Two-phase flow analysis system and method based on differential pressure flowmeter and electromagnetic flowmeter

Abstract

The present invention belongs to the technical field of flow meter calibration, and discloses a two-phase flow analysis system and method based on a differential pressure flow meter and an electromagnetic flow meter; the method comprises: deploying a differential pressure flow meter and an electromagnetic flow meter at adjacent sections of a pipeline, the electromagnetic flow meter collecting voltage signals for analysis to obtain the liquid phase volume flow rate, and combining temperature correction to obtain the liquid phase mass flow rate; the differential pressure flow meter calculates the gas density based on temperature and pressure using the ideal gas law; inputting multi-sensor time series data into a weighted optimization model to optimize the volumetric gas fraction and the total mass flow rate; calibrating baseline parameters to obtain zero-point drift when the pipe is full of single-phase flow, and combining real-time temperature and pressure dynamic correction to improve metering accuracy and adaptability to working conditions; the present invention solves the calibration deviation problem of traditional flow meters, realizes high-precision and high-reliability measurement of complex gas-liquid two-phase flows, and provides efficient and reliable technical support for precise measurement and process control of two-phase flows in the fields of chemical industry and energy.

Description

Technical Field

[0001] The present invention relates to the technical field of flowmeter calibration, and more particularly to a two-phase flow analysis system and method based on a differential pressure flowmeter and an electromagnetic flowmeter. Background Art

[0002] In industrial production, such as in the petroleum, chemical, and energy sectors, accurate measurement of gas-liquid or liquid-solid two-phase flows is often required. Traditional flow measurement methods and devices present numerous challenges when dealing with two-phase flows, making it difficult to meet the demands for high-precision and high-reliability measurement.

[0003] For example, some conventional flow meters cannot accurately measure the flow distribution of each phase in a two-phase flow, resulting in large overall measurement errors; some devices have complex structures, high maintenance costs, and are not suitable for two-phase flow measurements under different working conditions.

[0004] Chinese patent application CN102997979B discloses a differential pressure flowmeter calibration system. The system includes an industrial computer, a differential pressure calibration module, an electromagnetic flowmeter standard table, and a HART converter. The differential pressure calibration module includes a data processing module and a control module and is built into the industrial computer. One end of the HART converter is connected to the HART interface built into the transmitter of the differential pressure flowmeter to be calibrated, and the other end is connected to the data processing module of the differential pressure calibration module via a computer interface. The electromagnetic flowmeter standard table is connected to the industrial computer via its built-in RS232 data interface. The HART converter can convert the HART protocol physical signals used by the differential pressure flowmeter to be calibrated into the RS-232 serial signals of the industrial computer. The data processing module can read and display data from the differential pressure flowmeter to be calibrated and the electromagnetic flowmeter standard table. Basic information of the differential pressure flowmeter to be calibrated includes the manufacturer identification code, manufacturer equipment type code, and equipment identification number, as well as the differential pressure value, current value, and flow percentage during the calibration process. Basic information of the electromagnetic flowmeter standard table includes instantaneous flow rate and accumulated flow rate. The invention avoids systematic errors in the data collection stage of the calibration table and errors caused by some misoperations, improves the accuracy of the calibration results, and improves work efficiency.

[0005] Although the above method can meet most scenarios, research and practical application of the above method and existing technology have found that the above method and existing technology have at least the following defects:

[0006] The current signal of the differential pressure flowmeter is collected through the current-voltage conversion circuit and the analog-to-digital conversion module (AD module). There are hardware errors and AD sampling resolution errors. At the same time, the calculation error when the transmitter processes the instantaneous flow will also lead to calibration deviation.

[0007] In view of this, the present invention proposes a two-phase flow analysis system and method based on a differential pressure flowmeter and an electromagnetic flowmeter to solve the above problems. Summary of the Invention

[0008] In order to overcome the above-mentioned defects of the prior art and to achieve the above-mentioned purpose, the present invention provides the following technical solution: a two-phase flow analysis method based on a differential pressure flowmeter and an electromagnetic flowmeter, comprising the following steps:

[0009] Install differential pressure flowmeters and electromagnetic flowmeters in adjacent sections of the pipeline;

[0010] The voltage signal of the electromagnetic flowmeter is collected and combined with the liquid thermal expansion coefficient and the density of the liquid at the reference temperature to calculate the liquid mass flow rate;

[0011] Collect the temperature and pressure of the fluid in the pipeline, calculate the gas density based on the temperature and pressure using the ideal gas law, and calculate the total mass flow rate based on the gas density;

[0012] The multi-sensor time series data including differential pressure, voltage, temperature and pressure are used as inputs to the weight optimization model to obtain the optimized volumetric gas fraction and total mass flow rate.

[0013] In the full pipe single-phase flow state, determine whether the preset trigger conditions are met. If so, calibrate the baseline parameters of the differential pressure flowmeter and the electromagnetic flowmeter to obtain the corresponding zero drift of the differential pressure flowmeter and the electromagnetic flowmeter, and update the corresponding flowmeter parameters according to the zero drift;

[0014] Combined with the real-time temperature and real-time pressure, the zero drift corresponding to the differential pressure flowmeter and the electromagnetic flowmeter, as well as the flowmeter parameters corresponding to the zero drift, are dynamically corrected.

[0015] Furthermore, the method for obtaining the liquid phase mass flow rate includes:

[0016] The voltage signal of the electromagnetic flowmeter is collected and analyzed to obtain the liquid volume flow rate. The liquid corrected density is calculated by combining the liquid thermal expansion coefficient and the density of the liquid at the reference temperature. The liquid mass flow rate is obtained by multiplying the liquid corrected density and the liquid volume flow rate.

[0017] Furthermore, the method for calculating the total mass flow rate includes:

[0018] Initialize the volumetric gas fraction. Based on the initialized volumetric gas fraction, calculate the average density by combining the gas density and the liquid corrected density. Calculate the initial total mass flow by combining the pressure difference collected by the differential pressure flowmeter, the liquid mass flow rate, the structural coefficient, and the average density.

[0019] An updated volumetric gas fraction is calculated based on the gas mass flow rate, liquid phase volumetric flow rate, liquid corrected density, and gas density. The initial total mass flow rate is updated based on the updated volumetric gas fraction to obtain an updated total mass flow rate. The volumetric gas fraction and total mass flow rate are repeatedly updated until the difference in the total mass flow rate is less than a preset change threshold. The last updated total mass flow rate is used as the final total mass flow rate.

[0020] Furthermore, the method for determining whether a preset trigger condition is met includes:

[0021] Preset trigger conditions. When the trigger conditions are met, the real-time flow calculation is suspended and the baseline parameters of the differential pressure flowmeter and the electromagnetic flowmeter are calibrated.

[0022] Furthermore, the method for calibrating the baseline parameters of the differential pressure flowmeter includes:

[0023] When the differential pressure flowmeter is in a no-flow state, collect the zero drift output by the differential pressure flowmeter N times, and calculate the average value of the zero drift output by the differential pressure flowmeter N times as the zero drift of the pressure difference;

[0024] Under known flow conditions, record the differential pressure of the differential pressure flowmeter, calculate the difference between the differential pressure and the zero drift of the differential pressure, and mark it as the actual differential pressure;

[0025] A pressure-flow relationship among the structural coefficient, actual pressure difference and known flow is established, and the corresponding structural coefficient value is calculated based on the pressure-flow relationship, and the corresponding structural coefficient value is used as the flowmeter parameter corresponding to the differential pressure flowmeter.

[0026] Furthermore, the method for calibrating the baseline parameters of the electromagnetic flowmeter includes:

[0027] When the electromagnetic flowmeter is in a no-flow state, collect the zero-point drift of the electromagnetic flowmeter output voltage N times, and calculate the average value of the zero-point drift of the electromagnetic flowmeter output voltage N times as the zero-point drift of the voltage;

[0028] Under known flow conditions, record the voltage of the electromagnetic flowmeter, calculate the difference between the voltage and the zero drift of the voltage, and mark it as the actual voltage;

[0029] A voltage-velocity relationship is established between the electromagnetic flowmeter sensitivity coefficient, actual voltage, pipe cross-sectional area and known flow rate, and the electromagnetic flowmeter sensitivity coefficient is calculated based on the voltage-velocity relationship; the electromagnetic flowmeter sensitivity coefficient is used as the flowmeter parameter corresponding to the electromagnetic flowmeter.

[0030] Furthermore, the method for updating corresponding flow meter parameters according to zero drift includes:

[0031] According to the temperature coefficients of the differential pressure flowmeter and the electromagnetic flowmeter, the outputs of the differential pressure flowmeter and the electromagnetic flowmeter are dynamically corrected.

[0032] Furthermore, the method for dynamically correcting the zero drift corresponding to the differential pressure flowmeter and the electromagnetic flowmeter includes:

[0033] The zero drift of the differential pressure flowmeter and the electromagnetic flowmeter is updated according to the zero drift of the differential pressure flowmeter and the electromagnetic flowmeter in combination with the proportional gain and the real-time error to obtain updated zero drift of the differential pressure flowmeter and the electromagnetic flowmeter.

[0034] Furthermore, the method for dynamically correcting the flow meter parameters corresponding to the zero drift includes:

[0035] The sensitivity coefficient of the electromagnetic flowmeter is updated according to the reference flow deviation and the flow deviation to obtain an updated sensitivity coefficient of the electromagnetic flowmeter;

[0036] At the standard temperature, calibrate the initial temperature drift coefficient, collect the real-time temperature, calculate the difference between the real-time temperature and the standard temperature, and obtain the temperature change;

[0037] Under the preset working conditions, fix the flow rate and change the temperature, and record the pressure drift corresponding to the temperature change;

[0038] The temperature drift coefficient compensation value is calculated based on the temperature change and pressure drift.

[0039] Furthermore, the method for obtaining the liquid phase volume flow rate includes:

[0040] The voltage signal of the electromagnetic flowmeter is collected, and the product of the voltage signal and the cross-sectional area of ​​the pipe is calculated to obtain the liquid phase volume flow rate.

[0041] A two-phase flow analysis system based on a differential pressure flowmeter and an electromagnetic flowmeter implements the two-phase flow analysis method based on the differential pressure flowmeter and the electromagnetic flowmeter, including:

[0042] Device construction module: Install differential pressure flowmeter and electromagnetic flowmeter in adjacent sections of the pipeline;

[0043] The first analysis module collects the voltage signal of the electromagnetic flowmeter, analyzes it to obtain the liquid volume flow rate, calculates the liquid corrected density based on the liquid thermal expansion coefficient and the density of the liquid at the reference temperature, and calculates the liquid mass flow rate based on the liquid corrected density and the liquid volume flow rate;

[0044] The second analysis module collects the temperature and pressure of the fluid in the pipeline, calculates the gas density based on the temperature and pressure using the ideal gas law, and calculates the total mass flow rate based on the gas density;

[0045] The third analysis module uses multi-sensor time series data as input to the weight optimization model to obtain the optimized volumetric gas fraction and total mass flow rate. The multi-sensor time series data includes pressure difference, voltage, temperature, and pressure.

[0046] Static calibration module: In the state of full pipe single-phase flow, it determines whether the preset trigger conditions are met. If so, it calibrates the baseline parameters of the differential pressure flowmeter and the electromagnetic flowmeter, obtains the corresponding zero drift of the differential pressure flowmeter and the electromagnetic flowmeter, and updates the corresponding flowmeter parameters according to the zero drift;

[0047] Feedback correction module: Combined with real-time temperature and real-time pressure, it dynamically corrects the zero drift corresponding to the differential pressure flowmeter and electromagnetic flowmeter, as well as the flowmeter parameters corresponding to the zero drift.

[0048] The technical effects and advantages of the two-phase flow analysis system and method based on the differential pressure flowmeter and electromagnetic flowmeter of the present invention are as follows:

[0049] The present invention collaboratively deploys two types of flow meters in adjacent sections of the pipeline. The electromagnetic flow meter directly collects the liquid phase voltage signal and combines it with temperature correction to accurately calculate the liquid phase mass flow rate, eliminating the influence of temperature on liquid density. The differential pressure flow meter combines temperature and pressure parameters to dynamically model gas density, providing key gas phase parameters for total mass flow calculation. By introducing a weighted optimization model, the coupling relationship between multi-sensor time series data such as pressure difference, voltage, temperature, and pressure is deeply explored, and the volume gas fraction and total mass flow rate are optimized in real time, significantly improving the measurement adaptability under complex flow patterns. At the same time, through the baseline parameter calibration triggered by full-pipe single-phase flow and the temperature and pressure dynamic compensation mechanism, the sensor zero point error and temperature drift are continuously calibrated to ensure the output stability of the flow meter under different working conditions. The present invention solves the calibration deviation problem of traditional differential pressure flow meters and electromagnetic flow meters through the fusion of multi-dimensional technologies, and achieves high precision and high reliability in the measurement of complex gas-liquid two-phase flows, providing efficient and reliable technical support for the precise measurement and process control of two-phase flows in the fields of chemical industry and energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Schematic diagram of a two-phase flow analysis method based on a differential pressure flowmeter and an electromagnetic flowmeter according to the present invention;

[0051] Figure 2 This is a schematic diagram of the installation of the differential pressure flowmeter and the electromagnetic flowmeter of the present invention;

[0052] Figure 3 Schematic diagram of gas-liquid distribution in the cyclone device of the present invention;

[0053] Figure 4 This is a schematic diagram of the layout of the temperature and pressure sensors of the Venturi flowmeter of the present invention;

[0054] Figure 5 Schematic diagram of the signal processing flow of the present invention;

[0055] Figure 6 This is a structural diagram of the two-phase flow analysis system based on the differential pressure flowmeter and the electromagnetic flowmeter of the present invention.

[0056] Figure numerals: 1. swirl device; 2. electromagnetic flowmeter; 3. Venturi tube; 4. pressure sensor; 5. differential pressure flowmeter; 6. temperature sensor. DETAILED DESCRIPTION

[0057] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0058] Example 1:

[0059] See also Figure 1 As shown, this embodiment provides a two-phase flow analysis method based on a differential pressure flowmeter and an electromagnetic flowmeter, comprising the following steps:

[0060] Install a differential pressure flowmeter 5 (such as a venturi tube 3) and an electromagnetic flowmeter 2 at adjacent sections of the pipeline;

[0061] Specific device diagram can be referred to Figure 2 , wherein the cyclone device 1 is installed upstream of the pipeline to force the gas and liquid to form a stratified flow, which can be referred to Figure 3 The cone angle of the guide tube inside the swirl device 1 is set to 30°-60° to adapt to different gas-liquid ratio working conditions. The diameter of the guide tube is 1-3 times the pipe diameter, and the pitch of the spiral blade is adjustable, which can force the gas and liquid to rotate, and use centrifugal force to separate the gas and liquid, forming a central gas column and an outer liquid ring. The swirl device 1 can achieve efficient pre-separation of gas and liquid and reduce sensor measurement interference; the downstream is connected in sequence to the electromagnetic flowmeter 2 and the Venturi tube 3; the electromagnetic flowmeter 2 is used to measure the overall volume flow of the two-phase flow; the Venturi tube 3 uses its special structure to obtain the flow velocity information of each phase in the two-phase flow by measuring the pressure difference before and after; refer to Figure 4 The venturi tube 3 integrates a differential pressure sensor, a temperature sensor 6 and a pressure sensor 4, which are symmetrically embedded on both sides of the tube wall to monitor the fluid physical parameters in real time.

[0062] Reference Figure 5When the two-phase flow passes through the electromagnetic flowmeter 2, based on the principle of electromagnetic induction, the electromagnetic flowmeter 2 outputs an electrical signal proportional to the overall volumetric flow rate. The fluid then enters the Venturi tube 3. In the contraction section and throat of the Venturi tube 3, the flow rate increases and the pressure decreases due to changes in the tube diameter. By measuring the pressure difference between the inlet and throat of the Venturi tube 3 and combining it with a pre-established model for the relationship between pressure difference and flow rate, the flow rate of each phase can be calculated. The data processing unit receives the signals from the electromagnetic flowmeter 2 and the Venturi tube 3, analyzes and processes them using a specific algorithm, and ultimately determines the gas flow rate, liquid flow rate, and overall flow rate in the two-phase flow.

[0063] right Figure 2 The device in the test was tested under the same test conditions as the traditional orifice plate method (the test conditions of each group were the same, and the average of the test results of M groups was taken as the final test result). The test results can be referred to Table 1:

[0064] Table 1 Performance parameters of different devices under the same test conditions

[0065] Test conditions Traditional orifice plate method This device Gas-liquid ratio 1:1 1:1 pressure fluctuations 5 5 Temperature deviation 10 10 Volume flow error ±4.2 ±1.2

[0066] It can be seen from Table 1 that the volume flow error of the device used in this embodiment is ±1.2, and the volume flow error of the traditional orifice plate method is ±4.2. The volume flow error of the device used in this embodiment is lower and has higher measurement accuracy. It can provide more accurate data for two-phase flow analysis, thereby more effectively helping related fields to accurately grasp and conduct in-depth research on flow conditions, and improve the accuracy and reliability of analysis.

[0067] The voltage signal of the electromagnetic flowmeter 2 is collected and analyzed to obtain the liquid phase volume flow rate. The liquid corrected density is calculated based on the liquid thermal expansion coefficient and the density of the liquid at the reference temperature. The liquid phase mass flow rate is calculated based on the liquid corrected density and the liquid phase volume flow rate. The volume flow rate measured by the electromagnetic flowmeter 2 is converted into a more accurate mass flow rate by correcting the density parameter with temperature, which effectively improves the measurement accuracy of the liquid phase mass flow rate in two-phase flow and provides reliable flow data support for industrial process control, energy metering and other fields.

[0068] Methods for obtaining liquid phase volume flow rate include:

[0069] The voltage signal of the electromagnetic flowmeter 2 is collected, and the product of the voltage signal and the pipe cross-sectional area is calculated to obtain the liquid phase volume flow rate.

[0070] The electromagnetic flowmeter 2 directly obtains the liquid phase volume flow rate by collecting voltage signals and combining them with the cross-sectional area of ​​the pipeline, laying the foundation for the measurement of liquid phase parameters; the differential pressure flowmeter 5 reflects the overall flow characteristics by capturing the pressure difference changes of the two-phase flow; the combination of the two can simultaneously take into account the accurate measurement of the liquid phase volume flow rate and the analysis of the comprehensive flow state of the two-phase flow. It can not only calculate the liquid phase mass flow rate through the liquid phase volume flow rate and the corrected density, but also analyze the influence of the gas phase based on the differential pressure characteristics, effectively reducing the measurement error of a single flow meter in a multiphase flow environment, and improving the comprehensiveness and reliability of flow measurement under complex working conditions.

[0071] Methods for obtaining liquid phase mass flow rate include:

[0072] Combined with the liquid thermal expansion coefficient and the density of the liquid at the reference temperature, the liquid correction density is calculated, and the product of the liquid correction density and the liquid phase volume flow rate is calculated to obtain the liquid phase mass flow rate; such as the liquid correction density The calculation formula is: ;in, is the thermal expansion coefficient of the liquid, which can be obtained by optimizing the natural inspiration optimization algorithm; is the density of the liquid at the reference temperature; is temperature; is the reference temperature.

[0073] The temperature and pressure of the fluid in the pipeline are collected, and the gas density is calculated based on the temperature and pressure using the ideal gas law. The total mass flow rate is calculated based on the gas density.

[0074] Electromagnetic flowmeter 2 acquires liquid volume flow by collecting voltage signals and calculates the corrected liquid density based on the liquid's thermal expansion coefficient and the liquid's density at a reference temperature, thereby accurately deriving the liquid mass flow rate. This effectively eliminates the effects of temperature on liquid density. Differential pressure flowmeter 5 collects fluid temperature and pressure within the pipeline, calculates gas density using the ideal gas law, and analyzes the gas flow state based on the characteristics of the differential pressure signal, ultimately achieving accurate calculation of the total mass flow rate. The two complement each other: electromagnetic flowmeter 2 offers high stability in measuring the volume flow of the conductive liquid phase, while differential pressure flowmeter 5 dynamically adapts to the calculation of gas density through a pressure-temperature coupling relationship. Together, they cover the key aspects of liquid mass flow correction and gas density modeling in two-phase flow. This combined measurement method not only addresses the sensitivity of single flowmeters to phase changes and insufficient metering accuracy in multiphase flow environments, but also comprehensively analyzes the mass flow distribution and phase characteristics of two-phase flow through the coupled calculation of the corrected liquid density and gas density. This provides high-precision and reliable flow data for the chemical, petroleum, and energy industries, facilitating process optimization and safe operation under complex operating conditions.

[0075] Methods for obtaining total mass flow include:

[0076] Initialize the volumetric gas content, calculate the average density based on the initial volumetric gas content, combined with the gas density and liquid corrected density, and calculate the initial total mass flow rate based on the pressure difference collected by the differential pressure flowmeter 5, the liquid mass flow rate, the gas density, the structural coefficient and the average density; if the gas density ;in, For pressure; is the molar mass of the gas; is the universal gas constant, specifically 8.314 J / (mol×K); the above formula is based on the ideal gas law, through the pressure , gas molar mass ,temperature and the universal gas constant Accurately calculate gas density, provide key gas phase parameters for subsequent average density modeling and total mass flow calculation, ensure the accuracy of gas phase physical parameters, and improve the calculation accuracy of gas phase contribution in two-phase flow; such as average density ;in, To initialize the volumetric gas fraction; the above formula combines the initial volumetric gas fraction with the gas and liquid two-phase densities to construct an average density model of the mixed medium, so that the differential pressure flowmeter 5 can calculate the initial total mass flow rate based on the differential pressure signal, effectively integrating the two-phase physical parameters, laying the foundation for the differential pressure method to measure the total mass flow rate, and realizing the dynamic characterization of the density of the gas-liquid mixed phase; the initial total mass flow rate ;in, is the structural coefficient; is the pressure difference; the above formula uses the structural coefficient, pressure difference and average density to calculate the initial total mass flow rate, converts the differential pressure signal into a specific flow value, and combines the two-phase average density to achieve preliminary quantification of the total amount of gas-liquid mixed flow, providing a starting point for subsequent iterative calculations and quickly establishing an initial estimation model for the total mass flow rate; the structural coefficient of the Venturi tube 3 can be calculated based on the inlet cross-sectional area and throat cross-sectional area, such as ;in, is the inlet cross-sectional area, is the inlet pipe diameter; is the throat cross-sectional area, is the throat diameter; the above formula calculates the structural coefficient through the inlet cross-sectional area and throat cross-sectional area of ​​the Venturi tube 3, accurately reflecting the influence of the geometric characteristics of the Venturi tube 3 on the flow measurement, ensuring that the differential pressure flowmeter 5 can accurately convert the pressure difference into the flow parameter under different pipe diameter structures. The structural coefficient is a key correction factor for the structural characteristics of the device, which directly affects the conversion accuracy of the differential pressure signal and flow.

[0077] Calculate the difference between the initial total mass flow rate and the liquid phase mass flow rate to obtain the gas mass flow rate. Calculate the updated volumetric gas fraction based on the gas mass flow rate, liquid phase volume flow rate, liquid corrected density, and gas density. Update the initial total mass flow rate based on the updated volumetric gas fraction to obtain an updated total mass flow rate. Repeat the updating of the volumetric gas fraction and the total mass flow rate until the difference in the total mass flow rate is less than the preset change threshold. The last updated total mass flow rate is used as the final total mass flow rate. ;in, is the updated volumetric air holdup; is the liquid phase volume flow rate; is the gas mass flow rate; the above formula updates the volumetric gas fraction based on the relationship between gas mass flow rate and liquid volume flow rate, dynamically adjusting the gas phase proportion to ensure that the volumetric gas fraction more closely matches the actual two-phase flow state. By correcting the volumetric gas fraction based on the liquid volume flow rate and gas mass flow rate measured by electromagnetic flowmeter 2 and the gas-liquid density ratio, this provides more accurate phase distribution parameters for iterative correction of the total mass flow rate, improving the accuracy of the gas phase content representation in two-phase flow.

[0078] Update the average density based on the updated volumetric gas fraction, and then update the initial total mass flow rate based on the updated average density to obtain an updated total mass flow rate; the updated volumetric gas fraction and total mass flow The relationship between can be expressed as: This formula repeatedly corrects the total mass flow rate by continuously substituting the updated volumetric gas fraction until its change is less than the preset change threshold. By deeply integrating the differential pressure signal of the differential pressure flowmeter 5 and the liquid phase flow data of the electromagnetic flowmeter 2, the initial assumption error is eliminated, and high-precision convergence of the total mass flow rate is achieved in the complex changes of the two-phase flow, ensuring that the measurement results fit the actual working conditions. It is the core calculation link for achieving coordinated optimization of the data of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2; it is iteratively updated according to the relationship between the volumetric gas fraction and the total mass flow rate. When the difference in the total mass flow rate before and after the update is less than the preset change threshold, the updated total mass flow rate is used as the final total mass flow rate.

[0079] The electromagnetic flowmeter 2 directly collects the liquid phase volume flow rate and obtains the liquid corrected density in combination with temperature correction, providing basic parameters for the calculation of the liquid phase mass flow rate; the differential pressure flowmeter 5 uses the structural characteristics of the Venturi tube 3 to collect the differential pressure signal, and constructs an average density model in combination with the initial volume gas fraction, gas density and liquid corrected density to obtain the initial total mass flow rate; on this basis, by establishing an iterative relationship between the volume gas fraction and the total mass flow rate, the volume gas fraction is continuously updated and the total mass flow rate is corrected until the difference in the total mass flow rate change is less than the preset change threshold, ensuring that the measurement result converges to the true value; this combined measurement method gives full play to the stable measurement advantage of the electromagnetic flowmeter 2 for the liquid phase volume flow rate and the sensitive capture ability of the differential pressure flowmeter 5 for the overall flow characteristics of the two-phase flow, eliminates the single-phase assumption error through the iterative algorithm, effectively solves the interference problem of phase change on density and flow type in gas-liquid two-phase flow, and significantly improves the accuracy and reliability of multiphase flow measurement. This solution has important application value in the fields of petrochemicals, energy extraction, process control, etc. It can provide real-time and accurate total mass flow data support for component analysis, process optimization and energy efficiency evaluation of gas-liquid two-phase flow, and facilitate efficient production and safety monitoring under complex working conditions.

[0080] Multi-sensor time series data is used as input to the weight optimization model to obtain the optimized volumetric gas fraction and total mass flow rate. Multi-sensor time series data includes pressure difference, voltage, temperature, and pressure. Inputting multi-sensor time series data such as pressure difference, voltage, temperature, and pressure into the Transformer weight optimization model can fully utilize the model's ability to capture time series features, deeply explore the dynamic correlation and complex coupling relationship between various parameters, and thus achieve intelligent optimization of volumetric gas fraction and total mass flow rate. This method effectively integrates the core measurement information of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2, and at the same time combines the effects of temperature and pressure on gas-liquid density to dynamically adapt to the complex and changeable working conditions of two-phase flow, significantly improving the calculation accuracy and reliability of volumetric gas fraction and total mass flow rate, providing more accurate and stable key parameters for two-phase flow analysis, and strongly supporting the efficient monitoring, precise control and optimized operation of related industrial processes.

[0081] The training methods for weight optimization models include:

[0082] W groups of type identification data are collected in advance, and the type identification data include multi-sensor time series data, optimized volumetric gas fraction and total mass flow rate.

[0083] Multi-sensor time series data is used as the input of the weight optimization model, and the optimized volumetric gas fraction and total mass flow rate are used as the output of the weight optimization model. With the goal of minimizing the error between the output optimized volumetric gas fraction and total mass flow rate and the actual optimized volumetric gas fraction and total mass flow rate, the network parameters of the weight optimization model are optimized through a nature-inspired optimization algorithm to obtain the network parameters that minimize the error between the optimized volumetric gas fraction and total mass flow rate output by the weight optimization model and the actual optimized volumetric gas fraction and total mass flow rate. The weight optimization model constructed with the corresponding network parameters is used as the trained weight optimization model; wherein, the weight optimization model is a Transformer model.

[0084] In the state of full pipe single-phase flow (such as pure liquid or pure gas), determine whether the preset trigger conditions are met. If so, calibrate the baseline parameters of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2 to obtain the corresponding zero point drift of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2, and update the corresponding flowmeter parameters according to the zero point drift.

[0085] Methods for determining whether the preset trigger conditions are met include:

[0086] Preset trigger conditions (such as pressure fluctuation less than 1% of the full scale, temperature fluctuation less than 0.5℃ / min, and electromagnetic flowmeter 2 signal noise less than 0.2% of the full scale). When the trigger conditions are met, the real-time flow calculation is suspended and the baseline parameters of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2 are calibrated.

[0087] By setting strict thresholds for pressure fluctuation, temperature fluctuation, and electromagnetic flowmeter 2 signal noise, calibration is triggered under stable conditions of full pipe single-phase flow to avoid external interference, ensure that the calibration process is in an ideal state, provide the premise for subsequent precise calibration of flowmeter parameters, and improve the basic reliability and accuracy of two-phase flow analysis.

[0088] The method for calibrating the baseline parameters of the differential pressure flowmeter 5 includes:

[0089] When the differential pressure flowmeter 5 is in a no-flow state, collecting N zero-point drifts output by the differential pressure flowmeter 5, and calculating an average value of the N zero-point drifts output by the differential pressure flowmeter 5 as the zero-point drift of the pressure difference;

[0090] Under known flow conditions, record the differential pressure of the differential pressure flowmeter 5, calculate the difference between the differential pressure and the zero drift of the differential pressure, and mark it as the actual differential pressure;

[0091] Establish the pressure-flow relationship between the structural coefficient, actual pressure difference and known flow rate; such as ;in, is the structural coefficient; is a known flow rate; is the actual pressure difference; is the fluid density in the differential pressure flowmeter 5; the corresponding structural coefficient value is calculated according to the pressure difference flow relationship, and the corresponding structural coefficient value is used as the flowmeter parameter corresponding to the differential pressure flowmeter 5.

[0092] When there is no flow, the zero drift is measured and averaged to determine the zero drift of the differential pressure. When the flow rate is known, the structural coefficient is calculated by combining the actual differential pressure with the differential pressure-flow relationship. This method eliminates zero-point errors in the differential pressure flowmeter 5, accurately determines structural characteristic parameters, and enables more accurate conversion of differential pressure signals into flow values, improving the accuracy and reliability of the differential pressure flowmeter 5 in two-phase flow measurements (especially for gas-liquid mixtures involving varying pressure differentials).

[0093] The method for calibrating the baseline parameters of the electromagnetic flowmeter 2 includes:

[0094] When the electromagnetic flowmeter 2 is in a no-flow state, the zero-point drift of the output voltage of the electromagnetic flowmeter 2 is collected N times, and the average value of the zero-point drift of the output voltage of the electromagnetic flowmeter 2 is calculated as the zero-point drift of the voltage;

[0095] Under known flow conditions, record the voltage of electromagnetic flowmeter 2, calculate the difference between the voltage and the zero-point drift of the voltage, and mark it as the actual voltage;

[0096] Establish a voltage-flow rate relationship between the sensitivity coefficient of electromagnetic flowmeter 2, actual voltage, pipe cross-sectional area and known flow rate; ;in, is a known flow rate; is the sensitivity coefficient of electromagnetic flowmeter 2, which can be obtained by optimizing the natural inspiration optimization algorithm; is the actual voltage; is the cross-sectional area of ​​the pipe; the sensitivity coefficient of the electromagnetic flowmeter 2 is calculated according to the voltage-flow velocity relationship; the sensitivity coefficient of the electromagnetic flowmeter 2 is used as the flowmeter parameter corresponding to the electromagnetic flowmeter 2.

[0097] Determine the voltage zero drift when there is no flow, and calculate the sensitivity coefficient based on the voltage-flow rate relationship when the flow rate is known. This process calibrates the electromagnetic flowmeter's zero-point deviation, clarifies the conversion relationship between voltage and flow rate, and ensures that its output voltage signal accurately reflects the liquid volume flow rate, laying the foundation for the accurate calculation of liquid parameters (such as volume flow rate and mass flow rate) in two-phase flow analysis.

[0098] Methods for updating corresponding flow meter parameters according to zero drift include:

[0099] According to the temperature coefficient of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2, the output of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2 are dynamically corrected. ; ;in, and They are the temperature coefficients of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2, which can be provided by the manufacturer or calibrated experimentally; is the actual pressure difference after dynamic correction; is the actual voltage after dynamic correction.

[0100] The above method can compensate for the influence of temperature on the flowmeter output, so that the differential pressure and voltage signals remain stable and accurate at different temperatures, adapt to complex working conditions, ensure that the flowmeter parameters in two-phase flow analysis are dynamically optimized with temperature, and maintain measurement accuracy and system adaptability.

[0101] In combination with the real-time temperature and real-time pressure, the zero drift corresponding to the differential pressure flowmeter 5 and the electromagnetic flowmeter 2, as well as the flowmeter parameters corresponding to the zero drift, are dynamically corrected.

[0102] The method for dynamically correcting the zero drift corresponding to the differential pressure flowmeter 5 and the electromagnetic flowmeter 2 includes:

[0103] The zero drift of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2 is updated according to the zero drift of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2 in combination with the proportional gain and the real-time error to obtain the updated zero drift of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2.

[0104] By dynamically adjusting the zero-point drift of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2 through real-time error and proportional gain, the zero-point drift caused by operating condition fluctuations or device aging can be corrected in a timely manner, ensuring the accuracy of the flowmeter output signal reference, providing a reliable original measurement starting point for two-phase flow analysis, and avoiding the accumulation of zero-point errors that affect the accuracy of subsequent flow calculations.

[0105] Methods for dynamically correcting flowmeter parameters corresponding to zero drift include:

[0106] The sensitivity coefficient of electromagnetic flowmeter 2 is updated according to the reference flow deviation and the flow deviation to obtain an updated sensitivity coefficient of electromagnetic flowmeter 2; the sensitivity coefficient of electromagnetic flowmeter 2 is adaptively optimized according to the flow deviation, so that it can better adapt to real-time flow changes, ensure the accuracy of liquid volume flow measurement, and thus ensure the reliability of liquid mass flow and total mass flow calculation, and improve the dynamic adaptability of electromagnetic flowmeter 2 to liquid parameter measurement in two-phase flow.

[0107] At the standard temperature, the initial temperature drift coefficient is calibrated, the real-time temperature is collected, and the difference between the real-time temperature and the standard temperature is calculated to obtain the temperature change. By determining the initial temperature drift coefficient at the standard temperature and combining the difference between the real-time temperature and the standard temperature, a quantitative basis for temperature change is established, providing basic data for compensating for the impact of temperature on the flowmeter output, enabling the differential pressure flowmeter 5 and the electromagnetic flowmeter 2 to adapt to temperature fluctuation conditions and maintain the stability of temperature-related parameters in two-phase flow analysis.

[0108] Under the preset working conditions, the flow rate is fixed and the temperature is changed, and the pressure drift corresponding to the temperature change is recorded; under the preset working conditions, the relationship between temperature and pressure drift is explored, and the specific influence of temperature change on pressure parameters is clarified, providing a measured basis for the pressure signal correction of the differential pressure flowmeter 5 at different temperatures, and optimizing the measurement accuracy of the differential pressure flowmeter 5 on pressure and flow parameters in a temperature-changing environment.

[0109] The temperature drift coefficient compensation value is calculated based on the temperature change and pressure drift. ;in, is the temperature drift coefficient compensation value; is the temperature change; is the pressure drift; is the regularization coefficient, which can be an empirical value , mainly used to prevent the denominator from approaching zero.

[0110] The temperature coefficient is compensated according to the temperature drift coefficient compensation value; the temperature drift coefficient compensation value is calculated using the temperature change, pressure drift and regularization coefficient, and the temperature coefficient is dynamically adjusted to effectively compensate for the impact of temperature on the flowmeter output characteristics, reduce the measurement deviation caused by temperature drift, ensure the parameter stability of the differential pressure flowmeter 5 and the electromagnetic flowmeter 2 under variable temperature conditions, and improve the measurement accuracy and reliability of the two-phase flow analysis in the full operating range.

[0111] Example 2:

[0112] See also Figure 6 As shown, this embodiment provides a two-phase flow analysis system based on a differential pressure flowmeter and an electromagnetic flowmeter, including:

[0113] Device construction module: Install differential pressure flowmeter and electromagnetic flowmeter in adjacent sections of the pipeline;

[0114] The first analysis module collects the voltage signal of the electromagnetic flowmeter, analyzes it to obtain the liquid volume flow rate, calculates the liquid corrected density based on the liquid thermal expansion coefficient and the density of the liquid at the reference temperature, and calculates the liquid mass flow rate based on the liquid corrected density and the liquid volume flow rate;

[0115] The second analysis module collects the temperature and pressure of the fluid in the pipeline, calculates the gas density based on the temperature and pressure using the ideal gas law, and calculates the total mass flow rate based on the gas density;

[0116] The third analysis module uses multi-sensor time series data as input to the weight optimization model to obtain the optimized volumetric gas fraction and total mass flow rate. The multi-sensor time series data includes pressure difference, voltage, temperature, and pressure.

[0117] Static calibration module: In the state of full pipe single-phase flow, it determines whether the preset trigger conditions are met. If so, it calibrates the baseline parameters of the differential pressure flowmeter and the electromagnetic flowmeter, obtains the corresponding zero drift of the differential pressure flowmeter and the electromagnetic flowmeter, and updates the corresponding flowmeter parameters according to the zero drift;

[0118] Feedback correction module: Combined with real-time temperature and real-time pressure, it dynamically corrects the zero drift corresponding to the differential pressure flowmeter and electromagnetic flowmeter, as well as the flowmeter parameters corresponding to the zero drift.

[0119] The system also realizes low-latency networking of multiple devices based on the RS485 protocol, is compatible with cloud data storage and remote monitoring, and is suitable for industrial Internet of Things scenarios.

[0120] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

[0121] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A two-phase flow analysis method based on a differential pressure flowmeter and an electromagnetic flowmeter, characterized in that: The steps include: Install differential pressure flowmeters and electromagnetic flowmeters in adjacent sections of the pipeline; The voltage signal of the electromagnetic flowmeter is collected and combined with the liquid thermal expansion coefficient and the density of the liquid at the reference temperature to calculate the liquid mass flow rate; Collect the temperature and pressure of the fluid in the pipeline, calculate the gas density based on the temperature and pressure using the ideal gas law, and calculate the total mass flow rate based on the gas density; The multi-sensor time series data including differential pressure, voltage, temperature and pressure are used as inputs to the weight optimization model to obtain the optimized volumetric gas fraction and total mass flow rate. In the full pipe single-phase flow state, determine whether the preset trigger conditions are met. If so, calibrate the baseline parameters of the differential pressure flowmeter and the electromagnetic flowmeter to obtain the corresponding zero drift of the differential pressure flowmeter and the electromagnetic flowmeter, and update the corresponding flowmeter parameters according to the zero drift; Combined with real-time temperature and real-time pressure, the zero drift corresponding to the differential pressure flowmeter and electromagnetic flowmeter, as well as the flowmeter parameters corresponding to the zero drift, are dynamically corrected; Methods for obtaining liquid phase mass flow rate include: The voltage signal of the electromagnetic flowmeter is collected and analyzed to obtain the liquid volume flow rate. The liquid corrected density is calculated by combining the liquid thermal expansion coefficient and the density of the liquid at the reference temperature. The liquid mass flow rate is obtained by multiplying the liquid corrected density and the liquid volume flow rate. The method for calculating the total mass flow rate includes: Initialize the volumetric gas fraction. Based on the initialized volumetric gas fraction, calculate the average density by combining the gas density and the liquid corrected density. Calculate the initial total mass flow by combining the pressure difference collected by the differential pressure flowmeter, the liquid mass flow rate, the structural coefficient, and the average density. An updated volumetric gas fraction is calculated based on the gas mass flow rate, liquid phase volumetric flow rate, liquid corrected density, and gas density. The initial total mass flow rate is updated based on the updated volumetric gas fraction to obtain an updated total mass flow rate. The volumetric gas fraction and total mass flow rate are repeatedly updated until the difference in the total mass flow rate is less than a preset change threshold. The last updated total mass flow rate is used as the final total mass flow rate.

2. The two-phase flow analysis method based on differential pressure flowmeter and electromagnetic flowmeter according to claim 1 is characterized in that: The method for determining whether a preset trigger condition is met includes: Preset trigger conditions. When the trigger conditions are met, the real-time flow calculation is suspended and the baseline parameters of the differential pressure flowmeter and the electromagnetic flowmeter are calibrated.

3. The two-phase flow analysis method based on differential pressure flowmeter and electromagnetic flowmeter according to claim 1, characterized in that: The method for calibrating the baseline parameters of the differential pressure flowmeter includes: When the differential pressure flowmeter is in a no-flow state, collect the zero drift output by the differential pressure flowmeter N times, and calculate the average value of the zero drift output by the differential pressure flowmeter N times as the zero drift of the pressure difference; Under known flow conditions, record the differential pressure of the differential pressure flowmeter, calculate the difference between the differential pressure and the zero drift of the differential pressure, and mark it as the actual differential pressure; A pressure-flow relationship among the structural coefficient, actual pressure difference and known flow is established, and the corresponding structural coefficient value is calculated based on the pressure-flow relationship, and the corresponding structural coefficient value is used as the flowmeter parameter corresponding to the differential pressure flowmeter.

4. The two-phase flow analysis method based on a differential pressure flowmeter and an electromagnetic flowmeter according to claim 1, characterized in that: The method for calibrating the baseline parameters of the electromagnetic flowmeter includes: When the electromagnetic flowmeter is in a no-flow state, collect the zero-point drift of the electromagnetic flowmeter output voltage N times, and calculate the average value of the zero-point drift of the electromagnetic flowmeter output voltage N times as the zero-point drift of the voltage; Under known flow conditions, record the voltage of the electromagnetic flowmeter, calculate the difference between the voltage and the zero drift of the voltage, and mark it as the actual voltage; A voltage-velocity relationship is established between the electromagnetic flowmeter sensitivity coefficient, actual voltage, pipe cross-sectional area and known flow rate, and the electromagnetic flowmeter sensitivity coefficient is calculated based on the voltage-velocity relationship; the electromagnetic flowmeter sensitivity coefficient is used as the flowmeter parameter corresponding to the electromagnetic flowmeter.

5. The two-phase flow analysis method based on differential pressure flowmeter and electromagnetic flowmeter according to claim 1, characterized in that: The method for updating corresponding flow meter parameters according to zero drift includes: According to the temperature coefficients of the differential pressure flowmeter and the electromagnetic flowmeter, the outputs of the differential pressure flowmeter and the electromagnetic flowmeter are dynamically corrected.

6. The two-phase flow analysis method based on differential pressure flowmeter and electromagnetic flowmeter according to claim 1, characterized in that: The method for dynamically correcting the zero drift corresponding to the differential pressure flowmeter and the electromagnetic flowmeter includes: The zero drift of the differential pressure flowmeter and the electromagnetic flowmeter is updated according to the zero drift of the differential pressure flowmeter and the electromagnetic flowmeter in combination with the proportional gain and the real-time error to obtain updated zero drift of the differential pressure flowmeter and the electromagnetic flowmeter.

7. The two-phase flow analysis method based on a differential pressure flowmeter and an electromagnetic flowmeter according to claim 1, characterized in that: The method for dynamically correcting the flow meter parameters corresponding to the zero drift includes: The sensitivity coefficient of the electromagnetic flowmeter is updated according to the reference flow deviation and the flow deviation to obtain an updated sensitivity coefficient of the electromagnetic flowmeter; At the standard temperature, calibrate the initial temperature drift coefficient, collect the real-time temperature, calculate the difference between the real-time temperature and the standard temperature, and obtain the temperature change; Under the preset working conditions, fix the flow rate and change the temperature, and record the pressure drift corresponding to the temperature change; The temperature drift coefficient compensation value is calculated based on the temperature change and pressure drift.

8. The two-phase flow analysis method based on a differential pressure flowmeter and an electromagnetic flowmeter according to claim 1, characterized in that: The method for obtaining the liquid phase volume flow rate comprises: The voltage signal of the electromagnetic flowmeter is collected, and the product of the voltage signal and the cross-sectional area of ​​the pipe is calculated to obtain the liquid phase volume flow rate.

9. A two-phase flow analysis system based on a differential pressure flowmeter and an electromagnetic flowmeter, implementing the two-phase flow analysis method based on a differential pressure flowmeter and an electromagnetic flowmeter according to any one of claims 1 to 8, characterized in that: include: Device construction module: Install differential pressure flowmeter and electromagnetic flowmeter in adjacent sections of the pipeline; The first analysis module collects the voltage signal of the electromagnetic flowmeter, analyzes it to obtain the liquid volume flow rate, calculates the liquid corrected density based on the liquid thermal expansion coefficient and the density of the liquid at the reference temperature, and calculates the liquid mass flow rate based on the liquid corrected density and the liquid volume flow rate; The second analysis module collects the temperature and pressure of the fluid in the pipeline, calculates the gas density based on the temperature and pressure using the ideal gas law, and calculates the total mass flow rate based on the gas density; The third analysis module uses multi-sensor time series data as input to the weight optimization model to obtain the optimized volumetric gas fraction and total mass flow rate. The multi-sensor time series data includes pressure difference, voltage, temperature, and pressure. Static calibration module: In the state of full pipe single-phase flow, it determines whether the preset trigger conditions are met. If so, it calibrates the baseline parameters of the differential pressure flowmeter and the electromagnetic flowmeter, obtains the corresponding zero drift of the differential pressure flowmeter and the electromagnetic flowmeter, and updates the corresponding flowmeter parameters according to the zero drift; Feedback correction module: Combined with real-time temperature and real-time pressure, it dynamically corrects the zero drift corresponding to the differential pressure flowmeter and electromagnetic flowmeter, as well as the flowmeter parameters corresponding to the zero drift.

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