Check valve device adopting dynamic pressure detection and compensation algorithm

Abstract

The invention discloses a check valve device adopting a dynamic pressure detection and compensation algorithm, and relates to the technical field of automatic control. The device comprises a valve, a pressure sensor group and a control part, the pressure sensor group comprises two pressure sensors which are respectively arranged at the upstream and the downstream of the valve and are used for continuously acquiring instantaneous pressure data; the control part is used for calculating the instantaneous pressure difference inside and outside the valve according to the obtained instantaneous pressure data, and performing nonlinear correction on the reference opening degree by using a correction factor to obtain the final command opening degree; the method comprises the following steps: constructing a kinetic equation of a valve core to represent an actual valve opening constraint under torque-free control; and torque control is conducted according to the deviation between the final command opening degree and the actual valve opening degree. The opening degree can be adjusted in real time to respond to the complex fluid environment, and the dynamic response performance, the energy utilization efficiency and the adaptability to complex working conditions are remarkably improved.

Description

Technical Field

[0001] This application relates to the field of automatic control technology, and particularly to a check valve device using a dynamic pressure detection and compensation algorithm. Background Art

[0002] Fluid control technology is widely used in fields such as energy, chemical industry, aerospace, and mechanical manufacturing. Among them, the check valve, as an important device for controlling the one-way flow of fluids, is widely used due to its simple structure, low cost, and strong adaptability. However, with the continuous improvement of the complexity of industrial systems and the diversity of fluid conditions, the deficiencies of traditional check valves in dynamic control, response speed, and energy efficiency have gradually emerged, and urgent improvements are needed to meet the high-performance requirements of modern industries.

[0003] In the prior art, the research on check valves mainly focuses on the following aspects: one is the optimization of the valve structure, including improving the sealing performance of the valve and reducing the mass of the valve core to reduce the resistance and inertia of the valve action; the second is to use material technology to improve the corrosion resistance, high temperature resistance, and high pressure resistance of the valve core and valve seat to meet the usage requirements of different fluid media; the third is to study the hydrodynamic characteristics and optimize the valve flow path design to reduce the resistance loss when the fluid passes through. However, these optimization measures mainly focus on the physical properties of the valve. Although good results can be achieved in certain specific fields, in high-dynamic fluid conditions, especially in scenarios where the pressure and flow rate change violently, the performance of traditional check valves is still greatly limited.

[0004] The opening and closing actions of traditional check valves usually rely on changes in fluid pressure and flow rate to drive, lacking the ability to actively control the dynamic changes of fluids. In scenarios where the fluid pressure fluctuates violently or the flow rate changes frequently, the opening and closing actions of the check valve are prone to lag, resulting in an increase in system energy loss. For example, in some high-pressure transmission pipelines, due to the lag of the check valve response, fluid backflow or water hammer phenomena may occur, which not only reduces the system operation efficiency but also may pose a threat to equipment safety. Existing check valves usually rely on mechanical structures or simple electronic induction devices to judge the opening and closing states of the valves, but it is difficult to accurately monitor parameters such as the real-time pressure, flow rate, and density of fluids. Lack of support from dynamic data makes the control strategy of check valves relatively single and difficult to adapt to complex fluid environments. For example, in the face of different fluid media (such as gases, liquids) or fluid states (such as turbulent flow, laminar flow), the check valves in the prior art lack targeted adjustment capabilities. Summary of the Invention

[0005] The embodiments of this application provide a check valve device using a dynamic pressure detection and compensation algorithm. The present invention can adjust the opening in real time to respond to complex fluid environments, significantly improving the dynamic response performance, energy utilization efficiency, and adaptability to complex working conditions.

[0006] The embodiment of the present application provides a check valve device adopting a dynamic pressure detection and compensation algorithm. The device includes: a valve, a pressure sensor group, and a control part. The pressure sensor group includes two pressure sensors, which are respectively installed upstream and downstream of the valve to continuously acquire instantaneous pressure data. The control part is used to calculate the instantaneous pressure difference inside and outside the valve according to the acquired instantaneous pressure data, select the instantaneous pressure differences at three known historical times in the past, and fit these discrete-time instantaneous pressure differences into an interpolation curve through quadratic Lagrange interpolation to obtain a dynamic pressure prediction value from it. Using the obtained dynamic pressure prediction value, it is weighted and fused with the measured pressure difference to obtain a corrected effective pressure difference. Combining the corrected effective pressure difference with physical parameters such as fluid density, viscosity, sound speed, and characteristic length, dimensionless processing is performed to calculate the reference valve opening. Based on the reference valve opening, the instantaneous effective flow area of the valve is obtained through the known opening-area nonlinear relationship, and then the reference flow velocity is estimated according to the corrected effective pressure difference and fluid density, and the Reynolds number and Mach number are further calculated. Using the effective flow area and reference flow velocity, the instantaneous mass flow rate is calculated. At the same time, the specific enthalpy is calculated through the fluid temperature and specific heat capacity at constant pressure. Coupling the mass flow rate and specific enthalpy, and constructing a performance index based on the sum of the upstream and downstream pressures. This performance index measures the thermodynamic energy transport efficiency carried by the fluid under specific head conditions. Lagrange interpolation is performed on the performance index values at different past times to predict the trend of the performance index and obtain a predicted value. Then, the predicted value is compared with the actual performance index to define a correction factor. The reference opening is nonlinearly corrected using the correction factor to obtain the final command opening. By constructing the dynamic equation of the valve core itself, the actual valve opening constraint under no torque control is represented. According to the deviation between the final command opening and the actual valve opening, torque control is performed.

[0007] Further, define the instantaneous pressure difference at time as which also represents the measured pressure difference at time Let be the instantaneous pressure data upstream at time Let be the instantaneous pressure data downstream at time ; wherein, and are integer subscript indices; Let be the dynamic pressure prediction value at time Let Instantaneous pressure difference over time; and are both known historical times.

[0008] Furthermore, through the following formula, using the obtained dynamic pressure prediction value, it is weighted and fused with the measured pressure difference to obtain the corrected effective pressure difference : ; wherein, is the adjustment factor, which is a set value and its value is between 0 and 1.

[0009] Furthermore, through the following formula, the corrected effective pressure difference is combined with physical parameters such as fluid density, viscosity, sound speed, and characteristic length, and after dimensionless processing, the reference valve opening is calculated: ; wherein, is the reference valve opening at time is the viscosity at time is the sound speed at time is the fluid density at time is the reference density; is the adiabatic index of air, and its value is 1.4; is the internal length of the valve; is the acceleration due to gravity.

[0010] Furthermore, based on the reference valve opening, the instantaneous effective flow area of the valve is obtained through the known opening-area non-linear relationship, and then based on the corrected effective pressure difference and fluid density, the reference flow velocity is estimated, and the Reynolds number and Mach number are further calculated: Define the effective flow area of the valve as: ; wherein, is the nominal diameter of the valve, is the maximum opening; through the following formula, using the reference opening the instantaneous effective flow area is obtained: ; Define the Reynolds number and the Mach number as: ; wherein, the reference flow velocity is calculated based on the Bernoulli approximation through the following formula: ; Furthermore, the instantaneous mass flow rate is calculated by the following formula using the effective flow area and the reference flow velocity: ; The specific enthalpy of the fluid is defined as ; where is the fluid temperature at time and is the specific heat capacity at constant pressure; the performance index ; Furthermore, the trend of the performance index is predicted by the following formula using the performance index values at the past three times to obtain the predicted value, where is an integer subscript index with a value range from 0 to 2: The predicted value is compared with the actual performance index by the following formula to define a correction factor , combined with the dimensionless parameters and where are the set reference Reynolds number and reference Mach number: ; where is a positive value less than 0.000001.

[0011] Furthermore, the reference opening is non-linearly corrected using the correction factor by the following formula to obtain the final commanded opening: ; where is the final commanded opening.

[0012] Furthermore, the dynamic equation of the valve spool itself is constructed by the following formula: ; where is the actual valve opening; is the moment of inertia; is the mechanical damping; is the elastic stiffness; (rad) is the nominal equilibrium point; is the hydrodynamic torque at time is the gravitational torque; The calculation formula is as follows: ; The calculation formula of is as follows: ; Among them, is the horizontal offset of the centroid of the valve relative to the rotating shaft; is the mass of the valve core.

[0013] Furthermore, the deviation between the final command opening and the actual valve opening is calculated through the following formula ; the flow velocity error is calculated through the following formula ; among them, is the designed flow velocity (m / s); the control torque is calculated through the following formula : ; The check valve device adopting the dynamic pressure detection and compensation algorithm provided by this application. The present invention adopts the real-time dynamic pressure detection and compensation algorithm, precisely captures the instantaneous pressure data upstream and downstream of the valve through a pressure sensor group, and calculates the change trend of the pressure difference, thereby adjusting the opening and closing state of the valve in real time. By using the quadratic Lagrange interpolation method to fit the pressure data and generate the dynamic pressure prediction value, the ability to predict the change of the fluid state is significantly improved. Compared with the traditional check valve that relies on a single mechanical structure to passively respond to the change of fluid pressure, the present invention can respond faster to pressure fluctuations in a dynamic fluid environment, thereby effectively avoiding the occurrence of backflow, water hammer or fluid oscillation phenomena, and ensuring the safe and stable operation of the system. The present invention introduces a dimensionless treatment that combines the corrected effective pressure difference with fluid physical parameters in the control algorithm, dynamically calculates the reference opening degree, and generates the final command opening degree in combination with the nonlinear correction algorithm. This method fully considers the characteristics of the fluid such as density, viscosity, and sound speed, and tightly couples fluid dynamics with the valve control system. By accurately calculating the effective flow area of the valve and the flow velocity error, it ensures that the movement of the valve core matches the fluid demand, thereby significantly reducing the resistance loss when the fluid passes through the valve and optimizing the energy transfer and utilization efficiency. Especially in a high-speed and high-pressure fluid environment, the present invention minimizes the energy loss of the fluid by dynamically adjusting the valve opening degree. The present invention adopts the dynamic modeling of fluid torque and gravity torque, combines the dimensionless Reynolds number and Mach number calculated in real time, and enables the system to flexibly adapt to different fluid working conditions. By dynamically monitoring the changes in fluid density, flow velocity and temperature, the system can accurately calculate the force on the valve core, and optimize the control strategy by constructing the dynamic equation of the valve core itself. For example, in a high-pressure and turbulent environment, the present invention uses the correction of the sound speed and compressibility parameters to dynamically adjust the control torque to ensure that the valve can remain stable under the impact of high-speed fluid; while in a low-flow velocity and laminar flow environment, the system reduces the damping torque to improve the opening and closing sensitivity to better adapt to the current fluid characteristics. Compared with the limitation that traditional check valves are difficult to achieve stable operation under variable working conditions, the multi-parameter dynamic regulation ability of the present invention significantly enhances its adaptability under complex working conditions. Description of the Drawings

[0014] The following will combine the drawings and describe the specific embodiments of this application in detail, making the technical solutions and other beneficial effects of this application obvious.

[0015] Figure 1 It is a schematic structural diagram of the check valve device adopting the dynamic pressure detection and compensation algorithm provided by the embodiment of the present invention. Specific Embodiments

[0016] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0017] Embodiment 1: Refer to Figure 1 , a check valve device adopting a dynamic pressure detection and compensation algorithm, the device comprising: a valve, a pressure sensor group and a control part; the pressure sensor group includes two pressure sensors, which are respectively installed upstream and downstream of the valve to continuously obtain instantaneous pressure data; the control part is used to calculate the instantaneous pressure difference inside and outside the valve according to the obtained instantaneous pressure data, select the instantaneous pressure differences at three known historical times in the past, and fit these instantaneous pressure differences at discrete times into an interpolation curve through quadratic Lagrangian interpolation, and obtain a dynamic pressure prediction value therefrom; use the obtained dynamic pressure prediction value, and perform weighted fusion with the measured pressure difference to obtain a corrected effective pressure difference; combine the corrected effective pressure difference with physical parameters such as fluid density, viscosity, sound speed and characteristic length, perform dimensionless processing and then calculate a reference valve opening; based on the reference valve opening, obtain the instantaneous effective flow area of the valve through the known non-linear relationship between opening and area, then estimate the reference flow velocity according to the corrected effective pressure difference and fluid density, and further calculate the Reynolds number and Mach number; use the effective flow area and reference flow velocity to calculate the instantaneous mass flow rate; at the same time, calculate the specific enthalpy through the fluid temperature and specific heat capacity at constant pressure; couple the mass flow rate and specific enthalpy, and construct a performance index based on the sum of the upstream and downstream pressures; this performance index measures the thermodynamic energy transfer efficiency carried by the fluid under specific head conditions; perform Lagrangian interpolation on the performance index values at different times in the past to predict the trend of the performance index and obtain a predicted value; then, compare the predicted value with the actual performance index to define a correction factor; use the correction factor to perform non-linear correction on the reference opening to obtain the final command opening; represent the actual valve opening constraint under no torque control by constructing the dynamic equation of the valve core itself; perform torque control according to the deviation between the final command opening and the actual valve opening.

[0018] Specifically, the dynamic pressure characteristics of the check valve are crucial for fluid control. By means of two pressure sensors installed upstream and downstream of the valve, the device can continuously collect real-time pressure data, which respectively reflect the pressure states of the upstream and downstream fluids at a certain moment. Through real-time differential processing of the upstream and downstream pressure data, the instantaneous pressure difference inside and outside the valve can be obtained. The instantaneous pressure difference is not only an important characteristic parameter of fluid dynamics but also an important basis for judging the dynamic behavior of the valve. Compared with the traditional method that relies on the static pressure average value or single-point pressure observation, the present invention can capture the rapid change characteristics of the fluid more accurately through dynamic pressure acquisition. Especially under unsteady or sudden flow conditions, this real-time data acquisition provides the necessary time-series information for subsequent prediction and control. After obtaining the instantaneous pressure difference inside and outside the valve, the present invention adopts an interpolation prediction method to establish a dynamic change model of the pressure difference. For this purpose, three representative historical instantaneous pressure difference values need to be selected from the past pressure records. These values correspond to three different time points, usually selected according to a uniform time interval or in combination with specific fluid change characteristics. These historical instantaneous pressure differences not only reflect the recent working state of the valve but also contain the non-linear change trend in fluid dynamics. The utilization of this historical data enables the prediction model to comprehensively consider the dynamic changes within a short period and provide a more accurate reference for the current real-time pressure difference.

[0019] To model these discrete historical pressure differences, the present invention introduces the quadratic Lagrange interpolation method. The advantage of this interpolation method is that it can connect the discrete time points by constructing a continuous interpolation curve while retaining the non-linear characteristics of the data. The interpolation curve can not only fit the existing historical pressure difference data but also predict the pressure state at a future moment. Mathematically, the interpolation model utilizes the polynomial relationship between historical time points. Through specific weight calculations, the interpolation curve can perfectly pass through each known time point. This process significantly improves the accuracy of dynamic pressure prediction because it avoids the error accumulation that may occur in simple linear prediction and can capture the non-linear changes in dynamic fluid pressure. The dynamic pressure prediction value is obtained through the extrapolation calculation of the interpolation curve. This prediction value reflects the possible change trend of the instantaneous pressure difference inside and outside the valve at a specific time point. Different from the method of directly using the current measured value for calculation, the prediction value is not only based on the current instantaneous data but also comprehensively considers the change rules of historical data. This dynamic prediction based on historical data provides stronger robustness for the pressure compensation algorithm. Especially in the case of drastic changes in fluid flow rate and pressure, the prediction value can significantly reduce the influence caused by instantaneous measurement errors or data fluctuations.

[0020] The predicted value of dynamic pressure is the interpolation result based on historical data, which can reflect the possible change trend of the instantaneous pressure difference at a certain future moment. However, the predicted value cannot completely replace the real-time measurement value because, under complex fluid conditions, the instantaneous pressure difference measured in real time contains the latest information of the current working condition. Therefore, the present invention adopts a weighted fusion method to combine the predicted value with the instantaneous pressure difference measured in real time to generate a corrected effective pressure difference. This correction process establishes a balance between the predicted value and the measured value through the design of the weighting factor, so that the final result can not only retain the accuracy of real-time measurement but also utilize the trend information of the prediction model to make up for the possible short-term fluctuations or data noise in instantaneous measurement. Through weighted fusion, the corrected effective pressure difference has more physical significance. It represents the actual pressure state of the fluid under the combined action inside and outside the valve and can provide a more stable basis for subsequent calculations. The corrected effective pressure difference is not only an independent control parameter but also needs to be combined with the basic physical properties of the fluid to comprehensively describe the dynamic behavior of the fluid inside the valve. In fluid mechanics, the density, viscosity, sound speed, and characteristic length of the fluid are important factors determining its dynamic and thermodynamic properties. These parameters and the corrected effective pressure difference act together to form a complex multi-dimensional system, directly affecting the flow pattern of the fluid and the control performance of the valve. However, directly dealing with these physical parameters with different dimensions will lead to an increase in computational complexity and reduce the generality of the algorithm. Therefore, the present invention adopts dimensionless processing to convert the corrected effective pressure difference and these physical parameters into dimensionless forms, greatly simplifying the system analysis and improving the adaptability of the control algorithm under different working conditions.

[0021] Dimensionless normalization is a classic method in fluid mechanics. Its core idea is to normalize physical quantities with different dimensions by constructing dimensionless parameters, enabling them to uniformly characterize the system characteristics. In the present invention, the dimensionless normalization process is based on the corrected effective pressure difference, combined with fluid density, characteristic length, and sound speed to form a dimensionless parameter. This dimensionless parameter can not only eliminate dimensional differences but also highlight the internal relationships between physical quantities, thus more intuitively reflecting the characteristic state of the fluid passing through the valve. For example, when describing the driving effect of the pressure difference on fluid flow, the dimensionless parameter can be directly related to dimensionless quantities such as the Reynolds number and Mach number, thereby revealing the dynamic characteristics of the fluid under different conditions. Based on the result of the dimensionless normalization process, the reference valve opening can be further calculated. The reference valve opening is the core variable in the check valve control, which directly determines the flow area of the valve and the fluid flow regulation ability. The calculation of the opening not only depends on the corrected effective pressure difference but also needs to consider the geometric characteristics of the valve and the dynamic behavior of the fluid. In the present invention, a non-linear relationship model is adopted for the calculation of the reference opening, breaking through the limitations of the traditional linear model. The non-linear model can more accurately describe the actual relationship between the valve opening and the flow area, especially under complex fluid conditions, where this relationship may exhibit highly non-linear characteristics. By combining the corrected dimensionless pressure difference and fluid characteristics, the reference valve opening can accurately reflect the ideal opening state that the valve needs to achieve under the current fluid state. The significance of the reference valve opening lies not only in providing a theoretical value but also in providing a benchmark for subsequent dynamic control and optimization. In practical applications, the final opening of the valve still needs to be further adjusted in combination with performance indicators, correction factors, and real-time dynamic responses. However, as the starting point of the entire control process, the reference opening directly determines the control accuracy and response speed. The present invention realizes the integrated design from data acquisition to parameter control by introducing dynamic pressure prediction values, weighted fusion correction, dimensionless normalization processing, and non-linear opening calculation, which not only improves the control accuracy of the valve but also significantly enhances the adaptability of the system under complex working conditions.

[0022] The reference valve opening is the core variable in valve control, which determines the instantaneous flow capacity of the valve. In the present invention, the reference opening is converted into an instantaneous effective flow area through a non-linear relationship that matches the actual geometry and physical properties. Traditional valve designs usually assume a simple linear relationship between the opening and the flow area, but this is often difficult to hold under actual fluid conditions, especially in complex fluid conditions with high pressure differences and high flow velocities. To improve the prediction accuracy, the present invention adopts a non-linear relationship model that is closer to the actual situation, so that the calculated flow area can more realistically reflect the actual situation of the fluid flowing through the valve. The effective flow area depends not only on the opening, but also on the valve design and fluid distribution. The introduction of this non-linear relationship provides a more accurate basis for subsequent parameter calculations. Based on the calculated effective flow area and the corrected effective pressure difference, the present invention further estimates the reference flow velocity. The flow velocity is an important parameter describing the hydrodynamic characteristics of the fluid, and its magnitude directly affects the momentum transfer and energy transfer of the fluid passing through the valve. The estimation of the reference flow velocity comprehensively considers the relationship between the fluid density and the effective pressure difference, and is determined by the principles of energy conservation and momentum conservation. The calculation of the flow velocity is not only the basis for subsequent mass flow calculation, but also provides necessary information for describing the hydrodynamic state. On this basis, the Reynolds number and Mach number are further calculated to comprehensively characterize the flow state of the fluid. The Reynolds number, as a dimensionless quantity, is used to describe the flow state characteristics of the fluid in the pipeline and judge whether it is laminar flow or turbulent flow. The Mach number reflects the ratio of the fluid velocity to the local speed of sound and is an important index for describing compressible fluids. The calculation of these parameters enables the system to accurately predict the fluid behavior under different working conditions, thus providing support for the dynamic adjustment of the valve.

[0023] After the flow rate calculation is completed, the present invention further calculates the instantaneous mass flow rate using the effective flow area and the reference flow rate. The mass flow rate is a key parameter describing the instantaneous conveying capacity of the fluid through the valve, and its magnitude is directly related to the working efficiency and stability of the system. By combining the effective flow area and the flow rate, the instantaneous mass flow rate of the fluid can be accurately obtained, laying a foundation for subsequent thermodynamic analysis. At the same time, in order to evaluate the thermodynamic properties of the fluid, the present invention calculates the specific enthalpy according to the fluid temperature and the specific heat capacity at constant pressure. The specific enthalpy is an important physical quantity describing the thermal energy contained in a unit mass of fluid, and its magnitude is affected by temperature and the nature of the substance (such as the specific heat capacity at constant pressure). During the control process of the check valve, the change in specific enthalpy directly affects the energy conveying capacity of the fluid and the thermal efficiency of the system. The combination of the mass flow rate and the specific enthalpy further enables the present invention to construct a thermodynamic performance index, which is used to measure the thermal energy conveying efficiency of the fluid under specific head conditions. The performance index is based on the sum of the upstream and downstream pressures, comprehensively considering the thermodynamic energy and kinetic characteristics of the fluid. The physical meaning of this index is that it not only describes the total amount of energy carried by the fluid but also reflects the effectiveness of the check valve in energy conveyance under dynamic working conditions. Compared with traditional single-flow control or static energy calculation methods, the present invention realizes a comprehensive evaluation of the system efficiency through the introduction of the performance index. The calculation of the performance index depends on the instantaneous state of the fluid and can also reflect the dynamic performance of the overall system operation, providing more guiding feedback information for subsequent optimization and control.

[0024] Performance indicators are key parameters for measuring the energy transfer efficiency of fluids in check valves. They are calculated based on the dynamic and thermodynamic characteristics of the fluid, taking into account factors such as upstream and downstream pressures, mass flow rate, and specific enthalpy. Under dynamic operating conditions, the changing trend of performance indicators directly reflects the changes in the system operating state. To predict this changing trend, the present invention uses the Lagrange interpolation method to perform interpolation calculations on the performance indicator values at different past time points. This interpolation method constructs a polynomial curve that can pass through all known data points, connecting the discrete time points to form a continuous performance indicator change curve. The core of interpolation lies in capturing the non-linear laws in the historical changes of performance indicators and using these laws to extrapolate into the future to predict the trend of performance indicators. This prediction method can provide forward-looking information for the control system under complex fluid conditions, enabling the control of the valve to respond to system changes in advance. The predicted value of the performance indicator is not used alone as a theoretical result, but rather provides a basis for defining the correction factor of the system by comparing it with the actual performance indicator. The actual performance indicator is calculated based on real-time measured physical quantities, which has high timeliness but may be affected by short-term data fluctuations; while the predicted value synthesizes the trend information of historical data and can better reflect the overall changing trend of the system. Therefore, comparing the two can effectively quantify the deviation between the current system state and the prediction model. This deviation is characterized by the correction factor, and the magnitude and direction of the correction factor reflect the difference between the system model and the actual state, providing an adjustment basis for subsequent control processes.

[0025] The correction factor is not simply applied to the performance index, but indirectly affects the valve control strategy through the non-linear correction of the reference opening. In the present invention, the reference opening is the valve opening value in the ideal state calculated based on the corrected effective pressure difference and dimensionless parameters. However, this value may be affected by the changes in working conditions and model errors during actual operation. Therefore, by performing non-linear correction on the reference opening through the correction factor, the finally generated command opening can better meet the actual requirements of the current working conditions. This non-linear correction process fully considers the non-linear dynamic characteristics of the system, making the valve control more flexible and adaptable. The command opening is not the final parameter directly applied to the valve because the actual valve opening is limited by the dynamic characteristics of the valve core. The present invention constructs the dynamic equation of the valve core itself to describe the movement law of the valve core under torque-free control. The dynamics of the valve core are affected by various factors, including fluid force, elastic restoring force, and the inertia and damping characteristics of the valve core itself. These factors jointly determine the opening range that the valve core can reach under no external torque control. By establishing the dynamic equation, the present invention accurately describes the constraint conditions of the actual valve opening, providing a physical basis for the actual execution of the command opening. In the final torque control link, the present invention compares the command opening with the actual valve opening to calculate the deviation between the two. This deviation reflects the gap between the current state and the target state of the valve core. The core task of torque control is to minimize this gap by adjusting the externally applied torque. Torque control not only needs to quickly respond to the changes in the deviation but also fully consider the constraint conditions of the valve core dynamics to avoid system oscillation or instability caused by excessive control input. The present invention realizes the rapid convergence of the command opening and the actual opening through a closed-loop control strategy, enabling the valve to maintain high-precision and high-response dynamic control capabilities under complex fluid working conditions.

[0026] Example 2: Definition The instantaneous pressure difference at time is , and it also represents the measured pressure difference at time; is the instantaneous upstream pressure data at time; is the instantaneous downstream pressure data at time; By the following formula, select the instantaneous pressure differences at the past three known historical times, and through quadratic Lagrange interpolation, fit these discrete-time instantaneous pressure differences into an interpolation curve to obtain the dynamic pressure prediction value from it: ; where and are integer subscript indices; is the dynamic pressure prediction value at time; is Instantaneous pressure difference over time; and All are known historical times.

[0027] Specifically, the formula constructs the basis function To allocate each historical pressure difference The weight, weight size and current prediction time The dynamic adjustment of weights enables the interpolation curve to smoothly transition within the local range of change, avoiding the error accumulation that may be caused by simple linear extrapolation. This fitting feature is particularly important in complex fluid environments, because the pressure changes upstream and downstream of the valve are usually affected by a variety of nonlinear factors, including fluid density, flow velocity fluctuations, and interference from the flow channel shape. Interpolation prediction value The physical meaning of is that it is not only a mathematical approximation based on the historical data of instantaneous pressure difference, but also a trend estimation of the current state of the fluid. , predicted value The change law of historical time points is integrated to more robustly reflect the evolution of pressure over time. This feature provides more forward-looking input parameters for the dynamic control of the check valve, which helps the system maintain stable response performance under conditions of drastic pressure changes or large measurement data noise. Specifically, when predicting dynamic pressure, the formula selects the three most recent time points. The instantaneous pressure difference , limiting the fluid pressure change model to a short time window to avoid excessive influence of long-term data on current predictions. This short-term trend prediction strategy, combined with the real-time dynamic compensation algorithm of the present invention, can quickly adapt to the frequency and amplitude of pressure changes upstream and downstream of the valve, and provide high-quality basic data for subsequent control calculations (such as dimensionless processing, opening correction, etc.).

[0028] Embodiment 3: The following formula is used to obtain the predicted dynamic pressure value and weightedly fuse it with the measured pressure difference to obtain the corrected effective pressure difference: : ; in, is the adjustment factor and is the set value, which is between 0 and 1.

[0029] Specifically, the formula It shows that the corrected effective pressure difference consists of two parts: one is the instantaneous pressure difference directly measured , which reflects the actual pressure difference between the upstream and downstream of the valve at the current moment; the second is the dynamic pressure prediction value The measured pressure difference The latter reflects the adjustment of the prediction model to the measured value. This adjustment is achieved through the adjustment factor Control its weight to balance the predicted data and measured data during the correction process. The physical meaning of is to weigh the contribution of the predicted value and the measured value in the correction process. Its value is between 0 and 1, and the specific value is set according to the system working conditions and dynamic characteristics. For example, when When it is close to 0, the corrected effective pressure difference is closer to the real-time measurement value, and the system has a stronger real-time response capability to the current working conditions; When it is close to 1, the correction value depends more on the forecast model, and the system pays more attention to the smoothness and anti-interference ability of historical trends. The value of usually needs to comprehensively consider the quality of the measurement data, the dynamic characteristics of the fluid and the accuracy of the prediction model. For measurement data with large noise, it is appropriate to increase The value of can effectively reduce the impact of fluctuations on control accuracy; when the measurement data is stable and the prediction model is reliable, a lower The predicted value in the formula can take full advantage of real-time measurement data. It is obtained by fitting historical instantaneous pressure difference data, and its role is to compensate for possible short-term fluctuations or delays in real-time measurement data. This dynamic prediction provides a trend reference for the system, especially in fluid environments with drastic pressure changes, and can predict pressure changes in advance, thereby improving the response speed and stability of the control system. By weighted fusion of the predicted value and the measured value, the corrected effective pressure difference not only retains the latest information of the current working conditions, but also integrates historical trends, making it more robust during dynamic adjustment.

[0030] Embodiment 4: The corrected effective pressure difference is combined with physical parameters such as fluid density, viscosity, sound velocity and characteristic length through the following formula, and the reference valve opening is calculated after dimensionless processing: ; in, for Reference valve opening for time; for The viscosity of time; for The speed of sound in time; for Fluid density of time; is the base density; is the adiabatic index of air, which is 1.4; is the internal length of the valve; is the acceleration due to gravity.

[0031] Specifically, the corrected effective pressure difference is obtained through the aforementioned weighted fusion method. It not only combines the instantaneous pressure difference measured in real time but also incorporates the dynamic pressure trend predicted based on historical data. This correction process ensures that the pressure difference value is both real-time and has a certain degree of smoothness and anti-interference ability, serving as a reliable input for subsequent control calculations. On this basis, is combined with the density of the fluid , viscosity , sound speed and characteristic length and other physical parameters. Through dimensionless processing, the reference valve opening is obtained. This process reflects the systematic and scientific nature of the present invention in fluid control. Dimensionless processing is of great significance in fluid mechanics. By constructing dimensionless parameters, it simplifies the relationship between different physical quantities into a unified framework, enabling the control algorithm to maintain consistent performance under different working conditions. Specifically, the calculation formula for the reference valve opening organically combines factors such as pressure difference, characteristic length, viscosity, sound speed, fluid density, and gravitational acceleration to form a comprehensive dimensionless parameter. This dimensionless parameter not only eliminates the dimensional differences between physical quantities but also highlights their internal connections, enabling the control algorithm to more intuitively reflect the flow characteristics and energy transfer process of the fluid inside the valve.

[0032] The first part in the formula combines the pressure difference, characteristic length, viscosity, and sound speed, reflecting the inertial and viscous characteristics of the fluid when flowing inside the valve. The pressure difference is the main driving force for fluid flow, the characteristic length determines the flow path and flow characteristics of the fluid inside the valve, the viscosity describes the frictional resistance inside the fluid, and the sound speed reflects the speed of sound wave propagation in the fluid. These factors jointly affect the flow response time and dynamic characteristics of the fluid in the valve, enabling the formula to comprehensively capture the flow behavior of the fluid under different working conditions. The second part considers the influence of the change in fluid density on the valve opening through the power of the density ratio. The fluid density is a key parameter in fluid dynamics, directly affecting the momentum and energy transfer ability of the fluid. The introduction of the reference density and the adiabatic index enables the formula to dynamically adjust the valve opening to adapt to the fluid characteristics under different density conditions, ensuring that the valve can still maintain high control performance when the fluid density changes. The design of this part not only enhances the flexibility of the control algorithm but also improves the versatility and adaptability of the system in the face of different fluid media. The third part The acceleration due to gravity is taken into account. Combining the characteristic length and the speed of sound, the reference opening is further adjusted. The acceleration due to gravity is usually related to the potential energy and pressure distribution of the fluid in fluid mechanics. Especially in vertical or inclined flows, the role of gravity cannot be ignored. Through this term, the formula can compensate for the fluid pressure changes caused by gravity, ensuring that the calculation of the valve opening is still accurate under different gravity environments. This design enables the check valve device to maintain stable control performance in different geographical locations and working environments, improving the applicable range and reliability of the system. By combining these physical parameters through dimensionless processing, the formula can provide a unified reference valve opening under different working conditions. Such a design enables the check valve device to maintain stable control performance in a changing fluid environment. Regardless of how the density, viscosity, or pressure of the fluid changes, the system can ensure that the opening and closing actions of the valve always conform to the expected hydrodynamic characteristics by dynamically adjusting the reference opening. In addition, the design of this dimensionless formula also takes into account the compressibility and non-linear characteristics of the fluid. By introducing the speed of sound and the adiabatic index , the formula is applicable not only to incompressible fluids but also to compressible fluids to a certain extent, which is particularly important in high-pressure fluid control. Whether it is a liquid or a gas, by adjusting the dimensionless parameters, the system can flexibly respond to different fluid properties, ensuring the universality and robustness of the control algorithm. In practical applications, the calculation result of the reference valve opening will be used as a key input in the subsequent control process. It not only determines the opening and closing degree of the valve but also directly affects the fluid flow rate and mass flow rate, thereby affecting the energy transmission efficiency and stability of the entire fluid system.

[0033] Example 5: Based on the reference valve opening, the instantaneous effective flow area of the valve is obtained through the known non-linear relationship between the opening and the area. Then, according to the corrected effective pressure difference and the fluid density, the reference flow rate is estimated, and the Reynolds number and Mach number are further calculated; Define the effective flow area of the valve as: ; where is the nominal diameter of the valve, is the maximum opening; through the following formula, the instantaneous effective flow area is obtained using the reference opening : ; Through the following formula, the Reynolds number and the Mach number are defined as: ; Among them, the reference flow velocity is calculated based on Bernoulli approximation by the following formula: .

[0034] Specifically, the effective flow area of the valve is defined by a non-linear function that establishes a dynamic relationship between the opening degree of the valve and the flow area . Specifically, by introducing a sine function into the formula, the actual situation of fluid passing through the valve at different opening degrees is reflected. This non-linear relationship can describe the flow path and flow resistance of the fluid inside the valve more realistically compared to the traditional linear assumption. As the opening degree of the valve changes, the flow path and flow characteristics of the fluid flowing through the valve will also change accordingly. The non-linear relationship formula can capture these complex flow behaviors more accurately, thus providing more reliable basic data for subsequent flow velocity estimation and flow characteristic analysis. After obtaining the reference valve opening degree , the instantaneous effective flow area can be calculated by substituting it into the non-linear relationship formula of the effective flow area. The importance of this calculation step lies in that the reference opening degree is an ideal opening value obtained based on the corrected effective pressure difference and dimensionless processing, which can reflect the flow state of the fluid at the valve in real time. By dynamically adjusting the reference opening degree, the system can ensure that the calculation of the flow area can accurately respond to pressure changes and fluctuations in fluid characteristics, thereby achieving efficient control of the valve opening and closing actions. This process not only improves the control accuracy but also enhances the adaptability of the system to different fluid conditions, ensuring that the check valve device can maintain a stable and efficient operating state in various complex fluid environments.

[0035] Next, based on the corrected effective pressure difference and fluid density , the reference flow velocity can be estimated through the Bernoulli approximation formula. This estimation process reflects the conversion relationship between fluid kinetic energy and pressure energy, that is, when the fluid passes through the valve, due to the existence of the pressure difference, the kinetic energy is released, thus driving the fluid to flow. The calculation of the reference flow velocity is not only the basis for subsequent flow characteristic analysis but also provides key parameters for the dynamic control of the system. By real-time monitoring and dynamically adjusting the flow velocity, the system can maintain the stability of the flow and the accuracy of control under different fluid conditions, thereby improving the operating efficiency and reliability of the overall system. Further, through the reference flow velocity and other physical parameters, the Reynolds number and Mach number 。The Reynolds number, as an important dimensionless parameter in fluid mechanics, is used to describe the ratio of the inertial force to the viscous force of fluid flow, thereby determining whether the flow state is laminar or turbulent. By calculating the Reynolds number, the system can accurately evaluate the flow characteristics of the fluid under the current flow state, and then adjust the control strategy of the valve to ensure the best control effect under different flow states. For example, in the case of a high Reynolds number, the fluid exhibits turbulent characteristics, and the system can appropriately adjust the valve opening to reduce the interference of turbulence on fluid flow and maintain the stability of the flow rate and the accuracy of control. The Mach number is the ratio of the fluid flow velocity to the speed of sound and is used to evaluate the compressibility effect of fluid flow. Under high-speed flow conditions, the compressibility effect is significant. The calculation of the Mach number helps the system understand the acoustic wave propagation characteristics and compressibility influence in fluid flow, so as to optimize the opening control of the valve and avoid unstable flow caused by compressibility. For example, in the case of a high Mach number, the compressibility of the fluid is significant, and the system can adjust the valve opening to reduce the energy loss and instability during fluid flow, ensuring efficient flow and energy transfer of the fluid at the check valve.

[0036] Example 6: Calculate the instantaneous mass flow rate using the effective flow area and the reference flow velocity through the following formula: ; Define the specific enthalpy of the fluid as ; where is the fluid temperature at time, is the specific heat capacity at constant pressure; the performance index is used to measure the thermodynamic energy transfer efficiency carried by the fluid under the unit total head, and the formula is: ; Specifically, by referring to the valve opening , combined with the known non-linear relationship between the opening and the area, the instantaneous effective flow area can be accurately calculated. This calculation is based on a non-linear function that describes in detail the dynamic relationship between the valve opening and the flow area. Specifically, as the valve opening changes, the flow path and flow resistance of the fluid passing through the valve also change accordingly, and this change is truly reflected by the introduction of the sine function. In this way, the calculation of the flow area not only considers the direct influence of the opening but also covers the complex flow behavior of the fluid at different openings, making the estimation of the flow area more in line with the actual working conditions and improving the accuracy and reliability of the control algorithm. After obtaining the instantaneous effective flow area, the next step is to estimate the reference flow velocity . This estimation is based on the Bernoulli approximation, using the corrected effective pressure difference and the fluid density Calculations are performed. Specifically, the flow velocity of the fluid can be derived from the ratio of the pressure difference to the density, which reflects the conversion relationship between the kinetic energy and pressure energy of the fluid. The accurate estimation of the reference flow velocity is crucial for subsequent analysis of flow characteristics and formulation of control strategies, as it directly affects the momentum transport and energy transfer capabilities of the fluid passing through the valve. By real-time monitoring and dynamic adjustment of the flow velocity, the system can maintain the stability of the flow and the accuracy of control under different fluid conditions, thereby improving the operating efficiency and reliability of the overall system.

[0037] Furthermore, based on the reference flow velocity and other physical parameters, the Reynolds number and Mach number can be calculated. The Reynolds number is an important dimensionless parameter in fluid mechanics, used to describe the ratio of the inertial force to the viscous force of fluid flow, thereby determining whether the flow state is laminar or turbulent. By calculating the Reynolds number, the system can accurately evaluate the flow characteristics of the fluid under the current flow state, and then adjust the control strategy of the valve to ensure the best control effect under different flow states. For example, in the case of a high Reynolds number, the fluid exhibits turbulent characteristics, and the system can appropriately adjust the valve opening to reduce the interference of turbulence on fluid flow and maintain the stability of the flow velocity and the accuracy of control. The Mach number is the ratio of the fluid flow velocity to the speed of sound , used to evaluate the compressibility effect of fluid flow. Under high-speed flow conditions, the compressibility effect is significant. The calculation of the Mach number helps the system understand the characteristics of sound wave propagation and compressibility influence in fluid flow, so as to optimize the opening control of the valve and avoid unstable flow caused by compressibility. Through dynamic monitoring and real-time adjustment, the system can effectively respond to the compressibility changes of the fluid in high-pressure fluid control, ensuring the efficient flow and energy transfer of the fluid at the check valve. After calculating the flow velocity and dimensionless parameters, the next step is to calculate the instantaneous mass flow rate . This formula reflects the law of conservation of mass, that is, at any moment, the mass flow rate of the fluid flowing through the valve should remain constant. By multiplying the density, flow area, and flow velocity, the instantaneous transport capacity of the fluid at the check valve can be accurately reflected. This calculation method not only takes into account the density change of the fluid but also combines the dynamically adjusted flow area and flow velocity, making the estimation of the mass flow rate more accurate and real-time, meeting the rapid change requirements in a complex fluid environment. To further evaluate the thermodynamic characteristics of the fluid, the present invention defines the specific enthalpy of the fluid This formula indicates that specific enthalpy is the product of the fluid temperature and the specific heat capacity at constant pressure, reflecting the thermal energy contained in unit mass of fluid. The definition of specific enthalpy is of great significance in thermodynamics because it is directly related to the energy transfer ability of the fluid. During the control process of the check valve, the changes in fluid temperature and specific enthalpy can reflect the thermodynamic state of the system and the energy transmission efficiency, providing key thermodynamic information for optimizing the control strategy. Based on the calculation of mass flow rate and specific enthalpy, the present invention further introduces a performance index , which is used to measure the thermodynamic energy transmission efficiency carried by the fluid under unit total head. This formula combines the mass flow rate and specific enthalpy, and through the normalization of the total head, provides a comprehensive evaluation criterion for energy transmission efficiency. The introduction of the performance index enables the system to not only focus on the flow rate and velocity of the fluid, but also comprehensively consider the energy transfer ability and pressure conditions of the fluid, thus comprehensively reflecting the working efficiency of the check valve under different working conditions.

[0038] Example 7: Through the following formula, using the performance index values at the past three time , predict the trend of the performance index to obtain the predicted value, where \(i\) is an integer subscript index with a value range from 0 to 2: ; Through the following formula, compare the predicted value with the actual performance index, define a correction factor , and combine the dimensionless parameters and , where are the set reference Reynolds number and reference Mach number: ; where, is a positive value less than 0.000001.

[0039] Specifically, in order to predict the trend of the performance index, this embodiment adopts the quadratic Lagrange interpolation method to construct a performance index prediction model using the performance index values at the past three time points. This model fits the data at discrete time points into a continuous curve through the interpolation formula, so as to obtain the predicted value of the performance index at the current time Provide a basis. The interpolation process can not only accurately capture the changing trend of performance indicators at past time points, but also predict the dynamic performance at future moments through the fitting of historical data. This method is particularly suitable for the non-linear variation characteristics of performance indicators in complex fluid environments, as it can comprehensively consider the trends in historical data while maintaining the response sensitivity to the current working conditions. Through interpolation prediction, the system can identify potential problems in advance when the performance indicators fluctuate violently, providing a reference basis for subsequent control adjustments. After the predicted value is generated, the system needs to compare it with the actually measured performance indicator value to quantify the deviation between the two, and define the correction factor through this deviation. The correction factor is not only an important tool for system adjustment, but also reflects the difference between the current system state and the model prediction. To more comprehensively capture the dynamic behavior of the system, the correction factor not only depends on the deviation of the performance indicator, but also introduces the dimensionless parameters of the fluid, including the Reynolds number ratio and the Mach number ratio. Through weighted processing of these dimensionless parameters, the perception ability of the correction factor to the fluid flow characteristics is further enhanced, enabling it to dynamically adapt to changes in different fluid working conditions.

[0040] Specifically, the Reynolds number and the Mach number respectively reflect the ratio of the inertial force to the viscous force of the fluid, and the ratio of the flow velocity to the sound velocity, representing the flow characteristics and compressibility effects of the fluid. The ratios of the Reynolds number and the Mach number are combined in the form of powers in the correction factor formula, and through and processing, the correction factor can be dynamically adjusted according to the specific state of the fluid. For example, when the Reynolds number is high, the fluid flow exhibits turbulent characteristics and the inertial force dominates. At this time, the weight of the correction factor for system adjustment increases to adapt to the impact of turbulence on performance indicators. When the Mach number is high, the compressibility effect of the fluid flow is significant, and the correction factor is weighted by the Mach number ratio to enhance the control adaptability to compressible flow. This dynamic adjustment mechanism combining dimensionless parameters ensures the robustness and stability of the system under different fluid working conditions. It should be noted that the overall deviation of the system is also reflected in the correction factor formula through the ratio of the predicted value to the actual value of the performance indicator. The expression of this part is , where a minimum value is introduced to avoid the denominator being zero. This ratio not only provides a quantification of the prediction deviation, but also guides the direction of system control adjustment through the directionality of positive and negative differences. For example, when the predicted value is higher than the actual value, the correction factor will tend to be positive, indicating that the system should increase the corresponding adjustment intensity to improve the performance indicator; conversely, when the actual value is higher than the predicted value, the correction factor is negative, indicating that the system should appropriately reduce the current adjustment intensity to prevent instability caused by overcompensation. Through this series of calculations, the correction factor Ultimately, it becomes an important parameter for real-time adjustment of the system. It not only reflects the dynamic changes of performance indicators but also enhances the sensitivity and response speed of the system to fluid state changes through the introduction of dimensionless parameters. In combination with practical applications, the correction factor acts as a dynamically adjusted weight parameter in system control, guiding the optimization of the opening degree of the check valve device and flow regulation. This process ensures that the system can always operate in an optimal state under complex working conditions, while making real-time corrections to possible disturbances and deviations, thus significantly improving the overall control accuracy and energy transmission efficiency.

[0041] Example 8: Through the following formula, the reference opening degree is nonlinearly corrected using the correction factor to obtain the final command opening degree: ; where is the final command opening degree.

[0042] Specifically, the formula for the command opening degree is constructed by the product of the correction factor and the reference opening degree , while introducing an exponential correction term and a power correction term. The correction factor is dynamically calculated by the system based on the deviation between the predicted real-time performance indicators and the actual measurement results, as well as the dimensionless parameters of the fluid (such as Reynolds number and Mach number). It comprehensively reflects the deviation degree between the current working condition and the control target, providing directional and amplitude information for subsequent corrections. Through the non-linear introduction of the correction factor, the adjustment of the command opening degree not only retains the basic information of the reference opening degree but also can dynamically enhance or suppress the correction effect according to the magnitude and direction of the correction factor. In the formula, the correction factor acts on the reference opening degree through the exponential term and the power term simultaneously. The design of this non-linear enhancement mechanism enables the correction effect to adapt to different ranges of the correction factor. For example, when the correction factor is small, the influence of the exponential term tends to be mild, and the adjustment provided by the power term is also relatively small. At this time, the change in the command opening degree is mainly reflected in fine-tuning to ensure the stability and accuracy of the system. When the correction factor is large, the non-linear amplification effect of the exponential term appears, and the correction intensity is significantly enhanced, enabling the system to quickly respond to drastic changes in the fluid working condition. This design is particularly crucial in the case of a complex and dynamically changing fluid environment because it can effectively balance the sensitivity and stability of control.

[0043] The exponential term The introduction reflects a non - linear amplification treatment of the influence of the correction factor. Especially when the correction factor is positive, the amplitude of the corrected opening increases exponentially with the increase of the deviation. This growth can compensate for the response lag of the system when the prediction is insufficient and quickly increase the commanded opening to match the fluid demand. When the correction factor is negative, the attenuation effect of the exponential term can avoid over - adjustment and reduce the commanded opening to stabilize the system. This two - way adjustment ability enables the system to respond sensitively to changes in working conditions and prevent instability caused by over - adjustment. The power term further refines the adjustment process. By introducing the absolute value, the directionality of the correction factor is eliminated, and only the absolute amplitude of the deviation is concerned. The power exponent is selected to ensure a smooth growth of the correction amplitude, and there will be no sudden change even when the correction factor is large. The existence of this term enhances the gradual adjustment ability of the commanded opening, enabling the system to achieve high - precision control under small - scale deviations and maintain the stability of the correction effect under large - scale deviations. Through this non - linear correction formula, the commanded opening can dynamically reflect the changes in fluid working conditions while taking into account the accuracy and robustness of control. This mechanism provides great flexibility and adaptability for the application of the check valve device in complex fluid environments. For example, under high - speed and high - pressure fluid conditions, the correction factor may increase due to enhanced turbulence or compressibility effects, and the system significantly adjusts the commanded opening through the exponential and power terms to ensure stable fluid transportation. Under relatively stable working conditions, the correction amplitude of the commanded opening is limited, and the system can maintain efficient operation at a small adjustment cost and avoid unnecessary control fluctuations.

[0044] Example 9: Construct the dynamic equation of the valve core itself through the following formula: ; In the formula, the inertia term reflects that the rotational motion of the valve core is restricted by its moment of inertia and angular acceleration. The moment of inertia of the valve core depends on its mass distribution and the position of the rotation axis. In practice, the role of the inertia term is particularly important because it describes the dynamic delay characteristics of the valve core under the action of external forces. That is, when a fluid or gravitational torque is applied, the opening of the valve core does not respond immediately but is gradually adjusted under the influence of inertia. This delay effect is particularly significant in high - speed fluid flow because the drastic changes in fluid forces will have a key impact on the response speed of the valve core through the inertia term. The damping term describes the energy loss caused by mechanical friction and fluid damping during the rotation of the valve core. The mechanical damping is a parameter closely related to system stability, and its function is to suppress excessive response or oscillation caused by sudden changes in external forces. Especially in a fluid environment with drastic changes, the damping term can effectively slow down the oscillation behavior of the system and ensure the smooth movement of the valve core. In addition, this term is also closely related to the response speed of the system. Reasonable design of the damping coefficient can achieve a balance between rapid response and stability. Elastic restoring force term introduces the elastic moment when the valve core opening deviates from the equilibrium point. Nominal equilibrium point is the static position of the valve core without external force, while the elastic stiffness determines the strength of the restoring force when deviating from the equilibrium point. When the actual opening of the valve core deviates from the nominal equilibrium point, the magnitude of the restoring moment is proportional to the offset. The introduction of this term ensures that the system has a natural recovery ability. Regardless of any external force disturbance, the valve core will gradually return to the stable state, thus avoiding energy loss or control error caused by long-term deviation from the target opening. The right side of the dynamic equation includes fluid torque and gravity torque . These external forces are the main driving forces causing the dynamic behavior of the valve core. Under dynamic fluid conditions, the fluid torque depends on the fluid characteristics upstream and downstream of the valve, including flow velocity, density, and pressure distribution. At the same time, the gravity torque is the comprehensive manifestation of the mass of the valve core and the action of gravity, describing the torque caused by the offset between the center of gravity position of the valve core and the rotating shaft. The dynamic changes of these two forces make the valve core always in a complex mechanical equilibrium during the opening and closing process. By combining inertia, damping, and elastic restoring force with fluid torque and gravity torque, the dynamic equation accurately captures the dynamic characteristics of the valve core under the action of fluid. The uniqueness of this formula lies in its ability to describe both static equilibrium and dynamic response, enabling the check valve to maintain a stable opening and closing state under various working conditions. For example, under high-speed fluid conditions, the change of fluid torque will directly affect the dynamic response of the valve core, and the introduction of inertia and damping terms can effectively balance this change, thus avoiding unnecessary oscillation or overshoot of the system. On the other hand, the elastic restoring force ensures that the system quickly returns to the initial equilibrium state after the external force disappears, further enhancing the robustness of the system.

[0045] Among them, is the actual valve opening; is the moment of inertia; is mechanical damping; is the elastic stiffness; (rad) is the nominal equilibrium point; is the fluid torque at time; is the gravity torque; The calculation formula of ; Density is a fundamental parameter describing hydrodynamic properties, and its change directly affects the magnitude of hydrodynamic torque. In high-density fluids (such as liquids), the growth of torque is more significant, while in low-density fluids (such as gases), the change of torque depends more on the combined effects of flow velocity and compressibility effects. Combining density changes, the hydrodynamic torque can dynamically adapt to the fluid characteristics under different working conditions, enabling the system to operate stably in high-pressure or low-pressure environments. Flow area is a key parameter related to the valve core opening, reflecting the actual flow path of the fluid in the valve. As the opening changes, the flow area also changes non-linearly. This non-linear characteristic is introduced into the flow area formula through a sine function to more realistically describe the acting torque of the fluid on the valve core. When the fluid passes through the valve, the magnitude of its acting torque depends not only on the flow velocity and density but also on the opening of the valve. This geometric characteristic ensures that under large and small opening conditions, the change of hydrodynamic torque can accurately reflect the actual distribution of fluid dynamics. Characteristic length As a geometric factor, it defines the effective torque arm length of the valve core relative to the fluid action center. The existence of the characteristic length ensures the physical meaning of the torque and couples the geometric shape of the valve core with the overall torque model of fluid action. Combining the product of density, flow area, and characteristic length, the first part of the formula constructs the main framework of fluid dynamics. The subsequent part of the formula is divided into two terms, respectively describing the contributions of fluid kinetic energy and compressibility effects to the torque. The first term describes the dynamic influence of flow velocity on hydrodynamic torque. The square term of the flow velocity reflects the magnitude of kinetic energy, while is directly related to the current opening of the valve core. The cosine function term of the angle introduces the directionality of fluid dynamics into the torque model, ensuring that the formula can dynamically capture the characteristics of fluid impact force changing with the valve core position. For example, when the opening is small, the direction of fluid impact force is more concentrated on the torque axis and its contribution is large; while when the opening is large, the direction of the impact force deviates from the axis and the torque effect is relatively weakened. The second term introduces the compressibility effect, and through the speed of sound and fluid temperature describes the contribution of the thermodynamic state of the fluid to the torque. The physical meaning of this part is that when the fluid is a compressible medium (such as gas), the influence of its temperature and pressure changes on fluid momentum needs to be fully considered. The speed of sound is the speed of wave propagation in the fluid, and its square term appears in the denominator, reflecting the dynamic balance relationship between kinetic energy and thermal energy in compressible fluids. Adiabatic index and gas constant The introduction further improves this model, enabling the formula to be applicable not only to incompressible fluids but also to maintain applicability in gas fluid environments. This design ensures that when the system faces different medium fluids, the calculation of fluid torque can accurately reflect the actual situation.

[0046] The calculation formula of ; Gravitational acceleration is a constant parameter in nature, providing a fixed vertically downward force on the torque of the valve core, while the horizontal offset defines the geometric relationship of the center of gravity of the valve core relative to the rotation axis. This offset is not only related to the structural design of the valve core but also directly affects the driving torque of gravity on the rotation of the valve core. When is larger, that is, when the center of gravity position is far from the rotation axis, the effect of the gravity torque will be significantly enhanced, making the system more sensitive to the gravity effect, while a smaller will weaken this effect, thus enhancing the anti-disturbance ability of the system. By adjusting , the refined control of the dynamic behavior of the valve core can be achieved. The introduction of the opening angle reflects the directionality and dynamic change of the gravity torque. As the rotation angle of the valve core changes, the acting direction and magnitude of the gravity torque also change accordingly. The sine function introduces this relationship into the formula, ensuring that the gravity torque can accurately reflect the actual physical state at different openings. For example, when the valve core opening is zero ( ), that is, when the valve core is in the fully closed state, is zero, and at this time the effect of the gravity torque on the valve core is zero; while when the valve core is at a certain opening angle, the gravity torque shows a non-linear increase with the sine change of . This non-linear characteristic can dynamically capture the gravity effect on the valve core at different openings, enabling the system to always maintain the accuracy of the mechanical model during the opening and closing process. In actual control, the influence of the gravity torque on the valve core is not only manifested in its static equilibrium state but also directly participates in the dynamic response process. Especially in the working conditions where the fluid environment is complex and changeable, the gravity torque significantly affects the dynamic stability of the valve core through the coupling effect with the fluid torque. For example, when the fluid flow rate is low or the fluid density is small, the effect of the fluid torque weakens, and the gravity torque may become the key factor dominating the opening and closing movement of the valve core. In this case, by accurately calculating , it can be ensured that when the fluid torque is not sufficient to maintain dynamic balance, the system can still maintain the opening and closing stability of the valve core through the gravity torque. The gravity torque formula also reflects the dependence of the system on the physical design of the valve core. In the design of the valve core mass, geometric shape, and center of gravity position, the precise torque model can provide a theoretical basis for design optimization. For example, by appropriately adjusting Or , it can significantly improve the response ability of the valve core to small disturbances and avoid the low-frequency oscillation problem caused by excessive gravitational torque. The close combination of this mechanical model and physical design enables the check valve device to exhibit stable and efficient control performance under different fluid conditions.

[0047] Among them, is the horizontal offset of the centroid of the valve relative to the rotating shaft; is the mass of the valve core.

[0048] Example 10: Calculate the deviation between the final command opening and the actual valve opening through the following formula ; calculate the flow rate error through the following formula ; among them, is the designed flow rate (m / s); calculate the control torque through the following formula : .

[0049] Specifically, the core of the deviation calculation formula lies in the real-time capture of the difference between the command opening and the actual opening. The command opening is dynamically corrected based on the reference opening through a correction factor and has incorporated multi-dimensional information on fluid characteristics, system prediction, and current operating conditions; while the actual opening directly reflects the true position of the valve core under the current mechanical equilibrium state. The deviation is the core feedback parameter of the control system, and its magnitude and direction determine the next correction force and adjustment direction. For example, when is positive, it indicates that the actual opening lags behind the command opening, and it is necessary to increase the control torque to accelerate the response; while when is negative, it means that the actual opening is ahead, and the system needs to reduce the torque to slow down the dynamic response. The flow rate error further expands the feedback range of the control system, and its role is to evaluate the deviation degree of the current flow state from the perspective of fluid dynamics. The reference flow rate is calculated based on the corrected effective pressure difference measured in real time and the fluid density, while the designed flow rate is the target flow rate preset by the system. By calculating the difference between the two, the flow rate error reflects the deviation between the current dynamic characteristics of the fluid and the system design target. In actual operating conditions, for example, when the fluid pressure fluctuates or the flow rate changes due to environmental factors, the introduction of the flow rate error can capture these changes in a timely manner and provide a basis for the dynamic adjustment of the system. The second term is driven by the flow rate error and combines the fluid viscosity 、Nominal diameter of the valve 、Speed of sound and density ratio , further refine the intensity and direction of torque adjustment. The introduction of flow rate error ensures that during the dynamic adjustment process of the system, the velocity characteristics of the fluid can be compensated in real time. For example, when the reference flow rate is significantly higher than the designed flow rate, the system will increase the torque to counteract the adverse effects of the excessive flow rate on the valve; while when the reference flow rate is lower than the design target, the torque adjustment aims to increase the flow rate. Through the combined action of these two parts, the control torque becomes the core driving force for the dynamic behavior of the valve element, which can adjust the response characteristics of the system in real time, making the actual opening gradually approach the commanded opening, while maintaining the stability of the fluid flow state. This control mechanism is particularly crucial in a dynamic environment. For example, when sudden changes occur in the fluid density or pressure, the control torque can quickly respond to these changes and ensure the system operates at an efficient state by adjusting the opening of the valve element.

[0050] The embodiments of the present invention have been introduced in detail above. Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, based on the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A check valve device adopting a dynamic pressure detection and compensation algorithm, characterized in that, The device includes: a valve, a pressure sensor group, and a control part; the pressure sensor group includes two pressure sensors, which are respectively installed upstream and downstream of the valve to continuously obtain instantaneous pressure data; the control part is used to calculate the instantaneous pressure difference inside and outside the valve according to the obtained instantaneous pressure data, select the instantaneous pressure differences at the past three known historical times, and fit these discrete-time instantaneous pressure differences into an interpolation curve through quadratic Lagrange interpolation, and obtain a dynamic pressure prediction value therefrom; use the obtained dynamic pressure prediction value, weight and fuse it with the measured pressure difference to obtain a corrected effective pressure difference; combine the corrected effective pressure difference with physical parameters such as fluid density, viscosity, sound speed, and characteristic length, perform dimensionless processing, and calculate the reference valve opening; based on the reference valve opening, obtain the instantaneous effective flow area of the valve through the known opening-area nonlinear relationship, then estimate the reference flow velocity according to the corrected effective pressure difference and fluid density, and further calculate the Reynolds number and Mach number; use the effective flow area and reference flow velocity to calculate the instantaneous mass flow rate; at the same time, calculate the specific enthalpy through the fluid temperature and specific heat capacity at constant pressure; couple the mass flow rate and specific enthalpy, and construct a performance index based on the sum of the upstream and downstream pressures; this performance index measures the thermodynamic energy transport efficiency carried by the fluid under specific head conditions; perform Lagrange interpolation on the performance index values at different past times to predict the trend of the performance index and obtain a predicted value; then, compare the predicted value with the actual performance index to define a correction factor; use the correction factor to perform nonlinear correction on the reference opening to obtain the final command opening; construct a dynamic equation of the valve core itself to represent the actual valve opening constraint under torque-free control; perform torque control according to the deviation between the final command opening and the actual valve opening.

2. The check valve device adopting the dynamic pressure detection and compensation algorithm as described in claim 1, characterized in that, Definition The instantaneous pressure difference at time , which also represents the measured pressure difference at time is the instantaneous pressure data at the upstream at time is the instantaneous pressure data at the downstream at time . By the following formula, select the instantaneous pressure differences at the past three known historical times, and through quadratic Lagrangian interpolation, fit these instantaneous pressure differences at discrete times into an interpolation curve, and obtain the dynamic pressure prediction value from it: ； wherein, and are integer subscript indices; is the predicted value of dynamic pressure at time is the instantaneous pressure difference at time and are both known historical times.

3. The check valve device adopting the dynamic pressure detection and compensation algorithm according to claim 2, characterized in that Through the following formula, using the obtained dynamic pressure prediction value, it is weighted and fused with the measured pressure difference to obtain the corrected effective pressure difference : ； Among them, is a regulatory factor and is a set value, and its value is between 0 and 1.

4. The check valve device adopting the dynamic pressure detection and compensation algorithm according to claim 3, characterized in that Through the following formula, combine the corrected effective pressure difference with physical parameters such as fluid density, viscosity, sound speed, and characteristic length, perform dimensionless processing, and calculate the reference valve opening: ； Among them, is the reference valve opening of time; is the viscosity of time; is the speed of sound of time; is the fluid density of time; is the reference density; is the adiabatic index of air, with a value of 1.4; is the internal length of the valve; is the acceleration of gravity.

5. The check valve device adopting the dynamic pressure detection and compensation algorithm according to claim 4, characterized in that, Based on the reference valve opening, obtain the instantaneous effective flow area of the valve through the known opening-area nonlinear relationship, then estimate the reference flow velocity according to the corrected effective pressure difference and fluid density, and further calculate the Reynolds number and Mach number: Define the effective flow area of the valve as: ； Among them, is the nominal diameter of the valve, is the maximum opening; through the following formula, using the reference opening the instantaneous effective flow area is obtained as follows: ； Define the Reynolds number by the following formula and the Mach number : ； Among them, the reference flow velocity is calculated based on the Bernoulli approximation by the following formula: 。 6. The check valve device adopting the dynamic pressure detection and compensation algorithm as described in claim 5, characterized in that, Through the following formula, use the effective flow area and reference flow velocity to calculate the instantaneous mass flow rate: ； Define the specific enthalpy of the fluid as ; where is the fluid temperature at time is the specific heat capacity at constant pressure; the performance index is used to measure the thermodynamic energy transport efficiency carried by the fluid under unit total head, and the formula is: 。 7. The check valve device adopting the dynamic pressure detection and compensation algorithm as described in claim 6, characterized in that, Using the following formula, and making use of the performance metric values for the past three time , predict the trend of the performance metric to obtain a predicted value, is an integer subscript index with a value range from 0 to 2: ； Define a correction factor by comparing the predicted value with the actual performance index through the following formula , combined with the dimensionless parameters and , where are the set reference Reynolds number and reference Mach number: ； Wherein, is a positive value less than 0.000001.

8. The check valve device adopting the dynamic pressure detection and compensation algorithm according to claim 7, characterized in that, Through the following formula, use the correction factor to perform nonlinear correction on the reference opening to obtain the final command opening: ； Among them, is the final command opening degree.

9. The check valve device adopting the dynamic pressure detection and compensation algorithm as described in claim 8, characterized in that, Through the following formula, construct a dynamic equation of the valve core itself: ； Among them, is the actual valve opening; is the moment of inertia; is the mechanical damping; is the elastic stiffness; (rad) is the nominal equilibrium point; is the hydrodynamic torque with respect to time; is the gravitational torque; The calculation formula of is as follows: ； The calculation formula is as follows: ； Among them, is the horizontal offset of the centroid of the valve relative to the rotating shaft; is the spool mass.

10. The check valve device adopting the dynamic pressure detection and compensation algorithm as described in claim 9, characterized in that, Calculate the deviation between the final command opening and the actual valve opening using the following formula ; Calculate the flow velocity error using the following formula ; where is the designed flow velocity (m / s); Calculate the control torque using the following formula : 。

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