Rectifying tower control loop evaluation method

Abstract

The invention provides a rectifying tower control loop evaluation method, and belongs to the field of chemical rectifying tower operation loop evaluation. Comprising the following steps: selecting a rectifying tower control loop; calculating the automatic input rate of the control loop; calculating a controlled variable mean value and a fluctuation variance of the control loop in a manual state; calculating a controlled variable mean value, a fluctuation variance and an error absolute value integral of the control loop in an automatic state; calculating the viscosity of the actuator of the control loop in the manual state; calculating the viscosity of the actuator of the control loop in the automatic state; calculating a mean value score and a fluctuation variance score of the control loop in a manual state; calculating a mean value score, a fluctuation variance score and an error absolute value integral score of the control loop in an automatic state; and calculating an automatic input rate of the control loop, an evaluation score in a manual operation state and an evaluation score in an automatic operation state. The method can quantitatively analyze the control quality of the rectifying tower control loop, and has very high application value.

Description

Technical Field

[0001] The present invention relates to the field of evaluating the operation loop of chemical distillation columns, and particularly to a method for evaluating the control loop of a distillation column. Background Art

[0002] As a core device for separating mixtures in the fields of chemical engineering, petroleum, pharmaceuticals, etc., the operation level of a distillation column directly affects product quality, energy consumption, and production efficiency.

[0003] Currently, there is little research on the evaluation method of the operation state of distillation columns. There are some studies on the loop evaluation of power systems, such as the secondary loop error state evaluation method (CN202411472868.1), the temperature control loop performance evaluation method (CN202311100060.6), the performance evaluation method of the PID control loop (CN202311382820.7), the performance evaluation method and system of the control loop of a distributed control system (CN202210859982.4), etc. The above loop evaluation methods pay more attention to the control performance in the automatic input state, ignoring the evaluation of the manual state in the distillation column system, and the implementation methods are difficult to implement. The present invention proposes a method for evaluating the control loop of a distillation column, which can calculate the automatic input rate of the distillation column loop, and normalize the control quality in the automatic state and the manual state to score, calculate the evaluation score in the manual operation state and the evaluation score in the automatic operation state, with clear calculation formulas, quantitative measurement, etc., and can be quickly realized, having strong application value. Summary of the Invention

[0004] The present invention proposes a method for evaluating the control loop of a distillation column, belonging to the field of evaluating the operation loop of chemical distillation columns. The method includes the following steps: selecting the control loop of the distillation column; calculating the automatic input rate of the control loop; calculating the mean value and fluctuation variance of the controlled variable of the control loop in the manual state; calculating the mean value, fluctuation variance, and integral of the absolute value of the error of the controlled variable of the control loop in the automatic state; calculating the viscosity of the actuator of the control loop in the manual state; calculating the viscosity of the actuator of the control loop in the automatic state; calculating the mean value score and fluctuation variance score of the control loop in the manual state; calculating the mean value score, fluctuation variance score, and integral of the absolute value of the error score of the control loop in the automatic state; calculating the automatic input rate of the control loop, the evaluation score of the control loop in the manual operation state, and the evaluation score of the control loop in the automatic operation state. This method can quantitatively analyze the control quality of the distillation column control loop and has strong practical application value.

[0005] A method for evaluating the control loop of a distillation column, characterized by comprising the following steps: Step 1: Select a control loop of the distillation column system and, according to a certain sampling period Collect n the controlled variable PV, the set value SP of the controlled variable, the actuator command value MV, the actuator feedback value MV f and the automatic input status Au of this control loop. It is "in" for input, indicating that the automatic mode is not engaged; Step 2: Calculate the automatic input rate of this control loop : Step 3: Calculate the average value of the controlled variable of this control loop in the manual state : Step 4: Calculate the variance of the fluctuation of the controlled variable of this control loop in the manual state : Step 5: Calculate the average value of the controlled variable of this control loop in the automatic state ; Step 6: Calculate the variance of the fluctuation of the controlled variable of this control loop in the automatic state ; Step 7: Calculate the integral of the absolute value of the error of the controlled variable of this control loop in the automatic state ; Step 8: Calculate the viscosity of the actuator of this control loop in the manual state ; Step 9: Calculate the viscosity of the actuator of this control loop in the automatic state ; Step 10: Based on the expected average value of the controlled variable of this control loop in the manual state , calculate the average value score of this control loop in the manual state ; Step 11: Based on the expected variance of the fluctuation of the controlled variable in the manual state , calculate the variance score of the fluctuation of this control loop in the manual state ; Step 12: Based on the expected average value of the controlled variable of this control loop in the automatic state , calculate the average value score of this control loop in the automatic state ; Step 13: Based on the expected variance of the fluctuation of the controlled variable in the automatic state , calculate the variance score of the fluctuation of this control loop in the automatic state ; Step 1: Based on the expected integral of the absolute value of the error of the controlled variable in the automatic state , calculate the integral score of the absolute value of the error of this control loop in the automatic state ; Step 15: Based on what is obtained in Step 8 , what is obtained in Step 10 , and what is obtained in Step 11 , obtain the evaluation score of the control loop in the manual operation state ; Step 16: Based on what is obtained in Step 9 , what is obtained in Step 12 , what is obtained in Step 13 , and what is obtained in Step 14 , obtain the evaluation score of the control loop in the automatic operation state ; Step 17: Obtain the automatic input rate of the control loop , the evaluation score of the control loop in the manual operation state , and the evaluation score of the control loop in the automatic operation state .

[0006] Further, in Step 2, use the following formula to calculate the automatic input rate of the control loop : (1); where i represents the i th data collection moment, represents the i th collected automatic input state data; In Step 3, use the following formula to calculate the mean value of the controlled variable of the control loop in the manual state : (2); where j represents the j th data collection moment, represents the automatic input state statistics, that is, when there is , when there is ; represents j controlled variable values, and when there is , when there is .

[0007] Further, in Step 4, use the following formula to calculate the fluctuation variance of the controlled variable of the control loop in the manual state : (3); represents that formula (3) is at Perform the calculation at this time, otherwise skip the calculation of formula (3) at the j th acquisition moment; In step five, use the following formula to calculate the average value of the controlled variable of this control loop in the automatic state : (4); Where p represents the p th acquisition data moment, represents the automatic input state statistics, that is when there is , when there is ; represents p the values of the controlled variables, and when there is , when there is .

[0008] Furthermore, in step six, use the following formula to calculate the fluctuation variance of the controlled variable of this control loop in the automatic state : (5); Where represents that formula (5) is calculated at this time, otherwise skip the calculation of formula (5) at the p th acquisition moment; In step seven, use the following formula to calculate the absolute value integral of the error of the controlled variable of this control loop in the automatic state : (6); Where x represents the x th acquisition data moment, represents that formula (6) is calculated at this time, otherwise skip the calculation of formula (6) at the x th acquisition moment.

[0009] Furthermore, in step eight, use the following formula to calculate the viscosity of the actuator of this control loop in the manual state : (7); Where z represents the z th acquisition data moment, when it represents that formula (7) is calculated at this time, otherwise skip the zCalculated by formula (7) at each acquisition moment.

[0010] In step nine, the viscosity of the actuator of this control loop in the automatic state is calculated using the following formula : (8); Where y represents the y th acquisition data moment, When it means that formula (8) is calculated at y otherwise, the calculation of formula (8) at the

[0011] th acquisition moment is skipped. Furthermore, in step ten, based on the expected mean value of the controlled variable of this control loop in the manual state, the mean value score of this control loop in the manual state is calculated: In step eleven, the fluctuation variance score of this control loop in the manual state: (10).

[0012] 7. In step twelve, the mean value score of this control loop in the automatic state: (11); In step thirteen, the fluctuation variance score of this control loop in the automatic state: (12).

[0013] Furthermore, in step fourteen, the integral score of the absolute value of the error of this control loop in the automatic state: (13).

[0014] Furthermore, in step fifteen, the evaluation score of this control loop in the manual operation state: (14) Where , and are the weight systems. Generally, there is , and , , .

[0015] Further, in step sixteen, the evaluation score in the automatic operation state of the control loop : (15) wherein 、 、 and are the weight systems. Generally, there is and 、 , and .

[0016] Step seventeen, obtain the automatic input rate of the control loop , the evaluation score in the manual operation state of the control loop , the evaluation score in the automatic operation state of the control loop .

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: Aiming at the problem that there are few research on the evaluation method of the operation state of the current distillation column, the present technical solution proposes a distillation column control loop evaluation method, which can calculate the automatic input rate of the distillation column loop, and normalize the control quality in the automatic state and the manual state, calculate the evaluation score in the manual operation state and the evaluation score in the automatic operation state. The present technical solution not only pays attention to the system operation quality in the automatic input state, but also pays attention to the system operation quality in the manual state. The present technical solution can quantitatively, visually and multi-dimensionally analyze the distillation column system, can guide the control optimization and evaluate the control quality before and after optimization, and has important value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A distillation column control loop evaluation method of the present invention DETAILED DESCRIPTION OF THE INVENTION

[0019] A distillation column control loop evaluation method, the process is as Figure 1 shown, and is characterized in that it includes the following steps: A distillation column control loop evaluation method, characterized in that it includes the following steps: 101: Select a certain control loop of the distillation column system, and collect at a certain sampling period n the controlled variable PV of this control loop, the set value SP of the controlled variable, the actuator command value MV, the actuator feedback value MV f , the automatic input state Au, is input, Indicates that the automatic mode is not engaged; in this embodiment, the light component content loop in the overhead product of the distillation column system is selected. The controlled variable is the light component content in the overhead product of the distillation column system. The set value of the controlled variable is the set value of the light component content in the overhead product of the distillation column system. The actuator command value is the reflux flow rate, and the actuator feedback value is the actual value of the reflux flow rate; seconds, ; 102: Calculate the automatic engagement rate of this control loop using the following formula : (1) where i represents the i th data acquisition moment, represents the i th acquired automatic engagement status data; in this embodiment ; 103: Calculate the mean value of the controlled variable of this control loop in the manual state using the following formula : (2) where j represents the j th data acquisition moment, represents the automatic engagement status statistics, that is when there is , when there is ; represents j controlled variable values, and when there is , when there is ; in this embodiment, the mean value of the light component content in the light component content loop of the overhead product of the distillation column system in the manual state ; 104: Calculate the variance of the fluctuation of the controlled variable of this control loop in the manual state using the following formula : (3) represents that formula (3) is calculated at , otherwise skip the calculation of formula (3) at the j th data acquisition moment; in this embodiment, the variance of the fluctuation of the light component content in the light component content loop of the overhead product of the distillation column system in the manual state ; 105: Calculate the mean value of the controlled variable of this control loop in the automatic state using the following formula : (4) Wherein p represents the p th data acquisition time, represents the automatic input state statistics, that is there is , there is ; represents p values of the controlled variables, and there is , there is ; In this embodiment, the average value of the light component content in the automatic state of the light component content loop of the overhead product of the distillation column system ; 106: The fluctuation variance of the controlled variable of this control loop in the automatic state is calculated by the following formula : (5) Wherein represents that the formula (5) is calculated at , otherwise the calculation of the formula (5) at the p th data acquisition time is skipped; In this embodiment, the fluctuation variance of the light component content in the automatic state of the light component content loop of the overhead product of the distillation column system ; 107: The integral of the absolute value of the error of the controlled variable of this control loop in the automatic state is calculated by the following formula : (6) Wherein x represents the x th data acquisition time, represents that the formula (6) is calculated at , otherwise the calculation of the formula (6) at the x th data acquisition time is skipped; In this embodiment, the integral of the absolute value of the error in the automatic state of the light component content loop of the overhead product of the distillation column system ; 108: The viscosity of the actuator of this control loop in the manual state is calculated by the following formula : (7) Wherein z represents the z th data acquisition time, represents that the formula (7) is calculated at , otherwise the z th data acquisition time is skippedThe viscosity of the actuator in the manual state of the light component content loop in the overhead product of the distillation column system is calculated according to Formula (7) at each acquisition moment. ; 109: Calculate the viscosity of the actuator of this control loop in the automatic state using the following formula : (8) where y represents the y th acquisition data moment, When it means that Formula (8) is calculated at , otherwise skip the calculation of Formula (8) at the y th acquisition moment; The viscosity of the actuator in the automatic state of the light component content loop in the overhead product of the distillation column system in this embodiment ; 110: Based on the expected mean value of the controlled variable of this control loop in the manual state, calculate the mean value score of this control loop in the manual state: (9) In this embodiment, , the mean value score of the light component content loop in the overhead product of the distillation column system in the manual state ; 111: Based on the expected fluctuation variance of the controlled variable in the manual state, calculate the fluctuation variance score of this control loop in the manual state: In this embodiment, , the fluctuation variance score of the light component content loop in the overhead product of the distillation column system in the manual state ; 112: Based on the expected mean value of the controlled variable of this control loop in the automatic state, calculate the mean value score (11) In this embodiment, , the mean value score of the light component content loop in the overhead product of the distillation column system in the automatic state ; 113: Based on the expected fluctuation variance of the controlled variable in the automatic state, calculate the fluctuation variance score (12) In this embodiment, , the fluctuation variance score of the light component content loop in the overhead product of the distillation column system under the automatic state ; 114: Integral of the absolute value of the expected error of the controlled variable under the automatic state , calculate the integral score of the absolute value of the error of this control loop under the automatic state : (13) In this embodiment, , the integral of the absolute value of the error of the light component content loop in the overhead product of the distillation column system under the automatic state ; 115: Based on what is obtained in step 108 , what is obtained in step 110 and what is obtained in step 111 , obtain the evaluation score of this control loop in the manual operation state : (14) Where , and are weight systems. Generally, there is , and , , ; In this embodiment , the obtained evaluation score of the light component content loop in the overhead product of the distillation column system in the manual operation state is ; 116: Based on what is obtained in step 109 , what is obtained in step 112 , what is obtained in step 113 and what is obtained in step 114 , obtain the evaluation score of this control loop in the automatic operation state : (15) Where , , and are weight systems. Generally, there is , and , , and ; In this embodiment , the obtained evaluation score of the light component content loop in the overhead product of the distillation column system in the automatic operation state is ; 117: Obtain the automatic input rate of this control loop and the evaluation score of this control loop in the manual operation state and the evaluation score of this control loop in the automatic operation state ; In this embodiment, the automatic input rate of the light component content loop in the top product of the distillation column system and the evaluation score of this control loop in the manual operation state and the evaluation score of this control loop in the automatic operation state .

Claims

1. A rectification column control loop evaluation method, characterized in that, Including the following steps: Step 1, select a control loop of the distillation column system; Step 2, calculate the automatic input rate of this control loop ; In Step 3 and Step 4, calculate the mean value of the controlled variable of this control loop in the manual state and the variance of the fluctuation of the controlled variable ; In Step 5 to Step 7, calculate the mean value of the controlled variable of this control loop in the automatic state , the variance of the fluctuation , the integral of the absolute value of the error ; In Step 8, calculate the viscosity of the actuator of this control loop in the manual state ; In Step 9 and Step 10, calculate the viscosity of the actuator of this control loop in the automatic state and the mean value score ; In Step 11, calculate the variance score of the fluctuation of this control loop in the manual state ; In Step 12 to Step 14, the mean value score , the variance score of the fluctuation and the integral score of the absolute value of the error of this control loop in the automatic state ; In Step 15, obtain the evaluation score of this control loop in the manual operation state ; In Step 16, obtain the evaluation score of this control loop in the automatic operation state ; In Step 17, obtain the automatic input rate of this control loop , the evaluation score of this control loop in the manual operation state , the evaluation score of this control loop in the automatic operation state .

2. A method for evaluating a rectification column control loop according to claim 1, characterized in that: In step one, according to a certain sampling period Collect n the controlled variable PV of this control loop, the set value SP of the controlled variable, the actuator command value MV, the actuator feedback value MV f , and the automatic input status Au, is input, indicating that the automatic mode is not engaged; In step 2, the automatic input rate of the control loop is calculated using the following formula :[[]]END]] （1）； Among them i represents the i th data acquisition moment, represents the i th automatically input status data acquired; In step 3, the mean value of the controlled variable of this control loop in the manual state is calculated using the following formula : （2）； Among them j represents the j th data acquisition moment, represents the automatic input status statistics, that is when there is , when there is ; represents j numerical values of controlled variables, and when there is , when there is .

3. The evaluation method of a rectification column control loop according to claim 1, wherein: In Step 4, the variance of the controlled variable fluctuation of the control loop in the manual state is calculated using the following formula :[[]]END]] （3）； It means that the formula (3) is calculated at , and conversely, the calculation of the formula (3) at the j th acquisition moment is skipped; In step five, the mean value of the controlled variable of this control loop in the automatic state is calculated using the following formula :[[]]END]] （4）； Among them p represents the p th data acquisition moment, represents the automatic input status statistics, that is, when there is , when there is ; represents p numerical values of the controlled variables, and when there is , when there is .

4. A rectification column control loop evaluation method according to claim 1, characterized in that: In step six, the fluctuation variance of the controlled variable of this control loop in the automatic state is calculated using the following formula :[[]]END]] （5）； Among them indicates that formula (5) is calculated at , and conversely, the calculation of formula (5) at the p th acquisition moment is skipped; In step seven, the integral of the absolute value of the controlled variable error of this control loop in the automatic state is calculated using the following formula : （6）； Among them x represents the x th data acquisition moment, represents that formula (6) is calculated at , and conversely, the calculation of formula (6) at the x th acquisition moment is skipped.

5. A method for evaluating a rectification column control loop according to claim 1, characterized in that: In Step 8, the viscosity of the actuator of this control loop in the manual state is calculated using the following formula : （7）； Among them z represents the z th data acquisition moment. When it is, it means that formula (7) is calculated at . Conversely, skip the calculation of formula (7) at the z th data acquisition moment; In Step 9, the viscosity of the actuator of the control loop in the automatic state is calculated using the following formula : （8）； Among them y represents the y th data acquisition moment. When it is, it means that formula (8) is calculated at ; otherwise, the calculation of formula (8) for the y th acquisition moment is skipped.

6. A method for evaluating a rectification column control loop according to claim 1, characterized in that: In Step 10, based on the expected mean value of the controlled variable of the control loop in the manual state , calculate the mean value score of the control loop in the manual state : （9）； In step eleven, based on the expected fluctuation variance of the controlled variable in the manual state , the fluctuation variance score of this control loop in the manual state : （10）。 7. A rectification column control loop evaluation method according to claim 1, characterized in that: In Step Twelve, based on the expected mean value of the controlled variable of this loop in the automatic state , calculate the mean value score of this control loop in the automatic state : （11）； In Step 13, based on the expected fluctuation variance of the controlled variable in the automatic state , calculate the fluctuation variance score of this control loop in the automatic state : （12）。 8. A rectification column control loop evaluation method according to claim 1, characterized in that: In Step 14, based on the integral of the absolute value of the expected error of the controlled variable in the automatic state , calculate the integral absolute error score of this control loop in the automatic state : （13）。 9. A rectification column control loop evaluation method according to claim 1, characterized in that: In Step 15, based on what is obtained in Step 8 , what is obtained in Step 10 and what is obtained in Step 11 , the evaluation score of the control loop in the manual operation state : （14） Among them and and weight systems, generally there are and , , .

10. A rectification column control loop evaluation method according to claim 1, characterized in that: In Step Sixteen, based on what is obtained in Step Nine , what is obtained in Step Twelve , what is obtained in Step Thirteen and what is obtained in Step Fourteen , the evaluation score in the automatic operation state of this control loop : （15） Among them 、 、 and are weight systems. Generally, there is and 、 , and ; Step 17: Obtain the automatic input rate of the control loop , the evaluation score of the control loop in the manual operation state , the evaluation score of the control loop in the automatic operation state .

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