JPH0674794B2 - Water pump operation controller - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a water supply pump device including a pressure tank,
In particular, the present invention relates to a water supply pump operation control device capable of reducing the frequency of starting even if the pressure tank is downsized.

[Background of the Invention]

The water supply pump facility may be equipped with a pressure tank in order to reduce fluctuations in the water supply pressure due to the use of water at the demand end and to cope with delays in starting and stopping the pump.

Even in such a case, however, it is desirable that the pressure tank be as small as possible from the viewpoint of downsizing of equipment and cost reduction.

However, if the pressure tank is downsized in this way,
As a result, the frequency with which the pump is started increases, which causes a problem that the life of the control device is shortened.

Therefore, in order to keep the starting frequency of the pump low even if the pressure tank is made small, a timer means for delaying the stop control of the pump by a predetermined fixed time, for example, 2 to 3 minutes is provided, and once the pump is operated. After the start, a device that allows the pump to continue operating for a certain period of time even after the conditions for stopping the pump, such as the water supply pressure rising to a predetermined value, has been known. The conventional example will be described.

First, FIG. 2 shows a general configuration of a water supply device that is equipped with a pressure tank and uses a constant-speed pump to turn the pump on and off to supply water. A suction pipe, 3-1 and 3-2 are gate valves, 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 switch.

Further, FIG. 3 is an operation characteristic diagram of the water supply device shown in FIG.
The vertical axis shows the pressure H and the horizontal axis shows the water amount Q. Here, P ₁ is the starting pressure of the pump, P ₂ is the stop pressure, and Q ₁ and Q ₂ indicate the amount of water at this operating pressure point. The pressure switch 8 shown in FIG. ₂ is set so as to be closed at the starting pressure P ₁ or less shown in FIG. 3 and to be opened at the stop pressure P ₂ or more.

Next, FIG. 4 shows a conventional example of the control circuit of the water supply device (FIG. 2). P ₂ is a contact of the pressure switch 8, T is a timer, T _b is its timed contact, M is a pump 4 An electromagnetic switch of a motor (not shown) for driving M _a is its contact.

The 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 ₂ and the pump 4 is stopped.

(1) If the pressure in the pressure tank 7 is reduced to the starting pressure P ₁ by using water at the terminal, the contact P _s of the pressure switch 8 is closed and the pump 4 is started. At the same time, the timer T is activated. The timer T is set to a time (fixed) sufficient to suppress the pump starting frequency in advance.

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

(3) When the state of the above (2) continues and the set time of the timer T elapses, the pump 4 stops.

Hereinafter, the operations (1) to (3) are repeated.

Therefore, according to this conventional example, as described above, once the pump has started the operation, the operation is always continued for a predetermined fixed time, so that the starting frequency is sufficient even if the pressure tank is made small. It can be kept small.

Next, as a method of operating a pump, a method of controlling the rotational speed of the pump at a variable speed is also widely used.

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

Now, FIG. 5 shows an operation characteristic diagram of the water supply device in which the pump 4 shown in FIG. 2 is operated at a variable speed, and the same symbols as those in FIG. 3 have the same meaning. Here, the curve A is the pump Q- when the operating speed of the pump is the maximum speed N _MAX.
Similarly, curves B, C and D show the Q performance of the pump when the operating speeds of the pump are N ₁ and N ₂ and the minimum speed N _MIN.
Show performance. Further, H _O is a target pressure for keeping the pressure on the discharge side of the pump constant at this value, and H _ON is a starting pressure. Further, Q _A , Q _B , Q _C , Q _MIN are the curves A, B, C, D described above.
Shows the amount of water at the intersection of the target pressure H _O and the target pressure H _O.

Next, FIG. 6 shows a main control circuit of a water supply device using a variable speed pump, where PW is an AC power supply, MCB is a circuit breaker for wiring, and M is a circuit breaker.
C is an electromagnetic switch, INV is a variable frequency inverter device (hereinafter,
It is simply called an inverter).

There are various variable speed driving means for the motor IM, and accordingly,
Although an inverter is used here, the invention is not limited to this.

Further, the CTL receives a signal from the pressure sensor 8 (in this example, the pressure sensor uses a signal that responds to the pressure of the water supply pipe 6) to control the entire system and to command the inverter to speed. It is a control circuit that emits a signal.

Next, the general operation of this conventional example is as follows.

(1) When the amount of water used is larger than Q _MIN , the pressure sensor 8 measures the pressure in the water supply pipe and generates a signal in response to this. The control circuit CTL compares this signal with the preset target pressure H _O, and issues a speed command signal to the inverter INV to match it and operates while changing the operating speed of the pump to supply water. I do. For example, the usage is Q _C
→ Q _B → Q _A , the pump operating speed increases from N ₂ → N ₁ → N _MAX
And speed up.

(2) If the amount of water used is small and is below Q _MIN , operate at the speed N _MIN corresponding to this for a certain period of time and stop the pump. By using the water at the end, the pressure in the water supply pipe 6 becomes H _ON
When the temperature falls below the range, the pump is started and (1) to (3) in the case of FIG. 4 described above are repeated. In addition, too little water Q _MIN
May be detected by adding a flow rate sensor to the speed signal of the pump or the water supply pipe 6 in FIG.

Therefore, according to this conventional example, even if the pressure tank is made small, the starting frequency can be suppressed sufficiently small.

However, in these conventional examples, after the pump is started, the pump operation is always continued for a certain period of time or more, regardless of the water supply state, and depending on the water supply situation, the pump may be operated wastefully. Will be done.

Specifically, for example, when the amount of water used is extremely low at night, for example, even if the amount of water used to open one of the water taps at the end of the pump (10 to 15 l / min) is small, the tank is small. Since the pump has been started, the pump is started, and at this time, even if it is said that the water supply amount can be operated for a short time, in the above-mentioned conventional example, the timer is set at this time as well. During this time, the operation is always forced to be continued, and this is repeated, resulting in wasteful operation.

Incidentally, such a conventional example is described in, for example, JP-A-51-9.
It is disclosed in Japanese Patent No. 2411, Japanese Patent Laid-Open No. 51-100306, and the like.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to sufficiently suppress the starting frequency of the pump even if the pressure tank is made small, and to prevent the pump from being wastefully operated. In order to provide sufficient energy saving, there is provided a water supply pump operation control device.

[Outline of Invention]

In order to achieve this object, the present invention provides a pump device in which an operating time after the pump is started is equal to or longer than a time set by a pre-determination timer, and then the following operation is performed after the pump is stopped. It is characterized in that the time until it is started is measured and the set time by the timer is shortened from a predetermined value according to the measurement result.

Example of Invention

Hereinafter, the water supply pump operation control device according to the present invention,
This will be described in detail with reference to the illustrated embodiment.

FIG. 1 shows an embodiment of the present invention, in which the same or equivalent parts as those in the conventional example shown in FIGS. 4 and 6 are designated by the same reference numerals. The structure of the entire pump is the same as that of the conventional example shown in FIGS. 4 and 6, and is as shown in FIG.

Now, in Fig. 1, SW is a switch, TR is a transformer,
Z is a rectified and smoothed power supply unit, μ _con is an arithmetic processing unit M
PU, memory M, power supply terminal E, I / O ports PIO-1, PIO-
Micro competent consisting of two like Yuta (hereinafter abbreviated as a microcomputer.), F ₁ is INTERFACE for more input and output ports PIO-1 reads to the microcomputer mu _con that said signal contact P _s of the pressure sensor -8, F ₂ Signals from the same microcomputer μ _con via the I / O port PIO-2
It is an interface for output to.

Next, FIG. 7 is a flow chart showing a control procedure of the present embodiment, and portions unrelated to the description are omitted. For the sake of convenience, the microcomputer μ explained in FIG. 1 is controlled so as to follow this procedure. _The program is stored in the memory M of _con . Then, in this embodiment, a timer T (which serves as a timer means for setting a predetermined set time) of a time sufficient to suppress the starting frequency of the preliminarily pump is set and the actual time is set. The operating time T ¹ of the pump and the stop time t of the pump are measured, and these times T ¹ and t are subtracted from the time of the timer T, and the remaining time is also larger than the preset time a. In this case, the operation is continued with this time set as it is, and when the remaining time becomes shorter than the time a, the operation is continued for the time a to suppress the starting frequency, and unnecessary operation is eliminated. It was done like this.

Here, the reason why the time a is set will be described. When the pump stop time is long, the remaining time is short and may be 0 seconds or less. If this happens, the pump will stop immediately the next time it starts, a so-called jogging (blink).
Will occur. Therefore, the time a of about 5 to 10 seconds is set, and when the pump is started once, the operation of the pump is continued for at least this time a.

More specifically, the water supply pipe 8 is provided at 101 to 102 steps.
The internal pressure is detected to check if this pressure is lower than the starting pressure P ₁ , and as a result, if the pressure reaches P ₁ , the next
In step 103, the pump 4 is started.

On the other hand, returns to 101 step if the pressure has not reached the P _1, repeats the processing of the loop L ₁ here until it reaches the pressure P _1.

At 104 steps, as described above, the timer T (soft timer in this embodiment) sufficient to suppress the pump starting frequency is set, and at 105 and 107 steps, the pressure of the water supply pipe 6 is measured again by the pressure switch 8. , Now check whether this pressure has reached the stop pressure P ₂ . As a result, if not reached until the stop pressure P ₂ is reached 106,
The operation time T ¹ is measured by repeating the processing at 105 and 107 steps, and if the operation time T ¹ is reached, the operation time T ¹ and the stop time t are subtracted from the preset timer T at the next 108 steps.
Therefore, the processing centering on the 108 steps constitutes an arithmetic means for variably controlling the predetermined set time. However, although not shown, this stop time t
Has been cleared to 0 at the time of initial setting, so it is 0 seconds only for the first time. Then, in the next 109 steps, 108
The remaining time of the timer T reduced by the step is compared with a sufficient time a necessary to prevent the timer from moving, and if the remaining time T is larger than a, proceed to 110 steps, where the operation is continued for only this time. , A, the operation is continued for a seconds. After this, in 112 steps, the stop time timer t
(This serves as a time measuring means for measuring the stop time) is cleared to 0, and the pressure of the water supply pipe is detected again at steps 113 and 114 to check whether the stop pressure P ₂ is reached. When the stop pressure P ₂ is reached, the pump is stopped at 116 steps, the pump stop time t is measured at the next 117 steps, and the timer T ¹ that counts the operation time at 118 steps is cleared to 0. Repeat from step 101 below. On the other hand, as a result of the judgment at 114 steps, if the stop pressure P ₂ has not been reached, the routine proceeds to 115 steps, where the operating time T ¹ of the pump is counted and the processing after 108 steps is executed again. Then, in the processing of 108 steps, the pump stop time t is reduced from the second time onward, so if the pump stop time becomes long, the forced continuation of the pump executed at 110 to 111 steps accordingly. The operating time is shortened, and the wasted time is reduced. For example, if the preset timer T is 100
Assuming that a sufficient time "a" for not moving for seconds or 10 seconds is set to 10 seconds, if the pump stop time is 100 seconds or more, the pump will continue to operate for 10 seconds. According to this, in any case, the previously set time is shortened as compared with the conventional technique in which the operation is always continued.

Next, another embodiment of the present invention will be described with reference to FIGS. FIG. 8 shows the control circuit of the control device according to this embodiment, and the same reference numerals as those in FIGS. 1 and 6 show the same parts. However, the pressure sensor 8 emits an electric signal proportional to the detected pressure. F ₃ is an interface for outputting the speed command signal from the microcomputer μ _con from the input / output port PIO-3 to the inverter.

Similar to FIG. 7, FIG. 9 is a flow chart showing a control procedure, and portions unrelated to the description are omitted. Of course, the microcomputer μ must be set so that control is performed according to this procedure.
_A program is stored in the memory M of _con .

To explain the operation, first, a time T (soft timer in this example) sufficient to suppress the starting frequency of the pump 4 is set in 201 and 202 steps, and the pump operating time T ^{1 is set.}
Also, the stop time t is measured and the counter for storing the time is cleared to 0. In 203 and 204, the pressure of the water supply pipe 6 is measured by the pressure sensor 8, and this pressure is the starting pressure.
Check to see if it is below H _ON . As a result of the examination, if it does not reach the starting pressure H _ON or less, the process returns to step 203 and the processing of loop L ₁₀ is continued. When the starting pressure H _ON is reached, the pump 4 is started at the next 205 steps, and at 206 steps, the target pressure _HO which is stored in advance is compared with the pressure measured by the sensor 8. As a result of comparison, if both are equal, jump to 210 steps, maintain the current speed, and if the measured pressure is smaller than the target pressure H _O , perform acceleration control at 208 steps and proceed to 210 steps. . If the measured pressure is higher than the target pressure H _{O, the} routine proceeds to step 207, where it is checked whether or not the preset minimum speed has been reached. Or flow sensor (first
It is detected whether or not the minimum water quantity Q _MIN has been reached by adding the water supply pipe 6 in the figure). Reached proceeds deceleration control at 209 step unless the means pursuant 210 step, an embodiment of FIG. 7 in 211 step later if they reached the same, the timer T from the operating time of pre Ji are then fit set T ¹ And stop time t
To check the remaining time, and if this time is longer than a sufficient time a for not jogging, continue operation for this time, and if the remaining time is less than a sufficient time a for not jogging, then time a Control to continue driving only. The description of each step is the same as that of the embodiment shown in FIG.

As described above, according to these embodiments, it is possible to suppress the starting frequency of the pump and reduce wasteful operation.

The present invention can be applied not only to the constant discharge pressure control as described above, but also to the constant end pressure control.

〔The invention's effect〕

As described above, according to the present invention, as the amount of water used decreases and the stop time of the pump increases, the minimum operation time set to suppress the starting frequency is shortened. Except for the drawbacks of the above, even if the pressure tank is downsized, there is no fear that the frequency of starting the pump will increase, and even when the amount of water used is small, the pump will not be wastefully operated, and the pump equipment will be downsized It is possible to provide a water supply pump operation control device that can sufficiently reduce the cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a water supply pump operation control device according to the present invention, FIG. 2 is a configuration diagram showing a general configuration of a pump device having a pressure tank, and FIG. FIG. 4 is a characteristic diagram when the device is turned on and off, FIG. 4 is a block diagram showing a conventional example of a pump operation control device, and FIG. 5 is a characteristic diagram when the device of FIG. 2 is operated at a variable speed, FIG. Is a block diagram showing another example of the conventional example, and FIG.
8 is a flow chart showing the operation of the embodiment shown in FIG. 8, FIG. 8 is a block diagram showing another embodiment of the present invention, and FIG. 9 is a flow chart showing the operation of the embodiment shown in 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, 8 …… Pressure switch, SW …… Switch, TR …… Transformer, Z …… Power supply unit, μ _con ……
Microcomputer, PW ...... AC power source, MCB ...... breaker, MC ...... electromagnetic switch, IM ...... motor, INV ...... inverter, F _1, F ₂ ...... INTERFACE.

Claims (3)

[Claims] 1. A water supply amount control is performed by repeatedly controlling starting and stopping of a pump according to a water supply condition, and stopping of the pump is prohibited during a period from when the pump is started until a predetermined set time elapses. In the feed water pump operation control device, the timer means for setting the predetermined set time, the time measuring means for measuring the stop time from when the pump is stopped to the next start, and the time measurement Arithmetic means for variably controlling the predetermined set time by the timer means according to the measurement result by the means, and the predetermined set time by the timer means is shortened as the stop time measured by the time measuring means becomes longer. A water supply pump operation control device characterized in that the water supply pump is configured to move forward. 2. A water supply pump operation control device according to claim 1, wherein a minimum value is set for a predetermined set time by the timer means. 3. The water supply pump operation control device according to claim 1, wherein the pump is a variable speed pump.