JPS58207113A - Pump number controller - Google Patents

Abstract

PURPOSE:To prevent an excessive or lowered level of the flow rate discharged from pumps although some large-diameter pumps are included, by stopping the sequence with a flow rate deviation corresponding to each pump despite diferent capacities of pups in pump groups. CONSTITUTION:First, the output DELTAP=P0-F0(P: simlated discharge flow rate signal, F0: flow rate setting signal) of a comparator 12 is checked. An alarm setting device 13-L delivers a signal DL when DELTAP>=DELTAPL(PL: flow rate dischrged from a large-diameter pump) is satisfied, and a pin board setting device 15 is lowered by a step via a stepping relay 14. Output signals 20-1-20-n of the device 15 deliver stop signals of the following stages via a stop command delay circuit 16 to stop the operation of a pump. When DELTAPS<=DELTAP<=DELTAPL(DELTAPS: flow rate discharged from a small-diameter pump) is satisfied, the deivce 15 is reset by a step. Then the DELTAP is checked at that moment. The operation of a small- diameter pump is stopped in the case of DELTAP>=0: while the number of working pumps is maintained in the case of DELTAP<0 respectively.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a pump number control device (which is a two-turn type) that controls the number of operating pumps in a group of pumps including pumps of different capacities according to the overall required flow rate (two). Rir.

[Technical background of the invention and its set points]

In recent water supply systems, a pump group operation system has been adopted in which a plurality of pumps, including pumps of different capacities, are operated in appropriate combinations to efficiently control the discharge flow rate in multiple stages.

Figure 1 shows an example of a two-way water supply system.

In Figure 1, the water in pump well 1 is pumped through pumps 2-1 to 2-.
When n pumps are operated, the number of pumps in operation is controlled by inputting the flow rate setting signal F.

Further (the current iF is detected by the flowmeter 5, and the flow rate setting signal F
The secondary controller 7 adjusts the opening of the control valve 4 so that the flow rate coincides with o, thereby performing continuous flow control.

In FIG. 1 (2), 3-1 to 3-n are pump discharge valves, which are opened during pump operation.

A system as shown in Figure 1 has been proposed as the number control system ft8 in Figure 1.

In Figure 2, the operating order of the pumps 2-1 to 2-n is arbitrarily set on the bin board 15.

22-1 to 22-n are resistance values ΔR-1 to ΔR-n proportional to the respective discharge flow rates of the pumps 2-1 to 2-n (two-pronged pump discharge flow rate simulating resistors, respectively). When the pumps 2-1 to 2-n are operated, the contacts 21-1 to 21-n
is opened (two is series (two is added).

The additional resistance 1 section R is converted into 2 through the resistance current converter 11 and compared with the Ryudo Setsugogo F0 in the comparison visit 12, and its deviation △P ''P
.

-FO is alarm setter 13 (two-man power, I. Deviation △P
When is △P△O, the alarm setter 13 outputs a signal R to lower the stepping relay 14, and when △P>△PG, it outputs a signal U to raise the stepping relay 14 and lower the stepping relay 14 to the corresponding bin board. 15 (2) Operate the collected pumps, and control the number of pumps by this 12.

In this case, the above-mentioned set value ΔPo is determined as the pump discharge 1illrN:t for Tori Otani among the J4 German pumps, so the flow rate setting is lowered and the next stop order (second small capacity pump is stopped). In the case of good conditions (the second stop command is not issued, this causes the problem of excessive continuous operation, such as increased throttling loss in the flowmeter).

If the special end-of-life pump is a small-capacity pump (=, the stop command is not issued until the end, and shut-off operation is performed, which may lead to a burnout accident of the pump.

[Purpose of the invention]

When controlling the number of pumps in a pump group including different types of pumps in a predetermined order, the invention stops the pumps at the following (flow rate according to the capacity of the pump to be stopped: tw difference), and thereby each pump in the pump group It is an object of the present invention to provide a control device for a pump platform 1 that performs sequential stopping at flow rate deviations corresponding to each pump even if the capacities of the pumps are different.

[Summary of the invention]

The present invention sets the operation rH order of a pump group including pumps of different capacities on a bin board, and controls the number of malfunctions of the pump group by setting the step of the bin board up and down according to the overall set flow rate. In the pump number control device, a pump discharge υ#'jk simulation circuit that simulates the overall discharge flow rate of the pump corresponding to the step position of the bin board, and a comparison circuit that compares the simulated discharge flow rate and the set flow rate, When the above simulated discharge #L amount is insufficient, raise the bin board by 1 step and start pump IIaW, and when the above simulated discharge flow rate exceeds a predetermined value, lower the bin board by 1 step, and after lowering the bin board by 1 step. It is equipped with a discrimination circuit that stops pump No. 11 when the simulated discharge flow rate does not fall below the set flow rate, and by this, the number of pumps is controlled according to the width of the discharge flow rate of the minimum capacity pump. This is a device for controlling the number of pumps that can prevent an excessive decrease in the discharge flow rate due to the mixture of

[-A Ming's implementation sequence] An embodiment of the invention is shown in FIG.

FIG. 3 (2) Simulated discharge flow! Operation circuit of signal Pa,
The stepping relay and bin board setting device are the same as those shown in Fig. 2, or in Fig. 3, the small pump iiF alarm foot 13-, which stores the small pump setting value △P8 as an alarm setting device, is used.
V# for dog bong with 8 and large pump useful value △PL
It is equipped with two sets of information setting devices 13-L (2. Outputs 20-1 to 21 of the pinboard setting device 15)-n is a simulated discharge #,
Amount multiplication signal 'fLJI1. The operation of the operation points 21-1 to 21-n (2 is used directly, but the actual starting and stopping of the pump is performed via the stop command delay circuit 16, and the next step (2) is to determine the size of the pump to be stopped. Pump size discrimination circuit 1
It has 7.

Next, the operation for controlling the number of near vehicles will be explained with reference to the flowchart shown in FIG.

First, check the output ΔP"Po FoQ value of the comparator 12, and if it is found to be ΔP<0, the iiF alarm setting setter 13 outputs the U signal, valves the stepping relay 14, and advances the bin boat setting #15 by one step. , activate one winning pump.

Since the stop command delay circuit 16 does not perform a delay operation for starting the pump, one of the C bombs is immediately activated.

When 0≦∆P〈△Ps (where 2∆Ps is the discharge flow rate of one small pump), the pumps are not suddenly started or stopped, and the number of pumps in operation does not change.

When ΔP≧ΔPL(here)2ΔPt is the discharge flow rate of one large pump), the fixed setting device 13-L outputs a DL signal, and via the stepping relay 14, the bin board setting device 15 is set in one step. Lower it.

Pinboard setting device output color number (20-1 to 21)-n
) outputs a stop signal for the next stage pump via the stop command delay circuit 16 to stop one pump.

Also, when △Ps≦ΔP≦Δh, f constant setting device 13-
8 outputs the old ps number, and in the same way (2), the pinboard setting device 15 is returned one step.
One contact point corresponding to the pump (2) that is next in stop order among 1 to 21-n opens, and PG decreases by the discharge volume of that pump.

Here, check △P' at that time.

When ΔP≧00, one pump may be delayed tg, and therefore, it is determined that the next pump to be stopped will be a small pump, so that pump is stopped via the stop command delay circuit 16.

When ΔP<00, when the pump is brought into pure soil, the pump's discharge flow i Po becomes the set flow rate F. (Since this is the second step, in this case, the U signal is output to return the pinboard setting device 15 to its original position, and the current number of pumps in operation is maintained.

1:: By repeating the above operation (2), it is possible to control the number of pumps that increase the number of pumps for each type of different S without causing an excessive decrease in the pump discharge flow rate, and to control the discharge flow rate of small pumps (2) with corresponding fine control. This is done with great care.

〔Effect of the invention〕

As explained above, (2 misfire E3) 4 (2) controls the pump group including pumps of different capacities according to the overall set flow rate (2). Using a simulation circuit, we predict and calculate the low discharge flow rate when the number of pumps is reduced by one, and then increase or decrease the number of pumps using the control wheel for the discharge flow rate of the small pumps. A logical pump group control device that prevents an excessive drop in discharge (LX) due to the mixture of (-) can be obtained.

[Brief explanation of drawings]

Figure 1 is a system diagram showing an example of a water conveyance system to which the invention is applied, Figure 2 is a system diagram showing an example of the conventional number-of-unit #itt system, and Figure 3 is a system diagram showing an example of a conventional #itt system for the number of pumps. A system diagram showing the first embodiment of the device, FIG. 4 is the IJ! The flowchart shows JJ Tsubo. 1 Pump wells 2-1 to 2-n Pump 3 Pump discharge valve 4 Flow control valve 5 Flow meter 7 Flow-jLv! 4-section total 8 Unit controller 11 Resistance current converter 13, 13L, 138 * Constant setting device 14
Stepping relay 15 Bin board 16 Stop command delay circuit 17 Pump size discrimination circuit 22-1 to 22-n Pump discharge flow rate simulation resistor (8
733) Agent: Yoshiaki Inomata, patent attorney (and 1 other person)
−. ＼ Figure 3

Claims (1)

[Claims] (1) The operation order of pump groups including pumps of different capacities can be arbitrarily determined using a pin board. Pump number control device (2) to control the number of pumps (2), step position of the pin board (2) overall discharge of the corresponding pump (A,
A pump discharge flow rate simulation circuit that simulates fik, a comparison circuit that compares the above simulated discharge flow rate and the set t & tj, and a pump discharge flow rate simulation circuit that compares the above simulated discharge flow rate with the set t & tj. At the same time as starting the inspection pump (when the amount exceeds 1a or more, lower the pin board by one step and simulate discharge ωt to lower the pin board by one step, if the amount does not go below the redundant flow cover, j1) The number of pumps on the market is characterized by being equipped with a discriminating circuit that stops the pump during inspection. The device for controlling the number of pumps according to claim 1, in which the discharge flow rate of the pump is set as the discharge flow rate of the pump. (3) When the simulated discharge flow rate for lowering the pin board by one step is lower than the set flow rate, the pin board is 1
A device for controlling the number of pumps according to claim 1, which increases the number of pumps by increasing the step to the original step (double and dying). (4) The simulated discharge flow rate is the set flow rate). 21. The device for controlling the number of pumps according to claim 1, in which the number of pumps is controlled to stop the first pump unconditionally (21) when the discharge flow rate exceeds the discharge flow rate.