JPS58161011A - Method for controlling number of operated pumps - Google Patents

Abstract

PURPOSE:To control the number of operated pumps stably, by calculating and comparing operation periods in consideration of operation frequencies of all pumps and determining a pump operation order so that operation periods and operation frequencies of all pumps are uniform. CONSTITUTION:Operation period integral values H1, H2...H5 of water supply pumps P1, P2...P5 are obtained, and a pump having a minimum operation period integral value is selected and is defined as the pump which is first operated. Next, if an opreration number signal 9 indicates that an already operated pump exists and the operation signal of an additional pump is inputted to an operation order setting circuit 10, operation period integral values of stopped pumps are read. These read operation period integral values are compared to select a pump having a minimum operation period integral value. A timer value of the operation period of the selected pump is read, and the timer value is added for every pump, and a pump having a maximum value is selected. A stop signal is sent to a controller 12 for the selected pump to reset it at a set time. This operation is repeated to continue the operation until all water supply pumps are stopped.

Description

Detailed Description of the Invention (&) Description of the Technical Field The present invention relates to an improvement in a method for controlling the number of operating pumps for the purpose of water level control or flow rate control in a water supply plant.

(b') Description of Prior Art In controlling the number of pumps installed in a water supply plant, equalizing the operating time and number of starts of each pump means using all pumps under the same conditions, And-
Important for prolonging life.

In the conventional method of controlling the number of pumps in operation, after determining the number of crawlers, the operation order selection method is changed manually or automatically according to a predetermined pattern, thereby controlling the operation time and number of starts. Equalization was being carried out.

FIG. 1 shows a conventional flow sheet and a circuit for determining the number of operating pumps, taking water level control in a water distribution process in such a water supply plant as an example. The water distribution process here is a simplified representation of actual water distribution equipment.

That is, after purified water 1 is stored in a pump well 2, it is sent to a water distribution reservoir 4 by a water supply pump 3, and is distributed to the bales stored in the water distribution reservoir 4. The water level of the water distribution reservoir 4 is detected by a water level meter 6 and then inputted as a water level signal 7 to the operating number determining circuit 8. The operation number signal 9 obtained by the operation number determination circuit 8 determines the pump operation number and order in the operation order setting circuit 10, and inputs it to the pump control device 12 as an operation signal 11. The number of water pump control devices 12 and 12 is controlled by a water pump control command 13.

Figure #2 is a known level diagram showing a method for determining the number of five water pumps in the number determining circuit 8. The vertical axis represents the reservoir water level 7, and the number determining circuit 8 sets the level 24f from level 15. Level 15 to level 19 are the starting water levels of the water pump, and level 1
5 is the starting water level for the first gold, level 16 is the starting water level for the second machine and below, and similarly, level 19 is the starting water level for the fifth gold. Levels 20 to 24 are the stop water levels of the water pumps, level 20 is the stop water level of the first pump, level 21 is the stop water level of the second pump, and similarly level 24 is the stop water level of the fifth pump.

FIG. 3 is a flowchart showing a conventional manual operation order setting method in the operation order setting circuit 10, and the details of the actual flowchart are shown in a simplified manner. Step 25 is a step of selecting a leading aircraft as an initial condition, and this is determined in advance so that even if 4 is calculated from the outside, 4≠ does not change. The following will explain the case where the first car is given the starting position with 1 step and 2 seconds.

Step! 6th place, the operating order setting when the first machine is shown is Kodai @ threshold machine 2, 3rd gold = machine 3, 4th gold - machine 4, 5 @! = No. 5, and the start signal 11 is set to the pump control system fl! according to the number of operating units signal 9! and operates the water pump 3. Water reservoir water level 7 is level! As the water level reaches the water level where all units stop at 0, the water pump operation signal 1 is activated.
Reset 1 and return to the start.

Konin, step! The starting choice has been changed in S! If the starting machine cannot be given, proceed to step 27. Step! In γ! The number of machines is operated in the same manner as in step 26, with the machine No. 3 as the starting machine, the second machine being the third machine, the third machine being the fourth machine, the fourth machine S-δ, and the S machine @-1. Thereafter, the number-of-units operation in step 28, step 9, and step 3o is performed in the same manner.

However, in the conventional control method described above, for example, when manually selecting the pump operating order, the operator reads the integrated value of the operating time and the integrated value of the number of starts of all pumps, and If a high degree of judgment is required to make the pattern uniform, or if you want to automatically change the operation order selection, set the pump operation order in sequence every time the number of pumps in operation changes. Although the rounding that is being changed will equalize the operating time and number of starts,
This setting is due to repeated settings. Changes in the number of pumps in operation are rounded off due to water level fluctuations or flow rate fluctuations, and it is difficult to make them uniform during long-term control. Requires operation of a friend.

(c) Purpose of the Invention The present invention evaluates the effect on equipment caused by starting each pump by converting it into operating time, and directly determines the pump operating order from the cumulative value of operating time. It is possible to equalize the pump operating time and number of starts even with the control of
It is an object of the present invention to provide a method for controlling the number of operating pumps that does not have the above drawbacks.

(a) Explain the structure and operation of the invention. FIG. 4 shows the operation order setting circuit 1 of FIG.
1 is a flowchart showing a method of setting an operating order according to the present invention. This program starts by specifying automatic operation of the water pump and ends by specifying S# for automatic operation, and can be easily realized using a sequence controller or the like.

First, in step 31, the cumulative operating time of each water pump is input.

at- is the cumulative unit operating time value H! Blasphemy! Accumulated value of running time of unit No. 1 = 4 H5 ■ Accumulated rolling time of unit B Next 1 step 3! Then, a comparison is made to determine whether the integrated operating time values of the water pumps read in step 31 are all the same, and if they are all the same, the process moves to step 33. In step 33, the first operating pump is determined. here,
The nine predetermined pumps or the externally selected pump is used as the first pump.

If it is determined in step 32 that the cumulative operating time values of the water pumps are not all the same, in step 33 the pump with the minimum cumulative operating time value is selected, and the nine selected pumps are set as the first operating pumps. Next, in step 35 and step 42, 1. Water pump operation signal from operation number signal 9,
And it is determined whether a stop signal is input 17 or not. Step 3
If the pump start signal is input in step S, proceed to step 36. In step 36, it is determined whether all the water pumps are currently stopped. If all the water pumps are stopped, the process proceeds to step 37, and the control device 12 of the first operating pump selected in step 33 or step 34 is sent. ,
A starting signal 11 is output.

In step 31s, if there is a pump already in operation,
In addition, if you are inputting the operation signal of an additional pump,
The process proceeds to step 38. In step 38, the cumulative operating time values of the stopped pumps are read. In step 39, the cumulative operating time values read in step 38 are compared and the pump with the minimum value is selected. In step 40, step 39
Select and output the start signal 11 to the control unit of the 9 pumps. Step 41'c/ sets the operating time timer of the started water pump.

In step 4!6, if the pump stop signal is input, proceed to the next step. In step 43, the operation time timer value of the pump in operation is read, and in step 4
In step 4, read the cumulative operating time of the pump in operation.
Step 4! In step I, the values read in steps 43 and 44 are added for each pump, and the pump with the maximum value is selected. In step 46, a stop signal 11 is output to the control device 1 of the nine pumps selected in step 45. In step 4, the timer value is set in step 41 and the timer value of 9 hours is saved, and the timer value is reset to 9 hours. In step 48,
The memory is updated with the cumulative operating time of the pumps that have completed stopping.

The cumulative operating time value Hn of unit n is: Ha - Hn' + Tn + N@K (time) where L, Ha': cumulative operating time value before memory update [
Time] Tn: Operation time timer value of unit n [time] N
: Number of starts [times] K : Constant
Calculate by [time 7 times].

Here, the constant is used to convert the influence of insulation deterioration of the windings on the pump driving motor when the pump is started once into operating time.

゛This depends on the starting method of the electric motor and the G borne by the electric motor.
D”, etc., so it is determined by experimenting in advance, but since there is a high possibility that various conditions will change over a long period of time, we will use a tortoise that can be adjusted.

In step 49, it is determined whether all the water pumps are stopped, and unless all the water pumps are stopped, the process returns to step 35 and repeats the process up to step 48 under the new cumulative operating time value. In the flowchart of Fig. 4, the number of starts N is N- because the memory is updated after one operation.
1, but the memory may be updated after several consecutive rotations. If all water pumps have stopped in step 49, it is determined whether the siprogram has ended in step SO.
In the case of execution, return to step 31 and enter the new operating time.
Repeat the same process under the calculated value.

(・) Comprehensive performance As explained above, according to the present invention, the operating time and number of starts of all pumps can be calculated by calculating and comparing the operating times, taking into account the number of starts of all pumps. Determining the order of pump operation in a uniform manner has the effect of preventing damage to bearings, deterioration of insulation of windings, etc. due to the long operation time of certain pumps or concentration of starting frequency.

[Brief explanation of the drawing]

Figure 1 is a flow sheet of a water distribution system and an explanatory diagram of a conventional number control device, Figure 2 is a known level diagram showing a method for determining the number of water pumps for five water pumps in the number determination circuit, and Figure 3 is a conventional system. Flowchart showing the operation order setting method, No. 4
The figure is a flowchart of an operation order setting method showing an embodiment of the present invention. 1...Water purification, 2...Pump well, 3
...Water pump, 4...Water reservoir,
5...Water distribution, 6...Water level gauge, 7.
...Water level signal, 8...Number of operating units determining circuit, 9...Number of operating units signal, IO...Operating order setting circuit, 11... Operation (start/stop) signal, 12...
... Pump control device, 13 ... Pump control command, 14 ... Water supply. (7317) Representative Patent Attorney Noriyuki Chika (and 1 others)
Name) Figure 1 Figure 4 (To X.3 Figure 4 (2)

Claims (1)

[Claims] In a method for controlling the number of pumps in operation in a water plant in which the water level or flow rate is controlled by controlling the number of pumps of the same capacity, the operation time of each pump is integrated, and the - number of starts is counted as the operation time. The number of pumps in operation is characterized in that the converted value is added to the previous cumulative operating time value, the operating order is determined based on the added cumulative operating time value, and the operating time and number of starts of all pumps are equalized. Control method.