An ultrasonic flow meter flow channel

Abstract

The utility model relates to an ultrasonic flowmeter flow channel. Its characterized in that the flow channel is equipped with the reference channel perpendicular to the cylindrical surface and perpendicular with the gas flow velocity direction, reference channel both ends respectively install sound velocity transducer A and sound velocity transducer B, sound velocity transducer A and sound velocity transducer B constitute the pair of radiation transducer group, namely sound velocity calibration subassembly, the umbrella structure symmetry is equipped with the air inlet end and the air outlet end of flow channel, the umbrella structure surface is provided with a plurality of transducer bosses, the upstream transducer group and downstream transducer group for measuring the upstream and downstream time difference are installed in transducer boss, upstream transducer group and downstream transducer group staggered pair of radiation set up, the middle part of two umbrella structures is equipped with the wire clamp for the regular transducer wire harness. The utility model sets up a vertical sound channel perpendicular to the cylindrical surface on the flow channel as the reference channel of obtaining the absolute sound velocity under the recent working condition, places transducer A and transducer B respectively on the sound channel, lower two end faces, for detecting the absolute sound velocity of flowmeter under the working condition.

Description

Technical Field

[0001] This utility model relates to an ultrasonic flow meter channel. Background Technology

[0002] Ultrasonic flow meters, with no moving parts inside and virtually no obstruction on the pipe wall, do not increase pressure loss and offer a wide rangeability and high sensitivity, leading to their rapid development in the gas metering industry. However, they frequently encounter user complaints due to seasonal or time-of-day metering deviations. The main reasons are poor adaptability to changes in gas composition and a lack of real-time adjustment for temperature and pressure effects. Although the deviation may only be a few percentage points, considering the large flow rate, the resulting losses are not insignificant.

[0003] The velocity of sound under gas operating conditions is crucial and is a direct factor in calculating flow rate.

[0004] However, the velocity of sound is significantly affected by the composition of the gas, which is also influenced by upstream pipeline gas sources or pressure regulation and mixing at distribution stations, resulting in irregular changes. Due to production limitations and equipment constraints, most manufacturers typically measure the velocity of sound in air at normal pressure during laboratory or factory testing of their ultrasonic flow meters. They then adjust the velocity by adding empirical formulas to account for errors and correct for temperature and pressure before shipping. While the velocity can be further corrected using temperature and pressure sensors during operation, the corrected velocity still deviates significantly from the actual operating velocity due to variations in the medium. Therefore, periodic monitoring of the absolute velocity of sound is crucial. Utility Model Content

[0005] In view of the problems existing in the prior art, the purpose of this utility model is to provide a technical solution for the flow channel of an ultrasonic flow meter.

[0006] The ultrasonic flow meter channel is characterized by comprising a cylindrical flow channel, an umbrella-shaped structure, and a sound velocity calibration component.

[0007] The flow channel is provided with a reference channel that is perpendicular to the cylindrical surface and perpendicular to the direction of gas flow. Sound transducer A and sound transducer B are installed at both ends of the reference channel, respectively. Sound transducer A and sound transducer B constitute a through-beam transducer group, i.e., sound velocity calibration component.

[0008] The umbrella-shaped structure is symmetrically arranged at the air inlet and air outlet of the flow channel. Multiple transducer protrusions are provided on the surface of the umbrella-shaped structure. An upstream transducer group and a downstream transducer group for measuring the time difference between forward and reverse flow are installed in the transducer protrusions. The upstream transducer group and the downstream transducer group are arranged alternately and oppositely.

[0009] The two umbrella-shaped structures have wire clamps in the middle for organizing the transducer wiring harness.

[0010] The ultrasonic flow meter channel is characterized in that the outer wall of the channel is provided with a staggered front turbulence groove and a rear turbulence groove, the positions of the front turbulence groove and the rear turbulence groove on the umbrella-shaped structures at both ends are staggered.

[0011] The ultrasonic flow meter channel is characterized in that the clamp does not interfere with the front turbulent flow groove and the rear turbulent flow groove.

[0012] The ultrasonic flow meter channel is characterized in that the staggered arrangement of the front turbulence groove and the rear turbulence groove satisfies the following: the transducer boss of the umbrella-shaped structure at the air inlet corresponds to the position of the rear turbulence groove of the umbrella-shaped structure at the air outlet, and the transducer boss of the umbrella-shaped structure at the air outlet corresponds to the position of the front turbulence groove of the umbrella-shaped structure at the air inlet.

[0013] The ultrasonic flow meter channel is characterized in that the reference channel uses the horizontal reference plane of the channel as the positioning reference, and the axis of the reference channel coincides with the vertical reference line of the channel.

[0014] The ultrasonic flow meter channel is characterized in that the upstream transducer group and the downstream transducer group are symmetrically distributed on both sides of the reference channel, and each upstream transducer group and the downstream transducer group includes at least one pair of opposing transducers.

[0015] The ultrasonic flow meter flow channel is characterized in that the transducer is fixed to the transducer boss by a fastening nut, and the fastening nut has cut edges on all four sides so as not to interfere with the flow channel structure.

[0016] The ultrasonic flow meter flow channel is characterized in that the wire clamps are configured as multiple, and the wire clamps are provided with two holes, front and rear, respectively corresponding to the threading of different transducer wire harnesses.

[0017] The ultrasonic flow meter channel is characterized in that one end of the reference channel can be replaced with a reflective surface structure.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1) This utility model sets a vertical sound channel perpendicular to the cylindrical surface on the flow channel as a reference channel for obtaining the absolute sound velocity under recent operating conditions. Transducer A and transducer B are placed on the upper and lower end faces of the sound channel, respectively, to detect the absolute sound velocity of the flow meter under operating conditions. Among them, sound velocity transducer A and sound velocity transducer B are a set of mutually transmitting and receiving transducers. This design can greatly improve the measurement deviation of the original flow meter caused by seasonality or time period.

[0020] 2) This utility model symmetrically processes multiple transducer protrusions on the umbrella-shaped structure on both sides of the reference flow channel, and installs upstream transducer groups and downstream transducer groups on the transducer protrusions respectively; in this way, multiple pairs of transducers can work simultaneously and be compared and verified by measuring the time difference between upstream and downstream flow of each transducer, thus avoiding measurement errors caused by the failure of individual transducers.

[0021] 3) This utility model has multiple turbulent flow channels on the outside of the cylindrical flow channel. The turbulent flow channels are staggered on the umbrella-shaped structures at the front and rear, which further changes the airflow direction to form a stable flow field and ensures the repeatability of measurement accuracy.

[0022] 4) The present invention has a wire clamp in the middle part of the two umbrella-shaped structures, which can make the wire harness of the transducer arranged neatly, reducing the interference to the airflow and the generation of secondary flow.

[0023] 5) In the flow channel processing process, this utility model ensures that the coaxiality of each channel meets the measurement requirements by processing the inner hole of the flow channel last. Attached Figure Description

[0024] Figure 1 This is an overall structural diagram of the flow channel of this utility model;

[0025] Figure 2 This is a vertical sectional view of the flow channel of this utility model;

[0026] Figure 3 This is a top view of the flow channel of this utility model;

[0027] Figure 4 This is a side view of the flow channel of this utility model;

[0028] Figure 5 This is a cross-sectional view of the reference channel of this utility model;

[0029] Figure 6 This is a schematic diagram of the flow channel working principle of this utility model;

[0030] In the diagram: 1-flow channel, 2-sonic transducer A, 3-upstream transducer group, 4-sonic transducer B, 5-downstream transducer group, 6-fastening nut, 7-line clamp, 8-front turbulence channel, 9-rear turbulence channel, 10-vertical reference line, 11-horizontal reference plane, 12-umbrella-shaped structure, 13-transducer boss. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings:

[0032] An ultrasonic flow meter flow channel includes a cylindrical flow channel 1, an umbrella-shaped structure 12, and a sound velocity calibration component. The flow channel 1 has a reference channel perpendicular to the cylindrical surface and perpendicular to the gas flow direction. The reference channel uses the horizontal reference plane 11 of the flow channel 1 as a positioning reference, and the axis of the reference channel coincides with the vertical reference line 10 of the flow channel 1. Sound velocity transducers A2 and B4 are respectively installed at both ends of the reference channel, forming a through-beam transducer group, i.e., the sound velocity calibration component. The umbrella-shaped structure 12 is symmetrically arranged at the inlet and outlet ends of the flow channel 1, and its surface is provided with multiple transducer protrusions 13. An upstream transducer group 3 and a downstream transducer group 5 for measuring the time difference between forward and reverse flow are installed inside the transducer boss 13. The upstream transducer group 3 and the downstream transducer group 5 are symmetrically distributed on both sides of the reference channel. The upstream transducer group 3 and the downstream transducer group 5 are staggered and face each other. Each upstream transducer group 3 and the downstream transducer group 5 contains at least one pair of face-to-face transducers. The outer wall of the flow channel 1 is provided with a staggered front turbulence groove 8 and a rear turbulence groove 9. The positions of the front turbulence groove 8 and the rear turbulence groove 9 on the umbrella-shaped structures at both ends are staggered. The middle of the two umbrella-shaped structures 12 is provided with a wire clamp 7 for straightening the transducer wire bundle. The wire clamp 7 does not interfere with the front turbulence groove 8 and the rear turbulence groove 9.

[0033] like Figure 1 As shown, this utility model provides an ultrasonic flow meter channel. The flow meter channel 1 is integrally machined. A horizontal reference surface 11 is machined on the flow meter channel 1. Based on this reference, a reference channel perpendicular to the center of the horizontal surface and penetrating the flow meter channel is machined. A sound velocity transducer A2 and a sound velocity transducer B4 are respectively installed on the upper and lower end faces of the channel. Further, multiple transducer bosses 13 are symmetrically machined on the umbrella-shaped structures 12 on both sides of the reference channel. An upstream transducer group 3 and a downstream transducer group 5 are respectively installed in each transducer boss. Each transducer is fixed to its respective transducer boss by a fastening nut 6. Next, multiple turbulence channels are formed on the outside of the flow channel. These channels are staggered on the two umbrella-shaped structures 12 at the front and rear, and a wire clamp 7 is provided in the middle of the two umbrella-shaped structures 12 to ensure that the transducer wiring harness is neatly arranged. The sound velocity transducers A2 and B4 are also calibrated for absolute sound velocity when gas is not supplied, thus solving the measurement accuracy problem caused by inaccurate sound velocity. For details on the user's non-gas time determination scheme, please refer to 202410676740.0 Dynamic Leakage Monitoring and Graded Early Warning System Based on IoT Smart Gas Meter.

[0034] The basic working principle of sound transducers A2 and B4 based on the time difference method is as follows: Figure 6 As shown: Sound path is the distance between transducer surfaces. Channel angle gas flow rate Speed ​​of sound The flight times for the upstream and downstream directions are respectively , According to the formula:

[0035] (1)

[0036] (2)

[0037] Typically, disinfection is used. The method, which eliminates the influence of sound speed measurement, yields the following formula:

[0038] (3)

[0039] However, in field applications, the transmission of sound waves is easily affected by external factors. and Measurements inevitably suffer from wave error or loss, leading to incorrect values ​​and resulting in calculated flow velocities with significant deviations. The value severely affects measurement accuracy; and and The time difference is minimally affected and can be ignored. Therefore, the modified formula can be derived from the above formula:

[0040] (4)

[0041] Due to the speed of sound Much greater than the flow rate ,and Typically within the range of 30° to 60°, therefore, an approximate formula can be further derived:

[0042] (5)

[0043] This leads to the flow rate. The calculation formula is:

[0044] (6)

[0045] In the formula and Since both are constants, the flow velocity can be determined. and and Closely related, a dedicated sound velocity calibration channel is designed in the flow channel. This channel is perpendicular to the gas flow velocity direction and is calibrated by the sound path. and transmission time This allows us to obtain the real-time operating speed of sound. This solved the measurement accuracy problem caused by inaccurate sound velocity.

[0046] like Figure 2 , 3As shown, this invention symmetrically processes multiple channels on both sides of the vertical reference plane to which the reference channel belongs. Each channel is machined at a corresponding transducer boss 13, and an upstream transducer and a downstream transducer are installed in each channel. Furthermore, by measuring the forward and reverse flow time difference of each transducer, the linear velocity of each channel is calculated, and the surface velocity of the channel is obtained using conventional methods. Each transducer is fixed to its respective channel by a fastening nut 6. The fastening nut 6 has a four-sided chamfered design, unlike the original circular structure, which makes it easier to fasten the transducer while minimizing interference between the fastening nut 6 and the channel structure.

[0047] like Figure 3 As shown, this utility model has umbrella-shaped structures 12 at both the inlet and outlet ends of the cylindrical flow channel 1; a turbulence groove of preset width is provided between the transducer protrusions 13 on the same side (since the number of transducer groups is designed according to the actual product's required flow parameters, the number of transducer groups will affect the preset width of the turbulence groove, which is set according to experimental results). The turbulence groove is divided into a front turbulence groove 8 and a rear turbulence groove 9, which are staggered in position. That is, the transducer protrusion 13 of the umbrella-shaped structure at the inlet end corresponds to the rear turbulence groove 9 of the umbrella-shaped structure at the outlet end, and the transducer protrusion 13 of the umbrella-shaped structure at the outlet end corresponds to the front turbulence groove 8 of the umbrella-shaped structure at the inlet end. The staggered design of the umbrella-shaped structure 12 and the turbulence groove allows more transducer protrusions 13 to be arranged on the circumference of the flow channel 1, and allows more transducer channels to be installed on the umbrella-shaped structure 12, thus improving the metering accuracy of the flow channel 1. Furthermore, the staggered design of the umbrella-shaped structure 12 and the turbulence channel allows the airflow to flow in the direction set by the structure, further changing the airflow direction to form a stable flow field and ensuring the repeatability of measurement accuracy.

[0048] This invention features a wire clamp 7 in the middle of the umbrella-shaped structures 12 on both sides. The wire clamp 7 has two holes, one at the front and one at the back, corresponding to the threading of different transducer wire harnesses at the front and back, respectively. The wire clamp 7 ensures that the transducer wire harnesses form a regular winding on the circumferential structure of the flow channel 1, greatly reducing interference with the airflow and the generation of secondary flow.

[0049] like Figure 1 , 4 As shown in Figure 5, in the processing flow of the flow channel 1, the reference channel is first processed, and then multiple transducer bosses are symmetrically processed on the umbrella-shaped structures on both sides of the vertical reference plane to which the reference channel belongs. Finally, the inner hole of the flow channel is processed. This method ensures that the coaxiality of each channel meets the measurement requirements, so that the transducers do not have angular deviations in ultrasonic wave transmission or reflection due to excessive coaxiality deviation. This greatly improves the accuracy of transducer detection in each channel and ensures the measurement results of the flow channel. A rectifier screen can be set at both the front and rear ends of the inner hole of the flow channel to further rectify the airflow and improve the stability of measurement accuracy.

[0050] In practice, a reflective surface structure can be replaced on one side of the reference channel to replace the sound transducer on that side. Although the sound wave will be slightly deflected due to the increased reflectivity during high-speed flow, the effect is comparable.

[0051] The specific examples described in this utility model are merely illustrative of the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific examples or use similar methods to replace them, but without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0052] Although this invention uses terms such as flow channel, transducer, fluid, clamp, turbulent channel, time difference, sound velocity, channel angle, and umbrella structure frequently, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this invention; interpreting them as any additional limitation would contradict the spirit of this invention.

Claims

1. An ultrasonic flow meter flow channel, characterized by It includes a cylindrical flow channel (1), an umbrella-shaped structure (12), and a sound velocity calibration component; The flow channel (1) is provided with a reference channel that is perpendicular to the cylindrical surface and perpendicular to the direction of gas flow. Sound transducer A (2) and sound transducer B (4) are installed at both ends of the reference channel respectively. Sound transducer A (2) and sound transducer B (4) constitute a pair of transducers, namely the sound velocity calibration component. The umbrella-shaped structure (12) is symmetrically arranged at the air inlet and air outlet of the flow channel (1). Multiple transducer protrusions (13) are provided on the surface of the umbrella-shaped structure (12). An upstream transducer group (3) and a downstream transducer group (5) for measuring the time difference between forward and reverse flow are installed in the transducer protrusions (13). The upstream transducer group (3) and the downstream transducer group (5) are arranged alternately. The two umbrella-shaped structures (12) have wire clamps (7) in the middle for organizing the transducer wire harness.

2. The flow channel for an ultrasonic flow meter of claim 1, wherein The outer wall of the flow channel (1) is provided with a staggered front turbulence channel (8) and a rear turbulence channel (9), and the positions of the front turbulence channel (8) and the rear turbulence channel (9) on the umbrella-shaped structures at both ends are staggered.

3. The flow channel of an ultrasonic flow meter of claim 2, wherein The clamp (7) does not interfere with the front turbulence channel (8) and the rear turbulence channel (9).

4. The flow channel for an ultrasonic flow meter of claim 2, wherein The staggered arrangement of the front turbulence groove (8) and the rear turbulence groove (9) satisfies the following: the transducer boss (13) of the umbrella-shaped structure at the air inlet corresponds to the rear turbulence groove (9) of the umbrella-shaped structure at the air outlet, and the transducer boss (13) of the umbrella-shaped structure at the air outlet corresponds to the front turbulence groove (8) of the umbrella-shaped structure at the air inlet.

5. The flow channel of claim 1 wherein The reference channel uses the horizontal reference plane (11) of the flow channel (1) as the positioning reference, and the axis of the reference channel coincides with the vertical reference line (10) of the flow channel (1).

6. The flow channel of an ultrasonic flow meter of claim 1, wherein The upstream transducer group (3) and the downstream transducer group (5) are symmetrically distributed on both sides of the reference channel, and each upstream transducer group (3) and downstream transducer group (5) contains at least one pair of opposing transducers.

7. The flow channel of an ultrasonic flow meter of claim 6, wherein The transducer is fixed to the transducer boss (13) by a fastening nut (6). The fastening nut (6) has cut edges on all four sides, so it does not interfere with the flow channel structure.

8. The flow channel of an ultrasonic flow meter of claim 1, wherein Multiple wire clamps (7) are provided, and two holes are provided on the wire clamps (7) to correspond to the threading of different transducer wire harnesses at the front and rear.

9. The flow channel of an ultrasonic flow meter of claim 1, wherein One end of the reference channel can be replaced with a reflective surface structure.

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