JP6750058B1 - Water supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water supply device capable of reliably performing a backup operation when a pressure detector fails. SOLUTION: A water supply device 1 includes an inverter 51 for driving a pump device 11, a plurality of first flow rate detectors 19 for detecting the flow rate on the secondary side of each of the plurality of pump devices 11, and a plurality of pump devices 11. A first pressure detector 20 provided on the secondary side, a storage unit 52 that stores the stop flow rate, the maximum operating frequency of the inverter 51, and a rated flow rate, and a storage unit that stores the stop operation frequency of the inverter 51 at the stop flow rate. The relationship between the flow rate detected by the first flow rate detector 19 and the operating frequency of the inverter 51, which is stored or updated in 52 and derived from the stopped operation frequency and the maximum operating frequency stored in the storage unit 52, and the first flow rate. A control unit 53 that controls the inverter 51 with an operating frequency calculated from the flow rate detected by the detector 19 is provided. [Selection diagram]

Description

The present invention relates to a water supply device that performs backup operation.

As a water supply device for supplying water to an apartment house or the like, there is known a water supply device that controls the operation frequency of the inverter and controls the drive of the pump device based on the detection value of the pressure detector provided on the secondary side of the pump device. ing. Further, for the purpose of energy saving operation, it is estimated that the operating frequency of the inverter is controlled so that the discharge pressure becomes the rated set pressure P ₁ at the rated flow rate and becomes the estimated end pressure P _{2 that} is lower than the rated pressure at the stop flow rate. A water supply device that employs a constant end pressure control system is also known.

In addition, as such a water supply device, there is also known a device that shifts to a backup operation in which the pump device is started at a preset time interval when the pressure detector fails.

As a water supply device that performs backup operation when the pressure detector fails, in order to prevent the occurrence of high voltage and unnecessary power consumption during backup operation, the inverter operating frequency during backup operation was not set to the maximum frequency and detected during normal operation. It is known to operate at the lowest frequency or a frequency obtained by adding a predetermined value to the lowest frequency.

In addition, as a water supply device that performs a backup operation when a pressure detector fails, there is also known a water supply apparatus that continues the operation at a fixed rotation speed without stopping the pump during the backup operation (for example, refer to Patent Document 1).

In addition, as a water supply device that performs backup operation when the pressure detector fails, it has a flow sensor that is installed downstream of the pump and sends a signal when a predetermined flow rate is detected. There is also known a direct connection water supply device that controls the start of the pump based on the detection result of (see, for example, Patent Document 2). Such a direct connection water supply device utilizes the fact that the pressure on the suction side of the pump becomes a positive pressure due to the pressure in the water pipe even when the pump is stopped, and when the on state of the flow sensor is detected while the pump is stopped, , Start pump as if water supply occurred.

JP, 2017-106363, A JP, 2016-50524, A

However, when the water supply device described above is operated with the operating frequency of the pump device fixed at a predetermined value, there is a risk that the pressure may be insufficient in the flow rate region where the water supply amount is large.

According to the technique of Patent Document 1, if the pump device is continued without stopping during the backup operation at the time of failure of the pressure detector, the pump device is operated even if the water supply is not occurring.

Further, in the technique of Patent Document 2, the above-described direct connection water supply device must meet the condition that the pressure on the suction side of the pump is positive and the pressure at the water supply destination is lower than the pressure on the pump suction side. However, it was not applicable because no water flow was generated.

Therefore, an object of the present invention is to provide a water supply device that can reliably perform backup operation when a pressure detector fails.

A water supply device according to an embodiment of the present invention detects a plurality of pump devices including a pump and a motor that drives the pump, an inverter that drives the motor, and a flow rate on the secondary side of each of the plurality of pump devices. The plurality of first flow rate detectors, the first pressure detectors provided on the secondary side of the plurality of pump devices, the stop flow rate Q0, the maximum operating frequency fmax of the inverter, and the operating frequency of the inverter are A storage unit that stores a rated flow rate Q1 when the discharge pressure of the pump apparatus is the rated set pressure P1 at the maximum operating frequency fmax, and the first flow rate detection during normal operation of the pump apparatus. The operating frequency of the inverter when the stop flow rate Q0 is detected by the device is stored in the storage unit as the operating frequency f0 during stop, or the operating frequency f0 during stop stored in the storage unit is updated. When the failure of the first pressure detector is detected, the normal operation is switched to the backup operation, and the first operation flow rate f0 and the highest operation frequency fmax stored in the storage unit are used to detect the first flow rate. The relationship between the flow rate detected by the detector and the operating frequency of the inverter was derived, and the operating frequency was calculated as the target operating frequency ft from the derived relationship and the flow rate detected by the first flow rate detector, and was calculated. A control unit that controls the operating frequency of the inverter to the target operating frequency ft, a connecting pipe that joins the secondary sides of the plurality of pump devices, a connecting pipe that is provided in the connecting pipe, and a connecting pipe that is provided in the connecting pipe. And a second flow rate detector provided in the connection pipe, and the control unit stops the pump device when the flow rate detected by the second flow rate detector is a predetermined value or more. And the predetermined value is a minute flow rate .

ADVANTAGE OF THE INVENTION According to this invention, the water supply apparatus which can reliably perform the backup operation at the time of a failure of a pressure detector can be provided.

The front view which shows the structure of the water supply apparatus which concerns on one Embodiment of this invention. The side view which shows the structure of the water supply apparatus in a partial cross section. The side view which shows a part of structure of the water supply apparatus by a partial cross section. It is a modification of the water supply apparatus and is a front view showing the configuration of the water supply apparatus.

Hereinafter, a water supply device 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.
1 is a front view showing the structure of the water supply device 1, FIG. 2 is a side view showing the structure of the water supply device 1 in a partial cross section, and FIG. 3 is a part of the structure of the water supply device 1. It is a side view which shows the discharge pipe 12, the check valve 13, and the 1st flow volume detector 19 by a partial cross section.

As shown in FIGS. 1 and 2, the water supply device 1 is provided with a plurality of pump devices 11, a plurality of discharge pipes 12 respectively connected to the secondary sides of the plurality of pump devices 11, and each discharge pipe 12. A plurality of check valves 13, a plurality of opening/closing valves 14 provided in each discharge pipe 12, a connecting pipe 15 connecting the plurality of discharge pipes 12, a connecting pipe 16 provided in the connecting pipe 15, and a connecting pipe 16. A pressure accumulator 17 provided, a relief pipe 18 connected to the plurality of pump devices 11, a plurality of first flow rate detectors 19 for detecting the flow rate of the secondary side of each pump device 11, and a connection pipe 15 inside. A first pressure detector 20 for detecting a pressure, a second flow rate detector 21 for detecting a flow rate flowing from the pressure accumulator 17 to the connecting pipe 15, and a control panel 22 for controlling the operation of each pump device 11 are provided. The water supply device 1 pumps water from a water source by a pump device 11 and supplies the water to a water supply destination via a discharge pipe 12 and a connection pipe 15.

As shown in FIGS. 1 and 2, the pump device 11 includes a motor 31 and a pump 32. The pump device 11 has a primary side connected to a water source. Here, the water source is, for example, a water receiving tank. The pump device 11 is, for example, a so-called vertical multi-stage turbine pump in which a rotating shaft extends along the direction of gravity and a motor 31 is arranged above the pump 32. For example, three pump devices 11 are provided.

The motor 31 is connected to the pump 32 via a rotating shaft. The motor 31 is electrically connected to the control panel 22.

The pump 32 is driven by the motor 31. The pump 32 has, for example, a suction port 32a and a discharge port 32b on the lower end side. The suction port 32 a of the pump 32 is connected to the water receiving tank, and the discharge port 32 b is connected to the discharge pipe 12.

As shown in FIG. 2, the discharge pipe 12 has one end connected to the discharge port 32b of each pump 32 and the other end connected to the connecting pipe 15. The discharge pipe 12 is extended along the gravity direction.

As shown in FIGS. 2 and 3, the check valve 13 is provided on the secondary side of the pump 32 and on the primary side of the connecting pipe 15, for example, in each of the discharge pipes 12. The check valve 13 prevents the reverse flow of water toward the pump 32 in the discharge pipe 12.

As shown in FIG. 2, the on-off valve 14 is provided on the secondary side of the pump 32 and on the primary side of the connecting pipe 15, for example, in each discharge pipe 12. The on-off valve 14 is provided, for example, at a position adjacent to the connecting portion between the discharge pipe 12 and the connecting pipe 15. The on-off valve 14 opens or closes the flow path that continues from the discharge pipe 12 to the connecting pipe 15.

As shown in FIGS. 1 and 2, the connecting pipe 15 connects the other ends of the plurality of discharge pipes 12. Further, the connecting pipe 15 has two open ends on the secondary side of the plurality of connected discharge pipes 12, one end of which is connected to a closing flange, and the other end of which is connected to a pipe communicating with a water supply destination. The connection pipe 15 joins the water that has passed through the discharge pipes 12 and forms a flow path to the secondary side that communicates with the connected pipes.

As shown in FIGS. 1 and 2, the connection pipe 16 is provided on the connection pipe 15 and is arranged on the secondary side of the position where the discharge pipe 12 is connected. Further, the connection pipe 16 is provided with a plurality of pressure accumulators 17. The connecting pipe 16 fluidly connects the plurality of pressure accumulators 17 and the connecting pipe 15.

As shown in FIGS. 1 and 2, a plurality of pressure accumulators 17 are provided in the connection pipe 16. In this embodiment, two pressure accumulators 17 are provided. The pressure accumulator 17 is fluidly continuous with the connecting pipe 15 via the connecting pipe 16.

As shown in FIGS. 1 and 2, the escape pipe 18 fluidly connects the secondary sides of the plurality of pumps 32 to the water receiving tank. The escape pipe 18 escapes a part of the water whose pressure has been increased in the pump 32 to the water receiving tank, and prevents the temperature in each pump 32 from rising.

As shown in FIGS. 2 and 3, the first flow rate detector 19 is provided in each discharge pipe 12. The first flow rate detector 19 is provided, for example, on the secondary side of the pump 32 and on the primary side of the check valve 13 provided in the discharge pipe 12. That is, the first flow rate detector 19 is configured to be able to detect the flow rate on the secondary side of each pump 32. The first flow rate detector 19 is a flow meter that outputs a signal corresponding to the flow rate. The first flow rate detector 19 sends a signal to the control panel 22. The first flow rate detector 19 is, for example, an impeller flow meter that includes a rotating shaft 41, an impeller 42, and a detection unit 43 that detects the rotation of the impeller 42.

The rotating shaft 41 is arranged in the discharge pipe 12 in a direction in which the axial direction is orthogonal to the flow direction of water.

The impeller 42 is fixed to the rotating shaft 41. The impeller 42 rotates the rotating shaft 41 by receiving the water flow passing through the discharge pipe 12.

The detection unit 43 includes, for example, a magnet provided on the rotation shaft 41, a sensor that detects the rotation of the magnet, and a detection substrate that is electrically connected to the sensor. As a specific example, the sensor is an alternating detection type Hall IC that is a magnetic detection element. The detection unit 43 converts the rotation of the magnet accompanying the rotation of the rotating shaft 41 into a pulse signal. The detection unit 43 is electrically connected to the control panel 22 via a signal line or the like. The detection unit 43 transmits the pulse signal to the control panel 22.

As shown in FIG. 1, the first pressure detector 20 is provided in the connecting pipe 15. The first pressure detector 20 is configured to be able to detect the pressure inside the connecting pipe 15. The first pressure detector 20 is electrically connected to the control panel 22 via a signal line or the like. The first pressure detector 20 is, for example, a pressure gauge that outputs a signal corresponding to the pressure. The first pressure detector 20 converts the detected pressure into a signal and sends the signal to the control panel 22.

As shown in FIG. 2, the second flow rate detector 21 is provided in the connection pipe 16 and is arranged between the connection portion of the connection pipe 16 and the connection pipe 15 and the pressure accumulator 17. That is, the second flow rate detector 21 is configured to be able to detect the flow rate of water flowing from the pressure accumulator 17 to the connecting pipe 15. The second flow rate detector 21 is a flow meter capable of detecting a minute flow rate that is caused by water supply such as pipe leakage. The second flow rate detector 21 is a flow meter that outputs a signal corresponding to the flow rate. The second flow rate detector 21 transmits a signal to the control panel 22. The second flow rate detector 21, for example, similar to the first flow rate detector 19, includes an impeller type flow meter including a rotating shaft 41, an impeller 42, and a detection unit 43 that detects the rotation of the impeller 42. Is.

As shown in FIG. 1, the control panel 22 includes an inverter 51, a storage unit 52, and a control unit 53.

The inverter 51 is electrically connected to the motor 31 and the control unit 53 via a signal line. The inverters 51 are provided in the same number as the motors 31, for example. In this embodiment, three inverters 51 are provided. The inverter 51 changes the rotation speed of the motor 31 by changing the operating frequency.

The storage unit 52 stores the stopped flow rate Q ₀ , the maximum operating frequency f _max of the inverter 51, the operating frequency of the inverter 51 is the maximum operating frequency f _max , and the discharge pressure of the pump device 11 is the rated set pressure P. The rated flow rate Q ₁ when it is ₁ is stored. In addition, the storage unit 52 stores a stop operating frequency f that is an operating frequency of the inverter 51 when the control unit 53 detects the stop flow rate Q ₀ from the first flow rate detector 19 while the pump device 11 is operating. Remember ₀ .

The stop flow rate Q ₀ is a flow rate at which the pump device 11 is stopped. The stop flow rate Q ₀ is replaced with, for example, the pulse number n ₀ of the pulse signal output by the first flow rate detector 19 when the flow rate passing through the installation location of the first flow rate detector 19 is the stop flow rate Q ₀ , It is stored in the storage unit 52. Hereinafter, the pulse number n _{0 is referred} to as the stop flow rate pulse number n ₀ .

The rated flow rate Q ₁ is the flow rate of the pump device 11 when the operating frequency of the inverter 51 is the maximum operating frequency f _max and the discharge pressure of the pump device 11 is the rated set pressure P ₁ . The rated flow rate Q ₁ is replaced with, for example, the pulse number n ₁ of the pulse signal output from the first flow rate detector 19 when the flow rate passing through the installation location of the first flow rate detector 19 is the rated flow rate Q ₁ . It is stored in the storage unit 52. Hereinafter, the pulse number n ₁ will be referred to as the rated flow rate pulse number n ₁ .

The control unit 53 detects the pulse number n of the pulse signal received from the first flow rate detector 19 and the second flow rate detector 21, respectively, as the flow rate detection value by the first flow rate detector 19 and the second flow rate detector 21. To do. Further, the control unit 53 converts a signal received from the first pressure detector 20 into a pressure value as a pressure detection value by the first pressure detector 20. The control unit 53, based on the detected values of the flow rate and the pressure by the first flow rate detector 19, the first pressure detector 20, and the second flow rate detector 21, and the information stored in the storage unit 52, the inverters 51. Control the operating frequency of. Further, the control unit 53 has a first function of determining whether the first pressure detector 20 is out of order or normal, and a second function of performing a normal operation or a backup operation. The first function and the second function of the controller 53 will be specifically described below.

The first function is that the control unit 53 determines that the first pressure detector 20 is out of order when the signal received from the first pressure detector 20 is out of the predetermined signal level range. is there.

As a specific example, a threshold value is stored in the storage unit 52 in advance, and the control unit 53 detects the first pressure when the detected pressure value by the first pressure detector 20 exceeds the threshold value stored in the storage unit 52 in advance. It is determined that the container 20 is out of order. Here, the threshold value can be set arbitrarily, and is, for example, the maximum value and the minimum value of the detected pressure values that can be detected by the normal first pressure detector 20 when the water supply device 1 is operating.

When the control unit 53 determines that the first pressure detector 20 is normal due to the first function, the second function performs normal operation, and the first function causes the first pressure detector 20 to malfunction. If it is determined that there is a backup operation, it is a function to perform backup operation.

As the operation of the control unit 53 during normal operation, the control unit 53 controls each inverter 51 so that the pressure detection value of the first pressure detector 20 becomes the target pressure. As a specific example, the control unit 53 sets the target pressure by the discharge pressure constant control or the estimated end pressure constant control, and each inverter so that the pressure detection value of the first pressure detector 20 becomes the target pressure. Control 51.

Further, the control unit 53 detects the stop flow rate Q ₀ by the first flow rate detector 19 while executing the normal operation, that is, when the first flow rate detector 19 detects the stop flow rate pulse number n ₀ , The pump device 11 is stopped and the operating frequency of the inverter 51 at this time is stored in the storage unit 52 as the operating frequency f ₀ during stop. Here, when the storage unit 52 already stores the stop operating frequency f ₀ , the control unit 53 updates the stop operating frequency f ₀ stored in the storage unit 52.

Further, when the control unit 53 determines that the first pressure detector 20 has a failure due to the first function while executing the normal operation, the control unit 53 shifts to the backup operation.

In this way, the control unit 53 controls each inverter 51 so that the detected value of the pressure by the first pressure detector 20 becomes the target pressure as the operation during the normal operation, and at the time of detecting the stop flow rate, the inverter 51 at that time. The operating frequency of is stored. Then, the control unit 53 shifts to the backup operation by determining that the first pressure detector 20 has failed.

As an operation of the control unit 53 during the backup operation, the control unit 53 activates each pump device 11 at preset time intervals. Specifically, when the pump device 11 is started, the control unit 53 continues the operation of the pump device 11 for a first predetermined time, and after the first predetermined time has elapsed from the start of the pump device 11, When the stop flow rate is detected by the first flow rate detector 19, the pump device 11 is stopped. Here, the first predetermined time is, for example, 10 seconds. Further, when the pump device 11 is stopped, the control unit 53 continues stopping the pump device 11 for a second predetermined time, and again after the second predetermined time has elapsed since the pump device 11 was stopped. 11 is started. Here, the second predetermined time is, for example, 60 seconds. The first predetermined time period during which the pump device 11 continues to operate and the second predetermined time period during which the pump device 11 continues to stop are stored in the storage unit 52 in advance, for example.

Further, the control unit 53 controls the operating frequency of each inverter 51 corresponding to each pump device 11 during the operation of each pump device 11 as described below.

First, the control unit 53 uses the stop flow rate Q ₀ , the maximum operating frequency f _max and the rated flow rate Q ₁ stored in the storage unit 52, and the stop operating frequency f ₀ to cause the first flow rate detector 19 to perform the operation. The relationship between the detected flow rate and the operating frequency of the inverter 51 is derived.

Then, the control unit 53 calculates the target operating frequency f _{t of the} inverter 51 from the flow rate detected by the first flow rate detector 19 based on the derived relationship between the flow rate detected by the first flow rate detector 19 and the operating frequency of the inverter 51. To calculate. The control unit 53 controls the operating frequency of the inverter 51 to the calculated target operating frequency f _t .

As a specific example, first, the control unit 53 sets the stop flow rate pulse number n ₀ , the maximum operation frequency f _max and the rated flow rate pulse number n ₁ stored in the storage unit 52, and the stop operation frequency f ₀ . Then, the operating frequency of the inverter 51 corresponding to the pulse number n detected by the first flow rate detector 19 between the stopped flow rate pulse number n ₀ and the rated flow rate pulse number n ₁ is determined by linear interpolation. Here, regarding the operating frequency of the inverter 51 corresponding to the pulse number n, the operating frequency of the inverter 51 when the first flow rate detector 19 detects the pulse number n ₀ at the stop flow rate is the stop operating frequency f _0, and The operating frequency of the inverter 51 when the number of pulses at the rated flow rate n ₁ is detected by the 1-flow rate detector 19 is determined as the maximum operating frequency f _max . The control unit 53 sets the operating frequency of the inverter 51 corresponding to the pulse number n as the target operating frequency f _t . That is, the control unit 53 obtains the target operating frequency f _t of the inverter 51 as the target operating frequency f _t1 shown in the following mathematical expression (1) as a linear function of the pulse number n detected by the first flow rate detector 19.

Subsequently, the control unit 53 calculates the target operating frequency f _t1 of the inverter 51 from the pulse number n of the pulse signal received from the first flow rate detector 19 using the mathematical expression (1). The control unit 53 controls the operating frequency of the inverter 51 to the calculated target operating frequency f _t1 .

Then, the control unit 53 is after the first predetermined time has elapsed from the activation of the pump device 11, and the pulse number n detected by the first flow rate detector 19 is not more than the stop flow rate pulse number n _0. Then, the pump device 11 is stopped. Moreover, the control part 53 will start the pump apparatus 11 again, if the 2nd predetermined time passes after the stop of the pump apparatus 11.

Further, when the pump device 11 is stopped, the control unit 53 activates the pump device 11 when the detected value of the flow rate by the second flow rate detector 21 is equal to or more than a predetermined value. Specifically, the storage unit 52 stores a predetermined pulse number as a predetermined value in advance, and the control unit 53 confirms that the pulse number of the pulse signal received from the second flow rate detector 21 is equal to or more than the predetermined value. When detected, the pump device 11 is activated. Here, the predetermined value is, for example, the number of pulses detected by the second flow rate detector 21 when the flow rate is a minute flow rate caused by pipe leakage or the like, and the value is, for example, 1 p/sec.

According to the water supply device 1 configured as described above, the relationship between the flow rate detected by the first flow rate detector 19 and the operating frequency of the inverter 51 is derived during the backup operation, and the operating frequency of the inverter 51 is detected by the first flow rate detection. By controlling the operating frequency corresponding to the flow rate detected by the device 19, it is possible to prevent the pressure required for water supply from becoming insufficient while suppressing the generation of high pressure unnecessary for water supply.

Further, in the water supply device 1, as in the above-described example, the first flow rate detector 19 is the impeller type flow rate sensor, and the operating frequency of the inverter 51 during the backup operation is the flow rate detected by the first flow rate detector 19. The operating frequency is calculated as a linear function. As a result, the water supply device 1 can control the operating frequency of the inverter 51 during the backup operation by approximating the operating frequency of the inverter 51 during the normal operation.

Further, in the water supply device 1, since the connection pipe 16 to which the pressure accumulator 17 is connected is provided with the second flow rate detector 21, water flows out from the pressure accumulator 17 even when the pump device 11 is stopped. Is detected as a state in which water supply has occurred, and the pump device 11 can be started appropriately. That is, the water supply device 1 can detect the water supply even when the pump device 11 is stopped during the backup operation, and can start the pump device 11 according to the water supply to supply the water.

Here, in the water supply device 1, when the number of pulses of the pulse signal acquired from the second flow rate detector 21 is 1 p/sec or more, as in the example described above, the control unit 53 sets the pump device 11 to start. By doing so, the flow rate of water flowing out of the pressure accumulator 17 for supplying a small amount of water such as water leakage from the pipe can be detected, and the pump device 11 can be activated. That is, the water supply device 1 can start the pump device 11 in response to the generation of a small amount of water supply such as pipe leakage when the pump device 11 is stopped during the backup operation.

As described above, according to the water supply device 1 according to the embodiment of the present invention, it is possible to reliably perform the backup operation when the pressure detector fails.

The present invention is not limited to the above embodiment. For example, in the above example, the control unit 53, a target operating frequency f _t of the backup operation time of the inverter 51, an example has been described of calculating as a linear function of the flow rate detected by the first flow rate detector 19, to Not limited.

For example, the control unit 53 may calculate the target operating frequency f _t of the inverter 51 during backup operation as a quadratic function of the flow rate detected by the first flow rate detector 19.

Specifically, during the backup operation, the control unit 53 causes the stop flow rate pulse number n ₀ , the maximum operation frequency f _max and the rated flow rate pulse number n ₁ stored in the storage unit 52, and the stop operation frequency. The target operating frequency f _t of the inverter 51 may be calculated by using f ₀ as a quadratic function of the pulse number n detected by the first flow rate detector 19. That is, the control unit 53, a target operating frequency f _t, it may be configured to calculate a target driving frequency f _t2 shown in the following equation (2). Here, the target operating frequency f _t2 of the inverter 51 is the operating frequency f ₀ during stop when the operating flow frequency of the inverter 51 when the first flow rate detector 19 detects the number n ₀ of pulses during stop flow rate The operating frequency of the inverter 51 when the number of pulses n ₁ at the rated flow rate is detected by the device 19 is determined as the maximum operating frequency f _max .

Even if the target operating frequency f _t is calculated in this way, the operating frequency of the inverter 51 that is similar to the operating frequency during normal operation can be controlled as in the above-described example.

In addition, the control unit 53 is configured to set an average value of the target operating frequency f _t1 calculated by the mathematical expression (1) and the target operating frequency f _t2 calculated by the mathematical expression (2) as the target operating frequency f _t. Good. That is, the control unit 53, a target operating frequency f _t, it may be configured to calculate a target driving frequency f _t3 shown in Equation (3) below.

The control unit 53 configured in this way can also control the operating frequency of the inverter 51 that is similar to the operating frequency during normal operation, as in the above-described example.

It should be noted that the target operating frequency f _t corresponding to a certain flow rate and the operating frequency during normal operation corresponding to the flow rate, which are calculated by Equations (1), (2), and (3), are actually used. As a result of comparison, the calculated value of the target operating frequency f _t3 by the formula (3) was closest to the operating frequency during normal operation. Therefore, the control unit 53 uses the target operating frequency f _t3 calculated by the formula (3) to use the target operating frequency f _t1 or the target operating frequency f _t2 calculated by the formula (1) or the formula (2). It can be said that the operating frequency of the inverter 51 can be controlled so as to be closest to the operating frequency during normal operation.

Further, in the above-described example, the water source to which the primary side of the pump device 11 is connected is the water receiving tank, but the present invention is not limited to this. The water source to which the primary side of the pump device 11 is connected may be a water pipe. That is, the water supply device 1 may be a so-called direct connection water supply device.

In the case of such a direct connection water supply device, the water supply device 1 is configured to be able to correct the operating frequency of the inverter 51 during the backup operation in consideration of the fluctuation of the suction pressure of the pump device 11. Specifically, as shown in FIG. 4, the water supply device 1 further includes a second pressure detector 23 provided on the primary side of the plurality of pump devices 11 in addition to the above-described configuration.

The second pressure detector 23 is configured to detect the suction pressure of the pump device 11. The second pressure detector 23 is electrically connected to the control panel 22 via a signal line or the like. The second pressure detector 23 is, for example, a pressure gauge that outputs a signal corresponding to the pressure. The second pressure detector 23 converts the detected pressure into a signal and transmits the signal to the control panel 22.

The control unit 53 of the water supply device 1 as described above performs constant estimated end pressure control during normal operation. When the first flow rate detector 19 detects the stop flow rate pulse number n ₀ during the normal operation, the control unit 53 further stores the pressure P ₀ detected by the second pressure detector 23 in the storage unit 52 at this time. ..

The control unit 53 further performs the following calculation during the backup operation. The control unit 53 uses a target pressure H corresponding to the flow rate, which is generally determined for performing the estimated constant end pressure control. The control unit 53 subtracts the pressure P detected by the second pressure detector 23 from the target pressure H corresponding to the flow rate detected by the first flow rate detector 19 during the backup operation. Further, the control unit 53 subtracts the pressure P ₀ stored in the storage unit 52 from the target pressure H. The control unit 53 calculates the square root of the ratio of these calculation results as the correction coefficient α as shown in the following mathematical expression (4).

Then, the control unit 53 further multiplies the target operating frequency f _t calculated by any one of the mathematical expressions (1) to (3) by the correction coefficient α as shown in the following mathematical expression (5), and the corrected target operation Calculate the frequency f _tc . The control unit 53 controls the operating frequency of the inverter 51 to the calculated corrected target operating frequency f _tc .

According to the water supply device 1 configured in this way, even if the suction pressure of the pump device 11 changes, the target operating frequency of the inverter 51 during backup operation can be corrected according to the amount of change in the suction pressure. .. That is, the water supply device 1 can control the operating frequency of the inverter 51 in consideration of the variation in the suction pressure of the pump device 11 even under the installation condition in which the suction pressure of the pump device 11 varies.

It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified at the stage of implementation without departing from the spirit of the invention. Further, the respective embodiments may be appropriately combined and implemented, in which case the combined effects can be obtained. Further, the above embodiments include various inventions, and various inventions can be extracted by a combination selected from a plurality of disclosed constituent features. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, if the problem can be solved and the effect can be obtained, the structure in which the constituent elements are deleted can be extracted as the invention.
A description equivalent to the invention described in the initial claims of the present application will be additionally given below.
[1] A plurality of pump devices having a pump and a motor for driving the pump,
An inverter for driving the motor,
A plurality of first flow rate detectors for detecting a flow rate on the secondary side of each of the plurality of pump devices, and a first pressure detector provided on a secondary side of the plurality of pump devices,
The stop flow rate Q0, the maximum operating frequency fmax of the inverter, and the rated flow rate Q1 when the operating frequency of the inverter is the maximum operating frequency fmax and the discharge pressure of the pump device is the rated set pressure P1. A storage unit for storing
During the normal operation of the pump device, the operating frequency of the inverter when the stop flow rate Q0 is detected by the first flow rate detector is stored in the storage unit as a stop operating frequency f0, or the storage unit. When the stop operating frequency f0 stored in the memory is updated and a failure of the first pressure detector is detected, the normal operation is switched to the backup operation, and the stop operating frequency f0 stored in the storage unit is stored. And using the highest operating frequency fmax, derive the relationship between the flow rate detected by the first flow rate detector and the operating frequency of the inverter, and from the derived relationship and the flow rate detected by the first flow rate detector, A control unit that calculates the operating frequency as a target operating frequency ft, and controls the operating frequency of the inverter to the calculated target operating frequency ft;
Water supply device.
[2] The first flow rate detector is an impeller type flow rate sensor that transmits a pulse signal,
The controller receives the pulse signal from the first flow rate detector, sets the pulse number of the pulse signal detected by the first flow rate detector at the stop flow rate Q0 to n0, and at the rated flow rate Q1 to the first pulse number. 1 The number of pulses of the pulse signal detected by the flow rate detector is n1, and the target operating frequency ft is calculated using the number of pulses n detected by the first flow rate detector,
ft1=(fmax-f0)/(n1-n0)*(n-n0)+f0, or
ft2=(fmax-f0)/(n1-n0)^2*(n-n0)^2+f0 or ft3=(ft1+ft2)/2 calculated using [1] Water supply equipment.
[3] A connecting pipe that joins the secondary sides of the plurality of pump devices,
A connecting pipe provided in the connecting pipe,
A pressure accumulator provided in the connection pipe,
A second flow rate detector provided on the connection pipe;
Further equipped with,
The water supply device according to [1] or [2], wherein the control unit starts the pump device that is stopped when the flow rate detected by the second flow rate detector is equal to or higher than a predetermined value.
[4] The second flow rate detector is an impeller type flow rate sensor that transmits a pulse signal,
The control unit receives the pulse signal from the second flow rate detector and, when the number of pulses detected by the second flow rate detector is 1 p/sec or more, activates the pump device that is stopped [3 ] Water supply device described in.
[5] The control unit performs constant estimated end pressure control during the normal operation of the pump device, and when detecting a failure of the first pressure detector, shifts from the normal operation to the backup operation [1]. Water supply device described in.
[6] The primary side of the plurality of pump devices is connected to a water pipe,
Further comprising a second pressure detector provided on the primary side of the plurality of pump devices,
The storage section further stores the pressure P0 detected by the second pressure detector at the stop flow rate Q0,
The control unit stores a pressure obtained by subtracting the pressure P detected by the second pressure detector from a target pressure H corresponding to the flow rate detected by the first flow detector and the target pressure H into the storage unit. The water supply device according to [1], wherein the target operating frequency ft is further multiplied by the square root of the ratio between the stored pressure P0 and the stored pressure P0.

DESCRIPTION OF SYMBOLS 1... Water supply device, 11... Pump device, 12... Discharge pipe, 13... Check valve, 14... Open/close valve, 15... Connection pipe, 16... Connection pipe, 17... Accumulator, 18... Relief pipe, 19... 1st Flow rate detector, 20... First pressure detector, 21... Second flow rate detector, 22... Control panel, 23... Second pressure detector, 31... Motor, 32... Pump, 32a... Suction port, 32b... Discharge port , 41... rotary shaft, 42... impeller, 43... detection unit, 51... inverter, 52... storage unit, 53... control unit.

Claims (5)

A plurality of pump devices having a pump and a motor for driving the pump;
An inverter for driving the motor,
A plurality of first flow rate detectors for detecting a flow rate on the secondary side of each of the plurality of pump devices;
A first pressure detector provided on the secondary side of the plurality of pump devices;
The stop flow rate Q0, the maximum operating frequency fmax of the inverter, and the rated flow rate Q1 when the operating frequency of the inverter is the maximum operating frequency fmax and the discharge pressure of the pump device is the rated set pressure P1. A storage unit for storing
During the normal operation of the pump device, the operating frequency of the inverter when the stop flow rate Q0 is detected by the first flow rate detector is stored in the storage unit as a stop operating frequency f0, or the storage unit. When the stop operating frequency f0 stored in the memory is updated and a failure of the first pressure detector is detected, the normal operation is switched to the backup operation, and the stop operating frequency f0 stored in the storage unit is stored. And using the highest operating frequency fmax, derive the relationship between the flow rate detected by the first flow rate detector and the operating frequency of the inverter, and from the derived relationship and the flow rate detected by the first flow rate detector, A control unit that calculates the operating frequency as a target operating frequency ft, and controls the operating frequency of the inverter to the calculated target operating frequency ft;
A connecting pipe that joins the secondary sides of the plurality of pump devices,
A connecting pipe provided in the connecting pipe,
A pressure accumulator provided in the connection pipe,
A second flow rate detector provided on the connection pipe;
Equipped with
When the flow rate detected by the second flow rate detector is equal to or higher than a predetermined value, the control unit starts the pump device that is stopped,
The water supply device in which the predetermined value is a minute flow rate . The first flow rate detector is an impeller type flow rate sensor that transmits a pulse signal,
The controller receives the pulse signal from the first flow rate detector, sets the pulse number of the pulse signal detected by the first flow rate detector at the stop flow rate Q0 to n0, and at the rated flow rate Q1 to the first pulse number. 1 The number of pulses of the pulse signal detected by the flow rate detector is n1, and the target operating frequency ft is calculated using the number of pulses n detected by the first flow rate detector,
ft1=(fmax-f0)/(n1-n0)*(n-n0)+f0, or
The ft2=(fmax-f0)/(n1-n0)^2*(n-n0)^2+f0 or the equation represented by ft3=(ft1+ft2)/2 is used for calculation. Water supply equipment. The second flow rate detector is an impeller type flow rate sensor that transmits a pulse signal,
Claim wherein the control unit receives the pulse signal from the second flow rate detector, the number of pulses detected by the second flow rate detector when is 1p / sec or more, to start the pump device suspended The water supply device according to 1 . The control section performs constant estimated end pressure control during the normal operation of the pump device, and shifts from the normal operation to the backup operation when a failure of the first pressure detector is detected. Water supply device. The primary side of the plurality of pump devices is connected to a water pipe,
Further comprising a second pressure detector provided on the primary side of the plurality of pump devices,
The storage section further stores the pressure P0 detected by the second pressure detector at the stop flow rate Q0,
The control unit stores a pressure obtained by subtracting the pressure P detected by the second pressure detector from a target pressure H corresponding to the flow rate detected by the first flow detector and the target pressure H into the storage unit. The water supply device according to claim 1, wherein the target operating frequency ft is further multiplied by a square root of a ratio between the stored pressure P0 and the stored pressure P0.