JPH03202698A - Pump control device of automatic water feeder - Google Patents

Abstract

PURPOSE:To facilitate pressure setting, by starting one pump when output of a sensor for outputting a detection value according to a pressure by means of starting following up and paralleling-off of a plurality of pumps becomes a specified value or lower, and starting the other pump for following-up when the sensor output is another specified value or lower. CONSTITUTION:A pressure sensor 11 which outputs a detection value according to a pressure in a pipeline is used as a pressure detecting means, and one pump is started when the pump discharge pressure is decreased to a starting point (a) according to an amount of water in use. When the amount of water in use is increased to set pressure to the point (a) again, the other pump is started for following-up. In case that the discharge amount of water in use is decreased, the pressure is increased to a (b) point and the pump is driven for following-up, any one pump is paralleled off. The rest pumps are also paralleled off when the amount of water in use is further decreased and the pressure reaches the (b) point again. In case that the water amount under the follow-up operation is in the range of l, the pressure after paralleling off is the value (b) or higher, and a timer is switched ON to avoid simultaneously stopping of two pumps. One pressure sensor is thus quite enough, and pressure setting is facilitated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention comprises a plurality of pumps, for example two pumps, and a normal pressure tank on the discharge side of the pump, and the pressure is lowered depending on the amount of water used to reduce the pressure to one pump. This invention relates to an automatic water supply device that starts a pump and then starts other pumps to follow the pressure drop.

[Prior art]

FIG. 6 is a diagram showing a conventional method of controlling the pump of this type of automatic water supply device. Conventionally, this type of automatic water supply device uses a pressure switch as a pressure detection means, and when the pressure drops depending on the amount of water used and reaches a predetermined pressure point a, the pressure switch for the original pump detects it. Then, when the pump is started and the pressure drops to a predetermined point due to an increase in the amount of water used, the pressure switch for the subsequent pump detects this and starts the pump accordingly.

In this state, when the water volume decreases, the pressure increases, and when the pressure rises to a predetermined pressure point C, the pressure switch for the subsequent pump detects this, disconnects the pump (stops), and further decreases the water volume. When the water pressure rose to a predetermined pressure point d, the pressure switch for the original pump detected this and stopped the pump.

Recently, there has been a pump control device for an automatic water supply device that includes a pressure reducing valve at the discharge port of the pump to control the discharge pressure to a constant level. FIG. 7 is a diagram showing the relationship between the amount of water used and the total head for explaining the operation of a conventional pump control device of this type. Starting is performed in the same manner as the control shown in FIG. 6, and when the flow rate switch detects that the flow rate has become equal to or higher than the follow-up flow rate 08 due to an increase in the amount of water used, the pump is started to follow.

[Problem to be solved by the invention]

In the conventional pump control method of the automatic water supply system shown in Fig. 6 above, two pressure switches are required, one for the first pump and one for the second pump (if there are multiple pumps, the number is equal to the number of pumps). ON and OFF settings must be made, and the following pressure point must be set lower than the starting pressure point A, and the disconnection pressure point C must be set lower than the stopping pressure point d. It gets complicated. Furthermore,
If the settings are incorrect (for example, the size settings are reversed), there is a problem in that two pumps may be operated at the same time or two pumps may be stopped at the same time.

Also, due to the mechanism of the pressure switch, the pressure may drop and the
N (for example, pressure point a), the OFF value (for example, pressure d)
Since the pressure cannot be turned off unless the pressure rises to a certain point, it has been impossible to control starting and follow-up with a single pressure switch.

Further, in the case of FIG. 7, in addition to the pressure switch, flow rate switches corresponding to the number of follow-up pumps are required, and there is a problem similar to that described above.

In addition, in the conventional pump control operation pattern, as shown in FIG. 8, after pump PI starts, pump P starts following operation due to an increase in water volume, and the following pump P is disconnected from the series due to decrease in water volume. Furthermore, due to a decrease in the amount of water, the pump P1 that had started earlier was stopped. However, with this pump operation pattern, for example, if a certain amount of water is always used that does not cause the pump to stop, and the pump repeats follow-up and disconnection as the water amount increases or decreases, pump P1 will be in continuous operation, and the pump will run continuously. There was also a problem in that pumps P and P performed follow-up and disengagement, resulting in an imbalance in the starting frequency between pumps P and P.

The present invention has been made in view of the above-mentioned points, and uses a pressure sensor that outputs a detected value according to pressure as a pressure detection means, and makes the pressure values for the start and follow-up, disconnection and stop the same. is possible, equipment can be reduced, and pressure setting is easy.
Another object of the present invention is to provide a pump control device for an automatic water supply device that reduces the imbalance in starting frequency between pumps.

[Means to solve the problem]

In order to solve the above problems, the present invention is equipped with a plurality of pumps, etc., detects a drop in the pressure inside the discharge side piping of the pump according to the amount of water used, and when the pressure falls below a predetermined level, the pressure inside the plurality of pumps is Start at least one pump, detect a drop in the pressure in the pipe or the amount of water due to an increase in the amount of water used while the pump is in operation, and when the pressure falls below a predetermined pressure or exceeds a predetermined water amount, other pumps follow and start. Furthermore, if the pressure inside the piping increases due to a decrease in the amount of water used during operation, and if the pressure exceeds a predetermined pressure, at least one pump will be disconnected, and if the pressure increases further or the pressure does not decrease, the pump will be disconnected. In the pump control device of an automatic water supply device that stops,
As a means of detecting the pressure inside the piping, a pressure sensor is used that outputs a detected value according to the pressure inside the piping, and when the output value of the pressure sensor becomes less than a predetermined value, at least one of the plurality of pumps is started. The present invention is characterized in that a control means is provided for causing other pumps to follow and start when the output of the pressure sensor becomes equal to or less than a predetermined value during operation of this pump.

Further, the output value of the pressure sensor at the time of starting the pump and the output value of the pressure sensor that is started following the pump are set to be the same output value.

Furthermore, the above-mentioned line disassembly/stopping is characterized in that after the first pump is discontinued, the subsequent pumps are stopped.

[Effect]

By controlling the pump control device of the automatic water supply device as described above, the pressure decreases according to the amount of water used, and when the output of the pressure sensor becomes less than a predetermined value, at least one of the plurality of pumps is started, If the output of the pressure sensor falls below a predetermined value during operation of this pump, other pumps will follow and start, so it is possible to replace the conventional pressure switch with the number of pumps, or the number of follow-up pumps. The problem of only bones needing a flow switch is eliminated.
Only one pressure sensor is required. Further, as will be described later, the pressure setting value is extremely easy to set because there are only two pressure settings: the starting follow-up pressure and the stop and disconnection pressure.

In addition, when disconnecting and stopping, the first pump is disconnected and then the subsequent pump is stopped, so as shown in Fig. 9, after pump P starts, pump P follows due to the increase in water volume.
As the amount of water decreases, the first pump P disassembles, and as the amount of water decreases, the following pump P2 stops, so compared to the operation pattern shown in Figure 8, it is possible to average the starting frequency among the pumps. .

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a diagram showing the relationship between the total head and the amount of water for explaining the operation of the pump control device of the automatic water supply device of the present invention.

The pump control device of this automatic water supply device includes two pumps, and uses a pressure sensor that outputs a detected value according to the pressure inside the pipe as a pressure detection means.

Depending on the amount of water used, the pressure inside the pump discharge side pipe drops to the starting pressure point a, and one pump is started. At this time,
Since the pump is started, the pressure inside the pipe is higher than the starting pressure point a. Furthermore, when the amount of water used increases and the pressure reaches point a again, other pumps are started to follow.

Next, when the amount of water used decreases and the pressure rises to point b, if the pumps are in follow-up operation (two pumps are in operation), only one pump is disconnected (stopped). Furthermore, when the amount of water used decreases and the pressure reaches point b again, the remaining pumps are also stopped.

However, if the water flow during follow-up operation is within the range of 2, the pressure after disconnection will also be b.
Since the number of pumps exceeds the point, two pumps must be stopped at the same time. Therefore, in order to avoid simultaneous stops, a timer element is included, and when the pressure during follow-up operation reaches point b, one pump is first disconnected, and then the other pump is turned off for the set timer time. Simultaneous stopping of the two pumps can be avoided by forcibly operating the pump, and then providing a means for stopping the remaining pump if the pressure is equal to or higher than point b.

FIG. 2 is a diagram showing the configuration of a pump control device that performs the control operation described in FIG. 1 above. In Figure 2,
11 is a pressure sensor that outputs a detected value according to the pressure inside the pipe, 12.13 is a comparator, 14.15 is a pressure setting device that inputs a pressure setting value to the comparator 12.13, and 16
．． 17 is an amplifier that amplifies the output of the comparators 12 and 13, 18 is a control unit equipped with a microcomputer, and 19 and 20 are pump drive devices that start and stop the pumps P, , P, respectively.

The pressure setter 14 sets the starting follow-up pressure a shown in FIG. 1, and the pressure setter 15 sets the stop line release pressure S. FIG. 3 is a flowchart showing the flow of the start follow-up operation of the control section 18, and FIG. 4 is a flowchart showing the flow of the stop and release operation.

When the pressure inside the pump discharge side piping drops to the starting pressure a according to the amount of water used, the comparator 12 passes through the amplifier 16,
The output is sent to the control section 18. The control unit 18 determines whether this output is present (step 110), then determines whether one pump is in operation (step 111), and if none is in operation, the first pump PI Start (
Step 112). When the first pump P is being operated, it is determined whether the pressure inside the pipe has remained below point a for 5 seconds (step 113), and if it continues for 5 seconds, the subsequent pump P is followed and started. (step 114)
.

If the amount of water used decreases and the pressure increases, first determine whether it is above the pressure point (step 101), and if it is above b, then determine whether the two pumps are operating (step 1).
Step 02), if two pumps are in operation, stop the first pump P1 (Step 103), then start counting on the timer in the control unit 18 and forcibly pump P until the timer counts up. It is forced to run for a certain period of time (step 104).

In the step 102, if the two pumps are not in operation, it is then determined whether the pumps have been operated to follow (step 105), and if the pumps have been operated to follow, it is determined whether or not the timer has counted up. If the count is up, the subsequent pump P is stopped (step 107). In step 102, if the follow-up operation is not being performed, the first pump P+ is stopped (step 108).

By configuring the pump control device as described above, the pressure detection means is performed by one pressure sensor, and it is only necessary to set the pressure a and the pressure a with the pressure setting device 14 and the pressure setting device 15, that is, ON and OFF. Since it is only necessary to set the OFF pressure, the pressure setting operation becomes extremely simple.

As an application example of the present invention, as shown in Fig. 5, a pressure sensor is used to detect a point a, which is the same as the starting pressure, and a follow-up operation is performed. Controlled operation that keeps the discharge pressure constant using the pressure reducing valve becomes possible.

In the above embodiment, the pump control was explained using an example of an automatic water supply device equipped with two pumps, but it goes without saying that the number of pumps is not limited to this.

〔Effect of the invention〕

As explained above, according to the present invention, the following excellent effects can be obtained.

(1) In the case of conventional pump start follow-up control using pressure, the pressure switch is set according to the number of pumps, or when the flow rate switch is used to perform follow-up operation of the pumps due to an increase in water volume, the contact signal of the flow rate switch is set according to the number of pumps to be followed. Although it was necessary, the present invention requires only one pressure sensor.

(2) There are two pressure settings: starting follow-up pressure and stop disconnection pressure.
Since only a point is required, pressure setting is extremely easy compared to the conventional example.

(3) In addition, since a pressure switch, which is a mechanical contact, is conventionally used as a pressure detection means, it has a short lifespan and is 0N-OFF.
However, since the present invention uses a pressure sensor, the circuit can be configured without contact, and can have a long life and be noiseless.

(4) Also, to disassemble and stop the line, after disassembling the starting pump,
Since the subsequent pump is stopped, as shown in Figure 9,
After pump P1 starts, pump P follows due to the increase in water volume, and pump P that was earlier discontinued due to decrease in water volume, and pump P follows due to further decrease in water volume.
2, it is possible to average the starting frequency among the pumps compared to the operation pattern shown in FIG.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the operation of the pump control device of the automatic water supply device of the present invention, FIG. 2 is a block diagram showing the configuration of the pump control device of the automatic water supply device of the present invention, and FIG.
FIG. 4 is a flowchart showing the flow of the start follow-up operation of the control section in FIG. 2, FIG. Figures 6 and 7 are diagrams for explaining the operation of the device, Figures 6 and 7 are diagrams for explaining the operation of the bomb control device of the conventional automatic water supply system, respectively, and Figure 8 is a diagram showing the operation pattern of the conventional pump. , FIG. 9 is a diagram showing the operation pattern of the pump of the present invention. In the figure, 11... pressure sensor, 12... comparator,
13...Comparator, 14...Pressure setting device, 15...
...Pressure setting device, 16...Amplifier, 17...
Amplifier, 18...control unit, 19...pump drive device, 20...pump drive device, P, ,P,...
pump.

Claims (3)

[Claims] (1) Equipped with a plurality of pumps, etc., detects a drop in the pressure inside the discharge side piping of the pump according to the amount of water used, and starts at least one of the plurality of pumps when the pressure falls below a predetermined pressure; As the amount of water used during operation of the pump increases, it detects a drop in the pressure inside the pipe or the amount of water, and when the pressure drops below a predetermined pressure or exceeds a predetermined amount of water, other pumps are started to follow, and the amount of water used during operation is detected. A pump in an automatic water supply system that detects an increase in the pressure in the pipe due to a decrease in the pressure, disconnects at least one pump if the pressure exceeds a predetermined pressure, and stops the pump if the pressure increases or the pressure does not decrease. In the control device, a pressure sensor that outputs a detected value according to the pressure inside the pipe is used as a means for detecting the pressure inside the pipe, and when the output value of the pressure sensor becomes less than a predetermined value, the internal pressure of the plurality of pumps is Pump control device for an automatic water supply system, characterized in that it is provided with a control means for starting at least one pump and causing other pumps to follow and start when the output of a pressure sensor becomes less than a predetermined value during operation of this pump. . (2) The pump control device for an automatic water supply device according to claim (1), wherein the output value of the pressure sensor at the time of starting the pump and the output value of the pressure sensor that is started following the pump are set to the same output value. . (3) Claim (1) characterized in that the line disassembly/stop is performed by disabling the first pump from the line and then stopping the subsequent pump.
Pump control device for the automatic water supply device described.