CN117707256A - Control method and control device for temperature of top of benzene removal tower and benzene removal device - Google Patents
Control method and control device for temperature of top of benzene removal tower and benzene removal device Download PDFInfo
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- CN117707256A CN117707256A CN202410023484.5A CN202410023484A CN117707256A CN 117707256 A CN117707256 A CN 117707256A CN 202410023484 A CN202410023484 A CN 202410023484A CN 117707256 A CN117707256 A CN 117707256A
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- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 title claims abstract description 126
- 238000000034 method Methods 0.000 title claims abstract description 33
- 230000008859 change Effects 0.000 claims abstract description 39
- 238000010992 reflux Methods 0.000 abstract description 22
- 238000013461 design Methods 0.000 abstract description 2
- 230000001105 regulatory effect Effects 0.000 description 7
- 230000008569 process Effects 0.000 description 6
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 3
- 230000033228 biological regulation Effects 0.000 description 2
- 238000004939 coking Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D23/00—Control of temperature
- G05D23/19—Control of temperature characterised by the use of electric means
- G05D23/20—Control of temperature characterised by the use of electric means with sensing elements having variation of electric or magnetic properties with change of temperature
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The application discloses a control method, a control device and a benzene removal device for the temperature of a benzene removal tower top, wherein the control method comprises the steps of determining a temperature change value based on the acquired actual measured temperature and target temperature of the benzene removal tower top; comparing the temperature variation value with a first threshold value, and determining a control mode based on a comparison result; based on the different control modes, valve position values corresponding to the control modes are output. The invention has reasonable design, and when the temperature change value is in the range of the first threshold value, the temperature of the top of the debenzolization tower is basically kept unchanged by adjusting the first valve position value; when the temperature variation value is not in the range of the first threshold value, the temperature of the top of the debenzolization tower is rapidly controlled by adjusting the second valve position value. The mode of combining fuzzy control and PID control is adopted, so that the stability of the fixed temperature and reflux quantity of the benzene removal tower is ensured, and the benzene removal efficiency is effectively improved.
Description
Technical Field
The application relates to the technical field of coking devices, in particular to a control method and device for the temperature of a top of a benzene removal tower and a benzene removal device.
Background
In recent years, the temperature control of the benzene removal tower top of the benzene elution section in many coking units is designed as PID regulation, and the control of physical quantities such as pressure, temperature, flow, liquid level and the like can be realized by utilizing PID control. The PID control changes the rich oil reflux flow according to the temperature change, and not the tower top temperature, and the regulating method belongs to indirect regulation.
The temperature of the top of the benzene removal tower is controlled by adjusting the opening of the rich oil reflux valve, the temperature of the top of the benzene removal tower is changed due to the rich oil reflux quantity when the opening of the rich oil reflux valve is controlled, the reflux is always opened to the maximum, then the reflux is closed, the hysteresis characteristic of the temperature is large, the unbalance of a process medium is caused, the yield and the quality of crude benzene are seriously influenced, and the closed reflux is extremely unfavorable for the service life of a reflux pump. The target temperature and the measured temperature are not in a linear relation in the control process, so that the temperature fluctuation of the top of the debenzolization tower is large as a result of PID control, and the process requirement cannot be met.
Disclosure of Invention
In view of the foregoing, an object of an embodiment of the present application is to provide a method for controlling a temperature of a top of a debenzolization tower, including:
determining a temperature change value based on the obtained measured temperature and the target temperature of the debenzolization tower top;
comparing the temperature variation value with a first threshold value, and determining a control mode based on a comparison result;
based on the different control modes, valve position values corresponding to the control modes are output.
As an alternative embodiment, the comparing the temperature change value with the first threshold value, and determining the control mode based on the comparison result includes:
when the temperature change value falls within the range of the first threshold value, determining a first control mode, wherein the first control mode is fuzzy control;
and determining a second control mode when the temperature change value does not fall within the range of the first threshold value, wherein the second control mode is PID control.
As an alternative embodiment, the outputting, based on different control modes, valve values corresponding to the control modes includes:
outputting a first valve position value in the first control mode, wherein the first valve position value is a preset value;
and outputting a second valve position value in the second control mode, wherein the second valve position value is calculated based on a PID module.
As an alternative embodiment, the first valve value includes a first valve opening and a second valve opening, wherein the first valve opening is greater than the second valve opening.
As an alternative embodiment, the control method further includes:
setting an initial valve opening based on preset conditions to determine the actual measured temperature of the top of the debenzolization tower;
determining a temperature change value based on the measured temperature and a target temperature;
and comparing the temperature change value with a first threshold value, determining the first valve opening degree in a first control mode based on a comparison result, and acquiring a second valve opening degree.
As an optional embodiment, the preset conditions include a preset pressure, a preset flow rate, and a preset duration, and the control method further includes:
when at least one of the preset pressure, the preset flow rate and the preset duration is changed, the first valve opening is adjusted along with the initial valve opening setting change in the first control mode.
As an optional embodiment, the determining a temperature variation value based on the obtained measured temperature and the target temperature of the debenzolization tower top includes:
determining a temperature difference value between the measured temperature and the target temperature of the benzene removal tower top based on the obtained measured temperature and the target temperature;
and calculating the absolute value of the temperature difference value to determine a temperature change value.
An object of an embodiment of the present application is to provide a temperature control device for a top of a debenzolization tower, including:
a determining module configured to determine a temperature variation value based on the obtained measured temperature and the target temperature of the tower top;
a comparison module configured to compare the temperature variation value with a first threshold value, and determine a control mode based on a comparison result;
and the output module is configured to output valve position values corresponding to different control modes based on the different control modes.
An object of an embodiment of the present application is to provide a debenzolization apparatus, including a debenzolization overhead temperature control apparatus as described above.
The beneficial effects of this application embodiment lie in:
the invention has reasonable design, and when the temperature change value is in the range of the first threshold value, the temperature of the top of the debenzolization tower is basically kept unchanged by adjusting the first valve position value; when the temperature variation value is not in the range of the first threshold value, the temperature of the top of the debenzolization tower is rapidly controlled by adjusting the second valve position value. The method combines fuzzy control and PID control, ensures the stability of the fixed temperature and reflux quantity of the benzene removal tower, is simple and easy to operate, reduces the labor degree of central control personnel, improves the yield of 19.5 tons per month on average through actual production verification, and effectively improves the recovery rate of 0.05 percent of crude benzene.
Drawings
FIG. 1 is a flow chart of a control method according to an embodiment of the present application;
FIG. 2 is a flowchart of S10 of a control method according to an embodiment of the present application;
fig. 3 is a flowchart of S20 of the control method according to the embodiment of the present application;
fig. 4 is a flowchart of S30 of the control method of the embodiment of the present application;
fig. 5 is a block diagram of a control device according to an embodiment of the present application.
Reference numerals:
100. a determining module; 200. a comparison module; 300. and an output module.
Detailed Description
Various aspects and features of the present application are described herein with reference to the accompanying drawings.
It should be understood that various modifications may be made to the embodiments of the application herein. Therefore, the above description should not be taken as limiting, but merely as exemplification of the embodiments. Other modifications within the scope and spirit of this application will occur to those skilled in the art.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and, together with a general description of the application given above and the detailed description of the embodiments given below, serve to explain the principles of the application.
These and other characteristics of the present application will become apparent from the following description of a preferred form of embodiment, given as a non-limiting example, with reference to the accompanying drawings.
It is also to be understood that, although the present application has been described with reference to some specific examples, those skilled in the art can certainly realize many other equivalent forms of the present application.
The foregoing and other aspects, features, and advantages of the present application will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings.
Specific embodiments of the present application will be described hereinafter with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely exemplary of the application, which can be embodied in various forms. Well-known and/or repeated functions and constructions are not described in detail to avoid obscuring the application with unnecessary or excessive detail. Therefore, specific structural and functional details disclosed herein are not intended to be limiting, but merely serve as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present application in virtually any appropriately detailed structure.
The specification may use the word "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments," which may each refer to one or more of the same or different embodiments as per the application.
The temperature of the top of the debenzolization tower is an important control index in the crude benzene distillation process, and directly influences the yield and quality of crude benzene. Excessive temperature can cause disqualification of products; low temperatures result in low yields. Therefore, the control of the temperature of the top of the debenzolization tower within a reasonable range is important for improving the yield and the quality of crude benzene.
The embodiment of the application provides a method for controlling the temperature of a debenzolization tower top, which is shown in fig. 1 and comprises the following steps:
s10, determining a temperature change value based on the obtained measured temperature and the target temperature of the top of the debenzolization tower. The target temperature is typically set to 87 ℃, and can be adjusted according to practical situations.
As an alternative embodiment, as shown in fig. 2, the determining a temperature variation value based on the obtained measured temperature and the target temperature of the debenzolization tower top includes:
s101, determining a temperature difference value of the measured temperature and the target temperature of the top of the debenzolization tower based on the obtained measured temperature and the target temperature. Specifically, assuming that the measured temperature is 89 ℃, the temperature difference from the target temperature is +2 ℃; assuming that the measured temperature is 86.5 ℃, the temperature difference from the target temperature is-0.5 ℃.
S102, calculating an absolute value of the temperature difference value, and determining a temperature change value. That is, the temperature difference was +2℃, the temperature change was 2 ℃, the temperature difference was-0.5 ℃, and the temperature change was 0.5 ℃.
S20, comparing the temperature change value with a first threshold value, and determining a control mode based on a comparison result. The application comprises a first control mode and a second control mode, wherein the two control modes are different, and the applicable preconditions are inconsistent. And, the present application sets the first threshold to 1.5 ℃.
As an alternative embodiment, as shown in fig. 3, the comparing the temperature change value with the first threshold value, and determining the control mode based on the comparison result includes:
and S201, determining a first control mode when the temperature change value falls within the range of the first threshold value, wherein the first control mode is fuzzy control, and the first control mode is within the range of the first threshold value when the actually measured temperature is 88 ℃ or 86 ℃. Specifically, when the temperature variation value of the measured temperature and the target temperature of the top of the debenzolization tower is within the range of a first threshold, the rich oil flow reflux valve position is immediately adjusted to a predetermined valve position, and the flow corresponding to the valve position can keep the temperature of the top of the debenzolization tower basically unchanged.
And S202, determining a second control mode when the temperature change value does not fall within the range of the first threshold value, wherein the second control mode is PID control. Specifically, the PID control is to calculate the deviation based on the target temperature and the measured temperature, and then calculate the deviation in proportion, integral and derivative to determine the control amount (the reflux flow rate adjusting valve position value) to control the controlled object (the debenzolization overhead temperature).
S30, outputting valve position values corresponding to different control modes based on the different control modes.
As an alternative embodiment, as shown in fig. 4, the outputting, based on different control modes, valve values corresponding to the control modes includes:
s301, outputting a first valve position value in the first control mode, wherein the first valve position value is a preset value. Specifically, the first valve value includes a first valve opening and a second valve opening, wherein the first valve opening is greater than the second valve opening.
Specifically, the flow corresponding to the opening of the first valve is large and can lower the temperature of the top of the benzene removal tower, and the flow corresponding to the opening of the second valve is small and can raise the temperature of the top of the benzene removal tower. The first valve opening and the second valve opening enable the temperature of the top of the benzene removal tower to be kept to be fluctuated within the range of a first threshold value when the temperature is regulated. The first valve position value can be increased or decreased according to the change condition of the temperature of the top of the benzene removal tower.
S302, outputting a second valve position value in the second control mode, wherein the second valve position value is calculated based on a PID module. Specifically, PID adjusts, and the input process quantity is the top temperature of the benzene removal tower, and according to the target set temperature, the PID block automatically calculates the valve position output quantity, and the output control quantity is the valve position of the rich oil reflux flow regulating valve.
The temperature of the benzene removal tower top is reduced by opening a rich oil reflux flow regulating valve when the temperature of the benzene removal tower top is high, thereby increasing the rich oil reflux flow, and the temperature of the benzene removal tower top is reduced by closing the rich oil reflux flow regulating valve when the temperature of the benzene removal tower top is low, wherein the reflux medium flow is directly changed by the change of the temperature, and then the tower top temperature is changed by the change of the reflux flow.
When the method is used, the temperature of the top of the debenzolization tower is measured to obtain the measured temperature, and then the measured temperature is subtracted from the target temperature to obtain a temperature difference value. The resulting temperature difference is taken to be absolute and compared to a first threshold. If the absolute value data is within the range of the first threshold, a first valve position value is selected for output to the rich return flow regulator valve for the first control mode. If the absolute value data is not within the range of the first threshold value, the second valve position value calculated by PID is selected to be output to the rich reflux flow regulating valve.
As an alternative embodiment, the control method further includes:
setting an initial valve opening based on preset conditions to determine the actual measured temperature of the top of the debenzolization tower; determining a temperature change value based on the measured temperature and a target temperature; and comparing the temperature change value with a first threshold value, determining the first valve opening degree in a first control mode based on a comparison result, and acquiring a second valve opening degree.
Specifically, the initial valve opening is set to 45, the initial valve is adjusted according to whether the measured temperature change value is within the range of the first threshold value, and if the adjusted temperature change value is within the range of the first threshold value, the first valve opening is determined. Then, the value of the second valve opening is determined by subtracting a preset value (set according to the actual situation) from the first valve opening.
As an alternative embodiment, the preset conditions include a preset pressure, a preset flow rate and a preset duration, and the pressure at the top of the debenzolization tower is controlled within a proper range by the preset pressure to ensure the stability and safety of the operation. The specific settings of the preset pressure, the preset flow and the preset duration of the debenzolization tower top are optimized and adjusted according to actual conditions. When the control scheme is designed, the characteristics and the process conditions of the device are required to be fully considered, and experimental verification and adjustment are carried out to ensure the stable operation of the device and the standard of the product quality.
The control method further comprises the step of adjusting the first valve opening along with the initial valve opening setting change in the first control mode when at least one of the preset pressure, the preset flow and the preset duration is changed, so that the corresponding valve position value in the first control mode can effectively adjust the temperature of the debenzolization tower top.
The embodiment of the application provides a device for controlling the temperature of a debenzolization tower top, which is shown in fig. 5 and comprises a determining module 100, a comparing module 200 and an output module 300.
The determination module 100 is configured to determine a temperature variation value based on the obtained measured temperature and the target temperature of the overhead of the tower. Specifically, based on the obtained measured temperature and target temperature of the top of the debenzolization tower, determining a temperature difference between the measured temperature and the target temperature, and calculating an absolute value of the temperature difference to determine a temperature change value.
The comparison module 200 is configured to compare the temperature change value with a first threshold value and determine a control mode based on the comparison result. Specifically, when the temperature variation value falls within the range of the first threshold value, determining a first control mode, wherein the first control mode is fuzzy control; and determining a second control mode when the temperature change value does not fall within the range of the first threshold value, wherein the second control mode is PID control.
The output module 300 is configured to output valve position values corresponding to different control modes based on the control modes. Specifically, a first valve position value is output in the first control mode, wherein the first valve position value is a preset value; and outputting a second valve position value in the second control mode, wherein the second valve position value is calculated based on a PID module.
In operation, the determining module 100 obtains the measured temperature and the target temperature, and compares the measured temperature with the target temperature to generate a temperature variation value. The comparison module 200 compares the temperature variation value with a first threshold value to obtain a corresponding control mode. And then the output module 300 outputs a corresponding valve value based on the type of the control mode so as to adjust the operation parameters of the benzene removal device, and finally control the temperature of the top of the benzene removal tower. The modules cooperate through the transmission of input and output signals to jointly realize the control of the temperature of the top of the debenzolization tower.
The embodiment of the application provides a benzene removal device, which comprises the benzene removal tower top temperature control device. The benzene removal device comprises temperature measurement, a temperature sensor is arranged at the top of the benzene removal tower and used for monitoring and measuring the temperature of the top of the benzene removal tower in real time, and the temperature control device of the benzene removal tower receives signals of the temperature sensor and processes the signals according to the set target temperature.
And then, according to the instruction of the debenzolization tower top temperature control device, the opening of a valve or a pump of the rich oil return pipeline is regulated, and the flow of the rich oil return is controlled. When the temperature of the top of the debenzolization tower is higher, the temperature control device of the debenzolization tower will send out a signal, and the rich oil reflux amount is required to be increased. Accordingly, increasing the rich reflux amount increases the distribution of the liquid phase at the top of the column, and decreases the gas phase concentration, thereby decreasing the temperature at the top of the column. The distribution condition of liquid phase and gas phase in the benzene removal tower can be changed by adjusting the rich oil reflux quantity, so as to realize the control of the temperature of the top of the benzene removal tower.
The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application, the scope of which is defined by the claims. Various modifications and equivalent arrangements may be made to the present application by those skilled in the art, which modifications and equivalents are also considered to be within the scope of the present application.
Claims (9)
1. The method for controlling the temperature of the top of the debenzolization tower is characterized by comprising the following steps:
determining a temperature change value based on the obtained measured temperature and the target temperature of the debenzolization tower top;
comparing the temperature variation value with a first threshold value, and determining a control mode based on a comparison result;
based on the different control modes, valve position values corresponding to the control modes are output.
2. The control method according to claim 1, wherein the comparing the temperature change value with a first threshold value, determining a control mode based on a comparison result, comprises:
when the temperature change value falls within the range of the first threshold value, determining a first control mode, wherein the first control mode is fuzzy control;
and determining a second control mode when the temperature change value does not fall within the range of the first threshold value, wherein the second control mode is PID control.
3. The control method according to claim 2, wherein the outputting a valve position value corresponding to the control mode based on the different control modes includes:
outputting a first valve position value in the first control mode, wherein the first valve position value is a preset value;
and outputting a second valve position value in the second control mode, wherein the second valve position value is calculated based on a PID module.
4. A control method as claimed in claim 3, wherein the first valve position value comprises a first valve opening and a second valve opening, wherein the first valve opening is greater than the second valve opening.
5. The control method according to claim 4, characterized in that the control method further comprises:
setting an initial valve opening based on preset conditions to determine the actual measured temperature of the top of the debenzolization tower;
determining a temperature change value based on the measured temperature and a target temperature;
and comparing the temperature change value with a first threshold value, determining the first valve opening degree in a first control mode based on a comparison result, and acquiring a second valve opening degree.
6. The control method according to claim 5, wherein the preset conditions include a preset pressure, a preset flow rate, and a preset duration, the control method further comprising:
when at least one of the preset pressure, the preset flow rate and the preset duration is changed, the first valve opening is adjusted along with the initial valve opening setting change in the first control mode.
7. The control method according to claim 1, wherein the determining a temperature variation value based on the obtained measured temperature and the target temperature of the debenzolization tower top comprises:
determining a temperature difference value between the measured temperature and the target temperature of the benzene removal tower top based on the obtained measured temperature and the target temperature;
and calculating the absolute value of the temperature difference value to determine a temperature change value.
8. A debenzolization overhead temperature control apparatus comprising:
a determining module configured to determine a temperature variation value based on the obtained measured temperature and the target temperature of the tower top;
a comparison module configured to compare the temperature variation value with a first threshold value, and determine a control mode based on a comparison result;
and the output module is configured to output valve position values corresponding to different control modes based on the different control modes.
9. A debenzolization apparatus comprising the debenzolization overhead temperature control apparatus of claim 8.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311868396 | 2023-12-29 | ||
| CN2023118683967 | 2023-12-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117707256A true CN117707256A (en) | 2024-03-15 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410023484.5A Pending CN117707256A (en) | 2023-12-29 | 2024-01-05 | Control method and control device for temperature of top of benzene removal tower and benzene removal device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117707256A (en) |
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2024
- 2024-01-05 CN CN202410023484.5A patent/CN117707256A/en active Pending
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