JPS5848108A - Water level regulator - Google Patents

Abstract

PURPOSE:To put a hydraulic power station in safe operation without fluctuating the water level in a surge tank excessively in case of disturbance of the quantity of flow, by controlling the guide vane of a hydraulic turbine according to the water level in a pondage and the water level in the surge tank. CONSTITUTION:A pondage water level HT is compared with a reference water level by an adder A1, which is multiplied by the reciprocal 1/HR of a water level drop rate HR at a gain circuit C1 to apply the result to an adder A2. The adder A2 adds the bias F of the opening extent of a guide vane to the input to calculate its deviation from an actual vane opening extent eta. The calculated deviation, i.e. an operation signal is outputted to a total transfer function B0 through a contact S1 or S2 closed by an increase command output circuit C5 or a decrease command output circuit C6 according to the polarity of the signal, thus regulating the guide vane opening extent eta.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water level adjustment device for a hydroelectric power generation land that controls a water turbine O guide vane according to the water level of a regulating pond and a surge tank provided upstream of a hydroelectric power plant.

Generally, in a conduit-type power plant, water upstream of the power plant is stored in a regulating pond from the headrace, and from there it is supplied to the water turbine via the pressure headrace and surge pressure iron pipe, and after rotating the water turbine generator. , water is discharged to the lower pond, and a water level adjustment device is provided to adjust the amount of water discharged at this time, that is, the flow rate of the water wheel according to the water level of the regulating pond and the surge tank water level.

Conventionally, in such waterway type power generation glands, the water level of the surge tank did not need to be adjusted so strictly, so the water level adjustment device was also configured with the main purpose of adjusting the water level of the regulating pond, and the water level of the surge tank was not adjusted. Ha, a1
However, recently, in order to make effective use of water resources, water upstream of power plants is used not only for power generation, but also for agricultural purposes and for drinking water. It is becoming more and more common to construct long pressure conduits from regulating reservoirs, install surge tanks near fields and private sectors, and take water for domestic use from there.

For this reason, if you try to apply a conventional water level adjustment device to a recent waterway type power generation gland, when a flow disturbance occurs,
As a result of excessive rises and falls in the surge tank water level, a large amount of water suddenly leaked out of the surge tank, making it impossible to take in water, which had the disadvantage of negatively impacting the surrounding living environment. .

The present invention provides a method for safely operating a waterway type power generating gland having a pressure conduit and a surge tank of not so large capacity without excessively raising or lowering the surge tank water level when a flow disturbance occurs. The purpose of the present invention is to provide a water level adjustment device that can adjust the water level. This will be explained with reference to examples.

This is a conceptual diagram of the waterway type power generation ground according to the 113a main issue -1I argument, where l is the headrace, 2 is the regulating pond,
3 is a pressure conduit, and 4 is a surge tank.

The container is a pressure iron pipe, 6 is a guide vane, 7 is a water tank #8 is a generator, 9 is a lower pond, and 10 is a water level regulator (WLR).

The water level adjustment device 10 receives as input the water level H1 of the regulating pond 2, the water level H of the surge tanker 40, and the height of the guide vane 6, and performs a predetermined calculation process as described later, and uses the output to drive the motor 11 to adjust the guide. It is configured to adjust the opening degree of the guide vane 6 via a vane driver $12.

In the figure, Ql represents the inflow amount to the regulating pond 2, Ql represents the outflow amount from the regulating pond 2, and Qs represents the outflow amount from the surge tank 4, that is, the water turbine flow rate. Further, several water turbine generators are also connected to the surge tank 4 via pressure iron pipes (not shown), but in this embodiment, these water turbine generators are not provided with a water level adjustment function. Therefore, in the following description, the illustrated water turbine generator will be referred to as a water turbine generator, and the water turbine generator not shown will be referred to as a non-water turbine generator.

FIG. 2 shows the internal structure of the water level adjusting device 10, and also shows the other 15th! Physical systems such as water channels and water turbines are shown in the diagram with an ear dam.The water level adjustment device 10 includes an addition@Atemu 1, a gain circuit °C1, and an incomplete differentiation circuit C1% low-frequency correction. Circuit Cps high frequency correction circuit C
4% increase command output circuit C1, decrease command output circuit Cp, lower limit detection circuit C? % upper limit detection circuit CI% contact Sle! II.In addition, in the figure, Href is the reference water level, HR
Fi, which will be described later, is the water level droop rate, Da is the guide vane opening bias, TD is the incomplete differential time constant, xD is the incomplete derivative in, - is the surge tank upper limit water level, Machi is the surge tank lower limit water level, and S is the Lagrass operation On the other hand, in the physical system other than the water level adjustment device 10, Bo represents the overall transfer function of the drive unit including the water level controller 11, the guide vane driver 112, and the guide vane 6.

B15B Depending on the difference between the inflow amount 1 to the snow control pond 2 and the flow rate Q of the pressure headrace 3, the integral time constant! □ indicates a transfer function element of the regulating reservoir 2 indicating that the water level H1 of the regulating reservoir 2 changes.

Bs*B4a Due to the difference between the flow rate Q3 of the pressure headrace 3 and the turbine flow rate Qs, the integral time constant! Press □ to set the surge tank 4 water level H.
1 is the transfer function element of the surge tank 4, which indicates the change in value.

``IeB@ is the pressure that indicates that the flow rate Q of the pressure conduit 3 changes with the first-order lag of the r-in-i1 time constant i according to the difference between the water level H1 of the regulating reservoir 2 and the water level H1 of the surge tank 4. The transfer function elements of the headrace 3, A and B, vary depending on the opening degree of the guide vane 6 of the water turbine 7.
It is assumed that ζζ is a transfer function element of the water turbine 7- that indicates the rate at which the water turbine flow rate Qs changes with the next lag, and r in Q11 indicates the water turbine rated flow rate.

In the configuration shown in the diagram, if the surge tank water level is not fluctuating, that is, in a stable state, the circuit C1*CI*c4act
ec is inactive, and the guide vane 6 is at the regulating pond water level H1.
The water turbine flow rate Q3 is controlled according to the relationship shown in FIG.

In other words, the regulating pond water level H? is the reference water level Href in addition weight
The deviation output is multiplied by the reciprocal of the water level droop rate plate in the r-in circuit C1, and the output is multiplied by the reciprocal of the water level droop rate plate.

R is added to the adder and the guide vane is opened f.
ls is added, and the actual vane opening degree and deviation are calculated.The calculated deviation, that is, the operation signal, is closed by the increase command output circuit csTo or the decrease command output circuit C, depending on its polarity. It is output to the overall transfer function B0 via contact B1 or 8, and the guide vane opening is adjusted.

As a result, the regulating pond water level It, is the reference water level Hr,! If the water level is lower than the standard water level Hr, f by the water level droop rate HR, the guide vane 6 is fully closed and the turbine flow rate Q
s is adjusted to 0.

On the other hand, the non-water control unit connected to surge tank 4 starts up.
In the event of a shutdown, a change in output, or a disturbance in the amount of koji immediately after the wood tone machine is changed from being excluded to being used, the water level in the surge tank will fluctuate significantly - The water level in the regulating pond and the water level in the surge tank at this time The water level between the regulating pond 2 and the surge tank 4 based on the difference from H1 is accelerated, and the water level of the regulating reservoir is increased to H7.
The function of the incomplete differential circuit C is to stabilize the surge tank water level H,0.

That is, when the flow rate outside tK> surge tank water level is in the decreasing direction, the adder m outputs a negative polarity signal proportional to the rate of decrease.
input to operate the guide vane 6 in the closing direction, reduce the water turbine flow rate Qs, suppress the drop in the surge tank water level, and keep the surge tank water level H1 constant.
Now, the water level H1 of the 111m pond has stabilized, and the water turbine flow rate Qm can be adjusted in response to changes in the inflow Q3 of the Atosha regulating pond, that is, changes in the water level of the regulating pond, while stabilizing the surge tank water level H. Become.

A similar operation is performed when the surge tank water level H1 rises outside of the flow rate.

However, Jin's incomplete differential circuit C Snow's incomplete differential time constant T
D1 (incomplete fine molecule in KDt) is set to be optimal for suppressing the formation of water between the regulating pond 2 and the surge tank 4 due to value expansion and minute flow rate changes. Therefore, when a flow rate external current is generated, the surge tank water level H tends to deviate significantly from the upper and lower limits H4mL due to the inertia peculiar to water. The function of the circuit C8e C4@cy and c port is to prevent this.

That is, if the surge tank water level H1 drops below the lower limit water level HL due to a flow rate disturbance, the lower limit detection circuit C7 is immediately activated, and its contact 8 is opened to issue a vane opening command to the motor ν11. . At the same time as the limp, the low frequency correction circuit C Hatake
-"LK outputs a proportional guide vane close signal and adds it to adder M3. As a result, the guide vane close signal is applied to peak 11 through contact output circuit C and contact 8. 6 is forcibly moved in the closing direction.

As a result, the recovery of the surge tank water level H1 can be accelerated, and an excessive drop in the surge tank water level H, t) can be prevented.

9, outside the flow rate tK], the same operation is performed when the surge tank water level H1 is about to deviate significantly from the upper limit water level H.

Next, the operation of the one or more water level adjusting devices 10 will be described in detail with reference to the time chart shown in FIG.

In the figure, before time i, the water level H1 of the regulating pond is Hr, f
-HR, the water level is slightly higher KTo! +, water turbine flow rate Qs
It is assumed that the device is in a buried state. On the other hand, the inflow amount Q1 to the regulating reservoir 2 is gradually increased from time T by an opening operation (not shown) upstream, and is finally increased by 2XQ-. Furthermore, time T- on the way to SoO
Start the non-water control unit at
It is assumed that the rated flow rate QIK has been reached at
1. If you follow the change in the water turbine flow rate Qs, it will be time T.

In the previous state IN, the surge tank water level R1 was “r*
The water level is lower by the loss of f-HR pressure headrace 3. As the water level H1 of the regulating pond gradually rises over time i~TIK, the water turbine flow rate Q1 of the water turbine is increased. . Then, especially when the pressure conduit 30 is long, III
! Since the outflow amount qs- from the surge tank 4 changes faster than the inflow amount Qm into the surge tank 4 due to the rise in the I-pond water level H7, the surge tank water level H1 tends to decrease. The output of the incomplete differentiator circuit C changes to suppress this downward direction, but as mentioned above, the excessive drop in the surge tank water level HI cannot be suppressed by the incomplete differentiator circuit C. Surge tank water level 11. from time TI. Fi will fall below the lower limit water level HL, but
Immediately when the surge tank water level H8 becomes below the lower limit water level H1, the lower limit detection circuit C operates and uses the contact 81 to issue an order to the motor 11 to increase the amount of sushi. At the same time, the low frequency correction circuit C1 outputs a guide vane closing signal proportional to jM,--, and this signal is sent from the adder M1 to the closed command output circuit C, through the contact 8 to the motor $11. In addition to this, the water turbine flow rate Q3 begins to decrease. As a result, the surge tank water level H
1 recovery is accelerated, and during that time, the surge tank water level H
1 is the lower limit water level HN, and the water level will stop at a slightly lower level.

When the surge tank water level H1 recovers at the lower limit water level H1 at time TI, the output of the low-frequency correction circuit Cs becomes 0], and the water turbine flow rate Q3 of the wood scale machine at that time becomes the same as that at time TI. After that, at time T, the water level of the regulating pond H? When the surge tank water level H rises to near the reference water level Href, the non-water control unit starts up and starts flowing the turbine flow rate Q8, but the surge tank water level H continues to rise due to the inertia peculiar to water, and eventually at time TI. When the surge tank water level H1 recovers to HL+α, the lower limit detection circuit, C! is not working and 1 & 2, contact S again
1 closes, and as shown in Figure 3, the water level of the regulating pond H? The water turbine flow rate Qs is adjusted so that the water turbine flow rate is based on ・On the other hand, the non-water turbine flow rate Q! increases, and when it reaches the rated flow rate Q at the time point, the surge tank water level H1 begins to decrease again due to the inertia peculiar to water, and at time point 7 it again falls below the lower limit water level 9. However, this In some cases, the water level adjustment device 10 operates in the same manner as in the case from time 71 to time 1, and despite the sudden change in the non-water level flow rate Qx, the low-frequency correction circuit Cs actively controls the guide vane closing. In addition to preventing the surge tank water level H1 from dropping excessively, it also reduces the surge tank water level H.

speed up recovery to within acceptable values.

In this way, a shorter time than before has passed since time T, and at time T & 9, the surge tank water level H1 becomes equal to or higher than the lower limit water level H1, and the low-frequency correction circuit C$ output becomes 0.
Until time T@, the lower limit detection circuit C1 operates and the water turbine flow rate Q
1 is kept constant and promotes the rise of the surge tank water level H1.
Eventually, at time Ts when the surge tank water level H1 recovers to HL+α, the lower limit detection circuit C is inactive, and as described above, the water turbine flow rate Q$ increases toward the rated flow Q, and at time TvK, the water turbine After the flow rate Qstj reaches the rated flow rate Q, the flow rate Q1 to the regulating pond 2 is 2.
Q.

In the water control number book, water turbine flow rate Qss, non-water non-water type car flow rate Qx, QB, regulating pond water level H1 is Hr@fs surge tank water level H
If the water level of the regulating pond is lower than the loss head difference based on , water position 2Q, then it will be stable at ζ.
Similarly, in the upward direction, when the surge tank water level becomes higher than the upper limit water level HM due to the operation of the high-frequency correction circuit C4o, if, -HIK ratio-, the guide vane opening command is sent to the control motor 1, To prevent an excessive rise in a surge tank water level H1 and to hasten the recovery of the surge tank water level H1.

Therefore, when a flow rate disturbance occurs, the surge tank H does not deviate significantly from the upper and lower limit water levels, and the amount of deviation can be minimized, and the time required to return to within the limit value can be greatly shortened. As a result, it becomes possible to optimally supply domestic water to living areas around the surge tank, making it possible to use water resources more effectively.

At the same time, in power plants, it is possible to set the upper and lower limit water levels close to the permissible limits of the surge tank, and it becomes possible to take a large value for the vertical interpupillary distance 1f, -H. As a result, it becomes possible to repeatedly start and stop the three-filter turbine generator as needed for power supply, rapidly and at a high bs degree. In addition, it is possible to widen the range of output fluctuations of other units, increase the number of startup and stop times, and make a large contribution to system operation.In addition, the surge tank water level can be increased.

As a result, even though the upper and lower limits have been made larger, there is no risk of damage to the civil engineering or water turbine generator cape due to the risk of overflow or drought due to cavitation forces, making the power plant safe. Kfi so that it can be operated.

Incidentally, the low frequency correction circuit C1% and the high frequency correction circuit C4 in the above embodiment can be combined into one dead band circuit. Also, the low-frequency correction circuit C-1 and the high-frequency correction circuit C4 are omitted, and the lower limit detection circuit C! It is also possible to add a constant closed signal bias and open signal bias to the adder A layer at the ON output of the upper limit detection circuit C.

As described above, according to this WRK, it is possible to safely operate a canal-type power generation blunt by effectively utilizing water resources without excessively raising or lowering the water level in one surge tank when a flow disturbance occurs. You can obtain a water level adjustment device that can

[Brief explanation of the drawing]

Figure 1 shows a waterway power generation plan according to one embodiment of this power plant)0
Figure 2 is a schematic diagram of the control system, Figure 3 is a water level control diagram of the regulating pond, and Figure 4 is a time chart to explain its operation. Water conduit, 2-Regulation reservoir, 3... Pressure conduit, 4-
・Surge tank, 5-pressure iron pipe, 6--guide vane, 7--water wheel, 8--generator, 9--lower pond, 10--
・Water level adjustment device, 11... Control motor, 12-... Guide vane drive mechanism, AltAI'' adder, BI・-
Ring metal transfer function, B,, l1l-・transfer function element of regulating pond,! 1lsB4...Surge tank transfer function element, l
ls transfer function element, c, -y-in 1 path, C, -... incomplete differentiation circuit, C - - low frequency correction circuit, C4 - high frequency correction (b) path, C@ - increase command output Circuit, C... Output command output circuit, C!・-lower limit detection circuit, C1-upper limit detection circuit, S...Laplace operator, 81e8 proverb"...contact, Q
B = inflow amount, Q proverb, outflow amount, Qs a Qz”・
Water turbine flow rate, Hl...Regulation pond water level, H,-...Surge tank water level,! ...Guide vane opening degree, ma, -Guide vane opening degree bias, town, f...Reference water level, HR-・
・Water level droop rate, T, - incomplete image. Minute time constant % KD - Incomplete micromolecule in, HI - Surge tank upper limit water level, HL... Surge tank lower limit water level %
m? ... Integral time constant, Q, -P in (water turbine rated flow rate)
. To~'r, -... time.

Claims (1)

[Claims] In a water level adjustment device for a hydropower generation grand that controls the opening degree of a guide vane of a water turbine according to the water level of a regulating reservoir and the water level of a surge tank installed in the Kano water system road from the regulating reservoir to the water turbine, the surge tank described above is used. circuit means for outputting a guide vane close command while outputting a guide vane open command when the water level of the surge tank reaches the lower limit water level; A water level adjusting device characterized by comprising a one-way means for outputting a guide vane closing command while the water level adjusts.