JP7511889B2 - Water supply device, water supply device control device, water supply device control method, and program - Google Patents

Description

The present invention relates to a water supply device that supplies water at increased pressure, a control device for the water supply device, and a control method and program for the water supply device.

To supply water to buildings and other structures, there are known direct-connected water supply systems that directly boost the pressure of water from the water main and water supply systems that boost the pressure of water in a water supply tank. A known technology for such water supply systems is to operate the system by controlling the number of pumps by arranging multiple pumps in parallel and providing check valves on the secondary side of each pump.

In addition, technology is known for switching between alternating operation, in which multiple pumps are driven alternately, and parallel operation, in which multiple pumps are driven simultaneously, for water supply equipment (see, for example, Patent Document 1).

Japanese Patent No. 3925956

The water supply system described above performs constant target pressure control operation by driving multiple pumps at variable speeds. For example, when multiple water supply systems are operating at synchronized speeds during high water volume, the conditions for increasing the number of units (including parallel operation) can be determined in the same manner as when multiple units are not operating at synchronized speeds (for example, the master unit operates at maximum frequency and the slave unit operates at variable speeds). However, when multiple units are operating at synchronized speeds, the flow detection device that determines low water volume cannot determine that the water volume is low even if the water volume decreases to the reduced water volume. In addition, when multiple units are operating at variable speeds at synchronized speeds, the head does not increase even if the water volume decreases to below the reduced water volume. Therefore, there is a problem in that the conditions for reducing the number of units (disconnecting) cannot be determined in the same manner when operating at synchronized speeds and when not operating at synchronized speeds.

The present invention aims to provide a water supply device, a control device for the water supply device, and a control method and program for the water supply device that can determine the condition for reducing the number of units without increasing the number of detection devices.

According to one aspect of the present invention, a water supplying device includes a plurality of pumps, a check valve provided on the secondary side of the plurality of pumps, a plurality of flow rate sensors respectively connected to the secondary side of the plurality of pumps, a pressure sensor connected to the secondary side of the plurality of pumps, and by increasing or decreasing the number of the pumps, the pumps are independently operated under constant target pressure control, or the plurality of pumps are operated at the same speed under constant target pressure control, and a first reduction condition is satisfied, where Fnow is the rotation speed of the pump, Fmin is the low water flow rotation speed at the time of low water flow, Fmax is the maximum rotation speed, n is the number of the pumps, and x is the number of the pumps to be reduced from the number n of the pumps, and Fnow<Fmin+(Fmax-Fmin)×{(n-x)/n} and a control device which reduces the number of pumps in operation when the condition is ² , and the control device continues the speed-matching operation by the multiple pumps without reducing the number of pumps even after the first reduction condition is met, when P2 < P1, the power consumption of one pump at the maximum rotation speed Fmax immediately before the number of pumps is increased is Pmax, the power consumption of the total number of pumps in operation (n-x) immediately before the number of pumps is increased is P1 = Pmax x (n-x), the power consumption when one pump is operating at a low water volume is Pmin, the power consumption of the total number of pumps in operation (n-x + 1) when the first reduction condition is met after the multiple pumps are operated in the speed-matching operation is P2, and the rotation speed of the pumps when the first reduction condition is met is F2, and then, as a second reduction condition,
Fnow<F2-{(P1-P2) x (Fmax-Fmin)}/{(Pmax-Pmin) x (n-x+1)}
When this is the case, the number of pumps in operation is reduced.

According to one aspect of the present invention, a water supply device includes a plurality of pumps, a check valve provided on the secondary side of the plurality of pumps, a plurality of flow rate sensors respectively connected to the secondary side of the plurality of pumps, a pressure sensor connected to the secondary side of the plurality of pumps, and by increasing or decreasing the number of pumps, operates any of the plurality of pumps independently under constant target pressure control, or operates the plurality of pumps at the same speed under constant target pressure control, and sets the rotation speed of the pump to Fnow, the low water flow rotation speed at the time of low water flow to Fmin, the maximum rotation speed to Fmax, the power consumption at the time of low water flow when operating one pump to Pmin, the maximum rotation speed immediately before the number of pumps is increased to Fmax, and the power consumption at the maximum rotation speed Fmax immediately before the number of pumps is increased to Pmax. where Pmax is the power consumption of one pump, P1=Pmax×(n−x) is the power consumption of the total number of operating pumps (n−x) just before the number of pumps is increased, n is the number of pumps, and x is the number of pumps to be reduced from the number n of pumps, then after operating the multiple pumps increased in the speed-matching operation, P2 is the power consumption of the total number of operating pumps (n−x+1) just before the reduction is reduced, and F2 is the rotation speed of the pump just before the reduction is reduced, and if P2<P1, the speed-matching operation by the multiple pumps is continued without reducing the number of pumps, and thereafter , when the condition for reducing the number of pumps is Fnow<F2-{(P1-P2)×(Fmax-Fmin)}/{(Pmax-Pmin)×(n−x+1)}, the control device reduces the number of operating pumps.

According to one aspect of the present invention, a method for controlling a water supply apparatus using a control device includes starting one of the pumps when a pressure on the secondary side of each of a plurality of pumps is equal to or lower than a start pressure;
a first reduction condition is satisfied when the pump is driven under constant target pressure control after being started and the increased number of pumps are operated at the same rotation speed under constant target pressure control, the rotation speed of the pump is Fnow, the low water flow rotation speed during low water flow is Fmin, the maximum rotation speed is Fmax, the number of pumps is n, and the number of pumps to be reduced from the number n of pumps is x;
Fnow < Fmin + (Fmax - Fmin) x {(n-x) / n} ²
and the power consumption of one pump at the maximum rotation speed Fmax immediately before the number of pumps is increased is Pmax, the power consumption of the total number of operating pumps (n-x) immediately before the number of pumps is increased is P1=Pmax×(n-x), the power consumption when one pump is operating at a low water volume is Pmin, the power consumption of the total number of operating pumps (n-x+1) when the first pump reduction condition is met after the multiple pumps that have been increased in the speed-matching operation are operated is P2, and the rotation speed of the pumps when the first pump reduction condition is met is F2.
When the first reduction condition is satisfied and P2≧P1 is satisfied, the number of pumps in operation is reduced; when the first reduction condition is satisfied and P2<P1 is satisfied, the number of pumps in operation is not reduced even after the first reduction condition is satisfied and the speed-matching operation is continued using the multiple pumps; when the first reduction condition is satisfied and P2<P1 is satisfied, the speed-matching operation is continued after the second reduction condition is satisfied.
Fnow<F2-{(P1-P2) x (Fmax-Fmin)}/{(Pmax-Pmin) x (n-x+1)}
When the above requirement is met, the number of pumps in operation is reduced.

According to one aspect of the present invention, a water supply device includes a plurality of pumps, a check valve provided on the secondary side of the plurality of pumps, a plurality of flow rate sensors respectively connected to the secondary side of the plurality of pumps, a pressure sensor connected to the secondary side of the plurality of pumps, and by increasing or decreasing the number of pumps, any of the plurality of pumps is independently operated under constant target pressure control, or the plurality of pumps are operated at the same speed under constant target pressure control, and when the rotation speed of the pump is Fnow, the low water flow rotation speed at the time of low water flow is Fmin, the maximum rotation speed is Fmax, the number of pumps is n, the number of pumps to be reduced from the number n of pumps is x, and the correction values are α and β, a third reduction condition is:
Fnow<Fmin+(Fmax-Fmin)×[{(n-x)/n} ² +α]+β
and a control device that reduces the number of operating pumps when the number of operating pumps is reduced.

The present invention provides a water supply device, a control device for the water supply device, and a control method and program for the water supply device that can determine the condition for reducing the number of units without increasing the number of detection devices.

FIG. 1 is an explanatory diagram showing a schematic configuration of a water supply device according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the water supply device 1. FIG. 2 is an explanatory diagram showing the configuration of the water supply device 1. 4 is a flowchart showing an example of control of the water supply device. FIG. 11 is an explanatory diagram showing a schematic configuration of a water supply device according to another embodiment.

First Embodiment
Fig. 1 is an explanatory diagram showing the configuration of a water supply device 1 according to a first embodiment of the present invention, Fig. 2 is a block diagram showing the configuration of the water supply device 1, Fig. 3 is an explanatory diagram showing an example of electrical wiring as a configuration of the water supply device, and Fig. 4 is a flow chart showing an example of control of the water supply device 1.

The water supply device 1 supplies water to a supply destination such as a faucet or shower head installed in a building. For example, the water supply device 1 is a so-called direct-connected water supply device that is connected to a water distribution pipe installed in a water main and boosts the pressure of the water supplied from the water distribution pipe. The water supply device 1 may also be configured to be connected to a water tank or the like and supply water from the water tank at boosted pressure. The water supply device 1 may also be used to boost the supply of industrial water or well water.

As shown in FIG. 1, the water supply device 1 includes multiple pump units 11, branch pipes 12, junction pipes 13, a flow rate sensor 14, a pressure sensor 15, a pressure accumulator 16, and a control device 17. The water supply device 1 operates each pump unit 11 independently using the control device 17, and also operates the multiple pump units 11 at the same rotation speed to pump water to the secondary side.

The pump unit 11 includes a first on-off valve 21, a pump 22, a motor 23, a check valve 24, and a second on-off valve 25. The primary side of each of the multiple pump units 11 is connected to the branch pipe 12, and the secondary side is connected to the junction pipe 13. In addition, in the pump unit 11, the first on-off valve 21, the pump 22, the check valve 24, and the second on-off valve 25 are sequentially arranged in the water flow direction from the primary side to the secondary side. In addition, the pump unit 11 includes a flow rate sensor 14 between the pump and the check valve 24.

The first on-off valve 21 and the second on-off valve 25 are, for example, switching valves that are manually opened and closed.

The motor 23 rotates the pump 22. The motor 23 is connected to the control device 17 and is driven and controlled by the control device 17. The check valve 24 regulates the flow of water from the secondary side to the primary side.

The branch pipe 12 includes a suction pipe 31 connected to the water distribution pipe, a branch section 32 provided on the suction pipe 31, which branches the suction pipe 31 into multiple branches, specifically the same number as the pump units 11, and multiple branch pipes 33 connected to the branch sections 32. The suction pipe 31 is connected to the water distribution pipe, for example, via a water meter.

The junction pipe 13 includes junction pipes 34 each connected to a pump 22, a junction section 35 that joins the junction pipes 34, and a discharge pipe 36 connected to the junction section 35. The discharge pipe 36 is connected to the supply destination, for example, via a vertical pipe of a building.

The flow rate sensor 14 detects the amount of water (flow rate) discharged from each pump 22 and outputs a detection signal to the control device 17. The flow rate sensor 14 is provided, for example, on the secondary side of each pump 22. As a specific example, the flow rate sensor 14 detects a small amount of water and outputs a detection signal to the control device 17.

The pressure sensor 15 is provided, for example, in the discharge pipe 36. The pressure sensor 15 linearly detects the pressure in the discharge pipe 36 as the discharge pressure discharged from the pump 22, and outputs the obtained detection signal to the control device 17.

The pressure accumulator 16 is, for example, an accumulator. The pressure accumulator is provided in the discharge pipe 36 via, for example, an on-off valve.

As shown in FIG. 2, the control device 17 is a computer for controlling the motor 23. The control device 17 includes, for example, an inverter box 41 and a control panel 42. The inverter box 41 and the control panel 42 may be arranged in the same housing, or in different housings. For example, the inverter box 41 may be provided in the motor 23, and the control panel 42 may be installed adjacent to the pump 22 and the motor 23. For example, the inverter box 41 and the control panel 42 as the control device 17, the pump unit 11, the branch pipe 12, the junction pipe 13, the flow sensor 14, the pressure sensor 15, and the pressure accumulator 16 may be packaged in the same housing.

The inverter box 41 includes an inverter 51 and an inverter control board 52. As an example, an example in which the inverter 51 and the inverter control board 52 are provided in the inverter box 41 will be described, but the inverter 51 and the inverter control board 52 may be provided in the control panel 42 or in a separate housing. Also, for example, the inverter 51 may be provided in the motor 23, and the inverter control board 52 may be provided in the control panel 42.

As shown in FIG. 3, the inverters 51 are provided in the same number as the pumps 22 (motors 23), for example. The inverters 51 receive an inverter control signal from a processor 67 (described later) of the control panel 42 via an inverter control board 52. The inverters 51 operate in response to this inverter control signal. For example, the inverter 51 stops or starts the operation of the motor 23 in response to an inverter control signal equivalent to an operation stop signal or an operation start signal. The inverter 51 also controls the rotation speed of the motor 23 (the rotation speed of the pump 22) in response to an inverter control signal equivalent to a rotation speed control signal. The inverter control board 52 controls the inverter 51 based on the inverter control signal. The inverter control board 52 includes, for example, a noise filter, a high-frequency countermeasure reactor, and a leakage current breaker. The inverter control board 52 may also have a memory.

The control panel 42 is electrically connected to the motor 23 and controls the rotation speed of the pump 22 by controlling the drive of the motor 23. Specifically, the control panel 42 controls the drive of the motor 23 via the inverter control board 52 and the inverter 51 based on the detection signals from each flow sensor 14 and pressure sensor 15.

For example, the control panel 42 stops and starts the motor 23 based on detection signals corresponding to the flow rate detected by the flow sensor 14 and the pressure detected by the pressure sensor 15. As a specific example, when the control panel 42 detects that the secondary pressure of the pump 22 calculated from the detection signal detected by the pressure sensor 15 has dropped below a predetermined starting pressure, it drives the motor 23 to start the pump 22. When the control panel 42 detects that the flow rate is low based on the detection signal from the flow sensor 14, it stops the pump 22. For example, the flow sensor 14 functions as a flow switch that outputs a detection signal when the stop flow rate (low water volume) is reached, and the control panel 42 controls the motor 23 to stop the pump 22 based on the detection signal output from the flow sensor 14.

The control panel 42 also controls the rotation speed of the motor 23 based on the detection signal corresponding to the pressure detected by the pressure sensor 15 and the operating frequency (output frequency) of the inverter 51, and controls the operation of the pump 22 by constant target pressure control such as constant discharge pressure control or constant estimated terminal pressure control. The rotation speed of the pump 22 is the same as the rotation speed of the motor 23, and the rotation speed of the pump 22 (motor 23) has a certain relationship with the operating frequency of the inverter 51.

In addition to controlling the pump unit 11, the control panel 42 may also wirelessly connect to the communication terminal 100 to transmit operating data to the communication terminal 100 as appropriate. Such a configuration involving communication with the communication terminal 100 constitutes a management system including the control device 17 and the communication terminal 100, or a management system including the water supply device 1 and the communication terminal 100. Such a configuration may also constitute a management system including the control device 17 and a program executed by the communication terminal 100, or a management system including the water supply device 1 and a program executed by the communication terminal 100.

Alternatively, such an embodiment may constitute a management system having a first program executed by the control device 17 and a second program executed by the communication terminal 100, or a management system having a first program executed by the water supply device 1 and a second program executed by the communication terminal 100. Here, the term "management system" may be rephrased as "system", "processing system" or "parameter processing system" as appropriate. Similarly, the term "program executed by..." may be rephrased as "program installed in..." or "program built into..." as appropriate.

The operating data is data indicating the operating state of the water supply device 1 at a certain operating point, such as the frequency, current, voltage, pressure, flow rate, vibration value, motor insulation resistance, and water tank settings. To add, the operating data of the water supply device 1 may be, for example, the latest status of the water supply device 1 at one or more logged points in time. Specifically, the operating data may include, for example, the voltage/current value at each point in time acquired from the inverter 51 of the water supply device 1, the detection signal at each point in time acquired from the flow sensor 14 or the flow rate value calculated based thereon, the detection signal at each point in time acquired from the pressure sensor 15 or the pressure value calculated based thereon, the operating speed (frequency) of the motor 23 at each point in time, and the accumulated operating data at each point in time. The accumulated operating data may also include, for example, at least one of the accumulated operating time and the accumulated number of starts.

2, the control panel 42 includes, for example, a communication unit 61, an input unit 62, an interface 63, a display unit 64, a setting unit 65, a memory 66, and a processor 67. The control panel 42 includes a housing and a control board in which each component is mounted or connected to each component within the housing.

The communication unit 61 is an arbitrary communication interface that is controlled by the processor 67 and can communicate with an external device such as the communication terminal 100 using wireless communication technology. The communication unit 61 may be implemented, for example, as a communication module or a communication board. The communication module may be detachably provided on the control board of the control panel 42 via a connector, for example. Specifically, the communication unit 61 can connect to an external device such as the communication terminal 100 using wireless communication technology such as the Bluetooth (registered trademark) Low Energy standard (hereinafter also referred to as the BLE standard), Wi-Fi (registered trademark), or NFC, or wired communication technology such as USB.

The BLE standard may be, for example, a standard of BLE version 4.0 or higher, and may be compatible with the BLE communication method. Accordingly, the "BLE standard" may be called the "Bluetooth 4.0 or higher standard." The communication unit 61 may also receive some data for establishing a connection between the communication terminal 100 and the control board 42, for example, a request from the communication terminal 100 as a scanner when the communication terminal 100 and the control board 42 are connected by Bluetooth as a scanner and an advertiser, respectively.

For example, the communication unit 61 broadcasts an advertising packet including identification information of the control board 42. Also, for example, the communication unit 61 may connect communication with the communication terminal 100 when it receives a connection request from the communication terminal 100 that receives the advertising packet. The communication unit 61 is electrically connected to the processor 67 and is an example of a communication means capable of connecting communication with the communication terminal 100.

The input unit 62 has at least one of a device that accepts user input, such as an operation panel including buttons, a touch panel, a keyboard, a mouse, and a sensor such as a pressure sensor, a microphone, a camera, and the like. The input unit 62 is a device that accepts user input, which is an instruction from any user, such as parameter setting, setting of each operation mode, and the like.

The interface 63 is a terminal or circuit to which the flow rate sensor 14, the pressure sensor 15, an external terminal, etc. can be electrically connected. In addition, if the water supply device is equipped with an electrode rod that controls the liquid level in the water tank, the electrode rod is electrically connected to the interface 63.

The display unit 64 has a display device such as a liquid crystal display or an organic EL display. The display unit 64 may have a speaker, an LED (Light Emitting Diode) lighting unit, etc. instead of or in addition to the display device.

The setting unit 65 is an input unit that physically sets the electrical connection state for acquiring read parameters among the control-related parameters. As the setting unit 65, for example, a dip switch or a jumper pin is appropriately used. The setting unit 65 is assigned read parameters such as the number of pumps, the type of water supply method, etc.

For example, the readout parameter for the number of pumps is the number of pumps 22, and the readout parameter for the type of water supply method is, for example, a direct water supply method or a water tank method. These readout parameters are set when the water supply device 1 is shipped or installed. Furthermore, the readout parameters are not limited to these, and various settings are possible. Note that the configuration may be such that the setting unit 65 is not provided, and the readout parameters are obtained by setting the input unit 62.

The memory 66 is capable of reading and writing data. The memory 66 stores data used by the processor 67, operation data of the pump 22, and various data and programs used to control the pump 22. The memory 66 includes non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) (registered trademark), a ROM (Read only memory), or a NAND flash memory. The memory 66 also includes an SSD (Solid State Drive) equipped with a flash memory.

Data stored in the memory 66 includes, for example, identification information, codes, tables, etc. that identify the control panel 42. The operating data stored includes accumulated operating data (hereinafter also referred to as operating data (accumulated)) relating to accumulated values that are periodically acquired from the operating data that indicates the operating state of the water supply device 1. The memory 66 also stores external parameters and internal parameters required for control and correction of the pump 22.

The external parameters are data related to the control target. Examples of the external parameters include rated pressure, end pressure, starting pressure, and rated flow rate. The "rated pressure" is the target pressure (control target) at the rated flow rate in constant target pressure control operation. The "end pressure" is the water pressure at the supply destination such as a faucet or shower head, and is a value that takes into account, for example, piping resistance. The "start pressure" is the reference pressure on the secondary side of the water supply device 1 when starting the pump. The "start pressure" may be calculated, for example, by subtracting a specified head of 4 m from the end pressure, so that the starting pressure = end pressure - 4 m. The "rated flow rate" is the flow rate when determining the rated pressure, and is the maximum usable flow rate. In this way, the external parameters "rated pressure", "end pressure", "start pressure", and "rated flow rate" are related to each other as control targets. In addition, when the water supply device 1 is ordered, if an order is placed as a so-called "single-point specification" tailored to the water supply site, the "rated pressure", "end pressure", and "start pressure" must be set specifically. Therefore, during the trial operation of the water supply device 1 in the manufacturing process or after the water supply device 1 is installed, an operator operates the input section 62 of the control panel 42, or connects an external terminal to the interface 63 and operates the external terminal to set the initial values of each external parameter.

The internal parameters are constants used for automatic operation, such as acceleration time, deceleration time, increase delay time, decrease delay time, upper limit frequency, and lower limit frequency. "Acceleration time" is the time it takes for the inverter output to reach the maximum frequency after starting. "Deceleration time" is the time it takes for the inverter to stop from the maximum frequency. "Increase delay time" is the delay time when starting a stopped pump and increasing the number of pumps. "Decrease delay time" is the delay time when stopping an operating pump and decreasing the number of pumps. "Upper limit frequency" is the upper limit frequency when increasing or decreasing the number of pumps. "Lower limit frequency" is the lower limit frequency when increasing or decreasing the number of pumps. The internal parameters "acceleration time", "deceleration time", "increase delay time", "decrease delay time", "upper limit frequency", and "lower limit frequency" are constants that are corrected from the initial value if a malfunction occurs during parallel startup, speed matching operation, or parallel off during trial operation at the time of manufacture or installation.

The internal parameters are determined by the motor rating, inverter manufacturer, inverter rating, etc., and include carrier frequency, minimum frequency, maximum frequency, inverter type, motor rated current, and overcurrent protection level. The "carrier frequency" is the frequency of the carrier, which is a fixed-period carrier (triangular wave) input to a comparator for generating a switching control signal used in inverter pulse width modulation (PWM) control, and a modulated wave (desired waveform). The "minimum frequency" is the minimum frequency that the inverter can output when operating. The "maximum frequency" is the maximum frequency that the inverter can output when operating. The "inverter type" is the type or format of the inverter. The "motor rated current" is the rated current of the motor 23. The "overcurrent protection level" is the current value at which the inverter 51 starts protecting the switching element from overcurrent, based on the current value of the switching element.

In addition to non-volatile memory, memory 66 may also include RAM having a work area in which data that may be erased when the power is cut off is stored.

The processor 67 is a general control unit. The processor 67 is typically a microcomputer, but may be a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), or other general-purpose or dedicated processor. The processor 67 performs any process, such as communication control, display control, and pump control. As shown in FIG. 3, the processor 67 is connected to each flow sensor 14, pressure sensor 15, and each inverter 51, for example, via an interface 63 or an inverter control board 52.

The processor 67 includes, for example, a processing circuit and a memory. The processor 67 includes, for example, a non-volatile EEPROM area 67a and a volatile DRAM area 67b. The processor 67 can also function as a processing unit 67c and a pump control unit 67d, etc., by executing a program stored in the memory 66 or the EEPROM area 67a. The division of functions among the various parts of the processor 67 is for convenience and can be changed as appropriate.

The programs stored may include, for example, firmware, an OS, a processing program mainly related to parameter processing, a pump control program (e.g., an automatic operation program), etc., as appropriate. Note that the programs may be obtained from the memory 66 by the processor 67 based on the connection state of the setting unit 65 when the power is turned on, and stored in the EEPROM area 67a. Alternatively, the programs may be stored in the memory 66, but not in the EEPROM area 67a, and the processor 67 may execute the programs stored in the memory 66.

Also, for example, when the power is turned on, the read parameters are acquired by the processor 67 from the memory 66 based on the connection state of the setting unit 65 and stored in the EEPROM area 67a. Note that the read parameters may not be stored in the EEPROM area 67a, and the processor 67 may acquire the read parameters stored in the memory 66.

The DRAM area 67b is provided in the processor 67 and stores the operating data. The operating data may be stored in a dedicated register provided in the DRAM area 67b. Examples of the operating data include discharge pressure, instantaneous flow rate, output current, operating frequency, output voltage, and power consumption.

The processing unit 67c executes processing related to each parameter. The pump control unit 67d acquires operating data indicating the operating state of the water supply device 1 based on detection signals from various sensors, and stores the operating data in the memory 66, the EEPROM area 67a, and/or the DRAM area 67b. Note that acquiring the operating data may include calculating the operating data according to the actual operating state of the water supply device 1, such as an integrated value.

The pump control unit 67d also generates an inverter control signal in response to the latest detection signal, etc., based on the program for pump control stored in the memory 66 or the EEPROM area 67a and each parameter, and outputs the inverter control signal to the inverter 51 via the inverter control board 52 to control the motor 23. As a result, the pump control unit 67d controls the pump 22 by constant target pressure control operation.

An example of the control function of the pump 22 by the processor 67 is described below. Here, the control function is a process in which the processor 67 drives the pump 22 with constant target pressure control operation based on a program. Note that each process by the processing unit 67c and the pump control unit 67d can be set as appropriate, and therefore, the process is described below as an example of the process of the processor 67. In addition, the memory 66, the EEPROM area 67a, and the DRAM area 67b can be set as appropriate for reading and storing various data, and therefore, the reading and storing of various data is described as an example using the memory 66.

The processor 67 performs constant target pressure control by driving one pump 22 independently under predetermined conditions based on the program. First, for example, the processor 67 performs a start-up process to start one pump 22 as a control function for the pump 22. That is, the program causes the control device 17 (processor 67) to function as a start-up means that performs the start-up process.

As a specific example, the processor 67 drives one of the motors 23 when the pressure on the secondary side of the pump 22 detected by the pressure sensor 15 is lower than a predetermined pressure value serving as a threshold value stored in the memory 66 or the like. Here, the predetermined pressure value is the starting pressure. That is, when the processor 67 determines that the pressure on the secondary side of the pump 22 is equal to or lower than the starting pressure, it generates an inverter control signal to start one of the motors 23, outputs the inverter control signal to the inverter 51, and controls the motor 23. This performs the starting process of the pump 22.

After the start-up process of the pump 22, the processor 67 performs a water supply process in which the pump 22 is operated independently under constant target pressure control as a control function of the pump 22 based on the program. That is, the program causes the control device 17 (processor 67) to function as a water supply means that performs the water supply process.

As a specific example, the processor 67 controls the operating frequency of the inverter 51 based on the flow rate and pressure detected by the flow rate sensor 14 and the pressure sensor 15, the rotation speed (frequency) of the motor 23, and various data and programs stored in the memory 66, etc., and drives and controls the pump 22 with estimated terminal pressure constant control as target pressure constant control. In this way, the water supply process is performed by operating the pump 22 alone.

Furthermore, when the pump 22 is driven under constant target pressure control based on the program, if the inverter 51's operating frequency is the highest operating frequency, the processor 67 performs an increase in the number of pumps 22. That is, the program causes the control device 17 (processor 67) to function as an increase in the number of pumps that performs the increase in the number of pumps.

As a specific example, the processor 67 drives and controls the pump 22 with estimated terminal pressure constant control as target pressure constant control, and monitors the operating frequency of the inverter 51. Then, when the operating frequency of the inverter 51 is the highest operating frequency, an inverter control signal is generated for the inverter 51 connected to the motor 23 of the stopped pump 22 in order to drive the motor 23 of the stopped pump 22. Then, the processor 67 outputs the inverter control signal to the inverter 51 to control the motor 23. This performs the process of increasing the number of pumps 22.

When only one pump 22 is in operation, the process of increasing the number of pumps 22 is performed to operate two pumps. When the water supply device 1 has three or more pumps 22, the process of increasing the number of pumps 22 is performed when one or more pumps 22 are in operation and not all pumps are in operation.

When the number of pumps 22 is increased and two or more pumps 22 are driven under constant target pressure control, the processor 67 performs water supply processing in a synchronized operation in which the multiple pumps 22 (motors 23) being driven are operated at the same rotational speed (rotational frequency) based on the program. In other words, the program causes the control device 17 (processor 67) to function as a water supply means that performs water supply processing.

As a specific example, the processor 67 generates an inverter control signal for the inverter 51 connected to the motor 23 of the pump 22 that was operating before the additional units were added, reduces the rotation speed of the motor 23 of the pump 22 that was operating before the additional units were added to make the rotation speeds of the multiple pumps 22 being driven the same, and then increases or decreases the rotation speeds of the multiple pumps 22 while maintaining the same frequency, thereby performing estimated terminal pressure constant control as target pressure constant control. In addition, in speed matching operation, the processor 67 operates the specified number of pumps 22 to be operated, specifically, all of the pumps 22, at the same rotation speed. In this way, water supply processing is performed by speed matching operation of the multiple pumps 22.

The processor 67 also performs a reduction process to reduce (disconnect) the pumps 22 when the pumps 22 are driven under constant target pressure control with speed matching based on the program. That is, the program causes the control device 17 (processor 67) to function as a reduction means for performing the reduction process.

As a specific example, when multiple (n) pumps 22 are operated at the same speed to control the target pressure to a constant level, the processor 67 constantly detects the operating frequency of the inverter 51 or the rotational speed (rotational frequency) of the pumps 22 (motor 23).

Here, the processor 67 can obtain the operating frequency of the inverter 51, and can detect the rotation speed of the pump 22 (motor 23) from the operating frequency of the inverter 51. Therefore, in the following description, in an example where the processor 67 performs processing based on the operating frequency of the inverter 51, the rotation speed of the pump 22 (motor 23) may be used instead of the operating frequency of the inverter 51, and in an example where the processor 67 performs processing based on the rotation speed of the pump 22 (motor 23), the operating frequency of the inverter 51 may be used.

Under the following reduction (disconnection) conditions, the processor 67 generates an inverter output signal to stop and reduce one or more of the multiple pumps 22 that are being driven, controls the operating frequency of the inverter 51 of the motor 23 of the pump 22 to be stopped, and stops the pump 22 to be stopped. For ease of explanation, the reduction condition in this embodiment may also be referred to as a first reduction condition.

Here, assuming that the current operating frequency of the inverter 51 or the rotation speed of the pump 22 (motor 23) is Fnow, the operating frequency of the inverter 51 or the rotation speed of the pump 22 (motor 23) during a low water volume is Fmin, the maximum operating frequency of the inverter 51 or the maximum rotation speed of the pump 22 (motor 23) is Fmax, the number of pumps 22 is n, and the number of pumps 22 to be reduced is x, then, for example, the condition (disconnection point) for reducing the number of pumps 22 (parallel-off) is as follows:
Fnow < Fmin + (Fmax - Fmin) x {(n-x) / n} ²
The number x of pumps 22 to be reduced can be set appropriately, but the maximum number x of pumps 22 to be reduced is n-1.

For example, when the number n of the pumps 22 is two (n=2) and the number x of the pumps 22 to be reduced is one (x=1), the off-parallel point is:
Fnow < Fmin + (Fmax - Fmin) x (1/2) ²
Then, when the current operating frequency of the inverter 51 or the rotation speed Fnow of the pump 22 (motor 23) satisfies the above condition, the processor 67 reduces (disconnects) the pump 22.

In addition, for example, when the number n of the pumps 22 is three (n=3) and the number x of the pumps 22 to be reduced is one (x=1), the off-parallel point is expressed as follows:
When reducing the number of pumps 22 from three to two,
Fnow < Fmin + (Fmax - Fmin) x (2/3) ²
And then,
When reducing the number of pumps 22 from two to one,
Fnow < Fmin + (Fmax - Fmin) x (1/3) ²
Then, when the current operating frequency of the inverter 51 or the rotation speed Fnow of the pump 22 (motor 23) satisfies the above condition, the processor 67 reduces (disconnects) the pump 22.

The equations for calculating these disconnection points are stored as a program in memory 66 or EEPROM area 67a. For example, in shipping tests of the water supply device 1, when actual measurements are obtained and disconnection occurs at the disconnection point according to the above equation, if there is a deviation from the target disconnection point, an equation for making a correction corresponding to the actual device may be stored as a program in memory 66 or EEPROM area 67a. For example, one example of a correction corresponding to the actual device is a configuration in which a coefficient is added as a correction value, but the correction can be set as appropriate.

In addition, for example, the maximum rotation speed of the pump 22 (motor 23) (maximum operating frequency of the inverter 51) Fmax and the rotation speed of the pump 22 (motor 23) when one pump is operating with a small water volume (operating frequency of the inverter 51) Fmin are stored by the processor 67 in at least one of the inverter control board 52, memory 66, EEPROM area 67a and/or DRAM area 67b, based on input by an operator during shipping inspection.

In addition, such various programs and data are stored in a storage medium such as memory 66 at the time of manufacture, but the various programs and data may be rewritten after installation of the water supply device 1 through data communication with a communication terminal 100, etc.

In addition, since the processor 67 has a plurality of pumps 22, in each process of increasing and decreasing the number of pumps 22, for example, an alternating operation or a rotation operation may be performed in which the pumps 22 to be increased and decreased are switched alternately or in sequence. For example, the pump 22 selected and driven by the processor 67 when increasing the number of pumps may be, for example, a pump 22 other than the pump 22 that was operating before the water supply device 1 was stopped, or a pump 22 other than the pump 22 that was operating alone when the water supply device 1 was operating before the stoppage. In addition, for example, the pump 22 selected and driven by the processor 67 when increasing the number of pumps may be, for example, a pump 22 with the shortest operating time, by comparing the cumulative operating time of each pump 22.

Similarly, the pump 22 that the processor 67 selects to stop when the number of pumps is reduced may be, for example, the pump 22 that was started first, or when multiple pumps 22 are being driven, the pumps 22 may be stopped in the order in which they were started. Also, for example, the pump 22 that the processor 67 selects to stop when the number of pumps is reduced may be, for example, the pump 22 with the longest operating time, which is selected by comparing the cumulative operating time of each pump 22.

Next, an example of a communication terminal 100 that performs data communication with such a water supply device 1 will be described below. The communication terminal 100 is an information processing device that can communicate with a management server (not shown) and the water supply device 1 that supplies water to a building. Examples of the communication terminal 100 include, but are not limited to, a PC or a mobile terminal (e.g., a tablet, a smartphone, a laptop, a feature phone, etc.).

Such a communication terminal 100 includes a communication unit 101, an input unit 102, a display unit 103, a memory 104, and a processor 105, as shown in FIG. 2.

The communication unit 101 is an arbitrary communication interface that is controlled by the processor 105 and can communicate with an external device such as the water supply device 1 using, for example, wireless communication technology. Specifically, the communication unit 101 can connect to an external device such as the water supply device 1 using, for example, a (short-range) wireless communication technology such as the BLE standard, Wi-Fi (registered trademark), or NFC, or a wired communication technology such as USB. As a specific example, the communication unit 101 performs wireless communication with the control panel 42 of the water supply device 1 based on the BLE standard. Note that the communication unit 101 may include a normal communication interface of a mobile terminal that can communicate with a management server or other communication terminals via a base station and a network, in addition to the above-mentioned BLE standard communication. For example, the communication unit 101 is controlled by the processor 105 and transmits data such as function parameters, internal parameters, and external parameters, various programs for performing constant target pressure control, and change instructions for changing these data and programs to the communication unit 61 of the control device 17.

The input unit 102 is an input I/F for accepting user input, and may be built into the communication terminal 100 or may be externally attached to the communication terminal 100. The input unit 102 may be, for example, a keyboard, a mouse, a numeric keypad, a microphone, a camera, or may have an output I/F function such as a touch screen. Here, user input includes, for example, tapping, clicking, dragging, pressing a specific key, and voice captured by a microphone.

The display unit 103 is an example of an output I/F for outputting images and/or audio in response to processing by the processor 105, and may include a display device for displaying moving images, still images, text, and the like. The display unit 103 may also include a speaker for outputting audio, music, and the like. The "display unit" may also be read as an "output unit." Examples of the display device include a liquid crystal display, an organic EL (electroluminescence) display, and a CRT (cathode ray tube) display. The display device displays display data including content. The display device may also have an input I/F function, such as a touch screen. The display unit 103 is an example of a display means.

Memory 104 stores programs executed by processor 105 to realize each process, data used by processor 105, and the like. Memory 104 may include a RAM having a work area in which such programs/data are expanded. Programs stored include, for example, firmware, an OS, and communication programs as appropriate. For example, the programs of communication terminal 100 store data such as names, units, and settable ranges for all internal parameters in advance, which can prevent erroneous values from being entered into control panel 42.

The processor 105 is typically a CPU, but may be a microcomputer, FPGA, DSP, or other general-purpose or dedicated processor. The processor 105 performs wireless communication with the water supply device 1 via the communication unit 101 and executes processing to manage the water supply device 1. The processor 105 can function as the communication control unit 105a and processing unit 105b of FIG. 2 by executing a program stored in the memory 104. The functional division of the various units within the processor 105 is for convenience and can be changed as appropriate. The communication control unit 105a and processing unit 105b are examples of a first receiving means, a first changing means, a first transmitting means, a second receiving means, a second changing means, and a second transmitting means.

The communication control unit 105a controls the communication unit 101 to perform wireless communication with the water supply device 1. For example, the communication control unit 105a transmits a connection request to the control panel 42 that transmitted the advertising packet. The communication control unit 105a may also transmit some data for establishing a connection with the water supply device 1 via the communication unit 101, or transmit a request to the water supply device 1 in response to an operation by an operator. Alternatively, the communication control unit 105a may receive some data for establishing a connection between the communication terminal 100 and the water supply device 1, for example, a request from the water supply device 1 as an advertiser when the water supply device 1 and the communication terminal 100 are connected via Bluetooth as a scanner and an advertiser, respectively.

When communication is established between the communication terminal 100 and the communication unit 61, for example, when the target device is in an automatic operation mode, the communication control unit 105a receives various operating data and external parameters from the communication unit 61 of the water supply device 1 via the communication unit 101.

The processing unit 105b performs information processing according to the work of the worker, such as inspection, maintenance, management, and parameter viewing and changing of the water supply device 1.

For example, when the communication unit 101 receives various operating data and external parameters, the processing unit 105b displays a portion of the received content on the display unit 103, and changes the portion to be displayed in response to the operator's scrolling operation.

Next, an example of water supply using constant target pressure control of the water supply device 1 according to this embodiment will be described using the flow chart shown in FIG.

When the water supply device 1 is powered on and a predetermined standby time has elapsed or the pump 22 is stopped, the processor 67 monitors the detection signal from the pressure sensor 15 and determines whether or not to perform start-up processing of the pump 22 (step ST11). As a specific example, the processor 67 compares the secondary pressure of the pump 22 detected by the pressure sensor 15 with a start-up pressure as a threshold value stored in the memory 66 or the like.

If the suction pressure detected by the pressure sensor 15 is higher than the start pressure (NO in step ST11), it is determined that there is no need to supply water to the destination, and the processor 67 keeps the pump 22 stopped, monitors the detection signal from the pressure sensor 15, and continues to determine whether to perform the start process for the pump 22.

If the suction pressure detected by the pressure sensor 15 is equal to or lower than the starting pressure (YES in step ST11), the processor 67 generates an inverter control signal, outputs the inverter control signal to the inverter 51, and controls the motor 23. That is, the processor 67 starts the pump 22 (step ST12).

After starting the pump 22, the processor 67 operates the pump 22 independently using constant estimated end pressure control (step ST13), as an example of constant target pressure control, and starts supplying water.

While the pumps 22 are operating under constant target pressure control, the processor 67 determines whether or not the pumps 22 need to be increased (step ST14). That is, the processor 67 monitors the operating frequency of the inverter 51, and if the operating frequency of the inverter 51 is not the maximum operating frequency (NO in step ST14), the processor 67 continues to drive the pumps 22 under constant target pressure control. If the operating frequency of the inverter 51 is at the maximum output (YES in step ST14), the processor 67 performs an increase in the number of pumps 22 and increases the number of pumps 22 (step ST15). After increasing the number of pumps 22, the processor 67 sets the operating frequencies of the multiple pumps 22 (two in this embodiment) to the same frequency, and controls the operation of the two pumps 22 under constant estimated terminal pressure control by speed matching operation (step ST16).

The processor 67 drives and controls the two pumps 22 in a speed matching operation and determines whether or not the pumps 22 need to be reduced (step ST17). That is, the processor 67 constantly detects the operating frequency of the inverter 51 or the rotation speed of the pumps 22 (motor 23) and determines whether the above-mentioned reduction condition is met. If the reduction condition is not met (NO in step ST17), the processor 67 continues to drive the two pumps 22 with constant estimated end pressure control by speed matching operation. If the reduction condition is met (YES in step ST17), the processor 67 stops one of the pumps 22 and reduces the number of pumps 22 (step ST18). Then, the process returns to step ST13, and the processor 67 drives and controls the pumps 22 in independent operation or speed matching operation with constant estimated end pressure control until the flow rate detected by the flow rate sensor 14 becomes the stop flow rate.

The water supply system 1 configured in this way uses multiple pumps with variable speed drives to efficiently operate at constant target pressure with uniform speed control, which is highly energy-efficient, and can determine the conditions for reducing the number of pumps (disconnecting the parallel-up) without increasing the number of detection devices.

That is, in conventional pump 22 reduction (disconnection), in multiple simultaneous speed operation, the flow sensor does not operate unless the water volume on the secondary side of the multiple pumps 22 decreases to the low water volume region, and therefore the pumps are disconnected at a water volume close to shutoff operation. For example, to solve this problem, it is necessary to separately install a flow sensor that outputs linearly for each water volume, but installing such a flow sensor separately increases manufacturing costs. However, with the water supply device 1 according to this embodiment, it is possible to find the disconnection point at which the operation changes from simultaneous speed operation to independent operation by using the operating frequency that can be output from the inverter 51 or the rotation speed of the pump 22 (motor 23) without installing a new flow sensor.

As described above, according to the water supply device 1 and the control method and program for the water supply device 1 of the first embodiment, it is possible to determine the condition for reducing the number of pumps when multiple pumps 22 are operating at the same speed without increasing the number of detection devices.

Second Embodiment
Next, a water supply device 1 according to a second embodiment of the present invention will be described. Note that the water supply device 1 according to the second embodiment has a different unit reduction (disconnection) condition from the water supply device 1 according to the first embodiment described above, but other configurations are similar, so the same reference numerals are used for similar configurations and descriptions are omitted.

Based on a program stored in memory 66 or the like, processor 67 performs processes for driving pump 22 with constant target pressure control operation, such as starting pump 22, water supply process by operating pump 22 alone, process for increasing pump 22, and water supply process by operating multiple pumps 22 at the same speed, as in the first embodiment. In addition, based on a program stored in memory 66 or the like, processor 67 performs a reduction process for reducing (disconnecting) pumps 22 when a reduction condition is satisfied while driving multiple pumps 22 with constant target pressure control operation with the same speed operation. For ease of explanation, the reduction condition in this embodiment will be described below as a second reduction condition.

A specific example of the unit reduction process performed by the processor 67 based on the second unit reduction condition is described below. The processor 67 performs unit reduction process to reduce (disconnect) the pumps 22 when multiple pumps 22 are driven under constant target pressure control with synchronized speed operation. As a specific example, the processor 67 constantly detects the operating frequency of the inverter 51 or the rotation speed of the pumps 22 (motor 23) when multiple (n) pumps 22 are driven under constant target pressure control with synchronized speed operation.

Furthermore, when the power consumption of one pump at the maximum rotation speed of the pump 22 (motor 23) Fmax (maximum operating frequency of the inverter 51) is Pmax, the power consumption of the total number of pumps (n-x) in operation immediately before the increase in the number of pumps is P1 = Pmax x (n-x), and the power consumption at the rotation speed of the pump 22 (motor 23) Fmin (operating frequency of the inverter 51) when one pump is operating with a low water volume is Pmin, the processor 67 stores at least one of Fmax, Pmax, and P1, Fmin, and Pmin in at least one of the inverter control board 52, memory 66, EEPROM area 67a, and/or DRAM area 67b.

Furthermore, if the power consumption of the total number of operating units (n-x+1) when the unit reduction (disconnection) condition is satisfied (immediately before the unit reduction) after multiple units are operated in parallel at the same speed is P2, and the operating frequency of the inverter 51 or the rotation speed of the pump 22 (motor 23) when the unit reduction (disconnection) condition is satisfied is F2, the processor 67 will not reduce (disconnect) the units when P2<P1, because not reducing (disconnecting) the units will result in a more efficient operating water volume, and will continue to operate the multiple pumps 22 at the same speed under constant target pressure control. Then, when the current operating frequency of the inverter 51 or the rotation speed of the pump 22 (motor 23) Fnow satisfies the second unit reduction (disconnection) condition below, the processor 67 will perform the unit reduction (disconnection) process.

The second reduction (disconnection) condition is:
Fnow<F2-{(P1-P2) x (Fmax-Fmin)}/{(Pmax-Pmin) x (n-x+1)}
It is.

For example, when the number n of the pumps 22 is two (n=2) and the number x of the pumps 22 to be reduced is one (x=1), the off-parallel point is:
Fnow<F2-{(Pmax-P2) x (Fmax-Fmin)}/{(Pmax-Pmin) x 2}
Then, when the current operating frequency of the inverter 51 or the rotation speed Fnow of the pump 22 (motor 23) satisfies the above condition, the processor 67 reduces (disconnects) the pump 22.

In addition, for example, when the number n of the pumps 22 is three (n=3) and the number x of the pumps 22 to be reduced is one (x=1), the off-parallel point is expressed as follows:
When reducing the number of pumps 22 from three to two,
Fnow<F2-{(Pmax x 2-P2) x (Fmax-Fmin)}/{(Pmax-Pmin) x 3}
And then,
When reducing the number of pumps 22 from two to one,
Fnow<F2-{(Pmax-P2) x (Fmax-Fmin)}/{(Pmax-Pmin) x 2}
Then, when the current operating frequency of the inverter 51 or the rotation speed Fnow of the pump 22 (motor 23) satisfies the above condition, the processor 67 reduces (disconnects) the pump 22.

The formula for calculating the disconnection point as a condition for reducing the number of units is stored as a program in memory 66 or EEPROM area 67a. For example, in shipping tests of the water supply device 1, if an actual measurement is obtained and the device is disconnected at the disconnection point determined by the above formula, and there is a deviation from the target disconnection point, a formula for making a correction corresponding to the actual device may be stored as a program in memory 66 or EEPROM area 67a. For example, one example of a correction corresponding to the actual device is a configuration in which a coefficient is added as a correction value, but the correction can be set as appropriate.

According to the water supply device 1, the control method and the program for the water supply device 1 of the second embodiment configured in this manner, it is possible to determine the reduction condition when multiple pumps 22 are operating at the same speed, without increasing the number of detection devices, as with the water supply device 1 of the second embodiment described above.

In addition, if the power consumption P1 of the total number of operating pumps 22 (n-x) after parallel-off is greater than the power consumption P2 of the total number of operating pumps (n-x+1) when the second reduction (disconnection) condition is met after multiple pumps are operated in parallel at the same speed (P2<P1), not reducing (disconnecting) the pumps will result in a more efficient operating water volume. For this reason, by not disconnecting the pumps when P2<P1, the water supply device can reduce power consumption and operate more efficiently.

Furthermore, the second unit reduction (disconnection) condition of the water supply device 1 according to the second embodiment may be used together with the first unit reduction condition, or may be used only with the second unit reduction condition.

That is, in a water supply device 1 using the first and second reduction conditions, when the rotation speed Fnow of the pump 22 (motor 23) satisfies the first reduction condition, if P2 ≧ P1, the pump 22 is reduced; when the rotation speed Fnow satisfies the first reduction condition and P2 < P1, the pump is not reduced; and when the rotation speed Fnow satisfies the second reduction condition, the pump 22 is reduced.

In addition, in the case of a water supply device 1 that uses only the second reduction condition, if the rotation speed Fnow satisfies the second reduction condition and P2 ≧ P1, the number of pumps 22 is reduced, and if the rotation speed Fnow satisfies the second condition and P2 < P1, the number of pumps is reduced the next time the rotation speed Fnow satisfies the second reduction condition.

In addition, the water supply device 1 may have both the first and second unit reduction conditions stored as programs in the memory 66, etc., so that the input unit 62 or the setting unit 65 can select whether to perform the unit reduction process under the first unit reduction condition, the second unit reduction condition, or the first and second unit reduction conditions. Also, at the time of shipment, the first unit reduction condition, the second unit reduction condition, or both unit reduction conditions may be selectively stored as programs so that either can be de-paralleled.

As described above, the water supply device 1, the control method and the program for the water supply device 1 according to the second embodiment make it possible to determine the condition for reducing the number of pumps when multiple pumps 22 are operating at the same speed without increasing the number of detection devices.

Third Embodiment
Next, a water supply device 1 according to a third embodiment of the present invention will be described. Note that the water supply device 1 according to the third embodiment has different conditions for reducing (disconnecting) the number of units from the water supply device 1 according to the first embodiment and the water supply device 1 according to the second embodiment described above, but since the other configurations are similar, the same symbols are used for similar configurations and descriptions are omitted.

Based on a program stored in memory 66 or the like, processor 67 performs processes for driving pump 22 with constant target pressure control operation, such as starting pump 22, water supply process by operating pump 22 alone, process for increasing pump 22, and water supply process by operating multiple pumps 22 at the same speed, as in the first embodiment. In addition, based on a program stored in memory 66 or the like, processor 67 performs a reduction process for reducing (disconnecting) pumps 22 when a reduction condition is satisfied while driving multiple pumps 22 with constant target pressure control operation with the same speed operation. For ease of explanation, the reduction condition in this embodiment will be described below as a third reduction condition.

A specific example of the unit reduction process performed by the processor 67 based on the third unit reduction condition is described below. The processor 67 performs unit reduction process to reduce (disconnect) the pumps 22 when multiple pumps 22 are driven under constant target pressure control with uniform speed operation. As a specific example, the processor 67 constantly detects the operating frequency of the inverter 51 or the rotation speed of the pumps 22 (motor 23) when multiple (n) pumps 22 are driven under constant target pressure control with uniform speed operation.

Furthermore, the maximum rotation speed of the pump 22 (motor 23) (maximum operating frequency of the inverter 51) Fmax and the rotation speed of the pump 22 (motor 23) when operating alone with a small water volume (operating frequency of the inverter 51) Fmin are stored in advance in at least one of the inverter control board 52, memory 66, EEPROM area 67a and/or DRAM area 67b.

Then, when the current operating frequency of the inverter 51 or the rotation speed Fnow of the pump 22 (motor 23) satisfies the third unit reduction (disconnection) condition below, the processor 67 performs the unit reduction (disconnection) process.

The conditions for the third reduction (disconnection) are:
Fnow<Fmin+(Fmax-Fmin)×[{(n-x)/n} ² +α]+β
Here, α and β are correction values and are preset coefficients.

For example, when the number n of the pumps 22 is two (n=2) and the number x of the pumps 22 to be reduced is one (x=1), the off-parallel point is:
Fnow < Fmin + (Fmax - Fmin) x {(1/2) ² + α} + β
Then, when the current operating frequency of the inverter 51 or the rotation speed Fnow of the pump 22 (motor 23) satisfies the above condition, the processor 67 reduces (disconnects) the pump 22.

In addition, for example, when the number n of the pumps 22 is three (n=3) and the number x of the pumps 22 to be reduced is one (x=1), the off-parallel point is expressed as follows:
When reducing the number of pumps 22 from three to two,
Fnow < Fmin + (Fmax - Fmin) x {(2/3) ² + α} + β
And then,
When reducing the number of pumps 22 from two to one,
Fnow < Fmin + (Fmax - Fmin) x {(1/3) ² + α} + β
Then, when the current operating frequency of the inverter 51 or the rotation speed Fnow of the pump 22 (motor 23) satisfies the above condition, the processor 67 reduces (disconnects) the pump 22.

Here, constant target pressure control includes constant discharge pressure control and constant estimated end pressure control.

First, in the case of constant discharge pressure control, the correction values α and β are α ≒ 0 and β ≒ 0.

Therefore, the disconnection condition in constant discharge pressure control is
Fnow < Fmin + (Fmax - Fmin) x (n - x) / ⁿ²
It becomes.

Next, in the case of constant estimated end pressure control, when the set head at the maximum rotation speed (maximum operating frequency of inverter 51) Fmax of pump 22 (motor 23) when the water volume is large is H1, and the set head at the rotation speed (operating frequency of inverter 51) Fmin of pump 22 (motor 23) when the water volume is small is H2, and the head difference between H1 and H2 is Hd = H1 - H2, the correction values α and β are α ≒ γ × Hd and β ≒ 0. Here, γ is set to the optimal value depending on the pump model (including bore, output, and type), number of units (n units), and number of units to be reduced (x units).

Therefore, the disconnection condition in the estimated constant terminal pressure control is as follows:
Fnow<Fmin+(Fmax-Fmin)×[{(n-x)/n} ² +γ×Hd]
It becomes.

The above-mentioned correction value β is set to β ≒ 0 because β ≒ 0 is acceptable for pumps 22 with a small maximum water volume, a high set head, or a small number of pumps n. On the other hand, for pumps 22 with a large maximum water volume, a low set head, or a large number of pumps n, constant estimated end pressure control will have a large effect due to the piping resistance, so adding a correction value β will result in more accurate control. For this reason, the correction value β is set appropriately for each model of water supply device 1 and installation conditions, etc., based on the effect of the piping resistance.

The formula for calculating the disconnection point as a condition for reducing the number of units is stored as a program in memory 66 or EEPROM area 67a. For example, in shipping tests of water supply device 1, if actual measurements are obtained and the device is disconnected at the disconnection point determined by the above formula, and there is a deviation from the target disconnection point, a formula for making corrections corresponding to the actual device may be stored as a program in memory 66 or EEPROM area 67a.

According to the water supply device 1, the control method and the program for the water supply device 1 of the third embodiment configured in this manner, as with the water supply device 1 of the first embodiment described above, it is possible to determine the condition for reducing the number of pumps when multiple pumps 22 are operating at the same speed without increasing the number of detection devices.

Fourth Embodiment
Next, a water supply device 1 according to a fourth embodiment of the present invention will be described. Note that the water supply device 1 according to the fourth embodiment has different unit reduction (disconnection) conditions from the water supply device 1 according to the third embodiment described above, but other configurations are similar, so the same reference numerals are used for similar configurations and descriptions are omitted.

Based on a program stored in memory 66 or the like, processor 67 performs processes for driving pump 22 with constant target pressure control operation, such as starting pump 22, water supply process by operating pump 22 alone, process for increasing pump 22, and water supply process by operating multiple pumps 22 at the same speed, as in the third embodiment. In addition, based on a program stored in memory 66 or the like, processor 67 performs a reduction process for reducing (disconnecting) pumps 22 when a reduction condition is satisfied while driving multiple pumps 22 with constant target pressure control operation with the same speed operation. For ease of explanation, the reduction condition in this embodiment will be described below as a fourth reduction condition.

A specific example of the unit reduction process performed by the processor 67 based on the fourth unit reduction condition is described below. The processor 67 performs unit reduction processing to reduce (disconnect) the pumps 22 when multiple pumps 22 are driven under constant target pressure control with uniform speed operation. As a specific example, when multiple (n) pumps 22 are driven under constant target pressure control with uniform speed operation, the processor 67 constantly detects the operating frequency of the inverter 51 or the rotation speed of the pumps 22 (motor 23).

Furthermore, when the power consumption at the maximum rotation speed Fmax (maximum operating frequency of inverter 51) of pump 22 (motor 23) is Pmax, the power consumption of the total number of operating units (n-x) immediately before the increase in units is P1 = Pmax x (n-x), and the power consumption at the rotation speed Fmin (operating frequency of inverter 51) of pump 22 (motor 23) when operating one unit with a low water volume is Pmin, the processor 67 stores at least one of Fmax, Pmax, and P1, Fmin, and Pmin in at least one of the inverter control board 52, memory 66, EEPROM area 67a, and/or DRAM area 67b.

Furthermore, after multiple pumps are operated in parallel in speed-matching operation, the power consumption of the total number of operating pumps (n-x+1) when the conditions for reducing (disconnecting) the pumps are satisfied (immediately before reducing) is P2, the rotation speed of the pumps 22 (motor 23) or the operating frequency of the inverter 51 when the conditions for reducing (disconnecting) the pumps are satisfied is F2, the power consumption of the total number of operating pumps in parallel operation in speed-matching operation immediately after the number of pumps 22 is increased is P3, and the operating frequency of the inverter 51 or the rotation speed of the pumps 22 (motor 23) when multiple pumps are operated in parallel in speed-matching operation immediately after the number of pumps 22 is increased is F3. Then, when P2<P1 or P3<P1, the processor 67 does not reduce (disconnect) the pumps because not reducing (disconnecting) the pumps results in a more efficient operating water volume, and continues the speed-matching operation of the multiple pumps 22 under constant target pressure control. Then, when the current operating frequency of the inverter 51 or the rotation speed Fnow of the pump 22 (motor 23) satisfies the fourth unit reduction (disconnection) condition below, the processor 67 performs the unit reduction (disconnection) process.

The conditions for the fourth reduction (disconnection) are:
If P2<P1,
Fnow<F2-(P1-P2)/δ+β
And then,
If P3<P1,
Fnow < F3 - (P1 - P3) / ε + β
Here, the coefficients δ and ε are design values that are set in advance by the water supply apparatus 1 when P2<P1 or P3<P1, and when the water supply apparatus 1 is disconnected, the operation after disconnection will be a highly efficient operating water amount. Note that the values of the coefficients (correction values) α, β, γ, δ, and ε may be obtained from values actually measured at the time of shipment, etc. for each model of the water supply apparatus 1. This is because a more suitable point for reducing the number of units (disconnection) can be obtained.

The formula for calculating the disconnection point as a condition for reducing the number of units is stored as a program in memory 66 or EEPROM area 67a. For example, in shipping tests of the water supply device 1, if an actual measurement is obtained and the device is disconnected at the disconnection point determined by the above formula, and there is a deviation from the target disconnection point, a formula for making a correction corresponding to the actual device may be stored as a program in memory 66 or EEPROM area 67a. For example, one example of a correction corresponding to the actual device is a configuration in which a coefficient is added as a correction value, but the correction can be set as appropriate.

According to the water supply device 1, the control method and the program for the water supply device 1 of the fourth embodiment configured in this manner, as with the water supply device 1 of the second embodiment described above, it is possible to determine the reduction condition when multiple pumps 22 are operating at the same speed without increasing the number of detection devices.

In addition, if the power consumption P1 of the total number of operating pumps 22 (n-x) after parallel-off is greater than the power consumption P2 of the total number of operating pumps (n-x+1) when the second reduction (disconnection) condition is met after multiple pumps are operated in parallel at the same speed (P2<P1), not reducing (disconnecting) the pumps will result in a more efficient operating water volume. Similarly, or if P3<P1, not reducing (disconnecting) the pumps will result in a more efficient operating water volume. For this reason, by not disconnecting the pumps when P2<P1 or P3<P1, the water supply system can reduce power consumption and operate more efficiently.

The fourth unit reduction (disconnection) condition of the water supply device 1 according to the fourth embodiment may be used together with the third unit reduction condition, or may be used only with the fourth unit reduction condition. The fourth embodiment has been described as an example in which the fourth unit reduction condition is Fnow<F2-(P1-P2)/δ+β when P2<P1, and Fnow<F3-(P1-P3)/ε+β when P3<P1, but is not limited to this. The fourth unit reduction condition may be only Fnow<F2-(P1-P2)/δ+β, or may be only Fnow<F3-(P1-P3)/ε+β.

That is, in the case of a water supply device 1 using the third and fourth reduction conditions, when the rotation speed Fnow satisfies the third reduction condition, it is determined that P2 ≧ P1 or P3 ≧ P1, and if this condition is met, the number of pumps 22 is reduced, when the rotation speed Fnow satisfies the third reduction condition and P2 < P1 or P3 < P1, the number of pumps is not reduced, and when the rotation speed Fnow satisfies the fourth reduction condition, the number of pumps 22 is reduced.

In addition, in the case of a water supply device 1 that uses only the fourth reduction condition, if the rotation speed Fnow satisfies the fourth reduction condition and P2 ≧ P1 or P3 ≧ P1, the number of pumps 22 is reduced, and if the rotation speed Fnow satisfies the fourth reduction condition and P2 < P1, the number of pumps is reduced the next time the rotation speed Fnow satisfies the fourth reduction condition.

In addition, the water supply device 1 may store both the third and fourth machine reduction conditions as programs in the memory 66, etc., so that the input unit 62 or the setting unit 65 can select whether to perform the machine reduction process under the third machine reduction condition, the fourth machine reduction condition, or the third and fourth machine reduction conditions. Also, at the time of shipment, the third machine reduction condition, the fourth machine reduction condition, or both machine reduction conditions may be selectively stored as programs so that any machine reduction can be performed. In addition, the water supply device 1 may be configured to store the first to fourth machine reduction conditions and select any of the machine reduction conditions.

As described above, the water supply device 1, the control method and the program for the water supply device 1 according to the fourth embodiment make it possible to determine the condition for reducing the number of pumps when multiple pumps 22 are operating at the same speed without increasing the number of detection devices.

The present invention is not limited to the above-mentioned embodiments. In other words, the water supply device 1, the control method and the program for the water supply device 1 are only required to be able to determine the reduction condition in the reduction (disconnection) process of the parallel operation of the parallel operation of the multiple pumps 22 at the same frequency without providing a new detection device such as a flow sensor. Therefore, each configuration of the water supply device 1 described above can be set appropriately.

For example, in the above example, the water supply device 1 is of a direct connection type, and the primary side of the multiple pumps 22 is connected to a water distribution pipe, but it may also be of a water tank type, and the primary side of the multiple pumps 22 may be connected to a water tank that is a water supply source.

In the above example, the water supply device 1 is configured to include two pumps 22 as the multiple pumps 22, and in the explanation of the unit reduction process, an example in which the number of pumps 22 is three in addition to two has been explained, but this is not limited to this, and the number of pumps 22 can be set as appropriate. In addition, the number of pumps 22 to be increased during unit increase processing, and the number x of pumps 22 to be disconnected during unit reduction (disconnection) processing may be one or more.

In the above example, examples of the calculation formulas were explained for the first to fourth unit reduction conditions when performing unit reduction processing in the control method of the water supply device 1. These calculation formulas are for finding the disconnection point, and the unit reduction conditions are set to values calculated by calculating the unit reduction conditions that result in an optimal unit reduction. This set calculation formula correction value is set, and if units are reduced (disconnected) with the water volume using this correction value, there is a risk of the so-called "chattering phenomenon" occurring, in which units are increased (connected in parallel) immediately after the reduction (disconnection).

Therefore, in the first and second reduction conditions, the formula may be one in which a correction value β is added to the formula, and the correction value β in the first and second reduction conditions may be a negative value, thereby instructing a subtraction to the formula for the parallel-off condition, thereby preventing the "chattering phenomenon". Similarly, in the third and fourth reduction conditions, the correction value β may be a negative value, thereby instructing a subtraction to the formula for the parallel-off condition, thereby preventing the "chattering phenomenon".

As a method for preventing chattering reduction, the processor 67 measures the time until the next machine increase process is performed after the machine reduction process is performed under any of the above-mentioned first machine reduction condition to fourth machine reduction condition, and determines that the chattering phenomenon is occurring if this measured time is shorter than a predetermined time previously stored in the memory 66 or the like, and adds a correction value β to the calculation formula for the machine reduction condition, or may set the correction value β to a negative value. In addition, the determination that the chattering phenomenon is occurring may be made by measuring the time until the next machine increase process is performed after the machine reduction process is performed, and determining that the chattering phenomenon is occurring if the measured time is shorter than the predetermined time previously stored in the memory 66 or the like multiple times, consecutively or discontinuously.

In the above example, the water supply device 1 has a pressure sensor 15 on the secondary side of the pump 22. However, as a modification of this embodiment, as shown in FIG. 5, the pressure sensor 15 may be provided on both the primary and secondary sides of the pump 22. For example, a first pressure sensor 15A is provided on the suction pipe 31, and the first pressure sensor 15A detects the pressure in the suction pipe 31 as the suction pressure, and outputs the obtained detection signal to the control device 17. A second pressure sensor 15B is provided on the discharge pipe 36, and the second pressure sensor 15B detects the pressure in the discharge pipe 36 as the discharge pressure or the pressure on the secondary side of the pump 22, and outputs the obtained detection signal to the control device 17.

As a specific example, when the control panel 42 detects that the suction pressure calculated from the detection signal detected by the first pressure sensor 15A is equal to or greater than a predetermined pressure value, and that the secondary pressure of the pump 22 calculated from the detection signal detected by the second pressure sensor 15B has dropped below a predetermined starting pressure, the control panel 42 drives the motor 23 to start the pump 22. When the control panel 42 detects that the flow rate is low based on the detection signal from the flow sensor 14, it stops the pump 22.

In this modified water supply device 1, for example, the processor 67 drives one of the motors 23 when the suction pressure detected by the first pressure sensor 15A is higher than a predetermined suction pressure as a first threshold value stored in the memory 66 or the like, and the secondary pressure of the pump 22 detected by the second pressure sensor 15B is lower than a predetermined starting pressure as a second threshold value stored in the memory 66 or the like. That is, when the processor 67 determines that the predetermined suction pressure is secured and that the secondary pressure of the pump 22 is equal to or lower than the starting pressure, it generates an inverter control signal to start one of the motors 23, outputs the inverter control signal to the inverter 51, and controls the motor 23. This performs the start-up process of the pump 22.

Therefore, for example, in step ST11 described above, if the suction pressure detected by the first pressure sensor 15A is lower than the first threshold value and/or if the suction pressure detected by the second pressure sensor 15B is higher than the second threshold value (NO in step ST11), the processor 67 keeps the pump 22 stopped, monitors the detection signal from the pressure sensor 15, and continues to determine whether or not to perform a start-up process for the pump 22.

In other words, when the suction pressure detected by the first pressure sensor 15A is lower than the first threshold, the supply pressure of the water distribution pipe is low, and the processor 67 does not drive the pump 22. Also, when the secondary pressure of the pump 22 detected by the second pressure sensor 15B is higher than the second threshold, the processor 67 does not drive the pump 22 because it is not necessary to supply water to the destination.

If the suction pressure detected by the first pressure sensor 15A is equal to or greater than the first threshold value and the suction pressure detected by the second pressure sensor 15B is equal to or less than the second threshold value (YES in step ST11), the processor 67 generates an inverter control signal and outputs the inverter control signal to the inverter 51 to control the motor 23. That is, the processor 67 starts the pump 22 (step ST12).

In the above example, an example of a program that causes each means to function to perform start-up processing, increasing the number of units, water supply processing, and decreasing the number of units is described as an example of control of each component of the control device 17 as a computer. However, this program is not limited to an example in which the program is stored in the memory 66 or the like as a storage medium of the control device 17 and the processor 67 executes the program stored in the memory 66 or the like. For example, it can also be realized by using a processor installed in a general-purpose computer as basic hardware.

The program that realizes the above processing may be provided by being stored in a computer-readable storage medium. The program is stored in the storage medium as a file in an installable format or an executable format. Examples of storage media include magnetic disks, optical disks (CD-ROM, CD-R, DVD, etc.), magneto-optical disks (MO, etc.), and semiconductor memories. Any storage medium can be used as long as it can store a program and is computer-readable. The program that realizes the above processing may be stored on a computer (server) connected to a network such as the Internet, and downloaded to a computer (client) via the network.

The present invention is not limited to the above-described embodiment, and various modifications can be made in the implementation stage without departing from the gist of the invention. The embodiments may be implemented in appropriate combination, in which case the combined effects can be obtained. Furthermore, the above-described embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple constituent elements disclosed. For example, if the problem can be solved and an effect can be obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the configuration from which these constituent elements are deleted can be extracted as an invention.

1...water supply device, 11...pump unit, 12...branch pipe, 13...junction pipe, 14...flow rate sensor, 15...pressure sensor, 15A...first pressure sensor, 15B...second pressure sensor, 16...pressure accumulator, 17...control device, 21...first on-off valve, 22...pump, 23...motor, 24...check valve, 25...second on-off valve, 31...suction pipe, 32...branch section, 33...branch pipe, 34...junction pipe, 35...junction section, 36...discharge pipe, 41...inverter box, 42...control panel, 51... inverter, 52... inverter control board, 61... communication unit, 62... input unit, 63... interface, 64... display unit, 65... setting unit, 66... memory, 67... processor, 67a... EEPROM area, 67b... DRAM area, 67c... processing unit, 67d... pump control unit, 100... communication terminal, 101... communication unit, 102... input unit, 103... display unit, 104... memory, 105... processor, 105a... communication control unit, 105b... processing unit.

Claims (12)

A plurality of pumps;
A check valve provided on a secondary side of the plurality of pumps;
A plurality of flow rate sensors respectively connected to the secondary sides of the plurality of pumps;
a pressure sensor connected to a secondary side of the plurality of pumps;
By increasing or decreasing the number of pumps, any of the plurality of pumps is independently operated under the target constant pressure control, or the plurality of pumps are operated at the same speed under the target constant pressure control, and the rotation speed of the pump is Fnow, the low water flow rotation speed during low water flow is Fmin, the maximum rotation speed is Fmax, the number of pumps is n, and the number of pumps to be reduced from the number n of pumps is x, the first reduction condition is:
Fnow < Fmin + (Fmax - Fmin) x {(n-x) / n} ²
a control device that reduces the number of pumps in operation when the
Equipped with
The control device defines the power consumption of one pump at the maximum rotation speed Fmax immediately before the number of pumps is increased as Pmax, the power consumption of the total number of operating pumps (n-x) immediately before the number of pumps is increased as P1=Pmax×(n-x), the power consumption when one pump is operating at a low water volume as Pmin, the power consumption of the total number of operating pumps (n-x+1) when the first unit reduction condition is satisfied after the multiple pumps are operated in the speed-matching operation as P2, and the rotation speed of the pump when the first unit reduction condition is satisfied as F2, and if P2<P1, the control device continues the speed-matching operation of the multiple pumps without reducing the number of pumps even after the first unit reduction condition is satisfied, and then, as a second unit reduction condition,
Fnow<F2-{(P1-P2) x (Fmax-Fmin)}/{(Pmax-Pmin) x (n-x+1)}
When the above condition is satisfied, the number of pumps in operation is reduced . A plurality of pumps;
A check valve provided on a secondary side of the plurality of pumps;
A plurality of flow rate sensors respectively connected to the secondary sides of the plurality of pumps;
a pressure sensor connected to a secondary side of the plurality of pumps;
By increasing or decreasing the number of pumps, any of the plurality of pumps is independently operated under the target pressure constant control, or the plurality of pumps are operated at the same speed under the target pressure constant control, and the rotation speed of the pump is set to Fnow, the low water flow rotation speed at the time of low water flow is set to Fmin, the maximum rotation speed is set to Fmax, the power consumption at the time of low water flow when one pump is operated is set to Pmin, the maximum rotation speed immediately before the number of pumps is increased to Fmax, and the power consumption of one pump at the maximum rotation speed Fmax immediately before the number of pumps is increased is set to Pmax, the power consumption of the total number of operating pumps (n-x) immediately before the number of pumps is increased is P1 = Pmax x (n-x), the number of pumps is n, and the number of pumps to be reduced from the number of pumps n is x. After operating the multiple pumps increased in the speed-matching operation, the power consumption of the total number of operating pumps (n-x+1) immediately before the reduction is P2, and the rotation speed of the pump immediately before the reduction is F2. If P2 < P1, the multiple pumps are not reduced and the speed-matching operation is continued, and then , as a reduction condition,
Fnow<F2-{(P1-P2) x (Fmax-Fmin)}/{(Pmax-Pmin) x (n-x+1)}
a control device that reduces the number of pumps in operation when the
A water supply device comprising: 3. The water supply apparatus according to claim 1, wherein the control device operates all of the plurality of pumps at the same speed when operating the plurality of pumps after increasing or decreasing the number of pumps. The water supply device according to any one of claims 1 to 3, wherein the control device, when reducing the number of pumps, stops the pumps in the order in which they were started, or stops the pumps in the reverse order of their starting order , or stops the pump with the longest accumulated operating time. A method for controlling a water supply device by a control device, comprising:
When the pressure on the secondary side of the plurality of pumps is equal to or lower than a starting pressure, starting one of the pumps;
The pump is driven under constant target pressure control.
When the pump is at a maximum rotation speed, the number of pumps is increased,
The increased number of pumps are operated at the same rotation speed under the constant target pressure control,
A first reduction condition is satisfied when the rotation speed of the pump is Fnow, the low water flow rotation speed during low water flow is Fmin, the maximum rotation speed is Fmax, the number of the pumps is n, and the number of the pumps to be reduced from the number n of the pumps is x.
Fnow < Fmin + (Fmax - Fmin) x {(n-x) / n} ²
Determine whether
When the power consumption of one pump at the maximum rotation speed Fmax immediately before the number of pumps is increased is Pmax, the power consumption of the total number of operating pumps (n-x) immediately before the number of pumps is increased is P1=Pmax×(n-x), the power consumption when one pump is operating at a low water volume is Pmin, the power consumption of the total number of operating pumps (n-x+1) when the first pump reduction condition is met after the multiple pumps that have been increased in the speed-matching operation are operated is P2, and the rotation speed of the pumps when the first pump reduction condition is met is F2, then
When the first reduction condition is satisfied, and P2≧P1 is satisfied, the number of pumps in operation is reduced;
When the first reduction condition is satisfied and P2<P1, the pumps are not reduced even after the first reduction condition is satisfied, and the speed matching operation is continued by the plurality of pumps;
When the first machine reduction condition is satisfied and P2<P1, the speed matching operation is continued, and then the second machine reduction condition is satisfied.
Fnow<F2-{(P1-P2) x (Fmax-Fmin)}/{(Pmax-Pmin) x (n-x+1)}
The method for controlling a water supply apparatus comprises reducing the number of pumps in operation when the above condition is met . A plurality of pumps;
A check valve provided on a secondary side of the plurality of pumps;
A plurality of flow rate sensors respectively connected to the secondary sides of the plurality of pumps;
a pressure sensor connected to a secondary side of the plurality of pumps;
By increasing or decreasing the number of pumps, any of the plurality of pumps is independently operated under the target constant pressure control, or the plurality of pumps are operated at the same speed under the target constant pressure control, and the rotation speed of the pump is Fnow, the low water flow rotation speed during low water flow is Fmin, the maximum rotation speed is Fmax, the number of pumps is n, the number of pumps to be reduced from the number n of pumps is x, and the correction values are α and β. When these are set as the third reduction condition,
Fnow<Fmin+(Fmax-Fmin)×[{(n-x)/n} ² +α]+β
a control device that reduces the number of pumps in operation when
A water supply device comprising: The water supply apparatus according to claim 6 , wherein the correction value β is set based on the influence of piping resistance. The water supply apparatus according to claim 6 or 7, wherein the correction value β is a negative value. When the power consumption of the total number of operating pumps (n-x) immediately before the number of pumps is increased is P1, the power consumption of the total number of operating pumps (n-x+1) when the third reduction condition is satisfied is P2, the rotation speed of the pumps when the third reduction condition is satisfied is F2, the power consumption of the total number of operating pumps in the speed-synchronized operation immediately after the number of pumps is increased is P3, the rotation speed of the pumps in the speed-synchronized operation immediately after the number of pumps is increased is F3, and correction values are δ and ε, if P2<P1 or P3<P1, the control device continues the speed-synchronized operation by the multiple pumps without reducing the number of pumps even after the third reduction condition is satisfied, and then, as a fourth reduction condition,
If P2<P1, then Fnow<F2-(P1-P2)/δ+β
or
If P3<P1, then Fnow<F3-(P1-P3)/ε+β
When the number of pumps in operation is reduced,
A water supply device according to any one of claims 6 to 8 . The water supply apparatus according to claim 6 , wherein the correction value is determined from an actual measurement value for each model. The water supply apparatus according to claim 6 , wherein the control device operates all of the plurality of pumps at the same speed when operating the plurality of pumps after increasing or decreasing the number of pumps. The water supply device according to any one of claims 6 to 11, wherein the control device, when reducing the number of pumps, stops the pumps in the order in which they were started, or stops the pumps in the reverse order of their starting order , or stops the pump with the longest accumulated operating time.