Laminar flow stable type micro-channel gas metering and rectifying structure

Abstract

The invention relates to the technical field of gas flow meters, in particular to a laminar flow stable type micro-channel gas metering and rectifying structure which comprises a rectifying cover, a mounting frame, a first ultrasonic transducer and a second ultrasonic transducer, and the rectifying cover comprises a first section, a second section and a third section which are sequentially connected from left to right. The first ultrasonic transducer is arranged in the first section through a mounting frame, the second ultrasonic transducer is arranged in the third section through a mounting frame, fuel gas to be detected flows in from the left end of the first section and flows out from the right end of the third section, and the fuel gas firstly diffuses and then gathers to enter the third section when flowing in the second section. By means of the second section and the third section, natural gas can be buffered and diffused in the flowing process, then flows in a laminar flow mode and finally gathers together, a dead zone of gas retention can be avoided during buffering and diffusion, turbulent flow can be reduced while the response speed of the flowmeter is guaranteed, and the measuring precision is effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of gas flow meters, in particular to a laminar flow stable micro-channel gas metering rectification structure. Background Art

[0002] A gas flow meter is an instrument that can measure volume and is a type of smart sensor. By combining a gas flow meter with Internet of Things technology, high-precision measurement of gas flow can be achieved in the field of Internet of Things technology. This is especially true in the measurement of industrial natural gas flow, which can not only improve energy utilization efficiency but also reduce energy costs.

[0003] To ensure the stability and safety of natural gas supply and prevent gas leaks and fires, accurate flow monitoring can effectively monitor the flow rate in pipelines in real time, thereby promptly identifying and resolving flow anomalies. Traditional monitoring methods typically employ V-, N-, and W-shaped flow channel structures to ensure a more stable and uniform flow of gas, thereby ensuring measurement accuracy. However, due to the square cross-section and large cross-sectional area of ​​the flow channel, the gas flow rate is reduced, which not only reduces measurement sensitivity but also affects measurement accuracy. To address these issues, there are already good solutions in the prior art, such as the ultrasonic flow channel structure and gas flow meter disclosed in Publication No. CN108593026B. This design utilizes a cavity, a fairing, and an inner tube assembly, and utilizes the coordination of the fairing and inner tube assembly to perform multiple rectifications on the measured gas flow, making it more stable and ensuring measurement accuracy. However, a drawback remains: the gas needs to pass through the annular space formed between the fairing, inner tube, and cavity during its flow, resulting in a "dead zone" where the gas stagnates during flow, thus affecting the flow meter's response speed and measurement accuracy.

[0004] Therefore, in order to solve the above problems, a laminar flow stable microchannel gas metering and rectifying structure is proposed. Summary of the Invention

[0005] The present invention aims to provide a laminar flow-stabilized microchannel gas metering and rectification structure that addresses the problem of "dead zones" where gas is retained during flow, affecting measurement accuracy. By providing segments two and three, the natural gas to be measured can first undergo buffered diffusion, then flow in a laminar manner and ultimately converge. This buffered diffusion process avoids the generation of "dead zones" where gas is retained, ensuring the response speed of ultrasonic transducers one and two. Simultaneously, the natural gas to be measured can be diffused in a laminar manner and then gently converged, reducing the original turbulence in the gas and preventing the generation of new turbulence due to sudden convergence, effectively ensuring measurement accuracy.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A laminar flow-stabilized microchannel gas metering and rectifying structure includes a fairing, a mounting bracket, an ultrasonic transducer 1, and an ultrasonic transducer 2. The fairing includes a first segment, a second segment, and a third segment connected sequentially from left to right. The first ultrasonic transducer is disposed inside the first segment via the mounting bracket, and the second ultrasonic transducer is disposed inside the third segment via the mounting bracket. The gas to be measured flows in from the left end of the first segment and flows out through the right end of the third segment. When flowing inside the second segment, the gas first diffuses and then gathers to enter the third segment. After entering the third segment, the gas first forms a laminar flow and then gradually gathers and flows out.

[0008] Preferably, the segment one and segment three are both circular tubes, the inner wall connection between the segment one and segment two is set to a circular arc chamfer, the radial cross-section of the segment two is annular and the inner diameter decreases in a parabolic form from the middle to the two ends along the axial direction, and the inner diameters at both ends of the segment two are the same.

[0009] By adopting the above scheme, the natural gas to be measured will diffuse along the radial direction of segment two when it enters segment two from segment one, until it flows to the middle position of segment two and then begins to converge toward the axis in the radial direction, achieving the effect of first diffusion and then convergence, avoiding the generation of a "dead zone" during the flow of the natural gas to be measured, ensuring the response speed of ultrasonic transducer one and ultrasonic transducer two, that is, ensuring measurement accuracy.

[0010] Preferably, the section three includes an outer tube, a rectifier block and a gathering tube, the rectifier block and the gathering tube are connected and coaxially arranged inside the outer tube, a plurality of microchannels are axially arranged inside the rectifier block, the gathering tube includes a connected tube one and a tube two, the tube one is arranged between the rectifier block and the tube two, the inner diameter of the left end of the tube one is equal to the overall outer diameter of the area occupied by the multiple microchannels on the outlet end face of the rectifier block, and the radial cross-sectional area of ​​the inner wall of the tube two is equal to the sum of the radial cross-sectional areas of the multiple microchannels.

[0011] By adopting the above solution, the natural gas to be measured, which flows out of the multiple microchannels in the rectifying block in a laminar flow form, can gradually converge toward the axial position inside the first tube, avoiding the generation of large turbulence during the re-convergence process. Moreover, the converged gas will not diffuse or be further compressed and converged after entering the second tube, further avoiding the generation of turbulence, ensuring the stability of the flow of the natural gas to be measured, and thus ensuring measurement accuracy.

[0012] Preferably, a transition groove is provided at the left end of the rectifier block, the inner wall of the left end of the transition groove is smoothly connected to the inner wall of the right end of the segment 2, and the axial cross-section of the segment 2 and the transition groove together form an elliptical shape.

[0013] By adopting the above solution, the natural gas to be measured can smoothly enter the interior of the multi-layer microchannel when flowing out from the right end of segment 1, avoiding the left end of the rectifier block causing serious obstruction to the flow path of the natural gas to be measured and generating serious turbulence, thereby ensuring measurement accuracy.

[0014] Preferably, the tube one is a truncated cone-shaped tubular structure and the inner diameter decreases linearly from left to right. The inner wall of the right end of the tube one is smoothly connected to the inner wall of the left end of the tube two. The inner wall of the tube one is provided with a guide groove, and the cross-section of the guide groove is "U"-shaped. The depth of the right end of the guide groove decreases smoothly to zero and is tangent to the inner wall of the tube two. Anti-escape grooves are provided on both sides of the guide groove. The depth of the right end of the anti-escape groove decreases to zero and is tangent to the inner wall of the corresponding guide groove.

[0015] By adopting the above scheme, when the natural gas to be measured flows out from the right end of multiple microchannels, part of the gas near the edge of the inner wall of tube one can enter the corresponding guide groove and then diffuse into the interior of the anti-escape groove on both sides of the guide groove, thereby preventing the gas at the edge from flowing along the radial direction of tube one and limiting the flow of gas in the guide groove, preventing the gas in the guide groove from escaping and colliding with nearby gas to produce unstable turbulence, and the gas flowing from the right end of the anti-escape groove to the guide groove and from the right end of the guide groove to the interior of tube two can achieve a smooth transition, further avoiding the generation of turbulence, thereby ensuring measurement accuracy.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. By setting up sections one, two, and three, the natural gas to be measured flows along the axial direction after entering from the left end of section one. The gas first diffuses and then gathers inside section two, which can avoid the formation of a "dead zone" where gas is retained, thereby ensuring the response speed of ultrasonic transducer one and ultrasonic transducer two. Moreover, when the gas flows into section three, it will first form a multi-layer laminar flow under the action of multiple microchannels inside the rectifier block, reducing turbulence during gas flow and making the flow rate of the natural gas to be measured more stable, thereby ensuring measurement accuracy.

[0018] 2. By opening a transition groove on the left end face of the rectifier block and utilizing the ellipsoidal space formed by the transition groove and the inner wall of the right end of segment 2, a smooth transition can be made to the natural gas to be measured before it enters the multi-layer microchannel, avoiding the left end face of the rectifier block from blocking the gas and causing unstable turbulence of the gas, further ensuring the measurement accuracy.

[0019] 3. Through the provided converging tube, the natural gas to be measured flows out from the multiple microchannels inside the rectifier block, and then gradually converges to the inside of tube 2 through tube 1 of the converging tube. In the process of convergence, part of the gas at the edge position will be restricted in flow direction by the action of the guide groove and the corresponding anti-escape groove, avoiding the gas flowing in the radial direction of tube 1 and generating turbulence, further ensuring the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall cross-sectional structure of the present invention;

[0021] Figure 2 Schematic diagram of the cross-sectional connection structure of segment 2 and segment 3 of the present invention;

[0022] Figure 3 For the present invention Figure 2 Enlarged view of part A in the middle;

[0023] Figure 4 For the present invention Figure 2 A schematic diagram of a top-view cross-sectional structure;

[0024] Figure 5 It is a structural schematic diagram of the gathering tube of the present invention;

[0025] Figure 6 Schematic diagram of the cross-sectional structure of the gathering tube of the present invention;

[0026] Figure 7 For the present invention Figure 6 Enlarged view of the middle part B;

[0027] Figure 8 For the present invention Figure 6 Enlarged view of part C in the middle.

[0028] In the figure: 1. Fairing; 11. Section 1; 12. Section 2; 13. Section 3; 131. Outer tube; 132. Rectifier block; 1321. Microchannel; 1322. Transition trough; 133. Converging tube; 1331. Tube 1; 13311. Guide trough; 13312. Anti-escape trough; 1332. Tube 2; 2. Mounting bracket; 3. Ultrasonic transducer 1; 4. Ultrasonic transducer 2. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] See also Figures 1 to 8 The present invention provides a laminar flow stable microchannel gas metering and rectification structure, and the technical solution is as follows:

[0031] For details, please refer to Figure 1 、 Figure 2 and Figure 3 A laminar stable microchannel gas metering and rectifying structure includes a fairing 1, a mounting bracket 2, an ultrasonic transducer 1 3, and an ultrasonic transducer 2 4. The fairing 1 includes a segment 1 11, a segment 2 12, and a segment 3 13 connected in sequence from left to right. The ultrasonic transducer 1 3 is arranged inside the segment 1 11 through the mounting bracket 2, and the ultrasonic transducer 2 4 is arranged inside the segment 3 13 through the mounting bracket 2. The gas to be measured flows into the left end of the segment 1 11 and flows out through the right end of the segment 3 13. When the gas flows inside the segment 2 12, it first diffuses and then gathers to enter the segment 3 13. After entering the segment 3 13, the gas first forms a laminar flow and then gradually gathers and flows out.

[0032] As an embodiment of the present invention, refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , segment 1 11 and segment 3 13 are both circular tubes, the inner wall connection of segment 11 and segment 2 12 is set to a circular chamfer, the radial cross-section of segment 2 12 is annular and the inner diameter decreases in a parabolic form from the middle to the two ends along the axial direction, the inner diameters of both ends of segment 2 12 are the same, and a transition groove 1322 is provided at the left end of the rectifier block 132, the inner wall of the left end of the transition groove 1322 is smoothly connected to the inner wall of the right end of segment 2 12, and the axial cross-sections of segment 2 12 and the transition groove 1322 together form an elliptical shape.

[0033] Under the above-mentioned setting conditions, after the natural gas to be tested enters from the left end of segment 11, it first contacts ultrasonic transducer 13. Ultrasonic transducer 13 sends a signal and follows the flow direction of the gas to be received by ultrasonic transducer 2 4. In addition, when the gas flows from segment 11 to the inside of segment 2 12, it can achieve a smooth transition from the arc chamfer. After entering the inside of segment 2 12, it can first diffuse in the direction away from the axis of segment 2 12 and then gather in the direction close to the axis of segment 2 12. In the slow expansion and slow contraction flow channel of segment 2 12, the gas first diffuses smoothly and fills its internal space, and then gently gathers towards the central axis, avoiding the existence of a "dead zone" of gas retention during the flow process, thereby ensuring the response speed of ultrasonic transducer 13 and ultrasonic transducer 2 4. At the same time, when the natural gas to be tested enters the transition groove 1322 from the right end of segment 2 12, it can avoid being suddenly blocked and generating more turbulence, effectively ensuring the subsequent measurement accuracy.

[0034] As an embodiment of the present invention, refer to Figure 2 、 Figure 3 、 Figure 4 、 Figure 5and Figure 6 Section three 13 includes an outer tube 131, a rectifying block 132 and a gathering tube 133. The rectifying block 132 and the gathering tube 133 are connected and coaxially arranged inside the outer tube 131. A plurality of microchannels 1321 are axially arranged inside the rectifying block 132. The radial cross-section of each microchannel 1321 is circular and passes through the rectifying block 132. The plurality of microchannels 1321 are closely arranged in a honeycomb shape. The gathering tube 133 includes a connected tube 1 1331 and a second tube 1332. The tube 1 1331 is arranged between the rectifying block 132 and the second tube 1332. The inner diameter of the left end of the tube 1 1331 is equal to the overall outer diameter of the area occupied by the plurality of microchannels 1321 on the outlet end face of the rectifying block 132. The radial cross-sectional area of ​​the inner wall of the tube 2 1332 is equal to the sum of the radial cross-sectional areas of the plurality of microchannels 1321.

[0035] Under the above-mentioned setting conditions, the natural gas to be measured is re-gathered from the right end of the second segment 12 and then dispersed into multiple layers, and respectively enters the interior of the corresponding microchannel 1321 to flow in a laminar manner, reducing turbulence in the natural gas to be measured and making the flow rate of the natural gas to be measured more stable. After flowing out from the right ends of the multiple microchannels 1321, the natural gas to be measured can smoothly enter the interior of the first tube 1331. After entering the interior of the first tube 1331, the natural gas to be measured is gradually gathered under the action of the gathering tube 133, which prevents the natural gas to be measured from being re-dispersed and also slows down its gathering speed, preventing turbulence from re-generating and affecting the measurement accuracy. At the same time, since the cross-sectional area of ​​the second tube 1332 is equal to the sum of the radial cross-sectional areas of the multiple microchannels 1321, the natural gas to be measured will not be excessively gathered, further ensuring the measurement accuracy.

[0036] As an embodiment of the present invention, refer to Figure 5 、 Figure 6 、 Figure 7 and Figure 8 Tube one 1331 is a truncated cone-shaped tubular structure and its inner diameter decreases linearly from left to right. The inner wall of the right end of tube one 1331 is smoothly connected to the inner wall of the left end of tube two 1332. A guide groove 13311 is provided on the inner wall of tube one 1331. The cross-section of the guide groove 13311 is "U"-shaped. The depth of the right end of the guide groove 13311 decreases smoothly to zero and is tangent to the inner wall of tube two 1332. Anti-escape grooves 13312 are provided on both sides of the guide groove 13311. The depth of the right end of the anti-escape groove 13312 decreases to zero and is tangent to the inner wall of the corresponding guide groove 13311.

[0037] Under the above-mentioned setting conditions, after the natural gas to be measured flows into tube one 1331 in the form of laminar flow from multiple microchannels 1321, it can gradually gather toward the axis inside the conical tube one 1331, and in the process of gathering, part of the gas at the edge position can enter the corresponding guide groove 13311. The gas entering the guide groove 13311 is prevented from escaping outward by the anti-escape groove 13312, so that the natural gas to be measured is prevented from diffusing to the surroundings during the gathering process, and thus the natural gas to be measured will not generate new turbulence after entering the interior of tube two 1332, thereby further ensuring the measurement accuracy.

[0038] Working principle:

[0039] The natural gas to be measured is introduced into the interior of segment 11, so that it flows through segment 11, segment 2 12, and segment 3 13 in sequence and flows out from the right end of segment 3 13. Ultrasonic transducers 1 3 and 2 4 are activated. The signal emitted by ultrasonic transducer 1 3 is transmitted along the flow direction of the gas and is received by ultrasonic transducer 2 4. The signal emitted by ultrasonic transducer 2 4 is transmitted against the flow direction of the gas and is received by ultrasonic transducer 1 3. The flow rate of the natural gas to be measured can be calculated using the time difference between the two received signals and the transmission speed of the ultrasonic signal. (The measurement process here is prior art and is not described in detail.)

[0040] Since the inner diameter of the second segment 12 decreases in a parabolic manner from the middle to both ends, and the transition groove 1322 opened at the left end of the rectifier block 132 forms an ellipsoid with the inner wall surface of the right end of the second segment 12, when the gas enters the second segment 12 from the first segment 11, it will diffuse toward the edge of the second segment 12 and then re-gather, avoiding the existence of a "dead zone" in the gas flow path that affects the response accuracy of the ultrasonic transducer 1 3 and the ultrasonic transducer 2 4. In addition, during the gathering process, the transition groove 1322 can be used for a smooth transition, avoiding the left end surface of the rectifier block 132 from blocking the flow of gas and generating unstable turbulence. The gas entering the transition groove 1322 is then separated into multiple layers under the action of the multiple microchannels 1321 and flows in the form of laminar flow, further reducing the unstable turbulence in the gas.

[0041] Multiple high-speed air flow beams flowing out from multiple microchannels 1321, after entering tube 1 1331, are gradually converged and gathered toward the central axis under the guidance of its conical inner wall. In the process of gathering, part of the gas located at the edge position will enter the corresponding guide groove 13311 and be restricted by the anti-escape groove 13312 on both sides of the guide groove 13311, so as to prevent the gas at the edge from rotating around the axis direction while flowing along the axis direction of tube 1 1331, until it finally enters the interior of tube 2 1332 and gathers, thereby reducing turbulence in the gas and avoiding the generation of new turbulence when the gas re-gathers, thereby ensuring the stable flow of the natural gas to be measured and thus ensuring the measurement accuracy.

[0042] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A laminar flow stable microchannel gas metering and rectifying structure, comprising a fairing (1), a mounting frame (2), an ultrasonic transducer 1 (3) and an ultrasonic transducer 2 (4), characterized in that: The fairing (1) includes a first section (11), a second section (12) and a third section (13) connected in sequence from left to right. The first ultrasonic transducer (3) is arranged inside the first section (11) through a mounting frame (2). The second ultrasonic transducer (4) is arranged inside the third section (13) through a mounting frame (2). The gas to be measured flows into the left end of the first section (11) and flows out through the right end of the third section (13). When the gas flows inside the second section (12), it first diffuses and then gathers to enter the third section (13). After entering the third section (13), the gas first forms a laminar flow and then gradually gathers and flows out.

2. The laminar flow stable microchannel gas metering and rectifying structure according to claim 1, characterized in that: The section one (11) and the section three (13) are both circular tubes. The inner wall connection between the section one (11) and the section two (12) is set to be an arc chamfered. The radial cross section of the section two (12) is annular and the inner diameter decreases in a parabolic form from the middle to the two ends along the axial direction. The inner diameters of the two ends of the section two (12) are the same.

3. The laminar flow stable microchannel gas metering and rectifying structure according to claim 2, characterized in that: The section three (13) includes an outer tube (131), a rectifying block (132) and a gathering tube (133), wherein the rectifying block (132) and the gathering tube (133) are connected and coaxially arranged inside the outer tube (131), and a plurality of microchannels (1321) are axially arranged inside the rectifying block (132), and the gathering tube (133) includes a connected tube one (1331) and a tube two (1332), wherein the tube one (1331) is arranged between the rectifying block (132) and the tube two (1332), and the inner diameter of the left end of the tube one (1331) is equal to the overall outer diameter of the area occupied by the plurality of microchannels (1321) on the outlet end face of the rectifying block (132).

4. The laminar flow stable microchannel gas metering and rectifying structure according to claim 3, characterized in that: A transition groove (1322) is provided at the left end of the rectifier block (132), the inner wall of the left end of the transition groove (1322) is smoothly connected to the inner wall of the right end of the segment 2 (12), and the axial cross-sections of the segment 2 (12) and the transition groove (1322) together form an elliptical shape.

5. The laminar flow stable microchannel gas metering and rectifying structure according to claim 3, characterized in that: The tube one (1331) is a truncated cone-shaped tubular structure with an inner diameter that decreases linearly from left to right. The inner wall of the right end of the tube one (1331) is smoothly connected to the inner wall of the left end of the tube two (1332). A guide groove (13311) is provided on the inner wall of the tube one (1331), and anti-escape grooves (13312) are provided on both sides of the guide groove (13311).

6. The laminar flow stable microchannel gas metering and rectifying structure according to claim 5, characterized in that: The cross section of the guide groove (13311) is "U"-shaped, and the depth of the right end of the guide groove (13311) decreases smoothly to zero and is tangent to the inner wall of the second tube (1332).

7. The laminar flow stable microchannel gas metering and rectifying structure according to claim 5, characterized in that: The depth of the right end of the anti-escape groove (13312) decreases to zero and is tangent to the inner wall of the corresponding guide groove (13311).

8. The laminar flow stable microchannel gas metering and rectifying structure according to claim 6, characterized in that: The radial cross-sectional area of ​​the inner wall of the second tube (1332) is equal to the sum of the radial cross-sectional areas of the multiple microchannels (1321).

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