JP5374188B2 - Compressor number control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compressor number control system preventing a hunting control repeating drive and stop to stabilize the number of driven compressors, so that worthless increase or decrease in number is prevented to save energy, when the compressors are automatically controlled by following change in consumption. <P>SOLUTION: A plurality of compressors C1, C2, C3, C4, C5 are connected to a common air tank 12, and differences in discharge amount and consumption among them are treated as pressure. An increasing tendency or a decreasing tendency in pressure change in a unit of time after the increase or decrease in number of compressors along with pressure fluctuation is detected to be applied to a controlling condition when an automatic control of the compressors C1, C2, C3, C4, C5 by the pressure change is performed, to perform an appropriate automatic control responding to fluctuation characteristics of a consumed air volume. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention captures changes in the amount of consumed air (gas) by pressure, and increases or decreases the number of compressors driven by the pressure change, thereby compressing in response to changes in the amount of consumed air (gas). The present invention relates to a compressor number control system for stably supplying air (gas).

  Conventionally, if the change in the amount of consumed air (gas) is detected by pressure and the detected pressure falls below the set pressure, the number of compressors to be driven is increased by one, and if the pressure rises above the set pressure The number of compressors to be driven is reduced by one.

  In such unit control, the compressor is driven according to the amount of air consumed (gas), but the flow rate measurement is highly variable and unsuitable as a control input. The difference is detected by pressure, and the number of compressors is increased or decreased.

  Further, in Patent Document 1, as a compressor drive control method capable of stably supplying air regardless of whether the pressure drop of compressed air in the air tank is slow or slow, each of a plurality of compressors is started / stopped, A compressor drive control method for collecting the discharge air of the compressor in an air tank and supplying it as a compressed air source in a predetermined pressure range is described. In this compressor drive control method, the pressure change per predetermined time in the air tank is calculated, and the time for the pressure in the air tank to reach the lower limit of the predetermined pressure range is calculated and predicted by the calculated pressure change per predetermined time. When the calculated predicted time is shorter than the predetermined time, the stopped compressor is started.

JP 11-287188 A

  By the way, in the conventional control described above, when the pressure continuously decreases or increases with the continuous change in the amount of consumed air (gas), after the set sequential start and stop intervals, In addition, the number of units will be increased or decreased. For example, the consumption amount of compressed air (gas) in a factory line always fluctuates, and the compressor is frequently driven and stopped following this.

  At this time, the digital control using the set pressure point and the interval time axis point cannot appropriately determine the pressure change after the increase or decrease. Therefore, even if the pressure is recovering toward the normal pressure range, if it is less than or equal to the set value after the interval, the number of units will be increased or decreased, and the compressor will be driven. Too much or too much stop and useless power is used by repeating useless drive stop.

  Therefore, the present invention has been made in view of the above circumstances, and its purpose is to prevent hunting control that repeats driving and stopping when automatically controlling a compressor following changes in consumption, An object of the present invention is to provide a compressor number control system capable of saving energy by minimizing and stabilizing the number of driven compressors to prevent unnecessary increase or decrease of the number of compressors.

  In order to solve the above-described problems and achieve the object, a compressor number control system according to the present invention has the following configuration.

[Configuration 1]
After a preset sequence starting Interval, if the pressure drops below increasing stage set pressure, the compressor units control system for increasing stage compressor for driving dynamic, lower than increasing stage set pressure pressure If you are, the compressor is increased stand, to detect the pressure change in the subsequent time unit, if the pressure change decreases the pressure further does not recover to the increase tendency, perform this multiplication table for continuous, If the recovery to not the pressure change in the pressure is less than the reduced base set pressure has been restored to the increasing tendency is to temporarily stop the next increase base for continuous, downward trend was reversed pressure after its the case became solves the temporary stop treatment, is characterized in that to perform the following increasing stand continuous.

[Configuration 2]
In the compressor units control system having the configuration 1, immediately after the increasing stage control of the start of the compressor caused by pressure change, when the pressure of the air tank is 0, to recovery to constant pressure, a preset constant If the pressure is still insufficient after the set time for waiting for pressure recovery, if the pressure is increasing, stop further increase of the number of compressors, and then the pressure In the case of a reversal trend due to inversion, the temporary stop treatment is solved and the number of units is increased.
[Configuration 3]
When the pressure rises above the reduction base set pressure in the compressor unit control system that reduces the drive compressor when the pressure rises above the reduction base set pressure after a preset sequential stop interval. , Reduce the compressor, and then detect the pressure change within the unit time, and if the pressure further increases and the pressure change does not recover to the decreasing trend, the next consecutive lowering is performed and the pressure is set to the lowering If the pressure has not recovered below the pressure, but the pressure change has recovered to a decreasing trend, the next consecutive decrease is temporarily stopped, and then the pressure reverses and increases In this case, the temporary stop treatment is solved and the next consecutive reduction is performed.

In the compressor units control system according to the present invention having the structure 1, when the pressure is lower than the increasing stage set pressure, the compressor is increased stand, to detect the pressure change in the subsequent time unit, the pressure If the pressure does not recover and the pressure change does not return to the increasing trend, perform the next consecutive increase, and if the pressure has not recovered below the set pressure, but the pressure change has recovered to the increasing trend , to temporarily stop the next increase table for continuous, in the case where the pressure was on the decline inverted after the Soviet Union solves the temporary cessation treatment, since the next increase base for continuous, Hunting control that repeats driving and stopping is prevented, the number of compressors driven is stabilized, and unnecessary addition of the number of units can be prevented.

That is, in the compressor number control system according to the present invention, by detecting the pressure change trend in an analog manner, hunting control of the additional number of compressors due to pressure fluctuation is prevented, and the minimum necessary compressor is used. It is possible to stabilize the pressure and maintain a more stable driving state.

In the compressor units control system according to the present invention having the structure 2, if the pressure of the air tank immediately after increasing stage control of the start of the compressor caused by the pressure change is zero, advance to recovery to constant pressure If a set number of compressors are driven and the pressure is still insufficient after this set time for waiting for pressure recovery, if the pressure is increasing, temporarily stop further expansion, and then When the pressure reverses and tends to decrease, the number of units is increased by releasing the temporary stop procedure, so that hunting control that repeats driving and stopping is prevented immediately after the start of control, and the number of compressors driven is stabilized. Unnecessary increase of the number can be prevented.
In the compressor number control system according to the present invention having the configuration 3, when the pressure is higher than the set reduction pressure, the compressor is reduced, and then the pressure change within the unit time is detected, and the pressure is If the pressure rises further and the pressure change does not return to a decreasing trend, the next consecutive lowering is performed, and if the pressure has not recovered below the set pressure, but the pressure change has recovered to a decreasing trend. , If the next continuous decrement is temporarily stopped and then the pressure reverses and then increases, the temporary stop procedure is solved and the next next decrement is performed. Hunting control that repeatedly stops is prevented, the number of driven compressors is stabilized, and unnecessary reduction of the number of units can be prevented.
That is, in the compressor number control system according to the present invention, by detecting the pressure change trend in an analog manner, the hunting control of the lowering of the compressor due to pressure fluctuation is prevented, and the minimum necessary compressor is used. It is possible to stabilize the pressure and maintain a more stable driving state.

  That is, the present invention prevents hunting control that repeats driving and stopping when automatically controlling a compressor following changes in consumption, minimizing and stabilizing the number of compressors driven. Thus, it is possible to provide a compressor number control system capable of saving energy by preventing unnecessary increase or decrease of the number of units.

It is a block diagram which shows the structure of the compressor number control system which concerns on this invention. It is a graph which shows the control condition of the pressure in the compressor number control system which concerns on this invention. It is a graph which shows the change of the pressure during the initial charge time in the compressor number control system which concerns on this invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a compressor number control system according to the present invention.

  As shown in FIG. 1, the compressor number control system according to the present invention is a system that controls the driving and stopping of each compressor for compressor groups having different compressor capacities or different compressor structures. is there.

  In this compressor number control system, the discharge air (gas) from the compressors C1, C2, C3, C4, and C5 is stored in the air tank 12 and supplied to the factory line 13. The pressure in the air tank 12 is measured by a pressure gauge 14. The pressure measured by the pressure gauge 14 captures the difference between the discharge amount from each of the compressors C1, C2, C3, C4, and C5 and the consumption amount in the factory line 13. The measurement result by the pressure gauge 14 is sent to the automatic control device 11.

  The automatic control device 11 controls the driving and stopping of the compressors C1, C2, C3, C4, and C5 based on the measurement result by the pressure gauge 14. When the pressure in the air tank 12 decreases, the automatic control device 11 determines that the supply amount of the discharge air (gas) is insufficient, sequentially drives the compressor, and when the pressure increases Then, it is determined that the supply amount has become excessive, and the compressor is sequentially stopped.

  More specifically, the automatic control device 11 increases the number of compressors to be driven when the pressure exceeds the increase set pressure after a preset sequential activation interval and when the pressure is still decreasing. Let In addition, the automatic control device 11 reduces the compressor to be driven when the pressure is still higher when the pressure exceeds (decreases) the lower set pressure after a preset sequential stop interval. Let

  The present invention is particularly suitable for controlling the compressor when the change in the amount of air consumed is gradual and the amount of change is small.

  FIG. 2 is a graph showing the pressure control status in the compressor number control system according to the present invention.

  In this compressor number control system, as shown in FIG. 2, when a pressure change within a unit time after an increase in the number of compressors due to a pressure change is detected, and this pressure change is recovered to an increasing trend, Suspends the next consecutive increase, and when the pressure reverses and then tends to decrease, solves the temporary stop and increases the number of machines scheduled for the next start. Further, in this compressor number control system, a pressure change within a unit time after the compressor is lowered due to a pressure change is detected, and when this pressure change is recovered to a decreasing trend, If the table is temporarily stopped and then the pressure reverses and increases, the temporary stop procedure is solved and the next scheduled machine is reduced.

  That is, in this compressor number control system, when a pressure drop is detected when the pressure reaches the increased base set pressure L, the number of compressors is increased by one. First, the pressure gradient after the no-load start-up time is reached. Is detected. Next, after the set time of the continuous start after the compressor is started, whether or not the pressure is equal to or lower than the increase base set pressure L, the inclination of the pressure change is detected, and based on this detection result, the following is performed: Take control.

  That is, as shown in (1) in FIG. 2, if the pressure is restored to the increased base setting pressure L or higher, the current state is maintained.

  In addition, as shown in (2) in FIG. 2, the pressure has not recovered to the increase base setting pressure L or more, but if the inclination is increasing, the current state is maintained.

  Then, as shown in (3) in FIG. 2, when the pressure decreases from the state of (2) and the inclination tends to decrease, the next scheduled starter is added.

  Further, as shown in (4) in FIG. 2, if the pressure further decreases and the inclination tends to decrease, the next scheduled stop machine is increased.

  In this compressor number control system, when the pressure in the air tank 12 is “0” immediately after the start of the drive for increasing or decreasing the compressor due to pressure fluctuation, C1, C2, C3, C4 and C5 are judged to have increased in consumption in the factory line 13 due to the discharge amount, and the pressure has been reduced. C3, C4, and C5 are sequentially driven, and the compressor is driven so that a discharge amount that is greater than the actual consumption amount can be secured.

  FIG. 3 is a graph showing changes in pressure during the initial charging time in the compressor number control system according to the present invention.

  FIG. 3 shows a case where the predetermined number (initial charge number) set in advance is two, and shows the pressure change after starting the initial charge number. Note that the initial charge number can be arbitrarily set.

  In this compressor number control system, as shown in FIG. 3, when the pressure in the air tank 12 is 0 immediately after the start of the increase or decrease of the compressor due to the pressure change, it is constant. A predetermined number of compressors are driven until pressure is restored. And if the pressure is still insufficient after the set time for waiting for pressure recovery (initial charging time), if the pressure is increasing, further increase is temporarily stopped, and then the pressure is reversed. If the tendency is to decrease, the temporary stopping procedure is solved and the number of compressors to be driven is increased.

  In this way, in this compressor number control system, the number of drive units is temporarily limited until the pressure in the air tank 12 recovers to a constant pressure, but the pressure still decreases after the set time for waiting for pressure recovery. If so, it is considered that the number of drives is insufficient, and the number of units is increased at that time.

  However, when the consumption in the factory line 13 has not increased and the pressure in the air tank 12 tends to increase, the pressure is reduced after a set time waiting for pressure recovery to prevent unnecessary compressor driving. The inclination of the change is detected, and the following control is performed based on the detection result.

  That is, as shown in (1) in FIG. 3, if the pressure has recovered to the upper base set pressure L or higher, the current state is maintained.

  In addition, as shown in (2) in FIG. 3, the pressure is not restored to the increase base setting pressure L or more, but if the inclination is increasing, the current state is maintained.

  Then, as shown in (3) in FIG. 3, if the pressure decreases from the state (2) and the inclination tends to decrease, one more unit is added.

  Thus, in this compressor number control system, it is possible to quickly recover to a predetermined pressure while preventing unnecessary compressor driving.

  The present invention captures changes in the amount of consumed air (gas) by pressure, and increases or decreases the number of compressors driven by the pressure change, thereby compressing in response to changes in the amount of consumed air (gas). This is applied to a compressor number control system that stably supplies air (gas).

C1, C2, C3, C4, C5 Compressor 11 Automatic controller 12 Air tank 13 Factory line 14 Pressure gauge

Claims (3)

After a preset sequence starting Interval, if the pressure drops below increasing stage set pressure, the compressor units control system for increasing stage compressor for driving dynamic,
If the pressure is lower than increasing stage set pressure, the compressor is increased stand, to detect the pressure change in the subsequent time unit, when further lowered pressure changes the pressure does not recover to the increasing trend, continuous If the pressure has not recovered above the set pressure, but the pressure change has recovered to an increasing trend, the next consecutive increase is temporarily stopped . compressor units control system pressure in the case became decrease inverted, that solves the temporary stop treatment, and performing the following increasing stage continuous after. Immediately after increasing stage control of the start of the compressor caused by pressure change, when the pressure of the air tank is 0, to recovery to constant pressure, to drive the compressor a certain number previously set, the pressure If the pressure is still insufficient after the set waiting time for recovery, if the pressure is increasing, temporarily stop further expansion, and then if the pressure reverses and then decreases, The system for controlling the number of compressors according to claim 1, wherein the number of units is increased by releasing temporary suspension.   In the compressor number control system for reducing the number of compressors to be driven when the pressure rises below the set pressure reduction after a preset sequential stop interval,
  If the pressure rises above the set pressure, the compressor is lowered, and then the pressure change within the unit time is detected.If the pressure rises further and the pressure change does not recover, it continues. If the pressure has not recovered below the set pressure, but the pressure change has recovered to a decreasing trend, the next consecutive decrease is temporarily stopped, and then If the pressure is reversed and increases, cancel the temporary stop procedure and perform the next consecutive reduction.
  This is a compressor number control system.

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