JP2969324B2 - Automatic operation control method of parallel operation pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the water level in a storage pit by discharging the water in a storage pit, which is likely to fluctuate under the influence of rainwater, to an external discharge destination such as a river. The operation control method of the pump used in such a case, specifically, a plurality of pumps including a movable blade pump in which the discharge water amount from the inside of the water storage pit to the external discharge destination can be changed by changing the blade angle in parallel. The present invention relates to an automatic operation control method for a pump during operation.

[0002]

2. Description of the Related Art As a method of controlling the operation of a plurality of pumps in parallel when the water level in a water storage pit increases and a plurality of pumps need to be operated in parallel, conventionally, a preceding operation pump has a maximum discharge water amount. As described above, a method has been adopted in which the blade angle of the following operation pump is controlled to an angle commensurate with the discharge amount that is insufficient at the maximum discharge amount of the preceding operation pump after the blade angle is maximized.

[0003]

However, in the above-described conventional automatic operation control method of the parallel operation pump, only the blade angle of the succeeding operation pump is kept at the water level while the blade angle of the preceding operation pump is kept at the maximum. Because there is a large difference between the blade angles of both pumps during parallel operation, if the water level in the storage pit fluctuates near the required start level of parallel operation, the subsequent operation The frequency of stopping and starting the pumps is very large, and the performance of a plurality of pumps operated in parallel tends to vary. Further, since the loads of the preceding operation pump and the succeeding operation pump are also unequal, there is a disadvantage that the durability of these pumps and the engine which is a driving source thereof is greatly varied.

The present invention has been made in view of the above circumstances, and has an automatic operation control method for a parallel operation pump capable of minimizing variations in the performance and durability of a plurality of pumps during parallel operation. It is intended to provide.

[0005]

In order to achieve the above object, an automatic operation control method for a parallel operation pump according to the present invention is characterized in that a discharge water amount from a water storage pit to an external discharge destination is changed by changing a blade angle. It is an automatic operation control method when a plurality of pumps including a movable blade pump that is enabled are operated in parallel, and it is determined whether or not the difference between the blade angles of the plurality of pumps is within an allowable angle difference range, If the blade angle difference between the plurality of pumps is not within the allowable angle difference range, the blade angle of the movable blade pump is increased or decreased to reduce the blade angle difference between the plurality of pumps. It is characterized in that it is automatically changed so as to be kept within the range.

[0006]

According to the present invention, when a plurality of pumps are operated in parallel, it is determined whether or not the difference between the blade angles of the plurality of pumps is within the allowable angle difference range. When it is determined that it exceeds, by increasing or decreasing the blade angle of the movable blade pump, by automatically changing the blade angle difference of the plurality of pumps to be kept within the allowable angle difference range, Even if the water level fluctuation in the water storage pit is near the required start level of parallel operation, it is possible to minimize the frequency of stopping and starting the subsequent operation pump and its drive source, and to reduce the number of pumps for multiple pumps. The load can be suppressed almost equally.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional perspective view showing a main part of an example of a mechanical movable vane pump used for carrying out an automatic operation control method for a parallel operation pump according to the present invention.
Reference numeral 1 denotes a wing provided in a discharge passage (not shown) of the pump so as to be able to change its angle by rotating around a support shaft 2.
Moves in the main shaft 4 in the axial direction a with the operation of the motor 3.
The driving rod 5 is driven and rotated around the support shaft 2 via the operating rod 5 that moves to -b, the crosshead 6 fixed to the tip of the operating rod 5, and the arm 7 that is linked to the movement of the crosshead 6, to change the angle. The discharge water amount is changed by changing the angle of the blade 1.

FIG. 2 is a schematic view showing the installation and use of the two vertical pumps 8A and 8B having the movable blade 1 as shown in FIG. 1, and these two vertical pumps 8A and 8B.
B is set in a water storage pit 9 and discharges water flowing into the water storage pit 9 to an external discharge destination 10 such as a river, thereby setting the internal water level to an upper limit indicated by H1 and a lower limit indicated by H2. Automatically control the range. Reference numeral 11 denotes a controller comprising a microcomputer, which is one of the two vertical pumps 8A and 8B (hereinafter, referred to as a preceding operation) of the two vertical pumps 8A and 8B based on a water level detection signal from a water level sensor 12 for detecting the water level of the water storage pit 9. Called pump,
A single operation mode in which only the other pump 8B is referred to as a subsequent operation pump),
A and 8B are automatically switched to the parallel operation mode in which the pumps 8A and 8B are simultaneously operated, and in the parallel operation mode, the blade angle changing motors 3 and 3 of both pumps 8A and 8B are controlled based on the judgment result of the judgment means described later. It is adapted to output a signal. The controller 11 is provided with a plurality of timer circuits (not shown) and a mode selection switch 14 for turning on / off the automatic operation mode.

Next, the mode selection switch 14 is turned on.
Then, when the controller 11 is in the automatic operation mode,
In addition, the water level in the water storage pit 9 is two vertical pumps 8, 8
The control operation when the controller 11 is switched to the parallel operation mode after increasing to the water level that requires the parallel operation will be described with reference to the flowchart shown in FIG.

In the parallel operation mode, first, the angle θ1 of the blade 1 in the preceding operation pump 8A and the following operation pump 8
It is determined whether or not the absolute value of the difference between the angles θ2 of the wing 1 in B is within the allowable angle difference range θ3 (dead zone) (step S10). The determination result is Yes. In other words, when the absolute value of the difference between the blade angle θ1 of the preceding operation pump 8A and the blade angle θ2 of the subsequent operation pump 8B is within the allowable angle difference range θ3 (dead zone), the blade angles of both pumps 8A and 8B are set. Performs the parallel operation with the stop fixed (step S11).

If the result of the determination in step S10 is No.
In the case of, the subtraction value (θ1) of the blade angle θ2 of the succeeding operation pump 8B from the blade angle θ1 of the preceding operation pump 8A
-Θ2), and the subtracted value is calculated as the allowable angle difference range θ3.
Is determined (step S12), and the determination result is Yes. In the case of, the motor 3 on the subsequent operation pump 8B side is operated in response to the control signal output from the controller 11, and the operation rod 5 accompanying the operation of the motor 3 is operated.
The blade 1 is driven and rotated about the support shaft 2 via the crosshead 6 and the arm 7 by the movement of the blade 1 in the one direction b with respect to the main shaft 4, and the blade angle θ2 of the subsequent operation pump 8B increases the discharge water amount. Is performed (step S13).

The operation of the blade angle θ2 in the state where the blade angle θ2 is changed from the standing state is continued until the time t1 (about 5 seconds) preset in the timer circuit elapses, and the operation is started from the blade angle θ1 of both pumps 8A and 8B. After waiting for the subtraction value of θ2 to return within the allowable angle difference range θ (step S14), the change (increase) of the blade angle θ2 of the subsequent operation pump 8B by the operation of the motor 3 is stopped (step S15). This state is determined by a time t2 (about 15) preset in the timer circuit.
Second) until the blade angles θ1 and θ2 of both pumps 8A and 8B stabilize (step S1).
6) Return to step S10.

On the other hand, if the result of the determination in the determination step S12 is No. In the case of, the subtraction value (θ2−θ1) of the blade angle θ1 in the preceding operation pump 8A is obtained from the blade angle θ2 in the subsequent operation pump 8B, and it is determined whether or not the subtraction value exceeds the allowable angle difference range θ3. Judgment (Step S
17), and the determination result is No. In the case of, the process returns to the step 10 and the steps 10 to 12 described above are repeated again. In the case of, the motor 3 of the preceding operation pump 8A is operated in response to the control signal output from the controller 11, and the operation rod 5 is moved in the one axial direction b with respect to the main shaft 4 in accordance with the operation of the motor 3. The blade 1 is driven and rotated around the support shaft 2 via the crosshead 6 and the arm 7 to perform an alignment control operation in which the blade angle θ1 of the preceding operation pump 8A is changed in the falling direction in the direction of decreasing the discharge water amount. (Step S18).

Then, the operation in the state in which the blade angle θ1 is changed in the lodging state is continued until the time t3 (about 5 seconds) preset in the timer circuit elapses.
After waiting for the subtraction value of θ1 from the blade angles θ2 of B and 8A to return within the allowable angle difference range θ (step S19), the blade angle θ1 of the preceding operation pump 8A is changed (decreased) by the operation of the motor 3. ) Is stopped (step S20),
This state is determined by a time t4 preset in the timer circuit.
(About 15 seconds) until both pumps 8B, 8
After waiting for the blade angles θ2 and θ1 of A to stabilize (step S21), the process returns to step S10.

As described above, in the automatic operation mode,
When the two pumps 8A and 8B enter the parallel operation mode,
First, it is determined whether or not the absolute value of the difference between the blade angles θ1 and θ2 of both pumps 8A and 8B is within the allowable angle difference range θ3. If the determination result indicates that the absolute value is not within the allowable angle difference range θ3, A determination is made as to which of the blade angles θ1 and θ2 of both pumps 8A and 8B causes the allowable angle difference range θ3 to be exceeded, and both pumps 8A and 8B are determined based on the determination result.
By automatically controlling the absolute value of the difference between the two wing angles θ1 and θ2 so that the absolute value of the difference between the two wing angles θ1 and θ2 is kept within the allowable angle difference range,
Even when the water level in the water storage pit 9 fluctuates near the required start level of the parallel operation, it is possible to reduce the frequency of stopping and starting the driving sources such as the subsequent operation pump 8B and the diesel engine as much as possible. The loads on both pumps 8A and 8B can be substantially equalized.

In particular, according to the above embodiment, it is possible to appropriately change the blade angle using a normal AC motor without using a special motor such as a servo motor.
Although there is an advantage that the cost of equipment used for implementing the automatic operation control method for the parallel operation pump can be reduced, the drive device for changing the blade angle is not limited to a motor, and may be, for example, a hydraulic device.

In the above embodiment, the case where both the vertical pumps 8A and 8B are pumps having the movable blade 1 has been described. However, one of the pumps is a fixed blade pump in which either one is fixed at a fixed blade angle. The other may be a movable blade pump. Further, the present invention may be applied to automatic operation control when three or more pumps are operated in parallel.

[0018]

As described above, according to the present invention, when a plurality of pumps are operated in parallel, it is determined whether or not the difference between the blade angles of the plurality of pumps is within an allowable angle difference range. When it is determined that the angle difference is out of the angle difference range, the blade angle of the movable blade pump is increased or decreased to automatically change the blade angle difference of the plurality of pumps so as to be kept within the allowable angle difference range described above. Therefore, even if the water level in the storage pit fluctuates near the required start level of parallel operation, the frequency of stopping and starting the subsequent operation pump and its driving source is reduced as much as possible, and Pump performance can be maintained substantially evenly. In addition, since the loads of the preceding operation pump and the succeeding operation pump can be substantially equalized, an adverse effect on the durability of these pumps and an engine as a driving source thereof can be suppressed as much as possible.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view showing a main part of an example of a mechanical movable vane pump used for carrying out an automatic operation control method for a parallel operation pump according to the present invention.

FIG. 2 is a schematic view showing an installation mode of use of the mechanical movable vane pump.

FIG. 3 is a flowchart showing a control operation when an automatic operation mode is selected and when two pumps are in a parallel operation mode.

[Description of Signs] 1 blade 8A, 8B movable blade pump 9 water storage pit 10 external discharge destination 11 controller θ1, θ2 blade angle θ3 allowable angle difference range

Claims (1)

(57) [Claims] 1. An automatic operation control method when a plurality of pumps including a movable wing pump, in which a discharge water amount from a water storage pit to an external discharge destination can be changed by changing a blade angle, is operated in parallel. It is determined whether or not the difference between the blade angles of the plurality of pumps is within the allowable angle difference range. If the determination result indicates that the blade angle difference between the plurality of pumps is not within the allowable angle difference range, the movable blade is determined. An automatic operation control method for a parallel operation pump, wherein a blade angle of a pump is increased or decreased to automatically change a blade angle difference between a plurality of pumps so as to be kept within the allowable angle difference range.