A method and system for adaptive operation decision of steam-jet mixer

Abstract

The present application relates to the technical field of industrial control, and particularly relates to a steam-jet mixer variable self-adaptive operation decision method and system, which comprises the following steps: obtaining real-time operation data of the steam-jet mixer; calculating a theoretical pressure-opening influence coefficient and a theoretical temperature-opening influence coefficient; obtaining a statistical pressure-opening influence coefficient and a statistical temperature-opening influence coefficient; obtaining a fusion pressure-opening influence coefficient and a fusion temperature-opening influence coefficient under a current working condition; and obtaining a steam valve feedforward adjustment amount and a desuperheating water feedforward compensation amount. The present application fuses a physical model and statistical data, estimates the dynamic sensitivity of pressure-opening and temperature-opening in real time, calculates a feedforward decoupling compensation amount based on energy conservation, synchronously executes pressure regulation and temperature compensation, realizes collaborative control of multivariables, and thus solves the problems of mutual coupling of pressure regulation and temperature regulation in existing double-loop independent PID control, oscillation caused by working condition change, and excessively long regulation time.

Description

Technical Field

[0001] This invention relates to the field of industrial control technology, and in particular to a variable adaptive operation decision-making method and system for a steam jet mixer. Background Technology

[0002] A steam jet mixer is a device that uses high-pressure steam to eject low-pressure steam or fluid, achieving mixing, pressure increase, or temperature regulation. It is widely used in industrial applications such as chemical reactors, pharmaceutical concentration equipment, and food sterilization devices. In practical applications, the steam pressure and temperature at the mixer outlet are two key parameters that require simultaneous and precise control. Current technology typically employs a multi-loop independent PID control method for controlling steam jet mixers: setting up a pressure control loop and a temperature control loop to regulate the steam flow regulating valve and the desuperheating water regulating valve, respectively. Each loop acquires feedback signals through sensors, compares them with setpoints, independently calculates its own control output, and drives the actuators accordingly.

[0003] This control method can basically meet the requirements under stable operating conditions and constant setpoints. However, in actual industrial production, steam jet mixers often face the following changes in operating conditions: random fluctuations in the steam pressure of the upstream steam supply network; the need for rapid adjustment of the outlet flow setpoint when switching production processes; and changes in the control priority of pressure and temperature at different production stages. During these changes, there is a strong coupling relationship between pressure regulation and temperature regulation: adjusting the steam flow valve changes the outlet pressure, which in turn changes the total energy of the steam entering the mixer, thus affecting the outlet temperature; adjusting the desuperheating water valve changes the outlet temperature, which in turn changes the total amount of mixed steam, thus affecting the outlet pressure. The two loops interfere with each other, leading to repeated oscillations, prolonged adjustment time, and increased overshoot during the control process. Summary of the Invention

[0004] The main objective of this invention is to provide a variable adaptive operation decision-making method and system for steam jet mixers, aiming to solve the technical problems mentioned in the background art.

[0005] This invention proposes a variable adaptive operation decision-making method for a steam jet mixer, comprising: Acquire real-time operating data of the steam jet mixer, wherein the real-time operating data includes at least inlet pressure, outlet pressure, outlet temperature, high-pressure steam mass flow rate, and low-pressure steam mass flow rate; The current ejector coefficient is calculated based on the high-pressure steam mass flow rate and the low-pressure steam mass flow rate, and the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, and the outlet steam isobaric specific heat are obtained based on the inlet pressure and the outlet pressure. The theoretical pressure-opening influence coefficient and the theoretical temperature-opening influence coefficient are calculated based on the current ejector coefficient, the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam constant pressure specific heat, and the preset design parameters of the mixer. Obtain historical sequences of real-time operating data, and based on the historical sequences, obtain the statistical pressure-opening degree influence coefficient and the statistical temperature-opening degree influence coefficient through linear regression; The confidence weight of the statistical coefficient is calculated based on the statistical pressure-opening influence coefficient and the theoretical pressure-opening influence coefficient. The theoretical pressure-opening influence coefficient and the statistical pressure-opening influence coefficient are then weighted and fused to obtain the fused pressure-opening influence coefficient under the current operating condition. The theoretical temperature-opening influence coefficient and the statistical temperature-opening influence coefficient are then weighted and fused to obtain the fused temperature-opening influence coefficient under the current operating condition. When a change in pressure setpoint or fluctuation in inlet pressure is detected, the steam valve feedforward adjustment amount is obtained according to the fusion pressure-opening influence coefficient, the temperature disturbance caused by the steam valve feedforward adjustment amount is calculated according to the fusion temperature-opening influence coefficient, and the desuperheating water feedforward compensation amount required to offset the temperature disturbance is calculated according to the energy conservation. The desuperheating water feedforward compensation amount is superimposed with the temperature PID feedback amount to generate a desuperheating water valve command; the steam valve feedforward adjustment amount is superimposed with the pressure PID feedback amount to generate a steam valve command; the steam valve command and the desuperheating water valve command are output to the corresponding actuators.

[0006] The present invention is further configured to include a mass balance verification step: The mass flow rate of the desuperheating water and the mass flow rate of the mixed steam are obtained. The mass balance error is calculated by combining the mass flow rate of the high-pressure steam and the mass flow rate of the low-pressure steam. It is then determined whether the mass balance error exceeds a preset threshold. If it does, an alarm signal is output and the update rate of the statistical pressure-opening influence coefficient and the statistical temperature-opening influence coefficient are reduced.

[0007] Preferably, the step of calculating the theoretical pressure-opening influence coefficient and the theoretical temperature-opening influence coefficient based on the current ejector coefficient, the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam constant-pressure specific heat, and the preset design parameters of the mixer includes: Obtain the preset design parameters of the mixer, including the total cross-sectional area of ​​the nozzle throat, the cross-sectional area of ​​the mixing chamber, the design ejector coefficient, the steam valve opening degree corresponding to the design operating condition, the nozzle efficiency, and the steam valve flow gain. The theoretical pressure-opening influence coefficient is calculated based on the inlet pressure, the total cross-sectional area of ​​the nozzle throat, the cross-sectional area of ​​the mixing chamber, the current ejector coefficient, the design ejector coefficient, the steam valve opening corresponding to the design operating condition, and the nozzle efficiency. The theoretical temperature-opening influence coefficient is calculated based on the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam constant-pressure specific heat, the outlet mixed steam mass flow rate, and the steam valve flow gain.

[0008] Preferably, the step of acquiring historical sequences of real-time operational data and obtaining statistical pressure-opening influence coefficients and statistical temperature-opening influence coefficients through linear regression based on the historical sequences includes: Obtain historical data from the most recent preset number of sampling periods to construct sequences of steam valve opening changes, desuperheating water valve opening changes, outlet pressure changes, and outlet temperature changes. Based on the steam valve opening change sequence and the outlet pressure change sequence, the statistical pressure-opening influence coefficient is fitted using the least squares method. Based on the sequence of steam valve opening changes and the sequence of outlet temperature changes, a statistical temperature-opening influence coefficient is fitted using the least squares method.

[0009] Preferably, the steps of calculating the confidence weight of the statistical coefficient based on the estimated variance of the statistical pressure-opening influence coefficient and the preset uncertainty of the theoretical pressure-opening influence coefficient, weighting and fusing the theoretical pressure-opening influence coefficient and the statistical pressure-opening influence coefficient to obtain the fused pressure-opening influence coefficient under the current operating condition, and weighting and fusing the theoretical temperature-opening influence coefficient and the statistical temperature-opening influence coefficient to obtain the fused temperature-opening influence coefficient under the current operating condition include: The estimated variance of the statistical pressure-opening influence coefficient is calculated based on the historical dataset. Obtain the preset uncertainty of the theoretical pressure-opening influence coefficient, and calculate the confidence weight of the statistical coefficient in combination with the estimated variance; The fusion pressure-opening influence coefficient under the current operating condition is obtained based on the confidence weight and the statistical pressure-opening influence coefficient. The fusion temperature-opening influence coefficient under the current operating condition is obtained based on the confidence weight and the temperature-opening influence coefficient.

[0010] Preferably, the steps of calculating the steam valve feedforward adjustment amount based on the fusion pressure-opening influence coefficient when a change in the pressure setpoint or fluctuation in the inlet pressure is detected, calculating the temperature disturbance caused by the steam valve feedforward adjustment amount based on the fusion temperature-opening influence coefficient, and then calculating the desuperheating water feedforward compensation amount required to offset the temperature disturbance based on energy conservation include: When a change in the pressure setpoint is detected, the target pressure change is obtained, and the steam valve feedforward adjustment is calculated by combining the fused pressure-opening influence coefficient. When a change in inlet pressure is detected, the amount of change in inlet pressure and the inlet pressure-outlet pressure influence coefficient are obtained, and the amount of steam valve compensation required to maintain a constant outlet pressure is calculated in combination with the fusion pressure-opening influence coefficient. The temperature disturbance is calculated based on the steam valve feedforward adjustment amount and / or the steam valve compensation amount, combined with the fusion temperature-opening influence coefficient. The change in desuperheating water flow rate required to offset the temperature disturbance is calculated based on the law of energy conservation. The change in the desuperheating water flow rate is converted into a desuperheating water feedforward compensation.

[0011] The present invention is further configured to include a step of modifying the command of the desuperheating water valve: Obtain the current outlet mixed steam mass flow rate, outlet steam density, and mixer outlet pipe cross-sectional area, and calculate the current steam velocity; Obtain the design flow rate under the design conditions to calculate the adaptive filtering time constant; The desuperheating water valve command is processed through a first-order inertial filter to obtain the final command.

[0012] The present invention also provides a variable adaptive operation decision system for a steam jet mixer, comprising: The data acquisition module is used to acquire real-time operating data of the steam jet mixer, which includes at least inlet pressure, outlet pressure, outlet temperature, high-pressure steam mass flow rate, and low-pressure steam mass flow rate. The ejector coefficient estimation module is used to calculate the current ejector coefficient based on the high-pressure steam mass flow rate and the low-pressure steam mass flow rate, and to obtain the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, and the outlet steam isobaric specific heat based on the inlet pressure and the outlet pressure. The physical model calculation module is used to obtain the historical sequence of real-time operating data, and based on the historical sequence, to obtain the statistical pressure-opening influence coefficient and the statistical temperature-opening influence coefficient through linear regression. The decoupled calculation module calculates the confidence weight of the statistical coefficient based on the statistical pressure-opening influence coefficient and the theoretical pressure-opening influence coefficient, performs weighted fusion of the theoretical pressure-opening influence coefficient and the statistical pressure-opening influence coefficient to obtain the fused pressure-opening influence coefficient under the current operating condition, and performs weighted fusion of the theoretical temperature-opening influence coefficient and the statistical temperature-opening influence coefficient to obtain the fused temperature-opening influence coefficient under the current operating condition. The feedforward compensation module is used to obtain the steam valve feedforward adjustment amount according to the fusion pressure-opening influence coefficient when a change in pressure setpoint or inlet pressure fluctuation is detected, calculate the temperature disturbance caused by the steam valve feedforward adjustment amount according to the fusion temperature-opening influence coefficient, and then calculate the desuperheating water feedforward compensation amount required to offset the temperature disturbance according to energy conservation. The collaborative control module is used to superimpose the feedforward compensation amount of the desuperheating water with the temperature PID feedback amount to generate a desuperheating water valve command; superimpose the feedforward adjustment amount of the steam valve with the pressure PID feedback amount to generate a steam valve command; and output the steam valve command and the desuperheating water valve command to the corresponding actuators.

[0013] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of a steam jet mixer variable adaptive operation decision method.

[0014] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of a steam jet mixer variable adaptive operation decision method.

[0015] The beneficial effects of this invention are as follows: This invention integrates physical models and statistical data to estimate the dynamic sensitivity of pressure-opening degree and temperature-opening degree in real time. Based on energy conservation, it calculates the feedforward decoupling compensation amount, so that pressure regulation and temperature compensation are executed synchronously, realizing multi-variable coordinated control. This solves the problems of pressure regulation and temperature regulation being coupled in existing dual-loop independent PID control, causing oscillations and excessively long adjustment time when the operating conditions change. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a method flow according to an embodiment of this application.

[0017] Figure 2 This is a schematic diagram of the system structure according to an embodiment of this application.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0020] like Figure 1 As shown, this application provides a variable adaptive operation decision-making method for a steam jet mixer, including: S1. Obtain real-time operating data of the steam jet mixer, including inlet pressure, outlet pressure, outlet temperature, steam valve opening, desuperheating water valve opening, high-pressure steam mass flow rate, low-pressure steam mass flow rate, desuperheating water mass flow rate, and mixed steam mass flow rate. The real-time operating data is acquired periodically according to a preset sampling period (e.g., 100 milliseconds). This real-time operating data includes: inlet pressure (MPa), measured by a pressure sensor installed on the high-pressure steam inlet pipe of the mixer; outlet pressure (MPa), measured by a pressure sensor installed on the outlet pipe of the mixer; outlet temperature (°C), measured by a temperature sensor (e.g., PT100 platinum resistance thermometer) installed on the outlet pipe of the mixer; steam valve opening (%), measured by the valve position feedback sensor of the steam flow regulating valve; and desuperheating water valve opening (%), measured by the valve position feedback sensor of the desuperheating water regulating valve. The following data are measured by a position feedback sensor: high-pressure steam mass flow rate (unit: t / h) is measured by a flow meter (e.g., V-cone flow meter or long-neck nozzle, accuracy ±1.5%) installed on the high-pressure steam pipeline; low-pressure steam mass flow rate (unit: t / h) is measured by a flow meter (e.g., vortex flow meter with pre-steam-water separator) installed on the low-pressure steam pipeline; desuperheating water mass flow rate (unit: t / h) is measured by a flow meter installed on the desuperheating water pipeline, or calculated through valve characteristic curves; mixed steam mass flow rate is measured by a flow meter installed on the outlet pipeline. The above data are stored in the processor's memory in real time, forming a time series. S2. Calculate the current ejector coefficient based on the high-pressure steam mass flow rate and the low-pressure steam mass flow rate, and query the steam property database based on the inlet pressure and the outlet pressure to obtain the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, and the outlet steam isobaric specific heat. S3. Based on the current ejector coefficient, the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam constant pressure specific heat, and the preset design parameters of the mixer, calculate the theoretical pressure-opening influence coefficient and the theoretical temperature-opening influence coefficient. S4. Based on the historical sequence of the real-time operating data, fit the statistical pressure-opening influence coefficient and the statistical temperature-opening influence coefficient using the least squares method; S5. Based on the estimated variance of the statistical pressure-opening influence coefficient and the preset uncertainty of the theoretical pressure-opening influence coefficient, calculate the confidence weight of the statistical coefficient, and perform weighted fusion of the theoretical pressure-opening influence coefficient and the statistical pressure-opening influence coefficient to obtain the fused pressure-opening influence coefficient under the current operating condition. Then, perform weighted fusion of the theoretical temperature-opening influence coefficient and the statistical temperature-opening influence coefficient to obtain the fused temperature-opening influence coefficient under the current operating condition. S6. When a change in pressure setpoint or fluctuation in inlet pressure is detected, the steam valve feedforward adjustment amount is calculated based on the fusion pressure-opening influence coefficient, the temperature disturbance caused by the steam valve feedforward adjustment amount is calculated based on the fusion temperature-opening influence coefficient, and the desuperheating water feedforward compensation amount required to offset the temperature disturbance is calculated based on energy conservation. S7. The feedforward compensation amount of the desuperheating water is superimposed with the temperature PID feedback amount to generate a desuperheating water valve command; the feedforward adjustment amount of the steam valve is superimposed with the pressure PID feedback amount to generate a steam valve command; the steam valve command and the desuperheating water valve command are output to the corresponding actuators, and the actuators control the steam flow rate and the desuperheating water flow rate based on the steam valve command and the desuperheating water valve command.

[0021] The feedback control employs a conventional PID control algorithm. The pressure PID controller calculates the pressure feedback based on the deviation between the setpoint and the measured outlet pressure, while the temperature PID controller calculates the temperature feedback based on the deviation between the setpoint and the measured outlet temperature. The processor converts the calculated steam valve opening command and desuperheating water valve opening command into current signals, which are then sent to the servo motors of the steam flow regulating valve and the desuperheating water regulating valve, respectively. The actuators drive the valves to the specified opening degree according to the received commands, thereby controlling the steam flow and desuperheating water flow entering the mixer.

[0022] As described in steps S1-S7 above, existing steam jet mixers using dual-loop independent PID control exhibit strong coupling between pressure and temperature regulation: adjusting the steam valve changes the outlet pressure, altering the total energy of the steam entering the mixer, thus disturbing the outlet temperature; adjusting the desuperheating water valve changes the outlet temperature, altering the total amount of mixed steam, thus disturbing the outlet pressure. The two loops interfere with each other, causing repeated oscillations during pressure setpoint switching or inlet pressure fluctuations, leading to prolonged adjustment time, decreased temperature control accuracy, and in severe cases, product quality defects or production interruptions. To address this technical problem, this invention provides a variable adaptive operation decision-making method for steam jet mixers, aiming to solve the problems of pressure and temperature regulation coupling, oscillations during operating condition changes, and excessively long adjustment times in existing dual-loop independent PID control. The core concept of this invention lies in: integrating physical models and statistical data to estimate the dynamic sensitivity of pressure-opening and temperature-opening in real time; calculating the feedforward decoupling compensation based on energy conservation; and enabling synchronous execution of pressure regulation and temperature compensation, thereby achieving multi-variable collaborative control.

[0023] Specifically, this invention obtains the current ejector coefficient and steam property parameters, ensuring that the theoretical coefficients maintain reasonable accuracy even in the early stages of drastic changes in operating conditions, thus avoiding the lag of purely data-driven methods. The theoretical influence coefficient is calculated using mixer design parameters and property parameters. This coefficient does not rely on historical data and still provides a reasonable sensitivity estimate in the early stages of drastic changes in operating conditions. The statistical influence coefficient is fitted using the least squares method to reflect the actual dynamic characteristics of the equipment. Then, the theoretical coefficients and statistical coefficients are weighted and fused based on confidence levels. The fusion weights are adaptively adjusted according to the estimated variance of the statistical coefficients. When the operating conditions are stable and historical data is sufficient, the statistical coefficients have a higher weight, fully utilizing measured information. When the operating conditions change drastically and historical data becomes invalid, the theoretical coefficient weights automatically increase, avoiding the lag of purely data-driven methods and ensuring accurate sensitivity estimates for the current moment under different operating conditions. Based on this, the steam valve feedforward adjustment is calculated according to the fusion coefficients, and the desuperheating water feedforward compensation required to offset temperature disturbances is simultaneously calculated based on energy conservation. This allows pressure regulation and temperature compensation to be executed collaboratively within the same control cycle, thus avoiding the coupled oscillation path of the pressure loop acting first and the temperature loop catching up in traditional schemes. Finally, the feedforward quantity and the PID feedback quantity are superimposed on the output, which ensures both dynamic response speed and steady-state accuracy with zero steady-state error.

[0024] To facilitate understanding of the practical role of this invention in solving technical problems, the following explanation uses a steam jet mixer in a pharmaceutical raw material synthesis workshop as an example. The upstream steam supply pressure of this mixer fluctuates randomly by ±0.1 MPa due to variations in the overall plant load. The reactor process requires the outlet pressure to switch rapidly between 1.2 MPa and 1.6 MPa (the preheating stage must be completed within 60 seconds), and the outlet temperature must be stable at 145 ± 2 °C. When using traditional dual-loop independent PID control, the pressure setpoint jumps from 1.2 MPa to 1.6 MPa, causing the pressure loop to instruct the steam valve to open significantly, resulting in a rise in outlet pressure. However, this is accompanied by a sudden increase in steam flow, leading to a rapid rise in outlet temperature (the measured maximum overshoot reaches 8 °C). The temperature loop detects the temperature deviation and then lags behind by closing the desuperheating water valve. However, by this time, the pressure is already close to the target value, and the desuperheating water valve's action reacts with the pressure, causing alternating oscillations in pressure and temperature. The adjustment time is as long as 27 seconds, and the temperature fluctuation exceeds the process allowable range. By employing the method of this invention, under the same pressure setpoint step scenario, the theoretical coefficient dominates the initial moment (when historical data has not yet been updated) by fusing the pressure-opening influence coefficient and the temperature-opening influence coefficient. The confidence-weighted fusion mechanism automatically increases the weight of the theoretical coefficient before the statistical coefficient is updated, ensuring the continuity of sensitivity estimation and thus accurately predicting the required change in steam valve opening and the resulting temperature disturbance. Then, based on energy conservation, the feedforward compensation amount of the desuperheating water is calculated synchronously and output simultaneously with the steam valve adjustment amount, realizing the synchronous execution of pressure regulation and temperature compensation, cutting off the coupling oscillation path between the pressure loop and the temperature loop, and reducing the temperature fluctuation amplitude due to the synchronous calculation of desuperheating water compensation. The desuperheating water command is then smoothly executed after adaptive filtering, coordinating with the steam valve action, thereby further matching the mixed dynamics under different flow rates and avoiding the problem of overcompensation at low loads and undercompensation at high loads caused by a fixed time constant.

[0025] It should be noted that this invention is particularly suitable for industrial applications where the steam state is saturated steam with a dryness fraction ≥0.95 or slightly superheated steam with a superheat ≤20℃, and the upstream steam pressure is between 70% and 130% of the design pressure, while the outlet pressure setpoint is between 50% and 150% of the design pressure. Typical applications include steam heating systems for API synthesis reactors in pharmaceutical companies, steam supply systems for reboilers in distillation columns in chemical companies, and steam temperature control for sterilizers in the food and beverage industry. In these scenarios, the steam jet mixer needs to simultaneously and precisely control both the outlet pressure and temperature, and the upstream steam pressure often fluctuates randomly, requiring rapid load adjustments during production process switching.

[0026] In one embodiment of the present invention, the step of calculating the current ejector coefficient based on the high-pressure steam mass flow rate and the low-pressure steam mass flow rate, and querying the steam property database based on the inlet pressure and the outlet pressure to obtain the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, and the outlet steam isobaric specific heat includes: S21. Calculate the current ejection coefficient based on the ratio of the low-pressure steam mass flow rate to the high-pressure steam mass flow rate; S22. Based on the inlet pressure and the outlet pressure, query the IAPWS-IF97 industrial water and steam property database to obtain the high-pressure steam specific enthalpy, outlet steam specific enthalpy, and outlet steam isobaric specific heat.

[0027] As described in steps S21-S22 above, this embodiment performs real-time estimation of the ejector coefficient and online query of steam property parameters. The purpose is to provide accurate input parameters for subsequent theoretical coefficient calculations based on physical models, while ensuring the reliability of measurement data and avoiding control failure caused by instrument malfunctions or measurement deviations.

[0028] The specific implementation of the ejector coefficient estimation is as follows: The processor reads the high-pressure steam mass flow rate output by the flow meter installed on the high-pressure steam pipeline and the low-pressure steam mass flow rate output by the flow meter installed on the low-pressure steam pipeline through the data acquisition unit. To improve anti-interference capability, the flow rate values ​​of three consecutive sampling periods are filtered by moving average to obtain a stable flow rate estimate. The ejector coefficient is defined as the ratio of the low-pressure steam mass flow rate to the high-pressure steam mass flow rate. This ratio is dimensionless and reflects the ejector capability of the mixer for high-pressure steam to low-pressure steam under the current operating conditions. When the ejector coefficient deviates from the design value, it indicates that the operating point of the mixer has changed, for example, due to fluctuations in upstream steam parameters or nozzle scaling after long-term operation, leading to a decrease in ejector efficiency. This information will be used to correct the pressure-opening sensitivity in the subsequent theoretical model. After completing the flow data processing, the processor queries the built-in IAPWS-IF97 industrial water and steam property database based on the inlet and outlet pressures. This database is an internationally recognized standard for the thermodynamic properties of water and steam. In this embodiment, a lookup table plus linear interpolation method is used, and the time consumption of a single query meets the real-time control requirements. The processor retrieves the high-pressure steam specific enthalpy, the outlet mixed steam specific enthalpy, and the outlet steam constant-pressure specific heat through querying. The high-pressure steam specific enthalpy is determined based on the inlet pressure and inlet temperature (or the saturation temperature at that pressure if the inlet temperature is not measured), while the outlet steam specific enthalpy and constant-pressure specific heat are determined based on the outlet pressure and outlet temperature. These physical property parameters directly participate in the heat-temperature conversion relationship in subsequent energy conservation calculations, and their accuracy determines the calculation precision of the feedforward compensation. In the above steps, the real-time acquisition of the ejector coefficient allows the control system to sense the deviation between the mixer's operating point and the design point. This information is used in the subsequent calculation of the theoretical pressure-opening influence coefficient to correct the impact of ejector efficiency changes on pressure sensitivity, ensuring that the theoretical model maintains a reasonable estimate even when equipment performance degrades. Online querying of steam physical property parameters means that the specific enthalpy and specific heat in energy conservation calculations are no longer fixed constants, but precise values ​​updated in real time with pressure and temperature. In applications such as pharmaceuticals and chemicals that require frequent switching of operating conditions, this feature can significantly reduce calculation errors introduced by changes in physical properties.

[0029] In one embodiment of the present invention, the method further includes obtaining the mass flow rate of the desuperheating water to calculate the mass flow rate of the outlet mixed steam, and determining whether the mass balance error exceeds a preset threshold. If it does, an alarm signal is output and the update rate of the statistical coefficients is reduced.

[0030] Calculation of mass balance error: in, Indicates the mass balance error. This indicates the mass flow rate of high-pressure steam. This indicates the mass flow rate of low-pressure steam. Indicates the mass flow rate of the desuperheating water. This indicates the mass flow rate of the mixed steam at the outlet.

[0031] During real-time operation, the processor acquires the mass flow rate of the desuperheating water measured by the flow meter on the desuperheating water pipeline and the mass flow rate of the mixed steam on the mixer outlet pipeline. It then calculates and determines whether the mass balance error exceeds a preset threshold. If the threshold is exceeded, a measurement anomaly is identified, and the processor outputs an alarm signal via the human-machine interface or communication bus to remind the operator to check the flow meters. This verification mechanism enables the control system to proactively identify anomalies such as sensor malfunctions or pipeline leaks, preventing erroneous data from entering subsequent calculations. Simultaneously, the update rate of statistical coefficients is reduced. Statistical coefficients refer to the statistical pressure-opening influence coefficient and statistical temperature-opening influence coefficient obtained by fitting historical data. Under normal operating conditions, they are continuously updated with operating data to adapt to equipment changes. However, if statistical coefficients are updated too quickly when data is abnormal, erroneous information may be introduced into the control model, leading to deterioration of control quality or even instability. Therefore, the system proactively slows down the update rate of statistical coefficients, keeping the model at relatively reliable parameters before the anomaly occurred, thereby ensuring the stability and safety of the control system until the fault is cleared or the data returns to normal, preventing control oscillations caused by faulty data.

[0032] In one embodiment of the present invention, the step of calculating the theoretical pressure-opening influence coefficient and the theoretical temperature-opening influence coefficient based on the current ejector coefficient, the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam constant-pressure specific heat, and the preset design parameters of the mixer includes: S31. Obtain the preset design parameters of the mixer, including the total cross-sectional area of ​​the nozzle throat, the cross-sectional area of ​​the mixing chamber, the design ejector coefficient, the steam valve opening degree corresponding to the design operating condition, the nozzle efficiency, and the steam valve flow gain. S32. Based on the inlet pressure, the total cross-sectional area of ​​the nozzle throat, the cross-sectional area of ​​the mixing chamber, the current ejector coefficient, the design ejector coefficient, the steam valve opening corresponding to the design operating condition, and the nozzle efficiency, calculate the theoretical pressure-opening influence coefficient: ; In the formula, This represents the theoretical pressure-opening influence coefficient. Indicates inlet pressure, This represents the total cross-sectional area of ​​the nozzle throat. This represents the cross-sectional area of ​​the mixing chamber. Indicates the current gravitational coefficient. Indicates the design ejection coefficient. This indicates the percentage of steam valve opening corresponding to the design operating conditions. Indicates nozzle efficiency. This represents the flow coefficient correction factor obtained from the valve characteristic curve. Let be the entrainment coefficient function, and Substitute them into the calculation: ; in, Indicates nozzle efficiency; The calculation process of the theoretical pressure-opening influence coefficient is as follows: The processor first reads the preset design parameters of the mixer from the non-volatile memory, including the total cross-sectional area of ​​the nozzle throat, the cross-sectional area of ​​the mixing chamber, the design ejector coefficient, the steam valve opening corresponding to the design operating condition, the nozzle efficiency, and the steam valve flow gain. The theoretical pressure boosting capacity of the mixer is determined by the nozzle's design ejector coefficient, which is a performance indicator of the mixer under rated operating conditions. Nozzle efficiency reflects the internal flow loss of the nozzle, determined by the nozzle geometry and surface roughness, and is provided by the equipment manufacturer. The processor calculates the theoretical pressure-opening influence coefficient according to the definition of the ejector coefficient function, based on the current inlet pressure, the total cross-sectional area of ​​the nozzle throat, the cross-sectional area of ​​the mixing chamber, the current ejector coefficient, the design ejector coefficient, the steam valve opening corresponding to the design operating condition, and the nozzle efficiency. The ejector coefficient function adopts a simplified form from one-dimensional compressible flow theory. The difference between the current ejector coefficient and the design ejector coefficient is calculated by mapping them through this function, and then divided by the steam valve opening corresponding to the design operating condition to obtain the change in ejector coefficient per unit opening change. This change is multiplied by the product of the inlet pressure and the area ratio, and then multiplied by the flow coefficient correction factor obtained from the valve characteristic curve to obtain the theoretical pressure-opening influence coefficient. The physical meaning of this coefficient is that when the ejector coefficient deviates from the design value, the change in steam valve opening required to maintain a constant outlet pressure must satisfy this proportional relationship with the changes in inlet pressure, area ratio, and ejector coefficient. The introduction of the flow coefficient correction factor allows theoretical calculations to adapt to the nonlinear effects caused by different valve flow characteristics (such as equal percentage or linear characteristics), improving the matching degree between the theoretical model and specific equipment. S33. Based on the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam isobaric specific heat, the outlet mixed steam mass flow rate, and the steam valve flow gain, calculate the theoretical temperature-opening influence coefficient: ; in, This represents the theoretical temperature-aperture influence coefficient. This indicates the specific enthalpy of high-pressure steam. Indicates the specific enthalpy of the outlet steam. This indicates the specific heat of the outlet steam at constant pressure. Indicates the mass flow rate of the mixed steam at the outlet. This indicates the steam valve flow gain, which is corrected based on the stated inlet pressure and the design inlet pressure. ; in, This indicates the design high-pressure steam mass flow rate. This indicates the design inlet pressure.

[0033] The calculation process of the theoretical temperature-opening influence coefficient is as follows. The processor calculates the theoretical temperature-opening influence coefficient based on the high-pressure steam specific enthalpy, outlet steam specific enthalpy, outlet steam isobaric specific heat, outlet mixed steam mass flow rate, and steam valve flow gain, according to the energy conservation principle. The numerator of this coefficient is the difference between the high-pressure steam specific enthalpy and the outlet steam specific enthalpy, representing the additional energy carried by a unit mass of high-pressure steam relative to the outlet steam; the denominator is the product of the outlet steam isobaric specific heat and the outlet mixed steam mass flow rate, representing the total heat capacity of the outlet steam. The ratio of the numerator to the denominator represents the temperature change caused by a unit change in steam flow rate. Multiplying this by the steam valve flow gain yields the temperature change caused by a unit change in valve opening. The steam valve flow gain is not a fixed constant but is corrected based on the ratio of the current inlet pressure to the design inlet pressure. The specific correction relationship is based on the critical or subcritical flow characteristics of the nozzle, i.e., the flow rate is proportional to the square root of the inlet pressure. This correction allows the theoretical estimate of temperature sensitivity to be dynamically adjusted with fluctuations in inlet pressure.

[0034] As described in steps S31-S33 above, this embodiment is based on the fluid dynamics and thermodynamics principles of a steam jet mixer. Using equipment design parameters and real-time acquired physical property data, it calculates the theoretical pressure-opening influence coefficient and the theoretical temperature-opening influence coefficient. These two coefficients characterize the theoretical sensitivity of changes in steam valve opening to outlet pressure and outlet temperature, respectively. Their calculation aims to provide prior physical information for subsequent coefficient fusion, enabling the control system to obtain reasonable sensitivity estimates even under drastic changes in operating conditions and when historical data has not yet been accumulated.

[0035] The theoretical coefficient calculation method described above differs from existing technologies in the control of steam jet mixers in that: in existing technologies, pressure-opening sensitivity and temperature-opening sensitivity are mainly obtained through offline calibration or online data fitting. Offline calibration cannot adapt to changes in operating conditions and long-term performance degradation, while online fitting lags due to insufficient data during sudden changes in operating conditions. This embodiment combines equipment design parameters with real-time operating parameters, directly deriving the theoretical values ​​of the sensitivity coefficients through a physical model. These theoretical values ​​can be obtained at the initial moment of a pressure setpoint step or inlet pressure change, providing timely prior information for feedforward control. The ejector coefficient function introduced in the calculation of the theoretical pressure-opening influence coefficient enables the theoretical model to reflect the nonlinear effect of changes in ejector efficiency on pressure sensitivity. In actual operation in the workshop, when the reactor load decreases, leading to a reduction in the demand for low-pressure steam, the ejector coefficient decreases. The value of the ejector coefficient function at the current ejector coefficient is less than the value at the design ejector coefficient, and the theoretical pressure-opening influence coefficient decreases accordingly. This automatic adjustment mechanism allows the theoretical coefficient to reflect equipment performance degradation such as nozzle scaling and decreased ejector efficiency without the need to recalibrate control parameters. This contributes to solving the problem of uneven mixing of steam and ejected fluid under variable operating conditions in traditional equipment. The steam valve flow gain correction used in the calculation of the theoretical temperature-opening influence coefficient allows the temperature sensitivity to be adjusted synchronously with inlet pressure fluctuations. During the preheating stage of the pharmaceutical reactor, when a rapid increase in outlet flow is required, the theoretical temperature-opening influence coefficient provides prior information on the temperature disturbance caused by changes in steam valve opening. This enables feedforward control to calculate the required desuperheating water compensation while performing pressure regulation, avoiding the chasing oscillations of the pressure loop acting first and the temperature loop responding later in traditional schemes. There is also an inherent synergistic relationship between the two theoretical coefficients: both are based on the same set of design parameters and real-time operating data, and both are derived using the principle of physical conservation. In the subsequent coefficient fusion step, their weights are determined by the same set of statistical variances and preset uncertainties, ensuring the physical consistency of the fused pressure sensitivity and temperature sensitivity, and avoiding contradictions caused by independent estimation. This prior estimation method based on a physical model enables the control system to maintain reasonable control behavior even when data is insufficient or operating conditions change drastically, providing a foundation for multivariable decoupled control.

[0036] In one embodiment of the present invention, the step of fitting the statistical pressure-opening influence coefficient and the statistical temperature-opening influence coefficient using the least squares method based on the historical sequence of the real-time operating data includes: S41. Obtain historical data for the most recent preset number of sampling periods, and construct the steam valve opening change sequence, the desuperheating water valve opening change sequence, the outlet pressure change sequence, and the outlet temperature change sequence. S42. Based on the steam valve opening change sequence and the outlet pressure change sequence, fit the statistical pressure-opening influence coefficient using the least squares method; S43. Based on the sequence of steam valve opening changes and the sequence of outlet temperature changes, fit the statistical temperature-opening influence coefficient using the least squares method.

[0037] As described in steps S41-S43 above, this embodiment achieves online fitting of statistical influence coefficients. Unlike the theoretical coefficients based on physical models in the previous steps, this step utilizes historical data from a recent period to online fit the statistical pressure-opening influence coefficients and statistical temperature-opening influence coefficients using the least squares method. These statistical coefficients reflect the actual dynamic characteristics of the steam jet mixer under current operating conditions, and can automatically adapt to individual equipment differences and performance degradation during long-term operation. This contributes to solving the problem that existing technologies, which use fixed empirical values ​​or offline calibration, cannot adapt to equipment differences and changes in operating conditions.

[0038] In the steps of acquiring historical data for the most recent preset number of sampling periods and constructing sequences of steam valve opening changes, desuperheating water valve opening changes, outlet pressure changes, and outlet temperature changes, the processor maintains a circular buffer in memory to store historical data for the most recent preset number of sampling periods. In this embodiment, the sampling period is set to 100 milliseconds, the preset number is 100 sampling points, corresponding to a 10-second time window. The choice of this window length is based on the following considerations: a window that is too short will cause the fitting results to be greatly affected by random noise, while a window that is too long will reduce the response speed to changes in operating conditions. A 10-second window is commonly used in industrial process control and can achieve a balance between noise suppression and response speed. For each sampling point, the processor calculates the following changes: steam valve opening change (the difference between the current steam valve opening and the previous steam valve opening); desuperheating water valve opening change (the difference between the current desuperheating water valve opening and the previous desuperheating water valve opening); outlet pressure change (the difference between the current outlet pressure and the previous outlet pressure); and outlet temperature change (the difference between the current outlet temperature and the previous outlet temperature). These changes are arranged in chronological order, forming four sequences, denoted as the steam valve opening change sequence, the desuperheating water valve opening change sequence, the outlet pressure change sequence, and the outlet temperature change sequence, respectively.

[0039] The statistical pressure-opening influence coefficient characterizes the actual average change in outlet pressure when the steam valve opening changes by a unit percentage under current operating conditions. The processor fits a linear relationship between the steam valve opening change sequence and the outlet pressure change sequence using the least squares method. The core of the least squares method is to minimize the sum of squares of the prediction error, i.e., to find a coefficient that minimizes the sum of squares of the differences between the measured and predicted values ​​of the outlet pressure change at all sampling points. This coefficient is calculated by dividing the sum of the products of the steam valve opening change and the outlet pressure change by the sum of the squares of the steam valve opening change. This statistical coefficient directly reflects the actual gain of the entire channel from the valve actuator to the pressure sensor, including the combined effects of pipeline resistance, valve nonlinearity, and sensor response. In long-term operation in a pharmaceutical plant, when valve wear leads to changes in flow characteristics, or when pipe scaling increases resistance, the statistical pressure-opening influence coefficient gradually deviates from its initial calibration value, allowing the control system to automatically adapt to these changes.

[0040] The statistical temperature-opening influence coefficient characterizes the actual average change in outlet temperature when the steam valve opening changes by a unit percentage under current operating conditions. The processor fits the statistical temperature-opening influence coefficient using the least squares method based on the steam valve opening change sequence and the outlet temperature change sequence. The coefficient is calculated by dividing the sum of the products of the steam valve opening change and the outlet temperature change by the sum of the squares of the steam valve opening change. This statistical coefficient reflects the actual impact of steam valve regulation on temperature. Unlike the theoretical temperature-opening influence coefficient, this statistical coefficient includes actual factors such as heat loss during steam transport through the pipeline and the response delay of the temperature sensor. During the reactor preheating stage, when the steam flow rate increases rapidly, the proportion of heat loss through the pipeline decreases relatively, and the statistical temperature-opening influence coefficient increases accordingly. This change is captured by the statistical coefficient in real time.

[0041] During the actual operation of a steam jet mixer, the equipment characteristics change slowly over time. For example, nozzles may wear or scale due to long-term use, leading to a decrease in the ejector coefficient; aging valve packing may alter flow characteristics; and scaling on the inner wall of the pipe may increase flow resistance. These changes cannot be fully captured by the theoretical model based on design parameters in step S3 because the theoretical model relies on the design values ​​at the time of manufacture and cannot be automatically updated. Step S4, by fitting historical data online, enables the control system to continuously track the actual characteristic changes of the equipment. When the ejector coefficient decreases due to nozzle scaling, the statistical pressure-opening influence coefficient automatically decreases, reflecting the need for a larger valve opening to maintain the same pressure regulation effect. This also applies when the flow characteristics of the desuperheating water valve change. More importantly, the statistical coefficients provided in step S4 complement the theoretical coefficients provided in step S3. Theoretical coefficients are advantageous during drastic changes in operating conditions because they do not rely on historical data and can provide reasonable estimates at the initial moment of the change; while statistical coefficients are advantageous under steady-state conditions because they accurately reflect the current actual situation of the equipment. This complementarity provides the basis for the weighted fusion in step S5, enabling the two coefficients to be dynamically combined according to their respective credibility, thereby maintaining an accurate description of dynamic characteristics across the entire operating range.

[0042] In practical applications, when a production batch switch causes the pressure setpoint to jump from 1.2 MPa to 1.6 MPa, the historical data window still contains a large amount of data from the old operating conditions within the initial second of the jump, and the statistical coefficients have not yet been updated. If the statistical coefficients are used alone, the control effect will deteriorate due to the coefficient lag. However, in this invention, the statistical coefficients are not used alone, but are integrated with the theoretical coefficients. When the variance of the statistical coefficients is large, the weight of the theoretical coefficients automatically increases, ensuring the accuracy of control. When the system enters a new steady state, the historical data window is gradually filled with data from the new operating conditions, the variance of the statistical coefficients decreases, and the weight of the statistical coefficients automatically increases, further improving the control precision. This adaptive mechanism, which relies on theory during rapid changes in operating conditions and on statistics during steady-state operation, is the result of the synergistic effect of the statistical coefficient fitting step and the subsequent fusion step. This effect cannot be achieved by using the statistical coefficients alone.

[0043] In one embodiment of the present invention, the steps of calculating the confidence weight of the statistical coefficient based on the estimated variance of the statistical pressure-opening influence coefficient and the preset uncertainty of the theoretical pressure-opening influence coefficient, weightedly fusing the theoretical pressure-opening influence coefficient and the statistical pressure-opening influence coefficient to obtain the fused pressure-opening influence coefficient under the current operating condition, and weightedly fusing the theoretical temperature-opening influence coefficient and the statistical temperature-opening influence coefficient to obtain the fused temperature-opening influence coefficient under the current operating condition include: S51. Calculate the estimated variance of the statistical pressure-opening influence coefficient based on the historical dataset: ; in, This represents the estimated variance of the statistical pressure-opening influence coefficient. Indicates the first The change in outlet pressure over each sampling period Indicates the first Change in steam valve opening over a sampling period This represents the statistical pressure-opening influence coefficient. Indicates the number of historical data; S52. Obtain the preset uncertainty of the theoretical pressure-opening influence coefficient and calculate the confidence weight of the statistical coefficient: ; in, Indicates the confidence weight. This represents the preset uncertainty (obtained through pre-shipment calibration tests). Specifically, before the steam jet mixer leaves the factory, it is installed on a test bench and tested at multiple steady-state operating points (covering 30%, 50%, 70%, 100%, and 120% load of the design operating range). At each test point, after the system pressure, temperature, and flow parameters stabilize, data such as inlet pressure, outlet pressure, steam valve opening, high-pressure steam flow, and low-pressure steam flow are recorded. The actual influence coefficient of the outlet pressure on the steam valve opening under this operating condition is measured through a small step disturbance test. Simultaneously, using the theoretical pressure-opening influence coefficient calculation formula, the theoretical pressure-opening influence coefficient is calculated based on the inlet pressure, ejector coefficient, and mixer design parameters under this operating condition. The difference between the theoretical coefficient and the actual coefficient at each test point is used to obtain the deviation value. Statistical analysis is performed on the deviation values ​​of all test points, and the variance is calculated as the preset uncertainty. This preset uncertainty reflects the degree of systematic deviation between the simplified physical model and the actual equipment (it is stored as a fixed parameter in the control system when the equipment leaves the factory). When the estimated variance increases, the confidence weight automatically decreases. S53. Calculate the fusion pressure-opening influence coefficient under the current operating conditions: ; in, This represents the fusion pressure-aperture influence coefficient. This represents the statistical pressure-opening degree influence coefficient. Indicates the confidence weight. This represents the theoretical pressure-opening influence coefficient after correction by the model deviation factor. (Under steady-state conditions, the ratio of the statistical pressure-opening influence coefficient to the theoretical pressure-opening influence coefficient is calculated as the measured value of the model deviation factor, and the model deviation factor is updated through a first-order low-pass filter to obtain the current model deviation factor. Under dynamic conditions, the model deviation factor is kept at the value after the most recent steady-state update. The theoretical pressure-opening influence coefficient is multiplied by the model deviation factor to obtain the corrected theoretical pressure-opening influence coefficient. The theoretical temperature-opening influence coefficient is multiplied by the model deviation factor to obtain the corrected theoretical temperature-opening influence coefficient. During long-term operation of the equipment, the model deviation factor will be slowly updated so that the theoretical coefficient can track the performance degradation trend of the equipment.) S54. Calculate the fusion temperature-aperture influence coefficient under the current operating conditions: ; in, This represents the fusion temperature-aperture influence coefficient. This represents the temperature-aperture effect coefficient. Indicates the confidence weight. This represents the theoretical temperature-opening influence coefficient after correction by the model bias factor (obtained using the same method as the theoretical pressure-opening influence coefficient).

[0044] As described in steps S51-S54 above, the present invention adaptively determines the fusion weight of theoretical coefficients and statistical coefficients based on the estimated variance of statistical coefficients, so that the control system prioritizes the use of statistical coefficients to reflect the actual dynamics when the operating conditions are stable, and automatically increases the weight of theoretical coefficients to ensure control quality when the operating conditions change drastically, thereby achieving complementary advantages.

[0045] The estimated variance of the statistical pressure-opening influence coefficient is a key indicator for measuring the reliability of the statistical coefficient. It is defined as the sum of squared residuals of all sampling points divided by the degrees of freedom. The fitted residual is the difference between the measured value of the outlet pressure change and the value predicted based on the statistical coefficient. The sum of squared residuals reflects the degree of fit of the statistical model to historical data. When the operating conditions are stable and the linear relationship between the steam valve opening change and the outlet pressure change is good, the fitted residual is small, and the estimated variance is also small, indicating that the statistical coefficient has high reliability. When the operating conditions change drastically and other disturbance factors exist, the fitted residual increases, and the estimated variance also increases accordingly, indicating that the reliability of the statistical coefficient decreases. During the batch switching process in a pharmaceutical workshop, when the pressure setpoint changes abruptly, the steam valve opening adjusts rapidly. However, due to pipeline capacitance and sensor response delay, the outlet pressure response has inertia. At this time, the linear relationship between the steam valve opening change and the outlet pressure change weakens, and the estimated variance temporarily increases.

[0046] The preset uncertainty of the theoretical pressure-opening influence coefficient reflects the systematic deviation between the theoretical model and the actual situation, and can be pre-calibrated using factory test data. At the time of equipment delivery, steady-state testing is performed to measure the actual pressure-opening influence coefficient under different operating conditions, and this is compared with the theoretically calculated value. The variance of the deviation between the two is then calculated, which is the preset uncertainty. This preset uncertainty represents the average deviation level of the theoretical model throughout the entire life cycle of the equipment and is a relatively stable constant. For example, in pharmaceutical workshop applications, the preset uncertainty is small when the equipment is newly put into use; as the equipment operates for a long time, and nozzles accumulate scale or wear, the deviation between the theoretical model and reality may increase, but the preset uncertainty remains unchanged as the factory calibration value. This design ensures the consistency of the fusion weight calculation.

[0047] The confidence weight of the statistical coefficients is calculated by dividing the preset uncertainty of the theoretical coefficients by the sum of the estimated variance of the statistical coefficients and the preset uncertainty of the theoretical coefficients. When the estimated variance of the statistical coefficients is small, it indicates a good fit to the historical data, and the statistical coefficients have high reliability. In this case, the confidence weight is large, and the statistical coefficients dominate the fusion result. When the estimated variance of the statistical coefficients is large, it indicates a poor fit to the historical data or drastic changes in operating conditions. The reliability of the statistical coefficients decreases, and the confidence weight is small. In this case, the theoretical coefficients dominate the fusion result. The physical meaning of this adaptive weighting mechanism is that when the measured data is reliable, the control system trusts the measured data; when the measured data is unreliable, the control system reverts to the theoretical model. Compared with existing technologies that use fixed weights or threshold switching based on the magnitude of changes in operating conditions, the confidence weight based on the estimated variance has clear statistical significance, does not require manual threshold setting, and can smoothly adapt to various changes in operating conditions.

[0048] At the initial stage of actual production batch switching, the estimated variance of the statistical coefficients is large, and the confidence weight is small. The fused pressure-opening influence coefficient is mainly contributed by the theoretical coefficients, ensuring the accuracy of the first action of the feedforward control. Once the system enters steady state, the estimated variance of the statistical coefficients decreases, the confidence weight increases, and the fused pressure-opening influence coefficient gradually transitions to being dominated by the statistical coefficients, ensuring that the control parameters accurately match the actual dynamics of the current operating condition. The fused temperature-opening influence coefficient is used in subsequent steps to calculate the temperature disturbance caused by the steam valve adjustment; its accuracy affects the calculation accuracy of the desuperheating water compensation. For example, in the isothermal reaction stage of a pharmaceutical reactor, temperature control accuracy is extremely high. At this time, the estimated variance of the statistical coefficients is small, the confidence weight is large, and the fused temperature-opening influence coefficient is mainly contributed by the statistical coefficients, accurately reflecting the temperature response characteristics under the current operating condition. When disturbances such as inlet pressure fluctuations occur, the estimated variance of the statistical coefficients temporarily increases, and the weight of the theoretical coefficients automatically increases, making the temperature disturbance estimation more robust and avoiding compensation errors caused by the lag of the statistical coefficients.

[0049] The fusion pressure-opening influence coefficient and the fusion temperature-opening influence coefficient are weighted by a confidence level fusion mechanism, which allows for synchronous adjustment of weights as operating conditions change, ensuring coordination and consistency between pressure regulation and temperature compensation. In practical applications, when the reactor switches from standby to reaction mode, the pressure setpoint increases dramatically. The fusion pressure-opening influence coefficient and the fusion temperature-opening influence coefficient simultaneously transition from being dominated by theoretical coefficients to being dominated by statistical coefficients. This ensures that the steam valve feedforward adjustment and the desuperheating water feedforward compensation always match the dynamic characteristics of the current operating condition, allowing for accurate action at the initial stage of operating condition changes. This avoids the mutual interference caused by separate settings for the pressure and temperature loops in traditional schemes, and prevents over-adjustment and oscillations caused by coefficient lag.

[0050] Furthermore, this fusion mechanism can automatically adapt to long-term degradation of equipment performance. For example, when the nozzle becomes scaled due to long-term use, and the ejector coefficient drops from 0.22 to 0.18, the theoretical coefficient automatically decreases, and the statistical coefficient is gradually updated using historical data during subsequent operation. In steady-state conditions, the statistical coefficient dominates, reflecting the actual state of the equipment; during periods of drastic change in operating conditions, the theoretical coefficient takes precedence, having already been automatically corrected based on the current ejector coefficient. The synergistic effect of these two mechanisms enables the control system to automatically track changes in equipment performance without requiring manual recalibration.

[0051] In one embodiment of the present invention, the steps of calculating the steam valve feedforward adjustment amount based on the fusion pressure-opening influence coefficient when a change in pressure setpoint or fluctuation in inlet pressure is detected, calculating the temperature disturbance caused by the steam valve feedforward adjustment amount based on the fusion temperature-opening influence coefficient, and then calculating the desuperheating water feedforward compensation amount required to offset the temperature disturbance based on energy conservation include: S61. When a change in the pressure setpoint is detected, calculate the target pressure change and, in conjunction with the fused pressure-opening influence coefficient, calculate the steam valve feedforward adjustment: ; in, This indicates the steam valve feedforward adjustment amount. This represents the change in target pressure. This represents the fusion pressure-aperture influence coefficient; S62. When a change in inlet pressure is detected, calculate the steam valve compensation required to maintain a constant outlet pressure based on the inlet pressure-outlet pressure influence coefficient obtained by fitting historical data: ; in, Indicates the steam valve compensation amount. This represents the inlet pressure - outlet pressure influence coefficient. This indicates the change in inlet pressure. This represents the fusion pressure-aperture influence coefficient. S63. Calculate the temperature disturbance caused by the steam valve feedforward adjustment or the steam valve compensation based on the fusion temperature-opening influence coefficient: ; or: ; in, This indicates the amount of temperature disturbance. This represents the fusion temperature-aperture influence coefficient. This indicates the steam valve feedforward adjustment amount. This indicates the steam valve compensation amount; when the pressure setpoint change and inlet pressure fluctuation occur simultaneously, the steam valve feedforward adjustment amount and the steam valve compensation amount are superimposed to calculate the temperature disturbance caused by the total compensation amount, and the calculation method is the same as above. S64. Calculate the change in desuperheating water flow rate required to offset the temperature disturbance based on the law of energy conservation: ; in, This indicates the change in the flow rate of the desuperheating water. Indicates the mass flow rate of the mixed steam at the outlet. This indicates the specific heat of the outlet steam at constant pressure. This represents the amount of temperature disturbance. This indicates the specific enthalpy of the desuperheating water, obtained by querying a physical property database based on the desuperheating water pressure and temperature. Indicates the specific enthalpy of the outlet steam; S65. Convert the change in desuperheating water flow rate into a change in the opening degree of the desuperheating water valve (the change in the opening degree of the desuperheating water valve is used as the feedforward compensation amount for the desuperheating water): ; in, This indicates the change in the opening degree of the desuperheating water valve. This indicates the change in the flow rate of the desuperheating water. This represents the flow gain of the desuperheating water valve at the current opening degree, obtained from the valve characteristic curve. Indicates the flow rate of the desuperheating water For valve opening The derivative; As described in steps S61-S65 above, this embodiment differs from the prior art in that the pressure loop and temperature loop are adjusted independently. This step enables pressure regulation and temperature compensation to be completed collaboratively within the same control cycle, thereby avoiding oscillations caused by the two loops chasing each other.

[0052] In the specific implementation process: The processor continuously monitors changes in the outlet pressure setpoint. When it detects that the pressure setpoint has changed from the previous value to the current value, it calculates the target pressure change, which is the difference between the current setpoint and the previous setpoint. For example, if the outlet pressure setpoint changes from 1.2 MPa to 1.6 MPa, the target pressure change is 0.4 MPa. Based on the fused pressure-opening influence coefficient, the required steam valve feedforward adjustment to achieve this pressure change is calculated, i.e., the target pressure change is divided by the fused pressure-opening influence coefficient. The significance of this calculation is that the fused pressure-opening influence coefficient characterizes the amount of outlet pressure change caused by a unit change in steam valve opening. Therefore, dividing the target pressure change by this coefficient yields the required feedforward opening adjustment. This feedforward adjustment is calculated and output at the initial moment of the pressure setpoint change, without waiting for pressure feedback deviation to occur, thus achieving rapid response.

[0053] When a change in inlet pressure is detected (e.g., the rate of change of inlet pressure exceeds a preset threshold over multiple consecutive sampling periods), the processor calculates the steam valve compensation amount required to maintain a constant outlet pressure based on the inlet pressure-outlet pressure influence coefficient. The inlet pressure-outlet pressure influence coefficient is obtained by fitting historical data, and its calculation method is similar to step S42, i.e., fitting a linear relationship between the change in inlet pressure and the change in outlet pressure, characterizing the change in outlet pressure caused by a unit change in inlet pressure. Since an increase in inlet pressure will cause a corresponding increase in outlet pressure, the steam valve needs to be closed to maintain a constant outlet pressure. Therefore, the compensation amount calculation formula includes a negative sign; that is, when the inlet pressure increases, the compensation amount is negative, indicating a reduction in the steam valve opening; when the inlet pressure decreases, the compensation amount is positive, indicating an increase in the steam valve opening. This compensation amount is also calculated and output at the initial moment of the inlet pressure fluctuation, playing a feedforward compensation role.

[0054] Whether the steam valve adjustment is due to changes in the pressure setpoint or fluctuations in the inlet pressure, it will alter the high-pressure steam flow rate into the mixer, thereby changing the total energy input to the mixer and causing a change in the outlet temperature. The processor calculates the magnitude of this temperature disturbance based on the fusion temperature-opening influence coefficient, which is calculated by multiplying the steam valve adjustment by the fusion temperature-opening influence coefficient. The fusion temperature-opening influence coefficient characterizes the change in outlet temperature caused by a unit change in steam valve opening; therefore, this product is the expected temperature disturbance value. When the steam valve opening increases, the energy entering the mixer increases, the outlet temperature rises, and the temperature disturbance is positive; when the steam valve opening decreases, the temperature disturbance is negative.

[0055] To counteract the aforementioned temperature disturbance, the desuperheating water flow rate needs to be adjusted synchronously. The processor calculates the required change in desuperheating water flow rate based on the law of conservation of energy. The principle of this calculation is as follows: After the desuperheating water is injected into the mixer, it vaporizes from liquid water and heats up to the outlet steam temperature. The heat absorbed is equal to the desuperheating water flow rate multiplied by the difference between the specific enthalpy of the desuperheating water and the specific enthalpy of the outlet steam. Since the temperature of the desuperheating water is usually much lower than the outlet steam temperature, this difference is negative, indicating that the desuperheating water has absorbed heat. The heat absorbed to counteract the temperature disturbance is equal to the mass flow rate of the outlet mixed steam multiplied by the specific heat at constant pressure of the outlet steam multiplied by the temperature disturbance value. By setting these two values ​​equal, the required change in desuperheating water flow rate can be solved. Since the denominator is negative, and the desuperheating water flow rate needs to be increased when the temperature disturbance is positive, a negative sign is set in the formula to make the calculation result positive. The calculation is based on the principle of energy conservation and uses the desuperheating water specific enthalpy and outlet steam specific enthalpy obtained from step S23, the outlet mixed steam mass flow rate calculated from step S22, and the outlet steam constant pressure specific heat obtained from step S23. All parameters are real-time physical property values ​​under the current operating conditions, rather than empirical constants. Therefore, the compensation calculation has high accuracy.

[0056] The change in desuperheating water flow rate is converted into a change in the opening degree of the desuperheating water valve. The processor obtains the flow gain of the desuperheating water valve at the current opening degree. This gain reflects the change in desuperheating water flow rate caused by a unit change in valve opening degree. It can be obtained by looking up a table based on the flow characteristic curve provided by the valve manufacturer, or estimated online using historical data. Dividing the change in desuperheating water flow rate calculated in step S64 by this flow gain yields the required change in the opening degree of the desuperheating water valve. This change in opening degree will be used as a feedforward compensation amount, which, when superimposed with the temperature PID feedback amount, jointly drives the desuperheating water valve.

[0057] In existing technologies, pressure regulation loops and temperature regulation loops typically operate independently. When the pressure setpoint changes, the pressure loop first adjusts the steam valve, bringing the outlet pressure closer to the new setpoint, but simultaneously, the outlet temperature deviates due to changes in steam flow. Subsequently, the temperature loop detects the temperature deviation and adjusts the desuperheating water valve to correct it; the adjustment of the desuperheating water valve then causes a change in the outlet pressure, triggering another response from the pressure loop. This alternating adjustment process results in oscillating convergence of pressure and temperature, with adjustment times lasting tens of seconds, and may lead to product quality defects in applications with stringent process requirements.

[0058] This invention achieves synchronized execution of pressure regulation and temperature compensation through steps S61-S65. While calculating the steam valve adjustment, the synchronous desuperheating water compensation is calculated based on energy conservation, enabling the actions of the two actuators to be coordinated within the same control cycle. This synchronization mechanism relies on the fusion influence coefficient and the real-time physical property parameters obtained in step S2. The fusion pressure-opening influence coefficient ensures the accuracy of the steam valve adjustment, the fusion temperature-opening influence coefficient ensures the accuracy of temperature disturbance prediction, and the energy conservation calculation based on the IAPWS-IF97 physical property database ensures the physical determinism of the desuperheating water compensation. This step integrates two disturbance sources—pressure setpoint changes and inlet pressure fluctuations—into the feedforward compensation framework. Whether the setpoint change is caused by active process switching or passive disturbance is caused by upstream pipeline fluctuations, the system can respond quickly without distinguishing the disturbance type, demonstrating good robustness. Furthermore, the introduction of the inlet pressure-outlet pressure influence coefficient allows the system to actively adjust the steam valve to maintain a constant outlet pressure when the inlet pressure fluctuates, preventing disturbances from being transmitted downstream. This mechanism is particularly important in industrial scenarios where steam supply pressure in thermal power plants fluctuates frequently, effectively isolating the impact of upstream disturbances on downstream processes. This solves the problem of mutual interference between the two circuits in existing technologies.

[0059] In one embodiment of the present invention, the method further includes a step of modifying the command of the desuperheating water valve: S71. Obtain the current outlet mixed steam mass flow rate, outlet steam density, and mixer outlet pipe cross-sectional area, and calculate the current steam velocity: ; in, Indicates the current steam flow rate. This indicates the cross-sectional area of ​​the mixer outlet pipe. Indicates the outlet steam density. Indicates the mass flow rate of the mixed steam at the outlet; S72. Calculate the adaptive filter time constant based on the design flow velocity under the design conditions:

[0060] in, This represents the adaptive filtering time constant. Indicates the design flow rate under the design conditions. Indicates the current steam flow rate. The reference time constant is defined as follows: when the current steam flow rate is lower than a preset percentage of the design flow rate, the upper limit of the adaptive filtering time constant is limited; when the current steam flow rate is higher than a preset percentage of the design flow rate, the lower limit of the adaptive filtering time constant is limited. S73. The desuperheating water valve command is processed through a first-order inertial filter to obtain the final command: ; in, Indicates the final instruction. This indicates a command for the desuperheating water valve. This indicates the filtered desuperheating water valve command from the previous moment. Indicates the sampling period. Represents the natural constant. This represents the exponential decay factor.

[0061] As described in steps S71-S73 above, this invention incorporates a dynamic response correction step. The core of this correction lies in the time delay between the desuperheating water being injected into the mixer and its complete vaporization and uniform mixing with the main steam. This delay varies with the steam flow rate. When the flow rate is high, the transmission time from the desuperheating water injection point to the temperature sensor measurement point is short, resulting in a faster mixing process; conversely, when the flow rate is low, the transmission time is prolonged, leading to a slower mixing process. If a filter with a fixed time constant is used, overcompensation (overshooting due to excessively fast filtering) or undercompensation (sluggish response due to excessively slow filtering) may occur when the flow rate changes. This step calculates the steam flow rate in real time and adaptively adjusts the filter time constant accordingly, ensuring that the dynamic characteristics of the desuperheating water regulation match the physical delay of the mixing process.

[0062] The processor first calculates the current steam velocity. The steam velocity equals the product of the outlet mixed steam mass flow rate divided by the outlet steam density and the cross-sectional area of ​​the mixer outlet pipe. The outlet mixed steam mass flow rate is calculated through a mass balance verification step, the outlet steam density is obtained from a physical property database based on the outlet pressure and temperature, and the cross-sectional area of ​​the mixer outlet pipe is a design parameter. The steam velocity directly affects the time constant of the mixing process: the higher the velocity, the shorter the transmission time of the fluid from the desuperheating water injection point to the temperature sensor location, resulting in faster mixing; the lower the velocity, the longer the transmission time, resulting in slower mixing. In the variable load operation of a pharmaceutical workshop, when the reactor switches from standby to reaction mode, the steam flow rate increases significantly, the steam velocity rises accordingly, and the mixing time constant decreases; when the reaction enters the heat preservation stage, the steam flow rate decreases, the steam velocity decreases, and the mixing time constant increases. This dynamic characteristic dictates that the filtering time constant should vary with the flow rate.

[0063] Then, the adaptive filtering time constant is calculated based on the design flow rate under the design conditions. The reference time constant is a mixed time constant at the design flow rate, which can be determined through a step response test, and can be set to, for example, 0.5 seconds. When the current steam flow rate is higher than the design steam flow rate, the filtering time constant is smaller than the reference time constant, the filtering effect is weakened, and the command response is faster; when the current steam flow rate is lower than the design steam flow rate, the filtering time constant is larger than the reference time constant, the filtering effect is enhanced, and the command response is slowed down. To prevent the filtering time constant from deviating excessively from a reasonable range under extreme conditions, the processor also sets upper and lower limit protection: when the current steam flow rate is lower than a preset proportion of the design flow rate, the upper limit of the filtering time constant is limited; when the current steam flow rate is higher than a preset proportion of the design flow rate, the lower limit of the filtering time constant is limited. For example, when the flow rate is lower than 50% of the design flow rate, the upper limit of the time constant can be set to 1 second to avoid slow filtering leading to sluggish response; when the flow rate is higher than 150% of the design flow rate, the lower limit of the time constant can be set to 0.2 seconds to avoid weak filtering leading to command oscillation.

[0064] The desuperheating valve command is then processed through a first-order inertial filter to obtain the final command. First-order inertial filtering is a commonly used signal smoothing method in industrial control. Its current output equals the original command multiplied by the filter coefficient, plus the previous filtered output multiplied by a minus filter coefficient. The filter coefficient is a subtraction of an exponential attenuation factor, determined by the sampling period and the filtering time constant. The filter coefficient ranges from 0 to 1; a larger filtering time constant results in a smaller filter coefficient and stronger suppression of high-frequency disturbances. In steam jet mixer applications, filtering the desuperheating valve command makes the actuator movement smoother, avoiding valve overshoot and fluid shock caused by sudden command changes.

[0065] The above steps also have a synergistic relationship with the feedforward compensation calculation step. The feedforward compensation calculation step provides steady-state compensation based on energy conservation, ensuring accuracy under steady-state conditions. The dynamic response correction step provides dynamic filtering based on flow velocity adaptation, ensuring smooth command execution under transient conditions. The combination of these two steps guarantees both the physical accuracy of the compensation and the dynamic adaptability of command execution. During the preheating stage of the pharmaceutical reactor, the feedforward compensation calculation step calculates a larger desuperheating water compensation to offset the temperature rise. The dynamic response correction step uses a smaller filtering time constant based on the higher steam flow rate at this time, enabling the desuperheating water valve to respond quickly. During the reaction stage, the feedforward compensation calculation step calculates a small compensation to maintain a constant temperature. The dynamic response correction step uses a larger filtering time constant based on the lower steam flow rate at this time, avoiding frequent operation of the desuperheating water valve. This design, which balances steady-state accuracy and dynamic response, allows the control system to maintain stable temperature control quality across different operating conditions.

[0066] like Figure 2As shown, the present invention also provides a variable adaptive operation decision system for a steam jet mixer, comprising: The data acquisition module includes a pressure sensor installed in the mixer inlet pipe, a pressure sensor and a temperature sensor installed in the mixer outlet pipe, a valve position feedback sensor installed in the steam flow regulating valve and the desuperheating water regulating valve, and flow meters installed in the high-pressure steam pipeline, the low-pressure steam pipeline, and the desuperheating water pipeline. The sampling period of each sensor can be set to 100 milliseconds to acquire real-time operating data of the steam jet mixer. The real-time operating data includes inlet pressure, outlet pressure, outlet temperature, steam valve opening, desuperheating water valve opening, high-pressure steam mass flow rate, low-pressure steam mass flow rate, desuperheating water mass flow rate, and mixed steam mass flow rate.

[0067] The ejector coefficient estimation module is used to calculate the current ejector coefficient based on the high-pressure steam mass flow rate and the low-pressure steam mass flow rate, and to query the steam property database based on the inlet pressure and the outlet pressure to obtain the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, and the outlet steam isobaric specific heat.

[0068] The physical model calculation module is used to store the design parameters of the mixer, and calculate the theoretical pressure-opening influence coefficient and the theoretical temperature-opening influence coefficient by combining the current ejector coefficient, the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, and the outlet steam isobaric specific heat.

[0069] The statistical fitting module is used to fit the statistical pressure-opening influence coefficient and the statistical temperature-opening influence coefficient using the least squares method based on the historical sequence of the real-time operating data.

[0070] The decoupled calculation module is used to calculate the confidence weight of the statistical coefficient based on the estimated variance of the statistical pressure-opening influence coefficient and the preset uncertainty of the theoretical pressure-opening influence coefficient, and to perform weighted fusion of the theoretical pressure-opening influence coefficient and the statistical pressure-opening influence coefficient to obtain the fused pressure-opening influence coefficient under the current operating condition. It also performs weighted fusion of the theoretical temperature-opening influence coefficient and the statistical temperature-opening influence coefficient to obtain the fused temperature-opening influence coefficient under the current operating condition.

[0071] The feedforward compensation module is used to calculate the steam valve feedforward adjustment amount based on the fusion pressure-opening influence coefficient when a change in pressure setpoint or inlet pressure fluctuation is detected, calculate the temperature disturbance caused by the steam valve feedforward adjustment amount based on the fusion temperature-opening influence coefficient, and then calculate the desuperheating water feedforward compensation amount required to offset the temperature disturbance based on energy conservation.

[0072] The collaborative control module is used to superimpose the feedforward compensation amount of the desuperheating water with the temperature PID feedback amount to generate a desuperheating water valve command; superimpose the feedforward adjustment amount of the steam valve with the pressure PID feedback amount to generate a steam valve command; and output the steam valve command and the desuperheating water valve command to the corresponding actuators. The actuators control the steam flow rate and the desuperheating water flow rate respectively based on the steam valve command and the desuperheating water valve command, thereby adjusting the steam temperature at the mixer outlet.

[0073] The above modules can be implemented by the processor in a PLC (Programmable Logic Controller), DCS (Distributed Control System), or embedded industrial controller, which executes the corresponding program modules.

[0074] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of a steam jet mixer variable adaptive operation decision method.

[0075] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of a steam jet mixer variable adaptive operation decision method.

[0076] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0077] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A variable adaptive operation decision-making method for a steam jet mixer, characterized in that, include: Acquire real-time operating data of the steam jet mixer, wherein the real-time operating data includes at least inlet pressure, outlet pressure, outlet temperature, high-pressure steam mass flow rate, and low-pressure steam mass flow rate; The current ejector coefficient is calculated based on the high-pressure steam mass flow rate and the low-pressure steam mass flow rate, and the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, and the outlet steam isobaric specific heat are obtained based on the inlet pressure and the outlet pressure. The theoretical pressure-opening influence coefficient and the theoretical temperature-opening influence coefficient are calculated based on the current ejector coefficient, the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam constant pressure specific heat, and the preset design parameters of the mixer. Obtain historical sequences of real-time operating data, and based on the historical sequences, obtain the statistical pressure-opening degree influence coefficient and the statistical temperature-opening degree influence coefficient through linear regression; The confidence weight of the statistical coefficient is calculated based on the statistical pressure-opening influence coefficient and the theoretical pressure-opening influence coefficient. The theoretical pressure-opening influence coefficient and the statistical pressure-opening influence coefficient are then weighted and fused to obtain the fused pressure-opening influence coefficient under the current operating condition. The theoretical temperature-opening influence coefficient and the statistical temperature-opening influence coefficient are then weighted and fused to obtain the fused temperature-opening influence coefficient under the current operating condition. When a change in pressure setpoint or fluctuation in inlet pressure is detected, the steam valve feedforward adjustment amount is obtained according to the fusion pressure-opening influence coefficient, the temperature disturbance caused by the steam valve feedforward adjustment amount is calculated according to the fusion temperature-opening influence coefficient, and the desuperheating water feedforward compensation amount required to offset the temperature disturbance is calculated according to the energy conservation. The desuperheating water feedforward compensation amount is superimposed with the temperature PID feedback amount to generate a desuperheating water valve command; the steam valve feedforward adjustment amount is superimposed with the pressure PID feedback amount to generate a steam valve command; the steam valve command and the desuperheating water valve command are output to the corresponding actuators.

2. The adaptive operation decision-making method for a steam jet mixer according to claim 1, characterized in that, It also includes a mass balance verification step: The mass flow rate of the desuperheating water and the mass flow rate of the mixed steam are obtained. The mass balance error is calculated by combining the mass flow rate of the high-pressure steam and the mass flow rate of the low-pressure steam. It is then determined whether the mass balance error exceeds a preset threshold. If it does, an alarm signal is output and the update rate of the statistical pressure-opening influence coefficient and the statistical temperature-opening influence coefficient are reduced.

3. The adaptive operation decision-making method for a steam jet mixer according to claim 1, characterized in that, The steps for calculating the theoretical pressure-opening influence coefficient and the theoretical temperature-opening influence coefficient based on the current ejector coefficient, the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam constant-pressure specific heat, and the preset design parameters of the mixer include: Obtain the preset design parameters of the mixer, including the total cross-sectional area of ​​the nozzle throat, the cross-sectional area of ​​the mixing chamber, the design ejector coefficient, the steam valve opening degree corresponding to the design operating condition, the nozzle efficiency, and the steam valve flow gain. The theoretical pressure-opening influence coefficient is calculated based on the inlet pressure, the total cross-sectional area of ​​the nozzle throat, the cross-sectional area of ​​the mixing chamber, the current ejector coefficient, the design ejector coefficient, the steam valve opening corresponding to the design operating condition, and the nozzle efficiency. The theoretical temperature-opening influence coefficient is calculated based on the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam constant-pressure specific heat, the outlet mixed steam mass flow rate, and the steam valve flow gain.

4. The adaptive operation decision-making method for a steam jet mixer according to claim 1, characterized in that, The steps of acquiring historical sequences of real-time operational data and obtaining statistical pressure-opening influence coefficients and statistical temperature-opening influence coefficients through linear regression based on the historical sequences include: Obtain historical data from the most recent preset number of sampling periods to construct sequences of steam valve opening changes, desuperheating water valve opening changes, outlet pressure changes, and outlet temperature changes. Based on the steam valve opening change sequence and the outlet pressure change sequence, the statistical pressure-opening influence coefficient is fitted using the least squares method. Based on the sequence of steam valve opening changes and the sequence of outlet temperature changes, a statistical temperature-opening influence coefficient is fitted using the least squares method.

5. The adaptive operation decision-making method for a steam jet mixer according to claim 1, characterized in that, The steps of calculating the confidence weight of the statistical coefficient based on the estimated variance of the statistical pressure-opening influence coefficient and the preset uncertainty of the theoretical pressure-opening influence coefficient, weighting and fusing the theoretical pressure-opening influence coefficient and the statistical pressure-opening influence coefficient to obtain the fused pressure-opening influence coefficient under the current operating condition, and weighting and fusing the theoretical temperature-opening influence coefficient and the statistical temperature-opening influence coefficient to obtain the fused temperature-opening influence coefficient under the current operating condition include: The estimated variance of the statistical pressure-opening influence coefficient is calculated based on the historical dataset. Obtain the preset uncertainty of the theoretical pressure-opening influence coefficient, and calculate the confidence weight of the statistical coefficient in combination with the estimated variance; The fusion pressure-opening influence coefficient under the current operating condition is obtained based on the confidence weight and the statistical pressure-opening influence coefficient. The fusion temperature-opening influence coefficient under the current operating condition is obtained based on the confidence weight and the temperature-opening influence coefficient.

6. The adaptive operation decision-making method for a steam jet mixer according to claim 1, characterized in that, The steps of calculating the steam valve feedforward adjustment amount based on the fusion pressure-opening influence coefficient when a change in pressure setpoint or inlet pressure fluctuation is detected, calculating the temperature disturbance caused by the steam valve feedforward adjustment amount based on the fusion temperature-opening influence coefficient, and then calculating the desuperheating water feedforward compensation amount required to offset the temperature disturbance based on energy conservation include: When a change in the pressure setpoint is detected, the target pressure change is obtained, and the steam valve feedforward adjustment is calculated by combining the fused pressure-opening influence coefficient. When a change in inlet pressure is detected, the amount of change in inlet pressure and the inlet pressure-outlet pressure influence coefficient are obtained, and the amount of steam valve compensation required to maintain a constant outlet pressure is calculated in combination with the fusion pressure-opening influence coefficient. The temperature disturbance is calculated based on the steam valve feedforward adjustment amount and / or the steam valve compensation amount, combined with the fusion temperature-opening influence coefficient. The change in desuperheating water flow rate required to offset the temperature disturbance is calculated based on the law of energy conservation. The change in the desuperheating water flow rate is converted into a desuperheating water feedforward compensation.

7. The adaptive operation decision-making method for a steam jet mixer according to claim 1, characterized in that, It also includes the step of modifying the command for the desuperheating water valve: Obtain the current outlet mixed steam mass flow rate, outlet steam density, and mixer outlet pipe cross-sectional area, and calculate the current steam velocity; Obtain the design flow rate under the design conditions to calculate the adaptive filtering time constant; The desuperheating water valve command is processed through a first-order inertial filter to obtain the final command.

8. A variable adaptive operation decision system for a steam jet mixer, characterized in that, include: The data acquisition module is used to acquire real-time operating data of the steam jet mixer, which includes at least inlet pressure, outlet pressure, outlet temperature, high-pressure steam mass flow rate, and low-pressure steam mass flow rate. The ejector coefficient estimation module is used to calculate the current ejector coefficient based on the high-pressure steam mass flow rate and the low-pressure steam mass flow rate, and to obtain the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, and the outlet steam isobaric specific heat based on the inlet pressure and the outlet pressure. The physical model calculation module is used to calculate the theoretical pressure-opening influence coefficient and the theoretical temperature-opening influence coefficient based on the current ejector coefficient, the high-pressure steam specific enthalpy, the outlet steam specific enthalpy, the outlet steam constant pressure specific heat, and the preset design parameters of the mixer. The statistical fitting module is used to obtain the historical sequence of real-time running data, and based on the historical sequence, to obtain the statistical pressure-opening influence coefficient and the statistical temperature-opening influence coefficient through linear regression. The decoupled calculation module is used to calculate the confidence weight of the statistical coefficient based on the statistical pressure-opening influence coefficient and the theoretical pressure-opening influence coefficient, to perform weighted fusion of the theoretical pressure-opening influence coefficient and the statistical pressure-opening influence coefficient to obtain the fused pressure-opening influence coefficient under the current operating condition, and to perform weighted fusion of the theoretical temperature-opening influence coefficient and the statistical temperature-opening influence coefficient to obtain the fused temperature-opening influence coefficient under the current operating condition. The feedforward compensation module is used to obtain the steam valve feedforward adjustment amount according to the fusion pressure-opening influence coefficient when a change in pressure setpoint or inlet pressure fluctuation is detected, calculate the temperature disturbance caused by the steam valve feedforward adjustment amount according to the fusion temperature-opening influence coefficient, and then calculate the desuperheating water feedforward compensation amount required to offset the temperature disturbance according to energy conservation. The collaborative control module is used to superimpose the feedforward compensation amount of the desuperheating water with the temperature PID feedback amount to generate a desuperheating water valve command; superimpose the feedforward adjustment amount of the steam valve with the pressure PID feedback amount to generate a steam valve command; and output the steam valve command and the desuperheating water valve command to the corresponding actuators.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

Images