JP2018066380A - Driving device of self-priming pump, liquid supply device, and driving method of self-priming pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability in decision whether a self-priming pump is performing a self-priming operation or not in a simple configuration.SOLUTION: A driving device (inverter 30) of a self-priming pump of the invention comprises a current detector 32 for detecting the driving current of a variable speed motor variably rotating a westco pump 500. The inverter 30 also comprises a judgement part 33 for deciding whether the westco pump 500 is performing the self-priming operation or the normal operation other than the self-priming operation based on the driving current detected by the current detector 32. On the basis the driving current of the variable speed motor, the decision whether the westco pump 500 is performing the self-priming operation or not is made, so that the reliability in decision can be improved in a simple configuration.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a self-priming pump operating device, a liquid supply device, and a self-priming pump operating method.

  Conventionally, various types of pumps have been used to transfer liquids. Among these, self-priming pumps are known. A self-priming pump is a pump that discharges gas by operating the pump itself even when the pump or suction pipe is not filled with liquid because the gas is mixed in the pump or suction pipe. It is a pump that can perform.

  The self-priming pump sucks the gas-liquid mixture by rotating the impeller during the operation for discharging the gas mixed in the pump or the suction pipe (self-priming operation). And gas and liquid are separated in the gas-liquid separation chamber. Further, the self-priming pump gradually exhausts the mixed gas by repeating the operation of exhausting the separated gas to the outside and sucking the separated liquid again with the impeller during the self-priming operation. The self-priming action proceeds. The self-priming pump shifts to a normal operation when the self-priming operation ends by discharging the mixed gas. In normal operation, load operation is performed, and the self-priming pump is operated at a rotational speed controlled by constant discharge pressure control and estimated terminal pressure constant control.

  Here, it is known that the self-priming characteristic of the self-priming pump is greatly influenced by the peripheral speed of the impeller. That is, when the peripheral speed of the impeller is large, the self-priming time is short and good self-priming characteristics can be obtained, but when the peripheral speed is low, the self-priming time is long or self-priming is not possible. There is a tendency.

On the other hand, as described in Patent Document 1, in the conventional technique, when the discharge pressure value of the self-priming pump detected using a pressure sensor or the like is equal to or lower than a predetermined value, the self-priming action is in progress. There is known a method of detecting a certain thing and rotating the impeller during the self-priming operation at a speed larger than the rotational speed in the steady operation.

JP-A-4-203389

  However, the prior art does not consider improving the reliability of the determination of whether or not the self-priming pump is performing a self-priming operation with a simple configuration.

  That is, the prior art detects the discharge pressure of the self-priming pump using a pressure sensor or a pressure switch, and determines whether or not the self-priming pump is performing a self-priming operation based on the detected pressure. To do.

  On the other hand, the pressure sensor or the pressure switch is likely to have a problem relatively easily depending on the use environment, the use period, or the like, and an error may easily occur in the detected value. Although it is conceivable to install a highly reliable pressure sensor or pressure switch, the cost increases and the configuration becomes complicated.

  Then, this invention makes it a subject to improve the reliability of determination of whether the self-priming pump is performing self-priming operation with a simple structure.

  The self-priming pump operating device of the present invention has been made in view of the above problems, and is detected by a current detection unit that detects a drive current of an electric motor that rotates the self-priming pump at a variable speed, and is detected by the current detection unit. And a determination unit that determines whether the self-priming pump is performing a self-priming operation or a normal operation other than the self-priming operation based on the driven current.

  In addition, when it is determined by the determination unit that the self-priming pump is performing a self-priming operation, the motor is operated via the electric motor at a rotational speed higher than a rotational speed when the self-priming pump is normally operated. An operation command unit that rotationally drives the self-priming pump can be further provided.

  The determination unit has a first threshold value set in advance, and when the value of the drive current is smaller than the first threshold value, the self-priming pump performs a self-priming operation. When the value of the drive current is equal to or greater than the first threshold value, it can be determined that the self-priming pump is operating normally.

  The determination unit further includes a second threshold value set larger than the first threshold value, and when the value of the drive current is smaller than the first threshold value, Determining that the suction pump is performing a self-priming operation, and determining that the self-priming pump is performing the normal operation when the value of the drive current is equal to or greater than the second threshold; When the value of the driving current shifts from a state smaller than the first threshold value to a state equal to or larger than the first threshold value and smaller than the second threshold value, the self-priming pump It is determined that the self-priming operation is being performed, and the drive current value shifts from a state equal to or greater than the second threshold value to a state equal to or greater than the first threshold value and smaller than the second threshold value. In this case, it can be determined that the self-priming pump is performing the normal operation.

  The determination unit may perform the self-priming when the amplitude of the drive current becomes larger than a preset amplitude threshold value or when the amplitude cycle of the drive current becomes shorter than a preset cycle threshold value. It can be determined that the pump is performing a self-priming operation.

  Further, in the case of further comprising a temperature detection unit that detects the temperature of the self-priming pump, the determination unit is configured when the rate of change of the temperature of the self-priming pump is greater than a preset temperature threshold value. It can be determined that the self-priming pump is performing a self-priming operation.

  In addition, the determination unit shifts from the self-priming operation to the normal operation when the duration time during which the self-priming pump is determined to be performing the self-priming operation is longer than a preset time threshold value. Can output alarm signal

  Further, when the determination unit shifts from a state where it is determined that the self-priming pump is performing the normal operation to a state where it is determined that the self-priming pump is performing the self-priming operation, an alarm signal is generated. Can be output.

  Further, the determination unit can determine whether the self-priming pump is performing a self-priming operation or a normal operation other than the self-priming operation when the self-priming pump is started.

  The self-priming pump can be a centrifugal pump or a vortex pump.

Further, the fluid supply device of the present invention is a self-priming pump that is driven to rotate by an electric motor by any of the above self-priming pump operating devices and the self-priming pump operating device, and lifts and discharges liquid. And a pump.

  The self-priming pump operating method of the present invention detects a driving current of an electric motor that rotationally drives the self-priming pump at a variable speed, and the self-priming pump is automatically operated based on the detected driving current. It is determined whether the suction operation is performed or whether the normal operation other than the self-priming operation is performed.

  According to this invention of this application, the reliability of determination of whether the self-priming pump is performing self-priming operation can be improved with a simple configuration.

FIG. 1 is a diagram illustrating a configuration of a self-priming pump operating device (self-priming centrifugal pump) and a water supply device using the same according to the present embodiment. FIG. 2 is a diagram illustrating a self-priming pump operating device (vortex pump (Wesco pump)) and a water supply device using the same according to the present embodiment. Drawing 3 is a figure showing an example of use of a water supply apparatus of this embodiment. FIG. 4 is a diagram showing the relationship between the flow rate and current of the self-priming pump (vortex pump (Wesco pump)) and the relationship between frequency and current. FIG. 5 is a diagram illustrating an example of switching between the self-priming operation and the normal operation of the self-priming pump. FIG. 6 is a diagram showing an example of a processing flow by the self-priming pump operating device of the present embodiment. FIG. 7 is a diagram illustrating an example of a processing flow by the self-priming pump operating device of the present embodiment. FIG. 8 is a diagram illustrating another example of switching between the self-priming operation and the normal operation of the self-priming pump. FIG. 9 is a diagram illustrating another example of switching between the self-priming operation and the normal operation of the self-priming pump.

  Hereinafter, a self-priming pump operating device, a liquid supply device, and a self-priming pump operating method according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiments, an inverter will be described as an example of a variable speed operation device of a self-priming pump, and a water supply device will be described as an example of a liquid supply device, but this is not a limitation.

  FIG. 1 is a diagram illustrating a configuration of a self-priming pump operating device (self-priming centrifugal pump) and a water supply device using the same according to the present embodiment. FIG. 1 shows a schematic configuration of a self-priming centrifugal pump 1 as an example of a self-priming pump and a water supply apparatus using the self-priming centrifugal pump 1.

  The water supply apparatus 100 includes a self-priming centrifugal pump 1. As shown in FIG. 1, a self-priming centrifugal pump 1 is provided with a suction port 2 at one end (left side in the figure), and a suction chamber 3 communicated with the suction port 2 inside the self-priming centrifugal pump 1. Is separated from the pump chamber 8 by the partition wall 4. The pump chamber 8 includes an impeller 5, a diffuser 6 surrounding the impeller 5, and an air / water separation chamber 7 and the like at the upper portion.

A check valve (flap valve) 9 is provided above the suction chamber 3 so as to be separated from the suction port 2. Prior to the operation of the self-priming centrifugal pump 1, the check valve 9 secures water necessary for filling the inside of the pump to perform self-priming, and prevents back flow of water when the pump is stopped. Has the role of filling the interior.

  The impeller 5 is attached to the motor shaft 11 and obtains the rotational force generated by the variable speed motor 20. In the figure, 12 is a partition rod, 13 is a shaft seal device (mechanical seal), and 14 is a drain plug.

  When the self-priming centrifugal pump 1 is started, makeup water (priming water) is injected into the pump casing, and when the impeller 5 is rotated in a full state, the supplementary water in the suction chamber 3 is sucked from the inlet of the impeller 5. Rarely, it is discharged from the impeller 5 into the pump chamber 8. At this time, since the suction chamber 3 becomes negative pressure, the check valve 9 is opened, the air on the suction side is sucked from the suction port 2, and is discharged into the pump chamber 8 together with the air.

  The air / water mixture discharged into the pump chamber 8 is separated in the air / water separation chamber 7, and only water is returned into the diffuser 6 and enters the blades of the rotating impeller 5. Then, the air is newly discharged from the suction chamber 3 into the impeller 5 and is discharged again into the pump chamber 8. The air / water mixture is separated again in the air / water separation chamber 7, the air is discharged out of the discharge port 16, and the water is returned again into the impeller 5. The air is gradually exhausted to advance the self-priming action.

  As means for returning only the water separated in the steam-water separation chamber 7 into the blades of the impeller 5, for example, the diffuser is divided into two (one pair), and each impeller is surrounded so as to be almost symmetrical. There are ones arranged on the left and right, or ones in which the pump chamber 8 and the suction chamber 3 are communicated with each other through a circulation passage with a valve.

  The self-priming centrifugal pump 1 enters a normal operation through a self-priming operation after starting, but during the self-priming operation, air and water are mixed in the impeller and the apparent specific gravity of the fluid is small. Therefore, the shaft power during the self-priming operation is much smaller than that during the normal operation. Therefore, during the self-priming operation, the rotation speed can be increased as compared with the normal operation. The present embodiment has been made in view of this point, and details thereof will be described later. In the present specification, the self-priming operation is an operation performed in a state where gas is mixed in the self-priming centrifugal pump 1 or in the suction pipe, and the normal operation is an operation other than the self-priming operation, That is, the operation is performed in a state where gas is not mixed in the self-priming centrifugal pump 1 or the suction pipe and is filled with the liquid.

  In order to prevent the water in the discharge pipe 18 from flowing back into the self-priming centrifugal pump 1 between the discharge port 16 and the discharge pipe 18 or in the vicinity thereof, the self-priming centrifugal pump 1 A check valve 17 is arranged. Further, a pressure gauge 19 is installed on the downstream side of the check valve 17. The pressure gauge 19 detects the pressure in the discharge pipe 18, converts the detected value into a signal, and outputs the signal to the outside.

  Here, the water supply apparatus of this embodiment can be similarly applied not only to the above-described self-priming centrifugal pump 1 but also to a self-priming pump constituted by a vortex pump (Wesco pump). Hereinafter, the Wesco pump will be described.

  FIG. 2 is a diagram illustrating a self-priming pump operating device (vortex pump (Wesco pump)) and a water supply device using the same according to the present embodiment. As shown in FIG. 2, the water supply device 300 includes a Wesco pump 500. In the self-priming operation of the Westco pump 500, first, the priming water tap 512 is opened and priming water is supplied from the priming water port 514. As a result, as shown in FIG. 2, the inside of the casing 516 is filled up to the priming water level 518. At this time, since the flow switch 506 is closed by the weight of the float 504, water does not flow into the suction port 502.

  In this state, the operation of the Wesco pump 500 is started. Then, the water in the casing 516 is agitated by the rotation of the impeller 524 of the pump chamber 520, and at the same time, a negative pressure is generated on the suction port 502 side. The air in the suction pipe coming from the suction port 502 pushes up the float 504 and is sucked into the pump chamber 520. A mixed liquid of the sucked air and water in the casing 516 is discharged from the pump chamber 520.

  The discharged mixed liquid collides with a baffle 526 provided in the casing 516 and flows into the steam-water separation chamber 510. The air separated in the steam / water separation chamber 510 flows to the discharge port 522 side, and the water returns to the pump chamber 520 again through a hole below the steam / water separation chamber 510. In the pump chamber 520, negative pressure is generated on the suction port 502 side by water that always returns.

  When the air in the suction pipe is exhausted and the water rises, the function of the steam / water separation chamber 510 ends, and the discharge side (including the steam / water separation chamber 510) of the pump chamber 520 is filled with the discharge pressure. Then, the air completely disappears in the casing 516, and the pressure increases when the casing 516 is filled with water. This can be detected by the pressure sensor 508 (or pressure switch).

  As described above, the water supply device of this embodiment can be applied to both the self-priming centrifugal pump 1 and the Wesco pump 500. In the following description, the water supply apparatus 300 having the Wesco pump 500 will be described as a representative. First, the usage example of the water supply apparatus 300 which has the Wesco pump 500 is demonstrated. Drawing 3 is a figure showing an example of use of a water supply apparatus of this embodiment.

  As shown in FIG. 3, a suction pipe 15 installed so that one end is buried in a water storage such as a well is connected to the suction port 502 of the Wesco pump 500 in the water supply apparatus 300 of the present embodiment. . A strainer 105 for removing foreign matter in the water storage is provided at the end of the suction pipe 15. Further, the discharge port 522 of the Wesco pump 500 is connected to a discharge pipe whose one end is connected to a customer side pipe (for example, the faucet 220).

  Returning to the description of FIG. 2, the configuration of the water supply apparatus 300 will be described. The water supply device 300 includes an inverter 30 and a water supply device controller 40 described below, but these configurations are the same as those of the water supply device 100 of FIG. I do. The water supply apparatus 300 includes an inverter 30 (self-priming pump operating apparatus) that converts electric power into an arbitrary voltage / an arbitrary frequency. A variable speed electric motor (motor) (not shown) is connected to the impeller 524. The variable speed electric motor receives electric power from the external commercial power source 200, obtains electric power from the inverter 30 through the electric power cable 36, and Acts as a power source.

  Further, the inverter 30 is an operation state signal (frequency value, pressure value, flow rate, temperature, voltage value, current value, etc. signal indicating the operation state of the device sent from the water supply controller 40 via the operation signal line 46. ), An inverter control unit 31 that performs voltage and frequency control and various calculations is included. Further, the inverter 30 includes a current detector (current detection unit) 32 that is used when determining whether or not the self-priming operation is being performed. The current detector 32 may use the output of the current sensor when the inverter 30 uses a current sensor or the like for control.

Further, based on the drive current detected by the current detector 32, the inverter 30 determines whether the Wesco pump 500 is performing a self-priming operation or a normal operation other than the self-priming operation. Have Furthermore, when the inverter 30 determines that the self-priming centrifugal pump 1 is performing the self-priming operation by the storage device 34 that stores various data of the criteria for determining whether or not self-priming operation is necessary, and the determination unit 33. The operation command unit 35 is configured to rotationally drive the Wesco pump 500 via the variable speed electric motor 20 at a rotational speed higher than the rotational speed when the Wesco pump 500 is normally operated.

  Further, the water supply device 300 includes a water supply device controller 40. The water supply controller 40 receives a signal from the pressure gauge 19 via the pressure signal line 47, and performs calculation processing in the water supply controller 44 according to the operation program stored in the storage device 45 in advance based on this signal. The result is output to the inverter 30 via the operation signal line 46. The operation program is a program necessary for operating as a water supply device, and examples of the operation method of the water supply device, that is, the control method include discharge pressure constant control and estimated terminal pressure constant control. In normal operation, load operation is performed, and the self-priming pump is operated at a rotational speed controlled by constant discharge pressure control and estimated terminal pressure constant control.

  The calculation result by the water supply device control unit 44 can be notified to the outside using the display 41, the alarm device 42, the external output terminal 43, and the like. The communication on the operation signal line 46 is not only from the output from the water supply controller 40 to the inverter 30, but also from the inverter 30 in order to enable the water supply controller 40 to grasp the abnormality of the inverter 30 such as overcurrent. Bidirectional communication is also possible to transmit signals to the water supply controller 40.

  For example, during the self-priming operation after the start of operation of the Wesco pump 500, the impeller 524 is in a mixed state of air and water, and the apparent specific gravity of the fluid is small, so that it is driven via the motor shaft of the variable speed motor. The shaft power of the impeller 524 is much smaller than that in steady operation. Therefore, the operating current of the variable speed motor is much smaller than that during steady operation.

  Therefore, in this embodiment, for example, when the operation of the Wesco pump 500 is started, the determination unit 33 compares the value of the current detector 32 with the current value stored in the storage device 34 and determines whether or not the self-priming operation is necessary. When it is determined that the self-priming operation is necessary, the self-priming operation is performed at the maximum rotational speed of the Wesco pump 500 after the start. Here, the maximum rotation speed of the Wesco pump 500 is a method of controlling the rotation speed of the Wesco pump 500 so that the driving current of the Wesco pump 500 is a predetermined value or less, and the maximum mechanically allowable value of the Wesco pump 500. The rotational speed is controlled in combination with a method for controlling the rotational speed of the Wesco pump 500 so as to be equal to or lower than the rotational speed. Moreover, it can also be set as the rotational speed in the load similar to the load at the time of normal driving | operation. The determination unit 33 determines whether or not the self-priming operation is necessary. When it is determined that the self-priming operation is not necessary, the self-priming operation is completed (completed), and the rotation speed of the Wesco pump 500 is set to the rotation speed during normal operation. It is designed to automatically lower.

  According to the present embodiment, during the self-priming operation as described above, by increasing the rotational speed of the impeller 524 and increasing the peripheral speed of the impeller 524, the self-priming action is promoted and good self-priming characteristics are obtained. That is, a large self-priming height and a short self-priming time can be obtained.

  In addition, since a variable speed electric motor is used in the present embodiment, after the self-priming action is completed, the optimum head and water amount are adjusted according to the use state (environmental conditions) even after the Wesco pump 500 enters normal operation. By changing the rotation speed so as to control the pressure and the flow rate, it is possible to achieve a wasteful energy saving effect.

The rotation speed of the impeller 524 is switched by detecting the operating current of the variable speed motor with the current detector 32 provided in the inverter 30. More specifically, according to the size of the impeller 524 and the output of the variable speed motor, the relationship between the operating voltage and / or frequency and the operating current is stored as table data in the storage device 34 in advance. When the Wesco pump 500 starts to start, the determination unit 33 compares the operating current value at the operating voltage and / or frequency with the operating current value of the table data stored in advance, and determines the operating current during operation. When the value is smaller, it is determined that the air and water are mixed, and a signal for performing the self-priming operation is output to the inverter control unit 31.

  When the Wesco pump 500 starts to start, the determination unit 33 compares the value of the operating current at the operating voltage and / or frequency with the operating current value of the table data stored in advance, and determines the operating current during operation. When the value is larger or when the value is changed from a smaller value to a larger value, it is determined that the current state is normal, and a signal for performing a normal pump operation is output to the inverter control unit 31.

  Next, control from when the Wesco pump 500 is in a normal state will be described. In this case, the determination unit 33 compares the operating current values of the table data stored in advance, and when the operating current value during operation changes from a large value to a small value, the mixed state of air and water It is determined that there is, and a signal for starting the self-priming operation is output to the inverter control unit 31.

  By configuring in this way, during the steady operation of the Wesco pump 500, when a situation (phenomenon) in which a large amount of air is sucked and the pumping action is temporarily interrupted and the self-priming action is required again occurs, Since the suction operation is started and the rotational speed of the impeller is increased, the self-priming time is shortened, and the pump operation in the steady state is quickly resumed.

  The operating device of the Wesco pump 500 of this embodiment will be described in further detail. FIG. 4 is a diagram illustrating the relationship between the flow rate and current of the self-priming pump and the relationship between frequency and current.

  In the left diagram of FIG. 4, the horizontal axis indicates the discharge flow rate of the Wesco pump 500, and the vertical axis indicates the drive current of the variable speed motor. In the right diagram of FIG. 4, the horizontal axis represents the frequency of the Wesco pump 500, and the vertical axis represents the drive current of the variable speed motor.

  The left diagram of FIG. 4 shows the relationship between the discharge flow rate of the Wesco pump 500 and the drive current of the variable speed electric motor for each rotational speed of the Wesco pump 500. For example, the curve 302 shows the relationship between the discharge flow rate and the drive current when the rotation speed is the normal operation speed or the rated operation speed, and the curve 304 shows the discharge flow rate and the drive current when the rotation speed is the maximum rotation speed. Shows the relationship.

  As shown in FIG. 4, the Westco pump 500 tends to have a drive current that decreases as the flow rate increases. Further, the driving current of the Wesco pump 500 increases as the rotational speed increases.

  In this embodiment, the value of the drive current when the Wesco pump 500 is operated at the rated frequency and the maximum flow rate is set as the second threshold value. A value smaller than the second threshold value is set as the first threshold value.

  As shown in the right diagram of FIG. 4, the relationship between the frequency and the drive current when the Wesco pump 500 is cut off is as shown by a curve 306, and the relationship between the frequency and the drive current when the Wesco pump 500 is operated at the maximum flow rate. Becomes a curve 308. On the other hand, when it is determined that the Wesco pump 500 is performing a self-priming operation, first, as shown by a curve 310, the frequency (rotational speed) of the Wesco pump 500 is increased to the maximum rotational speed. Then, the drive current of the variable speed motor gradually increases with the progress of the self-priming action by the self-priming operation, and becomes equal to or higher than the second threshold value. Then, it is determined that the self-priming operation has been completed, and the Wesco pump 500 is determined to have shifted from the self-priming operation to the normal operation, and the frequency of the Wesco pump 500 is reduced to the frequency during normal operation.

Next, the mode of switching determination between the self-priming operation and the normal operation of the self-priming pump will be described. FIG. 5 is a diagram showing the relationship between the threshold value and the switching (transition) between the self-priming operation and the normal operation of the self-priming pump. In FIG. 5, the horizontal axis indicates the passage of time, and the vertical axis indicates the drive current of the variable speed motor. In FIG. 5, characteristic lines 402 and 406 indicate a state in which the Wesco pump 500 is performing a self-priming operation, and a characteristic line 404 indicates a state in which the Wesco pump 500 is performing a normal operation.

  First, the determination unit 33 determines that the Wesco pump 500 is performing a self-priming operation when the value of the drive current of the variable speed motor is smaller than the first threshold value. That is, as illustrated in FIG. 5, the determination unit 33 determines that the variable speed motor drive current value is smaller than the first threshold value in the characteristic line 402 and the variable speed motor When the value of the drive current is smaller than the first threshold value, it is determined that the Wesco pump 500 is performing a self-priming operation.

  The determination unit 33 determines that the Wesco pump 500 is operating normally when the value of the drive current of the variable speed electric motor is equal to or greater than the second threshold value. That is, as shown in FIG. 5, when the value of the drive current of the variable speed electric motor is greater than or equal to the second threshold value in the characteristic line 404, the determination unit 33 performs normal operation of the Wesco pump 500. It is determined that

  Further, when the value of the drive current of the variable speed motor is equal to or larger than the first threshold value and smaller than the second threshold value, the determination unit 33 determines whether the current driving state has been reached. That is, when the determination unit 33 shifts from the state where the drive current of the variable speed motor is smaller than the first threshold value to a state where the value is equal to or larger than the first threshold value and smaller than the second threshold value, It is determined that the Wesco pump 500 is performing a self-priming operation. This shows a case where the value of the drive current of the variable speed motor is greater than or equal to the first threshold value and smaller than the second threshold value among the characteristic lines 402 in FIG.

  On the other hand, when the determination unit 33 shifts from the state in which the drive current of the variable speed motor is equal to or greater than the second threshold value to a state that is equal to or greater than the first threshold value and smaller than the second threshold value, It is determined that the Wesco pump 500 is operating normally. This indicates a case where the value of the drive current of the variable speed motor is greater than or equal to the first threshold value and smaller than the second threshold value among the characteristic lines 406 in FIG.

  In the above example, by providing the first threshold value and the second threshold value, the switching between the self-priming operation and the normal operation is frequently performed by hunting the value of the driving current of the variable speed motor. This is not limited to this. For example, the determination unit 33 can set only one threshold value (for example, the first threshold value). In this case, the determination unit 33 determines that the Wesco pump 500 is performing a self-priming operation when the value of the drive current of the variable speed motor is smaller than the first threshold value, and the value of the drive current is the first value. If it is equal to or greater than the threshold value, it can be determined that the Wesco pump 500 is operating normally.

  Next, a processing flow when only one threshold is set will be described. FIG. 6 is a diagram showing an example of a processing flow by the self-priming pump operating device of the present embodiment.

  First, the switch of the water supply apparatus controller 40 is turned ON (step S101).

  When the switch of water supply device controller 40 is turned on, inverter control unit 31 starts operation of Wesco pump 500 at the rotation speed during normal operation (step S102).

  Subsequently, the determination unit 33 determines whether or not a predetermined time has elapsed from the start of operation (step S103). The determination part 33 repeats the process of step S103, when predetermined time has not passed since the driving | operation start (step S103, No).

On the other hand, when a predetermined time has elapsed from the start of operation, the determination unit 33 (step S103, Ye
s), it is determined whether or not the drive current value of the variable speed electric motor driving the Wesco pump 500 (current value detected by the current detector 32) ≧ current threshold value (step S104).

  If it is determined that the driving current value of the variable speed motor ≧ the current threshold value (Yes in step S104), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (step S105). This means that because the determination unit 33 determines that the Wesco pump 500 is performing normal operation, the Wesco pump 500 is rotationally driven at the rotation speed during normal operation.

  On the other hand, when it is determined that the driving current value of the variable speed motor is not greater than the current threshold value (No in step S104), the operation command unit 35 increases the rotational speed of the Wesco pump 500 (step S106). In other words, the Wesco pump 500 is operated at a rotational speed for self-priming operation. This means that since the determination unit 33 determines that the Wesco pump 500 is performing a self-priming operation, the Wesco pump 500 is driven to rotate at a high rotational speed accordingly. The operation command unit 35 can rotationally drive the Wesco pump 500 at the maximum rotation speed of the Wesco pump 500, for example.

  After driving the Wesco pump 500 at a high rotational speed in step S106, the determination unit 33 determines whether or not the driving current value of the variable speed motor ≧ the current threshold value (step S107).

  If it is determined that the driving current value of the variable speed motor ≧ the current threshold value (Yes in step S107), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (step S105). This means that since the determination unit 33 determines that the Wesco pump 500 has shifted from the self-priming operation to the normal operation, the Wesco pump 500 is returned from the high rotation speed to the low rotation speed during the normal operation.

  On the other hand, when the determination unit 33 determines that the driving current value of the variable speed motor is not equal to or greater than the current threshold (No in step S107), the discharge side pressure of the Wesco pump 500 (pressure detected by the pressure sensor 508) ≧ It is determined whether it is a pressure threshold value (step S108).

  If it is determined that the discharge side pressure of the Wesco pump 500 is equal to or greater than the pressure threshold (Yes in Step S108), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (Step S105). . This is because when the discharge side pressure of the Wesco pump 500 is increased to some extent, it can be assumed that the Wesco pump 500 has shifted from the self-priming operation to the normal operation. It means to return to a low rotation speed.

  On the other hand, if the determination unit 33 determines that the discharge side pressure of the Wesco pump 500 is not equal to or greater than the pressure threshold value (No in step S108), has a predetermined time or more elapsed since the rotation speed is increased in step S106? It is determined whether or not (step S109).

  When it is determined that the predetermined time or more has elapsed (step S109, Yes), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (step S105). This is because if the self-priming operation time continues to some extent, it can be assumed that the Wesco pump 500 has shifted from the self-priming operation to the normal operation. Therefore, the Wesco pump 500 is changed from a high rotation speed to a low rotation speed during normal operation. It is to return. By controlling in this way, it is possible to protect when self-priming is not completed for some reason.

On the other hand, when the determination unit 33 determines that the predetermined time or more has not elapsed (step S109).
, No), the process returns to step S107 and is repeated.

  The determination unit 33 determines whether or not the switch of the water supply controller 40 is turned off after operating the Wesco pump 500 at the rotation speed at the time of normal operation in Step S105 (Step S110). If it determines with the switch of the water supply apparatus controller 40 having been turned off (step S110, Yes), a process will be complete | finished, On the other hand, if it determines with the switch of the water supply apparatus controller 40 not being turned off (step S110, No), it will progress to step S104. Return and repeat the process.

  According to this embodiment, the driving current of the Wesco pump 500 is detected, and whether the Wesco pump 500 is performing a self-priming operation or a normal operation other than the self-priming operation based on the detected driving current. Can be determined. Thereby, since it is not necessary to determine the self-priming operation and the normal operation using a pressure sensor or a pressure switch as in the prior art, the reliability of the determination as to whether or not the Wesco pump 500 is performing the self-priming operation. Can be improved with a simple configuration.

  In the above example, the inverter 30 is used to rotationally drive the Wesco pump 500 at a variable speed. However, the present invention is not limited to this. For example, it is also possible to drive the Wesco pump 500 by a constant speed electric motor via a transmission, and to increase the rotation speed during the self-priming operation than during the normal operation.

  Moreover, although the example which provided the determination part 33 and the operation command part 35 in the inverter 30 was shown in said example, it is not restricted to this, For example, it can also provide in the water supply apparatus controller 40. Moreover, the water supply apparatus 300 may store the Wesco pump 500, the variable speed electric motor, the inverter 30, and the water supply apparatus controller 40 in one housing. Furthermore, the variable speed motor and the inverter 30 may be integrated, or the inverter 30 and the water supply device controller 40 may be integrated. In addition, each functional block in the inverter 30 and each functional block of the water supply device controller 40 may be integrated into one substrate or one CPU. In the above example, an example is shown in which power is supplied from the commercial power supply 200 to both the inverter 30 and the water supply controller 40. However, the present invention is not limited thereto, and for example, power is supplied from the commercial power supply 200 only to the inverter 30. It is also possible to supply power from the inverter 30 to the water supply controller 40.

  In the above example, the determination between the self-priming operation and the normal operation when the Wesco pump 500 is started has been mainly described. However, the present invention is not limited to this. For example, due to leakage at a pipe connection portion of the Wesco pump 500, the inside of the Wesco pump 500 may remain in a mixed state of air and water, and the self-priming operation may be continued. In order to avoid this self-priming operation continuation state, the determination unit 33 goes to the outside when the duration time determined that the Wesco pump 500 is performing the self-priming operation becomes longer than a preset time threshold value. An alarm signal can be output. Specifically, the determination unit 33 can output from the alarm device 42 that the self-priming operation has continued for a long time.

  In addition, when the continuation time determined that the Wesco pump 500 is performing the self-priming operation becomes longer than a preset time threshold, the operation command unit 35 stops the self-priming operation, and the Wesco pump 500 can be stopped. The above time threshold value can be given to the operation command unit 35 with an input / setting function or can be arbitrarily set through the water supply controller 40. The determination unit 33 also performs the same operation as described above even when the state is determined to be that the Wesco pump 500 is performing a normal operation from the state in which the Wesco pump 500 is determined to be performing a normal operation. An alarm signal can be output to the outside.

In the above example, the determination between the self-priming operation and the normal operation when the Westco pump 500 is started has been mainly described. However, the same operation can be performed when the Westco pump 500 is started from a small water amount stop. This point will be described with reference to FIG.

  FIG. 7 is a diagram illustrating an example of a processing flow by the self-priming pump operating device of the present embodiment. First, when the Wesco pump 500 stops a small amount of water (step S201), the determination unit 33 determines whether a start condition from the stop of the small amount of water is satisfied (step S202). Step S202 is repeated until the start condition from the small water amount stop is satisfied.

  On the other hand, when the start condition from the stop of the small water amount is satisfied (step S202, Yes), the inverter control unit 31 starts the operation of the Wesco pump 500 at the rotation speed during the normal operation (step S203).

  Subsequently, the determination unit 33 determines whether or not a predetermined time has elapsed from the start of operation (step S204). The determination part 33 repeats the process of step S204, when predetermined time has not passed since the driving | operation start (step S204, No).

  On the other hand, when a predetermined time has elapsed from the start of operation (Yes in step S204), the determination unit 33 drives the current value of the variable speed motor that drives the Wesco pump 500 (current value detected by the current detector 32) ≧ current. It is determined whether it is a threshold value (step S205).

  If it is determined that the driving current value of the variable speed motor ≧ the current threshold value (Yes in step S205), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (step S206). This means that because the determination unit 33 determines that the Wesco pump 500 is performing normal operation, the Wesco pump 500 is rotationally driven at the rotation speed during normal operation.

  On the other hand, if it is determined that the drive current value of the variable speed motor is not greater than the current threshold value (No in step S205), the operation command unit 35 increases the rotational speed of the Wesco pump 500 (step S207). In other words, the Wesco pump 500 is operated at a rotational speed for self-priming operation. This means that since the determination unit 33 determines that the Wesco pump 500 is performing a self-priming operation, the Wesco pump 500 is driven to rotate at a high rotational speed accordingly. The operation command unit 35 can rotationally drive the Wesco pump 500 at the maximum rotation speed of the Wesco pump 500, for example.

  After driving the Wesco pump 500 at a high rotational speed in step S207, the determination unit 33 determines whether or not the driving current value of the variable speed electric motor ≥ current threshold value (step S208).

  If it is determined that the driving current value of the variable speed motor ≧ the current threshold value (Yes in step S208), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (step S206). This means that since the determination unit 33 determines that the Wesco pump 500 has shifted from the self-priming operation to the normal operation, the Wesco pump 500 is returned from the high rotation speed to the low rotation speed during the normal operation.

  On the other hand, when the determination unit 33 determines that the driving current value of the variable speed motor is not equal to or greater than the current threshold value (No in step S208), the discharge side pressure of the Wesco pump 500 (pressure detected by the pressure sensor 508). It is determined whether or not ≧ pressure threshold value (step S209).

If it is determined that the discharge side pressure of the Wesco pump 500 is equal to or greater than the pressure threshold (Yes in Step S209), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (Step S206). . This is because when the discharge side pressure of the Wesco pump 500 is increased to some extent, it can be assumed that the Wesco pump 500 has shifted from the self-priming operation to the normal operation. It means to return to a low rotation speed.

  On the other hand, when it is determined that the discharge side pressure of the Wesco pump 500 is not equal to or higher than the pressure threshold value (No at Step S209), the determination unit 33 has elapsed a predetermined time or more after increasing the rotation speed at Step S207. It is determined whether or not (step S210).

  If it is determined that the predetermined time or more has elapsed (step S210, Yes), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (step S206). This is because if the self-priming operation time continues to some extent, it can be assumed that the Wesco pump 500 has shifted from the self-priming operation to the normal operation. Therefore, the Wesco pump 500 is changed from a high rotation speed to a low rotation speed during normal operation. It is to return.

  On the other hand, when determining that the predetermined time or more has not elapsed (No at Step S210), the determining unit 33 returns to Step S208 and repeats the process.

  The determination unit 33 determines whether or not the operation of the Wesco pump 500 is completed after the operation of the Wesco pump 500 is performed at the rotation speed during the normal operation in Step S206 (Step S211). If it is determined that the operation of the Wesco pump 500 has not ended (No at Step S211), the determination unit 33 returns to Step S205 and repeats the process.

  On the other hand, when determining that the operation of the Wesco pump 500 has ended, the determination unit 33 determines whether or not the switch of the water supply controller 40 is turned off (step S212). If it determines with the switch of the water supply apparatus controller 40 having been turned off (step S212, Yes), the determination part 33 will complete | finish a process, on the other hand, if it determines with the switch of the water supply apparatus controller 40 not being turned off (step S212, No) ), Returning to step S201, the process is repeated.

  According to this embodiment, the driving current of the Wesco pump 500 is detected, and whether the Wesco pump 500 is performing a self-priming operation or a normal operation other than the self-priming operation based on the detected driving current. Can be determined. Thereby, since it is not necessary to determine the self-priming operation and the normal operation using a pressure sensor or a pressure switch as in the prior art, the reliability of the determination as to whether or not the Wesco pump 500 is performing the self-priming operation. Can be improved with a simple configuration.

  When the self-priming pump is not the Westco pump 500 but the self-priming centrifugal pump 1, the relationship between the discharge flow rate and the drive current value is the same as that in the case of the Wesco pump 500 until the normal operation is reached. When the normal operation is reached, in the self-priming centrifugal pump 1, unlike the Wesco pump 500, the drive current value increases as the discharge flow rate increases.

  In the above example, the determination unit 33 determines whether the Wesco pump 500 is performing a self-priming operation or a normal operation based on the comparison result between the value of the driving current of the variable speed motor and the threshold value. Although the example which determines this is shown, it is not restricted to this.

  FIG. 8 is a diagram illustrating another example of switching between the self-priming operation and the normal operation of the self-priming pump. In FIG. 8, the horizontal axis indicates the passage of time, and the vertical axis indicates the drive current of the variable speed motor. FIG. 8 is a diagram schematically showing the drive current of the variable speed motor when the Wesco pump 500 shifts from the self-priming operation to the normal operation.

  As shown in FIG. 8, during the self-priming operation, since the air and water are mixed in the impeller 524, the amplitude (α) of the drive current of the variable speed motor is set to the normal operation. There is a tendency to change greatly compared to the case where it is conducted. Therefore, the determination unit 33 can determine that the Wesco pump 500 is performing a self-priming operation when the amplitude (α) of the drive current of the variable speed motor becomes larger than a preset amplitude threshold value.

  Further, as shown in FIG. 8, when the self-priming operation is performed, since the air and water are mixed in the impeller 524, the amplitude cycle (β) of the drive current of the variable speed motor is It tends to be shorter than when performing normal operation. Therefore, the determination unit 33 can determine that the Wesco pump 500 is performing a self-priming operation when the amplitude period (β) of the drive current of the variable speed motor becomes shorter than a preset period threshold value. . The determination of the self-priming operation based on the amplitude period (β) of the drive current can be performed instead of the determination based on the drive current value. Furthermore, by determining the self-priming operation based on the drive current value of the variable speed motor and its vibration cycle (β), even if the absolute value of the drive current value is small and difficult to determine, the vibration cycle (β) is detected. Since it is possible, the reliability of determination is further improved. The processing after it is determined that the Wesco pump 500 is performing the self-priming operation is the same as described above.

  FIG. 9 is a diagram illustrating another example of switching between the self-priming operation and the normal operation of the self-priming pump. In FIG. 9, the horizontal axis indicates the passage of time, and the vertical axis indicates the temperature of the Wesco pump 500. FIG. 9 is a diagram schematically showing the temperature of the Wesco pump 500 when the Wesco pump 500 shifts from the self-priming operation to the normal operation.

  As shown in FIG. 9, after the self-priming operation is completed and the normal operation is started, the casing of the Wesco pump 500 is sufficiently filled with a liquid such as well water. It can be suppressed. On the other hand, when the self-priming operation is performed, since the air and water are mixed in the impeller 524 and the temperature of the air and water is often different, the temperature change of the Wesco pump 500 is changed. Will grow. Therefore, the determination unit 33 can determine that the Wesco pump 500 is performing a self-priming operation when the rate of change of the temperature of the Wesco pump 500 is greater than a preset temperature threshold value. The determination of the self-priming operation based on the temperature can be performed instead of the determination based on the drive current value. Furthermore, even when the absolute value of the drive current value is small and difficult to determine by determining the self-priming operation based on the drive current value of the variable speed motor and the temperature in the outer surface of the casing or the liquid flow path. The reliability of determination is further improved by detecting the temperature. The processing after it is determined that the Wesco pump 500 is performing the self-priming operation is the same as described above.

DESCRIPTION OF SYMBOLS 1 Self-priming centrifugal pump 19 Pressure gauge 20 Variable speed motor 30 Inverter 32 Current detector 33 Judgment part 35 Operation command part 40 Water supply apparatus controller 42 Alarm 100 Water supply apparatus 500 Wesco pump 508 Pressure sensor

Claims (12)

A current detection unit that detects a drive current of an electric motor that rotationally drives the self-priming pump at a variable speed;
A determination unit that determines whether the self-priming pump is performing a self-priming operation or a normal operation other than the self-priming operation based on the drive current detected by the current detection unit;
A device for operating a self-priming pump, comprising: In the operation device of the self-priming pump according to claim 1,
If it is determined by the determination unit that the self-priming pump is performing a self-priming operation, the self-priming pump is operated via the electric motor at a rotational speed higher than the rotational speed at which the self-priming pump is normally operated. An operation command unit that rotationally drives the suction pump,
An operation device for a self-priming pump, further comprising: In the operation device of the self-priming pump according to claim 1 or 2,
The determination unit has a preset first threshold value, and the self-priming pump performs a self-priming operation when the value of the drive current is smaller than the first threshold value. And when the value of the drive current is equal to or greater than the first threshold value, it is determined that the self-priming pump is performing the normal operation.
A self-priming pump operating device. In the operation device of the self-priming pump according to any one of claims 1 to 3,
The determination unit further includes a first threshold value set in advance and a second threshold value set larger than the first threshold value, and the value of the drive current is the first threshold value. If it is smaller than the threshold value, it is determined that the self-priming pump is performing a self-priming operation,
When the value of the drive current is equal to or greater than the second threshold value, it is determined that the self-priming pump is performing the normal operation,
When the value of the driving current shifts from a state smaller than the first threshold value to a state equal to or larger than the first threshold value and smaller than the second threshold value, the self-priming pump Determine that you are in self-priming,
When the value of the drive current shifts from a state equal to or greater than the second threshold value to a state equal to or greater than the first threshold value and smaller than the second threshold value, the self-priming pump It is determined that the normal operation is performed.
A self-priming pump operating device. In the operation device of the self-priming pump according to any one of claims 1 to 4,
When the amplitude of the drive current becomes larger than a preset amplitude threshold value or the amplitude cycle of the drive current becomes shorter than a preset cycle threshold value, the determination unit Is determined to be self-priming,
A self-priming pump operating device. In the operation device of the self-priming pump according to any one of claims 1 to 5,
A temperature detection unit for detecting the temperature of the self-priming pump;
The determination unit determines that the self-priming pump is performing a self-priming operation when a rate of change in temperature of the self-priming pump is greater than a preset temperature threshold value. Self-priming pump operating device. In the operation device of the self-priming pump according to any one of claims 1 to 6,
The determination unit outputs an alarm signal when a duration time determined that the self-priming pump is performing a self-priming operation becomes longer than a preset time threshold value. Operation device for suction pump. In the operation device of the self-priming pump according to claim 7,
The determination unit outputs an alarm signal when a transition is made from a state where it is determined that the self-priming pump is performing the normal operation to a state where it is determined that the self-priming pump is performing the self-priming operation. A self-priming pump operating device. In the operation device of the self-priming pump according to any one of claims 1 to 8,
The determination unit determines whether the self-priming pump is performing a self-priming operation or a normal operation other than the self-priming operation when starting the self-priming pump. Type pump operating device. In the operation device of the self-priming pump according to any one of claims 1 to 9,
The self-priming pump is a centrifugal pump or a vortex pump,
A self-priming pump operating device. The operation device of the self-priming pump according to any one of claims 1 to 10,
A self-priming pump that is rotationally driven via an electric motor by the operation device of the self-priming pump and pumps up and discharges a liquid;
A liquid supply apparatus comprising: Detecting the drive current of the motor that rotates the self-priming pump at a variable speed,
Based on the detected drive current, it is determined whether the self-priming pump is performing a self-priming operation or a normal operation other than the self-priming operation.
An operation method of a self-priming pump characterized by the above.

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