JPH06257572A - Controller for operation of direct coupled feed water supply system - Google Patents

Abstract

PURPOSE:To prevent generation of negative pressure on the suction side of a pump during startup and to prevent generation of water hammer when the pump is stopped. CONSTITUTION:A controller for operation of a direct coupled feed water supply system is provided with soft-start control means (phase control portion 7, frequency converter) which cause the number of revolution of a booster pump 4 to gradually increase during startup, soft-stop control means (phase control portion 7, frequency converter) which cause the number of revolution to gradually decrease during a stop, and an operation control portion 5 for controlling both of the means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a direct water supply system to supply water only by mains water pressure without passing through a receiving tank installed on the ground. The present invention relates to an operation control device for a direct connection water supply device that increases a water supply pressure with a booster pump installed near a building of a branch pipe of a water main when a predetermined pressure is not reached.

[0002]

2. Description of the Related Art Conventionally, direct water supply has been performed up to a two-story building, and water has been supplied to a middle or high-rise building with three or more floors by a water tank system.

Further, in the water receiving tank system, the pressure control water is returned to the pump suction side at the discharge port of the pump so as to eliminate the temperature change during use of the hot and cold water mixing tap and the shower and to provide a comfortable feeling. A pressure reducing valve provided with a pressure valve portion is used to keep the pressure on the outlet side of the water supply device constant.

[0004] In recent years, due to the water quality problem of small-scale water receiving tanks, which occupy most of the water receiving tanks, and the advent of three-story houses due to a partial revision of the Building Standards Act, the need for expanding the range of direct water supply has increased, and the administration The guideline of the guide was also announced, and for the time being, the range of direct water supply to five-story buildings is being expanded.

Under such a background, a problem is a method of increasing the pressure of water. Among several pressure increasing methods, a booster pump is installed near the building entrance of a branch pipe (hereinafter referred to as water supply pipe) branched from a water main (hereinafter referred to as water distribution pipe) to directly connect with the water supply pipe to increase the water supply pressure. There is a method of increasing pressure to supply water.

[0006]

This booster pump pressure increasing method is a method of increasing the booster pump pressure to secure the water supply pressure when the pressure in the water supply pipe decreases.
Since the pump suction side is directly connected to the water supply pipe, not to the receiving tank, when the booster pump starts, the suction side water supply pipe and distribution pipe suddenly become negative pressure, or when the booster pump stops. , A water hammer etc. due to stoppage occurred, water supply to surrounding buildings other than the building supplied by the booster pump became extremely unstable, pressure shortage occurred,
Alternatively, there is a concern that adverse effects such as backflow may be exerted, or that the operation of the pressure reducing valve provided at the discharge port of the pump or the outlet side of the direct connection water supply device may be affected, and the constant pressure function of the pressure reducing valve may be impaired.

The present invention has been made in view of the above-mentioned problems. Therefore, when the pump is started, the suction side water supply pipe and the water distribution pipe have a negative pressure, and when the pump is stopped, a water hammer is generated to supply water to surrounding buildings. It is an object of the present invention to provide an operation control device for a direct connection water supply device that prevents the adverse effect thereof and that maintains the constant pressure function of the pressure reducing valve.

[0008]

According to the present invention, when water is directly supplied to a building on the third floor or above by a water supply system in which water is supplied only by mains water pressure without using a receiving tank installed on the ground, In a direct connection water supply system that boosts the water supply pressure with a booster pump installed near the building of the branch pipe of the water main when the main water pressure does not reach the prescribed pressure, software that gradually increases the pump rotation speed when the booster pump is started. A start control means, a soft stop control means for gradually reducing the booster pump rotation speed when the booster pump is stopped, and a predetermined time necessary for operating the booster pump with the soft start control means and reaching a predetermined rotation speed from the start of operation. Perform constant speed operation at the normal rated speed, and connect the booster pump directly after the booster pump stop signal is output from the direct water supply device. Operating at toss-top control unit is provided with a driving control means for stopping the booster pump after a predetermined time required to stop.

Further, according to the present invention, the soft start control means and the soft stop control means have the function of controlling the slip of the induction motor for driving the booster pump to adjust the rotation speed of the booster pump.

Further, according to the present invention, the soft start control means and the soft stop control means control the input frequency and the input voltage to the induction motor for driving the booster pump to adjust the rotation speed of the booster pump. Is equipped with.

According to the invention, the operation control means is
Equipped with a timer for soft start, set a predetermined time from the start of operation to reaching a predetermined number of rotations, start the timer at the same time as the start of operation, and booster pump rotation speed reaches the normal rated rotation after the predetermined time elapses. It also has a timer for soft stop, and sets a predetermined time necessary for stopping the booster pump after the booster pump stop signal is output from the direct connection water supply device to the timer. At the same time as the output of the booster pump, and the booster pump is stopped after the elapse of the predetermined time.

Further, according to the present invention, a relief valve type constant pressure valve for maintaining a constant pressure on the outlet side of the booster pump or the direct connection water supply apparatus equipped with the soft start control means and the soft stop control means is provided on the outlet side. It is provided.

Further, a pressure reducing valve for maintaining a constant pressure on the outlet side of the booster pump or the direct connection water supply apparatus provided with the soft start control means and the soft stop control means is provided.

Also, according to the present invention, the pressure fluctuation of the water mains can be prevented by minimizing the area of the pressure regulating valve returning portion on the outlet side of the booster pump provided with the soft start control means and the soft stop control means. A pressure reducing valve is provided to keep the pressure on the outlet side of the direct water supply system constant without being affected.

[0015]

In the operation controller for the direct connection water supply apparatus configured as described above, when the booster pump incorporated in the direct connection water supply apparatus is started and stopped, the soft start operation and the soft stop operation are performed. Sometimes the suction side water supply pipe and distribution pipe become negative pressure, water hammer etc. occurs when the booster pump is stopped, and the water supply pressure becomes extremely unstable in the surrounding buildings other than the building receiving the water supply,
It is possible to prevent adverse effects such as insufficient pressure and backflow.

Even if the water supply pressure becomes extremely unstable, the pressure on the outlet side of the direct connection water supply device becomes constant without being affected by the pressure fluctuation, and when the hot and cold water mixing tap or shower is in use. There is no temperature change and you can get a comfortable feeling.

The pressure on the discharge side can be made constant by providing a relief valve type constant pressure valve on the outlet side of the direct connection water supply apparatus. However, in order to return a part of the water passing through the relief valve type constant pressure valve to the suction side of the pump, the discharge amount of the pump is increased by the escape amount of the escape water rather than the actual amount of water used,
Running costs increase.

In order not to increase the discharge amount of the pump, a pressure reducing valve may be provided instead of the relief valve. Generally, the pressure reducing valve has a characteristic that the pressure decreases as the amount of water increases. Therefore, if a pressure reducing valve provided with a pressure regulating valve unit that returns the pressure regulated water to the pump suction side is used, it is possible to obtain a constant pressure with respect to the amount of water.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a water supply pipe 11 branched from a water distribution pipe 12 is provided with a booster pump 4 and a bypass pipe 10 for bypassing the booster pump 4. Upstream of the pump 4 of the water supply pipe 11,
A suction side pressure detector 8 and a discharge side pressure detector 9 are provided on the downstream side of the merging portion of the bypass pipe 10, respectively, and a pressure tank 14 is provided. Also, pump 4
A check valve 13 is provided on each of the downstream side and the bypass pipe 10.

On the other hand, the induction motor 3 for driving the booster pump 4 is an operation control unit which is an operation control means for outputting an operation / stop signal of the booster pump through the three-phase control element 2 and the electromagnetic switch 1. Connected to 5. Both pressure detectors 8 and 9 are connected to the operation control unit 5, and the phase of the voltage supplied to the timer circuit 6 and the induction motor 3 for setting the soft start time and the soft stop time at the time of starting and stopping. The phase control element 2 is connected via a phase control unit 7 which is a soft start control means and a soft stop control means for adjusting the angle.

The electromagnetic switch 1 is for opening and closing the power supply of the phase control element 2, and the suction side pressure detector 8 is the pump 4.
Is for detecting an abnormal decrease in the suction side pressure, the discharge side detector 9 is for determining the operation / stop of the pump 4, and the bypass pipe 10 is a water supply pipe to the end even when the pump 4 is stopped. The pressure tank 14 serves to secure the pressure, and to mitigate the pressure fluctuation at the end by the pressure holding effect even if a rapid pressure fluctuation or the like occurs in the pipe. The phase control element 2 is a combination of phase control elements such as a triac and a thyristor capable of controlling the firing angle.

Next, the control mode will be described.

In FIG. 2, when the booster pump is stopped (step S1), the pressure on the discharge side of the pump decreases and the pressure detector 9 detects the starting pressure of the pump 4 (step S1).
2) The operation control unit 5 outputs a closing command to the electromagnetic switch 1 (step S3), and outputs a soft start timer start command to the timer circuit 6 (step S4). at the same time,
A preset phase signal is sent from the phase control unit 7 to the phase control element 2 to phase control the voltage supplied to the electric motor 3. With the phase-controlled supply voltage, the slip of the electric motor 3 becomes larger than when the full voltage is supplied, and the soft start operation is started (step S5). Next, when the predetermined number of rotations is reached by soft start and the timer for soft start is up (step S6), the phase control signal from the phase control unit 7 is switched to the full voltage signal, and constant speed operation by normal rated rotation is performed. (Step S7).

When the pressure on the discharge side of the pump rises and the pressure detector 9 detects the stop pressure of the pump 4 (step S
8), the operation control unit 5 outputs a soft stop timer start command to the timer circuit 6 (step S9). At the same time, a preset phase angle signal is sent from the phase control unit 7 to the phase control element 2 to phase control the voltage supplied to the electric motor 3. With the phase-controlled supply voltage, the slip of the electric motor 3 becomes larger than the total supply voltage, and the soft stop operation is started (step S10). Next, when the pump 4 is stopped by the soft stop or is in a state just before the stop, and the timer for the soft stop is up (step S11), the operation control unit 5 outputs a shutoff command to the electromagnetic switch 1. Stop all pumps 4 (step S1)
2).

FIG. 3 shows the discharge side pressure detector 9 corresponding to the steps of the control flow, the operations of both timers, and the changes in the rotation speed of the booster pump 4 and the discharge pressure. As can be seen from the figure, the changes in the rotational speed and the pressure are extremely smooth, and the conventional problems are solved.

In the above control, the phase angle signal to the phase control element 2 set by the phase control unit 7 at the time of soft start and soft stop is the case where the phase angle is constant,
It is possible that the phase angle is variable.

FIG. 4 shows an example of the voltage waveform at the time of soft start of only one phase output from the phase control element 2 when the phase angle is constant. Similarly, an operation in which the time axis t of FIG. 4 is reversed is an example of the voltage waveform during soft stop of only one phase.

FIG. 5 shows an example of the voltage waveform at the time of soft start of only one phase output from the phase control element 2 when the phase angle is variable. Similarly, the time axis t of FIG. 5 is operated in the opposite direction, which is an example of the voltage waveform at the time of soft stop of only one phase.

FIG. 6 shows a second embodiment of the present invention, which is an example in which two phase control elements 15 are provided and the other parts are configured in the same manner as in FIG. The control mode and effect of this embodiment are the same as those in FIGS. 2 and 3. Also in this embodiment, the phase angle signal to the phase control element 15 set by the phase control unit 7 at the time of soft start and soft stop is the same when the phase angle is constant,
It is possible that the phase angle is variable.

FIG. 7 shows an example of the voltage waveforms of the U-phase or W-phase and the V-phase output by the phase control element 15 at the time of soft start when the phase angle is constant. Similarly, an operation in which the time axis t in FIG. 7 is reversed is an example of each voltage waveform during soft stop of the U phase or W phase and V phase.

FIG. 8 shows an example of the voltage waveforms of the U-phase or W-phase and the V-phase output by the phase control element 15 at the time of soft start when the phase angle is variable. Similarly, the time axis t of FIG. 8 is operated in the opposite direction, which is an example of each voltage waveform during soft stop of the U phase or the W phase and the V phase.

FIG. 9 shows a third embodiment of the present invention, in which the induction motor 3 is connected to the operation control section 5a via a frequency converter 17 having a variable voltage / variable frequency function and an acceleration / deceleration time setting timer function. Then, the electromagnetic switch 1 shown in FIG.
In addition, the timer circuit 6 and the phase control unit 7 are omitted,
This is an example in which the other parts are configured similarly to FIG.

The control mode will be described with reference to FIGS. 10 and 11. When the detector 9 detects the starting pressure of the pump 4 while the pump 4 is stopped (step S20) (step S2).
1), the operation control unit 5a outputs an operation command to the frequency converter 17 (step S22). The frequency converter 17 is
The soft start operation is performed by gradually increasing the input frequency and the input voltage to the electric motor 3 by the preset acceleration time (step S23). Next, when the set acceleration time is reached (step S24), rated operation is performed (step S25). Therefore, the starting time suitable for the soft start for the pump 4 to operate at the rated speed can be obtained.

When the detector 9 detects the stop pressure of the pump 4 (step S26), the operation controller 5a outputs a stop command to the frequency converter 17. Frequency converter 17
Performs the soft stop operation by gradually reducing the input frequency and the input voltage to the electric motor 3 by the preset deceleration time (step S27), and then when the set deceleration time is reached (step S28), the operation is started. The control unit 5a outputs a stop command to the frequency converter 17 to completely stop the pump 4 (step S29). Therefore, the stop time suitable for the soft stop for stopping the pump 4 can be obtained. As control means for soft start and soft stop when starting and stopping the pump 4, a method of controlling slip of the induction motor 3 (first and second embodiments), and input frequency and input voltage are used. However, the soft start and soft stop control means are not limited to these, and any known technique can be used.

FIG. 12 shows a fourth embodiment of the present invention, in which a pressure reducing valve 19 provided on the downstream side of the booster pump 4 is provided with a return pipe 18 which is connected to the upstream side of the pump 4, and the others are the same as in FIG. It is a configuration example. It should be noted that the same can be applied to FIGS. 6 and 9.

In FIG. 13, a cylinder 21 is provided inside the main body 20 of the pressure reducing valve 19. A piston 22 housed in the cylinder 21 and provided with an orifice 23
A throttle valve 25 having substantially the same diameter as that of the piston 24 is provided at the other end of the piston rod 24, and the main body 20 has a first opening 26, a second opening 27, and a third opening 28. Has been formed.

The first opening 26 is connected to the pump 4 side of the water supply pipe 11, the second opening 27 is connected to the check valve 13 side of the water supply pipe 11, and the third opening 28 side. Is provided with a pressure regulating valve generally denoted by reference numeral 30.

A diaphragm 32 is provided on the body 31 of the pressure regulating valve 30, and a spring 34 is interposed between the upper surface of the diaphragm 32 and an adjusting screw 33 screwed onto the upper portion of the body 31. . Further, a return passage 35 that is opened and closed by the diaphragm 32 is provided, and the return passage 18 is connected to the return passage 35. And the return passage 3
The pressure regulating chamber 36 that is selectively communicated with 5 is communicated with the third opening 28 by the passage 29.

Next, the operation of the pressure reducing valve 19 will be described.

The water discharged from the booster pump 4 flows into the main body 20 through the first opening 26. At that time, on the surface B of the throttle valve 25, the throttle valve 25
Is exerted on the surface C of the piston 22. Here, since the throttle valve 25 and the piston 22 have almost the same diameter, the above two forces are balanced.

Next, a part of the water flowing into the main body 20 is
It is guided to the pressure adjusting chamber 36 through the orifice 23. Here, the pressure is regulated by the pressure regulating valve 30, and the pressure of the third opening 28 is always kept constant. Therefore, the piston 22
The force acting on the surface D of is always constant. Therefore,
The piston rod 24 moves so that the force acting on the surface A of the throttle valve 25 is always constant, and the pressure in the second opening 27 is kept constant.

In FIG. 14, the force Fs of the spring 34 adjusted by the adjusting screw 33 acts on the diaphragm 32 downward. On the other hand, the area a of the diaphragm 32 facing the pressure adjusting chamber 36 and the area facing the return passage 35 are b,
When the pressure in the pressure regulating chamber 36 is P1 and the pressure at the suction port of the booster pump 4 is P2, an upward force of a × P1 + b × P2 acts on the diaphragm 32. Here, when FS> a × P1 + b × P2, the diaphragm 32 closes the return passage 35, and when FS <a × P1 + b × P2, the diaphragm 32 is lifted and the pressure adjusting chamber 3
The water in 6 is returned to the return passage 35, that is, the suction side of the booster pump 4. By this operation, the pressure in the pressure regulation chamber 36 is kept constant.

Now, if the upper surface side and the lower surface side of the diaphragm 32 are balanced, the following equation is established.

FS = a × P1 + b × P2 (1) That is, FS = a {P1 + (b / a) P2} (2) Here, the pressure P2 on the suction side of the pump 4 is directly connected. In the water supply system, it is expected that there will be large fluctuations. Therefore, in order to always satisfy equation (2), (b /
a) The value of P2 may be reduced. That is, by making the area b of the diaphragm 32 facing the return passage 35 as small as possible, the constant pressure function of the pressure regulating valve 30 can be satisfied without being affected by the fluctuation of the pressure P2 on the suction side of the booster pump 4. it can.

FIG. 15 shows another example of the pressure regulating valve.
0a return passage 35a is formed to have a large diameter, and the passage 35a
A throttling mechanism such as a valve 37 and an orifice is provided in FIG.
This is an example in which the same action and effect as in (3) are obtained.

[0047]

Since the present invention is constructed as described above, it has the following operational effects.

(1) Soft start and soft stop control means such as controlling the slip of the induction motor at the time of starting and stopping the booster pump of the direct connection water supply device, or controlling the input frequency and the input voltage to the induction motor. Since the pump is operated within the specified time, the suction side water supply pipe and distribution pipe will have a negative pressure when the booster pump is started, and a water hammer etc. will occur when the booster pump is stopped and the building is receiving water from the booster pump. It is possible to prevent adverse effects such as extremely unstable water supply, insufficient pressure, or backflow on other buildings in the vicinity.

(2) Further, by combining with a timer, within a preset time for each starting and stopping of the pump,
After performing the soft start and soft stop operation, and after the time set in the timer has passed, the automatic operation is switched to the constant speed operation at the rated rotation during the soft start and to the pump stop during the soft stop. The operation relying on is unnecessary.

(3) Further, even if the pressure applied to the suction side of the pump fluctuates greatly depending on the water supply status of the surrounding buildings,
If a pressure reducing valve with a pressure regulating valve that is not affected by it, that is, a pressure reducing valve that returns the pressure controlled water to the pump suction side is provided on the discharge side of the booster pump, the discharge pressure becomes constant and a comfortable feeling is obtained. .

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a control flowchart.

FIG. 3 is a control timing chart diagram.

FIG. 4 is a diagram showing an example of a voltage waveform when the phase angle is constant.

FIG. 5 is a diagram showing an example of a voltage waveform when the phase angle is variable.

FIG. 6 is an overall configuration diagram showing a second embodiment of the present invention.

FIG. 7 is a drawing corresponding to FIG.

FIG. 8 is a drawing corresponding to FIG.

FIG. 9 is an overall configuration diagram showing a third embodiment of the present invention.

FIG. 10 is a control flowchart.

FIG. 11 is a control timing chart.

FIG. 12 is an overall configuration diagram showing a fourth embodiment of the present invention.

13 is a side sectional view showing the pressure reducing valve of FIG.

14 is a side sectional view showing an example of the pressure regulating valve of FIG.

FIG. 15 is a side sectional view showing another example of the pressure regulating valve.

[Explanation of symbols]

 1 ... Electromagnetic switch 2, 15 ... Phase control element 3 ... Induction motor 4 ... Booster pump 5, 5a ... Operation control unit 6 ... Timer circuit 7 ... Phase control unit 8 ... Suction side pressure detector 9 ... Discharge side pressure detector 10 ... Bypass pipe 11 ... Water supply pipe 12 ... Water distribution pipe 13 ... Check valve 14 ... Pressure tank 16・ ・ ・ Circuit breaker 17 ・ ・ ・ Frequency converter 18 ・ ・ ・ Return pipe 19 ・ ・ ・ Pressure reducing valve 20 ・ ・ ・ Main body 21 ・ ・ ・ Cylinder 22 ・ ・ ・ Piston 23 ・ ・ ・ Orifice 24 ・ ・ ・ Piston rod 25 ... Throttle valve 26 ... 1st opening 27 ... 2nd opening 28 ... 3rd opening 29 ... Passage 30,30a ... Pressure regulating valve 31 ... Body 32 ... Diaphragm 33 ... Adjusting screw 34 ... Spring 5,35a ··· return passage 36 ... the pressure regulating chamber 37 ... valve

Claims (7)

[Claims] 1. The main water supply system does not reach a predetermined pressure when supplying water to a building on the third floor or higher by a direct water supply water supply system in which water is supplied only by the main water supply pressure without passing through a receiving tank installed on the ground. In this case, in a direct connection water supply system that increases the water supply pressure with a booster pump installed near the building of the main branch of the water mains, a soft start control means that gradually increases the pump speed when the booster pump is started, and a booster when the booster pump is stopped. A soft stop control means for gradually reducing the pump rotation speed and a constant speed operation at a normal rated rotation speed after a predetermined time required to reach a predetermined rotation speed from the start of the operation by operating the booster pump with the soft start control means. Also, the booster pump is operated and stopped by the soft stop control means after the booster pump stop signal is output from the direct connection water supply device. And a driving control means for stopping the booster pump after a lapse of a predetermined time required for the operation of the direct coupling water supply apparatus. 2. The soft start control means and the soft stop control means have a function of controlling a slip of an induction motor for driving the booster pump to adjust a rotation speed of the booster pump. The operation control device of the direct connection water supply device according to 1. 3. The soft start control means and the soft stop control means have a function of controlling an input frequency and an input voltage to an induction motor for driving the booster pump to adjust a rotation speed of the booster pump. The operation control device of the direct connection water supply device according to claim 1. 4. The operation control means is provided with a soft start timer, which sets a predetermined time from the start of operation until a predetermined number of revolutions is reached, starts the timer at the same time as the start of operation, and increases the number of revolutions of the booster pump. Is required to stop the booster pump after performing the constant speed operation by the normal rated rotation after the lapse of the predetermined time, and also including a soft stop timer, and the booster pump stop signal is output from the direct connection water supply device to the timer. 2. The operation control of the direct connection water supply apparatus according to claim 1, further comprising a function of setting a predetermined time, starting the timer at the same time as outputting the pump stop signal, and stopping the booster pump after the predetermined time has elapsed. apparatus. 5. A relief valve type constant pressure valve for maintaining a constant pressure on the outlet side of the booster pump or the direct connection water supply apparatus provided with the soft start control means and the soft stop control means is provided. The operation control device of the direct connection water supply device according to claim 1. 6. A pressure reducing valve for maintaining a constant pressure on the outlet side of the booster pump or the direct connection water supply apparatus provided with the soft start control means and the soft stop control means is provided. Item 1. An operation control device for a direct connection water supply device according to item 1. 7. The influence of the pressure fluctuation of the water mains is minimized by minimizing the area of the pressure regulating valve return section at the outlet side of the booster pump or the direct connection water supply apparatus having the soft start control means and the soft stop control means. The operation control device of the direct connection water supply device according to any one of claims 1 to 5, further comprising a pressure reducing valve that keeps the pressure on the outlet side of the direct connection water supply device constant without receiving the pressure.