JP2019086004A - Driving device of self-priming pump, liquid supply device, and driving method of self-priming pump - Google Patents

Abstract

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 an operating device for a self-priming pump, a liquid supply device, and an operating method for a self-priming pump.

  In the past, various types of pumps have been used to transfer liquid, and among these self-priming pumps are known. Self-priming pump is a pump that discharges gas by operation of the pump itself even if the inside of the pump or suction piping is not filled with liquid due to the gas mixing inside the pump or in the suction piping. It is a pump that can do

  The self-priming type pump sucks the gas-liquid mixture by rotating the impeller during the operation (self-priming operation) for discharging the gas mixed in the inside of the pump or in the suction pipe, and the gas-liquid separation chamber To separate gas and liquid in the gas-liquid separation chamber. In the self-priming pump, in the self-priming operation, the mixed gas is gradually exhausted by repeatedly discharging the separated gas to the outside and sucking the separated liquid again by the impeller. Promote self-priming action. The self-priming pump shifts to the normal operation when the self-priming operation is finished 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 discharge pressure constant 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 high, the self-priming time is short and good self-priming characteristics are obtained, but when the peripheral speed is low, the self-priming time is long or self-priming can not be performed. There is a tendency.

On the other hand, as described in Patent Document 1, in the prior art, the self-priming action is being performed when the discharge pressure value of the self-priming pump detected using a pressure sensor or the like is equal to or less than a predetermined value. There is known a method of detecting an occurrence and rotating an impeller in self-priming operation at a speed higher than the rotational speed in steady operation.

JP-A-4-203389

  However, in the prior art, it is not considered to improve the reliability of the determination as to whether or not the self-priming pump is performing 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 the self-priming pump is performing self-priming operation based on the detected pressure. It is

  On the other hand, the pressure sensor or the pressure switch is relatively likely to cause a problem depending on the use environment, the use period, and the like, and an error may easily occur in the detected value. In addition, although it is conceivable to install a highly reliable pressure sensor or pressure switch, the cost is increased and the configuration is also complicated.

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

  The driving apparatus for a self-priming pump according to the present invention is made in view of the above problems, and is detected by a current detection unit that detects a driving current of a motor that rotationally drives the self-priming pump at variable speeds, and 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 drive current.

  In addition, when it is determined by the determination unit that the self-priming pump is performing self-priming operation, the rotational speed at which the self-priming pump normally operates is higher than the rotational speed at the time of normal operation via the electric motor. The system may further include an operation command unit that rotationally drives the self-priming pump.

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

  Further, the determination unit further includes a second threshold set larger than the first threshold, and when the value of the drive current is smaller than the first threshold, It is determined that the suction pump is performing the self suction operation, and when the value of the drive current is equal to or more than the second threshold value, it is determined that the self suction pump is performing the normal operation. When the value of the drive current is shifted from a state smaller than the first threshold to a state larger than the first threshold and smaller than the second threshold, the self-priming pump It is determined that the self-priming operation is performed, and the value of the drive current is changed from the state of the second threshold or more to the state of the first threshold and the second threshold. In this case, it can be determined that the self-priming pump is in the normal operation.

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

  When the temperature detection unit for detecting the temperature of the self-priming pump is further provided, the determination unit determines that the rate of change of the temperature of the self-priming pump is larger than a preset temperature threshold. It can be determined that the self-priming pump is performing self-priming operation.

  In addition, the determination unit shifts from the self-priming operation to the normal operation when the duration time determined that the self-priming pump is performing the self-priming operation is longer than a time threshold set in advance. Can output an alarm signal

  In addition, when the determination unit transitions to a state where it is determined that the self-priming pump is performing self-priming operation from a state where it is determined that the self-priming pump is performing the normal operation, an alarm signal 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.

  Also, the self-priming pump can be a centrifugal pump or an eddy current pump.

Further, the fluid supply device of the present invention is a self-priming type that is driven to rotate via an electric motor by the driver of the self-priming pump according to any of the above and the driver of the self-priming pump. And a pump.

  In the method of operating a self-priming pump according to the present invention, a driving current of an electric motor that rotationally drives the self-priming pump at variable speed is detected, and the self-priming pump is self-priming based on the detected driving current. It is characterized in that it is determined whether the suction operation is being performed or the normal operation other than the self-priming operation is being performed.

  According to the present invention, it is possible to improve the reliability of the determination as to whether or not the self-priming pump is performing the self-priming operation with a simple configuration.

FIG. 1 is a view showing a configuration of a driving device for a self-priming pump (self-priming centrifugal pump) of the present embodiment and a water supply device using the same. FIG. 2 is a view showing an operation device (vortex pump (Wesco pump)) of the self-priming pump of the present embodiment and a water supply device using the same. FIG. 3: is a figure which shows the usage example of the water supply apparatus of this embodiment. FIG. 4 is a view showing the relationship between the flow rate and the current of the self-priming pump (vortex pump (Wesco pump)), and the relationship between the frequency and the current. FIG. 5 is a diagram showing an example of switching between the self-priming operation and the normal operation of the self-priming pump. FIG. 6 is a view showing an example of a processing flow by the driving device for a self-priming pump of the present embodiment. FIG. 7 is a view showing an example of a processing flow by the driving device for a self-priming pump of the present embodiment. FIG. 8 is a diagram showing another example of switching between the self-priming operation and the normal operation of the self-priming pump. FIG. 9 is a diagram showing another example of switching between the self-priming operation and the normal operation of the self-priming pump.

  Hereinafter, an operating device for a self-priming pump, a liquid supply device, and an operating method of the self-priming pump according to an embodiment of the present invention will be described with reference to the drawings. Although the following embodiment demonstrates an inverter as an example of the variable-speed driving | running apparatus of a self-priming type | mold pump, and demonstrates a water supply apparatus as an example of a liquid supply apparatus, it is not restricted to this.

  FIG. 1 is a view showing a configuration of a driving device for a self-priming pump (self-priming centrifugal pump) of the present embodiment and a water supply device using the same. 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 has a self-priming centrifugal pump 1. As shown in FIG. 1, the suction port 2 is provided at one end (left side in the figure) of the self-priming centrifugal pump 1, and the suction chamber 3 communicated with the suction port 2 is provided inside the self-priming centrifugal pump 1. Are provided separately from the pump chamber 8 by the bulkhead 4. The pump chamber 8 is provided with an impeller 5, a diffuser 6 surrounding the same, and an air-water separation chamber 7 and the like at the top.

A check valve (flap valve) 9 is provided in the upper part of the suction chamber 3 separately from the suction port 2. Prior to the operation of the self-priming centrifugal pump 1, the check valve 9 fills the inside of the pump to secure water necessary for self-priming and prevents backflow of water when the pump is stopped. It has a role to fill the inside with water.

  The impeller 5 is attached to the motor shaft 11 to obtain 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 (prime water) is injected into the pump casing and the impeller 5 is rotated in a fully filled state, the makeup water in the suction chamber 3 is suctioned from the inlet of the impeller 5 And is discharged from the impeller 5 into the pump chamber 8. At this time, since the suction chamber 3 has a negative pressure, the check valve 9 is opened to suck in the air on the suction side from the suction port 2 and discharge the air together with the air into the pump chamber 8.

  The air-water mixture discharged to the pump chamber 8 is separated in the air-water separation chamber 7, and only water is returned to the inside of the diffuser 6 and enters the wing of the rotating impeller 5. Then, it is discharged to the pump chamber 8 again together with the air newly sucked into the impeller 5 from the suction chamber 3. The air-water mixture is separated again in the air-water separation chamber 7, the air is expelled from the discharge port 16, the water is returned again into the impeller 5, and the above operation is repeated. The air is gradually exhausted to promote self-priming action.

  As a means to return only the water separated in the air-water separation chamber 7 back into the wing of the impeller 5, for example, the diffuser is divided into two (one pair), and the impeller is surrounded in a substantially symmetrical manner. There are those disposed on the left and right or those in which the pump chamber 8 and the suction chamber 3 are in communication with each other through a valved circulation passage.

  After starting up, the self-priming centrifugal pump 1 enters a normal operation through self-priming operation, but during 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 self-priming operation is much smaller than that during normal operation. Therefore, during the self-priming operation, the rotational speed can be increased as compared to that during the normal operation. This embodiment is made in view of this point, and the details 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 inside of 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 the gas is not mixed in the suction pipe or the inside of the self-priming centrifugal pump 1 and the liquid is filled.

  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 of the self-priming centrifugal pump 1, A check valve 17 is arranged. Furthermore, a pressure gauge 19 is installed downstream 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 the present embodiment can be applied not only to the self-priming centrifugal pump 1 described above but also to a self-priming pump formed of a vortex flow pump (Wesco pump). Hereinafter, the Wesco pump will be described.

  FIG. 2 is a view showing an operation device (vortex pump (Wesco pump)) of the self-priming pump of the present embodiment and a water supply device using the same. As shown in FIG. 2, the water supply device 300 has a Wesco pump 500. In the self-priming operation of the Wesco pump 500, first, the priming faucet 512 is opened to prime water from the priming port 514. As a result, as shown in FIG. 2, the inside of the casing 516 is filled 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 rotation of the impeller 524 in the pump chamber 520 causes the water in the casing 516 to be stirred and, at the same time, a negative pressure is generated on the suction port 502 side. The air in the suction pipe entering from the suction port 502 pushes the float 504 and is sucked into the pump chamber 520. A mixture of sucked air and water in the casing 516 is discharged from the pump chamber 520.

  The discharged mixture collides with a baffle 526 provided in the casing 516 and flows to the air-water separation chamber 510. The air separated in the air-water separation chamber 510 flows to the outlet 522 side, and the water returns to the pump chamber 520 again from the lower hole of the air-water separation chamber 510. In the pump chamber 520, negative pressure is generated on the suction port 502 side by the water that always returns.

  When the air in the suction pipe is exhausted and the water rises, the role of the air-water separation chamber 510 is finished, and the discharge side (including the air-water separation chamber 510) of the pump chamber 520 is filled with the discharge pressure. Then, the air is completely exhausted in the casing 516, and when it is filled with water, the pressure rises. The pressure sensor 508 (or pressure switch) can detect this.

  As described above, the water supply device of the present 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 representatively described. First, a usage example of the water supply device 300 having the Wesco pump 500 will be described. FIG. 3: is a figure which shows the usage example of the water supply apparatus of this embodiment.

  As shown in FIG. 3, a suction pipe 15 installed so that one end thereof is buried in 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 this embodiment. . At the end of the suction pipe 15, a strainer 105 is provided for removing foreign matter in the stored water. Further, the discharge port 522 of the Wesco pump 500 is connected to a discharge pipe whose one end is connected to the customer-side pipe (for example, the faucet 220).

  Returning to the description of FIG. 2, the configuration of the water supply device 300 will be described. In addition, although the water supply apparatus 300 has the inverter 30 and the water supply apparatus controller 40 grade | etc., Demonstrated below, since these structures are the same also about the water supply apparatus 100 of FIG. 1, it demonstrates representatively only about the water supply apparatus 300. I do. The water supply device 300 has an inverter 30 (a driving device for a self-priming pump) that converts power to an arbitrary voltage / arbitrary frequency. A variable speed motor (motor) (not shown) is connected to the impeller 524. The variable speed motor receives power from the external commercial power supply 200 and obtains power from the inverter 30 through the power cable 36, Act as a power source.

  In addition, the inverter 30 is an operation state signal (a frequency value, a pressure value, a flow rate, a temperature, a voltage value, a current value, etc.) indicating the operation state of the device sent from the water supply device controller 40 via the operation signal line 46 And an inverter control unit 31 that performs control of voltage and frequency and various calculations. Moreover, the inverter 30 has the current detector (current detection part) 32 used when determining whether self-priming operation is performed. When the inverter 30 uses a current sensor or the like for control, the current detector 32 may use the output of the current sensor.

In addition, based on the drive current detected by the current detector 32, the inverter 30 determines whether the Wesco pump 500 is performing self-priming operation or normal operation other than self-priming operation. Have. Furthermore, when it is determined that the self-priming centrifugal pump 1 is performing the self-priming operation by the storage device 34 storing the various data of the determination reference of the self-priming operation necessity and the determination unit 33 The operation command unit 35 rotationally drives the Wesco pump 500 via the variable-speed motor 20 at a rotational speed higher than the rotational speed at the time of normal operation of the Wesco pump 500.

  Further, the water supply device 300 has a water supply device controller 40. The water supply device controller 40 receives a signal from the pressure gauge 19 via the pressure signal line 47, and based on this signal, the water supply device control unit 44 performs arithmetic processing in accordance with an operation program stored in advance in the storage device 45. 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 there are, for example, discharge pressure constant control, estimated terminal pressure constant control, and the like as an operation method of the water supply device, that is, a control method. In normal operation, load operation is performed, and the self-priming pump is operated at a rotational speed controlled by discharge pressure constant control and estimated terminal pressure constant control.

  The calculation result by the water supply apparatus control unit 44 can also be notified to the outside using the display 41, the alarm 42, the external output terminal 43, and the like. In addition, not only the output from the water supply device controller 40 to the inverter 30 but also communication with the operation signal line 46 allows the water supply device controller 40 to recognize abnormality of the inverter 30 such as an overcurrent, etc. It is bidirectional communication which can also transmit a signal to the water supply device controller 40.

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

  Therefore, in the present embodiment, for example, at the start of operation of the Wesco pump 500, the determination unit 33 compares the value of the current detector 32 with the current value stored in the storage device 34 to determine whether self-priming operation is necessary. If it is determined that the self-priming operation is necessary, the self-priming operation is performed at the maximum rotation speed of the Wesco pump 500 after the start. Here, the maximum rotational speed of the Wesco pump 500 refers to a method of controlling the rotational speed of the Wesco pump 500 such that the drive current of the Wesco pump 500 is less than a predetermined value, and the mechanically acceptable maximum of the Wesco pump 500. The rotational speed is controlled in combination with a method of controlling the rotational speed of the Wesco pump 500 so as to be equal to or lower than the rotational speed of the above. In addition, it is also possible to set the rotational speed at a load similar to the load at the time of normal operation. Determination of necessity of self-priming operation by the judgment unit 33 is performed at any time, and when self-priming operation is judged to be unnecessary, the self-priming action is completed (completed), and the rotational speed of the Wesco pump 500 Is automatically lowered.

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

  Further, since the variable speed motor is used in the present embodiment, after the self suction operation is finished, even after the Wesco pump 500 enters the normal operation, the head and the amount of water are optimized according to the use condition (environmental conditions). Thus, by changing the rotational speed to control the pressure and the flow rate, it is possible to achieve an energy saving effect without waste.

The switching of the rotational speed of the impeller 524 described above is performed by detecting the operating current of the variable speed motor with the current detector 32 provided in the inverter 30. More specifically, in accordance with the size of the impeller 524 and the output of the variable-speed motor, the relationship between the operating voltage and / or the frequency and the operating current is stored as table data in the storage device 34 in advance. Then, 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 If the value is smaller, it is determined that air and water are mixed, and a signal for performing self-priming operation is output to the inverter control unit 31.

  Further, 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 When the value is larger or changes from a smaller value to a larger value, it is determined that the normal state is established, and a signal for performing a normal pump operation is output to the inverter control unit 31.

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

  By this configuration, during steady operation of the Wesco pump 500, when a large amount of air is suctioned and the pump action is temporarily interrupted, and a self-priming action is required again (a phenomenon), Since the suction operation is started and the rotational speed of the impeller is increased, the self-sucking time is shortened, and the pump operation at the steady state is promptly resumed.

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

  In the left view of FIG. 4, the horizontal axis represents the discharge flow rate of the Wesco pump 500, and the vertical axis represents the drive current of the variable speed motor. Moreover, in the right figure of FIG. 4, a horizontal axis is a frequency of the Wesco pump 500, and a vertical axis | shaft is a drive current of a variable speed motor.

  The left view of FIG. 4 shows the relationship between the discharge flow rate of the Wesco pump 500 and the drive current of the variable-speed 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 rotational speed is the normal operating speed or the rated operating speed, and the curve 304 shows the discharge flow rate and the drive current when the rotational speed is the maximum. Shows the relationship between

  As shown in FIG. 4, in the Wesco pump 500, the drive current tends to decrease as the flow rate increases. Also, as the rotational speed of the Wesco pump 500 increases, the drive current increases.

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

  As shown on the right side of FIG. 4, the relationship between the frequency and the drive current when the Wesco pump 500 is shut off is as shown by the 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 like the curve 308. On the other hand, when it is determined that the Wesco pump 500 is performing self-priming operation, first, as shown by the 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 rises with the progress of the self-priming action by the self-priming operation, and becomes equal to or more than the second threshold. Then, it is determined that the Wesco pump 500 has completed self-priming, and it is determined that self-priming operation has shifted to normal operation, and the frequency of the Wesco pump 500 is reduced to the frequency during normal operation.

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

  First, when the value of the drive current of the variable speed motor is smaller than the first threshold value, the determination unit 33 determines that the Wesco pump 500 is performing self-priming operation. That is, as shown in FIG. 5, when the value of the drive current of the variable-speed motor is smaller than the first threshold value in the characteristic line 402, the determination unit 33 detects the variable-speed motor as shown by the characteristic line 406. If the value of the drive current is smaller than the first threshold value, it is determined that the Wesco pump 500 is performing self-priming operation.

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

  Further, when the value of the drive current of the variable speed motor is equal to or greater than the first threshold and smaller than the second threshold, the determination unit 33 divides the determination depending on the operation state up to that point. In other words, when the value of the drive current of the variable speed motor is smaller than the first threshold value, the determination unit 33 shifts to a state that is larger than the first threshold value and smaller than the second threshold value. It is determined that the Wesco pump 500 is performing self-priming operation. This shows the case where the value of the drive current of the variable speed motor is greater than or equal to the first threshold and smaller than the second threshold in the characteristic line 402 in FIG.

  On the other hand, when the value of the drive current of the variable speed motor is shifted from the state of the second threshold or more to the state of the first threshold or more and smaller than the second threshold. It is determined that the Wesco pump 500 is in normal operation. This shows the case where the value of the drive current of the variable-speed motor is greater than or equal to the first threshold and smaller than the second threshold in the characteristic line 406 in FIG.

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

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

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

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

  Subsequently, the determination unit 33 determines whether a predetermined time has elapsed from the start of driving (step S103). If the predetermined time has not elapsed from the start of the operation (No at Step S103), the determination unit 33 repeats the process at Step S103.

On the other hand, when the predetermined time has elapsed from the start of the operation (step S103, Ye
s) It is determined whether or not the drive current value of the variable speed motor (the current value detected by the current detector 32) for driving the Wesco pump 500500the current threshold (step S104).

  When it is determined that the drive current value of the variable speed motor 電動 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 since the determination unit 33 determines that the Wesco pump 500 is operating normally, the Wesco pump 500 is rotationally driven at the rotation speed during normal operation.

  On the other hand, when it is determined that the drive current value of the variable speed motor ≧ the current threshold value is not satisfied (step S104, No), the operation command unit 35 speeds up 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 suction operation, the Wesco pump 500 is rotationally driven at a high rotation speed according to this. 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 drive current value of the variable speed motor 電動 the current threshold (step S107).

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

  On the other hand, if the determination section 33 determines that the drive current value of the variable speed motor ≧ the current threshold value is not satisfied (step S107, No), 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 (step S108).

  When it is determined that the discharge side pressure of the Wesco pump 500 ≧ pressure threshold value (step S108, Yes), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (step S105). . This can be inferred that the Wesco pump 500 has shifted from the self-priming operation to the normal operation when the pressure on the discharge side of the Wesco pump 500 has increased to a certain degree, so that the Wesco pump 500 is operated from the high rotation speed during normal operation. It is to return to a low rotational speed.

  On the other hand, if the determination unit 33 determines that the discharge side pressure of the Wesco pump 500 does not satisfy the pressure threshold (step S108, No), whether the predetermined time or more has elapsed since the rotational speed is increased in step S106 It is determined whether or not (step S109).

  If it is determined that the predetermined time or more has elapsed (Yes at Step S109), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (Step S105). Since it can be inferred that the Wesco pump 500 has shifted from the self-priming operation to the normal operation if the self-priming operation continues for a certain amount of time, the Wesco pump 500 changes from the high rotational speed to the low rotational speed during normal operation. It is to return. By this control, it is possible to protect the case where self-priming is not completed for some reason.

On the other hand, if the determining unit 33 determines that the predetermined time or more has not elapsed (step S109
, No), return to step S107 and repeat the process.

  After the operation of the Wesco pump 500 is performed at the rotation speed at the normal operation time in step S105, the determination unit 33 determines whether or not the switch of the water supply device controller 40 is turned off (step S110). If it is determined that the switch of the water supply device controller 40 is turned off (Yes at step S110), the process ends, and if it is determined that the switch of the water supply device controller 40 is not turned off (No at step S110), the process proceeds to step S104. Go back and repeat the process.

  According to this embodiment, whether the drive current of the Wesco pump 500 is detected, and whether the Wesco pump 500 is performing self-priming operation or normal operation other than self-priming operation based on the detected driving current Can be determined. Thus, it is not necessary to determine the self-priming operation and the normal operation using a pressure sensor or a pressure switch or the like as in the prior art, so the reliability of the determination of whether the Wesco pump 500 is performing 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, but the present invention is not limited to this. For example, it is also possible to drive the Wesco pump 500 by a constant speed motor via a transmission and to make the rotational speed larger than that during normal operation during self-priming operation.

  Moreover, although the example which provides the determination part 33 and the driving | operation command part 35 in the inverter 30 was shown in said example, it can not restrict to this and can also be provided in the water supply apparatus controller 40, for example. Moreover, the water supply apparatus 300 may enclose the Wesco pump 500, a variable speed motor, the inverter 30, and the water supply apparatus controller 40 in one housing | casing. 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. Further, each functional block in the inverter 30 and each functional block of the water supply device controller 40 may be integrated into one board or one CPU. Moreover, although the example which supplies electric power from the commercial power supply 200 to both the inverter 30 and the water supply apparatus controller 40 was shown in said example, for example, supply of electric power from the commercial power supply 200 is not limited to this, for example. To supply the power from the inverter 30 to the water supply device controller 40.

  Further, in the above example, the determination of the self-priming operation and the normal operation at the start of the Wesco pump 500 has been mainly described, but it is not limited thereto. For example, due to a leak or the like 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 the self-priming operation continuation state, the determination unit 33 goes to the outside when the duration time when it is determined that the Wesco pump 500 is performing 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 42 that the self-priming operation has continued for a long time.

  In addition, when the duration time when it is determined that the Wesco pump 500 is performing the self-priming operation becomes longer than the time threshold set in advance, the operation command unit 35 cancels the self-priming operation and the Wesco pump Can stop 500. In addition, the above-mentioned time threshold value enables the operation command unit 35 to have an input / setting function or can be arbitrarily set through the water supply device controller 40. Further, the determination unit 33 also shifts to the state where it is determined that the Wesco pump 500 is performing self-priming operation from the state where it is determined that the Wesco pump 500 is in normal operation, as described above. An alarm signal can be output to the outside.

Further, in the above example, the determination of the self-priming operation and the normal operation at the start of the Wesco pump 500 has been mainly described, but the same can be performed when the Wesco pump 500 is started from the small water amount stop. This point will be described with reference to FIG.

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

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

  Subsequently, the determination unit 33 determines whether a predetermined time has elapsed from the start of driving (step S204). When the predetermined time has not elapsed from the start of the operation (No at Step S204), the determination unit 33 repeats the process at Step S204.

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

  When it is determined that the drive current value of the variable speed motor 電動 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 since the determination unit 33 determines that the Wesco pump 500 is operating normally, the Wesco pump 500 is rotationally driven at the rotation speed during normal operation.

  On the other hand, when it is determined that the drive current value of the variable speed motor is not equal to or larger than the current threshold (step S205, No), the operation command unit 35 speeds up 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 suction operation, the Wesco pump 500 is rotationally driven at a high rotation speed according to this. 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 drive current value of the variable speed motor 20 ≧ the current threshold (step S208).

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

  On the other hand, if it is determined that the drive current value of the variable speed motor ≧ the current threshold value is not the determination part 33 (No at 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 ≧ pressure threshold value (Yes at Step S209), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during normal operation (Step S206). . This can be inferred that the Wesco pump 500 has shifted from the self-priming operation to the normal operation when the pressure on the discharge side of the Wesco pump 500 has increased to a certain degree, so that the Wesco pump 500 is operated from the high rotation speed during normal operation. It is to return to a low rotational speed.

  On the other hand, when it is determined that the discharge side pressure of the Wesco pump 500 does not satisfy the pressure threshold value (No at step S209), the determination unit 33 increases the rotational speed at step S207 and then elapses a predetermined time or more. It is determined whether or not there is (step S210).

  When it is determined that the predetermined time or more has elapsed (Yes at Step S210), the inverter control unit 31 operates the Wesco pump 500 at the rotation speed during the normal operation (Step S206). Since it can be inferred that the Wesco pump 500 has shifted from the self-priming operation to the normal operation if the self-priming operation continues for a certain amount of time, the Wesco pump 500 changes from the high rotational speed to the low rotational speed during normal operation. It is to return.

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

  After the operation of the Wesco pump 500 is performed at the rotation speed at the normal operation time in Step S206, the determination unit 33 determines whether the operation of the Wesco pump 500 is ended (Step S211). If the determination unit 33 determines that the operation of the Wesco pump 500 has not ended (step S211, No), the process 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 determining unit 33 determines whether the switch of the water supply device controller 40 is turned off (step S212). If the determination unit 33 determines that the switch of the water supply device controller 40 is turned off (Yes at step S212), the process ends, and if it is determined that the switch of the water supply device controller 40 is not turned off (No at step S212, ), Return to step S201 and repeat the process.

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

  When the self-priming pump is not the Wesco 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 the relationship with 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 case of the Wesco pump 500, the drive current value increases as the discharge flow rate increases.

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

  FIG. 8 is a diagram showing 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 self-priming operation to normal operation.

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

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

  FIG. 9 is a diagram showing 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 time lapse, and the vertical axis indicates the temperature of the Wesco pump 500. FIG. 9 is a view schematically showing the temperature of the Wesco pump 500 when the Wesco pump 500 shifts from self-priming operation to normal operation.

  As shown in FIG. 9, after the self-priming operation is completed and the normal operation is started, the inside of the casing of the Wesco pump 500 is sufficiently filled with a liquid such as well water, for example. It is suppressed. On the other hand, when performing self-priming operation, air and water are mixed in the impeller 524, and the temperature of the air and water is often different. Will grow. Therefore, when the rate of change of the temperature of the Wesco pump 500 is larger than a preset temperature threshold value, the determination unit 33 can determine that the Wesco pump 500 is performing self-priming operation. The determination of the self-priming operation based on the temperature may be performed instead of the determination based on the drive current value. Furthermore, even if 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 flow path of the liquid. By detecting the temperature, the reliability of the determination is further improved. The process after it is determined that the Wesco pump 500 is performing self-priming operation is the same as that described above.

1 Self-priming centrifugal pump 19 pressure gauge 20 variable speed motor 30 inverter 32 current detector 33 determination unit 35 operation command unit 40 water supply device controller 42 alarm device 100 water supply device 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 variable speeds;
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 driving device for a self-priming pump, comprising: In the apparatus for operating a self-priming pump according to claim 1,
When it is determined by the determination unit that the self-priming pump is performing self-priming operation, the self-priming pump may be driven by the motor at a rotational speed higher than that when the self-priming pump is normally operated. Operation command unit that rotationally drives suction pump,
The driving device for a self-priming pump, further comprising: In the apparatus for operating a self-priming pump according to claim 1 or 2,
The determination unit has a first threshold value set in advance, and the self-priming pump performs self-priming operation when the value of the drive current is smaller than the first threshold value. If the value of the drive current is greater than or equal to the first threshold value, it is determined that the self-priming pump is in the normal operation.
A driving device for a self-priming pump characterized by The driving device for a self-priming pump according to any one of claims 1 to 3.
The determination unit further has 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 value. If the self-priming pump is performing self-priming operation if it is smaller than the threshold value of
When the value of the drive current is equal to or more than the second threshold value, it is determined that the self-priming pump is in the normal operation,
When the value of the drive current is shifted from a state smaller than the first threshold to a state larger than the first threshold and smaller than the second threshold, the self-priming pump Determined that self-priming operation was being performed,
When the value of the drive current is shifted from the state of the second threshold or more to the state of the first threshold or more and smaller than the second threshold, the self-priming pump It is determined that the normal operation is being performed,
A driving device for a self-priming pump characterized by In the driving device for a self-priming pump according to any one of claims 1 to 4,
The determination unit may determine that the self-priming pump is operated when the amplitude of the drive current becomes larger than a preset amplitude threshold or the amplitude cycle of the drive current becomes shorter than a preset cycle threshold. Determine that the driver is self-priming,
A driving device for a self-priming pump characterized by In the driving device for a self-priming pump according to any one of claims 1 to 5,
It further comprises a temperature detection unit that detects the temperature of the self-priming pump,
The determination unit determines that the self-priming pump is performing self-priming operation, when the rate of change of the temperature of the self-priming pump is larger than a preset temperature threshold. Self-priming pump operating device. In the apparatus for operating a self-priming pump according to any one of claims 1 to 6,
The determination unit is configured to output an alarm signal when the duration time determined that the self-priming pump is performing self-priming operation is longer than a preset time threshold. Operating device for suction pump. In the device for operating a self-priming pump according to claim 7,
The determination unit outputs an alarm signal when it is determined that the self-priming pump is performing self-priming operation from the state where it is determined that the self-priming pump is performing the normal operation. A driving device for a self-priming pump characterized by: The driving device for a 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. Pump operating device. The driving device for a self-priming pump according to any one of claims 1 to 9.
The self-priming pump is a centrifugal pump or an eddy current pump.
A driving device for a self-priming pump characterized by The driving device for a self-priming pump according to any one of claims 1 to 10.
A self-priming pump which is driven to rotate via an electric motor by a driving device of the self-priming pump and lifts and discharges liquid;
A liquid supply apparatus comprising: It detects the drive current of the motor that drives the self-priming pump to rotate at variable speed,
Based on the detected drive current, it is determined whether the self-priming pump is performing self-priming operation or normal operation other than self-priming operation.
Method of operating a self-priming pump characterized by

Images