JPH02136593A - Water supply device - Google Patents

Abstract

PURPOSE:To prevent the useless parallel operation of a pump by driving the first pump according to the turning-ON of the first pressure switch and carrying out control so that another pump is started, added with the first pump, when the second pressure switch is in turned ON state and the turning-ON time reaches a set time. CONSTITUTION:The discharge water of the first and second pumps 1 and 2 is sent into a water supply pipe 4 in each house through a convergence pipe 3, and if the pressure in the convergence pipe 3 lowers and a pressure switch 5 for alternate operation is turned-ON, the first pump 1 is started. Simultaneously with the operation, a delay timer 8a for alternate operation which is built in a control part 8 is turned-ON, and during the set time, the first pump 1 continues operation even if the pressure switch 5 is turned OFF. Further, if the turning-ON pressure by a switch 6 for parallel operation is achieved after the turning-ON of the pressure switch 5, a timer 9 operates, and after the lapse of a set time, the second pump is started, added with the first pump 1.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a water supply device used for supplying water to housing complexes and the like.

2. Description of the Related Art An example of a conventional water supply device will be described with reference to FIGS. 5 to 9. In FIG. 5, 1 is the first pump, 2 is the second pump, 3 is a confluence pipe connecting these two pumps 1.2 and the water supply pipe 4 to each home, and 5.6 is the confluence pipe 3. A pressure switch for alternate operation and a pressure switch for parallel operation are installed on the The on-pressure and off-pressure of this pressure switch 5 for alternate operation are set higher than the on-pressure and off-pressure of the pressure switch 6 for parallel operation, respectively.

7 is a pressure tank attached to the merging pipe 3;
A control section 8 controls the operation of the two pumps 1 and 2 based on signals from the pressure switch 5 for alternate operation and the pressure switch 6 for parallel operation.

Next, operation control of the water supply device configured as described above will be explained.

In the parallel-alternating operation type water supply system, when the amount of water used is small, one of the pumps is operated, and when the pressure switch 5 for alternate operation is turned off, the pump to be started is switched when the next time is turned on, resulting in alternate operation. . Further, when the amount of water used increases and the pressure in the merging pipe 3 decreases, and the pressure switch 6 for parallel operation is turned on, the second pump is also started and starts parallel operation.

In addition, the control unit 8 includes a delay timer 8a for alternate operation that responds to the operation of the pressure switch 5 for alternate operation, and a pressure switch 6 for parallel operation to reduce the frequency of starting the pump.
A day timer 8b for parallel operation is built in and responds to the operation of each pressure switch, and each day timer turns on in synchronization with the turn on of each pressure switch. The pump is forcibly operated. Therefore, if the corresponding pressure switch is off while the day timer is operating, the pump will stop when the day timer is turned off, and the corresponding pressure switch will be turned off when the day timer is turned off. Turning off stops the pump.

A timing chart of the control operation described above is shown in FIG. In addition, the range indicated by A in Fig. 6 indicates the alternating operation range of one pump in which the pumps to be started are switched each time the pump is started, and the range indicated by C indicates the parallel-to-single operation range (one pump is operated by one pump). One unit is in continuous operation, the other is in intermittent operation). Section 7 shows the relationship between the pump performance curve and the set pressures of the pressure switch 5 for alternate operation and the pressure switch 6 for parallel operation. This is a region of alternate operation.

In addition, the area indicated by B in FIG. 7 indicates the continuous operation area by one pump. Further, the area indicated by C is an area where one unit is in continuous operation and the second unit is in intermittent operation, and corresponds to area C in FIG. Further, the region D indicates the continuous operation region of two pumps.

Problems to be Solved by the Invention By the way, in a water supply system having the above configuration, the pressure tank occupies a considerable size, so in order to downsize the overall shape of the water supply system, it is necessary to downsize this pressure tank. There is a need.

As mentioned above, when two pumps are operated alternately or in parallel, the following problems occur when the pressure tank is downsized.

In other words, when the pressure tank is large, the pressure accumulation effect is large, so the amount of water used is large (although the water pressure does not drop too rapidly by the time the pressure switch is turned on and the pump starts pressurizing). As the pressure tank becomes smaller, the pressure accumulation effect also decreases accordingly, so when the amount of water used is large, it takes only a short time (usually 1 second) for the pressure switch to turn on and the pump to pressurize. (Hereinafter, this time will be referred to as time lag)
This causes a problem in that the water pressure in the water supply pipe decreases rapidly as well, and the pressure in the water supply pipe also decreases rapidly.

As a result, even within the water usage range where one pump would normally operate alternately, a problem arises in which two pumps end up operating in parallel due to the rapid pressure drop in the water supply pipe due to this time lag. Resulting in.

This corresponds to A in the pump performance curve shown in Figure 7.
At a point where the amount of water used is relatively large within the range of Parallel operation will be started. When the pressure tank is made small in this way, two pumps end up operating in parallel even though the amount of water used is originally within the range of alternate operation of one pump. When the second pump is started, the pressure in the merging pipe rises rapidly and immediately reaches the off pressure of the pressure switch for parallel operation and the pressure switch for alternate operation, and both subsequent pumps stop. After that, the same phenomenon described above continues to occur.

Note that FIG. 9 shows a timing chart of control operations.

In view of this problem, in a water supply system equipped with a plurality of pumps, the purpose is to prevent unnecessary parallel operation of the pumps from being started due to the sudden change in water pressure as described above.

Means for Solving the Problems In order to achieve the above object, the water supply device of the present invention starts the first pump when the first pressure switch is turned on, and starts the first pump when the second pressure switch is turned on. A control means is provided for controlling to start another pump in addition to the first pump when the on-time of the second pressure switch reaches a certain set time.

Effect With the above configuration, when one pump is operating alternately, even if the pressure switch for parallel operation is momentarily turned on due to a pressure drop in the merging pipe, the signal will not start parallel operation. .

Embodiment Hereinafter, one embodiment of the water supply device of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a water supply device according to an embodiment, and in the figure, components having the same configuration as the conventional one are given the same numbers as the conventional one, and the explanation thereof will be omitted.

The difference from the conventional configuration is the pressure switch 6 for parallel operation.
A timer 9 is added to measure the continuous time of the ON operation of the pressure switch 6 for parallel operation. However, in this embodiment, this timer 9 is
), and when the time measured by the timer 9 reaches a predetermined value, the control unit 8
The point is that the operation instruction is given to the second pump. Note that, similarly to the conventional example shown in FIG. 5, the on-pressure and off-pressure of the pressure switch 6 for parallel operation provided in the merging pipe 3 are set lower than the on-pressure and off-pressure of the pressure switch 5 for alternate operation, respectively. . Note that the time set to the timer 9 is determined based on the following conditions.

That is, when the amount of water used is at the point closest to area B in area A in FIG. 7, the parallel operation pressure switch 6 is turned on for the above-mentioned reason, and the time is set slightly longer than the time required for it to be turned off. It is.

Next, the operation of the water supply device of this embodiment configured as described above will be explained with reference to the flowchart of FIG. 2.

First, when the pressure in the merging pipe 3 decreases, the pressure switch 5 for alternate operation is turned on, and at the same time, the first pump 1 is started (steps (a) and (b)). The delay timer 8a for alternate operation built into the control unit 8 turns on when the pressure switch 5 for alternate operation is turned on (step (c)).
While the alternate operation day timer 8a is on, the first pump 1 continues to operate even if the alternate operation pressure switch 5 turns off (steps (D) and (H)). ), step (to)). Then, when the alternate operation day timer 8a turns off, the control unit 8 stops starting the first pump l (step (G)).
. Then, the process proceeds to step (H), where the control unit 8 switches the pump to be started next time to the second pump 2, and then proceeds to step (H).
Returning to step (a), the second pump 2 is started at the same time as the pressure switch is turned on.

Further, when the on-pressure of the pressure switch 6 for parallel operation is reached after the pressure switch 5 for alternate operation is turned on, the process advances from step (d) to step (s), and the on output from this pressure switch 6 for parallel operation is controlled. Issued to Section 8. Upon receiving this output, the control section 8 turns on the timer 9 to start a timekeeping operation. Here, for the above-mentioned reason, that is, when the pressure switch 6 for parallel operation is turned on even though it is originally an alternate operation region with one pump, the following operation control is performed. That is, the first pump has already been started by turning on the pressure switch 5 for alternate operation, and the pressure in the merging pipe 3 increases during the timer 9's timing operation, that is, for 2 seconds, and the pressure switch 5 for parallel operation increases. pressure switch 6
As a result, the continuous ON time of the pressure switch 6 for parallel operation does not reach the predetermined time and returns from Step (N) to Step (L) and back to Step (E). 8 will not start the second pump.

In addition, the amount of water used is even higher than in this state, and there is an area where one unit is in continuous operation and the second unit is in intermittent operation (C@ in Figure 6).
area) and the area where both pumps are operated continuously (area D in Figure 6), the pressure in the confluence pipe 3 does not rise during the time period (2 seconds) measured by the timer 9, so this The timer 9 completes its timing operation, and the process advances from step (nu) to step (subukuwo), where the control unit 8 starts the second pump.

In this way, by making it so that the second pump does not start unless the pressure switch for parallel operation is turned on continuously for a predetermined period of time, the problem that previously occurred, that is, the alternate operation of one pump, can be solved. Even though the amount of water used for acid is within the range of continuous operation with one pump, it is possible to solve the problem of the second pump starting up.

Furthermore, although the above-described embodiments have been described using two pumps, it goes without saying that the above-described technique can be applied to systems that use three or more pumps.

Furthermore, Fig. 3 is a characteristic curve diagram showing the relationship between the pressure in the confluence pipe and time in the water supply system of this embodiment, and Fig. 4 is a timing chart showing the timing when performing the operation shown in Fig. 3. be.

As described in detail, the present invention provides a water supply system using a plurality of pumps, in which the first pump is activated when the first pressure switch is turned on, and when the second pressure switch is turned on, the first pump is activated. By providing a control means that controls to start another pump in addition to the first pump when the on time of the second pressure switch reaches a certain set time, during alternate operation with one pump, Even if the pressure switch for parallel operation is turned on momentarily due to a pressure drop in the merging pipe, the signal will not start parallel operation, which solves the problems that occurred with conventional pumps of this type. It is very effective in practice.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a water supply system according to an embodiment of the present invention, Fig. 2 is a flowchart showing the operation flow of the water supply system according to the embodiment, and Fig. 3 is a diagram showing the pressure and time in the confluence pipe in the copper embodiment. Fig. 4 is a timing chart showing the operation timing of the same embodiment, Fig. 5 is a configuration diagram of the conventional water supply device, and Fig. 6 shows the operation timing of the conventional example. Timing chart, Figure 7 is a characteristic curve diagram showing the relationship between the amount of water used and the pressure in the merge pipe, Figure 8 is a characteristic curve diagram showing the relationship between the pressure in the merge pipe and time in the conventional example, and Figure 9 is a characteristic curve diagram showing the relationship between the pressure in the merge pipe and time in the conventional example. 9 is a timing chart when performing the operation shown in FIG. 8. l...first pump, 2...second pump, 3...merging pipe, 4...water supply pipe,
5... Pressure switch for alternate operation 6...
Pressure switch for parallel operation 7...Pressure tank, 8
...Control unit, 8a...Delay timer for alternate operation 8b...Delay timer for parallel operation 9...Timer Fig. 1 8o: Crossover Delay timer 7 for operation: Name of pressure tank agent: Patent attorney Shigetaka Awano and one other person Figure 8 o: Day timer for alternate operation 7: Pressure tank alternate operation ON Pressure switch OFF For parallel operation ON Pressure Switch OFF For alternate operation ON Day-timer OFF For parallel operation ON Day-timer OFF, ON Bonfu P1 oOFF Pressure switch for parallel operation OFF pressure Pressure switch for alternate operation ON pressure Pressure switch for parallel operation ON pressure Diagram

Claims (1)

[Claims] (1) A plurality of pumps connected to the same water supply pipe, a pressure tank, a confluence pipe that connects the plurality of pumps and the water supply pipe, and a pressure inside the confluence pipe is detected and the pressure is set at the first pressure. a first pressure switch that is turned on and turned off at a second pressure set higher than the first pressure; a second pressure switch that is turned on at a pressure lower than the turn-on pressure of the first pressure switch; a control unit that controls the operation of the pump according to the output from the two pressure switches, and this control unit starts the first pump in response to turning on the first pressure switch, and controls the operation of the pump according to the output from the second pressure switch. A water supply device characterized in that when the second pressure switch is turned on and the on time of the second pressure switch reaches a certain set time, another pump is activated in addition to the first pump.