Method and system for recycling waste gas from chemical production

Abstract

The present invention provides a recovery and treatment method and system based on waste gas produced by chemical products, which relates to the field of waste gas treatment technology, including: collecting waste gas process record data; performing time sequence identification to determine a time sequence waste gas parameter table, which stores waste gas time sequence nodes and the waste gas type, waste gas concentration, and waste gas content corresponding to each node in a time sequence order; performing stage division and outputting a multi-stage waste gas process; connecting a multi-branch waste gas recovery device, including multiple recovery branches, inputting the multi-stage waste gas process into a multi-branch mapping encoder to obtain a recovery mapping code; when producing chemical products, controlling the valves of multiple recovery branches to start or close according to the recovery mapping code timing. The present invention solves the technical problems of the prior art that most chemical waste gas adopts unified recovery and centralized treatment, and the equipment cannot adjust the working mode according to the characteristics of different waste gases during treatment, resulting in low waste gas treatment efficiency and excessive equipment burden.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas treatment, and in particular to a method and system for recycling waste gas produced by chemical products. Background Art

[0002] During the production of chemical products, the generation of waste gas is an inevitable byproduct. Different chemical reactions produce different types of waste gas, which may have adverse effects on the environment, human health, and the equipment itself. Therefore, timely and effective waste gas recovery and treatment has become an important part of the production process. However, existing chemical waste gas recovery methods usually collect waste gas together for unified treatment. This method leads to interference between different waste gas components and may affect the recovery efficiency. For example, when the waste gas contains different gases, some gases may be over-recovered, while the recovery efficiency of other gases is low, resulting in waste of resources. In addition, the process of chemical product production is usually divided into stages, and waste gas is also generated in stages. The waste gas generated in different stages may have different components, concentrations, flow rates, and other characteristics. Existing waste gas recovery usually does not optimize the treatment method according to the different stages of the waste gas, resulting in timing mismatch in the treatment process, which in turn leads to unnecessary energy waste and reduced treatment efficiency. Summary of the Invention

[0003] This application provides a method and system for recycling and treating waste gas from chemical product production, aiming to solve the technical problems in the chemical production process of the existing technology, in which chemical waste gas is mostly recovered and treated in a unified and centralized manner, and the equipment is unable to adjust its working mode according to the characteristics of different waste gases during treatment, resulting in low waste gas treatment efficiency and excessive equipment burden.

[0004] The first aspect disclosed in the present application provides a method for recycling and treating waste gas produced by chemical products, the method comprising: collecting waste gas process record data for producing chemical products; performing time sequence identification on the waste gas process record data to determine a time sequence waste gas parameter table, wherein the time sequence waste gas parameter table stores waste gas time sequence nodes and the waste gas type, waste gas concentration and waste gas content corresponding to each node in a time sequence; performing stage division according to the time sequence waste gas parameter table to output a multi-stage waste gas process; connecting a multi-branch waste gas recovery device, wherein the multi-branch waste gas recovery device includes multiple recovery branches, inputting the multi-stage waste gas process into a multi-branch mapping encoder, establishing a mapping code between the multi-stage waste gas process and the multiple recovery branches, and obtaining a recovery mapping code; when producing the chemical product, the multi-branch waste gas recovery device controls the valves of the multiple recovery branches to start or close according to the recovery mapping code timing.

[0005] The second aspect disclosed in the present application provides a recovery and treatment system for waste gas produced by chemical products, which is used for the above-mentioned recovery and treatment method for waste gas produced by chemical products. The system includes: a data acquisition module for collecting waste gas process record data for producing chemical products; a timing identification module for performing timing identification on the waste gas process record data and determining a timing waste gas parameter table, wherein the timing waste gas parameter table stores waste gas timing nodes and the waste gas type, waste gas concentration and waste gas content corresponding to each node in a chronological order; a stage division module for performing stage division according to the timing waste gas parameter table and outputting a multi-stage waste gas process; a mapping coding module for connecting a multi-branch waste gas recovery device, wherein the multi-branch waste gas recovery device includes multiple recovery branches, and the multi-stage waste gas process is input into a multi-branch mapping encoder to establish a mapping code between the multi-stage waste gas process and the multiple recovery branches to obtain a recovery mapping code; a valve control module for controlling the valves of the multiple recovery branches of the multi-branch waste gas recovery device to start or close according to the recovery mapping code timing when the chemical products are produced.

[0006] One or more technical solutions provided in this application have at least the following beneficial effects:

[0007] By collecting real-time data on waste gas emissions during chemical production, accurate waste gas generation conditions can be obtained, ensuring that waste gas recovery and treatment can be controlled based on accurate and complete data, and enhancing the reliability of subsequent steps; through time series recognition, the waste gas process data is arranged in chronological order and organized into a time series waste gas parameter table, so that each waste gas node can be clearly calibrated on the time axis, ensuring that the generation rules and characteristics of the waste gas can be clearly and accurately reflected; by dividing the waste gas process into multiple different stages according to the time series waste gas parameter table, more targeted treatment methods can be adopted at each stage, avoiding the limitations of a single treatment method, and the multi-stage waste gas process enables the system to be flexible. Respond to the changes in different types of waste gas during the production process and adapt to the diverse needs in the production of chemical products; by connecting multi-branch waste gas recovery devices and using multi-branch mapping encoders to map the waste gas process and recovery branches, it can automatically select the appropriate recovery branch for waste gas recovery according to the needs of waste gas at different stages, avoid resource waste or improper configuration, thereby improving recovery efficiency and reducing unnecessary energy consumption; through the recovery mapping code timing control of the recovery branch valve start and close, realize the precise scheduling of the waste gas treatment process, and according to the recovery mapping code, the waste gas recovery device can automatically adjust the working status of multiple recovery branches, reducing the need for manual intervention, making the waste gas recovery process more automated and intelligent.

[0008] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic flow chart of a method for recycling and treating waste gas from chemical production provided in an embodiment of the present application.

[0010] Figure 2 The exemplary waste gas concentration changes with time series nodes in the recovery and treatment method based on chemical product production waste gas provided in the embodiment of the present application.

[0011] Figure 3 Schematic diagram of the structure of the recovery and treatment system for chemical product production waste gas provided in the embodiment of the present application.

[0012] Description of reference numerals: data acquisition module 10 , timing recognition module 20 , stage division module 30 , mapping encoding module 40 , valve control module 50 . DETAILED DESCRIPTION

[0013] The embodiments of the present application provide a method and system for recycling and treating waste gas produced by chemical products, thereby solving the technical problems in the prior art chemical production process, in which chemical waste gas is mostly recovered and treated in a unified and centralized manner, and the equipment is unable to adjust its working mode according to the characteristics of different waste gases during treatment, resulting in low waste gas treatment efficiency and excessive equipment burden.

[0014] After introducing the basic principles of this application, various non-limiting embodiments of this application will be specifically described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to explain this application and are not used to limit this application.

[0015] Example 1, as Figure 1 As shown, the embodiment of the present application provides a method for recycling and treating waste gas from chemical product production, the method comprising:

[0016] Collect waste gas process record data from the production of chemical products.

[0017] During chemical production, multiple waste gas sensors or monitoring devices are used to monitor various waste gas parameters in real time, including waste gas type (such as organic gas, inorganic gas, etc.), concentration, and flow rate. These monitoring devices are typically installed at key nodes of waste gas emission sources or pipelines to continuously record waste gas emissions. The collected waste gas process record data can provide detailed information on waste gas generation and emissions.

[0018] The exhaust gas process record data is time-series identified to determine a time-series exhaust gas parameter table, which stores exhaust gas time-series nodes and the exhaust gas type, exhaust gas concentration, and exhaust gas content corresponding to each node in a time-series order.

[0019] Time series recognition is performed on waste gas process data. The purpose of time series recognition is to identify the time series patterns of waste gas generation. Waste gas emissions in chemical production are not released continuously and evenly, but are associated with different stages of the production process. For example, at the beginning of a reaction, a certain type of waste gas is emitted, and after a certain period of time, another type of waste gas is produced, and then the waste gas enters a stage with different composition and concentration. Using data mining techniques such as time series analysis and cluster analysis, the time series information in the data is identified, distinguishing each time series node, that is, the key time point of waste gas generation.

[0020] Based on the time series nodes, a time series exhaust gas parameter table is constructed. The table records each time series node in chronological order and assigns the corresponding exhaust gas type, concentration and content to each node. For example, if a certain exhaust gas is generated within 10 minutes after the start of the reaction, then the time series node of 10 minutes is recorded and the type, concentration and content of the exhaust gas are clearly marked on the node. An exemplary time series exhaust gas parameter table is shown in Table 1. Figure 2 FIG. 1 shows exemplary changes in exhaust gas concentration at various time nodes.

[0021] Table 1: Time series exhaust gas parameters

[0022]

[0023] The exhaust gas flow is divided into stages according to the time sequence exhaust gas parameter table and a multi-stage exhaust gas flow is output.

[0024] Arrange the nodes in the time series exhaust gas parameter table in chronological order and construct a feature vector for each time series node. The feature vector includes the exhaust gas concentration, flow rate, gas type and the change trend of these parameters over time. For example, at a certain moment, the exhaust gas concentration is a certain value. Over time, the concentration may change, forming a concentration change rate. This information is included in the feature vector.

[0025] In order to reasonably divide the different stages of the exhaust process, the sliding window technology is used to calculate the similarity between time series feature vectors. By calculating the similarity of feature vectors between adjacent time nodes, the time points with large similarity changes are identified as candidate mutation time series nodes. These points are important moments in the exhaust gas generation process that usually mean the beginning of a new stage.

[0026] A K-value clustering algorithm is used to cluster candidate variant time series nodes and determine the boundaries of different stages. The K-value clustering algorithm divides candidate nodes into different stages based on cost functions, such as minimizing intra-group distance and maximizing inter-group distance. The final K-value optimal solution is the optimal stage division result. Based on the K-value clustering results, the time series exhaust gas parameter table is divided into multiple stages, and a multi-stage exhaust gas process flow is output. Each stage corresponds to specific exhaust gas characteristics and treatment requirements. These stage divisions provide a basis for subsequent exhaust gas recovery branch control, so that different exhaust gas flows and components can be directed to the appropriate recovery device for treatment.

[0027] Connect a multi-branch exhaust gas recovery device, which includes multiple recovery branches. Input the multi-stage exhaust gas process into a multi-branch mapping encoder, establish a mapping code between the multi-stage exhaust gas process and the multiple recovery branches, and obtain a recovery mapping code.

[0028] Connect a multi-branch exhaust gas recovery device, which contains multiple recovery branches. Each recovery branch has different processing capabilities. For example, some recovery branches are suitable for processing single exhaust gas components, while others are suitable for processing mixed gases. Each recovery branch may also have different processing efficiency, exhaust gas flow processing capacity, exhaust gas concentration adaptability and other characteristics.

[0029] The multi-stage exhaust gas process is input into the multi-branch mapping encoder. The function of this encoder is to select a suitable recovery branch for each stage based on the characteristics of the exhaust gas in each stage. In other words, the encoder will map the exhaust gas process of each stage to one or more recovery branches through rule matching.

[0030] In the multi-branch mapping encoder, the relationship between the exhaust gas process in each stage and multiple recovery branches is represented by the recovery mapping code. The recovery mapping code contains multiple information, such as the type and concentration of the exhaust gas in each stage and the corresponding recovery branch. The code provides a clear control diagram, telling the system which recovery branches should be started in each timing stage and how to control the valves of these branches.

[0031] When the chemical product is produced, the multi-branch waste gas recovery device controls the valves of the multiple recovery branches to start or close according to the recovery mapping code timing.

[0032] During the production of chemical products, the type, concentration, and amount of waste gas emissions vary with the different stages of the production process. Therefore, the opening and closing of the recovery branches must be precisely controlled based on the waste gas characteristics of each stage. In this step, the recovery mapping code indicates the recovery branch required for each waste gas stage. The recovery device adjusts the valves of the recovery branches in real time based on this code. For example, in one stage, a single recovery branch needs to be opened to treat a specific type of waste gas, while in another stage, multiple recovery branches need to be opened to treat mixed waste gas. The control system uses the timing information in the recovery mapping code to accurately control which recovery branches are opened or closed at what time. For example, after a waste gas stage begins, the valves of the recovery branches will open at a specified time to begin recovering the waste gas generated in that stage. At the same time, the opening and closing states of the recovery branches are dynamically adjusted. If the waste gas volume or composition changes, the valves will also be adjusted according to the new recovery mapping code.

[0033] This control method is implemented using an automation system (such as a PLC system, DCS system, etc.). The system reads the recovery mapping code in real time and adjusts the status of the recovery branch stage by stage according to the timing nodes of the exhaust gas process to ensure the efficiency and accuracy of exhaust gas recovery and treatment.

[0034] Furthermore, the multiple recovery branches include at least one single-component recovery branch and at least one mixed-component recovery branch; the single-component recovery branch is used to recover and process a single type of waste gas, and the mixed-component recovery branch is used to recover and process mixed types of waste gas.

[0035] During the waste gas recovery process, according to the type and composition of the waste gas, the recovery branch is designed as a single-component recovery branch specifically for processing a single waste gas component, and a mixed-component recovery branch for processing multiple waste gas components.

[0036] Among them, the single-component recovery branch is specifically used to treat a specific type of waste gas. For example, the gas produced during a chemical reaction, if its composition is fixed and single, can be recovered through the single-component recovery branch. This branch is targeted and can efficiently treat and recover a single waste gas component, such as carbon dioxide, nitrogen, ammonia, etc.

[0037] Unlike single-component recovery branches, mixed-component recovery branches are used to treat mixed waste gas, that is, waste gas containing multiple different components. Many chemical production processes generate such mixed waste gas, which contains different harmful gases. Mixed-component recovery branches have more complex processing capabilities to accommodate the recovery and treatment of multiple waste gas components. In actual operation, the choice of waste gas recovery branch depends on the type and composition of the waste gas and the changes in the waste gas during the production process. For example, at a certain stage, if the waste gas contains only a single gas (such as ammonia), the single-component recovery branch is activated. However, when the waste gas is a mixed gas, the mixed-component recovery branch needs to be activated.

[0038] The setting of these recovery branches ensures the flexibility and efficiency of the waste gas recovery process, and the appropriate recovery branch can be dynamically selected for processing based on the actual waste gas composition and recovery needs.

[0039] Furthermore, the multi-branch mapping encoder includes a preset rule base, which stores the rule labels of the multiple recovery branches, and the rule labels include the single / mixed component processing capacity of each recovery branch, the exhaust gas type adapted for processing, and the branch processing efficiency; when the multi-branch mapping encoder receives the multi-stage exhaust gas process, the timing exhaust gas parameter table of each stage exhaust gas process is matched with the rule labels of each recovery branch in the preset rule base, the recovery branch that passes the match is obtained, the encoding between each stage exhaust gas process and the recovery branch that passes the match is established, and the recovery mapping code is output.

[0040] The multi-branch mapping encoder includes a preset rule base, in which the multi-branch mapping encoder needs to select the most appropriate recovery branch to process the exhaust gas based on the time-series exhaust gas parameter table of different stages. The preset rule base stores rule labels for multiple recovery branches, describing the exhaust gas types, processing capabilities, and recovery efficiency that the recovery branches can adapt to. Among them, the single / mixed component processing capability indicates whether each recovery branch can process a single exhaust gas component (such as nitrogen, carbon dioxide, etc.) or a mixed exhaust gas (exhaust gas containing multiple components); the adapted exhaust gas type indicates the type of exhaust gas that each recovery branch is suitable for processing, for example, some recovery branches are suitable for organic gases, while others are suitable for inorganic gases or specific gases; the branch processing efficiency indicates the processing efficiency of each recovery branch under different exhaust gas concentrations, flow rates, and other conditions. This determines the effectiveness of the branch in recovering exhaust gas. Recovery branches with higher processing efficiency can recover exhaust gas more quickly. These rule labels provide a detailed reference for the selection of recovery branches, and the encoder can perform reasonable recovery branch matching based on these rule labels.

[0041] When the multi-branch mapping encoder receives the exhaust gas process of any stage, it first analyzes the timing exhaust gas parameter table of the exhaust gas process. The timing exhaust gas parameter table contains information such as the exhaust gas type, concentration, flow rate, etc. of this stage. For example, the timing exhaust gas parameter table includes: in the first stage, the exhaust gas is mainly nitrogen with a concentration of 100ppm and a low flow rate; in the second stage, the exhaust gas is a mixed exhaust gas with a concentration of 500ppm and a higher flow rate.

[0042] The encoder matches these exhaust gas parameters with the recovery branch rule labels in the preset rule library. For example, if the exhaust gas in the first stage is nitrogen, the encoder searches for all recovery branches suitable for processing nitrogen and determines which branches are most suitable for processing the exhaust gas. If the exhaust gas in the second stage is mixed exhaust gas, the encoder selects a recovery branch suitable for processing the mixed gas and further screens suitable branches based on the flow rate, concentration, etc. of the exhaust gas.

[0043] Based on the tag matching results, a recovery mapping code is created for each exhaust gas stage. This code represents the precise mapping relationship between the exhaust gas process and the recovery branch. This code can be used to determine which branches need to be activated at what time. For example, the recovery mapping code is: in the first stage, single-component recovery branch A is used to treat nitrogen; in the second stage, mixed-component recovery branch B is used to treat mixed exhaust gases.

[0044] Furthermore, the method of dividing the exhaust gas flow into stages according to the time sequence exhaust gas parameter table and outputting a multi-stage exhaust gas flow includes:

[0045] According to the arrangement of the time series nodes of the time series exhaust gas parameter table, a time series feature vector sequence is constructed for each time series node, wherein the time series feature vector sequence includes the concentration of each gas corresponding to the time node and the rate of change of the concentration with time; a time series feature vector sequence set of each time series node is obtained; a sliding window is used to calculate the vector similarity change of the time series feature vector sequence set, and candidate variation time series nodes are output, and the candidate variation time series nodes are output as a candidate partition point set; the candidate partition point set is used as a stage boundary candidate and a cost function is used to perform K value clustering, and a K value optimal solution is output, wherein the K value is the number of stage divisions; the time series exhaust gas parameter table is divided into stages according to the K value optimal solution, and a multi-stage exhaust gas process is output.

[0046] In the time series exhaust gas parameter table, each time series node contains specific exhaust gas data, including exhaust gas type, concentration, and time. Time series nodes are arranged in chronological order and can be time nodes in units such as minutes or seconds. For example, if a time series node represents the 10th minute of the production process and the exhaust gas concentration is 50 ppm, the following time series nodes will be listed in chronological order.

[0047] The characteristic vector of each time series node includes not only the exhaust gas concentration, but also the rate of change of concentration over time. The rate of change can reflect the speed and trend of concentration change. It can be obtained by calculating the concentration difference and time difference between adjacent time series nodes. It is used to determine the turning point and change of the exhaust gas stage. Each time series node will be represented as a characteristic vector containing concentration and rate of change. For example, if the concentration at a certain moment is 50ppm and the rate of change is 2ppm / min, then the characteristic vector of the time series node is (50,2).

[0048] The obtained feature vectors of each time series node are organized into a feature vector sequence set, which represents the overall trend of the exhaust gas concentration and its changes over time.

[0049] Sliding window is a time series analysis method that defines a window in a set of time series feature vector sequences, calculates the similarity between feature vectors within the window, and slides the sliding window across the entire sequence to obtain a similarity measure at each position. For example, assuming the window size is 3 time series nodes, the first window contains the first 3 nodes, the second window contains nodes 2 to 4, and so on.

[0050] In each window, the similarity between the feature vector sequences is calculated, and measurement methods such as cosine similarity, Euclidean distance or Pearson correlation coefficient are used to measure the similarity of the feature vectors in the window. If the similarity in the window changes greatly, that is, the vector in the window changes greatly, it means that the exhaust process has changed, which may be a sudden change in the exhaust gas composition, concentration or flow.

[0051] By calculating similarity changes, we identify time series nodes with significant similarity changes and use them as candidate mutation time series nodes. For example, if the similarity change between two adjacent time series nodes exceeds a set threshold, the node represents a change in the exhaust process and becomes a candidate mutation time series node. All identified candidate mutation time series nodes are combined into a set of candidate partition points. These points represent possible stage change points in the exhaust process, providing possible split points for subsequent stage division and helping to identify different stages of exhaust treatment.

[0052] The set of candidate partition points represents the time nodes where the exhaust gas process may change and is the potential stage boundary in the exhaust gas process. The cost function is used to measure the quality of the stage division. Its goal is to find the optimal division by minimizing the intra-group similarity and maximizing the inter-group difference. That is, time series nodes with similar exhaust gas characteristics are grouped into the same stage and the difference between stages is maximized. The cost function is based on the following: intra-group similarity, that is, the similarity of the feature vectors of time series nodes in the same stage. If the intra-group similarity is too high, the cost is low; inter-group difference, that is, the difference in exhaust gas characteristics between different stages. If the inter-group difference is large, the cost is low.

[0053] A K-value clustering algorithm is used to cluster the time series nodes in the candidate partition point set. The goal is to divide these nodes into K stages, where K is the number of clusters. The K value is determined by optimizing the cost function. The clustering algorithm adjusts the K value to select the most appropriate number of stages, making the exhaust gas characteristics within each stage as similar as possible while maximizing the differences between stages. The K value is determined based on the optimal value of the cost function. The K value obtained when minimizing the cost function is the optimal number of stage divisions. This K value defines the start and end time series nodes for each stage.

[0054] Based on the number of stages and the set of candidate partition points determined in the optimal K value solution, the timing nodes of the exhaust gas process are divided into several stages. Each stage corresponds to a continuous time segment within which the exhaust gas characteristics are relatively consistent. For example, if the K value is 3 and the candidate partition points are nodes 5, 10, and 15, the exhaust gas process will be divided into three stages: the first stage from the first node to node 5, the second stage from node 5 to node 10, and the third stage from node 10 to node 15. After completing the stage division, a multi-stage exhaust gas process is obtained, providing the necessary information for subsequent exhaust gas recovery branch control and staged processing.

[0055] Furthermore, a sliding window is used to calculate the vector similarity change of the time series feature vector sequence set and output candidate variant time series nodes. The method includes:

[0056] The vector similarity change includes calculating the cosine similarity change rate of the time series feature vector sequence set; performing a significance test on the cosine similarity change rate, and outputting the time series nodes with a cosine similarity change greater than a preset cosine similarity change threshold as candidate variant time series nodes.

[0057] The change in similarity between different time nodes is measured by calculating the cosine similarity change rate of the time series feature vector sequence set. Cosine similarity is a method for measuring the similarity between two vectors. It evaluates their similarity by calculating the cosine value of the angle between the two vectors. In the time series exhaust gas treatment process, each time series node has a feature vector containing concentration, change rate, etc. Cosine similarity is used to calculate the similarity between adjacent time series nodes.

[0058] The rate of change is calculated by calculating the change in cosine similarity between adjacent time series nodes. The cosine similarity change rate reflects the changing trend of exhaust gas characteristics over time. If the similarity change rate between adjacent time series nodes is large, it means that the exhaust gas characteristics between the two nodes are quite different, which may be due to important changes in the exhaust gas production process. For example, the increase in reaction time leads to changes in exhaust gas composition.

[0059] Significance testing can use statistical methods such as t-tests and z-tests to verify whether the rate of change is statistically different enough. Another simple method is to set a preset cosine similarity change threshold. The threshold is set according to the actual situation and is used to filter out those time series nodes with insignificant changes. If the similarity change between time series nodes exceeds the threshold, it is considered that the node represents a significant change in the exhaust process, and the time series node is output as a candidate mutation time series node. The candidate mutation time series node represents a potential stage turning point in the exhaust process, that is, it represents the transition of exhaust gas from one stage to another. For example, assuming that the cosine similarity change rate between the 10th and 11th time series nodes in the exhaust process exceeds the preset threshold, the 11th time series node will be marked as a candidate mutation time series node as a reference point for stage division.

[0060] Furthermore, the start and end time points corresponding to the multi-stage exhaust gas process are recorded, and the multi-branch exhaust gas recovery device controls the valves of the multiple recovery branches to start or close according to the recovery mapping coding timing and the start and end time points.

[0061] Record the start and end time points corresponding to the multi-stage exhaust process. The start and end time points represent the start and end moments of each stage in the exhaust process. These time points are determined through cluster analysis or changes in the time series feature vector in the previous step. Typically, the start and end time of each stage are clearly recorded. For example, suppose that after stage division, the exhaust process is divided into three stages: the first stage starts at time point t1 and ends at time point t2; the second stage starts at time point t2 and ends at time point t3; and the third stage starts at time point t3 and ends at time point t4. The start and end time points of each stage are key time information for adjusting the recovery branch valve during the exhaust gas recovery process.

[0062] The recovery mapping code is a timing control code that indicates which recovery branches should be used for exhaust gas recovery in each stage. The recovery mapping code contains detailed information about the recovery branches that need to be started in each stage, including the type of recovery branch, working time, etc. For example, in the first stage (from t1 to t2), the mapping code indicates that the single-component recovery branch A needs to be started to process nitrogen; in the second stage (from t2 to t3), it indicates that the mixed-component recovery branch B needs to be started to process multiple exhaust gas components.

[0063] Based on the recovery mapping code timing and the start and end time points of the stages, the exhaust gas recovery device realizes dynamic treatment of exhaust gas through valve control. At the start time of each stage, the corresponding recovery branch is opened according to the recovery mapping code, and the corresponding branch is closed at the end time. For example, when the exhaust gas process enters the first stage (from t1 to t2), the single-component recovery branch A is opened according to the recovery mapping code instruction, and the branch is closed at the end of the stage (at t2). If other branches need to be opened in the second stage, the corresponding recovery branch will be opened at t2 according to the recovery mapping code instruction.

[0064] To achieve this process, an automated control system is used to execute the control instructions of the recovery branch valve. The control system reads the recovery mapping code and stage time point, and sends a switch signal to the recovery device at the appropriate time to ensure efficient and accurate waste gas recovery throughout the entire production process.

[0065] Furthermore, the multi-branch exhaust gas recovery device controls the valves of the multiple recovery branches to start or close according to the recovery mapping code timing and the start and end time points, and the method further includes:

[0066] Identify the valve closing timing corresponding to the recovery branch in the startup state; collect the gas flow rate and pressure feedback information corresponding to the recovery branch in the startup state; predict the predicted gas flow rate and predicted pressure feedback information under the closing timing based on the gas flow rate and the pressure feedback information; judge whether each recovery branch meets the closing response condition based on the predicted gas flow rate and the predicted pressure feedback information, and if not, dynamically correct the closing timing of the valve corresponding to the recovery branch.

[0067] In an exhaust gas recovery system, multiple recovery branches operate in parallel. The system monitors in real time which recovery branches are active, i.e., the branches currently recovering exhaust gas. Specifically, feedback from sensors or control systems determines which recovery branch valves are open and operating normally, marking these branches as active. The system also identifies the valve closing sequence for the activated recovery branches. Each recovery branch valve has a closing sequence, which is a predetermined time at which it should close.

[0068] Flow meters and pressure sensors are installed at the inlet and outlet of each recovery branch to collect real-time gas flow rate and pressure data of each recovery branch. These data can reflect the actual situation during the exhaust gas recovery process and provide a basis for predicting the valve closing timing.

[0069] Based on gas flow rate and pressure feedback, mathematical models, physical models, or machine learning algorithms are used to predict changes in exhaust gas flow rate and pressure during valve closure. These models, based on historical data, production process parameters, and the dynamic characteristics of the exhaust gas recovery system, can predict the flow of exhaust gas after valve closure. The goal of the prediction is to determine whether abnormal fluctuations in exhaust gas flow rate and pressure will occur at the specific moment the valve is closed. Through prediction, the changes in exhaust gas flow rate and pressure when the valve is closed can be obtained. For example, if at a certain moment, closing the valve may cause a sudden increase or decrease in exhaust gas flow rate, this change can be foreseen through predictive analysis.

[0070] Some closing response conditions are pre-set, such as the maximum fluctuation range of flow rate and pressure. These conditions are formulated based on the design and operation requirements of the exhaust gas recovery equipment to ensure that the equipment will not suffer a reduction in treatment efficiency or damage to the equipment due to unstable exhaust gas flow when the valve is closed. If the predicted flow rate or pressure change of a certain recovery branch exceeds the closing response condition, for example, the flow rate is too high or the pressure is too low, the closing timing of the valve corresponding to the recovery branch will be dynamically corrected. The dynamic correction includes delaying the closing time of the valve or closing the valve in advance to ensure the smooth flow of exhaust gas. For example, if the flow rate is predicted to be too fast after closing the valve, the valve closing time can be extended to gradually reduce the exhaust gas flow and prevent sudden pressure changes.

[0071] Furthermore, the candidate division point set is used as the stage boundary candidate to perform K value clustering using a cost function, including a clustering constraint condition; the clustering constraint condition is that the K value is less than the total number of recovery branches in the multi-branch exhaust gas recovery device.

[0072] Clustering constraints are added to the K-value clustering process to ensure that the number of stage divisions is less than the total number of recovery branches of the exhaust gas recovery device. The total number of recovery branches is a fixed resource parameter determined by the design of the exhaust gas recovery device. For example, the recovery device has 10 recovery branches, which can process exhaust gas from different stages. In the clustering process, the constraint condition is set: the K value is less than the total number of recovery branches, which means that the number of stages of the exhaust gas process must be less than the number of recovery branches. This ensures that each stage has enough recovery branches for processing and avoids some stages without corresponding recovery branches. For example, if the recovery device has 10 recovery branches, then the K value (that is, the number of exhaust gas stages) must be less than 10, which ensures that each stage can be allocated to the corresponding recovery branch for processing.

[0073] Furthermore, the coding between the exhaust gas process at each stage and the matching recovery branch is established, and the method includes:

[0074] If multiple matching recovery branches are returned, obtain the recovery effect index corresponding to the matching recovery branches; determine the first recovery branch from the matching recovery branches based on the recovery effect index, and establish the coding between the exhaust gas process in each stage and the first recovery branch.

[0075] When the exhaust gas process at a certain stage matches multiple recovery branches, the effectiveness of each recovery branch is evaluated to determine which recovery branch is most suitable for treating the exhaust gas at that stage. For example, if the exhaust gas contains multiple components, multiple recovery branches can process these components, but the efficiency and processing capacity of each branch will vary. Each recovery branch has a set of recovery performance indicators. These indicators describe the branch's recovery efficiency, processing capacity, exhaust gas composition adaptability, and processing time under specific conditions. These performance indicators help the system evaluate the performance of each recovery branch and make a selection.

[0076] By comparing the recovery performance indicators of multiple recovery branches, the recovery branch with the best performance is selected as the first recovery branch. For example, if recovery branch A has higher recovery efficiency and stronger processing capacity, branch A is selected as the first recovery branch for this stage. After the first recovery branch is selected, a mapping code is established between the exhaust gas process flow at each stage and the first recovery branch. This mapping code includes information such as the time node of the exhaust gas stage, the exhaust gas type, and the identification of the recovery branch. Through this coding, the exhaust gas recovery process can be accurately controlled in subsequent operations, ensuring that the exhaust gas at each stage is processed by the appropriate recovery branch.

[0077] In summary, the recovery and treatment method for chemical product production waste gas provided in the embodiments of the present application has the following technical effects:

[0078] By collecting real-time data on waste gas emissions during chemical production, accurate waste gas generation conditions can be obtained, ensuring that waste gas recovery and treatment can be controlled based on accurate and complete data, and enhancing the reliability of subsequent steps; through time series recognition, the waste gas process data is arranged in chronological order and organized into a time series waste gas parameter table, so that each waste gas node can be clearly calibrated on the time axis, ensuring that the generation rules and characteristics of the waste gas can be clearly and accurately reflected; by dividing the waste gas process into multiple different stages according to the time series waste gas parameter table, more targeted treatment methods can be adopted at each stage, avoiding the limitations of a single treatment method, and the multi-stage waste gas process enables the system to be flexible. Respond to the changes in different types of waste gas during the production process and adapt to the diverse needs in the production of chemical products; by connecting multi-branch waste gas recovery devices and using multi-branch mapping encoders to map the waste gas process and recovery branches, it can automatically select the appropriate recovery branch for waste gas recovery according to the needs of waste gas at different stages, avoid resource waste or improper configuration, thereby improving recovery efficiency and reducing unnecessary energy consumption; through the recovery mapping code timing control of the recovery branch valve start and close, realize the precise scheduling of the waste gas treatment process, and according to the recovery mapping code, the waste gas recovery device can automatically adjust the working status of multiple recovery branches, reducing the need for manual intervention, making the waste gas recovery process more automated and intelligent.

[0079] Example 2 is based on the same inventive concept as the method for recycling and treating waste gas from chemical production in the previous embodiment. Figure 3 As shown, the embodiment of the present application provides a recovery and treatment system based on chemical product production waste gas, the system comprising:

[0080] The data acquisition module 10 is used to collect the waste gas process record data of the production of chemical products.

[0081] The time sequence identification module 20 is used to perform time sequence identification on the exhaust gas process record data and determine a time sequence exhaust gas parameter table. The time sequence exhaust gas parameter table stores exhaust gas time sequence nodes and the exhaust gas type, exhaust gas concentration and exhaust gas content corresponding to each node in a time sequence order.

[0082] The stage division module 30 is used to divide the exhaust gas into stages according to the time sequence exhaust gas parameter table and output a multi-stage exhaust gas process.

[0083] The mapping coding module 40 is used to connect a multi-branch exhaust gas recovery device, which includes multiple recovery branches. The multi-stage exhaust gas process is input into the multi-branch mapping encoder, and a mapping code is established between the multi-stage exhaust gas process and the multiple recovery branches to obtain a recovery mapping code.

[0084] The valve control module 50 is used to control the valves of the multiple recovery branches to start or close according to the recovery mapping code timing when the multi-branch exhaust gas recovery device is producing the chemical product.

[0085] Furthermore, the multiple recovery branches include at least one single-component recovery branch and at least one mixed-component recovery branch; the single-component recovery branch is used to recover and process a single type of waste gas, and the mixed-component recovery branch is used to recover and process mixed types of waste gas.

[0086] Furthermore, the multi-branch mapping encoder includes a preset rule base, which stores the rule labels of the multiple recovery branches, and the rule labels include the single / mixed component processing capacity of each recovery branch, the exhaust gas type adapted for processing, and the branch processing efficiency; when the multi-branch mapping encoder receives the multi-stage exhaust gas process, the timing exhaust gas parameter table of each stage exhaust gas process is matched with the rule labels of each recovery branch in the preset rule base, the recovery branch that passes the match is obtained, the encoding between each stage exhaust gas process and the recovery branch that passes the match is established, and the recovery mapping code is output.

[0087] Furthermore, the stage division module 30 is configured to perform the following steps:

[0088] According to the arrangement of the time series nodes of the time series exhaust gas parameter table, a time series feature vector sequence is constructed for each time series node, wherein the time series feature vector sequence includes the concentration of each gas corresponding to the time node and the rate of change of the concentration with time; a time series feature vector sequence set of each time series node is obtained; a sliding window is used to calculate the vector similarity change of the time series feature vector sequence set, and candidate variation time series nodes are output, and the candidate variation time series nodes are output as a candidate partition point set; the candidate partition point set is used as a stage boundary candidate and a cost function is used to perform K value clustering, and a K value optimal solution is output, wherein the K value is the number of stage divisions; the time series exhaust gas parameter table is divided into stages according to the K value optimal solution, and a multi-stage exhaust gas process is output.

[0089] Furthermore, the stage division module 30 is configured to perform the following steps:

[0090] The vector similarity change includes calculating the cosine similarity change rate of the time series feature vector sequence set; performing a significance test on the cosine similarity change rate, and outputting the time series nodes with a cosine similarity change greater than a preset cosine similarity change threshold as candidate variant time series nodes.

[0091] Furthermore, the start and end time points corresponding to the multi-stage exhaust gas process are recorded, and the multi-branch exhaust gas recovery device controls the valves of the multiple recovery branches to start or close according to the recovery mapping coding timing and the start and end time points.

[0092] Furthermore, the stage division module 30 is configured to perform the following steps:

[0093] Identify the valve closing timing corresponding to the recovery branch in the startup state; collect the gas flow rate and pressure feedback information corresponding to the recovery branch in the startup state; predict the predicted gas flow rate and predicted pressure feedback information under the closing timing based on the gas flow rate and the pressure feedback information; judge whether each recovery branch meets the closing response condition based on the predicted gas flow rate and the predicted pressure feedback information, and if not, dynamically correct the closing timing of the valve corresponding to the recovery branch.

[0094] Furthermore, the candidate division point set is used as the stage boundary candidate to perform K value clustering using a cost function, including a clustering constraint condition; the clustering constraint condition is that the K value is less than the total number of recovery branches in the multi-branch exhaust gas recovery device.

[0095] Furthermore, the mapping encoding module 40 is configured to perform the following steps:

[0096] If multiple matching recovery branches are returned, obtain the recovery effect index corresponding to the matching recovery branches; determine the first recovery branch from the matching recovery branches based on the recovery effect index, and establish the coding between the exhaust gas process in each stage and the first recovery branch.

[0097] Through the above detailed description of the recovery and treatment method based on chemical product production waste gas in this specification, those skilled in the art can clearly understand the recovery and treatment system based on chemical product production waste gas in this embodiment. Since it corresponds to the method disclosed in the embodiment, the description is relatively simple. For relevant matters, please refer to the method part.

[0098] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for recycling and treating waste gas from chemical production, characterized in that: The method comprises: Collecting waste gas process record data of chemical products; Performing time sequence identification on the exhaust gas process record data to determine a time sequence exhaust gas parameter table, wherein the time sequence exhaust gas parameter table stores exhaust gas time sequence nodes and the exhaust gas type, exhaust gas concentration, and exhaust gas content corresponding to each node in a time sequence order; Divide the exhaust gas flow into multiple stages according to the time sequence exhaust gas parameter table; Connecting a multi-branch exhaust gas recovery device, the multi-branch exhaust gas recovery device including multiple recovery branches, inputting the multi-stage exhaust gas process into a multi-branch mapping encoder, establishing a mapping code between the multi-stage exhaust gas process and the multiple recovery branches, and obtaining a recovery mapping code; When producing the chemical product, the multi-branch waste gas recovery device controls the valves of the multiple recovery branches to start or close according to the recovery mapping code timing; The multi-branch mapping encoder includes a preset rule base, wherein the preset rule base stores rule labels of the multiple recovery branches, and the rule labels include the single / mixed component processing capacity of each recovery branch, the exhaust gas type adapted for processing, and the branch processing efficiency; When the multi-branch mapping encoder receives the multi-stage exhaust gas process, it matches the time-series exhaust gas parameter table of each stage exhaust gas process with the rule label of each recycling branch in the preset rule library, obtains the recycling branch that passes the match, establishes the code between each stage exhaust gas process and the recycling branch that passes the match, and outputs the recycling mapping code; The method for dividing the exhaust gas flow into stages according to the time sequence exhaust gas parameter table and outputting a multi-stage exhaust gas flow includes: Arrange the time series nodes of the time series exhaust gas parameter table, and construct a time series feature vector sequence for each time series node, wherein the time series feature vector sequence includes the concentration of each gas corresponding to the time node and the rate of change of the concentration with time; Obtain the time series feature vector sequence set of each time series node; Using a sliding window to calculate the vector similarity change of the time series feature vector sequence set, outputting candidate variation time series nodes, and outputting the candidate variation time series nodes as a candidate partition point set; The candidate partition point set is used as the stage boundary candidate to perform K value clustering using the cost function, and the K value optimal solution is output, where the K value is the number of stage divisions; The time sequence exhaust gas parameter table is divided into stages according to the K value optimal solution, and a multi-stage exhaust gas process is output.

2. The method according to claim 1, wherein The multiple recovery branches include at least one single-component recovery branch and at least one mixed-component recovery branch; The single-component recovery branch is used for recovering and processing a single type of waste gas, and the mixed-component recovery branch is used for recovering and processing mixed types of waste gas.

3. The method according to claim 1, wherein A sliding window is used to calculate the vector similarity change of the time series feature vector sequence set, and the candidate variation time series node is output. include: The vector similarity change includes calculating the cosine similarity change rate of the time series feature vector sequence set; A significance test is performed on the cosine similarity change rate, and time series nodes with a cosine similarity change rate greater than a preset cosine similarity change threshold are output as candidate variant time series nodes.

4. The method according to claim 1, wherein The start and end time points corresponding to the multi-stage exhaust gas process are recorded, and the multi-branch exhaust gas recovery device controls the valves of the multiple recovery branches to start or close according to the recovery mapping coding timing and the start and end time points.

5. The method according to claim 4, wherein The multi-branch exhaust gas recovery device controls the valves of the multiple recovery branches to start or close according to the recovery mapping code timing and the start and end time points, and the method further includes: Identify the valve closing sequence corresponding to the recovery branch in the start-up state; Collect the gas flow rate and pressure feedback information corresponding to the recovery branch in the startup state; predicting the predicted gas flow rate and the predicted pressure feedback information at the closing time sequence according to the gas flow rate and the pressure feedback information; Based on the predicted gas flow rate and predicted pressure feedback information, it is determined whether each recovery branch meets the closing response condition. If not, the closing timing of the valve corresponding to the recovery branch is dynamically corrected.

6. The method according to claim 1, wherein Using the candidate partition point set as stage boundary candidates, and performing K-value clustering using a cost function, including clustering constraints; The clustering constraint condition is that the K value is less than the total number of recovery branches in the multi-branch exhaust gas recovery device.

7. The method according to claim 1, wherein Establish the coding between each stage of the exhaust gas process and the matching recovery branch, the method includes: If multiple matching recycling branches are returned, obtain the recycling effect indicators corresponding to the matching recycling branches; The first recovery branch is determined from the recovery branches that have been matched according to the recovery effect index, and a code is established between the exhaust gas process of each stage and the first recovery branch.

8. A recycling and treatment system for waste gas produced by chemical products, characterized in that: A system for implementing the method for recovering and treating waste gas from chemical product production according to any one of claims 1 to 7, comprising: Data acquisition module, used to collect waste gas process record data of chemical products; a time sequence identification module, configured to perform time sequence identification on the exhaust gas process record data and determine a time sequence exhaust gas parameter table, wherein the time sequence exhaust gas parameter table stores exhaust gas time sequence nodes and the exhaust gas type, exhaust gas concentration, and exhaust gas content corresponding to each node in a time sequence order; A stage division module, used to divide the stages according to the time sequence exhaust gas parameter table and output a multi-stage exhaust gas process; a mapping encoding module, configured to connect to a multi-branch exhaust gas recovery device, the multi-branch exhaust gas recovery device including a plurality of recovery branches, input the multi-stage exhaust gas process into a multi-branch mapping encoder, establish a mapping code between the multi-stage exhaust gas process and the plurality of recovery branches, and obtain a recovery mapping code; The valve control module is used to control the valves of the multiple recovery branches to start or close according to the recovery mapping code timing when the chemical product is produced.

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