JPH03202697A - Pump controlling device of automatic water feeder - Google Patents

Abstract

PURPOSE:To simplify an equipment by starting at least one of a plurality of pumps when a discharge pressure thereof is a specified value or lower, starting the other pump for following-up, and stopping partial pumps as a means of paralleling off when a motor electric current drops to specified value or lower. CONSTITUTION:A pump 101 is started when pressure in a discharge collecting pipe 105 of pumps 101, 102 is lowered to a starting pressure point (a) according to an amount of water in use. A pressure sensor which outputs a value according to a detected pressure is used as a pressure detecting means. When the amount of water in use is increased to reach the range shown by l2, the performance of the unit is decreased together with the performance of the pump 101. When the pressure reaches the point (a), the follow-up by pump 102 is performed. The pump 102 is paralleled off when the amount of water in use is decreased and the higher electric value out of plural motors which drive respective pumps gets lower than the predetermined electric value. The equipment can be simplified, and repetition of follow-up and parallel off can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pump control device for an automatic water supply device that is equipped with a normal pressure tank on the outlet side.

[Prior art]

FIG. 8 is a diagram showing the relationship between the total head H and the amount of water Q for explaining the operation of a pump control device of a conventional automatic water supply system, and FIG. 9 is a diagram showing the structure of the automatic water supply system.

Conventionally, in the pump control device of this type of automatic water supply device,
In particular, as shown in FIG.
In the case where pressure reducing valves 103 and 104 are provided at the outlet, the pressure decreases according to the amount of water used as shown in Fig. 8, and the pump starting pressure (point a) is detected by the pressure switch, and the pump 1
01 is started. Furthermore, the flow rate switch 106 installed at the outlet of the discharge collecting pipe 105 installed through the pressure reducing valve 103, 104 of each pump 101, 102 controls the amount of water (0 point) that follows the pump as the amount of water used increases. It was detected and the pump 102 was made to follow. When the water volume decreases, the same flow rate switch 106 detects the water volume and disconnects the pump 102. Furthermore, the pressure increases due to the decrease in flow rate, and the pump stop pressure value (point b) is detected and the pump 101 is stopped. are doing.

Therefore, when performing control for follow-up operation, it is necessary to attach the flow rate switch 106 to the device, resulting in a disadvantage that the external dimensions become large.

The present invention has been made in view of the above-mentioned problems, and eliminates the need for a flow rate switch by eliminating the above-mentioned problems and performing follow-up operation of the pump using pressure and disconnection using the current value of the motor that drives the pump. The purpose of the present invention is to provide a pump control device for an automatic water supply device.

[Means to solve the problem]

In order to solve the above problems, the present invention includes a plurality of pumps, detects a decrease in the pressure inside the pump discharge side piping according to the amount of water used, and if the pressure is below a predetermined pressure, the plurality of pumps are activated. At least one of the pumps is started, and the pipe pressure decreases due to an increase in the amount of water used while the pump is operating.
Equipped with a disconnection means that starts other pumps to follow when the pressure falls below a predetermined pressure, and stops some of the pumps in operation when the pressure in the same piping exceeds a predetermined level due to a decrease in the amount of water used. In a pump control device for an automatic water supply system, the disconnection means detects the current of the electric motor that drives the pumps, and stops some of the pumps in operation when the current falls below a predetermined value. It is characterized by

Further, it is characterized in that a pressure sensor that outputs a detected value in accordance with the detected pressure is used as the pressure detecting means of the means for starting and following.

Also, during follow-up operation, if the current of the motor with the larger current among the motors that drive each of the plurality of pumps becomes smaller than the predetermined current for disconnecting the pumps, some of the pumps in operation will be stopped. It is characterized by

In addition, even if there is a problem with disconnection due to current detection,
The pump is characterized by comprising a disconnection means for detecting the pressure inside the pump discharge side piping and stopping some of the pumps in operation.

[Effect]

By configuring the pump control device for automatic water supply equipment as described above, conventional pump control equipment for automatic water supply equipment of this type uses a flow rate switch to follow or disconnect the pumps depending on the increase or decrease in flow rate. However, in the present invention, by starting and following operation using a pressure sensor and disconnecting based on a current value, it is possible to simplify the equipment without providing a flow rate switch in the discharge collecting pipe, as shown in Fig. 2. .

Further, by determining the current value of disconnection based on the current of the largest value among the electric motors that drive the pumps being operated, repetition of follow-up disconnection can be avoided.

Further, even if a problem occurs in uncoupling due to the current value, it is possible to uncouple with pressure, so it is possible to go through a stage of pseudo uncoupling and stopping.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a diagram showing the relationship between the total head H and the water amount Q for explaining the operation of the pump control device of the automatic water supply system of the present invention. The structure of the automatic water supply device of the present invention is generally the same as the conventional example shown in FIG. 9, except that the flow rate switch 106 is not provided, as shown in FIG.

Pump 101, 102 (pressure reducing valve 103) depending on the amount of water used
．． 104), the internal pressure of the discharge collecting pipe 105 is the starting pressure (
When the temperature drops to point a), the pump 101 is started. As the pressure detection means at this time, a pressure sensor is used which outputs an output value in accordance with the detected pressure. In addition, the pressure after the pump starts is the set pressure H0 of the pressure reducing valve 103 (water volume 2
．． range).

Furthermore, the amount of water used increases, and the amount of water is 2. When the pressure reaches the range of , the performance of the unit decreases along with the performance of the pump 101, and when the pressure reaches point a, the pump 102 follows.

Next, when the amount of water used decreases and the higher current value of the electric motor driving each pump becomes lower than a predetermined set current value A, the pumps are disconnected from the series.

Figure 3 shows each pump (temporarily No. 1 pump (
For example, pump 101), No. 2 pump (for example, pump 10
2) shows the current value of 2). Naturally, there are variations in performance between the two pumps, so the current values of the driving motors are different even if the load is the same. Therefore, when looking at the current values of both, set the disconnection setting current value to A1.
Then, if the series is disconnected at the lower current value, the flow rate after the series is disconnected will be Q, and if the series is disconnected at the higher current value, the flow rate after the series is disconnected will be Q.

Now, if the flow rate Q is larger than the flow rate Q in FIG. 1, the pressure will immediately fall below point a and follow the flow after disconnection. Therefore, such a problem will not occur if the current value is disconnected at the larger current value.

Furthermore, in the case where a pressure reducing valve is attached to the discharge port of the pump, the load of the two pumps during follow-up operation is greatly different, so the difference in current value becomes even larger. That is,
As shown in Figure 4, even if the current characteristics of the two pumps are exactly the same due to changes in water volume,
If a pressure reducing valve is attached to the discharge port of a pump, the load (amount of water flowing through the pump) of each pump will be different even when two pumps are operated at the same time, and at a certain water volume during parallel operation, pump No. 1 will have a water flow of Q1, pump No. 2 will have a different load (amount of water flowing through the pump). is a phenomenon called water amount Q1. Therefore, the difference in current value becomes large, and as described above, it is necessary to disassemble the array at the higher current value.

Next, due to age-related changes in the pump, changes in power supply voltage, and variations, if the line does not disconnect even if the water volume reaches Q or less in Figure 3, the pressure reducing valve may )
Taking advantage of the characteristic that the pressure rises at point B, one pump is stopped when the pressure reaches point b while two pumps are in operation, and the remaining pump is forced to operate for the set timer, and then the pressure rises to point b again. When the point is reached, the pump is also stopped. By doing so, it becomes possible to perform control from follow-up operation to decoupling and stopping in a pseudo manner.

FIG. 5 is a block diagram showing the circuit configuration of a control device that performs the above control. In the figure, 11 is a pressure sensor that outputs an output value according to the detected pressure, 12 and 13 are comparators, respectively, 14 is a starting pressure setting variable resistor that sets the starting pressure a in FIG. 1, and 15 is a starting pressure setting variable resistor. Variable resistors for setting stop pressure, 16 and 17 are inverting amplifiers, respectively.
B is a control unit composed of a microcomputer, etc., 19
．． 20 are relays, 19a and 20a are normally open contacts of relays 19 and 20, 21 is a current detector that detects the current of the motor M that drives pump PI (pump 101 in Figure 2), and 22 is pump PG. (Pump 102 in FIG.
); a current detector that detects the current of the motor M that drives the motor M;
23 and 24 are comparators, 25 is a variable resistor for setting the string disconnection current A in FIG. 3, and 27
is an AND circuit, and 28 is an inverting amplifier.

The pressure within the discharge collecting pipe 105 is detected by a pressure sensor 11, and its detection output is input to comparators 12 and 13.

The current of motor M1 is detected by a current detector 21, and its detection output is input to a comparator 23. The current of motor M1 is detected by a current detector 22, and its detection output is input to a comparator 23.
4 is input. The operation of the control device having the above configuration will be explained below.

FIG. 6 is a flowchart showing the flow of starting and follow-up operations of the pump, and FIG. 7 is a flowchart showing the flow of stopping and disconnecting the pumps. If the pressure in the discharge manifold pipe 105 in FIG. 2 is lower than the starting pressure in FIG. 1, the pressure sensor 11
Since the output of is smaller than the set voltage value of the variable resistor 14 for setting the starting pressure, the output of the comparator 12 becomes L (low) level, which is sent to the control unit 18 through the inverting amplifier 16 as H (high) level.
Input as a level signal. As a result, the control unit 18 determines that the pressure is equal to or less than a (step 201). Next, it is determined whether one pump is in operation or not (step 202).
If NO, start the starter pump (step 203).
). For example, relay 19 is operated, normally open contact 19a is closed, and power is supplied from source AC to motor M, which drives pump P. If one pump is in operation in step 202; Next, it is determined whether the pressure has been below point a for 5 seconds, that is, whether the L level output of the comparator 12 has been continued for 5 seconds (step 204). If YES, the subsequent pump is operated to follow. (Step 205
). For example, a motor M that operates the relay 20, closes the normally open contact 20a, and drives the pump P from the electric fiAC,
to supply power.

Here, if the pressure in the discharge manifold pipe 105 is less than or equal to the stop pressure shown in FIG. The output of is at L level, and this L level signal is transmitted to control section 18 through inverting amplifier 17 as H level. Since the signal level of the comparator 13 is L, the control unit 18 determines that the pressure in the discharge collecting pipe 105 is below the stop pressure (step 210), and then determines whether the two pumps are in operation, and In this case, since two units are in operation, the motor M, which drives the pump P,
Compare the current X of the pump P with the current of the motor M2 that drives the pump P, and determine whether the higher current value is less than the flow AI shown in FIG. 3 (Step 212), if YES. The preceding pump, here pump 101, is stopped. That is,
When the current of the motor M becomes equal to or less than the decoupling current A, the output of the current detector 4 becomes smaller than the set voltage value set by the variable resistor 25 for setting the decoupling current, and the voltage of the comparator 23 increases. The output becomes L level. Further, the output of the motor 4 becomes L level. When both the current value of motor M and the current value of motor M2 become equal to or less than the decoupling current A1 (that is, when the higher current value becomes equal to or less than the decoupling current fILA), AND
The output of the circuit 27 becomes L, and an H level signal is input to the control section 18 through the inverting amplifier 28. As a result, the control unit 18 selects the motor with the higher current value.
” #& It is determined that the current has become less than A1, and the relay 19 is deactivated and its normally open contact 19a is turned OFF, and the motor M1 is turned off.
, that is, the pump P1 is stopped.

In step 210, if the internal pressure of the discharge collecting pipe 105 is higher than the stop pressure, it is determined that two pumps are in operation (step 214), and if YES, the pump 101 is stopped in the same manner as described above (step 215). Then, a timer starts counting in order to forcibly operate the succeeding pump 102 for a certain period of time (step 216).

In step 214, if the two pumps are not in operation, then it is determined whether or not follow-up operation is performed in step 21.
7) If YES, then it is determined whether or not the series has been disconnected based on the current value (step 218); if YES, the subsequent pump 102 is stopped (step 220). That is, the relay 20 is deactivated, its normally open contact 20a is turned off, and the motor M3, that is, the pump P2 is stopped. If the answer in step 218 is No, it is then determined whether the timer has counted up, that is, whether the pump has been forced to operate for a predetermined period of time (step 219), YES.
If so, the subsequent pump 102 is stopped in the same manner as described above.

In the step 217, if the follow-up operation is not to be performed, the procedure is the same as described above, that is, the relay 19 is deactivated, its normally open contact 19a is turned OFF, and the preceding pump 101 is stopped.

The circuit configuration shown in FIG. 5 is an example of the pump control device of the present invention, and the key point is to determine from the output of the pressure sensor 11 whether the internal pressure of the discharge collecting pipe is above or below the pump starting/following pressure, or whether it is above the pump stopping pressure. A control means for starting and following operation of the pump based on these judgment results, and a means for determining whether the higher current value of the motor driving each of the two pumps is less than or equal to the disconnection current. have the means to determine whether
It goes without saying that any specific configuration may be used as long as the configuration includes a control means for controlling the pumps to be disconnected from each other based on the result of this determination.

Although the above embodiment describes pump control of an automatic water supply device equipped with two pumps, the present invention is not limited to this, and can be applied to any automatic water supply device equipped with a plurality of pumps. Of course.

Further, although the above embodiments have been described using an automatic water supply device that uses a pressure reducing valve as an example, the present invention can also be applied to an automatic water supply device that does not use a pressure reducing valve.

〔Effect of the invention〕

As explained above, according to the present invention, in a pump control device for an automatic water supply system, the pumps are disconnected from each other based on the current value of the electric motor that drives the pumps, so that the following excellent effects can be obtained.

(1) In the conventional pump control device of this type of automatic water supply system, a flow rate switch was used to follow or disconnect the pump according to the increase or decrease in flow rate, but instead of starting and following operation using a pressure sensor, By disconnecting the line by , it becomes possible to simplify the equipment without providing a flow rate switch in the discharge collecting pipe.

(2) By determining the current value of the disconnection based on the current of the largest value among the electric motors that drive the pumps being operated, repetition of the follow-up disconnection can be avoided.

(3) Even if a problem occurs in uncoupling due to the current value, decoupling can be done by pressure, so it is possible to go through the stages of decoupling and stopping in a pseudo manner.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the total head H and water amount Q to explain the operation of the pump control device of the automatic water supply device of the present invention, and FIG. 2 is a diagram showing the structure of the automatic water supply device of the present invention. Figure 3 is a diagram showing the current value of each pump depending on the water volume Q, Figure 4 is a diagram showing the case where the current characteristics of two pumps are exactly the same due to changes in water volume, and Figure 5 is a diagram showing the current value of each pump according to the water volume Q. A diagram showing the configuration of the pump control device of the automatic water supply device, FIG. 6 is a flowchart showing the flow of starting and follow-up operations of the pump, and FIG. 7 is a flowchart showing the flow of stopping and disconnecting the pumps.
Figure 8 shows the conventional automatic water supply system's bong 27...AND
Circuit, 28...Inverting amplifier.

Claims (3)

[Claims] (1) Equipped with multiple pumps, detects a drop in the pressure inside the pump outlet pipe according to the amount of water used, and starts at least one of the multiple pumps if the pressure is below a predetermined pressure. , the pressure in the same pipe decreases due to an increase in the amount of water used during operation of the pump, and when the pressure falls below a predetermined pressure, other pumps are started to follow, and the pressure in the same pipe becomes higher than the predetermined level due to the decrease in the amount of water used. In a pump control device for an automatic water supply system, which is equipped with a disconnection means for stopping at least one pump in operation when A pump control device for an automatic water supply device, characterized in that the pump control device for an automatic water supply device is characterized by having a disconnection means that stops some of the pumps in operation when the following conditions occur. (2) A pump control device for an automatic water supply device according to claim (1), characterized in that a pressure sensor that outputs a detected value according to a detected pressure is used as the pressure detecting means of the means for starting and following. . (3) If the current of the motor with the larger current among the motors that drive each of the plurality of pumps during the follow-up operation falls below the predetermined current value for disconnecting the pumps, some of the pumps in operation A claim characterized in that the pump is stopped (
1) Pump control device for the automatic water supply device described above. (4) A claim characterized in that, even if an inconvenience occurs in the disconnection due to the current detection, a disconnection means is provided that detects the pressure inside the pump discharge side piping and stops some of the pumps in operation. A pump control device for an automatic water supply device according to item (1).