Method for detecting content of high-boiling solvent in water at top of rectification column

Abstract

The present application provides a method for detecting the content of high-boiling-point solvents in water at the top of a distillation tower, comprising: when detecting that the content of high-boiling-point solvents in water at the top of the tower is greater than a first preset threshold, obtaining the tower top temperature; if the tower top temperature is higher than a second preset threshold, obtaining multiple distillation parameters; determining whether the multiple distillation parameters are all within the corresponding multiple preset ranges; if so, obtaining multiple feed parameters; determining that at least one feed parameter exceeds the corresponding preset range; determining a target control scheme based on a preset cause query list and at least one feed parameter; if not, determining at least one abnormal distillation parameter, and determining a target control scheme based on the cause query list and at least one distillation parameter; and executing the target control scheme. The present application can achieve accurate and flexible control of the content of high-boiling-point solvents in water at the top of a distillation tower.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic control in rectification process, and particularly relates to a detection method for high-boiling-point solvent content in overhead water of a rectification tower. BACKGROUND

[0002] In a solvent recovery process, rectification is a core technology for separating high-boiling-point solvents (such as DMF, NMP, ethylene glycol, etc.) from water or low-boiling-point impurities. High-boiling-point solvents and water usually form azeotropic or near-boiling systems, which are difficult to separate, and high-efficiency separation needs to be achieved by accurately controlling rectification parameters such as temperature, reflux amount, and feed load. In actual production, the high-boiling-point solvent content in the overhead water of the rectification tower is unstable and often exceeds the standard, and the high-boiling-point solvent content exceeding the standard in the overhead product may be accompanied by abnormal tower temperature. The high-boiling-point solvent content exceeding the standard in the overhead water leads to the quality of the recovered rectification product failing to meet the production requirements, causing resource waste and economic loss, and also affecting the normal operation of the subsequent production process.

[0003] The existing detection scheme for the high-boiling-point solvent content in the overhead water of the rectification tower has the following disadvantages: only relying on a single parameter adjustment, which cannot cope with the influence of multiple parameter coupling; lacking a coordinated processing mechanism for abnormal conditions such as feed amount fluctuation and concentration mutation, which easily leads to tower balance disorder; using fixed threshold control without dynamic adjustment combined with parameter change rate, which has the problems of adjustment lag or over-adjustment; and the overhead water and abnormal discharge are not effectively recycled, causing resource waste. SUMMARY

[0004] The present application provides a detection method for the high-boiling-point solvent content in the overhead water of a rectification tower, which determines the condition of the high-boiling-point solvent content exceeding the standard in the overhead water by auxiliary determination of the tower temperature. When the reboiler steam amount, cooling water flow, and reflux amount are normal, the high-boiling-point solvent content exceeding the standard in the overhead water can also be caused by the feed amount and feed concentration, and then the high-boiling-point solvent content in the overhead water is adjusted by adjusting the feed amount and feed concentration. When the reboiler steam amount, cooling water flow, and reflux amount are abnormal, the condensation amount of the overhead gas phase components is adjusted by adjusting the value corresponding to the abnormal parameter, so as to reduce the concentration of the high-boiling-point solvent in the overhead water.

[0005] In a first aspect, the present application provides a method for detecting the content of a high-boiling-point solvent in overhead water of a distillation column, the distillation column being used to purify the high-boiling-point solvent by distilling waste liquid at the bottom of the column, the bottom of the distillation column being provided with a reboiler, a gas-phase outlet at the top of the column being connected to a condenser and a reflux tank in sequence by pipelines, wherein the reboiler is connected to hot steam to heat and distill the waste liquid at the bottom of the column, the condenser is connected to cooling water to condense the gas-phase components discharged from the gas-phase outlet at the top of the column to obtain a mixed liquid phase, the mixed liquid phase in the reflux tank is separated into a liquid-phase component and the overhead water mainly composed of liquid water, and the liquid-phase component is refluxed to the top of the distillation column to continue the distillation and purification; the method comprises:

[0006] When the content of the high-boiling-point solvent in the overhead water is detected to be greater than a first preset threshold, the temperature at the top of the distillation column is obtained;

[0007] If the temperature at the top of the distillation column is detected to be higher than a second preset threshold, a plurality of distillation parameters are obtained, the plurality of distillation parameters including the reflux amount at the top, the cooling water flow rate and the steam flow rate;

[0008] It is determined whether the parameter values of the plurality of distillation parameters are all within a plurality of first preset ranges;

[0009] If yes, a plurality of feed parameters are obtained, the plurality of feed parameters including the waste liquid feed amount and the waste liquid feed concentration; it is determined that the parameter value of at least one feed parameter is out of at least one second preset range; a target control scheme is determined according to a preset cause query list and the parameter value of the at least one feed parameter, the cause query list being used to represent a plurality of control schemes corresponding to the abnormal parameter values of the plurality of distillation parameters and the plurality of feed parameters; and

[0010] If no, at least one distillation parameter with an abnormal parameter value is determined, and the target control scheme is determined according to the cause query list and the parameter value of the at least one distillation parameter;

[0011] The target control scheme is executed, and after the execution is completed, it is detected that the content of the high-boiling-point solvent in the overhead water is less than the first preset threshold.

[0012] In a second aspect, the embodiments of the present application provide an electronic device, including a processor, a memory, and one or more programs, the one or more programs being stored in the memory and configured to be executed by the processor, the programs including instructions for executing the steps in the first aspect of the embodiments of the present application.

[0013] In a third aspect, the embodiments of the present application provide a computer readable storage medium, which stores computer programs / instructions, and the computer programs / instructions are executed by a processor to implement the steps of the method in the first aspect.

[0014] It can be seen that, in the embodiments of the present application, when it is detected that the content of the high-boiling-point solvent in the overhead water is greater than the first preset threshold, the overhead temperature of the rectifying tower is obtained; if it is detected that the overhead temperature is higher than the second preset threshold, a plurality of rectifying parameters are obtained; it is determined whether the parameter values of the plurality of rectifying parameters are all within the corresponding plurality of first preset ranges; if yes, a plurality of feed parameters are obtained; and it is determined that the parameter value of at least one feed parameter is out of the corresponding at least one second preset range; and a target control scheme is determined according to the preset cause query list and the parameter value of the at least one feed parameter; and if no, at least one rectifying parameter with an abnormal parameter value is determined, and a target control scheme is determined according to the cause query list and the parameter value of the at least one rectifying parameter; the target control scheme is executed, and after the execution is completed, it is detected that the content of the high-boiling-point solvent in the overhead water is less than the first preset threshold. Thus, compared with the existing detection scheme of the content of the high-boiling-point solvent in the overhead water, the present application breaks through the limitation of traditional single-parameter adjustment, and realizes accurate and flexible control of the content of the high-boiling-point solvent in the overhead water of the rectifying tower through linkage analysis of the overhead temperature, the rectifying parameters and the feed parameters. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0016] Figure 1 is a structural schematic diagram of a detection system for the content of the high-boiling-point solvent in the overhead water of a rectifying tower provided by the embodiments of the present application;

[0017] Figure 2 is a system architecture schematic diagram of a detection system for the content of the high-boiling-point solvent in the overhead water of a rectifying tower provided by the embodiments of the present application;

[0018] Figure 3 is a structural schematic diagram of a control module provided by the embodiments of the present application;

[0019] Figure 4 is a process flow diagram of overhead water provided by the embodiments of the present application;

[0020] Figure 5 is a structural schematic diagram of an electronic device provided by the embodiments of the present application;

[0021] Figure 6 is a step flow chart of a detection method for high-boiling-point solvent content in water in a distillation column overhead provided by an embodiment of the present application;

[0022] Figure 7 is a flow diagram of a tower top temperature drop control scheme provided by an embodiment of the present application;

[0023] Figure 8 is a whole flow diagram of a detection method for high-boiling-point solvent content in water in a distillation column overhead provided by an embodiment of the present application;

[0024] Figure 9 is a functional module diagram of a detection device for high-boiling-point solvent content in water in a distillation column overhead provided by an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the personnel in the technical field better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor are within the scope of protection of the present application.

[0026] The terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, not to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0027] In this document, the term "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it independent or alternative to other embodiments. The person skilled in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0028] In the embodiments of the present application, "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships. For example, A and / or B can represent the following three cases: A exists alone; A and B exist simultaneously; B exists alone. Wherein, A, B can be singular or plural.

[0029] In the embodiments of the present application, the symbol " / " can represent that the front and rear associated objects are in an "or" relationship. In addition, the symbol " / " can also represent the division sign, that is, performing division operation. For example, A / B can represent A divided by B.

[0030] In the embodiments of the present application, "at least one" or similar expressions refer to any combination of these items, including any combination of single item or multiple items, refer to one or more, and multiple refers to two or more. For example, at least one of a, b or c can represent the following seven cases: a, b, c, a and b, a and c, b and c, a, b and c. Wherein, each of a, b and c can be an element or a set containing one or more elements.

[0031] In the embodiments of the present application, "equal to" can be used with greater than, which is applicable to the technical solutions adopted when greater than, or can be used with less than, which is applicable to the technical solutions adopted when less than. When "equal to" is used with greater than, it is not used with less than; when "equal to" is used with less than, it is not used with greater than.

[0032] The existing detection scheme of high-boiling-point solvent content in overhead water of a rectifying column has the following disadvantages: only a single parameter is adjusted, which cannot cope with the influence of multiple parameter coupling; abnormal working conditions such as fluctuation of feed quantity and mutation of concentration lack a cooperative processing mechanism, which easily leads to disorder of balance in the column; a fixed threshold value is used for control without dynamic adjustment combined with the parameter change rate, which has the problems of adjustment lag or over-adjustment; the overhead water and abnormal discharge are not effectively recycled, which causes waste of resources.

[0033] In view of the above problems, the embodiments of the present application provide a detection method of high-boiling-point solvent content in overhead water of a rectifying column, which will be described in detail below in combination with the drawings.

[0034] Please refer to Figure 1 , Fig. 1 is a structural schematic diagram of a detection system of high-boiling-point solvent content in overhead water of a rectifying column provided by the embodiments of the present application, as shown in Fig. 1, Figure 1 The detection system of high-boiling-point solvent content in overhead water of a rectifying column in the embodiments of the present application includes a control module 110 and a rectifying column 120.

[0035] The control module 110 is the core control unit of the entire detection system, which is responsible for receiving, processing and analyzing relevant data from the rectifying column 120. It can control the detection process of high-boiling-point solvent content in overhead water of the rectifying column 120 according to the preset algorithm, threshold value, etc. For example, when the high-boiling-point solvent content is detected to be out of the set range, the control module 110 can automatically issue an instruction to adjust the operating parameters (such as reflux ratio, heating amount, etc.) of the rectifying column 120, so that the rectifying process returns to normal.

[0036] The distillation tower 120 is a key component in separating mixtures. Through multiple cycles of partial vaporization and condensation, it produces a distillate (including overhead water) rich in low-boiling-point components at the top of the tower, and a still residue rich in high-boiling-point components at the bottom. In this detection system, the distillation tower 120 is the source for high-boiling-point solvent content detection, with the overhead water serving as the sample and the high-boiling-point solvent content as the parameter being measured. The distillation tower 120 provides feedback to the control module 110 regarding the overhead water (e.g., via a sensor installed on the overhead water outlet pipe). The distillation tower 120 also receives control commands from the control module 110 and adjusts its operating parameters (such as the reflux ratio and steam input) to maintain a stable separation process within the distillation tower 120 and maintain an appropriate high-boiling-point solvent content within the overhead water.

[0037] Specifically, see Figure 2 , Figure 2 Schematic diagram of the system architecture of a detection system for the content of high-boiling-point solvents in water at the top of a distillation tower provided in an embodiment of the present application. Figure 2 As shown, the detection system for the high-boiling-point solvent content in the water at the top of the distillation tower includes a distillation tower 120 and a control module 110, wherein the distillation tower 120 includes a monitoring module 121 and a distillation module 122, the monitoring module 121 includes a temperature sensor 1211, a distillation parameter monitoring device 1212 and a feed parameter monitoring device 1213, and the distillation module 122 includes a distillation component 1221 and a valve component 1222.

[0038] Among them, the temperature sensor 1211 is used to monitor the temperature of key parts (such as the top and bottom of the distillation tower 120) in real time; the distillation parameter monitoring device 1212 is used to monitor distillation-related parameters such as pressure, reflux ratio, tower plate efficiency, etc., for example, it may include: pressure sensor, flow monitoring component, liquid level monitoring component, composition monitoring component, etc.; the feed parameter monitoring device 1213 is used to monitor the flow rate, temperature, concentration, pressure and other parameters of the feed, for example, it may include: electromagnetic flowmeter, vortex flowmeter, mass flowmeter, pressure transmitter, near-infrared spectrometer, gas chromatograph, density meter, refractometer, etc.

[0039] The distillation assembly 1221 includes a reboiler, a condenser, a reflux drum, and a tower body, and the valve assembly 1222 includes a steam valve, a cold water valve, a reflux valve, a feed valve, and a discharge valve. The reboiler is connected to hot steam through the steam valve to heat and distill the waste liquid at the bottom of the tower, and the condenser is connected to cooling water through the cold water valve to condense the gaseous components discharged from the gas phase outlet at the top of the tower to obtain a mixed liquid phase. The mixed liquid phase in the reflux drum is separated into liquid components and liquid water to form tower top water. The liquid components are refluxed to the top of the distillation tower 120 through the reflux valve to continue distillation and purification.

[0040] Further, for the specific functions of the control module 110, please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of a control module provided in an embodiment of the present application. Figure 3 As shown, the control module 110 includes a detection unit 310 and a processing unit 320 .

[0041] The detection unit 310 is used to receive real-time data from multiple monitoring devices in the distillation column, including parameters such as temperature, pressure, flow rate, liquid level, and component concentration. This data is the basis for understanding the operating status of the distillation column and provides a basis for subsequent analysis and decision-making.

[0042] The processing unit 320 performs in-depth analysis and processing on the data transmitted by the detection unit 310. Based on pre-set algorithms, models, and control strategies, it calculates, compares, and determines the data to assess the normal operation of the distillation column. If an anomaly is detected (e.g., a parameter exceeding a set threshold), it generates corresponding control instructions to adjust the distillation column's operating parameters, achieving optimized control of the distillation process. The processing results are also fed back to the operator or other monitoring systems.

[0043] It can be seen that in this embodiment, the entire control module 110 realizes real-time monitoring and precise control of the operating status of the distillation column through the coordinated work of the detection unit 310 and the processing unit 320, thereby ensuring stable and efficient operation of the distillation process.

[0044] The following combination Figure 4 A process for generating overhead water provided in an embodiment of the present application is described. Figure 4 This is a process flow chart of overhead water provided in the embodiment of the present application, such as Figure 4 As shown, the distillation tower 120 purifies the high-boiling-point solvent by distilling the waste liquid at the bottom of the tower, and produces tower top water during the distillation process.

[0045] Among them, the reboiler 42 is connected to the steam pipe 422 through the steam valve 421, and the steam valve 421 is used to regulate the steam flow of hot steam. The condenser 43 is connected to the cold water pipe 432 through the cold water valve 431, and the cold water valve 431 is used to regulate the cooling water flow of the cooling water. The reflux tank 44 is connected to the reflux valve 441, and the reflux valve 441 is used to regulate the reflux amount of the liquid phase component refluxed to the top of the tower. The liquid phase component is the high-boiling point solvent after this distillation purification, and the reflux tank 44 is also used to output the top water through the pipeline 442.

[0046] Furthermore, the distillation tower 120 is further provided with an inlet 45 and a discharge port 46. Inlet 45 is connected to a feed valve 451, which is used to control the feed rate of waste liquid materials into the tower. Discharge port 46 is connected to a discharge valve 461, which is used to discharge the high-purity product corresponding to the high-boiling point solvent after multiple refluxes and purification. Discharge valve 461 is also used to control the discharge rate of waste liquid materials from the tower under abnormal operating conditions. Furthermore, a temperature sensor, indicated by the letter "T," is provided at the top of distillation tower 120 to monitor the top temperature in real time.

[0047] It can be understood that based on the connection structure of the above-mentioned distillation tower 120, the process flow of the top water can be clearly defined as follows: the waste liquid is placed in the kettle of the distillation tower 120 through the feed port 45; the kettle is connected to the reboiler 42 through a liquid phase pipeline to transport the waste liquid to the reboiler 42; the reboiler 42 is connected to hot steam to heat and distill the waste liquid to obtain a gas phase component, and the reboiler 42 is connected to the distillation tower 120 through a gas phase pipeline to transport the gas phase component back to the distillation tower 120; the gas phase component is discharged from the top gas phase outlet to the condenser 43; the condenser 43 is connected to cooling water to condense the gas phase component to obtain a mixed liquid phase, and the mixed liquid phase is transported to the reflux tank 44; the mixed liquid phase is separated by stratification in the reflux tank 44 to obtain a liquid phase component and top water, and then the liquid phase component is refluxed to the top of the distillation tower 120 through the reflux valve 441, and the top water is output through the pipeline 442.

[0048] The present application also provides an electronic device 50, such as Figure 5 As shown, Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device 50 may include one or more of the following components: a memory, a processor, a communication bus, a communication interface, and one or more programs. The one or more programs are stored in the memory and configured to be executed by the processor. The one or more programs include instructions for executing any step in the following method embodiments. In a specific implementation, the processor is used to execute any step in the following method embodiments, and when performing data transmission such as sending, it may optionally call the communication interface to complete the corresponding operation.

[0049] The following combination Figure 6 A method for detecting the content of high-boiling-point solvents in water at the top of a distillation tower provided in an embodiment of the present application is described. Figure 6 This is a flow chart of the steps of a method for detecting the content of high-boiling-point solvents in water at the top of a distillation tower provided in an embodiment of the present application, which specifically includes the following steps:

[0050] Step S610: When it is detected that the content of the high-boiling-point solvent in the water at the top of the tower is greater than a first preset threshold, the top temperature of the distillation tower is obtained.

[0051] The rectification tower is provided with a temperature sensor at the top, which can detect the temperature at the top in real time.

[0052] It can be understood that the essence of the high-boiling-point solvent in the tower top water is the result of incomplete rectification separation, and the tower top temperature is a core parameter reflecting the gas-liquid balance in the rectification process. Abnormal temperature is often directly related to separation efficiency. For example, too high temperature may cause high-boiling-point components to be insufficiently condensed and escape with the gas phase into the tower top water.

[0053] In step S620, if the tower top temperature is higher than the second preset threshold, a plurality of rectification parameters are obtained.

[0054] The plurality of rectification parameters include the tower top reflux flow, the cooling water flow, and the steam flow.

[0055] The rectification tower is provided with a plurality of sensors for obtaining the tower top reflux flow, the cooling water flow, and the steam flow.

[0056] Specifically, the three parameters need to be collected synchronously to avoid data correlation distortion caused by time difference (for example, it takes 30 seconds for the steam flow adjustment to be reflected in the tower top temperature), and the accuracy of each parameter sensor needs to be matched (for example, temperature ±0.5℃, flow ±1%) to avoid misjudgment caused by measurement error.

[0057] It can be understood that the reflux flow directly affects the gas-liquid contact efficiency and the separation capacity of the rectification section. When the reflux flow is insufficient, the high-boiling-point solvent is easily entrained in the light components (such as water) at the tower top, causing the temperature to rise. When the cooling water flow is small, if the cooling is insufficient, the gas phase components cannot be fully condensed, and part of the high-boiling-point solvent enters the tower top water in the gaseous form, causing the tower top temperature to remain high. When the steam flow is too large, the upward gas velocity in the tower may be too fast, causing entrainment of mist (high-boiling-point droplets are carried to the tower top by the gas flow), and increasing the heat supply at the tower bottom, causing the overall temperature to rise.

[0058] Further, if the temperature does not exceed the second preset threshold, the tower top temperature is normal, indicating that the gas-liquid balance in the rectification tower is basically maintained, and other non-temperature dominant factors (such as equipment failure, parameter matching imbalance, etc.) may need to be checked.

[0059] Specifically, the equipment failure can include: (1) reflux system failure: reflux pump failure such as impeller wear, motor failure, which can make the reflux unstable or insufficient, and cannot fully wash the high-boiling point solvent in the tower top steam, resulting in its discharge with water. Reflux instrument failure cannot accurately measure and control the reflux, which makes the gas-liquid balance in the rectification tower disorder, and the separation effect of the high-boiling point solvent becomes poor. (2) Poor performance of the condenser: condenser fouling can reduce the heat transfer efficiency, so that the tower top steam cannot be fully condensed, and part of the high-boiling point solvent vapor mixes into the tower top water without being liquefied. Cooling water pipeline leakage or blockage can cause insufficient or uneven distribution of cooling water, affecting the condensation effect and causing fluctuations in the content of high-boiling point solvent in the tower top water. (3) Tower internals damage: tower plate deformation, blockage or packing damage can disrupt the gas-liquid mass transfer process in the tower, making the high-boiling point solvent cannot be fully separated in the tower, increasing the content of high-boiling point solvent in the tower top water. At the same time, tower internals damage can also cause uneven gas-liquid distribution, further deteriorating the rectification effect.

[0060] It should be noted that the embodiments of the present application only give some common examples of hardware equipment failure that can cause abnormal temperature rise of the rectification tower top, and do not limit other possible situations that can cause failure, and the problems of equipment failure need to be determined by periodic manual investigation.

[0061] It can be seen that in the present embodiment, through temperature anomaly triggering and multi-parameter collaborative analysis, the fault diagnosis is deepened from a single index to multi-dimensional parameter linkage, and the physical correlation between parameters is used for fault diagnosis to provide a scientific basis for subsequent precise control. Through data cross-validation, the root cause of temperature anomaly is quickly locked, and system shock caused by blind adjustment is avoided.

[0062] In step S630, it is determined whether the parameter values of the plurality of rectification parameters are all within the corresponding plurality of first preset ranges.

[0063] Among them, the preset first reflux amount range corresponding to the tower top reflux amount, the preset first cooling water flow range corresponding to the cooling water flow, and the preset first steam flow range corresponding to the steam flow.

[0064] It can be understood that after obtaining the rectification parameters such as reflux amount, cooling water flow, and steam flow, the parameters are compared with the corresponding preset range to determine whether the parameters are in normal working condition. If all parameters are within the preset range, it means that the rectification operation parameters have no direct abnormality, and the problem may be caused by the feed end or equipment hidden failure; if at least one parameter exceeds the range, the parameter abnormality source is directly located, and the corresponding operation is preferentially adjusted.

[0065] At step S640, if yes, a plurality of feed parameters are obtained; and it is determined that a parameter value of at least one feed parameter is out of a corresponding at least one second preset range; and a target control scheme is determined according to a preset cause query list and the parameter value of the at least one feed parameter.

[0066] The cause query list is used to represent a plurality of control schemes corresponding to the parameter value abnormalities of the plurality of rectification parameters and the plurality of feed parameters. The cause query list can be constructed and optimized based on a process design file, expert experience, historical fault records, machine learning training, abnormal case iteration, and fusion of AI models.

[0067] The second preset range includes a second preset feed range corresponding to the waste liquid feed amount and a second preset feed concentration range corresponding to the waste liquid feed concentration.

[0068] In one possible embodiment, the target control scheme is determined according to the preset cause query list and the parameter value of the at least one feed parameter, including: if it is determined that the waste liquid feed amount is greater than a maximum threshold of the corresponding second preset feed range, the target control scheme is determined according to the cause query list to be reducing the opening degree of the feed valve to reduce the feed speed of the waste liquid material, and increasing the opening degree of the discharge valve to discharge part of the waste liquid material in the tower through the discharge port and participate in the rectification process again; if it is determined that the waste liquid feed concentration is greater than a maximum threshold of the corresponding second preset feed concentration range, the target control scheme is determined according to the cause query list to be increasing the opening degree of the reflux valve to increase the reflux amount of the tower top, thereby improving the rectification efficiency in the tower; and increasing the opening degree of the cold water valve to increase the cooling water flow, thereby ensuring that the gas phase components are fully condensed, so that the content of the high-boiling-point solvent in the tower top water is reduced.

[0069] When the waste liquid feed amount exceeds the upper limit of the second preset range, the “feed-discharge” double valve cooperation can quickly restore the material balance in the tower.

[0070] When the high-boiling-point solvent concentration in the feed exceeds the preset upper limit, the opening degree of the reflux valve is increased, the reflux amount is increased, the separation capacity of the rectification section is improved, but the condensation amount needs to be increased synchronously to avoid the tower top temperature rising, thereby the opening degree of the cold water valve is simultaneously increased to increase the cooling water flow, breaking through the limitation of traditional “single parameter adjustment”, and the concentration fluctuation is coped with through double parameter cooperation.

[0071] In one possible embodiment, the method further comprises: if it is determined that the waste liquid feed quantity is greater than the maximum threshold of the corresponding second preset feed quantity range and the waste liquid feed concentration is greater than the maximum threshold of the corresponding second preset feed concentration range, determining the parameter priority of the waste liquid feed quantity and the waste liquid feed concentration, determining the feed parameter with greater parameter priority, and determining the target control scheme corresponding to the feed parameter with greater parameter priority according to the cause query list.

[0072] The applicable scenario of simultaneously executing the independent control schemes corresponding to the two parameters given in the above examples is that the two abnormalities do not form a strong coupling effect (for example, the processing capacity of the tower equipment is relatively high, or the over-standard amplitude of the feed quantity and concentration is relatively small), and the control measures of different parameters can be executed in parallel as allowed in the cause query list (for example, the reflux valve, the feed valve, and the cold water valve can be adjusted at the same time).

[0073] In one possible embodiment, the method further comprises: if it is determined that the waste liquid feed quantity is greater than the maximum threshold of the corresponding second preset feed quantity range and the waste liquid feed concentration is greater than the maximum threshold of the corresponding second preset feed concentration range, determining the parameter priority of the waste liquid feed quantity and the waste liquid feed concentration, determining the feed parameter with greater parameter priority, and determining the target control scheme corresponding to the feed parameter with greater parameter priority according to the cause query list.

[0074] The applicable scenario of executing a single control scheme according to the priority given in the above examples is that the two abnormalities have a causal relationship or a coupling risk (for example, the excessively large feed quantity is the main cause of the deviation of the concentration detection), and the priority order of the parameter abnormalities is defined in the cause query list (for example, “the feed quantity is prior to the feed concentration”).

[0075] For example, if it is determined that the over-standard amplitude of the feed quantity is greater than the over-standard amplitude of the concentration, the control scheme of “excessively large feed quantity” is preferentially executed, or if the over-standard concentration may lead to direct unqualified product quality (for example, the critical value of the content of the high-boiling-point solvent), the scheme of “excessively large concentration” is preferentially executed.

[0076] In one possible embodiment, the method further comprises: if it is determined that the waste liquid feed quantity is greater than the maximum threshold of the corresponding second preset feed quantity range and the waste liquid feed concentration is greater than the maximum threshold of the corresponding second preset feed concentration range, determining the target control scheme corresponding to the simultaneous abnormality of the waste liquid feed quantity and the waste liquid feed concentration according to the cause query list.

[0077] The application scenarios of the trigger composite control scheme given by the above examples are: the probability of the simultaneous occurrence of two abnormalities is high, or there is a significant risk of parallel adjustment (such as large tower equipment needs to avoid sudden load changes); and the cause query list predefines a dedicated scheme for double-parameter abnormalities, and the dedicated scheme is not simply superimposed on the original rules.

[0078] Exemplarily, when the waste liquid feed quantity and the waste liquid feed concentration are simultaneously abnormal, the target control scheme corresponding thereto can be: reducing the feed valve opening degree to 70% of the original opening degree, and increasing the reflux valve opening degree to 120% of the original opening degree, while increasing the cold water valve opening degree by 15%, and after a delay of 5 minutes, deciding whether to increase the discharge valve opening degree according to the tower kettle liquid level (to avoid liquid level fluctuation caused by instantaneous discharge).

[0079] It should be noted that the cause query list usually at least contains an independent control scheme for single-parameter abnormalities, and if complex working conditions need to be handled, the list can be extended to contain a composite control scheme for double-parameter or multi-parameter combinations.

[0080] As can be seen, in this embodiment, by monitoring parameters such as feed quantity and feed concentration in real time and comparing them with preset ranges, using a cause query list constructed based on process experience and machine learning, an independent control strategy is provided for single-parameter abnormalities, and for double-parameter simultaneous abnormalities, parallel execution, priority selection or a pre-defined composite scheme is supported, thereby realizing accurate diagnosis and intelligent control of complex working conditions of a rectification process, improving system stability and separation efficiency, and reducing the cost of manual intervention.

[0081] In step S650, if not, at least one rectification parameter with an abnormal parameter value is determined, and a target control scheme is determined according to the cause query list and the parameter value of the at least one rectification parameter.

[0082] It can be understood that when a rectification parameter (reflux quantity, cooling water flow, steam flow) is abnormal, the problem source is quickly located and targeted control is implemented directly through the cause query list.

[0083] In one possible embodiment, determining at least one rectification parameter with an abnormal parameter value includes: determining a preset first reflux quantity range corresponding to the tower top reflux quantity, a preset first cooling water flow range corresponding to the cooling water flow, and a preset first steam flow range corresponding to the steam flow; if it is determined that the tower top reflux quantity is less than a minimum threshold of the first reflux quantity range, the tower top reflux quantity is determined to be an abnormal rectification parameter; if it is determined that the cooling water flow is less than a minimum threshold of the first cooling water flow range, the cooling water flow is determined to be an abnormal rectification parameter; and if it is determined that the steam flow is greater than a maximum threshold of the first steam flow range, the steam flow is determined to be an abnormal rectification parameter.

[0084] Wherein, the reflux flow range is usually 1.2-1.5 times of the minimum reflux ratio (e.g. 500-700 L / h), and the lower limit value needs to ensure the continuity of the liquid film on the tray.

[0085] Wherein, the cooling water flow range is usually calculated according to the overhead gas phase load (e.g. Qc=8-12 m³ / h), and the lower limit needs to ensure that the condensation temperature is lower than the dew point of the solvent. The dew point refers to the temperature at which the gas phase component is cooled to start condensing into a liquid phase under a fixed pressure. For example, for a mixed gas phase of a high-boiling-point solvent and water, when the temperature drops below the dew point, the solvent will start to condense. If the cooling water flow is insufficient to cause the condensation temperature to be higher than the dew point, part of the solvent will enter the overhead water in a gaseous form, causing its content to exceed the standard.

[0086] Wherein, the steam flow range is calculated based on the demand for vaporization at the bottom of the tower (e.g. Qs=300-400 kg / h), and the upper limit needs to avoid entrainment of mist (F factor ≤0.8 Pa^0.5).

[0087] It can be understood that the reflux flow and the cooling water flow only have lower limits to prevent insufficient flow, and the steam flow only has an upper limit to prevent overload, which is consistent with the characteristics of the rectification process.

[0088] In one possible embodiment, the target control scheme is determined according to the cause query list and the parameter value of the at least one rectification parameter, including: if the at least one rectification parameter is the overhead reflux flow, the target control scheme is determined according to the cause query list to increase the opening of the reflux valve to increase the overhead reflux flow, thereby reducing the overhead temperature to improve the rectification efficiency in the tower; if the at least one rectification parameter is the cooling water flow, the target control scheme is determined according to the cause query list to increase the opening of the cooling water valve to increase the cooling water flow, thereby ensuring that the gas phase component is fully condensed, so that the content of the high-boiling-point solvent in the overhead water is reduced; if the at least one rectification parameter is the steam flow, the target control scheme is determined according to the cause query list to reduce the opening of the steam valve to reduce the steam flow, thereby stabilizing the gas-liquid equilibrium in the tower and avoiding the rapid rise of water vapor in the tower, which causes the gas phase component to not be fully condensed and dissolved in the overhead water.

[0089] Wherein, if the reflux valve is fully open and still cannot meet the standard, the automatic standby pump switching logic is triggered; and the lower limit of the cooling water temperature is set (e.g. >5°C) to prevent freezing from damaging the condenser; and if the steam flow suddenly decreases, it may affect the liquid holdup at the bottom of the tower, the discharge amount at the bottom of the tower can be reduced simultaneously, such as reducing the discharge amount at the bottom of the tower by 10%.

[0090] Further, if there are two or more abnormal rectification parameters, the target control scheme can be determined according to the scheme given in the foregoing example when two discharge parameters are simultaneously abnormal, and the control is performed by parallel execution, priority selection or a predefined composite scheme.

[0091] It can be seen that, in the embodiment, by presetting the reasonable range of the rectification parameter, comparing the parameter value with the threshold value in real time, accurately identifying the abnormal parameter, and executing the targeted control scheme based on the cause query list, the rapid positioning and intelligent control of the rectification parameter abnormality are realized, the gas-liquid balance in the tower and the separation efficiency are ensured, and the system stability and safety are improved.

[0092] In step S660, the target control scheme is executed, and it is detected that the content of the high-boiling-point solvent in the tower top water is less than the first preset threshold value after the execution is completed.

[0093] The content of the high-boiling-point solvent in the tower top water can be monitored in real time by an online infrared analyzer (for example, data is updated every 2 minutes), so that the control effect is fed back in time.

[0094] It should be noted that the application does not limit the execution subject of the target control scheme, and the detection and execution process can be fully automatically processed based on an automatic system, or the target control scheme can be output on an interactive interface to prompt a user to execute the target control scheme.

[0095] In one possible embodiment, after the target control scheme is executed, the method further includes: if it is detected that the waste liquid feed concentration decreases, reducing the opening degree of the reflux valve to reduce the tower top reflux amount, and reducing the opening degree of the cold water valve to reduce the cooling water flow.

[0096] It can be understood that, after the target control scheme is executed, the reflux and cooling parameters are dynamically adjusted by monitoring the change of the feed concentration in real time, so that the waste of energy caused by “over-regulation” is avoided, and the dynamic balance of “separation efficiency and energy consumption control” is realized.

[0097] In one possible embodiment, after the target control scheme is executed, the method further includes: determining a minimum temperature threshold value corresponding to the tower top temperature, the minimum temperature threshold value being a preset minimum temperature value that the tower top can adapt to when the rectification tower can maintain normal operation; detecting that the tower top temperature decreases; and adjusting the parameter value of the at least one rectification parameter according to the falling speed of the tower top temperature, so as to avoid the tower top temperature from falling below the minimum temperature threshold value.

[0098] The change speed of the tower top temperature is monitored in real time, and the rectification parameters (reflux ratio, cooling water flow, etc.) are dynamically adjusted, so that the low-temperature fluctuation caused by over-regulation is prevented, the rectification tower is ensured to operate in a safe temperature range, and malignant working conditions such as liquid flooding and mist entrainment are avoided.

[0099] It can be seen that in the embodiment, the content of the high-boiling-point solvent in the water at the top of the tower is determined by the temperature in the tower. When the steam quantity of the reboiler, the cooling water flow rate, and the reflux quantity are normal, the content of the high-boiling-point solvent in the water at the top of the tower can also be caused by the feed quantity and the feed concentration, and then the content of the high-boiling-point solvent in the water at the top of the tower is adjusted by adjusting the feed quantity and the feed concentration. When the steam quantity of the reboiler, the cooling water flow rate, and the reflux quantity are abnormal, the condensation quantity of the gaseous component at the top of the tower is adjusted by adjusting the value corresponding to the abnormal parameter, so as to reduce the concentration of the high-boiling-point solvent in the water at the top of the tower. The traditional single-parameter adjustment limitation is broken through, the linkage analysis of the tower top temperature, the rectification parameter, and the feed parameter is realized, and the content of the high-boiling-point solvent in the water at the top of the tower is accurately and flexibly controlled.

[0100] Please refer to Figure 7 , Figure 7 is a flowchart of a tower top temperature drop regulation scheme provided by the embodiment of the application. In adjusting the parameter value of the at least one rectification parameter according to the drop speed of the tower top temperature, the above method can further include the following steps:

[0101] Step S710, detecting that the tower top temperature drops.

[0102] Specifically, the tower top temperature is monitored in real time by a temperature sensor, and is triggered when the temperature shows a downward trend in a plurality of (for example, 3) sampling periods (for example, once every 30 seconds) and the cumulative drop amplitude reaches a preset amplitude (for example, > 0.5℃).

[0103] Step S720, determining a lowest temperature threshold corresponding to the tower top temperature.

[0104] The lowest temperature threshold is a preset lowest temperature value that the tower top can adapt to when the rectification tower can maintain normal operation. The lowest temperature threshold can be calculated based on the material characteristics (for example, 65℃ for a methanol-water system), and is dynamically adjusted according to the feed composition (for example, increased by 2℃ when the high-boiling-point component increases).

[0105] Step S730, determining a target speed according to the drop speed of the tower top temperature.

[0106] The target speed is a “safe regulation speed” calculated according to the current tower top temperature drop speed, which is used to guide the adjustment of the rectification parameter. It is not a fixed value, but a parameter that is dynamically adjusted with temperature changes. The essence is to convert the temperature change rate into an execution basis for parameter adjustment.

[0107] It can be understood that when the overhead temperature is too high and the parameter value of the rectification parameter is abnormal, the rectification parameters have been adjusted based on the target control scheme, specifically by adjusting the corresponding valve opening, if the overhead temperature is detected to drop, and the valve opening is still not adjusted, it will cause the rectification tower to run abnormally, therefore, it is necessary to adjust the rectification parameters (overhead reflux flow, cooling water flow, steam flow) based on the overhead temperature drop speed.

[0108] For example, when the overhead temperature drops at a low speed (such as <1℃ / min), the target speed = drop speed x 0.8 (allow slower adjustment to avoid excessive intervention); when the overhead temperature drops at a high speed (such as >1℃ / min), the target speed = fixed safety upper limit (such as 1℃ / min), forced to suppress the speed to prevent out of control. It needs to be clear that the present application does not limit the relationship between the target speed and the overhead temperature drop speed, and the calculation method of the target speed includes but is not limited to one of the above examples.

[0109] Step S740, whether the at least one rectification parameter with abnormal parameter value is the overhead reflux flow.

[0110] Specifically, if yes, step S741 is executed, and if no, step S750 is executed.

[0111] Step S741, reducing the opening of the reflux valve so that the overhead reflux flow decreases at a target speed.

[0112] Wherein, the relationship between the target speed and the reflux flow reduction rate can be obtained through historical data, for example, the target speed is 0.6℃ / min, and the corresponding reflux flow reduction rate is 0.3L / min.

[0113] Further, the reflux valve opening can be determined based on the linear relationship, mapping relationship or large model between the reflux flow reduction rate and the reflux valve opening, so as to adjust the opening of the reflux valve.

[0114] Step S750, whether the at least one rectification parameter with abnormal parameter value is the cooling water flow.

[0115] Specifically, if yes, step S751 is executed, and if no, step S752 is executed.

[0116] Step S751, reducing the opening of the cooling water valve so that the cooling water flow decreases at a target speed.

[0117] Wherein, the relationship between the target speed and the cooling water flow reduction rate can be obtained through historical data, for example, the target speed is 0.6℃ / min, and the corresponding cooling water flow reduction rate is 0.5L / min.

[0118] Further, the cold water valve opening degree can be determined based on a linear relationship, a mapping relationship or a large model between the cold water flow rate reduction rate and the cold water valve opening degree, so as to adjust the opening degree of the cold water valve.

[0119] Step S752, increase the opening degree of the steam valve, so that the steam flow rate increases according to the target speed.

[0120] The relationship between the target speed and the steam flow rate reduction rate can be obtained through historical data, for example, the target speed is 0.6℃ / min, and the steam flow rate reduction rate is 0.45L / min.

[0121] Further, the steam valve opening degree can be determined based on a linear relationship, a mapping relationship or a large model between the steam flow rate reduction rate and the steam valve opening degree, so as to adjust the opening degree of the steam valve.

[0122] Step S760, it is detected that the tower top temperature has not decreased below the minimum temperature threshold.

[0123] It can be understood that the tower top temperature below the minimum temperature threshold may cause: the tower top condenser liquid phase load increases suddenly, causing liquid flooding; the tray efficiency decreases, and the heavy components escape with the gas phase; the condensate viscosity increases, causing the risk of pipeline blockage. Therefore, it is necessary to detect the tower top temperature in real time, and timely adjust the valve opening degree corresponding to at least one rectification parameter, so as to ensure that the tower top temperature does not decrease below the minimum temperature threshold.

[0124] It can be seen that in the embodiment, through the real-time monitoring of temperature change trend, dynamic calculation of threshold value, parameter hierarchical regulation and safety verification closed loop control, the tower top temperature reduction rate is converted into quantifiable valve adjustment instruction, the coordinated optimization of rectification parameters (reflux, cooling, steam) is realized, the risk of liquid flooding is effectively prevented, the stability of rectification process and product quality are improved.

[0125] Please refer to Figure 8 , Figure 8It is a kind of rectification tower overhead water high-boiling point solvent content detection method provided by the embodiment of the application, the whole flow schematic diagram of the method, the method comprises the following steps: step S810, determine whether the content of high-boiling point solvent in the overhead water is greater than the first preset threshold value;Specifically, if yes, then execute step S820;Step S820, obtain the overhead temperature of the rectification tower;Step S830, detect that the overhead temperature is higher than the second preset threshold value;Step S840, obtain a plurality of rectification parameters;Step S850, determine whether the parameter values of the plurality of rectification parameters are located in the corresponding plurality of first preset ranges;Specifically, if yes, then execute step S851, if no, then execute step S860;Step S851, obtain a plurality of feed parameters;Step S852, determine whether at least one parameter value of the feed parameters exceeds at least one second preset range;Specifically, if yes, then execute step S853;Step S853, determine the target control scheme according to the preset reason query list and the parameter value of at least one feed parameter;Step S860, determine at least one rectification parameter with abnormal parameter value;Step S870, determine the target control scheme according to the reason query list and the parameter value of at least one rectification parameter;Step S880, execute the target control scheme;Specifically, after executing step S880, repeat the judgment operation of step S810.

[0126] It can be seen that in the embodiment, the content of high-boiling point solvent in the overhead water is determined by the tower temperature, and when the reboiler steam quantity, cooling water flow and reflux quantity are normal, the content of high-boiling point solvent in the overhead water can also be caused by the feed quantity and feed concentration, and then the content of high-boiling point solvent in the overhead water is adjusted by adjusting the feed quantity and feed concentration;When the reboiler steam quantity, cooling water flow and reflux quantity are abnormal, the condensation amount of the overhead gas phase component is adjusted by adjusting the value corresponding to the abnormal parameter, thereby reducing the concentration of high-boiling point solvent in the overhead water, breaking the limitation of traditional single parameter adjustment, and realizing accurate and flexible control of the content of high-boiling point solvent in the overhead water of the rectification tower through the linkage analysis of the overhead temperature, rectification parameters and feed parameters.

[0127] The above mainly introduces the scheme of the embodiment of the application from the perspective of the execution process of the method. It can be understood that the mobile electronic device contains the hardware structure and / or software module corresponding to the execution of each function in order to realize the above functions. Those skilled in the art should easily realize that the units and algorithm steps of each example described in combination with the embodiments provided in the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in hardware or computer software driven hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0128] The embodiment of the present application can divide the functional units of the electronic device according to the above method example. For example, each functional unit can be divided according to each function, or two or more functions can be integrated into one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of software functional units. It should be noted that the division of units in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0129] See also Figure 9 , Figure 9 A functional module diagram of a device for detecting the content of high-boiling-point solvents in water at the top of a distillation tower provided in an embodiment of the present application is shown in FIG. Figure 9 As shown, the device includes the following modules:

[0130] a detection module 910 configured to obtain a top temperature of the distillation tower when it is detected that the content of the high-boiling-point solvent in the top water is greater than a first preset threshold; and obtain a plurality of distillation parameters, including a top reflux flow rate, a cooling water flow rate, and a steam flow rate, when it is detected that the top temperature is greater than a second preset threshold;

[0131] Processing module 920 is configured to determine whether the parameter values ​​of the plurality of distillation parameters are all within corresponding plurality of first preset ranges; if so, obtain a plurality of feed parameters, the plurality of feed parameters including a waste liquid feed amount and a waste liquid feed concentration; and determine that the parameter value of at least one feed parameter exceeds at least one corresponding second preset range; and determine a target control scheme based on a preset cause query list and the parameter value of the at least one feed parameter, the cause query list being used to characterize the plurality of distillation parameters and a plurality of control schemes corresponding to abnormal parameter values ​​of the plurality of feed parameters; and if not, determine at least one distillation parameter having an abnormal parameter value, and determine the target control scheme based on the cause query list and the parameter value of the at least one distillation parameter;

[0132] The execution module 930 is configured to execute the target control scheme, and after the execution is completed, detect that the content of the high-boiling-point solvent in the tower top water is less than the first preset threshold.

[0133] It can be seen that in the embodiment, the case that the content of the high-boiling-point solvent in the water at the top of the column exceeds the standard is determined by the temperature in the column, when the steam quantity of the reboiler, the cooling water flow and the reflux flow are normal, the content of the high-boiling-point solvent in the water at the top of the column can also be caused by the feed quantity and the feed concentration, and then the content of the high-boiling-point solvent in the water at the top of the column is adjusted by adjusting the feed quantity and the feed concentration; when the steam quantity of the reboiler, the cooling water flow and the reflux flow are abnormal, the condensation quantity of the gas phase component at the top of the column is adjusted by adjusting the value corresponding to the abnormal parameter, so as to reduce the concentration of the high-boiling-point solvent in the water at the top of the column.

[0134] In one embodiment, the processing module 920 is specifically configured to determine the target control scheme according to the preset cause query list, the parameter value of the at least one feed parameter, and the aspect that the target control scheme is determined. If it is determined that the waste liquid feed quantity is greater than the maximum threshold value of the corresponding second preset feed range, the target control scheme is determined to be that the opening of the feed valve is reduced to reduce the feed speed of the waste liquid material, and the opening of the discharge valve is increased to discharge part of the waste liquid material in the column through the discharge port and participate in the rectification process again according to the cause query list. If it is determined that the waste liquid feed concentration is greater than the maximum threshold value of the corresponding second preset feed concentration range, the target control scheme is determined to be that the opening of the reflux valve is increased to increase the reflux flow at the top of the column, and then the rectification efficiency in the column is improved according to the cause query list. In addition, the opening of the cold water valve is increased to increase the cooling water flow, and then the gas phase component is fully condensed, so that the content of the high-boiling-point solvent in the water at the top of the column is reduced.

[0135] In one embodiment, the processing module 920 is specifically configured to determine the parameter value of the at least one rectification parameter in the aspect of determining the parameter value. The preset first reflux flow range corresponding to the reflux flow at the top of the column, the preset first cooling water flow range corresponding to the cooling water flow, and the preset first steam flow range corresponding to the steam flow are determined. If it is determined that the reflux flow at the top of the column is less than the minimum threshold value of the first reflux flow range, the reflux flow at the top of the column is determined to be an abnormal rectification parameter. If it is determined that the cooling water flow is less than the minimum threshold value of the first cooling water flow range, the cooling water flow is determined to be an abnormal rectification parameter. If it is determined that the steam flow is greater than the maximum threshold value of the first steam flow range, the steam flow is determined to be an abnormal rectification parameter.

[0136] In an embodiment, the processing module 920 is specifically configured to determine the aspect of the target regulation scheme according to the cause query list, the parameter value of the at least one rectification parameter, and specifically configured to: if the at least one rectification parameter is the reflux flow rate at the top of the tower, determine, according to the cause query list, that the target regulation scheme is to increase the opening degree of the reflux valve to increase the reflux flow rate at the top of the tower, so as to increase the rectification efficiency in the tower by reducing the temperature at the top of the tower; if the at least one rectification parameter is the cooling water flow rate, determine, according to the cause query list, that the target regulation scheme is to increase the opening degree of the cold water valve to increase the cooling water flow rate, so as to ensure that the gas phase component is sufficiently condensed, so that the content of the high-boiling-point solvent in the water at the top of the tower is reduced; and if the at least one rectification parameter is the steam flow rate, determine, according to the cause query list, that the target regulation scheme is to reduce the opening degree of the steam valve to reduce the steam flow rate, so as to stabilize the gas-liquid equilibrium in the tower and avoid the rapid rise of water vapor in the tower, which causes the gas phase component to be insufficiently condensed and dissolved in the water at the top of the tower.

[0137] In an embodiment, after the processing module 920 executes the target regulation scheme, the processing module 920 is further configured to: if it is detected that the concentration of the waste liquid feed is reduced, reduce the opening degree of the reflux valve to reduce the reflux flow rate at the top of the tower, and reduce the opening degree of the cold water valve to reduce the cooling water flow rate.

[0138] In an embodiment, after the processing module 920 executes the target regulation scheme, the processing module 920 is further configured to: detect that the temperature at the top of the tower is reduced; determine a minimum temperature threshold corresponding to the temperature at the top of the tower, the minimum temperature threshold being a preset minimum temperature value that the tower at the top can adapt to when the rectification tower can maintain normal operation; and adjust the parameter value of the at least one rectification parameter according to the falling speed of the temperature at the top of the tower, so as to avoid the temperature at the top of the tower from falling below the minimum temperature threshold.

[0139] In an embodiment, the processing module 920 is specifically configured to determine the target speed according to the falling speed of the temperature at the top of the tower, and adjust the opening degree of at least one valve corresponding to the at least one rectification parameter according to the target speed, so that the parameter value of the at least one rectification parameter is reduced or increased at the target speed.

[0140] In one embodiment, the processing module 920 is configured to adjust the opening degree of the at least one valve corresponding to the at least one rectification parameter according to the target speed, so that the parameter value of the at least one rectification parameter decreases or increases according to the target speed. For example, if the at least one rectification parameter is the reflux flow rate, the opening degree of the reflux valve is decreased, so that the reflux flow rate decreases according to the target speed; if the at least one rectification parameter is the cooling water flow rate, the opening degree of the cooling water valve is decreased, so that the cooling water flow rate decreases according to the target speed; if the at least one rectification parameter is the steam flow rate, the opening degree of the steam valve is increased, so that the steam flow rate increases according to the target speed.

[0141] The above-described embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, the above-described embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another, for example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center through a wired or wireless manner. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, or the like containing one or more available medium collections. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state disk.

[0142] The embodiments of the present application also provide a computer storage medium, in which a computer program / instruction is stored, and the computer program / instruction is executed by a processor to implement some or all steps of any method described in the above method embodiments.

[0143] The embodiments of the present application also provide a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program. The computer program is operable to cause a computer to perform some or all steps of any method described in the above method embodiments.

[0144] It should be understood that the size of the sequence number of each process described above does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0145] In several embodiments provided in the present application, it should be understood that the disclosed methods, devices and systems can be implemented in other ways. For example, the device embodiments described above are only schematic; for example, the division of units is only a logical function division, and actual implementation can have another division manner; for example, a plurality of units or components can be combined or integrated into another system, or some features can be omitted or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other form.

[0146] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the present embodiment.

[0147] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically included separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of hardware plus software functional unit.

[0148] The integrated unit in the form of software function unit can be stored in a computer readable storage medium. The software function unit is stored in a storage medium, including a plurality of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute part of the steps of the method of various embodiments of the present application. The storage medium includes a U disk, a mobile hard disk, a magnetic disk, an optical disk, a volatile memory or a non-volatile memory. The non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example, but not limitation, many forms of random access memory (RAM) can be used, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synch link dynamic random access memory (SLDRAM) and direct rambus random access memory (DRRAM), etc. Various media that can store program codes.

[0149] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions without departing from the spirit and scope of the present application, and various modifications can be made, including combinations of different functions and implementation steps, including software and hardware implementations, which are all within the scope of the present application.

Claims

1. A method for detecting the content of high-boiling-point solvents in water at the top of a distillation tower, characterized in that: The distillation tower purifies the high-boiling-point solvent by distilling the waste liquid at the bottom of the tower. The bottom of the distillation tower is provided with a reboiler, and the gas phase outlet at the top of the tower is connected to a condenser and a reflux tank in sequence through a pipeline, wherein the reboiler is connected to hot steam to heat and distill the waste liquid at the bottom of the tower, and the condenser is connected to cooling water to condense the gas phase components discharged from the gas phase outlet at the top of the tower to obtain a mixed liquid phase. The mixed liquid phase in the reflux tank is separated into liquid phase components and the top water with liquid water as the main component. The liquid phase components are refluxed to the top of the distillation tower to continue distillation and purification. The method comprises: When it is detected that the content of the high-boiling-point solvent in the water at the top of the tower is greater than a first preset threshold, obtaining the top temperature of the distillation tower; If it is detected that the tower top temperature is higher than a second preset threshold, a plurality of distillation parameters are obtained, wherein the plurality of distillation parameters include a tower top reflux flow rate, a cooling water flow rate, and a steam flow rate; Determining whether the parameter values ​​of the plurality of distillation parameters are all within corresponding plurality of first preset ranges; If so, obtaining a plurality of feed parameters, the plurality of feed parameters including a waste liquid feed amount and a waste liquid feed concentration; and determining that a parameter value of at least one feed parameter exceeds at least one corresponding second preset range; and determining a target control scheme based on a preset cause query list and the parameter value of the at least one feed parameter, the cause query list being used to characterize a plurality of control schemes corresponding to when the parameter values ​​of the plurality of distillation parameters and the plurality of feed parameters are abnormal; and, If not, determining at least one distillation parameter with an abnormal parameter value, and determining the target control plan according to the cause query list and the parameter value of the at least one distillation parameter; executing the target control scheme, and detecting, after the execution is completed, that the content of the high-boiling-point solvent in the tower top water is less than the first preset threshold; detecting a temperature drop at the tower top; Determining a minimum temperature threshold corresponding to the tower top temperature, where the minimum temperature threshold is a preset minimum temperature value that the tower top can adapt to when the distillation tower can maintain normal operation; adjusting the parameter value of the at least one distillation parameter according to the decreasing rate of the tower top temperature to prevent the tower top temperature from decreasing below the minimum temperature threshold; If it is detected that the tower top temperature does not exceed the second preset threshold value, the tower top temperature is normal, indicating that the gas-liquid equilibrium in the distillation tower is basically maintained, and other non-temperature-dominant factors are checked.

2. The method according to claim 1, characterized in that The reboiler is connected to a steam valve, which is used to regulate the steam flow of the hot steam; the condenser is connected to a cold water valve, which is used to regulate the cooling water flow of the cooling water; the reflux tank is connected to a reflux valve, which is used to regulate the reflux rate of the liquid phase component flowing back to the top of the tower, and the liquid phase component is the high-boiling point solvent after the current distillation purification; The tower body of the distillation tower is also provided with a feed port and a discharge port. The feed port is connected to the feed valve, and the feed valve is used to regulate the feed rate of the waste liquid material into the tower; the discharge port is connected to the discharge valve, and the discharge valve is used to output the high-purity product corresponding to the high-boiling point solvent after multiple refluxes and purifications, and the discharge valve is also used to control the discharge rate of the waste liquid material in the tower under abnormal operating conditions.

3. The method according to claim 2, characterized in that The formation process of the tower top water is as follows: the waste liquid is placed in the bottom of the distillation tower through the feed port; the bottom of the tower is connected to the reboiler via a liquid phase pipeline to transport the waste liquid to the reboiler; the reboiler is connected to hot steam to heat and distill the waste liquid to obtain the gas phase component, and the reboiler is connected to the distillation tower via a gas phase pipeline to transport the gas phase component back to the distillation tower; The gas phase components are discharged from the gas phase outlet at the top of the tower to the condenser; The condenser is connected to cooling water to condense the gas phase components to obtain the mixed liquid phase, and the mixed liquid phase is transported to the reflux tank; the mixed liquid phase is separated by stratification in the reflux tank to obtain the liquid phase components and the top water.

4. The method according to any one of claims 2 to 3, characterized in that: The determining of the target control scheme according to the preset cause query list and the parameter value of the at least one feeding parameter includes: If it is determined that the waste liquid feed amount is greater than the maximum threshold of the corresponding second preset feed range, determining, according to the cause query list, that the target control scheme is to reduce the opening of the feed valve to reduce the feed rate of the waste liquid material, and to increase the opening of the discharge valve to discharge part of the waste liquid material in the tower through the discharge port and re-enter the distillation process; If it is determined that the waste liquid feed concentration is greater than the maximum threshold of the corresponding second preset feed concentration range, the target control scheme is determined according to the cause query list to increase the opening of the reflux valve to increase the top reflux volume, thereby improving the distillation efficiency in the tower; and, increase the opening of the cold water valve to increase the cooling water flow rate, thereby ensuring that the gas phase components are fully condensed, so that the content of the high-boiling point solvent in the top water is reduced.

5. The method according to claim 4, characterized in that The determining of at least one distillation parameter having an abnormal parameter value includes: Determining a preset first reflux flow range corresponding to the tower top reflux flow, a preset first cooling water flow range corresponding to the cooling water flow, and a preset first steam flow range corresponding to the steam flow; If it is determined that the tower top reflux amount is less than the minimum threshold value of the first reflux amount range, determining that the tower top reflux amount is an abnormal distillation parameter; If it is determined that the cooling water flow rate is less than a minimum threshold value of the first cooling water flow rate range, determining that the cooling water flow rate is an abnormal distillation parameter; If it is determined that the steam flow rate is greater than a maximum threshold value of the first steam flow rate range, the steam flow rate is determined to be an abnormal distillation parameter.

6. The method according to claim 5, characterized in that The determining the target control scheme according to the cause query list and the parameter value of the at least one distillation parameter includes: If the at least one distillation parameter is the tower top reflux rate, determining, according to the cause query list, that the target control scheme is to increase the opening of the reflux valve to increase the tower top reflux rate, thereby improving the distillation efficiency in the tower by lowering the tower top temperature; If the at least one distillation parameter is the cooling water flow rate, determining, based on the cause query list, that the target control scheme is to increase the opening of the cooling water valve to increase the cooling water flow rate, thereby ensuring that the gas phase components are fully condensed, thereby reducing the content of the high-boiling-point solvent in the overhead water; If the at least one distillation parameter is the steam flow rate, the target control scheme is determined according to the cause query list to be reducing the opening of the steam valve to reduce the steam flow rate, thereby stabilizing the gas-liquid equilibrium in the tower and avoiding the rapid rise of water vapor in the tower, which causes the gas phase components to be not fully condensed and dissolved in the water at the top of the tower.

7. The method according to claim 6, characterized in that After executing the target control scheme, the method further includes: If it is detected that the concentration of the waste liquid feed decreases, the opening of the reflux valve is reduced to reduce the tower top reflux amount, and the opening of the cold water valve is reduced to reduce the cooling water flow rate.

8. The method according to claim 2, characterized in that The adjusting the parameter value of the at least one distillation parameter according to the decreasing rate of the tower top temperature includes: determining a target speed according to a decreasing rate of the tower top temperature; The opening of at least one valve corresponding to the at least one distillation parameter is adjusted according to the target speed, so that the parameter value of the at least one distillation parameter decreases or increases according to the target speed.

9. The method according to claim 8, characterized in that The adjusting the opening of at least one valve corresponding to the at least one distillation parameter according to the target speed so that the parameter value of the at least one distillation parameter decreases or increases according to the target speed includes: If the at least one distillation parameter is the tower top reflux rate, reducing the opening of the reflux valve so that the tower top reflux rate decreases according to the target rate; If the at least one distillation parameter is the cooling water flow rate, reducing the opening of the cooling water valve so that the cooling water flow rate decreases according to the target rate; If the at least one distillation parameter is the steam flow rate, the opening of the steam valve is increased so that the steam flow rate increases according to the target speed.

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