JP4873328B2 - Water supply control method and apparatus, and water supply control system including the apparatus - Google Patents

Description

The present invention, water control method and apparatus for a stable water by a plurality of water pumps, related to water supply control system provided with the device.

When supplying and distributing water to a receiving tank or a distribution reservoir in a water supply facility, fine control is performed by operating two or more multiple pumps in parallel and controlling the rotation speed in order to respond to greatly changing demand. ing.
Conventionally, there is a system using a water supply control device that controls a plurality of water supply pumps as shown in FIG. In the figure, 1 is a flow meter, 2 is a pressure gauge, 3 is a motor control device, 8 is a variable speed pump, 9 is a fixed speed pump, 10 is a discharge valve, and 13 is a water supply control device. The water supply control device 13 includes an adjustment unit 4, a rotation speed command unit 5, a number determination unit 6, and an operation / stop command unit 7.
The water supply control device 13 operates as follows. That is, although the amount of water supply is changing every moment, in order to always ensure a stable water supply pressure, the adjustment unit 4 eliminates the deviation between the current value 2A of the pressure gauge 2 and the pressure command 2B (set value). The number of revolutions of the pump is calculated, and a command value for the number of revolutions is passed from the number of revolutions command unit 5 to the number of revolutions control device 3 for control. Only one of the variable speed pumps 8 operates in a time zone where the flow rate is small, such as at night. A command is given to increase the rotational speed as the amount of water supplied increases, but if the current value of the flow rate exceeds the maximum flow rate that can be supplied by the variable speed pump 8, the pump number discriminating unit 6 should switch the pump. to decide. The fixed speed pump 9 is started by an operation command, confirms that the pressure on the discharge side has increased, and opens the discharge valve 10 to start water supply. The variable speed pump 8 supplies water at a rotational speed that compensates for the flow rate that cannot be achieved by the fixed speed pump 9. By such control, stable water pressure and flow rate are supplied for a wide range of demand.
As another conventional example, when a fixed-speed pump and a variable-speed pump are operated in parallel, the characteristic curve of the pump is read in advance in the calculation device, and the range that does not result in a cutoff operation is calculated even if the head changes. An operation for controlling a variable speed pump has also been proposed (see, for example, Patent Document 1).
JP-A-60-19988

However, in the conventional parallel operation of a plurality of pumps, if the operating point of the variable speed pump is lower than the operating pressure of the fixed speed pump, a deadline state occurs. The shut-off operation overheats the pump, resulting in a problem that the life of the pump is shortened and an emergency stop of the system occurs due to the occurrence of non-feeding water, so that the feeding pressure and flow rate cannot be secured stably. In addition, the pump's performance deteriorates as it ages, and the conditions under which the shutoff operation is performed simultaneously change.Therefore, it is necessary to check the pump so that it does not lose its service life due to excessive operation such as the shutoff state, and to perform careful control. There is.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to ensure a stable amount of water and pressure when operating while switching a plurality of pumps, and to safely operate a water supply control system by eliminating the pump cutoff state.

In order to solve the above problem , according to one aspect of the present invention , an appropriate operation amount is calculated by the adjustment unit from the deviation between the set value and the current value, and motor control of a plurality of pumps is performed based on the calculation result. The control command to be sent to the device is calculated by the rotation speed command unit, the number of pumps is determined by the number determination unit based on the fluctuation of the water supply amount, and the number of rotations according to the fluctuation of the water supply amount while operating the plurality of pumps in parallel. In the water supply control method for controlling the pump and controlling the switching of the pump, when the pumps are operated in parallel, the variable speed pump controlled at the variable speed and the fixed speed pump controlled at the fixed speed are not cut off. Furthermore, a water supply control method is applied in which the variable speed range of the variable speed pump is detected and controlled by a speed calculation unit .
In addition, the speed calculation unit includes a rotation speed search command unit of the variable speed pump, a non-water supply determination unit that determines whether the variable speed pump and the fixed speed pump are in a non-water supply state, and rotation in the non-water supply state. There may be provided a rotation speed storage section for storing the number, and a rotation speed determination section for determining the variable speed range of the variable speed pump from the rotation speed of the variable speed pump and the fixed speed pump in the non-feeding state .
Further, when the rotation speed search command unit first sets the operation amount of the variable speed pump to 100%, and then gradually decreases the rotation speed and detects non-feeding of the variable speed pump, finally the fixed speed pump A series of commands may be issued to increase the rotational speed until non-water-feeding is detected .
Further, the rotation speed determination unit may instruct the adjustment unit to set a variable speed range in which the variable speed pump and the fixed speed pump are not cut off .
According to another aspect of the present invention, an adjustment unit that calculates an appropriate operation amount from a deviation between a set value and a current value, and a control that is sent to a motor control device of a plurality of pumps based on a result of the adjustment unit It has a rotation speed command section that calculates a command and a pump number determination section that determines switching to a pump based on fluctuations in the water supply amount, and operates the pumps in parallel while changing the rotation speed according to the fluctuations in the water supply amount. In the water supply control device that controls and performs the switching control of the pump, when the pumps are operated in parallel, the variable speed pump controlled at the variable speed and the fixed speed pump controlled at the fixed speed are not cut off. A water supply control device provided with a speed calculation unit that automatically detects and controls the variable speed range of the variable speed pump is applied.
In addition, the speed calculation unit is a variable speed pump rotation speed search command unit, the variable speed pump and the fixed speed pump determine whether the fixed speed pump is in a non-water supply state, and the rotation speed in the non-water supply state. And a rotation speed determination unit that determines a variable speed range of the variable speed pump from the rotation speed of the variable speed pump and the fixed speed pump in a non-water-feeding state .
The rotation speed search command unit first sets the operation amount of the variable speed pump to 100%, then gradually decreases the rotation speed and detects the non-feeding of the variable speed pump. A series of commands may be issued to increase the rotational speed until non-water-feeding is detected .
Further, the rotational speed determination unit may instruct the controller to set a variable speed range in which the variable speed pump and the fixed speed pump are not cut off .
According to another aspect of the present invention, the water supply control device according to any one of claims 5 to 8 , a plurality of water supply pumps, a motor control device that drives the water supply pump, and the discharge of the water supply pump. A system including a discharge valve and a non-feed detector provided on the side is applied.

According to the present invention, since the rotation speed of the variable speed pump is controlled within a range in which the fixed speed variable speed pump and the variable speed variable speed pump are not in the cutoff state, it is possible to prevent overheating damage due to the cutoff operation.
Further , since the variable speed pump, which is a variable speed, is controlled within the range where the fixed speed and variable speed pumps do not perform the cutoff operation, it is possible to prevent the pump from being overheated by the cutoff operation.
Further , according to the third and eighth aspects of the invention, since the operating point of the variable speed pump that is a variable speed pump can be automatically calculated, it is possible to reduce human load and easily determine the optimum control range. I can .
In addition, since the variable speed pump and the fixed speed pump can be controlled so that no water is generated, water can be stably supplied without causing an emergency stop.
It is also possible to construct an automatic control system that can supply water without causing an emergency stop of the system.

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

FIG. 1 is a block diagram of a water supply control system showing an embodiment of the present invention. In the figure, reference numeral 12 denotes a speed calculation unit. The water supply control device 13 of the present invention includes a number determination unit 6, a speed calculation unit 12, an adjustment unit 4, and a rotation speed command unit 5. In addition, the same code | symbol is attached | subjected about the same component as the past, the description is abbreviate | omitted, and only a different point is demonstrated.
The configuration in which the present invention is different from the prior art is that a speed calculation unit 12 is provided.
Details of the speed calculator 12 are shown in the block diagram of FIG. In the figure, reference numeral 120 denotes a rotation speed search command unit for issuing a rotation speed command to search for an operating point where no water is supplied, and 121 is a determination of the rotation speed where water is not supplied from an external non-water supply contact signal and the rotation speed. A non-water supply determination unit 122 is a rotation speed storage unit that stores a rotation speed N% at which the variable speed pump 8 in the variable speed operation is non-water-feeding, and 123 is a variable speed pump in which the fixed speed pump 9 at the fixed speed operation is non-water-feeding. A rotational speed storage unit 124 for storing the rotational speed M% of 8 is a rotational speed determination unit that determines the control range of the variable speed pump from the speed search result and transmits the control range to the controller unit 4.
Next, operation | movement of the water supply control apparatus of this invention is demonstrated using FIG.
FIG. 2 is a determination flow of the speed calculation unit. It is assumed that the variable speed pump 8 is controlled and operated by the adjusting unit 4 so that the discharge pressure becomes constant even when the water supply flow rate changes.
(1) When the demand increases and it becomes impossible to cover only one of the variable speed pumps 8, the number determination unit 6 issues a command to start the fixed speed pump 9 of the subsequent machine.
(2) When the fixed speed pump 9 is operated, the rotation speed search command unit 120 passes a command for rotating the variable speed pump 8 at 100% rotation speed to the rotation speed command unit 5.
(3) After the variable speed pump 8 reaches 100% rotation speed, a speed reduction command is output from the rotation speed search command unit 120 in order to gradually decrease the rotation speed from 100%. When the non-water supply contact signal of the variable speed pump 8 is input to the non-water supply determination unit 121 while the rotational speed is decreased from 100%, the rotational speed N% of the variable speed pump at this time is stored in the rotational speed storage unit 122. .
(4) Next, the rotation speed search command unit 120 outputs a speed increase command to the variable speed pump. When a non-water supply contact signal of the fixed speed pump is input to the non-water supply determination unit 121 while the rotation speed is increased from N%, the rotation speed storage unit 123 stores the rotation speed M% of the variable speed pump at this time.
(5) Next, the stored rotational speeds N% and M% are input to the rotational speed determination unit 124, and the rotational speed determination unit determines that the control range of the variable speed pump is N% or more and M% or less. This operation control range is output to the adjusting unit 4 as the minimum speed and the maximum speed of the variable speed pump, and the adjusting unit 4 controls the variable speed pump within this control range.
In this way, when the variable speed pump 8 and the fixed speed pump 9 are operated at the same time, it is possible to avoid a non-water-feeding state. Therefore, in any case, it is possible to stably feed water without cutting off water supply.
In addition, when both pumps are variable speed pumps, one can be operated at the maximum speed, and one can be controlled within the range where there is no cutoff operation, so that energy-saving operation can be performed without causing no water supply. .

  Thus, since the water supply control device according to the present invention can smoothly switch between pumps, it does not cause water shut-off and can prevent overheating damage to the pump from eliminating the shut-off operation of the pump. Can supply water.

It is a block diagram which shows the water supply control system of this invention. It is a determination flowchart which shows a part of operation | movement of the water supply control apparatus of this invention. It is a block diagram which shows the conventional water supply control system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flowmeter 1a Current flow value 2 Pressure gauge 2a Current pressure value 2b Pressure set value 3 Rotational speed control device 4 Adjustment part 5 Rotational speed command part 6 Number determination part 7 Run / stop command part 8 Variable speed pump 9 Fixed speed pump 10 Discharge valve 11 Non-water-feed detector 11a Non-water-feed contact signal 12 Speed calculator 120 Rotation speed search command section 121 No-water feed determination section 122 Rotational speed storage section N%
123 Number of rotations storage M%
124 Rotational Speed Determination Unit 13 Water Supply Control Device

Claims (9)

Based on the deviation between the set value and the current value, an appropriate operation amount is calculated by the adjustment unit, and based on the calculation result, a control command to be sent to the motor controller of multiple pumps is calculated by the rotation speed command unit, and the water supply amount fluctuates. In the water supply control method for determining the pump switching by the number determining unit, controlling the rotation speed according to the fluctuation of the water supply amount and performing the pump switching control while operating the plurality of pumps in parallel.
When operated in parallel the pump, constant-speed pump which is controlled by a fixed speed and variable speed pump which is controlled by the variable speed is so as not to discharge operation, the velocity calculating section variable speed range of the variable speed pump A water supply control method characterized by detecting and controlling.   The speed calculation unit includes a rotation speed search command unit of the variable speed pump, a non-water supply determination unit that determines whether the variable speed pump and the fixed speed pump are in a non-water supply state, and a rotation speed in the non-water supply state. 2. A rotation speed storage section for storing the rotation speed, and a rotation speed determination section for determining a variable speed range of the variable speed pump from a rotation speed of the variable speed pump and the fixed speed pump in a non-water-feeding state. The water supply control method described.   The rotation speed search command unit first sets the operation amount of the variable speed pump to 100%, then gradually decreases the rotation speed and detects the non-feeding of the variable speed pump. The water supply control method according to claim 2, wherein a series of commands for increasing the number of revolutions is issued until water supply is detected. The rotation speed determination unit, according to claim 2 or 3 water control method wherein a commanding variable speed range that do not deadline operation of fixed-speed pump and the variable speed pump regulation unit. An adjustment unit that calculates an appropriate operation amount from the deviation between the set value and the current value, a rotation speed command unit that calculates a control command to be sent to the motor control devices of a plurality of pumps based on the result of the adjustment unit, and a water supply amount A pump control unit that determines the number of pumps to be switched based on fluctuations in the number of pumps, and controls the number of revolutions according to fluctuations in the amount of water feed while controlling multiple pumps in parallel, and performs pump switching control. In the device
When the pumps are operated in parallel, the variable speed range of the variable speed pump is automatically detected and controlled so that the variable speed pump controlled at a variable speed and the fixed speed pump controlled at a fixed speed do not perform a cutoff operation. The water supply control apparatus characterized by providing the speed calculating part which performs. The speed calculation unit includes a variable speed pump rotation speed search command unit, a non-water supply determination unit that determines whether the variable speed pump and the fixed speed pump are in a non-water supply state, and a rotation speed in the non-water supply state. the rotation speed storing section for storing, according to claim 5, characterized in that consisting of the variable speed pump and the rotational speed determining portion determines the rotational speed of the variable speed range of variable speed pump-free water state of constant-speed pump Water supply control device. The rotation speed search command unit first sets the operation amount of the variable speed pump to 100%, then gradually decreases the rotation speed and detects the non-feeding of the variable speed pump. The water supply control device according to claim 6 , wherein a series of commands for increasing the rotational speed until water supply is detected is issued. 8. The water supply control device according to claim 6, wherein the rotational speed determination unit instructs the adjustment unit to set a variable speed range in which the variable speed pump and the fixed speed pump are not cut off. 9. The water supply control device according to any one of claims 5 to 8 , a plurality of water supply pumps, a motor control device for driving the water supply pump, a discharge valve and a non-water supply detector provided on the discharge side of the water supply pump A water supply control system characterized by comprising:

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