JP3293193B2 - Weir discharge calculation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic weir control device that automatically controls the opening of a gate of a weir installed in a river in accordance with a predetermined condition while calculating a discharge amount. The present invention relates to an improvement in a discharge flow calculation method for a weir.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram of an example of an automatic weir control system, and FIG. 4 is a diagram showing a Henry equation used for calculating a discharge rate of a weir.

An automatic weir control device 30 shown in FIG. 3 inputs a weir upstream water level h ₁ and a weir downstream water level h ₂ from a water level meter.
2 is also inputted, and the discharge amount is calculated by the discharge amount calculating unit 31. According to the conditions specified in advance according to the flood control and the flood,
The opening of the gate 32 is automatically controlled.

Conventionally, the discharge flow rate is calculated by the discharge flow rate calculation section 31 using a Henry equation. The Henry equation is represented by Q = c ₁ aB (2gh ₁ ) shown in FIG.
^As shown in FIG. 4 (2), when x ≦ 0 or h ₂ / a <K, free outflow c _{1 is} used, and FIG. 4 (3)
As shown in the figure, when x> 0 and h ₂ / a ≧ K, c ₁ of dive outflow with h ₂ larger than a is used, and weir discharge Q
Is used to automatically control the opening degree of the gate of the automatic weir control device in accordance with conditions specified in advance.

[0005] The obtained discharge flow rate is output to a printer 33, a work station 34, a console 35 and a host device.

[0006]

[SUMMARY OF THE INVENTION However, it is flooding, if you open the gate of the dam, the relationship between the weir upstream water level h ₁ and weir downstream water level h ₂ is at h ₁ ≦ h ₂ (sensors, measuring the water level H ₁ <h ₂ due to the effect of waves, etc.), the calculation becomes impossible, and the automatic weir control device cannot automatically control the gate opening continuously according to the conditions specified in advance. There is a problem that must be done manually.

According to the present invention, the weir upstream water level h ₁ and the weir downstream water level h
Regardless of the relationship with ₂ , the purpose of the purpose of the present invention is to provide a weir discharge flow calculation method capable of calculating the discharge flow rate and automatically controlling the gate opening continuously according to the conditions specified in advance by the weir automatic control device. I have.

[0008]

FIG. 1 is a diagram illustrating the principle of the present invention. As shown in FIG. 1, in Step 1, the weir upstream water level h
The difference Δh between ₁ and the weir downstream water level h ₂ is calculated. If it is larger than a predetermined value, it is calculated by Henry's formula in step 2, and if it is smaller than the predetermined value, it is calculated by river flow formula in step 3. In such a case, it is determined whether or not the flow rate has decreased in spite of the rise in the water level downstream of the weir when switching from the Henry formula to the calculation of the river flow rate in step 5, and the flow rate has decreased despite the rise in the water level downstream of the weir. At the time, the discharge rate calculated by the previous Henry's formula is used in step 7; if not reduced, the current discharge rate is used in step 8; At the time of switching, it is determined whether or not the flow rate has increased in spite of the decrease in the weir downstream water level. If the flow rate has increased in spite of the decrease in the weir downstream water level, the discharge calculated by the previous river flow rate calculation equation in step 6 is used. Use flow rate to increase When you are not is to use the current discharge amount in step 9.

[0009]

According to the present invention, in step 1, the weir upstream water level h
The difference Δh between ₁ and the weir downstream water level h ₂ is obtained, and when it is larger than a predetermined value, it is calculated by the Henry formula in Step 2, and when it is smaller than the predetermined value, it is a normal river state without a weir. In step 3, the discharge flow rate is calculated using a river flow rate calculation equation of discharge quantity Q = AH ² + BH + C (where A, B, and C are constants, and H is the weir upstream water level).

However, in step 5, when the calculation is switched from the Henry type to the river flow type calculation type, it is determined whether or not the flow rate has decreased despite the rise in the water level downstream of the weir. Is generated by accident due to the change of the arithmetic expression. Therefore, in step 7, the discharge amount calculated by the previous Henry's expression is used, and if not reduced, the current discharge amount is used in step 8. .

When the flow rate is switched from the river flow rate calculation type to the Henry type calculation in step 4, it is determined whether the flow rate has increased despite the decrease in the water level downstream of the weir. , Which happens to occur because the formula has been changed. Therefore, the discharge rate calculated by the previous river flow rate calculation equation is used in step 6; if not increased, the current discharge rate is used in step 9 To do it.

That is, even if the relationship between the weir upstream water level h ₁ and the weir downstream water level h ₂ satisfies h ₁ ≦ h ₂ , the discharge amount can be calculated,
In addition, when switching from the river flow rate calculation formula to the Henry formula, if the current discharge rate increases despite the lowering of the water level downstream of the weir, it occurred accidentally due to a change in the calculation formula, so the previous calculation was performed. When using the discharge rate and switching from the Henry formula to the river flow rate formula, if the current discharge rate decreases despite the rise in the water level downstream of the weir, this has happened due to a change in the formula. Therefore, since the previously calculated discharge flow rate is used, the discharge flow rate can be precisely calculated, and the automatic weir control device can automatically control the gate opening continuously according to the conditions specified in advance.

[0013]

FIG. 2 is a block diagram of a discharge amount calculating section according to an embodiment of the present invention. 2 shows an embodiment of the present invention of the discharge amount calculating section 31 of the automatic weir control device 30 of FIG. 3, and the discharge amount calculation is usually performed at intervals of 2 seconds.

The water level opening input unit 10 in FIG.
h₁, Weir downstream water level h_Two, Gate opening a every 2 seconds, for example
And h₁, H_Two, A when saved in the storage unit 20
The weir upstream water level h₁, Weir downstream water level h_TwoIs the water level difference calculation unit
11 and Δh = h₁-H _Two, And based on Δh
Let the quasi-value comparison unit 12 send
Compared with the quasi-value c, when Δh ≧ c, the Henry's formula operation unit 1
H at 3₁, H_Two, A Water level h upstream from the storage unit 20₁,
Weir downstream water level h_Two, The gate opening a is read out and shown in FIG.
Calculate discharge flow by Henry formula and calculate discharge flow last time
Sent to the formula judgment unit 15-1, and when Δh <c, the river flow rate
In the calculation unit 13, h₁, H_Two, A upstream water from the storage unit 20
H₁And discharge flow Q = AH^Two+ BH + C (however
A, B, C are constants, H is the weir upstream water level)
And the discharge flow rate is sent to the previous calculation method determination unit 15-2.
You.

The last calculation method storage unit 21 stores whether the last discharge flow was calculated by the Henry formula or the river flow calculation formula, and the last discharge flow storage unit 22 stores the discharge flow calculated last time.

The previous calculation method judging section 15-1 reads the previous calculation method from the previous calculation method storage section 21. In the case of the Henry method, outputs the discharge amount obtained this time from the discharge amount output section 17, and outputs the river flow amount. In the case of using the formula, the discharge amount is sent to the discharge amount increase determination unit 16-1, and the previously calculated discharge amount is read from the previous discharge amount storage unit 22. , Because the calculation formula was changed by chance, the previously calculated discharge flow is output from the discharge flow output unit 17, and if it has decreased, the discharge flow calculated this time is output from the discharge flow output unit 17. .

The previous calculation method judging section 15-2 reads the previous calculation method from the previous calculation method storage section 21 and, in the case of the river flow rate calculation equation, uses the discharge amount obtained this time as the discharge amount output section 17.
In the case of Henry type use, it is sent to the discharge rate increase determination section 16-2, and the previously calculated discharge rate is read out from the previous discharge rate storage section 22. If it has decreased, it has happened because the arithmetic expression has been changed. Therefore, the previously calculated discharge flow is output from the discharge output unit 17, and if it has increased, the discharge flow calculated this time is output. Output from the unit 17.

The above operation is repeated, for example, every two seconds. That is, irrespective of the water level difference, the discharge flow can be calculated, and when the river discharge calculation formula is switched to the Henry formula, if the discharge flow this time increases despite the water level drop, the calculation formula is Since it happened because of the change, using the discharge rate calculated last time, when switching from the Henry type to the river flow rate calculation type, if the current discharge rate is decreasing despite the rise in water level, Since it happened because the formula was changed, the discharge flow calculated last time is used, so the discharge flow can be calculated precisely, and the automatic weir controller continuously changes the gate opening according to the conditions specified in advance. Automatic control.

[0019]

As described above in detail, according to the present invention, regardless of the difference between the weir upstream water level and the weir downstream water level,
The discharge flow rate can be precisely calculated, and the automatic weir control device has the effect that the gate opening can be continuously and automatically controlled according to the conditions specified in advance.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention,

FIG. 2 is a block diagram of a discharge amount calculation unit according to the embodiment of the present invention;

FIG. 3 is a block diagram of an example of a weir automatic control system,

FIG. 4 is a diagram showing a Henry equation used for calculating the discharge flow rate of a weir.

[Explanation of symbols]

10 is a water level opening input section, 11 is a water level difference calculation section, 12 is a reference value comparison section, 13 is a Henry type calculation section, 14 is a river flow rate calculation section, 15-1 and 15-2 are previous calculation method determination sections, 16-2 1,16 - 2 is discharged amount increase determination unit, the discharge amount output unit 17, 20 h _1, h _2, a storage unit, 21 previously calculated mode storage unit, 22 the previous discharge amount storage unit, 30 Denotes a weir automatic control device, 31 denotes a discharge amount calculation unit, 32 denotes a gate, 33 denotes a printer, 34 denotes a work station, and 35 denotes a console.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01F 1/00 G01F 1/52 E02B 7/20 105 G05D 9/12

Claims (1)

(57) [Claims] When calculating the discharge flow rate by a weir automatic control device that automatically controls the degree of opening of a weir gate, the weir upstream water level (h
_When the difference (Δh) between ₁ ) and the weir downstream water level (h ₂ ) is larger than a predetermined value, it is calculated by the Henry equation (S2), and when it is smaller than the predetermined value, it is calculated by the river flow rate calculation equation (S3). ), When the flow rate is changed from the Henry type to the river flow type calculation type, and the flow rate is reduced despite the rise of the weir downstream water level, the discharge flow rate calculated by the previous Henry type is used (S7). When the flow rate is changed from the river flow rate calculation formula to the Henry formula calculation, and when the flow rate increases despite the decrease in the weir downstream water level, the discharge rate calculated by the previous river flow rate calculation formula is used (S6). Calculation method of discharge of weir.