CN117848426A - High-precision vibration-resistant wide-temperature vortex shedding flowmeter - Google Patents
High-precision vibration-resistant wide-temperature vortex shedding flowmeter Download PDFInfo
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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
- G01F1/05—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 using mechanical effects
- G01F1/20—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 using mechanical effects by detection of dynamic effects of the flow
- G01F1/32—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 using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters
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- 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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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract
The invention relates to the technical field of vortex shedding flowmeters, in particular to a high-precision vibration-resistant wide-temperature vortex shedding flowmeter. The pipeline connecting flange plate comprises a pipeline connecting flange plate; the surface of the pipeline connecting flange is provided with a connecting mobile adjusting component, the surface of the connecting mobile adjusting component is provided with a fluid detection processing component, the connecting mobile adjusting component and the fluid detection processing component adopt a double-channel processing mode, frequency uncertainty is introduced as a judging basis for vortex street useful signal processing, then vortex frequency generated when a triangular column in the pipeline is utilized on the basis, and the source and the amplitude of a vibration direction are measured to distinguish and distinguish interference signals, so that the frequency of flow signals can be identified in various interference environments; the device has the characteristics of vibration prevention, wide range, wide temperature range, high precision and the like, and has no movable mechanical parts in the structure because the device adopts the principle based on vortex street measurement, so that extremely strong working stability is realized, and the device can be used for measuring the flow of industrial pipeline medium fluid.
Description
Technical Field
The invention relates to the technical field of vortex shedding flowmeters, in particular to a high-precision vibration-resistant wide-temperature vortex shedding flowmeter.
Background
Currently, vortex shedding flowmeters are fluid vibratory flowmeters in nature, and therefore are particularly sensitive to external vibrations, fluid flow conditions, such as pipe vibrations, impact forces on pipe fluids, and random pulsating pressures due to changes in fluid pressure, etc., where disturbances in the field have a significant impact on flow measurements.
For vortex shedding flowmeters, there are many prior art techniques, such as:
chinese patent publication No. CN108731750a discloses a vortex shedding flowmeter, which comprises a pipeline, the pipeline is inside to be equipped with the sensor, the sensor pass through screw fixed mounting in the sensor casing of pipeline outer wall, the sensor casing pass through vertical connecting rod and be connected with the display, the sensor casing with between the connecting rod, still be provided with and be used for consolidate the sensor casing with connect between the connecting rod, reduce the bracing piece group of vibrations, the pipeline is inside to be equipped with the vortex shedding generator that can change not unidimensional, the vortex shedding generator with the pipeline is fixed by movable joint terminal, there is the pull ring on the vortex shedding generator, the both ends of pipeline are provided with the flange spare of other pipeline connections. The vortex street flowmeter adopts the replaceable vortex street generator, so that the adaptability to the measurement of dirty media is enhanced, the maintenance difficulty is reduced, and the measurement accuracy is improved.
Therefore, the vortex shedding flowmeter is used for flow measurement, and the key problem to be studied is to restrain the influence of flow field noise. The stability and uniformity of the flow field not only have influence on the formation and separation of karman vortex streets, but also have direct influence on the detection effect of various sensitive elements, and the additional vortex interferes with vortex street signals, so that the signal-to-noise ratio is reduced;
secondly, accurately measure the small flow, because the lateral lift force that the small flow produced is less, initial signal is very weak, easily receive fluid impact vibration noise and pipeline vibration noise's influence, there is a range lower limit dead zone to cause the range ratio limited, the small flow can not measure, for example the theoretical range ratio of vortex shedding flowmeter is 1:100, and the range ratio of the current simulation vortex shedding flowmeter is 1 at maximum: when measuring small flow, the vortex street useful signal is very weak and is easily submerged by noise signals, which causes great difficulty in measuring at low flow rate.
In view of this, the present invention provides a high-precision vibration-resistant wide-temperature vortex shedding flowmeter.
Disclosure of Invention
The invention aims to provide a high-precision vibration-resistant wide-temperature vortex shedding flowmeter so as to solve the problems in the background technology.
In order to achieve the above purpose, the invention aims to provide a high-precision vibration-resistant wide-temperature vortex shedding flowmeter, which comprises a pipeline connecting flange plate;
the surface of the pipeline connecting flange is provided with a connecting movement adjusting component, the surface of the connecting movement adjusting component is provided with a fluid detection processing component, the connecting movement adjusting component and the fluid detection processing component adopt a double-channel processing mode, frequency uncertainty is introduced as a judgment basis for vortex street useful signal processing, then the vortex frequency generated when a triangular column in the pipeline is utilized on the basis, the source and the amplitude of a vibration direction are measured, and interference signals are distinguished and distinguished, so that the frequency of flow signals can be identified in various interference environments;
meanwhile, the movable adjusting component and the fluid detection processing component are connected, and the internal parts are fixedly assembled in the medium fluid detection process, so that the vibration limiting force drives the parts to move.
As a further improvement of the technical scheme, the connecting movement adjusting assembly comprises a test pipeline, the test pipeline is arranged on the surface of the pipeline connecting flange, and a connecting frame is welded at the top of the test pipeline.
As a further improvement of the technical scheme, a protection tube is arranged at the top of the connecting frame, a fixing frame is arranged at the top of the protection tube, and a first protection sleeve is fixedly connected to the surface of the test pipeline.
As a further improvement of the technical scheme, the other section of the first protective sleeve is fixedly connected with a fixed pipe, the top of the fixed pipe is provided with a second protective sleeve, and a fixed buckle is arranged on the surface of the fixed pipe.
As a further improvement of the technical scheme, the second protective sleeve is fixedly connected with the fixing tube through the fixing buckle, the other end of the second protective sleeve is connected with the fluid detection processing assembly, and the two fixing frames are attached and fixed through bolts.
As a further improvement of the technical scheme, the fluid detection processing assembly comprises a measurement compensation module, wherein the measurement compensation module is arranged inside a fixing frame, and the measurement compensation module is sealed inside the fixing frame through mutual lamination of the fixing frame so as to limit the movement of the measurement compensation module.
As a further improvement of the technical scheme, a core processing module is arranged in the fixing frame, a display module is connected to the surface of the core processing module, and the measurement compensation module, the core processing module and the display module are communicated with each other, so that data analysis and data calculation are completed.
As a further improvement of the technical scheme, a flow blocking column is arranged inside the test pipeline, a temperature sensor is arranged inside the test pipeline, a piezoelectric sensor is arranged inside the test pipeline, and the piezoelectric sensor adopts a piezoelectric vortex street sensing head.
As a further improvement of the technical scheme, the measurement compensation module comprises a low-temperature piezoelectric crystal, an automatic frequency-selecting charge amplifier and a digital output MEMS accelerometer, and the core processing module comprises a charge amplifier, a low-pass filter, a limiter, a Schmidt trigger MSP4 fluid detection processing module singlechip, an operational amplifier, an application diaphragm and a piezoelectric crystal element.
As a further improvement of the technical scheme, the display module comprises a display screen and a gauge outfit, the core processing module further comprises a core processing chip, the core processing module and the measurement compensation module are used for receiving data, analyzing the data and outputting the data to the display module, and the display module is used for displaying the data through the display screen.
Compared with the prior art, the invention has the beneficial effects that:
1. in the high-precision vibration-resistant wide-temperature vortex shedding flowmeter, the device has the advantages of vibration resistance, wide range, wide temperature range, high precision and the like, and because the device adopts the principle based on vortex shedding measurement, no movable mechanical parts are arranged in the structure, extremely strong working stability is realized, and the device can be used for measuring the flow of industrial pipeline medium fluid, such as various mediums of gas, liquid, vapor and the like, and has extremely wide application range.
2. In the high-precision vibration-resistant wide-temperature vortex shedding flowmeter, the device adopts the low-temperature piezoelectric crystal to detect fluid, and the vortex frequency generated when triangular columns in a pipeline are utilized, so that the measuring precision is improved, the resistance loss is reduced, and the working temperature range is improved.
3. In the high-precision vibration-resistant wide-temperature vortex shedding flowmeter, the device adopts an intelligent automatic gain technology, and an automatic frequency-selecting charge amplifier is adopted, so that a wide range ratio of 100:1 is realized.
4. In the high-precision vibration-resistant wide-temperature vortex shedding flowmeter, a micro-power consumption, 3-axis, +/-2 g/+/-4 g/+/-8 g digital output MEMS accelerometer is added in a circuit, and vibration direction sources and amplitude values are measured, so that interference signals can be distinguished and distinguished conveniently, and the problem of vibration resistance of vortex shedding is solved.
Drawings
FIG. 1 is a schematic diagram of the overall structure of the present invention;
FIG. 2 is a schematic view of a fixing frame according to the present invention;
FIG. 3 is a schematic diagram of a display module according to the present invention;
FIG. 4 is a schematic view of a karman vortex street according to the present invention;
FIG. 5 is a schematic diagram of liquid data analysis according to the present invention.
The meaning of each reference sign in the figure is:
11. the pipeline is connected with the flange plate;
20. connecting a movement adjusting assembly; 21. testing the pipeline; 22. a connecting frame; 23. a protective tube; 24. a fixing frame; 25. a first protective sleeve; 26. a fixed tube; 27. a second protective sleeve; 28. a fixing buckle;
30. a fluid detection processing assembly; 31. a measurement compensation module; 32. a core processing module; 33. and a display module.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the invention, are within the scope of the invention based on the embodiments of the invention.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus 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 invention.
Referring to fig. 1-5, the present embodiment is directed to providing a high-precision vibration-resistant wide-temperature vortex shedding flowmeter, which includes a pipe connection flange 11;
the surface of the pipeline connecting flange 11 is provided with a connecting mobile adjusting component 20, the surface of the connecting mobile adjusting component 20 is provided with a fluid detection processing component 30, the connecting mobile adjusting component 20 and the fluid detection processing component 30 adopt a double-channel processing mode, frequency uncertainty is introduced as a judging basis for vortex street useful signal processing, then the vortex frequency generated during a triangular column in the pipeline is utilized on the basis, the source and the amplitude of a vibration direction are measured, and interference signals are distinguished and distinguished, so that the frequency of flow signals can be identified in various interference environments;
meanwhile, the internal parts of the movable adjusting assembly 20 and the fluid detection processing assembly 30 are fixedly assembled in the medium fluid detection process, so that the vibration limiting force drives the parts to move.
Because of the dense power lines and power equipment in the industrial field, a great deal of electromagnetic interference affects the vortex shedding flowmeter signal processing circuit, and the interference is mainly divided into three types: high frequency electromagnetic radiation interference, alternating current-direct current power supply interference and low frequency electromagnetic interference. Wherein high frequency electromagnetic radiation interference acts on the signal processing circuit mainly through a spatial electromagnetic field; the AC/DC power supply interference comes from the mutual influence between the power supplies; the low-frequency electromagnetic interference is the most main electromagnetic interference to the vortex shedding flowmeter, and the source of the low-frequency electromagnetic interference is very complex, and is related to the installation position, the installation mode, the grounding position, the shielding condition, the characteristics of an amplifier and the like, such as: the metallic shield has limited ability to shield electromagnetic radiation in space and is not resistant to electromagnetic fields having frequencies below 50 Hz; if a stepping current exists between the grounding point watchcase of the piezoelectric sensing element and the grounding point of the processing circuit, 50Hz stepping voltage interference is generated at two ends of the ground wire; when power supply disturbances are present and the common mode rejection of the processing circuitry is relatively low, 50Hz power supply common mode disturbances are introduced into the circuitry. The low-frequency interference is in the vortex street frequency band, so eliminating the low-frequency electromagnetic interference is an important problem of vortex street field application;
disturbances within industrial field pipes have a significant impact on the flow field distribution near the vortex generators. Because of the presence of various resistance elements such as valves, bends, tees, expansion and contraction tubes, etc. upstream and downstream of the pipe, the impact of these elements on the pipe has two aspects: (1) affecting the pressure distribution in the pipeline, resulting in uneven pressure distribution in the pipeline and thus uneven flow rate distribution in the pipeline; (2) fluid turbulence and turbulent eddies can be created. The interference can reduce the signal-to-noise ratio of vortex street signals and destroy the uniformity and symmetry of flow fields in the pipeline;
the pipeline is generally connected with devices such as a fan, a water pump or a compressor, and the vibration generated by the fan, the water pump and the compressor, the random noise generated by manually striking the pipeline and the local resistance piece are sometimes very strong and can be superimposed into vortex street signals, so that great difficulty is brought to the extraction of useful signals;
the ideal vortex street signal is a regular sine wave signal after passing through the charge amplifier and the low-pass filter, but the vortex street signal with low flow rate is basically submerged by noise under the working condition, therefore, the connecting movement adjusting assembly 20 comprises a test pipeline 21, the test pipeline 21 is arranged on the surface of a pipeline connecting flange plate 11, a connecting frame 22 is welded at the top of the test pipeline 21, a protection pipe 23 is arranged at the top of the connecting frame 22, a fixing frame 24 is arranged at the top of the protection pipe 23, a first protection sleeve 25 is fixedly connected to the surface of the test pipeline 21, a fixing pipe 26 is fixedly connected to the other section of the first protection sleeve 25, a second protection sleeve 27 is arranged at the top of the fixing pipe 26, and a fixing buckle 28 is arranged on the surface of the fixing pipe 26;
the second protective sleeve 27 is fixedly connected with the fixed pipe 26 through the fixed buckle 28, the other end of the second protective sleeve 27 is connected with the fluid detection processing assembly 30, the two fixing frames 24 are attached and fixed through bolts, the fluid detection processing assembly 30 comprises a measurement compensation module 31, the measurement compensation module 31 is arranged inside the fixing frames 24, the measurement compensation module 31 is sealed inside the fixing frames 24 through mutual attachment of the fixing frames 24, movement of the measurement compensation module 31 is limited, a core processing module 32 is arranged inside the fixing frames 24, the surface of the core processing module 32 is connected with a display module 33, and the measurement compensation module 31, the core processing module 32 and the display module 33 are in data communication, so that analysis and calculation of data are completed;
the inside of the test pipeline 21 is provided with a flow blocking column, the inside of the test pipeline 21 is provided with a temperature sensor, the inside of the test pipeline 21 is provided with a piezoelectric sensor, the piezoelectric sensor adopts a piezoelectric vortex street sensing head, the measurement compensation module 31 comprises a low-temperature piezoelectric crystal, an automatic frequency-selecting charge amplifier and a digital output MEMS accelerometer, the core processing module 32 comprises a charge amplifier, a low-pass filter, a limiter, a Schmitt trigger MSP4 fluid detection processing module 30, an operational amplifier, an application diaphragm and a piezoelectric crystal element, the display module 33 comprises a display screen and a gauge head, the core processing module 32 further comprises a core processing chip, the core processing module 32 and the measurement compensation module 31 receive data, analyze the data and output the data to the display module 33, and the display module 33 displays the data through the display screen;
the method is characterized in that the method is shown in figures 1-5, firstly, the working principle of the vortex street flowmeter is started, the composition of vortex street flow signals is analyzed, then the overall design of the pulse output type digital vortex street flowmeter is carried out, a double-channel processing mode is adopted, and the concept of frequency uncertainty is introduced as the judgment basis of a vortex street useful signal processing method. Then, an anti-vibration technology and a wide temperature technology are adopted to carry out improvement and optimization on the basis, and finally, the high-precision, anti-vibration and wide temperature performance is realized.
Working principle of vortex shedding flowmeter: the theoretical basis of vortex shedding flowmeter for realizing flow measurement is the well-known 'karman vortex street' principle in fluid mechanics, as shown in fig. 4, a bluff body (such as triangular column, cylinder, etc.) perpendicular to the flow direction is placed in the flowing fluid, which is called vortex generator, as the flow speed of the fluid along the vortex generator is gradually increased, the Reynolds number Re is gradually increased, when the flow speed reaches about 40, two rows of vortex columns which are opposite in rotation direction and are arranged in parallel and staggered are generated at the downstream of the vortex generator due to the fact that the fluid mass in the surface layer of the rear half part of the vortex generator is more retarded;
wherein the Reynolds number Re is defined as:
wherein Y is the kinematic viscosity of the fluid in the working state, m 2 /s；
V is the average flow velocity of the incoming flow of the measured medium, m/s;
d is the characteristic dimension of the vortex generator, m;
due to the interaction between the vortices, which are usually unstable, karman has studied the stability conditions of the vortex trains, only two rows of vortices are formed which alternate with each other and the vortex street produced is stable h/l≡0.281 when the ratio between the distance h between two vortex trains and the distance l between two vortices in the same train is satisfied.
Measurement of vortex street: a large number of experiments prove that: in two-dimensional flow state (incoming flow single phase, steady; flow blocking body has regular section and can be regarded as infinite length), when the condition of vortex street stabilization is satisfied, the single-side vortex shedding frequency (vortex street frequency for short) F of vortex street and average flow velocity v of two sides of flow blocking body 1 The relationship is as follows:
wherein d is the maximum width of the windward surface of the choke body, m;
S t is the Styloha number.
From the theory of continuity of fluid flow, it is readily known that:
wherein V is the average flow velocity of the incoming flow of the measured medium, and m/s;
m is the ratio of the flow area at both sides of the vortex generator to the cross-sectional area of the pipe.
The volume flow of the measured medium is as follows:
wherein D is the diameter of the pipeline and m;
k is the instrument coefficient, frequency value/m of vortex shedding flowmeter 3 。
From the following componentsIt can be seen that for a given vortex street flow sensor, its tube diameter D, vortex generating body characteristic dimensions D, m and Stohawa number S t It is known that the instrument coefficient K is also determined, and the velocity V of the fluid to be measured can be known as long as the separation frequency f of the vortex is accurately measured, so that the purpose of measuring the flow in the pipeline is achieved;
at the same time, the method comprises the steps of,and->The precondition for establishment is to ensureAs is clear from the study of vortex street phenomenon by viscous fluid mechanics, the Reynolds number of the fluid is 3×10 for a typical cylindrical generator 2 ～2×10 5 The number of sterhaos is constant over a range of (a), and other types of shedders (e.g., trapezoidal columns) are on the order of magnitude. Obviously, the lower limit of the measuring range of the vortex shedding flowmeter is far higher than the theoretical value.
A vortex shedding flowmeter design scheme; after simple processing of the charge signal led out from the vortex street sensor by the charge amplifier and the filter, a voltage signal with amplitude of about several volts is formed, and the voltage signal is messy and irregular, wherein the voltage signal comprises a signal component representing vortex street frequency, namely a useful signal, and also comprises various noise or interference signals. Wherein noise can be divided into three parts: electromagnetic interference, flow field interference, and pipe vibration interference. Then the vortex street signal can be expressed as:
Yy(t)＝s(t)+n 1 (t)+n 2 (t)+n 3 (t)；
wherein s (t) represents a vortex street frequency signal, which is called a useful signal;
n 1 (t) is an electromagnetic interference signal;
n 2 (t) is a flow field interference signal;
n 3 (t) is a pipe vibration disturbance signal;
the pre-amplifying circuit of the common analog vortex shedding flowmeter comprises a charge amplifier, a low-pass filter, a limiter and a Schmitt trigger; the MSP430 singlechip is adopted for vortex street signal processing, the external interrupt function of the I/O port is utilized for counting the frequency of the square wave signal output by the pre-amplifying circuit, and then the square wave signal is output by the pulse of the other I/O port of the singlechip;
the circuit is shown in fig. 5, the circuit preprocesses vortex street signals, the weak charge signals (the amplitude is about a few mV) which are output by the vortex street piezoelectric sensing head and contain various noises are processed in four aspects of charge amplification, low-pass filtering, amplitude limiting and schmitt trigger shaping by using the charge amplifier, the low-pass filter, the amplitude limiter and the schmitt trigger, so that sine charge signals which are generated by piezoelectric ceramics and have the same vortex separation frequency are converted into pulse signals which are in direct proportion to flow, the pulse signals are input into an I/O port which is provided with an external interrupt function of the MSP430F149 single chip microcomputer, the pulse edge frequency is calculated as an external interrupt source of the pulse signals, the pulse signals are processed by the single chip microcomputer, the pulse signals are output by the other I/O port, meanwhile, the liquid data analysis working state of the single chip microcomputer is controlled by a keyboard, and the single chip microcomputer displays the analysis liquid data to a user through a liquid crystal display screen;
the device designs a hardware circuit of the pulse output type digital vortex shedding flowmeter from the two angles of anti-interference and power consumption reduction, and the whole structure adopts a hardware structure taking an MSP430F149 single-chip microcomputer as a core, so that powerful control functions (12-bit A/D, on-site display, parameter setting, pulse output and the like) of the MSP430 single-chip microcomputer and ultra-low power consumption characteristics of the device are integrated.
The integral structure of the instrument can be divided into four parts of a pre-amplifying circuit for vortex street signals output by the piezoelectric sensor, a singlechip acquisition, control and pulse output circuit and a power supply voltage conversion circuit; the functions of double-channel signal acquisition, data transmission, data processing, on-site LCD display, pulse output, accumulation storage, key set setting, and the like are realized;
the stress type detection mode is adopted by selecting the piezoelectric vortex street sensing head, namely detecting the vortex street frequency signal. After the diaphragm and the piezoelectric crystal element are used as the detecting element and are arranged on the vortex generating body, when the vortex is generated near the vortex generating body, an alternating lifting force is generated on the detecting element, the frequency of the lifting force is the same as that of the vortex generated by the vortex generating body, the lifting force plus pipeline noise and fluid vibration noise are simultaneously acted on the detecting element to generate stress change, the stress difference acts on the diaphragm to change the induced charge of the piezoelectric crystal element in the detecting element, the charge change quantity is led out, and the piezoelectric crystal element is a weak charge signal (the amplitude is about a few mV) containing various noises, namely, the output signal of the piezoelectric sensing head is also the input signal of the vortex street pre-amplifying circuit.
The pre-amplifier circuit is used for processing the weak electric signal provided by the detection element into a pulse signal effectively representing vortex street frequency, and the digital vortex street frequency counter pulse signal is directly subjected to frequency counting by a singlechip.
The pre-amplifier circuit is mainly composed of four parts of a charge amplifier, a low-pass filter, a limiter and a Schmidt trigger shaper, and a specific hardware circuit is realized by an analog circuit taking an operational amplifier as a main body.
Meanwhile, according to the working principle of the vortex shedding flowmeter, in a certain Reynolds number range, the output frequency signal is not influenced by fluid components, density, pressure and temperature, namely, the instrument coefficient is only related to the geometric dimensions of a vortex generating body and a pipeline, and the vortex shedding flowmeter has the problems of low sensitivity of a signal detector and weak signal noise at ultralow temperature;
the device develops the high-precision vortex shedding flowmeter for ultra-low temperature fluid measurement through researching the low-temperature characteristics of piezoelectric materials, the structural optimization of detectors, weak signal extraction and other technologies, and provides a novel measuring means with high performance, high reliability and low price for low-temperature flow measurement.
The flow signal detection flow of the vortex shedding flowmeter comprises the following steps: flow rate- & gt vortex frequency- & gt detection rod alternating lift force- & gt piezoelectric ceramic stress- & gt alternating charge- & gt charge amplifier- & gt filtering shaping- & gt TTL square wave- & gt frequency measurement- & gt output flow rate display.
The piezoelectric ceramic is used as a key sensitive element of the vortex shedding flowmeter, the low-temperature characteristic of the piezoelectric ceramic directly influences the performance of the flowmeter, the performance characteristic of the piezoelectric material can change to a certain extent along with the reduction of temperature, and the performance of different materials is different along with the change of temperature due to the different manufacturing methods and chemical compositions, so that PZT-4, PZT-5 and PZT-8 are preferably adopted.
In addition, when the low-temperature signal detector of the component parts is used, on one hand, the introduced heat of the low-temperature signal detector to the low-temperature medium is considered, and the low-temperature medium cannot be obviously gasified, so that the stability of vortex and the quality of low-temperature propellant are influenced, and measurement or test cannot be performed; on the other hand, the temperature of the piezoelectric ceramic is not too low as much as possible, so that the requirements on the performance of the piezoelectric ceramic are reduced and the service life of the piezoelectric ceramic is prolonged;
therefore, the device reduces heat introduction through the heat insulation sleeve, the temperature of the piezoelectric ceramic reaches ideal through the extension rod, and parameter optimization is performed through heat transfer calculation.
The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the above-described embodiments, and that the above-described embodiments and descriptions are only preferred embodiments of the present invention, and are not intended to limit the invention, and that various changes and modifications may be made therein without departing from the spirit and scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (10)
1. High accuracy anti-vibration wide temperature vortex shedding flowmeter, its characterized in that: comprises a pipeline connecting flange plate (11);
the surface of the pipeline connecting flange plate (11) is provided with a connecting movement adjusting component (20), the surface of the connecting movement adjusting component (20) is provided with a fluid detection processing component (30), the connecting movement adjusting component (20) and the fluid detection processing component (30) adopt a double-channel processing mode, frequency uncertainty is introduced as a judging basis for vortex street useful signal processing, then vortex frequency generated when a triangular column in a pipeline is utilized on the basis, and the source and the amplitude of vibration directions are measured to distinguish and distinguish interference signals, so that the frequency of flow signals can be identified in various interference environments;
meanwhile, the movable adjusting component (20) and the fluid detection processing component (30) are connected, and internal parts are fixedly assembled in the medium fluid detection process, so that vibration force is limited to drive the parts to move.
2. The high-precision vibration-resistant wide-temperature vortex shedding flowmeter of claim 1, wherein: the connecting movement adjusting assembly (20) comprises a test pipeline (21), the test pipeline (21) is arranged on the surface of the pipeline connecting flange plate (11), and a connecting frame (22) is welded at the top of the test pipeline (21).
3. The high-precision vibration-resistant wide-temperature vortex shedding flowmeter of claim 2, wherein: the top of the connecting frame (22) is provided with a protection tube (23), the top of the protection tube (23) is provided with a fixing frame (24), and the surface of the test pipeline (21) is fixedly connected with a first protection sleeve (25).
4. A high precision vibration resistant wide temperature vortex shedding flowmeter as claimed in claim 3, wherein: the other section of the first protective sleeve (25) is fixedly connected with a fixed pipe (26), a second protective sleeve (27) is arranged at the top of the fixed pipe (26), and a fixed buckle (28) is arranged on the surface of the fixed pipe (26).
5. The high-precision vibration-resistant wide-temperature vortex shedding flowmeter of claim 4, wherein: the second protective sleeve (27) is fixedly connected with the fixed pipe (26) through a fixed buckle (28), the other end of the second protective sleeve (27) is connected with the fluid detection processing assembly (30), and the two fixing frames (24) are attached and fixed through bolts.
6. A high precision vibration resistant wide temperature vortex shedding flowmeter as claimed in claim 3, wherein: the fluid detection processing assembly (30) comprises a measurement compensation module (31), wherein the measurement compensation module (31) is installed inside the fixing frame (24), and the measurement compensation module (31) is sealed inside the fixing frame (24) through mutual lamination of the fixing frame (24), so that movement of the measurement compensation module (31) is limited.
7. The high-precision vibration-resistant wide-temperature vortex shedding flowmeter of claim 6, wherein: the inside core processing module (32) that is equipped with of mount (24), core processing module (32) surface connection has display module (33), measurement compensation module (31), core processing module (32) and display module (33) data are linked together to accomplish analysis and the calculation of data.
8. The high-precision vibration-resistant wide-temperature vortex shedding flowmeter of claim 2, wherein: the inside of test pipeline (21) is equipped with keeps off the class post, the inside temperature sensor that is equipped with of test pipeline (21), the inside piezoelectric sensor that is equipped with of test pipeline (21), piezoelectric sensor adopts piezoelectric vortex street sensing head.
9. The high-precision vibration-resistant wide-temperature vortex shedding flowmeter of claim 7, wherein: the measuring and compensating module (31) comprises a low-temperature piezoelectric transistor, an automatic frequency-selecting charge amplifier and a digital output MEMS accelerometer, and the core processing module (32) comprises a charge amplifier, a low-pass filter, a limiter, a Schmidt trigger MSP4 fluid detection processing module (30) and a singlechip, an operational amplifier, an application diaphragm and a piezoelectric crystal element.
10. The high-precision vibration-resistant wide-temperature vortex shedding flowmeter of claim 7, wherein: the display module (33) comprises a display screen and a gauge outfit, the core processing module (32) further comprises a core processing chip, the core processing module (32) and the measurement compensation module (31) are used for receiving data, analyzing the data and outputting the data to the display module (33), and the display module (33) is used for displaying the data through the display screen.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118111540A (en) * | 2024-04-30 | 2024-05-31 | 上海宝宬冶金科技有限公司 | AI intelligent flowmeter for blast furnace leak detection |
| CN118641123A (en) * | 2024-07-29 | 2024-09-13 | 苏州优湖流体科技有限公司 | Intelligent detection system for leakage rate of low-load and high-frequency switching valve of exhaust gas treatment oxidation furnace |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118111540A (en) * | 2024-04-30 | 2024-05-31 | 上海宝宬冶金科技有限公司 | AI intelligent flowmeter for blast furnace leak detection |
| CN118641123A (en) * | 2024-07-29 | 2024-09-13 | 苏州优湖流体科技有限公司 | Intelligent detection system for leakage rate of low-load and high-frequency switching valve of exhaust gas treatment oxidation furnace |
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