JP7110046B2 - Water supply system and control method for water supply system - Google Patents

Description

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

A water supply system is widely used as a device for supplying water (tap water) to buildings such as office buildings and condominiums. A water supply system generally includes a pump for pumping water and a controller for controlling the operation of the pump. The suction port of the pump is connected to the water pipe (water main), and the water that is sucked into the pump from the water pipe is pressurized by the pump and then sent to each faucet through the water pipe installed inside the building. (water supply target). A water supply apparatus directly connected to such a water pipe is generally called a direct water supply apparatus.

Further, conventionally, a water supply system has been proposed that includes a first water supply apparatus that is directly connected to a water pipe, and a second water supply apparatus that is connected to the discharge side of the first water supply apparatus. Such a water supply system is used, for example, to supply water to high-rise buildings, where a first water supply device pressurizes water from a water pipe and supplies it to the lower floors, and a second water supply device supplies water from the first water supply device. is further boosted and supplied to the upper floors.

In 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 A negative pressure may be created due to a drop in pressure in the water line connecting the device. In this state, when a water tap communicating with the drain pipe is opened, air is sucked from the water tap. Therefore, in the water supply device described in Patent Document 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 varies. The pump in the first water supply is started when the starting pressure is reached.

Patent No. 5643385

In the water supply system as described above, the first water supply device and the second water supply device exchange their operating states by communication. Each water supply device performs its own operation control according to the operating state of the other water supply device, for example, preventing the pressure in the pipe connecting the two water supply devices from becoming unintended low pressure as described above. there is For this reason, when a problem occurs in communication between the first water supply device and the second water supply device, it becomes difficult to properly control the operation of the water supply system. However, the water supply to the water supply target is a lifeline, and it is preferable to continue the operation of the water supply device as much as possible in order to avoid water interruption as much as possible.

SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances described above, and it is an object of the present invention to appropriately control each water supply device in a water supply system including a plurality of water supply devices that are communicable with each other. Let it be one.

According to one aspect of the present invention, there is proposed a water supply system for supplying water to a water supply target in a building using a plurality of water supply apparatuses, wherein the water supply system includes a first water supply apparatus and a discharge side of the first water supply apparatus. and 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, and the first A 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 the power line of the building as a communication line. The second controller starts the second pump at a first starting speed, and the second controller detects an abnormality in the power line communication. The second pump is started at a second starting speed that is slower than the first starting speed.
According to this aspect, when an abnormality is detected in the power line communication, the second pump can be gently started to supply water.

It is a figure showing a schematic structure of a water supply system concerning one embodiment of the present invention. It is a figure for demonstrating the 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. 5 is a diagram showing an example of the relationship between the output of the second pump and the followability of the first pump; FIG. 8 is a diagram showing another example of the relationship between the output of the second pump and the followability of the first pump; FIG. 8 is a diagram showing another example of the relationship between the output of the second pump and the followability of the first pump; FIG. 8 is a diagram showing 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 structural example of a 2nd water supply apparatus. It is a schematic diagram which shows the other structural example 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 abnormality performed by the control part of the 2nd water supply device. It is a figure which shows schematic structure of the water supply system which concerns on another one Embodiment. It is a figure which shows schematic structure of the water supply system which concerns on another one Embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding constituent elements are denoted by the same reference numerals, and redundant explanations are omitted.

[First embodiment]
FIG. 1 is a diagram showing a schematic configuration of a water supply system according to one embodiment of the present invention. In the following, as an example of a water supply system, a system for supplying water to a building 16 that is a high-rise building (for example, a building with 16 stories or more) will be described, but the system is not limited to this. 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 device BP1 connected in series to the discharge side of the first water supply device BP1. and a water supply device BP2. In this 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 .

A 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 pipe 14a. It is connected to a plug (first water supply target) 18a via a branch pipe 17a. A second water distribution pipe 14b is connected to the discharge port of the second water supply device BP2. 18b via a branch pipe 17b. With such a configuration, the first water supply device BP1 pressurizes the water from the water pipe 12 and supplies the water to the building 16.
water is supplied to each faucet 18a on the lower floor. 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 high floor of the building 16. FIG.

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

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

The pump P1 includes a rotation speed sensor RS1 that detects the rotation speed (frequency, rotation speed) of the pump P1, an ammeter AS1 that measures the current value flowing through the motor M1, and a power meter that measures the amount of power consumed by the pump P1. A thermometer TS1 is provided to measure the temperature of ES1 and pump P1. Here, the rotation speed sensor RS1 may directly measure the rotation speed of the impeller (not shown) of the pump P1, or may measure the rotation speed of the motor M1. Alternatively, the rotation speed of the pump P1 may be estimated from the output frequency of the inverter device INV1 without providing the rotation speed sensor RS1. Incidentally, in this embodiment, the impeller of the pump P1 and the motor M1 are synchronized, and the impeller rotation speed 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 gear ratio of the transmission (the current gear ratio if variable) and the number of revolutions of the motor M1. You can get the number. Further, ammeter AS1 or wattmeter ES1 may measure a current value or power amount flowing through motor M1, or may measure a current value or power amount flowing through inverter device INV1. Furthermore, the amount of electric power of the pump P1 may be calculated based on the current value of the pump P1 or the like. Also, 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. Furthermore, the thermometer TS1 may measure the temperature of the motor M1 or the temperature of the inverter device INV1.

A backflow preventer 21 is connected to the suction port of the pump P1. This backflow preventer 21 is installed to prevent backflow of water to the water pipe 12 . In this embodiment, as the backflow preventer 21, a decompression type backflow preventer having a configuration in which two check valves sandwich an intermediate chamber in which a relief valve is arranged is used.

The first water supply device BP1 also includes a control section (controller, first control section) CN1 that controls the water supply operation. An inverter device INV1, a flow switch SW1, a pressure sensor PS1, a rotation speed sensor RS1, an ammeter AS1, a wattmeter ES1, and a thermometer TS1 are connected to the control unit CN1 via signal lines.

When the discharge pressure (the water pressure in the discharge pipe L1) drops to a predetermined starting pressure while the pump P1 is stopped, the controller CN1 issues a command to the inverter INV1 to start the operation of the pump P1. During the operation of the pump P1, control such as constant estimated terminal pressure control or constant target pressure control is performed according to 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, and in the case of the target pressure constant control, The set pressure is used as it is as the target pressure (SV). Also, the discharge pressure detected by the pressure sensor PS1 is assumed to be the current pressure (PV). Then, a PI calculation using the proportional gain Gp and the integral gain Gi or a PID calculation using the proportional gain Gp, the integral gain Gi, and the differential gain Gd is performed on the difference between the SV and the PV, and the pump P1 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. Specifically, the target pressure (SV) may be calculated by adding the suction pressure to the target pressure control curve.

When the water usage in the building decreases while the pump P1 is running, the flow switch SW1 detects the insufficient amount of water and sends the detection signal to the controller CN1. Upon receiving this detection signal, the control unit CN1 issues a command to the pump P1 to increase the rotation speed of the pump P1 until the discharge pressure reaches a predetermined operation stop pressure. small amount of water stop). After the pump P1 stops for a small amount of water, when water is used again in the building, the discharge pressure drops below the starting pressure and the pump P1 starts. As a method for detecting a small amount of water, other means such as a low load based on the current value of the motor section or shut-off pressure 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 given corresponding reference numerals. This second water supply system BP2 differs from the first water supply system BP1 in that it does not have a backflow preventer. However, the second water supply device BP2 may have a backflow preventer like the first water supply device BP1.

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

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

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

As noted above, pumps P1 and P2 are started when their respective discharge pressures drop to a predetermined starting pressure. Therefore, starting pressures S1 and S3 that serve as triggers for starting the pumps P1 and P2 are set in the controllers CN1 and CN2, respectively. Further, a second starting pressure S2 for starting the pump P1 is set in the controller CN1. This second starting pressure S2 is a second threshold for starting based on the discharge pressure of the second water supply system BP2 (measured by pressure sensor PS2). The second starting pressure S2 is set higher than the starting pressure (second pump starting pressure) S3 of the pump P2 (S2>S3). This is to start pump P1 before pump P2 is started, as described above.

The controller CN1 starts the pump P1 based on two triggers when the pressure sensor PS1 measurement drops to a first starting pressure S1 and when the pressure sensor PS2 drops to a second starting pressure S2. Let When the discharge pressure of the pump P2 drops, the pressure sensor PS2 detects the starting pressure S2 before the starting pressure S3. The controller CN1 starts the pump P1 when the measured 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.

When water is used on the lower floors while the pump P1 is stopped, the discharge pressure of the pump P1 drops. When the discharge pressure drops to the starting pressure S1, the pump P1 is started. Thus, the pump P1 is actuated based on the measurements of the two pressure sensors PS1, PS2.

The controller CN2 preferably starts the pump P2 after confirming that the pump P1 has been started. For example, the controller CN2 detects that the number of rotations of the pump P1 exceeds a predetermined number of rotations (eg, 30% or 40% of the rated number of rotations), or that the current value or power consumption of the motor M1 has reached a predetermined threshold value. and that the temperature of the motor M1 exceeds a predetermined temperature, it may be determined whether the pump P1 has started.

The operation of the pump P1 is maintained while the pump P2 is operating. Here, even during the operation of the pump P1, the negative pressure in the first water pipe 14a connecting the pumps P1 and P2 may be caused by the operating state of the second water supply device, for example, when the discharge flow rate of the pump P2 suddenly increases. may be formed. Therefore, 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, the controller CN1 sets the rotation speed (frequency) of the pump P1 so that the discharge pressure of the pump P1 reaches the target pressure when the pump P2 is operating at the first output. to control the operation of the pump P1. Further, when the pump P2 is operated at a second output larger than the first output, the controller CN1 controls the discharge pressure of the pump P1 to reach the target pressure with a second followability higher than the first followability. is set to the number of revolutions of the pump P1 to control the operation of the pump P1.

In this embodiment, the controller 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 output of the pump P2 increases. Here, the controller CN1 may determine the magnitude of the output of the pump P2 based on the rotation speed of the pump P2. That is, 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 rotation speed of the pump P2 increases. Specifically, the controller CN1 may increase the proportional gain Gp of the PI control or 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 rotation speed of the pump P2 using a map or a relational expression that preliminarily determines the relationship between the rotation speed Np2 (output) of the pump P2 and the proportional gain Gp by experiment or the like. It is conceivable to set Here, as shown in FIG. 4, the proportional gain Gp may increase in proportion to the rotational speed Np2 (output) of the pump P2. Alternatively, as shown in FIG. 5, the proportional gain Gp may increase with a larger amount of change as the rotational speed Np2 (output) of the pump P2 increases. Alternatively, as shown in FIG. ), the proportional gain Gp may increase with a smaller amount of change. Further, as shown in FIG. 7, when the output of the pump P2 is smaller than the predetermined number of revolutions, the proportional gain Gp increases with a larger amount of change as the output of the pump P2 increases. The proportional gain Gp may be increased with a smaller amount of change as the output of is increased. With 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. As a result, the output of the pump P1 can be quickly changed according to the change in the operating state of the pump P2, and it is possible to prevent the inside of the first water pipe 14a from becoming an unintended low pressure. Further, when the pump P2 is operating with a small output, the rotation speed of the pump P1 changes with low followability. Thereby, the rotation speed of the pump P1 can be gently changed, and the energy efficiency of the water supply system 20 can be improved.

Further, 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 provisional target rotation speed based on the discharge pressure (PV) of the pump P1 and the target pressure (SV). Subsequently, the current rotation speed of the pump P1 is subtracted from the set provisional target rotation speed to calculate the amount of change in the rotation speed of the pump P1. Then, the calculated rotation speed change amount of the pump P1 is multiplied by a correction coefficient Kp that increases as the rotation speed Np2 (output) of the pump P2 increases, thereby correcting the rotation speed change amount of the pump P1. 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, the correction coefficient Kp may be determined in advance by a map or a relational expression based on experiments or the like with respect to the rotation speed Np2 of the pump P2, similarly to the proportional gain Gp described with reference to FIGS. . Even in such control, it is possible to obtain the same effect as in the case of changing the proportional gain Gp described above.

Furthermore, 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. That is, the controller 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 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 experiments or the like (see FIGS. 4 to 7). The operation of pump P1 can be controlled in the same manner as when Np2 is used. Note that the control unit CN1 may use the current value flowing through the second water supply device BP2 instead of the current value A2 flowing through the motor M2 to determine the magnitude of the output of the pump P2.

Further, the control unit CN1 may determine the magnitude of the output of the pump P2 based on the amount of electric power E2 consumed by the pump P2. That is, 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 power consumption E2 of the pump P2 increases. In this case, as an example, a map or a relational expression indicating the relationship between the electric energy E2 and the proportional gain Gp or the correction coefficient Kp is determined in advance by experiment or the like (see FIGS. 4 to 7). The operation of the pump P1 can be controlled in the same way as when the number Np2 or the like is used. Note that the control unit CN1 may use the amount of power consumed by the second water supply device BP2 instead of the amount of power E2 consumed by the pump P2 to determine the magnitude of the output of 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 discharge pressure of the pump P1 reaches the target pressure with higher followability as the temperature T2 of the pump P2 is higher. In this case, as an example, a map or a relational expression showing 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). The operation of the pump P1 can be controlled in the same manner as when 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 changes smoothly so as to increase as the output of the pump P2 increases. However, without being limited to this, the proportional gain Gp or the correction coefficient Kp may change stepwise in two or more steps according to the output of the pump P2.

When the water supply operation is to be stopped while both the pumps P1 and P2 are in operation, the pump P1 is stopped after the pump P2 is stopped. These cooperative operations are performed based on the driving information transmitted between the control units CN1 and CN2. For example, the control unit CN1 determines that the rotation speed of the pump P2 is less than a predetermined rotation speed (eg, 30% or 40% of the rated rotation speed), or that the current or power of the motor M2 is less than a predetermined threshold value. and that the temperature of the motor M2 is less than a predetermined temperature, it may be determined whether the pump P2 has stopped. Such cooperative operation can prevent the pump P1 from stopping before the pump P2 stops, and can prevent negative pressure from forming in the first water pipe 14a.

In the water supply system 20 of the present embodiment, two water supply apparatuses BP1 and BP2 are provided, but even when three or more stages of water supply apparatuses are connected in series, the pumps are similarly started from the lowest hierarchical order. and the pumps should be stopped in descending order of hierarchy.

If only the pump P2 of the second water supply BP2 is running when the first water supply BP1 fails, the air ingestion problem described above can occur. Therefore, when the first water supply device BP1 fails, the controller CN1 transmits the failure information to the controller CN2, and the controller CN2 stops the operation of the pump P2. In this case, even if water is being used on the upper floors, the pump P2 is forcibly stopped.

If the second water supply system BP2 fails, the water supply will be interrupted on the upper floors. When the water supply capacity of the first water supply device BP1 has a margin, 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 controller CN2 transmits the failure information to the controller CN1, and the controller CN1 operates the pump P1 at its maximum water supply capacity. Although the first water supply device BP1 cannot always supply water to all the water taps 18b on the upper floors, the first water supply device BP1 can supply water to at least part of the upper floors. You can avoid water outages on the entire floor.

FIG. 8 is a schematic diagram showing 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 installed upstream of the pump P2. The rest of the 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 controller CN2 via a signal line. The measured value (that is, suction pressure) of the pressure sensor 30 is sent to the first water supply device BP1 via the power line 22 as operating information.

The controller CN1 of the first water supply device BP1 adjusts the water supply pressure (terminal pressure) of the water tap 18a on the lower floors to a predetermined target value based on the measured 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 controller CN1 controls the operation of the pump P1 so as to maintain a predetermined target pressure (SV) with the measured value of the pressure sensor 30 as the current pressure (PV). Since the lower floor end pressure is substantially equal to the suction pressure of the second water supply system BP2, the measurement of the pressure sensor 30 is considered to indicate the water supply pressure (end pressure) of the lower floor faucet 18a. can be done. Therefore, from the pressure sensor 30 measurements, the actual end pressure of the lower floors 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, constant terminal pressure control is realized that is not affected by the pressure drop caused by the frictional resistance in the water pipe. . Therefore, it is possible to supply water at the desired terminal 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.

As described above, when only the pump P2 is in operation while the pump P1 is stopped, or when the pump P2 is in operation even when the pump P1 is in operation, the pumps P1 and P2 may be connected. There is a possibility that the pressure inside the first water pipe 14a becomes an unintended low pressure. Therefore, in the configuration example shown in FIG. 8, the controller CN2 of the second water supply device BP2 controls the inflow of the pump P2 when the suction pressure of the pump P2 is equal to or lower than a predetermined threshold and a predetermined time (for example, several seconds) has elapsed. It should be stopped as a pressure drop.

Each of the first water supply device BP1 and the second water supply device BP2 described above has only one pump, but may have a plurality of pumps as shown in FIG. FIG. 9 is a schematic diagram showing a first water supply device BP1 having a plurality of pumps. Although not shown, the second water supply BP2 can also be provided with multiple pumps according to a similar arrangement. By equipping multiple pumps, multiple pumps can be operated with rotation and number control, and if an abnormality is detected in a pump or inverter during operation, operation will be 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 controller 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 controller CN1 controls the operation of the pump P1 by setting the rotation speed of the pump P1 so that the discharge pressure of the pump P1 reaches the target pressure with higher followability as the total output of the plurality of pumps P2 increases. may As an example, the control unit CN1 controls the proportional gain Gp Alternatively, the correction coefficient Kp may be set large. Further, 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. Furthermore, instead of the number of revolutions of the plurality of pumps P2, a plurality of 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 of using the rotation speed of the pump P2.

In the above-described embodiment, 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, power amount, or temperature of the pump P2 of the second control device BP2. shall be. However, the control unit CN1 may use two or more of these parameters to determine the output of the pump P2. 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 controller 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. By doing so, it is possible to more reliably prevent the negative pressure in the first water pipe 14a.

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 a power line as a communication line, communication may be temporarily performed depending on the state of power usage. Anomalies may occur. Therefore, in a temporary communication abnormality whose cause can be estimated, the water supply system 20 continues to supply water.

First, as described above, in the configuration example shown in FIG. The operation of pump P1 is controlled based on the suction pressure of . Specifically, pressure constant 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 preferably controls the operation of the pump P1 based on the discharge pressure of the pump P1. Specifically, the control unit CN1 may execute constant discharge pressure control so that the discharge pressure of the pump P1 becomes a predetermined target pressure, or may Estimated terminal pressure constant control may be executed so that the estimated suction pressure of the pump P2 becomes a predetermined target pressure. Even when there is an abnormality in the communication between the control units CN1 and CN2, 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. . In addition, when executing the estimated terminal pressure constant control based on the discharge pressure of the pump P1, the output of the pump P1 is A margin should be provided. However, since the energy efficiency is reduced by providing a margin for the output of the pump P1, when the communication between the control units CN1 and CN2 is normal, the control unit CN1 controls the pump pressure based on the discharge pressure of the pump P2. It is preferable to control the operation of P1 so that the terminal pressure is constant.

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 determines that the discharge pressure of the first water supply device BP1 (pump P1) is the starting pressure. The pump P1 is started when the pressure drops below S3 or when the discharge pressure of the second water supply device BP2 drops below the second starting pressure S2. However, if there is an abnormality in the communication between the control units CN1 and CN2, the control unit CN1 cannot acquire the discharge pressure of the second water supply device BP2. It is preferable to start the pump P1 when the pressure drops further.

In the water supply system 20 of this embodiment, the controllers 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, such as when the water supply system 20 is installed, when maintenance is completed, or after a power failure, the power line is interrupted to charge a rush current or a capacitor or a UPS (Uninterruptible Power Supply). 22, and it is assumed that an abnormality will occur in the power line communication. Such an abnormality in power line communication is not due to an abnormality in the water supply system 20, but is resolved over time. On the other hand, the water supply system 20 is related to a lifeline, and if water is to be used in the building 16 after power is turned on, it is preferable to start and operate the pumps P1 and P2 as soon as possible. Therefore, in the present embodiment, the following controls are performed when the water supply system 20 is activated.

FIG. 10 is a flow chart showing an example of the water supply system start-up control process executed by the control unit CN2 of the second water supply apparatus BP2. This process is started when the water supply system 20 is activated, particularly when the controller CN2 is activated. In addition, when the first water supply device BP1 is forced to stop by a power failure, an abnormal stop, or a stop button or the like, the pump P2 stops due to a decrease in the inflow pressure. Therefore, when the inflow pressure of the pump P2 is low, the flowchart of FIG. 10 is not executed.

When the water supply system 20 is activated, the controller CN2 first determines whether or not there is an abnormality in communication with the controller CN1 via the power line 22 (S12). This determination may be made in accordance with determination of communication abnormality in normal power line communication. If there is no abnormality in the communication (S12: No), the control unit CN2 can obtain operation information from the control unit CN1 through power line communication, so it controls the pump P2 as usual (S14 ). Then, if the power line communication is normal, wait until the elapsed time tm from the activation of the water supply system 20 reaches the predetermined time tm1 (S26), and terminate this process. Here, as the predetermined time tm1, a predetermined time that is considered to stabilize the startup of the water supply system 20 may be used. Also, the predetermined time tm1 may be set by an external input or the like.

If there is an abnormality in communication (S12: Yes), the controller 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 main process described later, and it is determined that the pump P2 is currently stopped (S16: Yes). Note that when the pump P2 is already in operation due to an instantaneous power failure or the like, it may be determined in S16 that the pump P2 is in operation.

When the pump P2 is stopped (S16: Yes), the controller CN2 determines whether the discharge pressure Pm2 of the pump P2 when this process is started (Pm2 at startup) is greater than a predetermined threshold value P3n. (S18). The threshold value P3n is preferably equal to or higher than the starting pressure P3 and equal to or lower 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 starting time Pm2, and compares the stored starting time Pm2 with the threshold value P3n. Then, when Pm2 at start-up is equal to or less than threshold value P3n (S18: No), control unit CN2 determines that starting pump (second pump) P2 may cause a problem, and starts pump P2. A stopped state is assumed (S24). This is based on the following reasons. When Pm2 at start-up is greater than threshold value P3n, the water supply device BP2 was stopped immediately before with a small amount of water and the pressure was accumulated in pressure tank PT2 until it reached stop pressure P3. The amount of water is relatively large. Therefore, there is little pressure fluctuation at the time of starting. Furthermore, since the pressure accumulated in the pressure tank PT2 decreases over time, it is assumed that the time during which the pump P2 is stopped is short. On the other hand, when Pm2 at start-up is equal to or less than threshold value P3n, the pressure tank PT2 is not charged, so the pressure fluctuation at start-up increases. That is, when the starting pressure Pm2 is equal to or lower than the starting pressure P3, if the pump P2 is started without establishing communication with the water supply device BP1, the first water pipe 14a may become an unintended low pressure.

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

When the elapsed time tm1 reaches the predetermined time tm1 (S26: Yes), the control unit CN2 terminates this process. Note that while S26 is No, the power line communication abnormality is not notified, and when the power line communication abnormality is not resolved even after S26 becomes Yes and this process is terminated, the control unit CN2 should notify the abnormality. As an example, the notification may be performed by displaying on a display unit (not shown), issuing an alarm by a buzzer (not shown), or transmitting a predetermined signal to the outside.

When power line communication is not established and it is determined in S18 that Pm2 at startup is greater than threshold value P3n (S18: Yes), controller CN2 sets current discharge pressure Pm2 of pump P2 (current Pm2) to 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 controller CN2 determines that the pump P2 does not need to be started, and stops the pump P2 (S24). Here, the current discharge pressure Pm2 of the pump P2 may be measured by the pressure sensor PS2. Then, 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 startup Pm2 is greater than the threshold value P3n (S18: Yes) and the discharge pressure Pm2 of the water supply device BP2 becomes lower than the startup pressure P3 due to the use of water after startup (S20: Yes), The controller CN2 starts the pump P2 (S22). Now, consider a case where there is an abnormality in communication with the control units CN1 and CN2. A gentle start is preferred. In other words, the controller CN2 should normally start the pump P2 at the first starting speed, and in the process of S22 start the pump P2 at the second starting speed, which is slower than the first starting speed. Specifically, the control unit CN2 lengthens 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 processing of S14. When the pump P2 is started, the discharge pressure of the pump P1 provided on the suction side of the pump P2 drops below the starting pressure P1, and the controller CN1 starts the pump P1. Here, as the pump P2 is gently started, the discharge pressure of the pump P1 is also gradually lowered. It is possible to prevent the pressure in the first water pipe 14a from becoming an unintended low pressure during the period from the start to the time water is supplied.

Then, the slow start-up of the pump P2 in S22 is completed, the elapsed time tm after the start-up of the water supply system 20 is before the predetermined time tm1 (S26: No), and the power line communication is abnormal (S12: Yes). If so, the controller CN2 determines in S16 that the pump P2 is in operation (S16: No), and controls the operation of the pump P2 in the same manner as in normal times (S14). In this way, even when the power line communication is not stable, such as when an abnormality in the power line communication is detected within the predetermined period tm1 after the power supply of the water supply system 20 is started, the pump P2 can be gradually started to allow access to the upper floors. Water can be supplied. However, if there is an abnormality in the power line communication, the pump P2 may be operated in a predetermined safe operation mode in which the output is lower than normal, for example. When the elapsed time tm reaches the predetermined time tm1 (S26: Yes), the control unit CN2 terminates this process. It should be noted that if the abnormality in the power line communication has not been resolved even after this processing is terminated, the control unit CN2 should notify the abnormality. Also, at this time, the pump P2 in operation may be stopped.

Next, an abnormality in power line communication that occurs when the rotational speeds of the pumps P1 and P2 are high will be described. In this embodiment, the pumps P1 and P2 are driven by driving the motors M1 and M2 via the inverter devices INV1 and INV2. Here, when the rotational speed of the pumps P1 and P2 increases, the influence of switching noise of the inverters INV1 and INV2 increases, and the noise is transmitted to the power line 22, which may make it impossible to establish power line communication between the control units CN1 and CN2. . Since such an abnormality in power line communication is not caused by an abnormality in the water supply system 20, in the present embodiment, different control is performed based on the rotation speed Np2 of the pump P2 when an abnormality in power line communication occurs.

FIG. 11 is a flow chart showing an example of a process during pump operation, which is executed 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 while the pumps P1 and P2 are in operation. In order to facilitate the explanation below, the second water supply device BP2 will be explained. When an abnormality in power line communication is not detected (S30: No), the control unit CN2 first executes normal processing (S14) as in S14 of FIG. When the power line communication is abnormal (S30: Yes), the controller CN2 first compares the rotation speed Np2 of the pump P2 with a predetermined rotation speed (threshold value) Nref (S32). The threshold value Nref is preferably a predetermined value based on the performance of the inverter INV2, such as the maximum frequency Nmax and the specified frequency. For example, the threshold value Nref may be 70% or more of the maximum frequency Nmax of the inverter INV2. Note that this threshold value Nref may be set by an external input or the like. Further, since the rotation speed of the pump is generally proportional to the amount of water and the current flowing through the inverter device, in S32, instead of/or in addition to the rotation speed Np2 and its threshold value Nref, the current value of INV2 and a predetermined threshold value are set. may be used.

When the rotation speed Np2 of the pump P2 is smaller than the threshold value Nref (S32: No), the controller CN2 determines that the power line communication abnormality is not caused by the high rotation speed Np2 of the pump P2. , a predetermined communication abnormality processing is executed (S34), and this processing ends. As the communication abnormality processing, for example, the control unit CN2 should 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 in normal operation, 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 controller CN2 determines that the abnormality in the power line communication is not due to an abnormality in the water supply system 20, and that the rotation speed Np2 of the pump P2 is high. , the operation of the pump P2 is continued (S36), and the present process is terminated. At this time, it is considered that the rotation speed Np2 of the pump P2 will decrease due to the use of water on the upper floors, etc., and the abnormality in the power line communication will be resolved and control will return to the normal state using the power line communication. In addition, in the process of S36, the control unit CN2 may perform control for resolving the abnormality of the power line communication. Specifically, the controller CN2 may reduce the rotational speed Np2 of the pump P2. In this case, the controller CN2 may, for example, gradually decrease the rotation speed Np2 of the pump P2 until the abnormality in the power line communication is resolved, or may set a predetermined rotation speed N2a as the rotation speed command. Further, the control unit CN2 may reduce the carrier frequency of the inverter INV2 instead of or in addition to reducing the rotation speed Np2 of the pump P2. In this case, the control unit CN2 may, for example, gradually lower the carrier frequency of the inverter INV2 until the power line communication abnormality is resolved, or may use a predetermined carrier frequency. By lowering the carrier frequency, switching noise can be reduced, and noise in the power line 22 can be reduced. It should be noted that the decrease in rotation speed and the change in carrier frequency may be set by external input.

Note that, as described above, when it is assumed that an abnormality has occurred in the power line communication when the water supply system 20 is started up or when the number of rotations of the pumps P1 and P2 is high, the power line communication is not performed as compared to normal times. The number of communication retries may be increased. Thus, when there is no abnormality in the water supply system 20 and there is an abnormality in the power line communication due to the start-up or operating state of the water supply system 20, many communication retries can be performed to prompt the establishment of communication.

(Modification)
In the embodiment described above, the water supply system 20 is provided with the two water supply devices BP1 and BP2. However, it is not limited to such an example, and the water supply system 20 may include three or more water supply devices. FIG. 12 is a diagram showing a schematic configuration of a water supply system according to another embodiment. A water supply system 20A shown in FIG. 12 includes three water supply devices BP1 to BP3. 1st water supply apparatus BP1 is connected to the water pipe 12 through the introduction pipe 13 like the water supply system 20 shown in FIG. 2nd water supply apparatus BP2 is provided in the discharge side of 1st water supply apparatus BP1, and is connected to 1st water supply apparatus BP1 via the 1st water 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 pipe 14b. The first water supply device BP1 pressurizes 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. . In addition, the second water supply device BP2 further increases the pressure of the water from the first water supply device BP1 so as to supply water to each water tap 18b on the middle floor of the building connected to the second water distribution pipe 14b. It's becoming Further, the third water supply device BP3 further boosts the pressure of the water from the second water supply device BP2 so as to supply water to each water tap 18c on the upper floor of the building connected to the third water pipe 14c. It's becoming

The first and second water supply devices BP1, BP2 may be configured similarly to the first and second water supply devices BP1, BP2 in the water supply system 10 described above (see FIGS. 2 and 3). Also, the third water supply device may be configured in the same manner as the second water supply system BP2 in the water supply system 10 described above (see FIG. 3). Each of the first to third water supply apparatuses 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. FIG.

Also in such a water supply system 10A, control similar to that of 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 are controlled in the same manner as the first water supply device BP1 and the second water supply device BP2 in the water supply system 10 described above. It is possible to prevent the water pipe 14a from becoming an unintended low pressure and appropriately control the water supply devices BP1 and BP2. Further, the second water supply device BP2 and the third water supply device BP3 are also controlled in the same manner as the first water supply device BP1 and the second water supply device BP2 in the water supply system 10 described above. It is possible to prevent the water distribution pipe 14b from becoming an unintended low pressure and appropriately control the water supply devices BP2 and BP3. In other words, the water supply device on the primary side (upstream side) is the "first water supply device", and the water supply device on the secondary side (downstream side) is the "second water supply device". By performing control in the same manner as the first water supply device BP1 and the second water supply device BP2, the same effect as 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 the first It shall be directly connected to 1st water supply apparatus BP1 via the water pipe 14a. However, it is not limited to such an example, and at least some 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 showing a schematic configuration of a water supply system 20B according to yet another embodiment. A 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 apparatuses BP1 and BP2 is of a water receiving tank type. In the water supply system 20B, water from the water pipe 12 is stored in the water tank 112A, and the primary side (suction side) of the water supply device BP1 is connected to the water tank 112A through the introduction pipe 13. Water from the water supply device BP1 is stored in a water tank 112B provided in the building 16, and the primary side (suction side) of the water supply device BP2 is connected to the water tank 112B via the second introduction pipe 13b. there is The introduction pipes 13, 13b are provided with inflow valves (for example, solenoid valves) 15a, 15b capable of shielding the flow paths to the water receiving tanks 112A, 112B. The opening and closing of the inflow valves 15a and 15b are controlled by the water supply devices BP1 and B.
It may be controlled by the control units CN1 and CN2 of P2, or may be controlled by an external control unit (not shown).

In the water supply system 20B as well, when the control unit CN2 of the second water supply device BP2 detects an abnormality in power line communication with the control unit CN1 of the first water supply device BP1, the first starting speed is slower than the normal first starting speed. It is preferable to start the pump P2 at the second starting speed (see FIG. 10: S22). Further, in the same manner as described in the processing shown in FIG. 11, when an abnormality in power line communication is detected and the rotation speeds of the pumps P1 and P2 are higher than a predetermined threshold value, the operation of the pumps P1 and P2 is continued. good. With such control, the water supply system 20B using the water tank system can also achieve the same effects as the water supply system using the above-described direct water supply system.

Further, 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 one in which the second water supply apparatus BP2 is arranged at a higher position than the first water supply apparatus BP1, and the second water supply apparatus BP2 and the first water supply apparatus BP1. They 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, there is proposed a water supply system for supplying water to a water supply target in a building using a plurality of water supply apparatuses, and the water supply system includes a first water supply apparatus and a discharge side of the first water supply apparatus. and a second water supply device provided in the 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 the power line of the building as a communication line. 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 starting speed that is slower than the first starting speed.
According to form 1, when an abnormality is detected in the power line communication, the second pump can be gently started to supply water.

[Mode 2] According to mode 2, in the water supply system of mode 1, when the second control unit detects an abnormality in the power line communication within a predetermined period after the power supply of the water supply system is started, the 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 controls the second starting speed when the discharge pressure of the second pump drops below a predetermined starting pressure. to start the second pump.

[Mode 4] According to Mode 4, in the water supply system of Modes 1 to 3, the second control unit controls the operation of the first control unit and the power line within a predetermined period after the water supply system is activated. If communication is not established and the discharge pressure of the second pump is less than a predetermined threshold when the water supply system is activated, until the power line communication is established with the first control unit The second pump is stopped.
According to form 4, it is possible to suppress negative pressure in the connection pipe between the first water supply device and the second water supply device when communication through 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 operation of the first pump, and the second water supply device includes a second pump and an operation of the second pump wherein 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, and the second control unit The control unit controls at least one of the discharge pressure and the suction pressure of the second pump even if an abnormality in the power line communication is detected while the second pump is operating at a predetermined rotational speed or higher. Based on this, the operation of the second pump is continued.
According to form 5, when an abnormality occurs in power line communication when the rotational 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, when the second control unit detects the power line communication while the second pump is being operated at the predetermined rotation speed or higher, , reducing the rotation speed of the second pump.
According to form 6, it is possible to eliminate an abnormality in power line communication.

[Mode 7] According to Mode 7, in the water supply system of Mode 5 or 6, the second water supply device includes a second motor as a drive source for the second pump, and an electric power supply to the second motor. and a second inverter device that supplies a second inverter device, wherein the second control unit detects an abnormality in the power line communication when the second pump is operated at the predetermined rotational speed or higher, the The carrier frequency of the second inverter device is lowered.
According to form 7, it is possible to eliminate an abnormality in power line communication.

[Mode 8] According to Mode 8, in the water supply system of Modes 1 to 7, when the power line communication is normally performed, the discharge pressure of the first pump is When the discharge pressure of the second pump falls below a predetermined first starting pressure and when the discharge pressure of the second pump falls below a predetermined second starting pressure, the first pump is started and the first control is performed. The unit starts the first pump when the discharge pressure of the first pump falls below the first starting pressure when the power line communication is detected.
According to form 8, the first pump can be properly started.

[Mode 9] According to Mode 9, in the water supply system of Modes 1 to 8, when the power line communication is normally performed, the first controller controls the suction pressure of the second pump based on the suction pressure of the second pump. 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 form, the operation of the first pump can be appropriately controlled depending on whether the power line communication is normal or abnormal.

[Mode 10] According to Mode 10, in the water supply system of Modes 1 to 9, when the power line communication is normally performed, the first controller controls the second pump after the second pump stops. 1 pump is stopped.
According to form 10, it is possible to suppress negative pressure in the connection pipe between the first water supply device and the second water supply device.

[Embodiment 11] According to Embodiment 11, in the water supply system of Embodiments 1 to 10, when the suction pressure of the second pump is equal to or lower than a predetermined threshold value and a predetermined time has elapsed, the second control unit Stop the pump.

[Mode 12] According to mode 12, in the water supply system of 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 the discharge side of the first water supply device. connected to

Although the embodiment of the present invention has been described above, the above-described embodiment of the present invention is for facilitating understanding of the present invention, and does not limit the present invention. The present invention may be modified and improved without departing from its spirit, and the present invention includes equivalents thereof. In addition, any combination of the embodiments and modifications is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects, and is described in the scope of claims and the specification. Any combination or omission of each component is possible.

DESCRIPTION OF SYMBOLS 12... Water pipe 13... Introduction pipe 14a... 1st water pipe 14b... 2nd water pipe 15a... Inflow valve 16... Building 17a, 17b, 17c... Branch pipe 18a, 18b, 18c... Water tap 20... Water supply system 21 Backflow prevention device 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... Power meter RS1... Revolution sensor TS1, TS2... thermometers

Claims (12)

In a water supply system that supplies water to a water supply target in a building with multiple water supply devices,
a first water supply device;
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 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,
The plurality of water supply devices are capable of communicating with each other by power line communication using the power line of the building as a communication line,
The second control unit starts the second pump at a first starting speed,
When detecting an abnormality in the power line communication, the second control unit starts the second pump at a second starting speed that is slower than the first starting speed.
water supply system. The second control unit is
starting the second pump at the second starting speed when an abnormality in the power line communication is detected within a predetermined period after the power supply of the water supply system is started;
The water supply system according to claim 1. The second control unit is
starting the second pump at the second starting speed when the discharge pressure of the second pump drops below a predetermined starting pressure;
The water supply system according to claim 1. If the power line communication with the first control unit is not established within a predetermined period after the water supply system is activated, the second control unit controls the power line communication when the water supply system is activated. 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. The water supply system according to any one of items 1 and 2. a first water supply device;
A water supply system comprising 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 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,
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 controls the discharge pressure and the suction pressure of the second pump even if an abnormality in the power line communication is detected while the second pump is being operated at a predetermined rotational speed or higher. continuing operation of the second pump based on at least one of
water supply system. 3. The second control unit reduces the rotation speed of the second pump when detecting an abnormality in the power line communication while the second pump is being operated at the predetermined rotation speed or higher. 5. The water supply system according to 5. The second water supply device includes a second motor as a drive source for the second pump, and a second inverter device that supplies power to the second motor,
When the second control unit detects an abnormality in the power line communication while the second pump is operating at the predetermined rotational speed or higher, the second control unit reduces the carrier frequency of the second inverter device.
The water supply system according to claim 5 or 6. The first control unit controls when the discharge pressure of the first pump falls below a predetermined first starting pressure when the power line communication is normally performed, and when the second pump starting the first pump when the discharge pressure drops below a predetermined second starting pressure;
The first control unit, when detecting an abnormality in the power line communication, starts the first pump when the discharge pressure of the first pump is lower than the first starting 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 controls the operation of the first pump when an abnormality in the power line communication is detected. The water supply system according to any one of claims 1 to 8, wherein the operation of said first pump is controlled based on the discharge pressure of said first pump. The said 1st control part is any one of Claim 1 to 9 which stops a said 1st pump after a said 2nd pump stops, when the said power line communication is normally performed. 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 the suction pressure of the second pump is equal to or less than a predetermined threshold value 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 the discharge side of the first water supply device,
The water supply system according to any one of claims 1 to 11.

Images