JPH07224765A - Water feeder - Google Patents

Abstract

PURPOSE:To provide a water feeder which can continue proper water supply while maintaining the constant pressure action inside a water supply pipe, and also can improve the life of an inverter for driving a speed-change pump, and can prevent the temperature rise of a control panel where the inverter is mounted and the size up, and also reduce noise in operation and cut down the cost. CONSTITUTION:The operation of plural variable speed pumps 1 and 2 and the speed are controlled first, according to the condition of water inside a water supply pipe 6, and following this, the operation of at least one constant speed pump 3 (and 4) is controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water dispenser having three or more pumps.

[0002]

2. Description of the Related Art As a water supply machine, it has two pumps,
An alternating parallel model in which these pumps are alternately operated independently or in parallel is generally used. However, if the amount of water used on the receiving side increases, the water supply may not catch up with the two pumps.

In such a case, three or more pumps are provided and the operation of these pumps is controlled according to the amount of water used. There are the following two system configurations when four pumps are used.

(1) A system configuration in which one variable speed pump is driven by one inverter and three constant speed pumps are driven by a commercial power source. (2) A system configuration in which four variable speed pumps are driven by four inverters.

The inverter drive of the variable speed pump is for controlling the water pressure in the water supply pipe, and the output frequency (=) of the inverter is controlled so that the water pressure in the water supply pipe becomes a constant value.
The operating frequency of the variable speed pump) is controlled.

[0006]

The system configuration of one inverter and three constant speed pumps has the following problems. (1) When the inverter trips, the constant pressure action in the water supply pipe disappears and proper water supply cannot be performed.

(2) Since the variable speed pump has to be operated almost always, the life of the inverter is shortened. On the other hand, the system configuration of four inverters has the following problems.

(1) During variable speed operation of four units in parallel, the temperature of the control panel on which each inverter is mounted rises sharply. Therefore, it is necessary to take measures to reduce the temperature of the intake and exhaust ducts, the forced air cooling fan, etc., which increases the equipment cost.

(2) The operation noise of each inverter becomes considerably high during the variable speed operation of four units in parallel. 1 in noise characteristics
Inferior to the stand inverter system. (3) When the operating frequency of the variable speed pump reaches the upper limit frequency, if the operating frequency is switched to the commercial power frequency, the energy saving effect can be enhanced, and the operating time of the inverter is reduced and the life of the inverter is reduced. Although it can be extended, there is a problem that an electromagnetic switch is required for switching from inverter drive to commercial power drive. That is, in the situation where four electromagnetic inverters are provided in addition to where there are four inverters, the control becomes complicated and the control panel becomes considerably large.
Moreover, when switching from commercial power frequency to inverter drive, it is necessary to install a speed search function for the pump motor in each inverter so that the overcurrent protection function does not operate and unnecessary stoppage occurs, resulting in a significant cost increase. Become.

(4) In the first place, the provision of four inverters is a major factor in cost increase. The present invention was made in consideration of the above circumstances, and an object thereof is to maintain a constant pressure action in a water supply pipe and continue proper water supply, and to improve the life of an inverter for driving a variable speed pump. Another object of the present invention is to provide a water supply device capable of preventing the temperature rise and size increase of a control panel equipped with an inverter, reducing operating noise, and further reducing costs.

[0011]

The water supply device of the first invention is
A plurality of speed change pumps, at least one constant speed pump, a water supply pipe for sending water discharged from these pumps to the water receiving side, and first of all the speed change gears according to the state of water in the water supply pipes. Control means for controlling the operation and speed of the pump, and controlling the operation of the constant speed pump following the control.

A water supply machine of a second invention is a plurality of variable speed pumps, at least one constant speed pump, a water supply pipe for sending water discharged from these pumps to a water receiving side, and the inside of the water supply pipe. Detecting means for detecting the pressure and flow rate of the water, and first, according to the detection result of the detecting means, the operation and speed of each of the variable speed pumps are controlled first, and the operation of the constant speed pump is controlled following the control. And a control means.

A water supply machine according to a third aspect of the present invention includes a plurality of variable speed pumps, a plurality of inverters for outputting drive power to the variable speed pumps, at least one constant speed pump, and a communication to the constant speed pumps. Switch means for opening and closing the electric path, a water supply pipe for sending water discharged from each of the pumps to the water receiving side, detection means for detecting the pressure and flow rate of water in the water supply pipe, and the detection result of this detection means According to the above, first, the control means for controlling the operation and output frequency of each of the inverters, and following the control means for controlling the opening and closing of the switch means,
Equipped with.

[0014]

In the water dispenser of the first invention, the operation and speed of the plurality of variable speed pumps are first controlled in accordance with the state of the water in the water supply pipe, and the operation of at least one constant speed pump is followed in accordance with this. To control.

In the water supply device of the second invention, the operation and speed of the plurality of variable speed pumps are first controlled according to the pressure and flow rate of the water in the water supply pipe, and following this, at least one constant speed pump is controlled. Control the operation of.

In the water dispenser of the third aspect of the invention, the operation and output frequency of the plurality of inverters for driving the variable speed pump are first controlled according to the pressure and flow rate of the water in the water supply pipe, and following these, the constant speed is maintained. Opening and closing of at least one switch means for driving the pump is controlled.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 2, a plurality of, for example, two transmission pumps 1 and 2 are provided as a starting group,
Further, at least one, for example, two constant speed pumps 3, 4 are provided as subordinate groups. The variable speed pumps 1 and 2 are
Also referred to as a variable displacement pump, the discharge pressure changes when the built-in motor is driven by an inverter to perform a speed change operation. The constant speed pumps 3 and 4 are also referred to as fixed displacement pumps, and the built-in motor is driven by a commercial power source and operates at a constant speed to discharge water at a constant pressure.

The intake ports of the pumps 1, 2, 3 and 4 are respectively connected to a water receiving tank (not shown) via a water absorbing pipe 5.
A liquid, such as water, is contained in the water receiving tank. A water supply pipe 6 is connected to the discharge ports of the pumps 1, 2, 3, 4. This water supply pipe 6 is extended to a place where it is necessary to receive water.

A pressure tank 7 is connected to an intermediate portion of the water supply pipe 6. A pressure sensor 8 as a pressure detecting means and a flow rate switch 9 as a flow rate detecting means are mounted on the water supply pipe 6 between the pressure tank 7 and each pump. Pressure sensor 8
Detects the pressure of water flowing in the water supply pipe 6. The flow rate switch 9 responds to the flow rate f of water in the water supply pipe 6,
When the flow rate f becomes equal to or more than the predetermined amount f ₂ , it is turned on, and the predetermined amount f ₁
It turns off when (<f ₂ ) or less.

The control circuit is shown in FIG. Commercial AC power supply 10
Is connected to the inverter 11, and the drive motor 1M of the pump 1 is connected to the output terminal of the inverter 11. Power supply 1
The inverter 12 is connected to 0, and the drive motor 2M of the pump 2 is connected to the output terminal of the inverter 12.

The inverters 11 and 12 rectify the power supply voltage, convert it into a voltage of a frequency (and level) according to a command from the control unit 20, and output it. This output becomes drive power for the speed change motors 1M and 2M.

The drive motor 3M of the pump 3 is connected to the power source 10 via the contactor contact 21a and the thermal relay 13. The drive motor 4M of the pump 4 is connected to the power source 10 via the contactor contact 22a and the thermal relay 14. Contactor contacts 21a and 22a are fixed speed pumps 3M and 4
It is used as a switch means for opening and closing the energization path to M.

Each of the thermal relays 13 and 14 has an electric heater which generates heat when an electric current is applied, and detects overcurrents flowing in the motors 3M and 4M by the heat generated by the electric heater. On the other hand, the control unit 20 is connected to the power supply 10. The pressure sensor 8, the flow rate switch 9, the inverters 11 and 12, the thermal relay contacts 13 a and 14 a, the electromagnetic contactors 21 and 22, and the operation display unit 23 are connected to the control unit 20.

As a main function, the control section 20 first controls the operation of the inverters 11 and 12 and the output frequencies F ₁ and F ₂ in accordance with the pressure detected by the pressure sensor 8 and the state of the flow rate switch 9 and follows them. Contactor contacts 21a, 22
Control the opening and closing of a.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG. When the water is not used, all pumps are stopped and the water pressure in the water supply pipe 6 is higher than the set value P ₁ . This pressure is detected by the pressure sensor 8.

[1] Single unit operation (speed change pump 1) When water is used, the water pressure in the water supply pipe 6 decreases. When the pressure P detected by the pressure sensor 8 falls below the set value P ₁ (P <
P ₁ ), the inverter 11 is started, and first, the operation of the variable speed pump 1 belonging to the starting group is started.

By operating one of the variable speed pumps 1, water is pumped up from the water suction pipe 5 and sent to the receiving side by the water supply pipe 6. At this time, the flow rate f of the water in the water supply pipe 6 becomes the set value f ₂ or more, and the flow rate switch 9 is turned on.

During operation of the variable speed pump 1, the operating frequency (= output frequency of the inverter 11) F _{1 of} the variable speed pump ₁ is controlled so that the pressure P detected by the pressure sensor 8 becomes equal to a preset target value Ps. Is performed (feedback control). This frequency control ensures the necessary and sufficient water supply pressure.

[2] Stop of water supply When the water supply is finished, the flow rate f of the water in the water supply pipe 6 is the set value f.
_{When the} pressure is reduced to ₁ (<f ₂ ) or less, the flow rate switch 9 is turned off. When the flow rate switch 9 is turned off, the operation of the inverter 11 is stopped and the variable speed pump 1 is turned off. During this stop, the water stored in the pressure tank 7 flows through the water supply pipe 6 to the use side.

[3] Single unit operation (speed change pump 2) When the water in the pressure tank 6 is reduced due to the progress of use of water,
The water pressure in the water supply pipe 6 decreases. When this decrease progresses and the detected pressure P of the pressure sensor 8 falls below the set value P ₁ , the inverter 12 is started this time and the operation of the variable speed pump 2 is started.

By operating one of the variable speed pumps 2, water is pumped up from the water suction pipe 5 and sent to the receiving side by the water supply pipe 6. At this time, the flow rate f of the water in the water supply pipe 6 becomes the set value f ₂ or more, and the flow rate switch 9 is turned on.

During operation of the variable speed pump 2, the operating frequency of the variable speed pump 2 (= output frequency of the inverter 12) F ₂ is set so that the pressure P detected by the pressure sensor 8 becomes equal to the target value Ps.
Is controlled. (Feedback control). By this frequency control, the necessary and sufficient water supply pressure is always secured.

[4] Two-unit operation (speed change pump 1 + constant speed pump 3) For example, when one speed change pump 1 is in operation, the amount of water used increases and the operation frequency F ₁ is set to a predetermined maximum allowable operation frequency Fmax. When it reaches, the electromagnetic contactor 21 is energized and the contactor contact 21a is turned on. When the contactor contact 21a is turned on, the operation of the constant speed pump 3 belonging to the follow-up group is started. As a result, two units, the variable speed pump 1 and the constant speed pump 3, are operated.

During the operation of the two vehicles, the operating frequency F ₁ of the variable speed pump ₁ is controlled so that the pressure P detected by the pressure sensor 8 becomes equal to the target value Ps. [5] Single unit operation (speed change pump 2) When the speed change pump 1 and the constant speed pump 3 are in operation with two units, the amount of water used decreases and the operation frequency F ₁ drops to a predetermined allowable minimum operation frequency F min. , Electromagnetic contactor 21
Is deenergized and the contactor contact 21a is turned off, and the constant speed pump 3
Is stopped. At the same time, the operation of the variable speed pump 1 is stopped and the operation of the variable speed pump 2 is started instead. Thereafter, operation frequency F ₂ of the transmission pump 2 is controlled.

[6] Three-unit operation (speed change pump 1 + constant speed pumps 3, 4) When two speed change pumps 1 and 3 are operated, the amount of water used further increases and the operating frequency F ₁ is the maximum allowable operation. Frequency F
When max is reached, the electromagnetic contactor 22 is energized to turn on the contactor contact 22a. When the contactor contact 22a turns on,
The operation of the constant speed pump 4 which has been on standby is started. As a result, three units of the variable speed pump 1 and the constant speed pumps 3 and 4 are operated.

During operation of the three units, the operating frequency F ₁ of the variable speed pump ₁ is controlled so that the pressure P detected by the pressure sensor 8 becomes equal to the target value Ps. [7] Two-unit operation (speed change pump 2 + constant speed pump 4) When three speed change pumps 1 and constant speed pumps 3 and 4 are operated, the amount of water used is reduced and the operation frequency F ₁ is the lowest allowable operation frequency Fmi.
When the pressure is reduced to n, the operation of the constant speed pump 3, 4, which has been started earlier, is stopped.
At the same time, the operation of the variable speed pump 1 is stopped and the operation of the variable speed pump 2 is started instead. Thereafter, operation frequency F ₂ of the transmission pump 2 is controlled.

[8] Four-unit operation (speed change pumps 1, 2 + constant speed pumps 3, 4) When three speed change pumps 1 and constant speed pumps 3, 4 are operated, the amount of water used further increases and the operating frequency F ₁ When the maximum allowable operating frequency Fmax is reached, the follow-up group does not have a standby pump anymore.
The operation of is started. As a result, full operation is performed by the four transmission pumps 1 and 2 and the constant speed pumps 3 and 4.

During the operation of the four vehicles, the operating frequency F ₂ of the variable speed pump 2 which is started later is controlled so that the pressure P detected by the pressure sensor 8 becomes equal to the target value Ps. [9] Three-unit operation (speed change pump 2 + constant speed pumps 3, 4) When four speed change pumps 1, 2 and constant speed pumps 3, 4 are in operation, the amount of water used is reduced and the operation frequency F ₂ is the lowest allowable operation. When the frequency decreases to the frequency Fmin, the operation of the speed change pump 1, which has been started earlier, of the speed change pump 1 is stopped. Thereafter, operation frequency F ₂ of the transmission pump 2 is controlled.

As described above, first, the variable speed pumps 1 and 2 of the starting group are alternately operated according to the amount of water used, and when the amount of water used increases from that state, the constant speed pumps 3 and 4 of the follower group.
If the standby pumps in the follow-up groups are removed as the usage increases and the standby pumps disappear, the operation of the variable speed pumps in the stopped starting group is increased to full operation. By decreasing the number of operating pumps one by one in the order opposite to the increase, it is possible to reliably supply water over a wide range from a small amount to a large amount.

Since the variable speed pumps 1 and 2 are alternately operated,
The operating times of the inverters 11 and 12 are substantially equalized and shortened, and the lifespan of the inverters 11 and 12 is improved.
Even if one of the inverters 11 and 12 trips, the other inverter can operate the variable speed pump, so that the constant pressure action in the water supply pipe 6 is maintained and the water can be supplied almost properly. it can. Even if one inverter trips, the water supply rate can be maintained at 75%.

In parallel operation of two or more pumps,
Since the operation of one of the constant speed pumps 3 or 4 is included, a higher energy saving effect can be obtained as compared with the conventional case where all four pumps are driven by the inverter.

Since the number of inverters driven is two even during full operation, noise is lower than in the conventional case where all four pumps are driven by inverters. The noise level is comparable to a system with one inverter.

Since the number of inverter drives is two even during full operation, the temperature rise of the control panel for mounting the inverter is not so large, and thus no special temperature reduction measures such as intake and exhaust ducts and forced air cooling fans are required. It is possible to prevent the equipment cost from rising. It is possible to avoid increasing the size of the control panel.

The fact that only two inverters are required in the first place is cheaper than the conventional case where all four pumps are driven by inverters. In the above embodiment, the case where the number of pumps is four has been described as an example, but the number of pumps is not limited, and the same can be performed with five pumps, six pumps or more. Further, although two speed change pumps and one constant speed pump are used, a plurality of speed change pumps and at least one constant speed pump may be used.

[0045]

As described above, according to the present invention, the water supply machine of the first invention first controls the operation and speed of a plurality of variable speed pumps in accordance with the state of water in the water supply pipe, and at least Since the configuration is such that the operation of one constant-speed pump is followed and controlled, it is possible to maintain a constant pressure action in the water supply pipe and continue proper water supply, and also to improve the life of the inverter for driving the variable speed pump. Further, it is possible to provide a water supply machine capable of preventing the temperature rise and size increase of the control panel equipped with the inverter, reducing the operating noise, and further reducing the cost.

In the water dispenser of the second invention, the operation and speed of the plurality of variable speed pumps are first controlled according to the pressure and flow rate of water in the water supply pipe, and the operation of at least one constant speed pump is followed. Since it is configured to control by water, it is possible to maintain a constant pressure action in the water supply pipe and continue proper water supply, and also to improve the life of the inverter for driving the variable speed pump, and increase the temperature of the control panel equipped with the inverter. In addition, it is possible to provide a water dispenser that can prevent an increase in size, reduce operating noise, and further reduce costs.

In the water dispenser of the third invention, the operations and output frequencies of the plurality of inverters for driving the variable speed pump are first controlled in accordance with the pressure and flow rate of the water in the water supply pipe, and following these, the constant speed is maintained. Since the opening and closing of at least one switch means for driving the pump is controlled, it is possible to maintain a constant pressure action in the water supply pipe and continue proper water supply, and also to improve the life of the inverter and reduce the inverter life. It is possible to provide a water dispenser capable of preventing the temperature and size of a control panel mounted therein from increasing, reducing operating noise, and further reducing costs.

[Brief description of drawings]

FIG. 1 is a block diagram of a control circuit according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a piping system of the same embodiment.

FIG. 3 is a flowchart for explaining the operation of the embodiment.

[Explanation of symbols]

1, 2 ... Variable speed pump, 3, 4 ... Constant speed pump, 6 ... Water supply pipe, 7 ... Pressure tank, 8 ... Pressure switch, 9 ... Flow rate switch, 11, 12 ... Inverter, 20 ... Control section 21,
22 ... Electromagnetic contactor.

Claims (3)

[Claims] 1. A plurality of variable speed pumps, at least one constant speed pump, a water supply pipe for sending water discharged from these pumps to a water receiving side, and a water supply pipe depending on the state of water in the water supply pipe. First, a water supply device comprising: a control means for controlling the operation and speed of each of the variable speed pumps, and following the control to control the operation of the constant speed pump. 2. A plurality of variable speed pumps, at least one constant speed pump, a water supply pipe for sending water discharged from these pumps to a water receiving side, and a pressure and a flow rate of water in the water supply pipe. And a control means for controlling the operation and speed of each of the variable speed pumps according to the detection result of the detection means, and controlling the operation of the constant speed pump following the control. A water dispenser characterized by that. 3. A plurality of variable speed pumps, a plurality of inverters for outputting drive power to these variable speed pumps, at least one constant speed pump, and switch means for opening and closing an energization path to the constant speed pumps. , A water supply pipe for sending the water discharged from each of the pumps to the water receiving side, a detection means for detecting the pressure and flow rate of the water in the water supply pipe, and first of all, according to the detection result of the detection means. A water supply unit, comprising: a control unit that controls the operation and output frequency of the inverter, and controls the opening and closing of the switch unit by following the control.