A mass flow meter measuring tube and a method for increasing the fundamental frequency difference of the measuring tube

Abstract

The present application relates to the field of flow detection equipment, and specifically discloses a mass flow meter measuring tube and a method for increasing the fundamental frequency difference of the measuring tube, which includes a tube body and a reinforcement member fixedly arranged on the outer wall of the tube body, wherein the reinforcement member is provided in two groups and is respectively located at the two ends of the tube body, and the length dimension of the overall structure in the cross section of the tube body and the reinforcement member is greater than the width dimension, so that the difference between the first-order fundamental frequency and the second-order fundamental frequency of the tube body is greater than 30Hz. The present application strengthens the local area of ​​the tube body, improves the local stiffness of the tube body, and realizes that the difference between the first-order fundamental frequency and the second-order fundamental frequency is increased while not causing a major change in the overall performance, thereby achieving comprehensive optimization of design, process and performance, and avoiding the defects of increased cost and extended cycle caused by increasing the fundamental frequency difference in the traditional method.

Description

Technical Field

[0001] The present application relates to the field of flow detection equipment, and in particular to a mass flow meter measuring tube and a method for increasing the fundamental frequency difference of the measuring tube. Background Art

[0002] Mass flow refers to the mass of fluid passing through the effective cross-section of a closed pipe or open slot per unit time. Mass flow can be expressed as the product of volume flow and fluid density. A Coriolis mass flowmeter is an instrument that directly and accurately measures the mass flow of a fluid. The Coriolis mass flowmeter includes one or more measuring tubes, a driver, and a sensor. The fluid can flow into the measuring tube; the driver is arranged on the measuring tube to drive the measuring tube to vibrate; the sensor is arranged at the inlet and outlet of the measuring tube to detect the vibration of the measuring tube.

[0003] When there is no relative motion between the measuring tube and the fluid, the vibrations at all points of the measuring tube are in the same phase after the measuring tube is stimulated to vibrate. When there is relative motion between the measuring tube and the fluid, that is, when the fluid flows in the measuring tube, a Coriolis force proportional to the mass flow of the fluid will be generated on the tube wall due to the inertia of the fluid, causing differences in the responses of various parts of the measuring tube structure, and a phase difference between the vibrations at the inlet and outlet of the measuring tube. The magnitude of the phase difference is proportional to the mass flow, so the mass flow in the measuring tube can be obtained by detecting the phase difference at both ends of the measuring tube.

[0004] The frequency used to drive the measuring tube to vibrate is usually the first-order fundamental frequency of the measuring tube. When the first-order fundamental frequency and the second-order fundamental frequency of the measuring tube are close, resonance is likely to occur when there is external interference or changes in fluid flow conditions, resulting in increased fluctuations and errors in the measurement signal, which seriously affects the performance of the mass flow meter. Therefore, how to effectively increase the fundamental frequency difference of the measuring tube has become one of the key technical issues in improving the performance of the mass flow meter.

[0005] The traditional way to increase the fundamental frequency difference is generally to increase the wall thickness, change the material, and change the configuration size. However, increasing the wall thickness will result in poor consistency in the bending process, a large number of auxiliary tooling, and special tooling needs to be designed for different wall thicknesses, which seriously affects cost control and implementation cycle. Due to the characteristics of the internal flow medium, the pipeline material is generally selected from stainless steel materials with good corrosion resistance such as 304 and 316L. Expanding other material systems is accompanied by engineering risks. Changes in configuration size require systematic evaluation of comprehensive performance, such as the impact of sudden temperature changes, unstable incoming flow, etc. on structural stress and strain, and the development cycle and the number of parameters that need to be evaluated increase. Therefore, the above traditional measures have increased higher costs while changing the fundamental frequency, resulting in changes in product system performance. Summary of the invention

[0006] In order to avoid the cost and cycle defects caused by increasing the fundamental frequency difference of the traditional measuring tube, the present application provides a mass flow meter measuring tube and a method for increasing the fundamental frequency difference of the measuring tube.

[0007] In a first aspect, the present application provides a mass flow meter measuring tube, which adopts the following technical solution: A mass flow meter measuring tube comprises a tube body and a reinforcement member fixedly arranged on the outer wall of the tube body, wherein the reinforcement member is provided in two groups and is respectively located at two ends of the tube body, and the length dimension of the overall structure in the cross section of the tube body and the reinforcement member is greater than the width dimension, so that the difference between the first-order fundamental frequency and the second-order fundamental frequency of the tube body is greater than 30 Hz.

[0008] By adopting the above technical solution, specific areas of the tube body are locally strengthened, and the fundamental frequency difference is increased without causing a major change in the overall performance, thereby achieving comprehensive optimization of design, process and performance; this method avoids the defects of improving the fundamental frequency performance through wall thickness, material and other means in the traditional method; since the difference between the first-order fundamental frequency and the second-order fundamental frequency is increased, when the frequency of the exciting force applied to the measuring tube is the first-order fundamental frequency of the measuring tube, the measuring tube will only perform first-order vibration, and will not perform second-order vibration, thereby effectively avoiding the resonance phenomenon caused by external interference or changes in fluid flow conditions, thereby improving the stability and accuracy of the measurement signal and enhancing the overall performance of the mass flowmeter.

[0009] Optionally, the reinforcement member includes two reinforcement sheets, which are arranged in a rectangular shape and arranged along the length direction of the tube body. The two reinforcement sheets are located in the same plane and are symmetrically arranged on both sides of the tube body.

[0010] By adopting the above technical solution, after the reinforcement sheet is correctly installed in place, it can not only directly enhance the stiffness of the local area of ​​the measuring tube and improve the measuring tube's ability to resist fluid impact, but also form additional mass damping to further suppress the occurrence of low-frequency vibrations; under high-frequency vibration conditions, the reinforcement sheet can effectively reduce the vibration intensity transmitted to the sensor due to its relatively large weight and geometric structure, thereby improving the stability of the entire system.

[0011] Optionally, a distance ring is fixedly provided on the outer wall of the tube body at one side of the reinforcement sheet, and the distance ring abuts against the end of the reinforcement sheet.

[0012] By adopting the above technical solution, the distance ring can play a limiting role, so that the ends of the two reinforcement plates at the same end of the pipe body are flush, which helps to improve the installation accuracy and thus ensure the impact on the fundamental frequency of the measuring tube; the setting of the distance ring can also increase the stiffness of the corresponding position of the pipe body, and can enhance the ability of the pipe body to resist external vibrations, thereby ensuring the accuracy of the measurement.

[0013] Optionally, the reinforcement includes an arc plate and a connecting plate, wherein two arc plates are provided and symmetrically distributed on both sides of the tube body, and two connecting plates are provided and symmetrically distributed on both sides of the tube body. The inner sides of the arc plate and the connecting plate are both in contact with the outer wall of the tube body, and the connecting plate is provided between the two arc plates. The connecting plate and the arc plate are integrated into one.

[0014] By adopting the above technical solution, the stiffness of the tube body in two directions can be improved, and the stiffness improved in one direction is greater than that in the other direction, so that the symmetry of the tube body can be weakened, thereby increasing the fundamental frequency difference of the measuring tube; because the connecting plate and the arc plate are integrated, the reinforcement member becomes a whole, the installation of the reinforcement member is simpler, which helps to ensure the installation accuracy.

[0015] Optionally, the reinforcement member includes two arc-shaped pieces, and the two arc-shaped pieces are symmetrically arranged on both sides of the tube body, and the sides of the two arc-shaped pieces close to each other are in contact with the outer wall of the tube body.

[0016] By adopting the above technical solution, the rigidity of the tube body in one direction can be improved, thereby increasing the fundamental frequency difference of the measuring tube.

[0017] Optionally, the reinforcement member includes two reinforcement rods, which are symmetrically arranged on both sides of the tube body. The reinforcement rods include a first connecting rod and a second connecting rod. The first connecting rod is arranged radially along the tube body, and the second connecting rod is arranged axially along the tube body. Two first connecting rods are provided, and the second connecting rod is fixedly connected between the two first connecting rods.

[0018] By adopting the above technical solution, the rigidity of the tube body in one direction can be improved, thereby increasing the fundamental frequency difference of the measuring tube.

[0019] Optionally, the reinforcement member includes a connecting ring and a connecting plate, the connecting ring is sleeved on the outer wall of the tube body, the connecting plate is fixedly connected to the outer wall of the connecting ring, and two connecting plates are provided and symmetrically arranged on both sides of the connecting ring.

[0020] By adopting the above technical solution, the stiffness of the tube body in two directions can be improved, and the stiffness improved in one direction is greater than that in the other direction, thereby weakening the symmetry of the tube body, thereby increasing the fundamental frequency difference of the measuring tube; since the two connecting pieces are fixed on the connecting ring, the reinforcement can form a whole, thereby making the installation process of the reinforcement easier.

[0021] Optionally, the reinforcement is made of stainless steel.

[0022] By adopting the above technical solution, it is possible to ensure that the reinforcement has good corrosion resistance and mechanical strength, extend the service life, and avoid the defect of inconsistent thermal expansion coefficient caused by temperature changes.

[0023] Optionally, the shape of the tube body is one of a straight tube type, a U-shape, and a gate shape.

[0024] By adopting the above technical solution, the reinforcement member can be applicable to various forms of pipe bodies, and thus has greater applicability.

[0025] In a second aspect, the present application provides a method for increasing the fundamental frequency difference of a measuring tube, using the following technical solution: A method for increasing the fundamental frequency difference of a measuring tube, based on any of the mass flow meter measuring tubes described above, the method for increasing the fundamental frequency difference of the measuring tube comprises the following steps: a. Clarify the structural parameters of the pipe body, including the length, diameter, wall thickness, material and connection method with other components of the pipe body; b. Based on the structural parameters of the pipe body, the mechanical model of the pipe body is established using finite element analysis software; c. Perform modal analysis on the established mechanical model and calculate the first-order fundamental frequency and second-order fundamental frequency of the pipe body; d. According to the calculated first-order fundamental frequency and second-order fundamental frequency, determine whether the difference between the two is greater than 30Hz. If the difference is greater than 30Hz, it indicates that the current tube structure has met the frequency requirements and no further optimization is required; if the difference is less than or equal to 30Hz, proceed to the next step; e. A reinforcement member is provided at the boundary of the pipe body. The characteristic parameters of the reinforcement member include length, width, height and installation position relative to the pipe body. The characteristic parameter adjustment strategies of the reinforcement member include but are not limited to the following: Change the length and width of the reinforcement; Changing the height dimension of the reinforcement; Changing the installation position of the reinforcement relative to the pipe body; f. After each adjustment of the characteristic parameters, re-use the finite element analysis software to perform modal analysis on the modified pipe body mechanical model, calculate new first-order fundamental frequency and second-order fundamental frequency, and again determine whether the difference between the two is greater than 30 Hz; repeat step e and step f until the difference between the first-order fundamental frequency and the second-order fundamental frequency is greater than 30 Hz; g. Perform phase difference simulation calculation based on the determined structural parameters; h. According to the finally determined tube structure parameters that meet the frequency requirements, manufacture the measuring tube of the mass flow meter.

[0026] By adopting the above technical solution, the difference between the first-order fundamental frequency and the second-order fundamental frequency of the mass flowmeter measuring tube can be effectively increased, avoiding resonance when external interference or changes in fluid flow conditions occur, thereby reducing the fluctuation and error of the measurement signal and improving the performance of the mass flowmeter.

[0027] In summary, this application includes the following beneficial technical effects: 1. Locally strengthen specific areas of the tube body to increase the fundamental frequency difference without causing major changes to the overall performance, thereby achieving comprehensive optimization of design, process and performance, and avoiding the defects of increased cost and extended cycle caused by increasing the fundamental frequency difference in the traditional way.

[0028] 2. The setting of the distance ring helps to improve the installation accuracy of the reinforcement sheet, thereby ensuring the symmetry of the reinforcement sheet, helping to ensure the reinforcement effect on the rigidity of the pipe body, thereby better increasing the difference between the first-order fundamental frequency and the second-order fundamental frequency of the measuring pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a finite element analysis diagram for displaying the first-order fundamental frequency and the second-order fundamental frequency in Example 1 of the present application; Figure 2 It is a schematic diagram of the overall structure of Example 1 of the present application; Figure 3 It is a schematic diagram of the overall structure of Example 2 of the present application; Figure 4 is a schematic structural diagram of a reinforcement member in Example 2 of the present application; Figure 5 It is a schematic diagram of the overall structure of Example 3 of the present application; Figure 6 It is a schematic diagram of the overall structure of Example 4 of the present application; Figure 7 It is a schematic diagram of the overall structure of Example 5 of the present application.

[0030] Figure numerals: 1, tube body; 2, reinforcing plate; 3, distance ring; 4, arc plate; 5, connecting plate; 6, arc plate; 7, reinforcing rod; 71, first connecting rod; 72, second connecting rod; 8, connecting ring; 9, connecting plate. DETAILED DESCRIPTION

[0031] The following combination Figure 1 - Figure 7 This application is described in further detail. Example

[0032] The present application embodiment discloses a mass flow meter measuring tube. Figure 1 and Figure 2The mass flow meter measuring tube includes a tube body 1 and a reinforcement. In this embodiment, the tube body 1 is arranged in a straight tube shape; in other embodiments, the tube body 1 can also be arranged in a U-shape or a gate shape. The reinforcement and the tube body 1 are both made of stainless steel, so while ensuring corrosion resistance, the defect of inconsistent thermal expansion coefficient caused by temperature changes can be avoided. The reinforcement is fixedly connected to the outer wall of the tube body 1, and two groups of reinforcements are arranged and are respectively located at the two ends of the tube body 1.

[0033] The reinforcement member includes two reinforcement sheets 2, which are rectangular thin sheet structures and have a thickness of 2 mm. The reinforcement sheets 2 are welded and fixed to the outer wall of the tube body 1. The reinforcement sheets 2 are arranged along the length direction of the tube body 1, and the two reinforcement sheets 2 are located in the same plane and symmetrically arranged on both sides of the outside of the tube body 1. Therefore, the arrangement of the reinforcement sheets 2 can increase the rigidity of the tube body 1 in one direction, while the rigidity of the tube body 1 in the other direction remains unchanged, thereby adjusting the natural frequency of the measuring tube, thereby increasing the difference between the first-order fundamental frequency and the second-order fundamental frequency of the measuring tube.

[0034] In other embodiments, the reinforcing sheet 2 may be thickened, and one side of the thickened reinforcing sheet 2 may be set as a curved surface that can abut against the outer wall of the tube body 1, so that the reinforcing sheet 2 can better fit the outer wall of the tube body 1 and enhance the connection effect.

[0035] Furthermore, a distance ring 3 is fixedly connected to the outer wall of the pipe body 1. Two distance rings 3 are provided and correspond to the two groups of reinforcements respectively; the two distance rings 3 are respectively located on the side away from each other of the two groups of reinforcements. The distance ring 3 is a circular ring, and the inner diameter of the distance ring 3 is the same as the outer diameter of the pipe body 1. The distance ring 3 is welded and fixed to the outer wall of the pipe body 1. One side of the distance ring 3 abuts against the ends of the two reinforcement sheets 2, and the distance ring 3 and the reinforcement sheet 2 are welded and fixed, so the setting of the distance ring 3 can position the installation of the reinforcement sheet 2, thereby improving the installation accuracy of the reinforcement sheet 2.

[0036] The implementation principle of Example 1 is as follows: the distance ring 3 is welded and fixed on the outer wall of the tube body 1, and the two distance rings 3 are arranged at intervals. Then, two reinforcing sheets 2 are placed on both sides of the tube body 1, and one end of the reinforcing sheet 2 is abutted against the distance ring 3, and then the reinforcing sheet 2 and the outer wall of the tube body 1 and the reinforcing sheet 2 and the distance ring 3 are welded and fixed, thereby completing the production of the measuring tube. Then, detection coils for detecting vibration can be set at both ends of the measuring tube, a magnet is set on the outer wall of the middle part of the measuring tube, and a driving coil is set outside the magnet. When the driving coil is energized, the measuring tube can be vibrated, and the vibration frequency of the measuring tube is its own first-order fundamental frequency; then, the phase difference of the vibration at both ends of the measuring tube is detected by the detection coil, and the mass flow in the measuring tube can be detected.

[0037] Since a reinforcement is provided on the measuring tube, the difference between the first-order fundamental frequency and the second-order fundamental frequency of the measuring tube is increased. Therefore, when the frequency of the vibration applied to the measuring tube by the driving coil is the first-order fundamental frequency of the measuring tube, the measuring tube will only vibrate at the first-order fundamental frequency and is not prone to vibrating at the second-order fundamental frequency, thereby avoiding the adverse effect of the superposition phenomenon caused by the simultaneous occurrence of the two vibrations on the measurement, thereby improving the detection accuracy.

[0038] This embodiment also discloses a method for increasing the fundamental frequency difference of a measuring tube, comprising the following steps: Step a. clarifying the structural parameters of the tube body 1, wherein the structural parameters include the length, diameter, wall thickness, material of the tube body 1 and the connection method with other components.

[0039] Step b: Based on the structural parameters of the tube body 1 , a mechanical model of the tube body 1 is established using finite element analysis software.

[0040] Step c: Perform modal analysis on the established mechanical model to calculate the first-order fundamental frequency and the second-order fundamental frequency of the tube body 1.

[0041] Step d. Based on the calculated first-order fundamental frequency and second-order fundamental frequency, determine whether the difference between the two is greater than 30 Hz. If the difference is greater than 30 Hz, it indicates that the current tube body 1 structure has met the frequency requirements and no further optimization is required; if the difference is less than or equal to 30 Hz, proceed to the next step.

[0042] Step e. A reinforcement member is provided at the boundary of the tube body 1. The characteristic parameters of the reinforcement member include length, width, height and installation position relative to the tube body 1. The characteristic parameter adjustment strategies of the reinforcement member include but are not limited to the following: (1) Change the length and width of the reinforcement.

[0043] (2) Changing the height of the reinforcement. By making reasonable adjustments, the torsion resistance of the tube body 1 in a certain direction can be improved, thereby increasing the difference between the first-order fundamental frequency and the second-order fundamental frequency of the tube body 1.

[0044] (3) Changing the installation position of the reinforcement relative to the pipe body 1. Different spatial layout differences will lead to changes in the fundamental frequency of pipeline vibration. For example, arranging it in a vibration-sensitive area can effectively increase the difference between the fundamental frequencies of each order. This method can also effectively improve the product's ability to resist fluid impact.

[0045] Step f. After each adjustment of the characteristic parameters, re-use the finite element analysis software to perform modal analysis on the modified mechanical model of the tube body 1, calculate the new first-order fundamental frequency and second-order fundamental frequency, and again determine whether the difference between the two is greater than 30 Hz; repeat steps e and f until the difference between the first-order fundamental frequency and the second-order fundamental frequency is greater than 30 Hz.

[0046] Step g. Perform phase difference simulation calculation based on the determined structural parameters.

[0047] Step h. manufacturing a measuring tube of the mass flowmeter according to the finally determined structural parameters of the tube body 1 that meet the frequency requirements.

[0048] in, Figure 1 The two figures above show the finite element analysis diagrams when no reinforcement sheet 2 is provided on the pipe body 1. The left figure shows that the first-order fundamental frequency is 1337.5 Hz, and the right figure shows that the second-order fundamental frequency is 1337.8 Hz. It can be seen that the difference between the two is 0.3 Hz. Figure 1 The two figures below show the finite element analysis diagrams after the reinforcement sheet 2 is set on the tube body 1. The left figure shows that the first-order fundamental frequency is 1341.5Hz, and the right figure shows that the second-order fundamental frequency is 1687Hz. It can be seen that the difference between the two is 345.5Hz. Therefore, the reinforcement sheet 2 can increase the difference between the first-order fundamental frequency and the second-order fundamental frequency of the measuring tube, thereby avoiding vibration superposition and helping to improve the measurement accuracy. Example

[0049] Reference Figure 3 and Figure 4 , the difference between this embodiment and embodiment 1 is that the reinforcement member in this embodiment includes an arc plate 4 and a connecting plate 5. Two arc plates 4 are provided and symmetrically arranged on two sides of the tube body 1, and two connecting plates 5 are provided and symmetrically arranged on the other two sides of the tube body 1. The two connecting plates 5 are both located between the two arc plates 4; the connecting plate 5 and the arc plate 4 are an integrated structure. The side where the two arc plates 4 are close to each other and the side where the two connecting plates 5 are close to each other are both set to be arc surfaces that can abut against the outer wall of the tube body 1, and the arc plates 4 and the connecting plates 5 are both welded to the outer wall of the tube body 1. Example

[0050] Reference Figure 5 The difference between this embodiment and embodiment 1 is that the reinforcement member in this embodiment includes two arc-shaped pieces 6, which are symmetrically arranged on both sides of the tube body 1, and the arc-shaped pieces 6 are welded to the outer wall of the tube body 1; the inner diameter of the arc-shaped piece 6 is the same as the outer diameter of the tube body 1, so the inner wall of the arc-shaped piece 6 fits the outer wall of the tube body 1. Example

[0051] Reference Figure 6The difference between this embodiment and embodiment 1 is that the reinforcement member in this embodiment includes two reinforcement rods 7, the two reinforcement rods 7 are located in the same plane, and the two reinforcement rods 7 are symmetrically arranged on both sides of the tube body 1. The reinforcement rod 7 includes a first connecting rod 71 and a second connecting rod 72, the first connecting rod 71 is arranged along the radial direction of the tube body 1, the end of the first connecting rod 71 is welded to the outer wall of the tube body 1, and the second connecting rod 72 is arranged along the axial direction of the tube body 1. Two first connecting rods 71 ​​are provided and arranged at intervals, and the second connecting rod 72 is welded between the two first connecting rods 71. The second connecting rod 72 is arranged at intervals from the outer wall of the tube body 1. Example

[0052] Reference Figure 7 The difference between this embodiment and embodiment 1 is that the reinforcement member in this embodiment includes a connecting ring 8 and a connecting piece 9. The connecting ring 8 is a circular ring, the inner diameter of the connecting ring 8 is the same as the outer diameter of the tube body 1, and the connecting ring 8 is welded and fixed on the outer wall of the tube body 1. The connecting piece 9 is arranged in a rectangular parallelepiped shape, and the connecting piece 9 is welded and fixed on the outer wall of the connecting ring 8; there are two connecting pieces 9, and the two connecting pieces 9 are located in the same plane and symmetrically arranged on both sides of the connecting ring 8.

[0053] The above are optional embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A mass flow meter measuring tube, characterized in that: It comprises a tube body (1) and a reinforcement member fixedly arranged on the outer wall of the tube body (1), wherein the reinforcement member is arranged in two groups and is respectively located at two ends of the tube body (1), and the length dimension of the overall structure in the cross section of the tube body (1) and the reinforcement member is greater than the width dimension, so that the difference between the first-order fundamental frequency and the second-order fundamental frequency of the tube body (1) is greater than 30 Hz.

2. A mass flow meter measuring tube according to claim 1, characterized in that: The reinforcement member comprises two reinforcement sheets (2), the reinforcement sheets (2) being arranged in a rectangular parallelepiped shape, the reinforcement sheets (2) being arranged along the length direction of the tube body (1), and the two reinforcement sheets (2) being located in the same plane and symmetrically arranged on both sides of the tube body (1).

3. A mass flow meter measuring tube according to claim 2, characterized in that: A distance ring (3) is fixedly provided on the outer wall of the tube body (1) at one side of the reinforcing sheet (2), and the distance ring (3) abuts against the end of the reinforcing sheet (2).

4. A mass flow meter measuring tube according to claim 1, characterized in that: The reinforcing member comprises an arc-shaped plate (4) and a connecting plate (5); two arc-shaped plates (4) are provided and are symmetrically distributed on both sides of the tube body (1); two connecting plates (5) are provided and are symmetrically distributed on both sides of the tube body (1); the inner sides of the arc-shaped plates (4) and the connecting plates (5) are both in contact with the outer wall of the tube body (1); the connecting plate (5) is provided between the two arc-shaped plates (4); and the connecting plate (5) and the arc-shaped plates (4) are provided in an integrated manner.

5. A mass flow meter measuring tube according to claim 1, characterized in that: The reinforcing member comprises two arc-shaped pieces (6), the two arc-shaped pieces (6) being symmetrically arranged on two sides of the tube body (1), and the sides of the two arc-shaped pieces (6) close to each other being in contact with the outer wall of the tube body (1).

6. A mass flow meter measuring tube according to claim 1, characterized in that: The reinforcement member comprises two reinforcement rods (7), the two reinforcement rods (7) are symmetrically arranged on both sides of the tube body (1), the reinforcement rod (7) comprises a first connecting rod (71) and a second connecting rod (72), the first connecting rod (71) is arranged along the radial direction of the tube body (1), the second connecting rod (72) is arranged along the axial direction of the tube body (1), two first connecting rods (71) are provided, and the second connecting rod (72) is fixedly connected between the two first connecting rods (71).

7. A mass flow meter measuring tube according to claim 1, characterized in that: The reinforcement member comprises a connecting ring (8) and a connecting plate (9); the connecting ring (8) is sleeved on the outer wall of the tube body (1); the connecting plate (9) is fixedly connected to the outer wall of the connecting ring (8); two connecting plates (9) are provided and are symmetrically arranged on both sides of the connecting ring (8).

8. A mass flow meter measuring tube according to claim 1, characterized in that: The reinforcement is made of stainless steel.

9. A mass flow meter measuring tube according to claim 1, characterized in that: The shape of the tube body (1) is one of a straight tube type, a U-shape, and a gate shape.

10. A method for increasing the fundamental frequency difference of a measuring tube, based on the mass flow meter measuring tube according to any one of claims 1 to 9, characterized in that: The method for increasing the fundamental frequency difference of the measuring tube comprises the following steps: a. clarifying the structural parameters of the tube body (1), wherein the structural parameters include the length, diameter, wall thickness, material of the tube body (1) and the connection method with other components; b. Based on the structural parameters of the pipe body (1), a mechanical model of the pipe body (1) is established using finite element analysis software; c. Performing modal analysis on the established mechanical model to calculate the first-order fundamental frequency and the second-order fundamental frequency of the tube body (1); d. Based on the calculated first-order fundamental frequency and second-order fundamental frequency, determine whether the difference between the two is greater than 30 Hz. If the difference is greater than 30 Hz, it indicates that the current tube body (1) structure has met the frequency requirement and no further optimization is required. If the difference is less than or equal to 30 Hz, proceed to the next step. e. A reinforcement member is provided at the boundary of the tube body (1). The characteristic parameters of the reinforcement member include length, width, height and installation position relative to the tube body (1). The characteristic parameter adjustment strategies of the reinforcement member include but are not limited to the following: Change the length and width of the reinforcement; Changing the height dimension of the reinforcement; Changing the installation position of the reinforcement member relative to the tube body (1); f. After each adjustment of the characteristic parameters, re-use the finite element analysis software to perform modal analysis on the modified mechanical model of the tube body (1), calculate new first-order fundamental frequency and second-order fundamental frequency, and again determine whether the difference between the two is greater than 30 Hz; repeat step e and step f until the difference between the first-order fundamental frequency and the second-order fundamental frequency is greater than 30 Hz; g. Perform phase difference simulation calculation based on the determined structural parameters; h. According to the finally determined structural parameters of the tube body (1) that meet the frequency requirements, a measuring tube of the mass flow meter is manufactured.

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