JPH09329084A - Water supply system - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a hygienic water supply without affecting the water distribution pipes and preventing the water in the elevated water tank from becoming turbid. SOLUTION: This is a water supply device for supplying water to a high water tank 12, and a pipe 2 for water supply directly connected to a water mains 1 via a check valve 9.
And a water supply pipe for supplying water to the elevated water tank 12 are connected, and a pump 8 is provided which is connected to the pipe 2 and sucks the water of the water mains 1 through the pipe 2 and discharges the water to the water pipe side, and detects the water pressure. The pressure detecting means 3 and the water level detecting means 14 for detecting the water level in the high water tank 12 are provided, and the pump 8
An inverter that controls the speed of the electric motor that drives the pump controls the pump according to the pressure detected by the pressure detection means 3 and the water level detected by the water level detection means 14 to drive the pump at a variable speed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a water supply device.

[0002]

2. Description of the Related Art Conventionally, a water supply device (water supply pump)
In order to prevent water pollution due to backflow and prevent erroneous measurement of a water meter (water meter) due to the influence of a water hammer, it was regulated to be directly connected to a water main. For this reason, it is branched from the distribution pipe, which is the mains of the water supply, and once injected into the receiving tank, this water is pumped up by the water supply pump and installed in the roof of the building (or apartment, condominium, etc.) The current situation is that water is stored in a tank (abbreviated as a water tank), and then water is sent to each customer by utilizing the head.

This example will be described below with reference to FIG. From the water distribution pipe 1 through the branch pipe 2, the water meter 3, and the ball tap 4, the water is once poured into the water receiving tank 5. The water stored in the water receiving tank 5 is pumped up by the water supply pump 8 and stored in the elevated water tank 12 installed on the roof of the building 18. The stored water is supplied to the faucet 16 of the consumer through the door meter 17 using the head. At this time, the water supply pump 8 is started when the liquid level relay 14 installed in the high water tank 12 detects the lower limit water level LWL of the water tank, and stops when the upper limit water level HWL is detected. In addition, 6 and 11 are water supply pipes, 7 and 10 are gate valves, 9 is a check valve, and 13 is a ball tap.

Recently, in order to utilize the pressure of a water distribution pipe of a water supply and to eliminate an unsanitary water receiving tank, studies have begun to directly connect a water supply device to the main pipe to supply water. This device is shown in Fig. 1 with dotted line piping 1 instead of the removed water tank.
It is directly connected to the water supply device by means of 9, and the water receiving tank 5 is omitted. In addition, it is considered that the water supply device using an inverter as a variable frequency power supply is effective in the following points. (1) The inverter has the functions of soft start and soft stop, and can suppress the pressure fluctuation on the water distribution pipe side at the time of starting and stopping, and prevent the influence on the water distribution pipe 1 side. (2) When the pressure of the water supply pipe 1 drops, the pump operating speed can be reduced by the inverter to adjust the water supply to the customer.

[0005]

If the elevated water tank type water supply device is used by directly connecting it to the water distribution pipe of the water supply, there are the following problems. (1) The pump always has a constant operating point Q (pump performance curve A
And a pipe resistance curve F are intersected with each other (see FIG. 3), a large amount of water is consumed during this period. Therefore, if this system spreads and many water supply devices are directly connected to the water distribution pipe, the pressure of the water distribution pipe may decrease. Further, the pump stops in a state where the usage amount is large, so that the water pipe pressure increases.

(2) There is a risk that a water amount exceeding the planned maximum water amount Q0 (see FIG. 3) will be consumed, in which case the water distribution pipe pressure will drop below the planned value. (3) The water supply pump of the conventional elevated water tank type water supply device operates at a constant speed, and this pump starts when the water tank water level is the lower limit water level LWL and stops when it is the upper water level HWL. Due to the large drop during this time, the falling water causes the foreign matter that has accumulated at the bottom to be rolled up and the water supply to become muddy. (4) Generally, the high water tank has a large margin,
Water stays for a long time and becomes unsanitary.

The object of the present invention is not to affect the water distribution pipe,
It is an object of the present invention to provide a water supply device that enables hygienic water supply without water in the elevated water tank becoming muddy.

[0008]

SUMMARY OF THE INVENTION The above-mentioned object is, in a water supply apparatus for supplying water to an elevated water tank, a pipe for direct connection water supply connected to a water main via a check valve, and the elevated water tank. To the water pipe, a pump connected to the pipe for sucking the water of the water main through the pipe and discharging to the water pipe side, a pressure detecting means for detecting water pressure, and a water level in the elevated water tank. Water level detecting means, an electric motor for driving the pump, and an inverter for speed control of the electric motor,
This is achieved by providing the inverter with control means for outputting a command according to the pressure detected by the pressure detection means and the water level detected by the water level detection means.

The above object is also to provide, in a water supply device for supplying water to an elevated water tank, a pipe for direct connection water supply connected to a water main, a water pipe for supplying water to the elevated water tank, and a pipe connected to the pipe. A pump that sucks in the water from the water main through the pipe and discharges the water to the water pipe side; a check valve provided between the discharge side of the pump and the water pipe; and a pressure detection unit that detects water pressure. A water level detecting means for detecting the water level in the elevated water tank, an electric motor for driving the pump, an inverter for speed control of the electric motor, and a detection pressure of the pressure detecting means and detection of the water level detecting means in the inverter. It is also achieved by including a control unit that outputs a command according to the water level.

The above object is also to provide, in a water supply device for supplying water to a high water tank, a direct connection water supply pipe connected to a water main via a first check valve, and a water supply to the high water tank. A water supply pipe, a pump connected to the pipe, sucking in water from the water main pipe through the pipe and discharging the water to the water pipe side, and a second reverse side provided between the discharge side of the pump and the water pipe. Stop valve, pressure detection means for detecting water pressure, water level detection means for detecting the water level in the elevated water tank, an electric motor driven by the pump, an inverter for speed control of the electric motor, and the pressure for the inverter. It is also achieved by including a control unit that outputs a command according to the pressure detected by the detection unit and the water level detected by the water level detection unit.

[0011]

[Function] The pump is directly connected to the water distribution pipe, which is a main water pipe, and pressurizes the shortage of main pressure to supply water to a high water tank installed at a high place such as a building. The water level detecting means detects whether the water level in the elevated water tank is at the lower limit water level, the upper limit water level, or the low water level operating water level, and issues a water level signal. The pressure detection means emits a pressure signal according to the detected pressure.

Based on the water level signal and the pressure signal, the control means controls the speed of the pump by the inverter. As a result, the pump can be started at the lower limit water level and stopped at the upper limit water level, or the pressure rising and falling characteristics can be controlled as illustrated in FIG. Further, the pump can be stopped or decelerated, the water level in the elevated water tank can be lowered to LWL, and LWL constant control can be performed during this time so that the pumped water amount and the demanded water amount are in the vicinity of this water level. Furthermore, when deceleration operation is started, speed control is performed so that the pump discharge pressure does not drop below the preset minimum guaranteed pressure HC, and when acceleration operation is started, the pump discharge pressure is preset. The speed can be controlled so as not to exceed the total head HT.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a configuration diagram of a water supply facility according to an embodiment of the present invention, and basically has a configuration in which the water receiving tank 5 shown in FIG. 1 is deleted. The same devices as those described with reference to FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. 20 is a pressure tank for absorbing pressure fluctuation having an air reservoir inside, 21 is a pressure sensor for detecting the pressure on the pump discharge side, 22 is a check valve for preventing contamination from the demand side, and 14 is a high water tank 12
Is a water level detection means that is installed in the high water tank 12 and detects the water level in the high water tank 12, for example, a lower limit water level LWL and an upper limit water level HWL.
Then, the water level LL for operating at a low water level slightly higher than LWL is detected. 6 and 11 are water pipes and 7 and 10
Is a gate valve, 9 is a check valve, and 13 is a ball tap.

FIG. 4 is a pump performance curve diagram shown in FIG. 2, in which the vertical axis represents the total head H and the horizontal axis represents the water amount Q. In the figure, F is a conduit resistance curve, and shows a value specific to the water supply system. Q0 is the planned maximum water supply (instantaneous maximum water supply), and HT is the total head. Generally 10
When 0% N (curve A), the pump is selected so as to satisfy the Q0 and HT. However, since general-purpose pumps are mass-produced, Q0 and HT do not necessarily match. On the other hand, the curve B is Q-H when the pump operating speed is NB, which satisfies the characteristic that the total head HT is obtained when the planned maximum water quantity is Q0.
Performance. Curve D is Q-H performance when the operating speed is ND, which satisfies an arbitrary water amount QD and head HD. Similarly, the curve C is the Q-H performance at the operating speed NC satisfying the minimum guaranteed pressure HC when the water amount is zero. Incidentally, since FIG. 4 shows the suction side pressure at the minimum value, it is obvious that the operating speeds NB, ND and NC mentioned above will change if this pressure changes. On the other hand, conventionally, as shown in FIG. 3, the pump is always operated at a constant operating point Q.

FIG. 5 is a characteristic diagram of startup and shutdown at the time of starting and stopping, in which the horizontal axis represents time and the vertical axis conceptually represents speed and pressure. The broken line is an example of a conventional constant speed pump.

A concrete embodiment of the water level detecting means shown in FIG. 2 is shown in FIGS. Figure 6 is an example of a float type water level detector,
FIG. 7 shows an example of a water level detector using the electrode rods E1 to E4.
Since these water level detectors are known, their description is omitted.

FIG. 8 is a block diagram of a control circuit according to an example of the present invention. 30 is a commercial power source, 31 is a circuit breaker for wiring, 3
2 is a fuse, R and S are control power supplies, 33 is an inverter, 34 is a console for setting control constants such as acceleration / deceleration time in the inverter, 35 is an induction motor for driving a pump, 36 is a switch for turning on / off, Reference numeral 37 is a power supply transformer for the control unit CU, and 38 is a relay for instructing an inverter operation. 39 is an interface circuit for driving the relay 38,
40 is a stabilizing power supply for the CU, 41 is an interface circuit (composed of a digital / analog converter D / A) for instructing the speed N of the inverter in response to a command from the CPU, and 42 is a memory (ROM, RAM). (Configured), 43 is an arithmetic unit CPU, 44 to 48 are input interface circuits, and 49 are constants HT, HC, LW.
Digital switch for setting L, HWL, LL, etc., 5
Similarly, 0 is a digital switch for setting the maximum speed NB and times t1 ', t2, t3, t4', 51 is an example of a liquid level relay of water level detecting means, 52 is also a water level sensor, 53 is a pressure sensor, and 54 is It is a timekeeping means.

The time measuring means 54 uses Δt (for example, 10 mse).
It is composed of an interrupt timer of c) and a timer of the time chart shown in FIG. 9 to 13 are flowcharts showing the control procedure, which are described in advance in the memory 42 as a program.

Next, the operation of the water supply equipment having the above-mentioned structure will be described. When the circuit breaker 31 is turned on and the switch 36 is closed, control power is established, and the controller CU executes the processing up to the initial setting in step 900 shown in FIG. That is, here, the CPU registers, the interface circuits 44 to 48, the interrupt register memory, and other initial values are set, and the digital switches 49 and 50 are further set.
To each set value HT (total head corresponding to the planned maximum water quantity Q0), HC (guaranteed head at water quantity 0), LWL (lower water level), LL (low water level start water level) HWL (upper water level), NB (maximum speed) ), The time constants t1 ', t2, t3, t4' shown in FIG. 5 are read and the respective values are written and stored in the RAM of the memory 42. Also memory TR
O is set to 00H (TRO contains data on whether to operate at low water level).

Next, at step 901, a soft timer Δt1 for the time required for interrupt processing is executed. During this process, the first interrupt process (FIGS. 12 and 13) is executed. First, step 110 is executed to read the pressure (pump discharge pressure) detected by the pressure sensor 53 from the interface circuit 47 and store it in the RAM of the memory 42. Similarly, in the next step 111, the water level of the high water tank 14 is read into the RAM of the memory 42 by reading the signal of the water level detecting means 51 or 52 via the interfaces 46 and 47. Generally, the liquid level relay 51 is often used as the water level detecting means, and the water level sensor is used when performing fine continuous control.

Next, step 120 of the interrupt process is executed. Here, it is determined whether T2 is ON, and if it is ON, the routine proceeds to step 121, where the value of TRO is set to 0FFH, and T2 is set.
Is not ON, the value of TRO is set to 00H in step 122.
, And exit from this loop and return to step 902. The TRO is set for each T2 pulse generated in each T1 cycle of the timing means 43. Further, this interrupt processing (FIGS. 12 and 13) is performed by the access of the timing means even when the main routine after step 902 is being executed.
It is executed every hour.

Returning to step 902, here, TRO
It is determined whether or not the data is 00H, and if it is 00H, the process proceeds to step 903, and the subsequent processes are executed. In step 903, it is determined whether the water level in the elevated water tank is LWL, and if it is not at this level, steps 902 to 9 are reached until it reaches this level.
03, and if yes, the next step 90
At 4,905, an ON signal of the relay 38 is output to drive the inverter, and a signal of the minimum speed NC is output as a speed command signal. Further, the inverter has preset acceleration time (t1'-t1) and deceleration time (t4-t4 ') by the console 34 as shown in FIG. As a result, the inverter 33 and the pump motor 35 are accelerated by the acceleration time (t1 '
-At t1), start operation by soft start.

In step 906, the memory 4 is initialized during initialization.
NB, NC, t2, t1 'stored in 2 are read out and (NB-N
C) = N, (t2-t1 ') / N = [Delta] t2 is calculated. In step 907, it is judged whether or not the pump discharge pressure detected by the pressure sensor 53 exceeds HT, and if it exceeds, it jumps to step 911 without accelerating, and the water of the planned maximum amount or more flows. Suppress not to. If it does not exceed the limit, the process proceeds to step 908, and the speed is increased by 1 Hz (1 bit may be used for control) from the current speed, and step 90 is performed.
In step 9, the waiting time for the calculated Δt2 is executed, and in step 910, it is determined whether or not the acceleration by N is completed, and the processing from step 907 is executed until the acceleration is completed.

When the speed increase by N is completed and the maximum speed is reached, the routine proceeds to step 911. By the way, in this state,
In FIG. 4 and FIG. 5, the pump starts operating in the state of speed Nc, gradually increases in speed and increases in pressure, and reaches speed NB and head HT from time t1 ′ to time t2. Step 91
In 1, it is judged whether the water level of the aquarium has reached the level HWL,
If not reached, steps 912 to 911 are executed until the level reaches HWL. When the level reaches HWL, the process proceeds to step 913 in FIG. 10, where NB-
NC = N '(t4'-t4) / N' = Δt3 is obtained, and the routine proceeds to step 914.

At step 914, the pump discharge side pressure is H
If it is less than C, it is judged. If it is less than C, it jumps to step 919 without decelerating, and if it is more than HC, it is 1 Hz from the current speed in step 915 (it may be 1 bit for control). Slow down, step 916
In step 917, the waiting time process for the calculated Δt3 is executed. In step 917, it is determined whether the deceleration changes by N '. Then, in step 919, the relay 38 is turned off, a signal that sets the speed command data to “0” is output, and the inverter 33
And the pump 8 is stopped. At this time, the deceleration time is (t4
-T4 '), which is a soft stop.

This state will be described with reference to FIGS. 4 and 5. Gradual deceleration and pressure reduction are started from the state of NB and HT, and NC and HC are reached in the period from time t3 to time t4 '. Stop after. After that, the process returns to step 902 in FIG. 9 and the subsequent processes are repeatedly executed.

When TRO is 0FFH as a result of the determination in step 902, the routine jumps to step 923, and the LWL constant operation control in the low water level state is performed. That is, step 9
At 23, determine whether the water level of the high water tank is higher than LWL,
If it is not in the upper rank, the process jumps to step 926, and if it is in the higher rank, the process proceeds to step 924, where step 9
A deceleration process similar to that of No. 15 is executed, a waiting time process of a fixed time (for example, several seconds) is executed in step 925, and the process returns to step 902 again. In step 926, a process of providing hysteresis (a process of setting LWL to LWL-ΔL, for example, a process of determining to operate at a minimum speed for about several minutes) is executed, and in step 927, the water level is lower than the updated LWL. Or not. If it is in the lower order, the same speed-up process as in step 908 is executed in step 928 and the process proceeds to step 925. If it is not in the lower order, the process proceeds to step 925 without shifting.

In this way, the LWL constant control is performed here. Further, FIG. 11 shows an example in which the LWL constant control of the portion X in FIG. 9 uses a liquid level relay instead of the water level sensor. In step 929, it is determined whether or not the water level is higher than LL. In step 932, it is determined whether or not the water level is lower than LWL without performing hysteresis calculation.
The other parts are the same as those in FIG.

[0029]

According to the present invention, the following effects can be obtained. (1) If the water surface is low at the time of start-up, the amount of pumped water falling in the high water tank increases, causing a problem that the water becomes turbid in the high water tank. However, in the present invention, as shown in FIG. Turbulence can be prevented because the amount of pumped water can be narrowed down and gradually raised. (2) In the case of the elevated water tank system, conventionally, the pressure increased when stopped in a constant operating state. However, in the present invention, as shown in FIG. 5, the amount of water can be reduced before stopping, so that the pressure does not rise. (3) Since the operation can be performed with the water level of the elevated water tank being lowered to near LWL on a regular basis, there is no accumulated water and it is hygienic.

[Brief description of drawings]

FIG. 1 is a view in which a water receiving tank used in a conventional technique is interposed in a water supply device for a water supply according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a water supply device according to an embodiment of the present invention.

FIG. 3 is a conventional pump operation characteristic diagram.

FIG. 4 is a pump operation characteristic diagram according to an embodiment of the present invention.

FIG. 5 is a pump operation schedule diagram according to an embodiment of the present invention.

FIG. 6 is a diagram showing a specific example of water level detection means.

FIG. 7 is a diagram showing another specific example of the water level detecting means.

FIG. 8 is a control circuit diagram of a specific example according to the present invention.

FIG. 9 is a control flowchart of a specific example according to the present invention.

FIG. 10 is a control flowchart of a specific example according to the present invention.

FIG. 11 is a control flowchart of a specific example according to the present invention.

FIG. 12 is a control flowchart of a specific example according to the present invention.

FIG. 13 is a control flowchart of a specific example according to the present invention.

FIG. 14 is a diagram showing an example of a time chart of the time counting means according to the present invention.

[Explanation of Codes] 1 ... Water pipe, 8 ... Pump, 21 ... Pressure sensor, 12 ... High water tank, 14 ... Water level detecting means, 33 ... Inverter, CU
... Control unit, 49, 50 ... Digital switch for setting control constants.

Claims (10)

[Claims] 1. A water supply device for supplying water to a high water tank, a pipe for direct connection water supply connected to a water main via a check valve, and a water pipe for supplying water to the high water tank, A pump which is connected to a pipe and sucks the water of the water main through the pipe and discharges it to the water pipe side, a pressure detecting means for detecting a water pressure, a water level detecting means for detecting a water level in the elevated water tank, and the pump. An electric motor for driving the motor, an inverter for controlling the speed of the electric motor, and a control means for outputting to the inverter a command according to the pressure detected by the pressure detection means and the water level detected by the water level detection means. Water supply device. 2. A water supply device for supplying water to a high water tank, a pipe for direct water supply connected to a water main, a water pipe for supplying water to the high water tank, and a pipe connected to the pipe. A pump that sucks in water from the water mains through the water supply pipe and discharges the water to the water supply pipe side, a check valve provided between the discharge side of the pump and the water supply pipe, a pressure detection unit that detects water pressure, and the high pressure Water level detection means for detecting the water level in the storage tank,
An electric motor that drives the pump, an inverter that controls the speed of the electric motor, and a control unit that outputs a command to the inverter according to the pressure detected by the pressure detection unit and the water level detected by the water level detection unit. Water supply device for water supply. 3. A water supply device for supplying water to a high water tank, a pipe for direct water supply connected to a water main via a first check valve, and a water pipe for supplying water to the high water tank. A pump which is connected to the pipe and sucks the water from the water main through the pipe and discharges the water to the water pipe side; and a second check valve provided between the discharge side of the pump and the water pipe. ,
Pressure detecting means for detecting water pressure, water level detecting means for detecting water level in the elevated water tank, electric motor driven by the pump, inverter for speed control of the electric motor, and detection of the pressure detecting means by the inverter. A water supply device, comprising: a control unit that outputs a command according to the pressure and the water level detected by the water level detection unit. 4. The water supply device according to claim 1, wherein the control means is provided separately from the inverter. 5. The water supply device according to claim 1, wherein the pressure detecting means is installed at a position for detecting a water supply pressure discharged from the pump. 6. The control means according to claim 1, wherein the control means outputs a soft start command to the inverter when starting the pump and outputs a soft start command to the inverter when stopping the pump. A water supply device for outputting a stop command. 7. The water supply system according to claim 1, wherein the control means includes a processing means for lowering the water level in the elevated water tank to perform constant water level control at a low water level. Supply device. 8. The water supply device according to claim 7, wherein the processing means is activated at regular intervals. 9. The water supply system according to claim 1, further comprising means for defining an upper limit speed of the pump so as not to exceed a planned maximum amount of water when the water is sent to the elevated water tank. Supply device. 10. A pump that sucks water in through a pipe directly connected to a water main and discharges it to a demand side, an electric motor that drives the pump, and an inverter that controls the speed of the electric motor.
A water supply device, comprising: a control unit that outputs a soft start command to the inverter when starting the pump, and outputs a soft stop command to the inverter when stopping the pump.