Multi-parameter vortex shedding flowmeter

Abstract

The utility model relates to a multi-parameter vortex shedding flowmeter which comprises a measuring tube, a first pressure tapping tube is arranged at the top end of the measuring tube, a second pressure tapping tube is arranged at the bottom end of the measuring tube, the first pressure tapping tube and the second pressure tapping tube are symmetrically distributed on the measuring tube, and pressure sensors are arranged on the first pressure tapping tube and the second pressure tapping tube. A vortex generating body is arranged in the measuring tube, a rectifying tube is arranged at the inlet end of the measuring tube, a first flange is arranged on the rectifying tube, a temperature sensor is arranged on the inner side of the first flange, a mounting sleeve is arranged on the outer side of the temperature sensor, and a plurality of connecting rods are arranged between the mounting sleeve and the first flange. And the plurality of connecting rods are uniformly distributed on the outer side of the temperature sensor in a star shape. Interference of turbulent flow generated by upstream temperature measurement on downstream flow velocity measurement based on the vortex street principle is reduced. The utility model has the advantages of convenient use and wide market prospect.

Description

Technical Field

[0001] The utility model relates to the field of vortex street flow devices, and particularly relates to a multi-parameter vortex street flowmeter. Background Technique

[0002] The vortex street flowmeter is a common gas flowmeter, which has the advantages of simple structure, large measuring range, high reliability, etc., and is widely used in the measurement of gas flow in industrial pipelines. The principle of the vortex street flowmeter is based on the Karman vortex theory. There is a triangular prism-shaped vortex generator in the meter body. When the fluid passes through the vortex generator, two rows of regular Karman vortices are generated behind the vortex generator. Part of the kinetic energy of the fluid is converted into a vibration frequency signal. Due to the existence of the vortex generator, there will be a pressure loss when the fluid flows through the vortex street flowmeter. Its pressure value decreases successively from the upstream of the flowmeter, the meter body, to the downstream, and the fluid pressure loss increases with the increase of the flow rate.

[0003] The detection of the vortex frequency is the key technology of the vortex street flowmeter, and the piezoelectric crystal method is the most commonly used detection method at present. However, the piezoelectric crystal detection method has two serious problems: First, the piezoelectric crystal is sensitive to the vibration of the pipeline; Second, the stability of the piezoelectric crystal during long-term use is poor. "Analysis of Influencing Factors in the Measurement of Wall Differential Pressure Type Vortex Street Flowmeter" in the 12th issue of the 40th volume of the Journal of Zhejiang University (Engineering Edition) in December 2006, author: Sun Zhiqiang. It gives another way to measure the vortex frequency, that is: measure the vortex frequency through the fluctuating pressure difference between two points symmetrically distributed on both sides of the vortex generator, so as to realize the measurement of the flow rate. The specific principle is: where there are vortices generated, there must be pressure changes. Specifically, the alternately generated vortices will inevitably cause regular changes in the pressure of the nearby flow field, and its change frequency corresponds one-to-one with the frequency of the vortices. Therefore, the vortex frequency can be measured through the fluctuating pressure difference between two points symmetrically distributed on both sides of the vortex generator, so as to realize the measurement of the flow rate.

[0004] Among them, temperature is also a necessary parameter for the feedback of mass flow rate in the measurement of flow velocity. Some customers also feedback the temperature of the conveying medium, so as to calculate the mass flow velocity more accurately. According to the requirement of measuring the temperature of the pipeline medium, the temperature of the fluid at the central axis of the pipeline is measured for liquid media, and then corrected to be able to more accurately feedback the temperature of the medium in the pipeline. However, when directly installing a temperature sensor in the measuring tube, the liquid medium will inevitably generate turbulence when passing through the mechanical components where the temperature sensor is installed, and this turbulence will interfere with the downstream measurement of the vortex street, resulting in a decrease in the measurement accuracy of the vortex street flowmeter. Therefore, there is room for improvement in the existing technology to reduce the interference of the turbulence generated by measuring the temperature upstream of the vortex generator on the measurement of the flow velocity using the vortex street principle, and thus improve the applicability of the product. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the utility model provides a multi-parameter vortex flowmeter that can reduce the interference caused by the turbulence generated by the upstream measured temperature to the downstream measurement of the flow rate using the vortex street principle, so as to overcome the defects in the prior art.

[0006] The technical solution adopted by the utility model is as follows: A multi-parameter vortex flowmeter includes a measuring tube. The inlet end of a first pressure-taking tube is arranged at the top end of the measuring tube, and the inlet end of a second pressure-taking tube is arranged at the bottom end of the measuring tube. The first pressure-taking tube and the second pressure-taking tube are symmetrically distributed on the measuring tube. Pressure sensors are arranged at the inlet end of the first pressure-taking tube and the outlet end of the second pressure-taking tube. A vortex generator is arranged in the measuring tube between the inlet end of the first pressure-taking tube and the inlet end of the measuring tube. A rectifying tube is arranged at the inlet end of the measuring tube. A first flange is arranged at the end of the rectifying tube away from the measuring tube. A temperature sensor is arranged inside the first flange. The central axes of the temperature sensor, the rectifying tube, and the measuring tube are on the same axis. An installation sleeve is arranged outside the temperature sensor. Connecting rods are arranged between the installation sleeve and the first flange. The number of connecting rods is several, and several connecting rods are evenly distributed in a star shape outside the temperature sensor.

[0007] Preferably, a third pressure-taking tube is arranged on the measuring tube between the vortex generator and the rectifying tube. A fourth pressure-taking tube is arranged inside the rectifying tube above the vortex generator, and a fifth pressure-taking tube is arranged inside the rectifying tube below the vortex generator. The fourth pressure-taking tube and the fifth pressure-taking tube are symmetrically distributed on the measuring tube. The number of the third pressure-taking tube, the fourth pressure-taking tube, and the fifth pressure-taking tube is several. First equalizing rings are arranged at the outlet ends of several fourth pressure-taking tubes and several fifth pressure-taking tubes. A second equalizing ring is arranged at the outlet ends of several third pressure-taking tubes. A differential pressure transmitter is arranged on the second equalizing ring and the first equalizing ring.

[0008] Preferably, the distance from the end of the vortex generator close to the rectifying tube to the central axis of the fourth pressure-taking tube and the distance from the end of the vortex generator close to the rectifying tube to the central axis of the fifth pressure-taking tube are both 0.15 times the diameter of the measuring tube to 0.2 times the diameter of the measuring tube.

[0009] Preferably, exhaust pipes are respectively arranged at the top ends of the first equalizing ring and the second equalizing ring. Exhaust valves are arranged on the exhaust pipes. Drain pipes are respectively arranged at the bottom ends of the first equalizing ring and the second equalizing ring. Drain valves are arranged on the drain pipes.

[0010] Preferably, sixth pressure-taking tubes are respectively arranged between the second equalizing ring and the differential pressure transmitter and between the first equalizing ring and the differential pressure transmitter; ball valves are respectively arranged on the third pressure-taking tube, the fourth pressure-taking tube, the fifth pressure-taking tube, and the sixth pressure-taking tube.

[0011] Preferably, a second flange is provided at one end of the rectifier tube close to the measuring tube, a third flange is provided at one end of the measuring tube close to the rectifier tube, a sealing protrusion is provided at one end of the third flange facing the second flange, and a sealing groove is formed at one end of the second flange facing the third flange along the direction from close to the third flange to away from the third flange. The shape of the sealing groove matches the shape of part of the sealing protrusion, and a sealing gasket is provided on the second flange inside the sealing groove and the sealing protrusion.

[0012] Preferably, fastening bolts are provided on the second flange outside the sealing protrusion and the third flange outside the sealing groove. The number of the fastening bolts is several, and several fastening bolts are evenly distributed in a star shape outside the central axis of the measuring tube. The central axis of the measuring tube, the central axis of the second flange, and the central axis of the third flange are located on the same axis.

[0013] The beneficial effects of the present utility model are as follows: First, the turbulent flow generated by the liquid medium through the temperature sensor, the mounting sleeve, and the connecting rod of the present utility model is rectified by the rectifier tube, thereby reducing the turbulent flow carried by the liquid medium entering the measuring tube, and further reducing the interference of the turbulent flow generated by the upstream measurement temperature on the Karman vortex street generated by the downstream passing through the vortex generator, improving the stability of the feedback parameters of the product.

[0014] Secondly, exhaust pipes are respectively provided at the tops of the first pressure equalizing ring and the second pressure equalizing ring of the present utility model, and exhaust valves are provided on the exhaust pipes. Drain pipes are respectively provided at the bottoms of the first pressure equalizing ring and the second pressure equalizing ring, and drain valves are provided on the drain pipes; installing the exhaust pipes facilitates exhausting the air temporarily stored at the top of the first pressure equalizing ring or the second pressure equalizing ring, and installing the drain pipes facilitates removing the mechanical impurities temporarily stored at the bottom of the first pressure equalizing ring or the second pressure equalizing ring.

[0015] The present utility model has the advantages of simple structure, convenient operation, ingenious design, greatly improving the working efficiency, having good social and economic benefits, and being a product easy to promote and use. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of the present utility model.

[0017] Figure 2 It is a schematic structural diagram of the present utility model.

[0018] Figure 3 It is a schematic structural diagram of the present utility model. Detailed Embodiment

[0019] Such as Figures 1 to 3As shown in the figure, a multi-parameter vortex flowmeter includes a measuring tube 1. The inlet end of a first pressure tapping tube 2 is provided at the top of the measuring tube 1, and the inlet end of a second pressure tapping tube 3 is provided at the bottom of the measuring tube 1. The first pressure tapping tube 2 and the second pressure tapping tube 3 are symmetrically distributed on the measuring tube 1. Pressure sensors 4 are provided at the inlet end of the first pressure tapping tube 2 and the outlet end of the second pressure tapping tube 3. A vortex generator 5 is provided in the measuring tube 1 between the inlet end of the first pressure tapping tube 2 and the inlet end of the measuring tube 1. A rectifying tube 6 is provided at the inlet end of the measuring tube 1. A first flange 7 is provided at one end of the rectifying tube 6 away from the measuring tube 1. A temperature sensor 8 is provided inside the first flange 7. The central axes of the temperature sensor 8, the rectifying tube 6, and the measuring tube 1 are on the same axis. An installation sleeve 9 is provided outside the temperature sensor 8. Connecting rods 10 are provided between the installation sleeve 9 and the first flange 7. The number of the connecting rods 10 is several, and the several connecting rods 10 are evenly distributed in a star shape outside the temperature sensor 8.

[0020] Due to the presence of the vortex generator, there will be pressure loss when the fluid flows through the vortex street flowmeter. Its pressure value decreases successively from the upstream of the flowmeter, the meter body to the downstream, and the fluid pressure loss increases with the increase of the flow rate. And if the conveyed medium is a liquid, scaling is likely to occur on the surface of the vortex generator, and the scaling on the surface of the vortex generator will cause the medium to be unable to generate a normal Karman vortex street after passing through the vortex generator, thus affecting the measurement. Therefore, a third pressure tapping pipe 11 is provided on the measuring pipe 1 between the vortex generator 5 and the rectifying pipe 6, a fourth pressure tapping pipe 12 is provided in the rectifying pipe 6 above the vortex generator 5, and a fifth pressure tapping pipe 13 is provided in the rectifying pipe 6 below the vortex generator 5. The fourth pressure tapping pipe 12 and the fifth pressure tapping pipe 13 are symmetrically distributed on the measuring pipe 1. The number of the third pressure tapping pipe 11, the fourth pressure tapping pipe 12 and the fifth pressure tapping pipe 13 is several. Several third pressure tapping pipes 11 are evenly distributed in a star shape outside the central axis of the measuring pipe 1. Several fourth pressure tapping pipes 12 are evenly distributed on the measuring pipe 1 below the vortex generator 5. Several fifth pressure tapping pipes 13 are evenly distributed on the measuring pipe 1 above the vortex generator 5. A first pressure equalizing ring 14 is provided at the outlet ends of several fourth pressure tapping pipes 12 and several fifth pressure tapping pipes 13. A second pressure equalizing ring 15 is provided at the outlet ends of several third pressure tapping pipes 11. A differential pressure transmitter 16 is provided on the second pressure equalizing ring 15 and the first pressure equalizing ring 14. The central axes of several fourth pressure tapping pipes 12 and the central axes of several fifth pressure tapping pipes 13 are in the same plane. This product is based on the pressure difference between the second pressure equalizing ring 15 and the first pressure equalizing ring 14 to judge whether the vortex generator 5 is in a normal working state, and can also use the pressure difference generated by the fluid passing through the vortex generator 5 as another basis to feedback the flow parameters. The distance from the end of the vortex generator 5 close to the rectifying pipe 6 to the central axis of the fourth pressure tapping pipe 12 and the distance from the end of the vortex generator 5 close to the rectifying pipe 6 to the central axis of the fifth pressure tapping pipe 13 are both 0.15 times the diameter of the measuring pipe 1 to 0.2 times the diameter of the measuring pipe 1. The distance from the end of the vortex generator 5 close to the rectifying pipe 6 to the central axis of the first pressure tapping pipe 2 and the distance from the end of the vortex generator 5 close to the rectifying pipe 6 to the central axis of the second pressure tapping pipe 3 are both 0.45 times the diameter of the measuring pipe 1 to 0.5 times the diameter of the measuring pipe 1. Exhaust pipes 17 are respectively provided at the tops of the first pressure equalizing ring 14 and the second pressure equalizing ring 15. Exhaust valves 18 are provided on the exhaust pipes 17. Drain pipes 19 are respectively provided at the bottoms of the first pressure equalizing ring 14 and the second pressure equalizing ring 15. Drain valves 20 are provided on the drain pipes 19. Sixth pressure tapping pipes 21 are respectively provided between the second pressure equalizing ring 15 and the differential pressure transmitter 16 and between the first pressure equalizing ring 14 and the differential pressure transmitter 16. Ball valves 22 are respectively provided on the third pressure tapping pipe 11, the fourth pressure tapping pipe 12, the fifth pressure tapping pipe 13 and the sixth pressure tapping pipe 21.

[0021] A second flange 23 is provided at one end of the rectifier tube 6 close to the measuring tube 1, a third flange 24 is provided at one end of the measuring tube 1 close to the rectifier tube 6, a sealing protrusion 25 is provided at one end of the third flange 24 facing the second flange 23, and a sealing groove 26 is provided at one end of the second flange 23 facing the third flange 24 along the direction from close to the third flange 24 to away from the third flange 24. The shape of the sealing groove 26 is matched with the shape of a part of the sealing protrusion 25. By providing the sealing groove 26 and the sealing protrusion 25, the shape of the gap between the second flange 23 and the third flange 24 through which the liquid medium passes is changed, and the flow resistance that the liquid medium needs to overcome when passing through the gap between the second flange 23 and the third flange 24 is increased; furthermore, a sealing gasket 27 is provided on the second flange 23 inside the sealing groove 26 and on the sealing protrusion 25. Thus, the gap between the sealing groove 26 and the sealing protrusion 25 is further reduced; in addition, it should be noted that fastening bolts 28 are provided on the second flange 23 outside the sealing protrusion 25 and on the third flange 24 outside the sealing groove 26. The number of the fastening bolts 28 is several, and the several fastening bolts 28 are evenly distributed in a star shape outside the central axis of the measuring tube 1. The central axis of the measuring tube 1, the central axis of the second flange 23, and the central axis of the third flange 24 are located on the same axis.

[0022] The usage method of this product is as follows, as Figures 1 to 3 shown, including the following steps: First, after this product is installed at the preset installation position, the upstream liquid medium enters the inner cavity of the first flange 7, the temperature of the liquid medium is fed back by the temperature sensor 8, and the liquid medium generates partial turbulence after passing through the temperature sensor 8, the mounting sleeve 9, and the connecting rod 10. The liquid medium carrying the turbulence enters the rectifier tube 6 for rectification. During the conveying process of the liquid medium in the rectifier tube 6, the turbulence carried by the liquid medium gradually weakens as the liquid medium gradually approaches the measuring tube 1 until after the liquid medium enters the measuring tube 1, the turbulence carried by the liquid medium is eliminated.

[0023] Then, during the transportation of the liquid medium in the measuring tube 1, the third pressure-taking tube 11 feeds back the first pressure value between the vortex generator 5 and the rectifying tube 6. A plurality of third pressure-taking tubes 11 convey pressure to the second pressure equalizing ring 15, and the pressure value fed back by the second pressure equalizing ring 15 is also the first pressure value; the fourth pressure-taking tube 12 and the fifth pressure-taking tube 13 feed back the second pressure value generated after throttling by the vortex generator 5. The fourth pressure-taking tube 12 and the fifth pressure-taking tube 13 jointly convey pressure to the first pressure equalizing ring 14, and the pressure value fed back by the first pressure equalizing ring 14 is also the second pressure value; the differential pressure transmitter 16 feeds back the difference between the first pressure value and the second pressure value. The first pressure-taking tube 2 and the second pressure-taking tube 3 jointly feed back pressure parameters to the pressure sensor 4, and the vortex frequency is measured according to the fluctuating differential pressure between the first pressure-taking tube 2 and the second pressure-taking tube 3 fed back by the pressure sensor 4, so as to realize the measurement of the flow rate. And according to the difference between the first pressure value and the second pressure value fed back by the differential pressure transmitter 16, the flow rate parameter can also be fed back, so as to provide it for the staff for comprehensive judgment.

[0024] Through this embodiment, the turbulence generated by the liquid medium passing through the temperature sensor 8, the mounting sleeve 9 and the connecting rod 10 is realized. The rectifying tube 6 is used for rectification to reduce the turbulence carried by the liquid medium entering the measuring tube 1, and further reduce the interference of the turbulence generated by the upstream measurement temperature on the Karman vortex street generated by the downstream passing through the vortex generator 5, thereby improving the stability of the feedback parameters of this product.

[0025] The above embodiments are only the preferred embodiments of the present invention, and do not limit the implementation scope of the present invention. Therefore, any equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the present invention patent shall be included in the scope of the patent application of the present invention.

Claims

1. A multi-parameter vortex flowmeter, characterized in that: The measuring tube (1) comprises a measuring tube (1), wherein the top end of the measuring tube (1) is provided with an inlet end of a first pressure-taking tube (2), the bottom end of the measuring tube (1) is provided with an inlet end of a second pressure-taking tube (3), the first pressure-taking tube (2) and the second pressure-taking tube (3) are symmetrically distributed on the measuring tube (1), a pressure sensor (4) is provided on the inlet end of the first pressure-taking tube (2) and the outlet end of the second pressure-taking tube (3), a vortex generator (5) is provided in the measuring tube (1) between the inlet ends of the first pressure-taking tube (2) and the measuring tube (1), and a rectifier tube is provided on the inlet end of the measuring tube (1). (6), a first flange (7) is provided at one end of the rectifier tube (6) away from the measuring tube (1), a temperature sensor (8) is provided inside the first flange (7), the central axis of the temperature sensor (8), the central axis of the rectifier tube (6) and the central axis of the measuring tube (1) are located on the same axis, a mounting sleeve (9) is provided outside the temperature sensor (8), a connecting rod (10) is provided between the mounting sleeve (9) and the first flange (7), the number of the connecting rods (10) is a plurality, and the plurality of connecting rods (10) are evenly distributed in a star shape on the outside of the temperature sensor (8).

2. The multi-parameter vortex flowmeter according to claim 1, characterized in that: A third pressure-taking tube (11) is arranged on the measuring tube (1) between the vortex generating body (5) and the rectifier tube (6), a fourth pressure-taking tube (12) is arranged in the rectifier tube (6) above the vortex generating body (5), and a fifth pressure-taking tube (13) is arranged in the rectifier tube (6) below the vortex generating body (5). The fourth pressure-taking tube (12) and the fifth pressure-taking tube (13) are symmetrically distributed on the measuring tube (1). The third pressure-taking tube (11), the fourth pressure-taking tube (12) and the fifth pressure-taking tube (13) are each arranged in plurality. A first pressure-equalizing ring (14) is arranged on the outlet ends of the plurality of fourth pressure-taking tubes (12) and the outlet ends of the plurality of fifth pressure-taking tubes (13), a second pressure-equalizing ring (15) is arranged on the outlet ends of the plurality of third pressure-taking tubes (11), and a differential pressure transmitter (16) is arranged on the second pressure-equalizing ring (15) and the first pressure-equalizing ring (14).

3. The multi-parameter vortex flowmeter according to claim 2, characterized in that: The distance between the end of the vortex generating body (5) close to the rectifying tube (6) and the central axis of the fourth pressure taking tube (12) and the distance between the end of the vortex generating body (5) close to the rectifying tube (6) and the central axis of the fifth pressure taking tube (13) are both 0.15 times to 0.2 times the diameter of the measuring tube (1).

4. The multi-parameter vortex flowmeter according to claim 2, characterized in that: The top end of the first pressure-equalizing ring (14) and the top end of the second pressure-equalizing ring (15) are each provided with an exhaust pipe (17), and the exhaust pipe (17) is provided with an exhaust valve (18); the bottom end of the first pressure-equalizing ring (14) and the bottom end of the second pressure-equalizing ring (15) are each provided with a sewage pipe (19), and the sewage pipe (19) is provided with a sewage valve (20).

5. The multi-parameter vortex flowmeter according to claim 2, characterized in that: A sixth pressure-taking tube (21) is provided between the second pressure-equalizing ring (15) and the differential pressure transmitter (16), and between the first pressure-equalizing ring (14) and the differential pressure transmitter (16); and a ball valve (22) is provided on the third pressure-taking tube (11), the fourth pressure-taking tube (12), the fifth pressure-taking tube (13), and the sixth pressure-taking tube (21).

6. The multi-parameter vortex flowmeter according to claim 1, characterized in that: A second flange (23) is provided on one end of the rectifier tube (6) close to the measuring tube (1), a third flange (24) is provided on one end of the measuring tube (1) close to the rectifier tube (6), a sealing protrusion (25) is provided on one end of the third flange (24) facing the second flange (23), a sealing groove (26) is provided on one end of the second flange (23) facing the third flange (24) in a direction from close to the third flange (24) to away from the third flange (24), the shape of the sealing groove (26) matches the shape of a part of the sealing protrusion (25), and a sealing gasket (27) is provided on the second flange (23) and the sealing protrusion (25) inside the sealing groove (26).

7. The multi-parameter vortex flowmeter according to claim 6, characterized in that: The second flange (23) outside the sealing protrusion (25) and the third flange (24) outside the sealing groove (26) are provided with fastening bolts (28). The number of the fastening bolts (28) is a plurality, and the plurality of fastening bolts (28) are evenly distributed in a star shape outside the central axis of the measuring tube (1). The central axis of the measuring tube (1), the central axis of the second flange (23) and the central axis of the third flange (24) are located on the same axis.

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