JP6348859B2 - Flow control system - Google Patents

Description

  The present invention relates to a flow rate control system that controls the flow rate of a fluid flowing through a pipe.

  Conventionally, in a chemical plant or the like, a positioner is provided for a valve (control valve) that regulates the flow rate of a fluid (process fluid) passing through the pipe (process pipe), and the opening degree of the valve is controlled by the positioner. I am doing so. This positioner detects the actual opening degree of the valve and controls the opening degree of the valve so that the actual opening degree of the valve coincides with the opening degree instruction value sent from the host controller (controller).

  FIG. 9 shows a general flow control system using a positioner. In the figure, 1 is a process pipe, 2 is a valve for regulating the flow rate of the process fluid passing through the process pipe 1, and 3 is a flow rate for measuring an actual flow rate (mass flow rate or volume flow rate) of the process fluid passing through the process pipe 1. A total of 4 is a controller, 5 is a positioner attached to the valve 2, and 6 is a host system.

In the flow control system, the host system 6 provides a flow indicator value Q _SP to the controller 4. The controller 4 compares the flow rate instruction value Q _SP sent from the actual flow rate Q _PV and host system 6 of the process liquid measured by the flow meter 3, the opening of the valve 2 required to match both The degree is obtained as the opening degree instruction value θ_SP. The opening instruction value θ_SP obtained by the controller 4 is sent to the positioner 5. The positioner 5 detects the actual opening θ_PV of the valve 2 and controls the opening of the valve 2 so that the actual opening θ_PV of the valve 2 matches the opening instruction value θ_SP sent from the controller 4.

Japanese Patent No. 3007587

  However, in such a flow rate control system, if the flow rate control system of the controller 4 operates improperly, the opening degree instruction value θ_SP from the controller 4 may adversely affect the opening degree control system of the positioner 5. For this reason, the improvement of management of the flow rate control system of the controller 4 has been demanded.

  Patent Document 1 discloses a valve positioner that can determine that hunting has occurred in the operation of an electric actuator that drives a valve. The valve positioner disclosed in Patent Document 1 is a hunting determination that determines, during the control process of an electric actuator, that hunting in which the operating angle of the electric actuator changes in a predetermined range centered on a set value has occurred. Means.

  However, the valve positioner disclosed in Patent Document 1 detects a hunting phenomenon due to the unsoundness of the positioner opening control system, and does not focus on the unsoundness of the flow control system of the controller. .

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a flow rate control system capable of improving the management of unhealthyness of a flow rate control system of a controller. It is in.

  In order to achieve such an object, the present invention measures the actual flow rate of a fluid passing through a pipe and a valve for regulating the flow rate of the fluid passing through the pipe in a flow control system that controls the flow rate of the fluid flowing through the pipe. Compare the actual flow rate of the fluid measured by the flow meter and the flow rate instruction value sent from the upper level, and obtain the opening degree of the valve necessary to match the two as the opening degree instruction value A controller, a positioner that detects the actual opening of the valve and controls the opening of the valve so that the actual opening of the valve matches the opening instruction value sent from the controller, and the opening instruction value and the valve At least one of the actual opening is acquired at a predetermined sampling cycle, and the control is performed from at least one of the opening instruction value and the actual opening of the valve within the predetermined period acquired at the predetermined sampling cycle. Characterized in that it comprises a management index calculating unit for obtaining the indication of the unsoundness potential of the flow control system of over La as a management indicator.

In the present invention, the management index calculation unit acquires at least one of the opening instruction value and the actual opening of the valve at a predetermined sampling period, and the opening instruction value and the valve within a predetermined period acquired at the predetermined sampling period. An index indicating the possibility of unhealthyness of the flow control system of the controller is obtained as a management index from at least one of the actual opening degrees. In this case, the management index calculation unit is a ratio of an integrated value of the change amount of the opening instruction value for each sampling cycle within a predetermined period and an integrated value of the change amount of the actual opening of the valve (corresponding to a management index Aj described later). ) As a management index, or the ratio between the integrated value of the change amount of the actual opening of the valve and the absolute value of the difference between the initial value and the final value of the actual opening of the valve for each sampling period within a predetermined period (described later) Or the absolute value of the difference between the integrated value of the change amount of the opening instruction value and the initial value and the final value of the opening instruction value for each sampling period within a predetermined period. Ratio (corresponding to a management index Cj described later) as a management index, or an integrated value of the absolute value of the difference between the actual opening of the valve and the opening instruction value for each sampling period within a predetermined period (a management index described later) Or equivalent to Dj) as a management index.

  In the present invention, the management index obtained by the management index calculation unit is compared with a predetermined threshold, and when the management index exceeds the threshold, an alarm may be issued. The average value of the opening instruction value within the predetermined period and the management index are recorded, and the relationship between the opening instruction value and the management index for each predetermined period and the threshold value for the management index are output as auxiliary information. The minimum and maximum values of the opening instruction value within the predetermined period for each predetermined period and the management index are recorded, and the relationship between the minimum and maximum values of the opening instruction value for each predetermined period and the management index And a threshold for the management index may be output as auxiliary information.

  According to the present invention, at least one of the opening instruction value and the actual opening of the valve is acquired at a predetermined sampling period, and the opening instruction value and the actual opening of the valve within a predetermined period acquired at the predetermined sampling period. Since an index indicating the possibility of unhealthyness of the controller's flow control system is obtained as a management index from at least one of the above, an alarm is issued by comparing the management index with a threshold value, etc. It becomes possible to improve management of unsoundness of the flow control system.

It is a figure which shows the principal part of one Embodiment of the flow control system which concerns on this invention. It is a functional block diagram of the principal part of this flow control system. It is a figure which shows the normal response when the flow rate instruction value is changed. It is a figure which shows the inappropriate response when a flow rate instruction | indication value is changed. FIG. 6 is a functional block diagram of a main part of a flow rate control system according to a second embodiment. It is a figure which shows the example of a display of the auxiliary information in the flow control system of Embodiment 2. FIG. 10 is a functional block diagram of a main part of a flow rate control system according to a third embodiment. It is a figure which shows the example of a display of the auxiliary information in the flow control system of Embodiment 3. It is a figure which shows the general flow control system using a positioner.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  Prior to the description of the embodiments, the technical idea (important points of focus) of the present invention will be briefly described. When the valve (control valve) is used as an actuator of the flow control system, the inventor of the present application follows the opening instruction value when the feedback control of the flow control gives the opening instruction value in vibration. In this case, a problem was found that useless U-turn tracking (described later) may occur. And, it is possible to know the possibility of unhealthy flow control system by focusing on useless U-turn tracking as a management target, calculating and monitoring a management index as an index reflecting this phenomenon I came up with it. The embodiments described below are based on such a technical idea and show specific examples for realizing the present invention.

[Embodiment 1]
FIG. 1 is a diagram showing a main part of an embodiment of a flow rate control system according to the present invention. The same reference numerals as those in FIG. 9 denote the same or equivalent components as those described with reference to FIG. The description is omitted. FIG. 2 is a functional block diagram of the main part of the flow control system (the flow control system of the first embodiment).

  In the present embodiment, the controller 4 includes an opening degree instruction determination unit 41, and the positioner 5 includes an opening degree control unit 51, an opening degree detection unit 52, a management index calculation unit 53, and a management index transmission unit 54. 6 includes a flow rate instruction setting unit 61, a management index receiving unit 62, an alarm notification unit 63, and a display unit 64.

  The processing operation of each unit in the controller 4, the positioner 5, and the host system 6 is realized by hardware including a processor and a storage device, and a program that realizes various functions in cooperation with these hardware. Specifically, the program is installed in the computer, and the processing operation of the CPU according to the installed program is realized.

In the host system 6, flow indicator setting unit 61 sends the flow indicator value Q _SP to the controller 4. In the controller 4, position indicator determining unit 41 compares the actual flow rate Q _PV process liquid measured by the flow rate instruction value Q _SP and flow meter 3 sent from the host system 6, to match both The required opening degree of the valve 2 is obtained as an opening degree instruction value θ_SP, and the obtained opening degree instruction value θ_SP is sent to the positioner 5.

In the positioner 5, the opening detector 52 detects the actual opening θ_PV of the valve 2, and the opening controller 51 detects the opening instruction value θ_SP sent from the controller 4 and the valve 2 detected by the opening detector 52. The opening degree of the valve 2 is controlled so that the actual opening degree θ_PV coincides with the actual opening degree θ_PV. Thus, the flow rate of the process fluid flowing through the process lines 1 are incorporated fit flow indicator value Q _SP from the host system 6.

  In the positioner 5, the management index calculation unit 53 calculates the opening instruction value θ_SP from the controller 4 and the actual opening θ_PV of the valve 2 detected by the opening detection unit 52 at a predetermined sampling period Δt (for example, Δt = 50 ms). The possibility that the flow rate control system of the controller 4 is unhealthy from the opening instruction value θ_SP and the actual opening θ_PV of the valve 2 within a predetermined period T (for example, T = 20 s) acquired at the sampling period Δt. A management index Aj is obtained for each predetermined period T as an index indicating.

  In the positioner 5, the management index transmission unit 54 transmits the management index Aj obtained by the management index calculation unit 53 to the upper system 6 by digital communication. The management index Aj will be described later.

  In the host system 6, the management index receiving unit 62 receives the management index Aj sent from the positioner 5. In the host system 6, the alarm reporting unit 63 compares the management index Aj received by the management index receiving unit 62 with a predetermined threshold Ath, and issues an alarm if the management index Aj exceeds the threshold Ath. I will inform you. This alarm is sent to the display unit 64. The display unit 64 notifies the operator of an alarm from the alarm notification unit 63 on the screen. Note that an alarm may be notified to the operator by a ringing sound such as a buzzer.

[About management index Aj]
The flow rate control system, the flow rate instruction value Q _SP from the host system 6 is changed, accordingly the controller 4 changes the opening degree instruction value Shita_SP, transmitted to the positioner 5. In this case, a response as shown in FIG. 3 is usually obtained.

  FIG. 3 plots time series changes of the opening instruction value θ_SP and the actual opening θ_PV, with time on the horizontal axis and opening on the vertical axis. Following the change 50% → 55% of the opening instruction value θ_SP, the actual opening θ_PV follows with waste time and response delay. The state of response varies depending on the size of the valve 2 and the like.

  FIG. 4 shows an inappropriate response. In this example, the opening degree instruction value θ_SP is once changed from 50% to 60% and changed to 55% after 2 seconds. In this case, the actual opening θ_PV is once controlled toward 60%, exceeds 55%, and then is controlled again to 55%. Such tracking is called U-turn tracking.

  The valve 2 has many sliding portions, and generally adopting an integrated value of the sliding distance as an index for maintenance. The greater the number of movements, the higher the probability of failure. Therefore, if the integrated value of the sliding distance increases, the priority of maintenance is increased.

  In the inappropriate response shown in FIG. 4, the integrated value of the sliding distance tends to increase. After the opening instruction value θ_SP has once increased for some reason, it has settled to the target opening instruction value θ_SP (55%), and it can be seen that the actual opening θ_PV that has been followed has moved excessively.

  In the present embodiment, the management index Aj is used as an index reflecting the result of the phenomenon shown in FIG. That is, by calculating and monitoring an index based on the opening degree instruction value θ_SP and the actual opening degree θ_PV, the possibility of unsoundness of the flow rate control system of the controller 4 is known.

This management index Aj is obtained by the following equation (1).
Aj = ΣΔθ_SPi ÷ ΣΔθ_PVi (1)

In this equation (1), the subscript i of Δθ_SPi = | θ_SPi−θ_SPi ₋₁ |, Δθ_PVi = | θ_PVi−θ_PVi ₋₁ | The subscript j of Aj is a management index sample (sample for each predetermined period T), ΣΔθ_SPi is an integrated value of Δθ_SPi within a predetermined period T, and ΣΔθ_PVi is an integrated value of Δθ_PVi within a predetermined period T.

  The management index Aj expressed by the equation (1) is an integration of the integrated value ΣΔθ_SPi of the change amount Δθ_SPi of the opening instruction value θ_SPi and the change amount Δθ_PVi of the actual opening θ_PVi of the valve 2 for each sampling period Δt within the predetermined period T. The ratio with the value ΣΔθ_PVi is shown.

  If the opening instruction value θ_SP moves more than the actual opening θ_PV, the management index Aj becomes large, and it can be estimated that this is a result of useless U-turn tracking. By monitoring this management index Aj, it is possible to know the possibility that the flow rate control system of the controller 4 is unhealthy.

  For example, the management index Aj at the normal response shown in FIG. 3 is Aj = 1.00, whereas Aj at the inappropriate response shown in FIG. 4 is Aj = 1.23 (i is Samples every 50 ms, j is every 20 s).

  If the opening degree instruction value θ_SP is normal, the management index Aj is close to 1.00, and as the management index Aj increases from 1.00, the sliding of the valve 2 due to the unhealthyness of the flow control system of the controller 4 There is a high possibility that the distance is unnecessarily large.

  Therefore, in the flow rate control system according to the present embodiment, the management index Aj is obtained every time the predetermined period T elapses in the management index calculation unit 53 provided in the positioner 5, and the management index Aj for each predetermined period T is obtained from the upper system 6. Monitoring is performed, and when the management index Aj exceeds the threshold value Ath, an alarm is automatically issued, thereby realizing unhealthy management of the flow control system of the controller 4.

The accumulated time for obtaining the management index Aj, that is, the predetermined period T (the number of samples I within the predetermined period T) in the management index calculation unit 53 is based on the following policies (1) and (2). decide.
(1) It is determined according to the time constant for the purpose of control (eg, it is sufficiently shorter than the time constant for temperature control).
* The change of the opening command value θ_SP accompanying the normal temperature setting value change is not unhealthy.
(2) It is determined according to the valve operating speed (the time required from fully closed to fully open) (eg, sufficiently longer than the valve operating speed).
* The management index is meaningless unless it is sufficiently longer than the actual opening θ_PV.

[Variations of management indicators]
In the above-described embodiment, the management index Aj represented by the above equation (1) is obtained as an index indicating the possibility of unhealthyness of the flow rate control system of the controller 4, but other similar management indices are available. There are various things.

[Management index Bj: Initial value and final value of θ_PV in a predetermined period (integrated time) T are also used]
For example, the management index Bj expressed by the following equation (2) is used to evaluate the difference between the endmost route to the value that is finally desired to be reached and the route that has actually passed (the absolute value integrated value).

Bj = ΣΔθ_PVi ÷ (| θ_PVi_Ij−θ_PVi_Ej |) (2)
In the equation (2), θ_PVi_Ij represents the value [%] of θ_PV at the start time of the sample j, and θ_PVi_Ej represents the value [%] of θ_PV at the last time of the sample j.

  The management index Bj represented by the above equation (2) is obtained by integrating the integrated value ΣΔθ_PVi of the change amount Δθ_PVi of the actual opening θ_PVi of the valve 2 and the initial value θ_PVi_Ij of the actual opening θ_PVi of the valve 2 for each sampling period Δt within the predetermined period T. And the absolute value | θ_PVi_Ij−θ_PVi_Ej | of the difference between the final value θ_PVi_Ej and the final value θ_PVi_Ej.

  When the management index Bj is greater than 1, θ_PV is passing through a useless route compared to the shortest route toward the final value. If the predetermined period (integrated time) T is sufficiently larger than the response speed of θ_PV, it is suggested that the sliding distance of the valve 2 may be increased unnecessarily due to the unsoundness of the flow control system of the controller 4. can do.

[Management index Cj: Initial value and final value of θ_SP in a predetermined period (integrated time) T are also used]
Similar to the management index Bj, the management index Cj represented by the following equation (3) is used to evaluate the difference between the most extreme path to the value to be finally reached and the actual path (the integrated value of the absolute value). Is used.

Cj = ΣΔθ_SPi ÷ (| θ_SPi_Ij−θ_SPi_Ej |) (3)
In the equation (3), θ_SPi_Ij represents the value [%] of θ_SP at the start time of the sample j, and θ_SPi_Ej represents the value [%] of θ_SP at the last time of the sample j.

  The management index Cj expressed by the above equation (3) includes the integrated value ΣΔθ_SPi of the change amount Δθ_SPi of the opening instruction value θ_SPi and the initial value θ_SPi_Ij and the final value θ_SPi_Ej of the opening instruction value θ_SPi for each sampling period Δt within the predetermined period T. And the absolute value | θ_SPi_Ij−θ_SPi_Ej |.

  When the management index Cj is larger than 1, it indicates that θ_SP tends to pass a useless route compared to the shortest route toward the final value. However, it is different from the management index Bj in that there is a possibility that such a change in θ_SP may be requested as a result of the control function of the host system 6, and attention should be paid to its use.

[Management index Dj: The difference between θ_PVi and θ_SPi is also used]
When the difference between the actual opening θ_PVi of the valve 2 and the opening instruction value θ_SPi is Ei = θ_PVi−θ_SPi, if the integrated value of | Ei | is large, the actual opening degree instruction value θ_SP is accompanied by a U-turn. There is a high possibility that the opening θ_PVi is also moving in vain. Therefore, paying attention to the integrated value of | Ei |, the management index Dj expressed by the following equation (4) is used.

Dj = Σ | Ei | (4)
In this equation (4), Σ | Ei | represents an integrated value of | Ei | within a predetermined period T.

  The management index Dj expressed by the above equation (4) indicates the integrated value of the absolute value | Ei | of the difference between the actual opening θ_PVi of the valve 2 and the opening instruction value θ_SPi for each sampling period Δt within the predetermined period T. ing.

  Since the actual opening θ_PVi of the valve 2 is delayed from the opening instruction value θ_SPi, the management index Dj is a management index having a certain size. Although the absolute value cannot be evaluated, it can be an index indicating the possibility of unsoundness of the flow control system of the controller 4 relative to the time series change of the management index Dj. For example, there is a high possibility that the flow rate control system of the controller 4 is unhealthy when, for example, the management index Dj tends to increase despite the control around the same opening degree.

[Embodiment 2]
FIG. 5 shows a functional block diagram of the main part of the flow control system of the second embodiment.

  In the flow rate control system according to the second embodiment, the positioner 5 includes an opening degree control unit 51, an opening degree detection unit 52, a management index calculation unit 53, and a management index transmission unit 54, and within a predetermined period T every predetermined period T. Is provided with an opening instruction average value calculation unit 55 for calculating an average value (opening instruction average value) Mean_θ_SPj.

  In this positioner 5, the management index transmission unit 54 includes an opening instruction average value for each predetermined period T from the opening instruction average value calculation unit 55 in addition to the management index Aj for each predetermined period T from the management index calculation unit 53. Mean_θ_SPj is transmitted to the host system 6 as a pair.

  In the flow rate control system according to the second embodiment, the host system 6 includes a predetermined period sent from the positioner 5 in addition to the flow rate instruction setting unit 61, the management index receiving unit 62, the alarm reporting unit 63, and the display unit 64. A recording unit 65 that records a pair of the management index Aj and the opening instruction average value Mean_θ_SPj for each T is provided.

  In the host system 6, the management index receiving unit 62 receives a pair of the management index Aj and the opening instruction average value Mean_θ_SPj for each predetermined period T sent from the positioner 5, and sends the management index Aj to the alarm reporting unit. On the other hand, a pair of the management index Aj and the opening instruction average value Mean_θ_SPj is sent to the recording unit 65.

  In the host system 6, the display unit 64 also displays auxiliary information on the relationship between the opening instruction average value Mean_θ_SPj and the management index Aj for each predetermined period T recorded in the recording unit 65 and the threshold value Ath for the management index Aj. Display as.

  FIG. 6 shows a display example of auxiliary information on the display unit 64. In this example, the horizontal axis is Mean_θ_SPj, the vertical axis is Aj, and the intersection indicating the pair of the opening instruction average value Mean_θ_SPj and the management index Aj for each predetermined period T is indicated by a black circle, so that the opening for each predetermined period T is indicated. A pair of the degree instruction average value Mean_θ_SPj and the management index Aj is plotted in the graph together with the threshold value Ath.

  As can be seen from this display example, since the opening degree of the valve 2 when the management index Aj exceeds the threshold value Ath is clear, useful assistance for verifying unhealthyness of the flow rate control system of the controller 4 It is information.

[Embodiment 3]
FIG. 7 shows a functional block diagram of the main part of the flow control system of the third embodiment.

  In the flow rate control system of the third embodiment, the positioner 5 includes an opening degree control unit 51, an opening degree detection unit 52, a management index calculation unit 53, and a management index transmission unit 54, and within a predetermined period T every predetermined period T. Is provided with a minimum value maximum value extraction unit 56 for extracting a minimum value Min_θ_SPj and a maximum value Max_θ_SPj from the opening degree instruction value θ_SP.

  In the positioner 5, the management index transmission unit 54 includes the minimum value Min_θ_SPj and the maximum value for each predetermined period T from the minimum value / maximum value extraction unit 56 in addition to the management index Aj for each predetermined period T from the management index calculation unit 53. Max_θ_SPj is transmitted as a pair to the host system 6.

  In the flow rate control system according to the second embodiment, the host system 6 includes a predetermined period sent from the positioner 5 in addition to the flow rate instruction setting unit 61, the management index receiving unit 62, the alarm reporting unit 63, and the display unit 64. A recording unit 65 that records a pair of the management index Aj for each T, the minimum value Min_θ_SPj, and the maximum value Max_θ_SPj is provided.

  In the host system 6, the management index receiving unit 62 receives a pair of the management index Aj, the minimum value Min_θ_SPj, and the maximum value Max_θ_SPj for each predetermined period T sent from the positioner 5, and issues an alarm notification of the management index Aj. Meanwhile, a pair of the management index Aj, the minimum value Min_θ_SPj, and the maximum value Max_θ_SPj is sent to the recording unit 65.

  Further, the display unit 64 displays the relationship between the minimum value Min_θ_SPj and the maximum value Max_θ_SPj for each predetermined period T recorded in the recording unit 65 and the management index Aj and the threshold value Ath for the management index Aj as auxiliary information.

  FIG. 8 shows a display example of auxiliary information on the display unit 64. In this example, the horizontal axis is Min / Max_θ_SPj, the vertical axis is Aj, the minimum value Min_θ_SPj and the maximum value Max_θ_SPj for each predetermined period T are connected by a bar along the horizontal axis, and the minimum value Min_θ_SPj and the maximum value are connected. By arranging at the position of the management index Aj sent as a pair with Max_θ_SPj, a pair of the minimum value Min_θ_SPj and the maximum value Max_θ_SPj and the management index Aj for each predetermined period T is plotted in the graph together with the threshold value Ath. Yes.

  As can be seen from this display example, the position of the opening instruction value θ_SP when the management index Aj exceeds the threshold value Ath and its upper and lower limits are clear, so the unsoundness of the flow rate control system of the controller 4 is verified. It is useful auxiliary information to do. In addition, similar statistics (median, 25% line, 75% line) can be useful auxiliary information.

  In the second and third embodiments described above, the display unit 64 corresponds to the auxiliary information output unit in the present invention. However, the auxiliary information displayed on the display unit 64 is printed out as a report. May be. In this case, the printer corresponds to the auxiliary information output unit.

  In the above-described embodiment, the management index calculation unit 53 is provided in the positioner 5, but it may be provided in the host system 6. On the contrary, the alarm notification unit 63 and the recording unit 65 may be provided in the positioner 5, and various modifications are possible.

[Extension of the embodiment]
The present invention has been described above with reference to the embodiment. However, the present invention is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the technical idea of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Process piping, 2 ... Valve, 3 ... Flow meter, 4 ... Controller, 5 ... Positioner, 6 ... Host system, 41 ... Opening direction determination part, 51 ... Opening control part, 52 ... Opening degree detection part, 53 ... management index calculation unit, 54 ... management index transmission unit, 55 ... opening instruction average value calculation unit, 56 ... minimum value / maximum value extraction unit, 61 ... flow rate instruction setting unit, 62 ... management index reception unit, 63 ... alarm generation Information section, 64 ... display section, 65 ... recording section.

Claims (7)

In the flow rate control system that controls the flow rate of the fluid flowing through the piping,
A valve for regulating the flow rate of the fluid passing through the pipe;
A flow meter for measuring the actual flow rate of the fluid passing through the pipe;
A controller that compares the actual flow rate of the fluid measured by the flow meter with the flow rate instruction value sent from the host, and obtains the opening degree of the valve necessary to match the two as the opening degree instruction value;
A positioner that detects the actual opening of the valve and controls the opening of the valve so that the actual opening of the valve matches an opening instruction value sent from the controller;
At least one of the opening instruction value and the actual opening of the valve is acquired at a predetermined sampling period, and from at least one of the opening instruction value and the actual opening of the valve within a predetermined period acquired at the predetermined sampling period A management index calculation unit for obtaining an index indicating the possibility of unhealthy flow rate control system of the controller as a management index ,
The management index calculation unit
A flow rate control characterized in that a ratio between an integrated value of the change amount of the opening instruction value and an integrated value of the change amount of the actual opening of the valve for each sampling period within the predetermined period is obtained as the management index. system. In the flow rate control system that controls the flow rate of the fluid flowing through the piping,
A valve for regulating the flow rate of the fluid passing through the pipe;
A flow meter for measuring the actual flow rate of the fluid passing through the pipe;
A controller that compares the actual flow rate of the fluid measured by the flow meter with the flow rate instruction value sent from the host, and obtains the opening degree of the valve necessary to match the two as the opening degree instruction value;
A positioner that detects the actual opening of the valve and controls the opening of the valve so that the actual opening of the valve matches an opening instruction value sent from the controller;
At least one of the opening instruction value and the actual opening of the valve is acquired at a predetermined sampling period, and from at least one of the opening instruction value and the actual opening of the valve within a predetermined period acquired at the predetermined sampling period A management index calculation unit for obtaining an index indicating the possibility of unhealthy flow rate control system of the controller as a management index,
The management index calculation unit
A ratio between the integrated value of the change amount of the actual opening of the valve and the absolute value of the difference between the initial value and the final value of the actual opening of the valve for each sampling period within the predetermined period is obtained as the management index. A flow control system characterized by that. In the flow rate control system that controls the flow rate of the fluid flowing through the piping,
A valve for regulating the flow rate of the fluid passing through the pipe;
A flow meter for measuring the actual flow rate of the fluid passing through the pipe;
A controller that compares the actual flow rate of the fluid measured by the flow meter with the flow rate instruction value sent from the host, and obtains the opening degree of the valve necessary to match the two as the opening degree instruction value;
A positioner that detects the actual opening of the valve and controls the opening of the valve so that the actual opening of the valve matches an opening instruction value sent from the controller;
At least one of the opening instruction value and the actual opening of the valve is acquired at a predetermined sampling period, and from at least one of the opening instruction value and the actual opening of the valve within a predetermined period acquired at the predetermined sampling period A management index calculation unit for obtaining an index indicating the possibility of unhealthy flow rate control system of the controller as a management index,
The management index calculation unit
Obtaining a ratio between the integrated value of the change amount of the opening instruction value for each sampling period within the predetermined period and the absolute value of the difference between the initial value and the final value of the opening instruction value as the management index. Characteristic flow control system. In the flow rate control system that controls the flow rate of the fluid flowing through the piping,
A valve for regulating the flow rate of the fluid passing through the pipe;
A flow meter for measuring the actual flow rate of the fluid passing through the pipe;
A controller that compares the actual flow rate of the fluid measured by the flow meter with the flow rate instruction value sent from the host, and obtains the opening degree of the valve necessary to match the two as the opening degree instruction value;
A positioner that detects the actual opening of the valve and controls the opening of the valve so that the actual opening of the valve matches an opening instruction value sent from the controller;
At least one of the opening instruction value and the actual opening of the valve is acquired at a predetermined sampling period, and from at least one of the opening instruction value and the actual opening of the valve within a predetermined period acquired at the predetermined sampling period A management index calculation unit for obtaining an index indicating the possibility of unhealthy flow rate control system of the controller as a management index,
The management index calculation unit
A flow rate control system characterized in that an integrated value of an absolute value of a difference between an actual opening degree of the valve and the opening degree instruction value for each sampling period within the predetermined period is obtained as the management index . In the flow control system according to any one of claims 1 to 4 ,
An alarm notification unit that compares the management index obtained by the management index calculation unit with a predetermined threshold and issues an alarm when the management index exceeds the threshold
Flow control system, characterized in that it comprises a. In the flow rate control system that controls the flow rate of the fluid flowing through the piping,
A valve for regulating the flow rate of the fluid passing through the pipe;
A flow meter for measuring the actual flow rate of the fluid passing through the pipe;
A controller that compares the actual flow rate of the fluid measured by the flow meter with the flow rate instruction value sent from the host, and obtains the opening degree of the valve necessary to match the two as the opening degree instruction value;
A positioner that detects the actual opening of the valve and controls the opening of the valve so that the actual opening of the valve matches an opening instruction value sent from the controller;
At least one of the opening instruction value and the actual opening of the valve is acquired at a predetermined sampling period, and from at least one of the opening instruction value and the actual opening of the valve within a predetermined period acquired at the predetermined sampling period A management index calculation unit for obtaining an index indicating the possibility of unhealthy flow rate control system of the controller as a management index;
A recording unit that records an average value of the opening instruction value and the management index within the predetermined period for each predetermined period;
An auxiliary information output unit that outputs, as auxiliary information, a relationship between an average value of opening instruction values recorded in the recording unit for each predetermined period and a management index, and a threshold value for the management index ; To flow control system. In the flow rate control system that controls the flow rate of the fluid flowing through the piping,
A valve for regulating the flow rate of the fluid passing through the pipe;
A flow meter for measuring the actual flow rate of the fluid passing through the pipe;
A controller that compares the actual flow rate of the fluid measured by the flow meter with the flow rate instruction value sent from the host, and obtains the opening degree of the valve necessary to match the two as the opening degree instruction value;
A positioner that detects the actual opening of the valve and controls the opening of the valve so that the actual opening of the valve matches an opening instruction value sent from the controller;
At least one of the opening instruction value and the actual opening of the valve is acquired at a predetermined sampling period, and from at least one of the opening instruction value and the actual opening of the valve within a predetermined period acquired at the predetermined sampling period A management index calculation unit for obtaining an index indicating the possibility of unhealthy flow rate control system of the controller as a management index;
A recording unit for recording the minimum value and the maximum value of the opening instruction value within the predetermined period and the management index for each predetermined period;
An auxiliary information output unit that outputs, as auxiliary information, the relationship between the minimum and maximum values of the opening instruction values recorded in the recording unit for each predetermined period and the management index and the threshold value for the management index. A flow control system characterized by

Images