CN219178641U - Ultrasonic flowmeter - Google Patents

Abstract

The utility model discloses an ultrasonic flowmeter, which comprises a module main body for forming a gas flow channel and an acoustic channel, a guide vane for rectifying gas, a guide vane baffle for assisting in fixing the guide vane, a transducer for transmitting and receiving ultrasonic waves, a transducer gland for positioning and fixing the transducer, a calculation control module circuit board, a circuit board fixing frame and an air outlet pipe, wherein the module main body is provided with a plurality of air inlet channels and air outlet channels; the assembly direction of two transducers arranged at the upstream and downstream of the module main body forms an included angle of 36.87 degrees with the gas flow passage, and the two transducers are mutually opposite. The ultrasonic flowmeter provided by the utility model has the advantages that the structure is compact, the installation is convenient, the installation shows good fitting property in the gas meter, the flow velocity of fluid is detected by adopting a correlation mode, the signal interference generated by the ultrasonic multipath phenomenon is greatly reduced compared with that of a reflection mode flowmeter, the metering precision is improved, the signal attenuation is greatly reduced compared with that of a reflection mode flowmeter, and the energy consumption of a metering module can be effectively reduced.

Description

Ultrasonic flowmeter

Technical Field

The utility model relates to the technical field of fuel gas metering, in particular to an ultrasonic flowmeter.

Background

An ultrasonic flowmeter (ultrasonic gas meter) is a novel gas meter different from the traditional gas flowmeter, and the working principle is as follows: the gas flow velocity in the specific flow channel is measured by adopting a time difference method principle, namely, the flow velocity of the fluid is reflected by measuring the difference between the velocity of the ultrasonic signal in the fluid during forward flow and backward flow propagation; the influence of errors caused by the change of the sound velocity along with the temperature of the fluid by the time difference method is small, and meanwhile, the development of electronic technology reaches the engineering requirement of time difference measurement, so that the application of the method is more and more extensive.

In the existing ultrasonic flowmeter, a pair of transducers (i.e., a pair of ultrasonic sensors) are generally adopted to transmit and receive ultrasonic signals, and the time difference is utilized to calculate the flow rate of fuel gas; in the prior art, the transducers are typically arranged in a diagonally opposite, reflective or double reflective manner within the flow meter so as to cooperate with each other, for example, an ultrasonic flow meter disclosed in chinese patent CN103270396 a, in which the transducers are arranged in a reflective manner.

However, existing ultrasonic flow meters often suffer from a number of disadvantages: 1. the reflection and double reflection modes have large signal attenuation, so that the signal to noise ratio is poor, and the interference and the energy consumption are increased, so that the improvement is needed; 2. the reflection and double reflection modes are easier to cause the problem of sound wave multipath, the influence of noise and drift is large, the time difference measurement interference becomes large, the measurement precision becomes poor, and the improvement is also carried out; 3. when the transducer is arranged in an oblique correlation way, an included angle exists between the flow direction of fluid and a sound channel (namely the propagation direction of ultrasonic waves), and due to the installation structure of the transducer, the problem of sound path in an installation nest outside a main runner is necessarily solved.

Therefore, it is highly desirable to perform appropriate algorithms and structural optimization for existing ultrasonic flow meters.

Disclosure of Invention

In view of this, the utility model provides an ultrasonic flowmeter, which has the following specific technical scheme:

an ultrasonic flowmeter comprises a module main body for forming a gas flow channel and an acoustic channel, a guide vane for rectifying gas, a guide vane baffle for assisting in fixing the guide vane, a transducer for transmitting and receiving ultrasonic waves, a transducer gland for positioning and fixing the transducer, a calculation control module circuit board, a circuit board fixing frame and an air outlet pipe;

the module main body comprises a gas flow channel and an acoustic channel, if the flow direction of gas is defined as the front, the gas flow channel comprises a fairing section positioned at the rear part, a main flow channel section positioned in the middle and an air outlet pipe connecting sleeve positioned at the front part, the section of the main flow channel section is rectangular, a plurality of guide vane mounting clamping grooves which are uniformly distributed at intervals are correspondingly arranged on the left and right inner side walls of the main flow channel section, a plurality of guide vanes are vertically arranged in the guide vane mounting clamping grooves, a rectangular flow channel array for gas circulation is formed in the main flow channel section, and a guide vane baffle is arranged at the tail part of the main flow channel section; the sound path channel is integrally arranged on the gas flow channel, the middle section of the sound path channel is intersected with the main flow channel section and is arranged at an included angle, two ends of the sound path channel are respectively provided with a transducer mounting nest with a rectangular section, and the outer end part of the transducer mounting nest is sequentially provided with a transducer mounting seat and a transducer gland mounting seat; the air outlet pipe connecting sleeve is connected with the air outlet pipe through an air outlet pipe buckle to realize the axial locking of the air outlet pipe, and the joint of the air outlet pipe connecting sleeve and the air outlet pipe is sealed by an O-shaped sealing ring;

the circuit board fixing frame is buckled on the module main body, and the calculation control module circuit board is arranged in the circuit board fixing frame; two transducers arranged on transducer mounting seats at the upstream and downstream of the module main body are respectively connected with a signal wire for a circuit board of the calculation control module, and are respectively positioned and fixed axially and circumferentially by a transducer gland arranged on the corresponding transducer gland mounting seat; the assembly direction of the upstream transducer and the downstream transducer forms an included angle of 36.87 degrees with the gas flow channel, and the two transducers are mutually opposite; the calculating control module circuit board calculates the flow of the gas according to the propagation time, the air temperature and the air pressure of the ultrasonic wave between the upstream transducer and the downstream transducer.

The ultrasonic flowmeter provided by the utility model has the advantages that the structure is compact, the installation is convenient, the installation shows good fitting property in the gas meter, the flow velocity of fluid is detected by adopting a correlation mode, the signal interference generated by the ultrasonic multipath phenomenon is greatly reduced compared with that of a reflection mode flowmeter, the metering precision is improved, the signal attenuation is greatly reduced compared with that of a reflection mode flowmeter, and the energy consumption of a metering module can be effectively reduced.

Preferably, the cross section of the fairing section is designed as a reduced rectangular cross section, and the corners are rounded with a variable radius.

Preferably, the middle section of the acoustic path channel intersects the main flow path section at an angle arctan 3/4.

Preferably, the process structure part between each transducer and the corresponding acoustic path channel is designed as an acoustic cavity, and two chamfers with angles slightly larger than 45 degrees are correspondingly arranged in the acoustic cavity.

Preferably, the circuit board fixing frame comprises a rectangular pit for placing the circuit board of the calculation control module and conformal buckles which are arranged at two sides of the rectangular pit and are buckled with the module main body in an adaptive manner; the circuit board of the calculation control module is placed on the rectangular pit, and is automatically sealed by the anti-corrosion soft rubber after the complete debugging of the module main body is completed.

Preferably, the computing control module circuit board is integrally provided with a temperature sensor and a pressure sensor.

Preferably, the main body of the air outlet pipe is an L-shaped pipe, an inlet sealing ring groove is correspondingly formed on the outer peripheral surface of the inlet of the L-shaped pipe, and an axial fixing clamping groove and a circumferential fixing clamping position are also formed on the L-shaped pipe positioned at the inner side of the inlet sealing ring groove; the connecting sleeve of the air outlet pipe is of a two-section circular pipe structure, the first section of circular pipe which is positioned inside is connected with the inlet of the air outlet pipe, and the sealing is formed by an O-shaped sealing ring sleeved on the sealing ring groove of the inlet; four through grooves are formed in the second section of outer round pipe, the air outlet pipe buckle penetrates through the through grooves and is clamped on the axial fixing clamping groove of the air outlet pipe, and the module main body and the air outlet pipe are axially locked; two tenons are simultaneously arranged on the second section of circular tube and are combined with a circumferential fixing clamping position formed by four bosses on the wall of the air outlet tube to form circumferential locking of the module main body and the air outlet tube; the air outlet pipe buckle is an n-like deformation body made of spring stainless steel.

Preferably, the tail part of the main runner section is provided with a guide vane baffle connecting structure, and the guide vane baffle connecting structure is two symmetrically arranged rivet posts; the guide vane baffle plate comprises a wafer base, a rectangular hole is formed in the middle of the wafer base, and two symmetrical holes are formed in two sides of the wafer base and are matched and connected with corresponding riveting columns.

Preferably, the head of the guide vane corresponding to the guide vane baffle is of a 'single bracket' shape-modified structure, and the front side and the rear side of the guide vane are provided with 0.3-degree slopes.

Preferably, the transducer mounting seats are internally provided with transducer mounting round holes, the end faces of the external mounting ends are planes, the transducer mounting round holes in the two transducer mounting seats are coaxial, and the planes of the two mounting ends are parallel; the energy converter gland comprises an annular base, four arc-shaped bosses are arranged on the edge of the inner ring of the annular base in an equidistant surrounding manner, two arc-shaped enclosures and two square hole pull buckles are arranged on the edge of the outer ring in an opposite direction, and a connecting line of the two arc-shaped enclosures is perpendicular to a connecting line of the two square hole pull buckles; the arc-shaped boss, the arc-shaped surrounding and the square hole pulling buckle are positioned on the same side of the annular base, the side oblique angle of the arc-shaped boss is large, the table top is narrow, and the square hole pulling buckle is provided with a square hole; two chamfer isosceles trapezoid bosses are arranged on the mounting seat of the pressure cover of the energy converter and are respectively contacted and combined with square holes on two square hole pull buckles on the pressure cover of the energy converter; two sides of the chamfer isosceles trapezoid boss on the transducer gland mounting seat are respectively provided with a rectangular boss, and grooves formed by the four rectangular bosses are used for performing auxiliary constraint on the mounting transducer gland in the front-rear direction.

By adopting the technical scheme, the utility model has the following beneficial effects:

(1) The ultrasonic flowmeter adopts an integrated structural design of the gas flow channel and the acoustic channel, so that the consistency of mass production is better ensured, the stability of the structure under the environments of transportation, falling and the like is also better ensured, and the accuracy and reliability of metering are better ensured.

(2) The ultrasonic flowmeter provided by the utility model has the advantages of compact structure, convenience in installation and good fitting property in the gas meter.

(3) The ultrasonic flowmeter of the utility model adopts a correlation mode to detect the flow velocity of fluid, the signal interference generated by ultrasonic multipath phenomenon is greatly reduced compared with a reflection mode flowmeter, the metering precision is improved, the signal attenuation is greatly reduced compared with a reflection mode flowmeter, and the energy consumption of the metering module can be effectively reduced.

(4) The ultrasonic flowmeter has the advantages that the section of the acoustic path in the transducer mounting nest is rectangular, and the ultrasonic flowmeter has a stable gas flow field.

(5) The ultrasonic flowmeter is provided with the temperature sensor and the pressure sensor, and the real-time gas temperature and pressure parameters enable a metering algorithm to be more reliable and real.

(6) According to the ultrasonic flowmeter, the circuit board of the calculation control module is automatically sealed by the anti-corrosion soft rubber, so that the service life of the module is prolonged.

(7) The ultrasonic flowmeter of the utility model has the advantages that the silencing structure (namely the silencing cavity) is arranged on the necessary process structure which damages the flow field or the acoustic path, so that the noise is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are only embodiments of the present utility model, and other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

Fig. 1 is a front view of an ultrasonic flow meter according to the present utility model.

Fig. 2 is a cross-sectional view taken along the direction B-B in fig. 1.

Fig. 3 is a front view of an ultrasonic flow meter according to the present utility model.

Fig. 4 is a cross-sectional view taken along the direction A-A in fig. 3.

Fig. 5 is a side view of an ultrasonic flow meter according to the present utility model.

Fig. 6 and 7 are perspective views of an ultrasonic flowmeter according to the present utility model at different angles.

Fig. 8 to 13 are detailed views of the structure of each main component (module body, guide vane baffle, etc.) in the ultrasonic flowmeter.

Fig. 14 is a detailed view of the structure of the transducer gland.

Fig. 15 is a detailed view of the structure of the circuit board fixing frame.

Fig. 16 is a detailed view of the structure of the outlet pipe.

In the figure: the device comprises a 1-module main body, a 2-deflector, a 3-deflector baffle, a 4-transducer, a 5-transducer gland, a 6-computation control module circuit board, a 7-circuit board fixing frame, an 8-air outlet pipe, a 9-fairing section, a 10-main runner section, an 11-air outlet pipe connecting sleeve, a 12-deflector mounting clamping groove, a 13-rib plate group, a 14-transducer mounting nest, a 15-transducer mounting seat, a 16-transducer gland mounting seat, a 17-air outlet pipe buckle, an 18-O-shaped sealing ring, a 19-sound-eliminating cavity, a 20-rectangular sink pit, a 21-conformal buckle, a 22-anti-corrosion soft rubber, a 23-L-shaped pipe, a 24-inlet sealing ring groove, a 25-axial fixing clamping groove, a 26-circumferential fixing clamping position, a 27-through groove, a 28-tenon, a 29-rivet column, a 30-annular base, a 31-arc boss and a 32-arc-shaped enclosure, and a 33-square hole pull buckle.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present utility model and should not be construed as limiting the utility model.

In the description of the present utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the drawings, are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Examples:

as shown in fig. 1 to 16, an ultrasonic flowmeter of the present utility model comprises a module body 1 for constituting a gas flow path and an acoustic path channel, a baffle 2 for rectifying gas, a baffle plate 3 for assisting in fixing the baffle 2, a transducer 4 for transmitting and receiving ultrasonic waves, a transducer gland 5 for positioning and fixing the transducer 4, a calculation control module circuit board 6, a circuit board fixing frame 7, and an air outlet pipe 8.

The module body 1 includes a gas flow path and an acoustic path, and if the flow direction of the gas is defined as the front, the gas flow path includes a cowling section 9 at the rear, a main flow path section 10 at the middle, and a gas outlet pipe connecting sleeve 11 at the front.

The section of the fairing section 9 is designed as a variable rectangular section necking, and corners are rounded with variable radii to perform effective fairing.

A group of (three) guide plates 2 for rectifying are arranged in the gas flow passage, specifically, the section of the main flow passage section 10 is 27mmX7.6mm rectangular, three guide plate mounting clamping grooves 12 which are uniformly distributed at intervals are correspondingly formed on the left inner side wall and the right inner side wall of the main flow passage section, the three guide plates 2 are vertically arranged in the six guide plate mounting clamping grooves 12, a rectangular flow passage array for gas circulation is formed in the main flow passage section 10, and the guide plate baffle 3 is arranged at the tail part of the main flow passage section 10 and used for limiting the three guide plates 2.

Because the flow channel drawing angle of the module main body exists, the rectangular section design standard of the module main body 1 is placed on the intersection point of the acoustic path center and the flow channel center, and the fitting of the flow velocity on the flow channel section is ensured as much as possible.

The utility model forms a rectangular flow channel array for gas circulation by using the flow guide plates 2 (in the embodiment, the main flow channel section is specifically divided into four flat rectangular section flow channels of the array), and the flow guide plates 2 are uniformly distributed at intervals, so that the utility model can be used for secondary rectification of air flow, improves the fitting property of a flow field in an acoustic channel volume in an algorithm, ensures the reliability and stability of the flow acoustic environment of a metering module, and further effectively improves the metering precision. Meanwhile, the head of the guide vane 2 corresponding to the guide vane baffle 3 is of a 'single bracket' shape-modifying structure, and the contours of the front side and the rear side of the guide vane have 0.3 degree of inclination, so that the installation is convenient, and the air inlet is improved.

More specifically, the tail of the main runner section 10 is provided with a baffle plate connecting structure, and the baffle plate connecting structure is two symmetrically arranged riveting columns 29 (heating can be formed into hemispherical rivets); the deflector baffle 3 comprises a wafer base, a rectangular hole for maximally passing gas is formed in the middle of the wafer base, and two symmetrical holes are formed in two sides of the wafer base and are matched with corresponding rivet posts 29 for limiting the deflector 2.

The tail end of the guide vane is limited by the guide vane baffle plate 3, and the specified position of the guide vane 2 is ensured in the circulation and transportation links of the module finished product. Meanwhile, the baffle plate 3 is fixed by riveting, so that the quick installation and reliability of the baffle plate 3 are ensured.

The acoustic path channel is integrally installed on the gas flow channel, wherein the middle section is intersected with the main flow channel section 10 and is arranged at an included angle, and particularly an arctan3/4 included angle is formed, two ends of the acoustic path channel are respectively provided with transducer installation sockets 14 with rectangular sections, as indicated by an A position in fig. 8, and as indicated by a B position in fig. 8 and 12, are respectively provided with an installation socket. The outer end part of the transducer mounting nest 14 is provided with a transducer mounting seat 15 and a transducer gland mounting seat 16 in sequence.

The ultrasonic flowmeter adopts the design of the integrated structure of the acoustic channel and the gas flow channel, thereby better ensuring the consistency of mass production and the stability of the structure under the environments of transportation, falling and the like, and further better ensuring the accuracy and reliability of metering.

The transducers at the two ends of the acoustic path channel are provided with the acoustic paths in the nest, the structural section of the acoustic paths is rectangular, the mathematical modeling difficulty of the flow field in the installation nest is simplified, and the gas flow field is stabilized.

The transducer mounting seat 15 is internally provided with a transducer mounting round hole, the end face of the external mounting end is a plane, the transducer mounting round holes in the two transducer mounting seats 15 are coaxial, and the planes of the two mounting ends are parallel, so that the accurate mounting of the transducer gland 5 and the coaxial mounting of the two transducers 4 are ensured.

The transducer gland 5 comprises an annular base 30, and four arc-shaped bosses 31 are arranged at the edge of the inner ring of the annular base 30 in an equidistant surrounding manner and used for axially positioning the transducer 4; two arc-shaped enclosures 32 and two square hole pull buckles 33 are oppositely arranged at the edge of the outer ring, the connecting line of the two arc-shaped enclosures 32 is perpendicular to the connecting line of the two square hole pull buckles 33, and the arc-shaped enclosures 32 are used for wrapping the soft rubber structure of the transducer 4 and are an assembly process structure for installing the transducer 4; the arc-shaped boss 31, the arc-shaped surrounding 32 and the square hole pull buckle 33 are positioned on the same side of the annular base 30, the side oblique angle of the arc-shaped boss 31 is large, the table top is narrow, and the square hole pull buckle 33 is provided with a square hole; two chamfer isosceles trapezoid bosses are arranged on the transducer gland mounting seat 16 and are respectively contacted and combined with square holes on two square hole pull buckles 33 on the transducer gland 5; two sides of the chamfer isosceles trapezoid boss on the transducer gland mounting seat 16 are respectively provided with a rectangular boss, and grooves formed by the four rectangular bosses are used for performing auxiliary constraint on the mounting transducer gland 5 in the front-rear direction.

The four convex point positioning surfaces on the energy converter gland 5 can improve the stress stability, and the square hole pull buckle structure can realize quick buckling. The arrangement of the transducer gland 5 can ensure the micro deformation of the transducer soft rubber structure and ensure the airtight, positioning and micro-force reliable fixation.

The process structure part between each transducer 4 and the corresponding sound path channel is designed as a sound-eliminating cavity 19, and two chamfers which are slightly larger than 45 degrees are correspondingly arranged in the sound-eliminating cavity 19, so that partial sound waves outside the effective sound wave projection boundary are weakened after multiple scattering refraction, and noise interference received by the transducers 4 is weakened from the surface. The utility model effectively reduces noise by arranging the silencing structure on the necessary process structure for destroying the flow field or the acoustic path.

The utility model is provided with the rib plate group 13 at the outer side of the module main body 1, so that the outer side plate is stressed and does not deform, and the bearing capacity is enhanced.

The air outlet pipe connecting sleeve 11 is connected with the air outlet pipe 8 through the air outlet pipe buckle 17, so that the axial locking of the air outlet pipe 8 is realized, and the joint of the air outlet pipe connecting sleeve and the air outlet pipe is sealed by using an O-shaped sealing ring 18.

Specifically, the main body of the air outlet pipe 8 is an L-shaped pipe 23, an inlet sealing ring groove 24 is correspondingly formed on the outer peripheral surface of the inlet of the L-shaped pipe 23, and an axial fixing clamping groove 25 and a circumferential fixing clamping position 26 are further formed on the L-shaped pipe 23 positioned at the inner side of the inlet sealing ring groove 24.

The air outlet pipe connecting sleeve 11 is of a two-section circular pipe structure, the first section circular pipe inside is connected with the inlet of the air outlet pipe 8, and sealing is formed by an O-shaped sealing ring 18 sleeved on the inlet sealing ring groove 24; four through grooves 27 are formed in the second section of outer round tube, the air outlet pipe buckle 17 penetrates through the through grooves 27 and is clamped on the axial fixing clamping groove 25 of the air outlet pipe 8, and the module main body 1 and the air outlet pipe 8 are axially locked; two tenons 28 are simultaneously arranged on the second section of circular tube and are combined with a circumferential fixing clamping position 26 formed by four bosses on the wall of the air outlet pipe 8 to form circumferential locking of the module main body 1 and the air outlet pipe 8.

The L-shaped pipe 23 is used as a bearing support of the module in the gas meter, so that the air flow ventilation and pressure loss are ensured to be small, and the turning part of the L-shaped pipe 23 is rounded. The inlet sealing ring groove 24, the axial fixing clamping groove 25 and the circumferential fixing clamping position 26 form quick and reliable connection between the module main body 1 and the air outlet pipe 8 together with the air outlet pipe connecting sleeve 11, the air outlet pipe buckle 17 and the O-shaped sealing ring 18, and the air tightness is ensured.

The air outlet pipe buckle 17 is an n-like deformation body made of spring stainless steel and is used for axially positioning and fixing the air outlet pipe connecting sleeve 11 and the air outlet pipe buckle 17.

The connecting structure of the air outlet pipe connecting sleeve 11 and the air outlet pipe 8 in the module main body 1 adopts a full-freedom constraint structure, so that the stability of the position of the module in the meter is ensured, and inaccurate measurement caused by the environmental change of a flow field is avoided. Meanwhile, the connecting structure of the air outlet pipe connecting sleeve 11 and the air outlet pipe 8 are matched with the air outlet pipe buckle 17, so that the module main body 1 and the air outlet pipe 8 are conveniently and quickly connected.

The circuit board fixing frame 7 is buckled on the module main body 1, and the calculation control module circuit board 6 is arranged in the circuit board fixing frame 7.

Specifically, the circuit board fixing frame 7 includes a rectangular pit 20 for placing the circuit board 6 of the calculation control module, and a shape-following buckle 21 mounted on two sides of the rectangular pit 20 and adapted to be buckled with the module main body 1; the calculation control module circuit board 6 is placed on the rectangular pit 20, and is sealed by the anti-corrosion soft rubber 22 after the complete debugging of the module main body 1.

According to the utility model, the circuit board fixing frame 7 is buckled on the module main body 1, and the calculation control module circuit board 6 is placed in the PCBA installation position (namely the rectangular pit 20), so that the automatic production and online debugging of the module are facilitated. The rectangular pit structure arranged on the circuit board fixing frame 7 is not only used for placing the calculation control module circuit board 6, but also can be used as a surrounding shield of the anti-corrosion soft rubber 22, and in addition, the shape-following buckle 21 on the circuit board fixing frame 7 can be conveniently buckled with the module main body 1.

In the utility model, the circuit board 6 of the calculation control module is sealed by the anti-corrosion soft rubber 22 in a self-flowing way, so that the service life of the module is prolonged, the circuit board is convenient to fix, and the connection reliability of the wiring of the transducer 4 and the meter-out wiring is improved.

The calculation control module circuit board 6 used in the present utility model is a product of the prior art, and will not be described here. The temperature sensor and the pressure sensor are integrally arranged on the calculation control module circuit board 6, so that the real-time gas temperature and pressure parameters are provided, and the metering algorithm can be more reliable and real.

Two transducers 4 arranged on transducer mounting seats 15 at the upstream and downstream of the module main body 1 are respectively connected with a computing control module circuit board 6 by signal wires, and are respectively positioned and fixed axially and circumferentially by a transducer gland 5 arranged on a corresponding transducer gland mounting seat 16; the assembly direction of the upstream transducer 4 and the downstream transducer form an included angle of 36.87 degrees with the gas flow passage, and the two transducers are mutually opposite; the calculation control module circuit board 6 calculates the flow rate of the gas based on the propagation time of the ultrasonic wave between the upstream and downstream transducers 4, the air temperature and the air pressure.

The transducer 4 of the present utility model is of a prior art type and will not be described further herein. The ultrasonic flowmeter provided in this embodiment measures the flow of the fuel gas by using a known time difference method, and the algorithm is not further described in this embodiment.

The ultrasonic flowmeter provided by the utility model has the advantages of compact structure, convenience in installation and good fitting property in the gas meter; the flow velocity of the fluid is detected by adopting a correlation mode, the signal interference generated by the ultrasonic multipath phenomenon is greatly reduced compared with a reflection mode flowmeter, the metering precision is improved, and the energy consumption of the metering module can be effectively reduced compared with the reflection mode signal attenuation.

The utility model provides the ultrasonic flowmeter with compact structure and high metering precision, a pair of transducers are arranged along a gas flow channel in an oblique correlation mode, and the ultrasonic flowmeter is determined by a large number of fluid simulation and actual measurement: firstly, setting an included angle of 36.87 degrees between the flow direction of fluid and the propagation direction of ultrasonic waves; secondly, the method aims at ensuring the emission projection area of the transducer, ensuring that the pressure loss of the gas meter reaches the standard, ensuring that XXHZ ultrasonic waves are well transmitted in a narrow slit, ensuring that the Reynolds number in a main flow channel reaches the standard under the maximum flow, ensuring that the rectification is good, and optimizing the length-width ratio and the rectification length of the section of the flow channel; thirdly, the section of part of the acoustic path in the transducer mounting nest is designed into a rectangle, and the flow fields under various flow rates in the main flow channel and the transducer mounting nest are optimized; fourth, the necessary process structure to destroy the flow field or acoustic path is optimized. Thereby improving the metering precision and effectively improving the metering performance of micro flow and large flow.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model. Thus, the present utility model is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. An ultrasonic flowmeter is characterized by comprising a module main body for forming a gas flow channel and an acoustic channel, a guide vane for rectifying gas, a guide vane baffle for assisting in fixing the guide vane, a transducer for transmitting and receiving ultrasonic waves, a transducer gland for positioning and fixing the transducer, a calculation control module circuit board, a circuit board fixing frame and an air outlet pipe;

the module main body comprises a gas flow channel and an acoustic channel, if the flow direction of gas is defined as the front, the gas flow channel comprises a fairing section positioned at the rear part, a main flow channel section positioned in the middle and an air outlet pipe connecting sleeve positioned at the front part, the section of the main flow channel section is rectangular, a plurality of guide vane mounting clamping grooves which are uniformly distributed at intervals are correspondingly arranged on the left and right inner side walls of the main flow channel section, a plurality of guide vanes are vertically arranged in the guide vane mounting clamping grooves, a rectangular flow channel array for gas circulation is formed in the main flow channel section, and a guide vane baffle is arranged at the tail part of the main flow channel section; the sound path channel is integrally arranged on the gas flow channel, the middle section of the sound path channel is intersected with the main flow channel section and is arranged at an included angle, two ends of the sound path channel are respectively provided with a transducer mounting nest with a rectangular section, and the outer end part of the transducer mounting nest is sequentially provided with a transducer mounting seat and a transducer gland mounting seat; the air outlet pipe connecting sleeve is connected with the air outlet pipe through an air outlet pipe buckle to realize the axial locking of the air outlet pipe, and the joint of the air outlet pipe connecting sleeve and the air outlet pipe is sealed by an O-shaped sealing ring;

the circuit board fixing frame is buckled on the module main body, and the calculation control module circuit board is arranged in the circuit board fixing frame; two transducers arranged on transducer mounting seats at the upstream and downstream of the module main body are respectively connected with a signal wire for a circuit board of the calculation control module, and are respectively positioned and fixed axially and circumferentially by a transducer gland arranged on the corresponding transducer gland mounting seat; the assembly direction of the upstream transducer and the downstream transducer forms an included angle of 36.87 degrees with the gas flow passage, and the two transducers are mutually opposite.

2. An ultrasonic flow meter according to claim 1, wherein the cross section of the fairing section is designed as a reduced rectangular cross section, the corners being rounded off with a varying radius.

3. An ultrasonic flow meter according to claim 1, wherein the mid-section of the acoustic path channel intersects the main flow path section at an angle arctan 3/4.

4. An ultrasonic flow meter according to claim 1, wherein the process structure between each transducer and the corresponding acoustic path is designed as a sound-damping chamber, in which two chamfers of slightly more than 45 ° are provided.

5. The ultrasonic flow meter of claim 1, wherein the circuit board fixing frame comprises a rectangular pit for placing the circuit board of the calculation control module, and conformal buckles arranged at two sides of the rectangular pit and matched with the module body for buckling; the circuit board of the calculation control module is placed on the rectangular pit and is automatically sealed by the anti-corrosion soft rubber.

6. The ultrasonic flow meter of claim 1, wherein the computing control module circuit board is integrally mounted with the temperature sensor and the pressure sensor.

7. The ultrasonic flowmeter of claim 1, wherein the main body of the air outlet pipe is an L-shaped pipe, an inlet sealing ring groove is correspondingly formed on the outer peripheral surface of the inlet of the L-shaped pipe, and an axial fixing clamping groove and a circumferential fixing clamping position are further formed on the L-shaped pipe at the inner side of the inlet sealing ring groove; the connecting sleeve of the air outlet pipe is of a two-section circular pipe structure, the first section of circular pipe which is positioned inside is connected with the inlet of the air outlet pipe, and the sealing is formed by an O-shaped sealing ring sleeved on the sealing ring groove of the inlet; four through grooves are formed in the second section of outer round pipe, the air outlet pipe buckle penetrates through the through grooves and is clamped on the axial fixing clamping groove of the air outlet pipe, and the module main body and the air outlet pipe are axially locked; two tenons are simultaneously arranged on the second section of circular tube and are combined with a circumferential fixing clamping position formed by four bosses on the wall of the air outlet tube to form circumferential locking of the module main body and the air outlet tube; the air outlet pipe buckle is an n-like deformation body made of spring stainless steel.

8. The ultrasonic flow meter of claim 1, wherein the tail of the main flow channel section is provided with a baffle plate connecting structure, and the baffle plate connecting structure is two symmetrically arranged rivet posts; the guide vane baffle plate comprises a wafer base, a rectangular hole is formed in the middle of the wafer base, and two symmetrical holes are formed in two sides of the wafer base and are matched and connected with corresponding riveting columns.

9. The ultrasonic flow meter of claim 8, wherein the head of the baffle corresponding to the baffle is a "single bracket" shaped configuration with a 0.3 degree slope on the front and back side profiles.

10. The ultrasonic flowmeter of claim 1, wherein the transducer mounting seats are internally provided with transducer mounting round holes, the end faces of the external mounting ends are planes, the transducer mounting round holes in the two transducer mounting seats are coaxial, and the planes of the two mounting ends are parallel; the energy converter gland comprises an annular base, four arc-shaped bosses are arranged on the edge of the inner ring of the annular base in an equidistant surrounding manner, two arc-shaped enclosures and two square hole pull buckles are arranged on the edge of the outer ring in an opposite direction, and a connecting line of the two arc-shaped enclosures is perpendicular to a connecting line of the two square hole pull buckles; the arc-shaped boss, the arc-shaped surrounding and the square hole pulling buckle are positioned on the same side of the annular base, the side oblique angle of the arc-shaped boss is large, the table top is narrow, and the square hole pulling buckle is provided with a square hole; two chamfer isosceles trapezoid bosses are arranged on the mounting seat of the pressure cover of the energy converter and are respectively contacted and combined with square holes on two square hole pull buckles on the pressure cover of the energy converter; two sides of the chamfer isosceles trapezoid boss on the transducer gland mounting seat are respectively provided with a rectangular boss, and grooves formed by the four rectangular bosses are used for performing auxiliary constraint on the mounting transducer gland in the front-rear direction.

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