Ultrasonic gas meter

Abstract

The utility model provides an ultrasonic gas meter which aims to solve the technical problems that an existing gas meter is unstable in gas flow velocity and large in measurement error. The gas meter comprises a shell provided with a gas inlet pipe and a gas outlet pipe which are communicated with a cavity; the ultrasonic flow metering module comprises a pipe body with a flow channel; the ultrasonic metering unit is arranged on the pipe body; the upstream rectification section and the downstream rectification section are arranged at the two ends of the straight pipe section, and the length sizes of the upstream rectification section and the downstream rectification section are smaller than those of the straight pipe section; a rectifying plate is arranged in the straight pipe section; the upstream rectification section is communicated with the cavity, and the upstream rectification section is of a trumpet-shaped structure outwards from one end of the straight pipe section; the inner diameter of the downstream rectification section is larger than that of the straight pipe section, a first step is formed at the joint of the downstream rectification section and the straight pipe section, and the downstream rectification section is communicated with the air outlet pipe through a connecting piece. By means of distribution of the diameter and the length of the pipe body and arrangement of the rectifying plates, turbulent flow can be reduced, airflow becomes more stable, and the flow metering precision is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of gas meters, in particular to an ultrasonic gas meter. Background Art

[0002] The ultrasonic gas meter can be used for measuring the flow of various gas media in residential houses and commercial shops. The ultrasonic gas meter is a high-precision, high-stability, non-contact measuring instrument, which has the advantages of long service life, wide flow range, low starting flow, etc. When a conventional ultrasonic gas meter is in use, the air flow velocity is not very stable, resulting in large measurement errors. Summary of the Invention

[0003] In view of the above situation, to overcome the defects of the prior art, the purpose of the utility model is to provide an ultrasonic gas meter, which solves the technical problem that the existing ultrasonic gas meter has large measurement errors due to unstable air flow velocity.

[0004] To achieve the above purpose, the utility model provides the following technical solutions:

[0005] An ultrasonic gas meter, comprising: a housing provided with an inlet pipe and an outlet pipe communicating with the internal chamber; an ultrasonic flow measurement module disposed in the chamber; the ultrasonic flow measurement module includes: a pipe body having a flow channel; and an ultrasonic measurement unit disposed on the pipe body for collecting the gas volume; wherein, the pipe body includes a straight pipe section and an upstream rectifying section and a downstream rectifying section disposed at both ends of the straight pipe section and having a length dimension smaller than that of the straight pipe section; a rectifying plate is disposed in the straight pipe section; the upstream rectifying section communicates with the chamber, and the upstream rectifying section is in a trumpet-shaped structure extending outward from one end of the straight pipe section; the inner diameter of the downstream rectifying section is larger than that of the straight pipe section, a first step is formed at the connection between the downstream rectifying section and the straight pipe section, and the downstream rectifying section is connected to the outlet pipe through a connecting member.

[0006] By distributing the diameter and length of the pipe body and setting the rectifying plate, the utility model can reduce the turbulence, make the air flow more stable, and improve the accuracy of flow measurement. Specifically, the upstream rectifying section is in a trumpet shape and its size is larger than that of the straight pipe section, which can conveniently guide the gas smoothly into the straight pipe section, reduce the generation of gas vortices, and the air flow entering the straight pipe section with a longer dimension is rectified by multiple rectifying plates, which can reduce the turbulence and make the air flow more uniform and stable, conducive to improving the accuracy of flow measurement.

[0007] Optionally, the ultrasonic measurement unit includes: an ultrasonic transducer for sensing the air flow; a flow measurement circuit module electrically connected to the ultrasonic transducer for receiving and processing the air flow signal sensed by the ultrasonic transducer to calculate the gas flow.

[0008] Optionally, the ultrasonic gas meter further includes: a cut-off valve connected to the lower end of the intake pipe and located in the chamber; a display module disposed on the front outer wall of the housing; wherein, the cut-off valve, the display module, and the flow measurement circuit module are all electrically connected to the control module, and the cut-off valve controls the on / off of the gas under the action of the control module.

[0009] Optionally, there are two ultrasonic transducers, and the two ultrasonic transducers are arranged in a V shape on the straight pipe section.

[0010] Optionally, a connecting plate is connected between the two ultrasonic transducers.

[0011] Optionally, the connecting piece includes a horizontally connected pipe section and a vertically connected pipe section. One end of the horizontally connected pipe section is connected to the downstream rectifying section, and the other end is a closed end. The upper end of the vertically connected pipe section is connected to the outlet pipe, and the lower end is perpendicularly connected to the horizontally connected pipe section. By making the outlet rectifying section larger than the straight pipe section and setting the closed end, it is convenient for the air flow to flow out and makes the output air flow stable.

[0012] Optionally, the horizontally connected pipe section includes a connecting part and an outlet rectifying part connected to the connecting part. A second step is formed at the connection between the connecting part and the outlet rectifying part. The inner diameter of the connecting part is adapted to the outer diameter of the downstream rectifying section, and the connecting part is hermetically connected to the downstream rectifying section. The lower end of the vertically connected pipe section is connected to the outer wall of the outlet rectifying part, and one end of the outlet rectifying part away from the connecting part is a closed end.

[0013] Optionally, the vertically connected pipe section is arranged close to the closed end, and the closed end has an arc-shaped structure. The arc-shaped closed end can reduce the generation of gas vortices.

[0014] Optionally, a groove is provided on the outer wall of the downstream rectifying section, and a sealing device is arranged in the groove.

[0015] Optionally, the inner diameter of the outlet rectifying section is equal to or slightly larger than the inner diameter of the downstream rectifying section.

[0016] Optionally, the cross-section of the straight pipe section has a rectangular structure.

[0017] Optionally, at least two rectifying plates are arranged inside the straight pipe section.

[0018] Optionally, a noise reduction device is provided at one end of the upstream rectifying section away from the straight pipe section. By adding a noise reduction device at the front end of the upstream rectifying section, while achieving noise reduction, it can also preliminarily rectify the gas entering the ultrasonic flow measurement module, further improving the uniformity and stability of the air flow and further improving the measurement accuracy.

[0019] Optionally, the noise reduction device is a foam board and / or a metal board disposed at the front end of the upstream rectifying section.

[0020] Optionally, there are two, six or ten rectifying plates.

[0021] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0022] 1. By distributing the diameter and length of the pipe body and setting the rectifying plates, the present utility model can reduce turbulence, make the air flow smoother, and improve the accuracy of flow measurement. Specifically, the upstream rectifying section is in a horn shape and its size is larger than that of the straight pipe section, which can conveniently guide the gas smoothly into the straight pipe section, reduce the generation of gas vortices, and the air flow entering the straight pipe section with a longer size is rectified by multiple rectifying plates, which can reduce turbulence and make the air flow more uniform and stable, being beneficial to improving the accuracy of flow measurement.

[0023] 2. By making the outlet rectifying part larger than the straight pipe section and setting the closed end with an arc-shaped structure, the present utility model can facilitate the outflow of the air flow, make the output air flow stable, and at the same time, the closed end with an arc-shaped structure can reduce the generation of gas vortices.

[0024] 3. By adding a noise reduction device at the front end of the upstream rectifying section, while achieving noise reduction, it can also preliminarily rectify the gas entering the ultrasonic flow measurement module, further improving the uniformity and stability of the air flow and further improving the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for description in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic side view structure diagram of an embodiment of the ultrasonic gas meter in the present utility model.

[0027] Figure 2 It is a schematic internal structure diagram of an embodiment of the ultrasonic gas meter in the present utility model.

[0028] Figure 3 It is a schematic side view structure diagram of an embodiment of the ultrasonic flow measurement module in the present utility model.

[0029] Figure 4 It is a schematic internal structure diagram of an embodiment of the ultrasonic flow measurement module in the present utility model.

[0030] Figure 5Schematic side view structure diagram of Embodiment 2.

[0031] Figure 6 Schematic internal structure diagram of Embodiment 2.

[0032] Figure 7 Schematic side view structure diagram of the ultrasonic flow measurement module in Embodiment 2.

[0033] Figure 8 Schematic internal structure diagram of the ultrasonic flow measurement module in Embodiment 2.

[0034] Reference numerals:

[0035] 1. Housing; 10. Chamber; 11. Inlet pipe; 12. Outlet pipe; 13. Cut-off valve;

[0036] 2. Ultrasonic flow measurement module; 21. Pipe body; 21a. Straight pipe section; 21b. Upstream rectifying section; 21c. Downstream rectifying section; 210. Flow channel; 211. First step; 212. Groove; 22. Rectifying plate; 23. Ultrasonic transducer; 24. Flow measurement circuit module;

[0037] 3. Connector; 31. Horizontal pipe section; 31a. Connection part; 31b. Outlet rectifying part; 311. Closed end; 32. Vertical pipe section;

[0038] 4. Display module; 5. Noise reduction device. Detailed implementation manners

[0039] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the embodiments of the present utility model application. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0040] In the description of the embodiments of the present utility model application, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", "end", "side", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present utility model application 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 should not be construed as a limitation to the embodiments of the present utility model application.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present utility model application, "a plurality of" means two or more, unless otherwise specifically defined.

[0042] In the embodiments of the present utility model application, unless otherwise clearly specified and limited, terms such as "installed", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present utility model application can be understood according to specific circumstances.

[0043] In the embodiments of the present utility model application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0044] The following disclosure provides many different embodiments or examples for implementing different structures of the embodiments of the present utility model application. To simplify the disclosure of the embodiments of the present utility model application, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the embodiments of the present utility model application. In addition, the embodiments of the present utility model application may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0045] The embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.

[0046] Embodiment 1

[0047] As Figures 1 to 4 shown, the embodiments of the present utility model application provide an ultrasonic gas meter, including: a housing 1, an ultrasonic flow measurement module 2, and a connecting member 3.

[0048] Inside the housing 1, there is a sealed chamber 10. On both sides of the top of the housing 1, an intake pipe 11 and an outlet pipe 12 communicating with the chamber 10 are respectively provided. A cut-off valve 13 is installed on the intake pipe 11. Optionally, the cut-off valve 13 is arranged at the lower end of the intake pipe 11 and is located in the chamber 10.

[0049] The ultrasonic flow measurement module 2 is arranged in the chamber 10. The ultrasonic flow measurement module 2 specifically includes a pipe body 21 and an ultrasonic measurement unit arranged on the pipe body 21. An ultrasonic flow channel 210 for the gas to flow through and provided with a flow rectifying plate is arranged in the pipe body 21. The ultrasonic flow channel 210 is used for air flow rectification; the ultrasonic measurement unit is used for collecting the gas flow rate of the gas flowing through the flow channel 210.

[0050] Further, the pipe body 21 includes a straight pipe section 21a and an upstream rectifying section 21b and a downstream rectifying section 21c arranged at both ends of the straight pipe section 21a and having a length dimension smaller than that of the straight pipe section 21a. The upstream rectifying section 21b communicates with the chamber 10, and the upstream rectifying section 21b is in a horn-shaped structure extending outward from one end of the straight pipe section 21a. The inner wall between the upstream rectifying section 21b and the straight pipe section 21a is a curved surface transition structure. The inner diameter of the downstream rectifying section 21c is larger than the inner diameter of the straight pipe section 21a, so that a first step 211 is formed at the connection between the downstream rectifying section 21c and the straight pipe section 21a.

[0051] Optionally, the pipe body 21 is located at the lower side of the intake pipe 11, that is, the upstream rectifying section 21b is located at the lower side of one side of the intake pipe 11.

[0052] Optionally, a flow rectifying plate 22 is arranged in the straight pipe section 21a. When the gas enters the straight pipe section 21a from the upstream rectifying section 21b, under the action of the flow rectifying plate 22, the air flow is flattened, the turbulence is reduced, and the air flow becomes more stable, which is beneficial to improving the accuracy of flow measurement.

[0053] Optionally, the cross-section of the straight pipe section 21a is in a rectangular structure.

[0054] Optionally, at least two flow rectifying plates 22 are arranged inside the straight pipe section 21a.

[0055] In an embodiment, the ultrasonic measurement unit includes an ultrasonic transducer 23 and a flow measurement circuit module 24. The ultrasonic transducer 23 is used for sensing the air flow. The flow measurement circuit module 24 is electrically connected to the ultrasonic transducer 23, receives and processes the air flow signal sensed by the ultrasonic transducer 23 to calculate the gas flow rate.

[0056] Furthermore, the flow metering circuit module 24 is also electrically connected to a control module, which is electrically connected to the cut-off valve 13 and the display module 4. The cut-off valve 13 controls the on-off of the gas under the action of the control module. The display module 4 is arranged on the front outer wall of the housing 1 and is used to display information such as gas volume.

[0057] Optionally, there are two ultrasonic transducers 23, which are arranged in a V shape on the straight pipe section 21a. Ultrasonic signals are emitted by the two ultrasonic transducers 23 to sense the air flow, which is beneficial to improving the measurement accuracy.

[0058] Optionally, a connecting plate is connected between the two ultrasonic transducers 23, which is beneficial to enhancing the stability.

[0059] In one embodiment, the downstream rectifying section 21c is connected to the air outlet pipe 12 through a connector 3.

[0060] The connector 3 is a pipe structure with a channel for the gas to flow through inside. Specifically, the connector 3 includes a horizontally arranged pipe section 31 and a vertically arranged pipe section 32 that are connected and communicate with each other. The pipe section 32 is arranged above the pipe section 31 and is perpendicular to the pipe section 31. The pipe section 31 and the pipe section 32 form an L-shaped structure. Specifically, one end of the pipe section 31 is connected to the downstream rectifying section 21c, and the other end is a closed end. The pipe section 32 is vertically arranged, its upper end is connected and communicates with the air outlet pipe 12, and its lower end is connected and communicates with the pipe section 31.

[0061] Optionally, the pipe section 31 includes a connecting portion 31a and an outlet rectifying portion 31b that are connected and communicate with each other. A second step is formed at the connection between the connecting portion 31a and the outlet rectifying portion 31b. The inner diameter of the connecting portion 31a is adapted to the outer diameter of the downstream rectifying section 21c, and the connecting portion 31a is hermetically connected to the downstream rectifying section 21c. The lower end of the pipe section 32 is connected to the outer wall of the outlet rectifying portion 31b. One end of the outlet rectifying portion 31b away from the connecting portion 31a is a closed end 311.

[0062] Optionally, the pipe section 32 is arranged close to the closed end 311.

[0063] Optionally, the closed end 311 has an arc-shaped structure.

[0064] Optionally, the inner diameter of the outlet rectifying portion 31b is equal to or slightly larger than the inner diameter of the downstream rectifying section 21c. One end of the downstream rectifying section 21c abuts against the second step.

[0065] Optionally, a groove 212 is arranged on the outer wall of the downstream rectifying section 21c, and a sealing device is arranged in the groove 212. Optionally, the sealing device can be an O-ring embedded in the groove 212.

[0066] Optionally, the housing 1 is a sealed iron shell. NBR O-rings can be used for sealing at all connection points of the ultrasonic gas meter.

[0067] During use, the cut-off valve 13 is opened, and gas continuously enters the sealed chamber 10 through the inlet pipe 11, and then flows into the ultrasonic flow measurement module 2, i.e., the gas in the chamber 10 flows into the straight pipe section 21a from one end of the upstream rectifying section 21b. Then, the ultrasonic transducer 23 senses the gas flow and transmits the gas flow signal to the flow measurement circuit module 24. The flow measurement circuit module 24 calculates the gas flow, and the calculated data is displayed as gas flow data through the display module 4.

[0068] The horn-shaped upstream rectifying section 21b of the ultrasonic gas meter can reduce the generation of gas vortices, and its size is larger than that of the straight pipe section 21a, which can facilitate the smooth guiding of the gas into the straight pipe section 21a. The gas flow entering the straight pipe section 21a is further rectified by multiple rectifying plates 22, which can further reduce the turbulence and make the gas flow more stable, which is beneficial to improving the accuracy of flow measurement. By setting the outlet rectifying section 31b larger than the straight pipe section 21a and the closed end 311 with an arc-shaped structure, it is convenient for the gas flow to flow out, further making the output gas flow more stable. At the same time, the closed end 311 with an arc-shaped structure can also reduce the generation of gas vortices.

[0069] As an implementation scenario, the above-mentioned ultrasonic gas meter is mainly used for civilian ultrasonic gas meters. When used for civilian ultrasonic gas meters, preferably two rectifying plates 22 are used, and the rectifying plates 22 are arranged along the length direction of the straight pipe section 21a to form multiple channels inside the straight pipe section 21a. As another implementation scenario, the above-mentioned ultrasonic gas meter can also be used for commercial ultrasonic gas meters.

[0070] Embodiment 2

[0071] As Figures 5 to 8 shown, the embodiment of the present utility model application provides an ultrasonic gas meter, which is different from Embodiment 1 in that in this embodiment, a noise reduction device 5 is further provided at the front end of the upstream rectifying section 21b.

[0072] Optionally, the noise reduction device 5 is a foam board and / or a metal board.

[0073] Optionally, the foam board and / or the metal board can be arranged at the front end of the upstream rectifying section 21b through a fixing ring connected to the front end of the upstream rectifying section 21b, i.e., a fixing ring is provided at the front end of the upstream rectifying section 21b, and a foam board and / or a metal board are arranged inside the fixing ring. Optionally, holes are provided on the foam board or the metal board, and the foam board and / or the metal board can adopt a porous structure.

[0074] Optionally, six or ten rectifying plates 22 are used.

[0075] That is to say, the ultrasonic gas meter described in this embodiment is different from that in Embodiment 1 in terms of the number of rectifying plates 22 and the noise reduction device provided at the front end of the upstream rectifying section 21b. The rest of the structure is basically the same as that of the ultrasonic gas meter described in Embodiment 1, so it will not be elaborated in this embodiment.

[0076] In this embodiment, through the setting of the noise reduction device 5, while achieving noise reduction, it can also preliminarily rectify the gas entering the ultrasonic flow measurement module 2, further improving the uniformity and stability of the air flow and the measurement accuracy. The ultrasonic gas meter is mainly used for commercial ultrasonic gas meters. When used for commercial ultrasonic gas meters, the rectifying plates 22 are preferably six or ten. Of course, in other implementation scenarios, it can also be used for household ultrasonic gas meters.

[0077] Matters not described in detail in this embodiment are well-known technologies in the art.

[0078] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various changes or substitutions, and these should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. Ultrasonic gas meter, characterized in that: include: The housing (1) is provided with an air inlet pipe (11) and an air outlet pipe (12) which are in communication with the internal chamber (10); The ultrasonic flow metering module (2) is arranged in the chamber (10); the ultrasonic flow metering module (2) comprises: A tube body (21) having a flow channel (210); and An ultrasonic metering unit disposed on the tube body (21); The pipe body (21) comprises a straight pipe section (21a) and an upstream rectifying section (21b) and a downstream rectifying section (21c) which are arranged at both ends of the straight pipe section (21a) and have a smaller length than the straight pipe section (21a); ​​a rectifying plate (22) is arranged in the straight pipe section (21a); ​​the upstream rectifying section (21b) is connected to the chamber (10), and the upstream rectifying section (21b) is in a trumpet-shaped structure from one end of the straight pipe section (21a) outwards; the inner diameter of the downstream rectifying section (21c) is larger than the inner diameter of the straight pipe section (21a), a first step (211) is formed at the connection between the downstream rectifying section (21c) and the straight pipe section (21a), and the downstream rectifying section (21c) is connected to the air outlet pipe (12) via a connecting piece (3).

2. The ultrasonic gas meter according to claim 1, characterized in that: The ultrasonic metering unit comprises: An ultrasonic transducer (23) for sensing airflow; The flow metering circuit module (24) is electrically connected to the ultrasonic transducer (23) and is used to receive and process the airflow signal sensed by the ultrasonic transducer (23) to calculate the gas flow.

3. The ultrasonic gas meter according to claim 2, characterized in that: The ultrasonic gas meter also includes: A cut-off valve (13) connected to the lower end of the air inlet pipe (11) and located in the chamber (10); A display module (4) is arranged on an outer wall of one side of the housing (1); The shut-off valve (13), the display module (4) and the flow metering circuit module (24) are all electrically connected to the control module, and the shut-off valve (13) controls the on-off of the gas under the action of the control module.

4. The ultrasonic gas meter according to claim 2, characterized in that: There are two ultrasonic transducers (23), and the two ultrasonic transducers (23) are arranged in a V-shape on the straight pipe section (21a).

5. The ultrasonic gas meter according to claim 1, characterized in that: The connecting piece (3) comprises a communicating transverse pipe section (31) and a vertical pipe section (32); one end of the transverse pipe section (31) is connected to the downstream rectifying section (21c), and the other end is a closed end (311); the upper end of the vertical pipe section (32) is connected to the air outlet pipe (12), and the lower end is vertically connected to the transverse pipe section (31).

6. The ultrasonic gas meter according to claim 5, characterized in that: The horizontal pipe section (31) comprises a connecting portion (31a) and an outlet rectifying portion (31b) connected to and in communication with the connecting portion (31a), wherein a second step is formed at the connection between the connecting portion (31a) and the outlet rectifying portion (31b); the inner diameter of the connecting portion (31a) is adapted to the outer diameter of the downstream rectifying portion (21c), and the connecting portion (31a) is sealedly connected to the downstream rectifying portion (21c); the lower end of the vertical pipe section (32) is connected to the outer pipe wall of the outlet rectifying portion (31b), and the end of the outlet rectifying portion (31b) away from the connecting portion (31a) is a closed end (311); the vertical pipe section (32) is arranged close to the closed end (311), and the closed end (311) is in an arc-shaped structure.

7. The ultrasonic gas meter according to claim 1, characterized in that: The straight pipe section (21a) has a rectangular cross-section, and at least two rectifying plates (22) are arranged inside the straight pipe section (21a).

8. The ultrasonic gas meter according to claim 7, characterized in that: The number of the rectifying plates (22) is two, six or ten.

9. The ultrasonic gas meter according to any one of claims 1 to 8, characterized in that: A noise reduction device (5) is provided at one end of the upstream rectifying section (21b) away from the straight pipe section (21a).

10. The ultrasonic gas meter according to claim 9, characterized in that: The noise reduction device (5) is a foam plate and / or a metal plate arranged at the front end of the upstream rectifying section (21b).

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