Vortex shedding flowmeter with oblate meter body

Abstract

The vortex shedding flowmeter comprises a pipe body, flow guide bosses are fixedly connected to the two sides of an inner cavity of the pipe body, an inlet curved surface is arranged at the left end of each flow guide boss, and an outlet curved surface is arranged at the right end of each flow guide boss; and a vortex generating body is fixedly mounted between the left ends of the sides, close to each other, of the two flow guide bosses. Through the cooperation between the pipe body and the two groups of diversion bosses in the pipe body, an oblate channel for fluid diversion can be formed, compared with a circular pipeline with the same pipe diameter, the flowing speed of internal fluid passing through is effectively increased, and under the action of the front-end inlet curved surfaces and the tail-end outlet curved surfaces of the diversion bosses, the flowing speed of the internal fluid is effectively increased. Constraint borne by fluid passing through the pipe body and the flow guide boss is effectively reduced, it is ensured that the low-flow-speed fluid can generate vortex signals detected by the converter and the detection element when passing through the vortex generation body, and the precision of flow lower limit detection operation is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of vortex flowmeters, in particular to a vortex flowmeter with an oblate body. Background Art

[0002] The vortex flowmeter is a flow measuring instrument based on the Karman vortex principle. It is mainly used to measure the volume flow of gas, steam or liquid. It has the characteristics of no moving parts, high stability and wide application range, especially in the measurement of high-temperature and high-pressure steam.

[0003] However, in the actual use of traditional vortex flowmeters, when the flow velocity of the fluid flowing through the inside is relatively low, although there is a vortex behind the vortex generator, the signal is extremely weak, making it difficult for the piezoelectric sensor at the end of the vortex generator to detect it. Therefore, the method of reducing the pipe diameter is often used to increase the flow velocity, so as to increase the signal strength. Although the flow lower limit can be expanded by reducing the pipe diameter, when the pipe diameter is smaller, the restraining effect of the circular pipe wall on the fluid becomes stronger, making it difficult for the circular pipe vortex flowmeter to form a stable vortex signal, hindering the further expansion of the flow lower limit. Summary of the Invention

[0004] The purpose of the present invention is to provide a vortex flowmeter with an oblate body, which has an oblate design that can pass through a pipeline and optimizes the constraints on the fluid, greatly improving the lower limit sensitivity of the vortex flowmeter and meeting the needs of small flow measurement in engineering.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a vortex flowmeter with an oblate body, comprising:

[0006] A tube body, wherein both sides of the inner cavity of the tube body are fixedly connected to a flow guide boss, the left end of the flow guide boss is provided with an inlet curved surface, the right end of the flow guide boss is provided with an outlet curved surface, and a vortex generator is fixedly installed between the left ends of the two flow guide bosses on the side close to each other;

[0007] A detection element, the surface of which is movably inserted into the middle end of the tube body and the upper guide boss, and the lower part extends into the interior of the tube body and is located downstream of the vortex generator. A converter is fixedly installed on the top of the detection element.

[0008] As a preferred solution, a mounting seat is fixedly connected to the middle end of the top outer surface of the tube body, the lower end of the detection element is movably inserted into the middle end of the mounting seat, and a hollow metal column is fixedly installed between the top of the mounting seat and the bottom of the converter, and the inner cavity of the hollow metal column is sleeved on the upper end of the detection element.

[0009] As a preferred solution, a rubber sealing pad is fixedly mounted on the bottom of the hollow metal column, and the bottom of the rubber sealing pad contacts the top of the mounting seat.

[0010] As a preferred solution, a rubber sealing ring is fixedly mounted on the middle end of the mounting seat, and the surface of the rubber sealing ring contacts the lower end of the detection element.

[0011] As a preferred solution, a transmission cable is fixedly installed on the upper end of the right side of the converter, the surface of the transmission cable is sheathed with a corrugated metal sleeve, and a display screen is fixedly installed on the front surface of the converter.

[0012] As a preferred solution, flanges are fixedly connected to both sides of the tube body, and rubber sealing rings are fixedly installed on the sides of the two flanges that are away from each other.

[0013] As a preferred solution, the ratio of the distance between the two flow-guiding bosses to the inner diameter of the tube body is 0.5-0.8.

[0014] As a preferred solution, the vortex generator is in a trapezoidal shape, and the width of the left end of the vortex generator is greater than the width of the right end.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention can form an oblate circular channel for fluid diversion through the cooperation between the tube body and the two sets of internal guide bosses. Compared with circular pipes with the same diameter, the flow velocity of the internal fluid passing through is effectively improved, and under the action of the front inlet curved surface and the end outlet curved surface of the guide boss, the constraints imposed on the fluid passing through the tube body and the guide boss are effectively reduced, ensuring that low-flow-rate fluid can generate a vortex signal detected by the converter and the detection element when passing through the vortex generator, thereby greatly improving the accuracy of the flow lower limit detection operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional diagram of the present invention;

[0018] Figure 2 This is a front cross-sectional structural diagram of the present invention;

[0019] Figure 3 This is a schematic diagram of a partial cross-sectional view of the front structure of a hollow metal column of the present invention;

[0020] Figure 4 This is a schematic diagram of the cross-sectional structure of the tube body of the present invention when viewed from above;

[0021] Figure 5 Streamline profile diagrams of the inlet and outlet curved surfaces of the present invention;

[0022] Figure 6The flow field simulation diagram of the fluid before and after the profile optimization of the present invention is 1m / s;

[0023] Figure 7 The flow field simulation diagram of the fluid at a flow rate of 10 m / s before and after the profile optimization of the present invention;

[0024] Figure 8 The flow field simulation diagram of the fluid at a flow velocity of 50 m / s before and after the profile optimization of the present invention;

[0025] Figure 9 The typical time domain waveform and frequency domain frequency distribution diagram of the vortex signal collected before and after the profile optimization of the present invention.

[0026] In the figure: 1. Tube body; 2. Mounting seat; 3. Flange; 4. Converter; 5. Hollow metal column; 6. Transmission cable; 7. Guide boss; 8. Vortex generator; 9. Inlet curved surface; 10. Outlet curved surface; 11. Detection element; 12. Rubber sealing ring; 13. Rubber sealing gasket. DETAILED DESCRIPTION

[0027] 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.

[0028] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0029] The components of the present application, such as the tube body 1, mounting base 2, flange 3, converter 4, hollow metal column 5, transmission cable 6, guide boss 7, vortex generator 8, inlet curved surface 9, outlet curved surface 10, detection element 11, rubber sealing ring 12 and rubber sealing gasket 13, are all universal standard parts or components known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0030] Example 1:

[0031] See also Figures 1-4 As shown, the present invention provides a vortex flowmeter with an oblate body, comprising:

[0032] The tube body 1 has a guide boss 7 fixedly connected to both sides of the inner cavity of the tube body 1. The left end of the guide boss 7 is provided with an inlet curved surface 9, and the right end of the guide boss 7 is provided with an outlet curved surface 10. A vortex generator 8 is fixedly installed between the left ends of the two guide bosses 7 on the side close to each other;

[0033] The detection element 11 has a surface that is movably inserted between the tube body 1 and the middle end of the upper flow guide boss 7 , and a lower portion that extends into the interior of the tube body 1 and is located downstream of the vortex generator 8 . A converter 4 is fixedly mounted on the top of the detection element 11 .

[0034] In this technical solution, through the cooperation between the tube body 1 and the two sets of internal guide bosses 7, an oblate circular channel for fluid diversion can be formed. Compared with a circular pipe with the same diameter, the flow velocity of the internal fluid passing through is effectively improved, and under the action of the front end inlet curved surface 9 and the end outlet curved surface 10 of the guide boss 7, the constraints imposed on the fluid passing between the tube body 1 and the guide boss 7 are effectively reduced, ensuring that the low-flow-rate fluid can generate a vortex signal detected by the converter 4 and the detection element 11 when passing through the vortex generator 8, thereby greatly improving the accuracy of the flow lower limit detection operation.

[0035] Example 2:

[0036] Based on the first embodiment, the present invention is as follows Figure 1-Figure 3 As shown, it is disclosed that the middle end of the top of the outer surface of the tube body 1 is fixedly connected to the mounting seat 2, the lower end of the detection element 11 is movably inserted into the middle end of the mounting seat 2, and a hollow metal column 5 is fixedly installed between the top of the mounting seat 2 and the bottom of the converter 4. The inner cavity of the hollow metal column 5 is sleeved on the upper end of the detection element 11, and a rubber sealing gasket 13 is fixedly installed at the bottom of the hollow metal column 5. The bottom of the rubber sealing gasket 13 contacts the top of the mounting seat 2, and a rubber sealing ring 12 is fixedly installed at the middle end of the mounting seat 2. The surface of the rubber sealing ring 12 contacts the lower end of the detection element 11.

[0037] In this technical solution, by setting the mounting seat 2 and the hollow metal column 5, the purpose of supporting and fixing the converter 4 and the tube body 1 is achieved, and at the same time, the surrounding of the detection element 11 can be protected. By setting the rubber sealing pad 13 and the rubber sealing ring 12, the sealing performance between the mounting seat 2 and the detection element 11 and the hollow metal column 5 during installation is effectively improved, and the probability of fluid leakage inside the tube body 1 is effectively reduced.

[0038] Example 3:

[0039] Based on the first embodiment, the present invention is as follows Figure 1 、 Figure 2 and Figure 4As shown, a transmission cable 6 is fixedly installed on the upper end of the right side of the converter 4, and a corrugated metal sleeve is provided on the surface of the transmission cable 6. A display screen is fixedly installed on the front surface of the converter 4. Flanges 3 are fixedly connected on both sides of the tube body 1, and a rubber sealing ring is fixedly installed on the side where the two flanges 3 are away from each other. The ratio of the spacing between the guide bosses 7 to the inner diameter of the tube body 1 is 0.5-0.8. The shape of the vortex generator 8 is trapezoidal, and the width of the left end of the vortex generator 8 is greater than that of the right end.

[0040] In this technical solution, by setting up a corrugated metal sleeve, protection can be provided around the transmission cable 6 required for data transmission of the converter 4, reducing the chance of damage to the transmission cable 6 due to collision and pressure. By setting up a flange 3 and a rubber sealing ring, it is convenient for personnel to install and fix the tube body 1 and the fluid pipeline, and the sealing performance of the installation and fixation is effectively improved.

[0041] Experimental plan

[0042] Because the upstream and downstream of the vortex flowmeter are circular pipes, and the length of the vortex flowmeter body needs to be basically the same as the length of the ordinary circular cross-section body, the inlet curved surface 9 and the outlet curved surface 10 of the oblate body are particularly important. The present invention has adopted a method of optimizing the Wei's curve through simulation. Figure 5 The streamlined profiles of the inlet and outlet surfaces are shown.

[0043] The streamlined profiles of the inlet surface 9 and the outlet surface 10 are described by the following expressions:

[0044]

[0045] Among them, the variable x is the distance from the entrance, the variable h is the profile height, and the parameters D, d, and L1 / L2 are the entrance height, outlet height, and variable diameter section length, respectively.

[0046] The profiles of the inlet curved surface 9 and the outlet curved surface 10 are optimized by using the computational fluid dynamics simulation method. Figure 6-Figure 8 It can be seen from the flow field simulation diagrams before and after profile optimization when the fluid flow rates are 1m / s, 10m / s and 50m / s respectively that the swirling vortex caused by the reverse pressure gradient will interfere with the normal vortex generated by the vortex generator 8, causing the detected vortex street frequency to be chaotic. Therefore, the reflux vortex must be weakened as much as possible.

[0047] Experimental results

[0048] like Figure 9This is a typical time domain waveform and frequency domain frequency distribution diagram of the vortex signal collected before and after profile optimization. It can be seen that the waveform is significantly improved and the spectrum is more single. After experimental testing on a gas flow standard device, the lower limit of gas flow measurement at normal temperature and pressure is extended from 3m / s to 0.7m / s, with significant results.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. The vortex flowmeter with an oblate body is characterized by: include: A tube body (1), wherein both sides of the inner cavity of the tube body (1) are fixedly connected with flow guide bosses (7), the left end of the flow guide boss (7) is provided with an inlet curved surface (9), the right end of the flow guide boss (7) is provided with an outlet curved surface (10), and a vortex generator (8) is fixedly installed between the left ends of the two flow guide bosses (7) on the side close to each other; A detection element (11) is provided, wherein the surface of the detection element (11) is movably inserted between the tube body (1) and the middle end of the upper flow guide boss (7), and the lower portion extends into the interior of the tube body (1) and is located downstream of the vortex generator (8). A converter (4) is fixedly mounted on the top of the detection element (11).

2. The vortex flowmeter with an oblate body according to claim 1, characterized in that: The middle end of the top of the outer surface of the tube body (1) is fixedly connected to a mounting seat (2), the lower end of the detection element (11) is movably inserted into the middle end of the mounting seat (2), a hollow metal column (5) is fixedly installed between the top of the mounting seat (2) and the bottom of the converter (4), and the inner cavity of the hollow metal column (5) is sleeved on the upper end of the detection element (11).

3. The vortex flowmeter with an oblate body according to claim 2, characterized in that: A rubber sealing pad (13) is fixedly mounted on the bottom of the hollow metal column (5), and the bottom of the rubber sealing pad (13) contacts the top of the mounting seat (2).

4. The vortex flowmeter with an oblate body according to claim 2, characterized in that: A rubber sealing ring (12) is fixedly mounted on the middle end of the mounting seat (2), and the surface of the rubber sealing ring (12) contacts the lower end of the detection element (11).

5. The vortex flowmeter with an oblate body according to claim 1, characterized in that: A transmission cable (6) is fixedly mounted on the upper end of the right side of the converter (4), a surface of the transmission cable (6) is sheathed with a corrugated metal sleeve, and a display screen is fixedly mounted on the front surface of the converter (4).

6. The vortex flowmeter with an oblate body according to claim 1, characterized in that: Flanges (3) are fixedly connected to both sides of the tube body (1), and a rubber sealing ring is fixedly installed on the side of the two flanges (3) that are away from each other.

7. The vortex flowmeter with an oblate body according to claim 1, characterized in that: The ratio of the distance between the two flow-guiding bosses (7) to the inner diameter of the tube body (1) is 0.5-0.

8.

8. The vortex flowmeter with an oblate body according to claim 1, characterized in that: The vortex generating body (8) is in the shape of a trapezoid, and the width of the left end of the vortex generating body (8) is greater than the width of the right end.

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