JP2844141B2 - Reservoir of drainage system, drainage system and method of operating the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for collecting inflow water such as rainwater flowing into a waterway including a small river into an inflow main pipe provided underground, and guiding the collected inflow water to a drainage pumping station. In particular, it relates to a drainage system configured to discharge water into rivers, etc., especially for maintenance / management operations that are favorable to the preliminary standby operation in which the inflow water starts to operate the drainage pump before it reaches the suction tank of the drainage pump. The present invention relates to a drainage system having a favorable reservoir and an operation method thereof.

[0002]

2. Description of the Related Art In urban areas, the ratio of rainwater that naturally penetrates into the ground decreases due to the increase in the area of pavement along with the development of the surrounding area. Increase in time. In order to cope with such an increase in the amount of inflow water, the diameter of the inflow main pipeline of the underground drainage facility is increased, the number and capacity of the drainage pumps are increased, and the amount of temporary inflow water such as flash flood is suppressed. For this purpose, measures have been taken, such as installing a reservoir.

On the other hand, in order to promptly cope with an increase in inflow water, a drain pump which requires a certain time for start-up preparation or the like is started to operate prior to arrival of inflow water. In such a preliminary standby operation, the water level of the water absorption tank is usually about the minimum water level LWL at which the drainage pump can be operated. Various measures have been taken to allow operation for a period of time (for example, 10 minutes).

Further, in the drainage system, in order to prevent a problem such as a failure to supply a predetermined amount of drainage when drainage is required due to a failure of a drainage pump, auxiliary equipment, etc., a maintenance operation similar to a drainage operation is performed.・ It is necessary to perform management operation. In the case of such a maintenance / management operation, as in the case of the preceding standby operation described above, since there is not a sufficient amount of water in the suction tank of the drainage pump, operation at a low speed, operation with a small amount of water, Circulation operation to return the discharged water of
Alternatively, various maintenance / management operation methods using a light load such as idling have been proposed.

[0005]

However, as the construction of the drainage channel including the inflow main pipeline progresses, the time required for the inflow water to reach the water absorption tank of the drainage pump from the start of rainfall is shortened, and the timing of the arrival timing is reduced. Since there is a prediction error, there is a problem that the allowable time of the preliminary standby operation is insufficient when the allowable time is about 10 minutes, and it is difficult to determine the start timing of the preliminary standby operation.

Further, even in the case of the conventional maintenance / management operation method, it is impossible if the water level in the water absorption tank is extremely low. Is difficult to find.

On the other hand, the conventional reservoir only has a function of absorbing a temporary increase in water, and is discharged as the water level of the water absorption tank decreases at the end of rainfall. Cannot be used for maintenance and management operations.

An object of the present invention is to solve the above-mentioned conventional problems, and a first object of the present invention is to provide a reservoir having a structure capable of sufficiently supplying an amount of water necessary for a preliminary standby operation and a maintenance / management operation, and the reservoir. And a method of operating the same.

A second object of the present invention is to provide a drainage system capable of performing a maintenance / management operation at full load and a method of operating the same.

[0010]

In order to achieve the first object, a drainage system according to the present invention is provided with a reservoir connected to an inflow main pipe for guiding rainwater or the like to a suction tank of a drainage pump,
An inflow regulating means for regulating a level of water flowing into the reservoir is provided at a communication portion between the inflow main pipeline and the reservoir, and an inflow water level set by the inflow regulating means is set to be equal to or less than an upper limit water level of the water absorption tank, and the reservoir is provided. A discharge channel for allowing the stored water to flow down to the water absorption tank via the inflow main conduit or directly, and a valve is provided in the discharge channel.

In the operation method, the valve of the discharge channel is opened before the inflow water reaches the water absorption tank according to the prediction of the inflow of the inflow water into the water absorption tank, and the preliminary standby operation of the drain pump is started. Things. In addition, the opening and closing operation of the valve of the discharge channel causes the amount of water necessary for the maintenance / management operation of the drain pump to flow down to the water absorption tank, thereby performing the maintenance / management operation of the drain pump.

On the other hand, in order to achieve the second object, the drainage system of the present invention, in addition to the above configuration, provides a return line by connecting a discharge pipe of the drainage pump and the reservoir, and the return line is provided in the return line. A valve is provided.

[0013] In the operation method, the valve of the return path is opened to perform a maintenance / management operation of the drainage pump.

[0014]

According to the present invention, the object of the present invention can be achieved by the following operation. First,
According to the reservoir of the drainage system of the present invention, when the water level at the communicating portion with the inflow main pipeline exceeds the level of the inflow regulating means, water flows into the reservoir, and when the discharge channel valve is closed at this time, the Inflow water is stored in the reservoir. The stored water is not discharged unless the discharge channel valve is opened. This stored water flows down to the water absorption tank by opening the valve of the discharge channel, so that it can be used as pre-standby operation and maintenance / management operation water.

It is desirable that the storage capacity of the reservoir is set at least to the amount of water necessary for the preliminary standby operation of the drainage pump. If the capacity of the reservoir is set sufficiently, it becomes possible to allow necessary water to flow down into the water absorption tank for a sufficient time, and the start timing of the preliminary standby operation can be determined with a margin. As a result, the prediction error of the arrival timing of the inflow water can be allowed within a certain range.

Here, the condition for closing the valve of the opened discharge channel is that the water absorption tank should be fully closed when the water level of the water absorption tank reaches the upper limit water level, or should be gradually closed as the water level of the water absorption tank rises. desirable. Thereby, it is possible to prevent the water level in the water absorption tank from exceeding the upper limit water level due to the water discharged from the reservoir, and to store new stored water in the reservoir.

When a plurality of drainage pumps are provided, the plurality of drainage pumps sequentially start the preliminary standby operation in accordance with the water level of the water suction tank, and open the discharge channel in accordance with the start of operation of the last drainage pump. May be half-closed and fully closed when the water level in the water absorption tank reaches the upper limit water level.

[0018] The inflow restricting means may communicate the communication shaft with the inflow main pipe at a position higher than the bottom of the side surface of the reservoir, or provide a weir in the inflow main pipe, and provide an upstream of the weir. It can also be realized by connecting to the reservoir by a communication passage connected to a position higher than the upper end of the weir in the main inflow pipe on the side. In the latter case, since the weir acts as a resistance to the water flow flowing down in the inflow main pipe, a rapid increase in the inflow amount such as flash flood can be suppressed to some extent. However, it is desirable to form an opening at the lower part of the weir in order to make a small amount of water flow smoothly in fine weather or the like.

If the inflow water level of the inflow control means is set at or near the upper limit water level of the water absorption tank, the reservoir functions as a buffer for absorbing a sudden increase in water such as flash flood.

On the other hand, according to the one provided with the return path, the drainage from the maintenance / management operation can be circulated and used between the reservoir and the reservoir, so that the reduction of the stored water can be prevented, and the maintenance / management operation at full load can be performed. Will be possible. In addition, the water for the next preparatory standby operation or the maintenance / management operation can be sufficiently retained as stored water.

[0021]

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

FIG. 1 is a longitudinal sectional view showing a conceptual configuration of a drainage system according to an embodiment of the present invention. As shown in the figure, an inflow main pipeline 1 is buried underground with a predetermined gradient, while a drainage channel 3 made up of a small river or a buried pipe disposed on or near the ground surface through an inflow shaft 2. Rainwater flows in from The downstream end of the inflow main pipe 1 is connected to a water absorption tank 5 of a drain pump 4. A plurality of drain pumps 4 (for example, 3
The tables a, b, and c) are provided in the same water absorption tank 5, and the number of operating units, the blade angle, or the rotation speed is controlled according to the water levels WL1 to WL3 in the water absorption tank 5. As a result, an amount of wastewater corresponding to the amount of inflow water is discharged to a discharge destination river or the like (not shown) via the discharge pipe 6 and the discharge valve 7.

Here, the configuration of the reservoir according to the features of the present invention will be described. The reservoir 10 is provided so as to communicate with the inflow main pipeline 1 through a shaft 11. This shaft 11
Is communicated from the bottom surface of the reservoir 10 to a side position at a constant height H, and the height H of the communication portion 12 constitutes an inflow regulating means for regulating the level of inflow water flowing into the reservoir 10. The bottom of the reservoir 10 is communicated with the inflow main pipe 1 through a discharge channel 13, and the discharge channel 13 is provided with a valve 14. Considering the number of drainage pumps 4, the size of the reservoir 10 is set to at least a capacity capable of storing the amount of water required for the preceding standby operation. For example, the number of drain pumps 4 is N, and all have the same capacity Q (m ³ / min).
Assuming that at least 30 minutes of advance standby operation can be performed, the storage amount = Q (m ³ / min) × 30 (min) × N units. Therefore, Q = 100 (m ³ / min), N
= In the case of 3 small drainage systems, the storage volume is 90
00m ³ , for example, the size of the reservoir 10 is 5 × 4
It becomes 2 × 42 m. In addition, the installation position of the reservoir 10 is set to a position where the flow time of the discharge water from the reservoir 10 to the water absorption tank 5 is as short as possible (for example, 10 minutes or less). In addition, the discharge channel 13 may be provided directly in communication with the water absorption tank 5. In addition, as long as the above conditions of the reservoir 10 are satisfied, the reservoir 10 may be configured as shown in FIG. That is, the reservoir 10 is installed at substantially the same level as the inflow main pipeline 1, a weir 17 is provided in the inflow main pipeline 1, and is connected to the reservoir 10 by a horizontal communication passage 19 whose lower end matches the upper end level of the weir. It may be. In this case, an opening 18 is provided in the lower part of the weir 17 so that a small amount of drainage that normally flows can flow smoothly, and the discharge channel 13
7 to the downstream side. According to the method of FIG.
Acts as flow resistance, so that momentum such as flash floods can be reduced.

On the other hand, the discharge valve 7 of the discharge pipe 6 of the drain pump 4
A return path 15 is provided which branches off from the upstream side and communicates with the reservoir 10, and a valve 16 is inserted into the return path 15.

Next, the operation of the embodiment constructed as described above will be described focusing on the operation in the preceding standby operation. The water level of the water absorption tank 5 during the last rainfall was
It is assumed that the inflow water level WL4 of 0 is exceeded, and the reservoir 10 has sufficient stored water. FIG. 3 shows a time chart of the preceding standby operation performed based on the prediction of the inflow amount after the start of rainfall. FIG. 2A shows a change curve of the actual inflow amount at the point A of the inflow main pipeline 1 corresponding to the position of the reservoir 10, and FIG. 2B shows a change curve of the actual inflow amount at the inlet of the water absorption tank 5. FIG. 3C shows the water level WL of the water absorption tank 5.
5 (d) shows the operation mode of the drainage pump 4 respectively. The drainage pump 4 is rated drainage Q =
It is assumed that N = 3 identical pumps of 100 (m ³ / min) are provided, and the storage amount of the reservoir 10 is set to 9000 m ³ . Further, a control device is arranged so that the preliminary standby operation of the drainage pumps 4a to 4c is automatically started according to a change in the water level of the water absorption tank 5. That is, FIG.
WL1 and 4b are activated when WL2 and 4c reach WL3.

Now, it has been detected by the system controller that heavy rain has started to fall in the target area of the drainage system,
It is assumed that the start command of the preliminary standby operation of the drain pump 4 is issued at t1. Based on this, an open command is output to the valve 14 of the discharge channel 13 by a preceding standby operation control device (not shown). As a result, when the discharge of the stored water is started, the discharged water reaches the water absorption tank 5 at t2 with a certain delay of the falling time. By the discharge of the stored water, the water level WL of the water absorption tank 5 is changed as shown in FIG.
Rise as shown. And at t3, the water level is WL1
, The operation of the drainage pump 4a is started, and t
When the water level reaches WL2 at 5:00, the operation of the drainage pump 4b is started. In the illustrated example, the arrival time of the inflow water due to rainfall is earlier than expected, and the head of the inflow water reaches the water absorption tank 5 at t4, whereby the water level rises greatly. At t6, the water level reaches WL3 and the drain pump 4c Is started. As a result, the operation of all the drainage pumps 4a to 4c is started and the water level of the water suction tank 5 is sufficiently high. , A half-close command), and the inflow of the water absorption tank 5 is reduced by that amount. Thereafter, at time t7 when the inflow amount due to the rain suddenly increases and the water level reaches a water level slightly lower than the upper limit water level HWL, a fully closed command is issued to the valve 14 from the advance standby operation control device, and the discharge of the advance standby operation water is performed. Stopped. As a result, the amount of water flowing into the water absorption tank 5 temporarily decreases, but the water level in the water absorption tank reaches HWL due to the difference in balance between the increase in the amount of water flowing in due to rainfall and the amount of water discharged by the pump. At this time, the inflow water level of the reservoir 10 becomes the inflow water level WL4
Therefore, the inflow water corresponding to the hatched portion in FIG. 3B flows into the reservoir 10, and the reservoir 10 functions as a surge absorber. Thereby, flood damage caused by exceeding the upper limit water level HWL can be prevented. When the water level in the water absorption tank 5 gradually decreases after the peak of the inflow water, the drain pumps 4a to 4c are sequentially stopped in response to the decrease.

In the example shown in FIG. 3, the case where the inflow water reaches the water absorption tank 5 before the start of all the drain pumps is shown. FIG. 4 shows a time chart in this case.

In the above description, the valve of the discharge channel 13 is closed in two stages. However, the present invention is not limited to this. The valve may be gradually closed in accordance with a rise in the water level of the water absorption tank 5. Also,
The timing of the fully closing may be a little higher than the starting water level (WL3) of the last drain pump.

When the water level at the location of the reservoir 10 does not exceed WL4 due to a small amount of rainfall, when the water level in the water absorption tank 5 exceeds the peak, the number of operating drain pumps is reduced or all pumps are stopped. Then, the water level is raised to WL4 or higher, thereby filling the reservoir 10 and then restarting the drainage pump to complete the predetermined drainage. In addition, as an alternative, when the return path 15 is provided, the valve 16 of the return path 15 is opened, and the water stored in the reservoir 10 can be supplied by this line.

On the other hand, when the maintenance / management operation is performed, the discharge valve 7 is closed, the valves 14 and 16 are opened, and the drain pump 4 is operated. Thereby, the discharge water of the drainage pump 4 is circulated, so that the pump can be operated at full load. In addition,
When using the well-known light load maintenance / management operation method,
When the amount of water in the water absorption tank 5 is insufficient, the valve 14 is opened to supply water. In this case, the reflux path 15 need not be provided.

[0031]

As described above, according to the present invention,
The following effects are obtained. First, according to the reservoir of the drainage system of the present invention, when the water level of the drainage system reaches a certain level or more, water flows into the reservoir and is stored. This stored water flows down to the water absorption tank by opening the valve of the discharge channel, so that it can be used as pre-standby operation and maintenance / management operation water.
Therefore, if the storage capacity of the reservoir is set sufficiently, it is possible to allow the required water to flow down to the water absorption tank for a sufficient time, and the start timing of the preliminary standby operation can be determined with a margin, and the arrival of the inflow water can be determined. Timing prediction errors can be tolerated within a certain range. It is easy to store the water again in the discharged reservoir by raising the water level of the drainage system above the inflow water level of the reservoir at an appropriate time during rainfall. In addition, even for drainage pumps to which no water supply bearings are applied,
Advance waiting operation becomes possible.

On the other hand, according to the one provided with the return passage for returning the discharge of the drain pump to the reservoir, the drainage from the maintenance / management operation can be circulated and used between the reservoir and the reservoir. Maintenance / management operation with full load becomes possible. In addition, the water for the next preparatory standby operation or the maintenance / management operation can be sufficiently retained as stored water.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a conceptual configuration of a drainage system according to one embodiment of the present invention.

FIG. 2 is a diagram showing a modification of the reservoir of the embodiment in FIG. 1;

FIG. 3 is a time chart of a preliminary standby operation performed based on prediction of an inflow amount after rainfall starts, for explaining the operation of the embodiment in FIG. 1;

FIG. 4 is a timing chart showing a modification of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inflow main pipeline 2 Vertical shaft 3 Small river 4 Drain pump 5 Water absorption tank 6 Discharge pipe 10 Reservoir 11 Vertical shaft 12 Communication part 13 Discharge channel 14 Valve 15 Return channel 16 Valve 17 Weir 18 Opening 19 Horizontal communication channel

Claims (14)

(57) [Claims] In a reservoir of a drainage system provided in communication with an inflow main conduit for guiding rainwater or the like to a suction tank of a drainage pump, a water level flowing into the reservoir at a communication portion between the inflow main conduit and the reservoir. Providing inflow regulation means to regulate,
An inflow water level set by the inflow regulating means is set to be equal to or lower than an upper limit water level of the water absorption tank, and a discharge flow path for causing the water stored in the reservoir to flow down to the water absorption tank through the inflow main pipe or directly is provided. A reservoir for a drainage system characterized by having a valve installed in the drainage system. 2. The inflow restriction according to claim 1, wherein the reservoir is communicated with the inflow main conduit via a communication shaft, and the communication shaft is provided at a position higher than a bottom surface of a side portion of the reservoir. A reservoir for a drainage system, characterized in that the means is formed. 3. The inflow restricting means according to claim 1, wherein the inflow restricting means is a weir provided in the inflow main conduit, and the reservoir is an inflow main conduit upstream of the weir and higher than an upper end of the weir. A reservoir for a drainage system, wherein the reservoir is connected to the inflow main conduit by a communication passage connected to a position. 4. The reservoir according to claim 3, wherein an opening is formed in a lower part of a weir provided in the main inflow pipe. 5. The reservoir of a drainage system according to claim 1, wherein a storage capacity of the reservoir is set to at least a water amount required for a preliminary standby operation of the drainage pump. 6. A waterway disposed on or near the ground surface,
An inflow main pipe into which rainwater or the like collected by the water channel flows, a reservoir provided in communication with the inflow main pipe, a water absorption tank provided at a downstream end of the inflow main pipe, and In a drainage system including a drainage pump that drains inflowing water into a discharge-destination river or the like, an inflow regulating unit that regulates a water level flowing into the reservoir at a communication portion between the inflow main pipeline and the reservoir. The inflow water level set by the inflow regulating means is set to be equal to or lower than the upper limit water level of the water absorption tank, and a discharge channel is provided for allowing the water stored in the reservoir to flow down to the water absorption tank via the inflow main pipeline or directly. A drainage system characterized by providing a valve in the discharge channel. 7. The drainage system according to claim 6, wherein a return line is provided by connecting a discharge pipe line of the drain pump to the reservoir, and a valve is provided in the return line. 8. A water reservoir provided in communication with an inflow main conduit for guiding rainwater or the like to a water suction tank of a drain pump, and a communicating portion between the inflow main conduit and the reservoir regulates a water level flowing into the reservoir. An inflow regulating means for setting the inflow water level by the inflow regulating means to be equal to or lower than an upper limit water level of the water absorption tank, and discharging the water stored in the reservoir through the inflow main pipe or directly to the water absorption tank. In the method of operating a drainage system provided with a passage, and provided with a valve in the discharge channel, the valve of the discharge channel is opened before the inflow water reaches the water absorption tank according to the prediction of inflow of the inflow water into the water absorption tank, A method for operating a drainage system, wherein a preliminary standby operation of the drainage pump is started. 9. The operating method of the drainage system according to claim 8, wherein the valve of the open discharge channel is closed when a water level of the water absorption tank reaches an upper limit water level. 10. The operating method of a drainage system according to claim 8, wherein the valve of the open discharge channel is gradually closed in accordance with a rise in the water level of the water suction tank. 11. The drainage system operating method according to claim 7, wherein a plurality of the drainage pumps are provided, and the plurality of the drainage pumps sequentially start a preliminary standby operation according to a water level of the water suction tank and open the drainage pumps. The method of operating a drainage system, wherein the valve of the discharge channel is half-closed in accordance with the start of operation of the last drainage pump, and fully closed when the water level of the water absorption tank reaches the upper limit water level. 12. A water reservoir provided in communication with an inflow main conduit for guiding rainwater or the like to a water suction tank of a drain pump, and a communicating portion between the inflow main conduit and the reservoir regulates a water level flowing into the reservoir. An inflow regulating means for setting the inflow water level by the inflow regulating means to be equal to or lower than an upper limit water level of the water absorption tank, and discharging the water stored in the reservoir through the inflow main pipe or directly to the water absorption tank. In the method of operating a drainage system comprising providing a passage and a valve in the discharge passage, the valve of the discharge passage is opened and closed to allow the amount of water required for the maintenance and management operation of the drainage pump to flow down to the water absorption tank. And performing a maintenance / management operation of the drainage pump. 13. A water reservoir provided in communication with an inflow main conduit for guiding rainwater or the like to a water absorption tank of a drain pump, wherein a water level flowing into the reservoir is regulated at a communication portion between the inflow main conduit and the reservoir. An inflow regulating means for setting the inflow water level by the inflow regulating means to be equal to or lower than an upper limit water level of the water absorption tank, and discharging the water stored in the reservoir through the inflow main pipe or directly to the water absorption tank. A method for operating a drainage system comprising: providing a return path, providing a valve in the discharge path, communicating a discharge pipe of the drain pump with the reservoir, and providing a return path, and providing a valve in the return path. A method for operating a drainage system, comprising: opening a valve in a road to perform maintenance / management operation of the drainage pump. 14. The method according to claim 13, wherein a valve of the discharge channel is opened during the maintenance / management operation.