How to operate a pump gate submersible pump

Abstract

To be able to reduce air-water mixed drainage operation time at a pump gate of which multiple pumps are mounted on one gate.SOLUTION: In step S107, when the suction side water level is equal to or lower than the second operating water level H2 (see FIG. 3), the first submersible pump 12 continues the full discharge operation mode M1 (see FIG. 4(a)). Next, in step S108, when the water level on the suction side is lower than the third operating water level H3 (see FIG. 3), in step S109, the first submersible pump 12 continues to operate in the air-water mixed drainage operation mode M2 (see FIG. 4(b)). At the same time, in order to start the second submersible pump 13 in step S117, when the suction side water level drops, by simultaneously operating two submersible pumps 12, 13, the air-water mixed drainage operation mode M2 shifts to the standby operation mode M3 (see Fig. 4(c)) at once, the operation time of the air-water mixed drainage operation mode M2 can be greatly reduced.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for operating a submersible pump of a pump gate, and more particularly to a method for operating a submersible pump of a pump gate that can shorten the air-water mixed drainage operation time in a pump gate equipped with a plurality of submersible pumps at the gate of a water gate. [Background technology]

[0002] The Gate Pump (registered trademark) developed and proposed by the present applicant is generally called a pump gate, and is a submersible pump mounted on the gate of a water gate. When the water level on the suction side of the submersible pump drops and the water depth at the suction port of the submersible pump is insufficient, the submersible pump sucks in air, and the pump operates in an air-water mixed drainage mode, which is different from the normal stable drainage operation state, and becomes unstable with vibration and noise. This air-water mixed drainage operation may cause significant vibration and noise in the submersible pump, and must be avoided as much as possible from the viewpoint of adverse effects on the submersible pump and consideration of the local environment. On the other hand, the pump gate of Patent Document 1 is a horizontal shaft submersible pump that gradually lets air in through the opening of the suction cover to alleviate the unstable state with vibration and noise. In addition, even in the operation mode below the water level in the full discharge operation mode, the pump maintains operation at the rated speed without using an inverter, suppressing repeated stopping and starting of the submersible pump. In addition, the pump gate of Patent Document 2 is equipped with multiple standby operation type submersible pumps at different height positions or at the same height position of the gate, and the output of the standby operation type submersible pumps is changed at different times in order to shorten the air-water mixing drainage operation time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO2016-178387 [Patent Document 2] JP 2018-59277 A Summary of the Invention [Problem to be solved by the invention]

[0004] The horizontal shaft submersible pump described in Patent Document 1 has an opening in the suction cover for actively sucking in air in order to alleviate unstable conditions accompanied by vibration, noise, etc., and to smooth the transition to each operation mode. However, the suction cover of this structure continues the air-water mixed drainage operation mode for a long time when the inflow and discharge volume are balanced and the inflow volume gradually decreases during operation in the air-water mixed drainage operation mode. For this reason, this horizontal shaft submersible pump cannot avoid adverse effects on the pump gate due to vibration caused by air bubbles and adverse effects on the local environment due to noise. In addition, when the discharge volume becomes zero and the operation mode transitions from the air-water mixed drainage operation mode to the standby operation mode, the inflow of water to the suction side continues, so the suction side water level rises and the operation mode immediately returns to the air-water mixed drainage operation mode. In other words, the air-water mixed drainage operation mode and the standby operation mode are alternately repeated until the inflow volume of water to the suction side increases significantly and the suction side water level rises to the full discharge operation mode, and adverse effects on the pump gate and the local environment due to the above-mentioned vibration, noise, etc. cannot be avoided.

[0005] The pump gate and its operating method described in Patent Document 2 change the output of multiple pumps arranged at the gate at different times according to the change in the water level of the waterway. This reduces the drop in the water level of the waterway during drainage and reduces the air-water mixed drainage operation time. This operating method can only reduce the air-water mixed drainage operation time when pumps are arranged above and below the gate. Also, as with the method described in Patent Document 1, the air-water mixed drainage operation mode and the standby operation mode are alternately repeated until the inflow rate increases significantly and the suction side water level rises to the full drainage operation mode, which inevitably causes adverse effects on the pump gate and the local environment due to vibrations, noise, etc.

[0006] [Objective of the Invention] In view of the above background, the present invention achieves the following objects. An object of the present invention is to provide a method for operating an underwater pump of a pump gate, which can shorten the air-water mixing drainage operation time in a pump gate equipped with multiple pumps on one gate. Another object of the present invention is to provide a method for operating a submersible pump of a pump gate, which can reduce the air-water mixing drainage operation time of each submersible pump in a pump gate equipped with multiple submersible pumps, regardless of the position of each submersible pump on the gate. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention takes the following measures. That is, the method of operating the submersible pump of the pump gate of the present invention 1 is as follows: A gate that can be opened and closed by moving up and down in a direction across the waterway; A plurality of submersible pumps mounted on the gate and disposed at the same height; A water level meter that detects the water level on the suction side of the submersible pump; an underwater pump control device that controls start and stop of the underwater pump based on the water level detection value of the water level meter; In a pump gate consisting of The submersible pump control device includes: A method for operating a submersible pump of a pump gate, comprising: controlling to start the second submersible pump when a first submersible pump in the submersible pump is in operation and a second submersible pump in the submersible pump is stopped, and when a water level detected by the water level meter falls within a set range for air-water mixed drainage operation, The water level detected by the water level meter that controls the start and stop of the underwater pump is In order from the top detected water level, A first operating water level (H1) at which the set water level is exceeded and the plurality of submersible pumps are operated during full drainage operation; A second operating water level (H2) below the first operating water level (H1), at which the first submersible pump is operated and the second submersible pump is stopped or operated; a first stop water level (L1) below the second operating water level (H2), at which the first submersible pump is operated and the second submersible pump is stopped; The water level is equal to or lower than the first stop water level (L1), During the air-water mixed drainage operation, a third operating water level (H3) at which the first submersible pump is operated and the second submersible pump is started; A second stop water level (L3) is set at which the first submersible pump is stopped and the second submersible pump is also stopped when the water level is equal to or lower than the third operating water level (H3); The first submersible pump and the second submersible pump stop when the water level is below the second stop water level (L3), and enter standby operation in the stopped state.

[0008] The method of operating an underwater pump of a pump gate of the present invention 2 is characterized in that, in the present invention 1, the underwater pump control device continues to stop the first underwater pump and the second underwater pump when the first underwater pump is stopped and the second underwater pump is also stopped below the second stop water level (L3), even after the water level detected by the water level gauge exceeds the second stop water level (L3) and the third operating water level (H3), and controls the operation of the first underwater pump after the water level detected by the water level gauge exceeds the second operating water level (H2).

[0009] The method of operating the submersible pump of the pump gate of the present invention 3 is 1 or 2, the number of the submersible pumps is two. Effect of the Invention

[0010] The method of operating a submersible pump with a pump gate of the present invention can shorten the air-water mixed drainage operation time, thereby making it possible to avoid the adverse effects of vibration on the pump gate and noise on the local environment. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 shows a pump gate according to an embodiment of the present invention, where FIG. 1(a) is a front vertical sectional view of the pump gate, and FIG. 1(b) is a sectional view taken along line AA of FIG. 1(a). [Diagram 2] FIG. 2 is a flowchart showing a method for operating a submersible pump of a pump gate according to an embodiment of the present invention. [Diagram 3] FIG. 3 is an explanatory diagram showing the suction side water level and operation mode of the pump gate of FIG. [Figure 4] FIG. 4 is an explanatory diagram showing the operating states of the submersible pump in the three operating modes M1, M2, and M3 of FIG. [Diagram 5] FIG. 5 is an explanatory diagram showing a change in water level at a pump gate according to an embodiment of the present invention. [Figure 6] FIG. 6 is a flow chart showing a method for operating a conventional pump gate submersible pump. [Figure 7] FIG. 7 is an explanatory diagram showing the suction side water level and operation mode of a conventional pump gate. [Figure 8] FIG. 8 is an explanatory diagram showing the operating states of the submersible pump in the three operating modes M1, M2, and M3 of FIG. [Figure 9] FIG. 9 is an explanatory diagram showing changes in water level at a conventional pump gate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] FIG. 1 shows a pump gate 1 according to an embodiment of the present invention, where FIG. 1(a) is a front longitudinal cross-sectional view of the pump gate, showing a cross-section cut perpendicular to the water flow direction, and FIG. 1(b) is a cross-sectional view taken along line AA of FIG. 1(a), showing a cross-section cut along the water flow direction. As shown in FIG. 1, the pump gate 1 according to the embodiment of the present invention includes a gate 11, a submersible pump 12 (first submersible pump), and a submersible pump 13 (second submersible pump). The gate 11 is installed so as to be able to move up and down the water passage 14 to open and close the water passage 14. That is, the water passage 14 is opened and closed by the gate 11 moving up and down. The water passage 14 is opened by moving the gate 11 up, and the water passage 14 is closed by moving the gate 11 down.

[0013] Submersible pumps 12 and 13 are provided so as to pass through the gate 11. The submersible pumps 12 and 13 each discharge water from one side of the gate 11 (the suction side on the left side in FIG. 1(b)) to the other side (the discharge side on the right side in FIG. 1(b)). In this example, the submersible pumps 12 and 13 are horizontal-axis submersible pumps capable of full-speed and full-level operation. The horizontal-axis submersible pumps 12 and 13 may be axial flow pumps, mixed flow pumps, spiral mixed flow pumps, etc. The two submersible pumps 12 and 13 are provided at the same height position on the gate 11. The height position refers to the height from the bottom surface 141 of the waterway 14 of the pump gate. A water level gauge 15 is provided in the waterway 14 to detect the water level on the suction side. A submersible pump control device 16 is connected to the water level gauge 15, and the start and stop of each of the submersible pumps 12 and 13 is controlled by the water level detection value of the water level gauge 15.

[0014] In order to facilitate understanding of the present invention, the case where the pump gate 1 in FIG. 1 is operated by a conventional operating method will be described first. FIG. 6 is a flowchart showing a conventional operating method of the submersible pump 12 (first submersible pump) and the submersible pump 13 (second submersible pump) of the pump gate 1. As shown in FIG. 6, at the start, the gate 11 is fully closed, and the first submersible pump 12 and the second submersible pump 13 are stopped. When the suction side water level exceeds the second operating water level H2 (see FIG. 7) in step S201, the first submersible pump 12 is operated in the full-discharge operating mode M1 (see FIG. 8(a)) in step S202. When the suction side water level exceeds the first operating water level H1 (see FIG. 7) in step S203, the second submersible pump 13 is operated in the full-discharge operating mode M1 (see FIG. 8(a)) in step S204. When the suction side water level becomes equal to or lower than the first stop water level L1 (see FIG. 7) in step S205, the second submersible pump 13 is stopped in step S206.

[0015] If the suction side water level is equal to or lower than the second operating water level H2 in step S207, the first submersible pump 12 continues to operate in the full-volume drainage operation mode M1. Next, if the suction side water level is equal to or lower than the third operating water level H3 (see FIG. 7) in step S208, the first submersible pump 12 operates in the air-water mixed drainage operation mode M2 ​​(see FIG. 8(b)) in step S209. If the suction side water level is equal to or lower than the second stop water level L3 (see FIG. 7) in step S210, the first submersible pump 12 operates in the standby operation mode M3 (see FIG. 8(c)) in step S211. In this state, when the downstream water level drops, the discharge pressure exceeds the shutoff pressure of the flap gate 17 and drainage is performed (see FIG. 7), the suction side water level starts to drop. When the suction side water level falls below the third stop water level L4 (see Figure 7) in step S212, the first submersible pump 12 is stopped in step S213, thereby preventing the first submersible pump 12 from being repeatedly stopped and started.

[0016] When the suction side water level does not become equal to or lower than the third stop water level L4 (see FIG. 7) in step S212 and exceeds the second stop water level L3 in step S214, the first submersible pump 12 continues to operate in the air-water mixed drainage operation mode M2 ​​in step S215. When the suction side water level exceeds the third operating water level H3 in step S216, the first submersible pump 12 operates in the full drainage operation mode M1 in step S217. Therefore, in the conventional operation method of the pump gate 1, when the suction side water level drops in steps S207 and S208 and the air-water mixed drainage operation mode M2 ​​is entered in step S209, the air-water mixed drainage operation mode M2 ​​continues for a long time if the inflow and drainage are in balance, the inflow gradually decreases, etc. Therefore, adverse effects on the pump gate due to vibrations caused by air bubbles and adverse effects on the local environment due to noise cannot be avoided.

[0017] Furthermore, in the conventional operation method of the pump gate 1, when the suction side water level drops in steps S207 and S208 to enter the air-water mixed drainage operation mode M2, as long as the suction side water level does not exceed the third operating water level H3 in step S216 when the suction side water level rises (i.e., until the amount of water inflow increases significantly and the suction side water level rises to the full drainage operation mode M1), the air-water mixed drainage operation mode M2 ​​and the standby operation mode M3 are alternately repeated (see FIG. 9). Therefore, adverse effects on the pump gate due to vibrations and adverse effects on the local environment due to noise are unavoidable.

[0018] FIG. 2 is a flowchart showing a method for operating the submersible pump 12 (first submersible pump) and the submersible pump 13 (second submersible pump) of the pump gate 1 according to an embodiment of the present invention. In the method for operating the submersible pump according to an embodiment of the present invention, the first submersible pump 12 and the second submersible pump 13 are each controlled by the submersible pump control device 16 of FIG. 1 based on the water level detection value of the water level gauge 15. As shown in FIG. 2, at the start, the gate 11 is fully closed and the first submersible pump 12 and the second submersible pump 13 are stopped. When the suction side water level exceeds the second operating water level H2 (see FIG. 3) in step S101, the first submersible pump 12 is operated in full discharge operation mode M1 (see FIG. 4(a)) in step S102 under the control of the submersible pump control device 16 of FIG. 1. When the suction side water level exceeds the first operating water level H1 (see FIG. 3) in step S103, the second submersible pump 13 is operated in the full-discharge operation mode M1 in step S104. When the suction side water level falls below the first stop water level L1 (see FIG. 3) in step S105, the second submersible pump 13 is stopped in step S106.

[0019] In step S107, when the suction side water level is equal to or lower than the second operating water level H2, the first submersible pump 12 continues to operate in the full-volume drainage operation mode M1. Next, in step S108, when the suction side water level is equal to or lower than the third operating water level H3 (see FIG. 3), the first submersible pump 12 continues to operate in step S109 and operates in the air-water mixed drainage operation mode M2 ​​(see FIG. 4(b)). At the same time, the second submersible pump 13 is started in step S117, so that when the suction side water level drops, the two submersible pumps 12 and 13 are operated simultaneously to immediately transition from the air-water mixed drainage operation mode M2 ​​to the standby operation mode M3 (see FIG. 4(c)), and the operation time of the air-water mixed drainage operation mode M2 ​​can be significantly shortened. This makes it possible to reduce the risk of failure of the submersible pump. If the suction water level is equal to or lower than the second stop water level L3 (see FIG. 3) in step S110, the first submersible pump 12 is stopped in step S111, and the standby operation mode M3 is entered in the stopped state. At the same time, the second submersible pump 13 is also stopped in step S118, and the standby operation mode M3 is entered in the stopped state.

[0020] Thereafter, in a phase where the suction side water level rises, even if the suction side water level exceeds the second stop water level L3 in step S112, the first submersible pump 12 continues to be stopped in step S113. Also, even if the suction side water level exceeds the third operating water level H3 in step S114, the first submersible pump 12 continues to be stopped in step S115. That is, in a phase where the suction side water level rises in the water level range of the air-water mixed drainage operation mode M2, the air-water mixed drainage operation mode M2 ​​can be avoided by controlling the two submersible pumps to stop, and the risk of failure of the submersible pumps can be reduced. Thereafter, when the suction side water level exceeds the second operating water level H2 in step S101, the first submersible pump 12 is operated in the full drainage operation mode M1 in step S102. Similarly, when the suction side water level exceeds the first operating water level H1 in step S103, the second submersible pump 13 is operated in the full discharge operation mode M1 in step S104.

[0021] Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. For example, in the above-described embodiment, the number of submersible pumps is two, but the number of submersible pumps is not limited to two, and may be two or more. Also, in the above-described embodiment, the two submersible pumps are provided at the same height position of the gate, but the height positions of the submersible pumps may be different height positions. [Explanation of symbols]

[0022] 1. Pump gate 11…Gate 12...Submersible pump (first submersible pump) 13…Submersible pump (second submersible pump) 14...Waterway 141…Bottom 15…Water level gauge 16...Submersible pump control device 17…Flap gate

Claims

1. A gate that can be opened and closed by moving up and down in a direction across the waterway; A plurality of submersible pumps mounted on the gate and disposed at the same height; A water level meter that detects the water level on the suction side of the submersible pump; an underwater pump control device that controls start and stop of the underwater pump based on the water level detection value of the water level meter; In a pump gate consisting of The submersible pump control device includes: A method for operating a submersible pump of a pump gate, comprising the steps of: while a first submersible pump is in operation, when a second submersible pump in the submersible pump is stopped, and when a water level detected by the water level gauge falls within a set range for air-water mixed drainage operation, controlling the second submersible pump to be started; The water level detected by the water level meter that controls the start and stop of the underwater pump is In order from the top detected water level, A first operating water level (H1) at which the set water level is exceeded and the multiple submersible pumps are operated during full drainage operation; A second operating water level (H2) below the first operating water level (H1), at which the first submersible pump is operated and the second submersible pump is stopped or operated; a first stop water level (L1) below the second operating water level (H2), at which the first submersible pump is operated and the second submersible pump is stopped; A third operating water level (H3) that is equal to or lower than the first stop water level (L1), during the air-water mixed drainage operation, in which the first submersible pump is operated and the second submersible pump is started; A second stop water level (L3) is set at which the first submersible pump is stopped and the second submersible pump is also stopped when the water level is equal to or lower than the third operating water level (H3); When the water level is equal to or lower than the second stop water level (L3), the first submersible pump and the second submersible pump stop, and the system enters standby operation in the stopped state. A method for operating a pump gate submersible pump.

2. The method for operating a submersible pump of a pump gate according to claim 1, The submersible pump control device includes: When the first submersible pump is stopped and the second submersible pump is also stopped below the second stop water level (L3), even after the water level detected by the water level gauge exceeds the second stop water level (L3) and the third operating water level (H3), the first submersible pump and the second submersible pump are continued to be stopped, and the first submersible pump is controlled to operate after the water level detected by the water level gauge exceeds the second operating water level (H2). A method for operating a pump gate submersible pump.

3. The method for operating a submersible pump having a pump gate according to claim 1 or 2, The submersible pump is two units. A method for operating a pump gate submersible pump.

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