Modular gas ultrasonic flowmeter

Abstract

The invention relates to the technical field of gas flow metering, in particular to a modularized gas ultrasonic flowmeter which comprises a measuring meter body, an ultrasonic transducer, an SPU signal processing unit, a pressure sensor and a temperature sensor, a measuring flow channel is formed in the measuring meter body, and a plurality of mounting holes are formed in the front end face and the rear end face of the measuring meter body; the mounting holes in the front end face and the rear end face of the measuring meter body are arranged in an X-shaped staggered mode, so that sound wave paths of the ultrasonic transducers are crossed, multi-angle measurement is formed, interference of vibration or displacement of a flow channel on an ultrasonic wave propagation path is effectively counteracted, and stability and accuracy of measurement are improved. The multiple ultrasonic transducers are installed in the multiple installation holes respectively, so that the transducers and the flow channel form a relatively stable whole, the influence of vibration on the relative positions of the transducers and the flow channel is reduced, and the measurement precision of the modularized gas ultrasonic flowmeter is guaranteed; and the operation stability and the anti-interference capability of the modularized gas ultrasonic flowmeter are improved.

Description

Technical Field

[0001] This invention relates to the field of gas flow measurement technology, specifically a modular ultrasonic gas flow meter. Background Technology

[0002] Modular ultrasonic gas flow meters are flow measurement devices based on ultrasonic technology. They achieve high-precision measurement of gas flow by integrating sensor, signal processing, and calibration functions into combinable modules. The core principle is to calculate flow velocity using the time difference of ultrasonic wave propagation in both upstream and downstream directions, combined with multi-channel design or intelligent algorithms to improve measurement accuracy. Existing integrated ultrasonic gas flow meters typically consist of a housing, a core unit, an ultrasonic transducer, a fluid channel, and an intelligent totalizer. The core unit has openings for the fluid channel at both ends, which are installed within mounting holes in the housing. The ultrasonic transducer is installed inside the core unit, and its external end connects to the intelligent totalizer, which is mounted on the core unit. The ultrasonic transducer uses an integrated design; there are no external removable parts on the ultrasonic transducer module. The module is installed as a whole, with each ultrasonic transducer individually packaged. In the existing technology, the measuring channel and the integrator base are combined into one unit. The combined structure has a large wall thickness, which leads to serious material waste. The integrated structure is bulky, difficult to process, and the processing accuracy is difficult to guarantee. During maintenance, the integrator needs to be removed together to perform maintenance operations, which makes maintenance inconvenient. At the same time, the integrated measuring channel and integrator base in the existing technology also have technical problems of difficult processing and inconvenient maintenance.

[0003] To address the aforementioned problems, existing technologies have proposed several solutions. For example, patent application CN202123173830.9 discloses a modular ultrasonic gas flow meter. This solution includes an integrator, an integrator base, a housing, a rectifier, and a measuring channel. The integrator is mounted on the integrator base, and the housing is connected to the integrator base. The housing contains a measuring channel, and the measuring channel contains a rectifier. The housing contains a limiting and positioning structure for installing the measuring channel, and the side of the housing has a side plate for easy insertion and removal of the measuring channel. This solution separates the measuring channel from the integrator base in existing technologies and opens it on the side of the housing, allowing the measuring channel and transducer to be installed independently from the side of the housing. Adding a process table and positioning surface to the independent measuring channel facilitates machining, ensures the accuracy of the probe hole position and installation positioning, and optimizes the overall structure to be lighter and reduce material waste. The measuring channel can be disassembled as a whole for easy maintenance. However, this solution still has some problems. While the measuring channel is installed inside the housing via a limiting and positioning structure, simplifying the installation process, it is prone to slight vibrations or displacements under high-velocity gas impact. This mechanical vibration can interfere with the propagation path of the ultrasonic signal, leading to measurement errors. Furthermore, the limiting structure does not employ an anti-loosening design, which may cause the connection to loosen under long-term vibration, further exacerbating measurement inaccuracies. Summary of the Invention

[0004] The purpose of this invention is to provide a modular ultrasonic gas flow meter to solve the problems of measurement errors caused by slight vibrations or displacements in the flow channel under high-velocity gas impact, and the further exacerbation of measurement inaccuracies due to loose connections caused by long-term vibration.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A modular ultrasonic gas flow meter includes a measuring body, ultrasonic transducers, an SPU signal processing unit, a pressure sensor, and a temperature sensor. The measuring body has a measuring flow channel. Multiple mounting holes are formed on the front and rear ends of the measuring body, all communicating with the measuring flow channel. These mounting holes are arranged in an X-shape, with multiple ultrasonic transducers installed within them. Cover plates are installed on the front and rear ends of the measuring body. The SPU signal processing unit is mounted on the upper end face of the measuring body. The pressure sensor and temperature sensor are respectively mounted on the front and rear inner walls of the measuring flow channel. All transducers are electrically connected to the SPU signal processing unit. Multiple mounting holes on the front and rear ends of the measuring instrument body are arranged in an X-shape, causing the ultrasonic transducer's sound wave paths to intersect and form multi-angle measurements. This effectively cancels out the interference of flow channel vibration or displacement on the ultrasonic wave propagation path, improving measurement stability and accuracy. Multiple ultrasonic transducers are installed in multiple mounting holes. This direct mounting method on the measuring instrument body makes the transducer and flow channel form a relatively stable whole, reducing the impact of vibration on the relative position between the transducer and flow channel, and ensuring accurate transmission of ultrasonic signals. This, in turn, ensures the measurement accuracy of the modular gas ultrasonic flow meter and improves its operational stability and anti-interference capability.

[0007] Preferably, the multiple mounting holes are arranged in low, middle, and high layers. The low-layer mounting holes are positioned higher than the inner wall of the bottom surface of the measuring channel. A flow-rectifying angle is provided at the connection point between the inner wall of each mounting hole and the inner wall of the measuring channel, and these angles are all arc-shaped. The arrangement of the low-layer mounting holes above the inner wall of the bottom surface of the measuring channel avoids the erosion and interference of liquid accumulation or impurities at the bottom of the channel on the low-layer ultrasonic transducer. The arc-shaped flow-rectifying angle at the connection point between the mounting hole and the channel reduces eddies and turbulence caused by structural abrupt changes when the gas flows through this area, preventing flow field disturbances from interfering with the ultrasonic wave propagation path. These design features collectively ensure the accuracy and stability of the modular gas ultrasonic flow meter, reduce the impact of impurities and flow field disturbances on the equipment, and improve the durability and measurement accuracy of the modular gas ultrasonic flow meter under complex operating conditions.

[0008] Preferably, a buffer groove is provided on the side of the multiple ultrasonic transducers near the mounting hole. The multiple buffer grooves are annular in shape, and a buffer ring is installed in each of the multiple buffer grooves. The multiple buffer rings are all made of rubber material. By setting the annular buffer groove and installing the rubber buffer ring on the side of the ultrasonic transducer near the mounting hole, the elastic buffering properties of rubber are utilized to avoid the problem of hard collision and loosening between the ultrasonic transducer and the mounting hole caused by vibration during equipment operation, as well as the problem of vibration transmission interfering with the propagation of ultrasonic signals. This ensures the structural stability of the modular gas ultrasonic flow meter, the accuracy of ultrasonic signal transmission, and improves the fatigue resistance and metering accuracy reliability of the modular gas ultrasonic flow meter under long-term vibration environment.

[0009] Preferably, multiple buffer grooves are provided with corrugated metal sheets located inside the buffer ring, and multiple ultrasonic transducers have a transmitting end at the end near the measuring flow channel. The transmitting end adopts a trapezoidal cross-section design. The corrugated metal sheets (located inside the buffer ring) in the buffer grooves form a dual vibration reduction structure by utilizing the elastic deformation of the corrugated metal sheets and the rubber damping characteristics of the buffer ring. This avoids the problems of loosening of the connection between the ultrasonic transducer and the mounting hole and interference of vibration transmission with ultrasonic signals caused by long-term vibration. By designing the transmitting end with a trapezoidal cross-section, the propagation angle and coverage of ultrasonic waves are expanded, avoiding the problem of unstable signal reception caused by local fluctuations in the flow field. These designs together ensure the structural shock resistance, signal transmission stability, and measurement accuracy consistency of the modular gas ultrasonic flow meter, and improve the long-term operational reliability of the modular gas ultrasonic flow meter under complex working conditions.

[0010] Preferably, each of the plurality of mounting holes has a guide section machined on the side near the front and rear end faces of the measuring instrument body. Each of the guide sections is tapered, with a taper of 15° to 30°. Anti-loosening rubber rings are installed on the inner walls of each of the mounting holes. Fine-pitch external threads are machined on the end of each of the ultrasonic transducers away from the measuring flow channel. The ultrasonic transducers are threadedly connected to the mounting holes. The 15° to 30° tapered guide sections on the mounting holes enable rapid alignment of the ultrasonic transducers during installation, preventing signal propagation angle shifts due to installation deviations. The anti-loosening rubber rings on the inner walls of the mounting holes engage with the fine-pitch external threads of the ultrasonic transducers, utilizing the elastic preload of the rubber rings and the self-locking properties of the fine-pitch threads to prevent loosening under long-term vibration. These designs collectively ensure the ease of installation and structural connection stability of the modular gas ultrasonic flow meter, reduce measurement deviations caused by installation errors and loosening, and improve the metering accuracy and long-term operational reliability of the modular gas ultrasonic flow meter.

[0011] Preferably, the ultrasonic transducer is made of any one of the following materials: duplex stainless steel, Hastelloy, and high-density tungsten carbide. Reinforcing surfaces are provided on the inner walls of the measuring channel and the mounting hole, and these reinforcing surfaces are ultra-polished with a surface roughness Ra ≤ 0.4 μm. Using duplex stainless steel, Hastelloy, or high-density tungsten carbide to make the ultrasonic transducer utilizes their high hardness and wear resistance, preventing erosion and wear from impurities in the gas. By providing ultra-polished reinforcing surfaces (surface roughness Ra ≤ 0.4 μm) to the inner walls of the measuring channel and the mounting hole, flow field disturbances and impurity adhesion during gas flow are reduced, avoiding ultrasonic wave propagation path deviation caused by surface roughness or wear. These design features collectively ensure the long-term structural integrity and measurement stability of the modular gas ultrasonic flow meter, and improve its wear resistance and the durability of its metering accuracy.

[0012] Preferably, the measuring channel is provided with an air inlet and an air outlet. A rectifier tube is installed on the air inlet, and the rectifier tube has multiple honeycomb holes inside. The length of the rectifier tube from the nearest mounting hole is 3 to 5 times the diameter of the measuring channel. Multiple microgrooves are machined on the inner wall of the multiple honeycomb holes. Installing a rectifier tube with honeycomb holes at the air inlet, and ensuring that the distance between the rectifier tube and the nearest mounting hole is 3 to 5 times the diameter of the measuring channel, allows sufficient distance for the gas to form a stable flow field after initial rectification through the honeycomb holes, avoiding interference from turbulent flow field on ultrasonic measurements. The microgrooves on the inner wall of the honeycomb holes further guide the orderly flow of air, reducing the generation of eddies and turbulence. These designs collectively ensure the accuracy and stability of the modular gas ultrasonic flow meter measurement and improve the adaptability of the modular gas ultrasonic flow meter to complex airflow conditions.

[0013] Preferably, a guide ring is installed within the measuring flow channel. This guide ring is composed of multiple variable-curvature airfoil blades and is located between the rectifier tube and multiple mounting holes. A damping layer, made of glass wool felt, is provided between the guide ring and the rectifier tube. The guide ring, composed of variable-curvature airfoil blades, further streamlines the airflow initially rectified by the rectifier tube, optimizes the flow field distribution, and avoids interference from residual eddies and turbulence on ultrasonic measurements. The glass wool felt damping layer between the guide ring and the rectifier tube absorbs airflow pulsations and vibration energy, reducing the impact of vibration transmission on the ultrasonic transducer. These design features collectively ensure the high accuracy and stability of the modular gas ultrasonic flow meter, enhancing its anti-interference capability and structural reliability under fluctuating airflow conditions.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. This invention provides multiple mounting holes on the front and rear ends of the measuring instrument body, with multiple ultrasonic transducers installed in these holes. This direct mounting method on the measuring instrument body allows the transducers and the flow channel to form a relatively stable whole, reducing the impact of vibration on the relative position between the transducers and the flow channel, and ensuring accurate transmission of ultrasonic signals. This, in turn, ensures the measurement accuracy of the modular gas ultrasonic flow meter and improves its operational stability and anti-interference capability.

[0016] 2. This invention incorporates flow-rectifying angles at the junctions of multiple mounting holes and the measuring channel. These arc-shaped flow-rectifying angles at these junctions reduce eddies and turbulence caused by structural abrupt changes when gas flows through these points, thus preventing flow field disturbances from interfering with the ultrasonic wave propagation path. These design features collectively ensure the accuracy and stability of the modular gas ultrasonic flow meter, reduce the impact of impurities and flow field disturbances on the equipment, and improve the durability and measurement accuracy of the modular gas ultrasonic flow meter under complex operating conditions.

[0017] 3. This invention provides buffer grooves on the side of multiple ultrasonic transducers near the mounting holes, and sets an annular buffer groove with a rubber buffer ring on the side of the ultrasonic transducer near the mounting hole. By utilizing the elastic buffering properties of rubber, it avoids hard collisions and loosening between the ultrasonic transducers and the mounting holes caused by vibration during equipment operation, as well as vibration transmission interference with ultrasonic signal propagation. This ensures the structural stability of the modular gas ultrasonic flow meter, the accuracy of ultrasonic signal transmission, and improves the fatigue resistance and metering accuracy reliability of the modular gas ultrasonic flow meter under long-term vibration environment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the modular ultrasonic gas flow meter of the present invention;

[0019] Figure 2 For the present invention Figure 1 Sectional view at point AA;

[0020] Figure 3 For the present invention Figure 2 Sectional view at point BB;

[0021] Figure 4 For the present invention Figure 3 A magnified view of a section at point C;

[0022] Figure 5 This is a schematic diagram of the ultrasonic transducer in the modular gas ultrasonic flow meter of the present invention;

[0023] Figure 6 This is a right view of the modular ultrasonic gas flow meter of the present invention;

[0024] Figure 7 This is an exploded view of the modular ultrasonic gas flow meter of the present invention.

[0025] In the diagram: 1. Measuring instrument body; 2. Ultrasonic transducer; 3. SPU signal processing unit; 4. Pressure sensor; 5. Temperature sensor; 601. Cover plate; 602. Measuring flow channel; 701. Mounting hole; 702. Rectifying angle; 703. Buffer groove; 704. Buffer ring; 705. Metal corrugated sheet; 706. Transmitter; 707. Guide section; 708. Anti-loosening rubber ring; 709. Fine external thread; 801. Reinforcing surface; 802. Air inlet; 803. Air outlet; 804. Rectifying tube; 805. Honeycomb holes; 806. Microgroove; 901. Guide ring; 902. Blade; 903. Damping layer. Detailed Implementation

[0026] Please see Figures 1 to 7 This invention provides a modular ultrasonic gas flow meter, the technical solution of which is as follows:

[0027] A modular ultrasonic gas flow meter, please refer to Figures 1 to 7The device includes a measuring instrument body 1, ultrasonic transducers 2, an SPU signal processing unit 3, a pressure sensor 4, and a temperature sensor 5. A measuring flow channel 602 is formed inside the measuring instrument body 1. Multiple mounting holes 701 are formed on the front and rear end faces of the measuring instrument body 1, all of which communicate with the measuring flow channel 602. The mounting holes 701 on the front and rear end faces of the measuring instrument body 1 are arranged in an X-shape, with low, middle, and high layers. The low-layer mounting holes 701 are positioned higher than the bottom inner wall of the measuring flow channel 602. A flow straightening angle 702 is provided at the connection between the inner wall of the mounting holes 701 and the inner wall of the measuring flow channel 602. All flow straightening angles 702 are arc-shaped. Multiple ultrasonic transducers 2 are respectively installed in the multiple mounting holes 701. Inside, multiple ultrasonic transducers 2 have buffer grooves 703 on the side near the mounting holes 701. These buffer grooves 703 are annular, and each buffer groove 703 contains a buffer ring 704 made of rubber. Metal corrugated sheets 705 are located inside the buffer rings 704. Each ultrasonic transducer 2 has a transmitting end 706 near the measuring channel 602, with a trapezoidal cross-section. Each mounting hole 701 has a guide section 707 on the side near the front and rear ends of the measuring instrument body 1. Each guide section 707 is conical with a taper of 20°. Anti-reflective materials are installed on the inner walls of each mounting hole 701. A rubber ring 708 is included. Fine external threads 709 are machined on the ends of multiple ultrasonic transducers 2 away from the measuring channel 602. The multiple ultrasonic transducers 2 are threadedly connected to multiple mounting holes 701. The ultrasonic transducers 2 are made of any one of the following materials: duplex stainless steel, Hastelloy, and high-density tungsten carbide. Reinforcing surfaces 801 are provided on the inner walls of both the measuring channel 602 and the mounting holes 701. The reinforcing surfaces 801 are ultra-fine polished, with a surface roughness Ra = 0.4 μm. The measuring channel 602 has an air inlet 802 and an air outlet 803. A rectifier tube 804 is installed on the air inlet 802. The rectifier tube 804 has multiple honeycomb holes 805. The length of the rectifier tube 804 from the nearest mounting hole 701 is equal to the diameter of the measuring channel 602. The inner wall of the multiple honeycomb holes 805 is machined with multiple microgrooves 806. A guide ring 901 is installed in the measuring channel 602. The guide ring 901 is composed of multiple variable curvature airfoil blades 902. The guide ring 901 is located between the rectifier tube 804 and multiple mounting holes 701. A damping layer 903 is provided between the guide ring 901 and the rectifier tube 804. The damping layer 903 is made of glass wool felt. Cover plates 601 are installed on the front and rear sides of the measuring instrument body 1. The SPU signal processing unit 3 is installed on the upper end face of the measuring instrument body 1. The pressure sensor 4 and the temperature sensor 5 are respectively installed on the front and rear inner walls of the measuring channel 602. Multiple ultrasonic transducers 2, pressure sensor 4 and temperature sensor 5 are all electrically connected to the SPU signal processing unit 3.

[0028] When working, please refer to Figures 1 to 7 After the gas enters through the inlet 802, it first flows through the rectifier tube 804. At this time, the honeycomb holes 805 in the rectifier tube 804 divide the turbulent airflow into multiple parallel streams. Meanwhile, the microgrooves 806 on the inner wall further guide the airflow along the axial direction, initially eliminating eddies and turbulence. Subsequently, the airflow enters the guide ring 901 region. The variable curvature airfoil blade 902 performs secondary sorting of the residual disturbed airflow through the gradual curvature design, making the flow field distribution more uniform. The glass wool felt damping layer 903 between the rectifier tube 804 and the guide ring 901 absorbs the high-frequency vibrations generated by the airflow pulsation, preventing the vibrations from being transmitted to the measurement area and interfering with the ultrasonic signal.

[0029] When a stable airflow enters the measurement channel 602, the ultrasonic transducers 2, which are distributed in the low, middle and high layers and arranged in an X-shape, start to work. The ultrasonic waves emitted by the transmitting end 706 (the trapezoidal cross-section design expands the ultrasonic wave propagation angle to ensure coverage of more flow field areas) propagate in the airflow through the arc-shaped rectification angle 702 at the connection between the mounting hole 701 and the channel (which reduces the influence of airflow disturbance on the sound wave path), and are received by the ultrasonic transducer 2 on the opposite side after penetrating the gas. Because gas flow causes a difference in the propagation time of ultrasonic waves in the forward and reverse directions, this time difference is captured by the ultrasonic transducer 2 and converted into an electrical signal. During this process, the ultrasonic transducer 2 achieves precise positioning through the 20° tapered guide section 707 of the mounting hole 701. The fine thread and the anti-loosening rubber ring 708 ensure a firm installation. The rubber buffer ring 704 and the metal corrugated sheet 705 in the buffer groove 703 form a double vibration reduction structure, which effectively offsets the impact of airflow and equipment vibration on the transducer and ensures stable sound wave transmission and reception. At the same time, the ultra-fine polished reinforced surface 801 (Ra=0.4μm) of the measuring channel 602 and the inner wall of the mounting hole 701 reduces the adhesion of impurities and the disturbance of airflow friction. The transducer, made of wear-resistant materials such as duplex stainless steel, resists long-term erosion and maintains structural stability.

[0030] Finally, the SPU signal processing unit 3 receives the time difference signals from each ultrasonic transducer 2, combines them with the real-time pressure and temperature data collected by the pressure sensor 4 and temperature sensor 5, and calculates the flow rate by temperature and pressure compensation through an algorithm to obtain an accurate gas flow rate value; the cover plate 601 provides protection for the internal components, ensuring that the entire system can operate stably for a long time under complex working conditions, and achieving high-precision and reliable gas flow rate measurement.

[0031] The specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments described above. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and ideas of the present invention should still fall within the protection scope of the present invention.

Claims

1. A modular ultrasonic gas flow meter, characterized in that, The device includes a measuring instrument body (1), an ultrasonic transducer (2), an SPU signal processing unit (3), a pressure sensor (4), and a temperature sensor (5). A measuring flow channel (602) is provided inside the measuring instrument body (1). Multiple mounting holes (701) are provided on the front and rear end faces of the measuring instrument body (1), and all mounting holes (701) communicate with the measuring flow channel (602). The mounting holes (701) on the front and rear end faces of the measuring instrument body (1) are arranged in an X-shape and staggered. Multiple ultrasonic transducers... The transducers (2) are installed in multiple mounting holes (701). The front and rear ends of the measuring instrument body (1) are each covered with a cover plate (601). The SPU signal processing unit (3) is installed on the upper end face of the measuring instrument body (1). The pressure sensor (4) and temperature sensor (5) are respectively installed on the front and rear inner walls of the measuring channel (602). Multiple ultrasonic transducers (2), pressure sensors (4) and temperature sensors (5) are electrically connected to the SPU signal processing unit (3).

2. The modular ultrasonic gas flow meter according to claim 1, characterized in that: The mounting holes (701) are arranged in a low layer, a middle layer and a high layer. The mounting holes (701) in the low layer are arranged higher than the inner wall of the bottom surface of the measuring channel (602). The inner wall of the mounting holes (701) and the inner wall of the measuring channel (602) are provided with a flow straightening angle (702). The flow straightening angle (702) is arc-shaped.

3. A modular ultrasonic gas flow meter according to claim 2, characterized in that: Each of the ultrasonic transducers (2) has a buffer groove (703) on one side near the mounting hole (701). The buffer grooves (703) are annular in shape, and each buffer groove (703) has a buffer ring (704) installed inside. Each buffer ring (704) is made of rubber material.

4. A modular ultrasonic gas flow meter according to claim 3, characterized in that: The buffer grooves (703) are provided with metal corrugated sheets (705), the metal corrugated sheets (705) are located inside the buffer ring (704), and the ultrasonic transducers (2) are provided with a transmitting end (706) at one end near the measuring channel (602), the transmitting end (706) adopts a trapezoidal cross section design.

5. A modular ultrasonic gas flow meter according to claim 4, characterized in that: Each of the mounting holes (701) has a guide section (707) machined on one side of the front and rear end faces of the measuring instrument body (1). Each of the guide sections (707) is tapered and the taper of each guide section (707) is 15° to 30°. Each of the mounting holes (701) has an anti-loosening rubber ring (708) installed on the inner wall of each mounting hole (701). Each of the ultrasonic transducers (2) has a fine external thread (709) machined on one end away from the measuring flow channel (602). The ultrasonic transducers (2) are threadedly connected to the mounting holes (701).

6. A modular ultrasonic gas flow meter according to claim 5, characterized in that: The ultrasonic transducer (2) is made of any one of the following materials: duplex stainless steel, Hastelloy and high-density tungsten carbide. The inner wall of the measuring channel (602) and the inner wall of the mounting hole (701) are provided with reinforcing surfaces (801). The reinforcing surfaces (801) are ultra-fine polished and have a surface roughness Ra≤0.4μm.

7. A modular ultrasonic gas flow meter according to claim 3, characterized in that: The measuring channel (602) is provided with an air inlet (802) and an air outlet (803). A rectifier tube (804) is installed on the air inlet (802). The rectifier tube (804) is provided with a plurality of honeycomb holes (805). The length of the rectifier tube (804) from the nearest mounting hole (701) is 3 to 5 times the diameter of the measuring channel (602). The inner walls of the plurality of honeycomb holes (805) are processed with a plurality of microgrooves (806).

8. A modular ultrasonic gas flow meter according to claim 7, characterized in that: A flow guide ring (901) is installed inside the measuring channel (602). The flow guide ring (901) is composed of multiple variable curvature airfoil blades (902). The flow guide ring (901) is located between the rectifier tube (804) and multiple mounting holes (701). A damping layer (903) is provided between the flow guide ring (901) and the rectifier tube (804). The damping layer (903) is made of glass wool felt.

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