Metering equipment and method for metering gas flow by utilizing ultrasonic sound velocity difference principle

Abstract

The invention discloses metering equipment and a method for metering gas flow by using an ultrasonic sound velocity difference principle, and the method comprises the following steps: rectifying gas flow in a pipeline by using a rectifier assembly to stabilize a flow field, and then measuring the ultrasonic sound velocity difference of forward and reverse propagation of the gas flow by using an ultrasonic sensor in a sensing assembly; the detected pulse signals are transmitted to the intelligent flow totalizer assembly for operation, and the actual flow velocity and flow of the gas are obtained; a pressure sensor and a temperature sensor in the sensing assembly respectively collect a pressure signal and a temperature signal of gas in the pipeline, and synchronously transmit the collected pressure signal and temperature signal to the intelligent flow totalizer assembly; and after receiving the pressure and temperature signals, the intelligent flow totalizer assembly performs temperature and pressure compensation operation in combination with actual flow velocity and flow data of the gas to finally obtain the flow velocity and flow of the gas under the standard condition. The problems of low measurement precision and large pressure loss in the traditional technology are solved.

Description

Technical Field

[0001] This invention belongs to the field of flow detection technology, specifically relating to a metering device and method for measuring gas flow using the principle of ultrasonic velocity difference. Background Technology

[0002] With the widespread application of natural gas and other gaseous energy sources in urban supply, petrochemicals, power industry, and residential boilers, the operation and management of the gas industry is gradually developing towards precision, intelligence, and efficiency. As a core link in energy trade and pipeline distribution control, gas flow metering places higher demands on the accuracy, stability, and ease of maintenance of metering equipment. Currently, the mainstream gas flow meters in the Chinese market are mainly divided into two categories: volumetric and velocity flow meters. Both types of products have significant shortcomings in practical applications and are difficult to meet the current needs of industry development.

[0003] A typical example of a volumetric gas flow meter is the Roots gas flow meter. Its working principle is based on the pressure difference between the inlet and outlet gases, which causes the internal rotor and the metering chamber to form a fixed-volume metering cavity four times the number of rotations, thus enabling continuous or intermittent measurement of the gas flow rate in the pipeline. While this type of flow meter has advantages such as reliable operation, robust durability, high measurement accuracy, and a wide measuring range, its structural design limits its performance. This results in complex transmission structures, cumbersome maintenance and repair, and a significant increase in size as the flow rate of the gas being measured increases, leading to poor installation and space adaptability in high-flow-rate measurement scenarios.

[0004] A typical example of a velocity-type gas flow meter is the turbine gas flow meter, which measures flow based on the principle that the angular velocity of the internal turbine is proportional to the gas flow rate. Compared to Roots gas flow meters, turbine gas flow meters have advantages such as lower pressure loss, lower initial flow rate, wider measurement range, lower maintenance difficulty, and relatively smaller size. However, key technological bottlenecks have not yet been overcome: on the one hand, the internal turbine blades, bearings, and other moving parts are easily worn by impurities in the gas medium, leading to a decrease in measurement accuracy and poor stability after long-term use; on the other hand, the complex design of the turbine assembly and signal acquisition structure still brings inconvenience to installation, commissioning, and subsequent maintenance. Especially in scenarios such as gas trade transfer metering stations where the accuracy of measurement is extremely important, these defects can easily lead to economic disputes between supply and demand parties. Summary of the Invention

[0005] Therefore, this invention provides a metering device and method for measuring gas flow rate using the principle of ultrasonic velocity difference, which solves the problems of low measurement accuracy, large pressure loss, complex internal structure, inconvenient installation and maintenance, poor stability, and easy wear and tear of moving parts in traditional technologies.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a metering device for measuring gas flow rate using the principle of ultrasonic velocity difference, comprising an intelligent flow totalizer assembly, a rectifier assembly, a rotating head assembly, a sensing assembly, and a metering housing assembly; the intelligent flow totalizer assembly is connected to the rotating head assembly and is used to process and display flow rate data; the rotating head assembly is connected to the metering housing assembly, and the rectifier assembly is connected to the metering housing assembly, and is used to rectify the gas flow; the internal channel of the metering housing assembly is interconnected with a gas pipeline, and the metering housing assembly is used to provide a gas metering carrier; the sensing assembly is connected to the housing assembly; the sensing assembly includes an ultrasonic sensor, a pressure sensor, and a temperature sensor, and is used to collect gas parameters.

[0007] As a preferred embodiment of a metering device that uses the principle of ultrasonic velocity difference to measure gas flow rate, the rectifier assembly includes a flange, a fan-shaped blade, and a rectifier pipe; the fan-shaped blade is disposed inside the rectifier pipe, and the rectifier pipe is connected to the gas pipe being measured through the flange.

[0008] As a preferred embodiment of a metering device that uses the principle of ultrasonic velocity difference to measure gas flow, the rotating head assembly includes a rotating head, a shaft elastic retaining ring, a fixed rotating head, a small shaft, and a second O-ring seal; the small shaft is threaded to the fixed rotating head, and the shaft elastic retaining ring and the second O-ring seal are provided between the fixed rotating head and the rotating head; the rotating head cooperates with the small shaft.

[0009] As a preferred embodiment of a metering device that uses the principle of ultrasonic velocity difference to measure gas flow, the sensing component includes a pressure sensor, a temperature sensor, and an ultrasonic sensor. The pressure sensor and the temperature sensor are used to collect the pressure and temperature signals of the gas in the pipeline, respectively, and the ultrasonic sensor is used to measure the propagation of ultrasonic waves in the gas.

[0010] As a preferred embodiment of a metering device that uses the principle of ultrasonic velocity difference to measure gas flow, the metering housing assembly includes a meter head base, a cover, and a metering chamber. The metering chamber provides a metering space for the gas. Two threaded holes and four screw threaded holes are machined on the top of the metering chamber. The two threaded holes on the top of the metering chamber are respectively used to install the pressure sensor and the temperature sensor. The four screw threaded holes on the top of the metering chamber are connected to the meter head base. Four threaded channels for installing the ultrasonic sensors are machined on the side of the metering chamber. Four oblique holes are provided on the top of the metering chamber, the depth of which extends beyond the threaded channels for installing the ultrasonic sensors to allow the sensor data lines to pass through. The meter head base is used to install an intelligent flow totalizer assembly, and the cover is installed in the metering chamber by screws to seal the ultrasonic sensors.

[0011] As a preferred embodiment of a metering device that uses the principle of ultrasonic velocity difference to measure gas flow, the ultrasonic sensor includes an ultrasonic sensing sleeve, an ultrasonic sensing element, and an ultrasonic sensing pressure sleeve. The ultrasonic sensing sleeve has a step inside to prevent the ultrasonic sensing element from falling out after being installed. The ultrasonic sensing sleeve has threaded structures processed inside and outside. The internal thread of the ultrasonic sensing sleeve engages with the external thread of the ultrasonic sensing pressure sleeve to press the ultrasonic sensing element tightly. The external thread of the ultrasonic sensing sleeve engages with the thread on the metering chamber.

[0012] As a preferred embodiment of a metering device utilizing the ultrasonic velocity difference principle to measure gas flow, the intelligent flow totalizer assembly includes a faceplate, a front cover, an aviation connector with a sealing gasket, a display screen, a support column, a circuit board, a battery pack, a mounting plate, a first O-ring seal, and a rear cover. The faceplate is made of soft PVC material and is mounted on the front cover. The transparent center of the faceplate is used to read data from the display screen. Two aviation connectors with sealing gaskets are located at the bottom of the front cover as flow meter output ports. A hole is provided in the center of the bottom of the front cover for the data cable of the sensing component to pass through. The front cover also has threaded holes for screws to pass through. The display screen is connected to the rotating head; the display screen is connected to the circuit board via the support column, and the display screen is also fixed inside the front cover with screws; the circuit board is used to realize temperature and pressure compensation reading of standard flow rate, real-time display of gas temperature, pressure, battery power and atmospheric pressure value at the use site in the pipeline, and storage of real-time data; the battery pack is fixed inside the rear cover with screws via the fixing plate; the sealing surfaces of the front cover and the rear cover are provided with corresponding concave and convex groove structures, the groove of the rear cover is filled with the first O-ring seal made of silicone material, and the convex groove of the front cover presses the first O-ring seal to achieve sealing and explosion protection.

[0013] This invention also provides a method for measuring gas flow rate using the principle of ultrasonic velocity difference, applied to the aforementioned metering device for measuring gas flow rate using the principle of ultrasonic velocity difference, comprising the following steps: Step 1: After starting the equipment, the rectifier assembly first rectifies the airflow in the pipeline to stabilize the flow field. Then, the ultrasonic sensor in the sensing assembly measures the difference in ultrasonic velocity between the forward and reverse propagation of the airflow. The detected pulse signal is transmitted to the intelligent flow totalizer assembly, which calculates the pulse signal to obtain the actual gas velocity and flow rate. Step 2: While the ultrasonic sensor measures and calculates the actual flow velocity and flow rate, the pressure sensor and temperature sensor in the sensing component collect the pressure signal and temperature signal of the gas in the pipeline, respectively, and transmit the collected pressure and temperature signals to the intelligent flow totalizer component simultaneously. Step 3: After receiving the pressure and temperature signals transmitted in Step 2, the intelligent flow totalizer component performs temperature and pressure compensation calculations in conjunction with the actual gas velocity and flow data obtained in Step 1, and finally obtains the gas velocity and flow under standard conditions, and transmits the results to the display screen for display.

[0014] As a preferred method for measuring gas flow rate using the principle of ultrasonic velocity difference, in step 1, the intelligent flow totalizer component calculates the pulse signal to obtain the formulas for the actual gas velocity and flow rate:

[0015]

[0016] In the formula, This represents the actual gas flow rate. The speed of sound is the speed of ultrasound in a stationary gas. This refers to the propagation speed of ultrasound downstream; The cross-sectional area for gas flow within the pipe. This represents the actual gas flow rate; In step 3, the formula for gas flow rate under standard conditions is obtained as follows:

[0017] In the formula, The flow rate under standard conditions. For standard pressure, This is the standard temperature.

[0018] As a preferred method for measuring gas flow rate using the principle of ultrasonic velocity difference, it also includes obtaining the actual gas flow velocity. and actual traffic Then, the intelligent flow totalizer component first performs automatic nonlinear correction on the actual flow velocity, using the following formula:

[0019] In the formula, To correct the gas flow rate, , This is a nonlinear correction coefficient; based on the corrected flow velocity. and pipeline flow cross-sectional area Through formula The corrected actual flow rate was calculated. .

[0020] As a preferred method for measuring gas flow using the principle of ultrasonic velocity difference, in step 3, when the intelligent flow totalizer component performs calculations in conjunction with temperature and pressure sensor signals, it performs automatic pressure and temperature compensation:

[0021] In the formula, To compensate for the flow rate under standard conditions, For standard pressure, This is the standard temperature.

[0022] The beneficial effects of this invention are as follows: First, this invention employs a multi-channel, bidirectional ultrasonic measurement structure, combined with a built-in rectifier to stabilize the airflow, effectively eliminating the interference of flow field turbulence on the measurement results. This achieves high-precision measurement of flow without boundaries, with a measurement accuracy of up to Class 1 throughout the entire process. Moreover, under Class 1 accuracy standards, the range ratio can reach 1:50, which is far superior to the existing Roots gas flow meters with their "wider range" and turbine gas flow meters with their "wider measurement range" but insufficient accuracy. It can be precisely adapted to scenarios with stringent accuracy requirements, such as gas trade transfer metering stations and industrial and commercial settlement metering, ensuring that the economic interests of both supply and demand parties are not affected by measurement deviations.

[0023] Secondly, the present invention adopts a design without moving parts, which fundamentally avoids the failure problem caused by the wear of moving parts, and at the same time eliminates pressure loss in the pipeline, reducing energy consumption during gas transportation. The overall structure of the equipment is simple and compact, requiring no complicated installation and commissioning process. Subsequent maintenance only requires routine inspections, without the need for frequent oiling or cleaning, which greatly reduces equipment maintenance time and costs, and is suitable for installation and use in various scenarios such as urban natural gas transmission and distribution networks and civil boilers.

[0024] Third, it can operate stably in an environment of 80℃, adapting to complex working conditions in industries such as petroleum and chemical engineering; it meets the requirements for use in explosion-proof environments, effectively isolating external temperature fluctuations, pressure changes, and other interference factors from affecting measurement accuracy; in addition, its wear-free design results in a low equipment failure rate and long service life, enabling long-term continuous and stable operation and reducing measurement interruptions caused by equipment failure.

[0025] Fourth, on the one hand, it can display the temperature, pressure, battery power, and atmospheric pressure of the gas in the pipeline in real time. It also has automatic pressure and temperature compensation and automatic nonlinear correction functions, which can accurately calculate and read the flow rate under standard conditions, effectively reducing the production and sales difference rate and solving the metering deviation problem caused by the lack of compensation or correction functions in existing flow meters. On the other hand, it has a timed data storage function, which can store more than six months of real-time data, which facilitates the query, analysis and traceability of metering data in the future. It is fully compatible with the current trend of the gas industry towards precision, intelligence and efficiency, as well as the demand for high-efficiency metering equipment in energy structure adjustment and smart city construction.

[0026] Fifth, this invention can be widely applied to urban natural gas metering and natural gas metering in gas transmission and distribution pipelines. It can also meet the gas metering needs of the petroleum, chemical, power industry and civil boiler fields, as well as gas pressure regulating station metering, gas trade transfer metering station industrial and trade settlement metering and other scenarios. Compared with the limited application scenarios of existing flow meters, this invention has stronger versatility and can provide a unified and accurate solution for gas flow metering in different fields. Attached Figure Description

[0027] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0028] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0029] Figure 1 This is a three-dimensional structural diagram of a metering device that uses the ultrasonic velocity difference principle to measure gas flow rate, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the rectifier assembly structure of a metering device that uses the ultrasonic velocity difference principle to measure gas flow rate in an embodiment of the present invention. Figure 3 This is a schematic diagram of the rotating head assembly of a metering device that uses the ultrasonic velocity difference principle to measure gas flow rate, provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the sensing component structure of a metering device that uses the ultrasonic velocity difference principle to measure gas flow rate in an embodiment of the present invention. Figure 5 This is a schematic diagram of the metering housing assembly structure of a metering device that uses the ultrasonic velocity difference principle to measure gas flow rate, provided in an embodiment of the present invention. Figure 6 This is a schematic diagram of the ultrasonic sensor structure of a metering device that uses the principle of ultrasonic velocity difference to measure gas flow rate, provided in an embodiment of the present invention. Figure 7 This is a schematic diagram of the intelligent flow totalizer component of a metering device that uses the ultrasonic velocity difference principle to measure gas flow rate, provided in an embodiment of the present invention. Figure 8 This is a schematic diagram of a method for measuring gas flow rate using the principle of ultrasonic velocity difference provided in an embodiment of the present invention.

[0030] In the diagram: 1. Face mask; 2. Front cover; 3. Aviation plug with sealing gasket; 4. Display screen; 5. Support column; 6. Circuit board; 7. Battery pack; 8. Fixing plate; 9. First O-ring seal; 10. Rear cover; 11. Flange; 12. Fan-shaped blade; 13. Rectifying pipe; 14. Rotating head; 15. Shaft elastic retaining ring; 16. Fixed rotating head; 17. Small shaft; 18. Second O-ring seal; 19. Ultrasonic sensing sleeve; 20. Ultrasonic sensing element; 21. Ultrasonic sensing sheath; 22. Pressure sensor; 23. Temperature sensor; 24. Ultrasonic sensor; 25. Meter head base; 26. Cover; 27. Metering chamber. Detailed Implementation

[0031] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0032] See Figure 1 This invention provides a metering device for measuring gas flow rate using the principle of ultrasonic velocity difference, comprising an intelligent flow totalizer assembly, a rectifier assembly, a rotating head assembly, a sensing assembly, and a metering housing assembly. The intelligent flow totalizer assembly is connected to the rotating head assembly and is used to process and display flow rate data. The rotating head assembly is connected to the metering housing assembly, and the rectifier assembly is also connected to the metering housing assembly, used to rectify the airflow. The internal channel of the metering housing assembly is interconnected with a gas pipeline, and the metering housing assembly is used to provide a gas metering carrier. The sensing assembly is connected to the housing assembly and includes an ultrasonic sensor 24, a pressure sensor 22, and a temperature sensor 23, used to collect gas parameters.

[0033] In the metering housing assembly, the metering chamber 27 serves as the core carrier. Its two convex surfaces and threaded holes are compatible with national standard flanges to ensure a sealed connection with the measured pipeline. The 45-degree angled threaded channel in the middle, the temperature and pressure sensor mounting holes and the oblique elongated holes at the top provide structural support for the installation of the sensor components and the routing of data cables. The rectifier assembly is installed at the gas inlet of the metering chamber 27, and forces the airflow to flow axially parallel through the fan-shaped blades 12 or honeycomb mesh, eliminating the interference of rotating flow and eddies on sound velocity measurement from the source. The sensor components are stably fixed to the metering chamber 27 with threaded connections. The ultrasonic sensor 24 has a four-channel 45-degree angle bidirectional measurement structure, and the temperature and pressure sensor has a shaft-like rod design to ensure the accuracy of multi-dimensional parameter acquisition. The rotating head assembly enables the intelligent flow totalizer assembly to rotate freely 340 degrees, which not only adapts to the reading requirements of different installation scenarios, but also ensures the connection sealing through O-rings and rubber gaskets. The intelligent flow totalizer assembly receives signals from various sensors, completes temperature and pressure compensation, standard volume flow calculation and data storage through the circuit board 6, and finally outputs the results through the display screen 4.

[0034] See Figure 2 In this embodiment, the rectifier assembly includes a flange 11, fan-shaped blades 12, and a rectifier pipe 13. The fan-shaped blades 12 are disposed inside the rectifier pipe 13, which is connected to the gas pipeline being measured via the flange 11. The flange 11 is stably fixed to the gas inlet of the metering chamber 27 with screws, ensuring that the gas flow enters the metering area without leakage. The fan-shaped blades 12 evenly distributed inside the rectifier pipe 13 can construct dense parallel channels. When the gas flows through, the turbulent airflow is forcibly guided by the blades to flow along the axial direction of the rectifier pipe 13, completely eliminating the interference of uneven flow field on ultrasonic wave propagation. If there are eddies in the airflow, the ultrasonic wave propagation path will be deflected, resulting in deviation in the sound velocity difference measurement. However, after rectification, the airflow velocity distribution is uniform, and the sound velocity difference captured by the ultrasonic sensor 24 is determined only by the actual gas flow velocity, providing interference-free raw data for flow velocity and flow rate calculation, thus improving metering accuracy.

[0035] See Figure 3 In this embodiment, the rotating head assembly includes a rotating head 14, a shaft elastic retaining ring 15, a fixed rotating head 16, a small shaft 17, and a second O-ring seal 18; the small shaft 17 is threadedly connected to the fixed rotating head 16, and the shaft elastic retaining ring 15 and the second O-ring seal 18 are provided between the fixed rotating head 16 and the rotating head 14; the rotating head 14 cooperates with the small shaft 17.

[0036] Specifically, the fixed rotating head 16 is connected to the meter head seat 25 of the metering housing assembly via screws. The elastic retaining ring groove and sealing groove on its surface are used to install the shaft elastic retaining ring 15 and the second O-ring seal 18, respectively. The shaft elastic retaining ring 15 restricts the axial displacement of the rotating head 14, ensuring no axial movement during rotation. The second O-ring seal 18 fills the gap between the rotating head 14 and the fixed rotating head 16, achieving a seal between them and preventing external impurities from entering or internal gas leakage. The small shaft 17 is connected to the fixed rotating head 16 via threads. Its structure, extending into the circular groove of the rotating head 14, allows the rotating head 14 to rotate freely 340 degrees around the small shaft 17, thereby driving the intelligent flow totalizer assembly to adjust its angle. This design solves the reading problem in confined installation scenarios and ensures connection stability and sealing during rotation, preventing the reliability of the metering system from being affected by component loosening or leakage.

[0037] See Figure 4 In this embodiment, the sensing components include a pressure sensor 22, a temperature sensor 23, and an ultrasonic sensor 24. The pressure sensor 22 and the temperature sensor 23 are used to collect the pressure and temperature signals of the gas in the pipe, respectively, and the ultrasonic sensor 24 is used to measure the propagation of ultrasonic waves in the gas.

[0038] Specifically, the ultrasonic sensor 24 adopts a four-channel, 45-degree-angle, bidirectional measurement structure. The stepped design of the ultrasonic sensing sleeve 21 ensures that the ultrasonic sensing element 20 does not fall out after installation. The internal thread engages with the ultrasonic sensing pressure sleeve 19, tightly pressing the sensing element and preventing signal deviation due to vibration displacement. The external thread engages with the threaded channel of the metering chamber 27, achieving a sealed fixation. During operation, the four sensors respectively emit and receive ultrasonic waves in both directions. The 45-degree angle design allows the ultrasonic wave propagation path to cover different cross-sections within the pipe, reducing the impact of uneven flow velocity distribution. By measuring the sound velocity difference (in the direction of flow)... ,countercurrent The gas flow rate is inferred to provide data for flow rate calculation. Pressure sensor 22 and temperature sensor 23 adopt a shaft-like rod structure and bonded sensing element structure. One end is threaded and engaged with the top thread of the metering chamber 27, ensuring that the sensor probe directly contacts the gas, and the collected pressure and temperature signals are closer to the actual working conditions. According to the ideal gas law, pressure and temperature directly affect gas density. The two signals work together to correct the actual flow rate to the standard condition flow rate, eliminating the influence of operating condition fluctuations on the measurement results. All sensing components are fixed by threaded connections, and silicone O-rings are used during installation to ensure the connection is firm, avoid measurement errors caused by gas leakage, and isolate the sensor elements from external environmental interference, ensuring long-term measurement stability.

[0039] See Figure 5In this embodiment, the metering housing assembly includes a meter head seat 25, a cover 26, and a metering chamber 27. The metering chamber 27 provides a metering space for the gas. Two threaded holes and four screw threaded holes are machined on the top of the metering chamber 27. The two threaded holes on the top of the metering chamber 27 are respectively used to install a pressure sensor 22 and a temperature sensor 23. The four screw threaded holes on the top of the metering chamber 27 are connected to the meter head seat 25. Four threaded channels for installing ultrasonic sensors 24 are machined on the side of the metering chamber 27. The top of the metering chamber 27 is provided with four oblique elongated holes, the depth of which reaches outside the threaded channels for installing ultrasonic sensors 24 to allow the sensor data lines to pass through. The meter head seat 25 is used to install the intelligent flow totalizer assembly, and the cover 26 is installed in the metering chamber 27 with screws to block the ultrasonic sensors 24.

[0040] Specifically, the inner bore of the metering chamber 27 is connected to the gas pipeline, ensuring that the gas flows through the metering area in its entirety; the convex faces and threaded holes at both ends are consistent with the dimensions of the national standard convex-face flat-welded steel flange, achieving a standardized sealed connection with the measured pipeline; the two sets of 45-degree angled threaded channels in the middle match the bidirectional measurement requirements of the four-channel ultrasonic sensor 24, ensuring that the ultrasonic wave propagation path covers the airflow cross section; the two threaded holes at the top allow the pressure sensor 22 and temperature sensor 23 to extend vertically into the metering chamber 27, acquiring signals without delay; the four screw threaded holes at the top are used to fix the meter head base 25, forming a stable foundation for component installation; the oblique elongated hole at the top extends to the outside of the ultrasonic sensor 24 channel, facilitating data cable routing and avoiding... If the wiring is bent or damaged, gas leakage can be prevented by sealing. The meter head base 25 has a square housing structure, which provides an installation platform for the rotary head assembly and the intelligent flow totalizer assembly, and also serves as a transition space to facilitate the neat entry of the data lines of each sensor into the totalizer assembly, avoiding signal interference caused by messy wiring. The cover 26 seals the ultrasonic sensor 24 with screws to prevent external dust and moisture from entering the sensor mounting hole and affecting the operation of the component. Rubber sealing gaskets are set between the various housing components before installation, and silicone O-rings are set during sensor assembly installation to form a seal, which not only avoids measurement deviation caused by gas leakage, but also isolates the influence of the external environment, ensuring stable operation of the equipment under complex working conditions.

[0041] See Figure 6 In this embodiment, the ultrasonic sensor 24 includes an ultrasonic sensing sleeve 21, an ultrasonic sensing element 20, and an ultrasonic sensing pressure sleeve 19. The ultrasonic sensing sleeve 21 has a step inside to prevent the ultrasonic sensing element 20 from falling out after being installed. The ultrasonic sensing sleeve 21 has threaded structures on both the inside and outside. The internal thread of the ultrasonic sensing sleeve 21 engages with the external thread of the ultrasonic sensing pressure sleeve 19 to press the ultrasonic sensing element 20. The external thread of the ultrasonic sensing sleeve 21 engages with the thread on the measuring chamber 27.

[0042] Specifically, the ultrasonic sensing sleeve 21 serves as the mounting and protective housing for the sensor. Its external threads engage with the threaded holes of the metering chamber 27 to achieve a sealed fixation and prevent gas leakage from the installation gap. The internal steps provide rigid positioning for the ultrasonic sensing element 20, ensuring that the element is fixed in position after installation and avoiding deviation of the propagation path due to vibration. The ultrasonic sensing pressure sleeve 19 engages with the internal threads of the sleeve and is screwed in to slowly and evenly press the ultrasonic sensing element 20. On the one hand, it ensures a tight fit between the component and the inner wall of the sheath, reducing energy loss of ultrasound during propagation. If gaps exist, ultrasound will be reflected and refracted, leading to attenuation of the received signal strength. On the other hand, the preload of the component can be finely adjusted by regulating the screw-in depth, allowing the piezoelectric crystal to operate in the optimal vibration frequency band and improving the accuracy of sound velocity measurement. Each flowmeter is equipped with four sets of ultrasonic sensors 24 of this structure, arranged bidirectionally at a 45-degree angle, which can simultaneously measure the propagation of ultrasound at different cross-sections in the pipe. By calculating the average of multiple sets of data, the influence of uneven airflow velocity distribution on sound velocity difference measurement is reduced, further improving the accuracy of flow velocity calculation and adapting to the metering needs under different flow velocity scenarios.

[0043] See Figure 7 In this embodiment, the intelligent flow totalizer assembly includes a faceplate 1, a front cover 2, an aviation connector with a sealing gasket 3, a display screen 4, a support column 5, a circuit board 6, a battery pack 7, a fixing plate 8, a first O-ring seal 9, and a rear cover 10. The faceplate 1 is made of soft PVC material and is set on the front cover 2. The transparent part in the middle of the faceplate 1 is used to read the data on the display screen 4. Two aviation connectors with sealing gaskets 3 are provided at the bottom of the front cover 2 as flow meter output ports. A hole is provided in the middle of the bottom of the front cover 2 to pass through the data cable of the sensing component. The front cover 2 also has a threaded hole to pass through the screw and rotating head 1. 4. Connection; Display screen 4 is connected to circuit board 6 via support column 5, and display screen 4 is also fixed inside front cover 2 by screws; Circuit board 6 is used to realize temperature and pressure compensation reading of standard flow rate, real-time display of gas temperature, pressure, battery power and atmospheric pressure value at the use site in the pipeline, and storage of real-time data; Battery pack 7 is fixed inside rear cover 10 by screws via fixing plate 8; The sealing surfaces of front cover 2 and rear cover 10 are provided with corresponding concave and convex groove structures, the groove of rear cover 10 is filled with first O-ring seal 9 made of silicone material, and the convex groove of front cover 2 presses the first O-ring seal 9 to achieve sealing and explosion protection.

[0044] Specifically, circuit board 6 integrates a microprocessor, signal processing circuit, and storage chip. The microprocessor runs a preset algorithm, receives the sound velocity difference signal from ultrasonic sensor 24, calculates the actual flow velocity and flow rate, and combines pressure and temperature signals to complete temperature and pressure compensation. At the same time, it processes and displays the gas temperature, pressure, battery power, and atmospheric pressure values ​​in the pipeline in real time. The storage chip can retain more than six months of real-time data for subsequent traceability and analysis. The display screen 4 is connected to circuit board 6 through support column 5. Support column 5 provides support and insulation to prevent short circuits and is fixed inside the front cover 2 with screws to ensure stable display. Combined with the transparent area of ​​the soft PVC film 1, it is convenient for operators to read the data. Two aviation plugs 3 with sealing gaskets at the bottom of the front cover 2 serve as output ports, allowing connection to external devices to export metering data. The sealing gaskets ensure no leakage at the connection between the plugs and the front cover 2. The central hole at the bottom is for the data cable of the sensing component to enter, enabling signal transmission between the sensor and the circuit board 6. The sealing surfaces of the front cover 2 and the rear cover 10 use a tongue-and-groove fit. The first O-ring 9 in the groove of the rear cover 10 undergoes elastic deformation when the groove is pressed, filling the gap. This achieves an IP65 or higher level of sealing and meets explosion-proof requirements, making it suitable for explosive environments such as natural gas. The battery pack 7 is fixed to the rear cover 10 with screws via a fixing plate 8. The fixing plate 8 acts as a shock absorber, preventing the battery from loosening due to equipment vibration. The battery pack 7 adopts a large-capacity, low-power design, which can continuously power the component for more than 3 years, ensuring long-term uninterrupted operation of the equipment. The threaded hole of the front cover 2 is connected to the rotating head 14 with screws, and a rubber sealing gasket is added between them. This allows for adjustable component angles and ensures a tight connection, adapting to different installation scenarios.

[0045] See Figure 8 This invention also provides a method for measuring gas flow rate using the principle of ultrasonic velocity difference, applied to the metering device for measuring gas flow rate using the principle of ultrasonic velocity difference described above, and includes the following steps: Step 1: After starting the equipment, the rectifier assembly first rectifies the airflow in the pipeline to stabilize the flow field. Then, the ultrasonic sensor in the sensing assembly measures the difference in ultrasonic velocity between the forward and reverse propagation directions of the airflow. The detected pulse signal is transmitted to the intelligent flow totalizer assembly, which calculates the actual gas velocity and flow rate. The rectifier assembly first rectifies the airflow because the airflow in the pipeline is prone to eddies or turbulence due to pipe bends and valve interference. If measured directly, the ultrasonic propagation path would be deflected by the turbulent airflow, leading to a deviation in the sound velocity difference measurement. After rectification, the airflow flows uniformly along the axial direction, and the sound velocity difference is determined only by the actual gas velocity. After the ultrasonic sensor captures the difference in sound velocity between the forward and reverse directions, it transmits the pulse signal to the totalizer, providing core raw data for subsequent calculations.

[0046] Step 2: While the ultrasonic sensor measures and calculates the actual flow velocity and flow rate, the pressure sensor and temperature sensor in the sensing component collect the pressure and temperature signals of the gas in the pipeline, respectively, and transmit the collected pressure and temperature signals synchronously to the intelligent flow totalizer component. A parallel acquisition design is adopted, simultaneously acquiring temperature and pressure signals while measuring the sound velocity difference. This avoids data time differences caused by sequential acquisition. If the flow velocity is measured first and then the temperature and pressure are measured, the gas pressure or temperature may change during this period, leading to a mismatch between the temperature and pressure parameters and the flow velocity parameters, affecting the accuracy of subsequent compensation. Synchronous acquisition ensures that the three sets of signals correspond to the same operating conditions at the same time.

[0047] Step 3: After receiving the pressure and temperature signals transmitted in Step 2, the intelligent flow totalizer component performs temperature and pressure compensation calculations based on the actual gas velocity and flow rate data obtained in Step 1. Finally, it obtains the gas velocity and flow rate under standard conditions and transmits the results to the display screen for display. Gas flow rate is significantly affected by temperature and pressure (according to the ideal gas law, an increase in temperature or a decrease in pressure will cause the gas volume to expand, increasing the deviation between the actual flow rate and the standard condition flow rate). The totalizer compensates for the actual flow rate by combining the temperature and pressure signals, correcting it to the flow rate under standard conditions to ensure the comparability of measurement results under different operating conditions.

[0048] In one possible embodiment, in step 1, the intelligent flow totalizer component calculates the pulse signal to obtain the formula for the actual gas velocity and flow rate:

[0049]

[0050] In the formula, This represents the actual gas flow rate. This represents the speed of sound of ultrasound in a stationary gas. This refers to the propagation speed of ultrasound downstream; The cross-sectional area for gas flow within the pipe. This represents the actual gas flow rate. This set of formulas is based on the principle of ultrasonic sound velocity difference, ensuring the accuracy of the calculated actual flow velocity and flow rate. Ultrasonic wave propagation speed downstream. Airflow accelerates ultrasound waves, increasing their propagation speed against the current. Airflow impedes and slows down ultrasonic waves. In practical applications, the gas flow rate... Much smaller than the speed of sound of ultrasound in still gas. c , Negligible, and the speed of backflow propagation It is approximately equal to c, therefore it simplifies to This simplifies calculations while ensuring accuracy. (Regarding the flow rate formula...) Its physical meaning is the volume of gas flowing through the cross-section of the pipe per unit time, and the pipe flow cross-sectional area.S Determined by the inner diameter of the pipe to which the metering equipment is compatible, the abstract flow velocity is converted into an intuitive flow rate through the calculation of flow velocity × cross-sectional area, thus completing the preliminary measurement of the actual flow rate.

[0051] In one possible embodiment, in step 3, the gas flow rate formula under standard conditions is obtained as follows:

[0052] In the formula, The flow rate under standard conditions. For standard pressure, This is the standard temperature.

[0053] Specifically, the ideal gas law is: In a metering scenario, the amount of gaseous substance flowing through the pipeline per unit time. n The volume V remains unchanged, therefore the volume V is the same as the volume V. Proportional to actual traffic. The current operating condition ( For actual pressure, The volumetric flow rate is at the actual temperature, while the standard condition is usually specified as... , (20℃) The actual flow rate can be corrected to the flow rate under standard conditions using a formula. When the actual pressure is higher than the standard pressure, the gas is compressed, and the standard flow rate will be less than the actual flow rate. When the actual temperature is higher than the standard temperature, the gas expands, and the standard flow rate will be greater than the actual flow rate. This correction ensures that the measurement results under different pressure and temperature conditions have a unified benchmark, meeting the needs of scenarios such as trade transfer and energy statistics.

[0054] In one possible embodiment, the method further includes obtaining the actual gas flow rate. and actual traffic Then, the intelligent flow totalizer component first performs automatic nonlinear correction on the actual flow velocity, using the following formula:

[0055] In the formula, To correct the gas flow rate, , This is a nonlinear correction coefficient; based on the corrected flow velocity. and pipeline flow cross-sectional area Through formula The corrected actual flow rate was calculated. .

[0056] Specifically, in actual measurements, when the gas velocity is low, the viscosity of the pipe wall reduces the airflow velocity near the wall, leading to uneven velocity distribution and disrupting the linear relationship between sound velocity difference and flow velocity. Conversely, at higher velocities, turbulence easily occurs, also causing nonlinear deviations. The nonlinear correction coefficient is calibrated experimentally. , (Different pipe diameters and gas media correspond to different coefficients, which are pre-stored in the integrator), using a quadratic polynomial. Correct the actual flow rate, coefficient Used to compensate for the viscous force effect in the low-velocity section, coefficient Used to compensate for the turbulent effects in the high-velocity section, so that the corrected flow velocity... It more closely approximates the actual gas flow rate. Then through... The corrected actual flow rate is calculated, and the nonlinear error is transferred from the flow velocity to the flow rate, eliminating the influence of nonlinear factors on the measurement results. This method is especially suitable for industrial measurement scenarios with extremely high accuracy requirements.

[0057] In one possible embodiment, when the intelligent flow totalizer component performs calculations in step 3 in conjunction with temperature and pressure sensor signals, it performs automatic pressure and temperature compensation:

[0058] In the formula, To compensate for the flow rate under standard conditions, For standard pressure, This is the standard temperature.

[0059] Specifically, under high-pressure conditions, the distance between gas molecules decreases, and the assumption of no intermolecular forces in the ideal gas law no longer holds. Therefore, the influence of gas compressibility on flow rate needs to be carefully considered. At this point, the relationship between gas density and pressure becomes non-linear, and the basic compensation formula cannot accurately correct for it. This formula introduces a square root term, which is essentially a simplified correction to the gas compressibility factor: the higher the pressure, the greater the impact of the compressibility factor on flow rate, and the square root term can more accurately reflect the non-linear effect of pressure changes on gas volume. At the same time, it retains the linear correction logic for temperature on gas volume, ensuring accurate compensation for both temperature and pressure parameters. The correction is based on the actual flow rate after non-linear correction. Based on this, further eliminate the measurement deviations caused by high pressure and high temperature, so that the final result is... It more closely reflects real-world standard flow conditions and is suitable for stringent metering scenarios such as long-distance natural gas pipelines and high-pressure petrochemical equipment.

[0060] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A metering device for metering the flow of a gas using the principle of ultrasonic velocity difference, characterized in that, The intelligent flow totalizer assembly, the rectifier assembly, the rotating head assembly, the sensing assembly and the metering housing assembly are included. The intelligent flow totalizer assembly is connected with the rotating head assembly and is used for processing and displaying flow data; the rotating head assembly is connected with the metering housing assembly; the rectifier assembly is connected with the metering housing assembly and is used for rectifying airflow; the internal passage of the metering housing assembly is communicated with the gas pipeline; and the metering housing assembly is used for providing a gas metering carrier. The sensing assembly is connected with the housing assembly; the sensing assembly includes an ultrasonic sensor, a pressure sensor and a temperature sensor and is used for collecting gas parameters.

2. The metering apparatus for measuring a gas flow using a principle of ultrasonic velocity difference according to claim 1, characterized by, The rectifier assembly includes a flange (11), a fan blade (12) and a rectifier pipeline (13); the fan blade (12) is arranged in the rectifier pipeline (13); and the rectifier pipeline (13) is connected with the measured gas pipeline through the flange (11).

3. The metering apparatus for measuring a gas flow rate using a principle of ultrasonic velocity difference according to claim 1, characterized by, The rotating head assembly includes a rotating head (14), an elastic shaft retainer (15), a fixed rotating head (16), a small shaft (17) and a second O-shaped sealing ring (18). The small shaft (17) is threadedly connected with the fixed rotating head (16); the elastic shaft retainer (15) and the second O-shaped sealing ring (18) are arranged between the fixed rotating head (16) and the rotating head (14); and the rotating head (14) is matched with the small shaft (17).

4. The flow metering apparatus for measuring a gas flow using a principle of ultrasonic velocity difference according to claim 3, characterized by, The sensing assembly includes a pressure sensor (22), a temperature sensor (23) and an ultrasonic sensor (24); the pressure sensor (22) and the temperature sensor (23) are respectively used for collecting pressure and temperature signals of gas in the pipeline; and the ultrasonic sensor (24) is used for measuring the propagation of ultrasonic waves in the gas.

5. The flow metering apparatus for measuring a gas flow using a principle of ultrasonic velocity difference according to claim 4, wherein The metering housing assembly includes a meter head base (25), a cover (26) and a metering chamber (27). The metering chamber (27) provides a metering space for gas; two threaded holes and four screw threaded holes are processed on the top of the metering chamber (27); the pressure sensor (22) and the temperature sensor (23) are respectively installed in the two threaded holes on the top of the metering chamber (27); and the four screw threaded holes on the top of the metering chamber (27) are connected with the meter head base (25). Four threaded holes for installing the ultrasonic sensor (24) are processed on the side of the metering chamber (27); four inclined long holes are arranged on the top of the metering chamber (27) and reach the depth of the threaded holes for installing the ultrasonic sensor (24) outside to pass the data line of the sensor; The meter head base (25) is used for installing the intelligent flow totalizer assembly; and the cover (26) is installed on the metering chamber (27) by screws to block the ultrasonic sensor (24).

6. The flow metering apparatus for measuring a gas flow using a principle of ultrasonic velocity difference according to claim 4, wherein The ultrasonic sensor includes an ultrasonic sensor sheath (21), an ultrasonic sensor element (20) and an ultrasonic sensor pressure sheath (19). The ultrasonic sensing sheath (21) is internally provided with a step to prevent the ultrasonic sensing element (20) from falling after being installed, and the ultrasonic sensing sheath (21) is internally and externally provided with a threaded structure, the internal thread of the ultrasonic sensing sheath (21) is engaged with the external thread of the ultrasonic sensing pressing sleeve (19) to be screwed in to press the ultrasonic sensing element (20), and the external thread of the ultrasonic sensing sheath (21) is engaged with the thread on the metering chamber (27).

7. The flow metering apparatus for measuring a gas flow using a principle of ultrasonic velocity difference according to claim 6, wherein The smart flow totalizer assembly includes a face mask (1), a front cover (2), an aviation plug with a sealing gasket (3), a display screen (4), a support (5), a circuit board (6), a battery pack (7), a fixing plate (8), a first O-shaped sealing ring (9), and a rear cover (10). The face mask (1) is made of soft PVC material, and is arranged on the front cover (2). The transparent position in the middle of the face mask (1) is used to read the data of the display screen (4). Two aviation plugs with sealing gaskets (3) are arranged at the bottom of the front cover (2) as the output ports of the flowmeter. A hole is arranged at the middle position of the bottom of the front cover (2) to pass through the data line of the sensing assembly. The front cover (2) is also provided with a threaded hole to be connected with the rotary head (14) through a screw. The display screen (4) is connected with the circuit board (6) through the support (5), and is fixed in the front cover (2) through a screw. The circuit board (6) is used to realize temperature and pressure compensation, read the standard cubic meter flow, display the temperature, pressure, battery capacity of the gas in the pipeline in real time, use the atmospheric pressure value in the field, and store the real-time data. The battery pack (7) is fixed in the rear cover (10) through the fixing plate (8) and a screw. The sealing surfaces of the front cover (2) and the rear cover (10) are provided with corresponding concave-convex groove structures. The first O-shaped sealing ring (9) made of silica gel is filled in the concave groove of the rear cover (10), and the convex groove of the front cover (2) presses the first O-shaped sealing ring (9) to realize sealing and explosion-proof.

8. A method for measuring gas flow using the principle of ultrasonic velocity difference, applied to the measuring device for measuring gas flow using the principle of ultrasonic velocity difference according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: Step 1: After starting the device, the rectifier assembly first rectifies the airflow in the pipeline to stabilize the flow field, then the ultrasonic sensor in the sensing assembly measures the ultrasonic wave velocity difference of the airflow in the forward and reverse directions, transmits the detected pulse signal to the smart flow totalizer assembly, and the smart flow totalizer assembly operates the pulse signal to obtain the actual flow rate and flow of the gas; Step 2: While the ultrasonic sensor measures and operates the actual flow rate and flow, the pressure sensor and temperature sensor in the sensing assembly respectively collect the pressure signal and temperature signal of the gas in the pipeline, and synchronously transmit the collected pressure and temperature signals to the smart flow totalizer assembly; Step 3: After receiving the pressure and temperature signals transmitted in step 2, the smart flow totalizer assembly performs temperature and pressure compensation operation combined with the actual flow rate and flow data obtained in step 1, finally obtains the flow rate and flow of the gas under standard conditions, and transmits the result to the display screen for display.

9. The method of claim 8, wherein the method is characterized by, In step 1, the formula for operating the pulse signal by the smart flow totalizer assembly to obtain the actual flow rate and flow of the gas is: ， ， wherein is the actual flow rate of the gas, is the speed of sound of the ultrasonic wave in the stationary gas, is the downstream propagation speed of the ultrasonic wave; is the cross-sectional area of the gas flow in the pipe, is the actual flow rate of the gas; In step 3, the gas flow formula under standard conditions is obtained as: ， wherein is the flow rate at standard conditions, is the standard pressure, is the standard temperature.

10. The method of claim 9, wherein the method is characterized by: Also included, obtaining the actual flow rate of gas and the actual flow After that, the intelligent flow totalizer component automatically corrects the actual flow rate in a non-linear manner, with the formula: ， wherein, is the corrected gas flow rate, , is a non-linear correction factor; based on the corrected flow rate and the pipe cross-sectional area , the corrected actual flow rate is calculated by the equation ; In step 3, the intelligent flow totalizer assembly combines temperature and pressure sensing signals for operation, and performs automatic pressure and temperature compensation: ， wherein Qs is the flow rate at standard conditions after compensation, Ps is the standard pressure, Ts is the standard temperature.

Images