A method for online sampling and control of reaction solution of gluconic acid derivatives under complex conditions

Abstract

This invention belongs to the field of gluconic acid derivative production and process control technology, and relates to an online sampling control method for gluconic acid derivative reaction solutions under complex environments. This invention acquires in-situ rheological signals of the reaction solution, obtains the viscosity change rate, compares it with gradient threshold intervals to obtain grade proportion coefficients, and calculates the target pulse frequency and target sampling cycle duration based on the control benchmark of the current sampling cycle. This generates a pulsed sampling drive signal to control the actuator for intermittent sampling. Simultaneously, it extracts the shear stress decay rate and thixotropic recovery time, calculates a comprehensive adjustment coefficient, and performs differentiated corrections to the sampling parameters, forming a closed-loop control. This invention solves the problems of traditional fixed-frequency sampling in complex rheological environments being susceptible to drastic viscosity fluctuations and unstable thixotropic recovery, leading to poor sampling representativeness and control lag. It achieves dynamic adaptive adjustment of sampling frequency and duration, improving the accuracy and stability of online sampling.

Description

Technical Field

[0001] This invention belongs to the field of gluconic acid derivative production and process control technology, and relates to an online sampling and control method for gluconic acid derivative reaction solution under complex environments. Background Technology

[0002] Gluconate derivatives, such as sodium gluconate, are widely used in chemical auxiliaries, bio-fermentation, and fine chemicals. Their production typically requires online sampling of the reaction system under continuous reaction conditions to obtain information on component changes during the reaction. Because the sodium gluconate reaction solution is susceptible to changes in temperature, material concentration, and salt precipitation during the reaction, the flow state of the reaction solution changes with the reaction progress, thus affecting the fluid transport stability during online sampling in complex environments.

[0003] Most existing online sampling methods employ a fixed-frequency drive structure or a constant-period extraction mode, meaning the sampling device is controlled to perform periodic extraction operations according to a preset cycle. However, in actual reaction processes, the flow resistance of the reaction liquid changes with the flow state. When the system's adhesion increases or the local flow state changes, the matching degree between the fixed sampling cycle and the current flow state of the reaction liquid decreases, easily leading to fluctuations in sample delivery within the sampling channel, thus affecting the continuity of online sampling control of the reaction liquid in complex environments.

[0004] Furthermore, while some existing control methods can be adjusted based on fluid state parameters, most rely on a single flow index to execute fixed threshold judgments, lacking a continuous adjustment mechanism to address changes in flow trends. When the sodium gluconate reaction solution experiences viscosity changes or a recovery in flow regime within a short period, the compatibility between the sampling control parameters and the current reaction solution state decreases, thus affecting the dynamic adjustment effect of online sampling control of the reaction solution under complex environments.

[0005] Furthermore, during continuous sampling, the flow regime recovery characteristics of the sodium gluconate reaction solution differ at different reaction stages after being subjected to extraction disturbances. Existing online sampling control methods rarely incorporate the recovery characteristics of the reaction solution after disturbances to adjust subsequent sampling parameters, resulting in low continuous adaptability of control parameters between different sampling cycles, thus affecting the stability of online sampling control of the reaction solution in complex environments. Summary of the Invention

[0006] In view of this, in order to solve the problems mentioned in the background art, an online sampling and control method for gluconic acid derivative reaction solution under complex environment is proposed.

[0007] The objective of this invention can be achieved through the following technical solution: an online sampling control method for reaction solutions of gluconic acid derivatives under complex environments, comprising: real-time acquisition of in-situ rheological signals of the reaction solution and obtaining the viscosity change rate, inputting it into multiple gradient threshold intervals for comparison to determine the grade number, obtaining the grade proportion coefficient based on the ratio of the grade number to the total number of gradient threshold intervals, and calculating the target pulse frequency and the target sampling cycle duration in combination with the control benchmark of the current sampling cycle.

[0008] Based on the target pulse frequency and the duration of a single sampling trigger, a pulsed sampling drive signal is generated to control the sampling actuator to perform intermittent sampling according to the duty cycle.

[0009] The in-situ rheological signal of the current sampling period is acquired and the actual flow characteristics parameters are extracted. The actual flow characteristics parameters include shear stress attenuation rate and thixotropic recovery time.

[0010] The relative deviation rate of the actual flow characteristic parameters relative to the corresponding parameters of the previous sampling period is calculated, and the average value is used to obtain the comprehensive adjustment coefficient. The comprehensive adjustment coefficient is used to perform differential correction on the target pulse frequency and the target sampling period duration to generate the final sampling control command, which serves as the control reference for the next sampling period.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention obtains the viscosity change rate by collecting in-situ rheological signals, inputs multiple gradient threshold intervals to determine the level number, and calculates the target pulse frequency and target sampling cycle duration in combination with the current control benchmark. This solves the problem of sample delivery fluctuation caused by the decrease in the matching degree between the fixed sampling cycle and the flow state of the reaction liquid. It realizes the dynamic adjustment of the sampling pulse frequency and cycle duration according to the viscosity change rate, effectively suppresses the sample delivery fluctuation in the sampling channel, and ensures the continuous stability of online sampling in complex environments.

[0012] (2) This invention calculates the target sampling parameters by using the grade ratio coefficient of viscosity change rate, and generates a pulsed drive signal based on the target pulse frequency and the duration of a single sampling trigger to control the sampling mechanism to perform intermittent sampling according to the duty cycle. This solves the problem that a single flow index with a fixed threshold cannot track the trend of reaction liquid flow changes. It realizes continuous adjustment of sampling parameters with viscosity changes, and improves the adjustment effect by combining duty cycle intermittent sampling to enhance the matching accuracy of action and flow recovery characteristics.

[0013] (3) This invention extracts the shear stress attenuation rate and thixotropic recovery time as actual flow state characteristic parameters, calculates the relative deviation rate to obtain the comprehensive adjustment coefficient, and performs differential correction on the sampling parameters. This solves the problem of low continuous adaptability caused by the lack of combined disturbance recovery characteristics to adjust the sampling parameters, realizes adaptive adjustment based on flow state recovery characteristics, enhances the continuous adaptability of control parameters during different sampling cycles, and ensures the long-term stability of online sampling control of reaction liquid under complex environments. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a flowchart of an online sampling and control method for gluconic acid derivative reaction solution under complex conditions according to the present invention;

[0016] Figure 2 This is a flowchart of the method for acquiring pulsed sampling drive signals in this invention;

[0017] Figure 3 This is a flowchart of the method for extracting actual flow characteristic parameters in this invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] The following description, in conjunction with the accompanying drawings, details the specific scheme of the online sampling and control method for gluconic acid derivative reaction solutions under complex environments provided by the present invention.

[0021] Please see Figure 1As shown, the implementation of the present invention includes S1 to S4: S1, real-time acquisition of in-situ rheological signals of the reaction liquid and acquisition of viscosity change rate, inputting it into multiple gradient threshold intervals for comparison to determine the grade number, obtaining the grade proportion coefficient based on the ratio of the grade number to the total number of gradient threshold intervals, and calculating the target pulse frequency and target sampling cycle duration in combination with the control benchmark of the current sampling cycle.

[0022] Typically, gluconic acid derivative reaction solutions exhibit nonlinear rheological responses due to complex temperature, pressure, and concentration fluctuations in their internal polymer chains or colloidal structures. Directly sampling at fixed frequencies and durations can easily lead to sample volume distortion or probe blockage. Therefore, in-situ rheological signal analysis is necessary to obtain the viscosity change rate, which reflects the trend of fluid state changes, and to map it into executable control parameters.

[0023] In one specific embodiment, the probe of the rheological sensor is first installed in situ inside the reaction vessel containing the reaction liquid. Low-frequency oscillation shearing is applied with a micron-level amplitude through the excitation element inside the probe. The damping response electrical signal sensed by the probe is collected synchronously and used as the in-situ rheological signal. Data is captured with a signal acquisition cycle of 1 second.

[0024] The continuous signal sequence is differentially processed to calculate the difference between signal values ​​at adjacent time nodes, which is then divided by the corresponding time interval. The quotient is multiplied by a preset rheological conversion coefficient to output the viscosity change rate, which reflects the transient rheological characteristics of the fluid. The rheological conversion coefficient is a linear proportionality constant between the electrical signal change rate and the fluid viscosity change rate, as specified in the factory calibration of the rheological sensor.

[0025] In order to convert continuously changing rate values ​​into discrete control levels, multiple viscosity change rate data points generated within multiple consecutive acquisition cycles, such as 10 acquisition cycles, are acquired. The maximum and minimum values ​​are extracted and the difference is calculated to obtain the rate range value.

[0026] Then, the total number of viscosity change rates within the time window is counted, and the rate range value is divided by the total number to obtain the uniformly divided interval span value. Using the minimum value as the initial boundary, the interval span values ​​are accumulated sequentially on the numerical axis to generate multiple gradient threshold intervals arranged in numerical order. Each gradient threshold interval is assigned an increasing level number according to the generation order.

[0027] Before calculating the target control parameters, it is necessary to establish the control baseline for the current sampling period. It is also necessary to determine whether the current sampling period is the first sampling period.

[0028] If so, the preset initial pulse frequency, such as 0.02Hz (i.e., a single pulse period of 50 seconds), and the initial sampling duration, such as 300 seconds, are used as the reference frequency and reference duration of the control reference, respectively. If not, the final sampling control command of the previous sampling period is extracted, and the corrected target pulse frequency and the corrected target sampling period duration are used as the reference frequency and reference duration of the current control reference to achieve closed-loop iteration of the control parameters.

[0029] Based on the aforementioned reference frequency, reference duration, and dynamically constructed gradient threshold intervals, the viscosity change rate calculated in real time from the latest signal acquisition cycle is used as the current value, and sequential comparisons are performed sequentially, starting from the first gradient threshold interval with the smallest value and proceeding backward.

[0030] Each step checks whether the current viscosity change rate is greater than or equal to the lower boundary of the current gradient threshold interval but less than its upper boundary. If the result is negative, the process continues to the next gradient threshold interval. If the result is positive, the current interval is locked and designated as the target gradient threshold interval, terminating the comparison traversal. The level number corresponding to the target gradient threshold interval is extracted, and the ratio of this level number to the total number of gradient threshold intervals is calculated to obtain the level proportion coefficient.

[0031] The control baseline for the current sampling cycle is analyzed, and the baseline frequency and baseline duration are extracted. Since a higher viscosity change rate indicates more drastic fluctuations in the internal structure of the reaction liquid, the sampling frequency needs to be reduced and the settling recovery time extended to avoid excessive sampling exacerbating fluid damage. Therefore, the target pulse frequency is obtained by multiplying the baseline frequency by 1 and the difference between it and the grade proportion coefficient, and then adding the preset minimum fundamental frequency, such as 0.01Hz. The target sampling cycle duration is obtained by multiplying the baseline duration by 1 and the sum of the grade proportion coefficient.

[0032] S2. Generate a pulsed sampling drive signal based on the target pulse frequency and the duration of a single sampling trigger, and control the sampling actuator to perform intermittent sampling according to the duty cycle.

[0033] In the synthesis of gluconic acid derivatives, as the molecular weight increases or a spatial network structure forms, the reaction solution often exhibits non-Newtonian fluid characteristics such as pseudoplasticity or thixotropy. If continuous mechanical suction is used, a high shear rate zone will form at the sampling tube inlet, leading to local polymer chain breakage, heat accumulation, and consequently, local concentration gradients and product quality distortion. Simultaneously, the opening and closing of pneumatic or electromagnetic sampling valves inherently involve mechanical delays and inertial impacts, making it impossible to achieve theoretically instantaneous on / off states. Therefore, by converting the continuous control target into a discrete pulse drive signal and utilizing the duty cycle to control the effective action time window of a single trigger, the sampling actuator can achieve micro-perturbation intermittent sampling under alternating high and low duty cycles.

[0034] In one specific embodiment, please refer to Figure 2 As shown, the method for obtaining the pulsed sampling drive signal is as follows: S201, the reciprocal of the target pulse frequency is used as the total time of a single pulse cycle, and a preset single sampling trigger duration is obtained. The single sampling trigger duration is obtained by pre-testing and calibrating the physical action time required for the sampling actuator to extract a single sampling volume under the rated differential pressure. The single sampling trigger duration is set to be less than the total time of a single pulse cycle, so as to retain a sufficient low-level interval as a fluid relaxation gap and avoid continuous shearing from causing cumulative damage to the microstructure of the reaction liquid.

[0035] S202. Calculate the ratio between the duration of a single sampling trigger and the total time of a single pulse cycle, and use the ratio as the pulse duty cycle.

[0036] S203. Using the time span corresponding to the pulse duty cycle as the high-level interval, and the remaining time span after deducting the high-level interval from the total time of a single pulse cycle as the low-level interval, the high-level interval and the low-level interval are alternately spliced ​​on the time axis to generate a pulsed sampling drive signal. This signal is a set of periodic square wave pulse sequences. The high-level interval represents the effective window of the trigger command of the sampling actuator, and the low-level interval represents the mechanism reset and reaction liquid static recovery window.

[0037] Furthermore, the generated pulsed sampling drive signal is output to a sampling actuator, such as an electromagnetic sampling valve. The sampling actuator is in a triggered state during the high-level range of the pulsed sampling drive signal, meaning the control circuit is on, the electromagnetic valve coil is energized, and the valve core opens, allowing the reaction liquid to be drawn into the sampling pipeline under the pressure difference between the inside and outside of the pipeline to complete a single micro-sample acquisition. During the low-level range, it is in an off state, meaning the control circuit is off, the electromagnetic valve coil is de-energized, and the valve core closes under the action of the return spring, physically cutting off the sampling flow channel and keeping the reaction liquid stationary within the reaction system to allow for stress relaxation of the internal structure.

[0038] Intermittent sampling is performed through the periodic alternation of high-level triggering and low-level disconnection. Through the above operation, a pulse sampling action is physically completed. This suction action, as an external excitation, changes the local spatial structure of the fluid around the sensor probe and induces transient flow regime changes. During subsequent detection, the rheological sensor captures in-situ rheological signals that record the complete dynamic response curve from shear failure to stress relaxation, providing a data basis for the feature parameter extraction in step S3.

[0039] S3. Obtain the in-situ rheological signal of the current sampling period and extract the current actual flow characteristic parameters, including the shear stress attenuation rate and thixotropic recovery time.

[0040] Considering the instantaneous opening and closing of the sampling actuator, which is equivalent to applying a step-shear disturbance to the reaction liquid, for thixotropic gluconic acid derivative reaction liquids, this disturbance will instantly destroy the internal spatial network structure of the fluid, causing a sharp drop in apparent viscosity or shear stress in a very short time. After the shear force is removed, it undergoes a recovery process of gradual reconstruction of the internal network and gradual recovery of the rheological signal. If the decay is too fast or the recovery is too slow, it indicates that the current pulse sampling intensity exceeds the self-healing limit of the fluid. Therefore, it is necessary to extract quantitative indicators reflecting the rate of structural damage and reconstruction from the dynamic rheological curve.

[0041] Therefore, by locating the peak signal point and the lowest reference point after the corresponding pulse sampling action ends on the in-situ rheological signal time series of the current sampling period, the falling segment and the rising segment of the signal are extracted respectively. The falling segment is linearly fitted to extract the slope as the shear stress attenuation rate, and the rising segment is calculated to use the time difference as the thixotropic recovery time.

[0042] In one specific embodiment, please refer to Figure 3 As shown, the method for extracting the actual flow characteristic parameters is as follows: S301, in the in-situ rheological signals collected within the current sampling period, the peak signal point is located by the sliding window maximum value detection algorithm. The peak signal point corresponds to the maximum response time of the instantaneous shear disturbance caused by the sampling action to the reaction liquid.

[0043] The falling segment of the signal, from the peak signal point to the lowest reference point, is extracted. This falling segment reflects the process of stress relief in the internal structure of the reaction liquid after the sampling disturbance stops, gradually removing stress from a state of stress failure. Least-squares linear fitting is performed on the falling segment signal, and the slope of the fitted line is used as the shear stress attenuation rate.

[0044] The shear stress decay rate characterizes the speed at which the stress relaxes in the gel network or molecular association structure inside the reaction liquid after sampling disturbance. The larger the absolute value of the slope, the faster the stress is released after the reaction liquid structure is destroyed, and the more the system is biased towards a fluid state; the smaller the absolute value of the slope, the slower the stress is released, and the more the internal structure of the system tends to be maintained.

[0045] S302. In the in-situ rheological signal, the time corresponding to the lowest reference point is determined as the recovery starting point of thixotropic recovery, and the rising segment signal from the recovery starting point is extracted. This rising segment signal corresponds to the process of the reaction liquid undergoing structural reconstruction and gradual viscosity recovery from the maximum damage state.

[0046] The method for determining the minimum reference point is as follows: a signal recovery window of a preset length is extracted from the peak signal point. The preset length of the signal recovery window is set according to the typical structural recovery time scale of the reaction liquid in a static state. The minimum value point of the signal is found within the signal recovery window and is taken as the minimum reference point. This point represents the moment when the sampling disturbance causes the maximum damage to the reaction liquid structure and the fluid resistance is the lowest. If no minimum value point is detected within the signal recovery window, it indicates that the reaction liquid structure immediately enters the recovery state after the disturbance stops. In this case, the signal value corresponding to the end time node of the signal recovery window is taken as the minimum reference point.

[0047] S303. Calculate the target time when the signal value of the rising segment signal reaches the average value of the baseline signal collected before triggering in the current sampling period. The method for obtaining the average value of the baseline signal is as follows: extract the in-situ rheological signal collected before the triggering of the sampling actuator in the current sampling period, and calculate its signal average as the average value of the baseline signal; if the sampling actuator is triggered at the beginning of the current sampling period and there is no signal before triggering, then the average value of the baseline signal calculated in the previous sampling period is used as the average value of the baseline signal in the current sampling; if it is the first sampling period, then the preset system initial calibration average value is used as the average value of the baseline signal.

[0048] The time difference between the target time and the recovery start point is taken as the thixotropic recovery time. This thixotropic recovery time characterizes the time period required for the internal structure of the reaction liquid to recover from the maximum damaged state to the normal reference state. The shorter the recovery time, the stronger the thixotropic reversibility of the reaction liquid and the better the structural reconstruction ability; the longer the recovery time, the more difficult it is to recover the damage to the structure of the reaction liquid caused by the sampling disturbance.

[0049] Using the shear stress attenuation rate and thixotropic recovery time as the actual flow characteristics parameters, this set of parameters characterizes the flow response of the reaction liquid under the current sampling strategy from both the velocity dimension of structural failure and the time dimension of structural recovery.

[0050] S4. Calculate the relative deviation rate of the actual flow characteristic parameters relative to the corresponding parameters of the previous sampling cycle, and obtain the comprehensive adjustment coefficient by averaging the values. Use the comprehensive adjustment coefficient to perform differential correction on the target pulse frequency and the target sampling cycle duration, and generate the final sampling control command as the control reference for the next sampling cycle.

[0051] Since the shear stress attenuation rate and thixotropic recovery time represent two independent physical dimensions of flow state disruption and structural reconstruction, a single parameter cannot fully reflect the comprehensive impact of flow state fluctuations on the sampling strategy. Furthermore, it is necessary to balance the constraints of sampling interference and flow field recovery in time sequence. Therefore, the multidimensional characteristic parameters are normalized into a unified comprehensive adjustment coefficient, and differential compensations with opposite directions are applied to the target pulse frequency and the target sampling period duration to maintain the dynamic balance of the control system.

[0052] In one specific embodiment, firstly, the shear stress attenuation rate and thixotropic recovery time extracted from the previous sampling cycle are used as the center values ​​of the corresponding parameters for the current sampling cycle; the center value represents the measured benchmark of the influence of the sampling action of the previous cycle on the flow state of the reaction liquid, and serves as a reference for judging the direction of change of the flow state characteristics in the current cycle.

[0053] Calculate the difference between the shear stress attenuation rate of the current sampling period and its corresponding center value, and divide the difference by its corresponding center value to obtain the first relative deviation rate; calculate the difference between the thixotropic recovery time of the current sampling period and its corresponding center value, and divide the difference by its corresponding center value to obtain the second relative deviation rate.

[0054] The average of the first relative deviation rate and the second relative deviation rate is used as the comprehensive adjustment coefficient, which represents the overall trend and magnitude of the change in the stability of the reaction liquid flow state relative to the previous period within the current sampling period. If the average value is greater than or equal to 1 or less than or equal to -1, it indicates that the instantaneous fluctuation amplitude of the characteristic parameter has exceeded the normal gradual adjustment range. To prevent the control parameter from overshooting due to extreme deviations, the amplitude is truncated to 0.2 or -0.2 respectively, so that the value of the comprehensive adjustment coefficient is kept within the range of greater than -0.2 and less than 0.2, thus preventing overshoot oscillations in the control parameter.

[0055] The target pulse frequency for the next sampling period is obtained by multiplying the target pulse frequency of the current sampling period by 1 and the difference between the target pulse frequency and the comprehensive adjustment coefficient; the target sampling period duration for the next sampling period is obtained by multiplying the target sampling period duration of the current sampling period by 1 and the sum of the comprehensive adjustment coefficient.

[0056] This correction logic achieves bidirectional regulation opposite to the trend of flow deterioration: when the comprehensive regulation coefficient is positive, it indicates that the structural damage of the reaction liquid is aggravated or the recovery ability is weakened. The system automatically reduces the target pulse frequency and extends the target sampling cycle time, and reduces the sampling density to reduce shear disturbance, providing sufficient time for structural reconstruction and stress relaxation for the reaction liquid; when the comprehensive regulation coefficient is negative, it indicates that the flow state tends to be stable and the self-repair ability is strong. The system automatically increases the target pulse frequency and shortens the target sampling cycle time, and increases the sampling density to meet the monitoring requirements.

[0057] Based on the modified target pulse frequency and modified target sampling period duration, a final sampling control command is generated. This command serves as the control reference for the next sampling period and is stored in the controller memory for recall in the next period, thereby achieving closed-loop adaptive iterative optimization of the sampling parameters.

[0058] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0059] Those skilled in the art will recognize that the algorithmic steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0060] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0061] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0062] Finally, 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 online sampling and control of reaction solutions for gluconic acid derivatives under complex environments, characterized in that, include: The in-situ rheological signal of the reaction liquid is acquired in real time and the viscosity change rate is obtained. The signal is then input into multiple gradient threshold intervals for comparison to determine the grade number. The grade proportion coefficient is obtained based on the ratio of the grade number to the total number of gradient threshold intervals. The target pulse frequency and target sampling cycle duration are calculated in combination with the control benchmark of the current sampling cycle. Based on the target pulse frequency and the duration of a single sampling trigger, a pulsed sampling drive signal is generated to control the sampling actuator to perform intermittent sampling according to the duty cycle; The in-situ rheological signal of the current sampling period is acquired and the actual flow characteristic parameters are extracted, including the shear stress attenuation rate and thixotropic recovery time. The relative deviation rate of the actual flow characteristic parameters relative to the corresponding parameters of the previous sampling period is calculated, and the average value is used to obtain the comprehensive adjustment coefficient. The comprehensive adjustment coefficient is used to perform differential correction on the target pulse frequency and the target sampling period duration to generate the final sampling control command, which serves as the control reference for the next sampling period.

2. The method for online sampling and control of reaction solution of gluconic acid derivative under complex environment as described in claim 1, characterized in that, The method for obtaining the viscosity change rate is as follows: In-situ rheological signals of the reaction solution are acquired in real time, and the signals contain a continuous signal sequence within a preset signal acquisition period; A continuous signal sequence is differentially processed to calculate the quotient of the difference between signal values ​​at adjacent time points and the corresponding time interval. The quotient is then multiplied by a preset rheological conversion coefficient to output the viscosity change rate.

3. The method for online sampling and control of reaction solution of gluconic acid derivative under complex environment as described in claim 1, characterized in that, The method for obtaining the gradient threshold interval is as follows: The viscosity change rate generated within multiple consecutive signal acquisition cycles is obtained, and the maximum and minimum values ​​are extracted and the difference is calculated to obtain the rate range value. The total number of viscosity change rates is counted, and the range of rates is divided by the total number to obtain the interval span value. Using the minimum value as the initial boundary, the values ​​are accumulated sequentially on the numerical axis according to the interval span to generate multiple gradient threshold intervals arranged in numerical order. Each gradient threshold interval is then assigned an incrementally increasing level number according to the generation order.

4. The method for online sampling and control of reaction solution of gluconic acid derivative under complex environment as described in claim 1, characterized in that, The method for obtaining the control benchmark for the current sampling period is as follows: Determine whether the current sampling period is the first sampling period; If so, the preset initial pulse frequency and initial sampling duration will be used as the reference frequency and reference duration of the control reference, respectively. If not, extract the corrected target pulse frequency and corrected target sampling period duration from the final sampling control command of the previous sampling period, and use them as the reference frequency and reference duration for the control reference.

5. The method for online sampling and control of reaction solution of gluconic acid derivative under complex environment as described in claim 4, characterized in that, The method for obtaining the target pulse frequency and the target sampling period duration is as follows: The viscosity change rate is sequentially input into multiple gradient threshold intervals arranged in numerical order; Perform sequential comparisons on multiple gradient threshold intervals, and determine whether the viscosity change rate is within the numerical boundary of the current gradient threshold interval until the target gradient threshold interval where the viscosity change rate is located is determined. Extract the level number corresponding to the target gradient threshold interval, calculate the ratio of the level number to the total number of gradient threshold intervals, and obtain the level proportion coefficient. The control reference for the current sampling period includes the reference frequency and reference duration. The target pulse frequency is obtained by multiplying the base frequency by 1 and the difference between the level ratio coefficient and the preset minimum base frequency. Multiply the baseline duration by 1 and sum it with the grade proportion coefficient to obtain the target sampling period duration.

6. The method for online sampling and control of reaction solution of gluconic acid derivative under complex environment as described in claim 1, characterized in that, The method for acquiring the pulsed sampling drive signal is as follows: The total time of a single pulse cycle is determined based on the target pulse frequency, and a preset single sampling trigger duration is obtained, wherein the single sampling trigger duration is less than the total time of a single pulse cycle. Calculate the ratio between the duration of a single sampling trigger and the total time of a single pulse cycle, and use this ratio as the pulse duty cycle; The high-level interval is defined by the time span corresponding to the pulse duty cycle, and the low-level interval is defined by the remaining time span after deducting the high-level interval from the total time of a single pulse cycle. The high-level interval and the low-level interval are alternately spliced ​​on the time axis to generate a pulse-type sampling drive signal.

7. The method for online sampling and control of reaction solution of gluconic acid derivative under complex environment as described in claim 6, characterized in that, Controlling the sampling actuator to perform intermittent sampling according to the duty cycle specifically includes: A pulsed sampling drive signal is output to a sampling execution mechanism. The sampling execution mechanism is in a triggered state during the high-level range of the pulsed sampling drive signal and in a disconnected state during the low-level range, thus performing intermittent sampling.

8. The method for online sampling and control of reaction solution of gluconic acid derivative under complex environment as described in claim 1, characterized in that, The method for extracting the actual flow regime characteristic parameters is as follows: In the in-situ rheological signals collected during the current sampling period, the peak signal point is located, and the falling segment signal from the peak signal point to the lowest reference point is extracted. The falling segment signal is linearly fitted, and the slope of the fitted line is used as the shear stress attenuation rate. In the in-situ rheological signal, the time corresponding to the lowest reference point is determined as the recovery start point of thixotropic recovery, and the rising segment signal from the recovery start point is extracted. Calculate the target time when the signal value of the rising segment signal reaches the average value of the baseline signal collected before triggering in the current sampling period, and use the time difference between the target time and the recovery start point as the thixotropic recovery time. Shear stress attenuation rate and thixotropic recovery time are used as actual flow characteristic parameters.

9. The method for online sampling and control of reaction solution of gluconic acid derivative under complex environment as described in claim 8, characterized in that, The method for determining the lowest reference point is as follows: Starting from the peak signal point, a signal recovery window of a preset length is extracted. Within the signal recovery window, the minimum value point of the signal is found, and this minimum value point is used as the lowest reference point. If no minimum point is detected within the signal recovery window, the signal value corresponding to the end time node of the signal recovery window is taken as the lowest reference point.

10. The method for online sampling and control of reaction solution of gluconic acid derivative under complex environment as described in claim 1, characterized in that, Generating the final sampling control command as the control reference for the next sampling cycle specifically includes: The shear stress attenuation rate and thixotropic recovery time extracted in the previous sampling period are used as the center values ​​of the corresponding parameters in the current sampling period. Calculate the difference between the shear stress attenuation rate of the current sampling period and its corresponding center value, and divide the difference by its corresponding center value to obtain the first relative deviation rate; Calculate the difference between the thixotropic recovery time of the current sampling period and its corresponding center value, and divide the difference by its corresponding center value to obtain the second relative deviation rate; The average of the first relative deviation rate and the second relative deviation rate is used as the comprehensive adjustment coefficient; Multiply the target pulse frequency of the current sampling period by 1 and the difference between the target pulse frequency and the comprehensive adjustment coefficient, and multiply the target sampling period duration of the current sampling period by 1 and the sum of the comprehensive adjustment coefficient to obtain the corrected target pulse frequency and the corrected target sampling period duration for the next sampling period. Based on the corrected target pulse frequency and the corrected target sampling period duration, the final sampling control command is generated.

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