CN109240353A - Adjust the system and method for revolution speed - Google Patents
Adjust the system and method for revolution speed Download PDFInfo
- Publication number
- CN109240353A CN109240353A CN201810910158.0A CN201810910158A CN109240353A CN 109240353 A CN109240353 A CN 109240353A CN 201810910158 A CN201810910158 A CN 201810910158A CN 109240353 A CN109240353 A CN 109240353A
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- China
- Prior art keywords
- pressure difference
- moment
- pump
- actual pressure
- output frequency
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D7/00—Control of flow
- G05D7/06—Control of flow characterised by the use of electric means
Abstract
The invention discloses a kind of system and methods for adjusting revolution speed, are related to the technical field of revolution speed adjustment.The system includes: monitoring device, and the actual pressure for real-time monitoring regulating valve inlet and outlet is poor；Controller, for calculating output frequency according to preset setting pressure difference P in actual pressure difference and its；Frequency converter makes actual pressure difference reach the setting pressure difference P for the revolving speed according to output frequency adjustment pump.This method comprises: the actual pressure of the inlet and outlet of regulating valve is poor on the pipeline that acquisition is connected to pump in real time；Output frequency is calculated according to the actual pressure difference and preset setting pressure difference P；The revolving speed of pump is adjusted in real time according to output frequency, so that actual pressure difference reaches the setting pressure difference P.The present invention adjusts the revolving speed of pump, makes control valve opening and output flow direct proportionality by the pressure difference of monitoring regulating valve two sides.
Description
Technical field
The present invention relates to the technical fields of revolution speed adjustment, are specifically related to a kind of system and method for adjusting revolution speed.
Background technique
In the automatic control of modern plant, regulating valve is played a very important role, and the production of many factories is depended on
In the correct distribution and control of fluid, such as: a certain amount of fluid is inputted into container by adjusting the aperture of regulating valve.It is logical
Often, regulating valve is set on pipeline, and the import of pipeline is connected to pump, and pump rotation exports fluid.But when the aperture of regulating valve becomes
When change, the cross-sectional area S of the current aperture of regulating valve changes, and the revolving speed pumped this moment is constant, then pumps the flow Q of the fluid of output not
Become, according to Q=V*S, flow Q is constant, cross-sectional area S variation, and the current opening cross sectional face area S of regulating valve and flow Q are just not
It is proportional, the aperture by adjusting regulating valve cannot achieve the purpose that control flow.
Summary of the invention
The purpose of the invention is to overcome the shortcomings of above-mentioned background technique, provide it is a kind of adjust revolution speed system and side
Method.The present invention adjusts the revolving speed of pump, keeps control valve opening directly proportional to output flow by the pressure difference of monitoring regulating valve two sides
Example relationship.
The present invention provides a kind of system for adjusting revolution speed, and the pump is communicated with pipeline, and the pipeline is equipped with regulating valve, institute
The system of stating includes:
Monitoring device, the actual pressure for real-time monitoring regulating valve inlet and outlet are poor；
Controller, for calculating output frequency according to preset setting pressure difference P in actual pressure difference and its；
Frequency converter makes actual pressure difference reach the setting pressure difference P for the revolving speed according to output frequency adjustment pump.
Based on the above technical solution, the calculation formula of the output frequency are as follows: fn=Δ fn+fn-1；
Wherein, fnFor n moment output frequency, n is acquisition moment, Δ fnFor the increment of n moment output frequency, fn-1For n-1
The output frequency at moment, and the n-1 moment is the last moment at n moment.
Based on the above technical solution, the increment Delta f of the output frequencynCalculation formula are as follows: Δ fn=KP×
(en-en-1)+Ki×en；
Wherein, en=P- Δ Pn, enIndicate the pressure deviations at n moment, en-1Indicate the pressure deviations at n-1 moment, Δ PnTable
Show that the actual pressure at n moment is poor, KPFor proportionality coefficient, KiFor integral coefficient.
Based on the above technical solution, the monitoring device is differential manometer.
Based on the above technical solution, the foundation of the revolving speed of the frequency converter adjustment pump are as follows:
When actual pressure difference is greater than setting pressure difference P, the revolving speed of pump is reduced, the output fluid flow Q of pump is reduced, practical
Pressure difference is reduced；
When actual pressure difference is less than setting pressure difference P, increase the revolving speed of pump, the output fluid flow Q of pump increases, practical
Pressure difference increases.
The embodiment of the present invention provides a kind of method for adjusting revolution speed, includes the following steps:
The actual pressure of the inlet and outlet of regulating valve is poor on the pipeline that acquisition is connected to pump in real time；
Output frequency is calculated according to the actual pressure difference and preset setting pressure difference P；
The revolving speed of pump is adjusted in real time according to output frequency, so that actual pressure difference reaches the setting pressure difference P.
Based on the above technical solution, the calculation formula of the output frequency are as follows: fn=Δ fn+fn-1；
Wherein, fnFor n moment output frequency, n is acquisition moment, Δ fnFor the increment of n moment output frequency, fn-1For n-1
The output frequency at moment, and the n-1 moment is the last moment at n moment.
Based on the above technical solution, according to en-1And enCalculate the increment Delta f of n moment output frequencyn, wherein en
Indicate the pressure deviations at n moment, en-1Indicate the pressure deviations at n-1 moment.
Based on the above technical solution, the increment Delta f of the output frequencynCalculation formula are as follows: Δ fn=KP×
(en-en-1)+Ki×en；
Wherein, en=P- Δ Pn, enIndicate the pressure deviations at n moment, en-1Indicate the pressure deviations at n-1 moment, Δ PnTable
Show that the actual pressure at n moment is poor, KPFor proportionality coefficient, KiFor integral coefficient.
Based on the above technical solution, the revolving speed of the adjustment pump includes:
Actual pressure difference and setting pressure difference P are compared；
When actual pressure difference is greater than setting pressure difference P, the revolving speed of pump is reduced, output fluid flow Q is reduced, actual pressure
Difference is reduced；
When actual pressure difference is less than setting pressure difference P, increase the revolving speed of pump, output fluid flow Q increases, actual pressure
Difference increases.
Compared with prior art, advantages of the present invention is as follows: the present invention passes through monitoring regulating valve front and rear sides pressure difference, when
When the aperture of regulating valve changes, according to the revolving speed of pressure difference adjustment pump, the flow corresponding change for exporting pump passes through adjusting
Valve front and rear sides actual pressure difference reaches setting pressure difference, so that actual pressure difference is constant, constant flow rate, to guarantee regulating valve
Aperture and output flow direct proportionality.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of the system of adjustment revolution speed of the embodiment of the present invention.
Fig. 2 is the flow chart of the method for adjustment revolution speed of the embodiment of the present invention.
Fig. 3 is the flow chart of the calculating output frequency of the method for adjustment revolution speed of the embodiment of the present invention.
Appended drawing reference: 1- pump, 2- regulating valve, 3- monitoring device, 4- controller, 5- frequency converter.
Specific embodiment
With reference to the accompanying drawing and specific embodiment the present invention is described in further detail.
Shown in Figure 1, the embodiment of the present invention provides a kind of system for adjusting revolution speed, for adjusting the revolving speed of pump 1,
In, pump 1 is communicated with pipeline, and pipeline is equipped with regulating valve 2, and system includes monitoring device 3, controller 4 and frequency converter 5, and frequency converter 5 connects
Pump 1 is connect, monitoring device 3 connects regulating valve 2, and controller 4 is separately connected monitoring device 3 and frequency converter 5, and implements to frequency converter 5
Control.Wherein, pump 1 is electrodynamic pump.
Specifically, monitoring device 3 is used for the actual pressure difference Δ P of 2 inlet and outlet of real-time monitoring regulating valven；Wherein, Δ
PnIndicate that the actual pressure at n moment is poor, n is the acquisition moment；Actual pressure difference Δ PnIt is the difference of the pressure of inlet and outlet, it can be with
It is directly measured by monitoring device 3.Optionally, monitoring device 3 is differential manometer.
Controller 4 is used to receive the actual pressure difference Δ P of the transmission of monitoring device 3nSignal, and according to actual pressure difference Δ
PnOutput frequency f is calculated with setting pressure difference P preset in itn；Wherein, fnIndicate the output frequency at n moment.
Frequency converter 5 is used to receive the output frequency f of the transmission of controller 4nSignal, according to output frequency fnAdjustment pump 1 turns
Speed makes actual pressure difference reach the setting pressure difference P.
The foundation of the revolving speed of the adjustment of frequency converter 5 pump 1 are as follows:
As actual pressure difference Δ PnWhen greater than setting pressure difference P, the revolving speed of pump 1 is reduced, 1 output fluid flow Q is pumped and subtracts
Few, actual pressure difference is reduced；
As actual pressure difference Δ PnWhen less than setting pressure difference P, increase the revolving speed of pump 1, pumps 1 output fluid flow Q increasing
More, actual pressure difference increases.
Specifically, output frequency fnCalculation formula are as follows: fn=Δ fn+fn-1；
Wherein, Δ fnFor the increment of n moment output frequency, fn-1For the output frequency at n-1 moment, the n-1 moment is the n moment
Last moment.
Specifically, the increment Delta f of output frequencynCalculation formula are as follows: Δ fn=KP×(en-en-1)+Ki×en；
Wherein, en=P- Δ Pn, enIndicate the pressure deviations at n moment, en-1Indicate the pressure deviations at n-1 moment, KPFor than
Example coefficient, KiFor integral coefficient.
Shown in Figure 2, the embodiment of the present invention provides a kind of method for adjusting revolution speed, and this method comprises the following steps:
The actual pressure difference Δ P of the inlet and outlet of regulating valve 2 on S1, the pipeline that acquisition is connected to pump 1 in real timen；Wherein,
ΔPnIndicate that the actual pressure at n moment is poor, n is the acquisition moment；
S2, according to actual pressure difference Δ PnOutput frequency f is calculated with preset setting pressure difference Pn；Wherein, fnFor the n moment
Output frequency；
S3, according to output frequency fnThe revolving speed of adjustment pump 1 in real time, so that actual pressure difference reaches setting pressure difference P.
It is shown in Figure 3, in step S2, calculate output frequency fnInclude:
S201, the pressure pressure deviations e for obtaining the n-1 momentn-1, according to en-1And enCalculate the increment of n moment output frequency
Δfn, wherein enIndicate the pressure deviations at n moment.
Specifically, the increment Delta f of output frequencynCalculation formula are as follows: Δ fn=KP×(en-en-1)+Ki×en；
Wherein, en=P- Δ Pn, enIndicate the pressure deviations at n moment, en-1Indicate the pressure deviations at n-1 moment, KPFor than
Example coefficient, KiFor integral coefficient.
S202, the output frequency f for obtaining the n-1 momentn-1, according to output frequency fn-1With increment Delta fnCalculate the defeated of n moment
Frequency f outn；
Specifically, output frequency fnCalculation formula are as follows: fn=Δ fn+fn-1；
Wherein, Δ fnFor the increment of n moment output frequency, fn-1For the output frequency at n-1 moment, and when the n-1 moment is n
The last moment at quarter.
Specifically, in step S3, the revolving speed of adjustment pump 1 includes: by actual pressure difference Δ PnIt is carried out pair with setting pressure difference P
Than；
As actual pressure difference Δ PnWhen greater than setting pressure difference P, the revolving speed of pump 1 is reduced, output fluid flow Q is reduced, real
Border pressure difference is reduced；
As actual pressure difference Δ PnWhen less than setting pressure difference P, increase the revolving speed of pump 1, output fluid flow Q increases, real
Border pressure difference increases.
The operation principle of the present invention is that: according to Q=V × S, when the variation of 2 aperture of regulating valve, flow Q is constant, regulating valve 2
The cross-sectional area S variation of current aperture, then flow velocity V changes；Make 2 aperture of regulating valve and output flow Q direct proportionality,
V need to be kept constant.
According to the thrust F of fluidIt pushes away=Δ Pn×S0, S0For conduit cross-sectional area, S0For definite value；
According to FResistance=f (V3), FIt pushes away-FResistance=ma, m are quality, and a is acceleration；As acceleration a=0, flow velocity V is constant, this
When, FIt pushes away=FResistance, when V is constant, Δ PnIt is constant.Therefore, after the revolving speed adjustment of pump 1, output flow Q is constant, Δ PnConstant, V is permanent
It is fixed, FIt pushes away=FResistance；As Δ PnWhen=P, FIt pushes awayFor definite value, V is also definite value, then 2 aperture of regulating valve and the pass in direct ratio output flow Q
System.
When 2 aperture of regulating valve becomes larger, the cross section S of the current aperture of regulating valve 2 increases, and the revolving speed pumped at this time is constant, stream
Amount Q is constant, and flow velocity V becomes smaller, FResistanceBecome smaller, acceleration is negative, FIt pushes awayAlso become smaller, actual pressure difference Δ PnAlso become smaller, actual pressure
Poor Δ PnLess than setting pressure difference P；Increase the revolving speed of pump, flow Q increases, and flow velocity V increases, Δ PnIncrease, FIt pushes awayIncrease, acceleration
For positive number, flow velocity V continues to increase, FResistanceIncrease, works as FResistanceClose to FIt pushes awayWhen, a=0, flow velocity V is constant, actual pressure difference Δ PnIt is constant.
When 2 aperture of regulating valve becomes smaller, the cross section S of the current aperture of regulating valve 2 reduces, and the revolving speed pumped at this time is constant, stream
Amount Q is constant, and flow velocity V becomes larger, FResistanceBecome larger, acceleration is positive value, FIt pushes awayIt also becomes larger, actual pressure difference Δ PnIt also becomes larger, actual pressure
Poor Δ PnGreater than setting pressure difference P；The revolving speed of pump is reduced, flow Q is reduced, and flow velocity V reduces, Δ PnReduce, FIt pushes awayReduce, acceleration
For negative, flow velocity V continues to reduce, FResistanceReduce, works as FResistanceClose to FIt pushes awayWhen, a=0, flow velocity V is constant, actual pressure difference Δ PnIt is constant.
Those skilled in the art can carry out various modifications to the embodiment of the present invention and modification, if these modifications and change
For type within the scope of the claims in the present invention and its equivalent technologies, then these modifications and variations are also in protection scope of the present invention
Within.
The prior art that the content being not described in detail in specification is known to the skilled person.
Claims (10)
1. a kind of system for adjusting revolution speed, the pump is communicated with pipeline, and the pipeline is equipped with regulating valve, which is characterized in that institute
The system of stating includes:
Monitoring device, the actual pressure for real-time monitoring regulating valve inlet and outlet are poor；
Controller, for calculating output frequency according to preset setting pressure difference P in actual pressure difference and its；
Frequency converter makes actual pressure difference reach the setting pressure difference P for the revolving speed according to output frequency adjustment pump.
2. the system of adjustment revolution speed as described in claim 1, which is characterized in that the calculation formula of the output frequency are as follows: fn
=Δ fn+fn-1；
Wherein, fnFor n moment output frequency, n is acquisition moment, Δ fnFor the increment of n moment output frequency, fn-1For the n-1 moment
Output frequency, and the n-1 moment be the n moment last moment.
3. the system of adjustment revolution speed as claimed in claim 2, which is characterized in that the increment Delta f of the output frequencynMeter
Calculate formula are as follows: Δ fn=KP×(en-en-1)+Ki×en；
Wherein, en=P- Δ Pn, enIndicate the pressure deviations at n moment, en-1Indicate the pressure deviations at n-1 moment, Δ PnWhen indicating n
The actual pressure at quarter is poor, KPFor proportionality coefficient, KiFor integral coefficient.
4. the system of adjustment revolution speed as described in claim 1, it is characterised in that: the monitoring device is differential manometer.
5. the system of adjustment revolution speed as described in claim 1, which is characterized in that the revolving speed of frequency converter adjustment pump according to
According to are as follows:
When actual pressure difference is greater than setting pressure difference P, the revolving speed of pump is reduced, the output fluid flow Q of pump is reduced, actual pressure
Difference is reduced；
When actual pressure difference is less than setting pressure difference P, increase the revolving speed of pump, the output fluid flow Q of pump increases, actual pressure
Difference increases.
6. a kind of method for adjusting revolution speed, which comprises the steps of:
The actual pressure of the inlet and outlet of regulating valve is poor on the pipeline that acquisition is connected to pump in real time；
Output frequency is calculated according to the actual pressure difference and preset setting pressure difference P；
The revolving speed of pump is adjusted in real time according to output frequency, so that actual pressure difference reaches the setting pressure difference P.
7. the method for adjustment revolution speed as claimed in claim 6, which is characterized in that the calculation formula of the output frequency are as follows: fn
=Δ fn+fn-1；
Wherein, fnFor n moment output frequency, n is acquisition moment, Δ fnFor the increment of n moment output frequency, fn-1For the n-1 moment
Output frequency, and the n-1 moment be the n moment last moment.
8. the method for adjustment revolution speed as claimed in claim 7, it is characterised in that: according to en-1And enThe calculating n moment exports frequency
The increment Delta f of raten, wherein enIndicate the pressure deviations at n moment, en-1Indicate the pressure deviations at n-1 moment.
9. the method for adjustment revolution speed as claimed in claim 8, which is characterized in that the increment Delta f of the output frequencynMeter
Calculate formula are as follows: Δ fn=KP×(en-en-1)+Ki×en；
Wherein, en=P- Δ Pn, enIndicate the pressure deviations at n moment, en-1Indicate the pressure deviations at n-1 moment, Δ PnWhen indicating n
The actual pressure at quarter is poor, KPFor proportionality coefficient, KiFor integral coefficient.
10. as claimed in claim 6 adjustment revolution speed method, which is characterized in that it is described adjustment pump revolving speed include:
Actual pressure difference and setting pressure difference P are compared；
When actual pressure difference is greater than setting pressure difference P, the revolving speed of pump is reduced, output fluid flow Q is reduced, actual pressure subtractive
It is few；
When actual pressure difference is less than setting pressure difference P, increase the revolving speed of pump, output fluid flow Q increases, and actual pressure difference increases
Greatly.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810910158.0A CN109240353A (en) | 2018-08-10 | 2018-08-10 | Adjust the system and method for revolution speed |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810910158.0A CN109240353A (en) | 2018-08-10 | 2018-08-10 | Adjust the system and method for revolution speed |
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Family
ID=65070042
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Application publication date: 20190118 |
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