JP3965887B2 - Backflow detection system and detection method in pump gate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pump gate having a submersible pump attached to a water stop gate, and more specifically, detecting a back flow from a discharge side of a submersible pump when a submersible pump is stopped, and detecting a back flow that flushes foreign matter caught in a flap valve. The method and its backflow detection system.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a pump gate that performs forced drainage in a closed state by disposing a submersible pump on a water stop gate supported by an irrigation or drainage sluice in a freely movable manner is well known. And as the pump gate , a vertical shaft or horizontal shaft type submersible pump is used, and a device in which a flap valve is arranged in the submersible pump in order to prevent a backflow of water from the discharge side to the intake side is disclosed in, for example, Patent No. It is known as described in US Pat. No. 2,644,864.
[0003]
[Problems to be solved by the invention]
A conventional submersible pump with a flap valve on the drain side can prevent backflow from the discharge side.However, a gap is generated in the flap valve due to biting of the falling material that occurs when the pump is stopped, and water flows from the discharge side. Inflow. When this reverse flow phenomenon occurs, flooding in the upstream region or salt damage in the upstream region occurs if the downstream region is seawater. One way to prevent this is to install an on-off valve inside the gate to prevent backflow, but this method not only increases the mass of the gate-integrated pump, but also allows the pump to be opened during natural flow. Since it is made to flow down, there is a point that it is difficult to open and close the on-off valve at the time of backflow. In addition, there is a method in which a position detector such as an encoder is mounted on the motor body to detect the rotation direction of the motor shaft, and the pump is operated at the time of reverse rotation, i.e., reverse flow. There are problems such as an increase in the number of wires, an increase in position detection wiring, and accuracy due to condensation of the position detector in the underwater seal inside the motor. Further, the method of operating the submersible pump by detecting the backflow by measuring the internal and external water levels and the flow velocity in the water channel has problems such as the installation location and wiring of the velocimeter, and maintenance over time. This invention removes the bitten on the discharge side of the flap valve of the pump gate falling object, and an object thereof is to provide a method of detecting the backflow phenomenon in pump gate to prevent backflow to the upstream side and its detection system .
[0004]
[Means for Solving the Problems]
In order to achieve the above object, a submersible pump is installed in a water stop gate supported so as to be movable up and down, a flap valve is provided on the drain side of the submersible pump, and a forced drainage is performed with the water stop gate closed. A control circuit is provided between the submersible pump and the power supply device, and an electromagnetic contactor for supplying power to the motor of the submersible pump and a backflow detection device for detecting the backflow of the submersible pump are provided in parallel in the control circuit, When the motor is stopped, disconnect the magnetic contactor from the main power system, connect the backflow detector to the motor, and detect the backflow voltage or frequency level generated by the reverse rotation of the impeller when the backflow detector detects it. signal to operate the timer and connecting a current circuit to the motor of the water pump, the driving for a predetermined time water pump, washing away foreign matter crowded engage the flap valve into the drain side Ponpuge It is a reverse flow detection method in. Specifically, this backflow detection method uses a motor with a built-in magnet as the motor for the submersible pump, and when the motor with a built-in magnet is stopped, the counter electromotive voltage generated in the stator winding by the permanent magnet by the rotation of the permanent magnet with the built-in rotor. Or it is the backflow detection method which detects a backflow determination from the submersible pump rotated by backflow water, detecting the level of a frequency with a backflow detection apparatus.
[0005]
A system for performing the above-described method for detecting the reverse flow phenomenon of the pump gate includes a control circuit provided between the submersible pump and the power supply device, an electromagnetic contactor for supplying power to the submersible pump to the control circuit, and a reverse flow of the submersible pump. A reverse flow detection device is installed in parallel, and the motor of the submersible pump is a motor with a built-in magnet. When the motor with a built-in magnet is stopped, the reverse generated in the stator winding by the permanent magnet due to the rotation of the permanent magnet with a built-in rotor. Detect the backflow of the submersible pump by detecting the back electromotive force or frequency level with a backflow detection device and comparing this detection signal with the preset frequency level or back electromotive voltage phase sequence with the control circuit comparator. Then, the backflow determination signal of the comparator is transmitted to the controller of the control circuit, and the current circuit connected to the backflow detection device is switched to the main power system by the controller command signal, and the motor with built-in magnet Even if the foreign matter caught in the flap valve is washed away to the drain side by driving for a predetermined time, or the current circuit connected to the backflow detection system is switched to the main power system, and the current circuit connected to the backflow detection device is It may be connected to an alarm device.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The pump gate backflow phenomenon detection system according to the present invention is configured as described above, and when the submersible pump is stopped, the electromagnetic contactor is disconnected from the main power system, and the backflow detection device is connected to the electric motor. When foreign matter is caught in the flap valve and backflow water flows into the pump from the drainage side, the impeller attached to the pump rotates in the reverse direction. Then, the rotor built-in permanent magnet of the motor with built-in magnet is rotated by the rotation of the impeller, and the backflow detecting device detects the level of the counter electromotive voltage or frequency generated in the stator winding. This backflow detection system measures the back electromotive voltage or frequency level, and performs backflow determination by examining the phase order of the back electromotive voltage of the detection result. Transmit the backflow determination signal of the comparator to the controller of the control circuit, switch the current circuit connected to the backflow detection system to the main power system according to the command signal of the controller, drive the motor with built-in magnet for a predetermined time, Wash away foreign matter caught in the flap valve to the drain side. Alternatively, the current circuit connected to the backflow detection system may be switched to the main power system, and the current circuit connected to the backflow detection system may be connected to the alarm device.
[0007]
【Example】
An embodiment of the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a conceptual diagram of a pump gate , in which a water stop gate 2 that can be opened and closed is arranged on a sluice gate 1 for irrigation and drainage. The horizontal shaft type submersible pump 3 is supported on the water stop gate 2. FIG. 2 is a longitudinal side view of the submersible pump 3, in which an impeller 5 is disposed inside the vane casing 4, and an impeller boss 6 fixed to the impeller 5 is connected to a motor 7 with a built-in magnet. It is. The motor 7 with a built-in magnet is supported by a guide blade 9 fixed to a discharge casing 8 connected to the rear end of the blade casing 4. The suction port 4 a of the blade casing 4 and the discharge port 8 a of the discharge casing 8 are arranged in the axial direction, and the discharge port 8 a of the discharge casing 8 is connected to a discharge pipe 22 that penetrates the inside of the water stop gate 2. . In this submersible pump 3, the flow direction in the pump and the flow of the river are parallel, so that when the water flows into the pump, the impeller 5 of the submersible pump 3 freely rotates under natural flow. In addition, when the water level a on the drain side is higher than the water level b on the water collection side, the impeller 5 of the submersible pump rotates in reverse with reverse flow water. Even in the vertical shaft submersible pump, the impeller rotates freely under natural flow, and the impeller rotates in reverse by reverse flow water. The submersible pump supported on the water stop gate 2 is a vertical shaft submersible pump. Is also good. And the flap valve 10 is pivotally attached to the drain side of the discharge pipe 22 connected to the discharge casing 8, and when the outer water level a on the discharge side becomes higher than the inner water level b on the water collection side, The discharge pipe 22 is closed with the flap valve 10 to prevent backflow from the discharge side.
[0008]
FIG. 3 is a diagram showing the principle of the motor 7 with built-in magnet. In the motor 7 with built-in magnet, a stator winding 11 provided with a three-phase winding and a rotor built-in permanent magnet 12 are arranged inside the stator winding 11. When a rotating magnetic field generated by the three-phase winding is generated in the stator winding 11, the magnetic pole is attracted and the rotor built-in permanent magnet 12 rotates to rotate the impeller 5. The electromotive voltages U, V, and W at the terminals of the three-phase winding of the stator winding 11 can be measured. As shown in FIG. 1, the submersible pump 3 and a three-phase power source 13 of the power supply device are connected by a current circuit 14 to supply power to the motor 7 with built-in magnet, and between the submersible pump 3 and the power supply device 13. Is provided with a control panel 15. The control panel 15 will be described in detail with reference to FIG. 4. The control circuit 16 is provided in the control panel 15, and the control circuit 16 is an electromagnetic contactor for operating power supply / stop to the motor 7 with built-in magnet of the submersible pump 3. 17 and a backflow detection device 18 for detecting the rotation of the impeller 5 of the submersible pump 3 are arranged in parallel. When the motor with built-in magnet 7 is stopped, the backflow detection device 18 is connected to the terminal of the stator winding 11 so that the electromotive voltages U, V, and W generated by the three-phase winding are the same as the voltage phase during the natural flow and the reverse flow. The voltage phase is detected. Further, the control circuit 16 includes a comparator 19 that compares the level of the frequency determined to be the backflow or the back electromotive voltage with a preset numerical value and the level of the back electromotive voltage or the frequency detected by the backflow detection device 18, a flap valve. When it is determined that a foreign object has entered 10 and backflow water flows into the submersible pump 3 from the drain side and the impeller 5 is rotating in reverse, the electromagnetic contactor 17 to the motor 7 with built-in magnet of the submersible pump 3 is determined. And a controller 20 for driving the submersible pump 3 for a predetermined time. Reference numeral 21 denotes a leakage breaker.
[0009]
The operation procedure of the backflow detection system will be described with reference to the flowchart of FIG. 5. When the submersible pump 3 is stopped with the water stop gate closed, that is, when the natural flow occurs, the electromagnetic contactor 17 is connected to the current circuit 14 of the main power system. The backflow detection device 18 is connected to the motor 7 with built-in magnet. When the backflow detection device 18 detects the presence or absence of a counter electromotive voltage or frequency due to the flow and compares the level of the preset frequency or the counter electromotive voltage and the detection signal is NO, the flap valve 10 is bitten by foreign matter. Judge that there is no intrusion, and feed back to the previous stage. If the counter electromotive voltage or frequency due to the flow is detected and the answer is YES, when the voltage phase sequence is lower than the counter voltage phase sequence compared to the preset frequency level or counter electromotive voltage, It is judged that there is little inflow water to the pump and feeds back to the previous stage. When the voltage phase sequence exceeds the reverse voltage phase sequence, it is determined that foreign matter is caught in the flap valve 10 and that the backflow water flows into the submersible pump 3 from the drain side, and is connected to the backflow detection device 18. The current circuit 14 thus switched is switched to the main power system and connected to the alarm device. Next, the current circuit 14 connected to the backflow detection device 18 is switched to the main power system, the built-in magnet motor 7 is driven for a predetermined time, and the foreign matter caught in the flap valve 10 is washed away to the drain side. Feed back when the submersible pump 3 stops. When the foreign matter biting of the flap valve 10 is not eliminated, the submersible pump 3 is driven again.
[0010]
【The invention's effect】
The present invention is configured as described above, and the backflow detection device detects the level of the counter electromotive voltage or frequency generated in the stator winding by the rotation of the permanent magnet built in the rotor of the motor with built-in magnet when the submersible pump is stopped. Since it is detected, the backflow from the discharge side of the submersible pump can be detected, and the foreign matter caught in the flap valve can be washed away. That is, the pump gate of the conventional device provided with the on-off valve has a drawback that it is difficult to adjust the on-off valve at the time of backflow. In addition, a method for detecting the rotation direction of the motor shaft by mounting a position detector such as an encoder has a problem that the pump body is large and there is a problem such as accuracy due to condensation of the position detector in the underwater sealing part inside the motor. Furthermore, the method of detecting the reverse flow by measuring the internal and external water levels and the flow velocity in the water channel has problems such as the installation location and wiring of the anemometer, and maintenance costs over time. In this invention, when the submersible pump is stopped, the back electromotive force or frequency level generated by the permanent magnet built in the rotor of the motor with built-in magnet is detected by the backflow detection device, and this detection signal is set at a preset frequency. The control circuit determines the level or phase sequence of the back electromotive force, switches the current circuit connected to the backflow detection system to the main power system, drives the submersible pump for a predetermined time, and removes foreign matter caught in the flap valve. It is washed away to the drainage side and can prevent backflow to the upstream side. The counter electromotive voltage can be detected by measuring the instruments in the control panel, and a separately installed detector is unnecessary, and can be detected without being influenced by the surrounding environment. Moreover, since the rotation of the impeller is used, the backflow can be detected quickly.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a backflow detection system in a pump gate according to the present invention.
FIG. 2 is a longitudinal side view of a submersible pump provided with a magnet built-in motor according to the present invention.
FIG. 3 is also a rotation principle diagram of a motor with a built-in magnet.
FIG. 4 is also a wiring diagram of the control panel.
FIG. 5 is also a flowchart of a backflow detection system.
[Explanation of symbols]
2 Water stop gate 3 Submersible pump 7 Motor with built-in magnet 10 Flap valve 12 Permanent magnet with built-in rotor 13 Three-phase power supply 14 Current circuit 16 Control circuit 17 Magnetic contactor 18 Backflow detection device 19 Comparator 20 Controller

Claims (5)

A submersible pump (3) is installed in the water stop gate (2) that can be raised and lowered, a flap valve (10) is installed on the drain side of the submersible pump (3), and forced drainage is performed with the water stop gate (2) closed. In this pump, a control circuit (16) is provided between the submersible pump (3) and the power supply (13), and electric power is supplied to the motor (7) of the submersible pump (3). An electromagnetic contactor (17) and a reverse flow detection device (18) for detecting the reverse flow of the submersible pump (3) are arranged in parallel. When the submersible pump (3) is stopped, the electromagnetic contactor (17) is connected to the main power system. The backflow detection device (18) is connected to the electric motor (7), and when the backflow detection device (18) detects the level of the back electromotive voltage or frequency generated by the reverse rotation of the impeller (5), the detection signal Current flow to the motor (7) of the submersible pump (3) (14) to connect the drives a predetermined time water pump (3), reverse flow detection method in the pump gate, characterized in that wash away foreign matter forme engage the flap valve (10) on the drainage side. The motor of the submersible pump (3) is a motor with built-in magnet (7), and when the motor with built-in magnet (7) is stopped, the back electromotive voltage or frequency level generated by the permanent magnet with built-in rotor (12) is detected. The backflow detection method in a pump gate according to claim 1, wherein the backflow is detected from the submersible pump (3) which is detected by the device (18) and is rotated by backflow water. A submersible pump (3) is installed in the water stop gate (2) that can be raised and lowered, a flap valve (10) is installed on the drain side of the submersible pump (3), and forced drainage is performed with the water stop gate (2) closed. In this pump, a control circuit (16) is provided between the submersible pump (3) and the power supply (13), and an electromagnetic contactor (17) for supplying electric power to the submersible pump (3) to the control circuit (16). ) And a backflow detection device (18) for detecting the backflow of the submersible pump (3), and the motor of the submersible pump (3) is a motor with built-in magnet (7). At the time of stoppage, the counter electromotive voltage or frequency level generated in the stator winding (11) by the permanent magnet due to the rotation of the rotor built-in permanent magnet (12) is detected by the backflow detection device (18). Preset frequency level or vice versa In contrast with the phase sequence and the control circuit of the voltage (16) of the comparator (19), back flow detection system in the pump gates and performing backflow determination of water pump (3). The backflow determination signal of the comparator (19) is transmitted to the controller (20), and the current circuit (14) connected to the backflow detector (18) is sent to the main power system by the command signal of the controller (20). 4. The backflow detection system for a pump gate according to claim 3, wherein the foreign substance caught in the flap valve (10) is washed away to the drain side by switching and driving the motor with built-in magnet (7) for a predetermined time. 4. A backflow detection system in a pump gate according to claim 3, wherein the current circuit (14) connected to the backflow detection device (18) is connected to an alarm device.

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