JPS63100297A - Water supply facility - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a water supply system, and more specifically, the present invention relates to a water supply system, and more specifically, a variable speed main pump that is normally operated, and a variable speed main pump that uses an increased amount of water during operation of the main pump. The present invention relates to a water supply device including a main pump and a sub-pump operated together with the main pump.

[Conventional technology]

Normally, this type of water supply device operates a variable speed main pump to supply water, but when the amount of water used increases, the amount of water supplied by the main pump is insufficient, so a sub pump is operated to supply water. Water can be supplied together with a pump. Therefore, since the operation of the sub-pump is stopped unless the amount of water used increases, water accumulates inside the pump, and as a result, the accumulated water turns into red water over time.

In order to eliminate this problem, conventional water supply devices
A stagnant water drainage mechanism configured to drain the stagnant water in the sub-pump at regular intervals is provided.

[Problem that the invention seeks to solve]

By the way, in the conventional technology, the accumulated water in the sub-pump is discharged at regular intervals, and although the accumulated water is clean when it is discharged, it turns red as time passes as shown in Fig. 4. It turns into Therefore, unless the pattern of water consumption is fixed over time, that is, the pattern of increase/decrease in water consumption is not fixed, there will be a time difference between the time the accumulated water is drained and the sub-pump is started. It may pass. In such a case, since the auxiliary pump also supplies red-colored accumulated water, there is a problem that clean water cannot be constantly supplied.

In addition, in order to solve this problem, it is easy to think of increasing the frequency of draining the accumulated water, but if this is done, there is a problem that the amount of drained water will be large and that it will become uneconomical.

SUMMARY OF THE INVENTION In view of the problems of the prior art, an object of the present invention is to provide a water supply device that can constantly supply clean water and can do so economically.

[Means for solving problems]

In the present invention, a variable speed main pump, a sub pump connected to the discharge side of the main pump in parallel with the main pump, and a control line on the discharge flow rate-discharge pressure performance curve of the main pump are provided. The operation is controlled using the intersection of control means for starting the sub-pump and the main pump and controlling the operation of both the sub-pump and the main pump using the intersection point with the control line on the discharge flow rate-discharge pressure performance curve of both as the operating point; The system is equipped with a stagnant water drainage mechanism that drains stagnant water.

Then, when the operating point of the main pump fluctuates in the direction of the sub-pump starting point on the discharge flow rate-discharge pressure performance curve, the accumulated water drainage mechanism operates at a predetermined point slightly before the sub-pump starting point. It has a detector that detects that the drainage start point has been reached, and flushing means that sends high-pressure water into the sub-pump to drain the stagnant water that has previously accumulated in the sub-pump when the detector detects that the water has reached the drainage start point. ing.

[Effect]

When the main pump is operated with the intersection of the control line on the discharge flow rate-discharge pressure performance curve as the operating point, if the amount of water used increases, the operating point will change to the point on the discharge flow rate-discharge pressure performance curve. It deviates from the control line and fluctuates toward the sub pump starting point.

In that case, when the operating point of the main pump is located at the drainage start point slightly before the sub pump starting point on the performance curve, the detector of the accumulated water drainage mechanism will detect this. The flushing means of the water drainage mechanism is activated, and high-pressure water is sent into the sub-pump to drain the accumulated water within the sub-pump.

Therefore, when the operating point of the main pump changes to a position where the sub-pump is started, the accumulated water in the sub-pump can be discharged, so the period from when the accumulated water is drained while the sub-pump is stopped until the sub-pump starts is The time required for this can be made extremely short, and the draining operation is performed almost immediately before the sub-pump is started, so that the accumulated water in the sub-pump can be reliably cleaned.

As a result, clean water can be supplied, and water required for draining accumulated water when the sub pump is stopped can be saved.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3. Fig. 1 is a piping diagram showing an embodiment of the present invention, Fig. 2 is a pump discharge flow rate-discharge pressure performance curve, and Fig. 3 is a comparative illustration of the embodiment of the present invention and a conventional example. be.

The water supply device of the embodiment is used in a constant discharge pressure control system in which the discharge pressure of the pump is controlled to be constant.

That is, as shown in FIG. 1, in the water supply system of the embodiment, a sub pump 2 is connected to the discharge side of a variable speed main pump 1 in parallel with the main pump 1. And main and sub pumps 1 and 2
A pressure transmitter 3 for detecting discharge pressure is provided on the discharge side of the pressure transmitter 3, and a control device 4 is connected to the output side of the pressure transmitter 3.

The control device 4 is composed of, for example, a microcomputer, and usually controls the main pump 1 to detect the intersection point with the control line Z on the flow rate-discharge pressure performance curves A to N, as shown in FIG. The operation is controlled as the operating point, and when the amount of water used increases, the operating point of the main pump 1 deviates from the intersection with the control line 2 on the discharge flow rate-discharge pressure performance curve A, and the sub-pump starting point Y
, the sub pump 2 is started and the operation of both the sub pump and the main pump is controlled using the intersection point with the control line 2 on the discharge flow rate-discharge pressure performance curve W of both as the operating point. . Note that FIG. 2 is a pump performance curve diagram in which the horizontal axis represents the pump discharge flow rate and the vertical axis represents the pump discharge pressure.

To describe the control device 4 in detail in FIG. 2, the main pump 1
are driven at respective rotational speeds Na=Nn, a discharge flow rate-discharge pressure performance curve A-N is obtained by and,
At this time, control is performed so that the operating point of the main pump 1 comes to the intersection with the control line 2 on the curve AN in view of the increase or decrease in the amount of water used. For example, if the main pump 1 is driven at a rotational speed Nb, and the discharge flow rate Q - discharge pressure H performance curve B
When operating with the fish eye as the operating point, when the amount of water used increases, the discharge pressure decreases, but as the discharge pressure detected by the pressure transmitter 3 is sent, the detection By calculating the target pressure from the pressure, increasing the rotation speed to Na to reach the target pressure, and setting point A on the discharge flow rate-discharge pressure performance curve A as the operating point, the discharge of the main pump 1 can be adjusted. The pressure is kept constant.

In addition, when the amount of water used further increases, the discharge pressure of the main pump 1 decreases, and when the operating point of the main pump reaches the starting point Y of the sub pump 2 on the discharge flow rate-discharge pressure performance curve A,
When the pressure transmitter 3 detects this, the sub pump 2 is started, and the main pump 1 +
By setting the operating point of the sub pump 2 to point C on the discharge flow rate-discharge pressure performance curve W, the discharge pressure can be kept constant to cope with an increase in the amount of water used.

The auxiliary pump 2 is used to compensate for the increase in the amount of water used when the water supply capacity of the main pump 1 is not sufficient to cope with the increase in the amount of water used. It is made up of things.

Since the accumulated water in the sub pump 2 becomes red water over time, a accumulated water drainage mechanism (not referenced) is provided to drain the accumulated water when the sub pump 2 is stopped.

The accumulated water drainage mechanism includes a main pump 1 as shown in FIG.
A flow meter 6 is provided on the downstream side of the water supply pipe 5 of the sub pump 2. On the other hand, a bypass pipe 7 having a supply valve 8 is connected between the discharge side of the sub pump 2 and the water supply pipe 5, and the sub pump 2 has a drain valve 9 for discharging internal water to the outside. An opening/closing control unit 11 to which a drain pipe 10 is connected and which opens and closes the supply valve 8 and the drain valve 9 is provided in the control device 4, and constitutes a flushing means.

Then, the main pump 1 has a discharge flow rate-discharge pressure performance curve A
When the main pump 1 is operated with point A above as the operating point, the operating point of the main pump 1 changes in the direction of the sub pump starting point Y on the curve A due to an increase in the amount of water used. When located at a predetermined drainage start point X, the flow meter 6 detects the discharge flow rate that has changed accordingly,
Detection by the flow meter 6 causes the opening/closing control section 11 of the flushing means to open the supply valve 8. When the drain valve 9 is opened, a portion of the flow discharged from the main pump 1 is sent into the sub pump 2 from the bypass pipe 7, thereby draining the accumulated water in the sub pump 2 into the drain pipe 1.
I am trying to drain water from 0.

The drainage start point X on the curve A is determined at a point where the drainage operation of the stagnant water drainage mechanism completely drains the stagnant water in the auxiliary pump 2 when the auxiliary pump 2 is started, although it depends on the degree of increase in the amount of water used. It's good to have.

Next, the operation of the water supply device of the embodiment will be described.

Now, when the main pump 1 is operated with point A on the discharge flow rate-discharge pressure performance curve A as the operating point, if the amount of water used increases, the operating point of the main pump 1 will change on the curve A to the sub pump. The starting point gradually changes in the Y direction.

In that case, when the operating point of the main pump I is located at a desired point X on the curve A before the starting point Y, the flow meter 6 of the accumulated water drainage mechanism detects this from a change in the discharge flow rate. Then, the opening/closing control section 11 of the sifting flushing means is activated by the detection by the flow meter 6 to control the supply valve 8. The drain valve 9 is opened and a portion of the high-pressure flow discharged from the main pump 1 is sent to the auxiliary pump 2 via the bypass pipe 7.
The accumulated water in the sub pump 2 is pumped into the drain pipe 1.
It can be drained from 0.

Therefore, when the operating point of the main pump 1 changes to a position on the curve A that starts the sub pump 2, the accumulated water drainage mechanism can drain the accumulated water in the sub pump 2, as shown in FIG. As shown in the figure, the secondary pump 2 is used to drain the accumulated water.
Compared to the conventional example, the time required until the engine starts can be shortened from T2 to T1, making it extremely short. Moreover, since the drainage operation is performed almost immediately before the sub pump 2 is started, the water stagnant in the sub pump 2 can be cleaned.

As a result, the auxiliary pump 2 does not supply red-colored stagnant water, and clean water can always be supplied, and there is no need to unnecessarily increase the frequency of draining stagnant water. That's how much waste water can be saved.

In the illustrated embodiment, the flow meter 6 is used as a detector for the accumulated water drainage mechanism, but if the operating point of the variable speed main pump 1 changes, the discharge pressure will change. A pressure detector can be used instead, and high-pressure water in an installed tank can also be used as a flushing means.

Therefore, the present invention is not limited to the illustrated embodiments, but only needs to have the desired function.

〔Effect of the invention〕

As described above, according to the present invention, the main pump for variable speed, the sub pump connected to the discharge side of the main pump in parallel with the main pump, and the main pump discharge flow rate - discharge. The operation is controlled using the intersection with the control line on the pressure performance curve as the operating point, and the sub pump is started when the operating point of the main pump 4 deviates from the intersection with the control line on the discharge pressure performance curve. When the flow rate changes to a point, the sub-pump is started and both the sub-pump and the main pump are adjusted so that the discharge flow rate of both - the discharge flow rate.
A control means for controlling operation using an intersection point with a control line on a 1-pressure performance curve as an operating point, and a stagnant water drainage mechanism for draining stagnant water in the auxiliary pump when the auxiliary pump is stopped, the stagnant water drainage mechanism. indicates that when the operating point of the main pump fluctuates on the discharge flow rate-discharge pressure performance curve in the direction of the sub-pump starting point, a predetermined drainage start point, which is slightly before the sub-pump starting point, has been reached. The structure includes a detector for detection and a flushing means that sends high-pressure water into the sub-pump to drain the accumulated water that has previously accumulated in the sub-pump when the detector detects the detection, so that the water inside the sub-pump can be drained. This makes it possible to extremely shorten the time between the drainage of accumulated water and the start of the sub-pump, and the ability to reliably clean the accumulated water in the sub-pump. You can save water.

[Brief explanation of the drawing]

Fig. 1 is a piping diagram showing an embodiment of the present invention, Fig. 2 is a pump discharge flow rate-discharge pressure performance curve diagram, and Fig. 3 is a comparative explanatory diagram of the embodiment of the present invention and a conventional example. FIG. 4 is an explanatory diagram showing the relationship between the color of the water remaining in the sub-pump and time. 1... Main pump for variable speed, 2... Sub pump, 4...
...Control device, 6...Detector (flow meter) of accumulated water drainage mechanism, 7-11...Flushing means of accumulated water drainage mechanism, X...Drainage start point, Y...Sub pump start point. Agent Patent Attorney Tadashi Akimoto Figure 1 Figure 2 Diagram Q 31 Figure 4

Claims (1)

[Claims] 1. A main pump for variable speed, a sub pump connected in parallel to the main pump on the discharge side of the main pump, and a discharge flow rate-discharge pressure performance curve of the main pump. The operation is controlled using the intersection with the control line as the operating point, and when the operating point of the main pump deviates from the intersection with the control line on the discharge flow rate-discharge pressure performance curve and changes to the sub pump starting point, a control means for starting the sub-pump and controlling the operation of both the sub-pump and the main pump using an intersection point with a control line on both discharge flow rate-discharge pressure performance curves as an operating point; and when the sub-pump is stopped;
A stagnant water drainage mechanism that drains stagnant water in the sub pump is provided, and the stagnant water drainage mechanism is configured to operate when the operating point of the main pump fluctuates in the direction of the sub pump starting point on the discharge flow rate-discharge pressure performance curve. , a detector that detects when a predetermined drainage start point has been reached, which is slightly before the sub-pump starting point; and when the detector detects, high-pressure water is sent into the sub-pump and stored in the sub-pump in advance. A water supply device characterized by having a flushing means for draining accumulated water. 2. The water supply device according to claim 1, wherein the detector detects either the discharge pressure or the discharge flow rate of the main pump. 3. In claim 1, the flushing means sends a part of the flow rate discharged from the main pump into the sub-pump at the time of detection by the detector, and removes the stagnant water previously accumulated in the sub-pump. A water supply device characterized by draining water.