JPS6122149B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for controlling the number of operating pumps that automatically selects the number of operating pumps that supply water to an aquarium in accordance with fluctuations in the water level of the aquarium.

[Technical background of the invention]

In various buildings, especially mid-to-high-rise buildings, there are generally a primary water tank installed underground, a secondary water tank installed on the rooftop, and multiple water tanks to supply water from the primary tank to the secondary tank. Water supply systems that are equipped with pumps and that variably control the amount of water supplied to a secondary water tank by increasing or decreasing the number of these pumps in operation are often used. When automatically selecting and controlling the number of operating pumps in this type of water supply system, conventionally, multiple levels of water levels corresponding to the number of pumps are set in the secondary water tank, and all pumps are operated when the water tank water level is below the lowest level. At the same time,
Each time the water level rises, one pump is stopped, and when the water level reaches the top level, all pumps are stopped. Conversely, when the water level drops, one pump is stopped each time the water level drops one step. I was trying to start each one one by one. In such conventional methods, as the number of pumps increases, the capacity of the secondary water tank increases due to multi-stage settings, and the structure of the control device including the detection end becomes complicated, resulting in high equipment costs and There are many targets that are disadvantageous in terms of maintenance. Moreover, the longer the pump is able to handle a high water level, the longer it takes to operate, resulting in an uneven lifespan of the pump device including the drive mechanism.

In contrast, the water level in the aquarium is detected at regular repeating intervals, and if the water level exceeds a predetermined high water level, one pump in operation is stopped, and if the water level falls below a predetermined low water level, one of the pumps in operation is stopped. A possible pump operating method is to start one pump. To further explain how to operate such a pump, in general, the amount of water flowing out of the secondary water tank per unit time Q _C is undefined, and if the discharge amount q per unit time of each pump is the same, then the amount of water flowing out per unit time from the water tank is The amount of water supplied per unit nq varies in stages depending on the number n of pumps in operation. Therefore, there are almost no cases where it is possible to set the number n for which the relationship nq = Q _c holds;
When increasing or decreasing the number of pumps one by one, generally nq'> Q _c > (n-1). When the relationship q holds true, this water supply system can be said to be in a metastable state. In such a quasi-stable state, if the cross-sectional area of the water tank is constant, the water level rise rate when n units are operated is proportional to (nq - Q _c ), and when (n-1) units are operated The rate of water level decline is {Q _C
-(n-1・q}. Therefore, the time t ₀ for n units operation and the time t ₁ for (n-1) units operation are ∫ ^t0 ₀ (n・q−Q _c )・dt = If the setting is made so that ∫ ^t1 ₀ {Q _c - (n-1)・q}・dt...(1) holds true, the average water level can be maintained constant, and the times t ₀ and t ₁ can be shortened. In this way, the range of water level fluctuation can be made smaller. However, as mentioned above, the outflow amount Q _c per unit time is generally indefinite, so it is impossible to set the times t ₀ and t ₁ in advance. It is.

Therefore, by using the predetermined high and low water levels as a reference, and increasing or decreasing the number of operating pumps n by one per predetermined repetition period T, the above formula (1) can be established at both the high and low water levels. It can be made to approximately hold within the range of the maximum error Tq.

According to such a method of controlling the number of operating pumps, by setting the predetermined repetition period T short, it is possible to improve the responsiveness of starting and stopping the pumps,
In addition, if the order of starting and stopping the pumps is made to start from the one that is stopped or started first, it is possible to prevent unbalanced operation in which only a specific pump is operated.

[Problems with background technology]

However, as mentioned above, if the repetition period T is shortened to improve the responsiveness of starting and stopping the pump, when the water level of the aquarium approaches the high water level or low water level, the pump will pick up the waves (noise) on the water surface and start the pump. , and there is a risk of malfunctions such as so-called chattering. Furthermore, if the cycle is lengthened in order to prevent such malfunctions such as chattering, there is a drawback that the responsiveness of starting and stopping the pump becomes slow.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and its purpose is to automatically select the appropriate number of pumps to operate in response to fluctuations in the water level of the aquarium, improve the responsiveness of starting and stopping pumps, and This paper attempts to provide a method for controlling the number of operating pumps that will not malfunction due to waves or the like.

[Summary of the invention]

In order to achieve the above object, the present invention sets a sampling time within a range that does not exceed the above-mentioned predetermined repetition period for each predetermined repetition period, and detects each water level corresponding to the high water level and low water level within the above sampling time. The water level of the water tank is determined by comparing each integral value obtained by time-integrating the output signal of the means with a preset threshold value, and the output signal of each of the water level detection means is detected within the sampling time. A storage means is provided to store each of two successive repetition periods, and when the water level of the water tank changes to above the water level in the two repetition periods, the storage means stores only one pump in operation regardless of the comparison and discrimination. When the pump is stopped and the water level changes to below the above-mentioned low water level, one of the stopped pumps is started by the above-mentioned storage means, regardless of the above-mentioned comparative determination.

By providing the above storage means, the direction of water level fluctuation can be determined using this storage means, and as a result, malfunctions such as chattering can be prevented even if the cycle time is shortened, and responsiveness can be improved as the cycle time is shortened. It is possible.

[Embodiments of the invention]

Hereinafter, the present invention will be described with reference to an illustrated embodiment. In Fig. 1, 1 is the primary water tank, 2 is the secondary water tank, 3 is the inflow pipe, 4 is the outflow pipe, 5 and 6 are high water level and low water level detectors, P ₁ , P ₂ ...P _N is the water supply It is a pump for A high water level H and a low water level L are set in the secondary water tank (hereinafter simply referred to as water tank) 2, and the area above the high water level H is defined as a supercharging area, and the low water level L
The area below this will be called the insufficient area, and the area between these will be called the intermediate area. The detectors 5 and 6 are equipped with detection ends 7 and 8 located at the high and low water levels H and L, respectively, and when the water level a of the water tank 2 is equal to or higher than these detection ends 7 and 8, a predetermined output signal is output. (for example
ON signal). The pumps P ₁ to P _N are each connected to a drive source such as an electric motor so that they can operate independently.

As shown in FIG.
2 and memory devices 13 and 14 to a changeover logic circuit 15, and the output of the changeover logic circuit ₁₅ is sent to each control _section ( (not shown). The processing device 10 also includes a clock 18.
The clock pulse signal from the timing setter 1
9, and a predetermined sampling time t(tT) is set for each predetermined repetition period T. An operating condition determination circuit 20 is connected to the arithmetic unit 16 and distributor 17. The condition determination circuit 20 is inputted with automatic/manual control mode information, identification information of pumps that are out of service due to failure or periodic inspection, etc., and if necessary, water level information of the primary water tank 1, etc. ,
In addition to the water level of the water tank 2, various predetermined information that affects the operation of the pump is input. When manually controlling the start and stop of each pump, the output signal of the calculator 16 is cut off by the signal from the condition determination circuit 20, and the control section of each pump is controlled with or without the distributor 17. It is done. Furthermore, if there is a pump that is inactive, only the operable pumps are selected based on a signal from the condition determination circuit 20.

Although not shown, the one judgment circuit 11 detects the detector 5 within the sampling time t every period T.
an integrator that integrates the time during which an output signal indicating that the water level is "present" is supplied, and a comparator that compares the integrated value of this integrator with a threshold value set to, for example, 1/2 of the sampling time t. It is equipped with Although not shown, the other discrimination circuit 12 includes an integrator that integrates the time during which the water level is "absent" from the detector 6 within the sampling time t for each period T, in substantially the same way as the one discrimination circuit 11 described above. A comparator is provided to compare the integrated value of this integrator with a threshold value similar to that described above. The storage unit 13 includes, for example, a shift register, and the detector 5 indicates whether the water level is "present" or "absent".
It is configured to memorize the moment at which the output signal was issued for the most recent two repetition cycles. Further, the memory 14 is configured in substantially the same manner as the memory 13, and is configured to memorize the moment when the detector 6 outputs an output signal indicating that the water level is "absent" or "present" for two recent repeat cycles. has been done.
Each of these storage devices 13 and 14 sends out their respective stored contents to a variable logic circuit 15.

The above-mentioned changeable logic circuit 15 includes a discriminating circuit 11,
The water level is determined according to each output signal of the memory device 12 and the memory devices 13 and 14, and a command signal for subtraction, addition, or maintaining the current state is sent to the arithmetic unit 16.

The arithmetic unit 16 generates a command signal to increase or decrease the number of pumps in operation at a rate of one pump per repetition period T, or to maintain the status quo, according to the output signals of the variable logic circuit 15 and the operating condition determination circuit 20. Send out.

The distributor 17 determines the starting order of each pump during operation,
It is equipped with a storage device that stores the stop order of each pump on standby, and when adding more pumps, the above stop order is followed.
When the number of pumps is reduced, the pumps to be started and stopped are selected according to the above-mentioned starting order.

In addition, instead of storing the start order and stop order as described above, the individual total operating times of all pumps may be stored, and starting and stopping may be selected depending on the individual total operating times. good.

Although not shown in the drawings, for example, a water level detector provided in the primary water tank 1, an abnormal water level detector provided in the water tank 2, and a water level indicator linked to these detectors and the detectors 5, 6, etc. , abnormality alarms, other various equipment, and auxiliary facilities will be installed as necessary.

A method of controlling the number of operating pumps using such a configuration will be explained.

It is now assumed that the water level a of the water tank 2 is in the intermediate range between the high water level H and the low water level L as shown in the cycle shown in FIG. 3, and n units of pumps P ₁ to P _N are in operation. In this state, since the water level a has not reached the upper detection terminal 7, the output signal b of the detector 5 is continuously "absent" at the water level, and the discrimination circuit 11
Since the integrated value (referred to as the first integrated value) d is less than the threshold value (referred to as the first threshold value) v ₁ for the high water level for each repetition period T, the discrimination circuit 11
The output signal of the water level is also "no". Also at this time,
In the storage device 13, the state of the repetition period is stored as water level "absent". On the other hand, since the lower detection end 8 is under the water surface, the output signal c of the detector 6 is continuously "present" at the water level, and the integrated value (referred to as the second integrated value) e in the discrimination circuit 12 decreases every repetition period T. Since the threshold value (referred to as the second threshold value) for the water level is less than _v2 , the output signal of the discrimination circuit 12 also indicates that the water level is "present". Further, even in the storage device 14, the state of the cycle is stored as water level "present". Therefore, in the changeable logic circuit 15, each output signal of the discrimination circuit 11 and the memory 13 indicates that the water level is "absent" as described above, and each output signal of the discrimination circuit 12 and the memory 14 indicates that the water level is "present". If so, it is determined that the water level a of the water tank 2 is in the above intermediate range, and the arithmetic unit 16
Neither addition nor subtraction command signals are sent to. Therefore, n pumps continue to operate as they are.

When the amount of outflow from the outflow pipe 4 decreases and the water level a rises, and the water surface approaches the detection end 7, the detection end 7 begins to come into contact with the water surface intermittently, since waves generally exist on the water surface. As the water level rises, the total contact time within the sampling time t becomes longer. In this way, for example, in a period, the first integrated value d does not reach the first threshold value _v1 , but the detection record of the high water level detector 5 appears as a water level "present". At this time, since the water level stored in the memory device 13 in the previous cycle was "absent", the change logic circuit 15 determines that the water level has shifted to the supercharging region regardless of the water level "absent" judgment of the discriminating circuit 11. It is determined that the calculation unit 1
A subtraction command signal is sent to 6. As a result, the arithmetic unit 16 and the distributor 17 select and stop the first one of the n pumps in operation, and the number of pumps in operation becomes (n-1).

In the period, the first integrated value d is the first threshold value v ₁
When the water level reaches the above level, the output signal of the discrimination circuit 11 becomes "present". Since the output signal of the memory device 13 indicates that the water level is "present" during the above-mentioned cycle and remains "present" during synchronization, the output signal of the converter logic circuit 15
determines that the water level is continuously in the supercharging range, sends a subtraction command signal, and stops the next one.

Even if the aquarium water level stops rising or falls due to such a pump reduction, as long as it is located above the above-mentioned high water level H, the same above-mentioned removal operation will be performed automatically at each repetition period T. Eventually, all pumps would be shut down.
In addition, as a result of the above-mentioned reduction operation,
For example, if the aquarium water level falls below the high water level H in cycle V, the output signal of the discrimination circuit 11 becomes water level "absent", and the memory 13 stores the water level "absent" after the water level "present", and in this case, The number n of pumps in operation is not increased or decreased, and is maintained at (n-2), for example.

When the water level further decreases from the above state and passes below the low water level L in the period shown in FIG. 3, for example, the second integration is performed after the output signal c of the detector 6 becomes "no" Even if the value e is less than the second threshold value _v2 , the memory 14 stores the water level as "absent" in the current cycle because the previous memory was that the water level was "present", that is, in the intermediate range. As a result, the changeable logic circuit 15 determines that the water level a has moved into the insufficient range, and sends an addition command signal g to the arithmetic unit 16. As a result, the calculator 16 and the divider 17 start one of the stopped pumps that is next to the last started pump or the first stopped pump.

During the cycle, the integrated value e of the water level "absent" exceeds the second threshold value _v2 , so the discrimination circuit 12 determines the water level "absent", and the memory 14 continuously stores the water level "absent". In order to do this, the changeable logic circuit 15 determines the shortage area, and further sends an addition command g to start one of the stopped pumps.

This increase in the cab diagram continues while the water level is in the shortage region, and if this state continues, all operable pumps become operational. In addition, the water level rises due to the increase in the number of operating vehicles, passes the low water level L upwards like a cycle, and the second integrated value e returns to the second threshold value.
If _v2 or less, the computing unit 16 will not issue an increase command signal, and the number of pumps in operation will remain unchanged. That is, while the water level of the water tank is in the above-mentioned shortage or decrease, the number of pumps in operation is gradually increased by one in each cycle, and when the water level rises to the above-mentioned intermediate range, the number of pumps in operation is maintained unchanged.

As mentioned above, since the number of pumps is increased or decreased by one pump per repetition period based on both the high and low water levels H and L, the appropriate number of operating pumps can be obtained regardless of the total number of pumps. The total discharge amount, that is, the amount of inflow into the water tank 2 can be made to be closest to the amount of outflow. In addition, since the time during which the detection signals of detectors 5 and 6 are present is integrated at each sampling time and compared with the threshold value, there is no chattering even if there are water surface waves, and the water surface When the water passes through the high water level H and the low water level L, the hysteresis phenomenon due to the passing direction cannot be determined, so the number of operating vehicles is automatically controlled in response to water level fluctuations.

In the case where the above-mentioned memory devices 13 and 14 are not provided, when the water level a shifts from the intermediate region to the supercharging region, the first integrated value d becomes the first threshold value, for example, as in the cycle shown in FIG. If v is less than ₁ , the output signal of the discrimination circuit 11 is in a water level "absent" state, and the arithmetic unit 16 does not send out the subtraction command signal f. Further, when the water level a shifts from the intermediate range to the insufficient range, that is, even in the period, the addition command signal g may not be sent out in the same manner as described above. Such a response delay can be dealt with by setting the repetition period T short, but if the repetition period T is shortened, it is not preferable because the pump will be started and stopped by picking up waves, etc. (noise) on the water surface.

However, when the memory devices 13 and 14 are provided,
When the water level a moves from the intermediate area to the supercharging area,
Due to the memory contents of the memory device 13, the output signal of the detector 5 may not be stored as water level "present" even once in one cycle, but may be stored as water level "present" even once in the next cycle. In the event that
Even if the output signal of the discrimination circuit 11 is the water level "absent", the changeable logic circuit 15 determines that the water level has shifted to the supercharging range, and sends a subtraction command signal to the calculator 16. Further, when the water level a shifts from the intermediate area to the shortage area, the storage device 14
According to the memory contents, if the output signal of the detector 6 is not stored as water level "absent" even once in one period, but is stored as water level "absent" even once in the next period, Even if the output signal of the discriminating circuit 12 indicates that the water level is "present," the changing logic circuit 15 determines that the water level has moved into the insufficient region, and sends an addition command signal g to the arithmetic unit 16.

As described above, since the changing control is performed with priority over the outputs of the discrimination circuits 11 and 12 depending on the storage contents of the memories 13 and 14, the storage contents of the memories 13 and 14 are
Addition or subtraction is performed by the arithmetic unit 16 based on the output signal of 4. In other words, for the period,
The number of machines is reduced without waiting for a cycle, and even in the case of a cycle, the number of machines is added before the cycle is reached. This improves responsiveness to increases and decreases in the number of pumps in operation.

In this way, the memory devices 13 and 14 monitor the fluctuation of the water level with respect to the high water level H and the low water level L,
If there is no variation with respect to the high water level H and the low water level L, the variable platform logic circuit 15 is controlled so as not to function. In any case, the storage devices 13, 14
By providing this, the repetition period T is set to be relatively long so that it is not affected by waves on the water surface, and the responsiveness of the water supply system is not impaired.

In addition, although the case where the water level moves from the intermediate region to the supercharging region or the deficient region has been described above,
In the reverse case as well, the memory devices 13 and 14 are given priority over the outputs of the discrimination circuits 11 and 12 in the same manner as described above.
The platform changing control may be performed based on the stored contents.

In the apparatus configured as described above, a predetermined sampling time t is set every predetermined repetition period T.
is set, and the processing device 10 is provided to control the number of pumps based on the integrated value of the water level signal detection time within this sampling time, so that chattering due to water surface waves etc. does not occur, and Coupled with the fact that the pumps are started and stopped one by one at each repeating cycle without causing hysteresis, the appropriate number of pumps to be operated is automatically set in response to fluctuations in the aquarium water level. can do. Furthermore, a memory device 13,1 stores the water level signal up to the next one repetition period.
4, the responsiveness of the water supply system can be improved. Furthermore, by providing a distributor 17 that can store the individual operating time of each pump, the starting order of pumps in operation, the stopping order of pumps in standby, etc., a total of N pumps P ₁ , P ₂ . . . P _N
The maximum activation frequency of each can be set to 1/NT, and the allocation of operating time can be optimized. Moreover, the water level detectors 5 and 6, the clock 18, the timing setter 19 and the processing device 1
0 etc. can be configured regardless of the number of pumps, and together with the fact that the processing device 10 is mainly composed of electronic components, it greatly contributes to standardization and miniaturization of the device. Furthermore, since only a pair of high and low water level detectors are required, the installation work can be carried out simply and easily, and the amount of effort required for maintenance of each part can be reduced, and many other excellent effects can be achieved.

It goes without saying that the present invention is not limited to the above-mentioned embodiments only, and that various modifications can be made within the scope of the gist thereof.

〔Effect of the invention〕

According to the present invention, as described above, a predetermined sampling time is set for each predetermined repetition period, and within this sampling time, the output signals of the water level detection means corresponding to both high and low water levels are time-integrated, and
When automatically controlling the start and stop of pumps at a rate of one pump per repetition period according to the difference between these integral values and a preset threshold value, a storage means is provided to determine the magnitude of the integral value. Regardless of this, the pump is automatically started and stopped when the water level in the tank changes to above the high water level or below the low water level in two repeat cycles, so that proper operation can be achieved in response to fluctuations in the water tank water level. The number of pumps can be automatically set, the structure of the control device is simple regardless of the number of pumps, and the quick response of pump start and stop can be improved without shortening the repetition cycle. Malfunctions can also be prevented.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a layout diagram, FIG. 2 is a block diagram of a control circuit, and FIG. 3 is a timing chart for explaining the operation. 1... Primary water tank, 2... Secondary water tank, 5, 6...
Water level detector, H...High water level, L...Low water level, P ₁ ~
P _N ... Pump, 10 ... Processing device, 11, 12
...Discrimination circuit, 13, 14...Memory device, 15...
Variable logic circuit, 16... Arithmetic unit, 17... Distributor, 18... Clock, 19... Timing setter.

Claims (1)

[Claims] 1 A water supply system having an aquarium and a plurality of pumps that supply water to the aquarium, which is provided with water level detection means for detecting a predetermined high water level and a predetermined low water level of the aquarium, respectively, and which sets a predetermined repetition period, When the high water level detection means detects the predetermined high water level, the pumps in operation are stopped one by one at each repetition period, and when the low water level detection means detects the predetermined low water level, the pumps are stopped. In a method for controlling the number of operating pumps in which the pumps in the pump are started one by one at each repetition period, a sampling time is set within a range that does not exceed the repetition period for each predetermined repetition period, and within the sampling period. The water level of the aquarium is determined by comparing each integral value obtained by time-integrating the output signal of each water level detection means corresponding to the high water level and the low water level with a preset threshold, and A storage means is provided for storing the output signals of each of the water level detection means for two consecutive repetition periods within the sampling time,
If the water level of the water tank changes to the above-mentioned high water level or higher in the repetition period, one pump in operation is stopped by the output of the above-mentioned storage means, regardless of the above-mentioned comparative judgment, and if the water level changes to the above-mentioned low water level or below, A method for controlling the number of pumps in operation, characterized in that, regardless of the comparison and discrimination, one stopped pump is started by the output of the storage means.