CN117007141A - Large-caliber multichannel runner partition and sound Cheng Jiexu ultrasonic gas meter - Google Patents

Large-caliber multichannel runner partition and sound Cheng Jiexu ultrasonic gas meter Download PDF

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CN117007141A
CN117007141A CN202210468456.5A CN202210468456A CN117007141A CN 117007141 A CN117007141 A CN 117007141A CN 202210468456 A CN202210468456 A CN 202210468456A CN 117007141 A CN117007141 A CN 117007141A
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transducer
caliber
flow
flowmeter
transducers
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Juelong Sensing Technology Shenzhen Co ltd
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Juelong Sensing Technology Shenzhen Co ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/66—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
    • G01F1/667—Arrangements of transducers for ultrasonic flowmeters; Circuits for operating ultrasonic flowmeters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/66—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
    • G01F1/662—Constructional details
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F15/00—Details of, or accessories for, apparatus of groups G01F1/00 - G01F13/00 insofar as such details or appliances are not adapted to particular types of such apparatus
    • G01F15/18—Supports or connecting means for meters

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  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Measuring Volume Flow (AREA)

Abstract

The invention belongs to the technical field of flow metering equipment, in particular to an ultrasonic gas meter with large-caliber multichannel runner partition and sound Cheng Jiexu, and aims to solve the problem that the prior art cannot realize an ultrasonic gas meter with caliber exceeding DN 500. According to the invention, eight transducer mounting columns are radially arranged in a pipe center on a plurality of sections arranged in a gas meter pipe body, a plurality of transducers can be arranged on each transducer mounting column, the transducers arranged on two rows of transducer mounting columns which are parallel and adjacent to each other on the same plane can be paired for measurement, the flow velocity of the interval is measured and calculated through time difference by an independent interval integrating circuit PCB, so that the measurement results of a plurality of groups of transducers arranged according to the length of a flowmeter pipeline are obtained, and the sectional measurement results are processed, namely the measured sound Cheng Jiexu is realized, and finally the total average flow velocity and the total flow value of the flowmeter are obtained; therefore, the ultrasonic large-caliber fuel gas metering is realized, and the maximization of the measuring range ratio is achieved.

Description

Large-caliber multichannel runner partition and sound Cheng Jiexu ultrasonic gas meter
Technical Field
The invention belongs to the technical field of flow metering equipment, and particularly relates to an ultrasonic gas meter with large-caliber multichannel runner partition and sound Cheng Jiexu.
Background
In the era of big data of the internet of things, artificial intelligence and industrial automatic control, the full-electronic mode flowmeter gradually replaces a mechanical or electromechanical combined mode flowmeter for the field of industrial and public water, heat and gas supply metering, and has become an irreversible big trend.
According to the requirements of practical application, the fluid metering industry or occasion expects standard flow metering devices with good caliber specification compatibility, low pressure loss, large range ratio, high precision, high reliability, no abrasion devices, durability and good economy. In recent years, thermal mass flow meters and ultrasonic flow meters have been used for gas, particularly gas flow metering, in all-electronic mode and with good compatibility.
Along with the start of high-precision ASIC gas time difference timing chips (2012-2017) which are successively pushed out by companies such as AMS (ACAM), TI and the like, the time difference mode of ultrasonic flow velocity measurement is applicable to gas flow measurement and metering and wide application and popularization thereof, wherein one important application field is gas metering.
In the field of gas metering, in particular gas metering, mechanical gas flow meters are still widely used at present. Such as membrane type flow meters (mainly for small caliber applications, such as consumer use), turbine flow meters, roots flow meters, etc., whereas vortex shedding flow meters, thermal flow meters, ultrasonic flow meters are electronic flow meters.
In the field of fuel gas metering, the flow of a large-caliber fuel gas pipeline is more focused on from the application technology to be measured or metered; compared with a gas pipeline with a medium diameter and a small diameter, the gas pipeline with a large diameter has the advantages that the caliber of the pipeline is large, and the distribution of the gas flow velocity in the pipeline is more uneven, so that the gas flow rate change range related to the flow in the pipeline is larger, the accuracy required for measuring the gas flow rate is higher, and the range ratio is larger; therefore, the accuracy and the measuring range for improving the flow measurement of the large-caliber gas pipeline are much more difficult than those of the medium-and small-caliber gas pipeline; the flow measuring method and the flow meter with the structure can be adopted to ensure that the flow measuring precision of the large-caliber gas pipeline is high and the measuring range ratio is large, which is the technical problem to be solved; the technical background of the large-caliber gas pipeline flow measurement is summarized and analyzed below.
Film type flowmeter, turbine flowmeter, roots flowmeter, and Roots flowmeter, whether its principle is volume mode or velocity mode, are mechanical type flowmeter; according to the principle, the mechanical flowmeter is passive in measuring fluid, and the fluid is required to provide kinetic energy; the common defects are short service life due to abrasion and narrow measuring range due to the need of a certain kinetic energy drive, and in addition, the measuring precision is reduced along with the prolonging of the service life.
The thermal mass flowmeter which is measured in an all-electronic way has the outstanding advantages that for single-component gas, the gas mass can be directly measured and metered, and the thermal mass flowmeter has good compatibility with different diameters and low pressure loss. However, in principle, it uses one point to sample and measure, so that it has the fatal defects that 1) for large caliber, the range of gas speed variation in the pipeline is large, if only one or a plurality of limited measuring points are arranged, the accuracy of the obtained value is limited; 2) When the gas containing water is encountered, the measured value is misaligned according to the principle, so that the gas cannot be measured; therefore, the application and popularization of the mode are difficult under the complex working condition.
The vortex shedding flowmeter which is measured in a full-electronic way has the advantages that the measured volume flow is not influenced by parameters such as temperature, pressure, density and the like of the measured fluid according to the principle; however, for compressible and variable-speed gases, one probe cannot accurately measure the working condition change in the pipe, and the measurement error is very large; in addition, the vortex shedding flowmeter is limited by the low limit of small Reynolds number, so that the range ratio of the vortex shedding flowmeter is low, and the application and popularization of the vortex shedding flowmeter are affected.
The ultrasonic flowmeter which is measured in an all-electronic way is a velocity flowmeter, and adopts the time difference measuring principle that: in the flowing fluid, two ultrasonic transducers are arranged at a certain interval in front and back to extract the time difference required by the forward flow and the backward flow of sound waves, the flow velocity of the flowing fluid is calculated simultaneously, and then the flow is calculated according to the sectional area of the pipeline and the flowing time. Therefore, measuring the flow rate of a fluid by ultrasonic transit time method is an active form, i.e. if the flow rate is 0, it does not affect its normal measurement (e.g. the temperature, density of the medium can be measured indirectly by transit time). The ultrasonic flow rate measurement is performed by sampling the columnar space formed by the sound wave between the two transducers instead of a point, so that if a plurality of pairs of combined transducers are arranged at different heights and orientations on the cross section in the pipe, the fluid flow rate can be measured representatively, omnidirectionally and effectively. In addition, since the sound velocity is different for media with different densities and different temperatures, the calibrated flowmeter can deduce and calculate the density of the fluid according to the ultrasonic sound velocity, the pipeline pressure and the pipeline temperature when the installation distance of the pair of transducers is determined.
From the above description of several principles for measuring gas volumes in an all-electronic manner, and implementations thereof, it can be seen that sampling the flow rate of a flowing fluid can be divided into two categories:
1) Calculating the volume flow by taking the point as the flow rate sampling basis: that is, a point or a plurality of points is taken as the representative of the fluid flow velocity of the section S of the flowmeter with the diameter D, and the total flow velocity Vt of the section S with the diameter D of the pipeline is deduced according to the relation of the flow velocity change of the points, and the time T of the section L of the flowmeter passes L After that, it passes through the fluid volume U L ＝S×Vt×T L Where Vt is the only variable, vt is at time T L Are all of varying internal, so the volume flow U L The accuracy of (2) depends on the accuracy of Vt, which depends on how many points are sampled on a surface and the distribution of points; typically, the number of sampling points is small, subject to the sensor mounting conditions, so that the measured volume U is caused L The accuracy is limited.
2) Calculating the volume flow by taking the columnar volume as a flow rate sampling basis: sampling the flow velocity by ultrasonic time difference method, calculating the flow velocity average value in the column-shaped volume between two transducersThe sampling time is Tx, here +.>The difference from Vt in 1) is: determination by Tx- >Is a definite value, and at T L The Vt in is the variation. The diameter of the cylinder is the diameter d of the transducer and the length of the cylinder is the distance between a pair of transducers. If can be conveniently distributed in the pipeline of the flowmeterThe flow is calculated in a more reasonable manner if a plurality of columnar volume samples of the transducers can represent the volume in the pipeline of the flowmeter. If the length L of the tube section of the flowmeter is smaller than T due to the sampling time Tx L Therefore, the method of calculating the flow rate and thus the push-out volume by the ultrasonic time difference method is much more scientific and accurate than the method of 1) above. Because Tx is nanosecond, the fluid can be sampled and overlapped for multiple times within one second, and an accurate flow value can be obtained.
From the above analysis of the fluid volume calculation according to different principles, it is known that the method of sampling the fluid velocity by using the ultrasonic time difference method needs to be more accurate and reasonable. Further, for a given length of flow meter, sampling the flow rate by ultrasonic jet lag method requires that the calculation of the exact and reasonable fluid volume satisfy at least three aspects: (1) A plurality of pairs of transducers are required to be distributed and installed in a pipeline of the flowmeter, and the transducers can be reasonably distributed according to the characteristic of flow distribution in the pipeline and are arranged on a plurality of sections of the pipeline in a pairing mode; (2) In order to stabilize and accurately measure the flow rate provided by transducers arranged at different positions, a flow stabilizing measure to the flow rate of a flow channel is needed, namely, the fluid is stabilized to be non-pulsating flow, and the adoption is more accurate; (3) Since the length of the flowmeter is a definite value, paired transducers are installed at two ends of the fluid inlet and outlet of the pipeline as much as possible, and the range of columnar volume samples obtained by the method is large, so that the maximum measuring range ratio can be obtained.
For the three aspects of improving the metering of the large-caliber fuel gas, according to the current practical application, the three principles are summarized as follows:
(one) multichannel principle: in order to make the large-caliber ultrasonic gas meter have high metering precision and reliability, the sampling of the large-caliber ultrasonic flowmeter should be multi-directional, namely, a multi-channel mode (namely, the combination measurement of a plurality of groups of transducers) is adopted. This is because, in the correlation multi-channel transducer mode, in addition to the capability of measuring and calculating the flow rate of the fluid at different height levels and positions in the pipe, respectively, the measurement accuracy and accuracy are improved, and in addition, the multi-channel transducer mode is an important guarantee for the measurement reliability, for example, even if one or several pairs of transducers stop working, other transducers can perform flow measurement.
And (II) steady flow and turbulent flow interference resistance principle are adopted for the multichannel sampling channels: as is known, the volume of gas is different from that of liquid, and the gas has compressibility, so that the gas can be pushed out to have larger flow velocity variation at different positions in the pipeline, and measures are needed to be taken to stabilize the flow velocity variation of the gas at different positions in the pipeline of the flowmeter as much as possible, so that a pair of transducers can sample the gas more accurately, and the metering precision is improved; in addition, for the installation of the flowmeter, the accepted standard is to ensure that the front end straight pipe section has ten times the length of the flowmeter and the rear end has five times the length of the flowmeter, so that the effective range ratio and the metering accuracy of the flowmeter can be ensured. This requirement is necessary, in particular, for large bore flow meters. However, in some special occasions, especially when the device is installed in a place with small space in a pipeline well, if the front end and the rear end are provided with bent pipes, the front end, the rear end and the rear end cannot be guaranteed, when gas flows into the flowmeter from the bent pipes, the flow velocity distribution of the gas is seriously biased to one side, and for a straight-through pipe ultrasonic flowmeter with insufficient sound channels, at the moment, the flow velocity sampling is out of alignment, the measuring range ratio and the measuring precision of the flowmeter are greatly reduced, and the problem to be solved by the industry is solved. If the requirement that the straight pipe sections are not required before and after the flowmeter can be solved, the flowmeter can be effectively ensured to be applied to various complex occasions. The invention adopts a grid partition structure to solve the problem, and the principle is as follows:
Parallel small-pipe-diameter flow speed stability deduction and conclusion:
for fluid flow within a tube, fluid mechanics indicates: the Reynolds number index is a performance criterion for determining whether a fluid flow is laminar or turbulent (i.e., turbulent), is a measure of the ratio of fluid inertia force to viscous force, and is a dimensionless number. When the Reynolds number is smaller, the influence of viscous force on the flow field is larger than that of inertia force, disturbance of flow velocity in the flow field can be attenuated due to the viscous force, fluid flow is stable, and the fluid flow is in laminar flow. On the contrary, if the reynolds number is larger, the influence of the inertia force on the flow field is larger than the viscous force, the fluid flow is unstable, and along with the pulsation, the tiny change of the flow speed is easy to develop and strengthen, and the turbulent flow with disorder and irregularity is formed, so that a theoretical experiment is conducted to deduce:
if the inner diameter of the large-caliber straight pipe is D, the flow velocity of fluid in the pipe is V, the density of the fluid is ρ, and the dynamic viscosity of the fluid is μ, the fluid flow area of the large-caliber straight pipe is A=ρD 2 And/4, the mass flow rate of the fluid is G=AρV, and the Reynolds number of the fluid is Re=ρVD/mu. If the fluid of the large-caliber straight pipe is led into a combined flow passage formed by connecting n small-caliber d straight pipes in parallel, the total fluid flow of the combined flow passage is kept to be the same as the fluid flow of the large-caliber straight pipe, and the flow area Az=n pi d of the combined flow passage is kept 2 And/4 is the same as the fluid flow area A of the large-caliber straight pipe, namely A2=A, the Reynolds number of the fluid in the small-caliber d straight pipe in the combined flow passage isIt follows that when n > 1, the following is concluded:
reynolds number Rez of fluid in the small-diameter d straight pipe in the combined flow channel is smaller than Reynolds number Re of fluid in the large-diameter straight pipe, namely Rez is smaller than Re, for example, n=9, and Rez=Re/3 exists, which reveals that the Reynolds number of fluid in the small-diameter d straight pipe in the combined flow channel is smaller than that of fluid in the large-diameter straight pipe, namely the stability of fluid flow in the small-diameter d straight pipe in the combined flow channel is higher, the pulsation is smaller, and the ultrasonic metering measurement of fluid flow velocity is more accurate. In particular, when the flowmeter is installed in a place with smaller space in a pipeline well, if the front end or the rear end is provided with the bent pipe, the strict condition limitation of the length of the front five straight pipes and the rear five straight pipes at the installation position of the flowmeter cannot be guaranteed, and the metering method of the combined flow passage is adopted, so that the automatic rectification of the fluid can be implemented, and meanwhile, the strict condition limitation of the length of the front five straight pipes and the rear five straight pipes at the installation position of the flowmeter can be eliminated or reduced, and the metering precision is improved.
For the local grid-shaped cavity subjected to partition treatment, under the state of forming stable laminar flow, the distribution of flow velocity is parabolic, and transducers are arranged in the middle of the grid, so that the flow velocity in the middle of each partition can be used as a sampling point with representative velocity.
(III) for ultrasonic measurements, in the case of a limited length of the flowmeter, the principle of maximization of the sound path is obtained: in order to ensure that the ultrasonic gas meter has a large measuring range, namely a measuring range ratio when meeting certain precision requirements, particularly for large-caliber gas meters, it is extremely important to adopt a mode of maximizing sound path between ultrasonic transducers; because for gas meters, the large scale ratio is an extremely important index for trade settlement, and is also the most important technical index for gas meters. For example, if the gas consumption of a certain production factory in the daytime industrial production period is 500 times that of the gas consumption of the night, and if the measuring range ratio of the flowmeter is low, such as the measuring range ratio r=200, the measurement of the large flow period in the daytime is considered, and the measurement consideration of the small flow period in the night is necessarily omitted; in other words, the flow meter may not meter under low flow conditions or the metering error may be large (the accuracy value is negative, such as a mechanical turbine gas meter), which inevitably causes the metering loss of the air supply side. Therefore, in order to enable the ultrasonic gas meter to have a large range ratio and achieve fair trade settlement, the projection distance of the distance connecting line between two transducers of the ultrasonic gas meter in the air flow direction in the main pipe of the flowmeter should be maximized so as to obtain a larger range ratio and a smaller starting flow.
In general, the performance index of the flowmeter is the measurement accuracy and the measuring range ratio, the measurement accuracy is the ratio of the flowmeter value of the flowmeter to the actual value of the flow, and improving the fluid flow stability and mass production consistency are important conditions for determining the measurement accuracy; the range ratio is the ratio of the common flow to the minimum flow under the guarantee of the metering precision of the flowmeter, the range capable of being precisely metered is reflected, and the increase of the effective distance between the ultrasonic transducers is a necessary condition for improving the range ratio; therefore, the higher the metering accuracy and the larger the measurement range ratio, the better the metering performance of the flowmeter.
Obviously, after being capable of inhibiting the turbulence influence of the airflow process, the larger the measured measuring range ratio is, the better the metering performance of the flowmeter is, and for this purpose, the volume flow Q and the measuring range ratio R of the ultrasonic flowmeter and the flowmeter tube areThere is a certain correlation between track lengths L (assumed to be the distance between a pair of transducers), in the metrology domain, the range ratio R is defined as r=q 3 /Q 1 Wherein Q is 3 The flow is a given value corresponding to the common flow under a certain pipe diameter; q (Q) 1 To meet the minimum flow rate required by a certain metering accuracy (for example, the metering accuracy of the secondary flowmeter is +/-5%).
The scheme is analyzed and deduced to obtain an important conclusion: for fluid passing through the flow meter line, the measured pickup flow rate Q q The lower (i.e., the minimum flow that the flowmeter can perceptively meter) is (corresponding to its flow velocity V q The lower and V q Related to the resolution of the time difference chip of the ultrasonic flowmeter and the pipeline structure of the flowmeter, Q 1 And also proportionally lower (i.e., the corresponding minimum flow velocity V 1 It becomes lower). Typically, in practice, the empirical value is Q 1 ＝(5～10)Q q (Q 1 The total zero drift generated by the ultrasonic flowmeter circuit and the transducer and the water resistance design of the flowmeter pipeline are different). Thus, Q can be derived at a certain caliber (Q flowing through the flowmeter pipeline 3 And Q is equal to 1 The time intervals used are equal), the relationship between the range ratio R and the two transducer spacing L is:
in the above, Q 3 Is the common flow of a flowmeter with a certain caliber, V 3 Is equal to Q 3 Corresponding flow rate, Q, of fluid in the flow meter pipeline 1 To meet the minimum flow rate required by a certain metering precision, V 1 Is equal to Q 1 Corresponding flow rate of fluid in flow meter pipeline, Q for certain caliber flow meter 3 And V 3 Is constant (selected value), pi is circumference ratio, r is inner radius of flowmeter pipeline, t is distance between opposite injection surfaces of two transducers in ultrasonic flowmeter pipeline, and alpha is included angle of connecting line between two transducers in fluid flow direction of flowmeter pipeline (alpha is acute angle, when alpha=0, connecting line of two transducers is connected with Fluid flow direction is uniform, cos (α) =1), k is a known quantity related to the measurement time difference and the sound velocity of the flowmeter, β is a known quantity related to the measurement time difference and the sound velocity of the flowmeter, and β=v 3 10k is constant and V 1 V is calculated through a time difference formula of the ultrasonic flowmeter q Derived, i.eThus, in the concrete calculation, V 1 According to V 1 ＝10V q Substitution. From the above relation of R, the following can be concluded:
by increasing the projected distance L.cos (alpha) between the two transducers in the flow direction of the fluid in the flow meter pipeline, the measuring range ratio R of the flow meter can be effectively improved.
For the implementation of the three principles described above, the former two aspects are easier to implement, while the third principle is difficult to implement, because:
(1) The attenuation change rule of sound intensity propagating along the unidirectional x-axis is as follows: i=i o e -2αx Wherein I o For the initial sound intensity, a is the absorption attenuation coefficient (here scattering attenuation is ignored) then,wherein f is the sound wave frequency, beta is the shear viscosity coefficient, the heat conductivity coefficient, the specific heat capacity, the specific heat pressure and various parameters related to the relaxation process, and rho o For density, C is the speed of sound.
(2) The higher the sound wave frequency f is, the higher the measurement accuracy is, so that the current fluid measurement is that for liquid, f is 1-4 MHz; the gas f is 0.2-0.5 MHz; from i=i o e -2αx A kind of electronic device with high-pressure air-conditioning systemAs can be seen, the intensity of the acoustic propagation is exponentially decaying, and the higher the frequency f, the greater the decay in the x-direction of propagation, the density ρ o And the smaller the sound velocity C, the greater the attenuation.
(3) According to the current practical application, for example, f=1 MHz, the distance between a pair of transducers is 1400mm, and the acoustic wave receiving value in waterThe measurement requirements can be met; however, for gas, such as air (or fuel gas), when f=0.2 MHz, the sound wave with the same intensity is formed, the distance between a pair of transducers is 100mm, and the sound intensity of a receiving end is weakened to about 1/10 of the original sound intensity; if the distance between a pair of transducers is 300mm, the excitation voltage of the transducer at the transmitting end is set to 18v, the received sound wave signal can only marginally meet the requirement of time difference measurement, and when the distance is greater than 300mm, the attenuated sound wave almost cannot identify and carry out time difference measurement on the signal received by the transducer; according to i=i o e -2αx The distance of the sound wave in the propagation direction increases, and the exponential decay exhibited by the sound wave is large.
In the above description, when ultrasonic measurement is adopted, 18v of transducer excitation voltage is set, and in a water 1MHz transducer, for a pair of flow meters with the transducer spacing of 1400mm, namely, the oblique insertion type DN1000 caliber, signal identification can be met and measurement can be realized; however, when the 0.2MHz transducer is used for fuel gas and the distance between a pair of transducers is 280mm for an oblique insertion type fuel gas flowmeter with a caliber of DN200, the oblique insertion type fuel gas flow metering with a caliber of DN150 can be realized only marginally. Thus, there is no application and data relating to ultrasonic gas meters of larger calibers, such as DN300 and greater (if transducers are mounted in an oblique insertion, a pair of transducers are spaced about 420mm apart and greater).
In summary, in view of the fact that the attenuation of acoustic energy propagating in gas by ultrasonic waves is far greater than that propagating in liquid, the application of the ultrasonic gas meter with large caliber (such as greater than DN 300) is a great difficulty in the application of the gas metering industry for the application of the ultrasonic time difference measurement principle.
In the field of gas metering, the purpose of realizing the metering application of an ultrasonic gas meter with a large ultrasonic caliber (such as more than DN 300) and simultaneously realizing the aim of a flowmeter with a large range ratio is to realize long-distance flow rate sampling and calculation under the same time interval by adopting ultrasonic waves.
Several structural modes of the existing ultrasonic transducer installed on an ultrasonic gas meter:
the ultrasonic gas meter is arranged in an oblique insertion type transducer, and the installation mode has the advantages of short sound path, less sound channels and high requirements on oblique hole processing precision: for example, the grant publication number CN 211696533U describes a large-caliber multi-channel oblique-insertion correlation ultrasonic flowmeter base table pipeline structure, and the projection distance of two transducer connecting lines in the water flow direction in the pipeline section is very short, which is contrary to the principle (III); in addition, when the caliber of the pipeline is smaller, the scheme has no space for arranging more sound channels at the outer end of the pipeline, which is contrary to the principle (I); the requirements on the processing angle of the inclined hole for installing the transducer are very high, the small angle is offset, and the sound wave receiving intensity is greatly reduced for large caliber, so that the processing is difficult.
In order to stabilize the fluid state, the large-caliber ultrasonic gas meter should be rectified in a pipe through which the gas flows, according to the variability and compressibility of the gas volume. Patent grant publication number CN 210166007U and patent grant publication number CN 210071019U both describe an ultrasonic flowmeter base table pipeline structure, for rectification, only a section of the pipeline inlet at the air inlet end is provided with a honeycomb-shaped gas runner, rectification of the whole pipeline section of the flowmeter is not realized, and the installation of the transducer still adopts an oblique insertion installation mode.
Patent application number CN 2021114261011 describes a structure of a multi-channel large-caliber ultrasonic water meter with layered layout of column type transducers, which has a larger distance between a pair of transducers than in the case of the oblique insertion type transducer arrangement, and the transducers are laid out according to different heights, so that the measurement accuracy and the measurement range ratio are improved.
Patent application number CN 2021218819643 describes a structure of a large-caliber multi-channel zoned correlation ultrasonic flowmeter, because the transducers are distributed in the flow channel, the distance between a pair of transducers is larger than that between an oblique insertion transducer placing mode and a column transducer placing mode, and ultrasonic flow measurement is performed: (1) A pair of opposite transducers are distributed in the fluid flow direction, so that the effective sound path can be fully utilized, and the application of the flowmeter with a larger caliber is facilitated; (2) multichannel, satisfying the omnibearing measurement; (3) The flow passage partition structure effectively stabilizes the fluid state, overcomes the influence of turbulence and the like; however, for example, when the caliber DN500 is set, the length of the flowmeter tube is 600mm, the distance between the pair of transducers is 550mm, and the normal metering can be realized in water, but the metering cannot be realized in fuel gas.
The above-mentioned several ultrasonic transducers are disposed in the flowmeter, but in terms of safety of gas metering, the application of gas metering cannot be realized when the caliber of the gas flowmeter exceeds the range of signal receivable identification between a pair of transducers, in consideration of the safety of gas metering, regardless of the oblique insertion type mounting structure, the upright type mounting structure or the opposite type mounting structure in the flow direction of the fluid in the pipe.
In summary, through the analysis of the prior art for measuring the gas flow of the pipeline, it is known in the gas metering field that the adoption of the ultrasonic flowmeter is most reasonable and advanced; however, for the measurement of gas flow in pipes, especially in large-caliber gas pipelines, the prior art has various disadvantages: the existing methods for arranging the ultrasonic transducers in the flowmeter cannot meet the requirement of metering when the caliber of the flowmeter is larger than DN300 or maximize the measuring range ratio under the limited length of the flowmeter. The invention provides a large-caliber gas ultrasonic flowmeter with a novel structure, which overcomes the defects of the prior art, meets the requirements of high accuracy and large range ratio of flowmeter measurement, and is a technical purpose of the scheme.
Disclosure of Invention
Aiming at the above industrial problems, the present invention provides an ultrasonic gas meter with large-caliber multichannel runner partition and sound Cheng Jiexu, which utilizes sound Cheng Jiexu between a pair of ultrasonic transducers to achieve total effective sound path extension, not only can realize the measurement of a gas large-caliber flow meter, but also can ensure that the range ratio of the flow meter is maximum, and solves the industrial problems that the large-caliber gas meter (such as more than DN 300) is difficult to realize the measurement, and the technical scheme is as follows:
dividing all flow passages of the large-caliber or ultra-large-caliber flowmeter into a grid structure by using a thin metal plate; the transducer mounting column with a spindle-shaped section is positioned by a metal liner tube and partition plates and is pressed and fixed by a fixing head; a plurality of transducers can be arranged on one transducer mounting column on one side or two sides; the two parallel and same-plane rows of transducer mounting columns are provided with paired measuring transducers, the flow velocity of the interval is measured and calculated by an independent interval integrating circuit PCB through time difference, the measurement results of a plurality of groups of transducers arranged according to the length of a pipeline of the flowmeter are obtained, finally, the flow velocity average value of the fluid after the fluid passes through the whole section and the length of the flowmeter is obtained, namely, the average velocity in the delta t time difference is measured, and the total average flow velocity of the flowmeter is finally obtained and the total flow value is deduced by the sound path continuing method.
The obvious effects obtained by implementing the technical scheme are as follows: dividing all flow channels of the large-caliber or ultra-large-caliber flowmeter into a grid structure by using a thin metal plate, and forming stable laminar flow in each small dividing cavity according to the stability deduction and conclusion of the flow velocity of the parallel small pipe diameter; a plurality of transducers can be arranged on one side or two sides of a transducer mounting column, each transducer is arranged in the center of a stable laminar flow formed in a small divided cavity, and the flow velocity measured by a pair of transducers is representative; the transducer mounting column with the spindle-shaped section is beneficial to reducing the fluid resistance and the flow guide, is positioned by the metal liner tube and the partition plate, is pressed and fixed by the fixing head, and ensures the stable direction and positioning of the transducer mounting column; the sectional independent interval integrating circuit PCB calculates the measured difference of a pair of transducers in the interval of two parallel transducer mounting columns in the same plane to obtain a flow velocity value, and finally obtains the flow velocity value of the flowmeter; when all the segmented metering superposition is calculated, an average flow velocity value which is almost equal to the total length of the flowmeter is formed, and the total flow value is calculated according to the average flow velocity value, so that the metering requirement of the large-caliber gas flowmeter can be realized, and the measuring range ratio of the flowmeter can be maximized.
The invention relates to an ultrasonic gas meter with large-caliber multichannel flow passage partition and sound Cheng Jiexu, which is characterized by comprising a water inlet flange, a water outlet flange, a tube sleeve, a fixed seat, a metal liner tube, a grid partition baffle plate, a two-way mounting column of a transducer, a one-way mounting column I, a one-way mounting column II, a fixed head, the transducer, a vertical signal wire protecting cover, a horizontal signal wire protecting cover, a section integrating circuit PCB and an instrument box; on a base meter tube body of a gas meter formed by connecting a water inlet flange, a water outlet flange and a tube body sleeve, eight transducer mounting columns are radially arranged in eight directions at the center of the tube through the flow passage section of the large-caliber ultrasonic gas meter, and the mounting sections of the transducer mounting columns in a pipeline can be multiple, and two sections are a group; a plurality of groups of paired transducer mounting columns are arranged on two planes between each group, a plurality of transducers can be mounted on each transducer mounting column, and flow velocity measurement multichannel and multi-combination modes are formed between the transducer columns and the transducers which are parallel side by side and are corresponding to each other in one plane; the paired transducers with different sections and parallel to each other are used for carrying out sectional measurement on the fluid in the total length of the casing pipe of the gas flowmeter, and the measurement results obtained by measuring the length of the pipeline are overlapped to form measurement sound Cheng Jiexu, so that a total flow velocity measurement value and a calculated push flow rate value are finally obtained, the metering of the large-caliber gas flowmeter is realized, and the maximum value of the measuring range ratio of the flowmeter is obtained under the condition that the length of the pipeline of the flowmeter is limited.
The partition plates are grid-shaped, are arranged on the inner side of the metal liner tube and are distributed in a square grid shape at certain intervals in the horizontal and vertical directions, and are connected with the inner wall of the metal liner tube through welding; the transducer is embedded and installed on a transducer bidirectional installation column or a transducer unidirectional installation column; the three transducer mounting columns are positioned by a metal liner tube and a partition plate and are pressed and fixed by a fixing head; the metal liner tube is positioned at the inner side of the tube body sleeve, and the metal liner tube and the tube body sleeve are positioned by the fixed head; the fixed head is positioned in the fixed seat on the pipe sleeve; the signal wire of the transducer is connected with the interval integrating circuit PCB from the transducer mounting column through the middle hole of the fixing head and the horizontal and vertical signal wire protecting covers, and the calculation result is finally led into the instrument box by the signal cable and is connected with the total integrating circuit PCB.
Further, the water inlet flange and the water outlet flange are respectively positioned at two ends of the pipe body sleeve, a fixed seat, an instrument box fixed column, a horizontal signal wire protecting cover and a vertical signal wire protecting cover are arranged on the water inlet flange and the water outlet flange, and the water inlet flange and the water outlet flange are connected with the pipe body sleeve through laser welding or spot welding; the metal liner tube is positioned at the inner side of the tube body sleeve, the gap between the metal liner tube and the tube body sleeve is small, and the metal liner tube is positioned and fixed by the fixing head.
The thickness of the partition plate is 1-3 mm, the partition plate can be selected according to different calibers of gas meters, and the partition plate is connected with the inner wall of the metal liner tube by laser welding.
The transducer is in a cylindrical equal-diameter shape, and a ceramic plate, a PCB, a negative electrode lead, a positive electrode lead and a signal wire which is led out are arranged in the transducer; the transducer is arranged in a transducer mounting hole of the transducer mounting column, the side surface of the transducer is positioned by matching the outer convex column and the outer convex groove, the lower part of the transducer is positioned by the positioning table, and the transducer mounting hole and the outer convex groove are connected by bonding with epoxy resin.
The transducer mounting column can be divided into a bidirectional mounting column, a unidirectional mounting column I and a unidirectional mounting column II, which are manufactured by engineering plastics such as PPS, PPO, PPA, PA 66; the sections of the mounting columns are in spindle shapes, and have a diversion effect in fluid so as to reduce water resistance, and in addition, the positioning heads can perform directional positioning; the two-way mounting column of the transducer is arranged in the middle of the tube body sleeve, and the one-way mounting column I and the one-way mounting column II are respectively arranged at two sides of the tube body sleeve; the two-way mounting columns are provided with two-way mounting holes, and the two-way mounting columns are respectively provided with two-way mounting holes, wherein the two-way mounting columns are respectively provided with two-way mounting holes; the positioning head of the transducer mounting column is matched with the first positioning hole on the metal liner tube to perform directional positioning; the transducer mounting column is positioned in the metal liner tube, and the positioning column penetrates into the second positioning hole corresponding to the partition plate to perform cut-off positioning; the fixed seat is positioned at the outer side of the pipe body sleeve, and the fixed seat and the pipe body sleeve are welded; the fixed head is positioned in the fixed seat, and the first positioning surface is used for positioning the height, and the second rubber ring is positioned in the second groove at the lower end of the fixed head and is in sealing fit with the first groove of the transducer column; the first rubber ring is positioned between the notch above the fixed head and the inner side of the external thread nut and the fixed seat to play a role in sealing.
The vertical signal wire protecting cover is positioned at the outer side of the tube body sleeve and covers the fixing seat to protect the led-out signal wire; the sectional vertical signal line protecting covers are connected by protecting cover connecting sheets.
The horizontal signal wire protecting cover is positioned at the outer side of the pipe body sleeve and is connected with the vertical signal wire protecting cover by adopting laser spot welding, so that the horizontal signal wire protecting cover is used for protecting the interval integrating circuit PCB; in the protecting cover of horizontal signal line, there are interval integrating circuit PCB to calculate the time difference measured by each pair of transducers on the pair of transducer mounting columns, and n interval integrating circuit PCB are connected via signal lines to the total control board in the instrument box to transmit the flow speed value or flow quantity value.
The instrument box is fixed on the instrument box fixing column by screws; the instrument box fixed column is connected with the tube body sleeve in a welded mode, the instrument box fixed column is located in the vertical signal line protecting cover and the horizontal signal line protecting cover, a section of the instrument box fixed column is provided with holes, the signal line is convenient to pass through, and the instrument box fixed column is communicated with the general control board in the instrument box.
The layout of the transducer mounting column and the transducer is as follows: the transducer mounting columns are radially arranged in eight directions according to the cross section of the metal liner tube, a plurality of groups of transducers on the transducer mounting columns, namely, the multi-channel transducers are arranged in the pipeline in eight directions from the center of the pipeline outwards, in different planes in two cross sections of the pipe body sleeve and between different planes of the two transducers, flow velocity values in different directions, different positions and different heights are obtained through columnar sampling measurement calculation, and the flow velocity values are finally summarized to a master control board in an instrument box through the operation of independent interval integrating circuits (PCB), so as to obtain total metering data and flow velocity values; as can be seen from the longitudinal section of the casing pipe, the opposite transducers are arranged in the metal liner pipe at different heights from top to bottom: first, second, third, fourth, fifth, sixth, seventh and eighth.
Because the straight pipe section where the large-caliber gas meter is installed is short or the front end is influenced by installation positions such as bent pipe connection, local turbulence is easy to generate in the large-caliber content, the grid partition plate can effectively partition and rectify turbulence possibly formed in a large pipeline, laminar flow can be obtained according to the conclusion of parallel small-pipe-diameter flow velocity stability, and the flow velocity of the laminar flow in the pipeline is stable according to the rule of parabolic distribution, namely the flow velocity of the central area of the pipeline is stable and representative, therefore, the transducer is arranged in the middle of the grid, and effective signals are acquired. In addition, the flow velocity of the central region of the whole large-caliber pipeline is stable, and the transducer is arranged in a circle of layout of the central region, so that the variation of the flow velocity of the central region can be effectively obtained.
The sound Cheng Jiexu of the present invention is realized as follows: if three rows of transducer mounting columns are longitudinally distributed along the length direction of the flowmeter, eight transducer mounting columns are radially distributed along eight directions in each row to form two groups of paired transducers, the paired transducers in one plane measure time difference simultaneously to obtain flow velocity average values in respective intervals, then the two independent results are averaged again to obtain flow velocity average values equivalent to the length of the whole flowmeter, and the volume flow can be calculated according to the sectional area and the length of the pipeline; since the flow rate is measured within a time interval Δt (this interval is in the order of nanoseconds) and can be measured several times (for example, ten times) in one second, the resulting flow rate change rate and the average value of the flow rate are quite accurate. For example, dividing the flow meter spool piece into two equal segments, the sum of the two segments being approximately the length of the spool piece, denoted by L, the spacing m between the two pairs of transducers being approximately 1/2 of the length of the spool piece for a group of pairs of transducers, the total length between the two pairs of transducers being approximately L, i.e., 2m.apprxeq.L, so that, based on the relationship between the turndown ratio R and the two transducer spacing L: in the present invention, the included angle α=0 between the pair of transducer connection lines and the fluid flow direction in the pipe is defined as r=β·l·cos (α), and the two transducer connection lines are aligned with the fluid flow direction, and cos (α) =1, so that r=β·l, it is known that the connection of sound paths is achieved, and not only the measurement of the large-caliber gas flowmeter is achieved, but also the maximum value of the flow meter measuring range ratio is obtained when the length of the pipe of the flow meter is limited.
In summary, the invention uses the layout of the transducer mounting columns to realize the compliance within the range that the effective signals of a pair of transducers can be received, and the ultrasonic sound Cheng Jiexu is made through the longitudinal layout of a plurality of groups of transducer mounting columns, so that the implementation of the gas meter metering with large caliber or ultra-large caliber (the caliber is larger than DN 300) is realized, and meanwhile, the range ratio of the gas meter reaches the maximum value, the problem of shortage of the ultra-large caliber gas meter is solved, and compared with the prior art, the invention realizes the technical improvement proposed by the technical scheme, has substantial remarkable progress, and is characterized in that:
the obvious effects obtained by implementing the technical scheme are as follows: dividing a flow channel of a large-caliber or ultra-large-caliber flowmeter into a grid structure by using a thin metal plate, and forming a stable laminar flow in each small dividing cavity according to the stability deduction and conclusion of the flow velocity of the parallel small pipe diameter; a plurality of transducers can be arranged on one side or two sides of a transducer mounting column, each transducer is arranged in the center of a stable laminar flow formed in a small divided cavity, and the measured flow velocity is representative; the transducer mounting column with the spindle-shaped section is positioned by the metal liner tube and the partition baffle plates and is pressed and fixed by the fixing head, so that the direction and the positioning stability of the transducer mounting column are ensured; the sectional independent interval integrating circuit PCB measures the time difference in the intervals of the two transducer mounting columns to finally obtain the flow value of the flowmeter, and when all sectional metering and superposition calculation are performed, the sound path with the length almost equal to that of the flowmeter is formed, so that the metering requirement of the large-caliber gas flowmeter can be realized, and the range ratio of the flowmeter is maximized.
Firstly, because of the change of the installation mode of the transducer, the flow channel of the large-caliber ultrasonic gas meter can be divided into a net structure by adopting the thin metal plate, so that stable laminar flow is formed in the small divided cavity, and representative flow velocity parameters can be conveniently measured in the net.
Secondly, a transducer is installed by using a transducer installation column, and the section of the transducer installation column is in a spindle shape, so that the water resistance is small, and fluid can pass through the transducer installation column; a plurality of transducers can be mounted on each transducer mounting post; the transducer is cylindrical in shape and equal in diameter, so that the thickness of the transducer mounting column is reduced; the transducer mounting column is positioned by the metal liner tube and the partition plate, so that the transducer mounting direction is ensured.
Thirdly, arranging eight transducer mounting columns in a radial manner in the center of a pipe in a radial manner in the flow passage section of the large-caliber ultrasonic gas meter, wherein a plurality of groups of mounting sections of the transducer mounting columns in a pipeline can be arranged; a plurality of transducers can be installed on each transducer installation column, and flow velocity measuring sound channels are formed between the transducer columns and the transducers which are parallel and parallel in a plane and correspond to each other in pairs, so that the flow velocity measuring sound channels are measured in a multi-combination mode.
Fourth, the transducer on the transducer mounting column is measured and calculated on different planes in two sections of the tube sleeve, and the flow velocity change values in different directions, different positions and different heights are obtained.
Fifth, in the length of the casing pipe of the gas flowmeter, since the ultrasonic wave is greatly attenuated in the gas and the propagation distance is short, the planes which are parallel to each other and are provided with a plurality of transducer mounting columns must be arranged on the section of the casing pipe according to the intensity of the acoustic wave and the attenuation rule thereof; the distance between two planes adjacent to each other is required to meet the requirements of sound wave receiving intensity and measurement; a plurality of transducers are arranged on the transducer mounting columns corresponding to the planes; thus, the fluid in the total length of the flowmeter tube sleeve can be measured in segments within the same time period, namely, within a few nanoseconds, and finally a total measured value is obtained, and according to R=beta.L.cos (alpha), the cos (alpha) =1, R=beta.L, the measurement of the large-caliber gas flowmeter is realized due to the succession of the sound paths, and the maximization of the measuring range ratio of the flowmeter is obtained under the condition that the length of the flowmeter tube is limited.
Drawings
FIG. 1 is a schematic view of the appearance of an ultrasonic gas meter with large-caliber multi-channel flow passage partition and sound Cheng Jiexu;
FIG. 2 is a sectional view of the flow channel partition and the position structure of the transducer mounting column of the large-caliber gas meter;
FIG. 3 is a schematic view of a cylindrical constant diameter transducer;
FIG. 4 is a cross-sectional view of a cylindrical constant diameter transducer;
FIG. 5 is a cross-sectional view of a two-way mountable transducer mounting post structure for a transducer;
FIG. 6 is a schematic diagram of a transducer mounting post for unidirectional mounting of a transducer;
FIG. 7 is a cross-sectional view of a transducer mounting post with a unidirectional mounting of the transducer;
FIG. 8 is a schematic diagram of a transducer mounting post for unidirectional mounting of a transducer;
FIG. 9 is a schematic diagram of a transducer mounting post positioning head and positioning hole relationship;
FIG. 10 is a cross-sectional view of the mounting and positioning of a transducer mounting post in a large caliber meter;
FIG. 11 is a cross-sectional view of a stationary head;
FIG. 12 is a cross-sectional view of the transducer mounting post, stationary head, external wire press ring position in relation to the metal liner and body sleeve;
FIG. 13 is a schematic view of the height position of the transducer on the transducer mounting post;
FIG. 14 is a cross-sectional view of the positional relationship of the transducer mounting posts, the section integrating circuit PCB, and the horizontal signal line cover;
FIG. 15 is a cross-sectional view of the positional relationship of five sections and eight transducer mounting posts in a large caliber gas meter;
FIG. 16 is a cross-sectional view of the positional relationship of four spaced apart arrays of five cross-section transducer mounting posts in a large caliber gas meter;
In the figure:
11. a water inlet flange; 12. a water outlet flange; 25. a tube sleeve; 251. a fixing seat; 22. a metal liner; 23. partition boards; 24. a diagonal support; 221. positioning holes I; 222. positioning holes II; 30. a two-way mounting column; 31. a unidirectional mounting column I; 32. a second unidirectional mounting column; 311. positioning columns; 312. a wiring hole; 313. a transducer mounting hole; 3131. a positioning table; 3132. an outer convex groove; 314. a flow guiding surface; 315. a positioning head; 316. a groove I; 36. a fixed head; 37. an outer wire nut; 3601. a notch; 3602. a middle hole; 3603. a second positioning surface; 3604. a hollow column; 3605. a second groove; 361. a rubber ring I; 362. a first positioning surface; 363. a second rubber ring; 313. a transducer mounting hole; 33. a transducer; 333. a signal line; 331. a ceramic sheet; a pcb;3312. a negative electrode lead; 3313. a positive electrode lead; u-shaped notch; 339. an outer column; 3302. a bottom surface; A1. a first height; A2. the second height; B1. the third height; B2. the height is four; C1. the height is five; C2. the height is six; D1. a height seven; D2. the height is eight; 44. a vertical signal line cover; 441. a protective cover connecting piece; 442. a horizontal signal line cover; 4421. interval integrating circuit PCB, 55, instrument box, 56, instrument box fixing column.
Detailed Description
The invention is described in further detail below with reference to the drawings and examples.
Embodiment one:
the embodiment is an ultrasonic gas meter with DN800 large-caliber multichannel runner partition and sound Cheng Jiexu.
As shown in fig. 16 and 1, the present embodiment is a DN800, a transducer mounting column, and an ultrasonic gas meter with a large-caliber multichannel flow channel partition and a sound Cheng Jiexu, in which the transducer is arranged in four sections of the flow channel, and the ultrasonic gas meter is characterized by comprising a water inlet flange 11, a water outlet flange 12, a pipe sleeve 25, a fixing seat 251, a metal liner 22, a partition baffle 23, a bidirectional mounting column 30 of the transducer, a unidirectional mounting column 31, a unidirectional mounting column 32, a fixing head 36, a transducer 33, a vertical signal line protecting cover 44, a horizontal signal line protecting cover 442, a section integrating circuit PCB 4421, and an instrument box 55; on a base meter tube body of a gas meter formed by connecting a water inlet flange, a water outlet flange and a tube body sleeve, eight transducer mounting columns are radially arranged in eight directions at the center of the tube through the flow passage section of the large-caliber ultrasonic gas meter, and the mounting sections of the transducer mounting columns in the pipeline can be multiple, in the embodiment, 5 sections are formed, two sections are combined into a group, and 4 groups are formed; if the distance between each group of transducers is 260mm, at the receiving end, the received sound wave signal meets the measurement requirement (the distance can be adjusted according to the actual test result), and a plurality of groups of paired transducer mounting columns are arranged, a plurality of transducers can be arranged on each transducer mounting column, and flow velocity measurement multichannel and multi-combination form are formed between every two corresponding transducer columns which are parallel side by side and in a plane and the transducers; and the paired transducers with different sections and parallel to each other and in the same plane are used for carrying out sectional measurement on the fluid in the total length of 1200mm of the casing pipe of the gas flowmeter, and the measurement result obtained by measuring along the length of the pipeline is overlapped to form measurement sound Cheng Jiexu with the length of 4 multiplied by 260=1040 mm, so that the total flow velocity measurement value and the calculated push-out flow value in the length of 1040mm are finally obtained, the metering of the large-caliber gas flowmeter is realized, and the maximization of the measuring range ratio of the flowmeter is obtained under the condition of the length of the pipeline with the flow-limiting meter.
As shown in fig. 15, 12 and 14, the partition plate 23 is in a grid shape, is installed on the inner side of the metal liner tube 22, is arranged in a square grid shape according to a certain interval in the horizontal and vertical directions, and is connected with the inner wall of the metal liner tube by welding; the transducer 33 is embedded and installed on a bidirectional installation column, a unidirectional installation column I31 and a unidirectional installation column II 32 of the transducer; the three transducer mounting columns are positioned by the metal liner tube 22 and the partition plate 23 and are pressed and fixed by the fixing head 36; the metal liner tube 22 is positioned on the inner side of the tube body sleeve 25 and is positioned by the fixed head 36; the fixed head is positioned in a fixed seat 251 on the tube sleeve 25; the signal wires 333 of the transducers are connected to the section integrating circuit PCB 4421 from several transducer mounting posts through the fixing head center hole, the horizontal signal wire protecting cover 442 and the vertical signal wire protecting cover 44, and the calculation result is finally led to the instrument box 55 by the signal cable and connected to the total integrating circuit PCB.
Further, the water inlet flange 11 and the water outlet flange 12 are respectively positioned at two ends of the pipe casing 25, a fixed seat 251, an instrument box fixed column 56, a horizontal signal line protecting cover 442 and a vertical signal line protecting cover 44 are arranged on the water inlet flange and the water outlet flange, and the water inlet flange and the water outlet flange are connected with the pipe casing by laser welding; the metal liner tube 22 is positioned inside the tube sleeve 25 with a small gap therebetween and is positioned and fixed by the fixing head 36.
The thickness of the partition plate 23 is 2mm, the partition plate can be selected according to different calibers of gas meters, and the partition plate is connected with the inner wall of the metal liner tube by laser welding.
The transducer 33 is in a cylindrical shape with equal diameter, and a ceramic plate 331, a PCB 332, a negative electrode lead 3312, a positive electrode lead 3313 and a signal wire 333 which is led out are arranged in the transducer; the transducer is placed in the transducer mounting hole 313 on the transducer mounting column, the side surface is matched and positioned by the outer convex column 339 and the outer convex groove 3132, the lower part is positioned by the positioning table 3131, and the two are bonded and connected by epoxy resin.
As shown in fig. 5, 6, 7, 8 and 9, the transducer mounting posts can be divided into a bidirectional mounting post 30, a unidirectional mounting post one 31 and a unidirectional mounting post two 32, which are made of engineering plastics such as PPS, PPO, PPA, PA and the like; the cross section of the mounting posts is in a spindle shape, and has a diversion effect in the fluid so as to reduce water resistance, and in addition, the positioning heads 315 can perform directional positioning; the two-way mounting column 30 of the transducer is arranged in the middle of the pipe body sleeve 25, and the one-way mounting column I31 and the one-way mounting column II 32 are respectively arranged at two sides of the pipe body sleeve; the transducer mounting holes 313 on the two sides of the bidirectional mounting column are layered according to different heights, and the transducers 33 mounted on the bidirectional mounting column are in linear correspondence with the transducers on the bidirectional mounting column, the unidirectional mounting column I and the unidirectional mounting column II which are mounted in the same row in a plane to form a pair of opposite pairs of opposite transducers; the positioning head 315 of the transducer mounting column is matched with the first positioning hole 221 on the metal liner tube 22 to perform directional positioning; the positioning column 311 of the transducer mounting column in the metal liner tube penetrates into the second positioning hole 222 corresponding to the partition plate 23 to perform cut-off positioning; the fixed seat 251 is positioned at the outer side of the tube body sleeve 25, and the fixed seat 251 and the tube body sleeve are welded; the fixing head 36 is positioned in the fixing seat 251, and is positioned at a height by the first positioning surface 362 and is pressed and fixed by the external thread nut 37; the second rubber ring 363 is positioned in a second recess 3605 at the lower end of the fixed head and is in sealing fit with a first recess 316 of the transducer column; the first rubber ring 361 is positioned at the notch 3601 above the fixed head and plays a role in sealing with the external thread nut 37 and the inner side of the fixed seat 251.
The vertical signal wire protecting cover 44 is located at the outer side of the tube body sleeve 25, and covers the fixing seat 251 to protect the led signal wire 333; the segmented vertical signal line covers are connected by cover connector pieces 441.
The horizontal signal line protecting cover 442 is positioned outside the tube body sleeve 25 and is connected with the vertical signal line protecting cover by adopting laser spot welding, and is used for protecting the interval integrating circuit PCB 4421; in the horizontal signal line protecting cover, there are interval integrating circuit PCBs to calculate the time difference measured by each of the paired transducers on the pair of transducer mounting columns, and n interval integrating circuit PCBs are connected via signal lines to the total control board in the instrument box 55 to transmit the flow speed value or flow quantity value.
The instrument box 55 is fixed on the instrument box fixing column 56 by a screw; the instrument box fixed column is connected with the tube body sleeve in a welded mode, the instrument box fixed column is located in the vertical signal line protecting cover and the horizontal signal line protecting cover, a section of the instrument box fixed column is provided with holes, the signal line is convenient to pass through, and the instrument box fixed column is communicated with the general control board in the instrument box.
As shown in fig. 13, the layout of the transducer mounting posts and transducers is: the transducer mounting columns are radially arranged in eight directions according to the cross section of the metal liner tube 22, a plurality of groups of transducers 33 on the transducer mounting columns, namely, the transducers 33 in multiple channels are arranged in eight directions in the pipeline and between different planes in two cross sections of the pipe body sleeve and different planes of the two transducers, flow velocity values in different directions, different positions and different heights are obtained through columnar sampling measurement calculation, and are calculated through independent interval integrating circuits PCB 4421, and finally summarized to a master control board in the instrument box 55 to obtain total metering data and flow velocity values; as can be seen from the longitudinal cross section of the casing of the tubular body, the opposite transducers are arranged in the metal liner 22 at different heights from top to bottom: height one A1, height two A2, height three B1, height four B2, height five C1, height six C2, height seven D1, height eight D2.
Because the straight pipe section where the large-caliber gas meter is installed is short or the front end is influenced by installation positions such as bent pipe connection, local turbulence is easy to generate in the large-caliber content, the grid partition plate can effectively partition and rectify turbulence possibly formed in a large pipeline, laminar flow can be obtained according to the conclusion of parallel small-pipe-diameter flow velocity stability, and the flow velocity of the laminar flow in the pipeline is stable according to the rule of parabolic distribution, namely the flow velocity of the central area of the pipeline is stable and representative, therefore, the transducer is arranged in the middle of the grid, and effective signals are acquired. In addition, the flow velocity of the central region of the whole large-caliber pipeline is stable, and the transducer is arranged in a circle of layout of the central region, so that the variation of the flow velocity of the central region can be effectively obtained.
The sound Cheng Jiexu of the present invention is realized as follows: if five rows of transducer mounting columns are longitudinally distributed in the length direction of the flowmeter, eight transducer mounting columns are radially distributed in eight directions in each row to form four groups of paired transducers, the four groups of paired transducers measure time differences simultaneously to obtain respective flow velocity average values, then the two independent results are averaged in an instrument box to obtain the flow velocity average value in the length of the whole flowmeter, and the volume flow can be calculated according to the sectional area and the pipeline length; since the measurement of the flow rate is performed within a Δt time interval (this interval is in the order of nanoseconds), and the measurement is performed 6 times in one second in this embodiment, the flow rate change rate and the average value of the flow rate are obtained quite accurately.
In this embodiment, the inside of the flow meter pipe section is divided into 4 equal sections, the sum 1040mm of the 4 sections is relatively close to the length 1200mm of the pipe, denoted by L, and for the interval m between a pair of transducers, the total length L of the connection between the 4 pairs of transducers is calculated according to the relationship between the range ratio R and the distance L between the two transducers: in the present invention, the included angle α=0 between the pair of transducer connection lines and the fluid flow direction in the pipe is equal to the two transducer connection lines and the fluid flow direction, and cos (α) =1, so that r=β·l, it is known that the connection of sound path is realized, the measurement of the large-caliber gas flowmeter is realized, and the maximization of the flow meter measuring range ratio is obtained under the condition that the length of the pipe of the flow-limiting flowmeter is provided.
By way of illustration, the invention is applied to an ultrasonic gas meter with DN800 large-caliber multichannel runner partition and sound Cheng Jiexu, but is not limited to the specific embodiment, if the size and frequency of a transducer ceramic plate are changed, the invention is also applicable to the field of liquid metering, and any modification or variation based on the content of the invention is within the scope of the invention claimed.

Claims (8)

1. The large-caliber multichannel runner partition and sound Cheng Jiexu ultrasonic gas meter is characterized by comprising a water inlet flange (11), a water outlet flange (12), a pipe sleeve (25), a fixed seat (251), a metal liner tube (22), partition baffles (23), a bidirectional mounting column (30) of a transducer, a unidirectional mounting column I (31), a unidirectional mounting column II (32), a fixed head (36), a transducer (33), a vertical signal wire protecting cover (44), a horizontal signal wire protecting cover (442), a section integrating circuit PCB (4421) and an instrument box (55); on a base meter tube body of a gas meter formed by connecting a water inlet flange, a water outlet flange and a tube body sleeve, 8 transducer mounting columns are radially arranged at the center of the tube on a plurality of sections arranged in the gas meter tube body, and a plurality of transducers can be arranged on each transducer mounting column; the transducers arranged on two rows of transducer mounting columns which are parallel and adjacent on the same plane can be paired and measured, the flow velocity of the interval is measured and calculated through the time difference by an independent interval integrating circuit PCB, so as to obtain the measurement results of a plurality of groups of transducers arranged according to the length of the pipeline of the flowmeter, and the sectional measurement results are processed, namely the measured sound Cheng Jiexu is realized, and finally the total average flow velocity and the total flow value of the flowmeter are obtained; therefore, the ultrasonic large-caliber fuel gas metering is realized, and the maximization of the measuring range ratio is achieved.
2. The large-caliber multi-channel flow passage partition and sound Cheng Jiexu ultrasonic gas meter is characterized in that the thickness of the partition plate (23) is 13mm, is installed in metal bushing pipe (22) inboard, is square grid form overall arrangement according to certain interval in horizontal and vertical direction, and partition baffle passes through welded connection with metal bushing pipe inner wall.
3. The ultrasonic gas meter with large-caliber multi-channel flow passage partition and sound Cheng Jiexu as set forth in claim 1, wherein the cross sections of the unidirectional mounting column I (31), the unidirectional mounting column II (32) and the bidirectional mounting column (30) are in spindle shapes; the one-way mounting column I (31) and the one-way mounting column II (32) are respectively positioned at the inner sides of two ends of the pipe body sleeve (25), and the two-way mounting column (30) is positioned at the middle part of the inner side of the pipe body sleeve (25); the transducer is mounted in a transducer mounting hole (313).
4. The ultrasonic gas meter with large-caliber multi-channel flow passage partition and sound Cheng Jiexu as set forth in claim 1, wherein the positioning heads (315) on the unidirectional mounting column I (31), the unidirectional mounting column II (32) and the bidirectional mounting column (30) are matched and positioned with the positioning holes I (221) on the metal liner tube (22); the positioning column (311) goes deep into the second positioning hole (222) of the partition plate (23) to perform cut-off positioning.
5. The ultrasonic gas meter with large-caliber multichannel flow passage partition and sound Cheng Jiexu as set forth in claim 1, wherein the fixed seat (251) is positioned at the outer side of the tube sleeve (25) and is welded with the tube sleeve; the fixed head (36) is positioned in the fixed seat (251) and is pressed and fixed by the first positioning surface (362) and the external thread nut (37); the second rubber ring (363) is positioned in a second groove (3605) at the lower end of the fixed head (36) and is in sealing fit with a first groove (316) of the transducer column; the first rubber ring (361) is positioned at the notch (3601) above the fixed head.
6. The ultrasonic gas meter with large-caliber multi-channel flow passage partition and sound Cheng Jiexu as set forth in claim 1, wherein the transducer (33) has a cylindrical constant diameter shape, and a ceramic plate (331), a PCB (332), a negative electrode lead (3312), a positive electrode lead (3313) and a signal wire (333) are arranged inside the transducer; the transducer is positioned in the transducer mounting hole (313), the side surface of the transducer is matched and positioned by an outer convex column (339) and an outer convex groove (3132), the lower part of the transducer is positioned by a positioning table (3131), and the transducer and the outer convex groove are connected by bonding with epoxy resin.
7. The large-caliber multichannel flow passage zoned and acoustic Cheng Jiexu ultrasonic gas meter is characterized in that the vertical signal wire protecting covers (44) are positioned on the outer side of the tube body sleeve (25), and the segmented vertical signal wire protecting covers are connected by using protecting cover connecting sheets (441); the horizontal signal wire protecting cover (442) is positioned at the outer side of the tube body sleeve (25) and is connected with the vertical signal wire protecting cover by adopting laser spot welding.
8. The ultrasonic gas meter with large-caliber multi-channel flow passage partition and sound Cheng Jiexu as set forth in claim 1, wherein the transducers (33) are arranged in the metal liner tube (22) at different heights from top to bottom: altitude one (A1), altitude two (A2), altitude three (B1), altitude four (B2), altitude five (C1), altitude six (C2), altitude seven (D1), altitude eight (D2).
CN202210468456.5A 2022-04-30 2022-04-30 Large-caliber multichannel runner partition and sound Cheng Jiexu ultrasonic gas meter Pending CN117007141A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210468456.5A CN117007141A (en) 2022-04-30 2022-04-30 Large-caliber multichannel runner partition and sound Cheng Jiexu ultrasonic gas meter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210468456.5A CN117007141A (en) 2022-04-30 2022-04-30 Large-caliber multichannel runner partition and sound Cheng Jiexu ultrasonic gas meter

Publications (1)

Publication Number Publication Date
CN117007141A true CN117007141A (en) 2023-11-07

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210468456.5A Pending CN117007141A (en) 2022-04-30 2022-04-30 Large-caliber multichannel runner partition and sound Cheng Jiexu ultrasonic gas meter

Country Status (1)

Country Link
CN (1) CN117007141A (en)

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