A method and system for program collaborative control of an intelligent extraction unit of flower raw materials

Abstract

The application relates to the field of intelligent extraction of flower raw materials, and discloses a kind of intelligent extraction unit program collaborative control method and system of flower raw materials, the method establishes steady state under the closed-loop control of steam and exhaust proportion regulating valve, calculates and latches average feedforward reference opening degree;When the detection period is reached, open the condenser cooling water valve in advance, open the exhaust valve after a delay to execute pressure reduction;After closing the exhaust valve, the steam closed loop is cut off, the feedforward opening degree is maintained, and the envelope area during the temperature drop to the target temperature is obtained to generate a thermal step recovery characteristic value;Calculate the gradient difference of adjacent period characteristic values, and when it continuously meets the zero convergence threshold, close the steam valve and discharge the liquid.The application introduces a physical decompression extraction thermodynamic characteristic index, converts the gradual change of material concentration into a control parameter, realizes automatic determination of the extraction endpoint without online chemical detection instruments, improves the stability of equipment operation and reduces the cost.

Description

Technical Field

[0001] This invention relates to the field of intelligent extraction of floral raw materials, specifically to a method and system for collaborative control of intelligent extraction units for floral raw materials. Background Technology

[0002] The industrial extraction process of floral raw materials mainly relies on heat source heating and solvent mass transfer to transfer the effective components inside the plant into the liquid medium. Accurately determining the leaching endpoint and maintaining the dynamic thermal balance of the system throughout the entire unit's operation cycle are fundamental to controlling the final product quality and reducing process energy consumption. As the extraction time increases, the rate at which the material releases effective components gradually decreases until saturation. At this point, continued heating not only fails to increase the yield but also wastes energy and may cause degradation of some heat-sensitive components.

[0003] Existing extraction units mostly use a fixed-time cutoff control method for endpoint determination. However, due to differences in moisture content and tissue structure among different batches and origins of floral raw materials, the fixed-time control logic cannot adapt to the actual extraction progress. Some units have installed online chemical composition analyzers on the circulation pipeline for concentration monitoring. However, in actual production, floral extracts typically contain polysaccharides, resins, and other viscous substances, as well as fine suspended particles. These substances easily adhere to the probe surface of the detection instruments, leading to distorted measurement data or sensor blockage. These precision instruments require frequent manual cleaning and calibration, increasing the cost of equipment purchase and daily maintenance.

[0004] Furthermore, to break down the concentration-laden layer on the material surface and accelerate mass transfer, the control system typically performs intermittent venting and depressurization operations during the extraction stage to generate physical disturbances. Existing venting control logic usually directly drives the vent valve to open at a set venting time, but this control method does not consider the response hysteresis of the condensation system. From receiving the water valve opening signal and the cooling water filling the pipes, to the establishment of a pre-cooling temperature gradient on the metal wall of the heat exchange tube bundle, the condenser needs to undergo a period of heat conduction. Opening the vent valve directly before the condenser's heat exchange capacity is ready means that the large amount of secondary steam generated by the instantaneous flash evaporation of the material inside the tank cannot be condensed and absorbed in time, leading to an increase in back pressure inside the venting pipe. This can easily cause the liquid inside the tank to churn and surge, disrupting the stability of the unit's operation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and system for intelligent extraction unit program coordination control of floral raw materials. It aims to solve the problems in existing technologies, such as the inability to adapt to batch differences of raw materials and high equipment maintenance costs due to the use of fixed time or online chemical analysis instruments to determine the extraction endpoint, and the easy occurrence of pipeline flushing due to the lack of coordination between exhaust pressure reduction operation and condensation system lag time.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of this invention provides a method for coordinated control of a smart extraction unit for floral raw materials, comprising the following steps: Under the PID closed-loop control of the steam proportional control valve and the exhaust proportional control valve, after determining that the real-time temperature and real-time pressure are both within the tolerance range, a reference state is established, the average feedforward reference opening is calculated and latched, and the detection cycle timer is started. When the timing reaches the detection cycle parameter, the condenser cooling water regulating valve is forced to open fully; after the delay corresponding to the time advance parameter, the exhaust proportional regulating valve is opened to the pulse amplitude command value and the pulse holding timer is started, and then closed after maintaining the pulse holding time parameter. After closing the exhaust proportional control valve, the PID closed-loop control of the steam proportional control valve is cut off, and the average feedforward reference opening is overwritten to the steam proportional control valve; the envelope area from the temperature drop minimum point to the point of recovery to the point of crossing the target temperature line is obtained to generate the thermal step recovery characteristic value, and then the dynamic PID control is resumed. The gradient difference of thermal step recovery characteristic values ​​is obtained by calculating the thermal step recovery characteristic values ​​of adjacent cycles. When the absolute value of the gradient difference of thermal step recovery characteristic values ​​is less than or equal to the continuous cumulative count value approaching the zero convergence threshold, the convergence determination count threshold is reached, the steam proportional control valve is closed and the liquid drainage process is started.

[0007] The core innovation of the above method lies in the following: After the extraction process reaches a steady state, the system outputs a pulsed venting and depressurization action into the extraction tank. This transient depressurization triggers flash evaporation, disrupting the concentration-bound boundary layer on the surface of the material particles and accelerating mass transfer. The venting and depressurization cause the mixed solvent to cool due to the absorption of latent heat of phase change. At this point, the system disconnects the PID closed-loop control, locks the feedforward heating opening, and observes the system's recovery to the target temperature under a constant heat source. The thermal step recovery characteristic value is obtained by calculating the integral area. As the effective components inside the flower raw material are continuously released, the physical properties of the mixed solvent, such as specific heat capacity and boiling point, gradually change. When the material leaching approaches saturation, the difference in thermodynamic response between adjacent cycles decays. By calculating the gradient difference of this characteristic value and performing a convergence judgment approaching zero, the system transforms the chemical concentration release process into a measurable control index, achieving adaptive shutdown control.

[0008] In one specific embodiment, the process of determining that the real-time temperature and real-time pressure are simultaneously within the tolerance range is as follows: The real-time temperature and real-time pressure are detected to be simultaneously within the tolerance range within the steady-state determination time window; the average feedforward reference opening is generated by arithmetically averaging the discrete control opening command sequence within the steady-state determination time window. Through arithmetic averaging, control output fluctuations caused by pipeline steam back pressure fluctuations within a single control cycle are eliminated, providing a stable basic feedforward reference for subsequent open-loop testing.

[0009] In one specific embodiment, the time advance parameter is calculated based on the sum of the action response time of the condenser cooling water regulating valve reaching its fully open state, the delivery time required for cooling water to flow from the regulating valve to the condenser inlet, and the heat conduction hysteresis time for establishing a pre-cooling temperature gradient on the metal wall of the condenser heat exchange tube bundle. If the flow velocity inside the tube is less than the minimum dead zone threshold, the time advance parameter is overwritten with a predetermined safety upper limit value. This control logic ensures that the exhaust pressure relief operation is performed after the condensation system has established cooling conditions, utilizing the pre-circulated cooling water to absorb the latent heat of the secondary steam and preventing material overflow caused by a sudden increase in back pressure in the exhaust pipe.

[0010] In one specific embodiment, the pulse amplitude command value is obtained by adding the product of the basic exhaust opening constant, the amplitude modulation gain coefficient, and the absolute value of the gradient difference of the historical thermal step recovery characteristic value, and is limited by the upper limit threshold of the maximum allowable opening of the exhaust valve. When the historical data is empty, the basic exhaust opening constant is assigned to the current exhaust proportional control valve pulse amplitude command value. This step realizes adaptive amplitude modulation, dynamically adjusting the opening of the current exhaust proportional control valve according to the changing trend of the material leaching state in the previous cycle.

[0011] Preferably, during the pressure relief period, the transient pressure drop slope is calculated using a backward differential algorithm by combining the real-time pressure value with the historical pressure value cached in the previous scan cycle. When the transient pressure drop slope is determined to be greater than the safety cutoff threshold, the remaining time of the pulse hold timer is forcibly cleared, and the exhaust proportional control valve is driven to close at the maximum mechanical rate to the zero-stroke state. This mechanism can suppress excessively rapid expansion of the liquid surface and prevent the vaporization rate from exceeding the heat exchange capacity of the condensing components.

[0012] In one specific embodiment, the process of obtaining the calculation interval corresponding to the envelope area includes: reading the real-time temperature sequence after the exhaust proportional control valve is closed; when the slope of the temperature change changes from a negative value across zero to a positive value, and the absolute value of the positive slope exceeds the noise dead zone threshold, it is determined that the temperature drop minimum point has been reached and is established as the integration lower limit minimum point; when the time window during which the real-time temperature is continuously higher than the target temperature line reaches the set filtering period threshold, the initial moment of crossing the target temperature line is determined as the integration upper limit recovery point; the integration lower limit minimum point to the integration upper limit recovery point is used as the integration interval for performing definite integral accumulation on the envelope area. This interval establishment method combines dead zone and filtering determination to eliminate false triggering caused by sensor signal fluctuations.

[0013] Furthermore, the process of performing definite integral accumulation includes: calculating the difference between the target temperature and the real-time temperature within the integration interval; setting the negative area term where the real-time temperature is higher than the target temperature to zero using a maximum value function; and accumulating the product of the positive difference and the time difference of the program scan cycle to complete the definite integral summation operation and generate the thermal step recovery feature value. Introducing the maximum value function avoids overshoot sampling values ​​generated during the hysteresis judgment stage from canceling the previously accumulated positive area, thus ensuring the accuracy of the feature value.

[0014] Preferably, the process of restoring dynamic PID control includes: invoking the smooth switching mechanism, reading the currently latched open-loop output value of the steam proportional control valve, ensuring that the calculated output of the PID function block at the moment of re-entering the closed loop is equivalent to the current actual opening degree of the steam proportional control valve, simultaneously clearing the proportional term buffer pool and the derivative term buffer pool, and connecting the closed-loop feedback connection from the field temperature transmitter to the PID control network. This operation prevents sudden valve action changes during control mode switching, achieving smooth switching.

[0015] Preferably, when the absolute value of the gradient difference of the thermal step recovery eigenvalue is less than or equal to the near-zero convergence threshold, a step pulse is sent to drive the continuous cumulative count value to increment by one; when the absolute value is greater than the near-zero convergence threshold, the continuous cumulative count value is forcibly cleared to zero; when the data depth is insufficient, the gradient calculation branch is skipped, and a preset external limit value is assigned to the decision register group. The forced clearing action ensures the continuity of convergence decision and eliminates misjudgments caused by accidental fluctuations; the data depth verification mechanism prevents equipment malfunctions caused by insufficient data in the initial stage of the process.

[0016] The second aspect of this invention provides a program-coordinated control system for an intelligent extraction unit of floral raw materials, which executes the program-coordinated control method for an intelligent extraction unit of floral raw materials described in the first aspect, comprising: The underlying execution hardware layer includes a steam proportional regulating valve, an exhaust proportional regulating valve, a condenser cooling water regulating valve, a discharge shut-off valve, and a liquid discharge pump configured on the extraction tank and auxiliary pipelines, as well as a temperature transmitter, a pressure transmitter, and a level transmitter or level switch for acquiring real-time data. The logic operation and coordination control layer communicates with the underlying execution hardware layer and includes a state transition module, a loop switching module, an operation analysis module, and a timing coupling module.

[0017] The logic operation and collaborative control layer controls the underlying execution hardware layer to establish benchmarks, regulate pressure, extract data, and determine endpoints through data interaction between internal modules, thereby achieving automatic control of the extraction process.

[0018] This invention provides a method and system for intelligent extraction unit program coordination control of floral raw materials. It has the following beneficial effects: 1. This invention generates thermal step recovery characteristic values ​​by injecting exhaust pressure reduction disturbance during the extraction process, cutting off the closed-loop control of the steam valve while maintaining the feedforward opening, and measuring the envelope area during the system temperature recovery to the target value. This method utilizes the gradient difference between adjacent periodic characteristic values ​​and performs convergence determination, transforming the gradual change in material concentration into a physical thermodynamic characteristic index. This avoids the need for online chemical analysis instruments in the pipeline, achieves automatic determination of the extraction endpoint, and reduces equipment costs.

[0019] 2. This invention introduces a time advance parameter control before executing the exhaust pulse action, opening the condenser cooling water regulating valve in advance. This advance takes into account the delay time of valve mechanical action, pipeline water flow, and the establishment of a temperature gradient on the heat exchange tube wall, allowing the secondary steam generated by the exhaust to be absorbed by the pre-cooled condenser system in a timely manner. This prevents the extraction tank from being overwhelmed due to a sudden increase in local exhaust back pressure, thus improving the stability of unit operation.

[0020] 3. During the pressure relief phase, this invention uses a backward differential algorithm to calculate the transient pressure drop slope in real time. When this slope exceeds a preset safety cutoff threshold, the system forcibly resets the pulse timer and closes the exhaust valve at the maximum mechanical rate. This interruption mechanism effectively limits the rate of transient pressure drop within the extraction tank, preventing excessive vaporization and liquid expansion of the mixed solvent due to drastic pressure reduction. It also avoids gas-liquid entrainment impacting the pipeline, ensuring safe equipment operation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the architecture of a program-coordinated control system for an intelligent extraction unit of floral raw materials according to an embodiment of the present invention.

[0022] Figure 2 This is a flowchart of a program-coordinated control method for an intelligent extraction unit of floral raw materials according to an embodiment of the present invention.

[0023] Appendix Figure 3 This is a schematic diagram of the process of system initialization and steady-state benchmark establishment in step S100 according to an embodiment of the present invention.

[0024] Appendix Figure 4 This is a schematic diagram of the process of step S200, which involves the anti-boiling timing constraint and the forced coupling of the condensate valve, according to an embodiment of the present invention.

[0025] Appendix Figure 5 This is a schematic diagram of the process of step S300, adaptive amplitude pressure perturbation injection and slope safety monitoring, according to an embodiment of the present invention.

[0026] Appendix Figure 6This is a schematic diagram of the process of PID control stripping, feedforward open-loop latching, and thermal step recovery characteristic value calculation in step S400 according to an embodiment of the present invention.

[0027] Appendix Figure 7 This is a schematic diagram of the process of determining the concentration gradient and adaptively trunculating the state machine in step S500 according to an embodiment of the present invention.

[0028] Appendix Figure 8 This is a schematic diagram illustrating the principle of thermal step recovery characteristic value calculation according to a specific application embodiment of the present invention.

[0029] Appendix Figure 9 This is a concentration gradient feature decay and adaptive truncation trend diagram in a specific application embodiment of the present invention. Detailed Implementation

[0030] The technical solutions in 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.

[0031] See attached document Figure 1 The present invention provides a program collaborative control system for an intelligent extraction unit of floral raw materials, which may include a bottom execution hardware layer and a logic operation and collaborative control layer that is communicatively connected to the bottom execution hardware layer.

[0032] The underlying hardware layer includes actuators and sensors configured on the extraction tank and its auxiliary pipelines. Actuators include a steam proportional control valve, an exhaust proportional control valve, a condenser cooling water regulating valve, a liquid outlet pump, and a discharge shut-off valve on the discharge pipeline. Sensors include a temperature transmitter located at the bottom of the tank, a pressure transmitter located at the top of the tank, and a level transmitter or level switch for determining the tank's evacuation status. It also includes a cooling water temperature transmitter located at the condenser cooling water outlet or on the condenser pipeline for routine temperature control of the condenser cooling water regulating valve. Furthermore, a flow sensor is installed on the condenser cooling water pipeline to acquire the cooling water flow rate, or the factory-calibrated average flow velocity within the cooling water pipeline is written as a fixed process parameter into the registers of the logic operation and collaborative control layer. The system's detection terminals all use conventional physical quantity sensors and do not involve chromatographic or spectroscopic online chemical detection instruments.

[0033] The logic operation and collaborative control layer employs a programmable logic controller (PLC) or distributed control system equipped with proportional-integral-differential (PI-DE) arithmetic function blocks and a calculus instruction set. The controller is internally divided into four functional modules based on its execution logic.

[0034] The state transition module is used to coordinate the timing jumps and process cutoffs between the various state nodes of the unit during initialization, baseline state maintenance, disturbance testing, data measurement, and liquid discharge output.

[0035] The loop switching module is used to intervene and switch between feedback closed-loop control and open-loop feedforward control, and to suspend, latch and reset the control actuators between PID regulation and constant output mode.

[0036] The computation and analysis module is used to receive transient data collected by the temperature transmitter, perform definite integral calculations of functions within a specific time window, and process the time difference and threshold comparison calculations of physical characteristic quantities in adjacent cycles.

[0037] The timing coupling module is used to handle the timing correlation of actions across system pipelines, execute the opening order of components according to the set time advance constraints, and handle the safety reverse cutoff logic under abnormal operating conditions.

[0038] See attached document Figure 2 This invention provides a method for collaborative control of a smart extraction unit for floral raw materials. The execution of this method relies on the above-mentioned system architecture and includes the following steps: S100, execute system initialization and steady-state reference establishment: configure target temperature value, target pressure value and corresponding tolerance threshold according to the process formula data issued by the upper system, switch to the dual single-loop PID closed-loop control mode composed of temperature PID loop and pressure PID loop to adjust steam proportional control valve and exhaust proportional control valve respectively; after determining that the real-time temperature and real-time pressure are simultaneously within the tolerance range within the steady-state determination time window, establish the reference state, calculate the average feedforward reference opening within the time window and solidify it into the holding register, while keeping the PID closed-loop control mode open and the detection cycle timer running. S200, executes anti-boiling timing constraints and forced coupling of condensate valve: when the periodic trigger triggers the test intervention pulse signal according to the set detection period parameter, it calculates the time advance parameter including structural constants and writes it into the action delay timer, and at the same time suspends the original PID loop of the condenser cooling water regulating valve and sends a forced full opening command to it; during the countdown of the action delay timer, it performs lock-up interception on the exhaust proportional regulating valve, and after the countdown ends, it generates a pressure relief enable flag, strictly constraining the exhaust pressure relief operation to be performed after the heat exchange boundary of the condensing system is ready; S300 performs adaptive amplitude pressure perturbation injection and slope safety monitoring: After obtaining the pressure relief enable flag, it calculates the current exhaust proportional control valve pulse amplitude command value based on the gradient difference mapping of historical thermal step recovery characteristic values; it cuts off the pressure PID closed-loop feedback and switches the exhaust proportional control valve to feedforward open-loop operation mode, opens the specified mechanical stroke according to the pulse amplitude command value to inject negative pressure perturbation, and starts the pulse holding timer; during the pressure relief period, it calculates the transient pressure drop slope in real time and compares it with the safety cutoff threshold. If it exceeds the limit, it executes a high-priority interrupt to forcibly close the exhaust proportional control valve. If it does not exceed the limit, it maintains the pressure relief until the timer ends and closes the exhaust valve. S400 performs PID control stripping, feedforward open-loop latching, and thermal step recovery characteristic value calculation: When calculating the slope of temperature change and identifying the minimum temperature drop point, the PID closed-loop control network of the steam proportional control valve is cut off, and the pre-latched average feedforward reference opening is forcibly overwritten to the steam proportional control valve to construct a feedforward open-loop constant power output mode; During the period when the temperature is constantly heated and rises to cross the target temperature line, the envelope area between the temperature recovery curve and the target temperature line is accumulated with the minimum temperature drop point as the lower limit and the crossing node as the upper limit, generating the thermal step recovery characteristic value of the current period and storing it in the data buffer area. Then, the disturbance-free switching mechanism is called to reconstruct the closed-loop control network to restore the dynamic PID regulation of the steam valve; S500 performs concentration gradient determination and state machine adaptive truncation: After meeting the data depth condition, it extracts the thermal step recovery feature values ​​of adjacent periods and performs a first-order backward difference operation to generate the thermal step recovery feature value gradient difference; it compares the absolute value of the thermal step recovery feature value gradient difference with the near-zero convergence threshold. When the continuous cumulative count value that meets the condition reaches the preset convergence determination count threshold, it confirms that the concentration release trend is weakening and generates a preparatory flag; it triggers a forced jump of the state machine, closes the steam proportional regulating valve to cut off the heat source, and starts the drainage process after determining that the pressure of the extraction tank has entered the safe range for drainage. It opens the discharge cut-off valve and activates the discharge pump until the liquid level feedback no-load signal terminates the extraction control closed loop.

[0039] During normal extraction operation, the logic operation and collaborative control layer continuously and cyclically executes steps S200 to S500 according to the set detection cycle. When the gradient difference of the eigenvalues ​​in S500 reaches the convergence condition, the cyclic process is interrupted, and the extraction operation of the current batch of materials is completed. If a safety interlock or abnormal shutdown condition is triggered during operation, the cyclic process is interrupted according to the corresponding abnormal handling logic.

[0040] The following section will elaborate on the processing steps and parameter calculation process of the above control method, taking into account the interaction between the underlying execution hardware layer, logic operation, and collaborative control layer. First, let's enter the system startup phase: See attached document Figure 3Step S100 is the system initialization and steady-state baseline establishment, which specifically includes the following sub-steps: S101, the state transition module loads initial control parameters based on the process recipe data issued by the upper-level system, writes the target temperature and target pressure values ​​into the registers of the logic operation and collaborative control layer, and synchronously configures temperature tolerance thresholds and pressure tolerance thresholds in the registers to define the steady-state deviation dead zone range. The temperature tolerance threshold is usually set to the range of ±0.2 to 0.5℃, and the pressure tolerance threshold is usually set to the range of ±0.01 to 0.02 MPa.

[0041] After parameter configuration is complete, the command switches to a dual single-loop PID closed-loop control mode. The logic operation and collaborative control layer receives real-time temperature signals from the temperature transmitter and real-time pressure signals from the pressure transmitter via an internally configured proportional-integral-derivative (PID) arithmetic function block. It calculates the temperature deviation between the real-time temperature signal and the target temperature value, and the pressure deviation between the real-time pressure signal and the target pressure value, respectively. The temperature PID loop outputs a heating opening command for the steam proportional control valve based on the temperature deviation, and the pressure PID loop outputs a pressure relief opening command for the exhaust proportional control valve based on the pressure deviation, thus causing the fluid state in the extraction tank to approach the target parameters. The conventional incremental or positional control logic and gain tuning process are well-known technologies in this field and will not be elaborated upon here.

[0042] S102, to filter high-frequency glitches from the sensor and prevent false triggering, the calculation and analysis module uses a moving average filtering algorithm to digitize the acquired analog signal. The state transition module allocates a steady-state timer in its internal register and extracts a preset value for the steady-state judgment time window as the timing threshold. This preset value is determined by the equipment personnel based on the extraction tank volume and the heat exchange area of ​​the heating jacket, typically an integer value within a 5-15 minute range. Within each control scan cycle, the calculation and analysis module reads the filtered real-time temperature and pressure, determining whether both are simultaneously within their corresponding tolerance judgment intervals. If both temperature and pressure fall within the interval formed by extending the tolerance thresholds outwards from the target value, the state transition module drives the steady-state timer to increment its current value step-by-step. If either the real-time temperature or pressure deviates from the tolerance interval boundary, a reset logic is triggered, clearing the current value of the steady-state timer to zero. The increment duration is then recalculated in subsequent scan cycles that meet the interval conditions. When the accumulated value of the steady-state timer reaches the preset timing threshold, a reference state establishment flag signal is generated to confirm that the unit fluid has overcome the thermal inertia of the initial heating stage and entered a dynamic equilibrium state.

[0043] S103, after receiving the reference state establishment flag signal, the loop switching module activates its internal control parameter latching program and sends data calculation instructions to the calculation and analysis module. The calculation and analysis module accesses the data buffer to retrieve the discrete control opening instruction sequence corresponding to the steady-state determination time window. To eliminate the minor oscillations caused by pipeline steam back pressure fluctuations within a single control cycle, the extracted discrete control opening instruction sequence is calculated using an arithmetic mean. The feedforward opening calculation formula is as follows: ; In the formula, The average feedforward reference opening is represented by N; N represents the total number of scan cycles with incremental increments within the steady-state determination time window; i represents the running sequence number of the scan cycle, which is a dimensionless integer; U(i) represents the real-time control opening value output to the steam proportional control valve in the i-th scan cycle within the steady-state determination time window. Here, N corresponds to the number of valid scan cycles within the last steady-state determination time window that continuously satisfies the steady-state determination condition. Before performing the division operation, the calculation and analysis module performs a non-zero validity check on the denominator N. If N is detected to be equal to zero, a system alarm is triggered and the subsequent calculation process is terminated. After normal calculation, the loop switching module writes the generated average feedforward reference opening into the holding register and maintains the current PID closed-loop control mode to start the detection cycle timing. The average feedforward reference opening latched in the holding register represents the constant thermal power input value required for the system to maintain the current thermodynamic equilibrium, and is used as a reference quantity for the fixed output of the steam proportional control valve in the subsequent feedforward open-loop test phase.

[0044] After successfully locking the average feedforward reference opening and establishing the basic thermodynamic balance of the extraction system in step S100, the unit overcomes initial thermal inertia, and the control logic smoothly transitions from the steady-state holding phase to the periodic active testing phase. To prevent subsequent active depressurization disturbances from causing gas-liquid mixture surges, sufficient condensation and absorption capacity must be built up before depressurization. Therefore, proceed to the next step: See attached document Figure 4 Step S200 involves the anti-boiling timing constraint and forced coupling with the condensate valve, specifically including the following sub-steps: S201, after the system writes the average feedforward reference opening to the holding register and starts the detection cycle timer, the state transition module calls the internal cycle trigger function block. The cycle trigger is configured with preset detection cycle parameters, which are determined based on the material extraction kinetics and the total process time. These parameters characterize the frequency at which the unit actively disturbs and samples the fluid state, and are typically set to a fixed value within the range of 10 to 20 minutes.

[0045] The state transition module continuously accumulates the running time using a hardware clock, comparing the accumulated time value with the detection cycle parameter in each program scan cycle. When the accumulated time value reaches the set detection cycle parameter, the cycle trigger flips the state and generates a test intervention pulse signal. This test intervention pulse signal, as a high-priority system-level interrupt instruction, forcibly cuts off the unit's current non-interference steady-state maintenance process. After receiving the test intervention pulse signal, the calculation and analysis module temporarily stores the current real-time temperature and pressure records and simultaneously suspends the judgment calculation for the steady-state tolerance range. At the state transition node, the steam proportional control valve and exhaust proportional control valve in the underlying execution hardware layer maintain their current PID closed-loop control output, ensuring no sudden changes in the basic thermodynamic environment. The control-level action scheduling authority is then transferred to the timing coupling module to implant the anti-boiling pre-action instruction.

[0046] S202, after the timing coupling module obtains the action scheduling authority, it calls the timing advance parameter loaded in the register to provide a timing compensation benchmark for offsetting the action delay and heat transfer lag of the underlying actuator. The calculation and analysis module calculates the timing advance parameter in conjunction with the equipment structure data. The timing advance calculation formula is as follows: ; In the formula, This represents the time lead parameter, in seconds. The response time of the condenser cooling water regulating valve from receiving a command to reaching the fully open position is expressed in seconds. This represents the length of the pipeline from the cooling water regulating valve to the condenser inlet, in meters. This represents the flow velocity of cooling water within the pipe under supply pressure, measured in meters per second. The heat conduction hysteresis time, in seconds, represents the time required for the metal wall of the condenser heat exchanger tube bundle to establish a pre-cooling temperature gradient. , and These are fixed structural constants that cannot be changed and are imported from the equipment's factory calibration file. The flow rate value is obtained by converting the flow rate collected by the cooling water flow sensor into the pipe cross-sectional area; in embodiments without a cooling water flow sensor, The average flow velocity in the pipe, obtained by factory calibration under rated water supply pressure, is used and written into the register as a fixed process parameter. This indicates the delivery time required for cooling water to flow from the cooling water regulating valve to the condenser inlet.

[0047] The calculation and analysis module analyzes the flow velocity inside the pipe. Perform a validity check; if a validity check is detected... A minimum dead zone threshold of less than 0.1 meters per second indicates a possible water supply interruption or sensor failure in the water supply pipeline. This triggers an interception logic that overwrites the time advance parameter with a predetermined safety upper limit, typically 10 to 30 seconds. Simultaneously, the state transition module generates a cooling water anomaly flag. If the cooling water anomaly flag persists and the pressure disturbance test has not yet started, the system prohibits subsequent exhaust perturbation procedures and maintains steady-state operation or enters an alarm shutdown state. The calculated time advance parameter is written into the action delay timer as a timing reference, strictly constraining the exhaust pressure relief operation to be executed only after the pre-cooling action is completely completed.

[0048] S203, after the time advance parameter is written to the action delay timer, the timing coupling module sends a forced full-open command to the condenser cooling water regulating valve, setting the valve opening to 100% full stroke. During operation, the logic operation and collaborative control layer suspend the independent conventional temperature control PID loop inside the condenser pipeline, stripping the action logic of the underlying execution hardware layer that is regulated by field temperature feedback. The action delay timer synchronously starts countdown calculation. During the countdown phase, the system performs lockout interception on the opening request received by the exhaust proportional regulating valve for test disturbance. When the pressure in the extraction tank exceeds the equipment's safe pressure relief threshold, the safe pressure relief interlock logic has higher priority than the test disturbance lockout logic, and the system allows the safe pressure relief action to be executed. In the full stroke state of the condenser cooling water regulating valve, cooling water continuously fills the heat exchange tube bundle and establishes a low-temperature heat exchange field. The subsequent exhaust pressure relief operation will cause a sudden drop in pressure in the space inside the extraction tank. The boiling point of the fluid decreases with the pressure, and the heat contained in the liquid phase is converted into latent heat of phase change, inducing flash evaporation and forming secondary steam with entrained droplets that rushes outward. Introducing a low-temperature heat exchange field in advance enables the condensation system to possess the thermodynamic boundary conditions for absorbing the latent heat of flash evaporation. Upon contact with the low-temperature pipe wall, the secondary steam rapidly liquefies and contracts, suppressing transient expansion of the gas phase volume and preventing material overflow caused by a sudden increase in back pressure in the exhaust pipe. When the countdown value decreases to zero, it indicates that the condensation pipe has completed heat exchange preparation. The timing coupling module then releases the action lockout state of the exhaust proportional control valve, generates a pressure relief enable flag, writes it into the register, and grants execution permission to subsequent actively disturbed processes.

[0049] With the condenser piping completing heat exchange preparation and successfully outputting the pressure relief enable flag in step S200, the control system officially gains the safe authority to execute active pressure disturbances. To break the concentration boundary layer on the material surface and accelerate mass transfer, while strictly preventing safety hazards caused by excessively rapid pressure relief, the system immediately proceeds to the next step: See attached document Figure 5 Step S300 is adaptive amplitude pressure perturbation injection and slope safety monitoring, including the following sub-steps: S301, the state transition module scans the internal register status. After detecting the pressure relief enable flag written in the previous process, it confirms that the heat exchange boundary of the condensation system is ready. The calculation and analysis module sends an instruction to the data buffer of the logic operation and collaborative control layer to read the gradient difference of the thermal step recovery characteristic value in the (n-1)th detection cycle. The gradient difference of the thermal step recovery characteristic value is the first-order difference component of the thermal step recovery characteristic values ​​of adjacent detection cycles, used to indirectly characterize the changing trend of the material leaching state in adjacent detection cycles. The calculation and analysis module calculates the pulse amplitude of the current exhaust proportional control valve based on the linear supplementation and saturation limiting mechanism. The pulse amplitude calculation formula is as follows: ; In the formula, The value represents the exhaust proportional control valve pulse amplitude command value generated in the nth detection cycle, with the dimension of percentage; the number of the detection cycle is a dimensionless integer. It represents the basic exhaust opening constant, with the dimension of percentage, and is usually set to a value in the range of 10% to 15%; Represents the amplitude modulation gain coefficient, which is set according to the material dissolution kinetic constant, and its dimension is percentage per °C / s. The gradient difference of the historical thermal step recovery feature value retained in the (n-1)th detection cycle; This represents the absolute value of the gradient difference of the eigenvalue; This represents the maximum permissible opening limit of the exhaust valve, expressed as a percentage. This represents the function that takes the minimum value. By using absolute value operations, the reverse offset of the exhaust valve opening command can be avoided when the characteristic values ​​of adjacent periods alternate between positive and negative due to sampling fluctuations.

[0050] The basic exhaust opening constant provides the lower limit energy support required to trigger the basic phase change. The amplitude modulation gain coefficient dynamically matches the required additional disturbance intensity based on the leaching state change trend reflected by the gradient difference of the thermal step recovery eigenvalue. The maximum opening upper limit threshold acts as a software-level protection bit, forcibly constraining the final output opening command within the safe boundary of the equipment's mechanical travel. For the initial operating condition of the unit in the first detection cycle, no eigenvalue gradient difference data has been accumulated in the data buffer. The calculation and analysis module is configured with a historical data validity flag and a null pointer interception verification step. When the historical data validity flag is invalid or the historical data is null, the relational mapping step is skipped, and the basic exhaust opening constant is assigned to the current exhaust proportional control valve pulse amplitude command value. When the historical data validity flag is valid, even if the historical thermal step recovery eigenvalue gradient difference is zero, this zero value is used as valid data in the pulse amplitude calculation. The generated pulse amplitude parameters are written into the command issuance queue.

[0051] S302, the logic operation and collaborative control layer extracts the current exhaust proportional control valve pulse amplitude command value generated from the command issuance queue. Before sending the command, the loop switching module disconnects the original PID closed-loop feedback connection between the exhaust proportional control valve and the pressure transmitter, forcing the exhaust proportional control valve to switch to feedforward open-loop operation mode, and shielding the automatic correction intervention of the conventional pressure regulation function block. After the command channel is ready, the exhaust proportional control valve opens to the specified percentage mechanical stroke according to the pulse amplitude command value. The mixed gas in the gas phase space at the top of the extraction tank escapes to the external low-pressure environment through the exhaust pipe, forming a step-like negative pressure perturbation. With the transient decrease in gas phase pressure, the saturated boiling point of the mixed solvent decreases accordingly, causing vaporization and turbulence in the liquid phase, breaking the concentration adhesion boundary layer on the surface of the material particles, and accelerating the mass transfer and diffusion process of the solute to the surrounding liquid phase solvent. The state transition module activates the internal pulse holding timer at the same time as opening the exhaust proportional control valve. The pulse holding time parameter is usually set to a fixed value in the range of 3 to 8 seconds, and the specific value is calculated and calibrated by the ratio of the exhaust pipe diameter to the total volume of the tank. During the countdown of the pulse hold timer, the underlying hardware layer locks the current opening state of the exhaust proportional control valve. The established timing constraint mechanism limits the pumping duration, ensuring that the disturbance action is presented as a transient pulse.

[0052] S303, during the countdown of the pulse hold timer, the extraction tank is under continuous pressure relief. The calculation and analysis module synchronously receives real-time pressure data collected by the pressure transmitter and performs monitoring calculations based on the pressure drop trend. It extracts the real-time pressure value in the current scan cycle and the historical pressure value cached in the previous scan cycle, and performs differentiation calculations using a backward difference algorithm. The formula for calculating the transient pressure drop slope is as follows: ; In the formula, This represents the slope of the transient pressure drop, with dimensions in megapascals per second. This represents the absolute pressure value recorded in the previous control scan cycle, with the dimension of megapascals. This represents the absolute pressure value read during the current control scan cycle, measured in megapascals. This represents the time difference between two consecutive data samples, measured in seconds. Less than hour, It is a positive value and characterizes the rate of pressure decrease; when Greater than or equal to At that time, the calculation and analysis module will Set to zero, or retain the calculated value but do not participate in the pressure drop exceeding the limit determination.

[0053] Before performing the division operation, the logic operation and the collaborative control layer perform a non-zero validity check on the time difference between the program scan cycles. If the denominator value is detected to be less than the set hardware clock precision lower limit, causing it to approach zero, the control program stops the data update operation of the current cycle and retains the calculation result of the previous cycle.

[0054] The state transition module calls the safety cutoff threshold loaded in the internal register and performs a real-time comparison with the calculated transient pressure drop slope in each scan cycle. The safety cutoff threshold is determined offline based on the design pressure bearing index of the extraction tank and the foaming characteristics of the material, and is usually set in the range of 0.005 to 0.015 MPa per second. When the transient pressure drop slope is determined to be less than or equal to the safety cutoff threshold, the unit maintains the current depressurization state until the pulse hold timer ends. When the pulse hold timer ends and the safety cutoff is not triggered, the state transition module generates a pulse end command, drives the exhaust proportional control valve to close to zero stroke, or restores the exhaust valve reference opening latched by the pressure PID loop before the test disturbance, and writes the exhaust pulse completion flag bit into the register. If the transient pressure drop slope is greater than the safety cutoff threshold, it indicates that the liquid vaporization rate in the extraction tank exceeds the absorption limit of the condenser. The state transition module generates a high-priority interrupt interception command, forcibly clearing the remaining time of the pulse hold timer to zero, driving the exhaust proportional regulating valve to perform a closing action at the maximum mechanical rate to the zero-stroke state, and simultaneously writing a safety cutoff flag. In this embodiment, the cutoff action cuts off the pressure relief channel between the tank space and the external low-pressure environment, curbing the continued churning and expansion of the liquid surface, and preserving a thermodynamic environmental margin for the subsequent thermodynamic parameter recovery stage.

[0055] After the exhaust pulse ends or is safely cut off, the loop switching module releases the feedforward open-loop pulse constraint of the exhaust proportional control valve and performs a disturbance-free reset based on the exhaust valve reference opening latched before the disturbance test intervention. Before the thermal step recovery characteristic value is calculated, the exhaust proportional control valve remains at zero stroke or the reference opening before the disturbance test, and no new active pressure disturbance is applied. After the thermal step recovery characteristic value is calculated and the tank pressure enters the target pressure tolerance range or the safe and stable range, the closed-loop feedback connection between the pressure transmitter and the pressure PID loop is reconnected.

[0056] The venting pulse depressurization action in step S300 inevitably causes a transient temperature drop in the mixed solvent inside the extraction tank due to the absorption of latent heat of phase change. To accurately quantify this difference in thermodynamic response caused by changes in material concentration, the system must eliminate interference from dynamic PID control. Therefore, following the previous disturbance condition, the system proceeds to the next step: See attached document Figure 6 Step S400 involves PID control stripping, feedforward open-loop latching, and thermal step recovery characteristic value calculation, specifically including the following sub-steps: After the exhaust proportional control valve S401 closes and cuts off the pressure relief channel, the mixed solvent inside the extraction tank exhibits a continuous temperature decrease trend due to the absorption of latent heat of phase change. The calculation and analysis module receives the real-time temperature sequence transmitted by the temperature transmitter and calculates the temperature change slope between adjacent sampling points. To prevent premature triggering caused by high-frequency thermal noise from the temperature sensor, the calculation and analysis module has a built-in noise dead zone threshold, typically set to 0.02 to 0.05°C per second.

[0057] When the temperature change slope is detected to change from negative to positive across zero, and the absolute value of the positive slope exceeds the noise dead zone threshold, the system determines that the temperature drop minimum point has been reached. The state transition module generates a trigger signal based on the temperature drop minimum point and sends a control decoupling command to the logic operation and collaborative control layer. Upon receiving the control decoupling command, the loop switching module disconnects the original PID closed-loop control network of the steam proportional control valve, freezes the integral and derivative operation buffer pool of the PID function block, and blocks the control link that calculates and generates the dynamic opening based on temperature feedback. While the PID control network is being stripped, the logic operation and collaborative control layer reads the average feedforward reference opening calculated during the preceding steady-state holding stage and forcibly overwrites the read value into the control output register of the steam proportional control valve. After receiving the feedforward command, the steam proportional control valve locks the mechanical valve core at a fixed stroke position, continuously supplying a constant flow of high-temperature steam to the heating jacket, thus constructing a pure feedforward open-loop constant power output mode at the bottom layer. In this embodiment, the decoupling of the control link eliminates the automatic correction intervention of external programs, ensuring that the heat recovery characteristics observed subsequently can mainly reflect the differences in thermodynamic properties caused by changes in the concentration of solid solutions inside the extraction solvent under the same perturbation conditions and the same feedforward heating conditions.

[0058] After the feedforward open-loop constant power output mode is established (S402), the heat recovery phase begins. The computational analysis module simultaneously initiates real-time temperature sequence tracking and integration boundary identification tasks, defining the temperature drop minimum point identified in the previous steps as the integration lower limit minimum point and recording the corresponding starting sampling number. The real-time temperature begins to rise continuously under constant steam heating, and the computational analysis module monitors the nodes where the temperature rises and crosses the process target temperature line. Hysteresis anti-jitter logic is introduced when determining the node; the system records the time window during which the real-time temperature is continuously higher than the target temperature line. The set filter cycle threshold is determined based on the equipment's thermal inertia time constant, typically ranging from 5 to 10 scan cycles.

[0059] When the conditions are met, the system determines the initial moment of crossing the target temperature line as the upper limit recovery point of integration and extracts the corresponding termination sampling sequence number. If the temperature has not recovered to the target temperature line after a preset maximum recovery time from the lower limit minimum point of integration, a recovery timeout exception is triggered, and the calculation of the thermal step recovery characteristic value for this cycle is skipped. If no recovery timeout exception is triggered and the temperature recovery judgment condition is met, the calculation and analysis module performs a definite integral summation operation on the envelope area formed between the temperature recovery curve and the target temperature line. The discrete accumulation calculation formula for the thermal step recovery characteristic value is as follows: ; In the formula, represents the thermal step recovery characteristic value calculated in the current nth detection cycle, with the dimension in °C / second; k represents the running sequence number of the discrete sampling cycle, which is a dimensionless integer; This represents the starting sampling number corresponding to the minimum point of the lower limit of integration, and is a dimensionless integer. This represents the termination sampling number corresponding to the recovery point of the integration upper limit, and is a dimensionless integer. This represents the target temperature set for the extraction process, with the dimension of °C. The temperature represents the real-time temperature recorded in the k-th discrete sampling period, with the dimension ℃; The time difference between two consecutive data sampling cycles is represented by seconds. The maximum value function is used to set the negative area term to zero when the real-time temperature exceeds the target temperature, preventing overshoot sampling values ​​generated during the hysteresis anti-jitter judgment stage from offsetting the previous heat deficit area. The difference between the target temperature and the real-time temperature maps the degree of heat deficit of the system at a single moment. The definite integral accumulation process summarizes the heat deficit values ​​over the time span, and the resulting thermal step recovery characteristic value reflects the comprehensive energy cost of the system in restoring thermodynamic equilibrium under constant power. The calculation and analysis module writes the thermal step recovery characteristic value of the current cycle into the circular cache queue of the data buffer. To prevent memory overflow caused by long-term integration operations, when the system detects accumulation and exceeding the storage boundary, it outputs the upper limit value of the word length supported by the register (e.g., 65535, an unsigned 16-bit integer) as a safe alternative value.

[0060] S403, if the calculation of the thermal step recovery characteristic value for this cycle is completed normally and the characteristic value is stored, it indicates that the fluid inside the extraction tank has crossed the heat deficit state and rebuilt the baseline thermodynamic equilibrium. The state transition module sends a closed-loop reconstruction command to the logic operation and collaborative control layer, triggering the reverse switching process of the control mode. Before safely exiting the feedforward open-loop latching mode, the logic operation and collaborative control layer calls the non-disruptive switching mechanism to perform initialization alignment of the underlying register state. The logic operation and collaborative control layer reads the currently latched feedforward open-loop output value of the steam proportional control valve and, through the tracking input of the PID function block, the manual / automatic switching interface, or the bias term initialization function, makes the calculation output of the PID function block at the moment of re-entering the closed loop equivalent to the current actual opening degree of the steam proportional control valve. The program synchronously performs a zeroing action on the proportional term buffer pool and the derivative term buffer pool.

[0061] The aforementioned state alignment operation ensures that the total command value output by the PID control module upon reawakening is precisely equivalent to the current actual position of the mechanical actuator. After data reset, the loop switching module releases the forced open-loop constraint, connects the closed-loop feedback connection from the field temperature transmitter to the PID control network, and releases the frozen state of the calculation buffer. The steam proportional control valve resumes its dynamic control logic. After the exhaust pulse ends and the extraction tank pressure recovers to a safe and stable range, the timing coupling module releases the forced fully open state of the condenser cooling water control valve and restores it to the control mode before the disturbance test or the preset standby opening. If the pressure fails to enter the safe and stable range within the preset pressure recovery time, the condenser cooling water control valve remains fully open and an alarm is triggered. The unit smoothly transitions to the steady-state holding stage. The state transition module resets the timing parameters of the cycle trigger and waits for the next detection cycle to start a new round of control decoupling and feature acquisition process, forming a parameter iterative operation network covering the entire process.

[0062] The single-cycle thermal step recovery characteristic value calculated in step S400 reflects the energy cost required for the fluid to restore thermal equilibrium under a specific disturbance at the current moment. To grasp the overall release progress of the material's effective components from a global perspective, the system needs to perform a macroscopic dynamic evaluation of the characteristic values ​​generated in each iteration. Therefore, the system enters the final determination stage of the circulation network: See attached document Figure 7 Step S500 involves concentration gradient determination and adaptive truncation of the state machine, specifically including the following sub-steps: After the closed-loop reconstruction and smooth transition to the steady-state maintenance phase, the S501 operation and analysis module immediately initiates the micro-concentration release trend assessment task, accessing the data buffer to read the discretely stored thermal step recovery feature value sequence. For operating conditions where the number of cached feature values ​​is less than two in the initial stage of the process, directly assigning a zero value to the decision unit would force the difference to meet the convergence condition and trigger a fatal logic dead zone of unit startup and immediate shutdown. Therefore, the system incorporates a preheating shielding mechanism. When insufficient data depth is detected, the control program actively skips the gradient calculation branch, assigns a preset external limit value (such as an unsigned integer upper limit of 9999.0) to the decision register group, forcibly avoiding the convergence judgment interval approaching zero, and maintains the existing unit operating state while waiting for data accumulation. The external limit value generated when data depth is insufficient is only used in the convergence judgment branch and is not used as a valid historical thermal step recovery feature value gradient difference in subsequent pulse amplitude calculations; when the historical data valid flag is invalid, S301 still generates the current exhaust proportional control valve pulse amplitude command value based on the basic exhaust opening constant.

[0063] When the data depth condition is met, the computation and analysis module extracts the thermal step recovery feature value of the current nth detection cycle and the historical thermal step recovery feature value recorded in the (n-1)th detection cycle, and calls the internal arithmetic unit to perform a first-order backward difference operation. The formula for calculating the gradient difference of the thermal step recovery feature value is as follows: ; In the formula, The gradient difference of the thermal step recovery feature value generated in the nth detection cycle is represented by °C / second. This represents the thermal step recovery characteristic value calculated in the current nth detection cycle, with dimensions in °C / second; This represents the historical thermal step recovery characteristic value corresponding to the (n-1)th detection cycle extracted from the data buffer, with dimensions in °C / s. The gradient difference of the characteristic value obtained by differential operation transforms the implicit material release kinetic decay process into an explicit and measurable digital control index. As soluble components in the floral raw materials continuously enter the solvent, the specific heat, boiling point, viscosity, and phase change response characteristics of the extract change. Under the same pressure disturbance and the same feedforward heating power, the heat deficit area corresponding to the temperature recovering from the minimum drop to the target temperature varies with the solute release state. When the thermal step recovery characteristic value of adjacent detection cycles tends to stabilize, it indicates that the thermal response change caused by continued disturbance has fallen below the range of sensor error and process fluctuation, and thus can be used as an indirect criterion for the extraction to be nearing completion. After completing the differential operation, the calculation and analysis module writes the generated data into the judgment register group. The logic operation and collaborative control layer synchronously perform queue maintenance operations on the data cache area. The data cache area adopts a first-in-first-out (FIFO) circular cache queue structure. Based on the FIFO mechanism, the oldest data with the oldest timestamp is destroyed, and the feature value of the current period is written to the latest storage location of the circular cache queue to ensure dynamic balance of memory space.

[0064] S502, the state transition module reads the generated thermal step recovery characteristic value gradient difference within the current control scan cycle and calls the pre-loaded near-zero convergence threshold to perform numerical comparison. The near-zero convergence threshold is set by considering both the quantization error band of the field temperature transmitter and the thermal inertia drift in the later stage of material leaching, and is typically taken as a value within the range of 0.5 to 2.0 °C seconds. The state transition module extracts the absolute value of the thermal step recovery characteristic value gradient difference and compares it with the near-zero convergence threshold. The convergence judgment condition is expressed as follows: ,in This represents the convergence threshold approaching zero. Absolute value calculation accommodates the alternating positive and negative data oscillations caused by sensor sampling deviations or localized material convection when the control system approaches the critical point, preventing the judgment algorithm from getting stuck in logic. Based on the comparison results, the state transition module drives the internally configured independent continuous convergence counter to perform a state update. When the absolute value is less than or equal to the convergence threshold approaching zero, a step pulse is sent to increment the continuous cumulative count by one; when the absolute value is greater than the convergence threshold approaching zero, it indicates that there is residual unreleased concentration driving force within the material particles or that the system is subject to external random interference, and the state transition module issues a reset command to forcibly clear the continuous cumulative count to zero. This forced zeroing action establishes a rigorous continuity verification rule and eliminates discrete noise contamination. After completing the counter state update, the state transition module calls the convergence judgment count threshold (calibrated according to batch extraction purity requirements, usually an integer value between 3 and 5) to perform a cutoff condition acceptance. If the cumulative count value does not reach the threshold, the existing alternating network is maintained; if the count value is equal to the threshold, it is confirmed that the concentration release trend has exhausted, and a preparatory flag for the underlying state machine to jump is generated.

[0065] S503: After the state transition module captures the preparatory flag generated at the lower level, it triggers a high-priority forced jump branch in the state machine. The state transition module issues a global interrupt instruction to the logic operation and collaborative control layer, synchronously clearing and freezing the process master timer, forcing the control program to exit the alternating loop network constructed by feedforward pulse perturbation injection and closed-loop steady-state maintenance. The logic operation and collaborative control layer responds to the instruction, driving the lower-level hardware to perform heat source isolation and state reset actions, resetting or disabling the PID function block associated with the steam proportional control valve, and clearing or freezing the relevant operation buffer pool. After receiving the zero-stroke closing instruction, the steam proportional control valve drops to the fully closed position, cutting off the high-temperature steam supply channel to the heating jacket. The system synchronously prohibits the exhaust proportional control valve from performing opening actions for non-safety pressure relief purposes. The heat source cutoff prevents the material that has reached the concentration saturation state from scorching or thermal degradation. Before initiating the fluid transfer procedure, the status transition module reads the pressure transmitter feedback value and determines whether the extraction tank pressure is lower than the preset safe discharge pressure threshold. If the tank pressure is higher than the safe discharge pressure threshold, the discharge shut-off valve remains closed, and controlled pressure relief is performed through the exhaust proportional regulating valve until the tank pressure enters the safe discharge range before initiating the discharge process. A confirmation message for hardware action completion is generated by the driver feedback signal, valve position feedback signal, or preset action completion delay signal of the corresponding execution component. The fluid transfer procedure is initiated according to the discharge sequence, sequentially opening the discharge shut-off valve on the discharge pipeline and activating the discharge pump. In this embodiment, the extract rich in the target solute in the extraction tank is transferred to the downstream section. The discharge action continues until the level transmitter or level switch installed at the bottom of the tank provides a no-load signal. In case of abnormal level detection, the system uses a preset discharge protection time as a backup termination condition. Once the above conditions are met, the extraction control closed loop relying on an adaptive dynamic cutoff mechanism to replace fixed-duration operations is completely terminated.

[0066] In the complete control flow of alternating cycles and adaptive judgments described above, the foundation for ensuring the accurate operation of each calculation and judgment logic lies in the reasonable calibration and configuration of the underlying process parameters. Therefore: The aforementioned temperature tolerance threshold, pressure tolerance threshold, steady-state judgment time window, detection cycle parameter, time advance parameter, pulse hold time parameter, safety cutoff threshold, near-zero convergence threshold, and convergence judgment count threshold can all be obtained through empty water medium testing of the same model of extraction tank, standard material batch testing, or calibration using historical production batch data, and written as process formula parameters into the registers of the logic operation and collaborative control layer. Under different flower raw materials or different loading conditions, the controller can call the corresponding formula parameter group to execute control.

[0067] Specific application examples: This embodiment applies the above-mentioned intelligent extraction unit program collaborative control system and method to process 100 kg of dried honeysuckle.

[0068] The process formula was issued, setting the target temperature at 90℃ with a temperature tolerance threshold of ±0.3℃; the target pressure at 0.12MPa with a pressure tolerance threshold of ±0.015MPa. The steady-state determination time window was set to 10 minutes. The unit started in dual single-loop PID closed-loop control mode. At the 25-minute mark, the temperature and pressure remained within the tolerance range for 10 consecutive minutes. Logical operations and the collaborative control layer then proceeded according to the formula... The average feedforward reference opening within the steady-state determination time window was calculated to be 42.5%, and then latched.

[0069] The detection period parameter set for the periodic trigger is 15 minutes. After the countdown is triggered, the system operates based on its inherent constants (the condenser cooling water regulating valve fully opens in 2 seconds, and the pipe length...). meters, flow velocity inside the pipe Heat conduction hysteresis Calculate the timing advance parameters: ; The system writes 15 seconds into the action delay timer, forcibly opens the condenser cooling water regulating valve to its full extent, and generates a pressure relief enable flag after 15 seconds to ensure that the condenser precooling is completed and to prevent material overflow.

[0070] Extract the feature values ​​from the previous cycle (initial value is zero), and calculate the current exhaust proportional control valve pulse amplitude command value as 15%. The exhaust valve opens rapidly to execute a perturbation, and the pulse hold timer is set to 5 seconds. During pressure relief, the monitoring program executes the formula... The transient pressure drop slope was calculated, and the measured maximum value was 0.008 MPa / s, which did not exceed the safe cutoff threshold (0.012 MPa / s). The exhaust valve closed after the pulse ended.

[0071] Pulsed exhaust causes a temperature drop in the extraction tank. When the minimum temperature drop (88.1℃) is detected, the temperature PID loop is cut off, and 42.5% of the average feedforward reference opening is forcibly written into the steam proportional control valve to maintain a constant input. Using the formula... A definite integral was performed on the envelope area of ​​the temperature recovery curve. The thermal step recovery characteristic value was calculated to be 185.0℃·s, and the dynamic PID control was restored.

[0072] As extraction proceeds, solutes such as chlorogenic acid from the honeysuckle are continuously precipitated and released. Due to the decay of mass transfer kinetics, the heat required for temperature recovery under the same perturbation gradually decreases. When the sixth detection cycle is reached... Substitute into the formula To obtain the absolute value This value is less than the convergence threshold approaching zero (set to 1.0℃·s). For the next three consecutive cycles (reaching the convergence determination threshold), the gradient difference of the eigenvalues ​​is less than 1.0. The system confirms the exhaustion of concentration release, forcibly shuts off the steam proportional control valve, opens the discharge shut-off valve, activates the liquid discharge pump, drains the material, and the extraction ends.

[0073] Experimental verification and effect comparison: To demonstrate the superiority of the technical solution of this application, a comparative experiment was conducted. The experimental subjects were honeysuckle from the same batch, and the traditional fixed-time double closed-loop isothermal extraction method (control group) and the adaptive feature-truncation extraction method of this invention (experimental group) were used respectively.

[0074] Combined with appendix Figure 8 The document provides an objective explanation of the data sources and truncation determination process for the experimental group. (See attached document.) Figure 8 During the experimental group's operation, the pulse opening of the exhaust proportional control valve caused a drop in the real-time temperature curve inside the extraction tank. The system accurately captured the minimum temperature drop point, immediately cut off the PID closed loop, and forcibly latched the steam valve to the average feedforward reference opening. (Appendix) Figure 8 The shaded area in the graph represents the envelope area formed between the real-time temperature feedback curve and the target temperature line, with the minimum temperature drop point as the lower limit and the crossing node as the upper limit. The system calculates this envelope area by definite integral accumulation to generate the thermal step recovery characteristic value for the current cycle. This calculation step eliminates interference from the automatic correction of the control network and directly quantifies the changes in fluid heat transfer characteristics caused by the release of honeysuckle solute using the heat deficit area under constant power input.

[0075] See attached document Figure 9 The thermal step recovery eigenvalues ​​of adjacent periods were extracted and subjected to first-order backward differencing to plot the evolution trend of the absolute value of the eigenvalue gradient difference. In the early to mid-stages of extraction (n=1 to n=4), due to the large release of components, the heat deficit difference between adjacent periods was significant, and the line data points were all distributed close to the zero convergence threshold. Above the threshold line; as extraction progresses into the later stages, soluble components tend to be depleted, and the broken line crosses below the threshold line starting from n=5. (See attached image) Figure 9 The data points for three consecutive detection cycles (n=5, n=6, n=7) all fall within the convergence interval. When the cumulative count value reaches the set threshold, the program automatically confirms that the release trend of the extract concentration is waning and triggers the adaptive truncation of the state machine at n=7.

[0076] Based on the above operating logic, the specific experimental comparison data are as follows: Regarding the total extraction time, the control group, limited by fixed process settings, took 150 minutes; the experimental group, relying on an adaptive dynamic truncation mechanism, took only 105 minutes, saving 30%. (See attached...) Figure 9As can be seen, the decision logic accurately captures the critical point of mass transfer equilibrium at n=7. The system performs a hard cutoff at this moment, completely avoiding subsequent meaningless and ineffective heating operations.

[0077] Regarding the chlorogenic acid transfer rate, the control group achieved 82.5%, while the experimental group reached 87.2%, an increase of 4.7%. The intermittently injected feedforward open-loop pressure perturbation effectively disrupted the concentration boundary layer on the material surface, accelerating the internal diffusion and transfer process of the solute.

[0078] Regarding total steam consumption, the control group consumed 315 kg, while the experimental group consumed 240 kg, resulting in a saving of 23.8%. In addition to the reduced total operating time, as shown in the attached... Figure 8 The open-loop feedforward constant power output mode shown strictly limits the heat source supply during the disturbance phase, eliminates the overshoot integral of PID control during the temperature drop period, and avoids additional energy loss.

[0079] Regarding the control of gas-liquid surging failures, the control group experienced occasional surging due to back pressure fluctuations, while the experimental group achieved stable operation with zero failures. The timing constraint mechanism and time advance equation ensured that the condensate valve pre-established a condensation field at its full stroke, effectively absorbing the system's latent heat of flash evaporation and successfully intercepting all transient boiling risks.

Claims

1. A method for coordinated control of a smart extraction unit for floral raw materials, characterized in that, Includes the following steps: Under the PID closed-loop control of the steam proportional control valve and the exhaust proportional control valve, after determining that the real-time temperature and real-time pressure are both within the tolerance range, a reference state is established, the average feedforward reference opening is calculated and latched, and the detection cycle timer is started. When the timing reaches the detection cycle parameter, the condenser cooling water regulating valve is forcibly fully opened; after the delay corresponding to the time advance parameter, the exhaust proportional regulating valve is opened to the pulse amplitude command value and the pulse holding timer is started, and then closed after maintaining the pulse holding time parameter. After closing the exhaust proportional control valve, the PID closed-loop control of the steam proportional control valve is cut off, and the average feedforward reference opening is overwritten to the steam proportional control valve. The envelope area from the minimum temperature drop point to the point of recovery and crossing the target temperature line is obtained to generate the thermal step recovery characteristic value, and then the dynamic PID regulation is restored. The gradient difference of the thermal step recovery characteristic value is obtained by calculating the thermal step recovery characteristic value between adjacent periods; When the absolute value of the gradient difference of the thermal step recovery characteristic value is less than or equal to the continuous cumulative count value approaching the zero convergence threshold, and the convergence determination count threshold is reached, the steam proportional regulating valve is closed and the liquid drainage process is started.

2. The intelligent extraction unit program collaborative control method according to claim 1, characterized in that, The process of determining that the real-time temperature and real-time pressure are both within the tolerance range is as follows: The real-time temperature and the real-time pressure are both within the tolerance range within the steady-state determination time window. The average feedforward reference opening is generated by averaging the discrete control opening command sequence within the steady-state determination time window.

3. The intelligent extraction unit program collaborative control method according to claim 1, characterized in that, The time advance parameter is obtained by summing the action response time of the condenser cooling water regulating valve to reach the fully open state, the delivery time required for the cooling water to flow from the cooling water regulating valve to the condenser inlet, and the heat conduction hysteresis time for the metal wall of the condenser heat exchange tube bundle to establish a pre-cooling temperature gradient. If the flow velocity inside the pipe is less than the minimum dead zone threshold, the time advance parameter is overwritten with a predetermined safety upper limit value.

4. The intelligent extraction unit program collaborative control method according to claim 1, characterized in that, The pulse amplitude command value is obtained by adding the product of the basic exhaust opening constant, the amplitude modulation gain coefficient, and the absolute value of the gradient difference of the historical thermal step recovery characteristic value, and is limited by the upper limit threshold of the maximum allowable opening of the exhaust valve. When the historical data is empty, the basic exhaust opening constant is assigned to the current exhaust proportional control valve pulse amplitude command value.

5. The intelligent extraction unit program collaborative control method according to claim 1, characterized in that, During the opening of the exhaust proportional control valve, the transient pressure drop slope is calculated by combining the real-time pressure value with the historical pressure value cached in the previous scan cycle and using a backward differential algorithm to perform differential operations. When it is determined that the transient pressure drop slope is greater than the safety cutoff threshold, the remaining time of the pulse hold timer is forcibly cleared to zero, and the exhaust proportional regulating valve is driven to perform a closing action at the maximum mechanical rate to the zero stroke state.

6. The intelligent extraction unit program collaborative control method according to claim 1, characterized in that, The process of obtaining the calculation interval corresponding to the envelope area includes: Read the real-time temperature sequence after the exhaust proportional control valve is closed. When the slope of the temperature change changes from a negative value to a positive value after crossing zero, and the absolute value of the positive slope exceeds the noise dead zone threshold, it is determined that the temperature drop minimum point has been reached and is established as the integral lower limit minimum point. When the time window during which the real-time temperature is continuously higher than the target temperature line reaches the set filter cycle threshold, the initial moment of crossing the target temperature line is determined as the integration upper limit recovery point. The interval from the minimum point of the lower limit of integration to the recovery point of the upper limit of integration is used as the integration interval for definite integral accumulation over the envelope area.

7. The intelligent extraction unit program collaborative control method according to claim 6, characterized in that, The process of performing definite integral accumulation includes: Within the integration interval, the difference between the target temperature and the real-time temperature is calculated. The negative area term after the real-time temperature is higher than the target temperature is set to zero by taking the maximum value function. The product of the positive difference and the time difference of the program scan cycle is accumulated to complete the definite integral summation operation and generate the thermal step recovery characteristic value.

8. The intelligent extraction unit program collaborative control method according to claim 1, characterized in that, The process of restoring dynamic PID control includes: The non-disruptive switching mechanism is invoked to read the currently latched feedforward open-loop output value of the steam proportional control valve, so that the calculation output of the PID function block at the moment of re-entering the closed loop is equal to the current actual opening degree of the steam proportional control valve. Simultaneously, the proportional term buffer pool and the derivative term buffer pool are cleared, and the closed-loop feedback connection from the field temperature transmitter to the PID control network is connected.

9. The intelligent extraction unit program collaborative control method according to claim 1, characterized in that, When the absolute value of the gradient difference of the thermal step recovery feature value is less than or equal to the zero convergence threshold, a step pulse is sent to drive the continuous cumulative count value to increment by one. When the absolute value is determined to be greater than the zero-approach convergence threshold, the continuous cumulative count value is forcibly cleared to zero. When the data depth is insufficient, skip the gradient calculation branch and assign a preset external limit value to the decision register group.

10. A program-coordinated control system for an intelligent extraction unit of floral raw materials, executing the program-coordinated control method for an intelligent extraction unit of floral raw materials as described in any one of claims 1-9, characterized in that, include: The underlying execution hardware layer includes a steam proportional regulating valve, an exhaust proportional regulating valve, a condenser cooling water regulating valve, a discharge shut-off valve, and a liquid discharge pump installed on the extraction tank and auxiliary pipelines, as well as a temperature transmitter, a pressure transmitter, and a level transmitter or level switch for acquiring real-time data. The logic operation and coordination control layer communicates with the underlying execution hardware layer and includes a state transition module, a loop switching module, an operation analysis module, and a timing coupling module.

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