A method and system for controlling an acetaldehyde rectification column

Abstract

This invention relates to a control method and system for an acetaldehyde distillation column, belonging to the field of chemical separation technology. It includes acquiring tray numbers, anhydrous copper sulfate test paper numbers, and detection time; responding to a moisture content detection signal, controlling the anhydrous copper sulfate test paper corresponding to each test paper number to perform detection according to the detection time; acquiring test paper images of the anhydrous copper sulfate test paper corresponding to each test paper number; analyzing the test paper images to obtain color values, and extracting depth values ​​from the color values; selecting high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than a preset depth threshold, and generating high-purity anhydrous copper sulfate test paper number groups based on these numbers; obtaining corresponding tray number groups based on the high-purity anhydrous copper sulfate test paper number groups; and controlling the trays corresponding to the tray number groups to be stored according to a storage mode. This invention improves the production efficiency of acetaldehyde.

Description

Technical Field

[0001] This invention relates to the field of chemical separation technology, and in particular to a control method and system for an acetaldehyde distillation column. Background Technology

[0002] Acetaldehyde is an important aliphatic aldehyde organic chemical raw material. It is a colorless and volatile liquid at room temperature and pressure. The acetaldehyde distillation column is a continuous gas-liquid separation device designed for the volatile and flammable characteristics of acetaldehyde. Its core function is to efficiently separate acetaldehyde from impurities such as water, acetic acid, methanol, and metaldehyde in crude acetaldehyde raw material to produce high-purity industrial-grade acetaldehyde products. It is an indispensable core purification equipment in the industrial production of acetaldehyde.

[0003] In related technologies, acetaldehyde distillation columns mostly adopt plate distillation columns or packed distillation columns. Among them, the plate distillation column is filled with multiple layers of trays, and the gas and liquid phases come into contact and transfer mass step by step on the trays, which can adapt to the working conditions of large-scale industrial acetaldehyde purification, and take into account both separation efficiency and operational stability.

[0004] Regarding the aforementioned technologies, the tray configuration of a plate distillation column is fixed. Traditional plate distillation columns have a fixed installation structure for the trays, and all trays continuously participate in the mass transfer separation process. When the impurity content in the feed is low and the purity of the gaseous acetaldehyde in some upper trays has reached the standard, these trays will prolong the gaseous rise time and reduce the acetaldehyde production efficiency. Summary of the Invention

[0005] To improve the production efficiency of acetaldehyde, this invention provides a method and system for controlling an acetaldehyde distillation column.

[0006] In a first aspect, the present invention provides a method for controlling an acetaldehyde distillation column, which adopts the following technical solution: A method for controlling an acetaldehyde distillation column includes: Step S1: Obtain the tray number, anhydrous copper sulfate test paper number, and detection time. The tray number and the anhydrous copper sulfate test paper number correspond one-to-one. Step S2: In response to the moisture content detection signal, control the anhydrous copper sulfate test paper corresponding to each anhydrous copper sulfate test paper number to perform detection according to the detection time; Step S3: Obtain the test paper image of the anhydrous copper sulfate test paper corresponding to the number of the anhydrous copper sulfate test paper; Step S4: Analyze the test strip image to obtain the chromaticity value, and extract the depth value from the chromaticity value; Step S5: Select the high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than the preset depth threshold, and generate a high-purity anhydrous copper sulfate test paper number group based on the high-purity anhydrous copper sulfate test paper numbers. Step S6: Obtain the corresponding tray number group based on the number group of the high-purity anhydrous copper sulfate test paper; Step S7: Control the trays corresponding to the tray number groups to be stored according to the preset storage mode.

[0007] By adopting the above technical solution, the high-purity trays can be accurately identified and stored based on the real-time detection results of the gas phase water content of each tray, thus cutting off ineffective mass transfer paths, shortening the process of the gas phase rising to the top of the tower, and significantly improving the production efficiency of acetaldehyde.

[0008] Optionally, the method for selecting high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than a preset depth threshold, and generating high-purity anhydrous copper sulfate test paper number groups based on these numbers, includes: Step S50: Select the high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than the preset depth threshold, and sort the high-purity anhydrous copper sulfate test paper numbers to obtain the smallest anhydrous copper sulfate test paper number. Step S51: Remove the smallest anhydrous copper sulfate test paper number from the high-purity anhydrous copper sulfate test paper numbering, and generate a high-purity anhydrous copper sulfate test paper numbering group based on the remaining high-purity anhydrous copper sulfate test paper numbers.

[0009] By adopting the above technical solution, the lowest tray in the high-purity tray can be removed, reducing the risk of purity fluctuations due to the proximity of the tray to non-compliant areas, ensuring that all trays collected are stable and compliant upper trays, and further guaranteeing the purity stability of acetaldehyde products.

[0010] Optional, also includes: Step S8: After all the trays corresponding to the tray number group are stored according to the preset storage mode, find the lowest tray number in the tray number group. Step S9: Find the corresponding anhydrous copper sulfate test paper number based on the lowest tray number, and perform steps S2 to S4 on the anhydrous copper sulfate test paper corresponding to the retest anhydrous copper sulfate test paper number to obtain the retest depth value. Step S10: When the re-inspection depth value is less than the depth threshold, control the distillation column to continue working; Step S11: When the re-inspection depth value is greater than the depth threshold, control the tray corresponding to the lowest tray number to extend according to the preset extension mode.

[0011] By adopting the above technical solution, a secondary purity check is performed on the critical region of the receiving tray, which can promptly detect the problem of gas phase purity rebound that may occur after the receiving operation. The lack of separation capacity can be quickly compensated by the extension operation of the lowest tray, thus balancing the improvement of production efficiency and the guarantee of acetaldehyde purity.

[0012] Optionally, when the re-inspection depth value is greater than the depth threshold, the method for controlling the tray corresponding to the lowest tray number to extend according to a preset extension mode includes: Step S110: After the tray corresponding to the lowest tray number is stretched according to the preset stretching mode, the lowest tray number is removed from the tray number group to form an optimized tray number group. Step S111: Find the lowest optimized tray number in the optimized tray number group, and execute step S9 to obtain the optimized re-inspection depth value based on the lowest optimized tray number; Step S112: When the optimized re-inspection depth value is less than the depth threshold, control the distillation column to continue working; Step S113: When the optimized re-inspection depth value is greater than the depth threshold, control the tray corresponding to the lowest optimized tray number to extend according to the preset extension mode, and repeat steps S110 to S111 until the optimized re-inspection depth value is less than the depth threshold.

[0013] By adopting the above technical solution, and through iterative re-inspection and extension operations, the number of trays required for acetaldehyde purification can be accurately determined. Under the premise of ensuring that the purity meets the standards, the efficiency of the collection operation can be maximized, and the dynamic control of the distillation process can be achieved.

[0014] Optionally, another control method for the tray is included when the re-inspection depth value is greater than the depth threshold, the method comprising: Step S114: When the re-inspection depth value is greater than the depth threshold, obtain the intermediate tray number according to the tray number group; Step S115: Control the trays corresponding to the intermediate tray numbers to extend in the extension mode, and obtain the upper tray numbers according to the intermediate tray numbers. Step S116: Find the corresponding upper anhydrous copper sulfate test paper number based on the upper tray number; Step S117: Perform steps S2 to S4 according to the number of the upper anhydrous copper sulfate test paper to obtain the upper layer depth value; Step S118: When the upper layer depth value is less than the depth threshold, control the distillation column to continue working; Step S119: When the upper layer depth value is greater than the depth threshold, control the tray corresponding to the upper layer tray number to extend according to the preset extension mode.

[0015] By adopting the above technical solution, the overall separation capacity is rapidly improved by prioritizing the extension of the middle trays. At the same time, the adjustment effect is verified by combining the purity detection of the upper trays. Compared with the layer-by-layer extension mode, this method has a faster adjustment speed and improves the adaptability of the distillation column under different conditions.

[0016] Optionally, when the re-inspection depth value is greater than the depth threshold, the method for obtaining the intermediate tray number based on the tray number group includes: Step S1140: Determine the number of trays based on the tray number group; Step S1141: When the number of tray numbers is odd, sort all tray numbers in the tray number group in ascending order of value, and define the tray number in the middle position as the middle tray number. Step S1142: When the number of tray numbers is even, sort all tray numbers in the tray number group in ascending order of value, and define the tray number with the larger value among the two tray numbers in the middle position as the middle tray number.

[0017] By adopting the above technical solution, the selection scheme for intermediate tray numbering was clarified. When the number of intermediate trays is even, the upper intermediate trays are selected first. This not only improves the separation accuracy quickly, but also avoids excessive extension of the mass transfer path, ensuring the rationality of the selection of intermediate trays and improving the stability of the adjustment scheme.

[0018] Optionally, methods for controlling the testing of anhydrous copper sulfate test strips corresponding to each test strip number based on the testing time include: Step S20: Obtain the radius of the tray and the radius of the test paper; Step S21: Calculate the path radius based on the tray radius and the test paper radius; Step S22: Calculate the path perimeter based on the path radius; Step S23: Calculate the detection speed based on the path perimeter and detection time, and form a circular path based on the path radius; Step S24: Control the anhydrous copper sulfate test paper to perform the test along the circumferential path at the detection speed.

[0019] By adopting the above technical solution, the circumferential detection path ensures that the test paper can evenly cover the gas phase distribution area of ​​the tray, avoiding misjudgment of water content due to detection position deviation. At the same time, by calculating the detection speed, the detection process is matched with the rhythm of distillation, achieving efficient collection of gas phase water content.

[0020] Optionally, it also includes a method for optimizing the circumferential path, which includes: Step S230: Divide the near-center region and the far-center region of the tray according to the test strip image; Step S231: Define the depth value of the area near the center of the tray as the near-center depth value, and define the depth value of the area far from the center of the tray as the far-center depth value. Step S232: Calculate the depth difference based on the depth values ​​near the center of the tray and the depth values ​​far from the center of the tray; Step S233: When the depth difference is greater than the preset difference threshold, calculate the optimized radius based on the path radius and the preset difference radius; Step S234: Perform steps S22 to S23 according to the optimized radius to obtain the optimized circumferential path.

[0021] By adopting the above technical solution, the detection path can be dynamically optimized according to the difference in gas phase water content in different areas of the tray. When the purity deviation between the center and the edge areas is large, the path radius can be adjusted to expand the detection coverage of the high deviation area and improve the accuracy of water content detection.

[0022] Optional, also includes: Step S235: When the depth difference is less than the preset difference threshold, calculate the difference ratio based on the depth difference and the difference threshold; Step S236: Calculate the difference ratio radius based on the difference ratio and the difference radius; Step S237: Perform steps S22 to S23 according to the difference ratio radius to obtain the fine-tuned and optimized circumferential path.

[0023] By adopting the above technical solution, when the gas phase purity deviation in different areas of the tray is small, the detection path can be finely adjusted by the difference ratio, avoiding the decrease in detection efficiency caused by large-scale path adjustment, and ensuring that high-quality gas phase moisture content detection can be achieved under different operating conditions.

[0024] Secondly, the present invention provides an acetaldehyde distillation column control system, which adopts the following technical solution: An acetaldehyde distillation column control system includes: The acquisition module is used to acquire the tray number, anhydrous copper sulfate test paper number, and detection time; A memory for storing a program for controlling an acetaldehyde distillation column as described above; The processor loads and executes programs from memory.

[0025] By adopting the above technical solution, the acquisition module can collect key information of the distillation column in real time, providing basic data support for subsequent water content detection and analysis. The memory can store the pre-written acetaldehyde distillation column control method program, which contains the detailed logic and algorithm of each of the above steps S. The processor, as the core of the system, loads and executes the program in the memory, and operates according to the data provided by the acquisition module, thereby realizing precise control of the acetaldehyde distillation column and improving the production efficiency and purity stability of acetaldehyde.

[0026] In summary, the present invention has at least one of the following beneficial technical effects: By real-time monitoring of the vapor content of each tray, the upper tray that has reached the high purity standard is accurately collected, ineffective mass transfer paths are cut off, and the process of vapor rising to the top of the tower is shortened, thereby increasing the acetaldehyde production rate. By conducting a second re-inspection of the critical tray, the risk of purity rebound can be avoided in a timely manner, adapting to the complex working conditions of raw material impurity fluctuations, and ensuring that the purity of acetaldehyde products remains stable and meets the standards. The design incorporates a standardized test strip circumferential detection path, and the path parameters are dynamically optimized based on the moisture content difference between the center and edge areas of the tray. This ensures both uniformity of detection coverage and efficient detection through fine-tuning. Attached Figure Description

[0027] Figure 1 This is a flowchart of an acetaldehyde distillation column control method according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of an acetaldehyde distillation column according to an embodiment of this application.

[0028] The parts referred to by the numbers in the above attached diagrams are as follows: 1. Gas outlet; 2. Thermometer; 3. Reflux port; 4. Liquid distributor; 5. Liquid collector; 6. Material inlet; 7. Tray; 8. Nitrogen inlet; 9. Material outlet. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0030] This invention discloses a control method for an acetaldehyde distillation column. (Refer to...) Figure 1 and Figure 2 A method for controlling an acetaldehyde distillation column includes: Step S1: Obtain the tray number, anhydrous copper sulfate test paper number, and detection time. The tray number and the anhydrous copper sulfate test paper number are in one-to-one correspondence.

[0031] The tray number is a unique identifier for each tray 7 pre-assigned in the acetaldehyde distillation column, used to distinguish the positions of different trays 7, such as T1, T2, T3, etc. The tray 7 numbered T1 is located at the bottom of the area where trays 7 are installed in the distillation column. As the number increases, the position of the tray 7 moves closer to the top of the area where trays 7 are installed in the distillation column. For example, the height of tray 7 numbered T7 in the distillation column is always greater than the height of tray 7 numbered T6 in the distillation column.

[0032] The anhydrous copper sulfate test paper number refers to the number of the anhydrous copper sulfate test paper (anhydrous copper sulfate test paper is a chemical test paper made of an inert porous fiber material as a carrier, uniformly loaded with a certain amount of anhydrous copper sulfate white powder, used to detect the water content of the gas phase at each tray 7 per unit time) placed on each tray 7. For example, CS1, CS2, CS3, etc. The anhydrous copper sulfate test paper number corresponds one-to-one with the tray number. For example, the anhydrous copper sulfate test paper numbered CS1 corresponds to tray 7 numbered T1. This means that the anhydrous copper sulfate test paper numbered CS1 is located at the position of tray 7 numbered T1 when it is being tested. It also means that the anhydrous copper sulfate test paper numbered CS1 is testing the water content of the gas phase at the position of tray 7 numbered T1 (the gas phase refers to the mixture of substances in the gaseous state in the distillation column. The gas phase near the upper tray 7 is usually mainly high-purity acetaldehyde vapor, and also contains trace amounts of water vapor).

[0033] The detection time refers to the duration for which the vapor phase water content (vapor phase refers to the mixture of substances in a gaseous state within the distillation column; the vapor phase near the upper tray 7 is typically dominated by high-purity acetaldehyde vapor, while also containing trace amounts of water vapor) needs to be detected at each tray 7 in the distillation column. This duration is pre-set by staff through multiple experiments and stored in the system. This timeframe ensures that the anhydrous copper sulfate test paper will not exhibit an indistinct color change due to an excessively short time, nor will it result in multiple anhydrous copper sulfate test papers having similar colors, making color differences difficult to distinguish, due to an excessively long time.

[0034] Step S2: In response to the moisture content detection signal, control the anhydrous copper sulfate test paper corresponding to each anhydrous copper sulfate test paper number to perform the detection according to the detection time.

[0035] The moisture content detection signal is a signal generated by the system or manually triggered by the operator to indicate the start of detection of the vapor phase moisture content at each tray 7. Upon receiving this signal, the system simultaneously controls each anhydrous copper sulfate test paper to perform detection according to the preset detection time, ensuring that the vapor phase moisture content of each tray 7 can be detected within the same detection time.

[0036] Step S3: Obtain the test paper image of the anhydrous copper sulfate test paper corresponding to the number of the anhydrous copper sulfate test paper.

[0037] Anhydrous copper sulfate test paper is a chemical test paper made by uniformly loading a quantitative amount of anhydrous copper sulfate white powder onto a carrier based on an inert porous fiber material. It is used to detect the moisture content of the gas phase at each of the seven trays per unit time. The anhydrous copper sulfate test paper is pre-installed by the staff at each of the seven trays.

[0038] The test strip image refers to a digital visual image obtained by taking a picture of each anhydrous copper sulfate test strip at the end of the detection time. The image contains information such as the color depth of the anhydrous copper sulfate test strip, which is used to determine the water content of the gas phase at the position of each tray 7. The test strip images are obtained by taking pictures of the anhydrous copper sulfate test strip at the end of the detection time using cameras installed at each tray 7.

[0039] Step S4: Analyze the test strip image to obtain the chromaticity value, and extract the depth value from the chromaticity value.

[0040] The chromaticity value refers to the numerical value used to characterize the color attribute of anhydrous copper sulfate test paper after the color feature quantification analysis of the test paper image through image recognition algorithms. The chromaticity value is obtained by first performing illumination compensation and background removal processing on the acquired test paper image, correcting the uneven illumination problem in the tower through the gray world algorithm, and then using an adaptive threshold segmentation method to remove the background and moisture interference areas of the tower plate 7 at the edge of the test paper, retaining only the image of the effective detection area of ​​the test paper. Subsequently, the processed image is converted from RGB color space to Lab color space, and the pixel values ​​of the a channel (red-green axis) and b channel (yellow-blue axis) are extracted. The average value of the b channel of all pixels in the effective area is calculated, and this average value is the chromaticity value that characterizes the blue feature of the test paper.

[0041] The depth value is a quantitative indicator specifically used to characterize the intensity of the blue color when anhydrous copper sulfate test paper turns blue upon contact with water. The depth value is positively correlated with the moisture content in the gas phase; a larger depth value indicates a deeper blue color, meaning a higher moisture content at plate 7 corresponding to that test paper. Conversely, a smaller depth value indicates a lower moisture content at plate 7. The depth value is extracted by using an image recognition algorithm to selectively filter the acquired chromaticity values ​​based on blue features. Color dimension parameters such as hue and lightness, which are irrelevant to the intensity of the blue color, are removed. Subsequently, the grayscale quantification of the blue features is extracted to obtain the depth value.

[0042] Step S5: Select the high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than the preset depth threshold, and generate a high-purity anhydrous copper sulfate test paper number group based on the high-purity anhydrous copper sulfate test paper numbers. The depth threshold refers to the depth value limit used to determine whether the test result of anhydrous copper sulfate test paper meets the high purity standard of acetaldehyde. The depth threshold is determined based on the production requirements of the acetaldehyde distillation column and data from multiple experiments, identifying the depth value at which acetaldehyde meets the purity requirements. When the depth value of the anhydrous copper sulfate test paper is less than the depth threshold, it indicates that the moisture content in the gas phase at position 7 of the corresponding tray is extremely low, meeting the high purity requirements of acetaldehyde. For example, when the depth value is less than the depth threshold, it means that the acetaldehyde content is greater than 99.5%.

[0043] The high-purity anhydrous copper sulfate test strip number refers to the number of anhydrous copper sulfate test strips that, after testing, exhibit a lighter blue color depth, meaning their depth value is less than a preset depth threshold. For example, if the depth value of anhydrous copper sulfate test strip numbered CS7 is less than the depth threshold, a specific letter (such as G) is added to the anhydrous copper sulfate test strip number as a suffix to distinguish high purity. For instance, CS7 is identified as CS7-G, indicating that the depth value of anhydrous copper sulfate test strip numbered CS7 is less than the depth threshold, and also indicating that the acetaldehyde content in the gas phase at position 7 of tray number T7 meets the high purity requirements for acetaldehyde. The screening method for high-purity anhydrous copper sulfate test strip numbers involves comparing the depth values ​​corresponding to each anhydrous copper sulfate test strip number one by one against the depth threshold, selecting anhydrous copper sulfate test strip numbers with depth values ​​less than the depth threshold, and marking these numbers as high-purity anhydrous copper sulfate test strip numbers.

[0044] The high-purity anhydrous copper sulfate test paper number group refers to the set of numbers associated with the high-purity anhydrous copper sulfate test papers. The method for generating the high-purity anhydrous copper sulfate test paper number group is described in detail in subsequent steps S50 to S51, and will not be repeated here.

[0045] Step S6: Obtain the corresponding tray number group based on the number group of the high-purity anhydrous copper sulfate test paper.

[0046] A tray number group refers to the set of tray numbers corresponding to each anhydrous copper sulfate test paper number in the high-purity anhydrous copper sulfate test paper number group. For example, if the high-purity anhydrous copper sulfate test paper number group includes CS8-G, CS9-G, and CS10-G, then the tray number group is the set of tray numbers including T8, T9, and T10.

[0047] Step S7: Control each tray 7 corresponding to the tray number group to be stored according to the preset storage mode.

[0048] The storage mode refers to the mode in which tray 7 is adjusted to a non-working state, meaning that tray 7 no longer participates in the mass transfer separation process between the gas and liquid phases. This means tray 7 no longer performs the function of purifying acetaldehyde; only the tray 7 that is not stored remains as the effective working tray. The storage mode is pre-set and stored in the system by the staff based on the actual structure of the acetaldehyde distillation column. The control scheme for the storage mode includes controlling tray 7 to move to the storage position and adjusting the closure of the vents on tray 7.

[0049] The reason why each tray 7 corresponding to the tray number group is stored according to the preset storage mode is that the moisture content in the gas phase at the tray 7 corresponding to the tray number group is extremely low, and the acetaldehyde purity already meets the production requirements. Storing each tray 7 corresponding to the tray number group can shorten the mass transfer path of the gas phase, speed up the speed at which high-purity acetaldehyde vapor reaches the top of the column, and improve the overall production efficiency of distillation.

[0050] Reference Figure 2 The vapor outlet 1 is installed at the top of the distillation column to remove the high-purity acetaldehyde vapor component before condensation at the top. Thermometers 2 are distributed throughout the distillation column to monitor the real-time temperature of each area. The reflux port 3 is located below the vapor outlet 1 at the top of the column to reflux a portion of the condensed liquid acetaldehyde back into the column. A liquid distributor 4 is installed near the top of the distillation column to increase the contact area between the liquid and gas, resulting in more uniform mass transfer. A liquid collector 5 is installed above the section of tray 7 to reduce liquid entrainment in the rising vapor phase and optimize separation. The material inlet 6 is the channel for the acetaldehyde mixture to be separated to enter the distillation column; it is installed in the feed section in the middle of the column and located above tray 7. Multiple trays 7 are vertically distributed at certain intervals within the distillation column, and each tray 7 has a gas passage. The rising gas phase transfers heat with the liquid on the tray 7 through the gas passage. High-boiling-point components in the gas phase are absorbed by the liquid (e.g., water vapor becomes liquid water), while low-boiling-point acetaldehyde in the liquid is vaporized and enters the gas phase. A nitrogen inlet 8 is installed at the bottom of the distillation column to introduce inert nitrogen gas. This not only assists in the upward movement of the gas phase but also isolates the column from air, preventing acetaldehyde from being oxidized and deteriorated at high temperatures, and also preventing the formation of an explosive gas mixture within the column. A material outlet 9 is installed at the bottom of the distillation column to discharge heavy components (such as liquid water).

[0051] The method for selecting high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than a preset depth threshold, and generating high-purity anhydrous copper sulfate test paper number groups based on these numbers, includes: Step S50: Select the high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than the preset depth threshold, and sort the high-purity anhydrous copper sulfate test paper numbers to obtain the smallest anhydrous copper sulfate test paper number.

[0052] The smallest anhydrous copper sulfate test paper number refers to the smallest number obtained after sorting all high-purity anhydrous copper sulfate test paper numbers according to their numerical values. For example, if the high-purity anhydrous copper sulfate test paper numbers are CS8-G, CS9-G, and CS10-G, then the smallest anhydrous copper sulfate test paper number after sorting is CS8-G.

[0053] Step S51: Remove the smallest anhydrous copper sulfate test paper number from the high-purity anhydrous copper sulfate test paper numbering, and generate a high-purity anhydrous copper sulfate test paper numbering group based on the remaining high-purity anhydrous copper sulfate test paper numbers.

[0054] A high-purity anhydrous copper sulfate test paper number group refers to the set of all remaining high-purity anhydrous copper sulfate test paper numbers after removing the smallest anhydrous copper sulfate test paper number. For example, if the high-purity anhydrous copper sulfate test paper numbers are CS7-G, CS8-G, CS9-G, and CS10-G, then the smallest anhydrous copper sulfate test paper number is CS7-G. The remaining high-purity anhydrous copper sulfate test paper numbers after removing the smallest anhydrous copper sulfate test paper number CS7-G will form a high-purity anhydrous copper sulfate test paper number group that includes CS8-G, CS9-G, and CS10-G.

[0055] The lowest anhydrous copper sulfate test paper number was removed from the high-purity anhydrous copper sulfate test paper numbering because, although the purity of acetaldehyde in the gas phase at position 7 of the tray corresponding to the lowest anhydrous copper sulfate test paper number met the standard, the gas phase detected at this position may have already participated in the mass transfer separation process between the gas and liquid phases at tray 7 corresponding to the anhydrous copper sulfate test paper number. In order to ensure the accuracy of acetaldehyde purity in the distillation process, the lowest anhydrous copper sulfate test paper number needs to be removed from the high-purity anhydrous copper sulfate test paper numbering.

[0056] This also includes: Step S8: After each tray 7 corresponding to the tray number group is stored according to the preset storage mode, the lowest tray number is found in the tray number group.

[0057] The lowest tray number refers to the tray number 7 with the smallest numerical value in the tray numbering group, which is also the tray number corresponding to the tray 7 with the lowest height. The lowest tray number is found by iterating through all the numbers in the tray numbering group, comparing their numerical values, and selecting the number with the smallest value as the lowest tray number. For example, if the tray numbering group contains tray numbers T8, T9, and T10, then the lowest tray number is T8.

[0058] Step S9: Find the corresponding anhydrous copper sulfate test paper number based on the lowest tray number, and perform steps S2 to S4 on the anhydrous copper sulfate test paper corresponding to the retest anhydrous copper sulfate test paper number to obtain the retest depth value.

[0059] The anhydrous copper sulfate test paper number for retesting refers to the number of the anhydrous copper sulfate test paper used for secondary moisture content testing on tray 7 corresponding to the lowest tray number. The numerical value of the anhydrous copper sulfate test paper number for retesting corresponds to the numerical value of the tray number. The method for finding the anhydrous copper sulfate test paper number for retesting is as follows: the system first finds the corresponding anhydrous copper sulfate test paper number based on the lowest tray number. For example, the anhydrous copper sulfate test paper number used for testing on tray 7 of tray T8 is CS8. Then, a specific letter (such as F) is used as the retest attribute distinguisher as the suffix of the anhydrous copper sulfate test paper number CS8, which is CS8-F.

[0060] The retest depth value refers to the depth value obtained after the anhydrous copper sulfate test paper corresponding to the retest anhydrous copper sulfate test paper number detects the vapor phase moisture content at the lowest tray 7. The method for obtaining the retest depth value is the same as the method for obtaining the depth value, and will not be repeated here. Steps S2 to S4 are performed on the anhydrous copper sulfate test paper corresponding to the retest anhydrous copper sulfate test paper number to control the detection of vapor phase moisture content at the lowest tray 7 by the anhydrous copper sulfate test paper corresponding to the retest anhydrous copper sulfate test paper number, and the retest depth value corresponding to the anhydrous copper sulfate test paper corresponding to the retest anhydrous copper sulfate test paper number is obtained.

[0061] Step S10: When the re-inspection depth value is less than the depth threshold, control the distillation column to continue working.

[0062] When the re-inspection depth value is less than the depth threshold, it means that after each tray 7 corresponding to the control tray number group is stored according to the preset storage mode, the remaining working tray 7 in the distillation column is sufficient to meet the distillation purity requirements of acetaldehyde. At this time, the control distillation column continues to work, which can not only improve the overall distillation production efficiency, but also ensure the distillation purity of acetaldehyde.

[0063] Step S11: When the re-inspection depth value is greater than the depth threshold, control the tray 7 corresponding to the lowest tray number to extend according to the preset extension mode.

[0064] The extension mode refers to the control mode that restores the tray 7, which is in the storage mode, to the working state. Specifically, it includes moving the tray 7 from the storage space to the corresponding work position and adjusting the vent of the tray 7 to be fully opened, thereby restoring the gas-liquid flow channel of the tray 7 and allowing the tray 7 corresponding to the lowest tray number to re-participate in the mass transfer and separation process between the gas and liquid phases, ensuring that the distillation purity of acetaldehyde can meet the production requirements.

[0065] When the re-inspection depth value is greater than the depth threshold, it indicates that after each tray 7 corresponding to the control tray number group is stored according to the preset storage mode, the remaining working tray 7 in the distillation column fails to meet the distillation purity requirements of acetaldehyde. This may be due to the mixing of vaporized water vapor into the gas phase with the acetaldehyde purity meeting the standard during the ascent. At this time, the tray 7 corresponding to the lowest tray number is controlled to extend according to the extension mode, so that the tray 7 corresponding to the lowest tray number can restart the distillation process and further purify the acetaldehyde in the gas phase.

[0066] Among them, when the re-inspection depth value is greater than the depth threshold, the method for controlling tray 7 corresponding to the lowest tray number to extend according to the preset extension mode includes: Step S110: After the tray 7 corresponding to the lowest tray number is stretched according to the preset stretching mode, the lowest tray number is removed from the tray number group to form an optimized tray number group.

[0067] An optimized tray number group refers to the set of tray numbers remaining after removing the lowest tray number. The optimized tray number group is formed by automatically removing tray number 7 (corresponding to the lowest tray number) from the tray number group after the system completes the extension operation, and then recombining the remaining tray numbers into an optimized tray number group. For example, if the tray number group contains T7, T8, T9, and T10, after extending tray 7 (corresponding to T7), T7 is removed from the original group, and the optimized tray number group is then the set of T8, T9, and T10.

[0068] Step S111: Find the lowest optimized tray number in the optimized tray number group, and execute step S9 to obtain the optimized re-inspection depth value based on the lowest optimized tray number.

[0069] The optimized lowest tray number refers to the tray number 7 with the smallest numerical value in the optimized tray number group. This number represents the tray 7 with the lowest height position in the optimized tray number group. The method for finding the optimized lowest tray number is the same as the method for finding the lowest tray number, that is, by traversing all the numbers in the optimized tray number group, comparing their values, and selecting the number with the smallest value as the optimized lowest tray number. For example, if the optimized tray number group contains tray numbers T8, T9, and T10, then the optimized lowest tray number is T8.

[0070] After finding the optimized lowest tray number, the operation in step S9 is performed according to the number, that is, to find the corresponding anhydrous copper sulfate test paper and perform a moisture content test on the test paper to obtain the optimized retest depth value, so as to further determine whether the working state of the distillation column meets the distillation purity requirements of acetaldehyde.

[0071] Step S112: When the optimized re-inspection depth value is less than the depth threshold, control the distillation column to continue working.

[0072] When the optimized re-inspection depth value is less than the depth threshold, it indicates that after the tray 7 corresponding to the lowest tray number is extended according to the preset extension mode, the working tray 7 in the distillation column can meet the distillation purity requirements of acetaldehyde. At this time, the distillation column continues to operate to ensure the continuous and efficient purification of acetaldehyde.

[0073] Step S113: When the optimized re-inspection depth value is greater than the depth threshold, control the tray 7 corresponding to the lowest optimized tray number to extend according to the preset extension mode, and repeat steps S110 to S111 until the optimized re-inspection depth value is less than the depth threshold.

[0074] When the optimized re-inspection depth value is greater than the depth threshold, it means that even after one adjustment, the working tray 7 in the distillation column still fails to fully meet the purity standard of acetaldehyde distillation. At this time, the system will automatically control the tray 7 corresponding to the lowest optimized tray number to extend again according to the preset extension mode, so that it can re-participate in the mass transfer separation process between the gas phase and the liquid phase. Then, the operation of steps S110 to S111 is repeated, that is, the extended lowest tray number is removed from the current tray number group to form a new optimized tray number group, and the new optimized lowest tray number is found. The water content is detected again to obtain a new depth value until the optimized re-inspection depth value is less than the preset depth threshold, ensuring that the working tray 7 in the distillation column can meet the purity requirements of acetaldehyde distillation, thereby ensuring the quality and production efficiency of acetaldehyde products.

[0075] This also includes another control method for tray 7 when the re-inspection depth value is greater than the depth threshold, the method comprising: Step S114: When the re-inspection depth value is greater than the depth threshold, obtain the intermediate tray number according to the tray number group.

[0076] The intermediate tray number refers to the number corresponding to tray 7, which is in the middle position in the tray number group. For example, if the tray number group includes T6, T7, T8, T9, and T10, then the intermediate tray number is T8. The method for obtaining the intermediate tray number is described in detail in subsequent steps S1140 to S1142, and will not be repeated here.

[0077] Step S115: Control the tray 7 corresponding to the intermediate tray number to extend in the extension mode, and obtain the upper tray number according to the intermediate tray number.

[0078] The upper tray number refers to the tray number of the tray 7 located one level above the tray numbered in the middle tray. For example, if T8 is the middle tray number, then the upper tray number is T9. The upper tray number is obtained by the system searching for and determining the directly adjacent upper tray number in the structural relationship of tray 7 based on the middle tray number.

[0079] By controlling the intermediate tray number corresponding to tray 7 to extend in the extension mode, the gas-liquid flow channel of the intermediate tray number corresponding to tray 7 is restored, so that the intermediate tray number corresponding to tray 7 can re-participate in the mass transfer separation process between the gas phase and the liquid phase, making the mass transfer separation process between the gas phase and the liquid phase more uniform in the overall structure of the distillation column.

[0080] Step S116: Find the corresponding upper anhydrous copper sulfate test paper number based on the upper tray number.

[0081] The upper anhydrous copper sulfate test paper number refers to the number of the anhydrous copper sulfate test paper used to detect the vapor phase moisture content at position 7 of the tray corresponding to the upper tray number. Its value corresponds to the upper tray number. The system will find the corresponding upper anhydrous copper sulfate test paper number based on the upper tray number. For example, if the upper tray number is T9, the corresponding upper anhydrous copper sulfate test paper number is CS9.

[0082] Step S117: Perform steps S2 to S4 according to the number of the upper anhydrous copper sulfate test paper to obtain the upper layer depth value.

[0083] The upper layer depth value refers to the depth value obtained after the anhydrous copper sulfate test paper corresponding to the upper layer tray number detects the vapor phase moisture content at tray 7 of the upper layer tray. The process of obtaining the upper layer depth value is the same as the method of obtaining the depth value, and will not be repeated here.

[0084] Step S118: When the upper layer depth value is less than the depth threshold, control the distillation column to continue working.

[0085] When the upper layer depth value is less than the depth threshold, it means that after the extension of the tray 7 corresponding to the intermediate tray number, the vapor water content at the tray 7 corresponding to the upper tray number has met the purity requirements of acetaldehyde distillation. At this time, the tray 7 working in the distillation column is reasonably configured, which can ensure the continuous and efficient purification of acetaldehyde. Therefore, the distillation column is controlled to continue to operate.

[0086] Step S119: When the upper layer depth value is greater than the depth threshold, control the tray 7 corresponding to the upper layer tray number to extend according to the preset extension mode.

[0087] When the upper layer depth value is greater than the depth threshold, it indicates that after controlling the extension of tray 7 corresponding to the intermediate tray number, the vapor phase water content at tray 7 corresponding to the upper tray number still does not meet the purity requirements of acetaldehyde distillation. At this time, the system will automatically control tray 7 corresponding to the upper tray number to extend in the extension mode, so that tray 7 corresponding to the upper tray number can re-participate in the mass transfer separation process between the gas phase and the liquid phase, thereby ensuring the purity requirements of acetaldehyde distillation.

[0088] Among them, when the re-inspection depth value is greater than the depth threshold, the method for obtaining the intermediate tray number based on the tray number group includes: Step S1140: Determine the number of trays based on the tray number group.

[0089] The tray number count refers to the total number of tray numbers contained in a tray number group. The tray number count is obtained by counting all the numbers within the tray number group. For example, if the tray number group is T6, T7, T8, T9, T10, then the tray number count is 5.

[0090] Step S1141: When the number of tray numbers is odd, sort all tray numbers in the tray number group in ascending order of value, and define the tray number in the middle position as the middle tray number.

[0091] When the number of tray numbers is odd, it means that there is a clear middle number in the tray number group. The system will first sort all the tray numbers in ascending order of value. For example, if the tray number group is T6, T7, T8, T9, T10, then T8, which is in the middle, is the middle tray number.

[0092] Step S1142: When the number of tray numbers is even, sort all tray numbers in the tray number group in ascending order of value, and define the tray number with the larger value among the two tray numbers in the middle position as the middle tray number.

[0093] When the number of tray numbers is even, since there is no single intermediate number, the system will first sort all tray numbers in ascending order of value. For example, if the tray number group is T7, T8, T9, T10, and there are two intermediate numbers, T8 and T9, the system will select the one with the larger value, T9, as the intermediate tray number. The purpose of selecting the tray number with the larger value as the intermediate tray number is to prioritize the placement of the relatively upper tray (T7), reducing the possibility of water vapor mixing into the acetaldehyde vapor as it rises within the distillation column, thus minimizing the likelihood of it meeting purity standards.

[0094] The method for controlling the anhydrous copper sulfate test paper corresponding to each test paper number based on the test time includes: Step S20: Obtain the radius of the tray and the radius of the test paper.

[0095] The tray radius refers to the radius of each tray in a distillation column. The tray radius is determined in advance by the staff based on the design drawings of the distillation column and stored in the system.

[0096] The test strip radius refers to the physical radius of the anhydrous copper sulfate test strip (the anhydrous copper sulfate test strip used here is a round test strip). This parameter is obtained by the staff based on the test strip's production information and entered into the system in advance.

[0097] Step S21: Calculate the path radius based on the tray radius and the test paper radius.

[0098] The path radius refers to the radius of the path that the anhydrous copper sulfate test paper needs to travel on tray 7 for testing. The path radius is calculated by subtracting the test paper radius from the tray radius.

[0099] Step S22: Calculate the path perimeter based on the path radius.

[0100] The path perimeter refers to the circumference of the path that the anhydrous copper sulfate test paper needs to travel on tray 7 for testing. The path perimeter is calculated using the formula for the circumference of a circle: the path perimeter equals 2 multiplied by π multiplied by the path radius, where π is the mathematical constant pi.

[0101] Step S23: Calculate the detection speed based on the path perimeter and detection time, and form a circular path based on the path radius.

[0102] The detection speed refers to the speed required for anhydrous copper sulfate test paper to move across tray 7 to detect moisture content. The detection speed is calculated by dividing the path circumference by the detection time.

[0103] The circular path refers to the trajectory that the anhydrous copper sulfate test paper must follow when detecting moisture content on tray 7. This trajectory is circular, and the radius of the circular path is the previously calculated path radius. The circular path is formed by the system planning a circular trajectory on the plane of tray 7 based on the calculated path radius. This circular trajectory is the circumferential path that the anhydrous copper sulfate test paper must follow when detecting moisture content.

[0104] Step S24: Control the anhydrous copper sulfate test paper to perform the test along the circumferential path at the detection speed.

[0105] The system adjusts the moving device of the anhydrous copper sulfate test paper to move along a pre-planned circular path on the tray 7 at a calculated detection speed, so that the anhydrous copper sulfate test paper can fully contact the gas phase on the tray 7 and detect the water content in the gas phase in real time, thereby accurately obtaining the gas phase water content at different positions on the tray 7.

[0106] This also includes a method for optimizing the circular path, which includes: Step S230: Divide the near-center region and the far-center region of the tray according to the test strip image.

[0107] The area near the center of the tray refers to the semi-circular area of ​​the anhydrous copper sulfate test paper close to the center of tray 7.

[0108] The area far from the center of the tray refers to the semi-circular area of ​​the anhydrous copper sulfate test paper located away from the center of tray 7.

[0109] The system divides the area near the center of the tray and the area far from the center of the tray into two semicircles based on the test strip image using image recognition technology, with the center of the test strip as the center. The semicircle closer to the center of tray 7 is the area near the center of the tray, and the semicircle farther from the center of tray 7 is the area far from the center of the tray.

[0110] Step S231: Define the depth value of the area near the center of the tray as the near-center depth value, and define the depth value of the area far from the center of the tray as the far-center depth value.

[0111] Step S232: Calculate the depth difference based on the depth values ​​near the center of the tray and the depth values ​​far from the center of the tray.

[0112] The depth difference refers to the difference between the depth value near the center of the tray and the depth value far from the center of the tray. The depth difference is calculated by subtracting the depth value near the center of the tray from the depth value far from the center of the tray; that is, the depth difference equals the depth value near the center of the tray minus the depth value far from the center of the tray.

[0113] Step S233: When the depth difference is greater than the preset difference threshold, calculate the optimized radius based on the path radius and the preset difference radius.

[0114] The difference threshold is a pre-set standard used to determine whether the difference in vapor phase water content between the near-center region and the far-center region of the distillation column is significant. When the calculated depth difference exceeds this threshold, it indicates a large difference in vapor phase water content between the near-center region and the far-center region. The difference threshold is pre-set and stored in the system by the staff based on the actual operating conditions of the distillation column and the purity requirements of acetaldehyde distillation.

[0115] The difference radius refers to a pre-set reference radius value used to adjust the radius of the circumferential path. This value is set by the staff according to the characteristics of the distillation column and the accuracy requirements of acetaldehyde distillation and stored in the system.

[0116] The optimized radius refers to the radius of the new path used when optimizing a circular path. The optimized radius is calculated by subtracting the difference radius from the original path radius.

[0117] Step S234: Perform steps S22 to S23 according to the optimized radius to obtain the optimized circumferential path.

[0118] After obtaining the optimized radius, the system recalculates the optimized path circumference using the formula for the circumference of a circle: path circumference equals 2 multiplied by π multiplied by the optimized radius (where π is pi). Then, the optimized path circumference is divided by the detection time to determine the new detection speed required for the anhydrous copper sulfate test paper on the optimized circular path. Based on this new detection speed and the optimized radius, the system re-plans a circular trajectory on the plane of tray 7, using the optimized radius as a reference. This newly planned circular trajectory is the optimized circular path. The optimized circular path enables the anhydrous copper sulfate test paper to more accurately detect the vapor phase moisture content in different regions of tray 7.

[0119] This also includes: Step S235: When the depth difference is less than the preset difference threshold, calculate the difference ratio based on the depth difference and the difference threshold.

[0120] The difference ratio refers to the ratio between the depth difference and the difference threshold. The difference ratio is calculated by dividing the depth difference by the difference threshold.

[0121] Step S236: Calculate the difference ratio radius based on the difference ratio and the difference radius.

[0122] The difference ratio radius refers to the radius obtained by adjusting the difference radius according to the difference ratio. The difference ratio radius is calculated by multiplying the difference ratio by the difference radius.

[0123] Step S237: Perform steps S22 to S23 according to the difference ratio radius to obtain the fine-tuned and optimized circumferential path.

[0124] Fine-tuning the circular path refers to the new path formed after fine-tuning and optimizing the original circular path. After obtaining the difference ratio radius, the system recalculates the path circumference using the formula for the circumference of a circle: the path circumference equals 2 multiplied by π multiplied by the difference ratio radius (where π is pi). Then, the newly calculated path circumference is divided by the detection time to determine the new detection speed required for the anhydrous copper sulfate test paper on the fine-tuned circular path. Based on this new detection speed and the difference ratio radius, the system then plans a new circular trajectory on the plane of tray 7, using the difference ratio radius as a reference. This newly planned circular trajectory is the fine-tuned circular path. Fine-tuning the circular path allows the anhydrous copper sulfate test paper to more precisely detect the vapor phase moisture content in different areas of tray 7 when the vapor phase moisture content difference is small, further improving the accuracy of vapor phase moisture content detection.

[0125] Based on the same inventive concept, embodiments of the present invention provide an acetaldehyde distillation column control system.

[0126] An acetaldehyde distillation column control system includes: The acquisition module is used to acquire the tray number, anhydrous copper sulfate test paper number, and detection time; A memory for storing a program for controlling an acetaldehyde distillation column; The processor loads and executes programs from memory.

[0127] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0128] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for controlling an acetaldehyde distillation column, characterized in that, include: Step S1: Obtain the tray number, anhydrous copper sulfate test paper number, and detection time. The tray number and the anhydrous copper sulfate test paper number correspond one-to-one. Step S2: In response to the moisture content detection signal, control the anhydrous copper sulfate test paper corresponding to each anhydrous copper sulfate test paper number to perform detection according to the detection time; Step S3: Obtain the test paper image of the anhydrous copper sulfate test paper corresponding to the number of the anhydrous copper sulfate test paper; Step S4: Analyze the test strip image to obtain the chromaticity value, and extract the depth value from the chromaticity value; Step S5: Select the high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than the preset depth threshold, and generate a high-purity anhydrous copper sulfate test paper number group based on the high-purity anhydrous copper sulfate test paper numbers. Step S6: Obtain the corresponding tray number group based on the number group of the high-purity anhydrous copper sulfate test paper; Step S7: Control each tray (7) corresponding to the tray number group to be stored according to the preset storage mode.

2. The method for controlling an acetaldehyde distillation column according to claim 1, characterized in that, The method for selecting high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than a preset depth threshold, and generating high-purity anhydrous copper sulfate test paper number groups based on these numbers, includes: Step S50: Select the high-purity anhydrous copper sulfate test paper numbers with depth values ​​less than the preset depth threshold, and sort the high-purity anhydrous copper sulfate test paper numbers to obtain the smallest anhydrous copper sulfate test paper number. Step S51: Remove the smallest anhydrous copper sulfate test paper number from the high-purity anhydrous copper sulfate test paper numbering, and generate a high-purity anhydrous copper sulfate test paper numbering group based on the remaining high-purity anhydrous copper sulfate test paper numbers.

3. The method for controlling an acetaldehyde distillation column according to claim 1, characterized in that, Also includes: Step S8: After each tray (7) corresponding to the control tray number group is stored according to the preset storage mode, the lowest tray number is found in the tray number group. Step S9: Find the corresponding anhydrous copper sulfate test paper number based on the lowest tray number, and perform steps S2 to S4 on the anhydrous copper sulfate test paper corresponding to the retest anhydrous copper sulfate test paper number to obtain the retest depth value. Step S10: When the re-inspection depth value is less than the depth threshold, control the distillation column to continue working; Step S11: When the re-inspection depth value is greater than the depth threshold, control the tray (7) corresponding to the lowest tray number to stretch according to the preset stretching mode.

4. The method for controlling an acetaldehyde distillation column according to claim 3, characterized in that, When the re-inspection depth value is greater than the depth threshold, the method for controlling the tray (7) corresponding to the lowest tray number to extend according to the preset extension mode includes: Step S110: After the tray (7) corresponding to the lowest tray number is stretched according to the preset stretching mode, the lowest tray number is removed from the tray number group and an optimized tray number group is formed. Step S111: Find the lowest optimized tray number in the optimized tray number group, and execute step S9 to obtain the optimized re-inspection depth value based on the lowest optimized tray number; Step S112: When the optimized re-inspection depth value is less than the depth threshold, control the distillation column to continue working; Step S113: When the optimized re-inspection depth value is greater than the depth threshold, control the tray (7) corresponding to the lowest optimized tray number to stretch according to the preset stretching mode, and repeat steps S110 to S111 until the optimized re-inspection depth value is less than the depth threshold.

5. The method for controlling an acetaldehyde distillation column according to claim 3, characterized in that, It also includes another control method for the tray (7) when the re-inspection depth value is greater than the depth threshold, the method comprising: Step S114: When the re-inspection depth value is greater than the depth threshold, obtain the intermediate tray number according to the tray number group; Step S115: Control the tray (7) corresponding to the intermediate tray number to extend in the extension mode, and obtain the upper tray number according to the intermediate tray number; Step S116: Find the corresponding upper anhydrous copper sulfate test paper number based on the upper tray number; Step S117: Perform steps S2 to S4 according to the number of the upper anhydrous copper sulfate test paper to obtain the upper layer depth value; Step S118: When the upper layer depth value is less than the depth threshold, control the distillation column to continue working; Step S119: When the upper layer depth value is greater than the depth threshold, control the tray (7) corresponding to the upper layer tray number to extend according to the preset extension mode.

6. The method for controlling an acetaldehyde distillation column according to claim 5, characterized in that, When the re-inspection depth value is greater than the depth threshold, the methods for obtaining the intermediate tray number based on the tray number group include: Step S1140: Determine the number of trays based on the tray number group; Step S1141: When the number of tray numbers is odd, sort all tray numbers in the tray number group in ascending order of value, and define the tray number in the middle position as the middle tray number. Step S1142: When the number of tray numbers is even, sort all tray numbers in the tray number group in ascending order of value, and define the tray number with the larger value among the two tray numbers in the middle position as the middle tray number.

7. The method for controlling an acetaldehyde distillation column according to claim 1, characterized in that, The method for controlling the testing of anhydrous copper sulfate test strips corresponding to each test strip number based on the testing time includes: Step S20: Obtain the radius of the tray and the radius of the test paper; Step S21: Calculate the path radius based on the tray radius and the test paper radius; Step S22: Calculate the path perimeter based on the path radius; Step S23: Calculate the detection speed based on the path perimeter and detection time, and form a circular path based on the path radius; Step S24: Control the anhydrous copper sulfate test paper to perform the test along the circumferential path at the detection speed.

8. The method for controlling an acetaldehyde distillation column according to claim 7, characterized in that, It also includes methods for optimizing circular paths, which include: Step S230: Divide the near-center region and the far-center region of the tray according to the test strip image; Step S231: Define the depth value of the area near the center of the tray as the near-center depth value, and define the depth value of the area far from the center of the tray as the far-center depth value. Step S232: Calculate the depth difference based on the depth values ​​near the center of the tray and the depth values ​​far from the center of the tray; Step S233: When the depth difference is greater than the preset difference threshold, calculate the optimized radius based on the path radius and the preset difference radius; Step S234: Perform steps S22 to S23 according to the optimized radius to obtain the optimized circumferential path.

9. The method for controlling an acetaldehyde distillation column according to claim 8, characterized in that, Also includes: Step S235: When the depth difference is less than the preset difference threshold, calculate the difference ratio based on the depth difference and the difference threshold; Step S236: Calculate the difference ratio radius based on the difference ratio and the difference radius; Step S237: Perform steps S22 to S23 according to the difference ratio radius to obtain the fine-tuned and optimized circumferential path.

10. A control system for an acetaldehyde distillation column, characterized in that, include: The acquisition module is used to acquire the tray number, anhydrous copper sulfate test paper number, and detection time; A memory for storing a program for a control method for an acetaldehyde distillation column as described in any one of claims 1 to 9; The processor loads and executes programs from memory.

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