CN202110190U

CN202110190U - A Flow Velocity Measuring Device Applied to Ultrasonic Heat Meter

Info

Publication number: CN202110190U
Application number: CN2011201315316U
Authority: CN
Inventors: 姚滨滨; 张宏建; 唐晓宇; 翁国杰
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2011-04-29
Filing date: 2011-04-29
Publication date: 2012-01-11
Anticipated expiration: 2021-04-29

Abstract

The utility model discloses a flow velocity measuring device applied to an ultrasonic heat meter. The flow rate measuring device is composed of a measuring base meter pipe and an integrator. The measuring base meter pipeline includes a threaded interface, a reduced-diameter pipeline, an ultrasonic transducer installation positioning hole, an ultrasonic transducer, an O-shaped rubber sealing ring, and an ultrasonic transducer fastening gasket. The calculator includes the main control chip, TDC-GP2 chip, XOR gate integrated chip, electronic strobe switch chip, ultrasonic signal processing circuit, LCD liquid crystal display, keys, power supply module. The specific steps of flow velocity measurement are: initial setting of the main control chip and TDC-GP2 chip; measurement of forward flow propagation time; measurement of upstream flow propagation time; flow velocity value calculation and numerical optimization processing. The utility model has reasonable structural design of the measurement base meter pipeline, simple and convenient processing and installation, and does not have the problem of measurement pipeline blockage. The circuit structure of the integrator is simple, the cost is low, and the data display and reading are convenient. The flow velocity measurement range is wide, the accuracy is high, and the linearity is good.

Description

A kind of flow rate measuring device that is applied to ultrasonic calorimeter

Technical field

The utility model relates to the research and the design field of ultrasonic calorimeter, relates in particular to a kind of flow rate measuring device that is applied to ultrasonic calorimeter.

Background technology

Calorimeter is measurement, calculating and shows that heat-exchange system discharges or absorb the instrument of calorie value.It mainly is made up of calorimeter basal meter, integrating instrument, flow sensor and pairing temperature sensor three parts.Thereby transit time ultrasonic flow meters is to converse flow through measuring the flow velocity that ultrasound wave concurrent-countercurrent propagation time difference in fluid detects liquid.According to the difference of the installation site of ultrasonic transducer on calorimeter basal meter, time difference method can specifically be divided into Z method (penetrant method), V method (reflectometry), X method (bracketing method) etc. again.V method and X method need be settled reflecting interface in pipeline, signal is through existing tangible signal attenuation phenomenon behind the reflecting interface and being prone to cause the blockage problem of measuring channel.And the mounting means of Z method need not settled any reflecting interface in measuring pipeline section, so there are not tangible obstruction parts, can solve the susceptible to plugging problem of measurement pipeline section that present most calorimeter exists well.

Integrating instrument and flow sensor are the topmost parts of calorimeter, and the flow sensor measuring accuracy will directly have influence on the measuring accuracy of whole calorimeter.Different calorimeters at present according to integrating instrument and flow sensor roughly can be divided into mechanical type, electromechanical and electronic type.Mechanical reliability is relatively poor, and mechanical gear is blocked or damages by impurity easily, and incompatible electronic trend.Electromechanical is on the basis of mechanical type table, to increase functional modules such as electronics shows, charges, checks meter.But it just adds the development of electronics control panel all the time on the basis of stem-winder, can't solve the relatively poor problem of reliability.Brand-new electronic type heat energy table arises at the historic moment under this environment.Electronic type is meant that then whole table is made up of electron device entirely, does not have mechanical part, does not exist to damage and the fault of card table, and reliability is better, and is very convenient aspect expansion and upgrading, meets the market development direction.At present, in the electronic type field, there are two kinds of ultrasonic calorimeter schemes.Wherein a kind of is the discrete device scheme, promptly mainly is made up of MCU controller unit and FPGA FPGA control module.It exists shortcomings such as technical threshold height, R&D cycle length, power consumption height, so can not get applying.Another kind is the TDC-GP2 scheme, promptly mainly is made up of MCU controller unit and TDC-GP2 chip, and its principle is simple, and integrated level is high, and is low in energy consumption, is fit to promote on a large scale.And existing ultrasonic calorimeter based on the TDC-GP2 chip is being measured in the design of base table pipeline configuration comparatively singlely, and the fluid-velocity survey performance is bad, the DATA REASONING out of true.

Summary of the invention

The purpose of the utility model is the deficiency that overcomes prior art, and a kind of flow rate measuring device that is applied to ultrasonic calorimeter is provided.

The flow rate measuring device that is applied to ultrasonic calorimeter comprises the upstream threaded interface; The downstream hickey; The undergauge pipeline; Integrating instrument; Ultrasonic transducer installing and locating hole, the upper reaches; Upper reaches ultrasonic transducer; The one O shape rubber seal; Upper reaches ultrasonic transducer ground wire; Upper reaches ultrasonic transducer signal wire; Ultrasonic transducer installing and locating hole, downstream; The downstream ultrasonic transducer; The 2nd O shape rubber seal; Downstream ultrasonic transducer ground wire; Downstream ultrasonic transducer signal wire; Fastening pad of upper reaches ultrasonic transducer and the fastening pad of downstream ultrasonic transducer; Upper reaches ultrasonic transducer and downstream ultrasonic transducer comprise metal waterproof sealing shell, piezoelectric crystal module, plastic stent and signal wiring circuit board; The undergauge pipe ends is respectively equipped with upstream threaded interface and downstream hickey; With undergauge pipeline center cross-sectional on the upper side roam all around the would to become 30 the degree angles the cross section on be provided with a through hole; Undergauge pipeline through hole end portion is provided with ultrasonic transducer installing and locating hole, the upper reaches at the upper reaches; Ultrasonic transducer installing and locating hole, upper reaches internal fixation has upper reaches ultrasonic transducer; Undergauge pipeline through hole end portion is provided with ultrasonic transducer installing and locating hole, downstream in downstream; Ultrasonic transducer installing and locating hole, downstream internal fixation has the downstream ultrasonic transducer, between upper reaches ultrasonic transducer and ultrasonic transducer installing and locating hole, the upper reaches, is provided with an O shape rubber seal, between downstream ultrasonic transducer and ultrasonic transducer installing and locating hole, downstream, is provided with the 2nd O shape rubber seal; The ultrasonic transducer end is provided with the fastening pad of upper reaches ultrasonic transducer and uses bolt at the upper reaches; The ultrasonic transducer end is provided with the fastening pad of downstream ultrasonic transducer and uses bolt in downstream, and metal waterproof sealing shell, plastic stent and signal wiring circuit board link to each other in order, and the cavity internal fixation between metal waterproof sealing shell and the plastic stent has the piezoelectric crystal module.

The circuit of described integrating instrument is: first lead links to each other with upper reaches ultrasonic transducer signal wire; Second lead links to each other with downstream ultrasonic transducer signal wire; The P1.0 of main control chip, P1.1, P1.2, P1.3, P1.4, P1.5 I/O port link to each other with INTN, SSN, SCK, SI, SO, the RSTN port of TDC-GP2 chip respectively; The P6.0 I/O port of main control chip allows control bit

Figure 2011201315316100002DEST_PATH_IMAGE001

to link to each other with the output of the first electronic strobe switch chip; The P6.1 I/O port of main control chip allows control bit

to link to each other with the output of the second electronic strobe switch chip; The signal input part A of the Fire1 port of TDC-GP2 chip, the first electronic strobe switch chip connects together with the signal input part A of XOR gate integrated chip and links to each other with first lead; The signal input part A of the Fire2 port of TDC-GP2 chip, the second electronic strobe switch chip connects together with the signal input part B of XOR gate integrated chip and links to each other with second lead; The Fire_In of TDC-GP2 chip, Stop2, En_Stop2 port ground wire; The En_Start of TDC-GP2 chip, En_Stop1 port connect power lead; The signal output part B of the signal output part B of the first electronic strobe switch chip and the second electronic strobe switch chip connects together and links to each other with the ultrasonic signal input end of ultrasonic signal treatment circuit; The ultrasonic signal output terminal of ultrasonic signal treatment circuit links to each other with the Stop1 port of TDC-GP2 chip; The signal output part Y of XOR gate integrated chip links to each other with the Start port of TDC-GP2 chip; The port one to 20 of LCD LCDs links to each other with the liquid crystal drive section output port S0 to S19 of main control chip respectively; The port 21 to 24 of LCD LCDs links to each other with the liquid crystal public output mouth COM0 to COM3 of main control chip respectively; Button links to each other resistance in series R1 between the P2.1 I/O port of main control chip and the power lead with the P2.1 I/O port of main control chip.The cathode output end of power module links to each other with the power port Vcc of main control chip.

Described ultrasonic signal treatment circuit is: single order high-pass filtering circuit, signal amplification circuit and threshold voltage comparator circuit are in sequential series; Series capacitance C1 between first amplifier forward signal input end+IN1 of ultrasonic signal input end and signal amplification circuit; Resistance in series R2 between first amplifier forward signal input end+IN1 of signal amplification circuit and the ground wire; Resistance in series R3 between first amplifier reverse signal input end-IN1 of signal amplification circuit and the ground wire; Resistance in series R4 between the first amplifier signal output part OUT1 of first amplifier reverse signal input end-IN1 of signal amplification circuit and signal amplification circuit; Resistance in series R5 between second amplifier reverse signal input end-IN2 of threshold voltage comparator circuit and the ground wire, resistance in series R6 between second amplifier reverse signal input end-IN2 of threshold voltage comparator circuit and the power lead.

The end face diameter of described metal waterproof sealing shell 17 is 11.5mm, highly is 2mm, and the diameter of plastic stent 19 is 12.5mm, highly is 4mm.Described main control chip 24 is selected the MSP430F417 super low power consuming single chip processor that has the liquid crystal drive functional module for use.First amplifier of described signal amplification circuit and second amplifier of threshold voltage comparator circuit have been selected AD8092 two-way operational amplifier for use.

The utility model compared with prior art has following advantage: fluid-velocity survey base table reasonable in design, installation and processing is simple and convenient and do not have a measuring channel blocking problem.The integrating instrument treatment circuit is simple in structure, cost is low, data presentation and reading conveniently.Fluid-velocity survey wide ranges, accuracy are high, the linearity is good.

Description of drawings

Fig. 1 is the flow rate measuring device structural representation that is applied to ultrasonic calorimeter;

Fig. 2 is the structure of ultrasonic transducer figure of the utility model;

Fig. 3 is the circuit structure diagram of the integrating instrument of the utility model;

Fig. 4 is the ultrasonic signal treatment circuit figure of the utility model;

Fig. 5 is the flow-speed measurement method process flow diagram of the utility model.

Embodiment:

Like Fig. 1, shown in 2, the flow rate measuring device that is applied to ultrasonic calorimeter comprises upstream threaded interface 1, downstream hickey 2, undergauge pipeline 3, integrating instrument 4, ultrasonic transducer installing and locating hole, the upper reaches 5, upper reaches ultrasonic transducer 6, an O shape rubber seal 7, upper reaches ultrasonic transducer ground wire 8, upper reaches ultrasonic transducer signal wire 9, ultrasonic transducer installing and locating hole, downstream 10, downstream ultrasonic transducer 11, the 2nd O shape rubber seal 12, downstream ultrasonic transducer ground wire 13, downstream ultrasonic transducer signal wire 14, the fastening pad 15 of upper reaches ultrasonic transducer and the fastening pad 16 of downstream ultrasonic transducer; Upper reaches ultrasonic transducer 6 comprises metal waterproof sealing shell 17, piezoelectric crystal module 18, plastic stent 19 and signal wiring circuit board 20 with downstream ultrasonic transducer 11; Undergauge pipeline 3 two ends are respectively equipped with upstream threaded interface 1 and downstream hickey 2; Water is flowed into by upstream threaded interface 1 place; Hickey 2 flows out from downstream; With undergauge pipeline 3 center cross-sectional on the upper side roam all around the would to become 30 the degree angles the cross section on be provided with a through hole; Undergauge pipeline through hole end portion is provided with ultrasonic transducer installing and locating hole, the upper reaches 5 at the upper reaches; Ultrasonic transducer installing and locating hole, the upper reaches 5 internal fixation have upper reaches ultrasonic transducer 6, and undergauge pipeline through hole end portion is provided with ultrasonic transducer installing and locating hole, downstream 10 in downstream, and ultrasonic transducer installing and locating hole, downstream 10 internal fixation have downstream ultrasonic transducer 11; Between upper reaches ultrasonic transducer 6 and ultrasonic transducer installing and locating hole, the upper reaches 5, be provided with an O shape rubber seal 7; Between downstream ultrasonic transducer 11 and ultrasonic transducer installing and locating hole, downstream 10, be provided with the 2nd O shape rubber seal 12, ultrasonic transducer 6 ends are provided with the fastening pad 15 of upper reaches ultrasonic transducer and use bolt at the upper reaches, and ultrasonic transducer 11 ends are provided with the fastening pad 16 of downstream ultrasonic transducer and use bolt in downstream; Metal waterproof sealing shell 17, plastic stent 19 and signal wiring circuit board 20 link to each other in order, and the cavity internal fixation between metal waterproof sealing shell 17 and the plastic stent 19 has piezoelectric crystal module 18.

Described upper reaches ultrasonic transducer 6 is selected the piezoelectric-type ultrasonic wave transducer of customization for use with downstream ultrasonic transducer 11, and wherein the end face diameter of metal waterproof sealing shell 17 is 11.5mm, highly is 2mm, and the diameter of plastic stent 19 is 12.5mm, highly is 4mm.

As shown in Figure 3; The circuit of integrating instrument 4 is: first lead 21 links to each other with upper reaches ultrasonic transducer signal wire 9; Second lead 22 links to each other with downstream ultrasonic transducer signal wire 14; The P1.0 of main control chip 24, P1.1, P1.2, P1.3, P1.4, P1.5 I/O port link to each other with INTN, SSN, SCK, SI, SO, the RSTN port of TDC-GP2 chip 23 respectively; Adopt simulation SPI mode to carry out communication between main control chip 24 and the TDC-GP2 chip 23; The P6.0 I/O port of main control chip 24 allows control bit

to link to each other with the output of the first electronic strobe switch chip 26; Be used to control the on off state of the first electronic strobe switch chip 26; The P6.1 I/O port of main control chip 24 allows control bit to link to each other with the output of the second electronic strobe switch chip 27; Be used to control the on off state of the second electronic strobe switch chip 27; The signal input part A of the Fire1 port of TDC-GP2 chip 23, the first electronic strobe switch chip 26 connects together with the signal input part A of XOR gate integrated chip 25 and links to each other with first lead 21; The signal input part A of the Fire2 port of TDC-GP2 chip 23, the second electronic strobe switch chip 27 connects together with the signal input part B of XOR gate integrated chip 25 and links to each other with second lead 22; The Fire_In of TDC-GP2 chip 23, Stop2, En_Stop2 port ground wire; The En_Start of TDC-GP2 chip 23, En_Stop1 port connect power lead; The signal output part B of the signal output part B of the first electronic strobe switch chip 26 and the second electronic strobe switch chip 27 connects together and links to each other with the ultrasonic signal input end 32 of ultrasonic signal treatment circuit 28; The ultrasonic signal output terminal 36 of ultrasonic signal treatment circuit 28 links to each other with the Stop1 port of TDC-GP2 chip 23; The signal output part Y of XOR gate integrated chip 25 links to each other with the Start port of TDC-GP2 chip 23; The port one to 20 of LCD LCDs 29 links to each other with the liquid crystal drive section output port S0 to S19 of main control chip 24 respectively; The port 21 to 24 of LCD LCDs 29 links to each other with the liquid crystal public output mouth COM0 to COM3 of main control chip 24 respectively; Button 30 links to each other resistance in series R1 between the P2.1 I/O port of main control chip 24 and the power lead with the P2.1 I/O port of main control chip 24.LCD LCDs 29 shows the real-time flow rate measured value when button 30 is pressed, and carries out fluid-velocity survey one time in per 5 seconds, and button 30 did not have operation LCD LCDs 29 in 30 seconds stops to show, to reduce system power dissipation.The cathode output end of power module 31 links to each other with the power port Vcc of main control chip 24.The power supply power supply mode adopts the lithium thionyl chloride cell of external 3.6V, 2400mAh.

Described main control chip 24 is selected the MSP430F417 super low power consuming single chip processor that has the liquid crystal drive functional module for use; It is the chip of 74CBTLV1G125DBV that the first electronic strobe switch chip 26 and the second electronic strobe switch chip 27 are selected TI company model for use, and it is the chip of SN74AHC1G86DBV that XOR gate integrated chip 25 is selected TI company model for use.The band field formula calorimeter LCDs that LCD LCDs 29 selects for use Hebei Thailand magnificent electronics technology company limited to produce.

As shown in Figure 4; Ultrasonic signal treatment circuit 28 is: single order high-pass filtering circuit 33, signal amplification circuit 34 and threshold voltage comparator circuit 35 are in sequential series; Series capacitance C1 between first amplifier forward signal input end+IN1 of ultrasonic signal input end 32 and signal amplification circuit 34; Resistance in series R2 between first amplifier forward signal input end+IN1 of signal amplification circuit 34 and the ground wire; Resistance in series R3 between first amplifier reverse signal input end-IN1 of signal amplification circuit 34 and the ground wire; Resistance in series R4 between the first amplifier signal output part OUT1 of first amplifier reverse signal input end-IN1 of signal amplification circuit 34 and signal amplification circuit 34; Resistance in series R5 between second amplifier reverse signal input end-IN2 of threshold voltage comparator circuit 35 and the ground wire, resistance in series R6 between second amplifier reverse signal input end-IN2 of threshold voltage comparator circuit 35 and the power lead, wherein power taking appearance C1 value is 100pF; Resistance R 2 values are 2K ohm, and the cutoff frequency of then high filter filtering is 0.8Mhz; Power taking resistance R3 value is 1K ohm, and resistance R 4 values are 100K ohm, and then signal amplification factor is 101 times; It is 1K ohm that the R5 value is held in power taking, and resistance R 6 values are 100K ohm, and then the threshold value comparative voltage is 0.03V.

First amplifier of described signal amplification circuit 34 and second amplifier of threshold voltage comparator circuit 35 have been selected AD8092 two-way operational amplifier for use.

As shown in Figure 5, the step of flow-speed measurement method that is applied to ultrasonic calorimeter is following:

1) earlier main control chip 24 and TDC-GP2 chip 23 are carried out the initialization setting after system powers on: the P1.1 of main control chip 24, P1.2, P1.3, P1.5, P6.0 and P6.1 I/O port are output state; The P1.0 of main control chip 24 and P1.1 I/O port are input state; The P2.1 I/O port of main control chip 24 is a negative edge external interrupt triggering mode; The mode of operation of TDC-GP2 chip 23 is measurement range 2 states and starts automatic calibration function; The umber of pulse of the Fire1 of TDC-GP2 chip 23 and the output of Fire2 port is 3; Pulsed frequency is 1MHz; The expection umber of pulse of the Stop1 passage of TDC-GP2 chip 23 is 4, and the shielding window time of first Stop signal of Stop1 passage of TDC-GP2 chip 23 is 20us, the P1.5 I/O port of main control chip 24 to one of the RSTN of TDC-GP2 chip 23 port input by level to the electrification reset of low level saltus step completion to TDC-GP2 chip 23;

2) the following current travel-time measures: high level signal of P6.0 I/O port output of main control chip 24 makes the first electronic strobe switch chip 26 be in off-state; Low level signal of P6.1 I/O port output of main control chip 24 makes the second electronic strobe switch chip 27 be in closure state; TDC-GP2 chip 23 is in following current measurement state at this moment, closes the Fire2 port of TDC-GP2 chip 23, and TDC-GP2 chip 23 is from Fire1 port output two same signals; Every road signal comprises three pulse signals; First via signal encourages in upper reaches ultrasonic transducer 6, the second road signal to be input to the Start port of TDC-GP2 chip 23 through XOR gate integrated chip 25 along first lead 21, and 23 timing of TDC-GP2 chip begin; Downstream ultrasonic transducer 11 receives ultrasonic signal; Ultrasonic signal is input to the ultrasonic signal input end 32 of ultrasonic signal treatment circuit 28 through the second electronic strobe switch chip 27, and ultrasonic signal is input to the Stop1 port of TDC-GP2 chip 23 again from ultrasonic signal output terminal 36 outputs of ultrasonic signal treatment circuit 28; 23 timing of TDC-GP2 chip finish; ALU in the TDC-GP2 chip 23 calculates following current travel-time value automatically, duplicate measurements 50～100 times, and the mean value of measurement is designated as following current travel-time T1;

3) the adverse current travel-time measures: the adverse current travel-time measures before and earlier TDC-GP2 chip 23 is carried out the initialization setting; High level signal of P6.1 I/O port output of main control chip 24 makes the second electronic strobe switch chip 27 be in off-state; Low level signal of P6.0 I/O port output of main control chip 24 makes the first electronic strobe switch chip 26 be in closure state; TDC-GP2 chip 23 is in the reverse-current metering state at this moment; Close the Fire1 port of TDC-GP2 chip 23, TDC-GP2 chip 23 is from three pulse signals of Fire2 port output, and three pulse signal first via encourage the ultrasonic transducer 11 in downstream along second lead 22; Three pulse signals the second tunnel are input to the Start port of TDC-GP2 chip 23 through XOR gate integrated chip 25; 23 timing of TDC-GP2 chip begin, and upper reaches ultrasonic transducer 6 receives ultrasonic signal, and ultrasonic signal is input to the ultrasonic signal input end 32 of ultrasonic signal treatment circuit 28 through the first electronic strobe switch chip 26; Ultrasonic signal is from ultrasonic signal output terminal 36 outputs of ultrasonic signal treatment circuit 28; Be input to the Stop1 port of TDC-GP2 chip 23 again, 23 timing of TDC-GP2 chip finish, and the ALU in the TDC-GP2 chip 23 calculates following current travel-time value automatically; Duplicate measurements 50～100 times, the mean value of measurement is designated as adverse current travel-time T2;

4) flow speed value calculates and data-optimized processing: with following current travel-time T1 and adverse current travel-time T2 substitution formula, calculation flow rate value

;

is the setting angle of ultrasonic transducer in the formula; C is the velocity of propagation of ultrasound wave in water; D1 is a calorimeter basal meter undergauge pipeline inner diameter values; Wherein

is 30 degree; C is 1450m/s; D1 is 15mm; In order to overcome the stochastic error that in measuring process, exists and the undulatory property problem of liquid flow, a kind of middle position value filtering algorithm based on recurrence average has been proposed, N the flow speed value that continuous coverage is arrived is as an array; Fixedly the length of array is N; Whenever measure a new array and remove the minimum and maximum flow speed value in the new array, N-2 remaining flow speed value averaged as flow rate measurements again, the N span is 12 to 20.

Claims

1. A flow rate measuring device applied to an ultrasonic heat meter, characterized in that it includes an upstream threaded interface (1), a downstream threaded interface (2), a reduced-diameter pipe (3), an integrator (4), and an upstream ultrasonic transducer positioning hole (5), upstream ultrasonic transducer (6), first O-shaped rubber sealing ring (7), upstream ultrasonic transducer ground wire (8), upstream ultrasonic transducer signal wire (9), Downstream ultrasonic transducer installation positioning hole (10), downstream ultrasonic transducer (11), second O-shaped rubber sealing ring (12), downstream ultrasonic transducer ground wire (13), downstream ultrasonic transducer signal line (14), upstream ultrasonic transducer fastening gasket (15) and downstream ultrasonic transducer fastening gasket (16); upstream ultrasonic transducer (6) and downstream ultrasonic transducer (11) include metal waterproof Sealed housing (17), piezoelectric crystal module (18), plastic bracket (19) and signal wiring circuit board (20); the two ends of the reduced-diameter pipe (3) are respectively provided with an upstream threaded interface (1) and a downstream threaded interface ( 2) A through hole is provided on the cross-section at an angle of 30 degrees to the upstream direction of the central cross-section of the reduced-diameter pipe (3), and an upstream ultrasonic transducer installation positioning hole is provided at the end of the through-hole of the upstream reduced-diameter pipe ( 5), the upstream ultrasonic transducer installation positioning hole (5) is fixed with the upstream ultrasonic transducer (6), and the downstream ultrasonic transducer installation positioning hole (10) is arranged at the end of the through hole of the downstream reducing pipe, and the downstream ultrasonic transducer installation positioning hole (10) is installed in the downstream A downstream ultrasonic transducer (11) is fixed in the ultrasonic transducer installation positioning hole (10), and a first O is arranged between the upstream ultrasonic transducer (6) and the upstream ultrasonic transducer installation positioning hole (5). O-shaped rubber sealing ring (7), a second O-shaped rubber sealing ring (12) is provided between the downstream ultrasonic transducer (11) and the downstream ultrasonic transducer installation positioning hole (10), and a second O-shaped rubber sealing ring (12) is installed between the upstream ultrasonic transducer (6) An upstream ultrasonic transducer fastening gasket (15) is provided at the end and fixed with bolts, and a downstream ultrasonic transducer fastening gasket (16) is provided at the end of the downstream ultrasonic transducer (11) and fixed with bolts Fixed, the metal waterproof sealed case (17), the plastic bracket (19) and the signal wiring circuit board (20) are connected in sequence, and the cavity between the metal waterproof sealed case (17) and the plastic bracket (19) is fixed with a piezoelectric Crystal Module (18).

2. A flow rate measurement device applied to an ultrasonic heat meter according to claim 1, characterized in that the circuit of the totalizer (4) is: the first wire (21) and the upstream ultrasonic transducer signal line (9), the second wire (22) is connected to the signal line (14) of the downstream ultrasonic transducer, and the P1.0, P1.1, P1.2, P1.3, P1. 4. The P1.5 I/O ports are respectively connected to the INTN, SSN, SCK, SI, SO, and RSTN ports of the TDC-GP2 chip (23), and the P6.0 I/O port of the main control chip (24) is connected to the first The output of the electronic strobe switch chip (26) allows the control bit connected, the P6.1 I/O port of the main control chip (24) is connected to the output enable control bit of the second electronic strobe switch chip (27) connected, the Fire1 port of the TDC-GP2 chip (23), the signal input terminal A of the first electronic strobe switch chip (26) and the signal input terminal A of the XOR gate integrated chip (25) are connected together and connected with the first wire (21) connected, the Fire2 port of the TDC-GP2 chip (23), the signal input terminal A of the second electronic gating switch chip (27) and the signal input terminal B of the XOR gate integrated chip (25) are connected together and connected with The second wire (22) is connected, the Fire_In, Stop2, En_Stop2 ports of the TDC-GP2 chip (23) are grounded, the En_Start, En_Stop1 ports of the TDC-GP2 chip (23) are connected to the power line, and the first electronic gating switch chip (26 ) signal output terminal B and the signal output terminal B of the second electronic gating switch chip (27) are connected together and connected with the ultrasonic signal input terminal (32) of the ultrasonic signal processing circuit (28), and the ultrasonic signal processing circuit (28 ) of the ultrasonic signal output terminal (36) is connected to the Stop1 port of the TDC-GP2 chip (23), and the signal output terminal Y of the XOR gate integrated chip (25) is connected to the Start port of the TDC-GP2 chip (23). The ports 1 to 20 of the display screen (29) are respectively connected to the output ports S0 to S19 of the liquid crystal drive section of the main control chip (24), and the ports 21 to 24 of the LCD liquid crystal display (29) are respectively connected to the output ports of the main control chip (24). The liquid crystal common output ports COM0 to COM3 are connected, the button (30) is connected to the P2.1 I/O port of the main control chip (24), and the P2.1 I/O port of the main control chip (24) is connected in series with the power line The resistor R1 is connected to the positive output terminal of the power module (31) and the power port Vcc of the main control chip (24).

3. A flow velocity measurement device applied to an ultrasonic heat meter according to claim 2, characterized in that the ultrasonic signal processing circuit (28) is: a first-order high-pass filter circuit (33), a signal amplification circuit (34 ) and the threshold voltage comparator circuit (35) are connected in series in sequence, the capacitor C1 is connected in series between the ultrasonic signal input terminal (32) and the positive signal input terminal + IN1 of the first operational amplifier of the signal amplification circuit (34), and the signal amplification circuit (34 ), the series resistance R2 between the forward signal input terminal +IN1 of the first operational amplifier and the ground wire, the series resistance R3 between the first operational amplifier reverse signal input terminal -IN1 and the ground wire of the signal amplification circuit (34), the signal The resistor R4 is connected in series between the first operational amplifier reverse signal input terminal -IN1 of the amplification circuit (34) and the first operational amplifier signal output terminal OUT1 of the signal amplification circuit (34), and the second operational amplifier of the threshold voltage comparison circuit (35) A resistor R5 is connected in series between the reverse signal input terminal-IN2 and the ground wire, and a resistor R6 is connected in series between the reverse signal input terminal-IN2 of the second operational amplifier of the threshold voltage comparator circuit (35) and the power supply line.

4. A flow velocity measuring device applied to an ultrasonic heat meter according to claim 1, characterized in that the metal waterproof sealed casing (17) has an end face diameter of 11.5mm, a height of 2mm, and a plastic bracket (19) The diameter is 12.5mm and the height is 4mm.

5. A flow velocity measurement device applied to an ultrasonic heat meter according to claim 2, characterized in that the main control chip (24) is an MSP430F417 ultra-low power consumption single-chip microcomputer with a liquid crystal drive function module.

6. A flow velocity measuring device applied to an ultrasonic heat meter according to claim 3, characterized in that the first operational amplifier of the signal amplification circuit (34) and the second operational amplifier of the threshold voltage comparison circuit (35) Put selected AD8092 dual operational amplifier.