Gas-liquid two-phase flowmeter checking method and system based on pipe flow state simulation

Abstract

The invention discloses a gas-liquid two-phase flowmeter checking method and system based on pipe flow state simulation, the system comprises a liquid supply pipeline, a gas supply pipeline and a gas-liquid two-phase manifold simulation controller, and a liquid supply control valve, a manifold display pipe section and a gas-liquid two-phase flowmeter to be checked are sequentially arranged on the liquid supply pipeline at intervals in the liquid flow direction; one end of the air supply pipeline is connected with the air pump, the other end of the air supply pipeline is communicated with the liquid supply pipeline, and an air supply control valve is arranged on the air supply pipeline; the liquid supply control valve and the gas supply control valve are electrically connected with the gas-liquid two-phase manifold simulation controller; according to the verification method, by controlling the opening degree of the liquid supply control valve and the opening degree of the gas supply control valve, manifolds possibly appearing in the gas-liquid two-phase fluid are simulated, so that the gas-liquid two-phase flowmeter can detect the liquid flow and the gas flow of the two-phase fluid in multiple manifolds; therefore, the gas-liquid two-phase flowmeter is checked under the condition that the checking error caused by manifold is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of gas-liquid two-phase flow meter calibration in a horizontal pipe gathering and transportation system, and in particular, relates to a gas-liquid two-phase flow meter calibration method and system based on pipe flow state simulation. Background Art

[0002] When measuring gas-liquid two-phase fluid, different flow meters need to be selected according to the type of fluid and the requirements of measurement accuracy, and the flow rates of gas and liquid are detected and displayed respectively. For split flow meters, the calibration process only needs to simulate the flow state of single-phase fluid respectively, and provide a stable fluid flow state for the flow meter, and the calibration requirements are relatively simple. However, with the emergence of gas-liquid two-phase flow meters, they are widely used in petrochemical, food and other industries. For one of the more commonly used vortex throttling gas-liquid two-phase flow meters, its calibration process requires the gas-liquid two-phase fluid to be diverted to ensure the calibration accuracy of this type of flow meter. However, for the inner cone gas-liquid two-phase detection device, since the flow rate of the gas-liquid two-phase fluid is detected simultaneously and synchronously, the above-mentioned diversion calibration method is not conducive to fully simulating the actual flow state changes of the two-phase fluid, which makes the calibration error of the inner cone gas-liquid two-phase detection device large. Summary of the invention

[0003] Based on the above-mentioned background technical needs, the present application provides a gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation, which is used to perform diversified flow state simulations for instruments that simultaneously detect gas-liquid two-phase flow velocities, so that the test state of the instrument is closer to the actual situation of the gas-liquid two-phase flow, thereby reducing calibration errors.

[0004] In order to achieve the above purpose, the technical solution of this application is:

[0005] A gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation includes a liquid supply pipeline and a gas supply pipeline, wherein the liquid supply pipeline is divided into a first section and a second section, the gas supply pipeline is connected between the first section and the second section, the second section serves as a gas-liquid two-phase flow pipe, and the second section is provided with a gas-liquid two-phase flowmeter to be calibrated, and further includes the following steps:

[0006] Step 1: respectively regulating the liquid supply flow rate and the gas supply flow rate to simulate the flow shape of the gas-liquid two-phase fluid in the gas-liquid two-phase flow tube;

[0007] Step 2: Collect the actual manifold in the gas-liquid two-phase flow tube, extract the features in the actual manifold, obtain the discriminant manifold features, compare the standard manifold features with the discriminant manifold features, and calculate the comprehensive approximation, and judge whether the manifold simulation is successful based on the comprehensive approximation;

[0008] Step 3: If yes, obtain the standard flow value of liquid, the standard flow value of gas, and compare them with the real-time flow value of liquid and the real-time flow value of gas displayed by the gas-liquid two-phase flow meter to determine whether the gas-liquid two-phase flow meter is accurate;

[0009] Step 4: Output the judgment result.

[0010] Preferably, collecting the actual manifold in the gas-liquid two-phase flow tube includes continuously acquiring N manifold images within a unit time T1.

[0011] Preferably, the unit time T1 = L / V, wherein L represents the pipeline distance between the position of collecting the actual manifold in the gas-liquid two-phase flow pipe and the installation position of the gas-liquid two-phase flow meter, and V represents the average flow velocity of the fluid in the gas-liquid two-phase flow pipe.

[0012] Preferably, the number of manifold images N = T1 / V t , where V t Indicates the shooting speed.

[0013] Preferably, the comparison between the standard manifold feature and the discrimination manifold feature comprises comparing the number of bubbles, the position of bubbles and the diameter of bubbles per unit cross-sectional area in the discrimination manifold feature and the standard manifold feature, respectively.

[0014] Preferably, the calculation of the comprehensive similarity includes calculation based on N sets of discriminant manifold features obtained continuously, and the calculation formula of the comprehensive similarity S is: Among them, Q i It represents the ratio of the number of bubbles in the discriminant manifold feature to the number of bubbles in the standard manifold feature, M i represents the ratio of the bubble position in the discriminant manifold feature to the standard manifold feature, D i It represents the ratio of the bubble diameter in the discriminant manifold feature to the bubble diameter in the standard manifold feature, and N represents the number of actual manifolds collected.

[0015] Preferably, after determining whether the manifold simulation is successful, the result of determining whether the manifold simulation is successful is reviewed based on a comparison between the liquid holdup of the actual manifold and the liquid holdup of the standard manifold.

[0016] A gas-liquid two-phase flowmeter calibration system based on pipe flow state simulation, comprising a liquid supply pipeline, an air supply pipeline and a gas-liquid two-phase manifold simulation controller, wherein a liquid supply control valve, a liquid single-phase flowmeter, a manifold display pipe section and a gas-liquid two-phase flowmeter to be calibrated are sequentially arranged on the liquid supply pipeline in the liquid flow direction; one end of the air supply pipeline is connected to an air pump, and the other end of the air supply pipeline is connected to the liquid supply pipeline between the liquid single-phase flowmeter and the manifold display pipe section, and an air supply control valve and a gas single-phase flowmeter are sequentially arranged on the air supply pipeline in the gas flow direction; the liquid supply control valve and the air supply control valve are both electrically connected to the gas-liquid two-phase manifold simulation controller, and the gas-liquid two-phase manifold simulation controller is used to control the opening of the liquid supply control valve and the air supply control valve.

[0017] Preferably, the gas-liquid two-phase manifold simulation controller includes: an observation module for obtaining the actual manifold displayed by the manifold display pipe segment; a simulation module for outputting a model of a standard manifold; a comparison module for outputting a valve opening adjustment signal based on the comparison results between the actual manifold and the model of the standard manifold; and a control module for respectively controlling the opening of the liquid supply control valve and the gas supply control valve based on the valve opening adjustment signal.

[0018] By adopting the above technical solution, compared with the prior art, the present application has at least the following beneficial effects:

[0019] By adjusting the liquid supply speed and the gas supply speed, multiple typical flow patterns that may appear in the gas-liquid two-phase fluid are simulated, so that the gas-liquid two-phase flowmeter can detect the gas and liquid flow rates under various flow pattern states during the calibration operation of the gas-liquid two-phase flowmeter, thereby improving the efficiency and standards of the calibration operation and reducing the calibration error. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of a gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation in an embodiment.

[0021] Figure 2 It is a structural schematic diagram of a gas-liquid two-phase flowmeter calibration system based on pipe flow state simulation in an embodiment.

[0022] In the figure: liquid supply pipeline 1, gas supply pipeline 2, gas-liquid two-phase flow pattern simulation controller 3, liquid supply control valve 4, liquid single-phase flow meter 5, flow pattern display pipe section 6, gas-liquid two-phase flow meter 7, air pump 8, gas supply control valve 9, gas single-phase flow meter 10. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The technical solution of the present application will be further described below in conjunction with the drawings of the embodiments of the present application, and the present application is not limited to the following specific implementation methods.

[0024] It should be understood that the same or similar reference numerals in the drawings of the embodiments correspond to the same or similar components. In the description of the present application, it should be understood that if there are terms such as "upper", "lower", "inner", "outer", "left", "right", "front", "rear", "top", "bottom" and the like indicating directions or positional relationships based on the orientations or positional relationships shown in the drawings, it is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the structure or component referred to must have a specific orientation, be constructed and operated in a specific orientation, therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on the present patent, and for those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0025] The following is combined with Figure 1 To Attachment Figure 2 And specific embodiments further describe the present application in detail.

[0026] The present application discloses a calibration method for a gas-liquid two-phase flowmeter 7 based on pipe flow state simulation, which is used to simulate various flow forms of the gas-liquid two-phase flow in the measuring pipe section according to the actual detection environment of the gas-liquid two-phase flowmeter 7, thereby providing a more comprehensive and realistic calibration environment for the calibration work of the gas-liquid two-phase flowmeter 7.

[0027] In one embodiment, water and air are used to simulate the gas-liquid two-phase flow, that is, the water flow and the air flow are combined at various flow rates in the pipe section (i.e., the gas-liquid two-phase flow pipe) equipped with the gas-liquid two-phase flow meter 7 and simulate the common flow shapes of the gas-liquid two-phase flow in the corresponding horizontal pipeline, such as: bubble flow, plug flow (also called long bubble flow or gas mass flow, the bubbles in the fluid are obviously larger than the dispersed small bubbles in the bubble flow), stratified flow (the flow layers of the gas-liquid two-phase are relatively smooth and distinct), wavy flow (compared with stratified flow, there are continuously fluctuating waves between the flow layers), elastic flow (also called liquid throttling) and annular flow. The gas-liquid two-phase flow meter 7 detects the gas-liquid two-phase fluid of each flow shape and comprehensively displays the liquid flow value and the gas flow value. The gas-liquid two-phase flow meter 7 is calibrated by judging the error of its displayed value.

[0028] Before implementing the method, the present application also provides a gas-liquid two-phase flowmeter 7 calibration system based on pipe flow state simulation, the calibration system includes a liquid supply pipeline 1 and a gas supply pipeline 2, the liquid supply pipeline 1 is provided with a liquid supply control valve 4, a liquid single-phase flowmeter 5, a flow shape display pipe section 6 and a gas-liquid two-phase flowmeter 7 to be calibrated in sequence along the liquid flow direction, one end of the liquid supply pipeline 1 is connected to a water source, the liquid supply control valve 4 is used to adjust the opening to achieve the purpose of adjusting the liquid supply pressure, the liquid single-phase flowmeter 5 is a calibrated standard The liquid flow meter is only used to display the liquid supply flow value. The flow shape display pipe section 6 is a transparent pipe section, which can facilitate the naked eye or machine vision to observe the flow shape of the gas-liquid two-phase flow; one section of the gas supply pipeline 2 is connected to the air pump 8, and the other end is connected to the liquid supply pipeline 1, and the connection is located between the above-mentioned liquid single-phase flow meter 5 and the flow shape display pipe section 6, so that the above-mentioned liquid supply pipeline 1 is divided into a first section and a second section, wherein the second section located at the end of the gas supply pipeline 2 is used as the above-mentioned gas-liquid two-phase flow tube for simulating the gas-liquid two-phase flow shape. The gas supply control valve 9 and the gas single-phase flow meter 10 are arranged in sequence along the gas flow direction on the gas supply pipeline 2. The gas supply control valve 9 is used to adjust the opening to achieve the purpose of adjusting the gas supply pressure. The gas single-phase flow meter 10 is a calibrated standard gas flow meter, which is only used to display the gas supply flow value. When the system is applied, the liquid and gas in the pipeline are allowed to meet at different speeds and form different gas-liquid two-phase flow shapes by adjusting the liquid supply control valve 4 and the gas supply control valve 9 respectively, so that the gas-liquid two-phase flow meter 7 to be calibrated can perform flow detection on gas-liquid two-phase flows of different flow shapes.

[0029] The specific implementation steps of this method are as follows:

[0030] Step 1: Adjust the liquid supply flow rate and gas supply flow rate respectively to simulate the flow shape of the gas-liquid two-phase fluid in the gas-liquid two-phase pipe.

[0031] Specifically, when the diameter of the liquid supply pipeline 1, the diameter of the gas supply pipeline 2, the temperature, state, purity and other parameters of the supplied liquid and gas are known and unchanged, that is, other factors other than the flow rate that may affect the flow shape of the gas-liquid two-phase fluid are controlled to be constant values, after the first liquid supply flow rate in the liquid supply pipeline 1 is gradually stabilized (by observing the flow indication of the above-mentioned liquid single-phase flowmeter 5 to be stable), the opening of the gas supply control valve 9 is adjusted to allow the gas to enter the liquid supply pipeline 1 at the first supply flow rate and form a flow shape similar to a bubble flow. In this flow shape state, the first supply flow rate is much lower than the first liquid supply flow rate; on the basis of forming the supply flow rate similar to the bubble flow, the opening of the gas supply control valve 9 is gradually increased to increase the supply flow rate to the second supply flow rate. After the above-mentioned bubbles become significantly larger, a flow shape similar to a plug flow is formed. In this flow shape state, the second supply flow rate is still lower than the first liquid supply flow rate; on the basis of forming the supply flow rate similar to the plug flow, the opening of the gas supply valve is gradually increased to increase the supply flow rate to the third supply flow rate. At this time, the interaction between gas and liquid is weak. Under the influence of gravity, the liquid flows below the gas, and the two phases are smoothly, continuously and obviously stratified, forming a flow shape similar to stratified flow; on the basis of the third supply gas flow rate, the supply gas flow rate is increased to the fourth supply gas flow rate by further increasing the opening of the supply valve. In the above-mentioned flow shape similar to stratified flow, the ripples on the water surface gradually increase to form turbulent waves. At this time, the gas-liquid two-phase fluid forms a flow shape similar to a wavy flow; by continuing to increase the supply gas flow rate to the fourth supply gas flow rate in the above manner, the gas bomb and the liquid bomb flow alternately, and at this time the gas-liquid two-phase fluid forms a flow shape similar to a bullet flow. In this flow shape state, the fourth supply gas flow rate is higher than the first liquid supply flow rate; by continuing to increase the supply gas flow rate to the fifth supply gas flow rate in the above manner, the liquid surface gradually becomes shallower and becomes an annular liquid film that flows continuously around the pipeline, and the gas flows rapidly in the middle of the pipeline, forming a flow shape similar to an annular flow, and reducing the first liquid supply flow rate to the second liquid supply flow rate. The above-mentioned annular liquid film is difficult to be continuous and gradually forms liquid mist, forming a flow shape similar to a mist flow.

[0032] Step 2: When the gas-liquid two-phase fluid in the above-mentioned liquid supply pipeline 1 forms various manifolds, a high-speed camera is set at the transparent manifold display tube section 6 to take pictures of the manifold to obtain the actual manifold of the gas-liquid two-phase fluid at various flow rates. By observing the photos of each actual manifold, obvious features that can represent each manifold are extracted as features for distinguishing the manifold. The information parameters embodied by these features are compared with the information parameters of each standard manifold feature (the manifold features obtained by taking pictures under the standard manifold are the standard manifold features), and the comprehensive approximation is calculated. Based on the comprehensive approximation, it is determined whether the manifold simulation is successful.

[0033] Specifically, before conducting the simulation manifold experiment, the standard manifold features of the standard manifold are first obtained and a database is formed, that is, under the premise of the same conditions as the above-mentioned simulation manifold, pictures of each standard manifold are collected, and the features in the standard manifold are extracted as the standard manifold features. Afterwards, the discriminant manifold features extracted from the actual manifolds formed by the simulation in the manifold simulation experiment are input into the database, and the features are compared through a suitable computer program, and the comprehensive approximation is calculated. The calculation logic of the comprehensive approximation is to add the information parameters of each discriminant manifold feature of a certain actual manifold and the difference between the parameters of the corresponding standard manifold features and then divide by the number of features to obtain a mean value, and assign a value greater than 0 as a limit value to the mean value. When the obtained mean value is less than the limit value, it means that the manifold simulation is successful; when the mean value is greater than the limit value, that is, the type of manifold simulated is not highly correlated with the basic features of the standard manifold, it means that the manifold simulation fails, and it is necessary to appropriately adjust the gas supply flow rate or liquid supply flow rate and re-simulate.

[0034] Step 3: If the above manifold simulation is successful, obtain the liquid standard flow value, that is, the liquid single-phase flow rate before the gas-liquid two-phase fluid is formed, and the gas standard flow value, that is, the gas single-phase flow rate before the gas-liquid two-phase fluid is formed, and the liquid real-time flow value and the gas real-time flow value displayed by the gas-liquid two-phase flowmeter 7 to be calibrated, and compare these four values ​​to determine whether the readings displayed by the gas-liquid two-phase flowmeter 7 are accurate.

[0035] Step 4: After comparing the above four values ​​through a computer program, the judgment result is automatically output based on the judgment program, and the judgment result is output by generating a report, displaying the results or other warning information such as sound and light with specific meanings, to inform whether the above-calibrated gas-liquid two-phase flow meter is accurate or inaccurate.

[0036] Specifically, when the manifold simulation is successful, that is, when the required manifold appears in the gas-liquid two-phase flow tube, the liquid supply flow rate at this time is obtained by the above-mentioned liquid single-phase flowmeter 5 as the liquid standard flow value, and the gas single-phase flowmeter 10 obtains the gas supply flow rate at this time as the gas standard flow value. The difference obtained by subtracting the liquid standard flow value from the liquid real-time flow value and the gas standard flow value from the gas real-time flow value is compared with the error range of the gas-liquid two-phase flowmeter 7. If the difference is greater than the minimum limit of gas and liquid and less than the maximum limit, respectively, it can be regarded that the indication of the gas-liquid two-phase flowmeter 7 is accurate.

[0037] In addition, the present application also provides some more specific implementation methods to improve the above-mentioned gas-liquid two-phase flowmeter 7 calibration method.

[0038] Furthermore, since there is a time difference between the acquisition of the acquisition manifold and the arrival of the acquired manifold at the detection position of the gas-liquid two-phase flowmeter 7, it is difficult to ensure that the various features of the acquired manifold that can be used to distinguish the manifold do not change when it reaches the position of the gas-liquid two-phase flowmeter 7 when only one manifold image is acquired. In order to avoid the error caused by the above time difference in the manifold identification result, in the above step 2, the actual manifold in the gas-liquid two-phase flow tube is collected, and N manifold images need to be continuously acquired within the unit time T1. From the N manifold images, images that continuously and completely display the manifold features can be obtained to ensure that the acquired manifold feature values ​​can fully represent the manifold related to it, thereby increasing the integrity of the acquired feature values ​​and achieving the effect of reducing the error range of manifold judgment. In addition, when the N manifold images continuously acquired within the unit time T1 can all show the same manifold, it can be ensured that the state of the gas-liquid two-phase flow collected by the gas-liquid two-phase flowmeter 7 is continuous and the same as the fluid state when the previous image was collected, thereby avoiding calibration errors of the gas-liquid two-phase flowmeter 7 when the manifold is unstable.

[0039] Preferably, the above-mentioned unit time T1=L / V, wherein L represents the pipe distance between the position of the actual manifold in the gas-liquid two-phase flow pipe to be collected and the installation position of the gas-liquid two-phase flow meter 7, and V represents the average flow velocity of the fluid in the gas-liquid two-phase flow pipe; the number of the above-mentioned manifold images N=T1 / V t , where V t By continuously acquiring N manifold images within the above time range, it is ensured that the manifold in the acquired image is consistent with the manifold state of the fluid measured by the two-phase flowmeter, thereby eliminating the error caused by the inconsistency between the installation position of the gas-liquid two-phase flowmeter 7 and the image acquisition position.

[0040] Preferably, in the above step 2, the standard manifold features are compared with the discriminant manifold features, mainly with the manifold features that are easily obtained from the image and have obvious differences. These features include the number of bubbles, bubble positions and bubble diameters within the same unit cross-sectional area of ​​the image. For example, the number of bubbles in the image is obtained within the same area range in the proportional graphics taken; within the same area range, a coordinate system is established with the point on the lower side of the entrance of the transparent tube as the origin, the horizontal flow direction of the liquid as the X-axis, and the direction perpendicular to the upward flow of the liquid as the Y-axis, and the positions of each bubble are marked in the coordinate system; the bubble diameter is measured within the same area range in the proportional graphics taken. By comparing the above discriminant manifold features with the standard manifold features pre-entered in the database in the same way, it is determined whether the simulated manifold has reached the state of the standard manifold.

[0041] Furthermore, on the basis of obtaining the above-mentioned discriminant manifold features and the database, the above-mentioned comprehensive similarity is calculated using the obtained N groups of discriminant manifold features, and the calculation formula for calculating the comprehensive similarity S is:

[0042]

[0043] Among them, Q i It represents the ratio of the number of bubbles in the discriminant manifold feature to the number of bubbles in the standard manifold feature, M i Indicates the bubble position in the discriminant manifold feature and the standard manifold feature (the average value of the height of each bubble in the coordinate axis is taken as the representative value of the bubble position, that is, value), D i It represents the ratio of the bubble diameter in the discriminant manifold feature to the bubble diameter in the standard manifold feature, and N represents the number of actual manifolds collected, that is, the number of images obtained by taking pictures of the above actual manifold within the unit time T1. The calculated S value is multiplied by 100%, and each S value obtained by the above calculation is assigned a limit range, such as 95% to 105%. If the similarity is equal to 100% or other values ​​within the limit range, it means that the simulated manifold is basically the same or the same as the standard manifold.

[0044] Furthermore, after determining that the simulated manifold is identical or substantially identical to the standard manifold by the above method, the liquid holdup of the simulated manifold is calculated and compared with the liquid holdup of the standard manifold to verify whether the manifold simulation is successful.

[0045] Specifically, by simulating bubble flow, stratified flow, wavy flow, plug flow, slug flow and annular flow in a horizontal pipe, and calculating respectively by the liquid holdup formula of water-air in the horizontal pipe corresponding to the simulated manifold and the obtained experimental data, whether the simulated manifold reaches the standard result is verified. Specifically, the calculation formula of liquid holdup of various flow states in horizontal pipes proposed by SPEP. Abduvayt et al. in 2003 is used for verification. Among them, the liquid holdup formula of dispersed bubble flow is used to verify the simulation results of the above bubble flow, the liquid holdup formula of laminar flow is used to verify the simulation results of the above stratified flow and wavy flow, the liquid holdup formula of intermittent flow is used to verify the simulation results of the above plug flow and slug flow, and the liquid holdup formula of annular flow is used to verify the simulation results of the above annular flow (the liquid holdup formula of the flow state of gas-liquid two-phase fluid in the horizontal pipe and the method of judging the manifold by liquid holdup are existing research results in the relevant technical field, and this application will not repeat them).

[0046] The gas-liquid two-phase flowmeter 7 calibration method based on pipe flow state simulation disclosed in the present application has the following technical effects: on the basis of control variables, by adjusting the liquid supply speed and the gas supply speed, multiple typical flow shapes that may appear in the gas-liquid two-phase fluid are simulated, so that in the calibration operation of the gas-liquid two-phase flowmeter 7, the gas-liquid two-phase flowmeter 7 can detect the gas and liquid flow rates under various flow shape states, thereby improving the efficiency and standards of the calibration operation and reducing the calibration error.

[0047] In addition, in order to enable the calibration system of the gas-liquid two-phase flowmeter 7 based on pipe flow state simulation disclosed in the present application to perform gas-liquid two-phase flow shape simulation experiments with higher standards and efficiency, so as to assist in completing the calibration method of the above-mentioned equipment application, the liquid supply control valve 4 and the gas supply control valve 9 in the system are both electronic automatic regulating valves, and the system also includes a gas-liquid two-phase flow simulation controller. The above-mentioned liquid supply control valve 4 and gas supply control valve 9 are both electrically connected to the gas-liquid two-phase flow shape simulation controller 3, and the gas-liquid two-phase flow shape simulation controller 3 is used to control the opening of the liquid supply control valve 4 and the gas supply control valve 9.

[0048] Specifically, the above-mentioned gas-liquid two-phase flow simulation controller 3 includes: an observation module, which is used to obtain the actual flow displayed by the above-mentioned flow display tube segment 6, and the observation module includes a high-speed camera, a video camera or other visual equipment for recording images of flow characteristics; a simulation module, which is used to output a model of a standard flow, and the simulation module includes a computer and other related equipment that can dynamically simulate the standard flow under the same experimental conditions as in the present application in real time; a comparison module, which is used to output a valve opening adjustment signal based on the comparison results between the actual flow and the model of the standard flow, and the comparison module includes a storage and a calculator, and the storage stores a program that can convert the comparison results between the above-mentioned actual flow and the model of the standard flow into a valve opening adjustment signal, and the calculator is used to run the program in the above-mentioned storage; a control module, which is used to control the opening of the liquid supply control valve 4 and the gas supply control valve 9 respectively based on the valve opening adjustment signal.

[0049] Combining the multiple structures and features in the above embodiments, the calibration system of the gas-liquid two-phase flowmeter 7 can simulate the flow shape of the gas-liquid two-phase fluid according to the requirements of the simulated flow shape to meet the calibration requirements of the gas-liquid two-phase flowmeter 7.

[0050] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the implementation methods of the present application. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation, characterized in that: It includes a liquid supply pipeline and a gas supply pipeline, the liquid supply pipeline is divided into a first section and a second section, the gas supply pipeline is connected between the first section and the second section, the second section is used as a gas-liquid two-phase flow pipe, and the second section is provided with a gas-liquid two-phase flow meter to be calibrated; The gas-liquid two-phase flowmeter calibration method comprises the following steps: S1. respectively regulating the liquid supply flow rate and the gas supply flow rate to simulate the flow shape of the gas-liquid two-phase fluid in the gas-liquid two-phase flow tube; S2. Collect the actual manifold in the gas-liquid two-phase flow tube, extract the features in the actual manifold, obtain the discriminant manifold features, compare the standard manifold features with the discriminant manifold features, calculate the comprehensive approximation, and judge whether the manifold simulation is successful based on the comprehensive approximation; S3. If so, obtain the standard liquid flow value, the standard gas flow value and the real-time liquid flow value and the real-time gas flow value displayed by the gas-liquid two-phase flowmeter, respectively, and compare them to determine whether the gas-liquid two-phase flowmeter is accurate; S4. Output the judgment result.

2. The gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation according to claim 1 is characterized in that: The collecting of the actual manifold in the gas-liquid two-phase flow tube includes continuously acquiring N manifold images within a unit time T1.

3. The gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation according to claim 2 is characterized in that: The unit time T1 = L / V, wherein L represents the pipeline distance between the position of collecting the actual manifold in the gas-liquid two-phase flow pipe and the installation position of the gas-liquid two-phase flow meter, and V represents the average flow velocity of the fluid in the gas-liquid two-phase flow pipe.

4. The gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation according to claim 2 is characterized in that: The number of manifold images N=T1 / V t , where V t Indicates the shooting speed.

5. The gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation according to claim 1 is characterized in that: The comparing the standard manifold feature with the discrimination manifold feature comprises comparing the number of bubbles, the position of bubbles and the diameter of bubbles per unit cross-sectional area in the discrimination manifold feature and the standard manifold feature respectively.

6. The gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation according to claim 1 is characterized in that: The calculation of the comprehensive similarity includes calculation based on N sets of discriminant manifold features obtained continuously. The calculation formula of the comprehensive similarity S is: Among them, Q i It represents the ratio of the number of bubbles in the discriminant manifold feature to the number of bubbles in the standard manifold feature, M i represents the ratio of the bubble position in the discriminant manifold feature to the standard manifold feature, D i It represents the ratio of the bubble diameter in the discriminant manifold feature to the bubble diameter in the standard manifold feature, and N represents the number of actual manifolds collected.

7. The gas-liquid two-phase flowmeter calibration method based on pipe flow state simulation according to claim 1 is characterized in that: After determining whether the manifold simulation is successful, the result of determining whether the manifold simulation is successful is reviewed based on the comparison between the liquid holdup of the actual manifold and the liquid holdup of the standard manifold.

8. A gas-liquid two-phase flowmeter calibration system based on pipe flow state simulation, characterized in that: It comprises a liquid supply pipeline, an air supply pipeline and a gas-liquid two-phase manifold simulation controller, wherein a liquid supply control valve, a liquid single-phase flowmeter, a manifold display pipe section and a gas-liquid two-phase flowmeter to be calibrated are sequentially arranged at intervals along the liquid flow direction of the liquid supply pipeline; one end of the air supply pipeline is connected to an air pump, and the other end of the air supply pipeline is connected to the liquid supply pipeline between the liquid single-phase flowmeter and the manifold display pipe section, and an air supply control valve and a gas single-phase flowmeter are sequentially arranged at intervals along the gas flow direction of the air supply pipeline; the liquid supply control valve and the air supply control valve are both electrically connected to the gas-liquid two-phase manifold simulation controller, and the gas-liquid two-phase manifold simulation controller is used to control the opening of the liquid supply control valve and the air supply control valve.

9. The gas-liquid two-phase flowmeter calibration system based on pipe flow state simulation according to claim 8, characterized in that: The gas-liquid two-phase manifold simulation controller comprises: An observation module, used for obtaining the actual manifold displayed by the manifold display pipe segment; A simulation module for outputting models of standard manifolds; A comparison module, used for outputting a valve opening adjustment signal based on a comparison result between the actual manifold and the standard manifold model; The control module is used to control the opening of the liquid supply control valve and the air supply control valve respectively based on the valve opening adjustment signal.

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