JP7461262B2 - Pump diagnostic method, pump gate diagnostic method, and pump diagnostic device - Google Patents

Description

The present invention relates to a pump diagnostic method, a pump gate diagnostic method, and a pump diagnostic device.

In recent years, pump gates have been installed in addition to or in place of existing sluice gates provided at the boundary between upstream and downstream channels in waterways with relatively low water flow, such as tributaries that join the main river. There are an increasing number of cases where A pump gate has a structure in which a submersible pump for draining water from an upstream waterway to a downstream waterway is provided on a door body that is openable and closable in a waterway. Pump gates can be installed directly into existing waterways, so there is no need for bypass channels or space for pumping stations, which is required for conventional drainage pumping stations. This significantly reduces the amount of civil engineering structures required for installation, significantly reducing total costs. It is excellent in that it can be reduced in size.

The pump gate closes when the water level in the downstream channel becomes high, for example during heavy rain, to prevent backflow from the downstream channel to the upstream channel. At this time, the submersible pump is operated to forcibly drain the water in the upstream channel into the downstream channel. Conversely, when the downstream water level is low, such as on sunny days, there is no risk of backflow as described above, so the gate is opened and the water in the upstream channel is allowed to naturally flow down into the downstream channel.

Due to the above characteristics, pump gates are only operated in emergencies such as torrential rain, but their operation must be reliable. In other words, it is necessary to reliably prevent failures, even though there are few opportunities to detect failures or their symptoms based on normal operating conditions. Therefore, it is preferable to perform regular management operations (diagnosis) of installed pump gates. As a method of such management operations, it is possible to apply publicly known management operations related to rotating equipment (for example, JP 2019-23473 A (Patent Document 1), JP 3525736 A (Patent Document 2), etc.) to the pump of the pump gate.

JP 2019-23473 Publication Patent No. 3525736

Since the pump of a pump gate is originally a device that is operated underwater, it is desirable to place the pump underwater during maintenance operations. However, in order to place the pump underwater, it is necessary to close the gate body to ensure the water level of the upstream waterway, which temporarily blocks the flow of the waterway. However, depending on the water use plan of the installation site, it may be difficult to implement even for a short period of closure. Also, when the flow rate is low, there are cases where a sufficient amount of water to place the pump underwater cannot be secured even if the gate body is closed. Therefore, there is a need to realize technology that can perform effective maintenance operations even when the pump is placed above the water surface, that is, in a state different from the pump's original operating state, but technologies such as those in Patent Documents 1 and 2, which are based on the premise that the operation will be performed under conditions close to the original operating conditions, were insufficient.

Therefore, there is a need for a pump diagnostic method, a pump gate diagnostic method, and a pump diagnostic device that can perform effective diagnosis even when the pump is placed above the water surface.

A first pump diagnostic method according to the present invention starts the pump in a stopped state, and measures a first current value, which is the value of the current flowing through the pump, over a predetermined measurement period after the pump starts. a first measuring operation step of stopping the power supply to the pump while the pump is in operation and causing the pump to coast for a predetermined period; a second measurement operation step of activating the pump and measuring a second current value that is the value of the current flowing through the pump over a predetermined measurement period after the startup; In the process, the first stabilization time, which is the length of time required from starting the pump to stabilizing the operation of the pump, is calculated, and the second measurement operation is performed based on the second current value. a calculation step of calculating a second stabilization time which is the length of time required from starting the pump to stabilizing the operation of the pump in the step; and a step of calculating the first stabilization time and the second stabilization time. The method is characterized by comprising a determination step of determining the state of the pump using time as a determination material.

A diagnostic method for a pump gate according to the present invention is a method for diagnosing a pump gate including a door body capable of blocking a flow path through which a liquid flows, a pump provided on the door body and capable of forcing the liquid from an upstream side to a downstream side of the flow path in a state in which the flow path is blocked by the door body, and a drive device capable of moving the door body up and down, the method including a first measurement operation step of starting the pump in a state in which the pump is stopped, and measuring a first current value that is a value of a current flowing through the pump over a predetermined measurement period after the start-up, a stop step of stopping power supply to the pump while the pump is in operation, and coasting the pump for a predetermined period, and starting the pump in a state in which the pump is coasting, and measuring a first current value that is a value of a current flowing through the pump over a predetermined measurement period after the start-up. the pump is operated in a state where the pump is positioned above the liquid level, and the first and second measurement operation steps are performed while the pump is positioned above the liquid level.

The pump diagnostic device according to the present invention includes a measuring device capable of measuring the value of a current flowing through a pump, and a computing device. The computing device has a control function for controlling the power supply to the pump so that a first power supply for supplying power to the pump when the pump is stopped, a power supply stop for stopping the power supply to the pump, and a second power supply for supplying power to the pump when the pump is coasting are performed in this order, a first measurement function for measuring and acquiring a first current value, which is the value of a current flowing through the pump, by the measuring device over a predetermined measurement period after the pump is started when the first power supply is performed, and a second measurement function for measuring and acquiring a first current value, which is the value of a current flowing through the pump, by the measuring device during the second power supply. The device is characterized in that it is configured to be capable of executing a second measurement function that measures and acquires a second current value, which is the value of the current flowing through the pump, by the measurement device over a predetermined measurement period after the pump is started; a calculation function that calculates a first stabilization time, which is the length of time required from starting the pump when the first power supply is implemented until the operation of the pump stabilizes, based on the first current value, and calculates a second stabilization time, which is the length of time required from starting the pump when the second power supply is implemented until the operation of the pump stabilizes, based on the second current value; and a determination function that determines the state of the pump using the first stabilization time and the second stabilization time as criteria.

According to these configurations, effective diagnosis can be performed even when the pump is placed above the water surface. By providing the first measurement operation process and the second measurement operation process, the effect of the operation at the time of diagnosis being performed in a state different from the original operation state of the pump can be avoided in two measurement operations. This is due to the fact that the measured values can be canceled out.

The second pump diagnosis method according to the present invention is characterized by comprising a stopping step of stopping the supply of power to the pump while the pump is operating and coasting the pump for a predetermined period of time, a measurement operation step of starting the pump while the pump is coasting and measuring a current value, which is the value of the current flowing through the pump for a predetermined measurement period after the start-up, a calculation step of calculating a stabilization time, which is the length of time required from starting the pump in the measurement operation step until the operation of the pump becomes stable, based on the current value, and a determination step of determining the state of the pump using the predetermined period and the stabilization time as criteria.

This configuration allows for effective diagnosis even when the pump is positioned above the water surface. This is because the relationship between the specified period and the stabilization time is less susceptible to the effects of the pump being operated in a state different from the pump's normal operating state during diagnosis.

Hereinafter, preferred embodiments of the present invention will be described. However, the scope of the present invention is not limited to the preferred embodiments described below.

In one aspect of the pump diagnostic method according to the present invention, in the determination step, it is preferable to determine the state of the pump based on the ratio between the first stabilization time and the second stabilization time.

According to this configuration, it is possible to clearly offset the influence caused by the pump being operated in a state different from its original operating state during diagnosis.

In one aspect of the pump diagnostic method according to the present invention, in the judgment step, it is preferable to calculate the sliding torque of the pump based on the rated rotation speed of the pump and the ratio between the first stabilization time and the second stabilization time, and judge the state of the pump using the sliding torque as a further criterion.

According to this configuration, for example, poor sliding of the pump can be detected through the direct factor of increased sliding torque, making it easy for the user to grasp the condition of the pump.

In one aspect of the pump diagnosis method according to the present invention, the ratio of the first stabilization time to the second stabilization time, and the inertial operation when starting the pump in the second measuring operation step are provided. The relationship between the rotational speed of the pump and the rotational speed of the pump that has been clarified in advance is determined in advance, and in the determination step, the relationship between the ratio of the first stabilization time and the second stabilization time and the rotation speed of the pump that is clarified in advance is When starting the pump in the second measuring operation step, the rotational speed of the pump that is coasting is calculated based on the relationship, and the state of the pump is determined using the rotational speed as a further determination material. It is preferable to do so.

With this configuration, for example, poor pump operation can be detected through a direct factor such as a drop in rotation speed, making it easier for the user to understand the condition of the pump.

Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments, which are given with reference to the drawings.

FIG. 3 is a schematic diagram of the pump gate in an open state according to the present embodiment. FIG. 3 is a schematic diagram of the pump gate in a closed state according to the present embodiment. FIG. 2 is a configuration diagram of a pump gate according to the embodiment. FIG. 4 is a flow chart of a pump diagnostic method according to the present embodiment. 6 is an example of a transition of a current measured in the pump diagnosis method according to the present embodiment. FIG. 11 is a diagram for explaining a calculation process in a calculation step.

Embodiments of the pump diagnostic method, pump gate diagnostic method, and pump diagnostic device according to the present invention will be described with reference to the drawings. Below, the pump diagnostic method according to the present invention is applied to the diagnosis of the pump 3 of the pump gate 1 installed in a water flow path 100 (an example of a flow path), and an example is described in which the pump gate diagnostic method according to the present invention is applied to the diagnosis of the pump gate 1. Note that, below, the pump diagnostic method and the pump gate diagnostic method may be collectively referred to as the "diagnosis method."

[Overview of pump gate]
First, an overview of the pump gate 1 to be diagnosed in the diagnostic method according to the present embodiment will be explained. The pump gate 1 includes a door body 2, a pump 3 provided on the door body, and a drive device 4 that can move the door body 2 up and down (FIG. 1). The pump gate 1 is installed in a flow channel 100 at a point where a main stream and a tributary of a river meet. The flow channel 100 has a tributary flow channel 101 (an example on the upstream side of the flow channel) and a main flow channel 102 (an example on the downstream side of the flow channel).

1, under normal circumstances, the gate 2 is placed above a water level 103 (an example of a liquid level) of water (an example of a liquid) flowing through the flow channel 100, and the operation of the pump 3 is stopped. Water flows down by gravity from the tributary side flow channel 101 to the mainstream side flow channel 102.

When the water level rises due to heavy rainfall or the like, the main stream may rise, causing the water level in the main stream side channel 102 to rise. In such a case, in order to prevent water from flowing back from the main stream side channel 102 to the tributary side channel 101, the gate body 2 is lowered to close the channel 100 (Figure 2). At this time, the pump 3 is positioned below the water level 103. When the pump 3 is operated, water is forced from the tributary side channel 101 to the main stream side channel 102, and can be forcibly discharged.

The pump 3 and the drive unit 4 are supplied with power through a distribution board 5. The distribution board 5 is provided with a control device 51 that controls the operation of the pump 3 and the drive unit 4 and receives signals from various instruments such as a water level gauge (not shown) installed in each part of the flow channel 100 and a position sensor (not shown) that detects the up and down position of the gate body 2, as well as a communication device 52 that can send the operating status and measurement information of the equipment controlled or acquired by the control device 51 to the server device 6 (Figure 3).

The operating state and measurement information collected at the pump gate 1 are accumulated in the server device 6 (FIG. 3). The administrator of the pump gate 1 and the like can view the information stored in the server device 6 from the user terminal 7 (computer, tablet terminal, smartphone, etc.) at hand, and can remotely monitor the operating state of the pump gate 1. It is also possible to remotely control the operation and stop of the pump 3 and the drive device 4 through the terminal.

[Pump gate diagnosis]
Due to the nature of the pump gate 1, the pump 3 is not operated under normal circumstances, but is operated only in the case of heavy rain. On the other hand, the pump 3 needs to be operated when emergency drainage is required, so it is required that the pump 3 can be operated reliably. That is, even though there is little opportunity to detect a failure or its symptom based on the operating state under normal circumstances, it is required to reliably prevent a failure. In view of such a requirement, the pump 3 is periodically diagnosed to check for the presence or absence of a failure and its symptom. The diagnosis method according to this embodiment has a preliminary operation step S10, a first measurement operation step S20, a stop step S30, a second measurement operation step S40, a calculation step S50, and a judgment step S60 (FIG. 4). The contents of each step will be described below.

Before performing diagnosis, the pump diagnostic device 8 is attached to the distribution board 5 (FIG. 3). The pump diagnostic device 8 includes an ammeter 81 (an example of a measuring device) and a computer 82 (an example of a calculation device), and a probe 81a of the ammeter 81 is attached to a power supply line that supplies power to the pump 3. Further, the current value measured by the ammeter 81 is input to the computer 82, and the current value can be used for analysis processing on the computer 82. In the present embodiment, measurement values are acquired using the ammeter 81 continuously over at least the first measurement operation step S20, the stop step S30, and the second measurement operation step S40.

As the ammeter 81 and the computer 82 mentioned above, known hardware can be used. Therefore, the computer 82 includes input devices (keyboard, mouse, etc.), output devices (display, speakers, etc.), arithmetic elements (CPU, etc.), storage devices (hard disk drive, etc.), communication devices (wired communication interface, etc.), all of which are publicly known. wireless communication interface, etc.).

The preliminary operation step S10 is performed as the first step of the diagnostic method according to this embodiment. In the first measurement operation step S20 and the second measurement operation step S40, the pump 3 is operated, but if the pump 3 is stuck or otherwise abnormal, attempting to force start the pump 3 may damage the pump 3. Therefore, in the preliminary operation step S10, the pump 3 is operated for a short period of time (e.g., 3 seconds) and then stopped. Thereafter, when the inertial operation of the pump 3 has completely stopped, the process proceeds to the subsequent steps.

The first measurement operation step S20 is a step in which the pump 3 is started from a completely stopped state, and the value of the current flowing through the pump 3 at this time is measured. As described above, after the preliminary operation step S10 is performed, the inertial operation of the pump 3 is completely stopped before proceeding to the next step, so that the pump 3 is in a completely stopped state at the start of the first measurement operation step S20.

The first measurement operation step S20 is performed in the state of the pump gate 1 under normal conditions, that is, in the state where the gate body 2 is placed above the water surface 103 of the water flowing through the flow channel 100, and therefore the pump 3 is placed above the water surface 103 (Figure 1). This is because the operating load of the pump 3 may vary depending on the state of the flow channel 100 (e.g., the amount of water), and it is difficult to maintain the measurement conditions constant when the first measurement operation step S20 is performed with the pump 3 placed below the water surface 103. Note that in a situation where the amount of water is small and the pump 3 is placed above the water surface 103 even if the gate body 2 is lowered to block the flow channel 100, the first measurement operation step S20 may be performed with the gate body 2 lowered. In the following explanation, operating the pump 3 above the water surface 103 is referred to as "idle operation".

In the first measurement operation step S20, the pump 3 is started and idled (an example of a first power supply). More specifically, after the operation to start the pump 3 is performed, the operation to stop the pump 3 is performed after a predetermined measurement period. The current flowing through the pump 3 is an alternating current, and the measured value of this current oscillates between positive and negative. As shown in FIG. 5, the value of the current flowing through the pump 3 during the first measurement operation step S20 (hereinafter referred to as the first current value I1) behaves such that a relatively large current flows immediately after the pump 3 is started, and then converges to a relatively small current. In the following explanation, the state in which the current value has converged is referred to as a steady state.

The subsequent stop step S30 is a period from when the power supply to the pump 3 is stopped at the end of the first measurement operation step S20 to when the pump 3 is started at the beginning of the second measurement operation step S40. This is a process in which power is not supplied to the pump 3 (an example of stopping power supply). Since the stop step S30 is a step after performing an operation to stop the pump 3 and before starting it, no current flows through the pump 3 in the stop step S30. However, the motor and impeller of the pump 3 are in a state of inertia operation in which they are still rotating due to inertia.

In the subsequent second measurement operation step S40, the pump 3 is started again (an example of second power supply). Also here, similarly to the first measurement operation step S20, after performing an operation to start the pump 3, an operation to stop the pump 3 is performed after a predetermined measurement period. The timing for starting the pump 3 is selected so that the duration of the stop step S30 is a predetermined period. This is to substantially equalize the duration of the stop step S30 to a predetermined period during multiple diagnoses of the pump gate 1. Note that, like the first measurement operation step S20, the second measurement operation step S40 is performed with the pump 3 disposed above the water surface 103 (FIG. 1). The reason is the same as the first measurement operation step S20.

In the second measurement operation step S40, similarly to the first measurement operation step S20, the pump Immediately after starting No. 3, a relatively large current flows, and then the current converges to a relatively small one. Here, the criteria for determining that a steady state has been reached in the second measurement operation step S40 are the same as in the first measurement operation step S20.

The calculation step S50 is implemented as an arithmetic process executed by the computer 82. As described above, the measurement values using the ammeter 81 are continuously acquired over at least the first measurement operation process S20, the stop process S30, and the second measurement operation process S40, and the measurement values are acquired. It is recorded in the computer 82 along with the time. In the calculation step S50, the pump 3 is started in each of the first measurement operation step S20 and the second measurement operation step S40 based on the change over time of the measured values (first current value I1, second current value I2). This is a step of calculating a stabilization time (first stabilization time Ts1, second stabilization time Ts2), which is the length of time required for the operation of the pump 3 to stabilize after the stabilization. In the following, a method for calculating the first stabilization time Ts1 will be described as an example with reference to FIG. 6, but the same applies to a method for calculating the second stabilization time Ts2.

First, the computer 82 executes a process of converting the first current value I1 into an absolute value Ia1. Because the current flowing through the pump 3 is an alternating current, in order to analyze the behavior of the pump 3 based on the value of the current, it is appropriate to base the analysis on the absolute value Ia1 of the first current value I1, rather than on the first current value I1 itself, which includes both positive and negative values.

Second, the computer 82 identifies the starting point P1a of the section P1 corresponding to the first stabilization time Ts1. Specifically, the moment when the absolute value Ia1 of the first current value I1 exceeds a predetermined threshold value is specified as the starting point P1a. That is, the time when the rush current that occurs when the pump 3 is started is specified as the starting point P1a.

Thirdly, the computer 82 calculates the envelope E1 of the absolute value Ia1 of the first current value I1 from the starting point P1a onwards. The envelope E1 is obtained, for example, by sequentially connecting the points at which the absolute value Ia1 of the first current value I1 is at its maximum value in each period of the waveform of the absolute value Ia1 of the first current value I1.

Fourth, the computer 82 calculates the steady-state value Es1 of the envelope E1. As mentioned above, when the pump 3 is started, a relatively large current flows immediately after starting, and then converges to a relatively small current. Converges to a certain value. Therefore, the absolute value Ia1 of the first current value I1 and its envelope E1 also converge. The steady-state value Es1 of the envelope E1 is obtained, for example, as the value of the envelope E1 at the time when a predetermined time has elapsed from the starting point P1a. Note that the "predetermined time" here may be any time when convergence of the first current value I1 is reliably observed, and may be longer than the time normally considered by those skilled in the art as the time required for the motor operation to stabilize. The time period may be set to a long time (for example, 10 seconds or more), or may be set to a time specified by performing a trial run when the pump 3 is manufactured.

Fifth, the computer 82 normalizes the envelope E1 by setting the constant value Es1 to 1.0, and calculates the normalized envelope En1.

Sixth, the computer 82 identifies the end point P1b of the section P1 corresponding to the first stabilization time Ts1. Specifically, the computer 82 identifies as the end point P1b the point at which the normalized envelope En1 falls below a predetermined value (e.g., 1.5) for the first time after the start point P1a.

Seventh, the computer 82 calculates the first stabilization time Ts1 as the length of time elapsed from the start point P1a to the end point P1b.

The first stabilization time Ts1 can be calculated as described above, but as described above, the second stabilization time Ts2 can be calculated based on the change over time of the second current value I2 by the same method as described above. At this time, the section P2 corresponding to the second stabilization time Ts2, as well as the start point P2a and end point P2b of the section P2 are also identified.

Furthermore, in the calculation step S50, the computer 82 calculates a stop time t, which is the duration of the stop step S30, in addition to the first stabilization time Ts1 and the second stabilization time Ts2. The section P3 corresponding to the stop time t is a section whose starting point P3a is the point at which the first current value I1 falls below a predetermined threshold after the end point P1b, and whose end point is the starting point P2a of the section P2. Therefore, the computer 82 calculates the stop time t as the length of time that has passed from the starting point P3a to the starting point P2a.

The determination step S60 is implemented as an arithmetic process executed by the computer 82, similarly to the calculation step S50. The determination step S60 is a step in which the computer 82 determines the state of the pump 3 using the first stabilization time Ts1 and the second stabilization time Ts2 as determination materials.

The computer 82 calculates a startup time ratio R, which is a ratio of the second stabilization time Ts2 to the first stabilization time Ts1. The startup time ratio R is given by the following formula (1).
R = Ts2/Ts1 (1)

There is a negative correlation between the start-up time ratio R and the rotation speed of the pump 3 rotating by inertia at the time when the second measurement operation process S40 is started. This is because the higher the rotation speed of the inertia rotation, the shorter the time required to reach a steady state after restarting the pump 3 in the second measurement operation process S40 (the shorter the second stabilization time Ts2).

The present inventors have discovered that the above correlation can be approximated by a simple straight line. The rotation speed N (min ⁻¹ ) at the time of restart is approximated by the following equation (2) using the rated rotation speed Nr (min ⁻¹ ) of the pump 3 and the startup time ratio R.
N=Nr(1-R) (2)

In equation (2), the rated rotational speed Nr of the pump 3 is a constant uniquely determined from the type of the pump 3 and the like. Therefore, by using equation (2), the rotational speed N can be calculated without actually measuring the rotational speed itself. Further, in determining the equation (2), preliminary experiments such as actually measuring the rotational speed N for various startup time ratios R are not required.

Furthermore, the sliding torque T (N·m) of the pump 3 is expressed by the following equation (3).
T=(2πI/60t)(Nr-N) (3)
Here, I (kg·m ² ) is the moment of inertia of the rotor of the pump 3 and is a constant. Moreover, t (seconds) is the above-mentioned stop time. Since each step of the diagnosis is performed such that the stop time t is substantially the same in the plurality of diagnoses performed on the pump gate 1, the stop time t is substantially constant.

A sliding torque ratio Kt, which is the ratio between the sliding torque T and an initial sliding torque _Ti , which is the sliding torque at the time when the pump 3 is first installed, is expressed by the following equation (4).
Kt = T / _Ti (4)

Here, by substituting equation (3) into equation (4) and rearranging the right side, equation (5) is obtained. Note that the rotational speed at the time of restarting the pump 3 when it was initially installed was set as N _i .
Kt=(Nr-N)/(Nr-N _i ) (5)

Furthermore, by transforming the right side of equation (5) using equation (2), equation (6) is obtained. Note that the start-up time ratio at the beginning of installation of the pump 3 is represented as _Ri .
Kt = R / R _i (6)

Since the starting time ratio R _i is a constant in equation (6), the sliding torque ratio Kt is expressed by a function using the starting time ratio R as a variable. The computer 82 stores the starting time ratio R _i in advance, and can calculate the sliding torque ratio Kt based on the starting time ratio R.

The sliding torque T of the pump 3 can increase due to factors such as distortion and wear of the rotating shaft, and the presence of foreign matter. That is, if the sliding torque T increases, there is a possibility that some abnormality has occurred in the pump 3. Since the initial sliding torque T _i is a constant in the formula (4), when the sliding torque T increases, the sliding torque ratio Kt also increases. Therefore, if the sliding torque ratio Kt obtained by the formula (6) increases, this means that the sliding torque T has increased, that is, it indicates the possibility that some abnormality has occurred in the pump 3. That is, by calculating the start-up time ratio R, it is possible to estimate whether or not there has been a change in the sliding torque T.

This can also be understood as follows. When the sliding torque T increases, the rotational resistance of the pump 3 increases, so the attenuation rate of the rotational speed during coasting operation increases. Therefore, the rotational speed of the inertial rotation at the start of the second measurement operation step S40 becomes smaller, and the second stabilization time Ts becomes longer. Therefore, at this time, the startup time ratio R becomes large. In this way, an increase in the starting time ratio R is a phenomenon that is observed when the sliding torque T is increasing, so if an increase in the starting time ratio R is observed, it means that the sliding torque T is increasing. there is a possibility.

Subsequently, the computer 82 compares the sliding torque ratio Kt with a predetermined reference to determine the state of the pump 3. If the sliding torque ratio Kt is 1.3 or less, the computer 82 determines that the pump 3 is in a "normal" state.

When the sliding torque ratio Kt is greater than 1.3 and is equal to or less than 1.7, the computer 82 determines that the pump 3 is in a state of "needing further observation." A pump 3 determined to be in a state of "needing further observation" is likely to be usable without maintenance, but is in a state in which maintenance is desirable for more stable operation.

If the sliding torque ratio Kt exceeds 1.7, the computer 82 determines that the pump 3 is in a state of "requiring further observation." A pump 3 that is determined to be in a state of "requiring maintenance" is in a state where there is a high possibility that it will become unusable without maintenance.

The state of the pump 3 determined in the determination step S60 is notified to the user via an output device provided in the computer 82. The output mode may be changed depending on the category of the determined state. For example, an alarm may be sounded when the state is determined to be "maintenance required" to prompt the user to check the determination result promptly. In addition, the values of the sliding torque ratio Kt, start-up time ratio R, etc. calculated in the determination step S60, and the values of the first stabilization time Ts1, second stabilization time Ts2, and stop time t, etc. calculated in the calculation step S50 may be displayed together with the state of the pump 3.

[Modifications]
A modified example of the pump diagnostic method according to the present invention will be described below. In this modified example, the calculation step S50 and the determination step S60 are different from those in the above embodiment. Note that the second measurement operation step S40 in this modified example is an example of the measurement operation step.

From the above formulas (1), (2), and (3), the following formula (7) is obtained.
T = (2πI / 60t) Nr (Ts2 / Ts1) (7)

Here, since the moment of inertia I and the rated rotational speed Nr of the pump 3 are constants, the sliding torque T is a function with variables of the stop time t, the first stabilization time Ts1, and the second stabilization time Ts2. expressed. Here, since the first stabilization time Ts1 hardly changes even if the state of the pump 3 changes, if the first stabilization time Ts1 is treated as a constant, the sliding torque T is ) and the second stabilization time Ts2 (stabilization time) as variables.

Specifically, a modification of the determination step S60 has the following procedure. First, for example, the first stabilization time Ts1 is determined in the initial test run after installing the pump 3, and the first stabilization time Ts1 is used as a constant in subsequent diagnosis. In each diagnosis, the computer 82 calculates the sliding torque T according to equation (7) using the stop time t and the second stabilization time Ts2 calculated by the method described above. Then, the computer 82 determines the state of the pump 3 based on the value of the sliding torque T. Furthermore, the determination result may be transmitted to the server device 6 and the user terminal 7 via the communication device of the computer 82 along with a series of measurement data.

Further, in the calculation step S50 in this modification, calculation of the first stabilization time Ts1 can be omitted.

[Other embodiments]
Finally, other embodiments of the pump diagnosing method, pump gate diagnosing method, and pump diagnosing device according to the present invention will be described. Note that the configurations disclosed in each of the embodiments below can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction occurs.

In the above embodiment, the configuration in which the diagnostic method according to the present invention is applied to diagnosis of the pump gate 1 (pump 3) has been described as an example. However, the pump diagnosis method according to the present invention can also be applied to diagnosis of pumps such as drainage station pumps, manhole pumps, and land pumps.

In the above embodiment, an example has been described in which the ammeter 81 of the pump diagnostic device 8 is installed on the distribution board 5 before diagnosis is performed. However, the present invention is not limited to such a configuration, and the diagnostic method according to the present invention may employ a method in which an ammeter capable of measuring the value of the current flowing through the pump is permanently installed and the measurement value of the ammeter is used.

In the above embodiment, a procedure including the preliminary operation step S10 has been described as an example. However, in the pump diagnostic method according to the present invention, the preliminary operation step does not have to be performed.

In the above embodiment, an example has been described in which, in the calculation step S50, the absolute values of the first current value I1 and the second current value I2 are calculated, and then the envelope of the absolute values is calculated, and the first stabilization time and the second stabilization time are calculated based on the normalized envelope obtained by normalizing the envelope. However, in the pump diagnosis method according to the present invention, the calculation method for calculating the first stabilization time and the second stabilization time is not particularly limited, and for example, the first stabilization time and the second stabilization time may be determined by regarding the time when the effective current value reaches a preset value as the time when stabilization occurs.

In the above embodiment, an example has been described in which the sliding torque ratio Kt of the pump 3 is calculated in the determination step S60, and the sliding torque ratio Kt is compared with a predetermined criterion to determine the state of the pump 3. However, in the pump diagnostic method according to the present invention, the method of determining the state of the pump is not particularly limited, and for example, a method of comparing the calculated start-up time ratio with a predetermined criterion may be used.

In the above embodiment, the determination step S60 uses the formula (2) to approximate the rotation speed N(min ⁻¹ ) at restart using the rated rotation speed Nr(min ⁻¹ ) of the pump 3 and the startup time ratio R.
N = Nr (1 - R) (2)
However, in the pump diagnostic method according to the present invention, the relationship between the rotation speed at restart and the start-up time ratio may be clarified in advance through a preliminary experiment, and during actual diagnosis, the rotation speed at restart may be obtained from the start-up time ratio using the previously clarified relationship.

Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects, and the scope of the present invention is not limited thereby. Those skilled in the art will easily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Therefore, other embodiments that are modified without departing from the spirit of the present invention are naturally included within the scope of the present invention.

The present invention can be used, for example, as a method for diagnosing pumps, such as pump gates, installed in flowing waterways.

1: Pump gate 2: Door body 3: Pump 4: Drive device 5: Distribution board 51: Control device 52: Communication device 6: Server device 7: User terminal 8: Pump diagnostic device 81: Ammeter 81a: Probe 82: Computer 100: Flow channel 101: Tributary flow channel 102: Main stream channel 103: Water surface E1: Envelope En1: Normalized envelope Es1: Steady value I1: First current value I2: Second current value Ia1: Absolute value Kt: Sliding torque ratio N: Rotational speed Nr: Rated rotational speed P1: Section P1a: Starting point of section P1 P1b: End point of section P1 P2: Section P2a: Starting point of section P2 P2b: End point of section P2 P3: Section P3a: Starting point of section P3 R: Start-up time ratio Ri: Start-up time ratio Ts: Second stabilization time Ts1: First stabilization time Ts2: Second stabilization time t: Stop time S10: Preliminary operation process S20: First measurement operation Process S30: Stop process S40: Second measurement operation process S50: Calculation process S60: Judgment process

Claims (7)

a first measurement operation step of starting the pump while the pump is stopped, and measuring a first current value, which is a value of a current flowing through the pump, for a predetermined measurement period after the start of the pump;
a stopping step of stopping the supply of power to the pump while the pump is in operation and coasting the pump for a predetermined period of time;
a second measurement operation step of starting the pump while the pump is coasting and measuring a second current value, which is a value of a current flowing through the pump for a predetermined measurement period after the start of the pump;
a calculation step of calculating a first stabilization time, which is a length of time required from when the pump is started in the first measurement operation step until the operation of the pump becomes stable, based on the first current value, and calculating a second stabilization time, which is a length of time required from when the pump is started in the second measurement operation step until the operation of the pump becomes stable, based on the second current value;
and a determination step of determining a state of the pump using the first stabilization time and the second stabilization time as criteria for determination. The method for diagnosing a pump according to claim 1, wherein in the determining step, the state of the pump is determined based on a ratio between the first stabilization time and the second stabilization time. The pump diagnosis method according to claim 2, wherein in the determination step, the sliding torque of the pump is calculated based on the rated rotation speed of the pump and the ratio between the first stabilization time and the second stabilization time, and the state of the pump is determined using the sliding torque as a further criterion. The relationship between the ratio of the first stabilization time to the second stabilization time and the rotational speed of the pump that is coasting when starting the pump in the second measurement operation step is determined in advance. It has been revealed that
In the determination step, when starting the pump in the second measurement operation step based on the ratio of the first stabilization time to the second stabilization time and the relationship that has been clarified in advance. 4. The method for diagnosing a pump according to claim 2, wherein the rotational speed of the inertial pump is calculated, and the state of the pump is determined using the rotational speed as further judgment material. a stopping step of stopping the supply of power to the pump during operation of the pump and coasting the pump for a predetermined period of time;
a measurement operation step of starting the pump while the pump is coasting and measuring a current value that is a value of a current flowing through the pump for a predetermined measurement period after the start of the pump;
a calculation step of calculating a stabilization time, which is a length of time required from when the pump is started in the measurement operation step until the operation of the pump becomes stable, based on the current value;
and a determination step of determining a state of the pump using the predetermined period and the stabilization time as criteria for determination. a door body capable of closing a flow path through which liquid flows;
a pump that is provided on the door body and is capable of urging the liquid from the upstream side to the downstream side of the flow path when the flow path is closed by the door body;
A method for diagnosing a pump gate, comprising: a drive device that can move the door body up and down;
a first measurement operation step of starting the pump in a state where the pump is stopped and measuring a first current value that is a value of the current flowing through the pump over a predetermined measurement period after the start;
a stopping step of stopping power supply to the pump while the pump is in operation, and causing the pump to coast for a predetermined period;
a second measurement operation step of starting the pump while the pump is inertial operation, and measuring a second current value that is the value of the current flowing through the pump over a predetermined measurement period after the start;
Based on the first current value, calculate a first stabilization time, which is the length of time required from starting the pump to stabilizing the operation of the pump in the first measurement operation step, and a calculation step of calculating a second stabilization time, which is the length of time required from starting the pump to stabilizing the operation of the pump in the second measuring operation step, based on the second current value; and,
a determination step of determining the state of the pump using the first stabilization time and the second stabilization time as determination materials,
A method for diagnosing a pump gate, wherein the first measurement operation step and the second measurement operation step are performed with the pump disposed above the liquid level. The present invention includes a measuring device capable of measuring a value of a current flowing through a pump, and a computing device,
The computing device includes:
a control function that controls the power supply to the pump so that a first power supply that supplies power to the pump when the pump is stopped, a power supply stop that stops the power supply to the pump, and a second power supply that supplies power to the pump when the pump is coasting are performed in this order;
a first measurement function of measuring and acquiring a first current value, which is a value of a current flowing through the pump, by the measurement device over a predetermined measurement period after starting the pump when the first power supply is performed;
a second measurement function of measuring and acquiring a second current value, which is a value of a current flowing through the pump, by the measurement device over a predetermined measurement period after starting the pump when the second power supply is performed;
a calculation function for calculating a first stabilization time, which is a length of time required from start-up of the pump when the first power supply is implemented until operation of the pump becomes stable, based on the first current value, and calculating a second stabilization time, which is a length of time required from start-up of the pump when the second power supply is implemented until operation of the pump becomes stable, based on the second current value;
a determination function for determining a state of the pump based on the first stabilization time and the second stabilization time;
A pump diagnostic device configured to be able to execute the above.

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