CN108593024B - Civil ultrasonic gas meter - Google Patents
Civil ultrasonic gas meter Download PDFInfo
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- CN108593024B CN108593024B CN201810576184.4A CN201810576184A CN108593024B CN 108593024 B CN108593024 B CN 108593024B CN 201810576184 A CN201810576184 A CN 201810576184A CN 108593024 B CN108593024 B CN 108593024B
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- 238000004891 communication Methods 0.000 claims abstract description 33
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- 239000003345 natural gas Substances 0.000 description 5
- 239000003245 coal Substances 0.000 description 4
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- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
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- 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
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Abstract
The invention discloses a civil ultrasonic gas meter which is composed of a data processing and control communication unit, a time measuring unit, an ultrasonic transmitting/receiving switching unit, an ultrasonic exciting unit, an ultrasonic receiving unit and a transducer integrated structural unit. The data processing and control communication unit adjusts the switch of the ultrasonic transmitting/receiving switching unit, the transmitting/receiving channel of the time measuring unit passes through the ultrasonic exciting/receiving unit and the transmitting/receiving channels respectively connected with the integrated structural unit of the transducer&A receiving dual-purpose transducer. The integrated structure of the n-shaped measuring tube integrated transducer has the advantages that the length of the horizontal section of the measuring tube is equivalent to the tube diameter, the defects of short ultrasonic propagation path and non-90 installation angles are overcome0The defect of (2); the ultrasonic wave propagation speed is corrected according to the measured temperature, and a time receiving window is compressed, so that the anti-interference capability and the measurement precision are improved; based on the microelectronic IC result, the ultrasonic transmitting/receiving switching circuit and the threshold zero-crossing detection circuit are designed, and the circuit is simple and reliable.
Description
Technical Field
The invention belongs to the technical field of gas flow detection; in particular to a civil gas meter based on a time difference method ultrasonic flow detection technology.
Background
In 2020, the conservative estimate of energy demand in China is 50 hundred million tons of standard coal. Satisfying the above requirements, the energy supply side will face a great pressure whether increasing domestic energy supply or utilizing foreign resources. The pollution generated by the coal serving as a main energy structure in China far exceeds the environmental capacity, and the environmental bearing capacity faces severe challenges; therefore, adjusting the dominant unreasonable energy structure of coal is not slow. The method of replacing coal with gas is a powerful measure for treating environmental pollution under the prior art.
Natural gas is a major concern as a clean energy source, and the consumption is continuously increasing. In 2001, the domestic consumption of natural gas is only 274 hundred million m3(ii) a In 2012, the pressure increased to 1471 hundred million m3The number of grade cities using natural gas is > 210, and 2 hundred million Chinese people receive . By 12 months in 2012, the quantity of the civil gas meters is more than 2075 thousands; the output of the gas meter is 1000 thousands/year, and the gas meter is exported 250 thousands/year; the domestic civil gas meter enterprises are about 100 families, and the leading product is the membrane gas meter. The membrane type gas meter has a history of hundreds of years, and the membrane type gas meter architecture invented by James and Bogdas in the United kingdom in 1833 continues to the present; the mechanical diaphragm gas meter has simple principle and low price
(90-140 yuan), the precision is 1.5 grade; however, the price of the digital membrane gas meter is several times that of the base meter, and the price is very high (450-550 yuan).
The ultrasonic gas flowmeter has high precision, small pressure loss, simple and convenient operation and maintenance and high reliability without moving parts; a third gas legal measuring instrument which endows trade settlement qualification is formed after the orifice plate flowmeter and the turbine flowmeter; for example, 13 sets of ultrasonic natural gas flow meters are arranged on the longest global China West gas east delivery pipeline. Nowadays, ultrasonic flow meter manufacturers in developed countries occupy the leading technical position, and famous enterprises include us Controlotron, germany Krohne, british Daniel, netherlands Instromet and the like. The standards followed by the industry are: in 1998, IS0 issued IS0/TR12765 "measuring fluid flow in closed pipes with time-propagation ultrasonic flow meters"; the national standard GB/T18604-2001 uses a gas ultrasonic flowmeter to measure the natural gas flow, and the industry standard domestic ultrasonic gas meter 2012 and 2016T-JB. The history of ultrasonic flow measurement in developed countries is long, which can be traced back to 1931 o.rutten german patent; the domestic ultrasonic gas meters in the countries are put into operation in batches for many years, and get unusual achievement. The research of the ultrasonic flowmeter in China starts in sixty years, the precision and the reliability of the domestic ultrasonic flowmeter and PK in developed countries have certain differences, and the imported ultrasonic flowmeter fills the domestic market. Although units such as Zhejiang Wexing instrument system integration limited successively release ultrasonic gas meters, type approval certificates are also obtained; unfortunately, market acceptance is limited, and commercialization of products has a long way to go.
The principle of ultrasonic flow measurement is as follows: when the ultrasonic wave propagates in the fluid, the ultrasonic wave signal is modulated by the fluid; therefore, the flow velocity and flow rate of the fluid can be extracted by detecting the modulated ultrasonic signal. The ultrasonic flow measurement methods include a propagation velocity difference method (time difference, phase difference, and frequency difference), a beam offset method, a doppler method, a correlation method, a spatial filtering method, a noise method, and the like; of which the time difference method is most commonly applied. The ultrasonic flowmeter transducer is classified according to the installation mode and is divided into an external clamping type, an insertion type and a pipe section type. The clip-on ultrasonic flowmeter is further classified into V, Z, N, W method and the like according to the probe attachment method and the ultrasonic propagation path. The time difference ultrasonic fluid flow velocity of the external clamping type V method is calculated according to the following formula
In the formula: t 1-forward flow propagation time, t 2-reverse flow propagation time; d- -tube wall diameter; theta-the angle between the ultrasonic propagation path and the pipe wall. On the basis of the domestic existing research results and process conditions, the problems of poor precision and difficulty in writing by a civil ultrasonic flowmeter are overcome through the improved design of the ultrasonic flowmeter; the method analyzes the source of errors of the civil ultrasonic flowmeter one by one from the formula cut-in of the flow rate of the ultrasonic fluid with the V-method time difference and provides a corresponding solution. Without loss of generality, the discussion is based on the typical working condition of the commercial ultrasonic flowmeter in XX.
The pipe diameter d of the household gas conveying pipe is 30mm, and the gas flow of a user is 0.025-4 m3The Reynolds number is 66.15-10584.53.
The diameter d of the household gas pipe is 30mm, and the propagation path of the ultrasonic wave is very short; the air propagation speed c of the ultrasonic wave in the standard state is 331.4 m/s; obviously, too short a propagation path penalizes the measurement accuracy of the flow. If a section of L & ltD & gt n-shaped measuring tube is inserted into the gas conveying pipe, and energy converters are arranged at two ends of the horizontal section of the measuring tube; when the flow measurement is carried out, the L of the horizontal section of the measuring tube is equivalent to the diameter D of the tube, and the inherent defect of very short propagation path is expected to be solved.
The measurement accuracy of the external clip V, Z, N, W method is related to the transducer mounting angle θ (ultrasonic incident angle), and considering that refraction occurs at the pipe wall and fluid interface when ultrasonic is incident, θ error will cause double measurement error. If the transducers are arranged at the two ends of the horizontal section of the n-shaped measuring tube, the mounting process is simple when theta is equal to 90 degrees, the precision is ensured, and the 90-degree incidence has no refraction phenomenon; therefore, the integrated structure of the n-shaped measuring tube integrated transducer is beneficial to eliminating double measuring errors generated by the error of the installation angle theta.
The ultrasonic waves are severely attenuated and distorted when propagating in the fuel gas, and larger ultrasonic wave transmitting power is necessary, so that an ultrasonic wave receiving end can be interfered by a transmitting end and an external noise environment; usually, the ultrasonic receiving end introduces a time receiving window technology to shield interference, namely the time t of the ultrasonic transmitting end signal reaching the receiving end0And when the power is 0.6-1.5 times of the power, the receiving circuit is switched on and off. In view of the fact that the ultrasonic propagation speed is related to the temperature, the real-time temperature is collected to correct the ultrasonic propagation speed U, and the U is calculated according to the following formula
U＝U0×(1+T/273)0.5＝331.4×(1+T/273)0.5(2)
Existing mainstream [0.6t ]0，1.5t0) The time receiving window can be compressed to (0.8 t)0，1.2t0) And the improvement of the anti-interference capability and precision of the boost ultrasonic flowmeter.
Acoustic impedance mismatching between the ultrasonic transducer and the gas, selecting an acoustic matching layer material with acoustic impedance between the piezoelectric ceramic and the gas medium, and taking the ultrasonic wave wavelength 1/4 as the matching layer thickness; in the integrated structure of the n-shaped measuring tube integrated transducer, the transducer belongs to a plug-in mounting mode, so that the defect of external clamping type ultrasonic signal attenuation is overcome, and short plates which are inconvenient to plug-in mount and large in workload are supplemented to a certain extent; the accuracy of the ultrasonic flowmeter is improved.
The study showed that a single pulse of ultrasound was emittedActual time of reception t ═ tTrue+ε+ζ+ω，tTrueTheoretical time from transmission to reception, epsilon circuit delay time, zeta counter time error, omega random noise error (satisfying normal distribution); from the view point of mathematical statistics, the multi-pulse measurement method can reduce epsilon, zeta and omega to tTrueThe influence further improves the precision of the ultrasonic flowmeter.
The summary of the more representative intellectual property achievements of the civil ultrasonic gas meter is as follows:
the invention discloses an ultrasonic gas meter mixed signal processing circuit (ZL201410140147.0), and provides an ultrasonic gas meter mixed signal processing circuit which adjusts the peak value of an ultrasonic signal in real time through an automatic gain fuzzy control circuit.
The invention discloses an ultrasonic flow gas chamber for an ultrasonic gas meter (ZL 201310084985.6), and provides the ultrasonic flow gas chamber for the ultrasonic gas meter, which changes the traditional mounting modes such as V-shaped and X-shaped modes and forms a long-distance correlation measurement path.
The beneficial exploration provides that the automatic gain fuzzy control circuit adjusts the peak value of the ultrasonic signal in real time, but the mixed signal processing circuit is realized by an analog device, so that the reliability is poor, the complexity is overhigh, and the function is limited; a long-distance correlation type measurement path air chamber is provided, but the air chamber is complex in structure, influences the distribution of a gas flow field, has corresponding countermeasure defects, and easily leaves impurities in a cavity of the lower straight pipe section to influence the measurement accuracy. Therefore, the exploration has a certain reference value, but the achievement still has limitation; further innovative design is needed on the basis of the existing results.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a civil ultrasonic gas meter. The specific technical scheme is as follows:
a civil ultrasonic gas meter is characterized in that the civil ultrasonic gas meter consists of a data processing and control communication unit, a time measuring unit, an ultrasonic transmitting/receiving switching unit, an ultrasonic exciting unit, an ultrasonic receiving unit and a transducer integrated structural unit; the data processing and control communication unit is connected with the time measuring unit and the ultrasonic transmitting/receiving switching unit, and the ultrasonic transmitting/receiving switching unit is connected with the time measuring unit, the ultrasonic exciting unit, the ultrasonic receiving unit and the transducer integrated structural unit.
The data processing and control communication unit controls the operation of the time measuring unit, reads a time difference measuring value output by the time measuring unit, generates gas flow and gas quantity through a data processing and control module of the data processing and control communication unit, and uploads the gas flow and the gas quantity through a Bluetooth communication module of the data processing and control communication unit; the data processing and control communication unit controls the on and off of the analog switch of the ultrasonic transmitting/receiving switching unit, and a transmitting/receiving channel of the time measuring unit is respectively connected to the ultrasonic exciting unit and the ultrasonic receiving unit through the ultrasonic transmitting/receiving switching unit; the ultrasonic excitation unit and the ultrasonic receiving unit are respectively connected to the 1 st transmitting and receiving dual-purpose transducer and the 2 nd transmitting and receiving dual-purpose transducer of the transducer integrated structural unit through the ultrasonic transmitting/receiving switching unit, or the 2 nd transmitting and receiving dual-purpose transducer and the 1 st transmitting and receiving dual-purpose transducer.
Preferably, the data processing and control communication unit comprises a data processing and control module taking an MSP430F135 chip as a core and a Bluetooth communication module with a model BLE-CC41-A, wherein MSP430F135 pins 32 and 33 are respectively connected with BLE-CC41- A pins 2 and 1; the data processing and control module cleans the time difference measurement value output by the time measurement unit, calculates the gas flow rate based on the cleaned time difference data, and gas flow obtained by integrating the gas flow and the flow, and transmits the gas flow and the gas flow through the Bluetooth communication module.
Preferably, the time measuring unit takes a TDC _ GP21 chip as a core, pins 4, 21 and 28 of TDC _ GP21 are grounded, pins 14 and 29 are connected with Vcc, and R is connected with Vcc230、C230、R240Is connected to the legs 17, 18, R230Is connected to the other end of the foot 20, 19, C230The other end of (A) is grounded, R240The other end of which is connected with the feet 24, 23; TDC _ GP21 pins 8, 9, 10, 11, 12 and data processing and control module respectivelyMSP430F135 pins 27, 28, 31, 29 and 30; r210、C210One end of which is connected with an ADG1234 pin 3, R of an ultrasonic wave transmitting/receiving switching unit210Is connected to pin 5 of TDC _ GP21, C210The other end of which is connected with a foot 30; r220、C220One end of which is connected with an ADG1234 pin 8, R of an ultrasonic wave transmitting/receiving switching unit220Is connected to TDC _ GP21 pin 6, C220The other end of which is connected with a TDC _ GP21 pin 27; the foot 5 and the foot 30 of the TDC _ GP21 form an ultrasonic channel, and the foot 6 and the foot 27 of the TDC _ GP21 form another ultrasonic channel; r240The model of the fuel gas temperature acquisition device is a Pt1000 platinum thermal resistor, and the fuel gas temperature T is acquired.
Preferably, the ultrasonic transmitting/receiving switching unit takes an ADG1234 chip as a core, and the ADG1234 chip is connected with the time measuring unit through pins 3 and 8; ADG1234 pins 1, 10, 11, 20 and 15 are respectively connected with MSP430F135 pins 44, 45, 46, 47 and 48 of a data processing and control module, ADG1234 pins 2, 9 and 13 are respectively connected with the Urge _ In and Urge _ Out ends of an ultrasonic excitation unit, ADG1234 pins 18, 4 and 7 are respectively connected with the Receive _ In and Receive _ Out ends of an ultrasonic receiving unit, and ADG1234 pins 12 and 15 and pins 14 and 17 are respectively connected with the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer of the transducer integrated structural unit;
the ultrasonic transmitting/receiving switching unit performs the switching of the transmitting/receiving channels of a TDC _ GP21 pin 5 and a pin 30 ultrasonic channel and another ultrasonic channel of a pin 6 and a pin 27, and performs the switching of the transmitting/receiving transducers of a 1 st transmitting and receiving dual-purpose transducer and a 2 nd transmitting and receiving dual-purpose transducer of the transducer integrated structural unit; two groups of transmitting/receiving switching of the ultrasonic channel and the transducer correspond to two groups of given values of control pins of a four-channel single-pole double-throw analog switch ADG1234 chip, and the switch states of the ADG1234 corresponding to the two groups of given values are shown in the following table:
when the control end is a given value 1, the information flow of the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer of the TDC _ GP21 pin 5 and pin 30 ultrasonic channel and the pin 6 and pin 27 ultrasonic channel are as follows: the TDC _ GP21 pin 5 outputs 200KHZ square wave signals to the ADG1234 pins D1, D1 and S1A to be closed, the signals to the ADG1234 pins D3, D3 and S3A to be closed through the ultrasonic wave excitation unit, and the signal output by the S3A drives the 1 st transmitting & receiving dual-purpose transducer to transmit ultrasonic waves; the 2 nd transmitting & receiving transducer receives the ultrasonic signals transmitted by the 1 st transmitting & receiving transducer, outputs the ultrasonic signals to the ADG1234 pins S4B, S4B and D4 to be closed, and outputs the ultrasonic signals to the ultrasonic receiving units S2B, S2B and D2 to be closed, and the signals output by the D2 are transmitted to a TDC _ GP21 pin 6;
when the control end gives a value of 2, the information flow of the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer of the TDC _ GP21 pin 5 and pin 30 ultrasonic channel and the pin 6 and pin 27 ultrasonic channel are as follows: the TDC _ GP21 pin 5 outputs a 200KHZ square wave signal to the ADG1234 pin D2, D2 and S2A to be closed, the ADG1234 pin D3, D3 and S3B to be closed through the ultrasonic wave excitation unit, and the signal output by the S3B drives the 2 nd transmitting & receiving dual-purpose transducer to transmit ultrasonic waves; the 1 st transmitting & receiving transducer receives the ultrasonic signals transmitted by the 2 nd transmitting & receiving transducer, outputs the ultrasonic signals to ADG1234 pins S4A, S4A and D4 to be closed, and outputs the signals to S2A, S2A and D2 to be closed through an ultrasonic receiving unit, and the signals output by D2 to TDC _ GP21 pin 6.
Preferably, the ultrasonic excitation unit comprises an IRL3410 insulated gate MOSFET, a step-up transformer; r410、C410、R420One end of which is connected to one end of the primary side of the step-up transformer, R410、C410The other end of (A) is grounded, R420The other end of the terminal is connected with Vcc; the source electrode of the MOSFET is grounded, the drain electrode of the MOSFET is connected with the other end of the primary side of the boosting transformer, and the grid electrode of the MOSFET is connected with the other end of the primary side of the boosting transformer through R430Accessing an Unge _ In end; two ends of the secondary side of the step-up transformer are connected in parallel with R440One end of the secondary side is grounded, and the other end of the secondary side is connected to an Urge _ Out end; the pulse sequence generated by a TDC _ GP21 pin 5 or pin 6 port of the time measurement unit is input through an Urge _ In end, when the input pulse is at a high level, the MOSFET is conducted, the secondary side of the booster transformer does not work, when the input pulse is at a low level, the MOSFET is cut off, the secondary side of the booster transformer is conducted, and the primary side energyReleased to secondary side, driving emission&The receiving dual-purpose transducer transmits ultrasonic waves.
Preferably, the ultrasonic receiving unit comprises a pre-amplification module, a second-order band-pass filtering module and a threshold zero-crossing detection module; the pre-amplification module takes an AD8221 gain programmable amplifier as a core, D511、D512Anti-phase parallel connection, one end of the parallel connection is connected with a Receive _ In end and C511Is connected with one end of the first resistor, and the other end of the first resistor is connected with a-Receive _ In end and a C end In parallel512Are connected to one end of C511Another end of (1) and R511One end of the connecting rod is connected with an AD8221 pin 1 and R511Is grounded at the other end, C512Another end of (1) and R512One end of the connecting rod is connected with an AD8221 pin 4 and R512The other end of the first and second electrodes is grounded; AD8221 pins 8, 5, 6 and 7 are respectively connected with Vcc, -Vcc, ground and OUT1 ends; the second-order band-pass filtering module takes OPA820 operational amplifier as a core, R521、R525、C521、C522Are connected at one end to R521To the OUT1 terminal, R522And C521、C522Is connected to another end of C522Is grounded at the other end, C521The other end of the OPA820 pin 3; r523、R524Are connected at one end to R523The other end of (A) is grounded, R524、R525The other end of which is connected to the OPA820 pin 6 and the OUT2 terminal.
The threshold zero-crossing detection module comprises a dual-channel comparator with a latch function and taking MAX9693 as a core, a 1 st NOR gate, a 2 nd NOR gate, an AND gate and a NOT gate, wherein a MAX9693 pin 7 is connected with an MSP430F135 pin 26 of the data processing and control module, MAX9693 pins 8 and 10 are connected with an OUT2 end, and pins 3, 9 and 14 are grounded; the MSP430F135 pin 58 of the data processing and control module is connected with one input end of a 1 st NOR gate and a 2 nd NOR gate, the other input end of the 1 st NOR gate is connected with a MAX9693 pin 2, and the output end of the 1 st NOR gate is connected with a MAX9693 pin 4; MAX9693 feet 1, 16 are connected with two input ends of an AND gate respectively, the output end of the AND gate is connected with a Receive _ Out end and the input end of a NOT gate, and the output end of the NOT gate is connected with the other input end of a 2 nd NOR gate; the information flow of the threshold zero crossing detection function is as follows:
a channel
MSP430F135 of the data processing and control module sets the reference level V of the A-channel input signal of the signal at the OUT2 terminalReference to，VReference toA threshold value; v if A channel inputs signal terminal INA +OUT2＞VReference to，VQAOUT＝5V、
With MSP430F135
Inputting a low level signal into a 1 st NOR gate, outputting a high level signal by the NOR gate, enabling the MAX9693 latch enable pin 4 and triggering the latch signal VQA OUT；
B channel
B channel input signal terminal INB + grounding, V ═ VGNDThe signal OUT2 is input to the reference level terminal INB-of the B channel, and the B channel is inversely compared with the A channel; v if the reference level terminal INB-of the B channelOUT2＜0，VQBOUT＝5V、
Enabling MAX9693 latch enable pin 13, triggering latch signal VQBOUT；
If the output V of channel AQAOUTOutput V of > 0, B channelQBOUTAnd > 0, and outputs high level and zero point representing the signal at the OUT2 end through an AND gate.
Preferably, the integrated structural unit of the energy converter comprises a 1 st transmitting and receiving dual-purpose energy converter, a 2 nd transmitting and receiving dual-purpose energy converter, a 1 st gas elbow, a 2 nd gas elbow and an n-shaped measuring tube, wherein the 1 st transmitting and receiving dual-purpose energy converter consists of a 1 st energy converter piezoelectric ceramic sensor of LHQ200-3 type and a 1 st energy converter acoustic impedance matching layer, and the 2 nd transmitting and receiving dual-purpose energy converter consists of a 2 nd energy converter piezoelectric ceramic sensor of LHQ200-3 type and a 2 nd energy converter acoustic impedance matching layer; the 1 st transmitting and receiving transducer and the 2 nd transmitting and receiving transducer are respectively arranged at the left end and the right end of the horizontal section of the n-shaped measuring tube; the n-shaped measuring pipe is connected into the gas conveying pipe through the 1 st gas elbow pipe and the 2 nd gas elbow pipe.
Compared with the background technology, the invention has the following beneficial effects:
the integrated structure of the n-shaped measuring tube integrated transducer has the advantages that the length of the horizontal section of the measuring tube is equivalent to the tube diameter, the transducer is installed at 90 degrees, and the defects that the ultrasonic wave propagation path is too short and the installation angle theta is not equal to 90 degrees are overcome; the ultrasonic wave propagation speed is corrected according to the measured temperature, and the time receiving window is compressed, so that the anti-interference capacity and the precision of the ultrasonic flowmeter are improved; based on the microelectronic IC result, the ultrasonic transmitting/receiving switching circuit and the threshold zero-crossing detection circuit are designed, and the circuit is simple and reliable.
Drawings
FIG. 1 is a schematic block diagram of a domestic ultrasonic gas meter;
FIG. 2 is a circuit diagram of a data processing and control communication unit;
FIG. 3 is a circuit diagram of a time measurement unit;
fig. 4 is a circuit diagram of an ultrasonic wave transmission/reception switching unit;
FIG. 5 is a circuit diagram of an ultrasonic excitation unit;
FIG. 6 is a circuit diagram of a pre-amplification module;
FIG. 7 is a circuit diagram of a second order band pass filter module;
FIG. 8 is a circuit diagram of a threshold zero crossing detection module;
fig. 9 is a schematic structural diagram of a transducer-integrated structural unit 600.
Detailed Description
As shown in fig. 1 and 4, the civil ultrasonic gas meter is composed of a data processing and control communication unit 100, a time measuring unit 200, an ultrasonic transmitting/receiving switching unit 300, an ultrasonic exciting unit 400, an ultrasonic receiving unit 500, and a transducer integrated structural unit 600; the data processing and control communication unit 100 is connected with the time measuring unit 200 and the ultrasonic wave transmitting/receiving switching unit 300, and the ultrasonic wave transmitting/receiving switching unit 300 is connected with the time measuring unit 200, the ultrasonic wave exciting unit 400, the ultrasonic wave receiving unit 500 and the transducer integrated structure unit 600;
the data processing and control communication unit 100 controls the operation of the time measuring unit 200, reads the time difference measurement value output by the time measuring unit 200, generates gas flow through a data processing and control module of the data processing and control communication unit 100, and uploads the gas flow through a Bluetooth communication module of the data processing and control communication unit 100; the data processing and control communication unit 100 controls the ultrasonic transmitting/receiving switching unit 300 to open and close the analog switch, and the transmitting/receiving channel of the time measuring unit 200 is respectively connected to the ultrasonic exciting unit 400 and the ultrasonic receiving unit 500 through the ultrasonic transmitting/receiving switching unit 300; the ultrasonic excitation unit 400 and the ultrasonic receiving unit 500 are respectively connected to the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer, or the 2 nd transmitting & receiving dual-purpose transducer and the 1 st transmitting & receiving dual-purpose transducer of the transducer integrated structural unit 600 through the ultrasonic transmitting/receiving switching unit 300.
As shown in fig. 2, the data processing and control communication unit 100 comprises a data processing and control module 110 with MSP430F135 chip as core, a bluetooth communication module 120 of type BLE-CC41-a, with MSP430F135 pins 32, 33 connected to BLE-CC41-a pins 2, 1, respectively; the data processing and control module 110 cleans the time difference measurement value output by the time measurement unit 200, calculates the gas flow rate based on the cleaned time difference data, and calculates the gas flow rate and the gas quantity obtained by integrating the gas flow rate and the gas quantity, and uploads the gas flow rate and the gas quantity through the bluetooth communication module.
Description 2: the time difference precision output by the time measuring unit 200 is not only limited by the velocity distribution of the non-ideal flow field of the fuel gas, but also influenced by the uncertainty of the ultrasonic transit time; therefore, cleansing data is necessary: selecting the same and similar time difference data, and eliminating the time difference data with overlarge difference.
As shown in FIG. 3, the time measurement unit 200 uses a TDC _ GP21 chip as a core, TDC _ GP21 pins 4, 21 and 28 are grounded, pins 14 and 29 are connected to Vcc, and R is connected to Vcc230、C230、R240Is connected to the legs 17, 18, R230Is connected to the other end of the foot 20, 19, C230The other end of (A) is grounded, R240The other end of which is connected with the feet 24, 23; TDC _ GP21 pins 8, 9, 10, 11, 12 are connected to MSP430F135 pins 27, 28, 31, 29, 30 of data processing and control module 110, respectively; r210、C210One end of which is connected with an ADG1234 pin 3, R of an ultrasonic wave transmission/reception switching unit (300)210Is connected to the foot 5 at the other end, C210The other end of which is connected with a foot 30; r220、C220One end of which is connected to an ADG1234 pin 8, R of the ultrasonic transmission/reception switching unit 300220Is connected to the other end of the pin 6, C220The other end of which is connected with a foot 27; the foot 5 and the foot 30 of the TDC _ GP21 form an ultrasonic channel, and the foot 6 and the foot 27 of the TDC _ GP21 form another ultrasonic channel; r240The model of the fuel gas temperature acquisition device is a Pt1000 platinum thermal resistor, and the fuel gas temperature T is acquired. Correcting the propagation speed U-U of the ultrasonic wave at the gas temperature according to the gas temperature T0×【1+T/273】0.5＝331.4×【1+T/273】0.5(ii) a Time receive window [0.8t ] for generating ultrasonic receive circuit0，1.2t0】，t0The theoretical time of the ultrasonic signal from the transmitting end to the receiving end. The TDC _ GP21 enables the ultrasonic receiving signal in the time receiving window, and improves the anti-interference capability and precision of the ultrasonic flowmeter.
As shown in fig. 4, the ultrasonic wave transmission/reception switching unit 300 has an ADG1234 chip as a core, and the ADG1234 is connected to the time measuring unit 200 through pins 3 and 8; ADG1234 pins 1, 10, 11, 20, 15 are respectively connected with MSP430F135 pins 44, 45, 46, 47, 48 of the data processing and control module 110, ADG1234 pins 2 and 9, pin 13 are respectively connected with the Urge _ In and Urge _ Out terminals of the ultrasonic excitation unit 400, ADG1234 pins 18, 4 and 7 are respectively connected with the Receive _ In and Receive _ Out terminals of the ultrasonic receiving unit 500, ADG1234 pins 12 and 15, and pins 14 and 17 are respectively connected with the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer of the transducer integrated structural unit 600;
the ultrasonic wave transmitting/receiving switching unit 300 performs the switching of the transmitting/receiving channels of the TDC _ GP21 pin 5 and pin 30 ultrasonic wave channel, and pin 6 and pin 27 another ultrasonic wave channel, and performs the switching of the transmitting/receiving transducers of the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer of the transducer integrated structural unit 600; two groups of transmitting/receiving switching of the ultrasonic channel and the transducer correspond to two groups of given values of control pins of a four-channel single-pole double-throw analog switch ADG1234 chip, and the switch states of the ADG1234 corresponding to the two groups of given values are shown in the following table:
TABLE 1 ADG1234 ON-OFF STATE CORRESPONDING TO TWO SET OF SET VALUES
Taking the given value 1 of the control end as an example, the information flow of the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer of the TDC _ GP21 pin 5 and pin 30 ultrasonic channel and the other ultrasonic channel of the pin 6 and pin 27 is as follows: the TDC _ GP21 pin 5 outputs 200KHZ square wave signals to the ADG1234 pin D1, D1 and S1A to be closed, the ADG1234 pin D3, D3 and S3A are closed through the ultrasonic wave excitation unit 400, and the signal output by the S3A drives the 1 st transmitting & receiving dual-purpose transducer to transmit ultrasonic waves; the 2 nd transmitting & receiving dual-purpose transducer receives the ultrasonic signals transmitted by the 1 st transmitting & receiving dual-purpose transducer, outputs the ultrasonic signals to ADG1234 pins S4B, S4B and D4 to be closed, and is closed by ultrasonic receiving units 500 to S2B, S2B and D2, and outputs the signals to TDC _ GP21 pin 6 by D2;
when the control end gives a value of 2, the information flow of the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer of the TDC _ GP21 pin 5 and pin 30 ultrasonic channel and the pin 6 and pin 27 ultrasonic channel are as follows: the TDC _ GP21 pin 5 outputs a 200KHZ square wave signal to the ADG1234 pin D2, D2 and S2A to be closed, the ADG1234 pin D3, D3 and S3B are closed through an ultrasonic wave excitation unit (400), and the signal output by the S3B drives the 2 nd transmitting & receiving dual-purpose transducer to transmit ultrasonic waves; the 1 st transmitting & receiving transducer receives the ultrasonic wave signal transmitted by the 2 nd transmitting & receiving transducer, outputs to the ADG1234 pins S4A, S4A and D4 to be closed, and is closed by the ultrasonic wave receiving unit (500) to S2A, S2A and D2, and outputs the signal of D2 to the TDC _ GP21 pin 6.
As shown in fig. 5, the ultrasonic excitation unit 400 includes an IRL3410 MOSFET 410 of an insulated gate type, a step-up transformer 420; r410、C410、R420Is connected to one end of the primary side of the step-up transformer 420, R410、C410The other end of (A) is grounded, R420The other end of the terminal is connected with Vcc; the source of the MOSFET 410 is grounded, the drain is connected to the other end of the primary side of the step-up transformer 420, and the gate is connected via R430Accessing an Unge _ In end; two ends of the secondary side of the step-up transformer 420 are connected in parallel with R440One end of the secondary side is grounded, and the other end of the secondary side is connected to an Urge _ Out end; the pulse sequence generated by the TDC _ GP21 pin 5 or pin 6 port of the time measurement unit 200 is input through the Urge _ In end, when the input pulse is at high level, the MOSFET 410 is switched on, the secondary side of the step-up transformer 420 does not work, when the input pulse is at low level, the MOSFET 410 is switched off, the secondary side of the step-up transformer 420 is switched on, the primary side energy is released to the secondary side to drive the emission&The receiving dual-purpose transducer transmits ultrasonic waves.
As shown in fig. 6-8, the ultrasonic receiving unit 500 includes a pre-amplification module 510, a second-order band-pass filtering module 520, and a threshold zero-crossing detection module 530; the pre-amplification module 510 takes an AD8221 gain programmable amplifier as a core, D511、D512Anti-phase parallel connection, one end of the parallel connection is connected with a Receive _ In end and C511Is connected with one end of the first resistor, and the other end of the first resistor is connected with a-Receive _ In end and a C end In parallel512Are connected to one end of C511Another end of (1) and R511One end of the connecting rod is connected with an AD8221 pin 1 and R511Is grounded at the other end, C512Another end of (1) and R512One end of the connecting rod is connected with an AD8221 pin 4 and R512The other end of the first and second electrodes is grounded; AD8221 pins 8, 5, 6 and 7 are respectively connected with Vcc, -Vcc, ground and OUT1 ends; the second-order band-pass filtering module 520 takes an OPA820 operational amplifier as a core, R521、R525、C521、C522Are connected at one end to R521To the OUT1 terminal, R522And C521、C522Is connected to another end of C522Is grounded at the other end, C521The other end of the OPA820 pin 3; r523、R524Are connected at one end to R523The other end of (A) is grounded, R524、R525The other end of the OPA820 pin 6 is connected with the OUT2 end;
the threshold zero-crossing detection module 530 comprises a dual-channel comparator 531 with a MAX9693 core and a latch function, a 1 st NOR gate 532, a 2 nd NOR gate 533, an AND gate 534 and a NOR gate 535, wherein a MAX9693 pin 7 is connected with an MSP430F135 pin 26 of the data processing and control module 110, MAX9693 pins 8 and 10 are connected with an OUT2 end, and pins 3, 9 and 14 are grounded; the MSP430F135 pin 58 of the data processing and control module 110 is connected to one input of a 1 st nor gate 532 and a 2 nd nor gate 533, the other input of the 1 st nor gate 532 is connected to a MAX9693 pin 2, and the output of the 1 st nor gate 532 is connected to a MAX9693 pin 4; pins 1 and 16 of the MAX9693 are respectively connected to two input ends of the and gate 534, an output end of the and gate 534 is connected to a Receive _ Out end and an input end of the not gate 535, and an output end of the not gate 535 is connected to the other input end of the 2 nd nor gate 533; the information flow of the threshold zero crossing detection function is as follows:
a channel
MSP430F135 of the data processing and control module 110 sets the A-channel input signal reference level V of the OUT2 side signalReference to，VReference toA threshold value; v if A channel inputs signal terminal INA +OUT2＞VReference to，VQAOUT＝5V、
With MSP430F135
Inputting a low level signal into the 1 st NOR gate 532, outputting a high level signal by the NOR gate 532, enabling the MAX9693 latch enable pin 4 and triggering the latch signal VQAOUT；
B channel
B channel input signal terminal INB + grounding, V ═ VGNDThe signal OUT2 is input to the reference level terminal INB-of the B channel, and the B channel is inversely compared with the A channel; v if the reference level terminal INB-of the B channelOUT2＜0，VQBOUT＝5V、
Enabling MAX9693 latch enable pin 13, triggering latch signal VQBOUT；
If the output V of channel AQAOUTOutput V of > 0, B channelQBOUTAnd > 0, and outputs a high level zero representing the signal at the terminal OUT2 through the and gate 534.
As shown in fig. 9, the integrated structural unit 600 of the transducer includes a 1 st transmitting & receiving dual-purpose transducer 610, a 2 nd transmitting & receiving dual-purpose transducer 620, a 1 st gas elbow 630, a 2 nd gas elbow 640, and an n-shaped measuring tube 650, wherein the 1 st transmitting & receiving dual-purpose transducer 610 is composed of a 1 st transducer piezoelectric ceramic sensor 611 and a 1 st transducer acoustic impedance matching layer 612 of LHQ200-3 type, and the 2 nd transmitting & receiving dual-purpose transducer 620 is composed of a 2 nd transducer piezoelectric ceramic sensor 621 and a 2 nd transducer acoustic impedance matching layer 622 of LHQ200-3 type; the 1 st transmitting & receiving transducer 610 and the 2 nd transmitting & receiving transducer 620 are respectively arranged at the left end and the right end of the horizontal section of the n-shaped measuring tube 650; the n-shaped measuring pipe 650 is connected to the gas conveying pipe through a 1 st gas elbow 630 and a 2 nd gas elbow 640;
the total thickness of the acoustic impedance matching layer 612 of the 1 st transducer is a circular sheet with the ultrasonic sound wave wavelength of 1/4 lambda, and the total thickness is 0.425mm by taking the sound wave wavelength of 200KHz at 25 ℃; the 1 st transducer acoustic impedance matching layer 612 is composed of a 1 st transducer epoxy resin colloid layer 613 and a 1 st transducer mica sheet 614, and the 1 st transducer epoxy resin colloid layer 613 tightly connects the 1 st transducer piezoelectric ceramic sensor 611 of LHQ200-3 type with the 1 st transducer mica sheet 614; the 1 st transmitting & receiving transducer 610 is installed in the 1 st transducer sleeve 615, the 1 st transducer sleeve 615 is positioned and fixed at the air inlet end of the n-shaped measuring tube 650 through the 1 st transducer four screws 616, and the 1 st transducer sealing washer 617 is placed between the 1 st transducer sleeve 615 and the n-shaped measuring tube 650 to ensure air tightness; the 2 nd transmit & receive transducer 620 is mounted in the same manner as the 1 st transmit & receive transducer 610.
Claims (2)
1. A civil ultrasonic gas meter is characterized in that the civil ultrasonic gas meter consists of a data processing and control communication unit (100), a time measuring unit (200), an ultrasonic transmitting/receiving switching unit (300), an ultrasonic exciting unit (400), an ultrasonic receiving unit (500) and a transducer integrated structural unit (600); the data processing and control communication unit (100) is connected with the time measuring unit (200) and the ultrasonic transmitting/receiving switching unit (300), and the ultrasonic transmitting/receiving switching unit (300) is connected with the time measuring unit (200), the ultrasonic exciting unit (400), the ultrasonic receiving unit (500) and the transducer integrated structural unit (600);
the data processing and control communication unit (100) controls the operation of the time measuring unit (200), reads the time difference measurement value output by the time measuring unit (200), generates gas flow and gas quantity through a data processing and control module of the data processing and control communication unit (100), and uploads the gas flow and gas quantity through a Bluetooth communication module of the data processing and control communication unit (100); the data processing and control communication unit (100) controls the opening and closing of an analog switch of the ultrasonic transmitting/receiving switching unit (300), and a transmitting/receiving channel of the time measuring unit (200) is respectively connected to the ultrasonic exciting unit (400) and the ultrasonic receiving unit (500) through the ultrasonic transmitting/receiving switching unit (300); the ultrasonic excitation unit (400) and the ultrasonic receiving unit (500) are respectively connected to the 1 st transmitting and receiving dual-purpose transducer and the 2 nd transmitting and receiving dual-purpose transducer of the transducer integrated structural unit (600) through the ultrasonic transmitting/receiving switching unit (300), or the 2 nd transmitting and receiving dual-purpose transducer and the 1 st transmitting and receiving dual-purpose transducer;
the integrated structural unit (600) of the energy converter comprises a 1 st transmitting & receiving dual-purpose energy converter (610), a 2 nd transmitting & receiving dual-purpose energy converter (620), a 1 st gas elbow (630), a 2 nd gas elbow (640), and an n-shaped measuring tube (650), wherein the 1 st transmitting & receiving dual-purpose energy converter (610) consists of a 1 st energy converter piezoelectric ceramic sensor (611) of LHQ200-3 type and a 1 st energy converter acoustic impedance matching layer (612), and the 2 nd transmitting & receiving dual-purpose energy converter (620) consists of a 2 nd energy converter piezoelectric ceramic sensor (621) of LHQ200-3 type and a 2 nd energy converter acoustic impedance matching layer (622); the 1 st transmitting & receiving dual-purpose transducer (610) and the 2 nd transmitting & receiving dual-purpose transducer (620) are respectively arranged at the left end and the right end of the horizontal section of the n-shaped measuring tube (650); the n-shaped measuring pipe (650) is connected to the gas conveying pipe through a 1 st gas elbow (630) and a 2 nd gas elbow (640);
the length L & gt D of the horizontal section and the length H & gt D of the vertical section of the n-shaped measuring tube (650), wherein D is the tube diameter of the n-shaped measuring tube (650);
the data processing and control communication unit (100) comprises a data processing and control module (110) taking an MSP430F135 chip as a core and a Bluetooth communication module (120) with a BLE-CC41-A model, wherein MSP430F135 pins 32 and 33 are respectively connected with BLE-CC41-A pins 2 and 1; the data processing and control module (110) is used for obtaining a gas flow rate and a gas quantity obtained by integrating the gas flow and the flow based on time difference measured values output by the cleaning time measuring unit (200) and uploading the gas flow and the gas quantity through the Bluetooth communication module (120);
the time measuring unit (200) takes a TDC _ GP21 chip as a core, pins 4, 21 and 28 of TDC _ GP21 are grounded, pins 14 and 29 are connected with Vcc, and R is connected with Vcc230、C230、R240Is connected to the legs 17, 18, R230Is connected to the other end of the foot 20, 19, C230The other end of (A) is grounded, R240The other end of which is connected with the feet 24, 23; TDC _ GP21 pins 8, 9, 10, 11, 12 are connected to MSP430F135 pins 27, 28, 31, 29, 30, respectively, of the data processing and control module (110); r210、C210One end of which is connected with an ADG1234 pin 3, R of an ultrasonic wave transmission/reception switching unit (300)210Is connected to pin 5 of TDC _ GP21, C210The other end of which is connected with a foot 30; r220、C220One end of which is connected with an ADG1234 pin 8, R of an ultrasonic wave transmission/reception switching unit (300)220Is connected to TDC _ GP21 pin 6, C220The other end of which is connected with a TDC _ GP21 pin 27; the foot 5 and the foot 30 of the TDC _ GP21 form an ultrasonic channel, and the foot 6 and the foot 27 of the TDC _ GP21 form another ultrasonic channel; r240Type of Pt1000 platinumThe thermal resistor is used for collecting the temperature T of the fuel gas; correcting the propagation speed U-U of the ultrasonic wave at the gas temperature according to the gas temperature T0×[1+T/273]0.5＝331.4×[1+T/273]0.5(ii) a Generating a time receive window [0.8t ] for an ultrasonic receive circuit0，1.2t0]，t0The theoretical time of the ultrasonic signal from the transmitting end to the receiving end is obtained; the TDC _ GP21 enables the ultrasonic reception signal in the "time reception window".
2. The civil ultrasonic gas meter according to claim 1, wherein the ultrasonic transmitting/receiving switching unit (300) takes an ADG1234 chip as a core, and the ADG1234 is connected with the time measuring unit (200) through pins 3 and 8; ADG1234 pins 1, 10, 11, 20 and 15 are respectively connected with MSP430F135 pins 44, 45, 46, 47 and 48 of a data processing and control module (110), ADG1234 pins 2, 9 and 13 are respectively connected with the Urge _ In and Urge _ Out ends of an ultrasonic excitation unit (400), ADG1234 pins 18, 4 and 7 are respectively connected with the Receive _ In and Receive _ Out ends of an ultrasonic receiving unit (500), and ADG1234 pins 12, 15 and 14 and 17 are respectively connected with the 1 st transmitting & receiving transducer and the 2 nd transmitting & receiving transducer of a transducer integrated structural unit (600);
the ultrasonic transmitting/receiving switching unit (300) performs the switching of the transmitting/receiving channels of a TDC _ GP21 pin 5 and a pin 30 ultrasonic channel and another ultrasonic channel of a pin 6 and a pin 27, and performs the switching of the transmitting/receiving transducers of a 1 st transmitting & receiving dual-purpose transducer and a 2 nd transmitting & receiving dual-purpose transducer of the transducer integrated structural unit (600); two groups of transmitting/receiving switching of the ultrasonic channel and the transducer correspond to two groups of given values of control pins of a four-channel single-pole double-throw analog switch ADG1234 chip, and the switch states of the ADG1234 corresponding to the two groups of given values are shown in the following table:
when the control end is a given value 1, the information flow of the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer of the TDC _ GP21 pin 5 and pin 30 ultrasonic channel and the pin 6 and pin 27 ultrasonic channel are as follows: the TDC _ GP21 pin 5 outputs 200KHZ square wave signals to the ADG1234 pin D1, D1 and S1A to be closed, the ADG1234 pin D3, D3 and S3A are closed through the ultrasonic wave excitation unit (400), and the signal output by the S3A drives the 1 st transmitting & receiving dual-purpose transducer to transmit ultrasonic waves; the 2 nd transmitting & receiving dual-purpose transducer receives the ultrasonic signals transmitted by the 1 st transmitting & receiving dual-purpose transducer, outputs the ultrasonic signals to the ADG1234 pins S4B, S4B and D4 to be closed, and is closed by the ultrasonic receiving units (500) to S2B, S2B and D2, and outputs the signals to a TDC _ GP21 pin 6 by a D2;
when the control end gives a value of 2, the information flow of the 1 st transmitting & receiving dual-purpose transducer and the 2 nd transmitting & receiving dual-purpose transducer of the TDC _ GP21 pin 5 and pin 30 ultrasonic channel and the pin 6 and pin 27 ultrasonic channel are as follows: the TDC _ GP21 pin 5 outputs a 200KHZ square wave signal to the ADG1234 pin D2, D2 and S2A to be closed, the ADG1234 pin D3, D3 and S3B are closed through an ultrasonic wave excitation unit (400), and the signal output by the S3B drives the 2 nd transmitting & receiving dual-purpose transducer to transmit ultrasonic waves; the 1 st transmitting & receiving dual-purpose transducer receives the ultrasonic signals transmitted by the 2 nd transmitting & receiving dual-purpose transducer, outputs the ultrasonic signals to ADG1234 pins S4A, S4A and D4 to be closed, is closed by an ultrasonic receiving unit (500) to S2A, S2A and D2, and outputs the signals to a TDC _ GP21 pin 6 by a D2 output signal;
the ultrasonic excitation unit (400) comprises an IRL3410 insulated gate type MOSFET (410) and a step-up transformer (420); r410、C410、R420One end of which is connected to one end of the primary side of the step-up transformer (420), R410、C410The other end of (A) is grounded, R420The other end of the terminal is connected with Vcc; the source electrode of the MOSFET (410) is grounded, the drain electrode is connected with the other end of the primary side of the boosting transformer (420), and the grid electrode is connected with the other end of the primary side of the boosting transformer (420) through the R430Accessing an Unge _ In end; two ends of the secondary side of the step-up transformer (420) are connected with R in parallel440One end of the secondary side is grounded, and the other end of the secondary side is connected to an Urge _ Out end; a pulse sequence generated by a TDC _ GP21 pin 5 or pin 6 port of the time measurement unit (200) is input through an Urge _ In end, when the input pulse is In a high level, the MOSFET (410) is conducted, the secondary side of the boosting transformer (420) does not work, when the input pulse is In a low level, the MOSFET (410) is cut off, and the secondary side of the boosting transformer (420) is conductedThe primary side energy is released to the secondary side to drive emission&Receiving the ultrasonic wave emitted by the dual-purpose transducer;
the ultrasonic receiving unit (500) comprises a preamplification module (510), a second-order band-pass filtering module (520) and a threshold zero-crossing detection module (530); the pre-amplification module (510) takes an AD8221 gain programmable amplifier as a core, D511、D512Anti-phase parallel connection, one end of the parallel connection is connected with a Receive _ In end and C511Is connected with one end of the first resistor, and the other end of the first resistor is connected with a-Receive _ In end and a C end In parallel512Are connected to one end of C511Another end of (1) and R511One end of the connecting rod is connected with an AD8221 pin 1 and R511Is grounded at the other end, C512Another end of (1) and R512One end of the connecting rod is connected with an AD8221 pin 4 and R512The other end of the first and second electrodes is grounded; AD8221 pins 8, 5, 6 and 7 are respectively connected with Vcc, -Vcc, ground and OUT1 ends; the second-order band-pass filtering module (520) takes OPA820 operational amplifier as a core, R521、R525、C521、C522Are connected at one end to R521To the OUT1 terminal, R522And C521、C522Is connected to another end of C522Is grounded at the other end, C521The other end of the OPA820 pin 3; r523、R524Are connected at one end to R523The other end of (A) is grounded, R524、R525The other end of the OPA820 pin 6 is connected with the OUT2 end;
the threshold zero-crossing detection module (530) comprises a double-channel comparator (531) with a latch function and taking MAX9693 as a core, a 1 st NOR gate (532), a 2 nd NOR gate (533), an AND gate (534) and a NOR gate (535), wherein a MAX9693 pin 7 is connected with an MSP430F135 pin 26 of the data processing and control module (110), MAX9693 pins 8 and 10 are connected with an OUT2 end, and pins 3, 9 and 14 are grounded; an MSP430F135 pin 58 of the data processing and control module (110) is connected with one input end of a 1 st NOR gate (532) and a 2 nd NOR gate (533), the other input end of the 1 st NOR gate (532) is connected with a MAX9693 pin 2, and the output end of the 1 st NOR gate (532) is connected with a MAX9693 pin 4; MAX9693 feet 1, 16 are respectively connected with two input ends of an AND gate (534), the output end of the AND gate (534) is connected with a Receive _ Out end and the input end of a NOT gate (535), and the output end of the NOT gate (535) is connected with the other input end of a 2 nd NOT gate (533); the information flow of the threshold zero crossing detection function is as follows:
a channel
MSP430F135 of the data processing and control module (110) sets the A-channel input signal reference level V of the OUT2 side signalReference to，VReference toA threshold value; v if A channel inputs signal terminal INA +OUT2＞VReference to，VQAOUT＝5V、
With MSP430F135
Inputting a low level signal into a 1 st NOR gate (532), outputting a high level signal by the NOR gate (532), enabling a MAX9693 latch enabling pin 4 and triggering a latch signal VQAOUT；
B channel
B channel input signal terminal INB + grounding, V ═ VGNDThe signal OUT2 is input to the reference level terminal INB-of the B channel, and the B channel is inversely compared with the A channel; v if the reference level terminal INB-of the B channelOUT2＜0，VQBOUT＝5V、
Enabling MAX9693 latch enable pin 13, triggering latch signal VQBOUT；
If the output V of channel AQAOUTOutput V of > 0, B channelQBOUTAnd > 0, and outputs a high level, zero point representing the signal at the OUT2 end through an AND gate (534).
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Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106353533A (en) * | 2015-07-18 | 2017-01-25 | 许亚夫 | High-precision three-dimensional wind measuring system |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI91106C (en) * | 1991-12-23 | 1994-05-10 | Kytoelae Instrumenttitehdas | Method and apparatus for monitoring gas flow, especially natural gas flow |
| US7117104B2 (en) * | 2004-06-28 | 2006-10-03 | Celerity, Inc. | Ultrasonic liquid flow controller |
| DE102007029957A1 (en) * | 2007-06-28 | 2009-01-02 | Robert Bosch Gmbh | Ultrasonic sensor with reciprocal transmitting and receiving circuit |
| JP2009236850A (en) * | 2008-03-28 | 2009-10-15 | Advance Denki Kogyo Kk | Ultrasonic flowmeter |
| CN102788617B (en) * | 2012-07-18 | 2016-07-06 | 湖南常德牌水表制造有限公司 | A kind of enclosed type ultrasonic water meter and heat energy meter |
| CN104697593B (en) * | 2015-03-24 | 2017-12-08 | 合肥工业大学 | A kind of gas ultrasonic flowmeter based on FPGA and DSP |
| CN105300508B (en) * | 2015-10-30 | 2018-05-01 | 北京控制工程研究所 | The dual threshold detection circuit and detection method of a kind of transit-time of ultrasonic |
| CN105333911A (en) * | 2015-11-01 | 2016-02-17 | 中国计量学院 | Low-power-consumption middle-low-pressure gas ultrasonic flow measuring circuit |
-
2018
- 2018-06-06 CN CN201810576184.4A patent/CN108593024B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106353533A (en) * | 2015-07-18 | 2017-01-25 | 许亚夫 | High-precision three-dimensional wind measuring system |
Non-Patent Citations (7)
| Title |
|---|
| 一种基于MSP430的超低功耗高精度超声波流量计的设计;郭菲;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20180131;C030-107 * |
| 一种小管径超声波流量计的设计;金松日;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20130930;C030-29 * |
| 关于改进超声波流量计性能的研究;黄建军;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20040131;C030-50 * |
| 基于WinCE6.0的超声波气体流量计设计;周敏岚;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20130331;C030-58 * |
| 基于幅值标记的超声流量检测方法研究;董登辉;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20140831;C030-129 * |
| 换能器双匹配层参数的计算;李珺，贺西平，张峰，朱奕蔓;《传感器与微系统》;20081231(第12期);106-108 * |
| 超声波流量仪的研究及设计;严海增;《中国优秀硕士学位论文全文数据库 基础科学辑》;20171231;A012-78 * |
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