Ultrasonic gas meter runner structure for reducing Karman vortex effect

Abstract

The utility model relates to the technical field of ultrasonic gas meters, in particular to an ultrasonic gas meter flow channel structure for reducing the Karman vortex effect, which comprises a Venturi tube and a rectifier, the rectifier is fixedly connected to a gas inflow end and a gas outflow end of the Venturi tube, an ultrasonic sensor is mounted in the rectifier, and the ultrasonic sensor is connected with the Venturi tube. The sensor is used for measuring gas flow; the venturi tube comprises a gradually-shrinking section, a throat diameter and a gradually-expanding section, a fluid channel is formed in the venturi tube, and a plurality of willow-leaf-shaped grooves are distributed in the inner wall of the gradually-shrinking section; the rectifier comprises an outer ring, a conical flow guide body is arranged in the outer ring, and the conical flow guide body is connected with the outer ring through a plurality of flow guide pieces. The hyperbolic sound guide channel is arranged in the conical flow guide body, so that sound energy can be effectively focused, signal strength can be improved, airflow can be prevented from directly impacting an ultrasonic sensor, formation of Karman vortexes is further reduced, and the sensor is protected from being polluted.

Description

Technical Field

[0001] The utility model relates to the technical field of ultrasonic gas meters, and particularly relates to a flow channel structure of an ultrasonic gas meter for reducing the Karman vortex effect. Background Technique

[0002] At present, there are mainly two technical routes for the flow channel structure of ultrasonic gas meters: one is the technical route of Panasonic Japan dominated by a rectangular cross-section, and the other is the technical route of domestic independent intellectual property dominated by a Venturi tube structure.

[0003] The technical route of the Venturi tube structure has obvious advantages, such as small pressure loss, dirt resistance, simple assembly, low cost, etc.; but there are also certain defects. For example, due to the relatively large outer diameter of the sensor, irregular Karman vortices will be generated in the flow field near the upstream sensor, affecting the accuracy and stability of flow measurement.

[0004] Therefore, a flow channel structure of an ultrasonic gas meter for reducing the Karman vortex effect is needed to solve the above problems. Content of the Utility Model

[0005] The purpose of the utility model is to provide a flow channel structure of an ultrasonic gas meter for reducing the Karman vortex effect. A hyperbolic sound guiding channel is arranged in the conical deflector. It can not only effectively focus the sound energy, improve the signal intensity, but also prevent the air flow from directly impacting the ultrasonic sensor, further reducing the formation of Karman vortices and protecting the sensor from pollution.

[0006] The technical solution adopted by the utility model to solve the above technical problems is: a flow channel structure of an ultrasonic gas meter for reducing the Karman vortex effect, including a Venturi tube and a rectifier. The rectifier is fixedly connected to the gas inlet end and the gas outlet end of the Venturi tube, and an ultrasonic sensor is installed inside the rectifier for measuring the gas flow;

[0007] The Venturi tube includes a converging section, a throat diameter and a diverging section. A fluid channel is opened inside the Venturi tube, and a plurality of willow leaf-shaped grooves are distributed on the inner wall of the converging section;

[0008] The rectifier includes an outer ring, and a conical deflector is arranged inside the outer ring. The conical deflector and the outer ring are connected to each other through a plurality of guide vanes;

[0009] A cavity and a hyperbolic sound guiding channel are arranged inside the conical deflector.

[0010] Further, the conical deflector has an opening, and the outer diameter dimension of the opening is less than 1 / 3 of the outer diameter of the ultrasonic sensor.

[0011] Furthermore, a plurality of tapered grooves are provided on the conical fluid guide, and the tapered grooves are uniformly distributed on the outer surface of the conical fluid guide centered on the fluid channel.

[0012] Furthermore, a raised buckle is provided on the rectifier.

[0013] Furthermore, clamping grooves are provided at both the gas inlet end and the gas outlet end of the Venturi tube, and the rectifier is fixed by the cooperation of the buckle and the clamping groove of the Venturi tube.

[0014] Furthermore, the ratio of the length of the tapered section to the length of the divergent section is not less than 4:1.

[0015] Furthermore, the guide vanes are uniformly distributed along the central axis of the outer ring.

[0016] Furthermore, the ultrasonic sensor is installed inside the cavity, and the ultrasonic signal of the ultrasonic sensor is transmitted and received through the hyperbolic acoustic guiding channel, focusing the acoustic energy and keeping the acoustic channel on the central axis of the fluid channel.

[0017] Furthermore, fixing ears are integrally connected to the left and right sides of the gas outlet end.

[0018] The advantages of the present utility model are as follows: The present utility model provides an ultrasonic gas meter flow channel structure for reducing the von Karman vortex effect, and the present utility model has the following advantages:

[0019] 1. Optimized hyperbolic acoustic guiding channel: The present utility model has a hyperbolic acoustic guiding channel provided inside the conical fluid guide. It can not only effectively focus the acoustic energy, improve the signal strength, but also prevent the airflow from directly hitting the ultrasonic sensor, further reducing the formation of von Karman vortices and protecting the sensor from contamination.

[0020] 2. Rectifying design of willow leaf-shaped grooves: The present utility model has willow leaf-shaped grooves provided on the inner wall of the tapered section. These grooves with special shapes help to delay the separation of the boundary layer, improve the flow pattern, thereby reducing the influence of von Karman vortices and improving the measurement accuracy.

[0021] 3. Reducing the influence area of the ultrasonic sensor: The conical fluid guide in the present utility model has an opening, and the outer diameter size of the opening is less than 1 / 3 of the outer diameter of the ultrasonic sensor. By encapsulating the ultrasonic sensor with the conical fluid guide, the influence of the sensor on the surrounding flow field is significantly reduced, and the generation of von Karman vortices is reduced.

[0022] 4. Optimization of the overall flow channel structure: The present utility model optimizes the contour of the main flow channel of the Venturi tube by smooth connection of the arc tangent and setting a specific ratio of the lengths of the tapered section and the divergent section. The entire flow channel structure is optimized, making the fluid flow more stable and further reducing the turbulence and vortex phenomena. Description of the Drawings

[0023] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Schematic diagram of the three-dimensional structure of the present utility model;

[0025] Figure 2 Schematic diagram of the sectional structure of the present utility model Figure 1 ;

[0026] Figure 3 Schematic diagram of the front view structure of the present utility model;

[0027] Figure 4 Schematic diagram of the sectional structure of the present utility model Figure 2 ;

[0028] Figure 5 Left view of the present utility model;

[0029] Figure 6 Schematic diagram of the three-dimensional structure of the rectifier in the present utility model;

[0030] Figure 7 Front view of the rectifier in the present utility model;

[0031] Figure 8 Left view of the rectifier in the present utility model;

[0032] Figure 9 Schematic diagram of the sectional structure of the rectifier in the present utility model;

[0033] Where:

[0034] 10. Venturi tube; 11. Gas inlet end; 12. Gas outlet end;

[0035] 13. Converging section; 14. Fluid channel; 15. Throat diameter;

[0036] 16. Diverging section; 17. Card slot; 18. Willow leaf-shaped groove;

[0037] 19. Fixed ear; 20. Rectifier; 21. Outer ring;

[0038] 22. Deflector; 23. Conical deflector; 25. Cavity;

[0039] 26. Hyperbolic sound guiding channel; 27. Converging groove; 28. Snap;

[0040] 29. Opening; 30. Ultrasonic sensor. Detailed implementation manner

[0041] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0042] In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. The terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0043] Embodiment 1:

[0044] Figure 1 is a three-dimensional structural schematic diagram of the present utility model, Figure 2 is a sectional structural schematic diagram of the present utility model Figure 1 , Figure 3 is a front view structural schematic diagram of the present utility model, Figure 4 is a sectional structural schematic diagram of the present utility model Figure 2 , Figure 5 is a left view of the present utility model, Figure 6 is a three-dimensional structural schematic diagram of the rectifier in the present utility model, Figure 7 is a front view of the rectifier in the present utility model, Figure 8 is a left view of the rectifier in the present utility model, Figure 9 The sectional structural schematic diagram of the rectifier in the present utility model is as Figures 1 to 9The flow path structure of an ultrasonic gas meter for reducing the Karman vortex effect is shown. It includes a Venturi tube 10 and a rectifier 20. The rectifier 20 is fixedly connected to the gas inlet end 11 and the gas outlet end 12 of the Venturi tube 10. Fixing ears 19 are integrally connected to the left and right sides of the gas outlet end 12. An ultrasonic sensor 30 is installed within the rectifier 20 for measuring gas flow. In addition to regulating the gas flow pattern, the rectifier 20 also houses and encapsulates the ultrasonic sensor 30, ensuring that the center vertical line of the end face of the ultrasonic sensor 30, which transmits and receives ultrasonic signals, is aligned with the central axis of the fluid channel 14 within the Venturi tube 10.

[0045] The venturi tube 10 in the present invention includes a tapered section 13, a throat diameter 15 and a gradually expanding section 16, wherein the length ratio of the tapered section 13 to the gradually expanding section 16 is not less than 4:1. A fluid channel 14 is opened inside the venturi tube 10, and a plurality of willow-leaf-shaped grooves 18 are distributed on the inner wall of the tapered section 13. The willow-leaf-shaped grooves 18 can be used to perform flow rectification on the gas flowing through the venturi tube 10, delay boundary layer separation, and reduce the influence of Karman vortex.

[0046] The rectifier 20 of the present invention includes an outer ring 21, within which is disposed a conical guide body 23. The conical guide body 23 and the outer ring 21 are interconnected by a plurality of guide vanes 22, which are evenly distributed along the central axis of the outer ring 21. The evenly distributed guide vanes 22 can reduce vortex formations and achieve flow rectification. The ultrasonic signal emitted by the ultrasonic sensor 30 is transmitted through a hyperbolic sound-conducting channel 26, which concentrates acoustic energy and maintains the sound channel on the central axis of the fluid channel 14. The present invention provides a cavity 25 and a hyperbolic sound-conducting channel 26 within the conical guide body 23. The conical guide body 23 has an opening 29, the outer diameter of which is less than one-third of the outer diameter of the ultrasonic sensor 30. The outer diameter of the opening 29 is 3 to 4 mm, which significantly reduces the influence of Karman vortices.

[0047] The utility model provides a plurality of tapered grooves 27 on the conical guide body 23 . The tapered grooves 27 are evenly distributed on the outer surface of the conical guide body 23 with the fluid channel 14 as the center, so as to further rectify the flow and delay the formation of the boundary layer.

[0048] The utility model is provided with a raised buckle 28 on the rectifier 20, and a clamping groove 17 is provided on the gas inlet end 11 and the gas outlet end 12 of the venturi tube 10. The rectifier 20 is fixed to the inlet and outlet of the venturi tube 10 by the buckle 28 and the clamping groove 17 of the venturi tube 10.

[0049] In the present utility model, the ultrasonic sensor 30 is installed inside the cavity 25. The ultrasonic signal of the ultrasonic sensor 30 is transmitted and received through the hyperbolic sound guiding channel 26, concentrating the acoustic energy and keeping the sound channel on the central axis of the fluid channel 14. Inside the hyperbolic sound guiding channel 26, the ultrasonic signal emitted by one of the ultrasonic sensors 30 accumulates and propagates along the central axis of the fluid channel 14 to the other ultrasonic sensor 30 on the opposite side, being received by it. The energy loss is small and the signal intensity is large. Due to the structural characteristics of the hyperbolic sound guiding channel 26, when there is a fluid pre - entry channel, the entry of air flow and dirty particles will be reduced due to the increased pressure. The present utility model can effectively delay the separation of the boundary layer, reduce the influence of the Karman vortex, and reduce the influence on the measurement accuracy and stability through the willow - leaf - shaped groove 18, the conical fluid guide 23 for wrapping the ultrasonic sensor 30 and its opening 29, and the tapered groove 27 on the outer surface of the conical fluid guide 23.

[0050] The following is the working process description of the flow channel structure of this ultrasonic gas meter:

[0051] 1. Gas entry

[0052] Gas inflow: The gas enters from the gas inlet end 11 of the Venturi tube 10. The rectifier 20 is fixed at the gas inlet end 11 of the Venturi tube 10.

[0053] 2. Rectification and flow regime adjustment

[0054] [[ID=I5]]Through the rectifier 20: The gas passes through the rectifier 20, which includes an outer ring 21 and a conical fluid guide 23, connected by a plurality of evenly distributed guide vanes 22.

[0055] The willow - leaf - shaped grooves 18 in the tapered section 13: The gas continues to flow through the tapered section 13 of the Venturi tube 10, and the multiple willow - leaf - shaped grooves 18 on the inner wall rectify the air flow.

[0056] The tapered grooves 27 on the conical fluid guide 23: When the gas flows through the conical fluid guide 23, the multiple tapered grooves 27 on its outer surface further rectify the air flow.

[0057] 3. Ultrasonic signal emission

[0058] The ultrasonic sensor 30 works: The ultrasonic sensor 30 installed inside the cavity 25 of the conical fluid guide 23 at the gas inlet end 11 emits ultrasonic signals.

[0059] The hyperbolic sound guiding channel 26: The ultrasonic signal propagates through the hyperbolic sound guiding channel 26, which is located inside the conical fluid guide 23.

[0060] 4. Ultrasonic signal propagation and reception

[0061] Signal propagation: The ultrasonic signal emitted by the ultrasonic sensor 30 within the conical fluid guide 23 at the gas inlet end 11 propagates along the central axis of the fluid passage 14 to the other ultrasonic sensor 30 on the opposite side.

[0062] Signal reception: The ultrasonic sensor 30 on the opposite side receives the ultrasonic signal.

[0063] 5. Flow measurement

[0064] Time difference measurement: The flow rate of the gas is calculated by measuring the time difference of the propagation of the ultrasonic signal between the two ultrasonic sensors 30.

[0065] Flow calculation: The volume flow rate of the gas is calculated based on the flow rate and the geometric parameters of the Venturi tube 10.

[0066] 6. Data processing and output

[0067] Data processing: The measured data is processed and provided to an external system or a display device.

[0068] Flow display: The processed flow rate data is displayed through a display screen or other output devices.

[0069] 7. Gas outflow

[0070] Gas outflow: The gas after measurement continues to flow to the gas outlet end 12 of the Venturi tube 10 and finally flows out of the entire device.

[0071] 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 it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultrasonic gas meter flow channel structure for reducing the Karman vortex effect, comprising a venturi tube (10) and a rectifier (20), wherein the rectifier (20) is fixedly connected to a gas inlet end (11) and a gas outlet end (12) of the venturi tube (10), and an ultrasonic sensor (30) is installed inside the rectifier (20) for measuring gas flow; It is characterized in that The venturi tube (10) comprises a tapered section (13), a throat (15) and a gradually expanding section (16); a fluid channel (14) is provided inside the venturi tube (10); and a plurality of willow-leaf-shaped grooves (18) are distributed on the inner wall of the tapered section (13); The rectifier (20) includes an outer ring (21), a conical guide body (23) is provided inside the outer ring (21), and the conical guide body (23) and the outer ring (21) are connected to each other via a plurality of guide plates (22); A cavity (25) and a hyperbolic sound guide channel (26) are provided in the conical guide body (23).

2. The ultrasonic gas meter flow channel structure for reducing the Karman vortex effect according to claim 1, characterized in that: The conical body guide (23) has an opening (29), and the outer diameter of the opening (29) is smaller than 1 / 3 of the outer diameter of the ultrasonic sensor (30).

3. The ultrasonic gas meter flow channel structure for reducing the Karman vortex effect according to claim 2, characterized in that: The conical body guide (23) is provided with a plurality of tapered grooves (27), and the tapered grooves (27) are evenly distributed on the outer surface of the conical body guide (23) with the fluid channel (14) as the center.

4. The ultrasonic gas meter flow channel structure for reducing the Karman vortex effect according to claim 1, characterized in that: A protruding buckle (28) is provided on the rectifier (20).

5. The ultrasonic gas meter flow channel structure for reducing the Karman vortex effect according to claim 4, characterized in that: A clamping groove (17) is provided on both the gas inlet end (11) and the gas outlet end (12) of the venturi tube (10), and the rectifier (20) is fixed to the clamping groove (17) of the venturi tube (10) by means of a buckle (28).

6. The ultrasonic gas meter flow channel structure for reducing the Karman vortex effect according to claim 1, characterized in that: The ratio of the length of the gradually contracting section (13) to the length of the gradually expanding section (16) is not less than 4:

1.

7. The ultrasonic gas meter flow channel structure for reducing the Karman vortex effect according to claim 1, characterized in that: The guide blades (22) are evenly distributed along the central axis of the outer ring (21).

8. The ultrasonic gas meter flow channel structure for reducing the Karman vortex effect according to claim 1, characterized in that: The ultrasonic sensor (30) is installed inside the cavity (25), and the ultrasonic signal of the ultrasonic sensor (30) is transmitted and received through the hyperbolic sound-conducting channel (26), which gathers sound energy and keeps the sound channel on the central axis of the fluid channel (14).

9. The ultrasonic gas meter flow channel structure for reducing the Karman vortex effect according to claim 1, characterized in that: The left and right sides of the gas outflow end (12) are integrally connected with fixing ears (19).

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