization calculation on the water supply network hydraulic model after DMA zoning through the secondary chlorine addition multi-objective optimization model, to generate a secondary chlorine addition optimization scheme set after DMA zoning; In the S4 step, the secondary chlorine addition multi-objective optimization model comprises a target function, a decision variable and a constraint condition; the target function takes minimizing the chlorine dosage, chlorine addition complexity and the number of chlorine addition stations as the target; The chlorine dosage in the secondary chlorine addition multi-objective optimization model comprises the sum of the chlorine dosage of the water source point and the dosage of all secondary chlorine addition station nodes within one simulation period; The chlorine addition complexity in the secondary chlorine addition multi-objective optimization model represents the degree of change of the non-constant chlorine concentration of the water source point and the secondary chlorine addition station nodes with time within one simulation period; The decision variable comprises whether each node in the water supply network hydraulic model is selected as a secondary chlorine addition station, and the chlorine concentration of each hydraulic step when selected as a secondary chlorine addition station; the constraint condition comprises the residual chlorine concentration limit value of all nodes and the residual chlorine concentration limit value of the finished water; S5, comprehensive benefit evaluation is performed on the secondary chlorine addition optimization scheme set after DMA zoning, and the secondary chlorine addition optimization scheme with higher comprehensive benefit in the set is output as a candidate scheme.

2. The water distribution network independent metering district secondary chlorination optimization method according to claim 1, characterized in that, In the secondary chlorine addition optimization scheme, the water source point in the water supply network hydraulic model and other nodes as the candidate secondary chlorine addition stations all adopt a non-constant chlorine addition mode, and the chlorine dosage changes with time.

3. The water distribution network independent metering district secondary chlorination optimization method according to claim 2, characterized in that, The expression of the secondary chlorine addition multi-objective optimization model is as follows: In the formula, OF 1. OF 2. OF 3 represent the objective functions for minimizing the chlorination amount, chlorination complexity, and number of chlorination stations, respectively; M This refers to the amount of chlorine added. express i Water source at all times j The chlorination concentration; express i Secondary chlorination station k Chlorination strength, express i real-time water source flow rate This indicates the chlorination time at each water source point. Indicates the duration for which a certain chlorination intensity is maintained at a secondary chlorination site; J is the total number of water source points, T is the total simulation time length; C represents the total complexity of the chlorination measures; represents i the residual chlorine concentration of the water source point j at time represents i the chlorination complexity of the chlorination site k at time K is the total number of secondary chlorination sites; B represents the number of chlorination sites, represents the node n whether it is a secondary chlorination site, if the node n is selected as a chlorination site, then , otherwise ; N is the total number of water demand nodes; Boolean(·) represents a Boolean value conversion function; represents i the residual chlorine concentration of the node n at time represents i the residual chlorine concentration of the water source point j at time 4. The water distribution network independent metering district secondary chlorination optimization method according to claim 3, characterized in that, In the constraint condition, the residual chlorine concentration limit value of all nodes ranges from 0.05 mg / L to 2 mg / L; the residual chlorine concentration of the finished water is not less than 0.3 mg / L.

5. The method according to any one of claims 1 to 4, characterized in that, In the S5 step, the step of performing comprehensive benefit evaluation on the secondary chlorine addition optimization scheme set after DMA zoning comprises: calculating the total chlorine dosage, the number of secondary chlorine addition stations and the complexity of chlorine addition operation of each day after DMA zoning according to the secondary chlorine addition optimization scheme set after DMA zoning.

6. A water supply network independent metering partition secondary chlorination optimization system applied to the water supply network independent metering partition secondary chlorination optimization method of any one of claims 1-5, characterized in that, It comprises: A data acquisition module for obtaining water supply network hydraulic model data; A water quality simulation setting module for constructing a residual chlorine decay model and configuring a residual chlorine decay coefficient according to the size of the water supply network hydraulic model and the influence degree of residual chlorine decay on water quality, and setting a chlorine dosage simulation mode; a water quality change evaluation module configured to set a DMA partitioning scheme according to the water supply network hydraulic model and evaluate water quality changes in the water supply network after the DMA partitioning; a secondary chlorination optimization module including a secondary chlorination multi-objective optimization model configured to perform secondary chlorination multi-objective optimization calculation on the water supply network hydraulic model after the DMA partitioning and generate a set of secondary chlorination optimization schemes after the DMA partitioning; a comprehensive benefit evaluation module configured to perform comprehensive benefit evaluation on the set of secondary chlorination optimization schemes after the DMA partitioning and output a secondary chlorination optimization scheme with higher comprehensive benefit in the set as a candidate scheme.

7. The water distribution network independent metering district secondary chlorination optimization system of claim 6, wherein, The secondary chlorination multi-objective optimization model in the secondary chlorination optimization module includes an objective function, decision variables, and constraint conditions; wherein the objective function aims to minimize the amount of chlorination, the complexity of chlorination, and the number of secondary chlorination sites; The amount of chlorination in the secondary chlorination multi-objective optimization model includes the sum of the amount of chlorination at the water source point and the amount of chlorination at all secondary chlorination site nodes within a simulation period; the complexity of chlorination in the secondary chlorination multi-objective optimization model represents the degree of change in the non-constant chlorination concentration at the water source point and the secondary chlorination site nodes over time within a simulation period; The decision variables include whether each node in the water supply network hydraulic model is selected as a secondary chlorination site and the chlorination concentration of each hydraulic step when selected as a secondary chlorination site; The constraint conditions include the residual chlorine concentration limit of all nodes and the residual chlorine concentration limit of the finished water.

8. A computer device comprising one or more processors; a memory; and one or more application programs; wherein the one or more application programs are stored in the memory and configured to be executed by the processor to perform the operations of the water supply network independent metering partitioning secondary chlorination optimization method according to any one of claims 1-5.

9. A storage medium, characterized by A computer program is stored thereon, and the computer program is loaded by a processor to perform the operations of the water supply network independent metering partitioning secondary chlorination optimization method according to any one of claims 1-5.

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