RU26341U1 - ULTRASONIC FLOW METER - Google Patents

Abstract

An ultrasonic flow meter (UR) containing 2N piezoelectric transducers (PES), a switching unit (BC), a probe pulse shaper (PPI), a control unit (BU) with control outputs, an I circuit, an amplifier-shaper (USF), a phase-locked loop (PLL), a controlled oscillator (AG), a frequency divider (DF) and a computing device (VU), characterized in that it is additionally equipped with a time counter (SChV), a counting device (SChU), a single-shot (S), 2N front-end shapers ( FF), communication unit (BS) and energozonesa a dependent storage device (memory), moreover, additional inputs are introduced into the VU and FZI, the number of which is 2N (where N≥1), two additional (second and third) additional inputs are entered into the USF, and an additional input and output into the control unit; The control system has two outputs, its input is connected to the output of the frequency converter, the first output is connected to the second PLL input, and the second output is connected to the third input of the USF and to the input of the OB; the second input of the usf is connected to the additional output of the control unit; the OB output is connected to the first inputs of the FDI, the second inputs of which are connected with the control outputs of the control unit; FDI outputs are connected to FF inputs, the outputs of which are connected to the probes inputs; the BS input is connected to an external information source, and the output is connected to the memory input, the output of which is connected to the second inputs of the control unit and the control unit; the first input of the control unit is connected to the MFB output, the second output of the control unit to the second input of the AND circuit, the output of which is connected to the first input of the control unit, the output of which is connected to the second input of the PM.

Description

ULTRASONIC FLOW METER

The utility model relates to the field of instrumentation and can be used in scientific research, industry and other sectors of the national economy to study the properties of liquids, measure the flow velocity and flow rate of fluids in pipelines, etc.

The inventive ultrasonic flow meter is intended, in particular, for measuring the flow rate and volume of a liquid by controlling the flow rate (hot, cold water and other liquids) in pipelines.

Ultrasonic flow meters measuring the difference in the transit time of ultrasonic signals along the flow and against the fluid flow are divided according to the number of acoustic rays (channels) into single-beam, double-beam and multi-beam. The former have only two piezoelectric elements, each of which in turn performs the functions of radiation and reception. The second have two acoustic beams that are parallel or intersect with each other. Multipath are used when necessary to measure the flow rate with a distorted kinematic structure.

 see, for example, g. World of measurements No. 3-4 2001g.s 4-9; No. 5 of 2001, p. 4-9, g. Instruments and control systems .f 11 1997 from. 17-18.

Ultrasonic flow meters based on direct methods for measuring controlled parameters are known. These devices contain piezoelectric transducers and various elements for the formation and processing of probe pulses.

i'm about .... and .... / - L1t 1 //: /:

 see, for example, p. RF No. 2160887, publ. 12/20/2000, IPC G 01F 1/66.

Also known are ultrasonic flow meters based on compensation methods for measuring controlled parameters.

These flowmeters consist of pulse generators, piezoelectric transducers, recording circuits, equipped with various measuring elements.

see, for example, V.K. Khamidullin “Ultrasonic measuring devices and systems, L. Publishing House of Leningrad University, 1989, p. 141-143; A.S. USSR 657255, publ. B.14 1979, IPC G 01F 1/66; p. RF № 2106602, publ. 03/10/1998, IPC G 01 F 1/66; p. RF .№ 2169906, publ. 06/27/2001, IPC G 01 F 1/66; p. of the Russian Federation No. 2165085, publ. 04/10/2001, IPC G 01 P 5/00, G 01 F 1/66.

The disadvantages of the known analogues are:

- insufficient measurement accuracy;

- Inadequate protection against interference, including reverb. The closest in technical essence and the achieved result to

The claimed utility model is an ultrasonic flow meter (UR) - a digital ultrasonic flow meter containing 2N piezoelectric transducers (NEP), a switching unit (BC), a probe pulse generator (PSI), a control unit (BU) with control outputs, a circuit I, an amplifier driver (UsF ), a phase locked loop (PLL), a controlled oscillator (AG), a frequency divider (DC) and a computing device (WU). Moreover, the SD is equipped with a quartz oscillator and shaper

number code; the switching unit contains 2N switches. Separate elements are interconnected but in the original scheme.

 see p. RF No. 2180432, publ. 03/10/2002, IPC G 01 F 1/66. The disadvantages of nrototin are as follows:

-low measurement accuracy due to the non-identical parameters of the switches included in the BC;

-inadequate protection from nomekh, including reverb;

-reliable work with measuring sections (DUT) having different levels of output signals.

The objective of the claimed model is to create a simple design of an ultrasonic flow meter having high noise immunity and high measurement accuracy, as well as the ability to work with DUTs having a large spread in the amplitude of the output signal.

The problem is solved in that the well-known ultrasonic flow meter (UR) containing 2N piezoelectric transducers (PEP), a switching unit (BC), a probe pulse shaper (PPI), a control unit (BU) with control outputs, circuit I, an amplifier-shaper ( USF), phase-locked loop (PLL), controlled oscillator (AG), frequency divider (DF) and computing device (WU), ACCORDING TO THE USEFUL MODEL, is additionally equipped with a time counter (SChV), counting device (SChU), one-shot (AB ), 2N formations ateliers of fronts (FF), a communication unit (BS) and non-volatile memory (memory), moreover, in the WU and FZI, the number of which is 2N (where) additional inputs are introduced; two are introduced in the USF (second and third)

additional inputs, in the control unit - additional input and output; The control system has two outputs, its input is connected to the output of the frequency converter, the first output is connected to the second PLL input, and the second output is connected to the third input of the USF and to the input of the OB; the second input of the usf is connected to the additional output of the control unit; the OB output is connected to the first inputs of the FDI, the second inputs of which are connected with the control outputs of the control unit; FDI outputs are connected to FF inputs, the outputs of which are connected to the probes inputs; the BS input is connected to an external information source, and the output is connected to the memory input, the output of which is connected to the second inputs of the control unit and the control unit; the first input of the control unit is connected to the MFB output, the second output of the control unit to the second input of the AND circuit, the output of which is connected to the first input of the control unit, the output of which is connected to the second input of the PM.

The inventive design of an ultrasonic flow meter is simple and provides:

- high accuracy of measurements due to the connection of fronts formers (FF) to the outputs of the FDI, which make it possible to equalize the characteristics of the FDI in terms of speed;

-Reducing the effect of reverberation and other interference on the reliability and accuracy of operation by supplying the USF with a third additional input connected to the output of the control system;

-reliable work with different DUTs having different levels of output signals due to the introduction of a second input connected to an additional output of the control unit into the ASF.

Analysis of the known technical solutions allows us to conclude that the claimed utility model is not known from the level of the technology being studied, which indicates its compliance with the criterion of “novelty. edema imp crete The possibility of manufacturing the proposed “Ultrasonic flow meter at natural instrument-making enterprises from available domestic or mercury component parts allows us to conclude that it complies with the“ industrial applicability. In FIG. 1 presents a block diagram of the inventive ultrasonic flow meter. Designations in figure 1: 1-piezoelectric transducer (PEP) 2-switching unit (BC) 3-probing pulse shaper (PPI) 4-control unit (BU) 5-circuit And 6-amplifier-former (USF) 7-phase circuit automatic frequency control (PLL) 8-controlled oscillator (AG) 9-frequency divider (DF) 10-computing device (VU) 11-time counter (SChV) 12-counting device (SChU) 13-one-shot (OV) 14-shaper fronts (FF) 15-unit communication (BS) 16-non-volatile memory (memory) 17-measuring section of the pipeline (IU).

The figure 2 presents a "Fragment of a timing diagram of the formation of signals from the outputs of the control unit at the stage of measuring flow in the K-th measuring section (where K is from 1 to N).

The figure 3 presents a "Fragment of the diagram of the formation of the output signals of the counting device, the probe pulses and the input signals of the amplifier-driver in the measuring section

The proposed SD (see figure 1) consists of a communication unit (BS) -15, the input of which is connected to an external information source (not shown in figure 1), and the output is connected to the input of a non-volatile storage device (memory) -16. ZU-16 has an output connected to a control unit (BU) -4 and a computing device (WU) -10. The BU-4, in addition to the control outputs E11 ... EN2, is equipped with two more outputs and an additional input connecting it to a time counter (SChV) -11. The first additional output of the BU-4 is connected to the second input of the amplifier-former (USF) -b; control outputs are connected to additional inputs of probing pulse shapers (FZI) -Z, the second output is to the second input of the I-5 circuit, which has a first input connected to the output of a controlled oscillator (AG) -8 and an output connected to the first input of the computing device (WU) -10. VU-10 is equipped with additional inputs connecting it to the control outputs of the BU-4. The output of VU-10 is connected to the second input of the frequency divider (DC) -9, equipped with a first input connecting it to the output of a controlled oscillator (AG) -8. The output of the DCH-9 is connected to the input of a counting device (SChU) 12, which has two outputs, the first of which is connected to the second input of the phase-locked loop (PLL) -7, and the second to the third input of the amplifier-former (USF) -b and to the input of a single vibrator (OV) -13, output

which is connected to the first inputs of the FZI-3, the number of which is 2N (where). The output of the UsF-6 is connected to the first input of the PLL-7, the output of which is connected to the input of the AG-8. FZI-3 is additionally equipped with second inputs connecting them to the control outputs of BU-4. The outputs of the FZI-3 are connected to the inputs of the front shapers (fF / I, for example, chokes, the outputs of which are connected to the inputs of the piezoelectric transducers (PEP) -1 installed on the measuring sections of the pipeline (IU) -17. The outputs of the PEP-1 are connected to the switching unit (B1u-2, which is a set of keys. The control inputs of the BK-2 are connected to the control outputs of the BU-4, and the output of the BK-2 is connected to the first input of the UsF-6.

The inventive ultrasonic flow meter operates as follows.

The UR has two operating modes: the “Programming” mode and the “Measurement.

In the "Programming in ZU-16 using BS-15 from an external source of information, the program of work of the BU-4 and the parameters of the IU-17 (from 1 to N) are entered, along which the fluid flow with the first and second PEP-1 installed on them .

Based on the parameters of the DUT recorded in the ZU-16, the VU-10 calculates for each IU-17 the conversion coefficients Knpl ... KnpN and the frequency division coefficients Kd1 ... KdK. The calculated data is stored in the ZU-16 and used by the VU-10 in the “Measurement.

 ///.

7

The BU-4 work program is recorded in the ZU-16 and determines the frequency of the flow measurement steps in each of the IU-17 in the “Measurement” mode, as well as the duration of the flow measurement step, depending on the required accuracy.

In the “Measurement BU-4 mode, using timestamps from SchV-11, it forms the signals E11, E12 .... EN1, EN2, Tsch and Ous at its outputs, organizing the stages of measuring the flow rate at one of the measuring sections of ИУ1 ... ИУК -17 with the frequency specified in the BU-4 work program in the “Programming.

All measurement steps are identical, and each of the steps contains two sub-steps, during which the WU-10 receives the information necessary to calculate the flow rate in the required IU-17, which is calculated at this stage.

The work of the SD at the stage K of the flow measurement in the IA, where .... N, occurs as follows (see figure 2).

Stage K consists of the first sub-stage (p / et1) with the issuance of the Ek1 signal from the BU-4 and the second sub-stage (p / et1) with the issuance of the Ek2 signal from the BU-4.

Each of the sub-stages contains two sections of the work - Uch1 and Uch2. Uch1 is used to connect the first and second PEP-1, respectively, and to tune the UsF-6 and PLL-7 to the input signal (i.e. this is a sub-stage of preparation for measurement). Uch2 is a measurement site.

Pa first sub-stage BU-4 generates signals Ek1, Ous and Tschk.

The Ek1 signal is generated during the entire sub-stage and is fed to the control input ФЗИКЗЗ, allowing it to work with PEP 1-1 IUk-17, and to БК-2, allowing the connection of PEP2-1 IUk-17 to the first input of UsF-6.

. / 8

in addition, the Ek1 signal arrives at the VU-10 input, which, having soldered this signal, requests the Kdk and Kprk data calculated in the Programming mode from the ZU-16 and generates a Kdk code at its output, which is fed to the second input of the DCH-9 . The Ous signal is fed to the second input of the UsF-6 and is a sign of the beginning of the adjustment of its gain to the signal Ak2 coming from the PEP-1 IUk-17. The signal Tschk is fed to the second input of the I - 5 circuit to Uch2 and determines the measurement time.

The detailed work of SD on Uch1 is presented below. The AG-8 generates a frequency fg at the output, which is fed to the first input of the DCH-9 with the division coefficient Kdk specified through the second input from the VU-10.

From the output of the DCH-9, the cdk frequency is fed to the counting input of the SchCh-12.

SChU-12 has a work cycle T3 (nl + n2 + n3) / fl,

-p1 - the number of periods of frequency fl from the beginning of the cycle to the issuance of signal C2, arriving at the first output of SChU-12;

-p2 - the number of frequency periods fl from the moment the signal C2 was issued to the signal Cz to the second output of the SChU-12;

-p3 - the number of frequency periods fl from the moment the SZ signal is issued to the end of the SChU-12 cycle of operation.

In accordance with the above, the signal C2 at the first output of the SChU-12 is generated after the time Tl-nl / fl after the cycle started, and the signal C3 is formed at the second output of the SChU-12 after the time T2- (nl + n2) / fl after the start of the cycle.

The signal Cz from the output of the SChU-12 is fed to the third input of the UsF-6 and to the input of the OV-13 (see Fig. 3).

On the front of the SZ signal, OV-13 produces an output signal of the required duration, which is supplied to the first inputs of the FZI-3, however, this signal is amplified only by the FZI, to the permissive input of which the signal Ek1 (in this case, FZi1) is applied. From the FZIK output, an amplified electric pulse (ZIK1), through the front driver, for example, the FFK1-14 choke falls on PEP1-1 IUk-17, where it is converted into an ultrasonic signal that will begin to propagate in the acoustic channel towards PEP2-1 IUk-17 and after a time Tk1, having reached it, it is converted into an electric signal Ak2.

The signal Ak2 through the included contact BK-2 will go to the first input of the UsF-6.

On Uch1, the UsF-6, based on the Ous signal from the BU-4, starts adjusting its gain to ensure accurate and reliable operation with the Ak2 signal received from the PEP-1.

Adjusting the gain of the UsF-6 to the input signal Ak2 is necessary, because the signals from different PEP-1 are different and can vary significantly in amplitude.

The SZ signal arriving at the third input of the UsF-6 provides blocking of its output signal for a period of 1 bln. Thus, the interference and reverberation signals arriving at the input of the UsF-6 outside the waiting time of the signal Ak2 do not get to the input of the PLL-7 Cl, which significantly increases the noise immunity of the UR.

Pa time T2 UsF-6 is unlocked and the amplified and generated signal from its output is fed to the first input Cl of PLL-7.

PLL-7, having received the signal Cl at the first input, and signal C2 from the first output of the SChU-12 to the second input, generates a signal at its output, which is fed to the control input of the AG-8.

; t / M..r

AT-8, under the influence of a control signal, tunes its frequency fg to ficl, at which signals Cl and C2 will arrive at the first and second PLL-7 inputs simultaneously. Thus, on Uch1, the gain of the UsF-6 is adjusted, the accuracy of the UR and the frequency of the AG-8 are set to the frequency fxl.

A fragment of the diagram in Fig. 3 corresponds to the moment of the end of tuning of the PLL-frequency ficl. The parameters СЧУ-12 (п1, п2, пЗ) are selected from the calculation of obtaining the minimum reverberation noise for the time T2 (waiting time for the signal Ak2). In addition, the overlapping of reverberation noise on the useful signal Ak2 is excluded, increasing the accuracy of the SD.

The frequency ficl and the propagation time of the ultrasonic signal in the acoustic channel Tk1, which depends on the flow rate in IU-17, are related by the formula: Tk1 TK + T1-T2 (p1 + pZ) Kdk / ficl.

The frequency ficl is determined on Uch2 as follows.

With the AG-8, the ficl frequency is fed to the first input of the I-5 circuit, the second input of which receives the signal Tchk. At the output of the I-5 circuit, which is connected to the measuring input of the VU-10, Mk1 pulses will appear during the time Tchk, which are fixed by the VU-10.

VU-10 determines the frequency ficl by the formula: ficl MKl / Tc4Kl.

On this, the first sub-stage of stage K ends.

The second sub-stage of stage K begins with the removal of the signal Ek1 from the output of the BU-4 and the establishment of the signal Ek2. The work on this sub-step is identical to the work on the first sub-step and ends with the calculation of the frequency fic2 according to the formula:

eleven

fK2 Mk2 / Tschk2.

Thus, at the end of stage K, the WU-10 has information on the frequencies ficl and Gk2. The propagation time of the ultrasonic signal in the IA by the liquid flow Tk1 and against the flow Tk2 VU-10 is determined by the formulas: Tk1 (p1 + pZ) Kdk / fKl Tk2 (p1 + pZ) Kdk / fK2. QK consumption in IAA is calculated in VU-10 according to the well-known formula:

(Tk2-Tk1) / (),

where Kprk is the conversion coefficient for a given IA recorded in ZU-16 in the “Programming.

FF-14, which are used, for example, inductors installed at the outputs of the FZI-3, can align the speed of the latter and get a more accurate value (Tk2-Tk1), which significantly increases the accuracy of the SD.

Similarly, the calculation of the flow rate in ИУ1 .. .ИУк. Improving the reliability and accuracy of measurements by the claimed UR is achieved by:

-inclusions in the design of UR SCHU with the proposed cycle of formation of its output signals, significantly reducing the influence of interference, including reverb to work ur;

- introducing an additional third input into the USF connected to the second output of the control system, which has a special signal generation diagram Cz, which eliminates the influence of all interference, including reverb, at the time of 1bl;

-use of FF, and connected to the outputs of the FZI, providing accurate calculation of the value of Tk2-Tk1 (where k from 1 to N), which is included in the formula for determining the flow rate;

- the introduction of an additional second input to the USF connected to the additional output of the control unit, which allows achieving reliability of the UR with DUTs having a different level of output signals Ac.

As can be seen from the description of the design and operation, the use of the inventive ultrasonic flow meter in comparison with the well-known, taken as a prototype, see p. RF No. 2180432, publ. 03/10/2002, IPC G 01 F 1/66, provides the following technical and socially useful benefits:

-high measurement accuracy;

-high noise immunity and reliability;

-operability with measuring sections having different levels of output signals.

Claims (1)

An ultrasonic flow meter (UR) containing 2N piezoelectric transducers (PES), a switching unit (BC), a probe pulse shaper (PPI), a control unit (BU) with control outputs, an I circuit, an amplifier-shaper (USF), a phase-locked loop (PLL), a controlled oscillator (AG), a frequency divider (DF) and a computing device (VU), characterized in that it is additionally equipped with a time counter (SChV), a counting device (SChU), a single-shot (S), 2N front-end shapers ( FF), communication unit (BS) and energozonesa a dependent storage device (memory), moreover, additional inputs are introduced into the VU and FZI, the number of which is 2N (where N≥1), two additional (second and third) additional inputs are introduced into the USF, and an additional input and output into the control unit; The control system has two outputs, its input is connected to the output of the PM, the first output is connected to the second PLL input, and the second output is to the third input of the USF and to the input of the OB; the second input of the usf is connected to the additional output of the control unit; the OB output is connected to the first inputs of the FDI, the second inputs of which are connected with the control outputs of the control unit; FDI outputs are connected to FF inputs, the outputs of which are connected to the probes inputs; the BS input is connected to an external information source, and the output is connected to the input of the memory, the output of which is connected to the second inputs of the control unit and the control unit; the first input of the control unit is connected to the output of the SChV, the second output of the control unit to the second input of the AND circuit, the output of which is connected to the first input of the control unit, the output of which is connected to the second input of the PM.