Flowmeter and flow measurement tube

Abstract

A flow measurement tube (100), comprising an inlet tube (1), a middle tube (2), and an outlet tube (3) which are communicated in sequence, wherein a height difference exists between the axis of the middle tube (2) and the axis of the inlet tube (1). The inlet tube (1) and the outlet tube (3) of the flow measurement tube (100) are straight tubes, and a height difference exists between the middle tube (2) and each straight tube, that is, the flow measurement tube (100) is bent; when the flow measurement tube (100) is applied to flow measurement, the frequencies of a working mode and an orthogonal mode are different, thereby avoiding affecting the flow measurement; meanwhile, since the flow measurement tube (100) is bent, the rigidity of the flow measurement tube (100) is reduced, thereby facilitating improving the signal sensitivity caused by the flow; in addition, compared with a single straight tube, the constraints at both ends of the flow measurement tube (100) are reduced, and the anti-stress interference capability is improved. Also provided is a flowmeter (200) comprising the flow measurement tube (100), wherein there is at least one flow measurement tube (100). By adopting the flow measurement tube (100), the measurement performance of the flowmeter (200) can be effectively improved.

Description

Flow meter and flow measuring tube Technical Field

[0001] The present invention relates to the technical field of flow measurement equipment and peripheral supporting facilities thereof, in particular to a flow meter and a flow measurement tube. Background Art

[0002] A Coriolis flowmeter is a mass flow measurement device based on the Coriolis principle that can also measure the density of a medium. Depending on the flow tube type, Coriolis flowmeters are classified into several types, including U-type, Ω-type, V-type, and straight-tube types. Straight-tube Coriolis flowmeter sensors are widely used due to their unique advantages, such as compact structure, minimal pressure loss, and self-draining. However, due to their tube shape, straight-tube Coriolis flowmeters also have significant disadvantages, such as orthogonal modal interference, low flow measurement sensitivity, and susceptibility to stress. These shortcomings have limited their further development.

[0003] Traditional straight-tube Coriolis mass flowmeters are inevitably affected by orthogonal modes, as shown in Figure 1. Because the orthogonal modal frequencies and operating modal frequencies of straight-tube flowmeters are almost identical, this has a significant impact on the flowmeter's performance. During the design process of straight-tube mass flowmeters, designers often employ additional mechanisms to shift the orthogonal modes away from the operating frequency. For example, by modifying the node plate structure or adding spring devices, this results in a complex structure for the straight-tube flowmeter, impacting its applicability. Furthermore, because straight tubes are stiffer than curved tubes, the flow-induced signal in straight-tube Coriolis mass flowmeters is typically smaller, reducing the flowmeter's measurement sensitivity. Furthermore, when the ambient temperature or the medium temperature changes suddenly, the thermal expansion and contraction of the straight tube are constrained at both ends, generating stress within the tube, which in turn changes its stiffness and affects measurement accuracy.

[0004] Therefore, how to change the current situation of poor measurement performance of flow meters in the prior art has become an urgent problem to be solved by those skilled in the art.

[0005] Summary of the Invention

[0006] The object of the present invention is to provide a flow meter and a flow measuring tube to solve the problems existing in the above-mentioned prior art and improve the measurement performance of the flow meter.

[0007] To achieve the above object, the present invention provides the following solution: The present invention provides a flow measuring tube, comprising:

[0008] an inlet pipe, wherein the inlet pipe is a straight pipe;

[0009] an intermediate pipe, wherein a height difference H exists between an axis of the intermediate pipe and an axis of the inlet pipe;

[0010] An outlet pipe, wherein the outlet pipe is a straight pipe, and the inlet pipe is coaxially arranged with the outlet pipe;

[0011] The diameter of the flow measuring tube is D.

[0012] Preferably, the intermediate tube comprises a main body section, and the axis of the main body section is an arc or a straight line.

[0013] Preferably, when the axis of the main body segment is an arc, there are multiple main body segments, and the centers of the axes of adjacent main body segments are located on different sides of the axis of the inlet pipe.

[0014] Preferably, when the axis of the main body segment is an arc, the radius of the axis of the main body segment is R, wherein R>10D;

[0015] An angle a is formed between a tangent line passing through an intersection point of the axis of the main body section and the axis of the inlet pipe and the axis of the inlet pipe, wherein a≤15°.

[0016] Preferably, the intermediate pipe further includes a transition pipe section, the axis of the transition pipe section is a curve, the number of the transition pipe sections is two, and the inlet pipe and the outlet pipe are respectively connected to the main section via the transition pipe sections.

[0017] Preferably, the transition pipe section includes a plurality of transition arc sections, and the centers of the axes of adjacent transition arc sections are located on different sides of the axis of the inlet pipe.

[0018] Preferably, the intermediate pipe further includes an inclined pipe section, which is a straight pipe. An angle is formed between the axis of the inclined pipe section and the axis of the inlet pipe. There are two inclined pipe sections, which are located between the transition pipe section and the main body section.

[0019] Preferably,

[0020] The present invention also provides a flow meter comprising the above-mentioned flow measuring tube, wherein the number of the flow measuring tube is at least one.

[0021] Preferably, the flow meter further comprises a sleeve, a sensor and a driver, the flow measuring tube, the sensor and the driver are all arranged in the sleeve, the sensor and the driver are both arranged on the flow measuring tube, and the inner diameter of the sleeve is 2R1, then:

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] The flow measuring tube of the present invention includes a straight tube and an intermediate tube. The inlet tube and the outlet tube are straight tubes. There is a height difference between the intermediate tube and the straight tube, that is, the flow measuring tube is bent. When the flow measuring tube of the present invention is used for flow measurement, the working mode and the orthogonal mode frequency are different, avoiding affecting the flow measurement; at the same time, due to the bending of the flow measuring tube, the stiffness of the flow measuring tube is reduced, which is conducive to improving the signal sensitivity caused by the flow; in addition, compared with the single straight tube in the prior art, the present invention reduces the constraints at both ends of the flow measuring tube and improves the ability to resist stress interference. The present invention also provides a flow meter including the above-mentioned flow measuring tube, the number of flow measuring tubes is at least one, and the use of the flow measuring tube of the present invention can effectively improve the measurement performance of the flow meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] FIG1 is a schematic diagram of the operation of a straight tube Coriolis flowmeter in the prior art;

[0026] FIG2 is a schematic structural diagram of a flow measuring tube according to the present invention;

[0027] FIG3 is a schematic structural diagram of a flow measuring tube according to the present invention when the axis of the main body section is an arc;

[0028] FIG4 is a schematic structural diagram of a flow measuring tube according to the present invention when the main body section is multi-segmented;

[0029] FIG5 is a structural schematic diagram 1 of the flow measuring tube of the present invention when the axis of the main body section is a straight line;

[0030] FIG6 is a second structural diagram of the flow measuring tube of the present invention when the axis of the main body section is a straight line;

[0031] FIG7 is a schematic structural diagram of a flow measuring tube according to the present invention when the intermediate tube includes an inclined tube section;

[0032] FIG8 is a graph showing the relationship between the frequency difference between the orthogonal mode and the operating mode of the flow measuring tube and H / D;

[0033] FIG9 is a schematic structural diagram of a flow meter according to the present invention;

[0034] FIG10 is a schematic cross-sectional view of the flow meter of the present invention;

[0035] FIG11 is a partial structural diagram of a flow meter according to the present invention;

[0036] FIG12 is a schematic diagram of the cross-sectional structure along the AA direction in FIG11 .

[0037] Among them, 100 is the flow measuring tube and 200 is the flow meter;

[0038] 1 is the inlet pipe, 2 is the middle pipe, 201 is the main section, 202 is the transition arc section, 203 is the inclined pipe section, 3 is the outlet pipe, 4 is the sleeve, 5 is the sensor, 6 is the driver, 7 is the transmitter, 8 is the connecting flange, 9 is the diverter, and 10 is the node plate;

[0039] H is the height difference between the axis of the intermediate tube and the axis of the inlet tube, D is the diameter of the flow measuring tube, R is the axis radius of the main section, and a is the angle between the tangent line passing through the intersection of the axis of the main section and the axis of the inlet tube and the axis of the inlet tube. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] The object of the present invention is to provide a flow meter and a flow measuring tube to solve the problems existing in the above-mentioned prior art and improve the measurement performance of the flow meter.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] The present invention provides a flow measuring tube 100, comprising an inlet tube 1, an intermediate tube 2, and an outlet tube 3 connected in sequence, wherein the inlet tube 1 is a straight tube; there is a height difference H between the axis of the intermediate tube 2 and the axis of the inlet tube 1; the outlet tube 3 is a straight tube, and the inlet tube 1 and the outlet tube 3 are coaxially arranged; the diameter of the flow measuring tube 100 is D.

[0044] The flow measuring tube 100 of the present invention includes a straight tube and an intermediate tube 2. The inlet tube 1 and the outlet tube 3 are straight tubes. There is a height difference between the intermediate tube 2 and the straight tube, that is, the flow measuring tube 100 is bent. When the flow measuring tube 100 of the present invention is used for flow measurement, the working mode and the orthogonal mode frequency are different, avoiding affecting the flow measurement; at the same time, due to the bending of the flow measuring tube 100, the stiffness of the flow measuring tube 100 is reduced, which is conducive to improving the signal sensitivity caused by the flow; in addition, compared with the single straight tube in the prior art, the present invention reduces the constraints at both ends of the flow measuring tube 100, improves the ability to resist stress interference, and effectively improves the measurement performance of the flow meter 200.

[0045] The intermediate tube 2 includes a main body section 201 , and the axis of the main body section 201 is an arc or a straight line.

[0046] When the axis of the main body segment 201 is an arc, the main body segment 201 can be provided in multiple segments, with the centers of the axes of adjacent main body segments 201 located on different sides of the axis of the inlet pipe 1. In other specific embodiments of the present invention, the main body segment 201 can be provided in two segments, as shown in FIG4 . The centers of the two main body segments 201 are located on either side of the axis of the inlet pipe 1, respectively. This improves the measurement performance of the flow meter 100 while reducing the space occupied by the flow meter 100, thereby increasing the adaptability of the flow meter 100.

[0047] In other specific embodiments of the present invention, when the axis of the main body section 201 is an arc, the axis radius of the main body section 201 is R, where R>10D. A main body section 201 with a larger radius is used to introduce a smaller bend into the flow measuring tube 100, so that the frequencies of the working mode and the orthogonal mode of the flow measuring tube 100 during operation are distinguished, further saving the space occupied by the flow measuring tube 100.

[0048] Specifically, the angle between the tangent line passing through the intersection of the axis of the main section 201 and the axis of the inlet pipe 1 and the axis of the inlet pipe 1 is a, as shown in Figures 3, 4 and 7, where a≤15°. Preferably, the value range of a is 3° to 12°. In practical applications, the bending range of the flow measuring tube 100 can be selected according to specific working conditions to adapt to various measurement requirements while reducing the difficulty of manufacturing the flow measuring tube 100.

[0049] In order to ensure smooth communication between the intermediate tube 2 of the flow measuring tube 100 and the inlet tube 1 and the outlet tube 3, and to avoid affecting the normal flow of the fluid in the flow measuring tube 100, the intermediate tube 2 also includes a transition tube section, the axis of which is a curve. As shown in FIG3 , there are two groups of transition tube sections, and the inlet tube 1 and the outlet tube 3 are respectively connected to the main section 201 via the transition tube sections.

[0050] In practical applications, the transition pipe section may include multiple transition arc sections 202, with the centers of the axes of adjacent transition arc sections 202 located on different sides of the axis of the inlet pipe 1, thereby introducing a bend into the flow measuring tube 100, reducing the difficulty of manufacturing the flow measuring tube 100, and improving the flexibility and adaptability of the flow measuring tube 100. It should also be noted that when the axis of the main section 201 is a straight line, the axis radius of the transition arc section 202 is R, as shown in FIG5 , to ensure that the height difference between the intermediate pipe 2 and the inlet pipe 1 and the outlet pipe 3 meets the measurement requirements. It should be explained here that when the transition pipe section includes the transition arc section 202, as shown in FIG5 and FIG6 , the angle between the tangent of the intersection of the axis of the transition arc section 202 and the axis of the inlet pipe 1 and the axis of the inlet pipe 1 is a, and similarly, a≤15°, and the preferred value range of a is 3° to 12°.

[0051] In other specific embodiments of the present invention, the intermediate tube 2 further includes an inclined tube section 203, which is a straight tube. An angle is formed between the axis of the inclined tube section 203 and the axis of the inlet tube 1. There are two inclined tube sections 203, which are located between the transition tube section and the main body section 201. The flow measuring tube 100 of the present invention has a flexible and changeable structure.

[0052] It should also be emphasized that when H / D is greater than 0, the frequency of the orthogonal modes of flow tube 100 will become increasingly greater than the driving frequency, which means that modal separation is increasingly improved. See Figure 8 for details, which plots the relationship between the frequency difference between the orthogonal and operating modes of flow tube 100 and H / D. When H / D equals 1, the orthogonal modal frequency separation is already greater than 200 Hz. In practical applications, an appropriate design point can be selected within the range of H / D < 1. When H / D < 1, finite element simulation results show that a virtual straight line can pass through the flow tube. This shape of flow tube 100 is similar to existing single straight tubes, offering excellent cleanability and drainability, as well as very low pressure loss.

[0053] Furthermore, the present invention also provides a flow meter 200, comprising the aforementioned flow measuring tube 100, wherein the number of the flow measuring tube 100 is at least one. In this specific embodiment, the flow meter 200 is explained by taking the flow meter 200 comprising two flow measuring tubes 100 as an example.

[0054] Furthermore, as shown in FIG10 , the flowmeter 200 further includes a sleeve 4, a sensor 5, and a driver 6. The flow measuring tube 100, the sensor 5, and the driver 6 are all disposed within the sleeve 4. The sensor 5 and the driver 6 are both disposed on the flow measuring tube 100. The sensor 5 and the driver 6 are both electromagnetic mechanisms, each including an inductor coil and a permanent magnet. The electromagnetic mechanisms of the sensor 5 and the driver 6 are conventional means used by those skilled in the art and will not be described in detail herein. It should be emphasized that, with reference to FIG12 , the inner diameter of the sleeve 4 is 2R1, the diameter of the flow measuring tube 100 is D, and h is the distance between the axis of the flow measuring tube 100 and the axis N of the inductor coil of the driver 6. h must meet the following conditions:

[0055] In addition, a transmitter 7 is provided, which maintains a certain distance from the sensor 5. In addition, the sleeve 4 is also connected to a connecting flange 8, which facilitates the connection between the flow meter 200 and the flow measuring tube 100. The node plate 10 can be set according to actual measurement requirements, and the diverter 9 can be set according to specific working conditions to improve the adaptability of the flow meter 200.

[0056] In addition, the height difference H between the axis of the intermediate pipe 2 and the axis of the inlet pipe 1 must meet the following conditions:

[0057] This ensures smooth assembly and disassembly of the flow measuring tube 100 and other components, thereby improving the working reliability of the flow meter 200.

[0058] Compared to the straight tubes used in the prior art, the flowmeter tube 100 of the present invention utilizes the height difference between the intermediate tube 2 and the inlet and outlet tubes 1 and 3 to introduce a small bend into the flowmeter tube 100. This allows the operating mode and the orthogonal mode to be separated without the need for additional structures. This also reduces the stiffness of the measurement area, thereby improving the signal sensitivity of the flow measurement. Under the same flow rate and dimensions, the flowmeter 200 including the flowmeter tube 100 of the present invention can increase the time difference by 20% to 30% compared to the existing Coriolis flowmeter. Furthermore, the present invention reduces the constraints on both ends of the flowmeter tube 100, improving its ability to resist stress interference. However, compared to the curved tube design, the stress effect is slightly greater. Therefore, the present invention also requires stress compensation similar to the straight tube design. This can be achieved by installing a strain sensor on the flowmeter tube 100 or a temperature sensor on the sleeve 4. The flow meter 200 of the present invention has the flow measuring tube 100 built into the sleeve 4, which eliminates the need for a protective housing compared to the V-bend mass flow meter in the prior art. This significantly reduces costs and simplifies assembly processes.

[0059] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A flow measurement tube, characterized in that, Comprising, connected in sequence: An inlet pipe, the inlet pipe being a straight pipe; An intermediate pipe, there being a height difference H between the axis of the intermediate pipe and the axis of the inlet pipe; An outlet pipe, the outlet pipe being a straight pipe, and the inlet pipe and the outlet pipe being coaxially arranged; The diameter of the flow measurement pipe is D.

2. The flow measurement tube according to claim 1, wherein: The intermediate pipe includes a main body section, the axis of the main body section being an arc or a straight line.

3. The flow measurement tube according to claim 2, wherein: When the axis of the main body section is an arc, the number of the main body sections is multiple, and the centers of the axes of adjacent main body sections are located on different sides of the axis of the inlet pipe.

4. The flow measurement tube according to claim 2, characterized in that: When the axis of the main body section is an arc, the axis radius of the main body section is R, wherein, R > 10D; The angle between the tangent line passing through the intersection point of the axis of the main body section and the axis of the inlet pipe and the axis of the inlet pipe is a, wherein, a ≤ 15°.

5. The flow measurement tube according to claim 2, wherein: The intermediate pipe further includes transition pipe sections, the axes of the transition pipe sections being curves, the number of the transition pipe sections being two groups, and the inlet pipe and the outlet pipe being respectively connected to the main body section through the transition pipe sections.

6. The flow measurement tube according to claim 5, wherein: Each of the transition pipe sections includes multiple transition arc sections, and the centers of the axes of adjacent transition arc sections are located on different sides of the axis of the inlet pipe.

7. The flow measurement tube according to claim 5, wherein: The intermediate pipe further includes inclined pipe sections, the inclined pipe sections being straight pipes, there being an included angle between the axes of the inclined pipe sections and the axis of the inlet pipe, the number of the inclined pipe sections being two, and the inclined pipe sections being located between the transition pipe sections and the main body section.

8. The flow measurement tube according to any one of claims 1-7, characterized in that:

9. A flowmeter, characterized in that, Comprising the flow measurement pipe according to any one of claims 1-8, the number of the flow measurement pipes being at least one.

10. The flowmeter according to claim 9, characterized in that: It further includes a sleeve, a sensor, and a driver. The flow measurement tube, the sensor, and the driver are all disposed within the sleeve. The sensor and the driver are both disposed on the flow measurement tube. The inner diameter of the sleeve is 2R1, then:

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