Urban rainwater resource optimization regulation and control method based on collection, storage and utilization whole process simulation

Abstract

The invention provides an urban rainwater resource optimization regulation and control method based on collection, storage and utilization whole-process simulation, and the method comprises the steps: carrying out long-series hydrological process simulation based on an urban rainwater resource collection, storage and utilization whole-process simulation model and long-series rainfall data, and obtaining the year-by-year available water storage in a long-series simulation period; according to the year-by-year available water storage amount, rigid available water amount and elastic available water amount are identified; and based on the rigid water use amount and the elastic water use amount, performing multi-objective optimization regulation and control simulation by combining water use characteristics of different users, and generating an optimization regulation and control scheme. According to the method, the rigid and elastic available water amount in the rainwater resources stored in the regulation and storage project is analyzed through long-series simulation, the water taking and using characteristics of different users are considered, optimization regulation and control simulation of the rainwater resource utilization project is carried out, and an urban rainwater resource utilization project regulation and control scheme considering the user characteristics is made based on the simulation result support; and optimal regulation and control of urban rainwater resource utilization engineering and efficient utilization of rainwater resources are supported.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of efficient utilization of water resources, and particularly relates to a city rainwater resource optimal regulation method based on a whole process simulation of collection and utilization. BACKGROUND

[0002] There are still some shortcomings in the current rainwater resource utilization practice, for example, the collection and utilization of rainwater resources in some cities are still mainly based on experience-based management, lacking scientific management system and basis; although some rainwater storage projects have formulated optimal regulation rules, they mainly face rainstorm regulation, and less consider long time series and rainwater resource regulation, the operability in rainwater resource optimal utilization is not strong, lacking dynamic allocation mechanism under long sequence rainfall conditions, and it is difficult to adapt to the dynamic allocation demand under long sequence rainfall conditions; in addition, the identification and distribution of water use structure in rainwater resource utilization are not fully considered at present, resulting in low matching degree of rainwater resources and actual water demand, low utilization efficiency of the project in actual long-term operation, and the optimal regulation of rainwater resources cannot be realized. SUMMARY

[0003] The present application provides a city rainwater resource optimal regulation method based on a whole process simulation of collection and utilization, to solve the defects in the prior art.

[0004] The present application provides a city rainwater resource optimal regulation method based on a whole process simulation of collection and utilization, comprising the following steps: constructing a whole process simulation model of city rainwater resource collection and utilization; based on the whole process simulation model and long series rainfall data, carrying out long series hydrological process simulation to obtain year-by-year available storage capacity in the long series simulation period; according to the year-by-year available storage capacity, identifying rigid available water and elastic available water, wherein the rigid available water is the minimum value of the available storage capacity in each year of the long series simulation period, and the elastic available water is the part of the available storage capacity in each year exceeding the rigid available water; based on the rigid available water and the elastic available water, combining the water use characteristics of different users, carrying out multi-objective optimal regulation simulation to generate an optimal regulation scheme; regulating city rainwater resources according to the optimal regulation scheme.

[0005] According to the city rainwater resource optimal regulation method based on a whole process simulation of collection and utilization provided by the present application, the construction process of the whole process simulation model comprises: using a city hydrological model, simulating surface runoff process by using an infiltration model, simulating surface confluence process by using a nonlinear reservoir method, and completing simulation of rainwater resource collection process; A pump station module is arranged in the urban hydrological model, and differentiated pump station operation rules are set according to water demand of different users, so that the simulation of the rainwater resource utilization process is completed.

[0006] According to the urban rainwater resource optimization control method based on the whole process simulation of collection and utilization provided by the application, the urban hydrological model is used, the surface runoff process is simulated by using the infiltration model, the surface flow concentration process is simulated by using the nonlinear reservoir method, and the simulation of the rainwater resource collection process is completed, including: The infiltration model is used to simulate the surface runoff process, the net rainfall intensity is calculated based on the rainfall intensity and the infiltration intensity, and the surface runoff flow is calculated based on the evaporation rate, the rainfall intensity and the infiltration intensity; The infiltration model is used to simulate the infiltration process, and the current infiltration capacity is calculated based on the minimum infiltration capacity and the maximum infiltration capacity; The nonlinear reservoir method is used to simulate the surface flow concentration process, the water balance equation is rewritten by using the Manning formula, the rewritten water balance equation is solved by iteration, and the surface outflow flow is obtained.

[0007] According to the urban rainwater resource optimization control method based on the whole process simulation of collection and utilization provided by the application, the urban hydrological model is used, the surface runoff process is simulated by using the infiltration model, the surface flow concentration process is simulated by using the nonlinear reservoir method, and the simulation of the rainwater resource collection process is completed, including: According to the continuity of water use, the seasonal fluctuation and the water supply guarantee rate requirement, the users are classified; According to the water use characteristics of different categories of users, the differentiated pump station operation rules are converted, and the pump station operation rules are used to specify the water intake time period and the water intake flow of each pump station; According to the actual operation requirements of the pump station, the control conditions of the pump station operation are set.

[0008] According to the urban rainwater resource optimization control method based on the whole process simulation of collection and utilization provided by the application, the infiltration model is the Horton model.

[0009] According to the urban rainwater resource optimization control method based on the whole process simulation of collection and utilization provided by the application, the rigid available water quantity and the elastic available water quantity are combined with the water use characteristics of different users to perform multi-objective optimization control simulation, and an optimization control scheme is generated, including: A multi-objective optimization algorithm is used to simulate and optimize the maximum rainwater resource utilization quantity and the minimum total power consumption of the pump station as the objective function; The decision variable of the simulation optimization includes pumping flow of each pump station and starting water level, and the constraint condition of the simulation optimization includes pumping flow range constraint, starting water level range constraint, annual starting times constraint of each pump station, and constraint that total water supply to users with rigid water demand is greater than or equal to rigid available water quantity and total water supply to users with elastic water demand is less than or equal to elastic available water quantity.

[0010] According to the urban rainwater resource optimization regulation method based on whole-process simulation of rainwater collection and utilization provided in the application, the total water supply to users with rigid water demand is the sum of rainwater resource utilization amounts of all pump stations serving the users with rigid water demand.

[0011] According to the urban rainwater resource optimization regulation method based on whole-process simulation of rainwater collection and utilization provided in the application, the total water supply to users with elastic water demand is the sum of rainwater resource utilization amounts of all pump stations serving the users with elastic water demand.

[0012] According to the urban rainwater resource optimization regulation method based on whole-process simulation of rainwater collection and utilization provided in the application, the multi-objective optimization algorithm is an NSGA-II algorithm.

[0013] According to the urban rainwater resource optimization regulation method based on whole-process simulation of rainwater collection and utilization provided in the application, the rainwater resource is regulated according to the optimization regulation scheme, and the regulation includes: The rainwater resource is regulated differently in different levels of years according to the optimization regulation scheme. In the dry year, water supply to users with rigid water demand is preferentially guaranteed, and regenerated water, municipal tap water and other water sources are used as emergency supplements; in the wet year, surplus water can be used for groundwater recharge, ecological water supplement and other purposes after meeting the demand of all users.

[0014] The urban rainwater resource optimization regulation method based on whole-process simulation of rainwater collection and utilization provided in the application can analyze rigid and elastic available water quantity in rainwater resources collected by a long series of simulation analysis and regulation engineering, consider water taking and using characteristics of different users, carry out optimization regulation simulation of rainwater resource utilization engineering, support the development of urban rainwater resource utilization engineering regulation scheme considering user characteristics based on simulation results, and support urban rainwater resource utilization engineering optimization regulation and efficient rainwater resource utilization. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0016] Figure 1 is a flowchart of the urban rainwater resource optimal regulation method based on the whole process simulation provided by the present application.

[0017] Figure 2 is a schematic diagram of rigid available water and elastic available water provided by the present application.

[0018] Figure 3 is a schematic diagram of multi-user water use under different level years provided by the present application.

[0019] Figure 4 is a schematic diagram of the pumping rule of the SWMM model provided by the present application.

[0020] Figure 5 is a schematic diagram of the solution result of rigid water use provided by the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely in combination with the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.

[0022] Due to many reasons such as management mode, the collection and utilization of urban rainwater resources in some cities are still in a relatively extensive way, mainly based on experience, and less through calculation to develop scientific and efficient rainwater resource regulation and control system, without considering multi-user demand and optimal regulation and control method. Part of the rainwater regulation and storage engineering develops optimal regulation and control rules, but still mainly faces rainwater regulation and control, less considers long time series and rainwater resource regulation and control, and the operability in rainwater resource optimal utilization is not strong, which is difficult to adapt to the dynamic allocation demand under long sequence rainfall condition, and the identification and distribution of water use structure in rainwater resource utilization are not fully considered, resulting in low utilization efficiency of the engineering in actual long-term operation.

[0023] The present application faces the efficient utilization and optimized management of urban rainwater resources, and proposes a method for optimizing and regulating urban rainwater resources based on simulation of the whole process of collection and utilization. Through long-term simulation analysis of the "rigidity" and "elasticity" of the water resources collected by the storage and regulation project, considering the characteristics of different users, the method carries out simulation of the optimization and regulation of rainwater resource utilization projects, and based on the simulation results, it supports the development of urban rainwater resource utilization project regulation schemes considering user characteristics, and supports the optimization and regulation of urban rainwater resource utilization projects and efficient utilization of rainwater resources.

[0024] wherein, Figure 1 is the flowchart of the method for optimizing and regulating urban rainwater resources based on simulation of the whole process of collection and utilization provided by the present application, as Figure 1 shown, the method comprises steps 110, 120, 130, 140 and 150.

[0025] Step 110, constructing a whole process simulation model of urban rainwater collection and utilization.

[0026] The whole process simulation model here refers to a model that can mathematically simulate the entire life cycle of urban rainwater from falling, forming surface runoff, being collected and stored (i.e. the "collection and storage" process), to being extracted and used from storage facilities (i.e. the "utilization" process).

[0027] In a specific embodiment, the construction of the whole process simulation model can include two main rainwater resource collection process simulations and rainwater resource utilization process simulations.

[0028] Among them, the rainwater resource collection process simulation mainly simulates the process of rainwater falling on the urban surface, passing through runoff and confluence, and finally entering the regulation and storage facilities (such as ecological water storage tanks, regulation and storage tanks, etc.). In one possible implementation, the simulation can be completed using a urban hydrological model, such as the SWMM model (Storm Water Management Model), which uses its surface runoff module and regulation tank module for simulation. The SWMM model is based on the physical processes of hydrology and hydrodynamics, and can accurately simulate complex phenomena such as surface runoff, pipe flow, unsteady flow, etc., and has been widely used in urban rainwater management, sponge city construction and waterlogging prevention work. The SWMM model integrates hydrology, hydrodynamics and water quality simulation into one, can handle from single event to long-term continuous simulation, and allows users to customize various parameters and control rules, with strong adaptability, and its simulation results are closer to reality. The SWMM model is one of the important technical tools in urban rainwater management.

[0029] In addition, the runoff generation process can adopt an infiltration model, such as a Horton model, for simulation. The Horton model is a classic infiltration capacity curve model that can effectively describe the attenuation process of soil infiltration rate over time during a rainfall process. The parameters of the Horton model are easy to preliminarily calibrate by common data, and the calculation efficiency is high. The Horton model is particularly suitable for urban rainwater system planning scenarios in which the underlying surface conditions are complex and long sequence simulation analysis needs to be quickly performed.

[0030] The rainwater resource utilization process simulation mainly simulates the process in which rainwater resources are extracted and utilized by different users through pump stations and other water extraction facilities from the storage facilities. In a possible implementation manner, a pump station module can also be set in the SWMM model, and differential pump station operation rules can be set according to the water demand of different users to simulate the utilization process of rainwater resources.

[0031] Step 120: Based on the whole-process simulation model and long-series rainfall data, long-series hydrological process simulation is performed to obtain the annual available storage capacity in the long-series simulation period.

[0032] Specifically, the long-series rainfall data refers to historical rainfall observation data with a long time span that can reflect the long-term fluctuation law of local rainfall. For example, the long-series rainfall data can be daily or hourly rainfall data in a time sequence of 30 years or more.

[0033] In this step, the long-series rainfall data is taken as the input condition of the whole-process simulation model constructed in step 110, and the model is run to perform continuous hydrological process simulation. After the simulation is completed, the total water quantity that can be provided by the storage facility to the outside in each simulation year (or hydrological year) is counted, so that a time sequence form of annual available storage capacity is obtained.

[0034] Step 130: According to the annual available storage capacity, the rigid available water quantity and the elastic available water quantity are identified. The rigid available water quantity is the minimum value of the available storage capacity in each year in the long-series simulation period, and the elastic available water quantity is the part of the available storage capacity in each year that exceeds the rigid available water quantity.

[0035] Here, the rigid available water quantity can be understood as the minimum value of the available storage capacity in all years in the long-series simulation period, that is, the water supply quantity in the driest year. This part of water quantity can be guaranteed in any year, and therefore has the "rigidity" characteristic of high reliability of water supply. The rigid available water quantity is suitable for supplying users with high requirements for water supply guarantee rate and continuous and stable water utilization process, such as production water.

[0036] The elastic available water amount can be understood as the available water storage amount of each year minus the rigid available water amount. The amount of this part of water fluctuates with the year, and is abundant in wet years, and can be very small or even zero in dry years, thus having the "elastic" characteristic of unstable supply reliability. The elastic available water amount is suitable for supplying users with low requirements for water supply guarantee rate, seasonal or interruptible water use, such as landscaping irrigation, road watering, etc.

[0037] wherein, Figure 2 is a schematic diagram of the rigid available water amount and the elastic available water amount provided by the present application, as shown in Figure 2 the horizontal axis represents time, such as year, and the vertical axis represents water storage amount. The shaded part is the rigid available water amount, and the non-shaded part above it is the elastic available water amount. As shown in Figure 2 the rigid available water amount can guarantee the water amount used in any year, and is suitable for supplying users with high requirements for water supply guarantee rate. The elastic available water amount changes with the use amount in wet and dry years, and is suitable for supplying users with large water change amount and low requirements for water supply guarantee rate.

[0038] Step 140, based on the rigid available water amount and the elastic available water amount, and combined with the water use characteristics of different users, multi-objective optimization control simulation is performed to generate an optimized control scheme.

[0039] The water use characteristics of different users here can be classified according to water continuity, seasonal fluctuation, and water supply guarantee rate requirements, etc. For example, users can be divided into: rigid water demand users, such as industrial production water users that do not interrupt all year round, whose water demand is stable and has high requirements for water supply guarantee rate. Elastic water demand users, such as landscaping irrigation users that only use water in spring and summer irrigation period, or municipal sanitation users that use water in spring and summer dust high period, whose water demand has obvious seasonality, and has relatively low requirements for water supply guarantee rate.

[0040] The multi-objective optimization control simulation aims to find an optimal scheme that balances multiple control objectives. For example, the maximum rainwater resource utilization and the minimum total power consumption of the pump station can be used as optimization objectives. In one possible implementation, NSGA-II (Nondominated Sorting Genetic Algorithm II) can be used for solving, which is a multi-objective optimization algorithm based on genetic algorithm, generates new individuals through selection, crossover and mutation operations, and selects excellent individuals using a non-dominated sorting method to finally obtain a Pareto optimal solution set. In dealing with the rainwater resource multi-objective optimization control problem, there is a high nonlinearity between the rainwater system regulation and storage, supply and use process and the rainfall sequence and user demand. As a heuristic global search algorithm, NSGA-II can effectively handle this complexity and avoid falling into local optimum. The optimization process involves discrete operations such as the start and stop of the pump and the opening and closing of the valve. The coding mechanism of NSGA-II is naturally suitable for handling such discrete decision variables, and can directly optimize to generate executable engineering control rules, which can better optimize the trade-off solution of multiple conflicting objectives.

[0041] In the optimization simulation, the decision variables can include the pumping flow of each pump station and the water level of the regulation and storage tank for starting pumping, and the constraint conditions can include: the pumping flow of each pump station and the starting water level must be within a reasonable range set; to avoid equipment wear and tear, the annual starting frequency of each pump station cannot be too frequent. The total water quantity allocated to all rigid water demand users must be greater than or equal to the rigid available water quantity to ensure the water use reliability. The total water quantity allocated to all elastic water demand users should be less than or equal to the elastic available water quantity.

[0042] Through the above multi-objective optimization control simulation, one or more optimal optimization control schemes containing specific pump station operation parameters can be obtained.

[0043] Step 150, according to the optimization control scheme, the urban rainwater resources are controlled.

[0044] Specifically, according to the optimization control scheme generated in step 140, the rainwater storage and utilization facilities in the city are actually operated.

[0045] Figure 3 is a multi-user water use schematic diagram provided by the present application under different levels of years, such as Figure 3As shown, in dry years, the precious rainwater resources are preferentially used to guarantee the needs of rigid users, and the needs of flexible users are compressed according to the water amount, and meanwhile, other water sources such as reclaimed water and municipal tap water can be used as emergency supplement. In wet years, after meeting the needs of all users, if there is still surplus, the surplus water amount can be used for groundwater recharge, supplement of ecological water and other purposes to improve the water supply guarantee capacity in subsequent dry years. Among them, user 1 is a water user with productive water characteristics, user 2 is a water user for green irrigation, and user 3 is a municipal water user. User 1 is a rigid user, and users 2 and 3 are flexible users. The water source corresponding to the rigid available water amount is used as a stable water source to supply user 1. Since there is still a part of rainwater resource supply shortage in some time periods of the first and last months, for this part of water, other stable water sources are used for supply. The water source corresponding to the flexible available water amount is used as a non-stable water source to supply users 2 and 3, and through optimization of water taking time period, flow and starting and adjusting water level, optimization control with the maximum water taking amount as the target is realized.

[0046] The urban rainwater resource optimization control method based on the whole-process simulation of collection and utilization provided by the embodiment identifies rigid available water amount and flexible available water amount with different supply reliabilities in rainwater resources by constructing a whole-process simulation model capable of reflecting the whole-process simulation of rainwater resource collection and utilization, and combining long-series rainfall data for simulation analysis, and reveals the important technical law that rainwater resource supply exists in reliability stratification gradient, and then multi-objective optimization is performed based thereon, so that a differentiated and refined water supply control scheme for different water users is generated. Since the embodiment distinguishes the supply attributes of rainwater resources and accurately matches and optimally configures them with the demand characteristics of users, the configuration efficiency and utilization value of rainwater resources are effectively improved. Specifically, the rigid available water amount identified by the embodiment is preferentially used to guarantee users with high requirements for water supply stability, and the flexible available water amount is flexibly configured to users with low requirements for water supply stability and can be flexibly adjusted, and the NSGA-II multi-objective optimization algorithm is used to find a global optimal balance between the two conflicting targets of maximizing rainwater resource utilization and minimizing total power consumption of the pumping station, so as to generate a control scheme set that meets the differentiated water supply reliability requirements of different users and realizes the optimal overall benefit of the system, thereby avoiding the problems of rainwater resource mismatch, supply-demand mismatch and low overall utilization rate caused by traditional “one-size-fits-all” or experience-based control.

[0047] Based on the above embodiment, the construction process of the whole-process simulation model includes: The urban hydrological model is used to simulate the surface runoff process by using the infiltration model, and the surface flow concentration process by using the nonlinear reservoir method, so as to complete the simulation of the rainwater resource collection process. In the infiltration model, the surface runoff process is simulated, the net rainfall intensity is calculated based on the rainfall intensity and the infiltration intensity, and the surface runoff flow is calculated based on the evaporation rate, the rainfall intensity and the infiltration intensity; in the infiltration model, the infiltration process is simulated, the current infiltration capacity is calculated based on the minimum infiltration capacity and the maximum infiltration capacity; in the nonlinear reservoir method, the surface confluence process is simulated, the water balance equation is rewritten by using the Manning formula, the rewritten water balance equation is solved by iteration, and the surface outflow flow is obtained.

[0048] In the urban hydrological model, a pump station module is set, and differentiated pump station operation rules are set according to the water demand of different users, so as to complete the simulation of the rainwater resource utilization process.

[0049] Specifically, the urban hydrological model is a mathematical model for simulating the hydrological response of a city area under a rainfall event. In a preferred implementation of the embodiment, the SWMM model is used to simulate the whole process of urban rainwater resource collection and utilization. The reason for choosing the SWMM model is that it is a widely used urban hydrological simulation software, which is powerful and has parameters that can be easily calibrated by common data, and has high calculation efficiency, and is especially suitable for complex urban rainwater system planning scenarios that need long sequence simulation analysis.

[0050] In the SWMM, the form of the storage tank is presented as a node, which contains specific parameters such as storage capacity, initial depth, ponding area, and maximum water storage depth. The storage capacity is described by a storage curve, which defines the shape of the storage tank by describing how the surface area changes with water depth, and finally calculates the volume by built-in integration.

[0051] In the SWMM, a water pump is defined as a pipe segment between two nodes, and the main input parameters include the positions of the inlet and outlet nodes, the water pump curve, the initial on / off state, and the start / stop depth. The operation of the water pump is defined by its characteristic curve, which relates the lifted flow to the water depth or volume of the inlet node, or to the provided lift (i.e. hydraulic head). By defining the opening and closing water depths of the inlet node, or by user-defined control rules, the opening / closing state of the water pump can be dynamically controlled.

[0052] Based on any of the above embodiments, the construction process of the whole process simulation model further includes: In the urban hydrological model, a pump station module is set, and differentiated pump station operation rules are set according to the water demand of different users, so as to complete the simulation of the rainwater resource utilization process.

[0053] Specifically, according to the continuity of water use, seasonal fluctuation and water supply guarantee rate requirements, the users are classified; for the water use characteristics of different categories of users, the differentiated pump station operation rules are converted, and the pump station operation rules are used to specify the water intake time period and water intake flow rate of each pump station; according to the actual operation requirements of the pump station, the control conditions of the pump station operation are set.

[0054] Among them, setting the pump station module is to establish one or more pump elements in the urban hydrological model (such as SWMM). In SWMM, a water pump is usually defined as a special pipe section connecting two nodes (such as a storage tank node and an outflow node). Setting the pump station module requires input of key parameters such as the location of the water inlet and outlet nodes, the water pump characteristic curve, the initial switch state, and the start and stop water level or control rules. For example, the pump station can be set to automatically start pumping when the storage tank water level reaches a certain set high water level, and stop pumping when the water level drops to a certain low water level, to prevent over-emptying the storage tank and to protect its subsequent storage function.

[0055] The most commonly used users of rainwater resource utilization include landscaping irrigation and municipal water, and the water demand of these two parts is relatively flexible, that is, the water quantity can be more or less, and the guarantee rate requirement is not high. In order to better play the benefits of rainwater resources, a part of rainwater resources can be assumed to supply productive water, and this part of water quantity is relatively rigid and has high guarantee rate requirements.

[0056] Setting differentiated pump station operation rules is the key to realizing fine simulation in this embodiment, and the core idea is that different types of users have different requirements for water quantity, water quality, water supply guarantee rate and water supply time, so these differentiated water demand needs to be converted into specific and executable pump station operation rules in the model.

[0057] Firstly, the users can be classified according to the continuity of water use, seasonal fluctuation and water supply guarantee rate requirements. For example, the following three types of users can be classified: User 1, productive water user, such as industrial cooling water. This type of user has high requirements for water source stability and high water supply guarantee rate, and the water demand is relatively stable throughout the year. User 2, landscaping irrigation water user, this type of user has obvious seasonal water demand, mainly concentrated in the spring and summer growing season, and has relatively flexible requirements for water supply guarantee rate, belonging to flexible water. User 3, municipal miscellaneous water user, such as road watering and dust control. This type of user also has seasonal water demand, and the water quantity can be flexibly adjusted according to the actual situation (such as weather, air quality), also belonging to flexible water.

[0058] Then, for the water use characteristics of different categories of users, the differentiated pump station operation rules are converted, and the water intake time period and water intake flow rate of each pump station are specified.

[0059] Among them, Figure 4This is a schematic diagram of the pumping rules for the pumping station in the SWMM model provided by this invention, as shown below. Figure 4 As shown, for User 1, their corresponding pump station (e.g., "PUMP_Ind1") is set to operate 24 / 7 year-round with a fixed water intake flow rate. For User 2, their corresponding pump station (e.g., "PUMP_Agri1") is set to operate from 8:00 AM to 6:00 PM daily from March to September each year. For User 3, their corresponding pump station (e.g., "PUMP_Urb1") is set to operate from 8:00 AM to 6:00 PM daily from February to June each year.

[0060] Through the steps described above, this embodiment can construct a full-process simulation model encompassing the two core aspects of rainwater "collection and storage" and "utilization." This model can not only simulate the transformation and collection process from rainfall to runoff based on physical mechanisms, but also simulate the water-taking behavior of different users under specific rules in a refined manner. This method of combining physical process simulation with user behavior simulation enables the model to fully and accurately reflect the actual operation of the urban rainwater resource system, providing a reliable model foundation for subsequent long-term simulations and optimized regulation.

[0061] Based on any of the above embodiments, and considering both rigid and flexible available water volume, combined with the water usage characteristics of different users, a multi-objective optimization and control simulation is performed to generate an optimized control scheme, including: A multi-objective optimization algorithm was adopted to simulate and optimize the process with the objective functions of maximizing rainwater resource utilization and minimizing the total power consumption of the pumping station. The decision variables in the simulation optimization include the pumping flow rate and activation water level of each pumping station. The constraints include constraints on the pumping flow rate range, activation water level range, and annual activation frequency of each pumping station. Additionally, the total water supply to users with rigid water demand must be greater than or equal to the rigid available water volume, and the total water supply to users with flexible water demand must be less than or equal to the flexible available water volume. The total water supply to users with rigid water demand is the sum of rainwater resource utilization by all pumping stations serving these users. The total water supply to users with flexible water demand is the sum of rainwater resource utilization by all pumping stations serving these users.

[0062] Multi-objective optimization algorithms refer to mathematical optimization algorithms that can simultaneously handle multiple objective functions. In this embodiment, the NSGA-II algorithm is preferably used. This is because there is a highly nonlinear relationship between the storage and supply process of the rainwater system and rainfall and user demand, and pump start-up and shutdown are discrete operations. As a heuristic global search algorithm, NSGA-II can effectively handle this complexity and discrete decision variables, avoid getting trapped in local optima, and ultimately obtain a set of solutions called Pareto optimal solutions, providing decision-makers with trade-offs between different objectives.

[0063] Simulations revealed that the pumping station's activation depth and pumping flow rate play a crucial role in assessing the rainwater storage capacity of the study area, and therefore are included as decision variables in the algorithm. The objective function is the rainwater resource utilization (total pumping volume of each pumping station) and the power consumption of the pumping stations. The constraints include pumping flow rate constraints, pumping station activation depth constraints, and pumping station activation frequency constraints.

[0064] In this embodiment, maximizing rainwater resource utilization is selected as the objective function for water quantity, which can characterize the simulated rainwater resource utilization in different year levels in the study area.

[0065] In the formula, For rainwater resource utilization, m 3 ; The total number of pumping stations is [number]. For the first The pumping flow rate of each pumping station, m 3 ; For the first The operating time of each pumping station, in seconds.

[0066] To achieve high efficiency, the power consumption of the pumping station is used as the objective function to characterize the power loss of the pumping station during the simulation process, and the cost of water intake and consumption is reduced as much as possible during the optimization process.

[0067] In the formula, The total power consumption of the pumping station is expressed in kW·h. The safety factor for the pumping station is taken as 1.2; The density of water is 1000 kg / m³. 3 ; The acceleration due to gravity is 9.8 m / s². 2 ; Let m be the inlet and outlet head difference of the i-th pump station with the j-th step size; Let m be the flow rate of the j-th pump station at step j. 3 / s; For the efficiency of the pumping station; is the time step, s.

[0068] In addition, the constraints are the restrictions that the decision variables must satisfy to ensure that the generated regulation scheme is feasible and reasonable in reality.

[0069] In the process of daily water use of the regulation and storage facility, the pump station flow and the pump station activation water level can directly affect the water volume change of the regulation and storage pool. At the same time, both of them are often used as important decision variables in the optimization process. Frequent start and stop of the pump station is a common problem in simulation research. Frequent start and stop is often caused by improper setting of the activation water level, and at the same time, it will cause damage and energy waste of the facility. In this embodiment, the pump station flow and the pump station activation water level are taken as decision variables, and the value range of both is constrained. In order to eliminate the influence of frequent start and stop, the start-up times of each pump station are constrained, which to some extent avoids the influence of frequent start and stop on the simulation results. The constraint conditions in this embodiment are as follows: In the formula, is the pumping flow of the i th pump station, m 3 / s; is the minimum flow of the i th pump station, m 3 / s; is the maximum flow of the i th pump station, m 3 / s.

[0070] In the formula, is the activation water level of the i th pump station, m; is the minimum activation water level of the i th pump station, m; is the maximum activation water level of the i th pump station, m. The minimum start-up depth is the initial water level of the storage pool, and the maximum depth is the water level of the storage pool.

[0071] In the formula, is the total number of start-ups of the i th pump station in a year; is the minimum number of pumping times of the i th pump station in a year; is the maximum number of pumping times of the i th pump station in a year. This constraint condition can ensure that the pump station is more in line with the ideal situation of not frequent start and stop in the real simulation state.

[0072] In the formula, is the rigidly constrained available water volume, m 3 ; is the number of pump stations of the water user rule with productive water characteristics; is the rainwater resource utilization amount obtained by the i th pump station, m3 This constraint condition can guarantee the rigid constraint of water use.

[0073] For elastic users, the total amount of water supply is limited within the range of elastic available water, that is, the total amount of water supply to users with elastic water demand is less than or equal to the elastic available water. The setting of this constraint, on the one hand, ensures the priority of rigid water use, and on the other hand, avoids excessive and inefficient use of rainwater resources in rainy years, so that more water can be used for higher value purposes or ecological water replenishment.

[0074] Based on any of the above embodiments, according to the optimized regulation scheme, the urban rainwater resources are regulated, including: According to the optimized regulation scheme, differentiated urban rainwater utilization engineering regulation is implemented for different levels of years; Among them, in dry years, the water supply to users with rigid water demand is prioritized, and recycled water, municipal tap water and other water sources are used as emergency supplements; in wet years, after meeting the needs of all users, the surplus water can be used for groundwater recharge, ecological water replenishment and other purposes.

[0075] The urban rainwater resource utilization engineering regulation scheme is developed considering the characteristics of users, and combined with long series simulation results and optimization results, a suitable regulation scheme is developed.

[0076] According to the method of the above embodiments, the multi-objective optimal solution set of the rigid constraint amount and the total amount of rainwater resources and energy consumption of the study area can be obtained, and the study area can be evaluated in different levels of years.

[0077] According to the demand difference of users for water supply stability and flexibility, combined with the rainwater supply characteristics of "rigid water supply" and "elastic water supply", the water use mode of different assumed water users is classified and arranged. For stable water supply users (water users with productive water use characteristics), because they have high requirements for water supply continuity, the "rigid water supply" mode is adopted: based on long sequence matching analysis and optimization results (the optimization results are selected according to local actual conditions), the available water quantity in dry years, normal years and wet years is Q1, Q2 and Q3 respectively. The basic water supply needs to meet Q min to meet the requirements of stable water supply users.

[0078] For elastic water users (such as green irrigation and environmental municipal water), because of their high tolerance to water supply time and scale flexibility, the "elastic water supply" mode is adopted, supplemented by other water sources: the elastic water supply quantity characteristics (the elastic water supply quantity in wet years accounts for (Q3-Q min ) / Q3, and the normal year is (Q2-Q minGreening irrigation in the rich, flat water year rain season when the period of use of flexible rainwater irrigation, dynamic matching of rainwater flexible supply of municipal water; dry year, then call the reclaimed water or moderate compression of flexible water scale. Multi-source complementary mechanism for dry year priority to protect the stability of the user rigid water, flexible water users can rely on multi-source complement; flat water year rainwater rigid supply and flexible supply cover most of the demand, municipal water, reclaimed water and other sources as an emergency supplement; rich water year rainwater resources dominant supply, after meeting all user demand, if there is still surplus, the surplus water can be used for groundwater recharge, supplement ecological water and other purposes.

[0079] The following is a specific embodiment of the method provided by the application as follows: Assume that a typical rainwater utilization project has been built in a city, with a catchment area of 8 km 2 , two rainwater storage tanks are provided in the area, SWMM simulation is constructed, sub-catchment division and storage tank generalization are carried out in the study area. Add pump station rules to clearly define three typical water users, and calibrate and verify the model according to the measured data.

[0080] According to the 60-year long series rainfall data of a city, the whole process simulation of rainwater resource collection and utilization is carried out, the annual water consumption is calculated, and the rigid water consumption Q min is 1.8 million m 3 , wherein Figure 5 is a schematic diagram of the solution of the rigid water consumption provided by the application.

[0081] Optimization simulation is carried out under three levels of years to obtain a solution set under different scenarios. The Pareto optimal solution set of this case selects the solution belonging to the maximum value of rainwater resource utilization (multi-aspect optimization can be carried out according to the city's power consumption and water resource status), and the results are shown in Table 1.

[0082] Table 1 Optimal solution set under different levels of years According to the obtained rigid water consumption Q min 1.8 million m 3 , the water consumption in dry year, flat water year and rich water year is 1.9 million m 3 , 2.5 million m 3 , 2.8 million m 3 . The flexible water supply in the rich water year accounts for 35.7% of the total water supply (1 million m 3 ), and the flat water year is 28% (700,000 m 3). The elastic water supply can be distributed to the user 2 and the user 3. In the wet year, water can be supplied according to the proportion (such as irrigation water: municipal water: storage = 5:3:2), and in the normal year, the storage water is set according to the actual situation, and the municipal water is generally stable, so the water supply can be according to the proportion (such as irrigation water: municipal water = 7:3).

[0083] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An urban rainwater resource optimal regulation method based on a whole process simulation of a storage utilization, characterized in that, The application relates to a method for optimizing and regulating urban rainwater resources. The method comprises the following steps: constructing a whole-process simulation model of urban rainwater resource collection and utilization; based on the whole-process simulation model and long-series rainfall data, carrying out long-series hydrological process simulation to obtain year-by-year available water storage capacity in a long-series simulation period; according to the year-by-year available water storage capacity, identifying rigid available water and elastic available water, wherein the rigid available water is the minimum value of the available water storage capacity in each year of the long-series simulation period, and the elastic available water is the part of the available water storage capacity in each year exceeding the rigid available water; based on the rigid available water and the elastic available water, and in combination with water use characteristics of different users, carrying out multi-objective optimization and regulation simulation to generate an optimization and regulation scheme; 2.The urban rainwater resource optimal regulation method based on the whole process simulation of the catchment utilization according to claim 1, characterized in that, regulating and controlling the urban rainwater resources according to the optimization and regulation scheme. The construction process of the whole-process simulation model comprises the following steps: adopting a city hydrological model, using an infiltration model to simulate the surface runoff process, using a nonlinear reservoir method to simulate the surface flow concentration process, and completing the simulation of the rainwater resource collection process; 3. The urban rainwater resource optimal regulation method based on the whole process simulation of the catchment utilization according to claim 2, characterized in that, setting a pump station module in the city hydrological model, and setting differential pump station operation rules according to the water use demands of different users, and completing the simulation of the rainwater resource utilization process. The simulation of the rainwater resource collection process by using the city hydrological model, using the infiltration model to simulate the surface runoff process, and using the nonlinear reservoir method to simulate the surface flow concentration process comprises the following steps: using the infiltration model to simulate the surface runoff process, calculating the net rainfall intensity based on the rainfall intensity and the infiltration intensity, and calculating the surface runoff flow based on the evaporation rate, the rainfall intensity and the infiltration intensity; using the infiltration model to simulate the infiltration process, and calculating the current infiltration capacity based on the minimum infiltration capacity and the maximum infiltration capacity; 4. The urban rainwater resource optimal regulation method based on the whole process simulation of the collection and utilization according to claim 2, characterized in that, using the nonlinear reservoir method to simulate the surface flow concentration process, based on the water balance equation, rewriting the water balance equation by using the Manning formula, and solving the rewritten water balance equation through iteration to obtain the surface outflow flow. The simulation of the rainwater resource utilization process by setting the pump station module in the city hydrological model and setting differential pump station operation rules according to the water use demands of different users comprises the following steps: classifying the users according to the continuity of water use, the seasonal fluctuation and the water supply guarantee rate requirements; for the water use characteristics of different categories of users, the differential pump station operation rules are converted, which are used to define the water intake time period and the water intake flow of each pump station; 5. The urban rainwater resource optimal regulation method based on the whole process simulation of the catchment utilization according to claim 2, characterized in that, setting the control conditions of the pump station operation according to the actual operation requirements of the pump station.

6. The urban rainwater resource optimal regulation method based on the whole process simulation of the collection and utilization according to any one of claims 1 to 5, characterized in that, The infiltration model is a Horton model. The multi-objective optimization and regulation simulation based on the rigid available water and the elastic available water, and in combination with the water use characteristics of different users to generate the optimization and regulation scheme comprises the following steps: adopting a multi-objective optimization algorithm to carry out simulation optimization with the maximum rainwater resource utilization and the minimum total power consumption of the pump station as the objective functions. The decision variable of the simulation optimization includes pumping flow and starting water level of each pump station, and the constraint condition of the simulation optimization includes pumping flow range constraint, starting water level range constraint, annual starting times constraint, and constraint that total water supply to users with rigid water demand is greater than or equal to the rigid available water amount, and total water supply to users with elastic water demand is less than or equal to the elastic available water amount.

7. The urban rainwater resource optimal regulation method based on the whole process simulation of the catchment utilization according to claim 6, characterized in that, The total water supply to users with rigid water demand is the sum of rainwater resource utilization amounts of all pump stations serving the users with rigid water demand.

8. The urban rainwater resource optimal regulation method based on the whole process simulation of the catchment utilization according to claim 6, characterized in that, The total water supply to users with elastic water demand is the sum of rainwater resource utilization amounts of all pump stations serving the users with elastic water demand. 9.The urban rainwater resource optimal regulation method based on the whole process simulation of the catchment utilization according to claim 6, characterized in that, The multi-objective optimization algorithm is an NSGA-II algorithm.

10. The urban rainwater resource optimal regulation method based on the whole process simulation of the collection and utilization according to any one of claims 1 to 5, characterized in that, The urban rainwater resource is regulated according to the optimization regulation scheme, including: Differentiated urban rainwater resource regulation is implemented for different levels of years according to the optimization regulation scheme; In dry years, water supply to users with rigid water demand is preferentially guaranteed, and recycled water, municipal tap water and other water sources are used as emergency supplements; in wet years, surplus water can be used for groundwater recharge, supplement of ecological water and other purposes after meeting the demand of all users.

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