CN111340350A - Gate group regulating method for realizing local hydraulic scouring of long-distance water delivery channel - Google Patents

Abstract

The invention discloses a sluice group regulation method for realizing local hydraulic scouring of a long-distance water conveyance channel. The constant flow simulation model calculates the duration of the flow-increasing phase and the duration of the flow-decreasing phase in the water-filling stage; determines the water-filling water flow control scheme in the flow velocity control area during the water-filling stage, and inputs the filling water flow control scheme into the one-dimensional non-constant flow The simulation model judges whether the peak water level of each canal and pond meets the conditions according to the output. If so, go to the next step. Otherwise, expand the canal and pond in the regulation and storage area one downstream, and return to the target flow calculation step; calculate the duration of the discharge stage and The flow control change value of each gate in the discharge stage determines the discharge flow control scheme in the discharge stage; the filling water flow control scheme and the discharge flow control scheme that meet the conditions are used as the gate group control scheme.

Description

Control method of gate group for realizing local hydraulic scouring of long-distance water conveying channel

technical field

The invention relates to a control method for gate groups in hydraulic engineering, in particular to a gate group control method for realizing local hydraulic scouring of a long-distance water conveyance channel.

Background technique

Channels are a common engineering form for long-distance water delivery. In order to raise the water level and adjust the water delivery flow, gates are set at certain distances to form a series of canal pools. For example, in the main canal of the middle line of the South-to-North Water Diversion Project, an average of 20km is set with a gate, and a total of 60 canal pools are connected in series. In the process of gate group regulation, in addition to limiting the water level within a safe range, it is also necessary to avoid damage to the lining structure caused by the rapid drop of the water level. The usual safety thresholds for water level drop are 0.15m/h and 0.30m/24h.

As an artificial water body, channels often experience abnormal proliferation of algae in spring and summer, which increases water resistance and pollutes water quality. By increasing the water delivery flow and implementing hydraulic scouring, it is an economical and environmentally friendly physical algae removal method. Studies have shown that when the flow rate reaches about 0.7m/s and the duration reaches 2h, the effect of hydraulic scouring for algae removal is obvious.

At present, the common operation methods of canals and ponds include constant water level before the gate (as shown in Figure 1), equal volume (as shown in Figure 2), and controlled storage method. When channel flushing is carried out, the operation mode of constant water level in front of the gate is mainly used, and there are two main deficiencies in the control process of hydraulic flushing. First, the number of gates involved in regulation and control is large, and the scope is wide. Although it is only necessary to increase the local flow velocity, the changes in flow and water level will be transmitted downstream, resulting in the need for the gate group of the entire channel to participate in the regulation. Second, the hydraulic transition time of regulation is long. Hydraulic scouring includes three processes of increasing flow, maintaining constant flow and reducing flow. Under the constant water level operation mode in front of the gate, each canal and pond needs to go through the repeated process of first filling and then discharging, and the hydraulic transition time is long.

SUMMARY OF THE INVENTION

In view of the above deficiencies in the prior art, the gate group control method for realizing local hydraulic flushing of a long-distance water conveyance channel provided by the present invention can effectively reduce the number of gates involved in the regulation when flushing a local channel.

In order to achieve the above-mentioned purpose of the invention, the technical scheme adopted in the present invention is:

Provided is a gate group control method for realizing local hydraulic scouring of a long-distance water delivery channel, comprising:

S1. Obtain the hydraulic flushing section to be hydraulically flushed, the flushing duration and the minimum flushing speed, and divide the channel into the flow velocity control area of the hydraulic flushing section, the regulation and storage area located downstream of the flow velocity regulation area, and the downstream of the regulation and storage area. normal operating area;

S2. Calculate the target flow rate of the final gate in the flow rate control area by using the minimum flushing speed and the cross-sectional area of the flow rate, and calculate the target flow rate of all gates in the flow rate control area during the water filling stage according to the flow rate of each water outlet in the flow rate control area.

S3. Calculate the target flow of each gate in the regulation and storage area in the water filling stage according to the principle of synchronously filling water in the canals and pools in the regulation and storage area and the target flow, initial flow and water outlet flow of the upper-level gate;

S4. According to the initial flow and target flow of the gate, the one-dimensional unsteady flow simulation model of the channel is used to calculate the water surface line of each canal pool, and the maximum value of the water surface line drop at the downstream end of all the canal pools and the increase of the upstream water surface line are used. The maximum value and the safety threshold of the water level drop, calculate the duration ΔT _increase of the flow increasing stage and the duration ΔT _decrease of the flow decreasing stage in the water filling stage;

S5. Based on the constant volume operation mode in the flow rate control area and the control storage operation mode in the adjustment and storage area, combined with the _increase of the duration ΔT, the _duration of the flushing duration ΔT and the _decrease of the duration ΔT, and the initial flow and target flow of each gate, determine The water-filling water-flow regulation scheme in the flow-rate control area and the regulation-storage area during the water-filling stage;

S6. Input the water-filled water flow regulation scheme into the one-dimensional non-constant flow simulation model to obtain the water level change of each canal and pond, and determine whether the peak water level of each canal and pond is less than its safety limit water level. If it is less than, then go to step S7, otherwise, expand the regulation and storage area downstream by a canal pool, and then return to step S3;

S7, using the maximum value of the water level rise in all canals and ponds obtained by the simulation in step S6, combined with the safety threshold of the water level drop, to calculate the duration of the water discharge stage ΔT water _discharge ; then according to the target flow of each gate in the water filling stage, calculate the water filling stage The volume of the water body increased in each canal and pool in the stage and the flow control change value of each gate in the flow rate control area and the regulation and storage area during the discharge stage:

S8. Based on the constant volume operation mode in the flow rate control area and the control storage operation mode in the adjustment and storage area, combined with the duration of the discharge stage ΔT _{water discharge} and the initial flow of each gate and the flow control change value in the discharge stage, determine The discharge water flow control scheme in the discharge stage; the filling water flow control scheme and the discharge water flow control scheme satisfying the conditions in step S6 are used as the gate group control scheme.

The beneficial effects of the invention are as follows: after the canal pool is divided into a flow rate control area, a regulation and storage area and a normal operation area, when the hydraulic flushing section is scoured, only the flow rate control area and the gate of the regulation and storage area need to be regulated. , the flushing of the hydraulic flushing section can be realized, and the water after flushing is stored in the regulation and storage area, so that the subsequent canals and ponds do not need to participate in regulation, reducing the number of gates involved in regulation, and shortening the hydraulic transition time.

Description of drawings

Figure 1 shows the operation mode of the channel at the constant water level before the gate.

Figure 2 shows the equal volume operation of the channel.

Figure 3 is a schematic diagram of the water delivery channel.

Figure 4 is a flow chart of the gate group control method for realizing local hydraulic scouring of the channel for long-distance water delivery channels.

Figure 5 shows the flow regulation process of the gates at the upstream and downstream ends of the canal pool Pool (i) in the flow velocity regulation area (i=1～M-1).

Fig. 6 Flow regulation process of the gates at the upstream and downstream ends of the pool (i) in the regulation and storage area (i=M～L-2).

Figure 7. The flow regulation process of the upstream and downstream end gates of Pool (L-1) in the end-stage canal pool in the regulation and storage area.

Figure 8 is a schematic diagram of the trunk canal of the middle line of the South-to-North Water Diversion Project.

FIG. 9 is the process of each gate flow QG(i) in the embodiment (i=1, 24).

FIG. 10 shows the water level process (Pool(1)-Pool(24)) in front of each canal, pool and gate in the embodiment.

FIG. 11 shows the water level process (Pool(1)-Pool(24)) of each canal and pool gate in the embodiment.

FIG. 12 shows the volume process (Pool(1)-Pool(24) of each canal and pond water body in the embodiment.

FIG. 13 shows the average flow rate process (Pool(1)-Pool(24)) of each canal and pond in the embodiment.

Detailed ways

The specific embodiments of the present invention are described below to facilitate those skilled in the art to understand the present invention, but it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, as long as various changes Such changes are obvious within the spirit and scope of the present invention as defined and determined by the appended claims, and all inventions and creations utilizing the inventive concept are within the scope of protection.

Referring to FIG. 4 , FIG. 4 is a flowchart of a method for regulating gate groups for realizing local hydraulic flushing of a long-distance water conveyance channel; the method S includes steps S1 to S8 .

In step S1, the hydraulic flushing section to be hydraulically flushed, the flushing duration and the minimum flushing speed are obtained, and the channel is divided into the flow rate control area of the hydraulic flushing section (between G(1)-G(M) in Fig. 3 ). between G(M) and G(L) in the downstream of the flow rate control area, and the normal operation area downstream of the adjustment and storage area (G(L)~G(N) in Fig. 3 )between).

When implemented, this scheme preferably consists of a flow rate control area consisting of a hydraulic scour section and a set number of canals upstream; The function of the flow rate control area is to increase the initial flow rate to the target flow rate v _target , and to maintain the scour time △T _{to continuously} scour the hydraulic scour section; increased storage.

In step S2, the minimum scour speed and the area of the overcurrent section are used to calculate the target flow rate QG _target (M)=A _M *v _target of the final gate in the flow rate control area, where A _M is the overcurrent section at the final gate in the flow rate control area area, _vtarget is the minimum scour velocity.

According to the flow rate of each water outlet in the flow rate control area, calculate the target flow rate of all gates in the flow rate control area during the water filling stage by canal and pool:

QG _target (i)=QG _target (i+1)+q(i), (i=1～M-1)

Among them, QG _target (i) and QG _target (i+1) are the target flow rates of the i and i+1 gates in the filling stage, respectively; M is the total number of gates in the flow rate control area; q(i) is the i-th gate A diverter flow.

In step S3, according to the principle of synchronous and equal water filling of the canals and pools in the regulation and storage area and the target flow, initial flow and water outlet flow of the upper-level gate, calculate the target flow of each gate in the regulation and storage area in the water filling stage:

QG _target (M) = A _M *v _target

Among them, A _M is the flow cross-sectional area at the final gate of the flow rate control area, and v _target is the minimum flushing speed; QG _target (i)=QG ₀ (i-1)-q(i-1)-(QG _target ( i-1)-QG ₀ (i-1))*(iM)/(LM)(i=M+1～L-1)

Among them, QG ₀ (i-1) is the initial flow of the i-1 gate; q(i-1) is the flow of the i-1 water outlet; i is the gate serial number; L is the flow rate control area and the storage area and the number of gates.

In step S4, according to the initial flow and target flow of the gate, the one-dimensional non-constant flow simulation model of the channel is used to calculate the water surface line of each canal pool, and the maximum value of the drop of the water surface line at the downstream end of all the canal pools and the water surface at the upstream end are used. The maximum value of the line rise and the safety threshold of the water level drop, calculate the duration ΔT _increase of the flow increasing stage and the duration ΔT _decrease of the flow decreasing stage in the water filling stage:

△T _increase ≥max(△H ₁ /0.15m·h ^-1 , △H ₁ /0.3m·d ^-1 ), △T _decrease ≥max(△H ₂ /0.15m·h ^-1 , △H ₂ / 0.3m·d ^-1 )

Among them, ΔH ₁ is the maximum drop of the water surface line at the downstream end of all canals and ponds; ΔH ₂ is the maximum drop of the water surface lines at the upper and middle ends of all canals and ponds; 0.15m·h ^-1 and 0.3m·d ^-1 are the channels Water level drop safety threshold.

In one embodiment of the present invention, the method for constructing the one-dimensional non-constant flow simulation model includes:

Based on the structural composition and geometric parameters of the channel, the water flow characteristics of the channel are described by the Saint-Venant equations; the water level and flow relationship through the sluice are described by the gate outflow formula, and the Saint-Venant equations and the gate outflow formula are expressed according to the Priceman implicit formula. The difference scheme is discrete, and the water outlet is used as the internal boundary, and the matrix equation model of the channel is established as a one-dimensional unsteady flow simulation model.

The one-dimensional unsteady flow simulation model of this scheme can also be constructed by using the existing commonly used software Mike11, HEC-RAS and so on.

In step S5 , based on the constant volume operation mode in the flow rate control area and the control storage operation mode in the regulation and storage area, combined with the _increase of the duration ΔT, the _duration of the flushing duration ΔT and the _decrease of the duration ΔT, and the initial flow and target of each gate Determine the flow rate control scheme of the flow rate control area and the regulation and storage area in the water filling stage.

When implemented, the preferred water-filled water flow regulation scheme of this scheme is:

The flow of the upstream gate of each canal pool in the flow rate control area changes synchronously with the flow of the downstream gate, and the flow of the upstream gate and the downstream gate of each canal pool in the regulation and storage area changes synchronously and with different amplitudes; as shown in Figure 5 to Figure 7 As shown, the gates 1-L-1 participating in water filling increase linearly from the initial flow QG ₀ (i) to the target flow QG _target (i) within the duration ΔT _increase (T ₁ ～T ₂ ), and then each gate is After the target flow QG _target (i) is continuously flushed for the _duration ΔT (T ₂ -T ₃ ), it linearly decreases to the initial flow QG ₀ (i) within the duration ΔT _minus period (T ₃ -T ₄ ).

The gate i included in the flow rate control area is 1～M, and the gate i involved in the regulation is 1～M-1; the gate i included in the regulation and storage area is M～L, and the gate i involved in the regulation is M～L-1; Water stage: when i=1～L-2, QG ₀ (i+1)<QG ₀ (i)<QG _target (i+1)<QG _target (i); when i=L-1, QG ₀ (L-1) < QG _target (L-1).

In step S6, the filling water flow control scheme is input into the one-dimensional non-constant flow simulation model to obtain the water level change of each canal and pond, and it is judged whether the peak value of the water level of each canal and pond is lower than its safety limit water level, if all canals and ponds have If the peak value of the water level is less than that, then go to step S7, otherwise, the regulation and storage area will be extended downstream by a canal pool, and then return to step S3;

In step S7, the maximum value of the water level rise in all canals and ponds obtained by the simulation in step S6 is used in combination with the safety threshold of the water level drop to calculate the duration ΔT of the water _discharge stage:

△T _discharge ≥max (△H ₃ /0.15m·h ^-1 , △H ₃ /0.3m·d ^-1 );

Among them, ΔH ₃ is the maximum value of the water level rise in all canals and ponds.

Then, according to the target flow rate of each gate during the water filling stage, calculate the volume of the water body added to each canal and pool during the filling stage and the flow rate control change value of each gate in the flow rate control area and the regulation and storage area during the discharge stage:

△QG _drain (i)=△V(M)/△T _drain , i=1～M

△QG _leak (i)=△QG _leak (i-1)-△QG _leak (M)/(LM), i=M+1～L-1

Among them, ΔV(i) is the volume of the water body added by the i-th canal pool; ΔQG _discharge (i) is the change value of the i-th gate flow regulation; QG(i) and QG(i+1) are the starting point of water filling, respectively. The real-time flow of gate i and gate i _{+ 1} between the start time T1 and the end time T4 of water filling;

In step S8, based on the constant volume operation mode in the flow rate control area and the control storage operation mode in the regulation and storage area, combined with the duration ΔT of the _discharge stage, the initial flow of each gate and the flow control changes in the discharge stage The value ΔQG _discharge (i) is determined, and the discharge water flow control scheme in the discharge stage is determined; the filling water flow control scheme and the discharge water flow control scheme that meet the conditions in step S6 are used as the gate group control scheme.

In one embodiment of the present invention, the described drainage water flow regulation scheme is:

The flow of the upstream gate of each canal and pool in the flow rate control area changes synchronously with the flow of the downstream gate, and the flow of the upstream gate of each canal and pool in the regulation and storage area changes synchronously with the flow of the downstream gate; refer to Figure 5~Figure again 7. The flow of gates 1 to L-1 participating in the discharge is reduced by the change value △QG _discharge (i) at the initial time T ₄ of the time period △T _discharge , and the reduced flow continues for the time period △T _discharge (T ₄ to T ₅ ), and recover to QG ₀ (i) at the time T ₅ when the _{water discharge} is cut off for the duration ΔT.

In the filling water flow control scheme and the discharge water flow control scheme, the synchronous and constant-amplitude change of flow is that the flow into the canal pool is equal to the outflow flow at the same time; the synchronous variable-amplitude change is that the flow into the canal and pool is not equal to The flow out of the canal pool is greater than the flow out of the canal pool during the filling stage, and the flow into the canal pool is smaller than the flow out of the canal pool during the discharge stage.

The gate group control scheme obtained in this scheme can be directly used in long-distance water conveyance channels that need local hydraulic flushing in the channel. This method can ensure that the substances that need to be flushed in the hydraulic flushing section are disposed of, and at the same time, it can reduce the The number of gates involved in regulation shortens the hydraulic transition time.

The following describes the control method of the gate group in this scheme in combination with the trunk canal of the middle line of the South-to-North Water Diversion Project:

The trunk canal of the middle line of the South-to-North Water Diversion Project is shown in Figure 8, which is divided into 60 canals and ponds by 61 gates. The downstream of each canal and pond is provided with a water distribution outlet to distribute water along the line. There is a problem of abnormal proliferation of algae in the area of Canal Head Gate G(1) ~ _Lanhe Control Gate G(16), which requires hydraulic flushing. and maintained for 2h.

The gate flow QG ₀ (1) ~ QG ₀ (20) at the initial moment are 123, 106, 102, 100, 100, 100, 100, 100, 94, 94, 94, 94, 94, 94, 94, 94, 94 respectively , 94, 94, 94, the water outlet flow q(1)~q(20) are 17, 4, 2, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0 respectively , 0, 0, 0, 0, 0, the water level in front of each gate is 0.30m below the design water level.

The control method of the gate group to implement local hydraulic flushing is as follows:

The first step is to delineate channel divisions and determine the overall control plan for each division. The area between G(1) and G(16) is designated as the flow rate control area, and the adjustment and storage area (between G(16) and G(20)) is defined according to about 1/4 of the number of canals and ponds contained in it. , and the downstream is the normal operation area (between G(20) and G(61)). The flow rate control area adopts the equal volume operation mode, the adjustment and storage area adopts the control storage operation mode, and the normal operation area is not regulated.

The entire regulation process is divided into a water filling stage (time duration ΔT _{water filling} ) and a water discharge stage (time length ΔT _{water discharge} ), in which the water filling stage is further subdivided into a flow increasing stage (time length ΔT _increase ) and a constant flow stage (time length ΔT). _duration ) and flow reduction phase (duration ΔT _reduction ).

The second step is to calculate the QG _target of the flow rate control target value of each gate in the flow rate control area during the water filling stage. First, based on the water flow continuity equation Q=Av, where v= _vtarget =0.70m/s, and the cross-sectional area A of the flow at G(16) is 283m ² , QG _target (16)=198m ³ /s is calculated. Then, based on the channel traffic conservation formula, that is, QG _target (i)=QG _target (i+1)+q(i), the calculated QG _target (1)~QG _target (15) are 210, 206, 204, and 198 respectively. , 198, 198, 198, 198, 198, 198, 198, 198, 198, 198, 198.

The third step is to calculate the QG _target value of the flow control target value of each gate in the regulation and storage area during the water filling stage. Based on the criterion that each canal and pond in the regulation and storage area are filled with water in an equal amount, calculate the QG _target (i)=QG ₀ (i-1 )-q(i-1)-(QG _target (i-1)-QG ₀ (i-1))*(i-16)/(20-16), (i=17～19), where QG ₀ (i-1) is the initial flow of the gate (i-1), we get: QG _target (17)=172m ³ /s, QG _target (18)=146m ³ /s, QG _target (19)=120m ³ / s.

The fourth step is to calculate the time length ΔT _increase of the flow increasing stage and the time length ΔT _decrease of the flow decreasing stage in the water filling stage. First, a one-dimensional unsteady flow simulation model of the channel is established, and then the one-dimensional unsteady flow simulation model is used to calculate the water surface line of each canal and pond when the initial flow rate and the target flow rate QG _target are respectively calculated. Then, the maximum value of the water surface line drop at the downstream end of each canal and pond is calculated to obtain ΔH ₁ =0.57m, and the maximum value of the rise of the water surface line at the upstream end of each canal and pond is calculated to obtain ΔH ₂ =0.51m. Finally, according to the safety threshold of the water level drop, it is calculated: ΔT _increase = 4h, ΔT _decrease = 4h.

The fifth step is the flow control method of the gate group in the flow rate control area in the water filling stage. As shown by the broken line in the period from 1:00 to 5:00 in Figure 9, the gate flow QG(i) at the upstream end of the canal pond and the gate flow QG(i+1) (i=1~15) at the downstream end of the canal pond synchronously change with equal amplitude, Taking 1h as the operation interval, increase from QG ₀ to QG _target in the period of 1:00-5:00, and decrease to QG ₀ in the period of 7:00-11:00 after _lasting for ΔT = 2h.

The sixth step is the flow regulation method of the gate group in the regulation and storage area in the water filling stage. For the canal pool Pool(16)~Pool(18), as shown by the broken line in the period from 1:00 to 11:00 in Fig. 9, the upstream gate flow QG(i) and the downstream gate flow QG(i+1 ) (i=1～15) Synchronous and different amplitude operation, with 1h as the operation interval, linearly increase from QG ₀ to QG _target in the period of 1:00～5:00, last for ΔT after _lasting =2h, at 7:00～ The 11:00 period linearly decreases to QG ₀ . For the end-canal pool Pool(19), only the gate flow QG(19) at the upstream end of the canal pool varies with time.

The seventh step is the simulation test of the regulation method in the water filling stage. Based on the one-dimensional unsteady flow simulation model of the channel, input the gate group control method in the fifth and sixth steps, and output the water level change process of each canal and pond, as shown in Figure 10 and Figure 11 during the period of 1:00 to 11:00 Shown as a broken line. Statistics show that the peak water level of each canal and pond is less than 1.0m, which is below the safety limit water level, which meets the safety requirements, indicating that the control method in the water filling stage is reasonable.

i＝16～19，QG(i)和QG(i+1)分别为充水的起始时刻T₁至充水的结束时刻T₄之间闸门i与闸门i+1的实时流量；The eighth step is to calculate the increased water volume ΔV in the regulation and storage area during the water filling stage. As shown by the broken line in the period from 1:00 to 11:00 in Figure 9, the volume of water body increased by each canal and pond

i=16-19, QG(i) and QG(i+1) are the real-time flow rates of gate i and gate i _{+ 1} between the start time T1 of water filling and the end time T4 of water filling, respectively;

The ninth step is to calculate the duration ΔT of the water discharge stage to _{discharge water} . First, based on the one-dimensional unsteady flow simulation model, according to the gate group flow regulation process in the fifth and sixth steps, the water surface lines of each canal and pond at the initial state and at the end of the filling stage were calculated respectively. Then, the maximum value of the rise of the water surface line of each canal and pond is calculated to obtain ΔH ₃ =0.86m. Finally, according to the safety threshold of the water level drop, it is calculated that ΔT _{water discharge} = 70h.

The tenth step is to calculate the flow regulation change value ΔQG of each gate in the _discharge stage. For the flow rate control area, follow the operation mode of equal volume, the ΔQG _leakage of each control gate is equal, ΔQG(i) _leakage = ΔV(16)/ΔT _{water discharge} (i=1～16); for the regulation and storage area, follow the control storage operation method, each canal and pond synchronously discharge water at the same amplitude, ΔQG(i) _discharge = ΔQG(i-1) _discharge - ΔQG(16) _discharge /(20-16) (i=17～19), we get: QG _target (17 ) = 172 m ³ /s, QG _target (18) = 146 m ³ /s, QG _target (19) = 120 m ³ /s.

The eleventh step is the flow control method of the gate group in the discharge stage. For Drainage Pool Pool(1)~Pool(15), the gate flow process is shown as the broken line in the period from 11:00 to 81:00 in Figure 9. The upstream gate flow QG(i) and the downstream gate flow QG(i+ 1) (i=1-15) synchronously changing with equal amplitude, reducing ΔQG _leakage (16) at 11:00, and recovering to QG ₀ (i) and QG ₀ (i+1) respectively at 81:00. For Pool(16)~Pool(18) in the pool, the gate flow process is shown as the broken line in the period from 11:00 to 81:00 in Figure 9. The upstream gate flow QG(i) and the downstream gate flow QG(i+ 1) (i=16～18) Synchronous and different amplitude changes, reduce _ΔQG (i) and _ΔQG (i+1) at 11:00, and restore to QG ₀ (i) and QG ₀ at 81:00 (i+1). For Pool(19) in the end channel of the regulation and storage area, the flow process of the gate is shown as the broken line in the period from 11:00 to 81:00 in Figure 9. QG(19) reduces ΔQG _leakage (19) at time 11, and time 81:00 Revert to QG ₀ (19).

Figure 12 shows the change process of the water volume of each canal and pond during the whole regulation process. It can be seen that the water volume of the 1-15 canal and pond remains unchanged, realizing the same volume operation. Controlled accumulation method. Combining Figure 10 and Figure 11, it can be seen that the water level and flow in the normal water delivery area below 20 canals and ponds are not affected by regulation. Figure 13 shows the variation process of the average flow velocity of each canal and pond. It can be seen that the flow velocity of the flow velocity control area Pool(1)~Pool(15) all reached more than 0.75m/s, and the duration reached or exceeded 2h, which achieved the hydraulic flushing requirements. Flow rate control target.

To sum up, it can be seen from the examples that compared with the operation mode of the constant water level before the gate, this scheme can realize the flushing of the substances in the hydraulic flushing section only with the participation of 20 canals and pools in the regulation and control, and does not need to start 60. Therefore, the number of gates involved in the regulation and control process is reduced, and the scope of influence of the regulation process is reduced; in addition, since the canal pools and gates involved in the regulation are greatly reduced, the hydraulic transition time is also greatly shortened.

Claims (9)

1. long-distance water conveyance channel realizes the sluice group control method of channel local hydraulic scour, it is characterized in that, comprises: S1. Obtain the hydraulic flushing section to be hydraulically flushed, the flushing duration and the minimum flushing speed, and divide the channel into the flow velocity control area of the hydraulic flushing section, the regulation and storage area located downstream of the flow velocity regulation area, and the downstream of the regulation and storage area. normal operating area; S2. Calculate the target flow rate of the final gate in the flow rate control area by using the minimum flushing speed and the cross-sectional area of the flow rate, and calculate the target flow rate of all gates in the flow rate control area during the water filling stage according to the flow rate of each water outlet in the flow rate control area. S3. Calculate the target flow of each gate in the regulation and storage area in the water filling stage according to the principle of synchronously filling water in the canals and pools in the regulation and storage area and the target flow, initial flow and water outlet flow of the upper-level gate; S4. According to the initial flow and target flow of the gate, the one-dimensional unsteady flow simulation model of the channel is used to calculate the water surface line of each canal pool, and the maximum value of the water surface line drop at the downstream end of all the canal pools and the increase of the upstream water surface line are used. The maximum value and the safety threshold of the water level drop, calculate the duration ΔT _increase of the flow increasing stage and the duration ΔT _decrease of the flow decreasing stage in the water filling stage; S5. Based on the constant volume operation mode in the flow rate control area and the control storage operation mode in the adjustment and storage area, combined with the _increase of the duration ΔT, the _duration of the flushing duration ΔT and the _decrease of the duration ΔT, and the initial flow and target flow of each gate, determine The water-filling water-flow regulation scheme in the flow-rate control area and the regulation-storage area during the water-filling stage; S6. Input the water-filled water flow regulation scheme into the one-dimensional non-constant flow simulation model to obtain the water level change of each canal and pond, and determine whether the peak water level of each canal and pond is less than its safety limit water level. If it is less than, then go to step S7, otherwise, expand the regulation and storage area downstream by a canal pool, and then return to step S3; S7, using the maximum value of the water level rise in all canals and ponds obtained by the simulation in step S6, combined with the safety threshold of the water level drop, to calculate the duration of the water discharge stage ΔT water _discharge ; then according to the target flow of each gate in the water filling stage, calculate the water filling stage The volume of the water body increased in each canal and pool in the stage and the flow rate control change value of each gate in the flow rate control area and the regulation and storage area during the discharge stage; S8. Based on the constant volume operation mode in the flow rate control area and the control storage operation mode in the adjustment and storage area, combined with the duration of the discharge stage ΔT _{water discharge} and the initial flow of each gate and the flow control change value in the discharge stage, determine The discharge water flow control scheme in the discharge stage; the filling water flow control scheme and the discharge water flow control scheme satisfying the conditions in step S6 are used as the gate group control scheme. 2. gate group regulation method according to claim 1, is characterized in that, described water-filled water flow regulation scheme is: The flow of the upstream gate of each canal and pool in the flow rate control area changes synchronously with the flow of the downstream gate, and the flow of the upstream gate of each canal and pool in the regulation and storage area changes synchronously with the flow of the downstream gate; the gate 1 involved in water filling ~L-1 _increases linearly from the initial flow rate QG ₀ (i) to the target flow rate QG _target (i) within the duration ΔT, and then each gate continues to flush with the target flow rate QG _target (i) for the _duration ΔT, and then The duration ΔT _decreases linearly to the initial flow rate QG ₀ (i) within the period. 3. gate group control method according to claim 1, is characterized in that, described discharge water flow control scheme is: The flow of the upstream gate of each canal pool in the flow rate control area changes synchronously with the flow of the downstream gate, and the flow of the upstream gate of each canal pool in the regulation and storage area changes synchronously with the flow of the downstream gate; the gate 1 involved in the discharge The flow rate of ~L-1 reduces the flow control change value △QG _discharge (i) at the initial time of △T water _discharge , and continues to _{discharge water with} the reduced flow for the time period △T, and returns to QG ₀ (i). 4. gate group control method according to claim 3, is characterized in that, described flow synchronous and constant amplitude change is that the flow that flows into canal pond is equal to the flow of outflow within the same time; Described synchronous variable amplitude change is that the same time flows into. The flow of the canal pool is not equal to the flow out of the canal pool. During the filling stage, the flow into the canal pool is greater than the flow out of the canal pool. During the discharge stage, the flow into the canal pool is smaller than the flow out of the canal pool. 5. gate group control method according to claim 1 is characterized in that, the calculation formula of the target flow rate of all gates in the water filling stage of described calculation flow rate control area is: QG _target (i)=QG _target (i+1)+q(i), (i=1～M-1) Among them, QG _target (i) and QG _target (i+1) are the target flow rates of the i-th and i+1-th gates in the filling stage, respectively; M is the total number of gates in the flow rate control area; q(i) is the i water distribution outlet flow; The formula for calculating the target flow of each gate in the storage area is: QG _target (M) = A _M *v _target Among them, A _M is the flow cross-sectional area at the final gate of the flow rate control area, and v _target is the minimum flushing speed; QG _target (i)=QG ₀ (i-1)-q(i-1)-(QG _target ( i-1)-QG ₀ (i-1))*(iM)/(LM)(i=M+1～L-1) Among them, QG ₀ (i-1) is the initial flow of the i-1 gate; q(i-1) is the flow of the i-1 water outlet; i is the gate serial number; L is the flow rate control area and the storage area and the number of gates. 6. The gate group control method according to claim 1, wherein in the water filling stage, the duration ΔT of the flow _increasing stage and the duration ΔT of the flow _decreasing stage are respectively: △T _increase ≥max(△H ₁ /0.15m·h ^-1 , △H ₁ /0.3m·d ^-1 ), △T _decrease ≥max(△H ₂ /0.15m·h ^-1 , △H ₂ / 0.3m·d ^-1 ) Among them, ΔH ₁ is the maximum drop of the water surface line at the middle and downstream ends of all canals and ponds; ΔH ₂ is the maximum drop of the water surface lines at the middle and upper ends of all canals and ponds; 0.15m·h ^-1 and 0.3m·d ^-1 are Water level drop safety threshold; The calculation formula of the duration ΔT of the water _discharge stage is: △T _discharge ≥max (△H ₃ /0.15m·h ^-1 , △H ₃ /0.3m·d ^-1 ); Among them, ΔH ₃ is the maximum value of the water level rise in all canals and ponds. 7. sluice gate group control method according to claim 1, is characterized in that, the flow control of each gate in the discharge stage of the water volume that each canal pond increases in described water filling stage and the flow rate regulation and control area of flow rate control area and regulation and storage area The formula for calculating the change value is:

△QG _drain (i)=△V(M)/△T _drain , i=1～M △QG _leak (i)=△QG _leak (i-1)-△QG _leak (M)/(LM), i=M+1～L-1 Among them, ΔV(i) is the volume of the water body added by the i-th canal pool; ΔQG _discharge (i) is the change value of the i-th gate flow regulation; QG(i) and QG(i+1) are the starting point of water filling, respectively. The real-time flow of gate i and gate i _{+ 1} between the start time T1 and the end time T4 of water filling. 8. The gate group control method according to any one of claims 1-7, wherein the construction method of the one-dimensional non-constant flow simulation model comprises: Based on the structural composition and geometric parameters of the channel, the water flow characteristics of the channel are described by the Saint-Venant equations; the water level and flow relationship through the sluice are described by the gate outflow formula, and the Saint-Venant equations and the gate outflow formula are expressed according to the Priceman implicit formula. The difference scheme is discrete, and the water outlet is used as the internal boundary, and the matrix equation model of the channel is established as a one-dimensional unsteady flow simulation model. 9. The gate group control method according to any one of claims 1-7, wherein the flow rate control area is composed of a hydraulic scouring section and a set number of canal pools upstream thereof; The number of pools is 1/4 to 1/3 of the number of canal pools in the flow rate control area.

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