Process for producing pyromellitic dianhydride by adopting liquid phase oxidation

Abstract

The invention belongs to the technical field of organic chemical synthesis, and provides a process for producing pyromellitic dianhydride by liquid-phase oxidation, which comprises the following steps: proportionally adding durene and acetic acid into a batching kettle, matching by using a catalyst, stirring and heating a liquid material to obtain the liquid material, and adding the liquid material into the batching kettle to obtain the pyromellitic dianhydride; when a liquid material is pumped into the micro-channel continuous reactor, the flow of the liquid material pumped into the micro-channel continuous reactor needs to be obtained, pumping peak-valley analysis is carried out according to the flow of the liquid material, a pumping peak time period and a pumping valley time period are screened out, and the change types of the pumping peak time period and the pumping valley time period are identified; according to the method, the oxygen introduction strategy is formulated, the gas introduction adjustment amount is obtained, and the oxygen introduction amount is dynamically adjusted, so that oxygen introduction and liquid material pumping are highly coordinated in the time dimension, and the problems of violent reaction fluctuation or incomplete reaction and the like caused by imbalance of the gas-liquid proportion are solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic chemical synthesis, in particular to a process for producing pyromellitic dianhydride by liquid phase oxidation. BACKGROUND

[0002] The production of pyromellitic dianhydride by liquid phase oxidation is an important process route, and the conventional reactor is usually used for mixing and reacting of materials. During the process of pumping into the reactor, due to the running characteristics of the pump, the pipeline resistance, and the instability of the raw material supply, the liquid material flow pumped into the reactor will fluctuate obviously. This fluctuation makes the distribution of materials in the reactor uneven, and it is difficult to maintain the material balance and energy balance required by the reaction system.

[0003] In the liquid phase oxidation reaction, oxygen is an important oxidizing agent, and the matching degree of its flow rate and the liquid material flow rate plays a decisive role in the reaction. However, in actual production, due to the lack of effective monitoring and control means, the oxygen flow rate cannot be dynamically adjusted according to the real-time changes of the liquid material flow rate, which leads to frequent imbalance between the gas and liquid when the liquid material flow rate fluctuates. In addition, the liquid material flow rate does not change uniformly, but there are obvious peak and valley values, so it is necessary to develop corresponding oxygen flow rate strategies for different time periods, otherwise it is impossible to realize the high coordination between oxygen flow rate and liquid material pumping in the time dimension.

[0004] Therefore, the application provides a process for producing pyromellitic dianhydride by liquid phase oxidation. SUMMARY

[0005] In order to make up for the deficiencies of the prior art and solve at least one technical problem raised in the background art.

[0006] The technical solution adopted by the application to solve its technical problems is: A process for producing pyromellitic dianhydride by liquid phase oxidation, comprising: heating and stirring of the uniform tetramethylbenzene, acetic acid and catalyst to obtain liquid material, and pumping into a micro-channel continuous reactor, setting a material pumping period, obtaining the liquid material flow rate pumped into the micro-channel continuous reactor, and analyzing the pumping peak and valley periods to screen out the pumping peak period and the pumping valley period; respectively obtaining the oxygen flow rate in the pumping peak period and the pumping valley period, and uniformly analyzing the liquid material flow rate in the pumping peak period and the pumping valley period, and evaluating the overall uniformity of gas and liquid pumping; If the gas-liquid pump is not uniform as a whole, the peak and valley pumping periods in the material pumping cycle are analyzed in the time dimension to obtain a peak-valley gas-liquid uniformity analysis value, and the change type of the peak and valley pumping periods is identified according to the peak-valley gas-liquid uniformity analysis value; The peak-pumping gas-liquid uniformity analysis value and the valley-pumping gas-liquid uniformity analysis value are summed to obtain a peak-valley gas-liquid uniformity analysis value, and if the peak-valley gas-liquid uniformity value is less than the peak-valley gas-liquid uniformity threshold value, a gas-liquid overall non-uniformity signal is displayed. According to the change type of the identified peak and valley pumping periods, an oxygen inlet strategy is formulated, a gas flux pre-adjustment period is extracted, and a gas flux adjustment amount corresponding to the gas flux pre-adjustment period is obtained for dynamic adjustment.

[0007] Preferably, the catalyst comprises a multi-metal salt: iron, vanadium, zinc, manganese, zirconium, aluminum, cobalt, guanidine, and bromide and chloride anions.

[0008] Preferably, the mass ratio of durene to acetic acid is 1:3-5, and 1%-5% of the catalyst relative to the mass percentage of the raw material durene is added for heating and stirring.

[0009] Preferably, during heating and stirring, the temperature is heated to 80-110°C, and after uniform stirring and dissolution in durene, the material is pumped into a microchannel continuous reactor, oxygen is introduced into the microchannel continuous reactor, the temperature of the microchannel continuous reactor is raised to 100-300°C, and the pressure is adjusted to 1-5 MPa.

[0010] Preferably, the selection process of the peak and valley pumping periods is as follows: The material pumping period is divided into several flow monitoring points, and adjacent flow monitoring points are combined as a group of adjacent monitoring groups to obtain multiple groups of adjacent monitoring groups. The liquid material flow of each flow monitoring point in the adjacent monitoring group is obtained, and the difference is calculated. The interval time between adjacent flow monitoring points is calculated by ratio to obtain a unit flow change rate, and a flow change sequence is constructed. The signs of the unit flow change rates corresponding to each group of adjacent monitoring groups in the flow change sequence are extracted respectively, the time period between adjacent flow monitoring points with positive signs is taken as the peak pumping period, and if there are continuous adjacent peak pumping periods, they are combined as the peak pumping period. The time period between adjacent flow monitoring points with negative signs is taken as the valley pumping period, and if there are continuous adjacent valley pumping periods, they are combined as the valley pumping period.

[0011] Preferably, the oxygen flow and liquid material flow in the peak pumping period are analyzed for uniformity, and the process is as follows: The oxygen flow and the liquid material flow of each flow monitoring point in the pump-in peak period are respectively obtained and substituted into a two-dimensional coordinate system to construct a peak pump oxygen flow change curve and a peak pump liquid material flow change curve; The adjacent coordinates of the peak pump oxygen flow change curve and the peak pump liquid material flow change curve are combined to obtain a plurality of peak pump oxygen adjacent groups and peak pump liquid material adjacent groups, and the coordinates in the peak pump oxygen adjacent groups and the peak pump liquid material adjacent groups with the same timestamp are respectively subjected to slope calculation to obtain a peak pump oxygen trend value and a peak pump liquid material trend value, and if the peak pump oxygen trend value and the peak pump liquid material trend value are consistent in sign, they are regarded as a same trend peak pump gas-liquid group, and the ratio of the number of the same trend peak pump gas-liquid groups to the total number of peak pump gas-liquid analysis groups is calculated to obtain a peak pump gas-liquid synchronous change value; In the same trend peak pump gas-liquid group, the peak pump oxygen trend value and the peak pump liquid material trend value are subjected to ratio calculation to output a peak pump gas-liquid synchronous trend ratio; The peak pump gas-liquid synchronous trend ratios in all same trend peak pump gas-liquid groups are calculated and processed by using a variation coefficient algorithm to output a peak pump gas-liquid synchronous degree value.

[0012] Preferably, the overall uniformity of the gas-liquid pump-in is evaluated, and the process is as follows: The liquid material flow in the pump-in valley period and the oxygen flow in the valley pump oxygen flow sequence are respectively substituted into a two-dimensional coordinate system to construct a valley pump liquid material flow change curve and a valley pump oxygen flow change curve; The adjacent coordinates of the valley pump liquid material flow change curve and the valley pump oxygen flow change curve are combined to obtain a plurality of valley pump oxygen adjacent groups and valley pump liquid material adjacent groups, and the coordinates in the valley pump oxygen adjacent groups and the valley pump liquid material adjacent groups with the same timestamp are respectively subjected to slope calculation to obtain a valley pump oxygen trend value and a valley pump liquid material trend value, and if the valley pump oxygen trend value and the valley pump liquid material trend value are consistent in sign, they are regarded as a same trend valley pump gas-liquid group, and the ratio of the number of the same trend valley pump gas-liquid groups to the total number of valley pump gas-liquid analysis groups is calculated to obtain a valley pump gas-liquid synchronous change value; In the same trend valley pump gas-liquid group, the valley pump oxygen trend value and the valley pump liquid material trend value are subjected to ratio calculation to output a valley pump gas-liquid synchronous trend ratio, and the valley pump gas-liquid synchronous trend ratios corresponding to all same trend valley pump gas-liquid groups are calculated and processed to output a valley pump gas-liquid synchronous degree value; The ratio of the valley pump gas-liquid synchronous change value and the valley pump gas-liquid synchronous degree value is calculated to output a valley pump gas-liquid uniformity analysis value.

[0013] Preferably, the change type of the pump-in peak period and the pump-in valley period is identified, and the process is as follows: The pump-in peak period and the pump-in valley period in each material pump-in period are sorted according to time sequence to obtain a period peak-valley period sequence; In each cycle peak valley period sequence, the time length corresponding to the pump-in peak period and the pump-in valley period is obtained respectively as the peak pump duration and the valley pump duration, and the standard deviation and the mean value are calculated respectively, and the peak pump duration standard deviation, the peak pump duration mean value, the valley pump duration standard deviation and the valley pump duration mean value are output; The valley pump duration standard deviation and the valley pump duration mean value are calculated by the coefficient of variation algorithm, and the valley pump duration stability value is output. The peak pump duration standard deviation and the peak pump duration mean value are calculated by the coefficient of variation algorithm, and the peak pump duration stability value is output. The valley pump duration stability value and the peak pump duration stability value are summed, and the single-period peak valley pump-in stability value is output. The single-period peak valley pump-in stability value corresponding to each material pump-in period is calculated by the standard deviation, and the type change recognition value is output. If the type change recognition value is greater than the type change recognition threshold value, a period change non-stable signal is displayed. If the type change recognition value is less than or equal to the type change recognition threshold value, a period change stable signal is displayed.

[0014] Preferably, according to the change type of the identified pump-in peak period and the pump-in valley period, an oxygen inlet strategy is formulated, and a gas flux pre-adjustment period is extracted, and the process is as follows: Based on the period change non-stable signal, the valley pump duration mean value corresponding to each cycle peak valley period sequence is extracted, the minimum valley pump duration mean value is selected as the peak pump pre-adjustment period length, the peak pump duration mean value corresponding to each cycle peak valley period sequence is extracted, and the minimum peak pump duration mean value is selected as the valley pump pre-adjustment period length; If the current is in the pump-in valley period, the current flow monitoring point of the pump-in valley period is extracted, and the peak pump pre-adjustment period length is summed to construct the gas flux pre-adjustment period; If the current is in the pump-in peak period, the current flow monitoring point of the pump-in peak period is extracted, and the valley pump pre-adjustment period length is summed to construct the gas flux pre-adjustment period; Based on the period change stable signal, the valley pump duration mean value corresponding to each cycle peak valley period sequence and the valley pump duration mean value corresponding to each cycle peak valley period sequence are extracted respectively, and the sum mean value calculation is performed respectively to obtain the peak pump pre-adjustment period length and the valley pump pre-adjustment period length; If the current is in the pump-in peak period, the current flow monitoring point of the pump-in peak period is extracted, and the peak pump pre-adjustment period length is summed to construct the gas flux pre-adjustment period; If the current is in the pump-in valley period, the current flow monitoring point of the pump-in valley period is extracted, and the valley pump pre-adjustment period length is summed to construct the gas flux pre-adjustment period.

[0015] Preferably, the process of obtaining the gas flux pre-adjustment period corresponding to the gas flux adjustment amount is as follows: If the current gas flux pre-adjustment period is in the pump-in peak period, the liquid material flow corresponding to each flow monitoring point before the current flow monitoring point is extracted, and a sliding window is set, and the liquid material flow of each flow monitoring point after the current flow monitoring point is obtained by using the sliding window method as the pre-adjustment liquid material flow; If the current gas flux pre-adjustment period is in the pump-in valley period, the liquid material flow corresponding to each flow monitoring point before the current flow monitoring point is extracted, and a sliding window is set, and the liquid material flow of each flow monitoring point after the current flow monitoring point is obtained by using the sliding window method as the pre-adjustment liquid material flow; The peak pump gas-liquid synchronous trend ratio corresponding to each group of the same trend peak pump gas-liquid group is extracted, and the sum mean calculation is performed to output the gas-liquid pre-adjustment coefficient; The pre-adjustment liquid material flow is multiplied by the gas-liquid pre-adjustment coefficient to output the gas flux adjustment amount.

[0016] The beneficial effects of the present application are as follows: In the material pump-in period, the liquid material flow pumped into the microchannel continuous reactor is obtained, and the pump-in peak and valley periods are screened out by analyzing the pump-in peak and valley of the liquid material flow. The oxygen flow in the pump-in peak and valley periods is obtained, and the uniformity analysis is performed on the liquid material flow in the pump-in peak and valley periods. The overall uniformity of the gas-liquid pump-in is evaluated, and the pump-in peak and valley periods are divided. The abnormal fluctuations that may occur in the material pump-in process can be found in time, and the material balance and energy balance of the reaction system can be maintained. Data support is provided for evaluating the overall uniformity of the gas-liquid pump-in. The analysis of the gas-liquid flow change trend in different periods can reflect the degree of material balance maintenance. In the case of overall uneven gas-liquid pump-in, the pump-in peak and valley periods in multiple material pump-in periods are analyzed in the time dimension, the change types of the pump-in peak and valley periods are identified, the oxygen inlet strategy is formulated according to the identified change types of the pump-in peak and valley periods, the gas flux pre-adjustment period is extracted, the gas flux adjustment amount corresponding to the gas flux pre-adjustment period is obtained, and the oxygen inlet amount is dynamically adjusted to realize high coordination between oxygen inlet and liquid material pump-in in the time dimension, avoid reaction violent fluctuations or incomplete reaction caused by imbalance of gas-liquid ratio, ensure the stability of the production process, and avoid waste or deficiency of oxygen by dynamically adjusting the oxygen inlet amount, thereby realizing optimal utilization of oxygen resources. BRIEF DESCRIPTION OF DRAWINGS

[0017] The present application will be further described below with reference to the accompanying drawings.

[0018] Figure 1is a process flow chart of a process for producing pyromellitic dianhydride by liquid phase oxidation according to the present application; Figure 2 is a determination flow chart in the process for producing pyromellitic dianhydride by liquid phase oxidation according to the present application. DETAILED DESCRIPTION

[0019] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the present application is further described below in conjunction with specific embodiments. Embodiment 1

[0020] The process for producing pyromellitic dianhydride by liquid phase oxidation according to the present embodiment mainly uses acetic acid as a solvent and uses a multi-metal salt: iron, vanadium, zinc, manganese, zirconium, aluminum, cobalt, guanidine, and bromide, chloride and other anions as a catalyst, and specifically includes the following steps: The durene and acetic acid are put into a batching kettle according to a ratio of 1:3, and the catalyst is added into the batching kettle according to a ratio of 1%, the material is stirred, heated to 80℃, and after being stirred and uniformly dissolved in the durene, the material is pumped into a micro-channel continuous reactor, and compressed air (or oxygen) is also introduced into the micro-channel continuous reactor, the temperature of the micro-channel continuous reactor is raised to 100℃, and the pressure is adjusted to 1Mpa, wherein the flow rate of oxygen is 10 times that of the mixed liquid. Embodiment 2

[0021] The process for producing pyromellitic dianhydride by liquid phase oxidation according to the present embodiment mainly uses acetic acid as a solvent and uses a multi-metal salt: iron, vanadium, zinc, manganese, zirconium, aluminum, cobalt, guanidine, and bromide, chloride and other anions as a catalyst, and specifically includes the following steps: The durene and acetic acid are put into a batching kettle according to a ratio of 1:4, and the catalyst is added into the batching kettle according to a ratio of 3%, the material is stirred, heated to 95℃, and after being stirred and uniformly dissolved in the durene, the material is pumped into a micro-channel continuous reactor, and compressed air (or oxygen) is also introduced into the micro-channel continuous reactor, the temperature of the micro-channel continuous reactor is raised to 200℃, and the pressure is adjusted to 3Mpa, wherein the flow rate of oxygen is 20 times that of the mixed liquid. Embodiment 3

[0022] The process for producing pyromellitic dianhydride by liquid phase oxidation according to the present embodiment mainly uses acetic acid as a solvent and uses a multi-metal salt: iron, vanadium, zinc, manganese, zirconium, aluminum, cobalt, guanidine, and bromide, chloride and other anions as a catalyst, and specifically includes the following steps: Put durene and acetic acid into the batching kettle according to the ratio of 1:5, and add the catalyst into the batching kettle according to the ratio of 5%, stir the material, heat to 110℃, after stirring and dissolving in durene, pump the material into the micro-channel continuous reactor, at the same time, introduce compressed air (or oxygen) into the micro-channel continuous reactor, increase the temperature of the micro-channel continuous reactor to 300℃, and adjust the pressure to 5Mpa, wherein the flow rate of oxygen is 30 times that of the mixed liquid. Example 4

[0023] In the production process of pyromellitic dianhydride, when pumping the material into the micro-channel continuous reactor, there is a pulse fluctuation in the pumping process, that is, the principle of the pulse fluctuation is that the instantaneous flow rate of the mixed liquid periodically appears peak (high instantaneous flow rate) and valley (low instantaneous flow rate) fluctuation with the mechanical movement law of the pump, instead of uniform and stable delivery, so that the pumping mode of the material is non-stable and uniform, if the amount of oxygen introduced is set to a fixed amount, the amount of oxygen introduced may be insufficient when the mixed liquid reaches the peak, and the amount of oxygen introduced may be excessive when the mixed liquid reaches the valley, resulting in the incoordination of the gas-liquid introduction amount, and finally destroying the uniformity of the material entering the micro-channel continuous reactor, please refer to Figure 1 Figure 2 The process for producing pyromellitic dianhydride by liquid phase oxidation according to the embodiment of the present application comprises the following steps: Step one: during the material pumping period, obtain the flow rate of the liquid material pumped into the micro-channel continuous reactor, and perform peak-valley analysis on the flow rate of the liquid material to screen out the pumping peak period and the pumping valley period; For example, the material pumping period is divided into several flow monitoring points, and the interval time length between adjacent flow monitoring points is equal; Combine adjacent flow monitoring points as an adjacent monitoring group to obtain a plurality of adjacent monitoring groups; It should be noted that the adjacent flow monitoring points in the adjacent monitoring group are the front flow monitoring point and the rear flow monitoring point, respectively; In the adjacent monitoring group, obtain the flow rate of the liquid material of each flow monitoring point, and perform difference calculation on the flow rate of the liquid material of adjacent flow monitoring points to obtain the adjacent flow difference; Obtain the interval time length between adjacent flow monitoring points, and perform ratio calculation on the adjacent flow difference and the interval time length between adjacent flow monitoring points to obtain the unit flow change rate; Take the time sequence of the front flow monitoring point in each adjacent monitoring group as the reference, sort the unit flow change rate corresponding to each adjacent monitoring group to construct a flow change sequence, wherein the flow change sequence comprises ​The unit flow rate change rate corresponding to each group of adjacent monitoring groups in the flow rate change sequence is extracted, and n represents the total number of unit flow rate change rates corresponding to adjacent monitoring groups; The sign of the unit flow rate change rate corresponding to each group of adjacent monitoring groups in the flow rate change sequence is extracted (the sign includes a positive unit flow rate change rate or a negative unit flow rate change rate), the adjacent monitoring group corresponding to the positive unit flow rate change rate is taken as a positive adjacent monitoring group, and the time period between the front flow monitoring point and the rear flow monitoring point in the group is taken as a pump-in peak period; If there are continuous adjacent pump-in peak periods, they are merged as pump-in peak periods until the next period is merged as a pump-in valley period; The adjacent monitoring group corresponding to the negative unit flow rate change rate is taken as a negative adjacent monitoring group, and the time period between the front flow monitoring point and the rear flow monitoring point in the group is taken as a pump-in valley period; If there are continuous adjacent pump-in valley periods, they are merged as pump-in valley periods until the next period is merged as a pump-in peak period; It should be noted that the purpose of obtaining the pump-in peak period and the pump-in valley period is to improve the control accuracy of the concentration and reaction rate of the material from the process production process. Specifically, in the pump-in peak period, a large amount of material quickly enters the reactor, which can promote the reaction to proceed quickly and meet the requirements of some stages with high requirements on reaction rate. In the pump-in valley period, the input of material is reduced, which can avoid excessive reaction and prevent side reactions from occurring, so that the reaction can be carried out under more stable and controllable conditions, thereby optimizing the entire production process. From the production stability, by accurately dividing the pump-in peak and valley periods, the abnormal fluctuations that may occur during the pumping of the material can be found in time, which provides data support for exploring the rules of pulse fluctuations when pumping the material into the microchannel continuous reactor. At the same time, reasonable division of the pump-in peak and valley periods helps to maintain the material balance and energy balance of the reaction system. In the pump-in peak period, the rapid increase of the material will cause a certain change in energy, which can be absorbed and converted by the reaction system in time through reasonable control to avoid the reaction from getting out of control due to energy accumulation. In the pump-in valley period, stable material input can maintain the relative balance of the reaction system to prevent the reaction from being interrupted or the product quality from being reduced due to material shortage. Step two: respectively obtain the oxygen flow in the pump-in peak period and the pump-in valley period, and correspondingly combine the liquid material flow in the pump-in peak period and the pump-in valley period to analyze the uniformity, and evaluate the overall uniformity of the gas-liquid pump-in; For example, the oxygen flow of each flow monitoring point in the pump-in peak period and the pump-in valley period is obtained, and the obtained time sequence is sorted to construct a peak pump oxygen flow sequence and a valley pump oxygen flow sequence, respectively. The oxygen flow in the peak pump oxygen flow sequence is substituted into a two-dimensional coordinate system, with the X-axis as time and the Y-axis as oxygen flow, to construct a peak pump oxygen flow change curve; The liquid material flow in the peak value period is substituted into a two-dimensional coordinate system, with the X-axis as time and the Y-axis as liquid material flow, to construct a peak pump liquid material flow change curve; The adjacent coordinates on the peak pump oxygen flow change curve are combined to obtain multiple peak pump oxygen adjacent groups; The adjacent coordinates on the peak pump liquid material flow change curve are combined to obtain multiple peak pump liquid material adjacent groups; The peak pump oxygen adjacent groups and the peak pump liquid material adjacent groups corresponding to the same timestamp are combined twice to obtain multiple peak pump gas-liquid analysis groups; It should be noted that the peak pump oxygen adjacent groups and the peak pump liquid material adjacent groups corresponding to the same timestamp specifically refer to the fact that the flow monitoring points on the X-axis corresponding to the adjacent coordinates in the peak pump oxygen adjacent groups and the peak pump liquid material adjacent groups are the same; In the peak pump gas-liquid analysis groups, the coordinates in the peak pump oxygen adjacent groups and the peak pump liquid material adjacent groups are substituted into the slope calculation formula to obtain the peak pump oxygen trend value and the peak pump liquid material trend value; If the peak pump oxygen trend value and the peak pump liquid material trend value are consistent in sign (both positive or both negative), it indicates that the coordinate change trends of the peak pump oxygen adjacent groups and the peak pump liquid material adjacent groups are consistent, and the peak pump gas-liquid analysis groups are marked as same-trend peak pump gas-liquid groups; If the peak pump oxygen trend value and the peak pump liquid material trend value are inconsistent (one is positive and the other is negative or one is negative and the other is positive), it indicates that the coordinate change trends of the peak pump oxygen adjacent groups and the peak pump liquid material adjacent groups are inconsistent, and the peak pump gas-liquid analysis groups are marked as non-same-trend peak pump gas-liquid groups; The ratio of the number of same-trend peak pump gas-liquid groups to the total number of peak pump gas-liquid analysis groups is calculated to obtain the peak pump gas-liquid synchronous change value; In the same-trend peak pump gas-liquid groups, the peak pump oxygen trend value and the peak pump liquid material trend value are calculated to obtain the peak pump gas-liquid synchronous trend ratio; The peak pump gas-liquid synchronous trend ratios in all same-trend peak pump gas-liquid groups are calculated and processed using the coefficient of variation algorithm to output the peak pump gas-liquid synchronous degree value; It can be understood that the coefficient of variation algorithm itself can analyze the dispersion of the degree difference between data, so that after calculating and processing the peak pump gas-liquid synchronous trend ratios in all same-trend peak pump gas-liquid groups, the dispersion of the gas-liquid synchronous degree between the same-trend peak pump gas-liquid groups can be reflected, that is, the stability of the correlation degree between the peak pump oxygen change amount and the peak pump liquid material change amount; The peak pump gas-liquid synchronous change value and the peak pump gas-liquid synchronous degree value are calculated to output the peak pump gas-liquid uniform analysis value; It can be understood that the meaning represented by the peak pumping gas-liquid uniformity analysis value is that the information of the overall proportion of the synchronous change of gas and liquid in the peak pumping period and the stability of the synchronous trend is integrated, and a higher peak pumping gas-liquid uniformity analysis value indicates that the period in which the flow change trends of oxygen and liquid material are consistent accounts for a large proportion, and the synchronous change trend is relatively stable in different periods, that is, the pumping of oxygen and liquid material has good coordination and consistency in flow change, and the overall pumping is relatively uniform; The liquid material flow in the pumping valley period is substituted into the two-dimensional coordinate system to construct a valley pumping liquid material flow change curve; The oxygen flow in the valley pumping oxygen flow sequence is substituted into the two-dimensional coordinate system to construct a valley pumping oxygen flow change curve; The adjacent coordinates on the valley pumping oxygen flow change curve are combined to obtain a plurality of valley pumping oxygen adjacent groups; The adjacent coordinates on the valley pumping liquid material flow change curve are combined to obtain a plurality of valley pumping liquid material adjacent groups; The valley pumping oxygen adjacent group and the valley pumping liquid material adjacent group corresponding to the same timestamp are twice combined to obtain a plurality of valley pumping gas-liquid analysis groups; It should be noted that the valley pumping oxygen adjacent group and the valley pumping liquid material adjacent group corresponding to the same timestamp specifically refer to that the flow monitoring points corresponding to the adjacent coordinates in the valley pumping oxygen adjacent group and the valley pumping liquid material adjacent group are the same on the X-axis; In the valley pumping gas-liquid analysis group, the coordinates in the valley pumping oxygen adjacent group and the valley pumping liquid material adjacent group are substituted into the slope calculation formula to obtain a valley pumping oxygen trend value and a valley pumping liquid material trend value; If the valley pumping oxygen trend value and the valley pumping liquid material trend value are consistent in sign (both positive or both negative), it indicates that the coordinate change trends of the valley pumping oxygen adjacent group and the valley pumping liquid material adjacent group are consistent, and the valley pumping gas-liquid group is marked as a same trend valley pumping gas-liquid group; If the valley pumping oxygen trend value and the valley pumping liquid material trend value are inconsistent in sign (one is positive and the other is negative or one is negative and the other is positive), it indicates that the coordinate change trends of the valley pumping oxygen adjacent group and the valley pumping liquid material adjacent group are inconsistent, and the valley pumping gas-liquid analysis group is marked as a non-same trend valley pumping gas-liquid group; The ratio of the number of same trend valley pumping gas-liquid groups to the total number of valley pumping gas-liquid analysis groups is calculated to obtain a valley pumping gas-liquid synchronous change value; In the same trend valley pumping gas-liquid group, the valley pumping oxygen trend value and the valley pumping liquid material trend value are calculated by ratio to output a valley pumping gas-liquid synchronous trend ratio; The valley pumping gas-liquid synchronous trend ratio in all valley pumping gas-liquid analysis groups is calculated and processed by using the coefficient of variation algorithm to output a valley pumping gas-liquid synchronous degree value; The gas-liquid uniformity value of the peak is calculated by dividing the gas-liquid synchronous change value of the peak by the gas-liquid synchronous degree value of the peak, and the gas-liquid uniformity value of the valley is calculated by dividing the gas-liquid synchronous change value of the valley by the gas-liquid synchronous degree value of the valley. It can be understood that the meaning represented by the gas-liquid uniformity value of the peak and the valley is that the information of the overall proportion of the gas-liquid synchronous change in the peak period and the stability of the gas-liquid synchronous trend in the valley period is comprehensively considered, and a higher gas-liquid uniformity value indicates that not only the proportion of the period in which the flow change trends of the oxygen and the liquid material are consistent is large, but also the synchronous change trend is relatively stable in different periods, that is, the oxygen and the liquid material have good coordination and consistency in the flow change during the pumping, and the overall pumping is relatively uniform. The peak-valley gas-liquid uniformity value is obtained by summing the peak gas-liquid uniformity value and the valley gas-liquid uniformity value. In detail, the meaning represented by the peak-valley gas-liquid uniformity value is that the peak-valley gas-liquid uniformity value considers both the peak period with large flow change and the valley period with small flow change during the pumping, and can more comprehensively evaluate the uniformity of the oxygen and the liquid material during the whole material pumping period. If the peak-valley gas-liquid uniformity value is high, it indicates that the flow change of the oxygen and the liquid material has good coordination and consistency during the whole material pumping period, and the gas-liquid pumping is relatively uniform as a whole. If the peak-valley gas-liquid uniformity value is greater than or equal to the peak-valley gas-liquid uniformity threshold value, it indicates that the flow change of the oxygen and the liquid material has good coordination and consistency during the whole material pumping period, and the gas-liquid pumping is relatively uniform as a whole, which is displayed as a gas-liquid overall uniform signal. If the peak-valley gas-liquid uniformity value is less than the peak-valley gas-liquid uniformity threshold value, it indicates that the flow change of the oxygen and the liquid material has poor coordination and consistency in a peak period or a valley period during the whole material pumping period, and the gas-liquid pumping is relatively non-uniform, which is displayed as a gas-liquid overall non-uniform signal. More specifically, the purpose of evaluating the overall uniformity of the gas-liquid pumping is to maintain the material balance and energy balance of the reaction system by dividing the peak period and the valley period from the perspective of the balance control precision of the reaction system, and the evaluation of the uniformity of the gas-liquid pumping is a further refined consideration of the balance state. In the peak period, the rapid increase of the material brings energy change, and good uniformity of the gas-liquid pumping can make the reaction system timely absorb and convert the energy. In the valley period, stable gas-liquid input is helpful to maintain the relative balance of the reaction system, and the evaluation result of step two can reflect the degree of balance maintenance. From the production stability dimension, the pump-in peak and valley period is divided, the abnormal fluctuation that can appear in the material pump-in process can be found in time, the overall uniformity of gas-liquid pump-in is evaluated, the accuracy of judging whether the abnormal fluctuation only appears in liquid material pump-in, oxygen pump-in or both is improved, and the degree and range of the abnormal fluctuation are improved, more detailed data support is provided for exploring the pulse fluctuation law existing in the material pump-in micro-channel continuous reactor; The embodiment is specific as follows: in a material pump-in period, the liquid material flow rate pumped into the micro-channel continuous reactor is obtained, and the pump-in peak and valley analysis is performed according to the liquid material flow rate, the pump-in peak period and the pump-in valley period are screened out, the oxygen flow rates in the pump-in peak period and the pump-in valley period are obtained respectively, and the uniformity analysis is performed on the liquid material flow rates in the pump-in peak period and the pump-in valley period, the overall uniformity of gas-liquid pump-in is evaluated, the pump-in peak and valley period is divided, the abnormal fluctuation that can appear in the material pump-in process can be found in time, and the material balance and energy balance of the reaction system can be maintained, data support is provided for evaluating the overall uniformity of gas-liquid pump-in, and the analysis on the gas-liquid flow rate change trend in different periods can reflect the degree of material balance maintenance.

[0024] Embodiment 5 Please refer to Figure 1 - Figure 2 As shown in the figure, the process for producing pyromellitic dianhydride by liquid phase oxidation according to the embodiment of the application comprises the following steps: Step three: if the overall gas-liquid pump-in is not uniform, the pump-in peak period and the pump-in valley period in multiple material pump-in periods are analyzed in the time dimension, and the change type of the pump-in peak period and the pump-in valley period is identified; In some embodiments, the pump-in peak period and the pump-in valley period in each material pump-in period are sorted in time sequence to obtain a period peak-valley period sequence; In each period peak-valley period sequence, the time length corresponding to the pump-in peak period and the pump-in valley period is obtained respectively as the peak pump duration and the valley pump duration; It should be noted that, since there are continuous adjacent pump-in peak periods, the pump-in peak periods are combined as pump-in peak periods, and there are continuous adjacent pump-in valley periods, the pump-in valley periods are combined as pump-in valley periods, and the principle of pulse fluctuation is that the instantaneous flow rate of the mixed liquid changes periodically with the mechanical movement law of the pump, and the peak (high instantaneous flow rate) and the valley (low instantaneous flow rate) fluctuation phenomenon appears, so that the pump-in peak period and the pump-in valley period in the material pump-in period are adjacent two periods; It can be understood that after the material enters the pump-in peak period, it enters the pump-in valley period, and vice versa; Therefore, it is helpful to understand that the peak pump duration can also be understood as the remaining duration of the material entering the next pump-in valley period, and the valley pump duration can also be understood as the remaining duration of the material entering the next pump-in peak period; The standard deviation and mean of all valley pump durations in the peak-valley period sequence of the extraction cycle are calculated, and the standard deviation and mean of the valley pump duration are output; The standard deviation and mean of all valley pump durations in the peak-valley period sequence of the extraction cycle are calculated, and the standard deviation and mean of the valley pump duration are output; The standard deviation and mean of all peak pump durations in the peak-valley period sequence of the extraction cycle are calculated, and the standard deviation and mean of the peak pump duration are output; The standard deviation and mean of all peak pump durations in the peak-valley period sequence of the extraction cycle are calculated, and the standard deviation and mean of the peak pump duration are output; In detail, the variation coefficient is used to calculate and process all peak pump durations and all valley pump durations in the peak-valley period sequence of the cycle, reflecting the stability of the pump-in peak period and the pump-in valley period in the time dimension of the material pump-in cycle. Subsequently, based on the reflected stability, an adjustment strategy for gas-liquid pump-in quantity can be developed to accurately improve the coordination of gas-liquid pump-in in the time dimension; The stability value of the valley pump duration and the stability value of the peak pump duration are summed up, and the single-period peak-valley pump-in stability value is output; The standard deviation of the single-period peak-valley pump-in stability value corresponding to each material pump-in cycle is calculated, and the type change recognition value is output; It can be understood that the physical meaning represented by the type change recognition value is to reveal the dispersion degree of the peak-valley fluctuation pattern in different cycles. Specifically, if the type change recognition value is smaller, it means that the stability of the interval duration between the pump-in peak period and the pump-in valley period in each material pump-in cycle is higher, and the stability of the duration corresponding to the pump-in peak period and the pump-in valley period is also higher. If the type change recognition value is larger, it means that the stability of the interval duration between the pump-in peak period and the pump-in valley period in each material pump-in cycle is lower, and the stability of the duration corresponding to the pump-in peak period and the pump-in valley period is also lower; If the type change recognition value is greater than the type change recognition threshold value, it means that the stability of the interval duration between the pump-in peak period and the pump-in valley period in each material pump-in cycle is lower, and the stability of the duration corresponding to the pump-in peak period and the pump-in valley period is also lower, which is displayed as a period change non-stable signal; If the type change identification value is less than or equal to the type change identification threshold value, it indicates that the interval duration stability between the pump-in peak period and the pump-in valley period in each material pump-in cycle is relatively high, and the duration stability of the pump-in peak period and the pump-in valley period is relatively high, and the signal is displayed as a period change stability signal; Step four: according to the change type of the identified pump-in peak period and the pump-in valley period, an oxygen input strategy is formulated, a gas flux pre-adjustment period is extracted, and a gas flux pre-adjustment amount corresponding to the gas flux pre-adjustment period is obtained, and a dynamic adjustment operation is performed on the oxygen input amount; For example, based on the period change non-stability signal, the average of the valley pump duration corresponding to each cycle peak-valley period sequence is extracted and compared in size, and the minimum average of the valley pump duration is selected as the peak pump pre-adjustment period duration; If the current is in the pump-in valley period, the current flow monitoring point of the pump-in valley period is extracted, and the peak pump pre-adjustment period duration is summed up to construct the gas flux pre-adjustment period; Similarly, the average of the peak pump duration corresponding to each cycle peak-valley period sequence is extracted and compared in size, and the minimum average of the peak pump duration is selected as the valley pump pre-adjustment period duration; If the current is in the pump-in peak period, the current flow monitoring point of the pump-in peak period is extracted, and the valley pump pre-adjustment period duration is summed up to construct the gas flux pre-adjustment period; Based on the period change stability signal, the average of the valley pump duration corresponding to each cycle peak-valley period sequence is extracted and summed up to calculate the average, and the peak pump pre-adjustment period duration is obtained; If the current is in the pump-in peak period, the current flow monitoring point of the pump-in peak period is extracted, and the peak pump pre-adjustment period duration is summed up to construct the gas flux pre-adjustment period; Similarly, the average of the valley pump duration corresponding to each cycle peak-valley period sequence is extracted and summed up to calculate the average, and the valley pump pre-adjustment period duration is obtained; If the current is in the pump-in valley period, the current flow monitoring point of the pump-in valley period is extracted, and the valley pump pre-adjustment period duration is summed up to construct the gas flux pre-adjustment period; If the current gas flux pre-adjustment period is in the pump-in peak period, the liquid material flow corresponding to each flow monitoring point before the current flow monitoring point is extracted, and a sliding window is set, and the liquid material flow of each flow monitoring point after the current flow monitoring point is obtained by using the sliding window method as the pre-adjustment liquid material flow; Similarly, if the current gas flux pre-adjustment period is in the pump-in valley period, the liquid material flow corresponding to each flow monitoring point before the current flow monitoring point is extracted, and a sliding window is set, and the liquid material flow of each flow monitoring point after the current flow monitoring point is obtained by using the sliding window method as the pre-adjustment liquid material flow; The gas-liquid pre-adjustment coefficient is obtained by extracting the synchronous trend ratio of each group of the same trend peak pump gas-liquid group and performing summation mean calculation; The gas-liquid pre-adjustment coefficient is obtained by extracting the synchronous trend ratio of each group of the same trend peak pump gas-liquid group and performing summation mean calculation; The specific scheme is as follows: in the case of uneven overall gas-liquid pump, the pump-in peak period and the pump-in valley period in the pump-in period of multiple materials are analyzed in the time dimension, the change type of the pump-in peak period and the pump-in valley period is recognized, the oxygen input strategy is formulated according to the change type of the pump-in peak period and the pump-in valley period, the gas flow pre-adjustment period is extracted, the gas flow pre-adjustment period corresponding to the gas flow adjustment amount is obtained, and the oxygen input amount is dynamically adjusted to realize high coordination between oxygen input and liquid material pump-in in the time dimension, avoid the problems of reaction violent fluctuation or incomplete reaction caused by imbalance of gas-liquid ratio, ensure the stability of the production process, and avoid waste or deficiency of oxygen by dynamically adjusting the oxygen input amount, so as to realize the optimized utilization of oxygen resources.

[0025] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A process for producing pyromellitic dianhydride using liquid-phase oxidation, characterized in that: include: Mesitylene, acetic acid, and catalyst were heated and stirred to obtain a liquid material, which was then pumped into a microchannel continuous reactor. The material pumping cycle was set, the flow rate of the liquid material pumped into the microchannel continuous reactor was obtained, and the peak and valley periods of the pumping were analyzed to screen out the peak and valley periods of the pumping. Oxygen flow rate during peak and trough periods of pumping was obtained separately, and the uniformity of liquid material flow rate during peak and trough periods was analyzed to evaluate the overall uniformity of gas-liquid pumping. If the overall gas-liquid pumping is uneven, the peak and trough periods of pumping in multiple material pumping cycles are analyzed in the time dimension to obtain peak-trough gas-liquid uniformity analysis values, and the change type of the peak and trough periods of pumping is identified based on the peak-trough gas-liquid uniformity analysis values. The peak pump gas-liquid uniformity analysis value and the valley pump gas-liquid uniformity analysis value are summed to output the peak-valley gas-liquid uniformity analysis value. If the peak-valley gas-liquid uniformity value is less than the peak-valley gas-liquid uniformity threshold, it is displayed as an overall gas-liquid non-uniform signal. Based on the identified peak and trough periods of pumping, an oxygen supply strategy is formulated, a pre-adjustment period for gas flux is extracted, and the corresponding gas flux adjustment amount is obtained for dynamic adjustment.

2. The process for producing pyromellitic dianhydride using liquid-phase oxidation according to claim 1, characterized in that: Catalysts include: It consists of polymetallic salts: iron, vanadium, zinc, manganese, zirconium, aluminum, cobalt, guanidine, as well as bromide and chloride anions.

3. The process for producing pyromellitic dianhydride using liquid-phase oxidation according to claim 2, characterized in that: Mesitylene and acetic acid are mixed at a mass ratio of 1:3 to 5, and a catalyst of 1% to 5% of the mass percentage of the raw material mesitylene is added, and the mixture is heated and stirred.

4. The process for producing pyromellitic dianhydride using liquid-phase oxidation according to claim 3, characterized in that: During heating and stirring, heat to 80℃-110℃. After the mixture is evenly dissolved in mesitylene, pump the material into the microchannel continuous reactor. At the same time, introduce oxygen into the microchannel continuous reactor, raise the temperature of the microchannel continuous reactor to 100℃-300℃, and adjust the pressure to 1-5 MPa.

5. The process for producing pyromellitic dianhydride using liquid-phase oxidation according to claim 1, characterized in that: The process for selecting peak and trough periods for pumping is as follows: The material pumping cycle is divided into several flow monitoring points. Adjacent flow monitoring points are combined into a group of adjacent monitoring points to obtain multiple groups of adjacent monitoring points. The liquid material flow rate of each flow monitoring point in the adjacent monitoring group is obtained and the difference is calculated. The ratio of the difference to the interval between adjacent flow monitoring points is calculated to obtain the unit flow rate change rate and construct the flow rate change sequence. Extract the sign of the unit flow change rate corresponding to each group of adjacent monitoring groups in the flow change sequence. Take the time period between adjacent flow monitoring points with positive signs as the pumping peak time period. If there are consecutive adjacent pumping peak time periods, merge them as the pumping peak time period. The time period between adjacent flow monitoring points with negative signs is taken as the pumping valley period. If there are consecutive adjacent pumping valley periods, they are merged and taken as the pumping valley period.

6. The process for producing pyromellitic dianhydride using liquid-phase oxidation according to claim 5, characterized in that: The uniformity analysis of oxygen flow rate and liquid material flow rate during the peak pumping period is performed as follows: The oxygen flow rate and liquid material flow rate at each flow monitoring point during the peak pumping period were obtained and substituted into the two-dimensional coordinate system to construct the peak pump oxygen flow rate change curve and the peak pump liquid material flow rate change curve. The adjacent coordinates of the peak pump oxygen flow rate change curve and the peak pump liquid flow rate change curve are combined to obtain multiple peak pump oxygen neighbor groups and peak pump liquid neighbor groups. The slopes of the coordinates in the peak pump oxygen neighbor group and peak pump liquid neighbor group with the same time stamp are calculated to obtain the peak pump oxygen trend value and peak pump liquid trend value. If the peak pump oxygen trend value and the peak pump liquid trend value have the same sign, they are regarded as peak pump gas-liquid groups with the same trend. The ratio of the number of peak pump gas-liquid groups with the same trend to the total number of peak pump gas-liquid analysis groups is calculated to obtain the peak pump gas-liquid synchronous change value. Within the same trend peak pump gas-liquid group, the ratio of the peak pump oxygen trend value and the peak pump liquid trend value is calculated, and the peak pump gas-liquid synchronous trend ratio is output. The coefficient of variation algorithm is used to calculate the peak pump gas-liquid synchronization trend ratio in all peak pump gas-liquid groups with the same trend, and the output is the peak pump gas-liquid synchronization degree value.

7. The process for producing pyromellitic dianhydride using liquid-phase oxidation according to claim 6, characterized in that: The process for assessing the overall uniformity of gas-liquid pumping is as follows: Substitute the liquid material flow rate during the off-peak period and the oxygen flow rate in the off-peak pump oxygen flow rate sequence into a two-dimensional coordinate system to construct the off-peak pump liquid material flow rate change curve and the off-peak pump oxygen flow rate change curve. The adjacent coordinates of the off-peak pump liquid flow rate change curve and the off-peak pump oxygen flow rate change curve are combined to obtain multiple off-peak pump oxygen neighbor groups and off-peak pump liquid neighbor groups. The slopes of the coordinates in the off-peak pump oxygen neighbor groups and off-peak pump liquid neighbor groups with the same time stamp are calculated to obtain the off-peak pump oxygen trend value and off-peak pump liquid trend value. If the off-peak pump oxygen trend value and off-peak pump liquid trend value have the same sign, they are regarded as the same trend off-peak pump gas-liquid group. The ratio of the number of the same trend off-peak pump gas-liquid group to the total number of off-peak pump gas-liquid analysis groups is calculated to obtain the off-peak pump gas-liquid synchronous change value. Within the same trend valley pump gas-liquid group, the ratio of the valley pump oxygen trend value and the valley pump liquid trend value is calculated to output the valley pump gas-liquid synchronization trend ratio. The valley pump gas-liquid synchronization trend ratios corresponding to all same trend valley pump gas-liquid groups are calculated and processed to output the valley pump gas-liquid synchronization degree value. The ratio of the synchronous change value of gas and liquid in the off-peak pump to the synchronous degree value of gas and liquid in the off-peak pump is calculated to output the gas-liquid uniformity analysis value of the off-peak pump.

8. The process for producing pyromellitic dianhydride using liquid-phase oxidation according to claim 1, characterized in that: The process for identifying the variation types during peak and trough periods of pumping inflow is as follows: The peak and trough periods of each material pumping cycle are sorted according to time series to obtain the cycle peak and trough period sequence; Within each periodic peak-valley time sequence, the durations corresponding to the peak pumping time and the trough pumping time are obtained as the peak pumping duration and the trough pumping duration, respectively. The standard deviation and mean are calculated, and the standard deviation of the peak pumping duration, the mean of the peak pumping duration, the standard deviation of the trough pumping duration, and the mean of the trough pumping duration are output. The standard deviation and mean of the off-peak pump duration are processed using the coefficient of variation algorithm to obtain a stable value for the off-peak pump duration. The standard deviation and mean of the peak pump duration are also processed using the coefficient of variation algorithm to obtain a stable value for the peak pump duration. The stable values ​​for the off-peak and peak pump durations are summed to obtain a stable value for single-period peak-valley pumping. The standard deviation of the stable values ​​for single-period peak-valley pumping for each material pumping cycle is calculated to obtain a type change identification value. If the type change identification value is greater than the type change identification threshold, it is displayed as a time-period change unstable signal; if the type change identification value is less than or equal to the type change identification threshold, it is displayed as a time-period change stable signal.

9. The process for producing pyromellitic dianhydride using liquid-phase oxidation according to claim 8, characterized in that: The oxygen inlet strategy was developed, and the pre-adjustment period for gas flux was determined. The process is as follows: Based on the time-varying non-stationary signal, the average valley pump duration corresponding to each periodic peak-valley time sequence is extracted, and the minimum average valley pump duration is selected as the peak pump pre-adjustment period duration. If the current period is the pumping valley period, the current flow monitoring point of the pumping valley period is extracted and summed with the peak pump pre-adjustment period duration to construct the gas flux pre-adjustment period. If the current period is the peak pumping period, the current flow monitoring point of the peak pumping period is extracted and summed with the duration of the valley pump pre-adjustment period to construct the gas flux pre-adjustment period. Based on the stable signal of time-varying changes, the average valley pump duration and the average valley pump duration corresponding to the peak-valley time-segment of each period are extracted respectively, and the summation average is calculated to obtain the peak pump pre-adjustment period duration and the valley pump pre-adjustment period duration. If the current period is the peak pumping period, the current flow monitoring point of the peak pumping period is extracted and summed with the peak pumping pre-adjustment period duration to construct the gas flux pre-adjustment period. If the current period is a pumping valley period, the current flow monitoring point of the pumping valley period is extracted and summed with the valley pump pre-adjustment period duration to construct the gas flux pre-adjustment period.

10. The process for producing pyromellitic dianhydride using liquid-phase oxidation according to claim 9, characterized in that: The process for obtaining the gas flow adjustment amount corresponding to the gas flow pre-adjustment period is as follows: If the current gas flow pre-adjustment period is within the pumping peak period, extract the liquid material flow rate corresponding to each flow monitoring point before the current flow monitoring point, and set a sliding window to obtain the liquid material flow rate of each flow monitoring point after the current flow monitoring point using the sliding window method, as the pre-adjustment liquid material flow rate; If the current gas flux pre-adjustment period is within the pumping trough period, extract the liquid material flow rate corresponding to each flow monitoring point before the current flow monitoring point, and set a sliding window to obtain the liquid material flow rate of each flow monitoring point after the current flow monitoring point using the sliding window method, as the pre-adjustment liquid material flow rate; Extract the peak pump gas-liquid synchronization trend ratio corresponding to each group of peak pump gas-liquid groups with the same trend, and calculate the summation mean to output the gas-liquid pre-adjustment coefficient; The pre-adjusted liquid flow rate is multiplied by the gas-liquid pre-adjustment coefficient to output the gas flow adjustment amount.

Images