Irrigation area water resource optimal configuration, scheduling and control system and software

Abstract

The invention provides an irrigation district water resource optimal configuration, scheduling and control system and software, the system comprises a water resource configuration module, a water volume optimal scheduling module and an operation control module, the water resource configuration module is used for realizing a water resource configuration process, and comprises three parts of objective function determination, model expression and model solution; and in the water volume optimization scheduling module, according to a water resource configuration model, time period parameters are substituted for solution to obtain the water distribution volume of each time period of each water consumption unit, and then water volume scheduling is carried out according to the water distribution volume. According to the invention, all-around and multi-layer configuration of water resources is realized; according to the method, a reasonable objective function is determined, for example, economic benefits, social benefits, natural resource balance and the like are considered, and a corresponding mathematical model is constructed to express a water resource allocation problem, so that a basis is provided for solution, and accurate management of water resources is realized. The objective function can reflect the demands of different benefit groups, and ensures the fairness and sustainability of water resource allocation.

Description

Technical Field

[0001] The present invention relates to the technical field of irrigation area water resource optimization, and in particular to an irrigation area water resource optimization configuration, dispatching and control system and software. Background Art

[0002] Due to historical reasons, there are many problems in irrigation areas, which have caused the irrigation areas to be unable to meet the overall needs of my country's agricultural, rural and even national economic development, and have even become one of the constraints on improving agricultural comprehensive production capacity and affecting national food security. These include: Incomplete supporting facilities and aging and disrepair in irrigation areas: Most irrigation projects have problems of incomplete supporting facilities and low construction standards due to historical reasons, and they have been seriously aging and disrepaired during long-term operation, resulting in low irrigation efficiency and serious waste of water resources.

[0003] Insufficient water resources and water waste: With the rapid development of the economy, the contradiction between water supply and demand has intensified, and the low effective utilization rate of irrigation water in irrigation areas has aggravated the water resource shortage.

[0004] Insufficient investment and extensive management: Insufficient investment and extensive management in irrigation areas have led to a decline in irrigation benefits, which cannot meet the needs of modern agriculture and rural development and have even become a constraint on improving the comprehensive agricultural production capacity.

[0005] Lack of advanced scheduling and control technology: The irrigation area’s water resource allocation and scheduling process lacks advanced scheduling and control technology, making it difficult to achieve precise scheduling and real-time control, and unable to make flexible adjustments based on actual demand and water source conditions, affecting the accuracy and efficiency of water transfer.

[0006] The operation control process is not sophisticated: Although the water resource allocation and scheduling process has been calculated and stored in the database, the operation control process is still not sophisticated enough to control the water use and water supply of water conservancy project buildings in a timely and appropriate manner, resulting in water resource waste and low irrigation efficiency. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an irrigation area water resources optimization configuration, scheduling and control system and software to solve the problems raised in the above-mentioned background technology. The present invention uses the canal system between the water source of the irrigation area and the terminal water supply gate as the boundary of the water project, and realizes the real-time collection, transmission, processing and analysis of water resources information through a scheduling algorithm model.

[0008] In order to achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions: an irrigation area water resource optimization configuration, scheduling and control system, including a water resource configuration module, a water quantity optimization scheduling module, and an operation control module, wherein the water resource configuration module is used to implement the water resource configuration process, including three parts: objective function determination, model expression and model solution; in the water quantity optimization scheduling module, according to the water resource configuration model, the time period parameters are substituted into the solution to obtain the water distribution volume of each water use unit in each time period, and then the water volume is scheduled according to the water distribution volume; the operation control module is used to calculate the water resource configuration and scheduling process, and the data are stored in the corresponding database table. The operation control process takes out the corresponding parameters from the data table to control the water use and supply of the gate and water source in a timely and appropriate manner. The refined control technology adopted by this module includes the opening and closing time and flow rate control of the water conservancy project buildings.

[0009] Furthermore, the objective function is to consider the cost and social benefits, and seek the highest economic benefit or the maximum water utilization rate of water resources in different time periods, or adopt a multi-objective optimization scheme and use "exhaustive enumeration" to dynamically solve the problem in multivariate three-dimensional space and time.

[0010] Furthermore, the constraints expressed by the model include: weight coefficient; the sum of total water consumption is less than or equal to the sum of water supply from various water sources; the sum of total water demand at each toll gate in each time period is less than or equal to water supply; water transfer time is shortest; water loss is minimum; the water flow rate of each water transfer section during the time period is less than the maximum flow capacity of the water transfer section; and the economic and social losses caused by reducing water supply are minimized.

[0011] Furthermore, during the model solving process, when the available water supply cannot meet the water demand, the water consumption of each water-using unit is coordinated, and the water-using units are ranked according to their importance and weighted; according to the possible combinations of each water-using unit, each water-using area and each water-using time period, the model solving process is first simplified to a two-dimensional matrix solution, and then the third dimension is calculated, and the optimal solution is first found by time period, and the optimal solution of all time periods is the optimal solution.

[0012] Furthermore, it also includes utilizing the water quantity optimization scheduling module to implement a water resource scheduling process, which includes calculating the gross water quantity of the water use unit in each time period, and calculating the starting water supply time and duration of the water source.

[0013] Furthermore, the gross water volume is the gross water supply of the water source calculated based on the net water volume of each water-using unit obtained under the water resource allocation model, taking into account various water losses. Therefore, the calculation of various water losses in the process of water delivery to the water-using units becomes the key. Water losses mainly include evaporation, seepage and leakage losses.

[0014] Furthermore, the water volume dispatching of the water intake of the water-using unit includes the determination of three elements, including: when water can be delivered to the water intake gate of the water-using unit; the opening degree of the water intake gate; the duration of water passing through the water intake gate. This part of the process is determined according to the water demand of each water-using unit during the period. When the water intake gate determines the required water flow and water demand time, the water delivery time from the water source to the intake gate is calculated according to the flow rate and the length of the water transmission channel. The water release time and flow rate of the water source can be determined to achieve timely and appropriate water supply. When the water reaches the intake gate, it will be stably and continuously delivered to the water user according to the water flow time of the intake gate to ensure that the water supply meets the water demand.

[0015] Furthermore, the operation control module can implement an operation control process, which includes gate flow mode selection, gate flow control, hole flow and weir flow determination, valve flow control, and operation control process.

[0016] Furthermore, the gate flow modes include hole flow and weir flow; in the flow control process, the water consumption requirement of the water-using unit in a certain period of time can be converted into the flow through the gate. According to the relationship between the flow and the water level before and after the gate and the gate opening, the flow of the gate is controlled through the gate opening, and the automatic control of the gate is realized by installing sensors at the project site to automatically collect the water level and gate position before and after the gate; in the operation control process, the intelligent technology and equipment operation control are used to realize the "automatic closed-loop control" from the bottom to the top or from the top to the bottom of the five-level canal system.

[0017] The invention discloses an irrigation area water resource optimization configuration, dispatching and control software, which is installed in a computer storage medium and is used to realize the optimization configuration, dispatching and control algorithm solution process of the above system when the software is executed by a computer processor.

[0018] Beneficial effects of the present invention:

[0019] 1. In the process of water resource allocation, the present invention not only takes into account the irrigation demand, but also comprehensively considers the water demand in life, industry, power generation, ecology, shipping and other aspects, thereby realizing the all-round and multi-level allocation of water resources; by determining a reasonable objective function, such as considering economic benefits, social benefits and natural resource balance, and constructing a corresponding mathematical model to express the water resource allocation problem, a basis is provided for solving the problem.

[0020] 2. According to the water resource allocation model, the present invention can calculate the water allocation of each water-using unit in each time period, and dispatch the water volume according to the allocation volume to ensure the timely and adequate supply of water resources; in the operation and control process, by taking out the corresponding parameters from the database, the opening and closing time and flow rate of water conservancy project buildings (such as sluices, pumping stations and valves) are finely controlled, thereby realizing the precise management of water resources.

[0021] 3. The present invention not only considers the basic balance between supply and demand, but also deeply analyzes the complex relationship between economic benefits, social benefits and natural resource protection. By introducing multi-objective optimization theory, such as hierarchical analysis method and fuzzy comprehensive evaluation method, an objective function that comprehensively considers multiple factors is determined. This objective function can reflect the needs of different interest groups and ensure the fairness and sustainability of water resource allocation.

[0022] 4. The present invention adopts a method combining advanced system dynamics models, hydrological models and economic models to comprehensively simulate the dynamic changes of water resource systems. By integrating these models, the actual situation of water resource allocation can be more accurately reflected, providing a scientific basis for decision-making; in terms of model solving, the present invention adopts efficient algorithms, such as genetic algorithms, particle swarm optimization algorithms, etc. These algorithms can quickly and accurately find the optimal solution or approximate optimal solution, and improve the efficiency and accuracy of water resource allocation.

[0023] 5. The present invention can calculate the water distribution of each water-using unit in real time and adjust it dynamically according to the actual situation. In this process, the joint scheduling of multiple water sources, the joint management of water quality and quantity, and the loss and efficiency problems in the water transmission process are fully considered; a complete database management system is established to store, retrieve and analyze a large amount of data in the process of water resource allocation and scheduling. This system not only improves the efficiency of data management, but also provides timely and accurate information support for decision-making; and adopts advanced intelligent control technologies, such as remote monitoring and automatic control, to realize remote management and real-time monitoring of water conservancy project buildings. This technology not only improves the efficiency of control, but also reduces labor costs and safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a model expression diagram in an embodiment of the present invention;

[0025] Figure 2 It is the multivariate three-dimensional space-time solution of the "exhaustive method" in the embodiment of the present invention;

[0026] Figure 3 It is an “envelope diagram” of the irrigation area water supply scheduling process in the embodiment of the present invention;

[0027] Figure 4 is the free outflow of the top flow gate in the embodiment of the present invention;

[0028] Figure 5 A diagram showing the flooded outflow of a gate in an embodiment of the present invention;

[0029] Figure 6 is an empirical relationship diagram in an embodiment of the present invention;

[0030] Figure 7Schematic diagram of rectangular weir flow in an embodiment of the present invention;

[0031] Figure 8 Schematic diagram of automatic closed-loop control in an embodiment of the present invention;

[0032] Fig. 9 It is a curve diagram showing the relationship between the water depth upstream and downstream of the gate, the gate opening and the flow rate in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0034] See also Figures 1 to 9 The present invention provides the following technical solutions: an irrigation area water resource optimization configuration, scheduling and control system, the system includes a water resource configuration module, a water volume optimization scheduling module, and an operation control module.

[0035] This embodiment provides a water resource allocation process and method. Irrigation area water resource allocation is to seek a balance between the required water volume and the available water volume. Here, we must consider the balance of natural resources, as well as the economic and social benefits and the balance with natural resources. The process mainly includes three steps: determining the objective function, expressing the model, and solving the model.

[0036] 1.1 Objective Function

[0037] Since it is difficult to commensurate between objectives, the benefit function is also very complex. Even if a complete benefit function can be constructed, these functions are usually highly nonlinear and discontinuous. Therefore, how to achieve large-scale, nonlinear water resource supply and demand balance and optimize it is a realistic and difficult problem. The irrigation area water resource allocation introduces target weights, which simplifies the objectives and constraints of the water resource allocation model into a linear problem. Therefore, mature linear programming algorithms can be used for solution and software implementation.

[0038] Therefore, the allocation of water resources in irrigation areas takes into account costs, social benefits (empowerment of each water supply object: dynamic weight), seeks the highest economic benefits of water resources utilization or the maximum water utilization rate in different time periods as the objective function (multi-objective optimization can also be achieved), and makes full use of the computing power (computing power) of modern computers, with the purpose of "all factors, full process, and full coverage", and adopts "exhaustive enumeration (full enumeration method)" to dynamically solve in multivariate three-dimensional space and time.

[0039] 1.2 Model Expression

[0040] The model expression is as follows Figure 1As shown in the figure, it is the objective function of maximizing economic benefits taking into account social benefits. In practical application, the objective function can also be the highest water utilization rate, etc., just need to redefine the function of f and the corresponding parameters. In fact, other objective functions can be converted into objective functions for calculating economic benefits.

[0041] In the model expression, MAX represents the maximum comprehensive economic benefit;

[0042] R is the weight coefficient of each water supply object (may be different in different time periods);

[0043] f is the economic benefits of water supply related to C1, C2, X1, and X2, where C1 is the revenue water price, C2 is the cost water price (the cost water price includes the price of water lost during the water delivery process), X1 is the net water consumption, and X2 is the gross water consumption;

[0044] i is the area where the water supply object is located, which can be defined as an administrative division, such as a village or town. (The water supply weight and water price may be different in different areas);

[0045] j is a water user (water use unit, which can be regarded as a "node" in the water supply system), such as hydropower water users, urban and rural domestic water users, urban and rural production water users, agricultural irrigation water users, ecological environment water users, etc. (similarly, different water users may have different water supply weights and water prices);

[0046] k is the water use period (similarly, the water supply weights, water prices, etc. may be different in different periods).

[0047] Constraints:

[0048] Weight coefficient: In general, urban and rural domestic water use > urban and rural production water use > agricultural irrigation water use > hydropower generation water use > urban and rural ecological water use. Under special circumstances, dynamic adjustments can be made manually. Weights can also be further defined for each water supply object. For example, the weight of cash crops in irrigation may be greater than that of food crops.

[0049] The sum of total water consumption (water consumption, water loss, water discharge, etc.) is less than or equal to the sum of available water from various water sources (including multiple water sources);

[0050] The total water demand of each toll gate in each period is less than or equal to the available water supply;

[0051] The water transfer (water delivery) time is the shortest (under the condition of multiple water sources);

[0052] Minimum water loss (including leakage in water channels, evaporation, water abandonment, head loss, etc., in the case of multiple water sources);

[0053] The water flow rate of each water delivery section during the period is less than the maximum flow capacity of the water delivery section;

[0054] The economic and social losses caused by reducing water supply are minimal (such as urban and rural production, agricultural irrigation, etc.).

[0055] 1.3 Model solution

[0056] The model constructed by the model expression is similar to a three-dimensional "game" matrix when it is unfolded. The so-called "game" is to coordinate the water consumption of each water-using unit when the available water supply cannot meet the water demand. The water-using units are ranked according to their importance and weighted (R). For example, in general, the priority ranking of the five water-receiving objects is: urban and rural domestic water > urban and rural industrial water > agricultural irrigation water > hydropower water > natural ecological water, and each water-receiving object is weighted accordingly. For example, assuming the weights are: R urban and rural domestic water = 1.00, R urban and rural industrial water = 0.85, R agricultural irrigation water = 0.80, R hydropower water = 0.65, R natural ecological water = 0.60. However, in different regions or different periods of the region, the priority ranking of water-receiving objects may be dynamically adjusted according to specific circumstances, so it is necessary to define it as a variable.

[0057] The solution process is very complicated according to the possible combinations of water use units, water use areas and water use time periods. Therefore, it can be simplified to a two-dimensional matrix solution first, and then the third dimension is calculated, that is, the optimal solution is first found by time period, and the optimal solution (sum of benefits) of all time periods is the optimal solution for the whole year.

[0058] This embodiment also provides a water resource allocation process and method:

[0059] Water optimization scheduling and water delivery is to substitute the time period parameters into the water resource allocation model to obtain the water allocation of each water unit in each time period, and then perform water scheduling according to the water allocation. The role of water scheduling mainly has two aspects.

[0060] Timely, adequate and optimized (minimum water shortage, minimum loss, maximum benefit, etc., multiple water sources) water supply to existing water-using units, including the number and degree of opening of water source water intake pumps, gates and valves and the number and degree of opening of water-using unit (gate) pumps, gates and valves.

[0061] Through the analysis of the water allocation process, the water use structure and block layout of water-using units are optimized, and the industrial structure and block layout, crop planting structure and block layout, settlement scale and layout, etc. are rationally adjusted based on the principles of "production based on water" and "development based on water".

[0062] 2.1 Calculation of gross water volume in each period of water-using unit

[0063] Gross water volume is the gross water supply of the water source calculated based on the net water volume of each water-using unit obtained under the water resource allocation model, taking into account various water losses (gross water volume = net water volume + water loss). Therefore, the calculation of various water losses in the process of delivering water to the water-using unit becomes the key. Water losses mainly include evaporation, seepage and leakage losses.

[0064] 2.2 Calculation of water supply start time and duration

[0065] The water volume dispatching of the water intake of the water-using unit (water volume metering or water fee collection port) includes the determination of three elements. The first is when water can be delivered to the water intake gate of the water-using unit (related to when the water source delivers water, how much flow is delivered, the length of the water transmission channel, the speed of water flow, etc.); the second is the opening of the water intake gate (in order to pass the required flow, in a certain period of time, it may be necessary to adjust the water intake gate opening according to the water demand and the water conditions at the water intake gate); the third is the duration of water flow through the water intake gate (when to close the gate). The above process is determined according to the water demand of each water-using unit during the period. For example, the irrigation period may be divided into different irrigation seasons and the ten days of each month in the irrigation season; for urban and rural domestic water use, it must be divided into months and days, and even the amount of water required for different periods of a day (day and night) may be different.

[0066] When the water inlet gate determines the required water flow and water demand time, the water delivery time from the water source to the inlet gate is calculated according to the flow rate and the length of the water delivery channel, and the water release time and flow rate of the water source can be determined to achieve timely and appropriate water supply. When the water reaches the inlet gate, it is stably and continuously delivered to the water user according to the water flow time of the inlet gate to ensure that the water supply meets the water demand.

[0067] The water resource dispatching process can be visually checked and displayed using an "envelope diagram", and of course it can also be presented in real time or virtually simulated using "digital twin" technology. After the irrigation area or a certain irrigation area is fully equipped with water condition monitoring devices, the calculated dispatching process parameters can be verified with measured data and corrected when necessary.

[0068] 2.2.1 Calculation of start and end time

[0069] The start and end time of water transfer is mainly related to the water flow time of the water channel between the water source and the "mouth" (water use unit). For existing projects, since the length of the water channel is known, the water flow time is only related to the flow rate.

[0070] 2.2.1.1 Calculation of flow velocity in trapezoidal and rectangular open channels

[0071] For a trapezoidal open channel:

[0072]

[0073] Because the flow rate Q (which can be calculated from the water consumption during the period: Q = W / time, where time is the number of seconds in the period) is known, v can be obtained by solving the water depth h from the above formula.

[0074]

[0075]

[0076] n is the roughness of the channel wall, n = 0.016 for cement lining, R = A / XR is the hydraulic radius, A is the cross-sectional area, and X is the wetted perimeter. Both are related to the water depth of the cross section and the geometric shape and size of the cross section (known), and only h is a variable. Therefore, substitute Then h can be found.

[0077]

[0078] i is the hydraulic slope (for uniform flow, the longitudinal slope of the channel can be used instead);

[0079] Water delivery time tj=L / v L is the length of water delivery section j.

[0080] Calculation process of flow velocity (v) and flow time (t):

[0081] Taking the trapezoidal section as an example, the calculation process is as follows:

[0082] A=((B+2×m×H)+B)×H / 2

[0083] H is the water depth, B is the bottom width, m is the slope coefficient, and m is 0 for rectangular section

[0084]

[0085] Substitute C, R, and A into and v = Q / A

[0086] Since Q is known, H and v can be calculated, and the water delivery time tj = L / v.

[0087] Assume that Q=1m3 / s (including the flow rate of the regulating gate), B=1m, m=0.75, i=0.001, L=1000m, n=0.016, and do the math.

[0088] Although only one canal section is calculated above, the calculation method for other canal sections is the same, except that the values ​​of Q, B, m, i, L, and n are different.

[0089] For a rectangular open channel:

[0090] The flow velocity calculation of a rectangular open channel is the same as that of a trapezoidal open channel. Since the rectangular open channel has a vertical channel wall, the slope coefficient is 0, that is, m=0.

[0091] 2.2.1.2 Calculation of flow rate in circular pipe (full pipe, pressurized)

[0092] For a circular duct, the travel velocity is calculated as:

[0093]

[0094] In the formula,

[0095] H is the water level difference between upstream and downstream of the pipeline;

[0096] g is the acceleration due to gravity;

[0097] ∑ζ is the sum of the local loss coefficients at the pipeline inlet and outlet;

[0098] L is the length of the pipeline;

[0099] D is the inner diameter of the pipe;

[0100] λ(Long-range loss coefficient)=8g / c2

[0101] In the above formula, c is the Xie Cai coefficient, so,

[0102]

[0103] In the above formula,

[0104] Based on the flow velocity, the water flow time from the water source to the toll gate can be calculated, and then the water release time and water stop time of the water source can be determined.

[0105] Water release time at the water source = water flow time in the upstream channel + water release time at the toll gate;

[0106] Water outage time at the water source = water outage time at the toll gate – water flow time in the upstream channel.

[0107] The water source release and water cut-off time here is not an absolute release and water cut-off time, but the release and water cut-off time of some toll gates will cause the change of water source release and water cut-off flow, so the adjustment time needs to be recalculated. Obviously, the scheduling process is dynamic.

[0108] From the above calculation process, it can be seen that the flow rate is different for different water depths, and the water depth is related to the flow rate. Therefore, the relationship between the water depth (water level) and the flow rate must be established first, and then the water depth can be obtained based on the required water flow rate (which is known). When the project is completed and water is flowing, the relationship between the water depth (water level) and the flow rate (usually expressed by a relationship curve) can be obtained through actual measurement (water level meter and flow meter); or a series of water levels can be assumed to calculate the flow rate, so as to establish the relationship between the two. Then, according to the flow rate requirement, the water depth can be found from the relationship (curve), and the flow rate can be calculated.

[0109] This embodiment also provides an operation control process and method, which specifically includes the following contents:

[0110] 3.1 Gate overcurrent mode

[0111] For gates (irrigation areas mainly use gates to control water flow), there are currently two main flow modes: bottom flow and top flow. The bottom flow is further divided into weir flow and hole flow.

[0112] 3.2 Gate flow control

[0113] The water consumption requirement of a water-using unit in a certain period of time can be converted into the flow through the gate. According to the relationship between the flow and the water level before and after the gate (needed when the outflow is submerged) and the gate opening, the flow through the gate can be controlled by the gate opening. By installing sensors on the project site, the water level before (upstream) and after (downstream) the gate and the gate position (gate opening) can be automatically collected to realize automatic control of the gate.

[0114] 3.2.1 Calculation of flow rate of underflow gate

[0115] There are two types of flow patterns for bottom flow gates, one is free outflow and the other is submerged outflow. The judgment conditions are: the water depth behind the gate / the water depth before the gate ≤ 0.7 is free outflow, and the water depth behind the gate / the water depth before the gate> 0.7, ≤ 0.9 is submerged outflow.

[0116] 3.2.1.1 Orifice flow

[0117]

[0118] In formula 3-(1) and 3-(2):

[0119] μ, μ' are flow coefficients (determined by the connection between the sluice and the channel), b is the gate width, hg is the gate opening, and H is the upstream water depth. The upstream water depth refers to a section of water flow close to "uniform flow" before the sluice, H is the water depth at the end of the uniform flow, and Z1 is the water depth difference before and after the sluice.

[0120] 3.2.1.2 Weir flow

[0121]

[0122] In formula 3-(3) and 3-(4):

[0123] is the flow coefficient (determined by the connection between the sluice and the channel), b is the gate width, h is the gate opening, and H is the upstream water depth. The upstream water depth refers to the water flow close to "uniform flow" before the gate, H is the water depth at the end of the uniform flow (near the gate), and h H It is the water depth downstream (behind the gate).

[0124] The so-called orifice flow means that there is no free water surface between the water flow under the gate and the bottom edge of the gate, forming a pressurized orifice outflow; while the weir flow is the opposite, there is a free water surface between the water flow under the gate and the bottom edge of the gate. Since the flow calculation methods of the two flow modes are different, it is necessary to first determine whether it is orifice flow or weir flow.

[0125] 3.2.1.3 Problems with flow control in underflow gates

[0126] Underflow flow control only requires the installation of upstream and downstream water level gauges (used to determine free outflow or submerged outflow. If it is free outflow, the flow calculation only requires the upstream water level to calculate the upstream water depth) and the gate level gauge to calculate the flow rate. Therefore, it is simple and convenient. However, in actual projects, the upstream of the built or planned sluice gates cannot form a smooth water flow (close to uniform flow), resulting in poor flow state and the monitored water level does not meet the flow calculation requirements.

[0127] 3.2.2 Flow calculation of top flow gate

[0128] The top-flow gate has two flow modes according to the gate opening. When the gate has a large inclination angle and a small opening, it is a free outflow mode. When the gate has a small inclination angle and a large opening, it is a submerged outflow mode. The flow calculation of the two modes is different. Similarly, the upstream and downstream water depths should also be used for judgment. If it is a Rubicon "trough gate" (top-flow type), its flow calculation results can also be used directly.

[0129] 3.2.2.1 Calculation of free outflow flow

[0130] The water flows through the top of the gate. According to the gate design, the thickness of the gate panel is less than 0.67H, where H is the water head on the weir. The gate flow rate can be calculated as the free outflow of the inclined thin-walled weir:

[0131]

[0132] In formula 3-(5), σ α It is the correction coefficient of gate inclination, which varies with the inclination angle α and can be determined according to the test results (Table 3-1).

[0133] Table 3-1 Gate tilt correction coefficient σα Value table

[0134] α 6° 13° 21° 30° 47° 59° 90° <![CDATA[σ α ]]> 1.070 1.100 1.125 1.127 1.105 1.088 1.000

[0135] m is the thin-wall weir flow coefficient. When the influence of the travel speed V0 is ignored, it is

[0136]

[0137] When considering the influence of V0,

[0138]

[0139] Where B is the gate width, m;

[0140] g is the acceleration due to gravity, m / s 2 ;

[0141] α is the gate panel inclination angle (°);

[0142] H is the water head above the weir, in m.

[0143] H=H0-Rsinα3-(8)

[0144] Where H0 is the total water head on the weir, that is, the overflow water level of the gate monitored by the gate's water level sensor;

[0145] R is the radius of the gate, unit: meter.

[0146] 3.2.2.2 Calculation of flooded outflow

[0147] When the gate opening is small, the water flows through the gate top, forming a free outflow. However, as the gate opening becomes larger and larger, the weir top becomes lower and lower. When the downstream water level is higher than the weir top and a submerged water jump occurs downstream of the weir, the downstream water level will affect the discharge of the gate, and submerged outflow will occur. Figure 5 As long as these two conditions are not met at the same time, the water flow at the weir top is still in a rapid flow state, and the flow state during discharge is still free flow.

[0148] The condition that the downstream water level is higher than the weir top is easy to determine, but the condition for a submerged hydraulic jump to occur downstream of the weir needs to be determined empirically. According to experiments, the empirical relationship for a submerged hydraulic jump is

[0149]

[0150] In the formula, the critical value and The empirical relationship is Figure 6 When the calculated The value is located at Figure 5 middle When the curve is below, a flooding jump will occur downstream. Where z is the water level difference between upstream and downstream, a1 is the downstream weir height, and H is the upstream head.

[0151] When the downstream water level is higher than the weir crest and a flooding water jump occurs downstream of the weir, the gate flow rate is calculated according to the flow formula of the thin-walled weir flooding outflow.

[0152]

[0153] Where σ is the flooding coefficient, which can be calculated using the following empirical formula:

[0154]

[0155] In the formula, h s It is the value when the downstream water level is higher than the gate top.

[0156] It should be noted that although the flow rate of the thin-walled weir during submerged outflow can be calculated, and there are also definition conditions for free outflow and submerged outflow, the system definition of free outflow or submerged outflow is somewhat complex due to the fact that the upstream water level, downstream water level and gate opening may change at the same time, and the calculation accuracy of the submerged outflow is lower than that of the free outflow. In order to ensure the measurement accuracy and reduce the complexity of the system calculation, try to avoid making the gate work under submerged outflow conditions and try to avoid a large gate opening.

[0157] The flow calculation for overhead gates can also be done using the "rectangular weir" flow calculation formula or the "waterfall" flow calculation formula and then compared with other water measurement methods, especially the velocity-area method of the rotor flowmeter and, if possible, compared with the Rubicon flow calculation method.

[0158] 3.2.2.3 Flow calculation of rectangular weir without side contraction

[0159] Rectangular weir without side contraction Figure 7 The flow rate can be calculated using formula 3-(12).

[0160]

[0161] Formula 3-(5) Applicable range: 0 <H / P<6

[0162] Where, m = 0.407 + 0.0533 H / P

[0163] H is the water head above the weir, unit: meter.

[0164] P is the height of the weir, unit: meter.

[0165] For top-flow gates, the weir height here can be calculated based on the inclination of the gate.

[0166] B is the width of the weir crest, unit: meter.

[0167] 3.3 Determination of hole flow and weir flow

[0168] To measure water using a gate, water level gauges must be installed before the gate (upstream) and after the gate (downstream), and a gate level gauge must be installed at the gate. The water depth can be calculated based on the water level, and the height from the gate bottom edge to the gate bottom plate can also be calculated based on the gate position. Therefore, when the height from the gate bottom edge to the gate bottom plate is less than the water depth in front of the gate, it can be determined as a hole flow. Conversely, when the height from the gate bottom edge to the gate bottom plate is greater than or equal to the water depth in front of the gate, it is determined as a weir flow. Select the appropriate formula for calculating the flow through the gate based on the determination result.

[0169] Based on the above concepts, the quantitative determination and calculation of weir flow and hole flow are as follows:

[0170] When e / H>0.75, it is weir flow; when e / H≤0.75, it is hole flow.

[0171] e is the gate opening height, and H is the water depth in front of the gate.

[0172] 3.4 Valve flow control

[0173] When the water diversion gate uses a valve to divide water, its flow control is relatively simple. Generally, ultrasonic pipeline flowmeters, electromagnetic pipeline flowmeters, remote water meters, etc. are installed behind the valve to achieve water volume measurement. Just like the water diversion gate using a gate and the "front control and rear measurement" method (the measurement method can be different), the valve controls the valve opening according to the flow value obtained by the flow meter. When the flow reaches the required flow, the valve opening is stabilized at a fixed value, and there is a certain fine-tuning process during the period.

[0174] 3.5 Operation Control Process

[0175] Due to changes in regional climate, natural environment, human behavior, social change and other factors, water resource allocation and dispatching have been increasingly dynamic and timely, resulting in the irrigation district operation and control process can no longer follow the traditional manual operation method, and must also adopt information technology to achieve automation and even intelligent control. Whether it is self-built and self-managed (in the near future) or social services, creating an operation and control platform is the only way out.

[0176] With the advancement and application of intelligent technology and equipment, operation control (from bottom to top or top to bottom control of the five-level channel system) will gradually achieve "automatic closed-loop control" (see Figure 8 ).

[0177] The operation control process of the irrigation area water resources scheduling process is to determine the device control during operation according to the water demand requirements of each "gate" in each period (pre-configured), based on the upstream and downstream water depths at the gate during the period or the flow of the downstream flow meter in the "front control and then quantity" engineering scenario and the relationship between the setting of the control device, for example, the number of gate openings and closings and the opening of each gate, the number of water pumps started and stopped and the opening of each water pump, the number of valves switched and the opening of each valve, etc., to ensure the flow demand.

[0178] Taking gate control as an example, according to the flow demand of the specific gate (from minimum to maximum), calculate the relationship between the upstream and downstream water depths and the gate position and flow in advance according to the previous calculation formula. For example, when the flow is Q1, the upstream water depth, downstream water depth (when it is free outflow, this data may not be needed), and gate opening should be how much; when the flow is Q2, the upstream water depth, downstream water depth, gate opening should be how much, and so on. Then establish the relationship between water depth and gate opening, you can use a table or a curve (see Fig. 9 , establish a mathematical expression). In actual operation, according to the flow requirements and the measured water depth, the corresponding gate opening can be found to control the operation.

[0179] For the "front control and rear quantity" method and valve control method, the control process is relatively simple. During the gate opening and closing process, the actual flow rate is automatically observed synchronously (realized by water metering equipment). When the flow rate is stable at the required flow rate, the gate opening can be fixed.

[0180] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention.

[0181] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An irrigation area water resources optimization configuration, dispatching and control system, characterized by: It includes a water resource allocation module, a water quantity optimization and scheduling module, and an operation control module. The water resource allocation module is used to realize the water resource allocation process, including three parts: objective function determination, model expression, and model solution. In the water quantity optimization and scheduling module, according to the water resource allocation model, the time period parameters are substituted into the solution to obtain the water distribution volume of each water use unit in each time period, and then the water volume is scheduled according to the water distribution volume. The operation control module is used to calculate the water resource allocation and scheduling process, and the data are stored in the corresponding database table. The operation control process takes out the corresponding parameters from the data table to control the water use and water supply of the gate and water source in a timely and appropriate manner. The module adopts refined control technology, including the opening and closing time and flow rate control of water conservancy project buildings.

2. The irrigation area water resources optimization configuration, dispatching and control system according to claim 1 is characterized by: Taking costs into consideration and social benefits into account, the objective function is to seek the highest economic benefits or the maximum water utilization rate of water resources in different periods of time, or to adopt a multi-objective optimization solution and use "exhaustive enumeration" to dynamically solve in multivariate three-dimensional space and time.

3. The irrigation area water resources optimization configuration, dispatching and control system according to claim 2 is characterized in that: The constraints expressed by the model include: weight coefficient; the sum of total water consumption is less than or equal to the sum of water supply from various water sources; the sum of total water demand at each toll gate in each period is less than or equal to water supply; The water transfer time is shortest; the water loss is minimal; the water flow rate in each water transfer section is less than the maximum flow capacity of the water transfer section; the economic and social losses caused by reducing the water supply are minimal.

4. The irrigation area water resources optimization configuration, dispatching and control system according to claim 3 is characterized by: During the model solving process, when the available water supply cannot meet the water demand, the water consumption of each water-using unit is coordinated, and the water-using units are ranked and weighted according to their importance. According to the possible combinations of each water-using unit, each water-using area and each water-using time period, the model solving process is first simplified to a two-dimensional matrix solution, and then the third dimension is calculated. The optimal solution is first found by time period, and the optimal solution of all time periods is the optimal solution.

5. The irrigation area water resources optimization configuration, dispatching and control system according to claim 1 is characterized in that: It also includes utilizing the water quantity optimization scheduling module to realize the scheduling process of water resources, and the process includes calculating the gross water quantity of each time period of the water use unit, and calculating the starting water supply time and duration of the water source.

6. The irrigation area water resources optimization configuration, dispatching and control system according to claim 5, characterized in that: The gross water volume is the gross water supply of the water source calculated based on the net water volume of each water-using unit obtained under the water resource allocation model, taking into account various water losses. Therefore, the calculation of various water losses in the process of water delivery to the water-using units becomes the key. Water losses mainly include evaporation, seepage and leakage losses.

7. The irrigation area water resources optimization configuration, dispatching and control system according to claim 5, characterized in that: The water volume scheduling at the water intake of the water-using unit includes the determination of three elements, including: when water can be delivered to the water intake gate of the water-using unit; the opening degree of the water intake gate; and the duration of water passing through the water intake gate. This part of the process is determined according to the water demand of each water-using unit during the period. When the water intake gate determines the required water flow and time, the water delivery time from the water source to the intake gate is calculated according to the flow rate and the length of the water transmission channel. The water release time and flow rate of the water source can be determined to achieve timely and appropriate water supply. When the water reaches the intake gate, it is stably and continuously delivered to the water user according to the water flow time of the intake gate to ensure that the water supply meets the water demand.

8. The irrigation area water resources optimization configuration, dispatching and control system according to claim 1 is characterized in that: The operation control module can realize the operation control process, which includes gate flow mode selection, gate flow control, hole flow and weir flow determination, valve flow control, and operation control process.

9. The irrigation area water resources optimization configuration, dispatching and control system according to claim 8, characterized in that: The gate flow modes include hole flow and weir flow; in the gate flow control process, the water consumption requirement of the water use unit in a certain period of time can be converted into the gate flow, and the gate flow is controlled by the gate opening according to the relationship between the flow and the water level before and after the gate and the gate opening, and the automatic control of the gate is realized by installing sensors on the project site to automatically collect the water level and gate position before and after the gate; in the operation control process, the intelligent technology and equipment operation control are used to realize the "automatic closed-loop control" from the bottom to the top or from the top to the bottom of the five-level channel system.

10. An irrigation area water resources optimization configuration, dispatching and control software, which is installed in a computer storage medium, characterized in that: When the software is executed by a computer processor, it is used to implement the optimization configuration, scheduling and control algorithm solution process of the system described in claim 1.

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