JPS61255295A - Water supply pump operation control device - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a water supply pump device equipped with a pressure tank.
In particular, the present invention relates to an operation control device for a water supply pump that can reduce the frequency of starting even if the pressure tank is downsized.

[Background of the invention]

Water supply pump equipment is sometimes equipped with a pressure tank in order to reduce fluctuations in water supply pressure due to water usage at the demand end and to cope with delays in starting and stopping the pump.

Even in such a case, however, it is desirable to make the pressure tank as small as possible from the standpoint of downsizing the equipment and reducing costs.

However, if the pressure tank is made smaller in this way,
This causes problems such as an increase in the frequency of starting the pump and a shortened life span of the control equipment.

Therefore, in order to keep the frequency of starting the pump low even if the pressure tank is small, a timer means is provided to delay the stop control of the pump by a predetermined fixed period of time, for example, 2 to 3 minutes, and once the pump is in operation. Conventionally, devices have been known that allow the pump to continue operating for the certain period of time described above even after the pump has started and the pump stop conditions such as the water supply pressure rises to a predetermined value are satisfied. , this conventional example will be explained.

First, Figure 2 shows the general configuration of a water supply system that is equipped with a pressure tank and uses a constant speed pump to operate the pump in ON-OFF mode to supply water. 1 is a water receiving tank, 2 is a A suction pipe, 3-1.3-2 is a gate valve, 4 is a pump, 5 is a check valve, 6 is a water supply pipe, 7 is a pressure tank, and 8 is a pressure gas pipe.

In addition, Fig. 3 is an operational characteristic diagram of the water supply device shown in Fig. 2.
The vertical axis represents the pressure H, and the horizontal axis represents the water amount Q. Here Pl
is the starting pressure of the pump, P2 is the stopping pressure, and ? ,Q,,
Q indicates the amount of water at this operating pressure point. The pressure switch 8 shown in FIG. 2 is set to close when the starting pressure is below P1 shown in FIG. 3, and to open when the stopping pressure is above P2.

Next, FIG. 4 shows a conventional example of a control circuit for the water supply system (FIG. 2), in which P2 is the connection/default of the pressure switch 8, T is the timer, Tb is its time contact, and M is the pump 4. The electromagnetic switch of the driving motor (not shown) is connected to the electromagnetic switch.

An outline of the operation of this conventional example is as follows.

To simplify the explanation, it is assumed that the pressure in the pressure tank 7 is now higher than the stop pressure P (tc), and the pump 4 is stopped.

Assuming that the pressure in the pressure tank 7 drops due to the use of water at the (+) terminal and reaches the starting pressure P1, the contact P8 of the pressure switch 8 closes and the pump 4 starts. At the same time, timer T is activated. This timer T is set in advance to a sufficient time (fixed) to suppress the pump starting frequency.

(2) Even when the pressure in the pressure tank 7 increases due to a decrease in the amount of water used and reaches the stop pressure P2, the pump 4 continues to operate within the time set by the timer T.

(3) When the above condition (2) continues and the set time of the timer T has elapsed, the pump 4 stops.

Thereafter, operations (1) to (3) are repeated.

Therefore, according to this conventional example, as mentioned above, once the pump starts operating, it always continues to operate for a predetermined fixed period of time, so even if the pressure tank is small, the starting frequency cannot be sufficiently increased. It can be kept small.

Next, as a method of operating the pump, a method of variable speed control of the rotation speed of the pump is also widely used.

Therefore, a conventional example in which the above-mentioned control is performed using a variable speed pump system will be described.

Now, FIG. 5 shows an operating characteristic diagram of a water supply system in which the pump 4 shown in FIG. 2 is operated at variable speed, and the same symbols as in FIG. 3 have the same meanings. Here, curve A shows the pump Q-H performance when the pump operating speed is set to the maximum speed NMAX, and similarly, curves B, C, and D show the pump operating speed N1. N2 and minimum speed NM work,
The Q-H performance of the pump is shown below. Further, No is the target pressure to keep the pressure on the discharge side of the pump constant at this value, and HoN is the starting pressure. Furthermore, QA, QB
, Qo, 9N represents the amount of water at the intersection of the curves A, B, C, and D described above and the target pressure H8.

Next, Figure 6 shows the main control circuit of a water supply system using a variable speed pump, where PW is an AC power supply, MCB is a molded circuit breaker, MC is an electromagnetic switch, and INV is a variable frequency inverter (hereinafter referred to as (simply called an inverter).

Note that there are various variable speed drive means for the motor IM, and therefore, although an inverter is used here, the present invention is not limited to this.

In addition, CTL is the pressure sensor 8 (however, in this example,
The pressure sensor is a control circuit that controls the entire system by receiving a signal from the water supply pipe (6) and issues a speed command signal to the inverter.

Next, the general operation of this conventional example is as follows. do. The control circuit CTL compares this signal with a preset target pressure H6, issues a speed command signal to the inverter INV so that it matches this, operates the pump while changing its operating speed, and supplies water. conduct. For example, the amount used is Qc→QB-+QA,! : The increasing pump operating speed increases from N2 to N1 to NMAx. The change in the operating point of the pump at this time is C → B → A.

(2) When the amount of water used is less than QM, the pump is operated for a certain period of time at the corresponding speed of NM, and then the pump is stopped. When the pressure in the water supply pipe 6 decreases to H8N or less due to the use of water at the end, the pump is started and steps (1) to (3) in the case of FIG. 4 described above are repeated. In addition, detection of insufficient water flow QM is performed using the pump speed signal or the second
This may be done by adding a flow rate sensor to the water supply pipe 6 shown in the figure.

Therefore, even with this conventional example, the starting frequency can be kept sufficiently low even if the pressure tank is made small.

However, in these conventional examples, after the pump starts, it always continues to operate for a certain amount of time regardless of the water supply status, and depending on the water supply status, the pump may be operated quite wastefully. ○ Specifically, when the amount of water used is extremely low, such as at night (C is when the end faucet is turned off once while the pump is stopped).
Because the tank is small, even if the amount of water used is as low as 10 to 15 t/min, the pump will start, and in this case, considering the amount of water supplied, it will only take a short time to operate. However, in the conventional example described above, even in this case, operation is forced to continue for the time set by the timer, and this ends up being repeated, resulting in unnecessary operation. It will be done.

Regarding such conventional examples, for example, Japanese Patent Application Laid-Open No. 1983
There are disclosures in JP-A-92411, JP-A-51-100306, and the like.

[Purpose of the invention]

The present invention was made in view of the above-mentioned circumstances, and its purpose is to suppress the frequency of starting the pump to a sufficiently low level even if the pressure tank is made small, and to prevent the pump from being operated unnecessarily. The object of the present invention is to provide a water supply pump operation control device that achieves sufficient energy savings.

[Summary of the invention]

In order to achieve this object, the present invention provides a pump device in which the operation time after the pump starts is longer than the time set in advance by a timer, and the pump is stopped and then restarted. The device is characterized in that the time until the end of the process is measured, and the time set by the timer is shortened from a predetermined value according to the measurement result.

[Embodiments of the invention]

μ Below, regarding the water supply pump operation control device according to the present invention,
This will be explained in detail with reference to the illustrated embodiment.

FIG. 1 shows one embodiment of the present invention, and the same or equivalent parts as in the conventional example shown in FIGS. 4 and 6 are given the same reference numerals. The overall configuration of the pump is the same as the conventional example shown in FIGS. 4 and 6, and is as shown in FIG. 2.

Now, in FIG. 1, SW is a switch, TR is a transformer, 2 is a rectified and smoothed power supply unit, and μ. ON is the processing unit MPU, memory M1 power supply terminal E1 person output port P
A microcomputer (hereinafter referred to as microcomputer) consisting of IO-1, PIO-2, etc., Fl is a pressure sensor 8
Input/output capo (input/output capo) with the signal of contact P8 of PIO-1
The on interface for reading into the microcomputer μ, F2 is the same microcomputer μ. . . This is an interface for outputting signals from the input/output capo to the electromagnetic switch-MC via the PIO-2.

Next, FIG. 7 is a flowchart showing the control procedure of this embodiment, and parts irrelevant to the explanation are omitted, and the microcomputer μ described in FIG. 1 is controlled in advance according to this procedure. . The program is stored in the memory M of the user. In this embodiment, a timer T is set in advance for a time sufficient to suppress the pump starting frequency, and the actual pump operation time T1 and pump stop time tfc are measured, and the timer T From the time, subtract 1 and the original by these times, and if the remaining time is greater than the time a, which is also set in advance, continue driving using this time as the set time, and calculate the remaining time. When the time becomes shorter than the time a, the operation is continued for only 8 hours, thereby suppressing the starting frequency and eliminating unnecessary operations.

Here, the reason for setting the time a will be explained. When the pump stop time becomes long, the above-mentioned remaining time becomes short, and may become 0 seconds or less. However, if this happens, the next time the pump starts, it will stop immediately, a so-called instantaneous movement.
will occur. Therefore, we set a time a of about 5 to 10 seconds so that once the pump is started, the pump continues to operate for at least this time a.
That's what I'm doing.

To explain in more detail, in steps 101 and 102, the pressure inside the water supply pipe 8 is detected and it is checked whether this pressure has decreased by the starting pressure P, and as a result, if the pressure has reached P, the next Proceed to step 103, where the pump 4 is started.

On the other hand, if the pressure has not reached Pl, the process returns to step 101 and repeats the process of loop L1 until the pressure reaches P1.

In step 104, the timer T (soft timer in this embodiment) is set sufficiently to suppress the pump starting frequency as described above, and in steps 105 and 107, the pressure in the water supply pipe 6 is set again by the N pressure switch 8. measure,
Next, it is checked whether this pressure has reached the stop pressure P2. As a result, if the stop pressure P2 has not been reached, the process in steps 106, 105, and 107 is repeated until the stop pressure P2 is reached, and the operating time T1 is measured. Subtract the operating time T1 and the stop time t from the timer T. However, only for the first time, although not shown, the stop time t is 0 seconds because it is cleared to 0 at the time of initial setting. And then the next 10
In step 9, the remaining time of the timer T decremented in step 108 is compared with the sufficient time a necessary to prevent the timer from inching, and if the remaining time T is greater than a, the process proceeds to step 110, where this The operation continues for a time, and if it is smaller than a, the operation continues for a second. After this, in step 112, the stop time timer t is cleared to O, and in steps 113 and 11,
In the 4th step, the pressure in the water supply pipe is detected again to see if it has reached the stop pressure P2. If the stop pressure P2 has been reached, the pump is stopped in step 116,
In the next step 117, the pump stop time t is measured, and 11
Turn off the timer T1 that counts the operating time in 8 steps.
Clear it and repeat the following 101 steps 6 times. On the other hand, as a result of the determination in step 114, the stopping pressure P
If the count has not reached 2, proceed to step 115, count the pump operating time T1, and then proceed to step 108 again.
Executes processing after the step.

In the process of step 108, the pump stop time is also reduced from the second time onwards, so if the pump stop time becomes longer, the pump is forced to continue running in steps 110 and 111 accordingly. Driving time is shortened, and wasted driving time is shortened. For example, if the preset timer T is set to 100 seconds and the sufficient time a without inching is set to 10 seconds, if the pump stops for more than 100 seconds, the pump will only run for 10 seconds. Therefore, according to this embodiment, compared to the conventional technology, which always continues operation for a preset time in any case, the time that would otherwise be wasted is reduced. becomes shorter.

Next, another embodiment of the present invention will be explained with reference to FIGS. 8 and 9. FIG. 8 shows a control circuit of the control device according to this embodiment, and the same reference numerals as in FIGS. 1 and 6 indicate the same parts. However, it is assumed that the pressure sensor 8 emits an electrical signal proportional to the detected pressure. Also, F3 is a microcomputer μ. . . Input/output speed command signal from P
This is an interface for outputting from IO-3 to the inverter.

Similar to FIG. 7, FIG. 9 is a flowchart showing the control procedure, and parts irrelevant to the explanation are omitted. Of course, the microcontroller μ should be controlled according to this procedure.
In the memory M of the computer, a program game is stored.

To explain the operation, first, in steps 201 and 202, a sufficient time T(
In this example, a soft timer (soft timer) is set to measure the pump operating time T1 and stop time t, and a counter for storing the times is cleared to O. 203.204
Then, the pressure in the water supply pipe 6 is measured by the pressure sensor 8, and it is determined whether this pressure has reached the starting pressure H8) or less. As a result of the investigation, if the starting pressure has not reached H0N or lower, the process returns to step 203 and continues processing in loop L1o until the starting pressure has not been reached. When the starting pressure H8)l is reached, the next 205
In step 206, the pump 4 is started, and in step 206, the target pressure H8 stored in advance is compared with the pressure measured by the sensor 8. As a result of the comparison, if the two are equal, the speed is jumped 210 steps to maintain the current speed, and if the measured pressure is smaller than the target pressure H6, speed increase control is performed in 208 steps and the process proceeds to 210 steps. If the measured pressure is greater than the target pressure H8, the process advances to step 207, where it is checked whether the preset minimum speed has been reached. Or flow rate sensor (
(Added to water supply pipe 6 in Figure 1) etc. due to insufficient water flow QM construction,
Detect whether or not it has been reached. 20 if not reached
Perform deceleration control in 9 steps and proceed to 210 steps,
If the time limit has been reached, from step 211 onward, as in the embodiment shown in FIG. If the remaining time is 8 or more, which is a sufficient time for no inching, the operation is continued for this time, and if the remaining time is less than a sufficient time a for no inching, the operation is continued for a time a. Note that the explanation for each step is omitted because it is the same as that in the embodiment shown in FIG.

As described above, according to these embodiments, the frequency of starting the pump can be suppressed and unnecessary operations can be reduced.

Note that the present invention can be applied not only to constant discharge/pressure control as described above, but also to constant terminal pressure control.

〔Effect of the invention〕

As explained above, according to the present invention, as the amount of water used decreases and the stop time of the pump becomes longer, the minimum operating time that is set to suppress the startup frequency is shortened. Except for the disadvantages of the above, even if the pressure tank is made smaller, there is no risk of the pump starting more frequently, and even when the amount of water used is low, the pump will not be operated unnecessarily. Therefore, it is possible to provide a water supply pump operation control device that can sufficiently reduce costs and reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the water supply pump operation control device according to the present invention, FIG. 2 is a block diagram showing the general configuration of a pump device equipped with a pressure tank, and FIG. Fig. 4 is a block diagram showing a conventional example of a pump operation control device; Fig. 5 is a characteristic diagram when the device shown in Fig. 2 is operated at variable speed; 6 is a block diagram showing another example of the same conventional example, FIG. 7 is a flowchart showing the operation of the embodiment of FIG. 1, and FIG. 8 is a block diagram showing another embodiment of the present invention. FIG. 9 is a flowchart showing the operation of the embodiment of FIG. 1...Water tank, 2...Suction pipe, 3-1
．． 3-2...Gate valve, 4...Pump,
5... Check valve, 6... Water supply pipe, 7.
...Pressure tank, B...Pressure switch,
SW...Switch, TR...Transformer, 2...Power supply unit, μ. . .・・・・・・
Microcomputer, PW... AC power supply, M
CB: Circuit breaker, MC: Electromagnetic switch, IM: Motor, NV: Inverter, F1F2: Interface. −: Il: ψ soni ri) ← 工

Claims (1)

[Scope of Claims] 1. A timer means is provided to continue the operation of the pump for a predetermined set time, and the operation and stop of the pump are controlled according to the water supply conditions, and the predetermined time does not elapse after the pump starts operating. In a water supply pump operation control system in which the pump continues to operate for the predetermined set time period even if the stop conditions are satisfied during the period, the stoppage occurs from when the pump is controlled to stop until when it is controlled to start operation. 1. A water supply pump operation control device, characterized in that a time measuring means for measuring time is provided, and a predetermined set time by the timer means is controlled to be shortened in accordance with the stop time. 2. The water supply pump operation control device according to claim 1, characterized in that a minimum value is set at a predetermined time after the shortening control by the timer means. 3. The water supply pump operation control device according to claim 1, wherein the pump is a variable speed pump.