CN201526809U - Natural gas pipeline leakage monitoring and positioning device based on internal audition - Google Patents

Abstract

A natural gas pipeline leakage monitoring and positioning device based on internal audition belongs to the technical field of natural gas pipeline leakage monitoring, can detect leakage and accurately determine position of leakage points, and is long in detection distance and simple in structure. The natural gas pipeline leakage monitoring and positioning device comprises an acoustic wave sensor, a preamplifier, an A/D converter, a microprocessor, a USB transmission interface, a host computer and a power supply, wherein the acoustic wave sensor is connected with an input end of the preamplifier, an output end of the preamplifier is connected with an input end of the A/D converter via an electrical lever raising circuit, an output end of the A/D converter is connected with an input end of the microprocessor, an output end of the microprocessor is connected with an input end of the USB transmission interface, an output end of the USB transmission interface is connected with the host computer, and the power supply which is respectively connected with the preamplifier, the A/D converter, the microprocessor and the USB transmission interface is used for providing work voltage for the preamplifier, the A/D converter, the microprocessor and the USB transmission interface.

Description

Natural gas line leakage monitoring and positioning device based on interior audition

Technical field:

The utility model belongs to natural gas line leakage monitoring technical field, relates in particular to a kind of natural gas line leakage monitoring and positioning device based on interior audition.

Background technique:

In case the natural gas line leakage can cause enormous economic loss and personal injury, the position of discovery leakage and definite leakage point becomes the matter of utmost importance after leaking in time.Along with the construction of pipeline, leak detection technology has also obtained continuous development, proposed multiple leak of liquid at present both at home and abroad and detected and localization method, yet detection and Position Research that natural gas line is leaked gets less.

At present, existing natural gas line leak detecting device normally when underground natural gas transmission pipeline generation corrosivity perforation, fracture, detects the micro-leakage that produces gas.When the air that will contain inflammable gas when leak detector is delivered to sensor by air pump, the resistance of Detecting element can change rapidly with gas concentration, the while output voltage signal, the voltage signal of output is delivered to the display unit through amplification circuit amplification, single-chip microcomputer after handling, and produces the alarm signal with change in concentration.But this type of natural gas line leak detecting device can not accurately be located, and it is shorter to detect distance, detects the apparatus complexity, is difficult to realize the automation of Monitoring and Controlling.

The model utility content:

At existing natural gas line leak detecting device can not accurately locate, detect distance short, detect the problem that the apparatus complexity is difficult to realize the automation of Monitoring and Controlling, the utility model provides a kind of position that can in time find to leak and accurately determine leakage point, detects distance long, simple in structure natural gas line leakage monitoring and positioning device based on interior audition.

To achieve these goals, the utility model adopts following technological scheme, a kind of natural gas line leakage monitoring and positioning device based on interior audition, comprise preamplifier, A/D converter, microprocessor, the USB transmission interface, upper-position unit, power supply and at least two sonic sensors, sonic sensor is connected with the input end of preamplifier, the output terminal of preamplifier is raised circuit through level and is connected with the input end of A/D converter, the output terminal of A/D converter is connected with the input end of microprocessor, the output terminal of microprocessor is connected with the input end of USB transmission interface, and the output terminal of USB transmission interface is connected with upper-position unit; Power supply is connected with preamplifier, A/D converter, microprocessor and USB transmission interface respectively, is used to preamplifier, A/D converter, microprocessor and USB transmission interface that operating voltage is provided.

Can more reliable work for the assurance system, the utility model also comprises reset circuit, the output terminal of reset circuit is connected with the reseting port of single-chip microcomputer; Described reset circuit can guarantee that system can reset reliably when powering on.

The model that described sonic sensor adopts is CZN-1E, the model that described preamplifier adopts is AD620, the model that described A/D converter adopts is TLV2553, the model that the serial ports of described USB transmission interface changes the employing of USB mouth chip is PL2303, what described microprocessor adopted is single-chip microcomputer, and its model is STC89C52; First sonic sensor is connected with the input end of preamplifier U1, the output terminal of preamplifier U1 is connected with an end of the input port A0 of A/D converter U3 and the 4th resistance R 4, the 5th resistance R 5 respectively through the 3rd resistance R 3, the other end of the 4th resistance R 4 is connected with power supply, and the other end of the 5th resistance R 5 is connected with ground; Second sound wave sensor is connected with the input end of preamplifier U2, the output terminal of preamplifier U2 is connected with an end of the input port A1 of A/D converter U3 and the 7th resistance R 7, the 8th resistance R 8 respectively through the 6th resistance R 6, the other end of the 7th resistance R 7 is connected with power supply, and the other end of the 8th resistance R 8 is connected with ground; The power input mouth REF-of A/D converter U3 is connected with ground, the power input mouth REF+ of A/D converter U3 is connected with voltage-reference, and output port CLK, the DIN of A/D converter U3, DOUT are connected with data transmission port P2.5, P2.4, P2.3 and the P2.2 of single-chip microcomputer U5 respectively with/CS; The output terminal of reset circuit is connected with the reseting port RESET of single-chip microcomputer U5, reading and writing port TXD, the RXD of single-chip microcomputer U5 is connected with reading and writing port TXD, the RXD of serial ports commentaries on classics USB mouth chip U4 respectively, and the output port that serial ports changes USB mouth chip U4 is connected with upper-position unit through USB interface J1.

The beneficial effects of the utility model:

Natural gas line leakage monitoring of the present utility model and positioning device can carry out the accurate location of leakage point when whether the tested pipeline of monitoring leaks; After in time finding leakage, close corresponding air-supplying valve, thus the generation of minimizing accident.And natural gas line leakage monitoring of the present utility model and positioning device structure are simple, and it is longer to detect distance; Do not need manual intervention during detection, the inspector only needs to judge that according to the prompting of computer the runnability of pipeline and the position of leakage point get final product.

In addition, natural gas line leakage monitoring of the present utility model and positioning device also have following characteristics:

1) adopt highly sensitive special-purpose sonic sensor, it is wide to gather remote faint leakage signal and detection range;

2) many group signal acquisition circuits can be disposed arbitrarily, the pipeline in the different sections can be detected simultaneously;

3) can set in advance and detect constantly, realize that timing automatic detects, and then realize that long-term unmanned the best time detects automatically;

4) adopt the USB transmission interface, can the scene or off-line gather operations such as setting, data read;

5) variable gain setting according to the power of leakage signal, can accurately be caught various leakage points.

Description of drawings:

Fig. 1 is a schematic block circuit diagram of the present utility model;

Fig. 2 is circuit theory diagrams of the present utility model;

Fig. 3 is the schematic representation that the utility model carries out the leakage point location;

Among Fig. 2, the 1-level is raised circuit, the 2-reset circuit.

Embodiment:

As shown in Figure 1, a kind of natural gas line leakage monitoring and positioning device based on interior audition, comprise preamplifier, A/D converter, microprocessor, the USB transmission interface, upper-position unit, power supply and two sonic sensors, sonic sensor is connected with the input end of preamplifier, the output terminal of preamplifier is raised circuit 1 through level and is connected with the input end of A/D converter, the output terminal of A/D converter is connected with the input end of microprocessor, the output terminal of microprocessor is connected with the input end of USB transmission interface, and the output terminal of USB transmission interface is connected with upper-position unit; Power supply is connected with preamplifier, A/D converter, microprocessor and USB transmission interface respectively, is used to preamplifier, A/D converter, microprocessor and USB transmission interface that operating voltage is provided.

As shown in Figure 2, the model that sonic sensor adopts is CZN-1E, the model that preamplifier adopts is AD620, the model that A/D converter adopts is TLV2553, the model that the serial ports of USB transmission interface changes the employing of USB mouth chip is PL2303, what microprocessor adopted is single-chip microcomputer, and its model is STC89C52.First sonic sensor is connected with the input end of preamplifier U1, the output terminal of preamplifier U1 is connected with an end of the input port AO of A/D converter U3 and the 4th resistance R 4, the 5th resistance R 5 respectively through the 3rd resistance R 3, the other end of the 4th resistance R 4 is connected with power supply, and the other end of the 5th resistance R 5 is connected with ground; Second sound wave sensor is connected with the input end of preamplifier U2, the output terminal of preamplifier U2 is connected with an end of the input port A1 of A/D converter U3 and the 7th resistance R 7, the 8th resistance R 8 respectively through the 6th resistance R 6, the other end of the 7th resistance R 7 is connected with power supply, and the other end of the 8th resistance R 8 is connected with ground; The power input mouth REF-of A/D converter U3 is connected with ground, the power input mouth REF+ of A/D converter U3 is connected with voltage-reference, and output port CLK, the DIN of A/D converter U3, DOUT are connected with data transmission port P2.5, P2.4, P2.3 and the P2.2 of single-chip microcomputer U5 respectively with/CS; The output terminal of rc reset circuit 2 is connected with the reseting port RESET of single-chip microcomputer U5, reading and writing port TXD, the RXD of single-chip microcomputer U5 is connected with reading and writing port TXD, the RXD of serial ports commentaries on classics USB mouth chip U4 respectively, and the output port that serial ports changes USB mouth chip U4 is connected with upper-position unit through USB interface J1.

1) signal acquisition circuit:

Preamplifier amplifies the acoustic signals that sonic sensor collects.Because the utility model has adopted the instrument preamplifier, and has adopted dual power source structure, promptly power supply and voltage-reference increase the dynamic range of the acoustic signals of the utility model detection greatly.But thing followed problem is that the level and the A/D conversion range of the acoustic signals that collects do not match, and must carry out level and raise and just can carry out the A/D conversion; So, raise circuit by level the acoustic signals after preamplifier amplifies carried out level conversion.Level is raised circuit can play buffer function to the input port of A/D converter, and it has the Slew Rate requirement to the preamplifier that inserts, and Slew Rate requires range greater than A/D converter divided by the sampling interval in principle.The Slew Rate minimum value of the preamplifier that the utility model is selected for use is 0.3V/us, and incoming level fluctuates in 3.3V.

2) A/D converter:

The A/D converter TLV2553 that the utility model adopts is 12 A/D converters that high-resolution, wide dynamic range, self calibration, low voltage, low power consumption, the 11 passage fully differentials of TI company release are imported, and has good noise robustness.TLV2553 has 4 line system serial line interfaces, is respectively sheet choosing end/CS, serial clock input end I/O CLOCK, serial data input end DATAIN and serial data output terminal DATA OUT.Can directly be connected, not need other external logics with the SPI device.Simultaneously, it also can communicate with main frame under up to the serial rate of 4MHz, can realize multiple communication mode and with the DSP compatibility.The high sampling rate 200K of reality can satisfy the requirement of real-time collection signal.

3) single-chip microcomputer:

The single-chip microcomputer STC89C52 that the utility model adopts is the low power consumption that Taiwan STC Corporation produces, 8 single-chip microcomputers of high-performance CMOS, but sheet includes the FLASH read-only program memory of the systems programming of 8K Bytes, compatibility standard 8051 instruction systems and pin.The STC89C52 single-chip microcomputer of low price can be used in the application system of many high performance-price ratios, can control different parameters flexibly, is applied to various controls field.

4) usb communication:

The serial ports that the utility model adopts changes USB mouth chip PL2303 and is used to realize conversion between USB and the standard RS-232 serial port, and the batch data that data buffer is used for USB transmits.Automatically handshake mode can be used for serial communication, thereby can reach much larger than the baud rate of standard UART controller.PL2303 supports USB power management and Remote Wake Up agreement.Consume minimum electric energy when main frame is hung up, all functions are integrated in the SOIC-28 encapsulation.This chip can also be installed in the elastic cable paper, and the user is as long as be connected in it on host computer or the USB HUB simply, just can realize and the communicating by letter of RS-232 device.

On single-chip microcomputer, set up the serial communication link block, communicate with PL2303 by the TXD/RXD port.Communication interface between PL2303 and the single-chip microcomputer is the basis of whole system, has only and can carry out reliable, fast data exchange between the two, and the every function and the behavior of usb host can normally realize.

STC89C52 is to the data transmission of PL2303 direction: in the port voltage characteristic of STC89C52, the port output low level is less than 0.45V, and the scope of port output high level is between the 2.4V to 5.5V; And in the port voltage characteristic of PL2303, the scope of port input low level is-0.3V to 0.45V that the scope of port input high level is between the 2.0V to 6.0V.So, can correctly be received by PL2303 fully from the level of the data of STC89C52 output.

PL2303 is to the data transmission of STC89C52 direction: in the port voltage characteristic of PL2303, the scope of port output low level is-0.3V to 1.0V that the scope of port output high level is between the 2.4V to 5.3V; And in the voltage characteristic of the port of STC89C52, the scope of port input low level is-0.3V to 0.45V that the scope of port input high level is between the 2.4V to 5.7V.So, can correctly be received by STC89C52 fully from the level of the data of PL2303 output.

5) voltage-reference:

For suitable voltage-reference being provided for A/D converter TLV2553 work, the utility model adopts chip LM4040A-33, for A/D converter provides stable 3.3V voltage reference.

6) reset circuit:

For the assurance system can more reliable work, the utility model adopts reset circuit, and described reset circuit can guarantee that system can reset reliably when powering on.

During use, sonic sensor of the present utility model is arranged on natural gas line inside.The acoustic signals of sonic sensor collection is uploaded to upper-position unit after treatment, upper-position unit is analyzed these data, energy size and frequency height according to the acoustic signals that collects judge whether to leak, or pipeline cut/knock/destruction of holing.When certain depot siding generation rupture and leakage, the fluid moment in this depot siding sprays from hole, and the inside and outside pressure difference of pipeline will produce the acoustic signals of characteristic frequency, and this acoustic signals can transmit along the upstream and downstream pipeline.Utilize this acoustic signals to arrive time difference of two sonic sensors in this depot siding, can calculate the position of leakage point.From energy point of view, the acoustic signals of leakage point is minimum to the ratio of extraneous dissipate energy, thereby can utilize the method for audition in the pipeline to reach pipeline monitoring and the optimum efficiency of locating.

The process of the position of described calculating leakage point is as follows:

As shown in Figure 3, establishing acoustic signals that leakage point produces passes to head end sonic sensor, required time of terminal sonic sensor and is respectively t ₁, t ₂, t ₁, t ₂Formula be:

$t_1=\frac{X}{a-V}---\left(1\right)$

${\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="H2009202477306E00021.png"\; state="\{\{state\}\}">t</figure-callout>}}_2=\frac{L-X}{a+V}---\left(2\right)$

When pipeline occur to leak, detect time difference of acoustic signals according to two sonic sensors, can estimate the position of leakage point, as shown in the formula:

$\mathrm{\&tau;}=t_2-t_1=\frac{L-X}{a+V}-\frac{X}{a-V}---\left(3\right)$

$X=\frac{1}{2a}[L(a-V)+(V^2-a^2)\mathrm{\&tau;}]---\left(4\right)$

In the formula: the distance of L-head, terminal sonic sensor, unit: m;

The X-leakage point is to the distance of head end sonic sensor, unit: m;

The velocity of propagation of acoustic signals in the a-pipeline, unit: m/s;

The flow velocity of rock gas in the pipeline during operation of V-pipeline, unit: m/s;

τ-acoustic signals arrives the time difference of head, terminal sonic sensor, unit: s.

Because the flow velocity V of rock gas can influence to some extent to the time that acoustic signals passes to head, terminal sonic sensor in pipeline when operation pipeline.When not considering V, suppose that head end sonic sensor place leaks, then have: t ₁=0, t ₂=L/ (a+V); Suppose that more terminal sonic sensor place leaks, then have: t ₂=0, t ₁=L/ (a-V).The absolute value of two time differences is:

$|t_2-t_1|=\frac{2V}{a^2-V^2}L---\left(5\right)$

Because $\frac{a}{V}>100,$ The positioning error that causes thus is in first, below 1 ‰ of terminal sonic sensor distance L; Therefore, reached quite high precision, so, can ignore the influence of V during calculating to a, make V=0.Then formula (4) can be reduced to:

$X=\frac{L-\mathrm{a\&tau;}}{2}---\left(6\right)$

Formula (6) is the location Calculation formula of the leakage point behind the abbreviation, and distance L first, terminal sonic sensor determines that in the sonic sensor installation process velocity of propagation a of acoustic signals is an empirical value in the pipeline.

The acoustic signals that sonic sensor will pick up is transferred to upper-position unit.Upper-position unit shows the acoustic signals the gathered form with waveform in real time, and according to the pressure and the acoustic signals at pipeline two ends, the leakage that occurs in the pipeline is in time reported to the police, and estimate the position of leakage point, realize storage and historical analysis simultaneously the line pressure data.

Pipeline leakage monitoring of the present utility model can reach following technical order with positioning device:

Detection and location resolution 1cm,

Location accuracy 〉=99%,

Warning rate of false alarm≤5%,

Alarm time≤1s.

Claims (3)

1. natural gas line leakage monitoring and positioning device based on an interior audition, it is characterized in that comprising sonic sensor, preamplifier, A/D converter, microprocessor, the USB transmission interface, upper-position unit and power supply, sonic sensor is connected with the input end of preamplifier, the output terminal of preamplifier is raised circuit through level and is connected with the input end of A/D converter, the output terminal of A/D converter is connected with the input end of microprocessor, the output terminal of microprocessor is connected with the input end of USB transmission interface, and the output terminal of USB transmission interface is connected with upper-position unit; Power supply is connected with preamplifier, A/D converter, microprocessor and USB transmission interface respectively, is used to preamplifier, A/D converter, microprocessor and USB transmission interface that operating voltage is provided.

2. a kind of natural gas line leakage monitoring and positioning device based on interior audition according to claim 1 is characterized in that also comprising reset circuit, and the output terminal of reset circuit is connected with the reseting port of single-chip microcomputer.

3. a kind of natural gas line leakage monitoring and positioning device according to claim 1 based on interior audition, it is characterized in that the model that described sonic sensor adopts is CZN-1E, the model that described preamplifier adopts is AD620, the model that described A/D converter adopts is TLV2553, the model that the serial ports of described USB transmission interface changes the employing of USB mouth chip is PL2303, what described microprocessor adopted is single-chip microcomputer, and its model is STC89C52; First sonic sensor is connected with the input end of preamplifier U1, the output terminal of preamplifier U1 is connected with an end of the input port A0 of A/D converter U3 and the 4th resistance R 4, the 5th resistance R 5 respectively through the 3rd resistance R 3, the other end of the 4th resistance R 4 is connected with power supply, and the other end of the 5th resistance R 5 is connected with ground; Second sound wave sensor is connected with the input end of preamplifier U2, the output terminal of preamplifier U2 is connected with an end of the input port A1 of A/D converter U3 and the 7th resistance R 7, the 8th resistance R 8 respectively through the 6th resistance R 6, the other end of the 7th resistance R 7 is connected with power supply, and the other end of the 8th resistance R 8 is connected with ground; The power input mouth REF-of A/D converter U3 is connected with ground, the power input mouth REF+ of A/D converter U3 is connected with voltage-reference, and output port CLK, the DIN of A/D converter U3, DOUT are connected with data transmission port P2.5, P2.4, P2.3 and the P2.2 of single-chip microcomputer U5 respectively with/CS; The output terminal of reset circuit is connected with the reseting port RESET of single-chip microcomputer U5, reading and writing port TXD, the RXD of single-chip microcomputer U5 is connected with reading and writing port TXD, the RXD of serial ports commentaries on classics USB mouth chip U4 respectively, and the output port that serial ports changes USB mouth chip U4 is connected with upper-position unit through USB interface J1.

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