JP2020045747A - Water supply system and control method thereof - Google Patents

Abstract

To appropriately control each water supply unit in a water supply system with multiple water supply units that can communicate with each other.SOLUTION: There is provided a water supply system that supplies water to objects in a building by means of multiple water supply units which communicate with each other by means of power line communication by using the power lines of the building as communication lines. A second controller starts the second pump at a first starting speed and, if the second controller detects an abnormality in the power line communication, starts the second pump at a second starting speed that is slower than the first starting speed.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a water supply system and a method for controlling the water supply system.

  A water supply device is widely used as a device for supplying water (tap water) to a building such as an office building or an apartment. The water supply device generally includes a pump for pumping water and a control unit for controlling the operation of the pump. The suction port of the pump is connected to a water pipe (main water pipe), and the water sucked into the pump from the water pipe is pressurized by the pump and then supplied to each water tap via a water pipe provided inside the building. (Water supply target). A water supply device directly connected to such a water pipe is generally called a direct connection type water supply device.

  In addition, conventionally, a water supply system including a first water supply device directly connected to a water pipe and a second water supply device connected to a discharge side of the first water supply device has been proposed. Such a water supply system is used, for example, for supplying water to a high-rise building, in which a first water supply device pressurizes and supplies water from a water pipe to a lower floor, and a second water supply device supplies water from the first water supply device. Is further boosted and supplied to higher floors.

  In such a water supply system including two water supply devices connected in series, when the second water supply device is operated while the first water supply device is stopped, the first water supply device and the second water supply device are operated. Negative pressure may be formed due to a decrease in pressure of a water pipe connecting the apparatus. In this state, when the water tap connected to the drain pipe is opened, air is sucked from the water tap. For this reason, in the water supply device described in Patent Literature 1, the pressure on the discharge side of the first water supply device, the pressure on the suction side of the second water supply device, or the pressure on the discharge side of the second water supply device is each When the starting pressure is reached, the pump in the first water supply device is started.

Patent No. 5643385

  In the water supply system as described above, the first water supply device and the second water supply device exchange operating states with each other by communication. Then, each water supply device performs its own operation control according to the operation state of each water supply device, for example, to prevent the pressure of the pipe connecting the two water supply devices from becoming an unintended low pressure as described above. I have. For this reason, when a failure occurs in communication between the first water supply device and the second water supply device, it becomes difficult to appropriately control the operation of the water supply system. However, the water supply to the water supply target is a lifeline, and it is preferable that the operation of the water supply device be continued as much as possible in order to avoid water outage as much as possible.

  The present invention has been made in view of the above-described circumstances, and has an object to appropriately control each water supply device in a water supply system including a plurality of water supply devices and including a water supply device that can communicate with each other. One.

According to one embodiment of the present invention, a water supply system for supplying water to a water supply target in a building by a plurality of water supply devices is proposed, wherein the water supply system includes a first water supply device and a discharge side of the first water supply device. A second water supply device provided, wherein the first water supply device has a first pump, and a first control unit that controls operation of the first pump, The second water supply device has a second pump and a second control unit that controls the operation of the second pump, and the plurality of water supply devices use a power line of the building as a communication line. The two control units can communicate with each other by power line communication, the second control unit starts the second pump at a first starting speed, and the second control unit detects an abnormality in the power line communication, The second pump is started at a second start speed that is slower than the first start speed. To.
According to this aspect, when an abnormality is detected in the power line communication, the second pump can be slowly started to supply water.

It is a figure showing the schematic structure of the water supply system concerning one embodiment of the present invention. It is a figure for explaining power line communication in this embodiment. It is a schematic diagram which shows a 1st water supply apparatus. It is a schematic diagram which shows a 2nd water supply apparatus. FIG. 4 is a diagram illustrating an example of a relationship between an output of a second pump and a followability of a first pump. FIG. 9 is a diagram illustrating another example of the relationship between the output of the second pump and the followability of the first pump. FIG. 9 is a diagram illustrating another example of the relationship between the output of the second pump and the followability of the first pump. FIG. 9 is a diagram illustrating another example of the relationship between the output of the second pump and the followability of the first pump. It is a schematic diagram which shows the other example of a structure of a 2nd water supply apparatus. It is a schematic diagram which shows the other example of a structure of a 1st water supply apparatus. It is a flow chart which shows an example of control processing at the time of water supply system starting performed by the control part of the 2nd water supply device. It is a flow chart which shows an example of control processing at the time of communication abnormalities performed by the control part of the 2nd water supply equipment. It is a figure showing the schematic structure of the water supply system concerning another embodiment. It is a figure showing the schematic structure of the water supply system concerning another embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same reference numerals, and redundant description will be omitted.

[First Embodiment]
Drawing 1 is a figure showing the schematic structure of the water supply system concerning one embodiment of the present invention. Hereinafter, as an example of the water supply system, a system for supplying water to the building 16 which is a high-rise building (for example, a building having 16 floors or more) will be described, but is not limited thereto. As shown in FIG. 1, the water supply system 20 includes a first water supply device BP1 connected to a water pipe (water main) 12, and a second water supply system BP1 connected in series to the discharge side of the first water supply device BP1. And a water supply device BP2. In the present embodiment, the first water supply device BP1 is installed on the ground or underground, and the second water supply device BP1 is installed on the middle floor of the building 16.

The suction port of the first water supply device BP1 is connected to the water pipe 12 via the introduction pipe 13. The discharge port of the first water supply device BP1 and the suction port of the second water supply device BP2 are connected by a first water distribution pipe 14a, and the first water distribution pipe 14a is connected to each lower-level water supply of the building 16. The plug (first water supply target) 18a is connected via a branch pipe 17a. Further, a second water pipe 14b is connected to a discharge port of the second water supply device BP2, and the second water pipe 14b is connected to each water tap on a higher floor of the building (second water supply target). 18b via a branch pipe 17b. With such a configuration, the first water supply device BP1 raises the pressure of water from the water pipe 12 and
The water is supplied to each of the water taps 18a of the lower hierarchy. Then, the second water supply device BP2 is configured to further increase the pressure of the water from the first water supply device BP1 and supply the water to each of the water taps 18b on the higher floor of the building 16.

  FIG. 2 is a schematic diagram showing the first water supply device BP1. As shown in FIG. 2, the first water supply device BP1 includes a pump (first pump) P1 connected to the water pipe 12 via the introduction pipe 13. In the present embodiment, the pump P1 will be described as including a motor (first motor) M1 as a drive source and an inverter (first inverter) INV1 that variably controls the rotation speed of the motor M1. . The first water supply device BP1 includes a check valve CV1 disposed on the discharge side of the pump P1, a flow switch SW1, a pressure sensor PS1, and a pressure tank PT1 disposed on the discharge side of the check valve CV1. It has. These components are housed in the cabinet CB1.

  The check valve CV1 is provided on the discharge pipe L1 connected to the discharge port of the pump P1, and is a valve for preventing the backflow of water when the pump P1 stops. The flow switch SW1 is a flow rate detector that detects that the flow rate of water flowing through the discharge pipe L1 has decreased to a predetermined value (a small amount of water). The pressure sensor PS1 is a water pressure measuring device for measuring the discharge pressure of the pump P1. The pressure tank PT1 is a pressure holder for holding the discharge pressure while the pump P1 is stopped. The discharge pipe L1 is connected to the first water distribution pipe 14a.

  The pump P1 includes a rotation speed sensor RS1 for detecting the rotation speed (frequency and rotation speed) of the pump P1, an ammeter AS1 for measuring a current value flowing through the motor M1, and a power meter for measuring the amount of power consumed by the pump P1. A thermometer TS1 for measuring the temperature of the ES1 and the pump P1 is provided. Here, the rotational speed sensor RS1 may directly measure the rotational speed of an impeller (not shown) of the pump P1, or may measure the rotational speed of the motor M1. Further, the rotation speed of the pump P1 may be estimated from the output frequency of the inverter INV1 without providing the rotation speed sensor RS1. In the present embodiment, the impeller of the pump P1 and the motor M1 are synchronized, and the rotation speed of the impeller and the rotation speed of the motor M1 are the same. When a transmission is interposed between the impeller of the pump P1 and the motor M1, the rotation of the pump P1 is determined based on the speed ratio of the transmission (current speed ratio if variable) and the rotation speed of the motor M1. You may get the number. Further, the ammeter AS1 or the wattmeter ES1 may measure a current value or a power amount flowing through the motor M1, or may measure a current value or a power amount flowing through the inverter INV1. Further, the electric energy of the pump P1 may be calculated based on the current value of the pump P1 and the like. Further, instead of the current flowing through the motor M1 and the power consumption of the pump P1, the current flowing through the water supply device BP1 and the power consumption may be measured. Further, the thermometer TS1 may measure the temperature of the motor M1 or may measure the temperature of the inverter INV1.

  The backflow prevention device 21 is connected to the suction port of the pump P1. The backflow preventer 21 is installed to prevent the backflow of water to the water pipe 12. In the present embodiment, a depressurization type backflow preventer having a configuration in which an intermediate chamber in which a relief valve is disposed is sandwiched between two check valves is used as the backflow prevention device 21.

  Further, the first water supply device BP1 includes a control unit (controller, first control unit) CN1 for controlling the water supply operation. An inverter INV1, a flow switch SW1, a pressure sensor PS1, a rotation speed sensor RS1, an ammeter AS1, a power meter ES1, and a thermometer TS1 are connected to the control unit CN1 via signal lines.

When the discharge pressure (water pressure in the discharge pipe L1) decreases to a predetermined starting pressure while the pump P1 is stopped, the control unit CN1 issues a command to the inverter INV1 to start the operation of the pump P1. During operation of the pump P1, control such as constant estimated end pressure control or constant target pressure control is performed by the set pressure (set pressure). Specifically, in the case of the estimated terminal pressure constant control, the target pressure (SV) for the discharge pressure of the pump P1 is set using the rotation speed of the pump P1 and the target pressure control curve. The set pressure is directly used as the target pressure (SV). Further, the discharge pressure detected by the pressure sensor PS1 is set as a current pressure (PV). Then, the PI calculation using the proportional gain Gp and the integral gain Gi or the PID calculation using the proportional gain Gp, the integral gain Gi, and the differential gain Gd is performed based on the deviation between the SV and the PV. The command speed is set. Note that the control unit CN1 may correct the target pressure control curve based on the suction pressure (inflow pressure) of the pump P1. More specifically, the target pressure (SV) may be calculated by adding the target pressure control curve by the suction pressure.

  When the use of water in the building decreases during the operation of the pump P1, the flow switch SW1 detects an underwater amount and sends a detection signal to the control unit CN1. The control unit CN1 receives this detection signal, issues a command to the pump P1, increases the number of revolutions of the pump P1 until the discharge pressure reaches a predetermined operation stop pressure, accumulates the pressure in the pressure tank PT1, and then stops the pump P1 ( Stop small water flow). When the water is again used in the building after the pump P1 has stopped for a small amount of water, the discharge pressure decreases to the starting pressure or less and the pump P1 starts. In addition, as a method of detecting the small amount of water, other means such as a low load or a cutoff pressure depending on the current value of the motor unit may be used without using the flow switch SW1.

  FIG. 3 is a schematic diagram showing the second water supply device BP2. The basic configuration and operation of the second water supply device BP2 are the same as those of the first water supply device BP1 described above, and the same components are denoted by the corresponding reference numerals. The second water supply device BP2 is different from the first water supply device BP1 in that the second water supply device BP2 is not provided with a backflow prevention device. However, the second water supply device BP2 may include a backflow prevention device, similarly to the first water supply device BP1.

  In the present embodiment, the control unit CN1 of the first water supply device BP1 and the control unit CN2 of the second water supply device BP2 communicate with each other by a so-called PLC (Power Line Communication) using the power line 22 as a communication line. Are configured to communicate. FIG. 1A is a diagram for describing power line communication in the present embodiment. As shown in the drawing, a power line 22 is connected from a power distribution panel 23 to each of the water supply devices BP1 and BP2, and power is supplied from a not-shown commercial power supply (system power supply 100). Electric power from the system power supply 100 is supplied to the motors M1, M2 and the pumps P1, P2 of the water supply devices BP1, BP2 via the power line 22. Further, in the example shown in FIG. 1A, each of the water supply devices BP1 and BP2 includes PLC units PLC1 and PLC2 that can communicate with the control units CN1 and CN2, and the power lines 22 from the distribution board 23 are connected to the PLC units PLC1 and PLC2. Connected. Each of the PLC units PLC1 and PLC2 is configured to be able to perform power line communication via the power line 22 (see the broken line), and the control units CN1 and CN2 communicate with the PLC units PLC1 and PLC2, thereby controlling the control unit CN1. , CN2 exchange information with each other.

  Operation / stop of pumps P1 and P2, measured values of pressure sensors PS1 and PS2 (discharge pressure), measured values of rotation speed sensors RS1 and RS2, measured values of ammeters AS1 and AS2, measured values of wattmeters ES1 and PS2 The operation information including the measurement values of the thermometers TS1 and TS2, the failure information of the water supply devices BP1 and BP2, and the operation commands for the pumps P1 and P2 are transmitted between the control unit CN1 and the control unit CN2 through the power line 22. Transmitted in the Such a communication function enables the cooperative operation of the first water supply device BP1 and the second water supply device BP2.

  If only the pump P2 is operating while the first water supply device BP1 is stopped, a negative pressure may be formed in the first water distribution pipe 14a. If the water tap 18a on the lower floor is opened in this state, air may be sucked from the water tap 18a. Therefore, in order to prevent such suction of air, the pump P1 is started and then the pump P2 is started.

  As described above, the pumps P1 and P2 are started when their respective discharge pressures decrease to a predetermined starting pressure. Therefore, starting pressures S1 and S3 that are triggers for starting the pumps P1 and P2 are set in the control units CN1 and CN2, respectively. Further, a second starting pressure S2 for starting the pump P1 is set in the control unit CN1. The second starting pressure S2 is a second threshold value for starting based on the discharge pressure of the second water supply device BP2 (measured value of the pressure sensor PS2). The second starting pressure S2 is set to be higher than the starting pressure (second pump starting pressure) S3 of the pump P2 (S2> S3). This is because the pump P1 is started before the pump P2 is started, as described above.

  The control unit CN1 starts the pump P1 based on two triggers when the measured value of the pressure sensor PS1 decreases to the first starting pressure S1 and when the measured value decreases to the second starting pressure S2 of the pressure sensor PS2. Let it. When the discharge pressure of the pump P2 decreases, the pressure sensor PS2 detects the starting pressure S2 before the starting pressure S3. The control unit CN1 starts the pump P1 when the measurement value of the pressure sensor PS2 sent through the power line 22 (that is, the discharge pressure of the pump P2) reaches the starting pressure S2.

  If water is used on a lower floor while the pump P1 is stopped, the discharge pressure of the pump P1 decreases. When the discharge pressure drops to the starting pressure S1, the pump P1 is started. Thus, the pump P1 is started based on the measured values of the two pressure sensors PS1 and PS2.

  It is preferable that the control unit CN2 starts the pump P2 after confirming that the pump P1 has been started. The control unit CN2 determines, for example, that the rotation speed of the pump P1 has exceeded a predetermined rotation speed (for example, 30% or 40% of the rated rotation speed) and that the current value or the power consumption of the motor M1 has a predetermined threshold value. May be determined based on at least one of the fact that the temperature of the motor M1 has exceeded the predetermined temperature and that the pump P1 has started.

  While the pump P2 is operating, the operation of the pump P1 is maintained. Here, even during the operation of the pump P1, depending on the operation state of the second water supply device, for example, the discharge flow rate of the pump P2 suddenly increases, the negative pressure in the first water distribution pipe 14a connecting the pumps P1 and P2. May be formed. For this reason, the control unit CN1 of the first water supply device BP1 changes the followability of the first pump P1 according to the output of the pump P2 of the second water supply device BP2. That is, when the pump P2 is operating at the first output, the control unit CN1 sets the rotation speed (frequency) of the pump P1 such that the discharge pressure of the pump P1 at the first followability reaches the target pressure. To control the operation of the pump P1. Further, when the pump P2 is operating at the second output larger than the first output, the control unit CN1 controls the discharge pressure of the pump P1 to reach the target pressure with the second following property higher than the first following property. To control the operation of the pump P1.

In the present embodiment, the control unit CN1 controls the operation of the pump P1 so that the discharge pressure of the pump P1 reaches the target pressure with higher tracking performance as the output of the pump P2 increases. Here, the control unit CN1 may determine the magnitude of the output of the pump P2 based on the rotation speed of the pump P2. In other words, the control unit CN1 controls the operation of the pump P1 so that the discharge pressure of the pump P1 reaches the target pressure with higher tracking performance as the rotation speed of the pump P2 increases. Specifically, the control unit CN1 may increase the proportional gain Gp of the PI control or the PID control for setting the target rotation speed (command frequency) of the pump P1 as the rotation speed of the pump P2 increases. At this time, the control unit CN1 determines the proportional gain Gp based on the rotational speed of the pump P2 using a map or a relational expression in which the relationship between the rotational speed Np2 (output) of the pump P2 and the proportional gain Gp is determined in advance by experiments or the like. It is possible to determine. Here, the proportional gain Gp may be increased in proportion to the rotation speed Np2 (output) of the pump P2, as shown in FIG. Further, as shown in FIG. 5, the proportional gain Gp may be increased with a larger change amount as the rotation speed Np2 (output) of the pump P2 increases, or as shown in FIG. ) May increase as the proportional gain Gp increases with a smaller change amount. Further, as shown in FIG. 7, when the output of the pump P2 is smaller than the predetermined rotation speed, the proportional gain Gp increases with a larger change amount as the output of the pump P2 increases. The proportional gain Gp may be increased with a small amount of change as the output of is increased. By such control, when the pump P2 of the second water supply device BP2 is operating with a large output, the rotation speed of the pump P1 changes with high followability. Thus, the output of the pump P1 can be quickly changed in accordance with the change in the operation state of the pump P2, and an unintended low pressure in the first water distribution pipe 14a can be prevented. Further, when the pump P2 is operating with a small output, the rotation speed of the pump P1 changes with low followability. Thus, the energy efficiency of the water supply system 20 can be improved by gradually changing the rotation speed of the pump P1.

  Also, instead of changing the proportional gain Gp, the controller CN1 increases the difference between the current rotation speed of the pump P1 and the target rotation speed (command frequency) as the rotation speed Np2 (output) of the pump P2 increases. The target rotation speed of the pump P1 may be corrected so as to increase. For example, the control unit CN1 sets a temporary target rotation speed based on the discharge pressure (PV) of the pump P1 and the target pressure (SV). Subsequently, the current rotational speed of the pump P1 is subtracted from the set provisional target rotational speed to calculate the amount of change in the rotational speed of the pump P1. Then, the rotational speed change amount of the pump P1 is corrected by multiplying the calculated rotational speed change amount of the pump P1 by a correction coefficient Kp that increases as the rotational speed Np2 (output) of the pump P2 increases. Then, the control unit CN1 sets the target rotation speed (command frequency) of the pump P1 by adding the corrected rotation speed change amount to the current rotation speed of the pump P1. Here, as for the correction coefficient Kp, in the same manner as described with reference to FIGS. 4 to 7 for the proportional gain Gp, a map or a relational expression or the like may be determined in advance by experiment or the like with respect to the rotation speed Np2 of the pump P2. . In such control, the same effect as in the case where the proportional gain Gp is changed can be obtained.

  Further, the control unit CN1 may determine the magnitude of the output of the pump P2 based on the current value A2 flowing through the motor M2 of the pump P2. In other words, the control unit CN1 controls the operation of the pump P1 so that the discharge pressure of the pump P1 reaches the target pressure with higher followability as the value of the current flowing through the motor M2 increases. In this case, as an example, a map or a relational expression indicating the relationship between the current value A2 and the proportional gain Gp or the correction coefficient Kp is determined in advance by an experiment or the like (see FIGS. 4 to 7), so that the rotation speed of the pump P2 is determined. The operation of the pump P1 can be controlled as in the case where Np2 is used. The control unit CN1 may determine the magnitude of the output of the pump P2 using the current value flowing through the second water supply device BP2 instead of the current value A2 flowing through the motor M2.

  Further, the control unit CN1 may determine the magnitude of the output of the pump P2 based on the electric energy E2 consumed by the pump P2. In other words, the control unit CN1 controls the operation of the pump P1 so that the discharge pressure of the pump P1 reaches the target pressure with higher tracking performance as the electric energy E2 consumed by the pump P2 increases. In this case, as an example, a map or a relational expression indicating the relation between the electric energy E2 and the proportional gain Gp or the correction coefficient Kp is determined in advance by an experiment or the like (see FIGS. 4 to 7), so that the rotation of the pump P2 is performed. The operation of the pump P1 can be controlled in the same manner as when using several Np2 or the like. In addition, the control unit CN1 may determine the magnitude of the output of the pump P2 using the amount of power consumed by the second water supply device BP2 instead of the amount of power E2 consumed by the pump P2.

Further, the control unit CN1 may determine the magnitude of the output of the pump P2 based on the temperature T2 of the pump P2. That is, the control unit CN1 controls the operation of the pump P1 so that the higher the temperature T2 of the pump P2 is, the higher the follow-up property is and the more the discharge pressure of the pump P1 reaches the target pressure. In this case, as an example, a map or a relational expression indicating the relationship between the temperature T2 and the proportional gain Gp or the correction coefficient Kp is determined in advance by experiments or the like (see FIGS. 4 to 7), and thereby the rotation speed of the pump P2 The operation of the pump P1 can be controlled as in the case where Np2 or the like is used.

  In the examples shown in FIGS. 4 to 7, it is assumed that the proportional gain Gp or the correction coefficient Kp smoothly changes so as to increase as the output of the pump P2 increases. However, the present invention is not limited to this, and the proportional gain Gp or the correction coefficient Kp may be changed in two or more steps according to the output of the pump P2.

  When stopping the water supply operation from a state where both the pumps P1 and P2 are operating, the pump P1 is stopped after the pump P2 is stopped. These cooperative operations are performed based on driving information transmitted between the control units CN1 and CN2. The control unit CN1 determines that, for example, the rotation speed of the pump P2 is lower than a predetermined rotation speed (for example, 30%, 40%, or the like of the rated rotation speed), and the current or power of the motor M2 is lower than a predetermined threshold value. Whether or not the pump P2 has stopped may be determined based on at least one of the fact that the temperature of the motor M2 is lower than the predetermined temperature. By such a cooperative operation, it is possible to prevent the pump P1 from stopping before the pump P2 stops, and to prevent a negative pressure from being formed in the first water distribution pipe 14a.

  In addition, in the water supply system 20 of the present embodiment, the two water supply devices BP1 and BP2 are provided. However, when three or more water supply devices are connected in series, the pumps are similarly started from the lowest order. Then, the pumps may be stopped from the highest order.

  When only the pump P2 of the second water supply device BP2 is operated when the first water supply device BP1 fails, the above-described problem of air suction may occur. Therefore, when the first water supply device BP1 fails, the control unit CN1 transmits the failure information to the control unit CN2, and the control unit CN2 stops the operation of the pump P2. In this case, even if water is used on a higher floor, the pump P2 is forcibly stopped.

  If the second water supply device BP2 breaks down, water is cut off on the higher floor. When there is room in the water supply capacity of the first water supply device BP1, it is preferable to increase the water supply pressure of the first water supply device BP1 to the maximum value. That is, when the second water supply device BP2 fails, the control unit CN2 transmits the failure information to the control unit CN1, and the control unit CN1 operates the pump P1 at its maximum water supply capacity. Although the first water supply device BP1 cannot supply water to all the water taps 18b on the higher floor, the first water supply device BP1 can supply water to at least a part of the higher floor. Water interruptions on the entire floor can be avoided.

  FIG. 8 is a schematic diagram illustrating another configuration example of the second water supply device BP2. As shown in FIG. 8, a pressure sensor (suction pressure sensor) 30 for measuring the suction pressure of the pump P2 is provided upstream of the pump P2. The other configuration of the second water supply device BP2 is the same as the configuration shown in FIG. The pressure sensor 30 is connected to the control unit CN2 via a signal line. The measurement value of the pressure sensor 30 (that is, the suction pressure) is sent to the first water supply device BP1 via the power line 22 as operation information.

The control unit CN1 of the first water supply device BP1 determines that the water supply pressure (terminal pressure) of the water tap 18a on the lower floor is a predetermined target value based on the measurement value of the pressure sensor 30 sent from the second water supply device BP2. Feedback control is performed so that That is, the first water supply device BP1 controls the operation of the pump P1 using the suction pressure of the second water supply device BP2 as the discharge pressure of the pump P1. Specifically, the control unit CN1 controls the operation of the pump P1 so as to maintain a predetermined target pressure (SV) using the measurement value of the pressure sensor 30 as the current pressure (PV). Since the terminal pressure of the lower floor is substantially equal to the suction pressure of the second water supply device BP2, it is considered that the measurement value of the pressure sensor 30 indicates the water supply pressure (terminal pressure) of the water faucet 18a of the lower floor. Can be. Therefore, from the measurement value of the pressure sensor 30, the actual terminal pressure of the lower floor can be monitored.

  According to such an operation control method, since the operation of the pump P1 is controlled based on the actual terminal pressure, the terminal pressure constant control that is not affected by the pressure drop caused by the frictional resistance in the water distribution pipe is realized. . Therefore, water can be supplied at a desired end pressure. Since the pressure sensor 30 of the second water supply device BP2 can be used as a substitute for the pressure sensor PS1 of the first water supply device BP1, the pressure sensor PS1 may be omitted.

  Note that, as described above, the pumps P1 and P2 are connected depending on whether only the pump P2 is operating while the pump P1 is stopped, or depending on the operating state of the pump P2 even when the pump P1 is operating. There is a possibility that the pressure in the first water distribution pipe 14a becomes an unintended low pressure. For this reason, in the configuration example shown in FIG. 8, when the suction pressure of the pump P2 is equal to or less than the predetermined threshold and a predetermined time (for example, several seconds) has elapsed, the control unit CN2 of the second water supply device BP2 performs the inflow of the pump P2. It may be stopped as a pressure drop.

  Each of the above-described first water supply device BP1 and second water supply device BP2 has only one pump, but may have a plurality of pumps as shown in FIG. FIG. 9 is a schematic diagram illustrating a first water supply device BP1 including a plurality of pumps. Although not shown, the second water supply device BP2 can include a plurality of pumps according to a similar arrangement. By providing multiple pumps, if multiple pumps are operated with rotation and unit control, or if an abnormality is detected in the pumps or inverters during operation, the operation is switched to another normal pump or inverter. Water supply can be continued.

  When the second water supply device BP2 includes a plurality of pumps P2, the control unit CN1 of the first water supply device BP1 may control the operation of the pump P1 based on the total output of the plurality of pumps P2. . That is, the control unit CN1 controls the operation of the pump P1 by setting the number of revolutions of the pump P1 so that the discharge pressure of the pump P1 reaches the target pressure with higher tracking performance as the total output of the plurality of pumps P2 is larger. You may. As an example, the control unit CN1 sets the proportional gain Gp in the first water supply device BP1 as the ratio of the total of the current rotational speeds of the plurality of pumps P2 to the total of the maximum rotational speeds of the plurality of pumps P2 increases. Alternatively, the correction coefficient Kp may be set large. The control unit CN1 may set the proportional gain Gp or the correction coefficient Kp in the first water supply device BP1 to be larger as the average rotation speed of the plurality of pumps P2 is larger. Further, instead of the number of rotations of the plurality of pumps P2, a plurality of pumps P2 based on a current value flowing through the motor M2, an amount of power consumed by the plurality of pumps P2, or a temperature of the plurality of pumps P2. The pump P1 may be controlled by setting the proportional gain Gp or the correction coefficient Kp in the first water supply device BP1 as in the case where the rotation speed of the pump P2 is used.

In the embodiment described above, the control unit CN1 of the first water supply device BP1 determines the output of the pump P2 based on the rotation speed, current value, electric energy, or temperature of the pump P2 of the second control device BP2. To do. However, the control unit CN1 may determine the output of the pump P2 using two or more of these parameters. As an example, a map or a relational expression indicating the magnitude of the output of the pump P2 with respect to a plurality of parameters may be determined in advance by experiments or the like and stored in the control unit CN1. Alternatively, the control unit CN1 may control the operation of the pump P1 based on the largest output of the pump P2 estimated based on each parameter. In this way, it is possible to more reliably prevent the first water distribution pipe 14a from becoming negative pressure.

  Next, an example of the operation of the water supply system 20 when an abnormality occurs in communication between the control unit CN1 of the first water supply device PB1 and the control unit CN2 of the second water supply device BP2 will be described. When the first water supply device PB1 and the second water supply device PB2 are configured to communicate operation information with each other by power line communication using the power line as a communication line, the first water supply device PB1 and the second water supply device PB2 temporarily communicate with each other depending on the power usage status or the like. Abnormality may occur. Therefore, in the case of a temporary communication abnormality for which the cause can be estimated, the water supply is continued by the water supply system 20.

  First, as described above, in the configuration example shown in FIG. 8, when the control unit CN1 of the first water supply device PB1 is normally communicating with the control unit CN2 of the second water supply device BP2, the pump P2 The operation of the pump P1 is controlled based on the suction pressure. Specifically, constant pressure control (terminal pressure constant control) based on a predetermined set pressure is performed. On the other hand, when an abnormality occurs in the communication between the control units CN1 and CN2, the control unit CN1 may control the operation of the pump P1 based on the discharge pressure of the pump P1. Specifically, the control unit CN1 may execute the discharge pressure constant control so that the discharge pressure of the pump P1 becomes a predetermined target pressure, or may perform the control based on the rotation speed and the discharge pressure of the pump P1. Thus, the constant estimated end pressure control may be executed such that the estimated suction pressure of the pump P2 becomes a predetermined target pressure. As described above, even when the communication between the control units CN1 and CN2 is abnormal, the control unit CN1 of the first water supply device PB1 can control the operation of the pump P1 based on the discharge pressure of the pump P1. . When executing the estimated terminal pressure constant control based on the discharge pressure of the pump P1, the output of the pump P1 is controlled so that the hydraulic pressure in the first water distribution pipe 14a is not insufficient due to the estimation error of the suction pressure of the pump 2. Preferably, a margin is provided. However, since the energy efficiency is reduced due to the margin provided in the output of the pump P1, when the communication between the control units CN1 and CN2 is normal, the control unit CN1 determines the pump based on the discharge pressure of the pump P2. It is preferable to control the operation of P1 at a constant terminal pressure.

  In the above-described embodiment, when the communication between the control units CN1 and CN2 is normal, the control unit CN1 of the first water supply device PB1 sets the discharge pressure of the first water supply device BP1 (pump P1) to the starting pressure. The pump P1 is started when the pressure becomes lower than S3 or when the discharge pressure of the second water supply device BP2 becomes lower than the second starting pressure S2. However, if the communication between the control units CN1 and CN2 is abnormal, the control unit CN1 cannot acquire the discharge pressure of the second water supply device BP2, so that the discharge pressure of the pump P1 is reduced to the starting pressure S3. It is preferable to start the pump P1 when the temperature falls further.

  In the water supply system 20 of the present embodiment, the control units CN1 and CN2 communicate operation information with each other by so-called power line communication using the power line 22 of the building 16 as a communication line. Here, when the power supply of the water supply system 20 is started, for example, at the time of installation of the water supply system 20, at the end of maintenance, or after a power outage, a power line for inrush current or charging of a capacitor or a UPS (Uninterruptible Power Supply) or the like. It is supposed that noise gets on the power line 22 and abnormality occurs in the power line communication. Such an abnormality in the power line communication is not caused by an abnormality in the water supply system 20, but is resolved by the passage of time. On the other hand, the water supply system 20 relates to a lifeline. If water is used in the building 16 after the power is turned on, it is preferable to start and operate the pumps P1 and P2 as soon as possible. For this reason, in the present embodiment, the following control is performed when the water supply system 20 is started.

FIG. 10 is a flowchart illustrating an example of a water supply system start-up control process executed by the control unit CN2 of the second water supply device BP2. This process is started when the water supply system 20 is started, particularly when the control unit CN2 is started. When the first water supply device BP1 is forcibly stopped by a power failure, abnormal stop, a stop button, or the like, the pump P2 is stopped due to a decrease in inflow pressure. Therefore, when the inflow pressure of the pump P2 decreases, the flowchart of FIG. 10 is not executed.

  When the water supply system 20 is started, the control unit CN2 first determines whether there is an abnormality in communication with the control unit CN1 via the power line 22 (S12). This determination may be made in accordance with the determination of a communication abnormality in normal power line communication. When there is no abnormality in the communication (S12: No), the control unit CN2 can obtain the operation information from the control unit CN1 by the power line communication, and thus controls the operation of the pump P2 as usual (S14). ). If the power line communication is normal, the process waits until the elapsed time tm from the activation of the water supply system 20 reaches the predetermined time tm1 (S26), and terminates the present process. Here, the predetermined time tm1 may be a predetermined time at which the activation of the water supply system 20 is considered to be stable. Further, the predetermined time tm1 may be set by an external input or the like.

  If there is an abnormality in the communication (S12: Yes), the control unit CN2 checks whether the pump P2 is stopped (S16). Here, the process of S16 is a process of determining whether or not the pump P2 has been started in the later-described process, and it is determined that the pump P2 is stopped (S16: Yes). If the pump P2 is already operating, for example, at the time of startup due to an instantaneous power failure, it may be determined in S16 that the pump P2 is operating.

  When the pump P2 is stopped (S16: Yes), the control unit CN2 determines whether or not the discharge pressure Pm2 (start-up Pm2) of the pump P2 when this process is started is larger than a predetermined threshold value P3n. Is determined (S18). The threshold value P3n is preferably not less than the starting pressure P3 and not more than the stop pressure of the pump P2. That is, when this process is started, the control unit CN2 stores the discharge pressure Pm2 of the pump P2 as the start-up time Pm2, and compares the stored start-up Pm2 with the threshold value P3n. When the startup time Pm2 is equal to or smaller than the threshold value P3n (S18: No), the control unit CN2 determines that starting the pump (second pump) P2 may cause a problem, and switches the pump P2. The state is stopped (S24). This is based on the following reasons. When the start-up time Pm2 is larger than the threshold value P3n, the water supply device BP2 is stored in the pressure tank PT2, for example, when the operation immediately before the water supply device BP2 is stopped and the pressure is accumulated in the pressure tank PT2 until the stop pressure P3 is reached. The water volume is relatively large. Therefore, pressure fluctuation is small at the time of starting. Furthermore, since the pressure accumulated in the pressure tank PT2 decreases with time, it is assumed that the time during which the pump P2 is stopped is short. On the other hand, when the start time Pm2 is equal to or less than the threshold value P3n, the pressure in the pressure tank PT2 is not accumulated, so that the pressure fluctuation at the start becomes large. That is, when the start time Pm2 is equal to or lower than the start pressure P3, if the pump P2 is started without establishing communication with the water supply device BP1, the first water distribution pipe 14a may have an unintended low pressure.

  Then, after the pump P2 is stopped in S24, if the elapsed time tm since the start of the water supply system 20 has not reached the predetermined time tm1 (S26: No), the control unit CN2 returns to the process of S12 again. Here, in the process of S18, the start time Pm2 is a numerical value at the start of the process and does not change thereafter. Therefore, in the processes after S12, the pump P2 is stopped unless the abnormality of the power line communication is eliminated (S12). At the same time, it is determined that the startup time Pm2 is equal to or smaller than the threshold value P3n (S16: Yes, S18: No), and the stop of the pump P2 is maintained (S24). When the abnormality of the power line communication is resolved before the elapsed time tm reaches the predetermined time tm1 (S12: No), the control unit CN2 controls the pump P2 as usual based on the information from the control unit CN1. (S14).

Then, when the elapsed time tm1 reaches the predetermined time tm1 (S26: Yes), the control unit CN2 ends this processing. In addition, while S26 is No, the abnormality of the power line communication is not reported, and when S26 becomes Yes and the abnormality of the power line communication is not resolved even if the process is terminated, the control unit CN2 may report the abnormality. The notification may be performed by, for example, displaying on a display unit (not shown), issuing an alarm by a buzzer (not shown), or transmitting a predetermined signal to the outside.

  When the power line communication is not established and the start-up Pm2 is determined to be larger than the threshold value P3n in S18 (S18: Yes), the control unit CN2 determines the current discharge pressure Pm2 (current Pm2) of the pump P2. It is compared with the starting pressure P3 (S20). When the current discharge pressure Pm2 is higher than the starting pressure P3 (S20: No), the control unit CN2 determines that the pump P2 does not need to be started, and stops the pump P2 (S24). Here, as the current discharge pressure Pm2 of the pump P2, a measurement value of the pressure sensor PS2 may be used. When the elapsed time tm1 has not reached the predetermined time tm1 (S26: No), the control unit CN2 returns to the process of S12 again.

  When the start-up time Pm2 is larger than the threshold value P3n (S18: Yes), and the discharge pressure Pm2 of the water supply device BP2 reaches the start-up pressure P3 or less due to the use of water after the start-up (S20: Yes), The control unit CN2 starts the pump P2 (S22). Here, it is assumed that an abnormality has occurred in the communication with the control units CN1 and CN2, and the control unit CN2 operates the pump P2 as compared with the normal state (when there is no abnormality in the communication). It is preferable to start slowly. That is, the control unit CN2 normally starts the pump P2 at the first start speed, and preferably starts the pump P2 at the second start speed slower than the first start speed in the process of S22. Specifically, the control unit CN2 increases the acceleration time of the inverter INV2, gradually increases the target pressure at a predetermined rate, gradually increases the rotation speed of the pump P2 at a predetermined rate, and / or performs PID calculation. By adjusting the proportional gain Gp or the like, the pump P2 is started more slowly than in the normal process of S14. When the pump P2 is started, the discharge pressure of the pump P1 provided on the suction side of the pump P2 decreases to the starting pressure P1 or less, and the control unit CN1 starts the pump P1. Here, as the pump P2 is slowly started, the discharge pressure of the pump P1 is also gradually reduced. Therefore, even when the communication between the control units CN1 and CN2 is not established, the pump P1 is kept at a low pressure. It is possible to prevent the pressure in the first water distribution pipe 14a from becoming an unintended low pressure during the period from starting to supplying water.

  Then, the gradual start of the pump P2 in S22 ends, and the elapsed time tm from the start of the water supply system 20 is before reaching the predetermined time tm1 (S26: No), and the power line communication is abnormal (S12: Yes). If, the control unit CN2 determines in S16 that the pump P2 is operating (S16: No), and controls the operation of the pump P2 in the same manner as in normal operation (S14). As described above, even when the power supply of the water supply system 20 is activated and the isoelectric line communication for detecting the abnormality of the electric line communication within the predetermined period tm1 is not stable, the pump P2 is started gently to move to the higher floor. Water can be supplied. However, when the power line communication is abnormal, for example, the pump P2 may be operated in a predetermined safe operation mode in which the output is smaller than normal. Then, when the elapsed time tm reaches the predetermined time tm1 (S26: Yes), the control unit CN2 ends this processing. It should be noted that if the abnormality of the power line communication is not resolved even after the end of this process, the control unit CN2 may notify the abnormality. At this time, the operating pump P2 may be stopped.

Next, abnormalities in power line communication that occur when the rotation speeds of the pumps P1 and P2 are high will be described. In the present embodiment, the pumps P1 and P2 are operated by driving the motors M1 and M2 via the inverter devices INV1 and INV2. Here, when the rotation speeds of the pumps P1 and P2 increase, the influence of the switching noise of the inverter devices INV1 and INV2 increases, and noise may get on the power line 22 and the power line communication of the control units CN1 and CN2 may not be established. . Since such an abnormality in the power line communication is not caused by an abnormality in the water supply system 20, in this embodiment, when an abnormality in the power line communication occurs, different control is performed based on the rotation speed Np2 of the pump P2.

  FIG. 11 is a flowchart illustrating an example of processing during pump operation performed by the control unit CN1 of the first water supply device BP1 and the control unit CN2 of the second water supply device BP2. This process is repeatedly executed during the operation of the pump P1 and the pump P2. Hereinafter, the second water supply device BP2 will be described for ease of description. When the abnormality of the power line communication is not detected (S30: No), the control unit CN2 first executes the normal processing (S14) as in S14 of FIG. When the power line communication is abnormal (S30: Yes), the control unit CN2 first compares the rotation speed Np2 of the pump P2 with a predetermined rotation speed (threshold) Nref (S32). As the threshold value Nref, a value determined in advance based on the maximum frequency Nmax of the inverter INV2, performance of a specified frequency, or the like may be used. For example, the threshold value Nref may be a value that is 70% or more of the maximum frequency Nmax of the inverter INV2. The threshold value Nref may be set by an external input or the like. In addition, since the pump generally has a proportional relationship between the rotation speed and the amount of water and the current flowing through the inverter device, in S32, the current value of INV2 and the predetermined threshold value are set instead of and / or in addition to the rotation speed Np2 and its threshold value Nref. May be used.

  When the rotation speed Np2 of the pump P2 is smaller than the threshold value Nref (S32: No), the control unit CN2 determines that the abnormality in the power line communication is not caused by the high rotation speed Np2 of the pump P2. Then, a predetermined communication abnormality process is executed (S34), and this process ends. As the communication abnormality process, for example, the control unit CN2 may notify the abnormality. Further, the control unit CN2 may operate the pump P2 in a predetermined safe operation mode in which the output is smaller than usual, or may stop the pump P2.

  On the other hand, when the rotation speed Np2 of the pump P2 is equal to or higher than the threshold value Nref (S32: Yes), the control unit CN2 determines that the abnormality in the power line communication is not due to the abnormality in the water supply system 20, and the rotation speed Np2 of the pump P2 is high. , The operation of the pump P2 is continued (S36), and this processing ends. At this time, it is considered that the rotation speed Np2 of the pump P2 is reduced due to, for example, calm use of water on the high floor, so that the abnormality of the power line communication is resolved and the control returns to the normal state using the power line communication. In the process of S36, the control unit CN2 may execute control for eliminating an abnormality in the power line communication. Specifically, the control unit CN2 may reduce the rotation speed Np2 of the pump P2. In this case, the control unit CN2 may gradually decrease the rotation speed Np2 of the pump P2, for example, until the abnormality of the power line communication is resolved, or may set the predetermined rotation speed N2a as the rotation speed command. Further, control unit CN2 may decrease the carrier frequency of inverter INV2 instead of or in addition to decreasing rotation speed Np2 of pump P2. In this case, the control unit CN2 may gradually decrease the carrier frequency of the inverter INV2, for example, until the abnormality of the power line communication is resolved, or may use a predetermined carrier frequency. By lowering the carrier frequency, switching noise can be reduced, and noise on the power line 22 can be reduced. Note that the rotation speed may be reduced and the carrier frequency may be changed by an external input.

  As described above, when it is assumed that an abnormality has occurred in the power line communication at the time of starting the water supply system 20 or because the rotation speeds of the pumps P1 and P2 are large, the power line communication is not performed as usual. The number of communication retries may be increased. Thus, when no abnormality has occurred in the water supply system 20 and an abnormality has occurred in the power line communication due to the activation or the operating state of the water supply system 20, it is possible to execute a large number of communication retries to prompt the establishment of the communication.

(Modification)
In the above embodiment, the water supply system 20 is provided with two water supply devices BP1 and BP2. However, the water supply system 20 is not limited to such an example, and may include three or more water supply devices. FIG. 12 is a diagram illustrating a schematic configuration of a water supply system according to another embodiment. The water supply system 20A shown in FIG. 12 includes three water supply devices BP1 to BP3. The first water supply device BP1 is connected to the water pipe 12 via the introduction pipe 13, similarly to the water supply system 20 shown in FIG. The second water supply device BP2 is provided on the discharge side of the first water supply device BP1, and is connected to the first water supply device BP1 via the first water distribution pipe 14a. The third water supply device BP3 is provided on the discharge side of the second water supply device BP2, and is connected to the second water supply device BP2 via the second water distribution pipe 14b. Then, the first water supply device BP1 increases the pressure of the water from the water pipe 12, and supplies the water to each water tap 18a on the lower floor of the building 16 connected to the first water pipe 14a. . Further, the second water supply device BP2 further increases the pressure of the water from the first water supply device BP1, and supplies the water to each water tap 18b on the middle floor of the building connected to the second water distribution pipe 14b. Has become. Further, the third water supply device BP3 further increases the pressure of the water from the second water supply device BP2, and supplies the water to each of the water taps 18c on the higher floor of the building connected to the third water distribution pipe 14c. Has become.

  The first and second water supply devices BP1 and BP2 may be configured similarly to the first and second water supply devices BP1 and BP2 in the water supply system 10 described above (see FIGS. 2 and 3). Further, the third water supply device may be configured similarly to the second water supply system BP2 in the above-described water supply system 10 (see FIG. 3). Each of the first to third water supply devices BP1 to BP3 is configured to be able to communicate with each other by power line communication through the power line 22 of the building 16.

  In such a water supply system 10A, the same control as in the above-described water supply system 10 can be executed. That is, the first water supply device BP1 and the second water supply device BP2 perform the same control as the first water supply device BP1 and the second water supply device BP2 in the above-described water supply system 10 to perform the first water supply device BP1. Each water supply device BP1, BP2 can be appropriately controlled by preventing the water distribution pipe 14a from becoming an unintended low pressure. In addition, the second water supply device BP2 and the third water supply device BP3 also perform the same control as the first water supply device BP1 and the second water supply device BP2 in the above-described water supply system 10 to perform the second water supply device BP2. It is possible to prevent each of the water supply devices BP2 and BP3 from being appropriately controlled while preventing the water distribution pipe 14b from becoming an unintended low pressure. In other words, the primary (upstream) water supply device is referred to as a “first water supply device”, and the secondary (downstream) water supply device is referred to as a “second water supply device”. By performing control in the same manner as in the first water supply device BP1 and the second water supply device BP2, the same effect as in the water supply system 10 of the embodiment can be obtained.

  Further, in the water supply system 10 of the above-described embodiment, the first water supply device BP1 is a direct water supply system connected to the water pipe 12 via the introduction pipe 13, and the second water supply device BP2 is provided with the first water supply device BP2. It was assumed that it was directly connected to the first water supply device BP1 via the water pipe 14a. However, the invention is not limited to such an example, and at least a part of the plurality of water supply devices in the water supply system may be of a water receiving tank type in which a water receiving tank is connected to the suction side.

FIG. 13 is a diagram illustrating a schematic configuration of a water supply system 20B according to still another embodiment. The water supply system 20B shown in FIG. 13 is the same as the water supply system 20 of the above-described embodiment, except that each of the water supply devices BP1 and BP2 is of a water tank type. In the water supply system 20B, water from the water pipe 12 is stored in the water receiving tank 112A, and the primary side (suction side) of the water supply device BP1 is connected to the water receiving tank 112A via the introduction pipe 13. Further, water from the water supply device BP1 is stored in a water receiving tank 112B provided in the building 16, and the primary side (suction side) of the water supply device BP2 is connected to the water receiving tank 112B via the second introduction pipe 13b. I have. The introduction pipes 13 and 13b are provided with inflow valves (for example, solenoid valves) 15a and 15b capable of blocking a flow path to the water receiving tanks 112A and 112B. The opening and closing of the inflow valves 15a, 15b is performed by the water supply devices BP1, B
The control unit P1 may be controlled by the control units CN1 and CN2, or may be controlled by an external control unit (not shown).

  Also in such a water supply system 20B, when the control unit CN2 of the second water supply device BP2 detects an abnormality in the power line communication with the control unit CN1 of the first water supply device BP1, the control unit CN2 is slower than the normal first startup speed. The pump P2 may be started at an appropriate second starting speed (see FIG. 10: S22). Also, as described in the processing shown in FIG. 11, when the rotation speed of the pumps P1 and P2 is higher than a predetermined threshold when an abnormality is detected in the power line communication, the operation of the pumps P1 and P2 is continued. Good. By such control, the same effect as the above-described water supply system using the direct water supply system can be achieved in the water supply system 20B using the water receiving tank system.

  In the water supply system 10 of the above-described embodiment, the first water supply device BP1 is installed on the ground or underground, and the second water supply device BP1 is installed on the middle floor of the building 16. . However, the water supply system is not limited to the one in which the second water supply device BP2 is disposed at a position higher than the first water supply device BP1, and the second water supply device BP2 is different from the first water supply device BP1. It may be arranged at the same height, or the second water supply device BP2 may be arranged at a position lower than the first water supply device BP1.

The present embodiment described above can also be described as the following modes.
[Mode 1] According to mode 1, a water supply system for supplying water to a water supply target in a building with a plurality of water supply devices is proposed, wherein the water supply system includes a first water supply device and a discharge side of the first water supply device. A first water supply device, wherein the first water supply device has a first pump, and a first control unit that controls the operation of the first pump, The second water supply device has a second pump and a second control unit that controls the operation of the second pump, and the plurality of water supply devices use a power line of the building as a communication line. Can communicate with each other by power line communication, the second control unit starts the second pump at a first starting speed, and the second control unit detects an abnormality in the power line communication, The second pump is started at a second start speed that is slower than the first start speed. To do.
According to the first mode, when an abnormality is detected in the power line communication, the second pump can be slowly started to supply water.

[Mode 2] According to mode 2, in the water supply system according to mode 1, the second control unit, when detecting an abnormality in the power line communication within a predetermined period after a power supply of the water supply system is activated, Starting the second pump at a second starting speed.

[Mode 3] According to Mode 3, in the water supply system according to Mode 1, the second control unit is configured to control the second starting speed when the discharge pressure of the second pump falls below a predetermined starting pressure. To start the second pump.

[Mode 4] According to the mode 4, in the water supply system according to the modes 1 to 3, the second control unit is connected to the first control unit and the power line within a predetermined period after the water supply system is activated. If communication is not established, if the discharge pressure of the second pump is less than a predetermined threshold when the water supply system is activated, the first control unit and the power line communication are established until It is assumed that the second pump is stopped.
According to the fourth aspect, it is possible to prevent the connection pipe between the first water supply device and the second water supply device from becoming negative pressure when communication via the power line is not established.

[Mode 5] According to mode 5, in the water supply system including the first water supply device and the second water supply device provided on the discharge side of the first water supply device, the first water supply device Has a first pump and a first control unit that controls the operation of the first pump, and wherein the second water supply device includes a second pump and an operation of the second pump. A first control unit and the second control unit are communicable with each other by power line communication using a power line as a communication line, and the second control unit controls the second control unit. When the second pump is operating at or above a predetermined rotation speed, the control unit detects at least one of the discharge pressure and the suction pressure of the second pump even when the abnormality of the power line communication is detected. Based on this, the operation of the second pump is continued.
According to the fifth aspect, when an abnormality occurs in the power line communication when the rotation speed of the second pump is high, the operation of the second pump can be continued to supply water.

[Mode 6] According to mode 6, in the water supply system of mode 5, the second control unit detects the power line communication when the second pump is operating at or above the predetermined rotation speed. The rotational speed of the second pump is reduced.
According to the sixth aspect, it is possible to eliminate the abnormality of the power line communication.

[Mode 7] According to the mode 7, in the water supply system according to the mode 5 or 6, the second water supply device supplies a second motor as a drive source of the second pump and electric power to the second motor. A second inverter that supplies the power supply, the second control unit, when the second pump detects an abnormality in the power line communication when the second pump is operating at or above the predetermined rotation speed, The carrier frequency of the second inverter device is reduced.
According to the seventh aspect, it is possible to eliminate the abnormality of the power line communication.

[Mode 8] According to mode 8, in the water supply system according to modes 1 to 7, the first control unit is configured to reduce the discharge pressure of the first pump when the power line communication is performed normally. The first pump is started when the pressure becomes lower than a predetermined first starting pressure and when the discharge pressure of the second pump becomes lower than a predetermined second starting pressure, and the first control is performed. The unit starts the first pump when the discharge pressure of the first pump is lower than the first starting pressure when the power line communication is detected.
According to the eighth aspect, the first pump can be started properly.

[Mode 9] According to mode 9, in the water supply system according to modes 1 to 8, the first control unit is configured to perform the control based on the suction pressure of the second pump when the power line communication is performed normally. The operation of the first pump is controlled, and when an abnormality is detected in the power line communication, the operation of the first pump is controlled based on the first discharge pressure.
According to the ninth aspect, the operation of the first pump can be appropriately controlled according to whether the power line communication is normal or abnormal.

[Mode 10] According to the mode 10, in the water supply system according to the modes 1 to 9, the first control unit is configured to stop the second pump after the second pump stops when the power line communication is normally performed. Stop the first pump.
According to the tenth aspect, it is possible to prevent the connection pipe between the first water supply device and the second water supply device from becoming negative pressure.

[Mode 11] According to the mode 11, in the water supply system according to the mode 1 to the mode 10, the second control unit is configured to perform the second control when the suction pressure of the second pump is equal to or less than a predetermined threshold and a predetermined time has elapsed. Stop the pump.

[Mode 12] According to mode 12, in the water supply system according to modes 1 to 11, the first water supply device is connected to a water pipe, and the second water supply device is connected in series with a discharge side of the first water supply device. Linked to

  Although the embodiments of the present invention have been described above, the embodiments of the present invention described above are intended to facilitate understanding of the present invention, and do not limit the present invention. The present invention can be changed and improved without departing from the spirit thereof, and it is needless to say that the present invention includes equivalents thereof. In addition, any combination of the embodiments and the modifications is possible within a range in which at least a part of the above-described problem can be solved, or a range in which at least a part of the effects is achieved, and described in the claims and the description. Arbitrary combinations of the components described above or omissions are possible.

DESCRIPTION OF SYMBOLS 12 ... Water pipe 13 ... Introductory pipe 14a ... 1st water distribution pipe 14b ... 2nd water distribution pipe 15a ... Inflow valve 16 ... Building 17a, 17b, 17c ... Branch pipe 18a, 18b, 18c ... Water tap 20 ... Water supply system 21 ... backflow preventer 22 ... power line 23 ... distribution board 30 ... pressure sensor BP1, BP2, BP3 ... water supply device P1, P2 ... pump CN1, CN2 ... control unit CV1, CV2 ... check valve L1, L2 ... discharge pipe M1, M2: Motor INV1, INV2: Inverter device SW1, SW2: Flow switch PS1, PS2: Pressure sensor CN1, CN2: Control unit PLC1, PLC2: PLC unit AS1, AS2: Ammeter ES1, ES2: Wattmeter RS1: Rotation speed sensor TS1, TS2 ... thermometer

Claims (12)

In a water supply system that supplies water to a water supply target in a building with a plurality of water supply devices,
A first water supply,
A second water supply device provided on the discharge side of the first water supply device,
The first water supply device has a first pump and a first control unit that controls operation of the first pump,
The second water supply device includes a second pump, and a second control unit that controls operation of the second pump,
The plurality of water supply devices can communicate with each other by power line communication using a power line of the building as a communication line,
The second control unit starts the second pump at a first start speed,
The second control unit, when detecting the abnormality of the power line communication, starts the second pump at a second start speed that is slower than the first start speed.
Water supply system. The second control unit includes:
If the abnormality of the power line communication is detected within a predetermined period after the power supply of the water supply system is started, the second pump is started at the second start speed,
The water supply system according to claim 1. The second control unit includes:
If the discharge pressure of the second pump drops below a predetermined starting pressure, start the second pump at the second starting speed;
The water supply system according to claim 1.   The second control unit, when the power line communication with the first control unit is not established within a predetermined period from the start of the water supply system, when the water supply system is started, the second control unit If the discharge pressure of the second pump is less than a predetermined threshold, the second pump is stopped until the power line communication with the first control unit is established. Water supply system according to any one of the preceding claims. A first water supply,
A second water supply device provided on the discharge side of the first water supply device.
The first water supply device has a first pump and a first control unit that controls operation of the first pump,
The second water supply device includes a second pump, and a second control unit that controls operation of the second pump,
The first control unit and the second control unit can communicate with each other by power line communication using a power line as a communication line,
The second control unit is configured to control the discharge pressure and the suction pressure of the second pump even when the second pump is operated at a predetermined rotation speed or higher, even when the abnormality of the power line communication is detected. Continuing the operation of the second pump based on at least one of:
Water supply system.   The second control unit, when detecting an abnormality in the power line communication while the second pump is operating at or above the predetermined rotation speed, reduces the rotation speed of the second pump. 6. The water supply system according to 5. The second water supply device includes a second motor as a drive source of the second pump, and a second inverter device that supplies power to the second motor.
The second control unit, when detecting an abnormality in the power line communication when the second pump is operating at or above the predetermined rotation speed, decreases the carrier frequency of the second inverter device.
The water supply system according to claim 5. The first control unit is configured to control that when the power line communication is performed normally, when the discharge pressure of the first pump falls below a predetermined first starting pressure, and when the second pump When the discharge pressure falls below a predetermined second starting pressure, the first pump is started,
The first control unit, when detecting an abnormality in the power line communication, starts the first pump when a discharge pressure of the first pump is lower than the first start pressure.
The water supply system according to any one of claims 1 to 7.   The first control unit controls the operation of the first pump based on the suction pressure of the second pump when the power line communication is normally performed, and detects an abnormality in the power line communication. The water supply system according to any one of claims 1 to 8, wherein operation of the first pump is controlled based on the first discharge pressure.   The said 1st control part is a said any one of Claim 1 to 9 which stops the said 1st pump after the said 2nd pump stops, when the said power line communication is performed normally. Water supply system.   The water supply according to any one of claims 1 to 10, wherein the second control unit stops the second pump when a suction pressure of the second pump is equal to or less than a predetermined threshold and a predetermined time has elapsed. system. The first water supply device is connected to a water pipe;
The second water supply device is connected in series to a discharge side of the first water supply device;
The water supply system according to any one of claims 1 to 11.

Images