JPH06341868A - Method for calculating quantity of discharged water - Google Patents

Abstract

PURPOSE:To provide a method for calculating a quantity of discharged water to obtain inflow or outflow rate of water to/from a reservoir. CONSTITUTION:A discharged quantity calculation circuit 5 calculates an approximate discharged quantity Q of water from an opening ratio M, a reservoir level H and a water passage level H2. A reserved quantity calculation circuit 6 detects a prescribed time unit (t) and a variation value DELTAh to send it to a correction coefficient calculation circuit 7. The circuit 7 calculates a total discharged quantity VQ=QXt from the discharged quantity Q and time (t) and a correction value from alpha=DELTAV/VQ to send them to a correction circuit 8 where Q'=QXalpha is calculated to be outputted as a discharged quantity per unit of time. Since, the operation of calculating the discharged quantity Q' is repeated periodically, even time the correction value alpha is updated, thereby always obtaining the discharged quantity with high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge amount calculation method for obtaining an inflow amount or discharge amount into a reservoir.

[0002]

2. Description of the Related Art FIG. 2 is a diagram for explaining the present invention. The calculation method is the same as the conventional calculation method until the approximate discharge amount is calculated. The conventional calculation method will be described with reference to FIG. . As shown in FIG. 2, the water level of the reservoir is H ₁ , the opening of the gate whose position is accurately known is M, and the water passing through the gate of this opening M is discharged to the water channel, When the water level is H ₂ , the discharge amount per unit time can be calculated by using the water level (H ₁ ), the opening (M), and the water level (H ₂ ) as is well known. .

However, with this calculation method, an accurate discharge amount cannot be obtained, and only a theoretical value can be obtained.
Conventionally, for example, a method of appropriately performing a discharge experiment to correct the flow coefficient and a method of performing an experiment using a simulated test device to correct the flow coefficient have been adopted, but it is not possible to perform an experiment by the method of performing a discharge experiment. Since there is also a whole operation (that is, regardless of the position of the water level in the reservoir)
It is difficult to obtain high measurement accuracy, and the method using the simulated test equipment requires the equipment.

As a method of obtaining the discharge amount, there is also a method of obtaining the amount of water actually discharged within a predetermined time from the amount of change in the water level of the reservoir and dividing this water amount by the time taken to obtain the discharge amount per unit time. However, since the calculated discharge amount is past data, immediacy cannot be ensured and it is not practical.

[0005]

As described above, the conventional discharge amount calculation method or discharge amount calculation method requires special equipment or cannot maintain high accuracy in all sections during operation. However, there were problems such as lack of immediacy.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a discharge amount calculation method which has a high measurement accuracy in all operational sections and does not deteriorate the immediacy.

[0007]

The discharge amount calculation method according to the present invention calculates the discharge amount (Q ') while feeding back the immediately preceding calculated data and changing the correction coefficient (α) appropriately. The data immediately before the feedback is determined by the fluctuation (ΔV) of the stored water amount within the predetermined time (t) and the extended discharge amount (V _Q ) within this time (t).

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.
In the figure, 1 is an opening gauge that measures the opening (M) of the gate, 2 is a water level meter that measures the water level (H ₁ ) of the reservoir, and 3 is the water level (H ₂ ) of the water channel that allows water to flow in or out of the reservoir Is a water level smoothing circuit for smoothing the water level of the reservoir even when the water level of the reservoir is unstable due to the influence of waves and the like. 4b is a water level smoothing circuit for smoothing the water level of the water channel. Water level (H ₁ ), water level in the canal (H ₂ ),
A discharge amount calculation circuit for calculating an approximate discharge amount (Q) from the opening degree (M) of the gate, 6 is a water level change (Δh) per unit time (t) of the reservoir to the stored water per unit time (t) A stored water amount calculation circuit for calculating a variation value (ΔV) of the amount, a correction coefficient calculation circuit 7 for calculating a correction coefficient (α), and a discharge amount 8 for the estimated discharge amount (Q) using the correction coefficient (α). This is a discharge amount correction circuit for obtaining (Q ').

Next, the operation will be described. The discharge amount calculation circuit 5 has an opening (M), a reservoir water level (H ₁ ) and a channel water level (H).
₂ ) and the approximate discharge amount (Q) is calculated. The operation up to this point is the same as the operation described in the related art. Also,
The water storage amount calculation circuit 6 detects the fluctuation value (Δh) of the water level of the reservoir in a predetermined time unit (t), and based on this fluctuation value (Δh), calculates the fluctuation value (ΔV) of the water storage amount at that time (t). The calculated variation value (Δh) is sent to the correction coefficient calculation circuit 7.

In the next correction coefficient calculation circuit 7, the estimated discharge amount (Q) input as information from the discharge amount calculation circuit 5 and the above time (t), Q × t = V _Q (1) The extended discharge amount (V _Q ) is obtained by the following equation, and the correction value (α) is obtained by α = ΔV / V _Q (2), and this correction value (α) is sent to the discharge amount correcting circuit 8. In the discharge amount correction circuit 8, Q '=
Q'is obtained from Q x α (3) and is output as the discharge amount per unit time. This correction value (α) is calculated and Q '
Since the operation of obtaining the ejection amount (Q ′) by = Q × α is periodically repeated and the correction value α is constantly updated, it is possible to always obtain a highly accurate ejection amount.

That is, the water storage fluctuation value (ΔV) is a value obtained from the shape of the reservoir measured as a known value and the actually measured water level change (Δh), and its accuracy is generally high. On the other hand, the extended discharge amount (V _Q ) that should coincide with this is the estimated discharge amount (Q) integrated over time (t), and there is an error in the formula for calculating the estimated discharge amount (Q). If this is included, this error will be accumulated in the extended discharge amount (V _Q ), but by using the method of the present invention, the cumulative error is removed by the correction coefficient (α) that is updated appropriately, so that the accuracy is always improved. Therefore, a high discharge amount (Q ') is required.
It should be noted that although the discharge amount is described in the above embodiment, it is needless to say that the inflow amount can be calculated by the same calculation method.

[0012]

As described above, according to the discharge amount calculation method of the present invention, it is possible to always obtain a discharge amount with a quick response and high accuracy of the calculation result without the need of providing special equipment.
Effective reservoir operation can be expected.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of calculating a discharge amount.

[Explanation of symbols]

 1 Openness meter 2 Reservoir water level meter 3 Channel water level meter 4a, 4b Water level smoothing circuit 5 Discharge amount calculation circuit 6 Reservoir amount calculation circuit 7 Correction coefficient calculation circuit 8 Discharge amount correction circuit

Claims (2)

[Claims] 1. A discharge amount per unit time (( ₁ ) of the reservoir (H ₁ ), a gate opening (M) and a discharge channel's water level (H ₂ ) calculated based on information on the discharge channel per unit time ( In a discharge amount calculation method for calculating Q) as data, the discharge amount (Q ′) is calculated by feeding back the immediately preceding calculated data and appropriately changing the correction coefficient (α). method. 2. The data immediately before the feedback is obtained by calculating (Q × t) the fluctuation (ΔV) of the storage amount obtained from the fluctuation (Δh) of the water level of the reservoir within a predetermined time (t). 2. The discharge amount calculation method according to claim 1, wherein the data is data divided by the total discharge amount (V _Q ) of.