Irrigation area multi-stage pipeline flow optimization method based on multi-library adjustment

Abstract

The invention relates to the technical field of water conservancy allocation, and discloses an irrigation area multi-stage pipeline flow optimization method based on multi-library adjustment, which comprises the following steps: carding and generalizing to determine irrigation area engineering arrangement; collecting daily water demand flow of each water user, and calculating daily water demand flow of each water inlet pipe and daily water demand flow of a canal head water diversion port; determining annual water supply and daily incoming water distribution flow of the canal head water diversion port; calculating the day-by-day initial water supply flow of each water inlet pipe; optimizing the water quantity of each water inlet pipe day by day in a virtual library adjustment mode by taking each regulation and storage library as a node; after optimization is completed, the water storage amount in the virtual library or the water shortage flow of each water user is calculated, and meanwhile the water storage amount of each regulation and storage library is calculated; adjusting the daily incoming water distribution amount of the canal head water diversion port and the maximum storage capacity of the storage reservoir according to an optimization result; and the optimization process is repeated until no water is stored in the virtual library and each water user does not lack water. Optimal allocation of water resources in an irrigation area can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of water conservancy allocation, and particularly relates to a multi-reservoir regulation-based multi-stage pipeline flow optimization method for irrigation districts. Background Art

[0002] In the planning and design stage of large-scale irrigation districts using pipeline water conveyance, due to the huge engineering system, long pipeline routes and numerous levels, after the water demand flows of the irrigation districts are superimposed, the flow variations of each level of pipelines are relatively large, and the adjustment time is too frequent. Multiple regulating reservoirs need to be set up to ensure that the interval time for adjusting the water conveyance flow of each level of water conveyance projects upstream of the regulating reservoir should not be too short; since the water conveyance pipelines mainly adopt pressure pipelines, considering the limitations of economic flow velocity and non-silting flow velocity, in order to avoid difficulties in selecting pipe materials, water machines and pumping station equipment along the line due to excessive pipeline pressure variations and facilitate operation and management, the flow should not have large variations, and it is advisable to use several relatively fixed water supply flow indicators.

[0003] Existing water distribution models mostly optimize the water distribution flow of channels based on the prior determination of the water diversion volume at the upstream water diversion inlet during the operation and scheduling stage, and most of them do not consider the regulating effect of the regulating reservoir. Moreover, due to the seasonal variation of the water demand flow in the irrigation district, there are water use contradictions between different water users and between different irrigation areas upstream and downstream. It is difficult to achieve optimal allocation of water resources in the irrigation district. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes a multi-reservoir regulation-based multi-stage pipeline flow optimization method for irrigation districts to optimize and determine the daily flow process of each level of water conveyance pipelines upstream of the regulating reservoir and the scale of the regulating reservoir according to the water demand of the terminal irrigation district and industrial and domestic water use, and to coordinate and solve the water use contradictions between different types of water users and between different irrigation areas upstream and downstream, so as to achieve optimal allocation of water resources in the irrigation district.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a multi-reservoir regulation-based multi-stage pipeline flow optimization method for irrigation districts, including: Step 1: Sort out and generalize to determine the engineering layout of the irrigation district. The irrigation district project includes a canal head water diversion inlet, the canal head water diversion inlet is connected to n parallel water inlet pipes, each water inlet pipe is connected to a regulating reservoir, each regulating reservoir is connected to multiple water outlet pipes, and each water outlet pipe corresponds to a water user; Step 2: Collect the daily water demand flow of each water user, and calculate the daily water demand flow of each water inlet pipe and the daily water demand flow of the canal head water diversion inlet; Step 3: Determine the annual water supply volume and daily incoming water distribution flow of the canal head water diversion inlet; calculate the daily initial water supply flow of each water inlet pipe; Step 4: Taking each storage reservoir as a node, determine whether the inflow corresponding to each storage reservoir on the first day is greater than the outflow. If it is greater, store the excess water in the storage reservoir or the virtual reservoir; if it is less, use the stored water in the virtual reservoir to supplement the outflow of each outlet pipe of the storage reservoir and the storage reservoir, and optimize the water supply flow of each inlet pipe according to the storage and supplementation conditions of the virtual reservoir until there is no stored water in the virtual reservoir or no water shortage for all water users; after the optimization is completed, calculate the stored water volume in the virtual reservoir, the water shortage flow of each water user, and the stored water volume of each storage reservoir. Step 5: Repeat Step 4 to determine the water supply flow of each inlet pipe from the second day to the last day. Step 6: Obtain the daily stored water volume in the virtual reservoir and the daily water shortage flow of each water user, and adjust the daily water intake distribution of the canal head diversion port and the maximum storage capacity of the storage reservoir according to the obtained data. Step 7: Repeat Steps 4 to 6 until there is no stored water in the virtual reservoir and no water shortage for each water user, and obtain the daily water supply flow of each inlet pipe, the daily water supply flow of the canal head diversion port, and the maximum storage capacity index of each storage reservoir after optimization.

[0006] In Step 6, the specific method for adjusting the daily water intake distribution of the canal head diversion port and the maximum storage capacity of the storage reservoir is as follows: Judge whether the daily stored water volume of the virtual reservoir is greater than zero. If the stored water volume of the virtual reservoir on a certain day is greater than zero, then reduce the daily water intake distribution flow of the canal head diversion port on that day; Judge whether the daily water shortage flow of each water user is greater than zero. If the water shortage flow of any water user on a certain day is greater than zero, then increase the daily water intake distribution of the canal head diversion port on that day or increase the maximum storage capacity of the corresponding storage reservoir.

[0007] In Step 6, the following steps are also included: Judge whether the stored water volume of each storage reservoir on the last day is greater than zero. If it is, then reduce the maximum storage capacity of that storage reservoir.

[0008] In Step 4, the water supply flow of the inlet pipe corresponding to each storage reservoir is the inflow, and the daily water demand flow of the corresponding inlet pipe is the outflow; The method for storing the excess water is: first store the excess water in the storage reservoir. If the stored water volume in the storage reservoir exceeds the maximum storage capacity, then store the excess part as waste water in the virtual reservoir.

[0009] In Step 4, the specific method for optimizing the water supply flow of each inlet pipe according to the storage and supplementation conditions of the virtual reservoir is: when the storage reservoir stores waste water in the virtual reservoir, reduce the water supply flow of the corresponding inlet pipe; when the storage reservoir or the corresponding water user needs to be supplemented by the virtual reservoir, increase the water supply flow of the corresponding inlet pipe.

[0010] In the second step, the calculation formula for the daily water demand flow of each water inlet pipe is as follows: ; where m represents the number of outlet pipes corresponding to the i-th water inlet pipe, represents the water demand flow of the j-th water user corresponding to the i-th water inlet pipe on the t-th day; represents the water demand flow of the i-th water inlet pipe on the t-th day; The calculation formula for the daily water demand flow of the canal head diversion port is: ; where n represents the number of water inlet pipes included in the canal head diversion port, represents the water demand flow of the canal head diversion port on the t-th day.

[0011] In the third step, the method for determining the daily water inflow distribution of the canal head diversion port is as follows: According to the daily water demand flow of the canal head diversion port, the daily water inflow distribution throughout the year is divided into multiple "reservoir filling - water supply" stages; for each "reservoir filling - water supply" stage, during the reservoir filling period, the daily water inflow distribution flow of the canal head diversion port is greater than the daily water demand flow of the canal head diversion port; during the water supply period, the daily water demand flow of the canal head diversion port is greater than the daily water inflow distribution flow of the canal head diversion port.

[0012] In the third step, the calculation formula for the daily initial water supply flow of each water inlet pipe is: ; where, represents the initial daily water supply flow of the i-th water inlet pipe on the t-th day; represents the total daily water demand flow of the canal head diversion port on the t-th day, represents the daily water inflow distribution flow of the canal head diversion port on the t-th day, represents the daily water demand flow of the i-th water inlet pipe on the t-th day.

[0013] In the fourth step, the calculation formula for the stored water volume in the virtual reservoir after optimization is: ; where, represents the stored water volume in the virtual reservoir on the t-th day after optimization, represents the stored water volume in the virtual reservoir on the t-th day, represents the supplementary water supply flow of the virtual reservoir to the j-th outlet pipe corresponding to the i-th water inlet pipe on the t-th day; represents the supplementary water supply flow of the virtual reservoir to the i-th regulating reservoir on the t-th day, T represents time; among them, there are: ; ; where, Denote the water discharge of the i-th storage reservoir on the t-th day, Denote the water supply flow rate of the i-th water inlet pipe on the t-th day; Denote the water supply flow rate of the j-th water outlet pipe corresponding to the i-th storage reservoir; Denote the maximum water storage capacity of the i-th storage reservoir; Denote the water storage volume of the i-th storage reservoir on the (t - 1)-th day.

[0014] In the fourth step described above, the calculation formula for the water shortage flow rate of each water user after optimization is: ; Among them, Denote the water shortage flow rate of the j-th water user corresponding to the i-th storage reservoir on the t-th day, Denote the water demand flow rate of the j-th water user corresponding to the i-th storage reservoir on the t-th day, Denote the supplementary flow rate of the virtual reservoir to the j-th water outlet pipe corresponding to the i-th storage reservoir.

[0015] The present invention has the following beneficial effects compared with the prior art: The present invention proposes a multi-reservoir regulation-based multi-stage pipeline flow optimization method for irrigation districts. By sorting out and generalizing and simplifying the irrigation district structure, starting from both the water demand and water supply sides, and introducing a "virtual reservoir" for water balance analysis and calculation to achieve complete water balance between the supply and demand sides. The optimization method of the present invention considers the regulation effects of multiple storage reservoirs, can realize the optimal distribution of the flow rate of the water inlet pipe of the storage reservoir in combination with the actual water storage volume, and further determine the storage reservoir capacity and multi-stage pipeline flow rate at the design stage of the irrigation district project. At the same time, under the conditions of knowing the storage reservoir capacity and the total annual water supply at the canal head, the multi-stage pipeline distribution flow process can also be determined, and the daily water inflow distribution volume of the canal head water intake can be optimized, ultimately realizing the optimal allocation of water resources in the irrigation district and providing technical support for the design and operation and scheduling of the irrigation district. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Is a flowchart of a multi-reservoir regulation-based multi-stage pipeline flow optimization method for irrigation districts provided by an embodiment of the present invention; Figure 2 Is a schematic diagram of the irrigation district structure for a multi-reservoir regulation-based multi-stage pipeline flow optimization method provided by an embodiment of the present invention; Figure 3 Is a schematic diagram of the encoded structure of the irrigation district project in an embodiment of the present invention; Figure 4 Is a detailed flowchart of a multi-reservoir regulation-based multi-stage pipeline flow optimization method for irrigation districts provided by an embodiment of the present invention; Figure 5 Is a graph of the supply-demand water process line of the canal head water intake of the irrigation district and the division of the "reservoir filling - water supply" period. Specific Embodiment

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0018] As Figure 1 shown, the embodiments of the present invention provide a method for optimizing the flow rate of multi-level pipelines in an irrigation area based on multi-library regulation, including the following steps: Step 1: Sort out and generalize to determine the engineering layout of the irrigation area.

[0019] First, as Figure 2 shown, in this embodiment, the engineering layout of the irrigation area is sorted out and generalized. The irrigation area structure obtained after sorting out and generalizing includes a canal head diversion port. The canal head diversion port is connected to n parallel inlet pipes, each inlet pipe is connected to a regulating reservoir, each regulating reservoir is connected to multiple outlet pipes, and each outlet pipe corresponds to an independent water user; the water users include irrigation areas and industrial and domestic water users.

[0020] Specifically, in this embodiment, the irrigation area consists of 1 canal head diversion port, 1 main trunk pipe, 8 trunk pipes, 41 branch trunk pipes, 41 regulating reservoirs, 72 water supply branch lines, and 72 irrigation areas. Since the flow rates of the main trunk pipe and the trunk pipes can be obtained by superimposing the flow rates of the controlled branch trunk pipes, during the generalization and sorting of the model, the main trunk pipe and the trunk pipes are removed. The 41 branch trunk pipes correspond to 41 inlet pipes, and the 72 water supply branch lines correspond to 72 outlet pipes; the engineering layout of the irrigation area is sorted out and generalized as 1 canal head diversion port connected to 41 parallel inlet pipes, each inlet pipe corresponds to a unique regulating reservoir, with a total of 41 regulating reservoirs; each regulating reservoir is connected to multiple outlet pipes, with a total of 72 outlet pipes; each outlet pipe corresponds to a unique water user, with a total of 72 water users.

[0021] Then, number the inlet pipes, regulating reservoirs, and outlet pipes. As Figure 3 shown, the inlet pipes are identified by two digits and numbered sequentially according to the water diversion order corresponding to the canal head diversion port. The inlet pipe numbers are 01, 02... 41; the regulating reservoir numbers are prefixed with "1" to the corresponding inlet pipe numbers, and the regulating reservoir numbers are 101, 102... 141; the outlet pipes are identified by four digits, and their numbers are the corresponding inlet pipe numbers plus the water diversion sequence numbers of the regulating reservoirs. For example, the two outlet pipe numbers of the first regulating reservoir are 0101 and 0102 respectively, and the four outlet pipe numbers of the second regulating reservoir are 0201, 0202, 0203, and 0204 respectively.

[0022] Step 2: Collect the daily water demand flow rates of each water user to obtain the daily flow rates of each outlet pipe, and calculate the daily water demand flow rates of each inlet pipe and the daily water demand flow rate of the canal head diversion inlet. Among them, the daily water demand flow rate of each water user is the daily flow rate of each outlet pipe.

[0023] As shown in Table 1, it is the daily flow rate table of each outlet pipe. By collecting the daily water demand flow rates of each water user, the daily water demand flow rates of each inlet pipe and the daily water demand flow rate of the canal head diversion inlet can be calculated.

[0024] Table 1 Daily flow rate table of each outlet pipe In the above Step 2, the calculation formula for the daily water demand flow rate of each inlet pipe is: ; (1) where m represents the number of outlet pipes corresponding to the i-th inlet pipe, represents the water demand flow rate of the j-th water user corresponding to the i-th inlet pipe on the t-th day, with the unit of m 3 / s; represents the water demand flow rate of the i-th inlet pipe on the t-th day, with the unit of m 3 / s; The calculation formula for the daily water demand flow rate of the canal head diversion inlet is: ; (2) where n represents the number of inlet pipes included in the canal head diversion inlet, represents the water demand flow rate of the canal head diversion inlet on the t-th day.

[0025] Step 3: Determine the annual water supply volume of the canal head diversion inlet and the daily incoming water distribution flow rate; calculate the initial daily water supply flow rate of each inlet pipe.

[0026] In the above Step 3, the method for determining the daily incoming water distribution volume of the canal head diversion inlet is as follows: According to the daily water demand flow rate of the canal head diversion inlet, divide the daily incoming water distribution throughout the year into multiple "filling the reservoir - water supply" stages; for each "filling the reservoir - water supply" stage, during the reservoir filling period, the daily incoming water distribution flow rate of the canal head diversion inlet is greater than the daily water demand flow rate of the canal head diversion inlet. First, ensure the water demand, and store the excess water in the reservoir; during the water supply period, the daily water demand flow rate of the canal head diversion inlet is greater than the daily incoming water distribution flow rate of the canal head diversion inlet, and the water demand is jointly met by the regulating reservoir and the water supply volume of the canal head diversion inlet.

[0027] Specifically, in this embodiment, the given annual water supply volume of the canal head diversion inlet is 1.392 billion m 3 . As shown in Table 2, according to the daily water demand flow rate process of the canal head diversion inlet, divide it into 3 "filling the reservoir - water supply" sections, and no water is diverted from June 1st to June 15th.

[0028] Table 2 "Filling the reservoir - water supply" time period table In the third step, the initial daily water supply flow of each water inlet pipe is calculated according to the ratio of the daily required water flow of each water inlet pipe to the total daily required water flow at the head of the canal. Specifically, the calculation formula for the initial daily water supply flow of each water inlet pipe is as follows: ; (3) Wherein, represents the initial daily water supply flow of the i-th water inlet pipe on the t-th day; represents the total daily required water flow at the water intake at the head of the canal on the t-th day, represents the daily water distribution flow of the water intake at the head of the canal on the t-th day, represents the daily required water flow of the i-th water inlet pipe on the t-th day.

[0029] Step Four: Taking each regulating reservoir as a node, determine whether the inflow corresponding to each regulating reservoir on the first day is greater than the outflow. If it is greater, store the excess water in the regulating reservoir or the virtual reservoir; if it is less, use the stored water in the virtual reservoir to supplement the outflow of each outlet pipe of the regulating reservoir and the regulating reservoir, and optimize the water supply flow of each water inlet pipe according to the storage situation and replenishment situation of the virtual reservoir until there is no stored water in the virtual reservoir or no water shortage for all water users; after the optimization is completed, calculate the stored water volume in the virtual reservoir, the water shortage flow of each water user, and the stored water volume of each regulating reservoir.

[0030] In the fourth step, the water supply flow of the water inlet pipe corresponding to each regulating reservoir is the inflow, and the daily required water flow of the corresponding water inlet pipe is the outflow.

[0031] The method for storing the excess water is as follows: The excess water is first stored in the regulating reservoir. If the stored water volume in the regulating reservoir exceeds the maximum reservoir capacity, the excess part is stored as waste water in the virtual reservoir.

[0032] In the fourth step, the specific method for optimizing the water supply flow of each water inlet pipe according to the storage situation and replenishment situation of the virtual reservoir is as follows: When the regulating reservoir stores the waste water in the virtual reservoir, reduce the water supply flow of the corresponding water inlet pipe. When the regulating reservoir or the corresponding water user needs to be replenished by the virtual reservoir, increase the water supply flow of the corresponding water inlet pipe.

[0033] Specifically, as Figure 4 shown, in this embodiment, the specific idea of water volume calculation with the regulating reservoir as the calculation node is as follows. Initially, it can be assumed that the initial reservoir capacity of each regulating reservoir is 0, and during the solution process, the reservoir capacity increases with the difference between the initial daily water supply flow of the water inlet pipe and the daily required water flow of each water inlet pipe.

[0034] (1)The water inflow of the inlet pipe corresponding to the storage reservoir first satisfies the water demand of the outlet pipe, and the excess water is stored in the storage reservoir. If the stored water volume in the storage reservoir is greater than the maximum storage capacity of the storage reservoir and there is water waste, the water supply flow rate of the i-th inlet pipe on the t-th day can be expressed as; ; (4) Among them, represents the stored water volume of the i-th storage reservoir of the model on the t-th day, with the unit of 10,000 m 3 ; represents the stored water volume of the i-th storage reservoir of the model on the (t - 1)-th day, with the unit of 10,000 m 3 ; represents the water supply flow rate of the j-th outlet pipe of the i-th inlet pipe (storage reservoir) of the model on the t-th day, with the unit of m 3 / s. represents the daily working hours of the pumping station, with the unit of hours.

[0035] If the water inflow of the inlet pipe cannot meet the water demand of the outlet pipe, the outlet pipe is short of water; ; (5) Among them, represents the water shortage flow rate of the j-th water user corresponding to the i-th inlet pipe (storage reservoir) on the t-th day, with the unit of m 3 / s, represents the water demand flow rate of the j-th water user corresponding to the i-th inlet pipe on the t-th day, represents the water supply flow rate of the j-th water user corresponding to the i-th inlet pipe.

[0036] Set up an "imaginary reservoir" with an infinite capacity; store all the water waste from the storage reservoirs into the "imaginary reservoir", then there is: T; (6) Among them, represents the stored water volume of the "imaginary reservoir" on the t-th day, with the unit of 10,000 m 3 ; Among them, T represents time, T = .

[0037] (2)Then, use the stored water volume in the "imaginary reservoir" to supplement the water shortage of each water user and the stored water volume of each storage reservoir.

[0038] Use the stored water volume in the "imaginary reservoir" to supplement the water shortage of each outlet pipe, and synchronously adjust the water supply flow rate of the corresponding inlet pipe; ; (7) Among them, represents the adjusted water supply flow rate of the j-th water user corresponding to the i-th inlet pipe (storage reservoir) on the t-th day, with the unit of m 3 / s; It represents the supplementary water supply flow rate of the virtual reservoir to the j-th outlet pipe of the i-th inlet pipe (regulation reservoir) on the t-th day, with the unit of m 3 / s. Among them, The maximum value of is equal to the water demand flow rate of the j-th water user corresponding to the i-th inlet pipe (regulation reservoir) on the t-th day

[0039] Use the stored water volume in the "virtual reservoir" to supplement the water storage volume of each regulation reservoir; ; (8) Among them, represents the optimized stored water volume of the i-th regulation reservoir on the t-th day, with the unit of 10,000 m 3 ; represents the supplementary water storage flow rate of the virtual reservoir to the i-th regulation reservoir on the t-th day, with the unit of m 3 / s. Among them, The maximum value of is equal to the maximum storage capacity of the i-th regulation reservoir

[0040] Update the stored water volume in the "virtual reservoir"; ; (9) represents the stored water volume of the model "virtual reservoir" after supplementary water supply on the t-th day, with the unit of 10,000 m 3 ; Update the water shortage volume of each outlet pipe; ; (10) Among them, represents the water shortage flow rate after supplementary water supply of the j-th outlet pipe of the i-th inlet pipe (regulation reservoir) of the model on the t-th day, with the unit of m 3 / s.

[0041] Therefore, in the fourth step described above, the calculation formula for the stored water volume of the virtual reservoir after optimization is: ; (11) Among them, represents the stored water volume of the optimized virtual reservoir on the t-th day, represents the stored water volume of the virtual reservoir on the t-th day, represents the supplementary water supply flow rate of the virtual reservoir to the j-th outlet pipe corresponding to the i-th inlet pipe on the t-th day; represents the supplementary water supply flow rate of the virtual reservoir to the i-th regulation reservoir on the t-th day, and T represents time; among them, there is: ; (12) ; (13) Among them, represents the water discharge volume of the i-th regulation reservoir on the t-th day, represents the water supply flow rate of the i-th water inlet pipe on the t-th day; represents the water supply flow rate of the j-th water outlet pipe corresponding to the i-th storage reservoir; represents the maximum water storage capacity of the i-th storage reservoir; represents the water storage volume of the i-th storage reservoir on the (t - 1)-th day.

[0042] In the fourth step, the calculation formula for the water shortage flow rate of each water user after optimization is: ; (14) where represents the water shortage flow rate of the j-th water user corresponding to the i-th storage reservoir on the t-th day, represents the water demand flow rate of the j-th water user corresponding to the i-th storage reservoir on the t-th day, represents the supplementary flow rate of the virtual reservoir to the j-th water outlet pipe corresponding to the i-th storage reservoir.

[0043] Step Five: Repeat Step Four to determine the water supply flow rates of each water inlet pipe from the second day to the last day.

[0044] In this embodiment, by repeating Step Four, adjusting the water inlet flow rate of each water inlet pipe every day until the virtual reservoir has no water storage or all water users have no water shortage, the optimization of the water supply flow rate of each water inlet pipe every day can be achieved, ensuring the balance of water use between each storage reservoir or water inlet pipe as much as possible, and at the same time, it can also achieve the purpose of minimizing the storage reservoir capacity.

[0045] Step Six: Obtain the daily water storage volume in the virtual reservoir and the daily water shortage flow rate of each water user, and adjust the daily water intake distribution volume of the canal head diversion port and the maximum storage capacity of the storage reservoir according to the obtained data.

[0046] In the sixth step, the specific method for adjusting the daily water intake distribution volume of the canal head diversion port and the maximum storage capacity of the storage reservoir is as follows: Judge whether the daily water storage volume of the virtual reservoir is greater than zero. If the water storage volume of the virtual reservoir on a certain day is greater than zero, then reduce the daily water intake distribution flow rate of the canal head diversion port on that day. If the water storage volume of the virtual reservoir on a certain day is greater than zero, it means that the daily water intake distribution flow rate of the canal head diversion port on that day is too large, so it is necessary to reduce the daily water intake distribution flow rate of the canal head diversion port on that day; Judge whether the daily water shortage flow rate of each water user is greater than zero. If the water shortage flow rate of any water user on a certain day is greater than zero, then increase the daily water intake distribution volume of the canal head diversion port on that day or increase the maximum storage capacity of the storage reservoir corresponding to the water user. If the water shortage flow rate of any water user on a certain day is greater than zero, it means that the daily water intake distribution flow rate of the canal head diversion port on that day is too small, or the maximum storage capacity of the corresponding storage reservoir is too small, so it is necessary to increase the daily water intake distribution volume of the canal head diversion port on that day or increase the maximum storage capacity of the corresponding storage reservoir.

[0047] Further, in the sixth step, the following steps are further included: Judge whether the stored water volume on the last day in each storage reservoir is greater than zero. If the stored water volume on the last day in a certain storage reservoir is greater than zero, then reduce the maximum storage capacity of the corresponding storage reservoir. If the stored water volume on the last day in a certain storage reservoir is greater than zero, it indicates that the final storage capacity of this storage reservoir is not emptied and the maximum storage capacity of the storage reservoir is on the large side, and it is necessary to reduce the maximum storage capacity of this storage reservoir.

[0048] Step 7: Repeat Steps 4 to 6 until there is no water storage in the virtual reservoir and each water user is not short of water, so as to obtain the daily water supply flow of each water inlet pipe after optimization, the daily water supply flow of the canal head diversion port, and the maximum storage capacity index of each storage reservoir.

[0049] Among them, the daily water supply flow of each water inlet pipe after optimization is: ; (15) represents the water supply flow of the i-th water inlet pipe on the t-th day after optimization, represents the supplementary flow of the virtual reservoir to the j-th outlet pipe corresponding to the i-th storage reservoir, and respectively represent the stored water volumes of the i-th storage reservoir on the t-th day and the (t - 1)-th day after optimization, and T represents time.

[0050] The daily water supply volume of the canal head diversion port after optimization is: ; (16) represents the water supply flow of the canal head diversion port on the t-th day after optimization, with the unit of m 3 / s. represents the water supply flow of the i-th water inlet pipe on the t-th day after optimization.

[0051] As Figure 5 shown, in the embodiment of the present invention, the daily flow curve corresponding to the agricultural water demand process and the regulated canal head incoming water process curve (i.e., the daily water supply flow curve of the canal head diversion port) are shown. It can be seen from the figure that after the optimization adjustment of the initially divided three filling - water supply periods, the water supply flow of the canal head diversion port obtained not only has a relatively stable water supply process, but also can meet the actual agricultural water demand flow, realizing the optimal allocation of water resources in the irrigation area. Moreover, the present invention can also optimize the design of the storage reservoir capacity.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi - reservoir - regulated multi - level pipeline flow optimization method for irrigation areas, characterized in that Including: Step 1: Sort out and generalize to determine the layout of the irrigation district project. The irrigation district project includes a canal head diversion inlet, the canal head diversion inlet is connected to n parallel inlet pipes, each inlet pipe is connected to a storage reservoir, each storage reservoir is connected to multiple outlet pipes, and each outlet pipe corresponds to a water user; Step 2: Collect the daily water demand flow of each water user, and calculate the daily water demand flow of each inlet pipe and the daily water demand flow of the canal head diversion inlet; Step 3: Determine the annual water supply of the canal head diversion inlet and the daily incoming water distribution flow; Calculate the daily initial water supply flow of each inlet pipe; Step 4: Taking each storage reservoir as a node, judge whether the incoming water flow corresponding to each storage reservoir on the first day is greater than the outgoing water flow. If it is greater, store the excess water in the storage reservoir or the virtual reservoir; if it is less, use the stored water in the virtual reservoir to supplement the outgoing water flow of each outlet pipe of the storage reservoir and the storage reservoir, and optimize the water supply flow of each inlet pipe according to the storage situation and supplementation situation of the virtual reservoir until there is no water storage in the virtual reservoir or all water users have no water shortage; after the optimization is completed, calculate the stored water volume in the virtual reservoir, the water shortage flow of each water user, and the stored water volume of each storage reservoir; Step 5: Repeat Step 4 to determine the water supply flow of each inlet pipe from the second day to the last day; Step 6: Obtain the daily stored water volume in the virtual reservoir and the daily water shortage flow of each water user, and adjust the daily incoming water distribution volume of the canal head diversion inlet and the maximum storage capacity of the storage reservoir according to the obtained data; Step 7: Repeat Steps 4 to 6 until there is no water storage in the virtual reservoir and each water user has no water shortage, and obtain the optimized daily water supply flow of each inlet pipe, the daily water supply flow of the canal head diversion inlet, and the maximum storage capacity index of each storage reservoir.

2. The multi - reservoir - regulated multi - stage pipeline flow optimization method for irrigation areas according to claim 1, wherein, In the said Step 6, the specific method for adjusting the daily incoming water distribution volume of the canal head diversion inlet and the maximum storage capacity of the storage reservoir is as follows: Judge whether the daily stored water volume of the virtual reservoir is greater than zero. If the stored water volume of the virtual reservoir on a certain day is greater than zero, then reduce the daily incoming water distribution flow of the canal head diversion inlet on that day; Judge whether the daily water shortage flow of each water user is greater than zero. If the water shortage flow of any water user on a certain day is greater than zero, then increase the daily incoming water distribution volume of the canal head diversion inlet on that day or increase the maximum storage capacity of the corresponding storage reservoir.

3. A multi-reservoir-regulated multi-stage pipeline flow optimization method for irrigation areas according to claim 1, characterized in that In the said Step 6, the following steps are also included: Judge whether the stored water volume of each storage reservoir on the last day is greater than zero. If it is, then reduce the maximum storage capacity of the storage reservoir.

4. A multi-reservoir-regulation-based multi-stage pipeline flow optimization method for irrigation areas according to claim 1, characterized in that In the said Step 4, the water supply flow of the inlet pipe corresponding to each storage reservoir is the incoming water flow, and the daily water demand flow of the corresponding inlet pipe is the outgoing water flow; The method for storing the excess water is: first store the excess water in the storage reservoir. If the stored water volume in the storage reservoir exceeds the maximum storage capacity water volume, then store the excess part as waste water in the virtual reservoir.

5. A multi-reservoir regulation-based multi-stage pipeline flow optimization method for irrigation areas according to claim 1, characterized in that In the said Step 4, the specific method for optimizing the water supply flow of each inlet pipe according to the storage situation and supplementation situation of the virtual reservoir is: when the storage reservoir stores waste water in the virtual reservoir, reduce the water supply flow of the corresponding inlet pipe; when the storage reservoir or the corresponding water user needs to be supplemented by the virtual reservoir, increase the water supply flow of the corresponding inlet pipe.

6. The multi-reservoir-regulation-based multi-stage pipeline flow optimization method according to claim 1, characterized in that In the said Step 2, the calculation formula for the daily water demand flow of each inlet pipe is: ； where m represents the number of outlet pipes corresponding to the i-th inlet pipe, represents the water demand flow rate of the j-th water user corresponding to the i-th inlet pipe on the t-th day; represents the water demand flow rate of the i-th inlet pipe on the t-th day; The calculation formula for the daily water demand flow of the canal head diversion inlet is: ； Among them, n represents the number of water inlet pipes included in the water intake at the canal head. represents the water demand flow rate of the water intake at the canal head on the t-th day.

7. A multi-reservoir regulation-based optimal method for the flow rate of multi-stage pipelines in an irrigation area according to claim 1, characterized in that, In the said Step 3, the method for determining the daily incoming water distribution volume of the canal head diversion inlet is as follows: According to the daily water demand flow of the canal head diversion inlet, the daily water inflow distribution throughout the year is divided into multiple "reservoir filling - water supply" stages; for each "reservoir filling - water supply" stage, during the reservoir filling period, the daily water inflow distribution flow of the canal head diversion inlet is greater than the daily water demand flow of the canal head diversion inlet; during the water supply period, the daily water demand flow of the canal head diversion inlet is greater than the daily water inflow distribution flow of the canal head diversion inlet.

8. A multi-reservoir regulation-based multi-stage pipeline flow optimization method for irrigation areas according to claim 1, characterized in that In the third step described above, the calculation formula for the initial daily water supply flow of each water inlet pipe is: ； Among them, represents the initial daily water supply flow rate of the i-th water inlet pipe on the t-th day; represents the total daily water demand flow rate of the canal head diversion inlet on the t-th day, represents the daily incoming water distribution flow rate of the canal head diversion inlet on the t-th day, represents the daily water demand flow rate of the i-th water inlet pipe on the t-th day.

9. A multi-reservoir-regulated multi-stage pipeline flow optimization method for irrigation areas according to claim 1, characterized in that In the fourth step described above, the calculation formula for the water storage volume of the virtual reservoir after optimization is: ； Among them, represents the stored water volume of the optimized virtual reservoir on the t-th day, represents the stored water volume of the virtual reservoir on the t-th day, represents the supplementary water supply flow rate of the virtual reservoir to the j-th outlet pipe corresponding to the i-th inlet pipe on the t-th day; represents the supplementary water supply flow rate of the virtual reservoir to the i-th storage reservoir on the t-th day, and T represents time; among them, there is: ； ； Among them, represents the water discharge of the i-th storage reservoir on the t-th day, represents the water supply flow rate of the i-th water inlet pipe on the t-th day; represents the water supply flow rate of the j-th water outlet pipe corresponding to the i-th storage reservoir; represents the maximum water storage capacity of the i-th storage reservoir; represents the water storage volume of the i-th storage reservoir on the (t - 1)-th day.

10. A multi - reservoir - regulated multi - stage pipeline flow optimization method for irrigation areas according to claim 1, characterized in that, In the fourth step described above, the calculation formula for the water shortage flow of each water user after optimization is: ； Among them, represents the water shortage flow of the j-th water user corresponding to the i-th storage reservoir on the t-th day, represents the water demand flow of the j-th water user corresponding to the i-th storage reservoir on the t-th day, represents the supplementary flow of the virtual reservoir to the j-th outlet pipe corresponding to the i-th storage reservoir.

Images