JP6343459B2 - Water supply equipment - Google Patents

Description

  The present invention relates to a water supply apparatus.

  Conventionally, a water supply device is sometimes provided between, for example, a water supply pipe or the like and a customer in order to supply sufficient water to a customer in a commercial building or a high-rise apartment.

  As such a conventional water supply device, water is usually supplied while operating the pump to pressurize, but from the viewpoint of energy saving, when the amount of water used at the customer is reduced below a certain amount, a certain low flow rate detection time It is known that the pump is stopped after confirming that the low flow rate state has continued (for example, Patent Document 1). In Patent Document 1, the small flow rate detection time is automatically set by fuzzy inference with reference to a data table based on the previous pump stop time, the previous pump operation time, and the number of times the flow switch is opened and closed.

Japanese Patent No. 3411137

  Here, although the low flow rate detection time during which the low flow rate state is monitored is shorter, the pump operation time decreases, so the energy saving effect is improved, but as a result, the pump start-up frequency can be increased accordingly. There is a risk that the service life may be shortened or a load may be applied to peripheral devices due to pressure fluctuation. On the other hand, if the low flow rate detection time is longer than necessary, the wasteful operation time of the pump becomes longer, resulting in a lower energy saving effect.

  In the technique of Patent Document 1, the low flow rate detection time is set without considering these long-term trends, even though the pump stop time and operation time can vary greatly depending on the amount of water used. Therefore, as described above, there is a possibility that the useless operation time of the pump becomes long.

  This invention is made in order to solve said subject, and provides the water supply apparatus which can reduce useless operating time of a pump, suppressing that the starting frequency of a pump becomes abnormally high. is there.

  In order to achieve the above object, the gist of the present invention is as follows.

A water supply apparatus according to the present invention comprises:
A pump,
A control unit for controlling the pump;
With
The control unit, after the low flow rate state continues over the stop confirmation time Tc during operation of the pump, to stop the pump,
The stop confirmation time Tc is determined based on the average Tt_ave of the pump stop times for the latest multiple times and the average Tr_ave of the pump operation time excluding the latest stop confirmation times for the plurality of times.

In the piping device of the present invention,
When the predetermined ideal water supply interval from when the pump is once stopped to being started and then stopped again is Tq_ideal, the stop confirmation time Tc is:
Tc = Tq_ideal − (Tt_ave + Tr_ave)
It is preferable to calculate using the following formula.

In the piping device of the present invention,
The stop confirmation time Tc is preferably set to the predetermined lower limit value when the value calculated using the above formula is lower than the predetermined lower limit value.

In the piping device of the present invention,
A pressure detector for detecting the pressure in the pipe;
A small flow rate detection unit that outputs a small flow rate detection signal when the flow rate in the pipe falls below a predetermined flow rate value;
Further comprising
A plurality of the pumps are provided,
The control unit is in the low flow state when the pipe internal pressure detected by the pressure detection unit exceeds a predetermined pressure value and the small flow rate detection signal is output from the small flow rate detection unit. It is preferable to judge.

  ADVANTAGE OF THE INVENTION According to this invention, the water supply apparatus which can reduce the useless operation time of a pump can be provided, suppressing that the starting frequency of a pump becomes abnormally high.

It is a schematic block diagram of the water supply apparatus which concerns on one Embodiment of this invention. It is a time chart which shows an example of operation | movement of the pump of FIG. It is a flowchart which shows an example of a process of the control part of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The water supply apparatus which concerns on one Embodiment of this invention is demonstrated with reference to FIGS. 1-3.
As shown in FIG. 1, in the water supply apparatus 20 in the present embodiment, for example, the suction port 1 is connected to a water supply water distribution pipe or a connection port to a water receiving tank or the like via a pipe, and the discharge port 7 is connected to a demand destination or the like. It is used in a state where it is connected to the connection port via a pipe. The water supply device 20 includes a plurality of (two in the illustrated example) pumps 2 and a flow switch 3 disposed on the downstream side of each pump 2 in a pipe flow path from the suction port 1 to the discharge port 7. (Low flow rate detection unit), check valve 4, pressure tank 5, and pressure transmitter 6 (pressure detection unit). Furthermore, the water supply apparatus 20 includes an inverter 9 electrically connected to the pump 2 by wire or wirelessly, a flow switch 3, a pressure transmitter 6, and a control unit 8 electrically connected to the inverter 9 by wire or wirelessly. And has.

  The pump 2 pressurizes and discharges water in the pump 2 by rotation of an impeller (not shown) by an electric motor (not shown). In the illustrated example, the two pumps 2 are arranged in parallel, and the flow switch 3 is connected to each downstream side. In the present embodiment, a plurality of pumps 2 are provided, but only one pump 2 may be provided.

  Each flow switch 3 is arranged on the downstream side of the corresponding pump 2 and is in an open state while water is used to some extent, but the water is hardly used and the flow rate becomes a predetermined flow rate value or less. When it is detected that the low flow rate state has been reached, the closed state is entered and a low flow rate detection signal is output to the control unit 8. Each check valve 4 is arranged on the downstream side of the corresponding flow switch 3, and the downstream side of each check valve 4 is joined and connected to the upstream side of the pressure tank 5. Each check valve 4 prevents water from flowing back to the upstream side.

  The pressure tank 5 is disposed on the downstream side of the check valve 4, and the air previously enclosed therein is compressed by the water flowing into the pressure tank 5. By the action of this compressed air, the water pressure in the pipe downstream from the check valve 4 is maintained even when the pump 2 is stopped. The pressure transmitter 6 is disposed on the downstream side of the check valve 4, detects the pressure in the pipe on the downstream side of the check valve 4, and notifies the control unit 8.

  The inverter 9 controls the rotation speed of the pump 2 in accordance with a command from the control unit 8. The control unit 8 is composed of a CPU board and the like, and the number of pumps 2 operated and the number of pumps 2 are determined based on information on the amount of water used obtained from the flow switch 3 and information on the pressure in the pipe obtained from the pressure transmitter 6. The inverter 9 is controlled so as to change the rotational speed of 2.

  Next, with reference to FIG.2 and FIG.3, operation | movement of the water supply apparatus 20 of this embodiment is demonstrated. FIG. 2 is a time chart showing the operation of the pump 2 until the pump 2 is started after being stopped once and then stopped again. In FIG. 2, the horizontal axis indicates time, and the vertical direction indicates whether the pump 2 is operating or stopped. In FIG. 2, the two pumps 2 are viewed comprehensively, that is, if at least one of the two pumps 2 is in operation, it is assumed that the operation is in FIG.

In the present embodiment, a time from when the pump 2 is temporarily stopped to when the pump 2 is started and then stopped again is defined as a water supply interval Tq. That is, one water supply interval Tq is the sum of one stop time Tt of the pump 2 and one operation time of the pump 2. The operation time of the pump 2 includes a normal operation time Tr ₁ , a stop confirmation time Tc for confirming whether or not the pump 2 should be stopped (stop confirmation process), and a pressure increase (pressure increase operation) of the pressure tank 5. This is the total of the boost operation time Tr ₂ to be performed.

Of the operating time of the pump 2, the sum of the normal operation time Tr ₁ and the step-up operation time Tr _2, and "operating time Tr except for the stop confirmation time" _{(Tr = Tr 1 + Tr 2} ).
Therefore, the water supply interval Tq is obtained by the following [Equation 1].
Tq = Tt + Tr ₁ + Tc + Tr ₂
= Tt + Tr + Tc [Formula 1]
In this example, the stop time Tt, the normal operation time Tr ₁ , and the stop confirmation time Tc are values that can be changed at any time by the control unit 8, and the boost operation time Tr ₂ is a fixed value set by the user or the like. .

  FIG. 3 shows processing performed by the control unit 8 at one water supply interval Tq. The control unit 8 performs the process of FIG. 3 by processing a program stored in a memory (not shown). First, when the pump 2 is stopped, the control unit 8 starts measuring the stop time Tt (step S1). While the pump 2 is stopped, the pressure tank 5 holds the pressure in the pipe.

And the control part 8 repeats judgment whether the starting condition for starting the pump 2 was satisfied until a starting condition is satisfied (step S2, NO). In this example, the starting condition is that the water in the pressure tank 5 decreases as the water is used, so that the pressure in the pipe downstream from the check valve 4 output from the pressure transmitter 6 is a predetermined pressure. It is established when the value falls below the value. When the start condition is satisfied (step S2, YES), the control unit 8 starts the pump 2 (step S3), and stores the stop time Tt (time from the stop to start of the pump 2) measured so far. At the same time, measurement of the normal operation time Tr ₁ is started (step S4). During this time, the control unit 8 repeats the determination of whether or not the stop confirmation condition as to whether the pump 2 should be stopped again is satisfied or not until the stop confirmation condition is satisfied (step S5, NO). In this example, the stop confirmation condition is that the pressure in the pipe on the downstream side of the check valve 4 output from the pressure transmitter 6 exceeds a predetermined pressure value when the water is hardly used, and the flow switch 3 is established when it can be confirmed that the flow switch 3 is closed in response to the small flow rate detection signal from 3.

When the control unit 8 determines that the stop confirmation condition is satisfied for a predetermined time (for example, 1 second) (step S5, YES), the normal operation time Tr ₁ measured until then (from the start of the pump 2 to the establishment of the stop confirmation condition) Is stored inside (step S6).

Then, the control unit 8 calculates the stop confirmation time Tc using each parameter including the preset boosting operation time Tr ₂ , the stop time Tt calculated in the above step, and the normal operation time Tr ₁ (step S7). ). A method for calculating the stop confirmation time Tc will be described later. The control unit 8 sets the calculated stop confirmation time Tc to the timer and starts the timer (step S8). And the control part 8 repeats judgment whether a stop confirmation condition is still satisfied until the timer counts up (step S9, Yes; step S11, NO). When the controller 8 determines that the stop confirmation condition is not satisfied for a predetermined time (for example, 1 second) before the timer counts up (step S9, NO), the controller 8 resets the timer (step S10). Return to step S5. As described above, in the stop confirmation process, it is determined that the pump 2 should be stopped when it is confirmed that the low flow rate state has continued for the stop confirmation time Tc.
When calculating the normal operation time Tr ₁ in step S6 again after returning to step S5, the control unit 8 establishes the stop confirmation condition after storing the previous normal operation time Tr ₁ (step S6). And the normal operation time Tr ₁ calculated previously are added together.

On the other hand, when the timer counts up without the stop confirmation condition not being satisfied for a predetermined time (step S11, YES), the control unit 8 increases the operation speed of the pump 2 over the predetermined boost operation time Tr ₂ or the like. Then, the pressure tank 5 is pressurized (accumulated) to perform a boost operation. After boosting operation time Tr ₂ has elapsed, the control unit 8, when the pipe pressure was confirmed to be more than a predetermined pressure value (step S13, YES), stops the pump 2 (step S14), and Returning to step S1 again, the same processing is performed at the next water supply interval Tq. If the pressure in the pipe does not reach the predetermined pressure value even after the boosting operation time Tr ₂ has elapsed (step S13, NO), the process returns to step S5.

  The stop confirmation conditions may be those other than those described above. For example, as the stop confirmation condition, only the fact that the flow switch 3 is in the closed state among the two conditions described above (the pressure in the pipe exceeds the predetermined pressure value and the flow switch 3 is in the closed state). good.

Next, the stop confirmation time Tc calculated in step S7 in FIG. 3 will be described.
The shorter the stop confirmation time Tc for monitoring the low flow rate state, the less wasteful operation time of the pump 2 will reduce the energy saving effect. However, the start frequency of the pump 2 can be increased accordingly. There is a possibility that the lifespan of 2 is shortened or a load is applied to peripheral devices due to pressure fluctuation. On the other hand, if the stop confirmation time Tc is longer than necessary, the wasteful operation time of the pump 2 becomes longer, resulting in a lower energy saving effect. In view of such points, in this embodiment, by suppressing the pump 2 from starting abnormally high, the pump 2 is wasted while improving the life of the pump 2 and reducing the load on peripheral devices. Optimize the stop confirmation time Tc in order to improve the energy saving effect by reducing unnecessary operation time.

  In order to optimize the stop confirmation time Tc, in this embodiment, in step S7 of FIG. 3, the average of the latest water supply intervals Tq for a plurality of times (at least once this time and immediately before) is a predetermined ideal water supply interval. The stop confirmation time Tc is adjusted so as to approach Tq_ideal. The ideal water supply interval Tq_ideal means a water supply interval at which the startup frequency of the pump 2 is not abnormally high and the most energy-saving effect can be expected. The ideal water supply interval can be arbitrarily set depending on the use environment and the installation environment.

For example, it is assumed that the ideal water supply interval Tq_ideal is set in advance to 70 seconds, and the boosting operation time Tr ₂ is set to 10 seconds.
At this time, assuming that the water supply interval Tq is always equal to the ideal water supply interval Tq_ideal,
70 seconds = Tt + Tr ₁ + Tc + 10 seconds.
In addition, the number of times the pump 2 is started per day is
Time of day / Tq_ideal = 86400 seconds / 70 seconds = 1234 times
It becomes.
Therefore, in this example, it is desirable that the number of activations of the pump 2 per day does not exceed 1234. By adjusting the stop confirmation time Tc so that the average of the most recent water supply intervals Tq approaches the ideal water supply interval Tq_ideal, the number of activations of the pump 2 per day can be prevented from exceeding 1234 times.

Here, the average Tq_ave of the water supply intervals Tq for the latest multiple times is the average of the stop time Tt for the latest multiple times, the operation time Tr excluding the stop confirmation time, and the stop confirmation time Tc as Tt_ave, Tr_ave, Tc_ave The following [Equation 2] derived from [Equation 1] can be obtained:
Tq_ave = Tt_ave + Tr_ave + Tc_ave [Formula 2]

When the average water supply interval Tq_ave is smaller than the ideal water supply interval Tq_ideal (Tq_ave <Tq_ideal), as shown in the following [Equation 3], by setting the stop confirmation time Tc longer by these differences, By extending the water supply interval Tq, it is possible to contribute to a decrease in the number of activations (activation frequency) of the pump 2 per day.
Tc = Tc_ave + (Tq_ideal − Tq _ave)
= Tc_ave + {Tq_ideal − (Tt_ave + Tr_ave + Tc_ave)} [Formula 3]

On the other hand, when the average Tq_ave of the water supply interval is equal to or greater than the ideal water supply interval Tq_ideal (Tq_ave ≧ Tq_ideal), the stop confirmation time Tc is set shorter by these differences as shown in the following [Equation 4]. It can contribute to energy saving.
Tc = Tc_ave − (Tq _ave − Tq_ideal)
= Tc_ave − {(Tt_ave + Tr_ave + Tc_ave) − Tq_ideal} [Formula 4]

Thus, although the method for deriving the stop confirmation time Tc differs depending on the magnitude relationship between the average Tq_ave of the water supply intervals and the ideal water supply interval Tq_ideal, when [Equation 3] and [Equation 4] are respectively decomposed, Equation 5] becomes:
Tc = Tq_ideal − (Tt_ave + Tr_ave) [Formula 5]

From the above consideration, in step S7 of FIG. 3, according to [Equation 5], the average Tr_ave of the operation time excluding the average stop time for the latest multiple times and the stop confirmation time for the latest multiple times from the ideal water supply interval Tq_ideal. The stop confirmation time Tc is calculated by subtracting the sum of.
When calculating the stop confirmation time Tc, instead of the operation time Tr excluding one stop time Tt and the stop confirmation time, the average of the latest stop times Tt_ave and the average of the operation time excluding the latest multiple stop confirmation times By using Tr_ave, it is possible to optimize the stop confirmation time Tc considering the long-term operation tendency of the pump 2.

However, in this embodiment, in order to keep the stop confirmation time Tc calculated by [Equation 5] within a predetermined adjustment range (10 seconds or more in this example), the stop confirmation time Tc uses [Equation 5]. When the value calculated in this way falls below a predetermined lower limit value (10 seconds in this example), the predetermined lower limit value is set.
That is, in this example,
When the calculated value is Tc <10 seconds, Tc = 10 seconds [Formula 6]
Set to.
Thereby, sufficient time can always be secured for monitoring the low flow rate state.

Next, in order to confirm the effect of the above-described embodiment, the pump operation example 1 is verified.
Table 1 below shows the value of the operation time Tr excluding the stop time Tt and stop confirmation time calculated for each water supply interval in the pump operation example 1, and the average Tt_ave of the stop time calculated using these values. The average Tr_ave of the operation time excluding the stop confirmation time and the value of the stop confirmation time Tc are shown. Each row of Table 1 shows values of Tt and Tr in the latest five water supply intervals Tq used for calculating average Tt_ave and Tr_ave. Each time the water supply interval Tq ends, the row in Table 1 advances to the next lower row. Tt_ave and Tr_ave were the average values of Tt and Tr for the latest five times (current and last four times), respectively. Tc was determined using [Formula 5] and [Formula 6]. Tr ₂ was 10 seconds and Tq_ideal was 70 seconds.

(Pump operation example 1)
In the pump operation example 1, the pump stop time Tt is temporarily increased in the middle of a plurality of continuous water supply intervals. Specifically, in the first five water supply intervals, Tt = 15 seconds and Tr = 15 seconds are constant (the first line of Table 1, Tt and Tr from this time to “four times before”). In the next water supply interval, Tt = 180 seconds and Tr = 15 seconds (second row in Table 1, “current” column of Tt and Tr), and in the subsequent water supply intervals again It becomes constant at Tt = 15 seconds and Tr = 15 seconds (the third to seventh rows in Table 1, “current” columns of Tt and Tr).

As can be seen from Table 1, when the stop time Tt becomes temporarily longer in the middle (the second row of Table 1, the “current” column of Tt), the stop confirmation time Tc becomes 5 at the subsequent water supply intervals. Therefore, it has a lower value (10 seconds) than the value at other water supply intervals (40 seconds) (2nd to 6th rows in Table 1, column of Tc).
If the stop confirmation time Tc is calculated using an equation in which the average values Tt_ave and Tr_ave in [Expression 5] are replaced with the latest values Tt and Tr, the stop confirmation time Tc is temporarily calculated in the second row of Table 1. Although it falls to 10 seconds, it will return to 40 seconds from the 3rd line. Therefore, in this pump operation example, when calculating the stop confirmation time Tc, by using the average values Tt_ave and Tr_ave, for example, compared to the case of using the values Tt and Tr for the latest one time, at a plurality of water supply intervals. Since the total stop confirmation time Tc is lowered, the unnecessary operation time of the pump can be reduced correspondingly, and the energy saving effect can be improved.

  Not only pump operation example 1, but if the total of the operation time Tr (Tt + Tr) excluding the stop time Tt and the stop confirmation time becomes temporarily longer and then Tt + Tr becomes shorter, the operation will stop. When calculating the confirmation time Tc, by using the average values Tt_ave and Tr_ave in [Equation 5], for example, it is possible to reduce the wasteful operation time of the pump as compared with the case of using the latest values Tt and Tr, for example. Become.

  The water supply apparatus according to the present invention can be applied to all kinds of water supply apparatuses for supplying water to demand destinations such as commercial buildings and apartment houses.

1: suction port, 2: pump, 3: flow switch (low flow rate detection unit), 4: check valve, 5: pressure tank, 6: pressure transmitter (pressure detection unit), 7: discharge port, 8: control , 9: Inverter, 20: Water supply device, Tc: Stop confirmation time, Tc_ave: Average of stop confirmation times for the latest multiple times, Tt: Stop time, Tt_ave: Average of stop times for the latest multiple times, Tr: Stop check time , Tr ₁ : Normal operation time, Tr ₂ : Boosting operation time, Tr_ave: Average operation time excluding the latest multiple stoppage confirmation times, Tq: Water supply interval, Tq_ave: Average of the latest multiple water supply intervals , Tq_ideal: Ideal water supply interval

Claims (3)

A pump,
A control unit for controlling the pump;
With
The control unit, after the low flow rate state continues over the stop confirmation time Tc during operation of the pump, to stop the pump,
The stop confirmation time Tc is determined based on the average Tt_ave of the pump stop time for the latest multiple times and the average Tr_ave of the pump operation time excluding the stop confirmation time for the latest multiple times ,
When the predetermined ideal water supply interval from when the pump is once stopped to being started and then stopped again is Tq_ideal, the stop confirmation time Tc is:
Tc = Tq_ideal − (Tt_ave + Tr_ave)
The water supply device calculated using the formula . 2. The water supply device according to claim 1 , wherein the stop confirmation time Tc is set to the predetermined lower limit value when a value calculated using the equation is below a predetermined lower limit value. A pressure detector for detecting the pressure in the pipe;
A small flow rate detection unit that outputs a small flow rate detection signal when the flow rate in the pipe falls below a predetermined flow rate value;
Further comprising
A plurality of the pumps are provided,
The control unit is in the low flow state when the pipe internal pressure detected by the pressure detection unit exceeds a predetermined pressure value and the small flow rate detection signal is output from the small flow rate detection unit. The water supply apparatus of Claim 1 or 2 which judges.

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