JP6613693B2 - Intake pit - Google Patents

Description

  The present invention relates to a water intake pit.

  For example, in a facility that uses a large amount of water as a water supply to a steam turbine or a cooling water for each device, such as a thermal power plant, water is introduced from the ocean or a river through a water intake facility. In particular, when seawater is introduced from the open sea, it is necessary to attenuate waves generated in the open sea at the intake of the pump in order to reduce the influence on the pump and the like. As an example of such a technique, a water intake tank including a dive weir described in Patent Document 1 below is known.

  A water intake tank described in Patent Document 1 is connected to a water conduit, and is provided at a suction water tank partitioned into a plurality of flow paths, a pump provided in each flow path, and an upstream end of the flow path. And a diving weir.

Japanese Utility Model Publication No. 6-87425

By the way, in the water intake tank described in the said patent document 1, the attenuation effect of a wave is so large that the resistance to the flow by a dive weir is large, and the water level of a suction water tank falls. That is, the water level difference between the suction tank and the open sea increases. When the water level of the suction tank becomes low, there is a problem that the running cost of the equipment increases because it is necessary to increase the pump head.
On the other hand, when the resistance to the flow by the diving weir is small, the difference in water level between the suction tank and the open sea is small, but there is a possibility that the attenuation effect on the waves cannot be obtained sufficiently.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a water intake pit that can be operated at a low cost while ensuring a sufficient wave attenuation effect.

A water intake pit according to one aspect of the present invention partitions an external water intake area and a water storage area, has a through-hole that communicates the external water intake area and the water storage area, and has an upper end that is the maximum of the external water intake area. A weir set higher than the water level, a pump for sucking up water in the water storage area, and a throttle part capable of adjusting an opening ratio of the through hole , wherein the throttle part has an opening ratio larger than 0%. The aperture ratio can be adjusted between a certain minimum aperture ratio and a maximum aperture ratio at which the aperture ratio is 100% .

According to this configuration, the resistance coefficient to water passing through the through hole can be changed by adjusting the aperture ratio of the throttle portion. Thereby, even if a high wave is generated in the external intake area, the wave can be sufficiently attenuated by changing the aperture ratio, and an appropriate water level in the reservoir area can be secured.
Furthermore, according to this configuration, since the through hole is not completely blocked by the throttle portion, the flow rate of water from the external intake area to the reservoir area can be maintained at a certain value or more. Thereby, since the pump can continue to suck up a certain amount of water, the possibility of occurrence of cavitation (empty drawing) or the like can be reduced.

  The water intake pit according to an aspect of the present invention may include a control unit that controls the pump so that the pump sucks up the water at a constant flow rate.

  According to this configuration, since the flow rate of water from the pump can be made constant, water can be stably supplied to external equipment.

  In the water intake pit according to an aspect of the present invention, the throttle portion may be a gate that can advance and retreat in a direction in which the submerged weir extends and that has a small opening extending in the same direction as the through hole. .

  According to this configuration, the aperture ratio of the through hole can be adjusted by moving the gate back and forth. In addition, since the small opening is formed in the gate, the opening ratio of the through hole can be maintained larger than 0% even when the gate is completely lowered. Thereby, the flow volume of the water which goes to a water storage area from an external intake area can be maintained to a value more than fixed.

  In the water intake pit according to one aspect of the present invention, the throttle portion may be a plurality of flaps that are rotatable around a rotation axis that extends in a direction intersecting a direction in which the through hole extends.

  According to this configuration, the aperture ratio of the through hole can be adjusted more precisely by the rotation of the flap. Furthermore, since the energy required for the rotation of the individual flaps can be kept small, the flaps can be quickly rotated in an emergency. Thereby, it can respond immediately to the change of the wave height and water level in an external intake area.

  In the water intake pit according to one aspect of the present invention, the throttle portion may be a plurality of butterfly valves that are rotatable around a rotation axis that extends in a direction intersecting a direction in which the through hole extends.

According to this configuration, the aperture ratio of the through hole can be precisely adjusted by the butterfly valve. Furthermore, since the energy required for the rotation of the individual butterfly valves can be further reduced, the butterfly valves can be rotated more rapidly in case of emergency.
Furthermore, the intake pit according to one aspect of the present invention partitions the external intake area and the water storage area, has a through hole that communicates the external intake area and the water storage area, and has an upper end at the external intake area. A weir set higher than the maximum water level, a pump for sucking up water in the water storage area, and a throttle part capable of adjusting an opening ratio of the through hole, and the throttle part extends in a direction in which the weir extends. The gate is formed with a small opening that can be advanced and retracted and extends in the same direction as the through hole.
In addition, the intake pit according to one aspect of the present invention partitions the external intake area and the reservoir area, has a through-hole that communicates the external intake area and the reservoir area, and has an upper end at the external intake area. A weir set higher than the maximum water level of the water area, a pump for sucking up water in the water storage area, and a throttle part capable of adjusting an opening ratio of the through hole, the throttle part extending the through hole These are a plurality of flaps that can rotate around a rotation axis that extends in a direction intersecting the direction.
The intake pit according to one aspect of the present invention has an external intake area and a water storage area, has a through-hole that connects the external intake area and the water storage area, and has an upper end at the external intake area. A weir set higher than the maximum water level, a pump for sucking up water in the water storage area, and a throttle part capable of adjusting an opening ratio of the through hole, wherein the throttle part extends in the direction in which the through hole extends. These are a plurality of butterfly valves that can be rotated around a rotation axis that extends in a direction intersecting with.

  According to the present invention, it is possible to provide a water intake pit that can be operated at a low cost while ensuring a sufficient wave attenuation effect.

It is a general view of the water intake pit which concerns on 1st embodiment of this invention, Comprising: It is a figure which shows the case where a gate is in an open state. It is a whole view of the intake pit which concerns on 1st embodiment of this invention, Comprising: It is a figure which shows the case where a gate is in a closed state. It is a figure which shows the aperture | diaphragm | squeeze part (flap) which concerns on 2nd embodiment of this invention. It is a figure which shows the aperture | diaphragm | squeeze part (flap) which concerns on 2nd embodiment of this invention. It is a figure which shows the modification of the aperture | diaphragm | squeeze part which concerns on 2nd embodiment of this invention. It is sectional drawing in the direction orthogonal to the upstream / downstream direction of FIG. It is a graph which shows the relationship between the loss coefficient in a through-hole, and the height of a wave.

[First embodiment]
A first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a water intake pit 100 according to the present embodiment partitions an external water intake area A and a water storage area B, a submerged weir (weir) 10 in which a through hole 11 is formed, and a water storage area B The pump 20 that sucks up the water and the control unit 90 that controls the rotational speed of the pump 20 are provided.

  The intake pit 100 is a facility for guiding water used as cooling water from an external facility (not shown) such as a power plant from a water source. The water source is appropriately selected according to the environment where the external facilities are located, such as the ocean, rivers, lakes and marshes.

  The submerged weir 10 includes a base portion 12 installed on the bottom of the water source, a weir body 13 extending upward from the base portion 12 (that is, a direction from the bottom to the water surface), and a penetration formed in the weir body 13. A tunnel portion 14 communicating with the hole 11 and a gate 17 as a throttle portion 16 capable of adjusting the aperture ratio of the through hole 11 are provided.

  The dam body 13 is formed in a plate shape by, for example, concrete and divides the water source into two sections. On the basis of this weir body 13, the water area on the land side is the water storage area B, and the water area on the water source side (the offshore side in the ocean) is the external intake area A. In the external intake area A, it is assumed that a change in the water level due to waves and tidal conditions occurs normally. The upper end of the weir body 13 is set to be at a position higher than the maximum water level of the external intake area A. In other words, the upper end of the weir body 13 is exposed on the water surface even when the external intake area A reaches the maximum water level.

Further, the weir body 13 is formed with a through hole 11 that allows the external water intake area A and the water storage area B to communicate with each other. The tunnel part 14 is provided in the edge part located in the external water intake area A side among the both ends of the through-hole 11. FIG. The tunnel part 14 is a cylindrical member formed of the same material as the dam body 13. That is, the tunnel part 14 forms the flow path (intake flow path 15) which connects the external intake area A and the water storage area B. Through such a water intake channel 15, the water on the external intake area A side is guided to the water storage area B side and stored in the water storage area B.
In the following description, the side where the external water intake area A is located on the basis of the dam body 13 is called the upstream side, and the side where the water storage area B is located is called the downstream side. Further, a direction from the upstream side to the downstream side is referred to as an upstream / downstream direction.

  Note that the opening size of the through hole 11 is appropriately set according to the environment in which the intake pit 100 is installed, the request for external equipment using the intake water, the specification, or the request for the aperture ratio described later. Good.

  On the intake area side, a pump 20 is provided for sucking up water in the intake area. The rotation speed of the pump 20 is controlled by a control unit 90 described later. More specifically, the control unit 90 controls the rotation speed of the pump so that the discharge amount (flow rate) of water from the pump becomes a constant value. The water sucked up by the pump 20 is used in external equipment such as the above-described power plant.

  The gate 17 opens and closes the through-hole 11 of the weir body 13 and can be advanced and retracted in the extending direction of the submerged weir 10 by a driving unit (not shown). As shown in FIGS. 1 and 2, when the gate 17 is displaced to the upper end side of the dam body 13 (open state), the through-hole 11 is entirely opened in the upstream and downstream directions. On the other hand, when the gate 17 is displaced to the bottom of the water (closed state), the through-hole 11 is almost closed in the upstream and downstream directions.

  Although not shown in detail, a specific mode of such a gate 17 can be appropriately selected from a roller gate method, a through gate method, a miter gate method, and the like.

  Furthermore, a plurality of small apertures 18 extending in the same direction (that is, the upstream / downstream direction) in which the through hole 11 extends is formed in a part of the gate 17 in the present embodiment. By forming these small openings 18, even if the gate 17 is displaced toward the bottom of the water, the opening ratio of the through hole 11 becomes a value larger than 0%. The aperture ratio represents the ratio of the area occupied by the portion covered by the gate 17 to the opening area of the through hole 11.

With respect to the intake pit 100 configured as described above, an operation during normal operation in which the gate 17 is opened and an operation during emergency operation in which the gate 17 is closed will be described.
As shown in FIG. 1, when the wave height and water level of the external intake area A are both normal in the water area, the gate 17 is opened in the intake pit 100. That is, the aperture ratio of the through hole 11 formed in the dam body 13 is 100% (maximum aperture ratio).

  In the above state, by continuing to drive the pump 20, the water in the reservoir B is continuously sucked up by the pump 20. Thereby, the water level of the water storage area B becomes lower than the water level of the external intake area A.

  Further, the water in the water storage area B is sucked up by the pump 20, so that the upstream side (external water intake area A side) to the downstream side (water storage area B side) in the tunnel portion 14 (water intake flow path 15) in the weir body 13. Flow of water occurs toward At this time, the amount of water discharged by the pump 20 is set to a constant value larger than the flow rate in the water intake passage 15 described above. Therefore, as shown in FIG. 1, the water level in the reservoir B is balanced in a state lower than the water level in the external intake area A. (The water level difference between the external water intake area A and the water storage area B in this state is d1.)

  Furthermore, since the water storage area B is separated from the external intake area A (outer sea) by the diving weir 10, the wave generated in the outer sea slightly propagates in the water storage area B, but is generally attenuated. Thereby, in the water storage area B, it becomes possible to reduce the influence on the pump 20 by a wave.

  On the other hand, as shown in FIG. 2, when the wave height and water level in the external intake area A change greatly compared to those during normal operation, the gate 17 is closed. 2 shows a state where the gate 17 is completely lowered (a state where the lower end of the gate 17 is in contact with the lower end of the dam body 13).

  Thus, when the gate 17 is in the closed state, resistance is generated by the gate 17 against the flow of water from the external water intake area A toward the water storage area B. In addition, since the plurality of small holes 18 are formed in the gate 17, a certain amount of water flows in the upstream and downstream directions. More precisely, the resistance coefficient to the water flow changes. In other words, even when the gate 17 is completely closed, the aperture ratio (minimum aperture ratio) of the through hole 11 is a value larger than 0%. The gate 17 as the narrowed portion 16 can adjust the aperture ratio of the through hole 11 between the maximum aperture ratio and the minimum aperture ratio. Specifically, the opening ratio of the through hole 11 is desirably 5 to 15%, more desirably 8 to 12%, and most desirably 10%.

  As a result, even if the wave height and water level in the external intake area A become high, including when a tsunami or storm surge occurs, the wave to the water storage area B can be obtained by closing the gate 17 of the diving weir 10. Can be suppressed. In addition, the flow of water from the external water intake area A toward the water storage area B can be secured by the plurality of small holes 18. Therefore, since it is possible to suppress a rapid drop in the water level in the reservoir B due to the lowering of the gate 17, it is possible to suppress malfunction such as cavitation in the pump 20 and increase in load applied to the pump 20, and Water can be stably supplied to external equipment that uses water.

  Specifically, when the opening ratio of the through hole 11 becomes small, the loss factor for the flow in the intake water flow path 15 increases. Here, as shown in FIG. 7, the loss coefficient is generally inversely proportional to the wave height (wave height). Therefore, when the aperture ratio of the through hole 11 is reduced, the wave height in the water storage area B changes small as the loss factor increases.

  Here, when the gate 17 is in the closed state as described above, the opening rate of the through-hole 11 is reduced, so that the flow rate of water from the external intake area A to the reservoir area B decreases. As the flow rate decreases, the water level difference between the external water intake area A and the water storage area B becomes larger than the water level difference d1 described above. More specifically, the water level on the reservoir B side is lower than when the gate 17 is in the open state. The water level difference between the external autumn water area A and the water storage area B is d2.

  When the water level difference between the external intake area A and the water storage area B is d2, the water discharge amount (flow rate) by the pump 20 under the same rotational speed is smaller than when the water level difference is d1. . When the discharge amount by the pump 20 becomes small, there is a possibility that stable water cannot be supplied to external equipment such as a power plant. Therefore, in the intake pit 100 according to the present embodiment, the rotational speed of the pump 20 is controlled by the control unit 90 described above. More specifically, the control unit 90 controls the rotation speed of the pump 20 based on a change in the discharge amount of water from the pump 20. When the discharge amount of the pump 20 becomes smaller than a predetermined target range, the control unit 90 increases the rotational speed of the pump 20. On the other hand, when the discharge amount of the pump 20 becomes larger than the target range, the control unit 90 decreases the rotational speed of the pump 20. Thereby, the discharge amount of the pump 20 is maintained within the above target range. That is, the pump 20 can suck up water at a constant flow rate.

More simply, by increasing the resistance to the water flow in the through-hole 11 as described above, the influence of waves propagating from the external intake area A to the water storage area B can be reduced. On the other hand, when the resistance in the through hole 11 is too large, the rotational speed (load) of the pump 20 required to suck up a constant flow rate is increased. As a result, the running cost may increase.
Therefore, in the above embodiment, the opening ratio is reduced by opening the gate 17 during normal operation and closing the gate 17 only when the wave height in the external intake area A is outstanding. As a result, the running cost during normal operation can be reduced.

  The first embodiment of the present invention has been described above with reference to the drawings. However, the above embodiment is merely an example, and various changes and modifications can be made without departing from the gist of the present invention.

  For example, in the above embodiment, an example in which the tunnel portion 14 is provided on the upstream side (external water intake area A side) of the through hole 11 has been described. However, it is possible to adopt a configuration in which the tunnel portion 14 is not provided.

  Moreover, in the said embodiment, the example which applied the intake pit 100 to external facilities, such as a power plant adjacent to the ocean, was demonstrated. However, the application facility of the intake pit 100 is not limited to this, and can be applied to various facilities using water, and is not limited to the ocean, but may be an environment having a water supply source such as a river, a lake, a canal, and the like. Any of them can be applied.

  Furthermore, in the above-described embodiment, an example in which the through hole 11 has the same inner diameter in the upstream and downstream directions has been described. However, the shape of the through hole 11 is not limited to this, and the through hole 11 may be configured to reduce or increase in diameter from the upstream side toward the downstream side. Moreover, it is also possible to make the downstream end part of the through-hole 11 into a diffuser shape. According to these structures, the vibration propagation of the wave into the water storage area B can be further suppressed.

  Further, in addition to the diving weir 10 in the above embodiment, a plate-like bank may be provided in the water area facing the through hole 11 on the external water intake area A side. According to such a structure, the influence of the wave with respect to the water in the water storage area B can be further reduced.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. As shown in the figure, in the intake pit 100 according to the present embodiment, the configuration of the throttle portion 16 is different from that of the first embodiment. More specifically, in the present embodiment, a plurality of flaps 30 are employed as the throttle unit 16. As shown in FIG. 4, the flap 30 includes a rotation shaft 31 extending along an axis O <b> 1 in a substantially vertical direction, and a plate-shaped flap body 32 provided integrally with the rotation shaft 31. . The flap body 32 has a pair of plates extending in a direction away from the outer periphery of the rotating shaft 31 toward the radially outer side.

  A plurality of the flaps 30 configured as described above are arranged in a direction (horizontal direction) orthogonal to the opening direction of the through hole 11. Each flap 30 is rotated around the rotation shaft 31 by a drive source (not shown). Further, the flap 30 includes a rotation restricting portion 33 that restricts the amount of rotation of the flap 30 around the rotation shaft 31. This rotation restricting portion 33 is, for example, a stopper provided integrally with the rotating shaft 31 and restricts the rotation of the flap 30 so that the opening rate of the through hole 11 is a value larger than 0%. maintain. More specifically, the rotation restricting portion 33 includes a projecting piece 33A provided on the rotating shaft 31, and an engaging portion 33B that engages with the projecting piece 33A. When the projecting piece 33A is engaged with the engaging portion 33B, the rotation amount of the rotating shaft 31 (the flap 30) is regulated.

  With the above configuration, the aperture ratio of the through hole 11 can be adjusted. In particular, by adjusting the rotation amount (opening degree) of the flap 30 for each flap 30, the aperture ratio can be adjusted more precisely than the gate 17 in the first embodiment.

  In addition, the energy required for the rotation of the individual flaps 30 can be kept small, and the flaps 30 can be quickly rotated in an emergency. Thereby, it can respond immediately to the change of the wave height and the water level in the external intake area A.

  In adjusting the opening degree (rotation amount) of the flap 30, each flap 30 may be adjusted by the same amount, or a different opening degree may be set for each flap 30. When a different opening degree is set for each flap 30, the aperture ratio of the through hole 11 can be adjusted more precisely.

Furthermore, the aspect of the rotation restricting portion 33 that restricts the opening degree of the flap 30 is not limited to the stopper described above. For example, a drive source that rotates the flap 30 and a control device that controls the drive source are provided. You may adjust so that the rotation amount of the flap 30 may become more than a fixed value with an apparatus.
Furthermore, although the said embodiment demonstrated the aspect which provided the flap 30 over the whole opening area of the through-hole 11, it is good also as a structure by which the flap 30 is not provided in the one part area | region of the through-hole 11. FIG. Even with such a configuration, the opening ratio of the through holes 11 can be set to a value larger than 0%.

  Further, instead of the flap 30, it is possible to adopt the configuration (butterfly valve 40) shown in FIG. 5 and FIG. As shown in the drawing, the narrowed portion 16 is provided at a tubular portion P, which is a plurality of tubular bodies arranged in the horizontal direction and the vertical direction of the through-hole 11, and an upstream end portion of these tubular portions P, respectively. A plurality of butterfly valves 40 provided.

  Each butterfly valve 40 includes a rotating shaft 41 extending in the direction of the substantially vertical axis O2 and a pair of semicircular valve bodies 42 extending radially outward from the outer periphery of the rotating shaft 41. The rotating shaft 41 extends in a direction crossing the direction in which the through hole extends. The valve body 42 is rotated around the axis O2 integrally with the rotary shaft 41 by a drive source (not shown). Although not shown in detail, the butterfly valve 40 also includes a device similar to the rotation restricting portion 33 (stopper) in the flap 30 described above.

  Furthermore, as shown in FIG. 6 (A), when the throttle portion 16 including the butterfly valve is viewed from the direction orthogonal to the upstream / downstream direction, each tubular portion P becomes more upstream in the upstream / downstream direction as it becomes the upper tubular portion P. The longer the dimension, the smaller the dimension in the upstream / downstream direction, the lower the tubular portion P. As a result, the plurality of rotating shafts 41 can be independently rotated.

  As shown in FIG. 6B, a pair of the tubular portion P and the butterfly valve 40 may be provided in the vertical direction. In this case, the upstream and downstream dimensions of the tubular portion P are the same.

  Further, in the example of FIGS. 6A and 6B, a circular valve body 42 is employed as the butterfly valve 40. However, the aspect of the butterfly valve is not limited to this, and may be a polygon.

  In addition, the mode of the rotation restricting portion 33 is not limited to the stopper described above. For example, a drive source that rotates the butterfly valve 40 and a control device that controls the drive source are provided, and the control device controls the butterfly valve 40. You may adjust so that rotation amount may become more than a fixed value.

DESCRIPTION OF SYMBOLS 10 ... Submersible weir 11 ... Through-hole 12 ... Base part 13 ... Weir body 14 ... Tunnel part 15 ... Intake flow path 16 ... Throttle part 17 ... Gate 18 ... Small hole 20 ... Pump 30 ... Flap 31 ... Rotating shaft 32 ... Flap Main body 33 ... Rotation restricting section 40 ... Butterfly valve 41 ... Rotating shaft 42 ... Valve body 90 ... Control section 100 ... Intake pit A ... External intake area B ... Reservoir area O1 ... Axis line O2 ... Axis line

Claims (8)

A weir that partitions the external water intake area and the water storage area, has a through-hole that connects the external water intake area and the water storage area, and has an upper end set higher than the maximum water level of the external water intake area,
A pump for sucking up water in the reservoir;
A throttle part capable of adjusting an aperture ratio of the through hole;
Equipped with a,
The throttle part is a water intake pit capable of adjusting the aperture ratio between a minimum aperture ratio which is an aperture ratio larger than 0% and a maximum aperture ratio at which the aperture ratio is 100% . The water intake pit according to claim 1 , further comprising a control unit that controls the pump so that the pump sucks up the water at a constant flow rate. 3. The water intake pit according to claim 1, wherein the throttle portion is a gate that is capable of moving forward and backward in a direction in which the weir extends and in which a small opening extending in the same direction as the through hole is formed. The intake pit according to claim 1 or 2 , wherein the throttle portion is a plurality of flaps that are rotatable around a rotation axis that extends in a direction intersecting a direction in which the through hole extends. 3. The water intake pit according to claim 1, wherein the throttle portion is a plurality of butterfly valves that are rotatable around a rotation axis that extends in a direction intersecting a direction in which the through hole extends.   A weir that partitions the external water intake area and the water storage area, has a through-hole that connects the external water intake area and the water storage area, and has an upper end set higher than the maximum water level of the external water intake area,
A pump for sucking up water in the reservoir;
A throttle part capable of adjusting an aperture ratio of the through hole;
With
The throttle portion is a water intake pit that is a gate that is movable in the extending direction of the weir and has a small opening extending in the same direction as the through hole. A weir that partitions the external water intake area and the water storage area, has a through-hole that connects the external water intake area and the water storage area, and has an upper end set higher than the maximum water level of the external water intake area,
A pump for sucking up water in the reservoir;
A throttle part capable of adjusting an aperture ratio of the through hole;
With
The throttle part is a water intake pit that is a plurality of flaps that are rotatable around a rotation axis that extends in a direction intersecting a direction in which the through hole extends.   A weir that partitions the external water intake area and the water storage area, has a through-hole that connects the external water intake area and the water storage area, and has an upper end set higher than the maximum water level of the external water intake area,
A pump for sucking up water in the reservoir;
A throttle part capable of adjusting an aperture ratio of the through hole;
With
The throttle part is a water intake pit that is a plurality of butterfly valves that are rotatable around a rotation axis that extends in a direction intersecting a direction in which the through hole extends.

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