JP3089267B2 - Automatic water supply apparatus and pump control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic water supply apparatus for controlling a pump to supply water to a customer and a method for controlling the pump. The present invention relates to an automatic water supply apparatus and a pump control method thereof.

[0002]

2. Description of the Related Art In recent years, an automatic water supply device having a small pressure tank has become widespread for water supply to apartment houses such as apartments and condominiums. As shown, the pump is started when the pressure in the pressure tank drops to the lower limit pressure by the combined use of the pressure switch and the timer, and the pump is stopped when the pressure reaches the upper limit pressure and the timer clock ends. There is something.

[0003]

However, in the prior art described above, the pump is operated and stopped by the pressure switch and the timer, so that the stop pressure changes and the pump is stopped and started. , The change in feedwater pressure is remarkably large, during which the feedwater pressure cannot be kept constant.

[0004] Therefore, if the water supply pressure is high when the user opens the faucet, not only there is a problem that water entrains the atmosphere and becomes cloudy or scatters, but also the water temperature of the instantaneous water heater or shower fluctuates. Problem.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide an automatic water supply apparatus capable of suppressing a change in water supply pressure between a start and a stop of a pump within a predetermined range and keeping the water supply pressure substantially constant. And a pump control method therefor.

Another object of the present invention is that once the starting pressure of the pump is set, the starting pressure can be automatically adjusted even if the stop pressure changes due to a change in water absorption level or pump wear. It is an object of the present invention to provide an automatic water supply device and a pump control method for adjusting a pump starting pressure thereof.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to start a pump when the supply water pressure decreases and reaches a starting pressure, supply water at the supply water pressure of the pump, and increase the supply water pressure to a stop pressure. In an automatic water supply device for stopping the pump when the pressure is reached, when the water supply pressure reaches the stop pressure and the pump is stopped, the pressure after the stop is detected and the detected pressure is stopped for the next time. Means for setting as pressure;
Means for setting a value obtained by subtracting a predetermined pressure from the pressure set by the means as the next starting pressure.

The above object is also achieved by starting a pump when the supply water pressure decreases to reach a starting pressure, supplying water at the supply water pressure of the pump, and increasing the supply water pressure to reach the stop pressure. In the pump control method of the automatic water supply device for stopping the pump, when the water supply pressure has reached the stop pressure and the pump is stopped, the pressure after the stop is detected, and the detected pressure is used as the next stop pressure. This is achieved by setting a value obtained by subtracting a predetermined pressure from the set pressure as the next starting pressure.

[0009]

The differential pressure between the start pressure and the stop pressure is maintained at a predetermined pressure, so that the fluctuation of the feed water pressure is kept constant whether the pressure on the pump suction side changes or the pump performance changes. It can be suppressed within the range.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

An automatic water supply apparatus according to a first embodiment of the present invention will be described with reference to FIGS. In the automatic water supply device of the present embodiment, as shown in FIG. 1, a water main 1 is connected to a suction part of a pump 3 via a suction pipe 2, and a discharge part of the pump 3 is connected to a water supply pipe 4. .

A gate valve 5 is provided at an intermediate position of the suction pipe 2. The water supply pipe 4 is provided with a check valve 6 and a sluice valve 7 at a position close to the pump 3, and at a downstream side of the sluice valve 7, discharge water from the pump 3 is stored and the pressure is increased to a desired pressure. A tank 8 is provided.

Further, the water supply pipe 4 has a pressure tank 8.
A pressure sensor 9 for detecting a feed water pressure is provided downstream of the pressure sensor. The pressure sensor 9 always detects the feedwater pressure and outputs the detected value to the control means 10 as a current (or a voltage).

The control means 10 starts the pump 3 when the feed water pressure reaches a pressure to start the pump 3 (hereinafter referred to as a pump starting pressure) based on the output from the pressure sensor 9. When the water supply pressure reaches a pressure at which the water supply pump 3 should be stopped (hereinafter, referred to as a pump stop pressure),
The pump 3 is controlled so as to be stopped, and the pump 3 is controlled to start and stop according to the pressure in the water supply pipe 4.

This will be described using a characteristic curve. FIG. 2 is an operation characteristic diagram of the pump 3 in which the pressure H is plotted on the vertical axis and the water amount Q is plotted on the horizontal axis. In the figure, A is a QH performance curve of the pump 3, B is the pressure of the water main 1,
That is, it is a QH performance curve of the pump 3 when the pushing pressure is increased. P1 is a predetermined starting pressure of the pump, which corresponds to the total head desired by the water supply system. P2
Is the upper limit pressure (stop pressure) higher than P1. Q1, Q
2 is a pump 3 corresponding to the pressures of P1 and P2, respectively.
Discharge amount.

Now, when the pressure of the water main 1 changes or the stop pressure P2 changes due to wear of the pump 3, etc., the difference from the predetermined starting pressure P1 of the pump 3 changes. In such a case, in the control using the conventional pressure switch, since the starting pressure P1 is fixed, the pressure fluctuation from the stop pressure may be large. For example, if the amount of water used immediately becomes zero after the operation, the feed water pressure rises to the cutoff pressure (the intersection of the curve A and the vertical axis in FIG. 2) along the performance curve A of the pump 3, and the water supply pressure increases. The pressure fluctuations between them increase. Therefore, in this embodiment, a microcomputer is used as the control means 10 so that the starting pressure P1 is automatically updated.

FIGS. 3 and 4 show the structure of the control means 10 and the flow of control for adjusting the pump starting pressure in this embodiment, respectively.

Specifically, in FIG. 3, R,
S and T are phases of a three-phase power supply to the pump 3, and R and S phases are used as control power supplies. IM is a motor for driving the pump 3, MB is a circuit breaker as a main power switch,
MCa is an electromagnetic switch MC for switching the current to the motor IM.
, TH is a sensor portion of the overload protection thermal relay attached to the motor IM, and THb is its contact. In the control circuit portion shown on the right side of FIG.
S connected in series with the DC smoothing stabilized power source Z between the phases S and S is a power switch. DC power is supplied from the stabilized power supply Z to the microcomputer MCON as the control means 10 via the power supply terminal A.

Microcomputer MCON as control means 10
Is a processor MPU, a memory (RAM) M as storage means, an input port Pio-B for taking in an output from the pressure sensor 9 via the interface I / O-2, and taking in outputs from the switches SW1 and SW2. Input port P
io-C, which has an output port Pio-A for outputting based on the processing result in the processing unit MPU.

Further, the microcomputer MCON also has a pump starting pressure adjusting function. Each time the pump 3 is stopped by the MPU, the pump starting pressure adjusting function detects the feed water pressure at the time of the stop by the pressure sensor 9 and stores it in the memory M as a stop pressure, and starts from this value. The result obtained by subtracting the pressure difference between the pressure and the stop pressure (which will be described later and is preset by a switch SW2) is obtained as a new starting pressure.

Further, SW1 and SW2 are the (initial) starting pressure P1 of the pump 3, and the differential pressure Δ between the starting pressure and the stopping pressure.
This is input means for selecting and inputting the value of H in advance, and is composed of, for example, a dip switch.

In this embodiment, when the preparation for the operation of the automatic water supply device is completed, the circuit breaker MB for wiring is turned on, and the power switch S is closed, the microcomputer MCON first sets the initial settings as shown in FIG. Executed (step 40
1,402). That is, if the (initial) starting pressure P1 of the pump 3 is selected from the switch SW1, and the differential pressure ΔH for starting and stopping the pump 3 is selected and input from the switch SW2, the starting pressure P1 and the differential pressure ΔH are stored in the memory. M, and further stores a soft timer value T for suppressing the start frequency of the pump 3 as necessary.

Thereafter, with the pump 3 stopped, the feed water pressure P measured by the pressure sensor 9 is taken in from the input port Pio-B via the interface I / O-2, and stored in the memory M. (Step 40
3) It is determined whether or not the water supply pressure P is equal to or lower than the previously stored starting pressure P1 of the pump 3 (step 404).

As a result of the determination, if the feed water pressure P is higher than the starting pressure P1, the flow proceeds to Step 4 until the feed water pressure P becomes lower.
03 and 404 are repeatedly executed. If the feed water pressure P is equal to or lower than the starting pressure P1, the microcomputer MCON
The pump 3 is started for the first time by exciting the electromagnetic switch MC through the output port Pio-A and the interface I / O-1 under the control of (step 405).

In the subsequent steps 406 to 408, a process based on the soft timer value T is executed in order to suppress the starting frequency of the pump 3, and the present water supply pressure P is measured by the pressure sensor 9. ing. It is determined whether the measured feed pressure P is equal to or higher than the stop pressure P2 of the pump 3 (step 40).
9). If it is determined that the stop pressure is equal to or higher than the stop pressure P2, the process in step 410 is executed. If the stop pressure is lower than the stop pressure P2, the process in steps 415, 406 to 409 or steps 415, 408, and 409 is repeated. It is to be executed. As a result, the pump 3 is stopped for the first time on condition that the time corresponding to the soft timer value T has elapsed and the feed pressure P is equal to or higher than the stop pressure P2 (steps 409 to 411).

After the operation of the pump 3 is stopped in step 411, the feed water pressure P is detected again in step 412. The detected feed water pressure P is updated as a new stop pressure P2 and the memory M Is stored in. Thereafter, in step 413, the differential pressure ΔH is subtracted from the updated stop pressure P2, and the result is updated as a new start pressure P1. Thereafter, the soft timer value T is reset in step 414, and the process returns to step 403. However, as can be seen from the above description, after all, every time the operation of the pump 3 is stopped, Stopping pressure P2 (after updating) and differential pressure ΔH
As a result, the starting pressure P1 is automatically updated.

Since the differential pressure ΔH is set as a constant value by the switch SW2, in FIG. 2, for example, when the pushing pressure of the water main 1 increases and the pump characteristic becomes B, that is, when the amount of used water is When stopping at P3 'in Q3, the next starting pressure P1 is updated to P3'-. DELTA.H. Similarly, when stopping at Q4, the starting pressure P
1 is automatically updated as P4 '-. DELTA.H. As described above, if the starting pressure P1 is set as an initial value by the switch SW1 and the differential pressure ΔH is set as a constant value by the switch SW2, even if the pushing pressure of the water main 1 fluctuates, the pump 3 Even if the discharge pressure fluctuates due to abrasion, the starting pressure P1 does not need to be manually adjusted as needed because the starting pressure P1 can be automatically updated while the differential pressure ΔH is kept constant at all times.

An automatic water supply apparatus according to a second embodiment of the present invention will be described with reference to FIGS. This embodiment is different from the first embodiment in that a flow sensor 12 as a flow detecting means is newly added.

This flow sensor 12 detects a case where the amount of water used is extremely small.
It is housed in the microcomputer MCON via the interface I / O-2 and the input port Pio-B.
Note that among the components shown in FIG. 5, components having the same reference numerals as those shown in FIG. 3 represent the same components, and a description thereof will be omitted here.

In this embodiment, as shown in FIG. 6, during operation of the automatic water supply device, the water supply pressure P is changed to the starting pressure P of the pump 3.
When the pressure falls below 1, the pressure sensor 9 detects this (steps 603 and 604), whereby the pump 3 is started (step 605). In this case, when the used water amount reaches the minimum water amount point Q2, this is detected by the flow rate sensor (flow switch) 12, and the pump 3 is stopped by the microcomputer.
Hereinafter, the water supply pressure can be kept substantially uniform by repeating the processing from step 611. Basically, the same effects as those of the embodiment shown in FIGS. 1 and 2 can be obtained. In this case, the flow sensor 12 closes the contact (ON) when the flow rate is equal to or less than Q2, and opens the contact at a higher flow rate than the flow rate Q2 (OF
F).

According to the above-described embodiment, since the starting pressure P1 of the pump 3 can be automatically updated as required, if the starting pressure P1 of the pump 3 is previously set as an initial value, the starting pressure is thereafter set. The pressure P1 does not need to be manually adjusted, so that the operability is good and the handling is easy. Also,
Since the value of the reference value can be adjusted, the water supply pressure can be delicately and easily controlled according to the scale and use of the automatic water supply device.

Even if the pressure on the suction side of the pump 3 fluctuates or the performance of the pump changes, the starting pressure P
Since 1 is successively updated in accordance with a predetermined differential pressure, the water supply pressure P can be kept uniform at a predetermined pressure, and as a result, there is an effect that reliability is improved accordingly.

Further, it is possible to suppress the fluctuation of the feed water pressure within a certain range without using an inverter and a pressure reducing valve.

In the above embodiment, an example is shown in which a microcomputer is used as the control means.
It is not limited to this. Although not shown, for example, the control unit inputs the starting pressure P1 and the differential pressure ΔH, an operating unit that operates and stops the pump 3, and an updating unit that continuously updates the starting pressure after the pump stops. If the pump starting pressure adjusting device is configured to include the components, the same operation and effect can be obtained even if these are configured by hardware such as an electronic circuit and a relay circuit.

[0035]

According to the present invention, the fluctuation of the water supply pressure between the start and the stop of the pump can be suppressed within a predetermined range, and the water supply pressure can be kept substantially constant. Also,
Once the starting pressure of the pump is set, the starting pressure can be automatically adjusted even if the stop pressure changes due to a change in water absorption level or pump wear.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of an automatic water supply device according to the present invention.

FIG. 2 is an operation characteristic diagram of the pump in the present embodiment.

FIG. 3 is an overall circuit diagram of the automatic water supply device according to the present embodiment.

FIG. 4 is a flowchart showing control contents of the automatic water supply device according to the embodiment.

FIG. 5 is an overall circuit diagram of an automatic water supply device according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing control contents of the automatic water supply device according to the present embodiment.

[Explanation of symbols]

3 pump, 9 pressure sensor, 10 control means, 12
Flow sensor, P1: Start pressure, P2: Stop pressure, SW1
… Switch for setting the initial starting pressure, SW2… Switch for setting the differential pressure.

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F04D 15/00 F04B 49/00-51/00

Claims (10)

(57) [Claims] When the supply pressure decreases and reaches a starting pressure, a pump is started to supply water at the supply pressure of the pump, the supply pressure increases and reaches a stop pressure, and a timer measures a predetermined time. An automatic water supply device for stopping the pump, a means for detecting a pressure after reaching the stop pressure and stopping the pump by counting a predetermined time, and setting the detected pressure as a next stop pressure; Means for setting a value obtained by subtracting a predetermined pressure from the pressure as a next starting pressure. Wherein Oite to claim 1, an automatic water supply device, characterized in that it comprises means for setting the value of the predetermined pressure. 3. The claim 1, 2, wherein the pump is an automatic water supply device according to claim Tei Rukoto is directly connected to the water mains through the suction pipe. 4. The pump is started when the supply water pressure decreases and reaches the starting pressure, water is supplied at the supply water pressure of the pump, the supply water pressure increases and reaches the stop pressure, and the timer measures a predetermined time. In the pump control method of the automatic water supply device for stopping the pump, when the stop pressure is reached and the timer measures a predetermined time to stop the pump and detects the pressure, the detected pressure is set as the next stop pressure. And a method of setting a value obtained by subtracting a predetermined pressure from the stop pressure as a next start pressure. 5. The pump is started when the supply water pressure decreases and reaches a starting pressure, water is supplied at the supply water pressure of the pump, and after a predetermined time from the increase of the supply water pressure to the stop pressure, the pump starts. In the pump control method of the automatic water supply device for stopping the pump, the pressure after the pump is stopped after a predetermined time has elapsed after the stop pressure has been reached, the detected pressure is set as the next stop pressure, and the predetermined pressure is determined from the stop pressure. A method for controlling a pump of an automatic water supply device, wherein a value obtained by subtracting the pressure is set as a next starting pressure. 6. A pump is started when the supply water pressure decreases and reaches a starting pressure, water is supplied at the supply water pressure of the pump, and the pump is stopped when the supply water pressure increases and reaches a stop pressure. In the pump control method of the automatic water supply device, when the pump is stopped by detecting that the water supply pressure has reached the stop pressure, the pressure after the stop is detected, and the detected pressure is set as the next stop pressure. And setting a value obtained by subtracting a predetermined pressure from the set pressure as a next starting pressure. 7. A pump is started when the supply water pressure decreases and reaches a starting pressure, water is supplied at the supply pressure of the pump, and the pump is stopped when the supply water pressure increases and reaches a stop pressure. In the automatic water supply device, when the supply pressure reaches the stop pressure and the pump is stopped, the pressure after the stop is detected, and the detected pressure is set as the next stop pressure. Means for setting a value obtained by subtracting a predetermined pressure from the pressure set by the means as the next starting pressure. 8. The automatic water supply apparatus according to claim 7 , further comprising: means for setting a value of the predetermined pressure, which is a differential pressure between the start pressure and the stop pressure. 9. The automatic water supply apparatus according to claim 7 , further comprising: means for storing the value of the predetermined pressure; and means for storing an initial value of the starting pressure. 10. The method of claim 7, wherein the pump is an automatic watering system, wherein it is in the write-free configuration sucks water from Tei Ru suction pipe is directly connected to the water mains.