JPH0633774B2 - Variable speed water supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention provides a pump device in which a plurality of pumps are provided for one water supply system and the pumps are alternately operated to supply water. Regarding

"Prior art" In a variable-speed water supply system that has multiple pumps and supplies water through a single water supply system, the pumps are operated alternately, but due to the nature of control, the pumps do not start and stop frequently, and in extreme cases, stop once they start moving. It may not be done. In this type apparatus having a plurality of pumps or is a major concern switching between any timing operation alternately (hereinafter simply referred to alternately) pump order to achieve averaging of the pump operation time.

2. Description of the Related Art There is a variable speed water supply device having a small water amount stop function of temporarily raising the pressure of water to a pressure tank and then stopping the pump when the water consumption becomes zero or extremely low due to low consumption.

Conventionally, in this type of device, it is a general method to set a few hours of a day when the amount of water tends to be small (for example, in the middle of the night) as an alternating time zone, and alternate once when a small amount of water is stopped within this time. It was target.

In a pump device that alternately operates a plurality of pumps, for example, in a variable speed water supply device that independently operates two pumps, it is planned that one pump has a power supply capacity capable of full load operation. In such a case, one pump can be operated depending on the conditions on the power supply side, and although the power supply capacity has a slight margin, it may not be possible to simultaneously operate two pumps unconditionally. That is, there is a case where the power supply capacity for one pump is equal to or more than one pump in order to perform the parallel operation when the pumps are alternated, but there is a shortage. In the following description, the power supply capacity is expressed as one pump, including the case where the power supply capacity is insufficient in order to simultaneously operate two pumps when such pumps alternate.

When such a power supply capacity is only for one pump, it is equipped with a small water volume stop device, and presets the time zone when the water supply amount becomes zero, and alternates by the small water volume stop function at a timing that has little effect on the load side. Was being done. (1 per day
"Problems that the invention is trying to solve." Regardless of the power supply capacity, once every day when a small amount of water is stopped, alternating pumps will run for several days if the small amount of water does not stop within the set time. It will disappear. If the pump is stopped for a long time, rust will accumulate, so there was a risk that red water would come out when the pumps alternate. In addition, alternating once every 24 hours may be too long, and red water may be generated.

If the capacity of the power supply equipment is enough to drive one pump, it will not generate red water even if it is not a small amount of water stop. Occurs.

Therefore, in the case of not stopping a small amount of water, it is not possible to maintain the water supply pressure and alternating pumps are used, for example, cooling water for an internal combustion engine,
In the case of a water-cooled refrigerator, the cooling water of the heat exchange medium rises in temperature and has a great adverse effect on the equipment.For loads using a mixing tap such as a shower, after restarting, the water supply pressure stabilizes. Until the time you reach the point where only hot water will come out.

The present invention relates to a variable speed water supply device having a plurality of pumps and a plurality of variable speed devices connected to a single power supply device, and in the case where the power supply device has a power supply capacity for operating one pump at full load. It is an object of the present invention to provide a variable speed water supply device capable of eliminating the possibility of long-term pump operation and averaging the operation times of a plurality of pumps.

[Structure of Invention]

"Means for Solving Problems" The present invention relates to a case where a plurality of pumps and power supply capacities are alternately arranged. In a variable speed water supply device having one variable speed device, a total operating current detection means for a plurality of variable speed devices is provided, and one day is divided into N equal parts, and the device is When a small amount of water is stopped for the second time, the pumps are operated alternately, and when the amount of water is not stopped at least once within a time zone that divides the day into N equal parts, the pumps are forced to alternate after the lapse of N equal parts of time. In addition, to monitor the total operating current of the variable speed device in order to prevent the feed water pressure from decreasing when the pumps are forcibly switched alternately, operate multiple omps simultaneously at variable speeds to prevent the load from exceeding the power capacity. Sometimes, control to stop the starting pump It is a variable speed water supply device equipped with a device.

[Operation] Therefore, in the present invention, since red water is not emitted, one day is divided into N equal parts in order to increase the number of alternations of the pump to some extent, and when the small water amount stop occurs within that time period, it is alternated on the spot at that time. Let However, it is alternated at most once within the N equal time period and is not alternated even if it is stopped for a smaller amount. Further, when a time period divided into N equal parts without stopping a small amount of water has elapsed, at the time of elapse, a plurality of pumps are simultaneously shifted and the pumps that have been started up to now are disconnected to maintain the water supply pressure. If two or more units are operating at the same time, the starter without stopping the pump,
Replace only the operation command of the generic machine. Furthermore, since the equipment has a power supply capacity of only one unit, the total operating current is monitored at this point, and if the rated current for one unit is exceeded, the starter is stopped immediately and the water supply pressure reaches the limit of the equipment capacity. Hold.

"Embodiment" FIG. 1 is a flow sheet of an embodiment of the present invention. Pumps 1, 11 are induction motors (hereinafter referred to as electric motors) 2, 1
2 can be driven respectively, and the electric motors 2 and 12 can be respectively driven by the inverters 10 and 110. The water sucked by the pumps 1, 11 from the water receiving tank 3 through the suction pipes 5, 15 is pressurized, discharged to the discharge pipes 6, 16 and joined to the water pipe 18 via the check valves 7, 17. There is. Reference numeral 19 is a pressure tank provided in the water supply pipe 18, 21 is a pressure sensor for detecting the discharge pressure of the pumps 1, 11 provided in the water supply pipe 18, and the pressure sensor 21
Signal is sent to the control device 22. The control device 22 outputs the frequency command signal S _f of the inverters 10 and 110 to make the electric motors 2 and 12 variable speed via the inverters 10 and 110.

The control device 22 is provided with a microcomputer timer, and the minimum frequency at which the pump stops under a small amount of water under the signal of the pressure sensor 21 stored in the control device 22 under the condition that the terminal pressure is constantly controlled and the required pressure signal. An AND gate that receives the signal and the H active signal of the microcomputer timer is provided. When the AND gate in the control device 22 outputs the H active signal, the pumps 1 and 11 are alternately operated. .

In the present invention, when the adjustment including one day is set to N and there is no small amount of water stop in a small time zone divided into N equal times, the microcomputer timer is set at the end time of the small time zone divided into N equal times. Pumps L active signal (pulse) to notify the time, pump 1,
It is designed to perform 11 alternations. In this case, since the pumps 1 and 11 are driven together to perform the constant end pressure control, the pump 1 or 11 that has been driven so far is decelerated.

The control device 22 controls the switches 24 and 124 between the inverters 10 and 110 and the power supply device 23, respectively.

A current detector 25 is provided on the power supply line from the power supply device 23, and the input current signal detected by the current detector 25 is input to the control device 22.

Such a variable speed water supply device performs a constant end water supply pressure control based on the discharge pressure of the supply water detected by the pressure sensor 21 and the pump rotation speed, for example. Alternatively, a flow meter (not shown) is provided with the water supply pipe 18, and the terminal water supply pressure constant control is performed by the water supply amount and the discharge pressure value. Alternatively, a constant flow rate control is performed by introducing a signal from the flow meter to a control device. The control of constant feed water pressure or constant flow rate is performed by a known control method.

In the variable speed water supply device having such a configuration, the power supply device 23
It is possible to operate the pumps 1, 11 and 2 with the maximum output, and the case where one pump is enough from the water supply mode at all times will be described first.

In FIG. 1, the control device 22 outputs the frequency command signal S _f to the inverter 10. Inverter 10 is switch 2
The commercial frequency power received from the power supply device 23 via 4 is frequency-converted and output. The control device 22 turns on the switch 24 and turns off the switch 124, for example, electric power having the same frequency as the frequency command signal S _f is sent to the electric motor 2, the electric motor 2 is energized, and the pump 1 is operated. The pump 1 draws water from the water receiving tank through the suction pipe 5 to raise the pressure, and the discharge pipe 6
To the water supply pipe 18 through the check valve 7. The discharge pressure is measured by the pressure sensor 21, and the pressure signal is sent to the control device 22, and the control device 22 combines the frequency command signal S _f used in place of the rotational speed of the pump and the pressure signal, for example, at a constant end pressure. The frequency command signal S _f is changed so as to supply water.

The operation of such a pump is similar to that of the pump 11. When the water supply amount is small, one of the pumps is operated, and when the maximum capacity of the pump is exceeded, the two pumps 1, 11 are operated.

When the pumps 1 and 11 each have a small amount of water, inconveniences such as heat generation and partial cavitation occur. Therefore, when the operating electric motor 2 or 12 has the minimum frequency command signal S _f at which the rotation speed is predetermined, Control device 2
2 controls the frequency command signal to, for example, the maximum frequency command signal S _fMAX that becomes the maximum rotation speed of the pump to replenish water in the pressure tank 19, and when the pressure sensor 21 reaches a predetermined pressure, the signal of the pressure sensor 21 is received. The control device 22 switches the operating electric motor 2 or 12 to the switch 24 or 12
Cut 4 and turn off the power. Alternatively, the switch 24 or 124
The frequency command signal S _{f is set} to zero with the
Or, stop 22. Then, while the pumps 1 and 11 are stopped, water is supplied by the pressure tank 19 and the pressure sensor 2
When the signal indicated by 1 indicates a predetermined pressure or less, the control device 22 receiving the signal turns on the switch 24 or 124 or raises the frequency command signal S _f to start the electric motor 2 or 12. Operate the pump 1 or 11.

FIG. 2 is a time chart of the apparatus shown in FIG. A shows the operation of the microcomputer timer provided in the control device 22, and B,
C indicates that the pumps 1 and 11 are stopped.

In the figure, time T0 to T24 is 24 hours, and the time period is divided into N equal parts, for example, 4 equal parts. The boundaries between these four divisions are 2:00 am, 8:00 am, 2:00 pm, 8:00 pm, and 2:00 am the next day. At the beginning of this equally divided time, the microcomputer timer outputs an H active signal and continues.

FIG. 3 is a flow chart showing the operation of the apparatus of FIG.

If the pump 1 is now in an isolated operation state and the reference time T0 is 2:00 am, the operation of the device shown in FIG. 1 is as follows as shown in FIGS. .

When the system starts, in step 101, the microcomputer timer provided in the control device 22 outputs an H active signal. For example, when the system is started at the reference time, it is time T0 in FIG. At this time, the pump 1 is operating independently.

In step 102, it is judged whether or not the microcomputer timer is outputting the H active signal. If it is not outputting, the process returns to the original state, and if it is outputting, the process proceeds to step 103.

In step 103, it is judged whether or not a small amount of water is stopped. Since the small amount of water is not stopped from time T0 to T1, the process moves to step 103B, it is determined whether 6 hours have elapsed from the reference time T0, and the process returns to the step before step 103 because it has not elapsed. Since a small amount of water has stopped at time T1, the process proceeds to step 104.

At step 104, the microcomputer timer stops the H active signal and the routine proceeds to step 105.

In step 105, the pressure signal of the pressure sensor 21 also decreases as the water level in the pressure tank 19 decreases, and the pressure sensor 21
The control device 22 determines whether or not the pressure signal of 1 is in the water supply condition. When the water supply condition is not satisfied, the process returns to the step before step 105, and when the water supply condition is satisfied, the process proceeds to step 106.

In step 106, the pumps are in the water supply condition as shown at time T2, and the pumps alternate and the pump 11 is operated.

The alternation of pumps ends here. The operation after the alternating pumps move to the subroutine 200.

Subroutine 200 shows the operation after the pumps are alternately changed once in a small time zone in which one day starting from the reference time T0 is divided into N equal parts.

In step 201, it is determined whether or not the small water amount is stopped from time T2 to T3, and if it is not the small water amount stop, the process returns to the original state. At time T3, the small water amount is stopped and the process proceeds to step 202.

At step 202, it is judged if the microcomputer timer is set or not. Since the microcomputer timer is not set, the routine proceeds to step 203.

In step 203, when the water supply condition is not satisfied, the process returns to the step before step 203, and when the water supply condition is satisfied as shown at time T4, the process proceeds to step 204.

In step 204, the pump 11 is restarted.

Similarly, at time T5, the pump 11 stops a small amount of water, and at time T6.
To restart. At time T7, 1 from 2:00 am of the standard time
At 8:00 am, which is divided into four equal parts, the microcomputer timer is set.

In the operation of the subroutine 200 at time T8, it is determined in step 201 that a small amount of water has stopped, the process proceeds to step 202, and the microcomputer timer is operating, so step 104
Return to. The microcomputer timer is stopped and the routine proceeds to step 105. When the water supply conditions are satisfied at time T9, the routine proceeds to step 106 where the pumps are alternated and the pump 1 is started.

At time T10, when the water supply load increases above the pump capacity for one unit, the pump 11 is started and the pumps are operated in parallel. When the water supply load decreases at time T11 and the water supply load becomes one pump, the pumps are already alternated in the small time zone from 8:00 am to 2:00 pm, which divides the day into four equal parts. The pump 11 that is operating stops and the pump 1 continues to supply water. At time T12 at 2:00 pm, which divides the day into four equal parts, the pumps are not alternated because there is a small water stop between 8:00 am and 2:00 pm.

Assuming that the pump 1 continues to operate during a small time period of 6 hours from time T12 to time T13, the microcomputer timer operates at step T13 at step 103, and since it is not a small water flow stop, the process proceeds to step 103B and the day is set to N. Whether or not the time is equally divided is determined by whether or not the microcomputer timer outputs the L active signal in the form of a pulse, and the process proceeds to step 105 by the L active signal of the microcomputer timer, and step 1
Since the water supply condition has already been entered in step 05, the pump 1 is operated and the pump 11 is operated, and the pump 1 is gradually operated in parallel and the pump 1 is stopped to alternate the pumps.

Now, as shown by the chain double-dashed line in FIG. 2, when the pump 11 is already in operation at 8 pm, which is a quarter of a day, the situation is as follows. In a small time period before time T13, there is no stop of a small amount of water, and the pumps 1 and 11 start parallel operation at time T12 'due to an increase in the water supply load. At time T13, the process proceeds to step 105 by step 103B. Since the water supply condition is already satisfied, the process proceeds to step 106. Here, since the apparatus is under the condition that the pumps 1 and 11 are operated in parallel, only the operation commands of the pumps 1 and 11 which are started earlier are replaced. Then, at time T13 ', the water supply load is reduced, the pump 1 is stopped, and only the pump 11 is operated.

At time T14, the pump is alternately operated due to the already stopped small amount of water.

When designing the normal power supply capacity, consider the maximum power capacity of one pump, the distance from the power supply, and the voltage drop of the main power supply from the thickness of the wire, so that the worst voltage drop will not occur and the equipment will not be adversely affected. It is often multiplied by the safety factor. Therefore, the normal pump 1
The operation of the vehicle does not reach the limit of the power supply. It depends on the water supply system under these conditions. Therefore, when there is a power supply capacity of only one pump as described above, there is a power supply capacity more than the power supply capacity of one pump, but the power supply capacity is such that two pumps cannot be operated at the maximum capacity, and the pumps alternate. In this case, the power supply capacity may be exceeded depending on the water supply load condition for the parallel operation of the pumps. In this sense, in order to simplify the explanation, the case where the power supply capacity for the pump device is only one pump is described, but the case where the power supply capacity is limited for parallel operation when the pumps are alternated is also included in the present invention. is there.

Next, the operation when the capacity of the power supply device 23 is only for one pump 1 or 11 will be described below with reference to the time chart of FIG. The operation from time T0 to T9 is the same as that described with reference to FIG.

When the pump 1 stops using water at time T10, it already stops at time T8 with a small amount of water, so at time T11 pump 1
Will restart. Then, at the time 12 when the day is divided into four equal parts, the pumps are not alternated because the small water flow was already stopped during the previous 6 hours, and the pump 1 is continuously operated. And from time T12 to T13, there is no small water stop.

At 8:00 pm at time T13, when the small time zone that divides the day into N equal parts ends, the microcomputer timer outputs a pulse signal of L active, and the pumps 1 and 11 are alternately operated. Since the small amount of water is not stopped here, there is an inconvenience that the water supply pressure is lowered when the pump 1 is stopped. Therefore, the pump 1 is operated, the pump 11 is started, and the pumps 1 and 11 are operated in parallel. Even in this parallel operation, it can be considered that the water supply load is almost the same as the state in which the pump 1 was supplying water. During this parallel operation, the detection signal of the current detector 25 is sent to the control device 22.

Here, the control device 22 is provided with a current monitoring unit 26, a calculation comparing unit 27, and an operation commanding unit 28 as shown in FIG. 1, and the signal detected by the current detector 25 is the current monitoring unit 26. Then, the current monitoring unit 26 sends the current value to the calculation comparing unit 27, and the calculation comparing unit 27 compares it with a predetermined maximum load current of one pump, and the comparison value is sent to the operation command unit 28. send. If the load command current is less than the maximum load current, the operation command unit 28 continues the temporary operation, and if the load current is more than the maximum load current, the switch 24 is turned off so that the pumps are immediately alternated, the pump 1 is stopped, and the pump 11 is operated.

〔The invention's effect〕

The present invention relates to a variable speed device having a plurality of variable speed devices that are supplied from one power supply device that has a limited capacity to perform parallel operation at full load when a plurality of pumps and power supply capacities are alternated. In the water supply device, a total operating current detection means for a plurality of variable speed devices is provided to divide the day into N equal parts, and if the device stops a small amount of water for the first time within the N equal parts of time, a pump The operation of the pump is alternated and the pump operation is forcibly alternated after the lapse of N equal time when a small amount of water is not stopped even within the time period divided into N equal parts of the day, and the operation of the pump is forced. The total operating current of the variable speed device is monitored in order to prevent the water supply pressure from decreasing during alternate switching, and multiple pumps are operated simultaneously at variable speeds, and when the load exceeds the power supply capacity, the pump that started earlier is stopped. As a variable speed water supply device equipped with a control device Therefore, the pump does not operate continuously for more than twice as long as the small time zone that divides the day into N equal parts, so that the red water of the pump during rest is prevented from occurring. Long running of the pump can be avoided.
Further, when a small amount of water is stopped, the alternation does not occur after the N equal time has elapsed, and the chance of forced alternate switching of the pumps after the N equal time has decreased. In addition, there is no small water volume stop during a small time period that divides the day into N equal parts, and the water supply pressure is not reduced during alternate switching when the small time period ends, so parallel operation is performed when pumps alternate. Even in equipment with only limited power supply capacity, the total operating current is monitored, and the control device and input current of the control device that stops the pump that started when the load exceeds this by operating multiple units at the same time Since the detection means is provided, even in equipment having a sufficient power supply capacity for alternate pumps, the water supply can be smoothly performed without a pressure drop of the water supply.

[Brief description of drawings]

FIG. 1 is a flow chart of an embodiment of the present invention, FIG. 2 is a time chart of the present invention as an embodiment, FIG. 3 is a flowchart of the same, and FIG. 4 is a time chart of another embodiment. 1 ... Pump, 2 ... Induction motor, 3 ... Water tank, 5 ...
… Suction pipe, 6 …… Discharge pipe, 7 …… Check valve, 10,1
10 ... Inverter, 11 ... Pump, 12 ... Induction motor, 15 ... Suction pipe, 16 ... Discharge pipe, 17 ... Check valve, 18 ... Water pipe, 19 ... Pressure tank, 21 ...
... pressure sensor, 22 ... control device, 23 ... power supply device,
24 ... Switch, 25 ... Current detector, 26 ... Current monitoring unit, 27 ... Comparison unit, 28 ... Run command unit, 1
24 ... switch, 200 ... subroutine, 101-
106 ... Step, 201-204 ... Step.

(72) Inventor Hironao Hiraiwa 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Ebara Corporation (72) Inventor Takao Akahori 1-3-1 Ginza, Chuo-ku, Tokyo Stock Company Ebara Densan (72) Inventor Hiroyuki Chino 1-3-1, Ginza, Chuo-ku, Tokyo Stock company Ebara Densan (56) Reference JP 58-117375 (JP, A) JP 57- 81182 (JP, A)

Claims (1)

[Claims] 1. When a plurality of pumps and power supply capacities are alternately arranged, a plurality of variable speed devices are supplied from one power supply device having a limited capacity for parallel operation under full load. In the variable-speed water supply device, a total operating current detection means for a plurality of variable-speed devices is provided to divide the day into N equal parts, and when the device is stopped for a small amount of water for the first time within the N equally divided time zones. Alternates the pump operation, forcibly alternates the pump operation when the N equal time has elapsed, and forcibly operates the pump when a small amount of water is never stopped within a time period that divides the day into N equal parts. The total operating current of the variable speed device is monitored in order to prevent the feed water pressure from decreasing during the periodical alternate switching, and multiple pumps are operated simultaneously at variable speeds. Variable speed water supply device with control device to stop