Laminar flow stable micro-channel gas metering rectifier structure

Abstract

The application relates to the technical field of gas flow meters, in particular to a laminar flow stable micro-flow channel gas metering rectifying structure, which comprises a rectifying cover, a mounting frame, an ultrasonic transducer one and an ultrasonic transducer two. The rectifying cover comprises section one, section two and section three which are sequentially connected from left to right. The ultrasonic transducer one is arranged in the section one through the mounting frame, and the ultrasonic transducer two is arranged in the section three through the mounting frame. The measured fuel gas flows into the section one from the left end and flows out from the right end of the section three, and the fuel gas diffuses first and then converges into the section three when flowing in the section two. The section two and the section three are arranged, the natural gas can flow in the form of laminar flow after buffering and diffusing in the process of flowing, and finally converges, the 'dead zone' of gas stagnation can be avoided when buffering and diffusing, the response speed of the flow meter can be ensured, the generation of turbulent flow can be reduced, and the measurement precision is effectively ensured.

Description

Technical Field

[0001] This invention relates to the field of gas flow meter technology, specifically to a laminar flow stable microchannel gas metering and rectification structure. Background Technology

[0002] A gas flow meter is an instrument that measures gas flow by volume. It is a type of smart sensor. By combining the gas flow meter with Internet of Things (IoT) technology, high-precision measurement of gas flow can be achieved in the field of IoT technology. Especially in industrial natural gas flow measurement, it 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, precise flow monitoring can effectively monitor the flow rate in pipelines in real time, allowing for timely detection and resolution of flow anomalies. Traditional monitoring methods typically employ V-shaped, N-shaped, and W-shaped flow channel structures to ensure more stable and uniform gas flow and guarantee measurement accuracy. However, the square cross-section and large cross-sectional area of ​​the flow channel reduce the gas velocity, affecting both measurement sensitivity and accuracy. Existing technologies offer solutions to these problems, such as the ultrasonic-based flow channel structure and gas flow meter (publication number CN108593026B). This meter utilizes a cavity, a rectifier, and an inner tube assembly. The rectifier and inner tube assembly work together to rectify the measured gas flow multiple times, making it more stable and ensuring measurement accuracy. However, this method still has drawbacks: the gas must pass through the annular space formed by the rectifier, inner tube, and cavity during flow, creating a "dead zone" that affects 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 rectification structure is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a laminar flow stable microchannel gas metering and rectification structure, which solves the problem of "dead zones" where gas stagnation occurs during flow, affecting measurement accuracy. Through the design of sections two and three, the natural gas to be measured can first undergo buffering and diffusion, then flow in a laminar flow manner and finally converge. During buffering and diffusion, the "dead zones" of gas stagnation are avoided, ensuring the response speed of ultrasonic transducers one and two. Simultaneously, the natural gas to be measured can be diffused and then gently converged in a laminar flow manner, reducing the original turbulence in the gas and preventing sudden convergence that could generate new turbulence, effectively ensuring measurement accuracy.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A laminar flow stable microchannel gas metering and rectification structure includes a rectifier shroud, a mounting frame, an ultrasonic transducer 1, and an ultrasonic transducer 2. The rectifier shroud includes three sections connected sequentially from left to right: section 1, section 2, and section 3. The ultrasonic transducer 1 is mounted inside section 1 via the mounting frame, and the ultrasonic transducer 2 is mounted inside section 3 via the mounting frame. The gas to be measured flows in from the left end of section 1 and flows out from the right end of section 3. When the gas flows inside section 2, it first diffuses and then converges before entering section 3. After entering section 3, the gas first forms a laminar flow and then gradually converges before flowing out.

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

[0009] By adopting the above scheme, the natural gas to be tested will diffuse along the radial direction of Section 2 as it enters Section 2 from Section 1, until it flows to the middle of Section 2 and begins to converge towards the axis in the radial direction. This achieves the effect of first diffusing and then converging, avoiding the "dead zone" of stagnation during the flow of the natural gas to be tested, and ensuring the response speed of ultrasonic transducer 1 and ultrasonic transducer 2, that is, ensuring measurement accuracy.

[0010] Preferably, segment three includes an outer tube, a rectifier block, and a converging tube. The rectifier block and the converging tube are connected and coaxially disposed inside the outer tube. The rectifier block has multiple microchannels arranged axially inside. The converging tube includes a first tube and a second tube connected to each other. The first tube is disposed between the rectifier block and the second tube. The inner diameter of the left end of the first tube is equal to the overall outer diameter of the area occupied by the multiple microchannels on the outlet end face of the rectifier block. The radial cross-sectional area of ​​the inner wall of the second tube is equal to the sum of the radial cross-sectional areas of the multiple microchannels.

[0011] By adopting the above scheme, the natural gas to be tested flowing out from multiple microchannels in the rectifier block in a laminar flow form can gradually gather towards the axis position inside the first pipe, avoiding the generation of large turbulence during the re-gathering process. Furthermore, the gathered gas will not diffuse or further compress and gather after entering the second pipe, further avoiding the generation of turbulence and ensuring the stability of the flow of the natural gas to be tested, thereby ensuring the measurement accuracy.

[0012] Preferably, the left end of the rectifier block is provided with a transition groove, the inner wall of the left end of the transition groove is smoothly connected to the inner wall of the right end of the second segment, and the axial cross section of the second segment and the transition groove together form an ellipse.

[0013] By adopting the above scheme, the natural gas to be tested can smoothly enter the interior of the multi-layer microchannel when it flows out from the right end of section one, avoiding severe obstruction of the flow path of the natural gas to be tested by the left end of the rectifier block and thus avoiding severe turbulence, thereby ensuring measurement accuracy.

[0014] Preferably, the first tube 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 first tube is smoothly connected to the inner wall of the left end of the second tube. A flow guide groove is formed on the inner wall of the first tube. The cross-section of the flow guide groove is U-shaped. The depth of the right end of the flow guide groove smoothly decreases to zero and is tangent to the inner wall of the second tube. An anti-escape groove is formed on both sides of the flow 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 flow guide groove.

[0015] By adopting the above scheme, when the natural gas to be measured flows out from the right end of multiple microchannels, a portion of the gas near the inner wall edge of pipe one can enter the corresponding guide groove and then diffuse into the interior of the anti-escape grooves on both sides of the guide groove. This prevents the gas at the edge from flowing radially along pipe one, while also restricting the gas flow in the guide groove, preventing the gas in the guide groove from escaping and colliding with nearby gas to generate unstable turbulence. 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 pipe two can achieve a smooth transition, further avoiding the generation of turbulence and thus ensuring measurement accuracy.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. Through the set sections one, two, and three, the natural gas to be tested enters from the left end of section one and flows along the axial direction. The gas diffuses and then converges inside section two, which can avoid the formation of "dead zones" where the gas stagnates. This ensures the response speed of ultrasonic transducers one and two. Furthermore, when the gas flows into section three, it first forms a multi-layer laminar flow under the action of multiple microchannels inside the rectifier block, reducing turbulence during gas flow and making the flow velocity of the natural gas to be tested more stable, thereby ensuring measurement accuracy.

[0018] 2. By using the transition groove opened on the left end face of the rectifier block, and the ellipsoidal space formed by the transition groove and the inner wall of the right end of section two, the natural gas to be measured can be smoothly transitioned before entering the multi-layer microchannel. This avoids the left end face of the rectifier block obstructing the gas and causing unstable turbulence, thus further ensuring the measurement accuracy.

[0019] 3. Through the set gathering pipe, the natural gas to be tested flows out from multiple microchannels inside the rectifier block and gradually gathers into the interior of the second pipe through the first pipe of the gathering pipe. During the gathering process, some gas at the edge position is restricted in its flow direction by the action of the guide groove and the corresponding anti-escape groove, which prevents the gas from flowing in the radial direction of the first pipe and generating turbulence, thus further ensuring the measurement accuracy. Attached Figure Description

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

[0021] Figure 2 This is a cross-sectional view of the connection structure between segment two and segment three of the present invention;

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

[0023] Figure 4 For the present invention Figure 2 A top-view sectional structural diagram;

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

[0025] Figure 6 This is a cross-sectional view of the convergence tube of the present invention;

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

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

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

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figures 1 to 8 This invention provides a laminar flow stable microchannel gas metering and rectification structure, the technical solution of which is as follows:

[0031] For details, please refer to Figure 1 , Figure 2 and Figure 3 A laminar flow stable microchannel gas metering and rectification structure includes a rectifier 1, a mounting frame 2, an ultrasonic transducer 3, and an ultrasonic transducer 4. The rectifier 1 includes three segments 11, 12, and 13 connected from left to right. The ultrasonic transducer 3 is installed inside the segment 11 via the mounting frame 2, and the ultrasonic transducer 4 is installed inside the segment 13 via the mounting frame 2. The gas to be measured flows in from the left end of the segment 11 and flows out from the right end of the segment 13. When the gas flows inside the segment 2, it first diffuses and then gathers before entering the segment 13. After entering the segment 13, the gas first forms a laminar flow and then gradually gathers before flowing out.

[0032] As one embodiment of the present invention, refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 Both Section 11 and Section 313 are circular tubes. The inner wall connection between Section 11 and Section 212 is set with a rounded chamfer. The radial section of Section 212 is annular and the inner diameter decreases parabolically from the middle to both ends along the axial direction. The inner diameters at both ends of Section 212 are the same. 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 Section 212. The axial sections of Section 212 and the transition groove 1322 together form an ellipse.

[0033] Under the above conditions, the natural gas to be tested enters from the left end of section 11 and first contacts ultrasonic transducer 3. Ultrasonic transducer 3 emits a signal, which is received by ultrasonic transducer 4 along the gas flow direction. When the gas flows from section 11 into section 2, it can achieve a smooth transition at the rounded corner. After entering section 2, it can first diffuse away from the axis of section 2 and then converge towards the axis of section 2. In the slow-expansion-slow-contraction channel of section 2, the gas first diffuses gently and fills its internal space, and then gently converges towards the central axis, avoiding the existence of "dead zones" of stagnation in the gas flow process, thereby ensuring the response speed of ultrasonic transducer 3 and ultrasonic transducer 4. At the same time, when the natural gas to be tested enters the transition tank 1322 from the right end of section 2, it can avoid being suddenly blocked and generating more turbulence, effectively ensuring the subsequent measurement accuracy.

[0034] As one embodiment of the present invention, refer to Figure 2 , Figure 3 , Figure 4 , Figure 5and Figure 6 Section 3 13 includes an outer tube 131, a rectifier block 132, and a converging tube 133. The rectifier block 132 and the converging tube 133 are connected and coaxially arranged inside the outer tube 131. Multiple microchannels 1321 are arranged axially inside the rectifier block 132. The radial cross-section of each microchannel 1321 is circular and penetrates the rectifier block 132. The multiple microchannels 1321 are arranged in a honeycomb pattern. The converging tube 133 includes a first tube 1331 and a second tube 1332 connected to each other. The first tube 1331 is arranged between the rectifier block 132 and the second tube 1332. The inner diameter of the left end of the first tube 1331 is equal to the overall outer diameter of the area occupied by the multiple microchannels 1321 on the outlet end face of the rectifier block 132. 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.

[0035] Under the above settings, the natural gas to be tested re-gathers from the right end of section 2 12 and disperses into multiple layers, which then enter the interior of the corresponding microchannels 1321 and flow in a laminar manner, reducing turbulence in the natural gas and making the flow velocity of the natural gas more stable. After the natural gas to be tested flows out from the right end of multiple microchannels 1321, it can smoothly enter the interior of pipe 1 1331. After entering the interior of pipe 1 1331, the natural gas to be tested gradually gathers under the action of the gathering pipe 133, which prevents the natural gas to be tested from redispersing and also slows down its gathering speed, preventing the regeneration of turbulence and affecting the measurement accuracy. At the same time, since the cross-sectional area of ​​pipe 2 1332 is equal to the sum of the radial cross-sectional areas of multiple microchannels 1321, the natural gas to be tested will not be excessively gathered, further ensuring the measurement accuracy.

[0036] As one embodiment of the present invention, refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 Pipe 1331 is a truncated cone-shaped tubular structure with its inner diameter decreasing linearly from left to right. The inner wall of the right end of pipe 1331 is smoothly connected to the inner wall of the left end of pipe 2 1332. A flow guide groove 13311 is provided on the inner wall of pipe 1331. The cross-section of the flow guide groove 13311 is "U" shaped. The depth of the right end of the flow guide groove 13311 smoothly decreases to zero and is tangent to the inner wall of pipe 2 1332. An anti-escape groove 13312 is provided on both sides of the flow 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 flow guide groove 13311.

[0037] Under the above conditions, after the natural gas to be tested flows into the first tube 1331 in a laminar flow from multiple microchannels 1321, it can gradually gather towards the axis inside the first tapered tube 1331. During the gathering process, some gas at the edge position can enter the interior of the corresponding guide groove 13311. The gas inside the guide groove 13311 is prevented from escaping outward by the anti-escape groove 13312, so that the natural gas to be tested avoids spreading to the surroundings during the gathering process. As a result, the natural gas to be tested will not generate new turbulence after entering the interior of the second tube 1332, further ensuring the measurement accuracy.

[0038] Working principle:

[0039] The natural gas to be tested is introduced into section 11, and then flows through section 11, section 2, and section 3 in sequence, exiting from the right end of section 3. Ultrasonic transducers 1 and 2 are activated. The signal emitted by ultrasonic transducer 1 is transmitted in the direction of gas flow to ultrasonic transducer 2 and 4, while the signal emitted by ultrasonic transducer 2 is transmitted against the direction of gas flow to ultrasonic transducer 1 and 3. The flow rate of the natural gas to be tested can be calculated using the time difference between the received signals and the transmission speed of the ultrasonic signal (the measurement process here is existing technology, so it is not described in detail).

[0040] Since the inner diameter of section 2 12 decreases parabolically 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 of the right end of section 2 12, when the gas enters section 2 12 from section 11, it will diffuse towards the edge of section 2 12 and then re-converge, avoiding the presence of a "dead zone" in the gas flow path that would affect the response accuracy of ultrasonic transducer 1 3 and ultrasonic transducer 2 4. In addition, during the convergence process, the transition groove 1322 can be used for a smooth transition, avoiding the left end face of the rectifier block 132 from blocking the gas flow and generating unstable turbulence. The gas entering the transition groove 1322 is then separated into multiple layers and flows in a laminar form under the action of multiple microchannels 1321, further reducing the unstable turbulence in the gas.

[0041] Multiple high-speed gas streams flowing from the microchannels 1321 gradually converge and gather towards the central axis after entering the first tube 1331, guided by its conical inner wall. During the convergence process, some gas at the edge enters the corresponding guide groove 13311 and is restricted by the anti-escape grooves 13312 on both sides of the guide groove 13311, preventing the gas at the edge from rotating around the axis while flowing along the first tube 1331. This process continues until the gas finally enters the second tube 1332 and converges, reducing turbulence in the gas and preventing new turbulence from being generated when the gas reconverges, thus ensuring the stable flow of the natural gas being measured and thereby guaranteeing measurement accuracy.

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

Claims

1. A laminar flow stable microchannel gas metering and rectification structure, comprising a rectifier shroud (1), a mounting bracket (2), an ultrasonic transducer one (3), and an ultrasonic transducer two (4), characterized in that: The shroud (1) includes three sections (11), (12) and (13) connected from left to right. The ultrasonic transducer (3) is installed inside the first section (11) via a mounting bracket (2). The ultrasonic transducer (4) is installed inside the third section (13) via a mounting bracket (2). The gas to be tested flows in from the left end of the first section (11) and flows out from 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 to flow out. Both the first segment (11) and the third segment (13) are circular tubes. The inner wall connection of the first segment (11) and the second segment (12) is set with a rounded chamfer. The radial section of the second segment (12) is annular and the inner diameter decreases from the middle to both ends in a parabolic manner along the axial direction. The inner diameters of the two ends of the second segment (12) are the same. The third section (13) includes an outer tube (131), a rectifier block (132), and a converging tube (133). The rectifier block (132) and the converging tube (133) are connected and coaxially arranged inside the outer tube (131). Multiple microchannels (1321) are arranged axially inside the rectifier block (132). The converging tube (133) includes a first tube (1331) and a second tube (1332) connected to each other. The first tube (1331) is arranged between the rectifier block (132) and the second tube (1332). The inner diameter of the left end of the first tube (1331) is equal to the overall outer diameter of the area occupied by the multiple microchannels (1321) on the outlet end face of the rectifier block (132). The left end of the rectifier block (132) is provided with a transition groove (1322), 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 second section (12), and the axial cross section of the second section (12) and the transition groove (1322) together form an ellipse. The first tube (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 first tube (1331) is smoothly connected to the inner wall of the left end of the second tube (1332). A flow guide groove (13311) is provided on the inner wall of the first tube (1331), and anti-escape grooves (13312) are provided on both sides of the flow guide groove (13311). The cross-section of the guide channel (13311) is U-shaped, and the depth of the right end of the guide channel (13311) smoothly decreases to zero and is tangent to the inner wall of the second pipe (1332). The right end of the anti-escape groove (13312) decreases to zero in depth and is tangent to the inner wall of the corresponding guide groove (13311); 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).

Images