CN114860006B - Concentration compensation method of gas flow control device - Google Patents
Concentration compensation method of gas flow control device Download PDFInfo
- Publication number
- CN114860006B CN114860006B CN202210395457.1A CN202210395457A CN114860006B CN 114860006 B CN114860006 B CN 114860006B CN 202210395457 A CN202210395457 A CN 202210395457A CN 114860006 B CN114860006 B CN 114860006B
- Authority
- CN
- China
- Prior art keywords
- actual
- flow
- differential pressure
- concentration
- theoretical
- Prior art date
- 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.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 24
- 230000001105 regulatory effect Effects 0.000 claims abstract description 36
- 230000001276 controlling effect Effects 0.000 claims description 6
- 238000005259 measurement Methods 0.000 abstract 2
- 238000004364 calculation method Methods 0.000 description 5
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000004868 gas analysis Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D27/00—Simultaneous control of variables covered by two or more of main groups G05D1/00 - G05D25/00
- G05D27/02—Simultaneous control of variables covered by two or more of main groups G05D1/00 - G05D25/00 characterised by the use of electric means
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Flow Control (AREA)
Abstract
The present disclosure provides a concentration compensation method of a gas flow control device, which obtains a theoretical differential pressure of a differential pressure sensor and an initial opening value of a flow regulating unit according to a target flow, controls the flow regulating unit based on the initial opening value, and obtains an actual differential pressure of the differential pressure sensor; judging whether the absolute value of the difference between the actual pressure difference and the theoretical pressure difference is larger than 0 and smaller than or equal to a threshold value, if not, correcting the initial opening value through the actual opening value to adjust the flow regulating unit; if so, comparing the actual pressure difference with the theoretical pressure difference, and if the actual pressure difference is larger than the theoretical pressure difference, adopting a first compensation coefficient to compensate the actual measurement concentration of the output gas, otherwise adopting a second compensation coefficient to compensate the actual measurement concentration of the output gas. The technical problem of gas concentration change caused when the flow control device cannot reach the target flow due to slight deviation of uncorrectable pressure of the air inlet end or small change of atmospheric pressure of the site environment is effectively solved.
Description
Technical Field
The disclosure relates to the technical field of gas analysis, in particular to a concentration compensation method of a gas flow control device.
Background
When the inlet end or the outlet end of the pressure type gas flow controller is changed, the flow can not be regulated to the target flow value all the time. For example, when the air inlet end or the flow regulating unit has a half-blockage fault, the air inlet resistance becomes large, so that the theoretical pressure difference cannot be reached when the flow regulating unit is fully opened, and the flow is smaller; or the service life of the flow regulating unit is reduced due to overlong service time, and the actual opening is larger than a theoretical opening control command issued by the singlechip, so that the flow is larger. On the other hand, the pressure of the air outlet end is atmospheric pressure, and the pressure of the air outlet end changes little with time under the indoor condition with better environment, but the pressure of the air outlet end changes little in a small way under the outdoor condition with worse environment, for example, the pressure of the air outlet end changes little gradually within +/-2 kpa, and the pressure of the air outlet end changes to cause the output flow of the air flow controller to be larger or smaller.
The concentration of the gas output from the gas flow controller is typically measured using a mass-type detector, and the volumetric flow rate is linearly related to the concentration of the gas because the concentration response of the mass-type detector is dependent on the mass of the gas entering the detector per unit time, i.e., the mass flow rate is linearly related to the concentration, and the mass flow rate can be converted to a volumetric flow rate. Therefore, when the pressure at the air inlet end is slightly deviated and uncorrectable or the ambient atmospheric pressure at the site is slightly changed to cause the flow controller to fail to reach the target flow rate, the measured output gas concentration of the pressure type gas flow controller is changed.
Disclosure of Invention
In view of the above, the present disclosure provides a concentration compensation method for a gas flow control device, which can effectively solve the problem that in the prior art, the gas inlet end pressure is slightly offset and the measured output gas concentration of the gas flow control device is changed due to small changes in the field ambient atmospheric pressure.
The following presents a simplified summary of the disclosure in order to provide a basic understanding of some aspects of the disclosure. It should be understood that this summary is not an exhaustive overview of the disclosure. It is not intended to identify key or critical elements of the disclosure or to delineate the scope of the disclosure. Its purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
According to a first aspect of the present disclosure, there is provided a concentration compensation method of a gas flow rate control device including an inlet end connected to an input end of a flow rate adjustment unit, an output end of the flow rate adjustment unit connected to an input end of the flow restrictor, an output end of the flow restrictor connected to an outlet end, a differential pressure sensor provided between the flow rate adjustment unit and the flow restrictor for detecting a differential pressure between the output end of the flow rate adjustment unit and the input end of the flow restrictor, the concentration compensation method comprising:
step one: acquiring a theoretical differential pressure of the differential pressure sensor and an initial opening value of the flow regulating unit according to a target flow;
step two: controlling the flow regulating unit based on the initial opening value, and acquiring the actual pressure difference of the differential pressure sensor;
step three: judging whether the absolute value of the difference between the actual differential pressure and the theoretical differential pressure is greater than 0 and less than or equal to a threshold value, if the absolute value of the difference between the actual differential pressure and the theoretical differential pressure is greater than the threshold value, calculating an actual opening value of the flow regulating unit based on the actual differential pressure, correcting the initial opening value according to the actual opening value, and returning to the step two; and if the absolute value of the difference between the actual pressure difference and the theoretical pressure difference is larger than 0 and smaller than or equal to the threshold value, comparing the actual pressure difference with the theoretical pressure difference, if the actual pressure difference is larger than the theoretical pressure difference, adopting a first concentration compensation coefficient to compensate the actual concentration of the output gas of the gas flow control device, and if the actual pressure difference is smaller than the theoretical pressure difference, adopting a second concentration compensation coefficient to compensate the actual concentration of the output gas of the gas flow control device.
In some embodiments, obtaining a theoretical differential pressure of the differential pressure sensor from a target flow based on the following equation includes:
PS 1 ＝Q*R-ΔPc
wherein PS 1 The theoretical differential pressure of the differential pressure sensor is that deltaPc is the critical differential pressure at two ends of the flow limiter, Q is the target flow, and R is the resistance of the flow limiter.
In some embodiments, in the case where the flow rate adjustment unit is an adjustable speed pump, the initial opening value of the adjustable speed pump is obtained from the target flow rate based on the following formula:
D 1 ＝m*Q
wherein D is 1 The initial opening value of the speed-adjustable pump is m, the opening parameter of the speed-adjustable pump is m, and Q is the target flow.
In some embodiments, the measured concentration of the gas output by the gas flow control device is compensated using a first concentration compensation factor based on the following equation:
C′＝(1-k 1 *ΔPS)*C，
ΔPS＝PS 2 -PS 1
wherein C' is the concentration, k of the output gas after compensation 1 Is a first concentration compensation coefficient, C is the measured concentration of the output gas, PS 2 For the actual pressure difference, PS 1 For the theoretical differential pressure ΔPS is a positive number.
In some embodiments, the first concentration compensation coefficient isWherein R is the resistance of the flow restrictor.
In some embodiments, the measured concentration of the gas output by the gas flow control device is compensated using a second concentration compensation factor based on the following equation:
C′＝(1-k 2 *ΔPS)*C，
ΔPS＝PS 2 -PS 1 ；
wherein C' is the concentration, k of the output gas after compensation 2 Is the second concentration compensation coefficient, C is the measured concentration of the output gas, PS 2 For the actual pressure difference, PS 1 ΔPS is a negative number for the theoretical differential pressure.
In some embodiments, the second concentration compensation coefficient isWherein R is the resistance of the flow restrictor.
In some embodiments, the absolute threshold value of the difference between the actual differential pressure and the theoretical differential pressure is 2.
According to the concentration compensation method of the gas flow control device, the actual differential pressure of the differential pressure sensor is obtained, the gas concentration measured at the output end is compensated based on the difference between the actual differential pressure and the theoretical differential pressure, and the problem that the measured output gas concentration of the gas flow control device changes when the flow control device cannot reach the target flow due to slight deviation of the pressure at the air inlet end or small change of the atmospheric pressure in the field environment is effectively solved.
Drawings
The preferred embodiments of the present disclosure will be described in detail below with reference to the attached drawings, wherein:
fig. 1 is a schematic structural diagram of a gas flow control device according to an embodiment of the present disclosure;
FIG. 2 is a flow chart of a method for concentration compensation of a gas flow control device according to an embodiment of the present disclosure;
FIG. 3 is a graph of the difference between the actual differential pressure and the theoretical differential pressure versus the compensated gas concentration provided by the embodiments of the present disclosure.
Detailed Description
The following description of the embodiments of the present disclosure will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present disclosure. Based on the embodiments in this disclosure, all other embodiments that a person of ordinary skill in the art would obtain without making any inventive effort are within the scope of protection of this disclosure.
In the description of the present disclosure, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present disclosure. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present disclosure, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this disclosure will be understood by those of ordinary skill in the art in the specific context.
In addition, technical features related to different embodiments of the present disclosure described below may be combined with each other as long as they do not make a conflict with each other.
As shown in fig. 1, an embodiment of the present disclosure provides a gas flow control device, including an air inlet end, a flow adjusting unit, a differential pressure sensor, a flow restrictor and an air outlet end, wherein the air inlet end is connected with an input end of the flow adjusting unit, an output end of the flow adjusting unit is connected with an input end of the flow restrictor, an output end of the flow restrictor is connected with the air outlet end, and the differential pressure sensor is disposed between the flow adjusting unit and the flow restrictor, and is used for detecting a pressure difference between an output end of the flow adjusting unit and an input end of the flow restrictor. Wherein the opening degree of the flow regulating unit is adjustable; the aperture of the flow restrictor is a fixed value, and the opening degree cannot be adjusted.
As shown in fig. 2, an embodiment of the present disclosure provides a concentration compensation method 200 applied to a gas flow control device as described above, where the concentration compensation method specifically includes:
step 210: and acquiring the theoretical differential pressure of the differential pressure sensor according to the target flow and the initial opening value of the flow regulating unit.
In the embodiment of the disclosure, the target flow is the output flow of the gas flow control device, and assuming that the target flow is Q, under the environment of constant temperature heating control, according to the poiseuille equation, the calculation method of the target flow Q is as follows:
Q＝(P 0 -P 2 )/R＝(P 0 -(P 1 -ΔPc))/R＝((P 0 -P 1 )+ΔPc)/R＝(PS 1 +ΔPc)/R
wherein P is 0 For the output pressure of the flow regulating unit, P 2 For the pressure at the output end of the flow restrictor, i.e. the pressure at the output end, P 1 For the pressure at the input end of the flow limiter, ΔPc is the critical pressure difference across the flow limiter, R is the resistance of the flow limiter, PS 1 Is the theoretical pressure difference.
It should be noted that, in the above calculation formula provided in the embodiments of the present disclosure, the critical pressure difference Δpc across the restrictor is the restrictor input pressure P 1 And the pressure P at the output end of the flow limiter 2 The difference, i.e. Δpc=p 1 -P 2 The method comprises the steps of carrying out a first treatment on the surface of the Theoretical differential pressure PS 1 For the output pressure P of the flow-regulating unit 0 And pressure P at the input of the restrictor 1 The difference, i.e. PS 1 ＝P 0 -P 1 。
In the embodiment of the disclosure, the theoretical differential pressure PS of the preset differential pressure sensor can be obtained by back-pushing the calculation formula of the target flow 1 =q×r- Δpc, where PS 1 The differential pressure sensor is a theoretical differential pressure, deltaPc is a critical differential pressure at two ends of the flow limiter, R is resistance of the flow limiter, and Q is a target flow.
In this embodiment of the disclosure, the target flow may be set according to actual needs, the resistance of the restrictor is a fixed value, and the critical pressure difference between two ends of the restrictor is a constant. Therefore, the theoretical differential pressure of the differential pressure sensor can be calculated based on the calculation formula of the theoretical differential pressure after the set target flow is obtained.
In the embodiment of the disclosure, the flow adjusting unit may be an adjustable speed pump, and other devices capable of adjusting and controlling the flow are also within the scope of the disclosure, which is not limited herein.
In the embodiment of the disclosure, in the case where the flow rate adjustment unit is an adjustable speed pump, the opening value of the flow rate adjustment unit may be obtained according to the target flow rate based on the following formula:
D 1 ＝m*Q
wherein D is 1 The opening value of the flow regulating unit is m, the opening parameter of the speed-adjustable pump is m, and Q is the target flow.
Step 220: and controlling the flow regulating unit based on the initial opening value, and acquiring the actual pressure difference of the differential pressure sensor.
In the embodiment of the disclosure, after the initial opening value of the flow regulating unit is obtained, the flow regulating unit is correspondingly controlled by the singlechip or the data processing unit, so that the actual differential pressure of the differential pressure sensor is obtained after the flow regulating unit operates according to the initial opening value.
In the embodiment of the present disclosure, the actual differential pressure of the differential pressure sensor may be acquired every 8 seconds, but the embodiment of the present disclosure is not limited to this period, and the period value may be set by those skilled in the art according to actual requirements.
Step 230: judging whether the absolute value of the difference between the actual differential pressure and the theoretical differential pressure is greater than 0 and less than or equal to a threshold value, if the absolute value of the difference between the actual differential pressure and the theoretical differential pressure is greater than the threshold value, calculating an actual opening value of the flow regulating unit based on the actual differential pressure, correcting the initial opening value according to the actual opening value, and returning to step 220; and if the absolute value of the difference between the actual pressure difference and the theoretical pressure difference is larger than 0 and smaller than or equal to the threshold value, comparing the actual pressure difference with the theoretical pressure difference, if the actual pressure difference is larger than the theoretical pressure difference, adopting a first concentration compensation coefficient to compensate the actual concentration of the output gas of the gas flow control device, and if the actual pressure difference is smaller than the theoretical pressure difference, adopting a second concentration compensation coefficient to compensate the actual concentration of the output gas of the gas flow control device.
In the embodiment of the disclosure, when the absolute value of the difference between the actual differential pressure and the theoretical differential pressure is greater than the threshold value, it is indicated that the actual differential pressure is not yet adjusted within the threshold value range around the theoretical differential pressure, and at this time, the influence of the pressure change of the air inlet end on the flow is greater, and thus the influence of the pressure change of the air inlet end on the gas concentration is greater, so that the concentration compensation method provided by the disclosure cannot be adopted to compensate the output gas concentration, but the actual opening value of the flow regulating unit should be calculated according to the actual differential pressure, for example, when the flow regulating unit is an adjustable pump, the actual opening value of the flow regulating unit may be calculated according to the actual differential pressure based on the following formula:
e＝PS 1 -PS 2
wherein D is 2 Is the actual opening value of the flow regulating unit, D 1 PS is the initial opening value of the adjustable speed pump 1 PS, theoretical differential pressure of differential pressure sensor 2 K being the actual differential pressure of the differential pressure sensor P For the proportional adjustment factor, K i For the integral adjustment factor, t is the integration time.
The singlechip feeds back the actual opening value of the flow regulating unit to the flow regulating unit, corrects the initial opening value of the flow regulating unit according to the actual opening value, and returns to step 220. In this embodiment of the present disclosure, the correcting the initial opening value of the flow rate adjustment unit according to the actual opening value specifically refers to assigning the actual opening value to the initial opening value.
And controlling the flow regulating unit based on the assigned initial opening value, namely the actual opening value, obtaining a new actual pressure difference, judging the magnitude of the actual pressure difference and the theoretical pressure difference again, and controlling the flow regulating unit continuously and circularly so as to finally ensure that the absolute value of the difference between the actual pressure difference and the theoretical pressure difference is smaller than or equal to the threshold value. In the above operation, the intake air amount of the gas flow control device is changed by adjusting the opening value of the flow rate adjustment unit based on the obtained actual differential pressure, thereby realizing the stable flow rate adjustment unit output end pressure P 0 And further to stabilize the flow rate in a range.
In the embodiment of the disclosure, when the absolute value of the difference between the actual differential pressure and the theoretical differential pressure is greater than 0 and less than or equal to a threshold value, it is indicated that the actual differential pressure has been adjusted within a threshold range around the theoretical differential pressure, and the influence of the pressure change of the air inlet end on the flow has been corrected by adjusting the opening of the flow adjusting unit, at this time, the deviation between the actual differential pressure and the theoretical differential pressure is mainly caused by a slight deviation that cannot be corrected by the pressure of the air inlet end or a small change of the atmospheric pressure of the field environment, and because the flow and the concentration are in a proportional relationship, the concentration compensation method provided later in the disclosure can be used to compensate the concentration of the output gas.
In the embodiment of the present disclosure, the threshold value of the absolute value of the difference between the actual differential pressure and the theoretical differential pressure may be 2, but is not limited to this value, and the person skilled in the art may set the threshold value of the absolute value of the difference between the actual differential pressure and the theoretical differential pressure according to the actual situation.
In the embodiment of the disclosure, when the absolute value of the difference between the actual differential pressure and the theoretical differential pressure is greater than 0 and less than or equal to a threshold value, the magnitude of the actual differential pressure and the theoretical differential pressure is further compared.
When the actual pressure difference is greater than the theoretical pressure difference, a first concentration compensation coefficient is used to compensate the measured concentration of the gas output by the gas flow control device, specifically, the measured concentration of the gas output by the gas flow control device may be compensated by using the first concentration compensation coefficient based on the following formula:
C′＝(1-k 1 *ΔPS)*C，
ΔPS＝PS 2 -PS 1
wherein C' is the concentration, k of the output gas after compensation 1 Is a first concentration compensation coefficient, C is the measured concentration of the output gas, PS 2 For the actual pressure difference, PS 1 For the theoretical differential pressure ΔPS is a positive number. In the embodiment of the disclosure, when the actual differential pressure is greater than the theoretical differential pressure, it is indicated that the flow is greater, Δps is a positive number, and the concentration C' after compensation is smaller than the concentration C before compensation, thereby correcting the problem of greater concentration caused by the greater flow.
When the actual pressure difference is smaller than the theoretical pressure difference, the second concentration compensation coefficient is adopted to compensate the actual concentration of the gas output by the gas flow control device, specifically, the actual concentration of the gas output by the gas flow control device can be compensated by adopting the second concentration compensation coefficient based on the following formula:
C′＝(1-k 2 *ΔPS)*C，
ΔPS＝PS 2 -PS 1 ；
wherein C' is the concentration, k of the output gas after compensation 2 Is the second concentration compensation coefficient, C is the measured concentration of the output gas, PS 2 For the actual pressure difference, PS 1 ΔPS is a negative number for the theoretical differential pressure. In the embodiment of the disclosure, when the actual differential pressure is smaller than the theoretical differential pressure, it is indicated that the flow is smaller, Δps is a negative number, and subtracting a negative number is equal to adding a positive number, and at this time, the concentration C' after compensation is greater than the concentration C before compensation, thereby solving the problem of smaller concentration caused by smaller flow.
In an embodiment of the disclosure, the first concentration compensation coefficient may beThe second concentration compensation coefficient may be +.>Wherein R is the resistance of the flow restrictor. The calculation method of the first concentration compensation coefficient and the second concentration compensation coefficient comprises the following steps:
because of the pressure differential between the input and output of the flow restrictor, the flow rate of the gas increases as the pressure differential increases as it flows through the flow restrictor. However, when the pressure differential exceeds the threshold pressure differential, the flow rate of the gas through the restrictor orifice reaches sonic velocity, at which point, regardless of the increase in pressure differential, the flow through the restrictor will remain at a value and will not increase as long as the pressure upstream of the restrictor remains constant. Flow restrictor restrictors are based on this principle to limit the flow and decrease the pressure of a fluid. Where Δpc is the critical differential pressure between the input and output of the current limiter, Δpc=p 1 -P 2 ，P 1 Is the input of the restrictorPressure at the inlet end, P 2 Is the output pressure of the restrictor, the output P is because the output is in the atmosphere 2 Is at ambient atmospheric pressure.
In the first case, the service life of the flow regulating unit is reduced due to overlong service time, and the actual opening is larger than the P caused by the theoretical opening control command issued by the singlechip 1 Is too large or when the ambient atmospheric pressure P 2 When getting smaller, P 1 -P 2 When the value of (1) exceeds the critical pressure difference deltapc, the flow rate of the gas through the orifice of the restrictor reaches sonic velocity, at which time, no matter P 1 How again the flow rate will not increase any more, so Δpc is unchanged.
Based on the following formula
Target flow rate: q= (PS 1 +ΔPc)/R，
Actual flow rate: q' = (PS 2 +ΔPc)/R，
Flow rate change amount:
since ΔPc is the critical pressure difference across the current limiter, which is a constant, PS 1 Is a theoretical differential pressure, a fixed value, R is the resistance of the restrictor, a constant, and only the actual differential pressure PS 2 When the flow becomes larger, the flow changes and the actual pressure difference PS are affected 2 The variation trend of (2) is the same, and thus the variable PS is taken in the embodiment of the disclosure 2 Is the first concentration compensation coefficientAlso, because of the linear proportional relationship of flow and concentration, the first concentration compensation coefficient may be applied to concentration compensation.
In the second case, the air inlet end or the flow regulating unit has half-blockage fault to cause P 0 Or P 1 Smaller, or ambient, atmospheric pressure P 2 When the flow rate is increased, the differential pressure delta Pc' =P between the front end and the rear end of the flow restrictor 1 -P 2 Will be below the critical pressure difference deltapc. Critical pressure difference Δpc=n×p 1 ＝N*(P 0 -PS 1 ) Wherein when the gas is saturated steamWhen steam, n=0.58; when the gas is superheated steam or a polyatomic gas, n=0.55; when the gas is air or a diatomic gas, n=0.53. The differential pressure between the front and back ends of the flow restrictor is no longer equal to the critical differential pressure, but is deltapc' =0.5×ps 2 . Based on the following formula
Target flow rate: q= (PS 1 +ΔPc)/R，
Actual flow rate: q' = (PS 2 +ΔPc′)/R，
ΔQ＝(PS 2 -PS 1 +0.5PS 2 -N*(P 0 -PS 1 ))/R
＝(1.5*PS 2 -PS 1 )/R-(N*(P 0 -PS 1 ))/R
Due to P 0 For the output pressure of the flow regulating unit, the pressure is stabilized to be a fixed value after the opening degree of the flow regulating unit is regulated, PS 1 Is a theoretical pressure difference, is a constant, PS 2 Is the actual pressure difference, the variable, R is the resistance of the restrictor, and is a constant, thus, the variable PS is taken in the embodiments of the disclosure 2 Is the second concentration compensation coefficientAlso, because of the linear proportional relationship of flow and concentration, a second concentration compensation coefficient may be applied to the concentration compensation.
FIG. 3 is a graph showing the relationship between the difference between the actual pressure difference and the theoretical pressure difference and the compensated gas concentration when the actual concentration of the output gas is 100ppm, and it can be seen from the graph that, when the actual pressure difference is smaller than the theoretical pressure difference, the pressure difference becomes smaller, so that the flow is smaller, and the actual concentration is lower than the actual concentration of the gas, and at this time, the compensated gas concentration obtained by the concentration compensation method provided by the present disclosure is greater than the actual concentration by 100ppm, so as to correct the smaller actual concentration; under the condition that the actual pressure difference is larger than the theoretical pressure difference, the flow is increased due to the fact that the pressure difference is increased, and then the actual measured concentration is larger than the actual concentration of the gas, and at the moment, the compensated gas concentration obtained by the concentration compensation method is smaller than the actual measured concentration by 100ppm, so that the larger actual measured concentration is corrected.
According to the technical scheme, the concentration compensation control method is used for correcting the concentration error of the output gas caused when the flow control device cannot reach the target flow, so that the technical problem that the concentration change is caused by slight deviation of the pressure of the air inlet end or slight change of the control flow caused by small change of the atmospheric pressure of the site environment is effectively solved, and the environment adaptability and the control precision of the flow control device are improved.
It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While nevertheless, obvious variations or modifications are contemplated as falling within the scope of the present disclosure.
Claims (6)
1. The concentration compensation method of a gas flow control device, the gas flow control device includes the inlet end, flow control unit, differential pressure sensor, flow restrictor and give vent to anger the end, the inlet end with the input of flow control unit is connected, the output of flow control unit with the input of flow restrictor is connected, the output of flow restrictor with give vent to anger the end is connected, differential pressure sensor sets up between flow control unit and the flow restrictor for detect the pressure differential between the output of flow control unit and the input of flow restrictor, its characterized in that, the concentration compensation method includes:
step one: acquiring a theoretical differential pressure of the differential pressure sensor and an initial opening value of the flow regulating unit according to a target flow;
step two: controlling the flow regulating unit based on the initial opening value, and acquiring the actual pressure difference of the differential pressure sensor;
step three: judging whether the absolute value of the difference between the actual differential pressure and the theoretical differential pressure is greater than 0 and less than or equal to a threshold value, if the absolute value of the difference between the actual differential pressure and the theoretical differential pressure is greater than the threshold value, calculating an actual opening value of the flow regulating unit based on the actual differential pressure, correcting the initial opening value according to the actual opening value, and returning to the step two; if the absolute value of the difference between the actual pressure difference and the theoretical pressure difference is greater than 0 and less than or equal to the threshold value, comparing the actual pressure difference with the theoretical pressure difference, and if the actual pressure difference is greater than the theoretical pressure difference, compensating the actual measured concentration of the output gas of the gas flow control device by adopting a first concentration compensation coefficient based on the following formula:
C′＝(1-k 1 *ΔPS)*C，
ΔPS＝PS 2 -PS 1
wherein C' is the concentration, k of the output gas after compensation 1 Is a first concentration compensation coefficient, C is the measured concentration of the output gas, PS 2 For the actual pressure difference, PS 1 Δps is a positive number for the theoretical differential pressure;
if the actual pressure difference is smaller than the theoretical pressure difference, the measured concentration of the output gas of the gas flow control device is compensated by adopting a second concentration compensation coefficient based on the following formula:
C′＝(1-k 2 *ΔPS)*C，
ΔPS＝PS 2 -PS 1
wherein C' is the concentration, k of the output gas after compensation 2 Is the second concentration compensation coefficient, C is the measured concentration of the output gas, PS 2 For the actual pressure difference, PS 1 ΔPS is a negative number for the theoretical differential pressure.
2. The method according to claim 1, wherein the theoretical differential pressure of the differential pressure sensor is obtained from the target flow rate based on the following formula:
PS 1 ＝Q*R-ΔPc
wherein PS 1 The theoretical differential pressure of the differential pressure sensor is that deltaPc is the critical differential pressure at two ends of the flow limiter, Q is the target flow, and R is the resistance of the flow limiter.
3. The method according to claim 1, wherein in the case where the flow rate adjustment unit is an adjustable speed pump, the initial opening value of the adjustable speed pump is obtained from a target flow rate based on the following formula:
D 1 ＝m*Q
wherein D is 1 The initial opening value of the speed-adjustable pump is m, the opening parameter of the speed-adjustable pump is m, and Q is the target flow.
4. The method of concentration compensation for a gas flow control device of claim 1 wherein said first concentration compensation factor isWherein R is the resistance of the flow restrictor.
5. The method of concentration compensation for a gas flow control device according to claim 1, wherein said second concentration compensation coefficient isWherein R is the resistance of the flow restrictor.
6. A concentration compensation method of a gas flow rate control device according to claim 1, characterized in that the threshold value of the absolute value of the difference between the actual pressure difference and the theoretical pressure difference is 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210395457.1A CN114860006B (en) | 2022-04-15 | 2022-04-15 | Concentration compensation method of gas flow control device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210395457.1A CN114860006B (en) | 2022-04-15 | 2022-04-15 | Concentration compensation method of gas flow control device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114860006A CN114860006A (en) | 2022-08-05 |
| CN114860006B true CN114860006B (en) | 2024-01-16 |
Family
ID=82630882
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210395457.1A Active CN114860006B (en) | 2022-04-15 | 2022-04-15 | Concentration compensation method of gas flow control device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114860006B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115388329B (en) * | 2022-08-25 | 2024-03-12 | 青岛明华电子仪器有限公司 | Gas cylinder gas supply device and pressure control method thereof |
| CN116929469B (en) * | 2023-09-18 | 2024-01-30 | 四川蜀谷仪表科技有限公司 | Differential pressure flowmeter high-low pressure conversion method and differential pressure flowmeter flow measuring method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1476831A (en) * | 1974-01-10 | 1977-06-16 | Process Systems | Digital fluid flow rate measurement or control system |
| CN1629756A (en) * | 2003-12-16 | 2005-06-22 | 孙怀禄 | Forward feed control and forward feed compensation control system for output terminal |
| CN102032167A (en) * | 2010-12-10 | 2011-04-27 | 浙江工业大学 | Flow compensation technology of digital frequency conversion metering pump |
| WO2018047248A1 (en) * | 2016-09-07 | 2018-03-15 | 日産自動車株式会社 | Engine control method and control device |
| CN109425699A (en) * | 2017-08-23 | 2019-03-05 | 张岩 | A kind of flue gas on-Line Monitor Device for medium and small boiler |
| CN114184744A (en) * | 2021-11-23 | 2022-03-15 | 南京浦蓝大气环境研究院有限公司 | Quantitative calibration method of mobile monitoring equipment based on pressure difference sample injection mode |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2001129B (en) * | 1977-07-12 | 1982-08-04 | Ntn Toyo Bearing Co Ltd | FUEL FEEDING APPARATUS FOR air fuel combustion mixture |
| US20050048195A1 (en) * | 2003-08-26 | 2005-03-03 | Akihiro Yanagita | Dispensing system and method of controlling the same |
-
2022
- 2022-04-15 CN CN202210395457.1A patent/CN114860006B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1476831A (en) * | 1974-01-10 | 1977-06-16 | Process Systems | Digital fluid flow rate measurement or control system |
| CN1629756A (en) * | 2003-12-16 | 2005-06-22 | 孙怀禄 | Forward feed control and forward feed compensation control system for output terminal |
| CN102032167A (en) * | 2010-12-10 | 2011-04-27 | 浙江工业大学 | Flow compensation technology of digital frequency conversion metering pump |
| WO2018047248A1 (en) * | 2016-09-07 | 2018-03-15 | 日産自動車株式会社 | Engine control method and control device |
| CN109425699A (en) * | 2017-08-23 | 2019-03-05 | 张岩 | A kind of flue gas on-Line Monitor Device for medium and small boiler |
| CN114184744A (en) * | 2021-11-23 | 2022-03-15 | 南京浦蓝大气环境研究院有限公司 | Quantitative calibration method of mobile monitoring equipment based on pressure difference sample injection mode |
Non-Patent Citations (2)
| Title |
|---|
| 外壳耐压试验中流量法配气精度的控制方法探讨;杨健;于帆;;电气开关(第01期);全文 * |
| 密度偏差对气体流量测量的影响分析;张建英;;仪器仪表用户(第03期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114860006A (en) | 2022-08-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114860006B (en) | Concentration compensation method of gas flow control device | |
| US10801867B2 (en) | Method and apparatus for self verification of pressured based mass flow controllers | |
| JP3577379B2 (en) | Method and apparatus for measuring and controlling flow and pressure | |
| US9823667B2 (en) | Flow rate control apparatus, storage medium storing program for flow rate control apparatus and flow rate control method | |
| KR101707877B1 (en) | Flow volume control device equipped with flow rate monitor | |
| US9234661B2 (en) | Burner control system | |
| KR101930304B1 (en) | Flow meter | |
| KR101722304B1 (en) | Mass flow controller | |
| US7085628B2 (en) | Apparatus for the correction of temperature drift for pressure sensor, pressure control apparatus and pressure-type flow rate control apparatus | |
| US7905139B2 (en) | Mass flow controller with improved dynamic | |
| US20180094809A1 (en) | Regulating Turbulent Flows | |
| US11421875B2 (en) | Burner control system | |
| US20120132291A1 (en) | Transient measurements of mass flow controllers | |
| US7090486B2 (en) | Control device for a burner and adjusting method | |
| US6430985B1 (en) | Multiple point calibrated HVAC flow rate controller | |
| US20120107753A1 (en) | Burner control systems and methods of operating a burner | |
| KR20210071044A (en) | A device for adjusting the mixing ratio of a gas mixture | |
| JP2008506116A (en) | Method and system for flow measurement and mass flow regulator validation | |
| CN111103020B (en) | Flow detection device, flow control system and flow detection method | |
| US8056579B2 (en) | Mass flow controller | |
| JPH081330B2 (en) | Temperature controller for continuous fluid heating device | |
| JP7194421B2 (en) | Flow control device and flow control method | |
| CN116400750A (en) | Fluid constant pressure control method and fluid constant pressure output system | |
| JPS5926269Y2 (en) | Pressure flow rate automatic measuring device | |
| JPH10198435A (en) | Hydraulic pressure controller |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |