De-noising structure and flowmeter

Abstract

The utility model provides a noise elimination structure and a flow meter, and relates to the field of instruments. The noise elimination structure comprises a shell and a flow guide piece. The shell extends in the first direction, an air inlet is formed in the first end of the shell, and an air outlet is formed in the second end of the shell; the flow guide part is arranged in the shell, the flow guide part and the shell are provided with an outer cavity, the outer cavity and the air inlet are arranged in the first direction, and the outer cavity is communicated with the air inlet; the inner wall of the outer cavity comprises a first reflecting part and a second reflecting part which are oppositely arranged in the first direction, the first reflecting part is close to the air inlet, and the second reflecting part is away from the air inlet; the flow guide piece is provided with an inner cavity and an air vent, and the inner cavity communicates with the outer cavity through the air vent and communicates with the air outlet. Noise of to-be-measured gas can be reduced, and the measurement accuracy of the flowmeter is improved.

Description

Technical Field

[0001] The present application relates to the field of instruments, and in particular to a noise reduction structure and a flow meter. Background Art

[0002] With the gradual development of ultrasonic measurement technology, flow meters using ultrasonic measurement technology are widely used in natural gas, petroleum gas and other fields. Flow meters are often used in conjunction with structures such as regulating valves to measure the flow of the gas to be measured. However, in the process of using flow meters to measure the flow of the gas to be measured, the gas to be measured is prone to generate noise, which affects the measurement accuracy of the flow meter. Utility Model Content

[0003] The embodiments of the present application provide a noise reduction structure and a flow meter, which are used to solve the problem that when using the flow meter to measure the flow rate of the gas to be measured, the gas to be measured is prone to generate noise, thereby affecting the measurement accuracy of the flow meter.

[0004] The noise reduction structure provided in the embodiment of the present application includes a shell, a flow guide and an air outlet pipe;

[0005] The shell extends along a first direction, an air inlet is provided at a first end of the shell, and an air outlet is provided at a second end of the shell;

[0006] The guide member is disposed in the shell, the guide member and the shell form an outer cavity, the outer cavity and the air inlet are arranged along the first direction, and the outer cavity is communicated with the air inlet;

[0007] The inner wall of the outer cavity comprises a first reflecting portion and a second reflecting portion which are arranged opposite to each other along the first direction, wherein the first reflecting portion is close to the air inlet and the second reflecting portion is far away from the air inlet;

[0008] The flow guide is provided with an inner cavity and a vent, the inner cavity is communicated with the outer cavity through the vent, and the inner cavity is communicated with the air outlet.

[0009] By adopting the above technical scheme, when the fluid to be measured passes through the noise reduction structure, the fluid to be measured can flow from the air inlet at the first end of the shell along the first direction to the outer cavity between the guide member and the shell, and the fluid to be measured will oscillate and reflect along the first direction between the first reflection part and the second reflection part, and the sound waves generated by the fluid to be measured will reflect and interfere between the shell and the guide member, and the sound energy of the sound waves of the fluid to be measured is reduced to achieve the effect of attenuating the noise of the fluid to be measured. The fluid to be measured can flow into the inner cavity through the air vent and flow out of the noise reduction structure through the air outlet, thereby improving the measurement accuracy of the flow meter.

[0010] In some possible implementations, the first guide portion is configured as a conical guide portion; taking a plane perpendicular to the first direction as a cross section, the cross-sectional area of ​​the conical guide portion gradually decreases in a direction away from the second guide portion;

[0011] The first part of the shell is configured as a conical portion, and the conical portion is coaxially configured with the conical guide portion; taking a plane perpendicular to the first direction as a cross section, the cross-sectional area of ​​the conical portion gradually decreases in a direction away from the second guide portion;

[0012] The second flow guide portion is configured as a cylindrical flow guide portion, and the cylindrical flow guide portion is connected to the second end of the shell; the second part of the shell is configured as a cylindrical portion, and the cylindrical portion is coaxially configured with the cylindrical flow guide portion.

[0013] In some possible implementations, the first guide portion is configured as a conical guide portion; taking a plane perpendicular to the first direction as a cross section, the cross-sectional area of ​​the conical guide portion gradually decreases in a direction away from the second guide portion;

[0014] The first part of the shell is configured as a conical portion, and the conical portion is coaxially configured with the conical guide portion; taking a plane perpendicular to the first direction as a cross section, the cross-sectional area of ​​the conical portion gradually decreases in a direction away from the second guide portion;

[0015] The second flow guide portion is configured as a cylindrical flow guide portion, and the cylindrical flow guide portion is connected to the second end of the shell; the second part of the shell is configured as a cylindrical portion, and the cylindrical portion is coaxially configured with the cylindrical flow guide portion.

[0016] In some possible implementations, taking a plane perpendicular to the first direction as a cross section, a width cross-sectional area of ​​the first outer cavity is smaller than a cross-sectional area of ​​the second outer cavity;

[0017] And / or, the diameter of the tapered portion is smaller than the diameter of the cylindrical portion.

[0018] In some possible implementations, the vent is provided on the cylindrical guide portion, and the number of the vent is set to be multiple;

[0019] The plurality of vents are arranged around the first direction, and the vents extend along the circumference of the cylindrical guide portion; or, the plurality of vents are arranged in multiple rows and columns, the row direction of the vents is parallel to the circumference of the cylindrical guide portion, and the column direction of the vents is parallel to the first direction;

[0020] And / or, in the first direction, a distance between the vent and the first reflecting portion is greater than a distance between the vent and the second reflecting portion.

[0021] In some possible implementations, in the first direction, the noise reduction structure further includes an air outlet pipe, the air outlet pipe is disposed in the inner cavity, and the air outlet pipe extends along the first direction; the vent faces the outer surface of the air outlet pipe;

[0022] The first end of the air outlet pipe faces the first end of the shell, and the first end of the air outlet pipe is communicated with the inner cavity; the second end of the air outlet pipe is communicated with the air outlet.

[0023] In some possible implementations, the housing includes a first mounting member, a connecting member, and a second mounting member sequentially arranged along the first direction;

[0024] The first mounting member is provided with the air inlet, and the first mounting member includes the first reflecting portion; the second mounting member is provided with the air outlet, and the second mounting member includes the second reflecting portion.

[0025] In some possible implementations, a first mounting groove is provided on a surface of the first mounting member facing the second mounting member; and a second mounting groove is provided on a surface of the second mounting member facing the first mounting member.

[0026] The first end of the connecting member is disposed in the first mounting groove, and the second end of the connecting member is disposed in the second mounting groove.

[0027] In some possible implementations, a plug-in slot is provided on a surface of the second mounting member facing the first mounting member, and the plug-in slot is connected to the guide member and is inserted into the plug-in slot;

[0028] And / or, a fixing groove is provided on a surface of the second mounting member facing the first mounting member, the fixing groove is coaxially arranged at the air outlet, and the air outlet pipe is accommodated in the fixing groove.

[0029] An embodiment of the present application further provides a flow meter, comprising the above-mentioned noise reduction structure and a flow meter body, wherein the noise reduction structure is arranged upstream of the flow meter body.

[0030] Since the flow meter includes the above-mentioned spray noise reduction structure, the advantages of the flow meter including the above-mentioned noise reduction structure can be specifically referred to the relevant description above, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0032] Figure 1 A schematic diagram of the structure of the noise reduction structure provided in the embodiment of the present application;

[0033] Figure 2 An exploded diagram of a noise reduction structure provided in an embodiment of the present application;

[0034] Figure 3 A cross-sectional view of a noise reduction structure provided in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of the flow of the fluid to be measured in the noise reduction structure provided in an embodiment of the present application;

[0036] Figure 5 A cross-sectional view of a shell of a noise reduction structure provided in an embodiment of the present application;

[0037] Figure 6 A schematic diagram of the structure of the flow guide provided in the embodiment of the present application;

[0038] Figure 7 A schematic diagram of the flow of the fluid to be measured in the outer cavity and the inner cavity provided in an embodiment of the present application.

[0039] Description of reference numerals:

[0040] 100. Shell;

[0041] 110, first mounting member; 111, first mounting groove; 120, connecting member; 130, second mounting member; 131, second mounting groove; 132, plug-in groove; 133, fixing groove; 140, lifting ring; 150, supporting bolt; 160, outer cavity; 161, first outer cavity; 162, second outer cavity; 170, air inlet; 180, air outlet;

[0042] 200, flow guide;

[0043] 210, first flow guide; 220, second flow guide; 230, inner cavity; 240, vent;

[0044] 300. Exhaust pipe.

[0045] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0046] As described in the background technology, flow meters are often used in conjunction with control valves and other structures to measure the flow of the gas to be measured. In the process of the control valve controlling the throttling of the gas to be measured, the mechanical energy of the gas to be measured will be converted into acoustic energy, thereby generating high-frequency noise. The frequency of the high-frequency noise is close to the operating frequency of the wave flow meter, thus affecting the measurement accuracy of the flow meter.

[0047] In order to solve the above technical problems, an embodiment of the present application provides a noise reduction structure and a flow meter. When the fluid to be measured passes through the noise reduction structure, the fluid to be measured can flow from the air inlet at the first end of the shell along the first direction to the outer cavity between the guide member and the shell. The fluid to be measured will oscillate and reflect along the first direction between the first reflection part and the second reflection part, and the sound waves generated by the fluid to be measured will reflect and interfere between the shell and the guide member. The sound energy of the sound waves of the fluid to be measured is reduced to achieve the effect of attenuating the noise of the fluid to be measured. The fluid to be measured can flow into the inner cavity through the vent and flow out of the noise reduction structure through the outlet, thereby improving the measurement accuracy of the flow meter.

[0048] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0049] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0050] Reference Figure 1-Figure 4 An embodiment of the present application provides a noise reduction structure, which is arranged at the air inlet of the flow meter body. The noise reduction structure may include a shell 100.

[0051] The housing 100 may extend in a first direction, a first end of the housing 100 in the first direction may be provided with an air inlet 170, and a second end of the housing 100 in the first direction may be provided with an air outlet 180. The housing 100 may be connected to a flow path of the gas to be measured, so that the gas to be measured can flow into the housing 100 through the air inlet 170 and flow out of the housing 100 through the air outlet 180.

[0052] Exemplarily, the noise reduction structure may further include a flow guide 200, which may be disposed in the housing 100. The flow guide 200 and the housing 100 are provided with an outer cavity 160, the outer cavity 160 and the air inlet 170 may be arranged along a first direction, and the outer cavity 160 may be connected to the air inlet 170, so that the gas to be measured can flow into the outer cavity 160 through the air inlet 170.

[0053] The guide member 200 may also be provided with an inner cavity 230 and a vent 240 . The inner cavity 230 may be provided inside the guide member 200 . The inner cavity 230 may be connected to the outer cavity 160 through the vent 240 . The gas to be tested in the outer cavity 160 may flow into the inner cavity 230 through the vent 240 .

[0054] The noise reduction structure may further include an air outlet pipe 300, which may be disposed in the inner cavity 230. The air outlet pipe 300 may extend in a first direction; a first end of the air outlet pipe 300 faces a first end of the housing 100, the first end of the air outlet pipe 300 may be connected to the inner cavity 230, and a second end of the air outlet pipe 300 may be connected to the air outlet 180, so that the gas to be measured in the inner cavity 230 can flow into the air outlet pipe 300, and flow to the air outlet 180 through the air outlet pipe 300.

[0055] Reference Figure 2 and Figure 5 In some possible implementations, the housing 100 may include a first mounting member 110 , a connecting member 120 , and a second mounting member 130 that are sequentially arranged along a first direction.

[0056] The first mounting member 110 may be provided with an air inlet 170, and a surface of the first mounting member 110 facing the second mounting member 130 may be provided with a first mounting groove 111. The second mounting member 130 may be provided with an air outlet 180, and a surface of the second mounting member 130 facing the first mounting member 110 may be provided with a second mounting groove 131.

[0057] Exemplarily, the first end of the connecting member 120 can be set in the first mounting groove 111, and the second end of the connecting member 120 can be set in the second mounting groove 131, so that the first mounting member 110 and the second mounting member 130 can be connected through the connecting member 120, so that the assembly process of the shell 100 is more convenient.

[0058] The first mounting member 110 can be a flange mounting member, and the second mounting member 130 can be a flange mounting member. The connecting member 120 can be a cylindrical connecting member 120, and the inner diameter of the cylindrical connecting member 120 can be greater than the diameter of the air inlet 170, and the inner diameter of the cylindrical connecting member 120 can be greater than the inner diameter of the air outlet 180.

[0059] Exemplarily, a plug-in groove 132 may be provided on the surface of the second mounting member 130 facing the first mounting member 110, the guide member 200 may be inserted into the plug-in groove 132, the guide member 200 may be connected to the second mounting member 130, and the inner cavity 230 of the guide member 200 may face the air outlet 180 located on the second mounting member 130.

[0060] And / or, a fixing groove 133 may be provided on the surface of the second mounting member 130 facing the first mounting member 110, and the fixing groove 133 may be coaxially arranged at the air outlet 180, and the fixing groove 133 accommodates the air outlet pipe 300, and the second end of the air outlet pipe 300 can be fixed in the fixing groove 133, and the first end of the air outlet pipe 300 can extend toward the air inlet 170 and be arranged in the inner cavity 230.

[0061] Exemplarily, the inner wall of the outer cavity 160 includes a first reflective portion 163 and a second reflective portion 164 arranged opposite to each other along the first direction. The first reflective portion 163 may be close to the air inlet 170, and the first mounting member 110 may be used to form the first reflective portion 163, for example, the first mounting member 110 may include the first reflective portion 163. The second reflective portion 164 may be away from the air inlet; the second mounting member 130 may be used to form the second reflective portion 164, for example, the second mounting member 130 may include the second reflective portion 164.

[0062] It is easy to understand that when the fluid to be measured passes through the noise reduction structure, the fluid to be measured can flow from the air inlet 170 at the first end of the housing 100 to the outer cavity 160 between the flow guide 200 and the housing 100, and the fluid to be measured can flow in the outer cavity 160 along the first direction toward the second reflection part 164; the fluid to be measured will be reflected when flowing to the second reflection part 164, and the fluid to be measured can flow toward the first reflection part 163, and the fluid to be measured can be reflected and oscillated between the first mounting member 110 and the second mounting member 130;

[0063] Moreover, when the fluid to be measured flows in the outer cavity 160, part of the fluid to be measured can also generate reflection and interference with the outer surfaces of the connecting member 120 and the flow guide member 200, thereby further reducing the flow velocity of the fluid to be measured and reducing the noise energy of the fluid to be measured, so as to achieve the effect of attenuating the noise of the fluid to be measured.

[0064] When the fluid to be measured enters the inner cavity 230 from the outer cavity 160 through the vent 240, the fluid to be measured can flow in the inner cavity 230 along the first direction toward the first end of the outlet pipe 300, and the fluid to be measured can flow between the first end of the outlet pipe 300 and the bottom wall of the inner cavity 230 into the outlet pipe 300, thereby reducing the flow rate of the fluid to be measured.

[0065] Furthermore, when the fluid to be measured flows between the flow guide member 200 and the air outlet pipe 300, the fluid to be measured can vibrate back and forth between the flow guide member 200 and the air outlet pipe 300, thereby causing friction damping in the fluid to be measured, and then the energy of the fluid to be measured can be consumed through the flow guide member 200 and the air outlet pipe 300. The fluid to be measured can flow to the air outlet 180 through the air outlet pipe 300, thereby reducing the noise of the gas to be measured and improving the measurement accuracy of the flow meter.

[0066] For example, refer to Figure 1 , Figure 2 and Figure 5 At least one of the first mounting member 110, the connecting member 120 and the second mounting member 130 may be provided with a lifting ring 140. In this way, when the noise reduction structure needs to be hoisted or moved, the noise reduction structure can be lifted by the lifting ring 140, thereby making the movement process of the noise reduction structure more convenient.

[0067] The lifting ring 140 can be detachably arranged on the noise reduction structure, so that the installation process of the lifting ring 140 is more convenient and the manufacturing process and assembly process of each component of the noise reduction structure are easier.

[0068] And / or, at least one of the first mounting member 110, the connecting member 120 and the second mounting member 130 may be provided with a plurality of supporting bolts 150, and the plurality of supporting bolts 150 may be arranged around the first direction, so that the noise reduction structure can be supported to a certain extent by the plurality of supporting bolts 150, and the placement of the noise reduction structure is more stable.

[0069] It is easy to understand that the support bolt 150 can be screwed in or out of the shell 100 of the noise reduction structure to adjust the relative position of the support bolt 150 and the shell 100 and change the length of the support bolt 150 located on the outer part of the shell 100, thereby making the use of the support bolt 150 more convenient.

[0070] Refer to the following Figure 3 , Figure 6 and Figure 7 The relative positional relationship between the flow guide 200 and the housing 100 is described.

[0071] Reference Figure 3 , Figure 6 and Figure 7 In some possible implementations, the guide member 200 may include a first guide portion 210 and a second guide portion 220 arranged along a first direction, and the first guide portion 210 is closer to a first end of the guide channel relative to the second guide portion 220 .

[0072] The outer cavity may include a first outer cavity 161 and a second outer cavity 162 that are connected to each other. The first guide portion 210 and the first portion of the housing 100 may be provided with the first outer cavity 161 , and the first outer cavity 161 is connected to the air inlet 170 .

[0073] The second guide portion 220 and the second part of the shell 100 can be provided with a second outer cavity 162, which can be connected to the end of the first outer cavity 161 away from the air inlet 170, and the fluid to be tested from the air inlet 170 can flow to the vent 240 through the first outer cavity 161 and the second outer cavity 162 in sequence.

[0074] The first guide portion 210 may be a tapered guide portion. Taking a plane perpendicular to the first direction as a cross section, the cross-sectional area of ​​the tapered guide portion may gradually decrease in a direction away from the second guide portion 220 .

[0075] The first portion of the housing 100 may be a tapered portion, and the tapered portion may be coaxially arranged with the tapered air guide portion. Taking a plane perpendicular to the first direction as a cross section, the cross-sectional area of ​​the tapered portion may gradually decrease in a direction away from the second air guide portion 220 .

[0076] The second guide portion 220 may be configured as a cylindrical guide portion, which is connected to the second end of the housing 100. The second portion of the housing 100 may be configured as a cylindrical portion, which is coaxially disposed with the cylindrical guide portion.

[0077] It is easy to understand that when the shell 100 includes a first mounting member 110, a connecting member 120 and a second mounting member 130 arranged in sequence along a first direction, the first mounting member 110 can form a first part of the shell 100, the connecting member 120 can form a second part of the shell 100, and the second mounting member 130 is arranged opposite to the first mounting member 110 along the first direction, and the second mounting member 130 can be used to block the second outer cavity 162.

[0078] Taking a plane perpendicular to the first direction as a cross section, a cross-sectional area of ​​the first outer cavity 161 is smaller than a cross-sectional area of ​​the second outer cavity 162 .

[0079] When the fluid to be measured flows from the first outer cavity 161 to the second outer cavity 162, the cross-sectional area of ​​the first outer cavity 161 and the cross-sectional area of ​​the second outer cavity 162 suddenly change, the flow rate of the fluid to be measured decreases, and the sound waves of the fluid to be measured can be reflected and interfered in the second outer cavity 162, and the sound energy of the sound waves of the fluid to be measured is reduced, thereby achieving the effect of attenuating noise.

[0080] Furthermore, when the fluid to be measured flows from the first outer cavity 161 to the second outer cavity 162 , the flow rate of the fluid to be measured decreases, thereby further achieving the effect of attenuating noise.

[0081] And / or, the diameter of the conical portion may be smaller than the diameter of the cylindrical portion, so as to increase the difference between the width of the first outer cavity 161 and the width of the second outer cavity 162, further increase the difference between the areas of the first outer cavity 161 and the second outer cavity 162, and increase the reflection and interference effects of the sound waves of the fluid to be measured.

[0082] The first guide part 210 and the second guide part 220 can be integrally arranged, or a plurality of vents 340 can be formed in the second guide part 220 by laser cutting or the like, and then the first guide part 210 and the second guide part 220 are connected by welding or the like, thereby realizing the preparation process of the guide member 200.

[0083] It is easy to see that when the fluid to be measured flows from the air inlet 170 at the first end of the shell 100 to the outer cavity 160 surrounded by the guide member 200 and the shell 100, the width of the first outer cavity 161 and the width of the second outer cavity 162 suddenly change, the sound waves of the fluid to be measured are reflected and interfered, and the flow rate of the fluid to be measured is reduced.

[0084] Furthermore, the fluid to be measured can flow from the first outer cavity 161 toward the second outer cavity 162 along the first direction in the outer cavity 160. When the fluid to be measured flows to the second mounting member 130, it flows from the second outer cavity 162 toward the first outer cavity 161. The fluid to be measured can be reflected between the first mounting member 110 and the second mounting member 130. The acoustic energy of the sound waves of the fluid to be measured is reduced, thereby attenuating the noise of the fluid to be measured.

[0085] Reference Figure 3 , Figure 6 and Figure 7 In some possible implementations, the vent 240 is disposed in the cylindrical guide portion, and the number of the vent 240 can be multiple, so that the outer cavity 160 is connected to the inner cavity 230 through the multiple vents 240 .

[0086] For example, the plurality of vents 240 may be arranged around the first direction, and the vents 240 may extend along the circumference of the cylindrical guide portion. Alternatively, the plurality of vents 240 may be arranged in multiple rows and columns, the row direction of the vents 240 is parallel to the circumference of the cylindrical guide portion, and the column direction of the vents 240 is parallel to the first direction.

[0087] The diameter of the vent 240 may be greater than or equal to 4 mm and less than or equal to 8 mm. For example, the diameter of the vent 240 may be set to one of 4 mm, 5 mm, 6 mm, 7 mm and 8 mm to reduce the possibility of the vent 240 being blocked.

[0088] In the first direction, the distance between the vent 240 and the first reflective portion 163 may be greater than the distance between the vent 240 and the second reflective portion 164 .

[0089] When the fluid to be measured can flow from the air inlet 170 at the first end of the shell 110 along the first direction to the outer cavity 160 between the flow guide 200 and the shell 100, the fluid to be measured will oscillate and reflect along the first direction between the first reflection part 163 and the second reflection part 164.

[0090] The vent 240 is relatively close to the second part of the outer cavity 160, thereby delaying the time for the measured fluid to flow to the vent 240, reducing the possibility of the measured fluid flowing directly to the inner cavity 230 through the vent 240, and increasing the time for the measured fluid to oscillate and reflect between the first part of the inner wall of the outer cavity 160 and the second part of the inner wall of the outer cavity 160, thereby improving the noise reduction effect of the noise reduction structure.

[0091] When the fluid to be measured enters the inner cavity 230 from the outer cavity 160 through the vent 240, the fluid to be measured can be reflected between the inner wall of the inner cavity 230 and the air outlet pipe 300, thereby having a certain attenuation effect on the fluid to be measured, and the fluid to be measured can flow between the first end of the air outlet pipe 300 and the bottom wall of the inner cavity 230 into the air outlet pipe 300.

[0092] In summary, when the fluid to be measured passes through the noise reduction structure, the fluid to be measured can flow from the air inlet 170 at the first end of the shell 100 to the outer cavity 160 surrounded by the flow guide 200 and the shell 100, and the fluid to be measured will generate reflection and interference with the outer surfaces of the shell 100 and the flow guide 200, and the sound energy of the sound wave of the fluid to be measured is reduced, so as to achieve the effect of attenuating the noise of the fluid to be measured;

[0093] When the fluid to be measured enters the inner cavity 230 from the outer cavity 160 through the vent 240, the fluid to be measured can propagate between the flow guide 200 and the air outlet pipe 300, and the flow guide 200 and the air outlet pipe 300 vibrate back and forth, thereby causing friction damping in the fluid to be measured, and then the energy of the noise sound waves of the fluid to be measured can be consumed by the flow guide 200 and the air outlet pipe 300. The fluid to be measured can flow to the air outlet 180 through the air outlet pipe 300, thereby reducing the noise generated by the gas to be measured during flow, thereby improving the measurement accuracy of the flow meter.

[0094] The embodiment of the present application further provides a flow meter, comprising the above-mentioned noise reduction structure and a flow meter body. The noise reduction structure can be arranged upstream of the flow meter body.

[0095] Since the flow meter includes the above-mentioned spray noise reduction structure, the advantages of the flow meter including the above-mentioned noise reduction structure can be specifically referred to the relevant description above, which will not be repeated here.

[0096] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present invention.

[0097] In the description of the present invention, it should be understood that the terms "including" and "having" and any variations thereof used herein are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0098] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be directly connected or indirectly connected through an intermediate medium, and it can make the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances. In addition, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A noise reduction structure, characterized in that: comprising a shell and a flow guide; The shell extends along a first direction, an air inlet is provided at a first end of the shell, and an air outlet is provided at a second end of the shell; The guide member is disposed in the shell, an outer cavity is disposed between the guide member and the shell, the outer cavity and the air inlet are arranged along the first direction, and the outer cavity is communicated with the air inlet; The inner wall of the outer cavity comprises a first reflecting portion and a second reflecting portion which are arranged opposite to each other along the first direction, wherein the first reflecting portion is close to the air inlet and the second reflecting portion is far away from the air inlet; The flow guide is provided with an inner cavity and a vent, the inner cavity is communicated with the outer cavity through the vent, and the inner cavity is communicated with the air outlet.

2. The noise reduction structure according to claim 1, characterized in that: The flow guide member includes a first flow guide portion and a second flow guide portion arranged along the first direction, the first flow guide portion being closer to the first end of the shell relative to the second flow guide portion; The outer cavity includes a first outer cavity and a second outer cavity which are connected to each other; the first outer cavity is arranged between the first air guide portion and the first part of the shell, and the first outer cavity is connected to the air inlet; the second outer cavity is arranged between the second air guide portion and the second part of the shell, and the second outer cavity is connected to an end of the first outer cavity which is away from the air inlet.

3. The noise reduction structure according to claim 2, characterized in that: Taking a plane perpendicular to the first direction as a cross section, a cross-sectional area of ​​the first outer cavity is smaller than a cross-sectional area of ​​the second outer cavity.

4. The noise reduction structure according to claim 2, characterized in that: The second guide portion is configured as a cylindrical guide portion, and the cylindrical guide portion is connected to the second end of the shell; the vent is configured in the cylindrical guide portion, and the number of the vent is configured as a plurality; A plurality of the vents are arranged around the first direction, and the vents extend along the circumference of the cylindrical guide portion; Alternatively, the plurality of vents are arranged in multiple rows and columns, the row direction of the vents is parallel to the circumferential direction of the cylindrical guide portion, and the column direction of the vents is parallel to the first direction; And / or, in the first direction, a distance between the vent and the first reflecting portion is greater than a distance between the vent and the second reflecting portion.

5. The noise reduction structure according to claim 2, characterized in that: The first guide portion is configured as a conical guide portion; taking a plane perpendicular to the first direction as a cross section, the cross-sectional area of ​​the conical guide portion gradually decreases in a direction away from the second guide portion; The first part of the shell is configured as a conical portion, and the conical portion is coaxially configured with the conical guide portion; taking a plane perpendicular to the first direction as a cross section, the cross-sectional area of ​​the conical portion gradually decreases in a direction away from the second guide portion; The second guide portion is configured as a cylindrical guide portion, which is connected to the second end of the shell; the second part of the shell is configured as a cylindrical portion, which is coaxially arranged with the cylindrical guide portion, and the diameter of the conical portion is smaller than the diameter of the cylindrical portion.

6. The noise reduction structure according to claim 1, characterized in that: The noise reduction structure further includes an air outlet pipe, which is disposed in the inner cavity and extends along the first direction; the vent faces the outer surface of the air outlet pipe; The first end of the air outlet pipe faces the first end of the shell, and the first end of the air outlet pipe is communicated with the inner cavity; the second end of the air outlet pipe is communicated with the air outlet.

7. The noise reduction structure according to any one of claims 1 to 6, characterized in that: The housing comprises a first mounting member, a connecting member and a second mounting member arranged in sequence along the first direction; The first mounting member is provided with the air inlet, and the first mounting member includes the first reflecting portion; the second mounting member is provided with the air outlet, and the second mounting member includes the second reflecting portion.

8. The noise reduction structure according to claim 7, characterized in that: A first mounting groove is provided on a surface of the first mounting member facing the second mounting member; a second mounting groove is provided on a surface of the second mounting member facing the first mounting member; The first end of the connecting member is disposed in the first mounting groove, and the second end of the connecting member is disposed in the second mounting groove.

9. The noise reduction structure according to claim 7, characterized in that: The surface of the second mounting member facing the first mounting member is provided with an inserting groove, and the flow guide member is inserted into the inserting groove; And / or, a fixing groove is provided on a surface of the second mounting member facing the first mounting member, and the fixing groove is coaxially arranged on the air outlet.

10. A flow meter, characterized in that: It comprises the noise reduction structure as described in any one of claims 1 to 9 and a flow meter body, wherein the noise reduction structure is arranged upstream of the flow meter body.

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