Pressure control method and system of pressure regulating valve based on PID control

Abstract

The present invention relates to the field of pressure control technology, and in particular to a pressure control method and system for a pressure regulating valve based on PID control. The method comprises: obtaining the pressure value, temperature value, fluid density and proportional gain coefficient of the PID controller at each moment during the multiple pressure regulation processes of the pressure regulating valve; analyzing the fluctuation characteristics of the pressure value during each historical pressure regulation process, the difference between the pressure value at each moment and the pressure setting value, and obtaining the abnormality of the change; determining the pressure responsiveness according to the correlation between the abnormality of the change and the proportional gain coefficient; combining the response of the fluid density and the temperature value, the fluctuation of the pressure deviation value, the fluctuation of the fluid density and the change characteristics of the pressure value during the current pressure regulation process, and obtaining the environmental sensitivity during the regulating valve regulation process; comprehensively considering the pressure deviation value, pressure responsiveness and environmental sensitivity during the current pressure regulation process, and controlling the pressure of the pressure regulating valve. The present invention improves the accuracy of the pressure control result of the pressure regulating valve.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure control, and in particular to a pressure control method and system for a pressure regulating valve based on PID control. Background Art

[0002] In the oil industry, the pressure regulating valve is an important device used to control the fluid pressure in the pipeline system. The main function of the pressure regulating valve is to adjust the fluid flow in the pipeline by adjusting the valve opening, thereby controlling the fluid pressure. In the process of oil extraction, transportation and processing, the pressure control of the regulating valve is intuitive and important, and directly affects the stability, safety and efficiency of the system.

[0003] At present, the common pressure control method of pressure regulating valve is mainly based on PID controller. PID controller is a feedback control system that makes the controlled quantity as close to the set value as possible by continuously adjusting the control quantity. In the process of using PID controller to control the pressure of pressure regulating valve in the petroleum industry, the pressure regulating valve may leak after long-term operation, resulting in the inability to effectively control the pressure. The leakage will cause the system pressure to deviate from the set value; the valve of the pressure regulating valve may become sticky due to dirt accumulation or insufficient lubrication after long-term operation, making the valve response speed slow down or even unable to be flexibly adjusted; and the speed of the pressure regulating valve and sensor may have a certain delay, especially in high pressure or high temperature environment, which will cause the PID controller to be unable to respond to pressure changes in time, causing control hysteresis and unable to accurately control the pressure. Therefore, how to accurately control the pressure of the pressure regulating valve is a problem that needs to be solved. Summary of the invention

[0004] In order to solve the problem that the existing method cannot accurately control the pressure of the pressure regulating valve, the purpose of the present invention is to provide a pressure regulating valve pressure control method and system based on PID control. The technical solution adopted is as follows:

[0005] In a first aspect, the present invention provides a pressure control method of a pressure regulating valve based on PID control, the method comprising the following steps:

[0006] Obtain the pressure value, temperature value, fluid density and proportional gain coefficient of the PID controller at each moment during the pressure regulation process of the pressure regulating valve; wherein the pressure regulation process includes the historical pressure regulation process of a preset number of times and the current pressure regulation process;

[0007] Analyze the fluctuation characteristics of the pressure values ​​at all times during each historical pressure regulation process, the difference between the pressure values ​​at each time and the pressure setting value, and obtain the abnormality of the change of the pressure monitoring data during each historical pressure regulation process; evaluate the correlation between the abnormality of the change and the proportional gain coefficient, and determine the pressure responsiveness in the pipeline where the pressure regulating valve is located;

[0008] In combination with the response between fluid density and temperature value, the fluctuation of pressure deviation value, the fluctuation of fluid density and the change characteristics of pressure value in the current pressure regulation process, the environmental sensitivity of the regulating valve in the regulation process is obtained, and the pressure deviation value is determined based on the difference between the pressure value and the pressure setting value; the dynamic coefficient of the control parameter is determined by combining the pressure deviation value, the pressure responsiveness and the environmental sensitivity in the current pressure regulation process;

[0009] The dynamic coefficient is used to control the pressure of the pressure regulating valve.

[0010] Preferably, the analysis of the fluctuation characteristics of the pressure values ​​at all times during each historical pressure regulation process, the difference between the pressure value at each time and the pressure setting value, and obtaining the abnormality of the change of the pressure monitoring data of each historical pressure regulation process includes:

[0011] According to the difference between the pressure values ​​at every two moments in the reference adjustment process and the difference between the pressure value at each moment and the pressure setting value, the change abnormality of the pressure monitoring data of the reference adjustment process is obtained, and the difference between the pressure values ​​at every two moments and the difference between the pressure value at each moment and the pressure setting value are both positively correlated with the change abnormality;

[0012] The reference adjustment process is any historical pressure adjustment process.

[0013] Preferably, the evaluation of the correlation between the abnormality of the change and the proportional gain coefficient to determine the pressure responsiveness in the pipeline where the pressure regulating valve is located includes:

[0014] Calculating the correlation between the variation abnormality sequence and the proportional gain coefficient sequence, and determining the correlation as the pressure responsiveness in the pipeline where the pressure regulating valve is located;

[0015] The variation abnormality sequence is composed of variation abnormalities of pressure monitoring data of all historical pressure regulation processes, and the proportional gain coefficient sequence is composed of proportional gain coefficients of PID controllers of all historical pressure regulation processes.

[0016] Preferably, the environmental sensitivity of the regulating valve during the current pressure regulation process is obtained by combining the response between the fluid density and the temperature value, the fluctuation of the pressure deviation value, the fluctuation of the fluid density and the change characteristics of the pressure value, including:

[0017] According to the mean square error between the fluid density and the temperature value at all times in the current pressure regulation process and the slope difference between every two adjacent moments in the current pressure regulation process, the contribution of the environment to the pressure oscillation regulation is obtained, the mean square error is negatively correlated with the contribution, and the slope difference is positively correlated with the contribution; the fluid density curve is obtained by curve fitting the fluid density at all times in the current pressure regulation process, and the slope at each moment is determined based on the fluid density curve;

[0018] According to the discrete degree of the pressure deviation value, the discrete degree of the fluid density and the contribution degree in the current pressure regulation process, the environmental sensitivity of the regulating valve in the regulation process is obtained.

[0019] Preferably, obtaining the environmental sensitivity of the regulating valve during the current pressure regulation process according to the discrete degree of the pressure deviation value, the discrete degree of the fluid density and the contribution degree includes:

[0020] The sum of the discrete degree of the pressure deviation value and the preset adjustment parameter is recorded as the first characteristic value, and the sum of the discrete degree of the fluid density and the preset adjustment parameter is recorded as the second characteristic value, and the preset adjustment parameter is greater than 0;

[0021] Calculating a ratio of the first eigenvalue to the second eigenvalue;

[0022] The product of the ratio and the contribution is determined as the environmental sensitivity during the regulating valve regulating process.

[0023] Preferably, the variance of the pressure deviation values ​​at all times in the current pressure regulation process is used as the discrete degree of the pressure deviation values ​​in the current pressure regulation process; the variance of the fluid density at all times in the current pressure regulation process is used as the discrete degree of the fluid density in the current pressure regulation process.

[0024] Preferably, the pressure deviation value, the pressure responsiveness and the environmental sensitivity in the current pressure regulation process are integrated to determine the dynamic coefficient of the control parameter, including:

[0025] According to the average level of the pressure deviation value in the current pressure regulation process, the environmental sensitivity and the pressure responsiveness, the dynamic coefficient of the control parameter is obtained, the average level and the environmental sensitivity are both positively correlated with the dynamic coefficient, and the pressure responsiveness is negatively correlated with the dynamic coefficient.

[0026] Preferably, the acquisition of the pressure deviation value includes:

[0027] At any moment, the difference between the pressure value at that moment and the pressure setting value is taken as the pressure deviation value at that moment.

[0028] Preferably, the controlling the pressure of the pressure regulating valve by using the dynamic coefficient includes:

[0029] The product of the dynamic coefficient and the proportional gain coefficient of the current PID controller is used as the adjustment amount of the proportional gain coefficient of the PID controller to control the pressure of the pressure regulating valve.

[0030] In a second aspect, the present invention provides a pressure control system for a pressure regulating valve based on PID control, the system comprising:

[0031] A data acquisition module, used to obtain the pressure value, temperature value, fluid density and proportional gain coefficient of the PID controller at each moment during the pressure regulation process of the pressure regulating valve; wherein the pressure regulation process includes the historical pressure regulation process of a preset number of times and the current pressure regulation process;

[0032] The pressure response calculation module is used to analyze the fluctuation characteristics of the pressure values ​​at all times during each historical pressure regulation process, the difference between the pressure values ​​at each time and the pressure setting value, and obtain the abnormality of the change of the pressure monitoring data during each historical pressure regulation process; evaluate the correlation between the abnormality of the change and the proportional gain coefficient, and determine the pressure response of the pipeline where the pressure regulating valve is located;

[0033] A dynamic coefficient determination module is used to obtain the environmental sensitivity of the regulating valve during the regulation process by combining the response between the fluid density and the temperature value, the fluctuation of the pressure deviation value, the fluctuation of the fluid density and the change characteristics of the pressure value during the current pressure regulation process, wherein the pressure deviation value is determined based on the difference between the pressure value and the pressure setting value; and to determine the dynamic coefficient of the control parameter by combining the pressure deviation value, the pressure responsiveness and the environmental sensitivity during the current pressure regulation process;

[0034] The pressure control module is used to control the pressure of the pressure regulating valve using the dynamic coefficient.

[0035] The present invention has at least the following beneficial effects:

[0036] The present invention first analyzes the fluctuation characteristics of the pressure values ​​at all times in each historical pressure regulation process and the difference between the pressure values ​​at each time and the pressure setting value, and obtains the change abnormality of the pressure monitoring data of each historical pressure regulation process. The greater the fluctuation degree of the pressure value, the more unstable the pressure monitoring data; the greater the difference between the pressure value and the pressure setting value, the more abnormal the change of the pressure monitoring data may be, that is, the greater the corresponding change abnormality; during the operation of the equipment, there is a certain correlation between the monitoring data and the proportional gain coefficient of the PID controller, so the correlation between the change abnormality and the proportional gain coefficient of the PID controller is evaluated to determine The pressure responsiveness of the pressure regulating valve in the pipeline is obtained. Taking into account that the pressure control process of the pressure regulating valve will be affected by relevant environmental factors, in order to improve the accuracy of the final regulation, the environmental sensitivity of the regulating valve in the regulation process is obtained by combining the response between the fluid density and the temperature value, the change of the pressure value, and the change of the fluid density in the current pressure regulation process. Then, the pressure of the pressure regulating valve is controlled by combining the pressure deviation value, pressure responsiveness and environmental sensitivity in the current pressure regulation process, which improves the accuracy of the pressure control result, ensures the real-time and timely response of the control system, and realizes the stability of the production process, efficient use of energy and improvement of equipment safety by precise pressure control. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A flow chart of a pressure regulating valve pressure control method based on PID control provided in an embodiment of the present invention;

[0039] Figure 2 A flow chart of a method for obtaining pressure responsiveness provided in an embodiment of the present invention;

[0040] Figure 3 A flow chart of a method for obtaining a dynamic coefficient provided by an embodiment of the present invention;

[0041] Figure 4 This is a structural block diagram of a pressure regulating valve pressure control system based on PID control provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the pressure control method and system of the pressure regulating valve based on PID control proposed by the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0043] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0044] The specific scheme of the pressure control method and system of the pressure regulating valve based on PID control provided by the present invention is described in detail below with reference to the accompanying drawings.

[0045] PID control based pressure regulating valve pressure control method embodiment:

[0046] The specific scenario targeted by this embodiment is: in the process of controlling the flow rate of liquid in the pipeline by using the pressure regulating valve pressure control system, the pressure regulating valve pressure control system needs to select a suitable pressure sensor and PID controller. The pressure sensor is used to monitor the real-time pressure, the pressure regulating valve is used to control the pressure, and the PID controller is used to process the signal from the pressure sensor and output control information to adjust the action of the pressure regulating valve. During the use of the system, the parameters of the PID control need to be adjusted, usually involving proportional gain, integral time and differential time to obtain the best control effect. This embodiment mainly accurately regulates the proportional gain parameters of the PID controller during the pressure regulating valve pressure adjustment process, thereby achieving accurate control of the pressure regulating valve pressure to ensure that the provided fluid flow rate can meet the requirements.

[0047] This embodiment proposes a pressure control method for a pressure regulating valve based on PID control, such as Figure 1 As shown, the pressure control method of the pressure regulating valve based on PID control in this embodiment includes the following steps:

[0048] Step S1, obtaining the pressure value, temperature value, fluid density and proportional gain coefficient of the PID controller at each moment in the pressure regulation process of the pressure regulating valve; wherein the pressure regulation process includes a preset number of historical pressure regulation processes and a current pressure regulation process.

[0049] In the petroleum industry, firstly, a pressure sensor is installed in the system where the pressure regulating valve is located to collect the pressure value, and the output of the pressure sensor is connected to the data acquisition system, which can be a special monitoring system or an industrial computer. The output of the sensor is usually an analog electrical signal, which needs to be converted into a digital signal using an analog-to-digital converter (ADC); after the pressure sensor is installed, the pressure sensor is calibrated to ensure its accuracy and stability, and the calibration process can be calibrated using standard pressure calibration equipment. The pressure value of the pressure regulating valve during pressure regulation is collected using a pressure sensor; it should be noted that the sensor is set at a position that can accurately reflect the pressure change of the entire system, and the specific setting position is selected according to the specific situation. The sensor selected in this embodiment is a sensor that can work reliably under high pressure and harsh environment, so as to minimize the impact of the environment on the data acquisition results. A temperature sensor is installed in the pipeline system to monitor the temperature in the pipeline system during the monitoring of pressure monitoring data. A density meter or an oscillating density meter is used in the pipeline system to monitor the fluid density in real time. Set a suitable data sampling frequency to ensure sufficient sampling of pressure values, temperature values, fluid density, and the proportional gain coefficient of the PID controller, so as to better capture the rapid changes in pressure in the system. In this embodiment, the data sampling frequency is once per second, that is, one pressure value, one temperature value, and one fluid density are collected every second, and the proportional gain coefficient of the PID controller in each pressure regulation process is obtained respectively. In specific applications, the implementer can set the sampling frequency according to specific circumstances. In this embodiment, the pressure values, temperature values, fluid density, and proportional gain coefficient of the PID controller in multiple pressure regulating valve pressure regulation processes are collected respectively, including the preset number of historical pressure regulation processes and the current pressure regulation process. The preset number in this embodiment is 10 times. In specific applications, the implementer can set the preset number according to specific circumstances.

[0050] At this point, the pressure value at each moment in each historical pressure regulation process, the temperature value at each moment, the fluid density at each moment and the proportional gain coefficient of the PID controller during each historical pressure regulation process, as well as the pressure value at each moment in the current pressure regulation process, the temperature value at each moment, the fluid density at each moment and the proportional gain coefficient of the PID controller are obtained.

[0051] Step S2, analyzing the fluctuation characteristics of the pressure values ​​at all times during each historical pressure regulation process, the difference between the pressure values ​​at each time and the pressure setting value, and obtaining the abnormality of the change of the pressure monitoring data of each historical pressure regulation process; evaluating the correlation between the abnormality of the change and the proportional gain coefficient, and determining the pressure responsiveness of the pipeline where the pressure regulating valve is located.

[0052] In the oil industry, effective control of the pressure of the pressure regulating valve can stabilize key production processes such as pipeline transportation and processing operations, ensuring that equipment and systems operate within a safe and efficient working range; too high or too low pressure may cause fluid dynamics problems or equipment failures, affecting production continuity. Changes in system load will cause changes in the pressure demand of the pressure regulating valve under different working conditions, and the control system must be able to adjust in real time to meet these changes.

[0053] Considering that the characteristics presented by the same pressure regulating valve in multiple pressure regulation processes are often similar, the pressure regulation of the pressure regulating valve will also be affected by its environmental factors and technical characteristics. Therefore, when accurately controlling the pressure in the current pressure regulation process, the changes in various monitoring data of the pressure regulating valve in the historical pressure regulation process can be referred to to determine the pressure responsiveness of the pipeline where the pressure regulating valve is located.

[0054] Step S21, obtaining the degree of abnormality of changes in the pressure monitoring data of each historical pressure regulation process according to the fluctuation characteristics of the pressure values ​​at all times in each historical pressure regulation process and the difference between the pressure values ​​at each time and the pressure setting value.

[0055] For any pressure regulation process, a pressure value will be set manually first, and the manually set pressure value will be recorded as the pressure setting value. If the difference between the monitored pressure value and the pressure setting value is larger during the entire pressure regulation process, it means that the pressure monitoring data is more likely to be abnormal during the entire process; the closer the pressure monitoring data is to the pressure setting value, the less the pressure is affected by the performance of the pressure regulating valve itself during the entire process, and the more the operating state of the equipment is in line with the expected operating state; during this regulation process, the smaller the fluctuation of the pressure monitoring data, the more stable the actual pressure is. Therefore, each historical pressure regulation process is analyzed separately, and the abnormal changes in the pressure monitoring data of each historical pressure regulation process are determined based on the fluctuation characteristics of the pressure values ​​at all times during each historical pressure regulation process and the difference between the pressure values ​​at each time and the pressure setting value.

[0056] Any historical pressure adjustment process is taken as an example for description, and other historical pressure adjustment processes can be processed by the method provided in this embodiment.

[0057] Specifically, any historical pressure regulation process is recorded as a reference regulation process, and the degree of abnormal change of the pressure monitoring data of the reference regulation process is obtained according to the difference between the pressure values ​​at every two moments in the reference regulation process and the difference between the pressure values ​​at each moment and the pressure setting value. The difference between the pressure values ​​at every two moments and the difference between the pressure values ​​at each moment and the pressure setting value are both positively correlated with the degree of abnormal change.

[0058] Among them, the positive correlation relationship means that the dependent variable will increase as the independent variable increases, and the dependent variable will decrease as the independent variable decreases. The specific relationship can be a multiplication relationship, an addition relationship, and the power of an exponential function.

[0059] The difference in pressure values ​​can be characterized by an absolute difference, a standard difference, a percentage difference, a standard difference, etc.; similarly, the difference between a pressure value and a pressure setting value can be characterized by an absolute difference, a standard difference, a percentage difference, a standard difference, etc.

[0060] In this embodiment, a specific calculation method for the abnormality of the change of the pressure monitoring data is given. The abnormality of the change of the pressure monitoring data of the r-th pressure adjustment process in history can be expressed as: in, represents the abnormal degree of change of pressure monitoring data in the r-th pressure regulation process in history, J represents the number of groups of pressure values ​​in the r-th pressure regulation process in history, It represents the first pressure value in the jth group of pressure values ​​during the rth pressure regulation process in history. represents the second pressure value in the jth group of pressure values ​​during the rth pressure regulation process in history, I represents the number of moments during the rth pressure regulation process in history, represents the pressure value at the i-th moment in the r-th pressure regulation process in history, Indicates the pressure setting value of the rth pressure regulation process in history, Indicates the absolute value sign.

[0061] The specific process of obtaining each set of pressure values ​​in the historical r-th pressure regulation process is as follows: the pressure values ​​at every two moments in the historical r-th pressure regulation process constitute a set of pressure values, that is, each set of pressure values ​​contains pressure values ​​at two moments, and these two values ​​may be equal or unequal.

[0062] It indicates the difference between the two pressure values ​​in the jth group of pressure values ​​during the rth pressure regulation process in history. The larger the value, the greater the difference between the two. It represents the average value of the difference between two pressure values ​​in all groups of pressure values ​​in the r-th pressure regulation process in history. The larger the value is, the more frequent the changes in the pressure monitoring data of the r-th pressure regulation process in history and the more obvious the fluctuations are. It represents the difference between the pressure monitoring data and the pressure setting value at the i-th moment in the r-th pressure regulation process in history. It indicates the average value of the difference between the pressure value at all times and the pressure setting value during the r-th pressure regulation process in history. The larger the value, the more the pressure monitoring data deviates from the pressure setting value during the whole process. When the average value of the difference between two pressure values ​​in all groups of pressure values ​​during the r-th pressure regulation process in history is larger, and the average value of the difference between the pressure value at all times and the pressure setting value is larger, it means that the pressure monitoring data changes more frequently and is more unstable, and the deviation from the pressure setting value is larger, and the pressure regulating valve may need to respond quickly to keep the output pressure stable, that is, the pressure monitoring data change abnormality is higher.

[0063] By adopting the above method, the degree of abnormal change of the pressure monitoring data of each historical pressure regulation process can be obtained.

[0064] Step S22, determining the pressure responsiveness in the pipeline where the pressure regulating valve is located according to the correlation between the abnormality of the change and the proportional gain coefficient.

[0065] Taking into account that during the pressure regulation process, there is a certain correlation between the change in the proportional gain parameter of the PID controller and the change in the abnormality of pressure change, when the abnormality of the change in the pressure monitoring data is high, the pressure regulating valve may need to respond quickly to maintain pressure stability, that is, it is necessary to increase the proportional gain parameter. Therefore, the correlation between the abnormality of the change in the pressure monitoring data and the proportional gain parameter of the PID controller is analyzed next, and then the pressure responsiveness of the pressure regulating valve in the pipeline is determined.

[0066] Specifically, the change abnormality of the pressure monitoring data of all historical pressure regulation processes is sorted in chronological order to obtain a change abnormality sequence, and the proportional gain parameters of all historical pressure regulation processes are sorted in chronological order to obtain a proportional gain coefficient sequence.

[0067] The correlation between the variation abnormality sequence and the proportional gain coefficient sequence is calculated, and the correlation is determined as the pressure responsiveness in the pipeline where the pressure regulating valve is located.

[0068] In this embodiment, the correlation between the change abnormality sequence and the proportional gain coefficient sequence can be specifically expressed as: Among them, B represents the correlation between the variation abnormality sequence and the proportional gain coefficient sequence, and also represents the pressure responsiveness in the pipeline where the pressure regulating valve is located. P represents the Pearson correlation coefficient between the variation abnormality sequence and the proportional gain coefficient sequence. The calculation method of the Pearson correlation coefficient is a prior art and will not be described in detail here. The Pearson correlation coefficient between the variation abnormality sequence and the proportional gain coefficient sequence is used to reflect the correlation between the change in the proportional gain parameter of the PID controller and the change in the pressure variation abnormality during the pressure control process of the pressure regulating valve; for example, when the variation abnormality of the pressure monitoring data is high, the pressure regulating valve may need to respond quickly to keep the pressure stable, that is, it is necessary to increase the proportional gain parameter, that is, there is a positive correlation. In order to prevent negative numbers from appearing in the calculation of the correlation coefficient, use The value range of P is converted, that is, the smaller the value is, the lower the pressure response of the pressure regulating valve is.

[0069] So far, the pressure response of the pressure regulating valve in the pipeline is obtained by using the above method, such as Figure 2 As shown, this figure is a flow chart of the method for obtaining pressure responsiveness.

[0070] Step S3, combining the response between fluid density and temperature value, the fluctuation of pressure deviation value, the fluctuation of fluid density and the change characteristics of pressure value in the current pressure regulation process, to obtain the environmental sensitivity of the regulating valve regulation process, wherein the pressure deviation value is determined based on the difference between the pressure value and the pressure setting value; comprehensively combining the pressure deviation value in the current pressure regulation process, the pressure responsiveness and the environmental sensitivity, to determine the dynamic coefficient of the control parameter.

[0071] In the pipeline system, when the equipment is running, there is a certain correlation between the density change of the fluid and the ambient temperature. The pressure control process of the pressure regulating valve will be affected by relevant environmental factors. The actual pressure value has a certain correlation with the environmental factors. Therefore, the response between the fluid density and the temperature value, the change of the pressure value, and the change of the fluid density in the current pressure regulation process can be analyzed, and the environmental sensitivity of the current pressure regulation process can be determined. The control parameters can be further dynamically adjusted in combination with the pressure responsiveness and environmental sensitivity.

[0072] Step S31, combining the response between fluid density and temperature value, the fluctuation of pressure deviation value, the fluctuation of fluid density and the change characteristics of pressure value in the current pressure regulation process, to obtain the environmental sensitivity of the regulating valve in the regulation process.

[0073] The fluid density at all moments in the current pressure regulation process is curve fitted to obtain a fluid density curve, where the horizontal coordinate of the fluid density curve is the moment and the vertical coordinate is the fluid density; curve fitting is a prior art and will not be described in detail here. The slope of each point on the fluid density curve is obtained and used as the slope at the corresponding moment, that is, a slope is obtained at each moment in the current pressure regulation process. The method for obtaining the slope of each point on the curve is a prior art and will not be described in detail here; for any moment, the difference between the pressure value at that moment and the pressure setting value is used as the pressure deviation value at that moment, that is, the result obtained by subtracting the pressure setting value from the pressure value at that moment is used as the pressure deviation value at that moment.

[0074] Then, according to the mean square error between the fluid density and temperature values ​​at all times in the current pressure regulation process and the slope difference between every two adjacent moments in the current pressure regulation process, the contribution of the environment to the pressure oscillation regulation is obtained, and the mean square error is negatively correlated with the contribution, and the slope difference is positively correlated with the contribution.

[0075] Among them, a positive correlation means that the dependent variable will increase as the independent variable increases, and the dependent variable will decrease as the independent variable decreases. The specific relationship can be a multiplication relationship, an addition relationship, or the power of an exponential function; a negative correlation means that the dependent variable will decrease as the independent variable increases, and the dependent variable will increase as the independent variable decreases. It can be a subtraction relationship, a division relationship, etc., which is determined by actual application.

[0076] In this embodiment, a specific calculation method of the contribution is given, and the contribution of the environment to the pressure oscillation regulation can be expressed as: Among them, H represents the contribution of the environment to the pressure oscillation regulation, Y represents the fluid density sequence, Z represents the temperature sequence, and V represents the number of moments in the current pressure regulation process. It represents the slope at the vth moment in the current pressure regulation process, Indicates the slope at the v+1th moment in the current pressure regulation process, represents the mean square error function, represents the mean square error between the fluid density series and the temperature series, To take the absolute value sign, It is the preset first adjustment parameter.

[0077] The process of obtaining the fluid density sequence is as follows: sorting the fluid density at all times in the current pressure regulation process in chronological order to obtain the fluid density sequence. The process of obtaining the temperature sequence is as follows: sorting the temperature values ​​at all times in the current pressure regulation process in chronological order to obtain the temperature sequence.

[0078] In this embodiment, the preset first adjustment parameter is introduced into the calculation formula of the contribution degree in order to prevent the denominator from being 0. In this embodiment, the preset first adjustment parameter is 0.01. In specific applications, the implementer can set it according to specific circumstances. It is used to reflect the mean square error between the fluid density and temperature values ​​at all times during the current pressure regulation process, and characterizes the response between the fluid density and temperature monitoring data. Generally, an increase in the temperature of the fluid in the pipeline or system will cause the density to decrease, and the fluid density sequence and temperature sequence will be "complementary", that is, the mean square error value will be larger; however, when the mean square error value is small, it means that the responsiveness between the fluid temperature change and the density change is reduced, which will affect the flow characteristics of the fluid in the pipeline, and then affect the actual pressure sensed by the PID controller.

[0079] It indicates the difference in slope between the vth moment and the v+1th moment in the current pressure regulation process. The larger the value, the greater the difference in slope between the two moments. It represents the average value of the slope difference of all adjacent moments in the current pressure regulation process, which is used to reflect the speed of fluid density change. The larger the average value, the faster the fluid density changes, which may cause pressure fluctuations or oscillation of the pressure regulating valve. The pressure regulating valve needs to respond quickly to maintain a stable output pressure. If the average value of the slope difference of all adjacent moments in the current pressure regulation process is larger and the mean square error between the fluid density sequence and the temperature sequence is smaller, it means that the more drastic the environmental changes in the pressure control process of the pressure regulating valve, the more likely it is to cause a greater degree of oscillation of the pressure regulating valve, that is, the response speed of the PID controller needs to be increased to suppress the oscillation of the pressure regulating valve, and the greater the contribution of the environment to the pressure oscillation regulation.

[0080] The sum of the discrete degree of the pressure deviation value and the preset adjustment parameter is recorded as the first eigenvalue, and the sum of the discrete degree of the fluid density and the preset adjustment parameter is recorded as the second eigenvalue, and the preset adjustment parameter is greater than 0; the ratio of the first eigenvalue to the second eigenvalue is calculated; the product of the ratio and the contribution is determined as the environmental sensitivity during the regulating valve adjustment process. The preset adjustment parameter is introduced into the calculation of environmental sensitivity to prevent the denominator from being 0. In this embodiment, the preset adjustment parameter is 0.01. In specific applications, the implementer can set it according to specific circumstances.

[0081] The degree of dispersion of the pressure deviation value can be characterized by indicators such as the standard deviation, variance, and range of all pressure deviation values. In this embodiment, the variance of the pressure deviation values ​​at all times in the current pressure regulation process is used as the degree of dispersion of the pressure deviation values ​​in the current pressure regulation process; the variance of the fluid density at all times in the current pressure regulation process is used as the degree of dispersion of the fluid density in the current pressure regulation process.

[0082] In this embodiment, a specific calculation formula for the environmental sensitivity during the regulating valve regulation process is given. The environmental sensitivity during the regulating valve regulation process can be expressed as: Among them, L represents the environmental sensitivity during the regulating valve adjustment process, H represents the contribution of the environment to the pressure oscillation regulation, Indicates the variance of the pressure deviation value at all times during the current pressure regulation process, which is used to reflect the discrete degree of the pressure deviation value during the current pressure regulation process. Indicates the variance of all fluid densities during the current pressure regulation process, which is used to reflect the discrete degree of fluid density during the current pressure regulation process. Indicates preset adjustment parameters.

[0083] represents the first eigenvalue, represents the second eigenvalue, It is used to reflect the ratio of the discrete degree of the pressure deviation value in the current pressure regulation process to the discrete degree of the fluid density. In the pipeline or system, the pressure control of the pressure regulating valve is to respond to the drastic fluctuations of the environment during the control process to achieve the effect of stabilizing the output pressure. When the ratio is small, it shows that the data fluctuation of the pressure deviation value is relatively gentle, but the data fluctuation of the fluid density is relatively drastic, indicating that the state of the pressure regulating valve in the control process can better respond to the changes in the fluid density and thus make the output pressure relatively stable, that is, to punish the contribution of the environment to the pressure oscillation regulation, that is, the adjustment force of the proportional gain coefficient of the PID controller will not be too large, and the environmental sensitivity of the regulating valve during the adjustment process is relatively small.

[0084] By using the above method, the environmental sensitivity during the regulating valve adjustment process is obtained.

[0085] Step S32, determining the dynamic coefficient of the control parameter by comprehensively considering the pressure deviation value, the pressure responsiveness and the environmental sensitivity in the current pressure regulation process.

[0086] During the pressure control process of the pressure regulating valve, the changes in the pressure monitoring data in the system and the responsiveness of the changes between the fluid density and temperature can be judged, and the setting of the control parameters of the PID controller in the current control process can be evaluated, and then the dynamic control parameters in the next pressure regulation process of the pressure regulating valve can be obtained. Therefore, the pressure deviation value, pressure responsiveness and environmental sensitivity in the current pressure regulation process will be comprehensively considered to determine the dynamic coefficient of the control parameter.

[0087] Specifically, the dynamic coefficient of the control parameter is obtained according to the average level of the pressure deviation value in the current pressure regulation process, the environmental sensitivity and the pressure responsiveness, the average level and the environmental sensitivity are both positively correlated with the dynamic coefficient, and the pressure responsiveness is negatively correlated with the dynamic coefficient.

[0088] Among them, a positive correlation means that the dependent variable will increase as the independent variable increases, and the dependent variable will decrease as the independent variable decreases. The specific relationship can be a multiplication relationship, an addition relationship, or the power of an exponential function; a negative correlation means that the dependent variable will decrease as the independent variable increases, and the dependent variable will increase as the independent variable decreases. It can be a subtraction relationship, a division relationship, etc., which is determined by actual application.

[0089] In this embodiment, the dynamic coefficient of the control parameter can be expressed as: in, represents the dynamic coefficient of the control parameter, L represents the environmental sensitivity of the regulating valve during the regulation process, B represents the pressure response of the regulating valve in the pipeline, th( ) represents the hyperbolic tangent function, V represents the number of moments in the current pressure regulation process, It represents the pressure deviation value at the vth moment in the current pressure regulation process, and norm( ) represents the normalization function.

[0090] It indicates the average level of pressure deviation in the current pressure regulation process. The larger the value is, the greater the pressure deviation is during the control process, which means that more force is needed to regulate the pressure regulating valve. The Euclidean norm of the normalized value of the environmental sensitivity of the pressure regulating valve during pressure regulation and the normalized value of the pressure responsiveness of the pipeline or system where the pressure regulating valve is located is used to output a comprehensive value based on the environmental sensitivity and pressure responsiveness to obtain the demand for pressure regulation during the control process. When the environmental sensitivity of the regulating valve during regulation is greater, the pressure responsiveness in the pipeline where the pressure regulating valve is located is smaller, and the average level of the pressure deviation value in the current pressure regulation process is greater, it means that the regulation force of the pressure regulating valve needs to be greater at this time, that is, the dynamic coefficient of the control parameter is greater.

[0091] Using the above method, the dynamic coefficients of the control parameters are obtained, such as Figure 3 As shown, this figure is a flow chart of the method for obtaining the dynamic coefficient.

[0092] Step S4, using the dynamic coefficient to control the pressure of the pressure regulating valve.

[0093] In the above steps, the dynamic coefficient of the control parameter has been determined. Next, the dynamic coefficient will be used to control the pressure of the pressure regulating valve.

[0094] Specifically, the product of the dynamic coefficient of the control parameter and the proportional gain coefficient of the current PID controller is used as the adjustment amount of the proportional gain coefficient of the PID controller, and then the opening of the pressure regulating valve is adjusted according to the change of the fluid density in the pipeline system. That is, when the fluid density increases, the pressure regulating valve needs a larger opening to provide sufficient flow; otherwise, the opening of the pressure regulating valve needs to be reduced.

[0095] The control parameters such as proportional gain coefficient, integral gain and differential time are input into the chip of the PID controller, and then the opening of the pressure regulating valve is controlled, so that the pressure in the system tends to a stable state.

[0096] At this point, the pressure of the pressure regulating valve is controlled using the method provided in this embodiment.

[0097] This embodiment first analyzes the fluctuation characteristics of the pressure values ​​at all times in each historical pressure regulation process and the difference between the pressure values ​​at each time and the pressure setting value, and obtains the change abnormality of the pressure monitoring data of each historical pressure regulation process. The greater the fluctuation of the pressure value, the more unstable the pressure monitoring data; the greater the difference between the pressure value and the pressure setting value, the more abnormal the change of the pressure monitoring data may be, that is, the greater the corresponding change abnormality; during the operation of the equipment, there is a certain correlation between the monitoring data and the proportional gain coefficient of the PID controller, so the correlation between the change abnormality and the proportional gain coefficient of the PID controller is evaluated to determine The pressure responsiveness of the pressure regulating valve in the pipeline is obtained. Taking into account that the pressure control process of the pressure regulating valve will be affected by relevant environmental factors, in order to improve the accuracy of the final regulation, the environmental sensitivity of the regulating valve in the regulation process is obtained by combining the response between the fluid density and the temperature value, the change of the pressure value, and the change of the fluid density in the current pressure regulation process. Then, the pressure of the pressure regulating valve is controlled by combining the pressure deviation value, pressure responsiveness and environmental sensitivity in the current pressure regulation process, which improves the accuracy of the pressure control result, ensures the real-time and timely response of the control system, and realizes the stability of the production process, efficient use of energy and improvement of equipment safety by precise pressure control.

[0098] PID control based pressure regulating valve pressure control system implementation example:

[0099] See also Figure 4 , which shows a structural block diagram of a pressure regulating valve pressure control system based on PID control provided by an embodiment of the present invention. The system may include a data acquisition module, a pressure responsiveness calculation module, a dynamic coefficient determination module and a pressure control module.

[0100] The data acquisition module is used to obtain the pressure value, temperature value, fluid density and proportional gain coefficient of the PID controller at each moment during the pressure regulation process of the pressure regulating valve; the pressure regulation process includes the historical pressure regulation process of the preset number of times and the current pressure regulation process;

[0101] The pressure response calculation module is used to analyze the fluctuation characteristics of the pressure values ​​at all times during each historical pressure regulation process, the difference between the pressure values ​​at each time and the pressure setting value, and obtain the abnormality of the change of the pressure monitoring data during each historical pressure regulation process; evaluate the correlation between the abnormality of the change and the proportional gain coefficient, and determine the pressure response of the pipeline where the pressure regulating valve is located;

[0102] A dynamic coefficient determination module is used to obtain the environmental sensitivity of the regulating valve during the regulation process by combining the response between the fluid density and the temperature value, the fluctuation of the pressure deviation value, the fluctuation of the fluid density and the change characteristics of the pressure value during the current pressure regulation process, wherein the pressure deviation value is determined based on the difference between the pressure value and the pressure setting value; and to determine the dynamic coefficient of the control parameter by combining the pressure deviation value, the pressure responsiveness and the environmental sensitivity during the current pressure regulation process;

[0103] The pressure control module is used to control the pressure of the pressure regulating valve using the dynamic coefficient.

[0104] It should be understood that Figure 4 The structural block diagram of the pressure control system of the pressure regulating valve based on PID control and its modules shown can be implemented in various ways. For example, in some embodiments, the system and its modules can be implemented by hardware, software or a combination of software and hardware. Among them, the hardware part can be implemented by using dedicated logic; the software part can be stored in the memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. Those skilled in the art can understand that the above-mentioned method and system can be implemented using computer executable instructions and / or included in the processor control code, for example, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The system and its modules of this specification can not only be implemented by hardware circuits such as ultra-large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., but can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software (for example, firmware).

[0105] For more details about the above modules, please refer to other places in this manual (for example Figure 1 , Figure 2 , Figure 3 part and its related description), which will not be repeated here.

[0106] In other embodiments, a device is also provided, including a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the device executes the above-mentioned pressure regulating valve pressure control method based on PID control. The device can be specifically a chip, a component or a module, and the chip may include a connected processor and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute the pressure regulating valve pressure control method based on PID control provided in the above-mentioned embodiment.

[0107] In other embodiments, a computer program product is also provided. When the computer program product is run on a computer, the computer executes the above-mentioned related steps to implement the pressure control method of the pressure regulating valve based on PID control provided in the above-mentioned embodiment.

[0108] In other embodiments, a computer-readable storage medium is also provided, in which a computer program code is stored. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement the pressure regulating valve pressure control method based on PID control provided in the above-mentioned embodiment.

[0109] Among them, the provided systems, devices, computer program products, and computer-readable storage media are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods provided above and will not be repeated here.

[0110] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A pressure control method for a pressure regulating valve based on PID control, characterized in that: The method comprises the following steps: Obtain the pressure value, temperature value, fluid density and proportional gain coefficient of the PID controller at each moment during the pressure regulation process of the pressure regulating valve; wherein the pressure regulation process includes the historical pressure regulation process of a preset number of times and the current pressure regulation process; Analyze the fluctuation characteristics of the pressure values ​​at all times during each historical pressure regulation process, the difference between the pressure values ​​at each time and the pressure setting value, and obtain the abnormality of the change of the pressure monitoring data during each historical pressure regulation process; evaluate the correlation between the abnormality of the change and the proportional gain coefficient, and determine the pressure responsiveness in the pipeline where the pressure regulating valve is located; In combination with the response between fluid density and temperature value, the fluctuation of pressure deviation value, the fluctuation of fluid density and the change characteristics of pressure value in the current pressure regulation process, the environmental sensitivity of the regulating valve in the regulation process is obtained, and the pressure deviation value is determined based on the difference between the pressure value and the pressure setting value; the dynamic coefficient of the control parameter is determined by combining the pressure deviation value, the pressure responsiveness and the environmental sensitivity in the current pressure regulation process; Using the dynamic coefficient to control the pressure of the pressure regulating valve; The analysis of the fluctuation characteristics of the pressure values ​​at all times during each historical pressure regulation process, the difference between the pressure values ​​at each time and the pressure setting value, and obtaining the abnormality of the pressure monitoring data during each historical pressure regulation process includes: According to the difference between the pressure values ​​at every two moments in the reference adjustment process and the difference between the pressure value at each moment and the pressure setting value, the change abnormality of the pressure monitoring data of the reference adjustment process is obtained, and the difference between the pressure values ​​at every two moments and the difference between the pressure value at each moment and the pressure setting value are both positively correlated with the change abnormality; The reference adjustment process is any historical pressure adjustment process; The evaluation of the correlation between the abnormality of the change and the proportional gain coefficient to determine the pressure responsiveness in the pipeline where the pressure regulating valve is located includes: Calculating the correlation between the variation abnormality sequence and the proportional gain coefficient sequence, and determining the correlation as the pressure responsiveness in the pipeline where the pressure regulating valve is located; The variation abnormality sequence is composed of variation abnormalities of pressure monitoring data of all historical pressure regulation processes, and the proportional gain coefficient sequence is composed of proportional gain coefficients of PID controllers of all historical pressure regulation processes; The environmental sensitivity of the regulating valve during the current pressure regulation process is obtained by combining the response between the fluid density and the temperature value, the fluctuation of the pressure deviation value, the fluctuation of the fluid density and the change characteristics of the pressure value, including: According to the mean square error between the fluid density and the temperature value at all times in the current pressure regulation process and the slope difference between every two adjacent moments in the current pressure regulation process, the contribution of the environment to the pressure oscillation regulation is obtained, the mean square error is negatively correlated with the contribution, and the slope difference is positively correlated with the contribution; the fluid density curve is obtained by curve fitting the fluid density at all times in the current pressure regulation process, and the slope at each moment is determined based on the fluid density curve; According to the discrete degree of the pressure deviation value, the discrete degree of the fluid density and the contribution degree in the current pressure regulation process, the environmental sensitivity of the regulating valve in the regulation process is obtained; The step of obtaining the environmental sensitivity of the regulating valve in the current pressure regulation process according to the discrete degree of the pressure deviation value, the discrete degree of the fluid density and the contribution degree in the current pressure regulation process includes: The sum of the discrete degree of the pressure deviation value and the preset adjustment parameter is recorded as the first characteristic value, and the sum of the discrete degree of the fluid density and the preset adjustment parameter is recorded as the second characteristic value, and the preset adjustment parameter is greater than 0; Calculating a ratio of the first eigenvalue to the second eigenvalue; Determine the product of the ratio and the contribution as the environmental sensitivity during the regulating valve regulating process; The variance of the pressure deviation value at all times in the current pressure regulation process is used as the discrete degree of the pressure deviation value in the current pressure regulation process; the variance of the fluid density at all times in the current pressure regulation process is used as the discrete degree of the fluid density in the current pressure regulation process; The step of comprehensively determining the dynamic coefficient of the control parameter by taking into account the pressure deviation value, the pressure responsiveness and the environmental sensitivity in the current pressure regulation process includes: According to the average level of the pressure deviation value in the current pressure regulation process, the environmental sensitivity and the pressure responsiveness, a dynamic coefficient of the control parameter is obtained, wherein the average level and the environmental sensitivity are both positively correlated with the dynamic coefficient, and the pressure responsiveness is negatively correlated with the dynamic coefficient; The method of controlling the pressure of the pressure regulating valve by using the dynamic coefficient includes: The product of the dynamic coefficient and the proportional gain coefficient of the current PID controller is used as the adjustment amount of the proportional gain coefficient of the PID controller to control the pressure of the pressure regulating valve; The calculation formula of the correlation between the change abnormality sequence and the proportional gain coefficient sequence is: , where B represents the correlation between the change abnormality sequence and the proportional gain coefficient sequence, and P represents the Pearson correlation coefficient between the change abnormality sequence and the proportional gain coefficient sequence; The calculation formula for the contribution of the environment to the pressure oscillation regulation is: Among them, H represents the contribution of the environment to the pressure oscillation regulation, Y represents the fluid density sequence, Z represents the temperature sequence, and V represents the number of moments in the current pressure regulation process. It represents the slope at the vth moment in the current pressure regulation process, Indicates the slope at the v+1th moment in the current pressure regulation process, represents the mean square error function, represents the mean square error between the fluid density series and the temperature series, To take the absolute value sign, It is the preset first adjustment parameter.

2. The pressure control method of the pressure regulating valve based on PID control according to claim 1, characterized in that: The obtaining of the pressure deviation value includes: At any moment, the difference between the pressure value at that moment and the pressure setting value is taken as the pressure deviation value at that moment.

3. A pressure control system for a pressure regulating valve based on PID control, used in the pressure control method for a pressure regulating valve according to claim 1, characterized in that: The system includes: A data acquisition module, used to obtain the pressure value, temperature value, fluid density and proportional gain coefficient of the PID controller at each moment during the pressure regulation process of the pressure regulating valve; wherein the pressure regulation process includes the historical pressure regulation process of a preset number of times and the current pressure regulation process; The pressure response calculation module is used to analyze the fluctuation characteristics of the pressure values ​​at all times during each historical pressure regulation process, the difference between the pressure values ​​at each time and the pressure setting value, and obtain the abnormality of the change of the pressure monitoring data during each historical pressure regulation process; evaluate the correlation between the abnormality of the change and the proportional gain coefficient, and determine the pressure response of the pipeline where the pressure regulating valve is located; A dynamic coefficient determination module is used to obtain the environmental sensitivity of the regulating valve during the regulation process by combining the response between the fluid density and the temperature value, the fluctuation of the pressure deviation value, the fluctuation of the fluid density and the change characteristics of the pressure value during the current pressure regulation process, wherein the pressure deviation value is determined based on the difference between the pressure value and the pressure setting value; and to determine the dynamic coefficient of the control parameter by combining the pressure deviation value, the pressure responsiveness and the environmental sensitivity during the current pressure regulation process; The pressure control module is used to control the pressure of the pressure regulating valve using the dynamic coefficient.

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