General flood regulation calculation method and device for reservoir

Abstract

The present invention discloses a general flood regulation calculation method and device for a reservoir. The method includes: for all time nodes within the flood regulation time period of the reservoir, calculating the water level, discharge flow rate, and inflow rate of the reservoir at each time node one by one in chronological order. After the calculation is completed, the allocated discharge flow rate is executed at the discharge structure corresponding to each time node. The calculation process of the time node includes: sequentially identifying whether there is a break time period, the downshift and peak point of the water level, the upshift and valley point of the water level, and the peak point or valley point of the current level of the water level between two adjacent time nodes. If any exists, corresponding time nodes are inserted between the two time nodes. The above technical solution establishes the identification of complex boundary conditions such as break time periods, up and down shifts, peak and valley values, clarifies the calculation method of the flood discharge amount of the inserted time nodes, has strong generality, solves the problem of deviation in the flood regulation calculation results of technicians, and realizes the generalization and consistency of reservoir flood regulation calculation.

Description

Technical Field

[0001] The invention relates to the technical field of reservoir control, and in particular to a universal reservoir flood control calculation method and device. Background Art

[0002] The calculation principle of reservoir flood control based on the static storage capacity method is clear, but the flood control calculation analysis under complex flood control and dispatching conditions requires solid professional knowledge and complicated calculation process, especially the processing of boundary conditions such as breaking time period, lifting and lowering, and peak and valley values requires a deep understanding and careful calculation. The above boundary conditions generally refer to the reduction or increase of the reservoir water level, and the obvious change of the water level before and after. In recent years, with the gradual advancement of the digital twin project of reservoirs and the construction of modern operation and management matrices, higher requirements have been put forward for the rapid and accurate forecasting and rehearsal of reservoir floods and flood dispatching. There is an urgent need for an automated, rapid and universal flood control calculation method or software program that can adapt to complex flood control and dispatching conditions.

[0003] However, there is currently no universal flood control calculation method or software program at home and abroad. Technical personnel use different methods when performing flood control calculations. When boundary conditions arise during the flood control process, they often selectively ignore or fail to handle the aforementioned boundary conditions properly, resulting in deviations between the flood control calculation results and the actual situation, which has a negative impact on the safety of reservoir dams and becomes a constraint on the in-depth construction of digital twins and modern operation and management matrices for reservoirs. Summary of the invention

[0004] Purpose of the invention: The present invention provides a universal reservoir flood control calculation method and device, aiming to solve the technical problem in the prior art that it is difficult to comprehensively and reasonably handle boundary conditions during reservoir flood control, resulting in deviations between flood control calculation results and actual conditions.

[0005] Technical solution: The present invention provides a general reservoir flood routing calculation method, including: for all time nodes within the reservoir flood regulation time period, calculate the water level, discharge flow rate, and inflow rate of the reservoir at each time node one by one in chronological order. After the calculation is completed, execute the allocated discharge flow rate at the discharge structure corresponding to each time node; the calculation process of the time node includes: sequentially identify whether there is a broken time period, a water level downshift and peak point, a water level upshift and valley point, and a peak point or valley point of the current water level between adjacent first and second time nodes. If any exists, insert a broken time period time node, a downshift time node or an upshift time node, a peak point time node or a valley point time node between the corresponding adjacent two time nodes; among them, the discharge flow rate between the first time node and the broken time period time node is increased compared to the original time period, the discharge flow rate of the downshift time node is decreased compared to the original time, the discharge flow rate of the upshift time node is increased compared to the original time, the discharge flow rate between the first time node and the peak point time node is increased compared to the original time period, and the discharge flow rate between the first time node and the valley point time node is decreased compared to the original time period; if the discharge capacity of the first time node is less than the inflow rate of the second time node, it is identified that there is a broken time period; if the water level of the second time node is lower than the flood limit water level, it is identified that there is a downshift; if the water level of the second time node is higher than the water level grade of the first time node, it is identified that there is an upshift; if the discharge flow rate of the first time node is less than the inflow rate and the discharge flow rate of the second time node is greater than the inflow rate, it is identified that there is a peak point; if the discharge flow rate of the first time node is greater than the inflow rate and the discharge flow rate of the second time node is less than the inflow rate, it is identified that there is a valley point.

[0006] Specifically, the calculation process of the time node further includes: if the initial water level of the initial time node is the flood limit water level, select the smaller value between the discharge capacity and the inflow rate of the initial time node as the discharge flow rate of the initial time node.

[0007] Specifically, the calculation process of the time node further includes: if among adjacent first and second time nodes, the discharge flow rate of the first time node is equal to the inflow rate and the water level of the first time node is the flood limit water level, identify a broken time period, otherwise identify a water level downshift.

[0008] Specifically, the calculation process of the time node further includes: when identifying a broken time period, if among adjacent first and second time nodes, the discharge capacity of the first time node is greater than or equal to the inflow rate of the second time node, control the discharge flow rate of the second time node to be equal to the inflow rate of the second time node, and the water level of the second time node is the flood limit water level.

[0009] Specifically, the calculation process of the time nodes further includes: for the break-period time nodes inserted between adjacent first and second time nodes, controlling the inflow rate of the break-period time nodes to be equal to the discharge capacity of the first time node, the discharge capacity of the break-period time nodes to be equal to the inflow rate, and the water level of the break-period time nodes to be the flood limit water level; before the water level is downshifted, at most one break period can be identified.

[0010] Specifically, the calculation process of the time nodes further includes: the identification of downshifting includes, among adjacent first and second time nodes, using the discharge capacity at the flood limit water level for the discharge capacity of the second time node, calculating the water level of the second time node, and if the calculated water level is lower than the flood limit water level, it is identified that there is a downshift; for the downshift time nodes inserted between adjacent first and second time nodes, controlling the water level of the downshift time nodes to be equal to the flood limit water level; when it is identified that there is a downshift and there is a peak point between adjacent first and second time nodes, only the peak point time nodes are inserted; for the peak point time nodes, controlling the discharge capacity of the peak point time nodes to be equal to the inflow rate.

[0011] Specifically, the calculation process of the time nodes further includes: when it is identified that there is a downshift and there is a peak point between adjacent first and second time nodes, if the water level grade of the calculated peak point time node is higher than the water level grade of the first time node, the identification of water level upshifting is performed and the peak point time nodes are not inserted.

[0012] Specifically, the calculation process of the time nodes further includes: the identification of upshifting includes, among adjacent first and second time nodes, using the discharge capacity of a higher grade than the first time node for the discharge capacity of the second time node, calculating the water level of the second time node, and if the calculated water level grade is higher than the water level grade of the first time node, it is identified that there is an upshift; for the upshift time nodes inserted between adjacent first and second time nodes, controlling the water level of the upshift time nodes to be equal to the water level of a higher grade of the first time node; when it is identified that there is an upshift and there is a trough point between adjacent first and second time nodes, only the trough point time nodes are inserted; for the trough point time nodes, controlling the discharge capacity of the trough point time nodes to be equal to the inflow rate.

[0013] Specifically, the calculation process of the time nodes further includes: when it is identified that there is an upshift and there is a trough point between adjacent first and second time nodes, if the water level grade of the calculated trough point time node is lower than the flood limit water level, the identification of water level downshifting is transferred to and the trough point time nodes are not inserted.

[0014] The present invention also provides a general reservoir flood regulation calculation device, including: a calculation unit and an execution unit, where: the calculation unit is used to calculate the water level, discharge flow rate, and inflow rate of the reservoir at each time step node in chronological order for all time step nodes within the reservoir flood regulation time period. The calculation process of the time step node includes: sequentially identifying whether there is a break period, a water level downshift and peak point, a water level upshift and valley point, and a peak point or valley point of the current water level between adjacent first and second time step nodes. If so, insert a break period time step node, a downshift time step node or an upshift time step node, a peak point time step node or a valley point time step node between the corresponding adjacent two time step nodes; where, the discharge flow rate between the first time step node and the break period time step node is increased compared to the original time period, the discharge flow rate of the downshift time step node is decreased compared to the original time, the discharge flow rate of the upshift time step node is increased compared to the original time, the discharge flow rate between the first time step node and the peak point time step node is increased compared to the original time period, and the discharge flow rate between the first time step node and the valley point time step node is decreased compared to the original time period; if the discharge capacity of the first time step node is less than the inflow rate of the second time step node, it is identified that there is a break period; if the water level of the second time step node is lower than the flood limit water level, it is identified that there is a downshift; if the water level of the second time step node is higher than the water level gear of the first time step node, it is identified that there is an upshift; if the discharge capacity of the first time step node is less than the inflow rate and the discharge capacity of the second time step node is greater than the inflow rate, it is identified that there is a peak point; if the discharge capacity of the first time step node is greater than the inflow rate and the discharge capacity of the second time step node is less than the inflow rate, it is identified that there is a valley point; the execution unit is used to, after the calculation is completed, execute the allocated discharge flow rate for the discharge structure at each time step node.

[0015] Advantageous effects: Compared with the prior art, the present invention has the following remarkable advantages: It establishes the identification of complex boundary conditions such as break periods, up and downshifts, peak and valley values, clarifies the calculation method of the flood discharge of the inserted time step nodes, has strong generality, solves the problem of deviation in the flood regulation calculation results of technical personnel, realizes the generalization and consistency of reservoir flood regulation calculation, and provides underlying technical support for the construction of reservoir digital twin projects and modern operation management matrices. Description of the Drawings

[0016] Figure 1 It is a flow chart of the general reservoir flood regulation calculation method provided by the present invention;

[0017] Figure 2 It is a schematic diagram of the break period provided by the present invention;

[0018] Figure 3 It is a schematic diagram of the upshift provided by the present invention;

[0019] Figure 4 It is a schematic diagram of the peak value provided by the present invention;

[0020] Figures 5 to 8 Schematic diagram of the calculation results of the general reservoir flood regulation calculation method provided by the present invention. Among them, Figure 5 Schematic diagram of the water level - storage capacity curve, Figure 6 Schematic diagram of the discharge capacity curve, Figure 7 Schematic diagram of the flood regulation process curve, Figure 8 Schematic diagram of the discharge distribution process curve. Specific implementation manner

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0022] The purpose of the present invention is to provide a general flood regulation calculation and analysis method applicable to complex scheduling conditions, which can meet the needs of more than 95% of reservoirs, and realize the unified processing of complex boundary conditions in flood regulation calculation.

[0023] In specific implementation, the general reservoir flood regulation calculation method provided by the present invention performs flood regulation calculations based on the static storage capacity method. The calculation process includes the identification and calculation of boundary conditions such as broken time periods, up - down shifts, peak - valley values, etc., and the calculation of the discharge distribution of buildings.

[0024] In specific implementation, the calculation process of flood regulation by the static storage capacity method includes assuming that the reservoir volume and water level change linearly within the dt time period, and writing the continuity equation in the Saint - Venant partial differential equation as the following water balance equation in finite - difference form:

[0025] (Q 初 +Q 末 ) / 2―(q 初 +q 末 ) / 2=(V 末 ―V 初 ) / △t, Formula (1).

[0026] In Formula (1), Q 初 、Q 末 are the reservoir inflow discharges at the beginning and end of the time period △t respectively; q 初 、q 末 are the reservoir outflow discharges at the beginning and end of the time period △t respectively; V 末 、V 初 are the reservoir water storages at the end and beginning of the time period △t respectively; △t is the water balance calculation time period.

[0027] The relationship between the reservoir discharge q and the water level Z in front of the dam is:

[0028] q = f(Z), Formula (2).

[0029] In formula (2), the relationship between q and Z depends on the flood discharge structures adopted in flood control operation. The relationship between the water storage volume V of the reservoir and the reservoir water level Z is given by the storage capacity curve, i.e.:

[0030] V = g(Z), formula (3).

[0031] By jointly solving the above formulas (1) to (3), the water level in front of the dam, the discharge flow rate, and the water storage volume values of the reservoir can be calculated for each time period, and thus their maximum values can be obtained. Starting from the initial water level, the processes of the reservoir water level, storage capacity, and discharge flow rate are recursively obtained for each time period.

[0032] In the embodiment of the present invention, the general flood regulation calculation method for the reservoir is to calculate the water level, discharge flow rate, and inflow rate of the reservoir at each time node in chronological order for all time nodes within the flood regulation time period of the reservoir. After the calculation is completed, the allocated discharge flow rate is executed at the flood discharge structure corresponding to each time node.

[0033] In the embodiment of the present invention, the calculation process of the time node includes: sequentially identifying whether there is a broken time period, a reduction in water level and peak point, an increase in water level and valley point, and a peak point or valley point of the current water level between the adjacent first time node and the second time node. If it exists, a broken time period time node, a reduction time node or an increase time node, a peak point time node or a valley point time node is inserted between the corresponding adjacent two time nodes.

[0034] In specific implementation, multiple time nodes are set within the flood regulation time period of the reservoir. The relevant parameters at each time node are calculated one by one, and the flood discharge capacity and discharge flow rate of the time node are adjusted according to the situation (such as the existence of a broken time period, etc.). Among them, the water level of the reservoir corresponds to multiple levels. For example, 1959.5m is the first level, 1962.25m is the second level, and 1962.65 is the third level. Different levels usually correspond to different flood discharge structures or combinations of flood discharge structures. The flood discharge capacities (maximum discharge flow rates) of different flood discharge structures are different, that is, the flood discharge capacities at different water level levels are different. The water level level determines the flood discharge capacity. In some cases, for example, in order to increase the flood discharge capacity and discharge flow rate in advance, or to reduce the flood discharge capacity and discharge flow rate in advance, etc., when the actual water level has not reached the corresponding water level level, the level can be increased or decreased in advance or postponed. For example, when the current water level is 1960.58m, it can also be maintained at the second level. However, when comparing the water level levels, the corresponding level is still determined by the actual water level. In addition, the flood limit water level is usually the lowest water level to ensure safety, and the initial water level is the starting water level for the reservoir flood regulation.

[0035] In specific implementation, when calculating the relevant parameters at each time-step node one by one, for example, when calculating the first time-step node, the second time-step node adjacent to it will be included in the calculation. Thus, it is calculated and identified whether there are boundary conditions (broken time periods, water level rising / falling grades, and peak / trough points) between the first time-step node and the second time-step node. When it is determined that there are such conditions, corresponding broken time-period time-step nodes will be inserted between the first time-step node and the second time-step node, and the discharge and discharge capacity of the broken time-period time-step nodes will be determined. Then, the calculation of the first time-step node and the inserted time-step nodes is completed. When it is determined that there are no boundary conditions, it may also be necessary to calculate and determine parameters such as the discharge of the second time-step node. After the determination is completed, the calculation of the first time-step node is completed, and then the calculation of the second time-step node follows. During the calculation process, in chronological order, the third time-step node adjacent to the second time-step node will be included in the calculation. The calculation method can refer to the calculation method of the first time-step node, that is, the general reservoir flood routing calculation method provided by the present invention.

[0036] In specific implementation, the order of identifying the boundary conditions between time-step nodes is carried out in sequence according to broken time periods, falling grades and peak points of the water level, rising grades and trough points of the water level, and peak or trough points of the current grade of the water level. That is, first, the identification of broken time periods is carried out (in specific implementation, in some cases, the identification of broken time periods will be skipped), then the identification of the falling grade of the water level is carried out. If there is a falling grade, the identification of peak points will be further carried out. If there is no falling grade of the water level, the identification of the rising grade of the water level will be directly carried out. If there is a rising grade, the identification of trough points will be further carried out. If there is still no rising grade of the water level, indicating that the water level remains in the current grade, the identification of peak or trough points will be done. When one boundary condition is identified between every two time-step nodes, the identification of the next boundary condition will no longer continue, that is, at most one time-step node may be inserted between every two time-step nodes. For example, when calculating the first time-step node, when a boundary condition of a falling grade of the water level is identified in the time period between the adjacent first time-step node and the second time-step node, a falling-grade time-step node will be inserted, and then the identification of the rising grade will no longer be carried out, and the calculation will directly transfer to the second time-step node.

[0037] In specific implementation, different grades set according to the flood routing principle usually include the safe discharges of each flood discharge structure and the total safe discharge (controlled discharge). By setting the priority level of building flood discharge, when the overall safe discharge is less than the sum of the discharge capacities of each flood discharge structure according to the scheduling principle, the discharge of the building is adjusted according to the priority level of flood discharge to meet the requirements of the safe discharge. The discharge capacity of a certain time-step node represents the maximum discharge of that time-step node, and the actual discharge of that time-step node is not necessarily equal to the maximum discharge.

[0038] Refer to Figure 1 , which is a schematic flow chart of the general reservoir flood routing calculation method provided by the present invention. The numbers marked in the circles in the figure represent the corresponding method steps.

[0039] Step 1, initialize the flood routing calculation data, and obtain the design flood hydrograph (inflow Q HS , the time period T of the inflow HS ), the water level - storage capacity curve (storage capacity V, reservoir water level Z), the discharge capacity curves of each building, the flood - regulation principle (gear setting and safety discharge), the flood - limit water level Z0 and the starting water level Z1. The flood - limit water level gear pointer P0 = 0 (P0 = 0 represents that the break - time period has not passed and break - time period identification can be carried out; P0 = 1 represents that the break - time period has passed and no break - time period identification will be carried out before the next down - shift). Calculate the flood - discharge scheduling gear pointer P T = 1, 2, 3, … If at the initial time - step node, Z1 = Z0, take the smaller value of the total discharge (discharge capacity) Q T (Z1) corresponding to the reservoir water level at the initial time - step node and the inflow Q HS (m) at the initial time - step node as the discharge Q T (1) at the initial time - step node, that is, Q T (1)=MIN(Q T (Z1), Q HS (1)).

[0040] Step 2, if the number m of the currently calculated time - step nodes is greater than or equal to all the time - step numbers N within the reservoir flood - regulation time period HS , it indicates that the calculation method has been completed. Then obtain the calculation processes and results of the inflow Q HS , the discharge Q T , the reservoir water level Z and the storage capacity V, allocate the discharge Q XH,i of each flood - discharge building, end and output the calculation results; otherwise, go to the next step.

[0041] Step 3, if the inflow Q HS (m) at the current time - step node is equal to the discharge Q T (m), and the reservoir water level Z(m) is equal to the flood - limit water level Z0, then enter Step 4 (break - time period identification); otherwise, enter Step 6 (water - level down - shift identification).

[0042] Step 4 (break - time period identification), if the discharge capacity (total discharge) Q T (Z(m)) corresponding to the reservoir water level at the currently calculated time - step node is greater than or equal to the inflow Q HS (m + 1) at the next time - step node, then control the total discharge Q T (m + 1) at the next time - step node to be equal to the inflow Q HS (m + 1) at the next time - step node, the reservoir water level Z(m + 1) at the next time - step node to be equal to the flood - limit water level Z0, and return to Step 2; otherwise, enter Step 5.

[0043] Step 5 (Insertion of breaking time period time nodes and calculation of related parameters). If P0 = 0 (not past the breaking time period), linearly insert breaking time period time nodes between the current time node and the next time node so that the inflow Q HS (m + 1) at the breaking time period time node is equal to the total discharge Q T (Z(m)) corresponding to the reservoir water level at the current time node. The discharge capacity (total discharge) at the breaking time period time node is equal to the inflow Q HS (m + 1) at the breaking time period time node. The reservoir water level Z(m + 1) at the breaking time period time node is equal to the flood limit water level Z0. Set P0 = 1 and return to Step 2; otherwise, go to Step 6.

[0044] Step 6 (Recognition of water level downshift). When P0 = 1 (indicating that the breaking time period has passed), perform discharge gear judgment. First, perform downshift judgment. Use the discharge capacity Q T (Z0) of the flood limit water level as the assumed discharge capacity of the next time node (m + 1). Calculate the reservoir storage V(m + 1) of the next time node from this. If the calculated V(m + 1) is less than the reservoir storage V(Z0) corresponding to the flood limit water level, that is, the water level is lower than the flood limit water level, then a downshift is required. Insert a downshift time node and calculate the discharge capacity of this downshift time node so that the reservoir storage V(m + 1) of this downshift time node is equal to the reservoir storage V(Z0) corresponding to the flood limit water level, that is, the water level is equal to the flood limit water level, and the discharge gear returns to the flood limit water level gear. Set P0 = 0 (return to not past the breaking time period, and the breaking time period can be recognized again later), P T = 1 (return to the flood limit water level gear), otherwise go to Step 8 (Recognition of water level upshift).

[0045] Step 7 (Recognition and calculation of peak points). If the discharge Q T (m) at the current time node is less than the inflow Q HS (m) at the current time node, and the discharge Q T (m + 1) at the next time node is greater than the inflow Q HS (m + 1) at the next time node, then there is a peak point in the reservoir water level process. Switch from inserting a downshift time node to searching for the peak point. For the inserted peak point time node (peak point), calculate the discharge capacity of this peak point time node so that the discharge capacity of this peak point time node is equal to the inflow Q HS (m + 1) at this peak point time node (that is, the discharge at this node is equal to the inflow). Calculate the reservoir water level Z(m + 1) at the peak point time node. If the gear of the peak point reservoir water level Z(m + 1) is higher than the current reservoir water level gear, go to Step 8 (Recognition of water level upshift); otherwise, insert the peak point time node as described above and return to Step 2.

[0046] Step 8 (identification of water level upshift), perform upshift judgment. Use the discharge capacity of the gear one higher than the current water level gear as the assumed discharge capacity at the next time node, calculate the reservoir capacity V(m + 1) at the next time node. If the corresponding gear of the calculated V(m + 1) is higher than the current reservoir water level gear, an upshift is required. Insert the upshift time node, calculate the discharge capacity of this upshift time node, so that the reservoir capacity V(m + 1) or the corresponding gear of the water level at this upshift time node is equal to the gear one higher than the current reservoir water level (for example, if the current reservoir water level is at the first gear, then the reservoir capacity V(m + 1) or the gear corresponding to the water level at this upshift time node is at the second gear, and usually it is the lower limit boundary water level of the gear), and the discharge gear is increased by one gear, P T =P T +1, otherwise go to Step 10.

[0047] Step 9 (identification and calculation of valley points), if the discharge Q T (m) at the current time node is greater than the inflow Q HS (m) at the current time node, and the discharge Q T (m + 1) at the next time node is less than the inflow Q HS (m + 1) at the next time node, then there is a valley point in the reservoir water level process. Switch from inserting the upshift time node to looking for the valley point. For the inserted valley point time node, try to calculate the discharge capacity of this valley point time node so that the discharge capacity of this valley point time node is equal to the inflow Q HS (m + 1) at this valley point time node (that is, the discharge at this node is equal to the inflow), calculate the reservoir water level Z(m + 1) at this valley point time node. If the reservoir water level Z(m + 1) at this valley point time node is less than the flood limit water level Z0, go to Step 6, otherwise insert the valley point time node as described above and return to Step 2.

[0048] Step 10 (identification and calculation of peak or valley points in this gear), when there is neither downshift nor upshift, then in the calculation of the water level in this gear, use the static reservoir capacity method to calculate the inflow Q HS (m + 1) and water level Z(m + 1) at the next time node. If Q T (m) is less than Q HS (m), and Q T (m + 1) is greater than Q HS (m + 1), there is a peak point in the reservoir water level process, then go to Step 7 (the parameter calculation of the peak point time node refers to the calculation method in Step 7); if Q T (m) is greater than Q HS (m), and Q T (m + 1) is less than Q HS(m + 1), if there is a valley point in the reservoir water level process, then go to step 9 (the parameter calculation of the valley point time node refers to the calculation method in step 9); if the above situation does not exist, then calculate the relevant parameters such as the water level, discharge, and inflow of the current time node according to the static storage capacity method. After the calculation of the current time node is completed, return to step 2.

[0049] In specific implementation, the identification and calculation of the break time period include that when the reservoir water level is equal to the flood limit water level and the discharge capacity of the flood discharge structure is greater than the inflow, the discharge can be controlled to be equal to the inflow; and when the inflow in a certain time period (the time period between two time nodes) rises beyond the discharge capacity of the flood discharge structure, there is a moment in this time period when the inflow is equal to the discharge capacity of the flood discharge structure, and this moment is the break time period; the identification condition of the break time period is that the reservoir water level at the current time node is equal to the flood limit water level and the inflow is equal to the discharge, and the inflow at the next time node is greater than the discharge capacity of the flood discharge structure. The calculation method uses linear interpolation to find the time node of the break time period within this time period so that the inflow at this node is equal to the discharge capacity of the flood discharge structure.

[0050] In specific implementation, the identification and calculation of the upshift and downshift of the water level include that the reservoir flood operation mode is usually set to open different flood discharge structures or adopt different safe discharges (controlled discharges) after reaching different reservoir water levels. The above different reservoir water levels are the boundary conditions for the upshift and downshift. The lowest gear is the flood limit water level gear, and the highest gear is generally the design flood water level gear. By identifying the position of the reservoir water level at the next time node, it is judged whether the reservoir flood discharge operation is upshifted, downshifted, or in the current gear; the identification condition for upshifting is whether the upper limit discharge capacity of this gear can discharge the flood volume of this time period. If it is insufficient, then shift up one gear (if the discharge capacity after shifting up one gear is still insufficient within the time period, continue to try to shift up). The calculation method uses the trial calculation method according to the static storage capacity method to calculate the time node when the reservoir water level reaches the upper limit of this gear (the boundary of the next gear) within this time period; the identification condition for downshifting is whether the discharge capacity of the flood discharge structure corresponding to the flood limit water level of this gear can exceed the flood volume of this time period. If it exceeds, then downshift directly to the lowest gear of the flood limit water level gear. The calculation method uses the trial calculation method according to the static storage capacity method to calculate the time node when the reservoir water level reaches the flood limit water level within this time period.

[0051] In specific implementation, the water level upshift is a step-by-step upshift, upgrading gear by gear after reaching different water levels, but the downshift is a one-time drop to the bottom. If the discharge capacity of the flood discharge structure corresponding to the flood limit water level of this gear exceeds the flood volume of this time period, then downshift directly to the lowest gear of the flood limit water level gear, because the downshift cannot be a step-by-step downshift, which will cause contradictions in the operation.

[0052] In specific implementation, the identification and calculation of peak and valley values include that within a certain time period of flood routing calculation by trial, if the discharge process line and the inflow process line intersect, there are peak and valley values at the reservoir water level at the intersection part, and peak and valley value nodes should be inserted within this time period; the identification condition of peak and valley values is that if the discharge of the previous node is less than the inflow and the discharge of the next node is greater than the inflow, there is a peak point in the reservoir water level process, and vice versa there is a valley point in the reservoir water level process. The calculation method adopts a trial calculation method according to the static storage capacity method to calculate the time node when the discharge and the inflow are equal within this time period, which is the peak and valley value node.

[0053] Refer to Figure 2 , which is a schematic diagram of the broken time period provided by the present invention.

[0054] As Figure 2 shown, it is a schematic diagram of the broken time period identification and calculation provided by an embodiment of the present invention. The DG section is the discharge capacity, and the AC section is the inflow. It can be seen that the intersection point B is the broken time period, and a broken time period time node needs to be inserted for subsequent calculation. If the broken time period is not identified, the AE section is the false discharge process calculated, and the actual discharge process should be the ABF section. Obviously, ignoring the broken time period will cause calculation deviation, and the envelope difference between AE and ABF is the water volume difference.

[0055] Refer to Figure 3 , which is a schematic diagram of the gear up provided by the present invention.

[0056] As Figure 3 shown, it is a schematic diagram of the gear up and down identification and calculation provided by an embodiment of the present invention. The AF and DJ sections are the discharge capacities before and after gear up, and the BG section is the inflow process. During the flood routing process, when the reservoir water level rises to the next gear within a certain time period, a gear up time node needs to be inserted for subsequent calculation. If the gear up section is not identified, the BH section is the false discharge process calculated, and the actual discharge process should be the BFDI section. Obviously, ignoring the gear up section will cause calculation deviation, and the envelope difference between BH and BFDI is the water volume difference.

[0057] The situation of gear down is similar to that of gear up. The present invention provides a method for identifying and calculating gear down. The characteristics of gear up and down are that gear up is one gear at a time, and gear down can only directly drop to the lowest flood limit water level gear. The reservoir water level will not be gear down if it does not drop to the flood limit water level. The main reasons are as follows: Assume that the discharge capacity below a certain gear is q1 and above is q2, and the inflow is Q, and q1 < Q < q2. When the reservoir water level drops to this gear, if it is gear down by one gear, because q1 < Q, the reservoir water level will rise, and rising requires gear up by one gear. And because Q < q2, the reservoir water level will drop, and gear down is required again, resulting in repeated contradictions. Therefore, gear down can only directly drop to the lowest flood limit water level gear. This is hereby explained.

[0058] Refer to Figure 4 , which is a schematic diagram of the peak value provided by the present invention.

[0059] As Figure 4 shown, it is a schematic diagram of peak and valley value identification and calculation provided by an embodiment of the present invention. The AL section is the incoming flow process. During the flood regulation process, the incoming flow process in a certain period intersects with the discharge process CFI, and peak and valley value points need to be inserted for subsequent calculations. If the peak and valley value points are not identified, taking the peak point as an example, the DJ section is the false discharge process calculated, and the actual discharge process should be the DFK section, making the water level process present the false process of the BG section, and the actual water level should be the BEH section, reaching the peak at point F. Obviously, ignoring the peak and valley value points will cause calculation deviation and lead to the inability to find the peak and valley values. The envelope difference between DJ and DFK is the water volume difference. Especially the peak value will affect the highest water level of the flood regulation calculation, causing relatively large safety problems.

[0060] Refer to Figures 5 to 8 , which is a schematic diagram of the calculation results of applying the general flood regulation calculation method of the reservoir provided by the present invention. Among them, Figure 5 is a schematic diagram of the water level - storage capacity curve, Figure 6 is a schematic diagram of the discharge capacity curve, Figure 7 is a schematic diagram of the flood regulation process curve, Figure 8 is a schematic diagram of the discharge distribution process curve.

[0061] Figures 5 to 8 The flood regulation principle of the actual reservoir shown is as follows: The starting regulation water level is the flood limit water level of 1959.50 m; when a design flood occurs, the open - type spillway, flood - discharging sediment - flushing tunnel, sediment - flushing tunnel, and power generation diversion tunnel participate in flood discharge; when a check - standard flood occurs, the open - type spillway, flood - discharging sediment - flushing tunnel, and sediment - flushing tunnel participate in flood discharge; when the incoming flow is less than the allowable safe discharge of the downstream river channel (890 m 3 / s), the water is discharged according to the incoming flow, and the flood limit water level remains unchanged; when the incoming flow is greater than the safe discharge of the downstream river channel (890 m 3 / s), but the reservoir water level is lower than the flood control high water level (1962.25 m), the downstream discharge is controlled not to exceed the allowable safe discharge of the downstream river channel; when the reservoir water level is higher than the flood control high water level of 1962.25 m and has not reached the design flood water level of 1962.65 m, the flood - discharging sediment - flushing tunnel and sediment - flushing tunnel are wide - open for discharge, the power generation diversion tunnel discharges according to two units considered (45 m 3 / s), and the spillway has a limited discharge of 400 m 3 / s, and the reservoir water level drops back to the flood limit water level as soon as possible; when the incoming flood continues to increase and the reservoir water level is higher than the design flood water level of 1962.65 m, to ensure the safety of the reservoir, the downstream discharge is no longer restricted by the allowable safe discharge of the downstream river channel, and all the flood - discharging buildings (flood - discharging sediment - flushing tunnel, sediment - flushing tunnel, spillway) are wide - open for discharge; after the reservoir water level in the recession section gradually drops to the starting regulation water level, the downstream discharge is controlled to maintain this water level unchanged.

[0062] According to the flood regulation principle, the operation modes (positions) of each flood discharge structure are shown in Table 1 as follows:

[0063] Table 1 (Flood regulation operation position table):

[0064]

[0065] It can be seen from the calculation results that the flood regulation calculation method provided by the present invention can adapt to various combinations of boundary conditions such as broken time periods, up and down shifting, and peak and valley values, and has the advantages of universality and consistency in dealing with complex flood regulation calculation boundary conditions. At the same time, it greatly improves the accuracy of the reservoir flood regulation calculation results.

[0066] Table 2-1 (Flood regulation calculation results table of general flood regulation method) (time period from 0 to 53h):

[0067]

[0068] Table 2-2 (time period from 53.14h to 99.72h):

[0069]

[0070] Table 2-3 (time period from 100h to 168h):

[0071]

[0072] The present invention aims to provide a general reservoir flood regulation calculation method under the complex boundary control operation conditions such as multiple flood discharge structures, multiple water levels, and flows in the reservoir. It establishes the identification, processing, and general calculation process of complex boundary conditions such as broken time periods, up and down shifting, and peak and valley values, and clarifies the flood discharge flow distribution method, which has extremely strong universality. In specific implementation, the boundary conditions are gradually identified and calculated according to the general process, and the flood discharge flow process at the complex boundary conditions is processed to adapt to different flood regulation rules. This method can adapt to various complex water level and flow boundary conditions in the flood regulation principle, can set and automatically distribute the flood discharge flow processes of multiple flood discharge structures, can meet more than 95% of the reservoir flood regulation calculation and analysis, and has the characteristics of no omission of boundary conditions, strong universality, and easy compilation.

[0073] The present invention also provides a general reservoir flood routing calculation device, comprising: a calculation unit and an execution unit, wherein: the calculation unit is configured to calculate the water level, discharge flow rate and inflow rate of the reservoir at each time node in chronological order for all time nodes within the reservoir flood routing time period. The calculation process of the time node includes: sequentially identifying whether there is a break period, a water level downshift and peak point, a water level upshift and valley point, and a peak point or valley point of the current water level between adjacent first and second time nodes. If any exists, insert a break period time node, a downshift time node or an upshift time node, a peak point time node or a valley point time node between the corresponding adjacent two time nodes; wherein, the discharge flow rate between the first time node and the break period time node is increased compared with the original period, the discharge flow rate of the downshift time node is decreased compared with the original time, the discharge flow rate of the upshift time node is increased compared with the original time, the discharge flow rate between the first time node and the peak point time node is increased compared with the original period, and the discharge flow rate between the first time node and the valley point time node is decreased compared with the original period; if the discharge capacity of the first time node is less than the inflow rate of the second time node, it is identified that there is a break period; if the water level of the second time node is lower than the flood limit water level, it is identified that there is a downshift; if the water level of the second time node is higher than the water level gear of the first time node, it is identified that there is an upshift; if the discharge capacity of the first time node is less than the inflow rate and the discharge capacity of the second time node is greater than the inflow rate, it is identified that there is a peak point; if the discharge capacity of the first time node is greater than the inflow rate and the discharge capacity of the second time node is less than the inflow rate, it is identified that there is a valley point; the execution unit is configured to, after the calculation is completed, execute the allocated discharge flow rate for the discharge structure at each time node.

[0074] In a specific implementation, for the general reservoir flood routing calculation device provided by the present invention, the method, steps or functions executed by the execution unit for executing the method, steps or functions can refer to the general reservoir flood routing method provided by the present invention.

Claims

1. A general flood routing calculation method for reservoirs, characterized in that, Including: For all time nodes within the flood regulation time period of the reservoir, calculate the water level, discharge, and inflow of the reservoir at each time node one by one in chronological order. After the calculation, execute the allocated discharge at the discharge structure corresponding to each time node. The calculation process of the time node includes: Successively identify whether there is a break period, a water level downshift and peak point, a water level upshift and trough point, and a peak point or trough point of the current water level between the adjacent first time node and the second time node. If any exists, insert a break period time node, a downshift time node or an upshift time node, a peak point time node or a trough point time node between the corresponding adjacent two time nodes. For the break period time node inserted between the adjacent first time node and the second time node, control the inflow of the break period time node to be equal to the discharge capacity of the first time node, the discharge capacity of the break period time node to be equal to the inflow, and the water level of the break period time node to be the flood limit water level; before the water level downshifts, at most one break period can be identified. The discharge between the first time node and the break period time node is increased compared to the original period, the discharge of the downshift time node is decreased compared to the original moment, the discharge of the upshift time node is increased compared to the original moment, the discharge between the first time node and the peak point time node is increased compared to the original period, and the discharge between the first time node and the trough point time node is decreased compared to the original period. If, among the adjacent first time node and the second time node, the discharge of the first time node is equal to the inflow and the water level of the first time node is the flood limit water level, then identify the break period; otherwise, identify the water level downshift. If the discharge capacity of the first time node is less than the inflow of the second time node, then identify that there is a break period; if the water level of the second time node is lower than the flood limit water level, then identify that there is a downshift; if the water level of the second time node is higher than the water level grade of the first time node, then identify that there is an upshift; if the discharge of the first time node is less than the inflow and the discharge of the second time node is greater than the inflow, then identify that there is a peak point; if the discharge of the first time node is greater than the inflow and the discharge of the second time node is less than the inflow, then identify that there is a trough point. Identify that there is a downshift and there is a peak point between the adjacent first time node and the second time node. If the water level grade of the calculated peak point time node is higher than the water level grade of the first time node, then transfer to the identification of the water level upshift and do not insert the peak point time node; identify that there is an upshift and there is a trough point between the adjacent first time node and the second time node. If the water level grade of the calculated trough point time node is lower than the flood limit water level, then transfer to the identification of the water level downshift and do not insert the trough point time node.

2. The general reservoir flood routing calculation method according to claim 1, characterized in that, The calculation process of the time node further includes: If the starting regulation water level of the initial time node is the flood limit water level, then select the smaller value between the discharge capacity and the inflow of the initial time node as the discharge of the initial time node.

3. The general reservoir flood routing calculation method according to claim 2, characterized in that The calculation process of the time node further includes: When identifying broken time periods, if the discharge capacity of the first time - step node is greater than or equal to the inflow of the second time - step node among adjacent first and second time - step nodes, control the discharge of the second time - step node to be equal to the inflow of the second time - step node, and the water level of the second time - step node is the flood - limit water level.

4. The general reservoir flood routing calculation method according to claim 3, characterized in that The calculation process of the time - step node further includes: The identification of down - shifting includes that among adjacent first and second time - step nodes, the discharge capacity of the second time - step node adopts the discharge capacity at the flood - limit water level to calculate the water level of the second time - step node. If the calculated water level is lower than the flood - limit water level, it is identified that there is a down - shift. For the down - shifting time - step node inserted between adjacent first and second time - step nodes, control the water level of the down - shifting time - step node to be equal to the flood - limit water level. When it is identified that there is a down - shift and there is a peak point between adjacent first and second time - step nodes, only insert the peak - point time - step node. For the peak - point time - step node, control the discharge capacity of the peak - point time - step node to be equal to the inflow.

5. The general reservoir flood routing calculation method according to claim 4, characterized in that The calculation process of the time - step node further includes: The identification of up - shifting includes that among adjacent first and second time - step nodes, the discharge capacity of the second time - step node adopts the discharge capacity of a higher gear than that of the first time - step node to calculate the water level of the second time - step node. If the calculated water - level gear is higher than the water - level gear of the first time - step node, it is identified that there is an up - shift. For the up - shifting time - step node inserted between adjacent first and second time - step nodes, control the water level of the up - shifting time - step node to be equal to the water level of the next higher gear of the first time - step node. When it is identified that there is an up - shift and there is a valley point between adjacent first and second time - step nodes, only insert the valley - point time - step node. For the valley - point time - step node, control the discharge capacity of the valley - point time - step node to be equal to the inflow.

6. A general reservoir flood routing calculation device, characterized in that, It includes: An arithmetic unit and an execution unit, where: The arithmetic unit is used to calculate the water level, discharge, and inflow of the reservoir at each time - step node one by one in chronological order for all time - step nodes within the flood - control time period of the reservoir. The calculation process of the time - step node includes: Successively identify whether there is a broken time period, a down - shift of the water level and a peak point, an up - shift of the water level and a valley point, and a peak point or a valley point of the same - level water level between adjacent first and second time - step nodes. If so, insert a broken - time - period time - step node, a down - shifting time - step node or an up - shifting time - step node, a peak - point time - step node or a valley - point time - step node between the corresponding adjacent two time - step nodes. For the broken - time - period time - step node inserted between adjacent first and second time - step nodes, control the inflow of the broken - time - period time - step node to be equal to the discharge capacity of the first time - step node, the discharge capacity of the broken - time - period time - step node to be equal to the inflow, and the water level of the broken - time - period time - step node to be the flood - limit water level; before the water level drops, at most one broken time period can be identified. The discharge between the first time-step node and the break-time-step node increases compared to the original time period. The discharge at the downshift time-step node decreases compared to the original time. The discharge at the upshift time-step node increases compared to the original time. The discharge between the first time-step node and the peak time-step node increases compared to the original time period. The discharge between the first time-step node and the trough time-step node decreases compared to the original time period; If, among adjacent first and second time-step nodes, the discharge at the first time-step node equals the inflow, and the water level at the first time-step node is at the flood limit water level, then identify the break time period. Otherwise, identify the downshift of the water level; If the discharge capacity of the first time-step node is less than the inflow of the second time-step node, then identify the existence of a break time period. If the water level of the second time-step node is lower than the flood limit water level, then identify the existence of a downshift. If the water level of the second time-step node is higher than the water level grade of the first time-step node, then identify the existence of an upshift. If the discharge capacity of the first time-step node is less than the inflow and the discharge capacity of the second time-step node is greater than the inflow, then identify the existence of a peak. If the discharge capacity of the first time-step node is greater than the inflow and the discharge capacity of the second time-step node is less than the inflow, then identify the existence of a trough; Identify the existence of a downshift, and there is a peak between adjacent first and second time-step nodes. If the calculated water level grade of the peak time-step node is higher than the water level grade of the first time-step node, then transfer to the identification of the upshift of the water level and do not insert the peak time-step node. Identify the existence of an upshift, and there is a trough between adjacent first and second time-step nodes. If the calculated water level grade of the trough time-step node is lower than the flood limit water level, then transfer to the identification of the downshift of the water level and do not insert the trough time-step node; The execution unit is used to execute the allocated discharge at each time-step node of the discharge structure after the calculation is completed.

Images