JPH06229000A - Large-depth underground drainage facility and operating method thereof - Google Patents

Abstract

PURPOSE:To reduce the cost of construction of large-depth underground drainage facilities, and to operate the large-depth underground drainage facilities stably. CONSTITUTION:An underground water channel 1 is buried in an underground deep place, and rain water, etc., flow into the water channel l from a floodway 3, a pipe conduit 3, a river 5, etc., through a shaft 2. A pump well 6 for a pump machine station communicates with the downstream end of the underground water channel 1, and an influent flowing into the pump well 6 is drained to a discharge water tank 8 as the destination of discharge by a pump 7. The pump 7 is installed at the central section of the underground water channel 1, and dischargeable minimum water levels L.W.L are used as the central sections of the underground water channel 1. The water level of the underground water channel 1 is held at the minimum water levels L.W.L in open channel operation in open-channel and closed-channel coexistent operation, and the underground water channel 1 is employed as an open channel. On the other hand, the underground water channel 1 is filled with water in closed channel operation, the water level is elevated up to the shaft 2, and the underground water channel 1 is used as a closed channel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention collects inflow water such as rainwater flowing into a waterway including a small river in an inflow waterway provided underground, and guides the collected inflow water to a pumping station to release the river. The present invention relates to a deep underground drainage facility that is released to a public site, and particularly to a deep underground drainage facility that can reduce construction costs and its operation method.

[0002]

2. Description of the Related Art Conventionally, from each shaft that discharges drainage from the surface or a discharge channel near the surface, it is operated while maintaining space in a deep underground underground channel that collects the drainage and leads it to a pump station. There are both open channel operation and closed channel operation in which the underground channel is fully operated.

FIG. 30 is an explanatory view for explaining the configuration of conventional open channel operation.

The open channel operation minimizes the risk of overflow from the shaft 2 to the ground due to a sudden inflow into the ground channel 1.
The diameter of the underground waterway 1 is increased to, for example, 12.5 m, and the water level is kept as low as possible.

Further, as shown in the figure, the installation level of the impeller of the pump 7 installed at the end of the groundwater channel 1 is
Since it is operated so that it is always empty, it is necessary to make it below the minimum water level of the drainage operation of the underground waterway 1, and normally the minimum water level L.
W. L is set to a level near the bottom of the underground waterway 1. The pump 7 is arranged in a rectangular pumping station, and the pump 7 is started and stopped at a predetermined water level in the pump well 6.

On the other hand, at least one underground canal is used for closed channel operation.
Is filled with water, and the pump is operated with the water level rising to the vertical shaft 2 in FIG. 30, and such a state occurs when the inflow exceeds the drainage capacity of the pump.

Further, the amount of inflow to the pumping station is calculated from the rainfall information, and the amount of inflow to the vertical shaft is calculated from this amount of rainfall and the outflow coefficient, which is a coefficient representing the ratio of the amount of rainfall that flows into the river. The amount of inflow into each shaft is calculated and calculated.

[0008]

Since the pumps in the conventional pumping station operating the open water channel are set at the level near the bottom of the ground water channel, the water level of the discharge water tank 8 and the minimum water level L. W. The head Ha between L is large, and therefore the total head of the pump 7 is large, and the equipment cost of the pump station including the pump 7 and the driving machine is high. In addition, groundwater channel 1
Since the water level is kept low, the storage effect is small, the water level immediately drops and the pump stops, and the water level recovers in a short time, so restarting often causes hunting.

Further, since the diameter of the underground water channel 1 which is several kilometers long is large, the underground water channel excavation work cost, which accounts for most of the construction cost of the deep underground drainage facility, becomes high. And since the installation position of the pump 7 is deep underground, the excavation work cost of the pump station also becomes high.

On the other hand, in closed channel operation, since the water level in the underground water channel is higher than in open channel operation, the total head of the pump 7 becomes smaller and the pumping station equipment cost including the pump 7 and the drive unit decreases, but from the vertical shaft to the ground. There is a large risk of overflow.

Next, in the conventional runoff coefficient, when predicting the inflow rate, if the rainfall interval is short, rain will flow into the drainage facility without penetrating into the ground, and there is no consideration that the inflow rate will increase.
There is a risk that the accuracy of estimation of the inflow rate to the vertical shaft due to changes in the rainfall pattern interval will be low, and appropriate pumping station operation will not be performed, resulting in overflow from the vertical shaft.

An object of the present invention is to reduce the construction cost of a deep underground drainage facility and to achieve stable operation of the deep underground drainage facility.

[0013]

[Means for Solving the Problems] The above-mentioned object is to provide a large-capacity underground waterway with a gentle slope, which is installed underground at a large depth, and a vertical shaft for allowing drainage to flow down from the surface or a discharge channel near the surface to the groundwater channel. In a deep underground drainage facility composed of a pump well provided at the downstream end of the underground waterway and a pump station for pumping water flowing into the pump well into a river or the sea, the pump of the pump station is replaced with the groundwater. This is achieved by installing the water level in the center of the road.

[0014] The above-mentioned object is to provide a large-capacity underground waterway arranged at a deep underground with a gentle slope, a shaft for draining drainage from the surface or a discharge channel near the surface to the underground waterway, and a downstream end of the underground waterway. In a deep underground drainage facility consisting of a pump well installed in the pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, It is achieved by having the pump characteristics such that it is installed at the pumping station and it can pump up from the closed channel water level at the rated flow rate and can pump up from the open channel water level at the minimum flow rate.

The above-mentioned object is to provide a large-capacity underground canal with a gentle slope, which is installed deep underground, a vertical shaft for draining drainage from the surface or a discharge channel near the surface to the underground channel, and a downstream end of the underground channel. In a deep underground drainage facility consisting of a pump well installed in the pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, Installed at the pump, the total head that can be pumped from the water level of the closed channel at the rated flow rate, the total head that can be pumped from the water level of the open channel at a specified flow rate, and the discharge between the closed channel and the open channel. This is achieved by having a pump characteristic that maximizes pump efficiency at the flow rate.

[0016] The above-mentioned object is to provide a large-capacity underground waterway arranged at a deep underground with a gentle slope, a shaft for draining the drainage from the surface or a discharge channel near the surface to the underground waterway, and a downstream end of the underground waterway. In a deep underground drainage facility consisting of a pump well installed in the pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, It is achieved by adopting a variable pitch type that is installed at the pump and has a total pump head that can pump water from the closed channel water level at the rated flow rate and a pump head that can pump water from the open channel water level at the minimum flow rate.

[0017] The above-mentioned object is to provide a large-capacity underground waterway arranged at a deep underground with a gentle slope, a vertical shaft for draining drainage from the surface or a discharge channel near the surface to the underground waterway, and a downstream end of the underground waterway. In a deep underground drainage facility consisting of a pump well installed in the pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, Installed at, the first blade that can obtain the total head that can be pumped from the closed channel water level at the rated flow rate, and the second blade that can obtain the total head that can be pumped from the open channel water level at the minimum flow rate. This is achieved by adopting a two-stage airfoil equipped with it.

The above-mentioned purpose is to cause the drainage to flow down from the surface or a discharge channel near the surface to the vertical shaft, and to flow down from the vertical shaft to a large-capacity underground water channel with a gentle slope, which is disposed deep underground, and downstream of the underground water channel. In an operation method of a deep underground drainage facility in which drainage flowing into a pump well provided at an end is pumped to a river or the sea by a pump at a pump station, the pump is installed at approximately the central water level of the underground waterway, Is operated at a rated flow rate when the waterway is full, and when the waterway in which the water level of the underground waterway drops and a space is created, the pump is operated at a minimum flow rate that does not make it a closed state. Achieved by coexistence operation of waterways.

[0019] The above-mentioned object is to provide a large-capacity underground waterway that is installed deep underground and has a gentle slope, a shaft that allows drainage to flow down from the surface or a discharge channel near the surface to the underground waterway, and the downstream end of the underground waterway. In a deep underground drainage facility composed of a pump well provided in the pump well and a pump station for pumping the water flowing into the pump well to a river or the sea, the pump at the pump station is at least shallower than the upper end of the ground water channel. It is achieved by installing it underground and providing a large-capacity water absorption tank whose bottom surface is at the same level as the pump between the pump well and the pump.

The above-mentioned object is to provide a large-capacity underground canal with a gentle slope, which is installed deep underground, a vertical shaft for draining drainage from the surface or a discharge channel near the surface to the underground channel, and a downstream end of the underground channel. Of the deep underground drainage facility that selects the type that minimizes the construction cost of the deep underground drainage facility consisting of the pump well installed in the pump well and a pump station for pumping the water flowing into the pump well into the river or the sea. In the selection method, if it is difficult to acquire the site of the pump station, select the deep underground drainage facility where the pump is installed at the water level in the central part of the underground waterway, and if the site acquisition is easy, select the pump of the pump station. This is achieved by selecting a deep underground drainage facility which is installed at least shallow underground from the upper end of the underground waterway and has a large-capacity water absorption tank between the pump well and the pump.

The purpose is to calculate the amount of rainfall from rainfall information, calculate the amount of inflow to the vertical shaft from the amount of rainfall and the outflow coefficient determined by the time interval between the rainfall pattern and the rainfall pattern, and to pump from the amount of inflow to the vertical shaft. This is achieved by calculating the inflow amount into the pumping station and determining the number of pumps and the capacity for draining the inflowing amount into the pumping station.

[0022]

[Operation] The pump at the pump station is installed at the water level in the central part of the underground waterway to operate the open waterway, and the rated flow rate of the pump can be obtained at the total head of a high water level when the closed waterway is operated with the underground waterway fully filled. By doing so, the total pump head will be smaller than when pumping the rated flow from the bottom level of the underground canal when operating the open channel, and the equipment cost of the pump and drive machine will be reduced and the energy consumption of pumped water will be low. Become. Also, by installing the pump in the center of the groundwater channel, a space from the center of the groundwater channel to the ceiling is obtained, and the risk of water level rise is reduced due to the storage effect of the long groundwater channel, so the diameter can be reduced, and Excavation costs are reduced.

Since the above pump is provided with a pump characteristic that it can pump water from a closed channel water level at a rated flow rate and a pump head that can pump water from an open channel water level at a minimum flow rate, a low total pump head can be obtained. The same pump can be used for both closed channel water level where pumping at a rated flow rate is required and open channel level when a minimum total flow rate is high with a high total head, and it is possible to suppress an increase in the number of pumps installed. Become.

By setting the efficiency of the pump to be the maximum at the discharge flow rate between the closed water channel and the open water channel, the equipment cost of the pump and the drive unit for the intermediate operation of the open water channel and the closed water channel can be reduced. It can be reduced.

By using a type in which the pitch of the blades is variable, the above pump is capable of pumping from the closed channel water level at the rated flow rate and the total head capable of pumping from the open channel level at the minimum flow rate. The same pump can be used for both the closed water level and the open water level, and it is possible to suppress an increase in the number of pumps installed.

The above-mentioned pump has a two-stage blade type equipped with blades corresponding to the total head capable of pumping from the closed channel water level at the rated flow rate and the total head capable of pumping from the open channel level at the minimum flow rate. By using it, it is possible to operate both the closed water level and the open water level with the same pump, and it is possible to suppress an increase in the number of pumps installed.

By operating the pump at the rated flow rate when the ground water channel is closed and operating the pump at the minimum flow rate when the ground water channel is open, the closed water channel / open water channel coexisting operation is performed, so that the state of the ground water channel can be maintained. This enables stable operation of deep underground drainage facilities.

By providing a large-capacity water absorption tank between the pump well and the pump of the deep underground drainage facility that operates the closed water channel, the risk of overflowing from the ground water channel to the ground due to its storage effect is reduced, The diameter of can be reduced. Also, due to the storage effect of the water absorption tank, stable operation of deep underground drainage facilities in closed channel operation becomes possible.

If it is difficult to acquire a site for the construction of a pumping station, select an open channel / closed channel coexistence type that does not require a large capacity water absorption tank, and if the site acquisition for a large capacity water absorption tank is easy, lift the pump head. By selecting a closed channel type with a small size, a deep underground drainage facility with a minimum construction cost can be selected.

Generally, the rainfall pattern is such that the amount of rainfall increases with the passage of time, drops to zero after reaching a peak, and the degree of penetration into the soil varies depending on the time interval until the start of the next rainfall. For example, if the time interval is short, It does not permeate into the shaft and the amount of inflow into the shaft increases. The runoff coefficient is changed at the time interval of this rainfall pattern and the rainfall pattern, and the amount of rainfall is calculated to obtain the inflow amount to the shaft,
By accurately predicting the flow rate into the pumping station,
Stable operation of deep underground drainage facilities will be possible through proper operation and management of pumping stations.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

First, the basic structure of the deep underground drainage facility will be described.

FIG. 1 is a perspective view showing the basic structure of a deep underground drainage facility of the present invention.

In the deep underground drainage facility, a groundwater channel 1 is buried deep in the underground as shown in the drawing, and rainwater or the like flows into the deepwater channel 1 through a shaft 2 from a discharge channel, a pipe or the like. The downstream end of the groundwater channel 1 communicates with the pumping station, and the inflow water flowing into the pumping station is drained to the discharge destination river by the pump 7.

Next, the construction of the characteristic parts of the embodiment of the deep underground drainage facility for coexisting operation of open channel and closed channel will be explained.

FIG. 2 is an explanatory view for explaining the structure of an embodiment of the present invention in which an open channel / closed channel coexisting operation is performed.

As shown in the figure, a groundwater channel 1 is buried deep underground, and rainwater and the like flow into it through a shaft 2 from a discharge channel 3, pipe 4, river 5, and the like. The downstream end of the groundwater channel 1 communicates with the pump well 6 of the pumping station, and the inflow water flowing into the pump well 6 is drained by the pump 7 to the discharge water tank 8 of the discharge destination.

Although the pump installation level in the conventional open water channel operation is the bottom of the ground water channel 1, in the open water channel operation of this embodiment, the pump 7 is installed in the central portion of the ground water channel 1 and the lowest water level L. W. L is the central part of the underground waterway 1. In the open channel operation of the open channel / closed channel coexisting operation, the water level of the ground channel 1 is set to the minimum level L. W. The ground water channel 1 is maintained at L, and the ground water channel 1 is an open water channel having a space from the center to the ceiling. On the other hand, in the closed channel operation, the underground channel 1 is filled with a closed channel to allow the water level to rise to the vertical shaft 2. Next, the total pump head H in the coexistence operation of the open channel and the closed channel will be described.

FIG. 3 is an explanatory view for explaining the pump starting water level when the open channel / closed channel coexisting operation of this embodiment is performed.

FIG. 4 is a table for explaining the pump characteristics of this embodiment and the prior art.

In general, the total pump head H is a value obtained by adding the discharge line loss to the actual pump head Ha and can be expressed by the following equation.

H = Discharge water tank water level-Water level at pump start-up W. L + Discharge pipe loss For example, as shown by the solid line in FIG. 4, the actual pump head Ha is 57.
m and the discharge pipe loss is 3.5 m, the total head H is 60.5 m = 57 m + 3.5 m. As shown by the dotted line in FIG. 4, in the conventional open channel operation, this minimum water level L. W. It is planned that the rated flow rate can be obtained at the total pumping height H that is pumped from L. However, when the open channel and closed channel coexist, the underground channel 1 becomes full and the vertical shaft 2
Drainage at the rated flow rate is required in the case of a closed channel where the water level has risen up to this point. As shown in FIG. 3A, the maximum water level H. W. If the actual pump head Ha from L is 35.5 m, the discharge line loss of 3.5 m is the same, so the total head H is 39.0 m = 35.5 m + 3.5 m, and 39.0 / 60.5 = It can be reduced to 64.4% at 0.644.

As shown in FIG. 3 (b), in the case of the open water channel in which the open water channel / closed water channel coexist, the water level W. L is the lowest water level L. W. Although the actual pump head Ha becomes L, the actual pump head Ha becomes large, but since the water level is low and the risk is small, the rated flow rate is not necessary, and the pump can be operated at the flow rate obtained by the total pump head H at that time.

The lowest water level L. W. L is the underground waterway 1
With a pipe diameter of 10 m and the water level W. When L is 30% to 90% of the pipe diameter, the pump installation position is 3
It can be installed above m or 9m, and excavation work cost can be reduced.

Thus, in this embodiment, the water level W.V. when starting the pump at the rated flow rate. L is the conventional minimum water level L.
W. Highest water level from L. W. By setting to L, the capacity of the pump can be reduced, the output of the diesel engine that drives the pump can be reduced, and the fuel consumption can be reduced.

The underground waterway 1 has a large-capacity temporary storage effect due to a long distance. For example, a pipe diameter of 10 m and a channel length of 10 km has a volume of about 400,000 m ³ , and a capacity of 200 m ³ / Sec is about 30. It has a storage time of 3 minutes, and this time allowance allows the pump 7 to be installed above, and the pipe diameter of the underground waterway 1 can be reduced from the conventional 12.5 m to 10 m because the risk of water level rise is reduced. . By reducing the pipe diameter of the underground waterway 1, it is possible to reduce the excavation work cost of the underground waterway 1 which accounts for most of the construction cost of the deep underground drainage facility. In addition, it is possible to prevent hunting in which the pump 7 frequently starts and stops due to the storage effect.

Next, a pump suitable for coexistence operation of an open channel and a closed channel will be described.

FIG. 5 is a table for explaining the pump characteristics suitable for the coexistence operation of the open water channel and the closed water channel of this embodiment.

A pump suitable for coexisting operation of open channel / closed channel as shown by the solid line in the figure is 10 when the closed channel is operated.
Maximum water level H. 0 at rated flow of 0%. W. A low total lift due to having a total lift A capable of pumping water from L and a total lift H-discharging amount Q characteristic of being a total lift B capable of pumping from the open channel water level at a minimum flow rate of 40%, for example. The same pump can be used for both closed channel water level, which requires pumping at the rated flow rate, and open channel level, where the minimum flow rate is sufficient for a high total head, and it is possible to suppress an increase in the number of pumps installed. Becomes

Further, as shown by the dotted line curve in the figure, the conventional pump that operates the open channel has a minimum water level L. W. The pump is designed to have the highest efficiency when the total head C capable of pumping water from L is obtained, but the efficiency of the pump of this embodiment is set to an intermediate discharge flow rate between the closed water channel and the open water channel, for example, 80. By setting it to be the highest in%, it is possible to reduce the equipment cost of the pump and the drive unit that perform the intermediate operation of the open channel and closed channel.

For the pump, use a type in which the pitch of the blades is variable between the total head allowing pumping from the closed channel water level at the rated flow rate and the total head allowing pumping from the open channel level at the minimum flow rate. As a result, the same pump can be used for both the closed water level and the open water level, and it is possible to suppress an increase in the number of pumps installed.

Further, the pump has a two-stage blade provided with blades corresponding to a total head capable of pumping from a closed channel water level at a rated flow rate and a total head capable of pumping from an open channel level at a minimum flow rate. By using the type, it is possible to operate both the closed water level and the open water level with the same pump, and it is possible to suppress an increase in the number of pumps installed.

In this way, by operating the pump at a rated flow rate when the groundwater channel is closed and by operating the pump at the minimum flowrate when the groundwater channel is open, the coexisting operation of the closed channel and open channel can be performed. The stable operation of deep underground drainage facilities is possible regardless of the state.

Next, an example of a deep underground drainage facility that operates a closed channel will be described.

FIG. 6 is an explanatory view for explaining the construction of an embodiment for operating a closed water channel according to the present invention.

As shown in the figure, a large-capacity water absorption tank 61 is provided between the pump wells 6 and 7 of the deep underground drainage facility that operates a closed water channel. The risk of overflow is reduced, and the diameter of the groundwater channel 1 can be reduced. Further, the storage effect of the large-capacity water absorption tank 61 enables stable operation of the deep underground drainage facility in the closed channel operation.

When it is difficult to acquire a site for construction of a pumping station, if an open channel / closed channel coexistence type that does not require a large capacity water absorption tank 61 is selected and it is easy to acquire a site for installing a large capacity water absorption tank 61 By selecting a closed channel type with a small pump head, a deep underground drainage facility with a minimum construction cost can be selected.

Next, a technique for accurately predicting and controlling the amount of inflow to the pumping station will be described.

The temporary storage effect of the underground waterway described above is also premised on accurately predicting and controlling the amount of inflow to the pumping station and performing stable operation commensurate with the amount of inflowing to the pumping station. Otherwise, overflow will occur from the shaft and pump well.

FIG. 7 is an explanatory view for explaining the constitution of an embodiment for accurately predicting and controlling the inflow amount into the pumping station of the present invention.

As shown in the figure, the rainfall amount is predicted by the data from the rainfall radar 71, the rainfall amount data is collected from the rain gauges arranged at the respective points, and the rainfall amount prediction value and the rainfall amount data are infiltrated into the ground. Without doing so, the outflow amount that flows into the vertical shaft 2 is analyzed to calculate the outflow amount. The flow rate in the underground waterway 1 and the water level are calculated by collecting the flow rate flowing into each shaft 2 and analyzing the flow inside the underground waterway 1. The inflow rate of the pump well 6 is calculated from the flow rate of the underground waterway 1, and the inflow rate and water level of the pump well 6 are calculated.
The operation of the pump is simulated based on the inflow amount and the water level into the pump well 6 to determine the number of pumps to be operated, the discharge amount, the timing of starting and stopping, and to control the pumps and feed them back to the flow analysis step in the underground waterway 1. Next, an embodiment of a method of accurately predicting the inflow amount to the pumping station will be described in which the inflow amount to the vertical shaft is accurately predicted with respect to the rainfall information, that is, the time change of the rainfall amount.

FIG. 8 shows a flowchart of a procedure from rainfall to determination of pump drainage.

FIG. 9 is a table showing the relationship between time and rainfall, and time and inflow.

When there is rainfall in the area subject to drainage, in step 1, the rainfall amount with respect to a change in time is obtained from the rainfall information, for example, a value such as how many millimeters per hour, and the soil time is calculated by the time interval ΔT between rainfall and rainfall. Since the infiltration degree of water into the shaft changes significantly, the outflow coefficient changes depending on the rainfall pattern. For example, the outflow coefficient is changed to 0.3 to 0.9 by ΔT in FIG. In step 2, the inflow rate to the shaft is obtained from the outflow coefficient and rainfall, in step 3, the inflow rate to the pump station is calculated from the inflow rate to the shaft by means of the inflow rate predicting means, and in step 4, the pump The pump discharge amount, that is, the number of pumps to be operated and the discharge amount are determined by the inflow amount to the machine and the pump operation plan.
As shown in FIG. 9, the change pattern of the inflow amount with respect to each time change is delayed, so that the prediction is made in the same manner.

Generally, the rainfall pattern is such that the amount of rainfall increases with the passage of time, drops to zero after reaching a peak, and the degree of penetration into the soil varies depending on the time interval until the start of the next rainfall. For example, if the time interval is short, It does not permeate into the shaft and the amount of inflow into the shaft increases. The runoff coefficient is changed at the time interval of this rainfall pattern and the rainfall pattern, and the amount of rainfall is calculated to obtain the inflow amount to the shaft,
By accurately predicting the flow rate into the pumping station,
Stable operation of deep underground drainage facilities will be possible through proper operation and management of pumping stations.

The following means may be mentioned as means for predicting the amount of inflow to the pumping station.

1. By physical simulation.

2. It depends on the water level change in the upstream shaft.

3. Detects flash floods upstream.

4. Predict with a neuro having a learning function.

Of these, the means for detecting flash flood upstream will be described in detail.

FIG. 10 is a flow chart showing the procedure of flash flood detection and arrival time prediction of the drainage system of this embodiment.

FIG. 11 shows the overall construction of the drainage system of this embodiment.

As shown in FIG. 11, in the drainage system of this embodiment, a drainage pump station 2 is arranged near the discharge destination river, and rainwater or the like is generated by the drainage channel 4 including the small river arranged in the drainage target area. The wastewater is collected, guided to the drainage pump station 2, and discharged to the river from here. The drainage channel 4 includes a main pipeline 6 and a plurality of branch pipelines 8-i (i in the figure).
= 1 to 4). The drainage pump station 2
As shown in the figure, a pump well 6 (not shown) that stores the drainage flowing from the main waterway 4, a drainage pump 12 that pumps up the drainage of the pump well 6 and discharges it to a river or the like at the discharge destination,
Pump control device 1 for controlling the operation of this drainage pump 12
4 is included.

The water level detectors 16 (a, b) are respectively provided at the upstream point a of the branch pipe 8-1 and the downstream point b thereof.
However, the upstream point e and the downstream point f of the branch pipeline 8-2 are also
, And water level detectors 16 (e, f) are installed in the respective. These water level detectors 16 detect the water level in the branch pipes, and a well-known configuration such as a capacitance type or an ultrasonic type can be applied. The water level detection value at each point detected by the water level detector 16 is transmitted to the pump control device 14 by communication equipment (not shown). Although the water level detectors are not provided in the other branch pipe lines 8-3 and 8-4, they may be provided if necessary. That is, since flash flood having a large flow rate and the flash flood that reaches the drainage pump station 2 earliest can be detected and the arrival time thereof can be predicted, the present embodiment considers the overall configuration of the drainage system, topography, etc. The target is a branch pipe near the pumping station 2 and covering a large drainage target area, and the flash flood is detected in the branch pipe.

In the drainage system constructed as described above, the drainage pumps P ₁ , P ₂ , P are normally operated by the operation of the pump controller 14 with reference to the internal water level of the drainage pump station 2.
The drainage capacity is automatically controlled by controlling the drainage capacity such as the number of operating units and the number of revolutions in ₃ . In addition, automatic control is performed based on a well-known inflow prediction.

Now, with reference to FIG. 10, a detailed structure relating to detection of flash flood and prediction of arrival time at the pump point of the flash flood of this embodiment will be described together with the operation.

Basically, the detection of flash flood and the prediction of the arrival time are executed by the pump controller 14 based on the water level data detected by the water level detectors 16a and 16b and 16e and 15f. The pump control device 14 is configured to include a computer, fetches the water level data transmitted from the water level detectors 16a to 16f at a predetermined sampling period, performs normal input signal processing, and then stores the data in a data table of a memory. , The stored water level data is read out as appropriate, as shown in FIG.
The processing shown in 0 is executed.

FIG. 10 shows the treatment of flash flood generated in the branch pipe line 8-1. Since the same processing is performed for the branch pipe line 8-2, only the branch pipe line 8-1 will be described here. Generation of flash floods (downflow) is steps 31 and 3
It is detected by the process of 2. The change pattern of the water level in flash flood is a pattern that increases rapidly. Therefore, in the present embodiment, the water level detection value ha (t) at the upstream point a is sampled, and the difference from the water level detection value ha (t + 1) one cycle before is sampled by Equation 1 to calculate the increase rate of the water level. Δha (t) is calculated (step 31).

[0080]

[Formula 1] Δha (t) = ha (t) −ha (t + 1) Next, the occurrence of flash flood is detected depending on whether or not the increase rate Δha (t) is equal to or greater than a preset flash flood judgment criterion set value k. (Step 32). When this determination is negative, the process returns to step 31 and the same processing is repeated for the next data. If affirmative, in step 33, the maximum water level hm of flash flood is detected. This detection is performed by monitoring the change in the water level detection value ha (t) in the data table and specifying the detection value showing the maximum value as the maximum water level. When the maximum water level is detected, a timer is set at the timing, and the actual measurement of the time for the flash flood to reach the downstream point b is started (step 34). It should be noted that when flash flood is detected, an alarm or the like may be issued by the detection signal, or that fact and the point of occurrence may be displayed on a display device such as a graphic panel. In addition, flash flood detection, in addition to the above water level increase rate,
It can be detected on the condition that the water level itself exceeds a predetermined set value or that the turbidity of the wastewater becomes abnormally high.
The following steps 35 to 43 are steps for obtaining the correction coefficient α for improving the accuracy of prediction of the arrival time of flash flood by hydraulic calculation. Various methods can be considered from the well-known hydraulic model as a principle used for the prediction of the arrival time, but in this embodiment, a method using a simple step wave model is applied in consideration of the processing time of the prediction. The propagation velocity (downflow velocity) ω of the flash flood according to this step wave model is expressed by Equation 2. This model is for a rectangular pipeline, but for a circular pipeline, the variables may be modified and applied accordingly.

[0081]

[Equation 2]

Here, ho is the initial water level at the front of the flash flood, and V is the initial flow velocity at the initial water level ho, which is obtained by equation (3). Further, g is a gravitational acceleration.

[0083]

[Equation 3]

Here, n is the roughness coefficient of the pipeline, and I is the gradient of the pipeline. Therefore, if the downflow velocity ω is obtained, the arrival time to reach the downstream point of the same drainage pipe can be obtained by dividing the distance to that point by ω.

According to the above hydraulic theory, in step 35, the initial flow velocity Va at the point a is obtained by the mathematical formula 3. Next, in step 36, the downflow velocity ωa is calculated by the equation 2. Then, in step 37, the predicted value T′ab of the arrival time to the downstream point b separated by the distance Lab is calculated by the mathematical expression 4.

[0086]

## EQU4 ## T'ab = Lab / ωa In the following steps 38 to 40, flash flood detection at the point b and the maximum water level hm are detected. Since the contents of this processing are the same as those in steps 31 to 33, their explanation is omitted. At the timing at which it is detected that the maximum water level of the flash flood has reached the point b in step 40, the timer is stopped (step 41), and the measured value Tab of the arrival time from the point a to b is obtained (step 42). And step 4
In 3, the correction coefficient α of the prediction time is calculated by the following equation 5.

[0087]

## EQU00005 ## .alpha. = T'ab / Tab Normally, .alpha..ltoreq.1.0 because the measured value is larger than the theoretically predicted value.

Next, the estimated time T'bd for the flash flood to reach the pumping point d from the point b is calculated by the equation (6).

[0089]

[Equation 6] For the prediction of T'bc and T'cd in the equation of T'bd = α (T'bc + T'cd), the equations 2, 3 and 4 are basically used. However, the main pipeline 6 is a branch pipeline 8
Since the pipe line conditions such as -1 and the pipe diameter are different, the initial water level ho
And the maximum water level hm are estimated by proportional calculation based on the detected value at the point a. In this case, for the initial water level ho, it is also necessary to consider the amount of drainage flowing into the junction c from the other branch pipe lines 8-2, 8-3, 8-4. Therefore, it is preferable to install a water level detector at the confluence point c to detect the initial water level ho. However, when the flash flood of the branch conduit 8-1 reaches the merging point c earliest, the merging point c from the other branch conduit
Since the amount of water flowing into the water is the flow at a normal time, the correlation coefficient based on the past flow rate data of each branch pipe is set, and the initial water level at point a is multiplied by the correlation coefficient. hand,
The initial water level at the confluence c can be estimated. This embodiment uses this method. In this embodiment, basically, the arrival time of the flash flood which reaches the drainage pump point may be predicted at the earliest, so that the flash flood occurring in the branch pipe 8-2 is the earliest than the branch pipe 8-1. When reaching the confluence c, the arrival time T'fd for flash flood of the branch pipe line 8-2
Predict.

Based on the arrival time T'bd predicted in this way, in step 45, the number of drainage pumps to be operated and the operation start timing are determined, and
According to the decision, the control of the preliminary standby operation for flash flood is performed. Normally, multiple drainage pumps are provided, so the number of drainage pumps to be operated is determined according to the strength of the flash flood.

As described above, according to this embodiment, the water level in the drainage channel is detected at the upstream point a of the drainage channel, and it is determined whether or not the rate of increase is rapid. Can be detected quickly. Thereby, the corresponding operation of the drainage pump can be performed with a margin.

The degree of flash flood (water level or rate of increase)
Also, based on the distance from the flash flood detection point to the drainage pump point and the drainage channel conditions, the flash flood arrival time to the drainage pump point is predicted and calculated according to hydraulic theory, so there is a further margin for drainage. The corresponding operation of the pump can be performed.

Since the number of drainage pumps to be operated in advance and the operation start timing are determined based on the prediction result, the arrival of flash flood can be easily dealt with.

Although the time during which the drainage pump can be operated in advance standby is limited by the cooling system of the pump bearings, etc., the above-described prediction can optimize the time in advance standby and prevent damage to the pump bearing. The following means can be mentioned as means for controlling the inflow to the vertical shaft and pumping station.

1) Control of the inflow amount from a plurality of drainage channels to the shaft.

2) Control of the inflow amount to the pumping station by the movable weir.

3) Drainage of open and closed channels.

4) Integrated management of multiple machines.

5) Flow control by the overflow weir on the pump discharge side.

First, 1) the means for controlling the inflow amount from a plurality of drainage channels to the vertical shaft will be described in detail. FIG. 12 shows an example of an underground drainage system, and as shown in the figure, a movable inflow amount adjusting device 8 is provided in a water conduit from a river or drain to the inflow shafts 1, 2 and 3. Thereby, the inflow amount from each river or drainage channel to the underground discharge channel 4 is adjusted, and the inflow shafts 1, 2 or 3 from each river or drainage channel are adjusted according to the water level or the inflow amount of each river or drainage channel.
The inflow to 3 can be adjusted separately.

Next, 2) control of the inflow amount to the pumping station by the movable weir will be described.

FIG. 13 shows the movable inflow amount adjusting device 8 shown in FIG. As the movable weir 9, as shown in FIG. 13, one that can adjust the height of the weir up and down and a swing type can be considered, but in a large-scale system, the control power can be made small and foreign matter is not easily caught. 13 is better.

FIG. 14 shows an inflow shaft 1 from a river or drainage channel.
The water conduit to 2 and 3 is a pipe, and the flow rate adjusting device 8 in FIG. 12 is a valve. In this case, as the valve, a butterfly valve whose flow rate can be adjusted and a relatively large one can be manufactured is suitable.

Next, a method of operating the underground drainage system configured as described above will be described. That is, from the operating state of the pump 7, the water level of the underground discharge channel 4, the total inflow rate, or the prediction result and the water level of each river or drainage channel, the optimum inflow amount from the river or drainage channel is determined, and the flow rate is determined. The adjusting device 8 adjusts to an optimum value. For example, when there is a large amount of inflow to a certain river or drainage channel due to weather conditions and the risk of submergence occurs, as long as the operating state of the pump 7, the water level of the underground discharge channel 4 and the total inflow amount allow, By preferentially discharging the water from the river or drainage channel, it is possible to prevent flood damage and maximize the capacity of the drainage system.

FIG. 15 is a block diagram of a flow rate adjusting device for determining an optimum inflow amount from a river or drainage channel and adjusting it to an optimum value in this embodiment.

As shown in the figure, it is assumed that a plurality of rivers A, drainage channels B and culverts C are controlled by an underground drainage facility. The controller 12 can constantly monitor the water level of the river A, the drainage channel B and the pipe C, the inflow rate Q into the inflow shafts 1, 2 and 3, the water level of the underground discharge channel 4, the drainage rate ΣQ of the drainage pump, etc. To do.

When the amount of rainfall in the basin of river A is large and the water level is rising, the operating state of the pump is ascertained from the water level of the underground discharge channel 4, the drainage amount of the drainage pump 7, etc.
When the capacity of the pump has a margin, a control signal is sent to the flow rate adjusting device 8 of the river A to increase the inflow amount Qa from the river A. At this time, even if the capacity of the drainage pump 7 is not sufficient, if the water level rising speed of the river A is large and there is a risk of flooding, if there is room in the water levels of the other drainage channels B and culverts C. If the control device 12 is configured to send a control signal to the flow rate control devices 8 to decrease the inflow amounts Qb and Qc, and then increase the inflow amount Qa from the river A, the drainage system It is possible to maximize the function of and to improve the reliability of the drainage system.

Further, based on the inflow amount of rainwater from a river or drainage or the prediction result thereof, a river or drainage where a rapid inflow is expected is preferentially led to the underground discharge channel 4 in advance, If you raise the water level to the lowest operable water level, then start the pump, perform drainage operation, and lower the water level of the river or drainage channel near the minimum water level, you can use the storage effect of the river or drainage channel itself. The standby operation of the pump can be performed in preparation for a sudden inflow.

At this time, if the pump 7 is composed of a movable vane pump or a pump capable of controlling the number of revolutions and the low flow rate drainage operation is performed, the drainage capacity by natural flow down of the river or drainage can be utilized to the maximum extent. It enables efficient standby operation.

FIG. 16 shows another embodiment.
A movable weir 11 is provided in the underground discharge channel 4 on the upstream side of the pump station. With such a configuration, it is possible to prevent the initial wastewater from flowing into the pump well 6 at the initial stage of inflow, so that the reliability of the pump 7 can be further improved.

When this drainage system is operated in an open channel, depending on the gradient θ of the underground discharge channel 4, for example, when the pump 7 is delayed in startup due to a malfunction of the pump 7 or the like. The movable weir 11 can be closed to maximize the storage effect of the underground discharge channel 4.

Further, with this structure, the water level of the pump well 6 is stabilized by adjusting the height of the movable weir 11 according to the inflow amount from the river or drainage or the prediction result thereof. Therefore, since the operation of the pump 7 can be stabilized, especially in the case of a large-scale pump system,
The reliability of the pump 7 can be improved.

Next, 3) the drainage when the underground discharge channel is in the open or closed channel will be described. A pump that can discharge the planned amount of water when the inflow channel is closed and that does not close even in the open channel is placed in the pump well. This pump is a movable vane pump, and the drainage standby operation is performed near the minimum blade angle, and the blade angle of the pump is adjusted according to the rising water level of the pump well or the rising speed of the water level to adjust the drainage amount. Further, this pump may be a rotation speed control type, and a drainage standby operation may be performed at a low speed rotation, and the rotation speed may be adjusted according to the water level rise of the pump well or the water level rise rate to adjust the drainage amount. Also,
In the pump well, there are a small-capacity high-lift pump that can discharge the planned amount of water when the underground inflow channel is open and a drainage standby operation, and a large-capacity low-lift pump that can discharge the planned amount of water when the channel is closed. May be combined. The flow rate can be controlled by forming an overflow weir or siphon without installing a valve on the discharge side of the pump.

Next, the following means can be mentioned for stable operation of the deep underground drainage facility (pump station).

(1) Drainage standby operation by controlling pump blade angle and rotation speed.

(2) Advance standby operation of the pump.

(3) A combination of small capacity / high head and large capacity / low head pumps.

(4) Application of the drainage priority operation algorithm.

(5) Pump well ON / OFF water level correction by rising / falling speed of water level.

(6) A surge prevention reservoir provided near the pump for temporary storage and prior discharge.

(1) The details of the drainage standby operation by controlling the pump blade angle / rotational speed are as described above, but they are also effective for stable operation of the pumping station.

(2) The preceding standby operation of the pump means an operation of opening the valve of the discharge passage and starting the operation of the pump before the inflow water reaches the water absorption tank according to the prediction of the inflow of the water into the water absorption tank.

FIG. 17 is a vertical sectional view showing the construction of the drainage facility of this embodiment.

As shown in the figure, a valve 14 is inserted into the discharge passage 13 which communicates with the main inflow conduit 1 from the reservoir 10. A water absorption tank 5 is provided at the end of the inflow main pipeline 1, and the pump 4 is immersed in the water absorption tank 5. Discharge pipe 6 of pump 4
Is connected to the reservoir 10 by branching from the upstream side of the discharge valve 7.
Has been inserted. When there is rainfall, the inflow of water into the water absorption tank 5 is predicted, and the discharge channel 13 is provided before the inflow water reaches the water absorption tank 5.
The valve 14 is opened to supply the water stored in the reservoir 10 to the water absorption tank 5. The discharge water arrives at the water absorption tank 5 after a certain delay, and the water absorption tank 5
Pump 4 when the water level rises to a level at which pump 4 can operate
Start driving. In this way, the standby operation can be performed prior to the full-scale inflow of the discharged water at the stage when the discharged water starts to flow.

(3) A combination of a small capacity / high head and a large capacity / low head pump will be described.

FIG. 18 is a vertical sectional view showing the structure of the drainage facility of this embodiment.

In general, when the buried depth of the underground waterway 1 becomes deep, the difference between the low water level LWL and the high water level HWL of the pump well 7 becomes large. Further, in the underground drainage facility, when the water level of the pump well 7 is low, the amount of drainage may be small, and the use of drainage may be increased as the water level rises. Therefore, as shown in FIG. 18, it is desirable that the drainage pumps that cover the required amount of drainage are divided and installed in layers, and the high lift pump 8a is installed in the lower hierarchy and the low lift pump 8b is installed in the upper hierarchy. In this case, the low head pump 8b is provided at least at a level below the bottom surface of the underground reservoir 10.

With this structure, the drainage pump 8b on the upper floors has a high installation level, and therefore the discharge river 9
Since the difference between the water level Ho and the water level Ho becomes smaller, the required head is also reduced accordingly, so that the drainage power can be saved. In particular, if the rating of the drainage pump 8b in the upper layer is set to a low lift / large capacity and the operation is started according to the rise of the water level, the pump with a low lift / large capacity has a high pump efficiency over a wide range. , The drainage power saving effect is remarkable. Further, when the water level in the pump well 7 is low, it is not necessary to drain the water so quickly.
Although a has a high head, a small capacity is sufficient.

Further, since a plurality of drainage pumps are installed in a hierarchy of at least the second floor, it is possible to reduce the required construction area of the underground pump building. As a result, the amount of work including underground excavation work can be reduced, and an increase in construction costs can be suppressed.

Next, (5) ON / OFF water level correction of the pump based on the rising / falling speed of the pump well water level will be described.

FIG. 19 shows the pump well water level rise rate of this embodiment. The solid line shows the case where the water level rise rate is high, the dotted line shows the case where the water level rises normally, and the chain line shows the case where the water level rise rate is small.

FIG. 20 shows the starting pattern when the pump well water level rising speed in this embodiment is high.

The starting water level is B2 lower than that of the conventional one. Further, the water level difference before starting all the units (3 units in this example) is A2, which is smaller than that of the conventional unit (A ₁ ). That is, when the rate of water level rise is high, the first unit rises at a low water level, and the water level at which all units stand up is low, and a rapid rise in water level can be dealt with quickly.

FIG. 21 shows a starting pattern when the pump well water level rising speed in this embodiment is slow.

The water level at the start of the first unit is high by B3, and the water level is stopped at the low water level even when stopped. That is, the water level difference between start and stop can be made larger (C3) compared to the conventional (C1), which is effective in preventing hunting.

Next, (6) the surge prevention reservoir provided near the pump for temporary storage and prior discharge will be described.

FIG. 22 is a vertical sectional view showing the conceptual structure of the underground drainage facility of this embodiment.

As shown in the figure, an underground reservoir 10 having a constant volume is buried in the intermediate position between the ground surface and the groundwater channel 1 on the relatively downstream side of the groundwater channel 1. The underground reservoir 10 is connected to the underground waterway 1 via a communication shaft 11. The level (inlet level) of the communicating portion of the communicating shaft 11 with the underground reservoir 10 is located on the side surface portion at a level higher than the bottom surface of the reservoir. The bottom of the underground reservoir 10 is connected to a communicating shaft 11 via a reservoir water discharge pipe 12. An on-off valve or a gate valve (hereinafter referred to as an on-off valve) 13 that opens and closes the conduit is provided in the discharge conduit 12. Here, the discharge pipe line 12 can be directly connected to the ground water channel 1. Further, a pumping pump 15 is provided so as to communicate with the bottom of the underground storage pond 10 so that the stored water can be pumped up to the ground. As a result, the stored water can be used for fire fighting, sprinkling roads and parks. It can be effectively used for business purposes. On the other hand, the upper part of the underground reservoir 10 is opened to the atmosphere through the air holes 14, and public facilities such as a park 17 and a playground are provided on the ground surface corresponding to the underground reservoir 10.
Further, facilities such as an underground parking lot 16 are provided by utilizing a space between the surface of the earth and the underground reservoir 10.

Further, the capacity of the underground reservoir 10 is set to be equal to or more than the storage capacity required by the conditions of the drainage system such as the inflow prediction and the drainage capacity of the drainage pump minus the storage capacity of the underground waterway 1. .

The operation and operating method of the embodiment thus constructed will be described below.

When it rains and the water level of the river 3 or the like rises, the amount of water flowing into the ground water channel 1 increases, and the water level of the ground water channel 1 rises according to the amount of rainfall. When a sudden increase in the inflow of water such as a torrential rain occurs, the groundwater channel 1 becomes full, and the water level of the communication shaft 11 of the underground storage pond 10 rapidly rises, resulting in the hydraulic gradient 20 shown in FIG. Accordingly, the water level reaches the entrance level of the underground reservoir 10. When the water level reaches this level, the storage effect of the underground reservoir 10 is exerted, so that a rapid rise in the water level thereafter is moderated. Therefore, it is possible to take a sufficient time from the arrival of the falling water to the pump well 7 to the start of the operation of the drainage pump 8. That is, even if the drainage pump 8 is started after the water level reaches the entrance level of the underground reservoir 10, the inflow water flows back from the river 3, the pipe 4, the discharge channel 5 or the air hole 6 of the upstream side water channel. Can prevent flooding.

Although the total drainage capacity of the drainage pump 8 is determined based on the inflow rate prediction, it is usually set to the total drainage capacity according to the inflow rate per unit time. Therefore,
If the drainage pump 8 is started after the water level reaches the underground storage pond 10, the rise in the water level can be suppressed.

In the present invention, the total head of the pump is reduced to reduce the size of the pump itself and the size of the prime mover to save space in the pumping station, but the following means are also available.

A. Hierarchical pump station.

B. A pumping station arranged in a circle.

C. A pumping station located vertically.

A. An example will be described in which the pumping stations of (1) are hierarchically arranged in a circle.

FIG. 23 is a vertical sectional view showing the conceptual structure of the drainage pump station of this embodiment.

FIG. 24 is a partial detailed view of FIG.

Inflow water such as rainwater collected by the groundwater channel 1 arranged in the drainage target area flows into the pump well 2, and the inflow water in the pump well 2 is pumped up by the drainage pump group 3 and collected. The water is discharged to the discharge destination river 6 through the discharge pipe line 4 and the drainage line 5. The drainage pump group 3 is composed of a plurality of drainage pumps PL1 to n (n is a natural number) and PH1 to n arranged in two layers at different installation levels. Here, a low head / large capacity pump is applied to the drainage pump PH, and a high head / small capacity pump is applied to the drainage pump PL. These drainage pumps PH and PL are installed in a circular shape for each floor. The suction pipe lines 7 and 8 of the drainage pumps PH and PL are communicated with the pump well 2 via annular collecting suction pipe lines 9 and 10, respectively. The collective suction pipe lines 7 and 8 are each formed in an annular shape in accordance with the circular arrangement of the drainage pumps. The suction sluice valve 11,
12 are provided. The collective discharge pipe line 4 is provided vertically at the center of the drainage pump group 3, and the discharge pipe lines 13 and 14 of the drainage pumps PH and PL are connected to each other. Collective discharge line 4
The upper part of the is connected to the river 6 by the drainage channel 5. Further, the pipe diameter of the collective discharge pipe line 4 is formed so as to become lower toward the lower layer in accordance with the drainage amount of the drainage pump for each layer. The outer shape of the underground pump building 20 in which the drainage pump group 3 is installed is formed in a truncated cone shape that spreads upward. This shape is due to the high heads installed on the lower floors.
This is because the small-capacity drainage pump PL requires a smaller installation area than the low-lift, large-capacity drainage pump PH installed on the upper floor. The underground pump building 20 is shown in Fig. 24.
As described above, only the lower layer portion may have a truncated cone shape, and the upper layer portion may have a cylindrical shape. In addition, maintenance areas 17 and 18 for maintaining the drainage pumps PH and PL and the electric motors 15 and 16 are provided in the underground pump building 20. In addition, as shown in the figure, the upper end of the collective discharge pipe line 4 is exposed to the ground,
For example, a fountain or a waterfall 21 may be provided in that portion, or the above-ground portion of the underground pump building 20 may be used as a park 22 or the like.

With such a configuration, according to the present embodiment, the difference between the drainage pump PH on the upper floors and the water level Ho of the discharge destination river 6 becomes smaller due to the higher installation level. Since the required head is smaller, drainage power can be saved. Especially, the drainage pump P of the higher floor
If the rating of H is set to low lift and large capacity, a pump with low lift and large capacity has high pump efficiency over a wide range, so that the drainage power saving effect is remarkable.

Further, in the drainage system, when the water level of the pump well 2 is low, the drainage amount may be small, and the drainage amount may be increased as the water level of the pump well increases. Therefore, for example, as shown in FIG. , Ho-60m)
And HWL (for example, Ho-15 m), intermediate water levels MWL1, 2 (for example, Ho-45 m,
Ho-30m) is set and the drainage pumps of higher floors are sequentially operated as the water level rises, whereby drainage power can be effectively saved.

Further, since the plurality of drainage pumps are installed in a hierarchy of at least the second floor, it is possible to reduce the required construction area of the underground pump building. As a result, the amount of work including underground excavation work can be reduced, and an increase in construction costs can be suppressed. In particular, since the drainage pumps are arranged in a circular shape, the outer shape of the underground pump building 20 can also be circular,
The effect of reducing construction costs is remarkable.

Further, when the water level of the pump well 2 is low, it is not necessary to drain water so quickly, so that the drain pump PL of the lower hierarchy has a high head but a small capacity. Therefore, the area of each floor of the underground building may be smaller as it goes down, and if at least the outer shape of the lower part is formed into a truncated cone shape, the amount of excavation can be reduced especially at deep places, thus reducing construction costs, etc. The effect is remarkable.

Next, c. The pumping station arranged in the vertical direction will be described.

FIG. 25 is a vertical cross-sectional view showing a pumping station in which the vertical axis driving multiplex pump of this embodiment is arranged.

As shown in the figure, reference numeral 1 is a drive machine which is a drive source of a pump impeller (not shown), and its main shaft 17 is in the vertical direction. 2 is a pump with a large capacity and a low head,
3 is a small-capacity, high-lift pump, which is arranged in the vertical direction. Reference numeral 4 denotes a joint capable of transmitting / not transmitting rotational torque, and the main shaft 17 of the driving machine 1 is connected to the main shafts 18 of the two pumps 2 and 3 arranged vertically by the joint 4. There is. That is, the driving machine 1 is located between the two pumps 2 and 3 arranged in the vertical direction, and has a double-screw drive structure, although not shown in detail.

Reference numeral 9 is an underground headrace, 10 is an intake shaft provided in connection with the underground headrace 9, and 13 is a discharge pipe associated with a discharge channel. Two or more units arranged vertically between the intake shaft 10 and the discharge pipe 13 (two units in FIG. 25)
Vertical drive multiple pumps are installed. The suction pipe 7-1 of the pump 2 on the upper side is connected to the upper part of the intake shaft 10 via the gate valve 8-1, and the pump 3 on the lower side is connected.
The suction pipe 7-2 is connected to the lower part of the water intake shaft 10 through a gate valve 8-2. The discharge sides of the pumps 2 and 3 are connected to the discharge pipe 13 via sluice valves 6-1 and 6-2.

The water that has flowed into the intake shaft 10 from the underground headrace 9 and pooled the suction pipe 7 (7-1, 7-2) when the sluice valve 8 (general term for 8-1, 8-2) is open. Generically) and is discharged to the discharge pipe 13 by the pump. The discharge pipe 13 has an enlarged cross-sectional area from a position where the discharge flows of the pump 2 having a large capacity and a low head are joined. The sluice valve 6 on the discharge side (collective term for 6-1 and 6-2) is closed when the pump is stopped, and prevents the reverse flow of the discharge flow. Also, 14 and 15 are water flow directions, and 11 and 1
2 shows the water level.

Since this embodiment is constructed as described above, it does not require a flat space in the underground drainage pump station as compared with the conventional horizontal arrangement of pumps.

Further, the main shaft 17 of the driving machine 1 and the pumps 2, 3
Since the main shaft 18 is connected to the main shaft 18 by the joint 4 capable of transmitting / not transmitting the rotational torque, only the necessary pump impeller can be rotated, and the waste of energy can be prevented.

Further, the two pumps 2 and 3 arranged in the vertical direction are configured such that the upper side has a large capacity and low head pump 2, and the lower side has a small capacity and high head pump 3.
When the water level of the intake shaft 10 is low 11, the pump 3 having a high head is operated to increase the water level 12 of the intake shaft 10.
At this time, the pump 2 with a low head can be operated.
Also, they can be operated simultaneously.

Further, the driving machine 1 has a simple structure as it is driven by both pumps.

Since the discharge pipe whose flow passage cross-sectional area increases in the downstream direction is provided, efficient operation is possible. Furthermore, one discharge pipe 1 for multiple pumps
Since 3 can be used together, there is also an effect that the structure of the pump device is simplified.

According to this embodiment, when the large capacity, low head pump 2 is not operated, the sluice valves 6-
1, 8-1 can be closed to drain water, and the pump 2 can be operated as a flywheel, which also has the effect of saving energy and preventing water hammer.

Further, another embodiment will be described with reference to FIG.

FIG. 26 is a vertical cross-sectional view showing a pumping station in which a vertical shaft driven multiple pump according to another embodiment is arranged.

In the figure, those having the same reference numerals as those in FIG. 25 are the same parts as those in the previous embodiment, and therefore their explanations are omitted.

In the embodiment shown in the figure, the impeller rotating shafts of the three pumps 20 arranged in the vertical direction are in the horizontal direction, and the three pumps 20 have the same structure.

In this figure, 1A is a driving machine which is a driving source of a pump (or a pump impeller), 17A is a main shaft of the driving machine 1, and 20 is two or more units vertically arranged (see FIG. 26). In the above example, three axial flow pumps, 17B are connecting shafts connecting these axial flow pumps 20 in the vertical direction, and 21 is a main shaft 17A of the driving machine 1 and each connecting shaft 1 of the axial flow pump 20.
7B is a shaft coupling that connects with 7B. The axial flow pump 20 includes an axial flow type impeller 19 and guide vanes 22 and 23.
18A is the rotation axis of the impeller 19 and lies in the horizontal direction. Two
Reference numeral 4 denotes the torque of the connecting shaft 17B for the rotary shaft 1 of each impeller.
A bevel gear 25 related to the orthogonal transmission mechanism that transmits to 8A is a shaft penetrating opening provided in the casing of the axial pump.

The rotary shaft 18A of each impeller and the bevel gear 24 are connected by a joint 4 capable of transmitting / not transmitting the rotational torque.

There is a pump chamber between the intake shaft 10 connected to the underground conduit 9 and the discharge pipe 13, and there are two or more (three in FIG. 26) axial flow pumps 20 arranged in the vertical direction. A vertical drive multi-axial pump consisting of The upstream side of each axial pump 20 is connected to the intake shaft 10 via the sluice valve 8.
In addition, the downstream side communicates with the discharge pipe 13 via the sluice valve 6. In the case of the present embodiment, as with the embodiment shown in FIG. 25 described above, an economical pumping station configuration and efficient pump operation are possible, and the rotary shaft 1 of the impeller 19 of each pump is
Since 8A is arranged horizontally, the pump impeller is not limited to the axial-flow impeller, and a mixed-flow impeller can be incorporated.

In this embodiment, the height of the drain port at the outlet of the discharge pipe 13 is constant, and the water in the intake shaft 10 acts as a push. The heads required for the axial pumps 20 are the same, and the pumps can have the same structure. Further, since each pump has the same structure, there is an effect peculiar to the present embodiment that it can be considered as a package type, the number of pumps can be easily increased, and the product cost can be reduced.

The pump arranged at the pumping station becomes large due to its large capacity, and if the vibration is large, the pump body,
This causes fatigue damage to the piping system, and vibration also causes noise, which affects the working environment. Therefore, a pump with reduced pulsation in order to reduce vibration will be described.

27 to 29 show a single suction centrifugal type diffuser pump of this embodiment.

FIG. 27 is a sectional view in a direction orthogonal to the pump rotation axis.

FIG. 28 is a sectional view taken along the line II-II of FIG.

FIG. 29 is a sectional view taken along the line III-III in FIG.

As shown in the respective drawings, the diffuser 3 is provided outside the one-suction centrifugal impeller 1 and the volute casing 10 is provided outside the diffuser 3. The volute casing 10 has a pump discharge port 1
1 is integrally formed. Further, a suction casing 16 having a pump suction port 15 is provided so as to be connected to the volute casing 10, and these constitute a flowing water portion of the diffuser pump.

A partition wall 5 is provided between the side walls 4A and 4B of the diffuser 3. Further, the flow path in the diffuser 3 by the partition wall 5 is two flow paths 6 independent in the axial direction.
It is divided into A and 6B. These two channels 6A, 6B
The diffuser blades 7A and 7B are respectively disposed in the. These blades 7A and 7B are arranged so that their positions in the rotational angle direction are displaced from each other. In the present embodiment, the positions are shifted so that the inlet ends of the diffuser blades of the other flow passage are located in the middle of the inlet ends of the diffuser blades of the one flow passage. In the example of FIG. 27, the inlet end 7B ′ of the blade 7B is at an angle ζ with respect to the inlet 7A ′ of the blade 7A in the rotating direction of the impeller.
Only shifted by °.

The operation of the present embodiment having such a configuration will be described below.

The flow flowing from the pump suction port 15 has its flow velocity increased by the rotation of the impeller 1 and is discharged to the diffuser 3. Here, the flow is decelerated, and the flow that has recovered the static pressure further passes through the volute casing 10 and is discharged from the pump discharge port 11.

As described above, the flow at the outlet of the impeller 1 is affected by the thickness of the impeller, the development of the boundary layer of the flow along the impeller surface within the impeller 1, and the like. Has a non-uniform flow velocity distribution with 1 as the pitch. Then, when this nonuniform flow passes through the inlets of the diffuser blades 7A and 7B, pressure pulsation having a basic period of time required for this one pitch rotation occurs. The generated pressure pulsation is transmitted to the volute outlet, and the combined pressure pulsation wave is transmitted to the discharge pipe. In addition, a part of it will be transmitted to the suction pipe through the inside of the impeller.

However, according to this embodiment, the diffuser flow passage is divided by the partition wall 5 into independent flow passages 6A and 6B,
And the diffuser blade inlet ends 7A ′, 7 of those flow paths
The position of B'is displaced from each other with respect to the rotating direction of the impeller. Therefore, the fluid flowing out from the impeller flow path will flow into and out of the two diffuser flow paths 6A and 6B in a relationship that the phase angle ζ ° of the rotation angle corresponding to the deviation amount is deviated. Therefore, the pressure pulsations generated at the inlets of the two diffuser flow paths 6A and 6B are canceled at the outlets according to the phase shift, and the pressure pulsations at the diffuser flow path outlets are reduced.

In particular, when the inlet ends 7A ', 7B' of the blades of the diffuser passages 6A, 6B are displaced by an angle of about half the blade pitch of the impeller, the diffuser passages 6A, 6B are alternately arranged. Since the phases of the pressure pulsations that are generated deviate from each other by 1/2 wavelength, the pressure pulsations of both flow paths cancel each other out, and the pressure pulsations are greatly reduced. That is, when the number of blades of the impeller is Zi and the number of blades of the diffuser is Zd, and the angle ζ is set to the following relationship, ζ ° = 1/2 × 360 ° / Zi or 360 ° / Zd-ζ ° = 1/2 × 360 ° / Zi Since the pulsations alternately generated from both flow paths 6A and 6B are out of phase with each other by 1/2 wavelength, the pressure pulsations transmitted through both flow paths interfere and the pressure pulsation is significantly reduced. To do.

The blade inlet end 7 of both flow paths 6A and 6B
By shifting the positions of A ′ and 7B ′, these positions and the distance to the pump discharge port are different. But,
Since the difference in the distance is generally significantly smaller than the wavelength of the pressure pulsation, the influence on the phase shift can be ignored. Therefore, it is sufficient to shift by ζ that satisfies the above expression. As described above, in this embodiment, the pulsation is reduced by devising the shape of the diffuser portion. And
The partition wall 5 has a disk shape, and the diffuser blades also usually have a two-dimensional shape. On the other hand, according to the prior art in which the flow passage in the impeller is partitioned by partition walls and the blades on both sides of this partition wall are displaced to reduce pressure pulsation, the partition wall in the case of the single-suction centrifugal impeller is along the streamline. It has a curved shape, and the blades of the impeller are usually formed in a three-dimensional curved surface. Therefore,
According to this embodiment, the pump can be easily manufactured as compared with the prior art.

Further, according to this embodiment, since the partition wall is not provided at the impeller inlet portion, the cavitation performance is not deteriorated.

Further, since there is no partition wall along the central streamline in the impeller, when the pump is operated at a small flow rate, the generation of centrifugal flow and backflow in the impeller is not suppressed, and the pump head curve becomes unstable. Does not cause deterioration of characteristics.

[0189] The deep underground drainage facility for coexisting open channel / closed channel operation described above has the following effects.

A. The total head of the pump is significantly reduced, and the equipment cost of the pumping station including the pump and the driving machine is reduced.

B. The cost of excavating the underground waterway is reduced.

C. The risk of overflow to the ground is reduced due to the storage effect of the long underground waterway.

D. Due to the storage effect described above, a pumping station can be constructed in the city center where land acquisition is difficult because a large capacity water absorption tank is not required.

Although various embodiments have been described with respect to the deep underground drainage facility, the present invention also includes a mode in which the techniques described in the above embodiments are appropriately combined and implemented.

[0195]

EFFECTS OF THE INVENTION According to the present invention, the pump installation position is set at the central portion of the underground waterway, and the open water channel and the closed water channel are coexistently operated, whereby the total pump head and pump equipment cost can be reduced. Since the risk of water level rise is reduced due to the storage effect of the long underground canal, the diameter can be reduced and the cost of excavating the underground canal can be reduced.

By using a pump of a type suitable for coexistence operation of an open water channel and a closed water channel, the equipment cost of the pump and the driving machine can be reduced.

By providing a large-capacity water absorption tank between the pump well and the pump to operate the closed water channel, the risk of overflowing from the ground water channel to the ground due to its storage effect can be reduced, and the diameter of the ground water channel can be reduced.

If it is difficult to acquire a site for construction of a pumping station, select an open channel / closed channel coexistence type that does not require a large capacity water absorption tank, and if it is easy to acquire a site for a large capacity water absorption tank, pump head By selecting a closed channel type with a small size, a deep underground drainage facility with a minimum construction cost can be selected.

Further, the outflow coefficient is changed at time intervals between rainfall patterns and the rainfall amount is calculated to calculate the inflow amount into the vertical shaft, and the inflow amount into the pumping station is accurately predicted to determine an appropriate pumping station. Operation management will be possible to enable stable operation of deep underground drainage facilities.

[Brief description of drawings]

FIG. 1 is a perspective view showing the basic configuration of a deep underground drainage facility of the present invention.

FIG. 2 is an explanatory diagram illustrating a configuration of an embodiment of the present invention in which an open channel / closed channel coexisting operation is performed.

FIG. 3 is an explanatory diagram illustrating a pump starting water level when the open channel / closed channel coexisting operation of the embodiment of the present invention is performed.

FIG. 4 is a chart illustrating pump characteristics according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating pump characteristics suitable for coexistence operation of an open water channel and a closed water channel according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram illustrating a configuration of an embodiment in which the closed water channel is operated according to the embodiment of this invention.

FIG. 7 is an explanatory diagram illustrating a configuration of an embodiment for accurately predicting and controlling an inflow amount into a pumping station of the present invention.

FIG. 8 shows a flowchart of a procedure from rainfall to determination of pump drainage according to an embodiment of the present invention.

FIG. 9 is a table showing the relationship between time and rainfall amount and time and inflow amount according to the embodiment of the present invention.

FIG. 10 is a flowchart showing a procedure for flash flood detection and arrival time prediction of the drainage system according to the embodiment of the present invention.

FIG. 11 shows an overall configuration diagram of a drainage system according to an embodiment of the present invention.

FIG. 12 is a vertical cross-sectional view showing the configuration of an underground drainage facility according to an embodiment of the present invention.

13 is a vertical cross-sectional view in which the movable inflow amount adjusting device in FIG. 12 is configured by a movable weir.

14 is a vertical cross-sectional view in which the movable inflow amount adjusting device in FIG. 12 is constituted by a valve.

FIG. 15 is a block diagram of a flow rate adjusting device that determines an optimum inflow amount from a river or a drainage channel and adjusts it to an optimum value according to an embodiment of the present invention.

FIG. 16 is a vertical cross-sectional view showing a movable weir provided in an underground discharge channel on the upstream side of a pumping station according to an embodiment of the present invention.

FIG. 17 is a vertical cross-sectional view showing the configuration of the drainage facility of the embodiment of the present invention.

FIG. 18 is a vertical cross-sectional view showing the configuration of the drainage facility of the embodiment of the present invention.

FIG. 19 is a chart showing the pump well water level rise rate in the example of the present invention.

FIG. 20 is a diagram showing a starting pattern when the pump well water level rising speed is high in the embodiment of the present invention.

FIG. 21 is a diagram showing a starting pattern when the pump well water level rising speed is slow in the example of the present invention.

FIG. 22 is a vertical cross-sectional view showing the conceptual configuration of the underground drainage facility of the embodiment of the present invention.

FIG. 23 is a vertical cross-sectional view showing the conceptual configuration of the drainage pump station according to the embodiment of the present invention.

FIG. 24 is a partial detailed view of FIG. 23.

FIG. 25 is a vertical cross-sectional view showing a pumping station in which the vertical drive multiplex pump according to the embodiment of the present invention is arranged.

FIG. 26 is a vertical cross-sectional view showing a pumping station in which a vertical drive multiple pump according to another embodiment of the present invention is arranged.

FIG. 27 is a cross-sectional view in a direction orthogonal to the rotation axis of the single-suction centrifugal diffuser pump of the embodiment of the present invention.

28 is a sectional view taken along the line II-II in FIG. 27.

29 is a sectional view taken along the line III-III in FIG. 27.

FIG. 30 is an explanatory diagram illustrating a configuration of conventional open channel operation.

[Explanation of symbols]

 1 Groundwater channel 2 Vertical shaft 3 Drainage channel 4 Pipe 5 River 6 Pump well 7 Pump 8 Discharge water tank 61 Large-capacity water absorption tank 71 Rainfall radar

Claims (10)

[Claims] 1. A gently sloping large-capacity underground waterway disposed deep underground, a vertical shaft for draining drainage from the surface or a discharge channel near the surface of the underground waterway, and a downstream end of the underground waterway. In a deep underground drainage facility consisting of a pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, the pump of the pump station is installed at the water level in approximately the center of the underground waterway. A deep underground drainage facility that has been characterized. 2. A gently sloping large-capacity underground waterway arranged deep underground, a shaft for draining the drainage from the surface or a discharge channel near the surface, and a downstream end of the underground waterway. In a deep underground drainage facility consisting of a pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, the pump of the pump station is installed at the water level in approximately the center of the underground waterway. However, the deep underground drainage facility is characterized by having pump characteristics such that the total head is capable of pumping from the closed channel water level at the rated flow rate and the total head is capable of pumping from the open channel water level at the minimum flow rate. 3. A gently sloping large-capacity underground waterway arranged deep underground, a vertical shaft for draining drainage from the surface or a discharge channel near the surface, and a downstream end of the underground waterway. In a deep underground drainage facility consisting of a pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, the pump of the pump station is installed at the water level in approximately the center of the underground waterway. However, the total head that can be pumped from the water level of the closed channel at the rated flow rate, the total head that can be pumped from the water level of the open channel at a predetermined flow rate, and the discharge flow rate between the closed channel and the open channel. A deep underground drainage facility characterized by having pump characteristics that maximize pump efficiency. 4. The deep underground drainage facility according to any one of claims 1 to 3, wherein a fixed blade is used for the pump. 5. A gently sloping large-capacity underground waterway arranged deep underground, a vertical shaft for draining the drainage from the surface or a discharge channel near the surface to the underground waterway, and a downstream end of the underground waterway. In a deep underground drainage facility consisting of a pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, the pump of the pump station is installed at the water level in approximately the center of the underground waterway. However, it is a deep pitch underground drainage facility characterized by a total pitch that allows pumping from the closed channel water level at the rated flow rate, and a variable pitch type that has a total pumping height that allows pumping from the open channel level at the minimum flow rate. 6. A gently sloping large-capacity underground waterway arranged deep underground, a vertical shaft for draining the drainage from the surface or a discharge channel near the surface to the underground waterway, and a downstream end of the underground waterway. In a deep underground drainage facility consisting of a pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, the pump of the pump station is installed at the water level in approximately the center of the underground waterway. However, it is possible to obtain a total head that allows pumping from the water level of the closed channel at the rated flow.
Deep-drainage drainage facility, characterized in that it is a two-stage wing type equipped with a blade of No.1 and a second blade that can obtain a total head that allows pumping from the open channel water level at the minimum flow rate. 7. The drainage is made to flow down from a surface or a discharge channel near the surface to a vertical shaft, and is made to flow from the vertical shaft to a deeply sloping large-capacity underground water channel arranged deep underground, at the downstream end of the underground water channel. In the operation method of the deep underground drainage facility that pumps the drainage flowing into the established pump well to the river or the sea by the pump at the pump station, the pump is installed at the water level in the center of the groundwater channel and the groundwater channel is fully filled. Coexistence of closed and open channels where the pump is operated at the rated flow rate when the channel is a pipe, and the pump is operated at the minimum flow rate that does not make a closed state when the open channel creates a space due to the water level of the underground channel decreasing. A method of operating a deep underground drainage facility characterized by operating. 8. A deeply sloping large-capacity underground waterway arranged deep underground, a vertical shaft for draining the drainage from the surface or a discharge channel near the surface to the underground waterway, and a downstream end of the underground waterway. In a deep underground drainage facility consisting of a pump well and a pump station for pumping the water flowing into the pump well into a river or the sea, the pump of the pump station is at least shallow underground from the upper end of the underground waterway. A deep underground drainage facility, which is installed and has a large-capacity water absorption tank having a bottom surface at the same level as the pump between the pump well and the pump. 9. A gently sloping large-capacity underground waterway arranged deep underground, a vertical shaft for draining drainage from the surface or a discharge channel near the surface to the underground waterway, and a downstream end of the underground waterway. Method for selecting a deep underground drainage facility that minimizes the construction cost of the deep underground drainage facility consisting of a pump well and a pumping station that pumps the water flowing into the pump well into a river or the sea. In, when it is difficult to acquire the site of the pump station, select a deep underground drainage facility where the pump is installed at the water level in the central part of the underground waterway,
If site acquisition is easy, select a deep underground drainage facility where a pump at the pumping station is installed at least shallow underground from the upper end of the underground waterway and a large capacity water absorption tank is provided between the pump well and the pump. A method of selecting a deep underground drainage facility, which is characterized in that 10. A rainfall amount is calculated from rainfall information, and an inflow amount into a vertical shaft is calculated from the rainfall amount and a runoff coefficient determined by a time interval between the rainfall pattern and the rain pattern, and the inflow amount into the vertical shaft is transferred to a pumping station. The method of operating a deep underground drainage facility, characterized in that the number of pumps and the capacity for draining the inflow to the pumping station are calculated.