Early warning system and method for monitoring abnormal polymerization rate in an acrylic plant and applications

Abstract

The application discloses a kind of early warning system and method and application for monitoring the abnormality of polymerization rate in acrylic device.The method comprises: (1) obtaining the real-time process parameters of target monitoring area in acrylic device, at least including temperature, acrylic acid concentration and inhibitor concentration;(2) based on the preset polymerization rate simplified calculation model, the polymerization reaction rate at the current time is calculated according to the real-time process parameters, (3) according to the polymerization reaction rate calculated, generate and output early warning signal.The application integrates the simplified polymerization kinetics model with DCS system, mainly used for polymerization risk monitoring in acrylic production process, realizes the real-time quantitative evaluation and early warning of polymerization risk, guides the accurate addition of inhibitor, effectively avoids large-scale polymerization, prolongs the running cycle of device, and reduces production cost.

Description

Technical Field

[0001] This invention relates to the field of chemical process control and safety early warning technology. Specifically, it relates to an early warning system, method and application for monitoring abnormal polymerization rates in acrylic acid plants, which is particularly suitable for real-time assessment and early warning of polymerization risks in key equipment such as deacetic acid towers during acrylic acid refining. Background Technology

[0002] Acrylic acid is an important basic organic chemical raw material, widely used in coatings, adhesives, superabsorbent resins, and other fields. During the production of acrylic acid, the unsaturated double bonds in the acrylic acid monomers make them highly susceptible to free radical polymerization under the influence of heat, light, or impurities. This polymerization reaction not only reduces product yield and quality, but more seriously, the resulting polymers can clog distillation column trays, reboilers, pipes, and valves, leading to increased pressure drop, decreased heat exchange efficiency, and ultimately forcing unplanned shutdowns for cleaning. This severely shortens the continuous operation cycle of the unit, causing significant economic losses and safety risks.

[0003] To inhibit the polymerization of acrylic acid during production and storage, the addition of polymerization inhibitors is commonly used in industry. Commonly used inhibitors include hydroquinone (HQ) and phenothiazine (PTZ). However, the mechanism of action of polymerization inhibitors is not well understood in current technology, and the knowledge of key production conditions affecting the polymerization rate (such as temperature, monomer concentration, impurity content, and residence time) is still incomplete. Currently, the addition scheme of polymerization inhibitors mainly relies on trial and error based on production experience, which has the following significant drawbacks:

[0004] 1. Excessive polymerization inhibitor: Adding too much polymerization inhibitor will not only increase the cost of raw materials, but also introduce additional impurities, affecting the purity of the final product and increasing the burden of subsequent separation.

[0005] 2. Insufficient polymerization inhibitor: When the amount of polymerization inhibitor added is insufficient, it cannot effectively inhibit the chain growth reaction of free radicals, resulting in an accelerated polymer formation rate, increased polymer accumulation in the unit, significantly shortened operating cycle, and frequent shutdowns for cleaning.

[0006] Therefore, developing an early warning system, method, and application for monitoring abnormal polymerization rates in acrylic acid plants has significant industrial value and practical implications. Summary of the Invention

[0007] To address the problems existing in current technologies, this paper proposes an early warning system, method, and application for monitoring abnormal polymerization rates in acrylic acid plants by utilizing the time difference mechanism between the rapid increase in instantaneous polymerization rate and the actual large-scale polymerization burst. This system enables quantitative assessment and real-time early warning of polymerization risks, guides the precise addition of polymerization inhibitors, thereby extending the plant's operating cycle and reducing production costs.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] In a first aspect, a method for monitoring abnormal polymerization rates in an acrylic acid plant is provided, comprising:

[0010] (1) Obtain real-time process parameters of the target monitoring area in the acrylic acid unit, wherein the real-time process parameters include at least temperature, acrylic acid concentration and polymerization inhibitor concentration;

[0011] (2) Based on a preset simplified calculation model for polymerization rate, the polymerization reaction rate at the current moment is calculated according to the real-time process parameters. The simplified calculation model for polymerization reaction rate is as follows:

[0012]

[0013] Where R P It is the chain growth rate of polyacrylic acid (mol·L⁻¹) -1 ·s -1 ), k i It is the chain initiation rate constant, k p It is the chain growth rate constant, k t [M] is the chain termination rate constant, and [M] is the acrylic acid concentration (mol·L⁻¹). -1 Cz is the polymerization inhibition constant of the inhibitor, and [Z] is the concentration of the inhibitor (mol·L⁻¹). -1 );

[0014] (3) Based on the calculated polymerization rate, generate and output an early warning signal.

[0015] Furthermore, the target monitoring area is the bottom of the acetic acid removal tower.

[0016] Furthermore, the chain initiation rate constant (k) i ), chain growth rate constant (k) p ) and chain termination rate constant (k t All are obtained through the Arrhenius formula ( The calculation yields the result, where A is the pre-exponential factor. R is the activation energy, R is the gas constant, and T is the temperature.

[0017] Furthermore, the chain initiation phase:

[0018]

[0019]

[0020] in This refers to the concentration of acrylic acid. =106 s -1 , =120 kJ·mol -1 .

[0021] Furthermore, the chain growth stage:

[0022]

[0023]

[0024] in =10 7 L·mol -1 ·s -1 , =30 kJ·mol -1 , This represents the concentration of free radicals.

[0025] Furthermore, the chain termination rate is R. t In this invention, the chain termination rate comprises two parts, denoted as R. t1 and R t2 .

[0026] Furthermore, the chain termination phase:

[0027]

[0028] in =10 9 L·mol -1 ·s -1 , =10 kJ·mol -1 In steady state .

[0029] Furthermore, in the presence of an inhibitor, the chain termination rate is:

[0030]

[0031]

[0032]

[0033]

[0034] The polymerization rate constant is denoted by . It is the polymerization inhibition constant. This represents the concentration of the polymerization inhibitor.

[0035] Further, the polymerization inhibitor comprises hydroquinone and / or phenothiazine, and the polymerization inhibition constant is: (hydroquinone) = 0.5, (Phenothiazine) = 0.7.

[0036] Furthermore, when a chain transfer agent is added to the reaction, the chain transfer rate equation is:

[0037]

[0038] in For example, the chain transfer constant. (Acetic acid) = 0.01 (Water) = 0.05 (Dimer) = 0.1

[0039] in The concentration of the chain transfer agent,

[0040] Chain transfer affects polymer molecular weight but has no effect on the overall polymerization rate.

[0041] Furthermore, when an initiator is present in the reaction, the free radical polymerization rate equation is:

[0042]

[0043] in (mol·L) -1 ·s -1 () represents the polymerization rate. Let be the chain growth rate constant. Let be the initiator decomposition rate constant. For initiator efficiency, Let be the chain termination rate constant. Initiator concentration, This represents the monomer concentration.

[0044] Furthermore, when no initiator is present in the reaction, the free radical polymerization rate equation is:

[0045]

[0046] in This is the thermal initiation rate constant, for example, at 80℃. =1.61×10 -13 L 0.5 ·mol -0.5 ·s -1 At 55℃ =1.41×10 -15 L 0.5 ·mol -0.5 ·s-1 .

[0047] Furthermore, based on the fact that the polymerization rate and chain growth rate are the same at steady state, and the total chain termination rate equals the chain initiation rate, the equilibrium free radical concentration is:

[0048]

[0049] The polymerization rate constant is denoted by . This represents the concentration of the polymerization inhibitor.

[0050] Furthermore, the simplified calculation model for the polymerization rate is a model corrected for production data, specifically as follows:

[0051]

[0052] Among them, R P Where is the polymerization rate, R is the ideal gas constant, T is the temperature, [M] is the monomer concentration, and [Z] is the total effective concentration of the inhibitor.

[0053] Furthermore, the method also includes: calculating the total amount of polymer generated within the time period based on the polymerization reaction rate and a preset time period.

[0054] Further, the total amount of polymer generated is calculated using the following formula: Total amount of polymer generated = Polyacrylic acid concentration × Total liquid volume of the target monitoring area × Molar mass of acrylic acid, wherein the polyacrylic acid concentration is obtained by multiplying the polymerization reaction rate by the time period.

[0055] Furthermore, the target monitoring area is the bottom of the deacetic acid tower in the acrylic acid unit.

[0056] Furthermore, generating and outputting the early warning signal includes: comparing the polymerization reaction rate with a preset threshold, and displaying alarm information on the DCS (Distributed Control System) interface when the polymerization reaction rate exceeds the threshold.

[0057] Based on production experience, the normal polymer production rate is within a fixed range, such as cleaning the filter twice a day, about 25 kg each time. The polymer production rate is calculated based on the normal daily polymer output as the normal threshold, which is the preset threshold.

[0058] Secondly, a system for monitoring abnormal polymerization rates in an acrylic acid plant is provided, comprising:

[0059] The data acquisition module is used to acquire real-time process parameters of the target monitoring area in the acrylic acid unit. The real-time process parameters include at least temperature, acrylic acid concentration, and polymerization inhibitor concentration.

[0060] The calculation module is used to calculate the polymerization reaction rate at the current moment based on a preset simplified polymerization rate calculation model and the real-time process parameters. The simplified polymerization rate calculation model is as follows:

[0061]

[0062] Where R P It is the chain growth rate of polyacrylic acid (mol·L⁻¹) -1 ·s -1 ), k i It is the chain initiation rate constant, k p It is the chain growth rate constant, k t [M] is the chain termination rate constant, and [M] is the acrylic acid concentration (mol·L⁻¹). -1 Cz is the polymerization inhibition constant of the inhibitor, and [Z] is the concentration of the inhibitor (mol·L⁻¹). -1 );

[0063] The early warning output module is used to generate and output an early warning signal based on the calculated polymerization reaction rate.

[0064] Furthermore, the simplified calculation model for the polymerization rate is a model corrected for production data, specifically as follows:

[0065]

[0066] Among them, R P Where is the polymerization rate, R is the ideal gas constant, T is the temperature, [M] is the monomer concentration, and [Z] is the total effective concentration of the inhibitor.

[0067] Thirdly, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the method described in this invention.

[0068] Fourthly, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method as described in this invention.

[0069] Fifthly, an acrylic acid production apparatus is provided, comprising the system as described in this invention or the computer-readable storage medium or electronic device described herein.

[0070] Compared with the prior art, the technical solution provided by the present invention has the following advantages or beneficial effects:

[0071] The core idea of ​​this invention is to construct an early warning system integrating a "mechanism model + data correction + DCS integration". First, based on the free radical polymerization mechanism, a simplified calculation model for the thermally initiated polymerization rate of acrylic acid in the presence of an inhibitor is derived. This model links the microscopic reaction steps, such as chain initiation, chain propagation, and chain termination, with macroscopically measurable process parameters (temperature, concentration) through the Arrhenius equation. Second, actual production data (such as the amount of polymer removed from the filter) is used to correct key parameters in the model (such as pre-exponential factor and activation energy), making the model more closely reflect the actual conditions of a specific device. Finally, the corrected model is embedded into the DCS system as a software module, which reads process parameters such as temperature, liquid level, and flow rate in real time, calculates the polymerization rate and daily polymer production online, and compares them with preset safety thresholds. An alarm is triggered if the threshold is exceeded. Specific advantages include:

[0072] (1) The complex free radical polymerization reaction kinetics theory is transformed into a simplified mathematical model that can be applied in engineering, realizing real-time and quantitative calculation of polymerization rate and overcoming the ambiguity of traditional empirical judgment.

[0073] (2) By integrating the calculation module into the DCS system, it is possible to dynamically calculate the aggregate risk based on the real-time fluctuation of process parameters, and issue timely warnings when the risk increases, providing operators with clear adjustment directions.

[0074] (3) The early warning information is directly related to the polymerization rate. Operators can adjust the amount of inhibitor added according to this information to achieve "addition on demand" and avoid the problem of excessive or insufficient addition. This ensures the safe operation of the equipment while reducing production costs and product impurities.

[0075] (4) Through proactive early warning and precise control, the occurrence of abnormal polymerization was effectively suppressed, and the accumulation of polymer in the equipment was significantly reduced, thereby extending the continuous operation cycle of the acrylic acid unit, especially key equipment such as the deacetic acid tower.

[0076] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Attached Figure Description

[0077] Figure 1 This refers to the early warning system calculation module in the embodiments of this application. Detailed Implementation

[0078] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0079] I. Research Approach

[0080] The research approach of this application, which constructs a parameterized kinetic calculation model—a real-time polymerization rate calculation engine, is as follows: Large-scale polymerization often occurs in acrylic acid plants. The complex polymerization reaction of acrylic acid within the plant is based on free radical polymerization and inhibition polymerization. Among them, free radical polymerization generates free radicals through thermal initiation. The activation energies and pre-exponential factors of chain initiation, chain propagation, chain transfer, and chain termination are determined by literature review, and the reaction rates of each step are calculated using the Arrhenius equation.

[0081] 1. Chain triggering

[0082] The acrylic acid thermal initiation process generates free radicals from the homolytic cracking of acrylic acid, with the acrylic acid itself acting as the initiator.

[0083] Thermal initiation rate equation:

[0084]

[0085]

[0086] in This refers to the concentration of acrylic acid. =10 6 s -1 , =120 kJ·mol -1 .

[0087] 2. Chain Growth

[0088] Chain growth rate equation:

[0089]

[0090]

[0091] in =10 7 L·mol -1 ·s -1 , =30 kJ·mol -1 , This represents the concentration of free radicals.

[0092] 3. Chain Termination

[0093] Chain termination rate equation:

[0094]

[0095]

[0096] in =10 9 L·mol -1 ·s-1 , =10 kJ·mol -1 In steady state .

[0097] In the presence of an inhibitor, the chain termination rate is:

[0098]

[0099]

[0100]

[0101]

[0102] The polymerization rate constant is denoted by . It is the polymerization inhibition constant. This represents the concentration of the polymerization inhibitor.

[0103] 4. Chain Transfer

[0104] This step does not change the overall reaction rate, but it significantly reduces the average molecular weight of the polymer, making it an important means of controlling molecular weight.

[0105] Chain transfer rate equation:

[0106]

[0107] in Let be the chain transfer constant. This represents the concentration of the chain transfer agent.

[0108] 5. The rate equation for free radical polymerization in the presence of an initiator is as follows:

[0109]

[0110] in (mol·L) -1 ·s -1 () represents the polymerization rate. Let be the chain growth rate constant. Let be the initiator decomposition rate constant. For initiator efficiency, Let be the chain termination rate constant. Initiator concentration, This represents the monomer concentration.

[0111] For free radical polymerization, the activation energy for chain growth is fixed. In the absence of an initiator, the generation of free radicals relies on thermal initiation and impurity initiation. The chain initiation rate is a function of temperature.

[0112]

[0113] in Here is the thermal initiation rate constant at 80℃. =1.61×10 -13 L 0.5 ·mol -0.5 ·s -1 At 55℃ =1.41×10 -15 L 0.5 ·mol -0.5 ·s -1 .

[0114] The polymerization inhibition reaction needs to consider the reaction of hydroquinone, phenothiazine, and acrylic acid radicals. The inhibition constant and reaction rate are determined by consulting the literature, and the pre-exponential factor is corrected by combining literature values ​​with production data. Calculate the reaction rate at polymerization and inhibition equilibrium, where the rate of free radical generation from chain initiation is the same as the rate of free radical consumption from chain termination (including the polymerization inhibition reaction). Calculate the polymer concentration at equilibrium.

[0115] Since the polymerization rate and chain growth rate are the same at steady state, and the total chain termination rate equals the chain initiation rate, the free radical concentration at steady state is:

[0116]

[0117] The thermally initiated polymerization rate in the presence of a polymerization inhibitor is as follows:

[0118]

[0119] =10 7 L·mol -1 ·s -1 , =30 kJ·mol -1 ; =10 9 L·mol -1 ·s -1 , =10 kJ·mol -1 ;

[0120] (hydroquinone) = 0.5, (Phenothiazine) = 0.7.

[0121] To simulate the polymerization process of acrylic acid in the tower, a polymerization model was established. Parameters affecting the polymerization rate, such as the amount of polymerization inhibitor fed, the temperature of the tower bottom, and the residence time, were replaced with equipment and process parameters. A dynamic polymerization rate calculation module was established that is related to actual production.

[0122] 2. Research Methods

[0123] Theoretical analysis shows that the thermally initiated polymerization rate of acrylic acid in the presence of an inhibitor is as follows:

[0124]

[0125] Where R P It is the chain growth rate of polyacrylic acid (mol·L⁻¹) -1 ·s -1 ), k i It is the chain initiation rate constant, k p It is the chain growth rate constant, k t [M] is the chain termination rate constant, and [M] is the acrylic acid concentration (mol·L⁻¹). -1 Cz is the polymerization inhibition constant of the inhibitor, and [Z] is the concentration of the inhibitor (mol·L⁻¹). -1 ).

[0126] The polymerization degree in the bottom column is significantly higher than in other locations. As the concentration of acrylic acid polymer increases, linear polyacrylic acid chains form branched chains through chain transfer, gradually crosslinking to form a network polymer. High polymer concentrations can cause severe clogging of the bottom column filter. The reaction rate equation parameters were corrected using production data, yielding the following results:

[0127]

[0128] Where R P Near steady-state polyacrylic acid production rate (mol·L) -1 ·s -1 The temperature of the reboiler (K) is known, and the concentration of acrylic acid (mol·L⁻¹) is known. -1 ).

[0129] The production data includes the type and amount of polymerization inhibitor added under different process conditions, as well as the liquid volume and temperature of the reboiler. Parameters for ten time periods were extracted based on different production conditions, and the polymerization rate was calculated by statistically analyzing the polymer yield under the corresponding operating conditions. AI was used to optimize the pre-exponential factors and polymerization inhibition constants.

[0130] The concentration of the polymerization inhibitor (mol·L) was calculated and determined based on the test results. -1The polymerization rate is determined based on the ratio of the inhibitor flow rate to the bottom flow rate. Therefore, a parameterized kinetic calculation module was constructed. This module integrates and embeds microscopic kinetic parameters such as the activation energy (Ea) and pre-exponential factor (A) of each elementary reaction (chain initiation, chain propagation, chain termination, chain transfer) obtained from the literature into an industrially usable calculation model. The simplified polymerization rate calculation model is a model corrected for production data. This model combines multiple kinetic constants into fewer parameters that can be directly fitted using production data, simplifying the calculation process while ensuring a high degree of agreement with actual operating data of specific plants.

[0131] The morphology of polyacrylic acid is affected by the chain transfer agent (AI-61 (copper acetate), AI-61R (N,N-di-n-butyldithiocarbamate)) and the residence time of a single cycle. Under steady-state conditions, the total polymer production is directly proportional to the tower's operating time. Setting the time to one day, the daily polymer production in the tower bottom can be calculated from the above data:

[0132] Daily production of polyacrylic acid (kg / day) = 0.001 (kg / g) × polyacrylic acid production rate (mol·L⁻¹) -1 ·s -1 × Time (86400 s / day) × Total volume of liquid phase in the bottom of the tower (L) × Molar mass of acrylic acid (g / mol).

[0133] Finally, R P Alternatively, the daily production of polyacrylic acid can be compared with a preset threshold to generate an early warning signal. The early warning module can predict the production of polyacrylic acid under continuous operation based on current process parameters, and effectively avoid abnormal polymerization by adjusting parameters in a timely manner or strengthening polymerization inhibition measures.

[0134] Regarding the determination of the preset threshold:

[0135] 1. Under normal production conditions, the daily output of acrylic polymer is within a certain range. This range is the total output under various production fluctuations. By statistically analyzing the number of times the polymer is cleaned and the amount produced each day, it is normally cleaned 2-3 times a day, with each cleaning producing about 25 kg. However, under abnormal conditions, it may be cleaned 10 times a day. Among these, 2-3 cleanings produce a daily output of about 50-75 kg, which is the normal threshold. A value greater than 75 kg is considered an abnormal value.

[0136] 2. When the operating conditions of the acrylic acid unit change, the process parameters except for the flow rate remain basically stable, and the polymer generation threshold remains basically unchanged. The parameters in the formula need to be adjusted. If the calculated value is abnormal due to the change in operating conditions, it is necessary to increase the concentration of the polymerization inhibitor by increasing the feed of the polymerization inhibitor and appropriately reduce the temperature of the tower bottom.

[0137] 3. False alarms caused by normal fluctuations can be resolved by setting a delayed alarm, such as setting an alarm only after the fluctuation lasts for more than 5 minutes.

[0138] II. Feeding System

[0139] This invention provides an early warning system for monitoring abnormal polymerization rates in an acrylic acid plant, comprising a data acquisition module, a calculation module, and an early warning output module. The data acquisition module is responsible for real-time data acquisition from field instruments (thermometers, level gauges, flow meters) and a laboratory analysis system (for obtaining acrylic acid concentration). The calculation module is the core of the system, typically a software function block deployed on a DCS controller or host computer. It encapsulates the simplified polymerization rate calculation model described above. The early warning system calculation module is as follows: Figure 1 As shown, the early warning output module is responsible for displaying the calculation results (such as the current aggregation rate and daily output) on the DCS operation interface, and alerting the operator in the form of audible and visual alarms, pop-up windows, etc. when the threshold is exceeded.

[0140] Example 1

[0141] An early warning system for monitoring abnormal polymerization rates in an acrylic acid plant was applied to the bottom of the deacetic acid tower in a certain acrylic acid plant, which is the location with the highest polymerization risk. The bottom temperature was controlled at 81 ℃, and the liquid phase volume was 31 m³. 3 The acrylic acid concentration was 13 mol / L. An early warning system for monitoring abnormal polymerization rates in the acrylic acid unit was operated, and the results are shown in Table 1.

[0142] Table 1 Application Results

[0143]

[0144] As shown in Table 1, the calculated daily polymer production is approximately 53.57 kg, which is very close to the amount of polymer removed during routine filter cleaning (approximately 50-60 kg), verifying the accuracy of the model. After this model was implemented as a DCS calculation module, when the reboiler temperature rises or the inhibitor flow rate decreases, causing the calculated polymerization rate or daily polymer production to exceed the preset safety limit (e.g., daily production exceeding 80 kg), an alarm will immediately pop up on the DCS interface, prompting the operator to increase the inhibitor dosage or check the process parameters.

[0145] Example 2

[0146] The difference from Example 1 is that the temperature of the deacetic acid tower bottom was increased from 81 °C to 85 °C (368.15 K), while other parameters remained unchanged.

[0147] The results showed that a temperature increase of only 4 °C led to a jump in daily polymer production from 53.57 kg to 250.85 kg, an increase of over 368%. This indicates that the model is highly sensitive to temperature changes and can promptly detect sharp increases in polymerization risk caused by temperature fluctuations. In such cases, the early warning module immediately issues a high-level alarm, reminding operators to take intervention measures, such as increasing the amount of polymerization inhibitor injected or investigating the cause of the temperature increase.

[0148] Example 3

[0149] The difference from Example 1 is that the concentration of the polymerization inhibitor was reduced from 0.0017 mol / L to 0.0010 mol / L, while the temperature remained at 81 °C.

[0150] The results showed that the daily polymer production increased from 53.57 kg to 91.80 kg, while the inhibitor concentration decreased by approximately 41%, resulting in an increase of approximately 71.3% in daily polymer production. Although the increase was not as dramatic as the temperature change, the model still accurately reflected this risk shift. The early warning module can be set to issue an alert when the polymer production exceeds 60 kg, thus reminding operators to check and address the issue at an early stage of inhibitor insufficiency, preventing the problem from worsening.

[0151] As can be seen from the above embodiments, by integrating the simplified polymerization kinetics model with the DCS system, real-time quantitative assessment and early warning of polymerization risks are achieved, guiding the precise addition of polymerization inhibitors, effectively avoiding large-scale polymerization, extending the plant's operating cycle, and reducing production costs. This invention is mainly used for monitoring polymerization risks in the acrylic acid production process. The technical solution provided by this invention can transform complex chemical reaction mechanisms into a practical and accurate engineering tool, providing strong technical support for the safe, long-term, and economical operation of acrylic acid plants.

[0152] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for monitoring abnormal polymerization rates in an acrylic acid plant, characterized in that, include: (1) Obtain real-time process parameters of the target monitoring area in the acrylic acid unit, wherein the real-time process parameters include at least temperature, acrylic acid concentration and polymerization inhibitor concentration; (2) Based on a preset simplified calculation model for polymerization rate, the polymerization reaction rate at the current moment is calculated according to the real-time process parameters. The simplified calculation model for polymerization reaction rate is as follows: ； Where R P It is the chain growth rate of polyacrylic acid (mol·L⁻¹) -1 ·s -1 ), k i It is the chain initiation rate constant, k p It is the chain growth rate constant, k t [M] is the chain termination rate constant, and [M] is the acrylic acid concentration (mol·L⁻¹). -1 Cz is the polymerization inhibition constant of the inhibitor, and [Z] is the concentration of the inhibitor (mol·L⁻¹). -1 ); (3) Based on the calculated polymerization rate, generate and output an early warning signal.

2. The method according to claim 1, characterized in that, The target monitoring area is the bottom of the acetic acid removal tower; Alternatively, the chain initiation rate constant, chain growth rate constant, and chain termination rate constant can all be obtained using the Arrhenius formula. The calculation yields, where A is the pre-exponential factor. R is the activation energy, R is the gas constant, and T is the temperature.

3. The method according to claim 1, characterized in that, The polymerization inhibitor includes at least one of hydroquinone and phenothiazine, and the polymerization inhibition constant is: (hydroquinone) = 0.5, (Phenothiazine) = 0.

7.

4. The method according to claim 1, characterized in that, When a chain transfer agent is added to the reaction, the chain transfer rate equation is as follows: ； in Let be the chain transfer constant. The concentration of the chain transfer agent affects the polymer molecular weight but has no effect on the overall polymerization rate. Alternatively, when an initiator is added to the reaction, the free radical polymerization rate equation is: ； in The polymerization rate, Let be the chain growth rate constant. Let be the initiator decomposition rate constant. For initiator efficiency, Let be the chain termination rate constant. Initiator concentration, Monomer concentration; Alternatively, when no initiator is added in the reaction, the free radical polymerization rate equation is: ； in is the thermal initiation rate constant.

5. The method according to claim 1, characterized in that... The simplified calculation model for the polymerization rate is a model corrected for production data, specifically as follows: ； Among them, R P Where is the polymerization rate, R is the ideal gas constant, T is the temperature, [M] is the monomer concentration, and [Z] is the total effective concentration of the inhibitor.

6. The method according to claim 1, characterized in that, The method further includes: calculating the total amount of polymer generated within the time period based on the polymerization reaction rate and a preset time period; Alternatively, the total amount of polymer generated can be calculated using the following formula: Total amount of polymer generated = Polyacrylic acid concentration × Total liquid volume of the target monitoring area × Molar mass of acrylic acid, wherein the polyacrylic acid concentration is obtained by multiplying the polymerization reaction rate by the time period.

7. The method according to claim 1, characterized in that, The generation and output of the early warning signal includes: comparing the polymerization reaction rate with a preset threshold, and displaying alarm information on the distributed control system interface when the polymerization reaction rate exceeds the threshold.

8. A system for monitoring abnormal polymerization rates in an acrylic acid plant, characterized in that, include: The data acquisition module is used to acquire real-time process parameters of the target monitoring area in the acrylic acid unit. The real-time process parameters include at least temperature, acrylic acid concentration, and polymerization inhibitor concentration. The calculation module is used to calculate the polymerization reaction rate at the current moment based on a preset simplified polymerization rate calculation model and the real-time process parameters. The simplified polymerization rate calculation model is as follows: ； Where R P It is the chain growth rate of polyacrylic acid, k i It is the chain initiation rate constant, k p It is the chain growth rate constant, k t [M] is the chain termination rate constant, [Z] is the acrylic acid concentration, Cz is the polymerization inhibition constant of the inhibitor, and [Z] is the inhibitor concentration. The early warning output module is used to generate and output an early warning signal based on the calculated polymerization reaction rate.

9. A computer-readable storage medium or electronic device, characterized in that, The device contains a computer program that, when executed by a processor, implements the method described in any one of claims 1 to 7.

10. An acrylic acid production apparatus, characterized in that, Includes the system of claim 8 or the computer-readable storage medium or electronic device of claim 9.

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