A coriolis flowmeter based on orthogonal test optimization and a structural design method thereof

Abstract

The application discloses a kind of based on orthogonal test optimization coriolis flowmeter and its structural design method.The optimization design solves the deficiency of many structure optimization experiment numbers and low optimization efficiency caused by the optimal selection of the structure of measuring tube under the condition of limited installation space.The design method comprises the following steps: 1) determining the total length of measuring tube;2) selecting the optimization variable of measuring tube;3) establishing the orthogonal test combination with interaction;4) screening the established orthogonal test combination with interaction, merging repeated test groups and calculating the actual size of each optimization variable;5) constructing fluid-structure coupling numerical model based on orthogonal test group, solving the flow coefficient of each test group;6) analyzing the results of orthogonal test, obtaining the optimal measuring tube type.The optimization design structure of the coriolis flowmeter disclosed in the application enables the measuring tube to have a larger flow coefficient under the condition of fixed length, improves the measurement accuracy and sensitivity of the coriolis flowmeter, and provides an efficient and convenient optimization design process for the structure optimization of the measuring tube of the coriolis flowmeter.

Description

Technical Field

[0001] This invention belongs to the field of flow measurement device design technology, and in particular relates to a Coriolis flow meter based on orthogonal experimental optimization and its structural design method. Background Technology

[0002] To reduce carbon emissions and develop clean energy, hydrogen energy has gradually become a hot topic in current research and application. Due to its advantages in large-scale storage and transportation, such as low cost, large capacity, and high purity, liquid hydrogen is gradually shifting from aerospace and military applications to civilian and commercial sectors. Fluid flow rate is a crucial control parameter in the production and application processes of liquid hydrogen, including preparation, storage, transportation, application, and trade settlement. Its accurate measurement directly affects the production efficiency, safe operation, and fair trade of the entire liquid hydrogen industry chain. Coriolis flow meters, as a type of mass flow meter, directly measure mass flow rate using the Coriolis force generated by fluid flow in a pipeline, which is proportional to the mass flow rate. They feature high accuracy, wide measurement range, low pressure loss, and long lifespan, making them particularly suitable for measuring mass flow rates in cryogenic environments. However, because the density of liquid hydrogen is significantly lower than that of cryogenic fluids such as liquid nitrogen and liquefied natural gas, this significantly reduces the measurement sensitivity and signal-to-noise ratio of Coriolis flow meters, hindering high-precision measurement of liquid hydrogen mass flow rate. As a key measuring component of a Coriolis flowmeter, the measuring tube is an important structure that significantly affects the measurement sensitivity and accuracy. Therefore, optimizing the design of the measuring tube structure is an important means to improve the measurement accuracy and sensitivity of liquid hydrogen Coriolis flowmeters.

[0003] In existing technologies, the paper "Highly sensitive micro Coriolis mass flow sensor" (Haneveld J, Lammerink T, Dijkstra M, et al. 2008 IEEE 21st International Conference on Micro Electro Mechanical Systems 2008; 920-923) analyzed the influence of the structural parameters of the measuring tube on the sensitivity improvement of Coriolis flowmeters under low flow conditions. The study proved that increasing the length of the straight-tube measuring tube or reducing the wall thickness of the measuring tube can improve the measurement sensitivity of the Coriolis flowmeter.

[0004] In existing technologies, the paper "Modeling a Coriolis Mass Flow Meter for Shape Optimization" (Hakvoort WBJ, Meijaard JP, Aarts RGKM, Jonker JB, Zwikker J.M. The 1st Joint International Conference on Multibody System Dynamics, 2010) established a theoretical model for optimizing the shape of the Coriolis mass flow meter measuring tube. In the model, the pressure drop of the measuring tube and the outer envelope shape of the tube axis are determined as optimization constraints. The optimized measuring tube improves the sensitivity by 68 times, and it is pointed out that increasing the length of the measuring tube is the main factor in improving the measurement sensitivity of the Coriolis mass flow meter.

[0005] In existing technologies, the paper "Effects of dissipative forces on Coriolis flowmeter readings" (Romanov VA. Flow Measurement and Instrumentation 2022; 86:102202) explores measuring tubes with different tube types but the same excitation frequency. The proposed gyro force coefficient has good consistency with the measurement sensitivity of the measuring tube, and the analysis of the dissipative force coefficients of different tube types points out that the two-phase flow has different effects on the measurement accuracy of Coriolis flowmeters with different tube types.

[0006] Chinese invention patent 201220728624.1 discloses a measuring tube structure comprising a horizontal inlet pipe section, an inclined inlet pipe section, a middle horizontal pipe section, an inclined outlet pipe section, and a horizontal outlet pipe section connected in sequence. The angles between the horizontal inlet pipe section and the inclined inlet pipe section, and between the inclined inlet pipe section and the middle horizontal pipe section, are internal offset angles, ranging from 90° to 150°. This structure improves the overall system elasticity of the measuring tube and reduces rigidity, thereby increasing the deformation of the measuring tube under the same Coriolis force. However, this patent only compares the structural deformation characteristics with existing structures, without providing measurement performance parameters for optimizing the structure, and the optimization design method provided by the patent does not solve the problem of low optimization efficiency of the measuring tube structure.

[0007] Chinese invention patent 201611121366.X discloses an ultra-micro-bent measuring tube structure, comprising two parallel measuring tubes. A large arc section at the bottom of each measuring tube extends to both sides, connecting to tangent straight sections. The other end of each straight section is tangently connected to a section of a small arc section. This ultra-micro-bent measuring tube structure allows the Coriolis flowmeter to combine the small size and low pressure loss of a straight tube type with the high sensitivity and wide rangeability of a bent tube type. However, this structure is developed based on a straight tube measuring tube, and its measurement sensitivity is still significantly lower than that of a bent tube measuring tube.

[0008] Considering the low sensitivity and low signal-to-noise ratio of Coriolis flowmeters when used to measure low-density working media such as liquid hydrogen, resulting in low measurement accuracy, optimizing the measuring tube design is crucial to improving the accuracy of Coriolis flowmeters for these media. However, current research lacks effective and feasible optimization schemes for the measuring tube structure, and the proposed methods of increasing the measuring tube length and decreasing the wall thickness have limited effectiveness for Coriolis flowmeters with limited installation space. Therefore, an effective and feasible method for optimizing the measuring tube design is urgently needed to further improve the measurement sensitivity of Coriolis flowmeters. Summary of the Invention

[0009] The purpose of this invention is to provide a Coriolis flow meter based on orthogonal experimental optimization and its structural design method, and to obtain an optimized Coriolis flow meter structure based on this design.

[0010] To achieve the above objectives, the technical solution provided by this invention is:

[0011] This invention first provides a Coriolis flow meter optimized based on orthogonal experimental design, comprising a measuring tube, a fixing support plate for fixing the measuring tube, interface flanges disposed at both ends of the measuring tube, a main transition pipe for adjusting the installation width of the Coriolis flow meter, signal detectors and an electromagnetic driver disposed on the measuring tube, and a control circuit module; two measuring tubes are fixed side by side on the fixing support plate, each measuring tube having an arched structure, the arched structure being composed of a vertical pipe section, a curved pipe section, a horizontal pipe section, a curved pipe section, and a vertical pipe section connected in sequence; the main transition pipe includes an inlet transition pipe and an outlet transition pipe, the inlet transition pipe being disposed between the measuring tube and an interface flange located on the inlet side of the measuring tube, and the outlet transition pipe being disposed between the measuring tube and an interface flange located on the outlet side of the measuring tube; two signal detectors are respectively disposed on the fluid inlet side and the fluid outlet side of the measuring tube; the electromagnetic driver is disposed in the middle position of the measuring tube; the control circuit module receives and processes the signals collected by the signal detectors; the control circuit module is also connected to the electromagnetic driver and provides alternating current to the electromagnetic driver.

[0012] As a preferred embodiment of the present invention, a flow divider is provided on the inlet transition pipe. The flow divider is used to evenly distribute the fluid in the inlet transition pipe into the measuring pipe when the fluid flows into the measuring pipe, thereby reducing the measurement error caused by uneven fluid distribution.

[0013] In a preferred embodiment of the present invention, the signal detector is fixed to two measuring tubes by a signal detector fixing bracket; the signal detector fixing bracket includes a first signal detector fixing bracket fixed to one measuring tube and a second signal detector fixing bracket fixed to the other measuring tube; the signal detector includes a signal detector permanent magnet resonator, a signal detector coil, and a signal detector coil frame, the signal detector permanent magnet resonator is fixed to the first signal detector fixing bracket, the signal detector coil frame is fixed to the second signal detector fixing bracket, and the signal detector coil is wound around the signal detector coil frame; during the measurement process, the signal detector permanent magnet resonator and the signal detector coil wound around the signal detector coil frame undergo relative motion, thereby generating a voltage signal in the signal detector coil, and the voltage signal is transmitted to the control circuit module.

[0014] In a preferred embodiment of the present invention, the electromagnetic driver is fixed to the measuring tube by an electromagnetic driver mounting bracket; the electromagnetic driver mounting bracket includes a first electromagnetic driver mounting bracket fixed to one measuring tube and a second electromagnetic driver mounting bracket fixed to another measuring tube; the electromagnetic driver includes an electromagnetic driver permanent magnet oscillator, an electromagnetic driver coil, and an electromagnetic driver coil frame; the electromagnetic driver permanent magnet oscillator is fixed to the first electromagnetic driver mounting bracket, the signal detector coil frame is fixed to the second electromagnetic driver mounting bracket, and the electromagnetic driver coil is wound around the electromagnetic driver coil frame; during the measurement process, the control circuit module outputs an alternating current signal to the electromagnetic driver coil, thereby causing the electromagnetic driver oscillator and the electromagnetic driver coil to reciprocate, which in turn drives the two measuring tubes to reciprocate.

[0015] As a preferred embodiment of the present invention, the control circuit module includes a serial communication module, a level conversion module, an algorithm control module, an excitation output module, a signal acquisition module, and a temperature acquisition module. The signal acquisition module is used to acquire the signal output from the signal detector and perform pre-filtering, voltage amplification, and analog-to-digital conversion. The analog-to-digital converted signal is input to the algorithm control module, which extracts the vibration signal frequency of the electromagnetic actuator and the signal phase difference between the two signal detectors. The algorithm control module transmits the calculated vibration signal frequency and signal phase difference to an external host computer via the serial communication module and displays them on the external host computer. At the same time, the algorithm control module generates a digital sinusoidal drive signal. The excitation output module includes a digital-to-analog conversion module and a power amplification module, which converts the sinusoidal digital drive signal generated by the algorithm control module into a sinusoidal analog drive signal and amplifies the signal drive power. The temperature acquisition module is used to acquire the temperature data of the measuring tube and input it to the algorithm control module for temperature compensation of the calculated phase difference. The level conversion module is used to supply power to each module.

[0016] The present invention also provides a design method for the Coriolis flowmeter based on orthogonal experimental optimization, comprising the following steps:

[0017] 1) Determine the installation space and the maximum measuring length of the measuring tube; the installation space refers to the installation dimensions reserved for the Coriolis flow meter in the system under test. The total length of the measuring tube is determined based on the reserved installation dimensions and weight requirements.

[0018] 2) Determine the optimization objective and select optimization variables for the measuring tube. The optimization objective is to increase the flow coefficient of the Coriolis flowmeter. Based on the installation space, initially select the measuring tube structure type, and based on the structure type, select the geometric variables for optimizing the measuring tube. The geometric variables of the measuring tube are the vertical pipe section length L of the measuring tube. H Length L of horizontal pipe section V and the radius L of the curved pipe section R ;

[0019] 3) Establish corresponding orthogonal experimental combinations for the optimization objective and optimization variables, and generate orthogonal experimental tables; given the length of the measuring tube, the optimization variables of the measuring tube structure influence each other, and the constructed orthogonal experimental combinations are orthogonal experiments with interactive effects;

[0020] 4) Check the constructed orthogonal experimental test groups and merge the repeated test groups; determine the actual size of each group of the orthogonal experimental test groups based on the total length of the measuring tube and the level values ​​of each optimization variable;

[0021] 5) Construct the corresponding Coriolis flowmeter bidirectional partitioned iterative fluid-structure interaction model according to the actual dimensions of the measuring pipe types of each group of the orthogonal test group obtained in step 4); extract the vibration displacement information of the two signal detectors from the calculated numerical results, perform Fourier transform on the vibration information to obtain the frequency domain characteristics of the vibration signal, and thus obtain the phase difference of the measuring pipe under the corresponding mass flow rate condition; calculate the phase difference results of the measuring pipe with the same structure under three different flow rates, and fit the phase difference and mass flow rate based on linear fitting to obtain the flow coefficient of the corresponding measuring pipe type;

[0022] 6) Perform range analysis on the orthogonal experiment results to obtain the ranking of the influence of the optimization variables on the flow coefficient of the measuring tube, and obtain the optimal combination of variables for the optimal flow coefficient of the measuring tube;

[0023] 7) Design a Coriolis flow meter based on the optimal variable combination method of the optimal flow coefficient of the measuring tube.

[0024] As a preferred embodiment of the present invention, in step 2), increasing the flow coefficient of the Coriolis flowmeter specifically means: maximizing the phase difference or time delay of the signals measured by the signal detectors of the inlet and outlet pipe sections of the measuring pipe under the same mass flow conditions.

[0025] As a preferred embodiment of the present invention, in step 5), the harmonic driving force is applied to the first structural point, and the vibration signal is obtained based on the second structural point and the third structural point, respectively; the first structural point is located at 1 / 2 of the arched structural part of the measuring tube, and the second and third structural points are located at 3 / 11 and 8 / 11 of the arched structural part of the measuring tube, respectively.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1) This invention adopts an orthogonal experimental design method, which effectively overcomes the shortcomings of the large number of structural optimization experiments and low optimization efficiency caused by selecting the optimal structure of the measuring tube under the fixed length of the measuring tube under limited installation conditions. It provides guidance for the structural optimization design of the measuring tube, saves optimization time, and improves optimization efficiency.

[0028] 2) The Coriolis flowmeter structure optimization design method disclosed in this invention can enable the measuring tube to have a larger flow coefficient under fixed length conditions, which significantly improves the measurement accuracy and sensitivity of the Coriolis flowmeter. Attached Figure Description

[0029] Figure 1 This is a flowchart illustrating the structural optimization design of the Coriolis flowmeter based on orthogonal experiments according to the present invention.

[0030] Figure 2 This is a schematic diagram of the measuring tube structure used in orthogonal experimental design according to the present invention.

[0031] Figure 3It is an isometric drawing of a Coriolis flowmeter optimized through orthogonal experimental design.

[0032] Figure 4 This is the left view of a Coriolis flowmeter optimized through orthogonal experimental design.

[0033] Figure 5 This is an isometric drawing of the electromagnetic actuator mounting bracket.

[0034] Figure 6 It is an isometric drawing of the splitter.

[0035] Figure 7 It is an isometric drawing of a fixed support plate.

[0036] Figure 8 It is an isometric view of a signal detector.

[0037] Figure 9 It is an isometric drawing of a measuring tube optimized through orthogonal experiments.

[0038] Figure 10 This is the main view of the measuring tube, which was optimized through orthogonal experiments.

[0039] Figure 11 It is an isometric view of a signal detector.

[0040] Figure 12 It is an isometric drawing of an electromagnetic actuator.

[0041] In the diagram: 1. First structural point; 2. Second structural point; 3. Third structural point; 4. Interface flange; 5-1. Inlet section transition pipe; 5-2. Outlet section transition pipe; 6. Fixed support plate; 7. Measuring pipe; 7-1. Vertical pipe section; 7-2. Bent pipe section; 7-3. Horizontal pipe section; 8. Diverter; 9. First signal detector mounting bracket; 10. Second signal detector mounting bracket; 11. Signal detector; 12. Electromagnetic actuator; 13. First electromagnetic actuator mounting bracket; 14. Second electromagnetic actuator mounting bracket; 15. Control circuit module. Detailed Implementation

[0042] The present invention will be further described and illustrated below with reference to specific embodiments. The embodiments described are merely examples of the content of this disclosure and do not limit the scope of the invention. The technical features of each embodiment in the present invention can be combined accordingly, provided that there is no mutual conflict.

[0043] A Coriolis flowmeter optimized based on orthogonal experiment includes a measuring tube 7, a fixing support plate 6 for fixing the measuring tube 7, interface flanges 4 disposed at both ends of the measuring tube 7, a main transition pipe for adjusting the installation width of the Coriolis flowmeter, a signal detector 11 and an electromagnetic driver 12 disposed on the measuring tube 7, and a control circuit module 15; two measuring tubes 7 are fixed side by side on the fixing support plate 6, and each measuring tube 7 has an arched structure, which is formed by sequentially connecting a vertical pipe section 7-1, a curved pipe section 7-2, a horizontal pipe section 7-3, a curved pipe section 7-2, and a vertical pipe section 7-1; the main transition pipe includes... The system includes an inlet transition pipe 5-1 and an outlet transition pipe 5-2. The inlet transition pipe 5-1 is located between the measuring pipe 7 and the interface flange 4 located on the inlet side of the measuring pipe 7, and the outlet transition pipe 5-2 is located between the measuring pipe 7 and the interface flange 4 located on the outlet side of the measuring pipe 7. Two signal detectors 11 are respectively located on the fluid inlet side and the fluid outlet side of the measuring pipe 7. The electromagnetic actuator 12 is located in the middle of the measuring pipe 7. The control circuit module 15 receives and processes the signals collected by the signal detectors 11. The control circuit module 15 is also connected to the electromagnetic actuator 12 and provides alternating current to the electromagnetic actuator 12. A flow divider 8 is provided on the inlet transition pipe 5-1. The flow divider 8 is used to evenly distribute the fluid in the inlet transition pipe 5-1 into the two measuring pipes 7 when the fluid flows into the measuring pipe 7, thereby reducing the measurement error caused by uneven fluid distribution.

[0044] The signal detector 11 is fixed to two measuring tubes 7 by a signal detector fixing bracket. The signal detector fixing bracket includes a first signal detector fixing bracket 9 fixed to one measuring tube 7 and a second signal detector fixing bracket 10 fixed to the other measuring tube 7. The signal detector 11 includes a signal detector permanent magnet resonator, a signal detector coil, and a signal detector coil frame. The signal detector permanent magnet resonator is fixed to the first signal detector fixing bracket 9, the signal detector coil frame is fixed to the second signal detector fixing bracket 10, and the signal detector coil is wound around the signal detector coil frame. During the measurement process, the signal detector permanent magnet resonator and the signal detector coil wound around the signal detector coil frame move relative to each other, thereby generating a voltage signal in the signal detector coil. The voltage signal is transmitted to the control circuit module 15.

[0045] The control circuit module 15 includes a serial communication module, a level conversion module, an algorithm control module, an excitation output module, a signal acquisition module, and a temperature acquisition module. The signal acquisition module is used to acquire the signal output by the signal detector (11) and perform pre-filtering, voltage amplification, and analog-to-digital conversion. The signal after analog-to-digital conversion is input to the algorithm control module, which extracts the vibration signal frequency of the electromagnetic driver and the signal phase difference between the two signal detectors. The algorithm control module transmits the calculated vibration signal frequency and signal phase difference to an external host computer through the serial communication module and displays it on the external host computer. At the same time, the algorithm control module generates a digital sinusoidal drive signal. The excitation output module includes a digital-to-analog conversion module and a power amplification module, which converts the sinusoidal digital drive signal generated by the algorithm control module into a sinusoidal analog drive signal and increases the signal drive power through the power amplification module. The temperature acquisition module is used to acquire the temperature data of the measuring tube and input it to the algorithm control module to perform temperature compensation for the calculated phase difference. The level conversion module is used to power each module.

[0046] The optimization design object of this invention is Figure 2 The arched structure of the measuring tube shown in the diagram has a first structural point 1 located at 1 / 2 of its total length, used to apply a harmonic driving force during coupled simulation. The second and third structural points 2 and 3 are located at 3 / 11 and 8 / 11 of the total length of the measuring tube, respectively, used to collect vibration displacement information of the measuring tube during coupled simulation. The optimization objective is to maximize the vibration phase difference between the second and third structural points 2 and 3, and the optimization variable is the length L of the vertical tube segment of the measuring tube. V , radius L of the bent pipe section R and the length L of the horizontal pipe section H To facilitate the description of the optimization variables in an orthogonal experiment, three variables L... V L R and L H They are represented by A, B, and C, respectively. In a specific embodiment of the present invention, the total length of the measuring tube is 1461 mm, and the inner diameter and outer diameter of the measuring tube are 47.6 mm and 50.8 mm, respectively.

[0047] like Figure 1 The diagram illustrates the optimized design method of this invention, with the following specific steps:

[0048] S1. Three levels are selected for each optimization variable. The actual length of each pipe segment is determined based on the measured length of the pipe arch structure and the level values ​​of the three optimization variables; for example, A1B2C3 represents the optimization variable A(L) V The level of ) is selected as one, and the optimization variable B(L) is selected as one. R The level selection is two, and the optimization variable is C(L). H The level is selected as three, namely A(L) V ):B(LR ):C(L H The ratio of the two pipe sections is 1:2:3; Since the arched structure of the measuring pipe has a fixed length of 1461mm, the actual length of each measuring pipe section can be calculated, and the length of the vertical pipe section L is also calculated. V The length is 129.52 mm, and the radius of the bent pipe section is L. R The length of the horizontal pipe section is 259.04 mm and L. H It is 388.56mm;

[0049] S2. Construct an orthogonal experimental table with interaction of three factors and three levels. 27 (3 13 ), calculate the actual size of the measuring tube for each test group in the orthogonal test table according to step S1 and construct a two-way partitioned iterative fluid-structure interaction model;

[0050] S3. Calculate and extract the vibration displacement information of the second structural point 2 and the third structural point 3 from the constructed fluid-structure interaction model, and obtain the phase difference of the vibration signals of the two structural points based on the fast Fourier transform.

[0051] S4. In the model established in step S3, the phase difference corresponding to three different mass flow conditions is obtained. The relationship between the phase difference and the mass flow is fitted based on linear fitting. The linear fitting deviation is required to be less than 2.5%. The flow coefficient of the corresponding test group measuring pipe structure is obtained, where the unit of the flow coefficient is rad·s / kg.

[0052] S5. Repeat step S4 for each test group structure to obtain the flow coefficients corresponding to each measurement tube structure as shown in Table 1, where A×B represents the interaction between optimization variable A and optimization variable B.

[0053] Table 1 Results of the Measured Pipe Flow Coefficient Based on Orthogonal Experiment Optimization

[0054]

[0055]

[0056] S6. Perform range analysis on the obtained flow coefficient results of the measuring tube to determine the degree of influence of each influencing factor. The range analysis table is shown in Table 2.

[0057] Table 2. Range analysis results of orthogonal experiments

[0058]

[0059] S7. Through range analysis, the results show that when the maximum length of the arched structure of the measuring tube in this embodiment is 1461 mm, the degree of influence of the optimized variable on the flow coefficient is A>B>(A×C)1>(A×B)2>(A×B)1>(B×C)2>(A×C)2=C>(B×C)1; further, the interaction results between optimized variable A and optimized variable C and the interaction results between optimized variable A and optimized variable B are extracted as shown in Table 3;

[0060] Table 3 shows the interaction results between optimization variables A and C, and the interaction results between optimization variables A and B.

[0061]

[0062] S8. Based on the comprehensive range analysis results and interaction results, in this embodiment, when the maximum length of the arched structure of the measuring tube is 1461 mm, the flow coefficient is maximized when the values ​​of optimization variable A and optimization variable C are equal; the smaller the value of optimization variable B, the larger the flow coefficient of the measuring tube; increasing optimization variable A can increase the flow coefficient of the measuring tube; the final optimized structure of the measuring tube is A3B1C3, i.e., L... V :L R :L H =3:1:3;

[0063] S9. Similar to the range analysis results, the fluid-structure interaction simulation results show that, under the condition of fixed measuring tube length, the maximum flow coefficient corresponding to the measuring tube structure A3B1C3 is 4.13E-5 rad·s / kg. Compared with the minimum flow coefficient of 1.92E-5 rad·s / kg, the flow coefficient of the measuring tube can be increased by 215% based on the orthogonal experimental optimization design method.

[0064] In summary, this invention optimizes the design of a Coriolis flowmeter structure with a fixed measuring tube length based on orthogonal experiments. It is an optimization design method that combines orthogonal experiments with numerical simulation technology to maximize the flow coefficient of the Coriolis flowmeter under the conditions of fixed installation space and fixed tube length.

[0065] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A design method for a Coriolis flowmeter based on orthogonal experimental optimization, characterized in that, The Coriolis flowmeter includes a measuring tube (7), a fixed support plate (6) for fixing the measuring tube (7), interface flanges (4) at both ends of the measuring tube (7), a main transition pipe for adjusting the installation width of the Coriolis flowmeter, a signal detector (11) and an electromagnetic driver (12) installed on the measuring tube (7), and a control circuit module (15); two measuring tubes (7) are fixed side by side on the fixed support plate (6), and the measuring tube (7) has an arched structure, which is composed of a vertical pipe section (7-1), a curved pipe section (7-2), a horizontal pipe section (7-3), a curved pipe section (7-2), and a vertical pipe section (7-1) connected in sequence; the main transition pipe includes an inlet transition pipe. (5-1) and outlet transition pipe (5-2), inlet transition pipe (5-1) is set between measuring pipe (7) and interface flange (4) located on the inlet side of measuring pipe (7), outlet transition pipe (5-2) is set between measuring pipe (7) and interface flange (4) located on the outlet side of measuring pipe (7); two signal detectors (11) are respectively set on the fluid inlet side and fluid outlet side of measuring pipe (7); electromagnetic actuator (12) is set in the middle position of measuring pipe (7); control circuit module (15) receives and processes the signals collected by signal detector (11); control circuit module (15) is also connected to electromagnetic actuator (12) and provides alternating current to electromagnetic actuator (12); The design method includes the following steps: 1) Determine the maximum measuring length of the measuring tube based on the installation space; the installation space refers to the installation dimensions reserved for the Coriolis flow meter in the system under test; determine the maximum measuring length of the measuring tube based on the reserved installation dimensions and weight requirements; 2) Based on the installation space, the structure type of the measuring tube is initially selected. Based on the structure type, the geometric variables used to optimize the measuring tube are selected. The geometric variables of the measuring tube are the length of the vertical tube section. L H Length of horizontal pipe section L V and the radius of the curved pipe section L R The optimization objective is to increase the flow coefficient of the Coriolis flow meter. 3) Establish corresponding orthogonal experimental combinations for the optimization objective and the geometric variables of the measurement tube, and generate an orthogonal experimental table; under the given tube length, the geometric variables of the measurement tube affect each other, and the constructed orthogonal experimental combinations are orthogonal experimental groups with interactive effects; 4) Check the constructed orthogonal test groups and merge the repeated test groups; determine the actual dimensions of each group in the orthogonal test groups based on the total length of the measuring tube and the horizontal values ​​of the geometric variables of the measuring tube; 5) Construct the corresponding Coriolis flowmeter bidirectional partitioned iterative fluid-structure interaction model according to the actual dimensions of the measuring pipe types of each group of the orthogonal test group obtained in step 4); extract the vibration displacement information of the two signal detectors from the calculated numerical results, perform Fourier transform on the vibration information to obtain the frequency domain characteristics of the vibration signal, and thus obtain the phase difference of the measuring pipe under the corresponding mass flow rate condition; calculate the phase difference results of the measuring pipe with the same structure under three different flow rates, and fit the phase difference and mass flow rate based on linear fitting to obtain the flow coefficient of the corresponding measuring pipe type; 6) Perform range analysis on the orthogonal experiment results to obtain the ranking of the influence of the optimization variables on the flow coefficient of the measuring tube, and obtain the optimal combination of variables for the optimal flow coefficient of the measuring tube; 7) Design a Coriolis flow meter based on the optimal variable combination method of the optimal flow coefficient of the measuring tube.

2. The design method according to claim 1, characterized in that, A flow divider (8) is provided on the inlet section transition pipe (5-1). When the fluid in the inlet section transition pipe (5-1) flows into the measuring pipe (7), the flow divider (8) distributes the fluid evenly to the two measuring pipes (7), thereby reducing the measurement error caused by uneven fluid distribution.

3. The design method according to claim 1, characterized in that, Both the signal detector (11) and the electromagnetic driver (12) include a coil, a coil frame and a permanent magnet oscillator; the number of coil turns of the signal detector (11) is less than the number of coil turns of the electromagnetic driver (12), and the size of the coil frame and the permanent magnet oscillator of the signal detector (11) is smaller than the size of the coil frame and the permanent magnet oscillator of the electromagnetic driver (12).

4. The design method according to claim 3, characterized in that, The signal detector (11) is fixed to two measuring tubes (7) by a signal detector fixing bracket; the signal detector fixing bracket includes a first signal detector fixing bracket (9) fixed to one measuring tube (7) and a second signal detector fixing bracket (10) fixed to the other measuring tube (7); the signal detector (11) includes a signal detector permanent magnet oscillator, a signal detector coil and a signal detector coil skeleton, the signal detector permanent magnet oscillator is fixed to the first signal detector fixing bracket (9), the signal detector coil skeleton is fixed to the second signal detector fixing bracket (10), and the signal detector coil is wound on the signal detector coil skeleton; During the measurement process, the permanent magnet oscillator of the signal detector and the signal detector coil wound on the coil skeleton of the signal detector undergo relative motion, thereby generating a voltage signal in the signal detector coil, which is transmitted to the control circuit module (15).

5. The design method according to claim 3, characterized in that, The electromagnetic driver (12) is fixed to the measuring tube (7) by an electromagnetic driver fixing bracket; the electromagnetic driver fixing bracket includes a first electromagnetic driver fixing bracket (13) fixed to one measuring tube (7) and a second electromagnetic driver fixing bracket (14) fixed to another measuring tube (7). The electromagnetic driver (12) includes an electromagnetic driver permanent magnet oscillator, an electromagnetic driver coil and an electromagnetic driver coil frame; the electromagnetic driver permanent magnet oscillator is fixed to the first electromagnetic driver fixing bracket (13), the electromagnetic driver coil frame is fixed to the second electromagnetic driver fixing bracket (14), and the electromagnetic driver coil is wound on the electromagnetic driver coil frame; during the measurement process, the control circuit module (15) outputs an alternating current signal to the electromagnetic driver coil, thereby causing the electromagnetic driver oscillator and the electromagnetic driver coil to reciprocate, which in turn drives the two measuring tubes (7) to reciprocate.

6. The design method according to claim 1, characterized in that, The control circuit module (15) includes a serial communication module, a level conversion module, an algorithm control module, an excitation output module, a signal acquisition module, and a temperature acquisition module. The signal acquisition module is used to acquire the signal output by the signal detector (11) and perform pre-filtering, voltage amplification, and analog-to-digital conversion. The signal after analog-to-digital conversion is input to the algorithm control module, which extracts the vibration signal frequency of the electromagnetic driver and the signal phase difference between the two signal detectors. The algorithm control module transmits the calculated vibration signal frequency and signal phase difference to an external host computer through the serial communication module and displays it on the external host computer. At the same time, the algorithm control module generates a digital sinusoidal drive signal. The excitation output module includes a digital-to-analog conversion module and a power amplification module, which converts the sinusoidal digital drive signal generated by the algorithm control module into a sinusoidal analog drive signal and amplifies the signal drive power through the power amplification module. The temperature acquisition module is used to acquire the temperature data of the measuring tube and input it to the algorithm control module to perform temperature compensation for the calculated phase difference. The level conversion module is used to supply power to each module.

7. The design method of the Coriolis flow meter according to claim 1, characterized in that, In step 2), increasing the flow coefficient of the Coriolis flow meter specifically means: under the same mass flow conditions, optimizing the geometric variables of the measuring tube to maximize the phase difference or time delay of the signal measured by the signal detectors of the inlet and outlet pipe sections of the measuring tube.

8. The design method of the Coriolis flow meter according to claim 1, characterized in that, In step 5), the simple harmonic driving force is applied to the first structural point (1), and the vibration signal is obtained based on the second structural point (2) and the third structural point (3). The first structural point (1) is located at 1 / 2 of the arched structure of the measuring tube, and the second structural point (2) and the third structural point (3) are located at 3 / 11 and 8 / 11 of the arched structure of the measuring tube, respectively.

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