阅读说明：本技术 用于煤矿井下的采空区高温火区位置声波探测方法及系统 (Method and system for acoustic detection of high-temperature fire zone position of goaf under coal mine ) 是由 孔彪 陆伟 程卫民 亓冠圣 贺正龙 李金亮 胡相明 曹英嘉子 李家亮 于 2019-09-20 设计创作，主要内容包括：本发明提供了一种用于煤矿井下的采空区高温火区位置声波探测方法及系统,涉及矿井安全技术领域,利用采空区煤岩体升温及煤自燃产生的声波信号判断高温异常区域位置的方法。包括确定接收声波信号的最佳频率,并布置声波传感器测点,再实时计算每个测点处的声波信号强度平均值判断自燃危险程度,通过分析声波强度的变化斜率判断自燃危险程度的变化趋势,并且通过克里金插值法进行自燃煤层高温火区位置的反演,实现高温火区定位；该方法通过声波探测系统进行实现,包括声波传感器模块、数字化监测传输模块、声波数据分析模块、存储模块和显示模块；实现了快捷、低成本、高精度的确定矿井采空区高温异常区域,并用于分析煤层自燃的发生和发展过程。(The invention provides a method and a system for detecting sound waves of a high-temperature fire zone position of a goaf under a coal mine, relates to the technical field of mine safety, and discloses a method for judging the position of a high-temperature abnormal zone by using sound wave signals generated by coal rock mass temperature rise and coal spontaneous combustion of the goaf. Determining the optimal frequency of a received sound wave signal, arranging sound wave sensor measuring points, calculating the mean value of the sound wave signal intensity at each measuring point in real time to judge the spontaneous combustion danger degree, judging the variation trend of the spontaneous combustion danger degree by analyzing the variation slope of the sound wave intensity, and carrying out inversion on the position of a high-temperature fire zone of the spontaneous combustion coal bed by a Krigin interpolation method to realize the positioning of the high-temperature fire zone; the method is realized by an acoustic wave detection system, and comprises an acoustic wave sensor module, a digital monitoring transmission module, an acoustic wave data analysis module, a storage module and a display module; the method and the device can be used for quickly, low-cost and high-precision determination of the high-temperature abnormal area of the mine goaf and analysis of the occurrence and development processes of spontaneous combustion of the coal bed.)

1. A method for detecting the acoustic wave at the position of a high-temperature fire zone in a goaf under a coal mine is characterized by comprising the following steps,

determining the optimal frequency of a received sound wave signal, and arranging measuring points of a sound wave sensor;

step two, calculating the average value of the sound wave signal intensity at the measuring point of each sound wave sensor in real time, and judging the spontaneous combustion risk degree;

and step three, analyzing the change slope of the sound wave intensity to determine the change trend of the spontaneous combustion danger degree, and carrying out inversion on the position of the high-temperature fire zone of the spontaneous combustion coal bed by a Krigin interpolation method to locate the position of the high-temperature fire zone.

2. The acoustic detection method for the high-temperature fire zone position of the goaf under the coal mine according to claim 1, wherein the arrangement of the measuring points of the acoustic sensor is determined according to hydrogeological conditions of a coal seam, spontaneous combustion characteristics of a coal body and temperature rise acoustic characteristics of coal rocks, and the temperature rise acoustic characteristics of the coal rocks are determined through a coal rock temperature rise acoustic test; and determining the optimal frequency, the test distance and the test point arrangement of the received acoustic signals according to the hydrogeological conditions, the coal spontaneous combustion characteristics and the coal rock temperature rise acoustic characteristics.

3. The method for detecting the position of the high-temperature fire zone in the goaf under the coal mine according to claim 1, wherein the arrangement of the measuring points of the acoustic wave sensor comprises the arrangement of the measuring points in the stoping process and the arrangement of the acoustic wave detecting measuring points in a closed region, and the acoustic wave sensor is arranged at the measuring points of the acoustic wave sensor.

4. The method for detecting the acoustic wave at the high-temperature fire zone position of the goaf under the coal mine according to claim 3, wherein the arrangement of the measuring points in the stoping process is as follows:

A. setting acoustic wave sensor measuring points at two positions where two stoping roadways and a working face hydraulic support intersect, and respectively setting 2 acoustic wave sensor measuring points in each stoping roadway, wherein each acoustic wave sensor is provided with a metal cover;

B. connecting the sound wave sensor and the detection host, testing the interference sound wave signal, and shielding the interference sound wave signal;

C. the detection host machine collects and records the parameters of the acoustic wave sensor, and the acoustic wave sensor and the detection host machine move along with the propulsion of the working face and test along the propulsion direction of the working face.

5. The method for detecting the acoustic wave at the high-temperature fire zone position of the goaf under the coal mine according to claim 3, wherein the arrangement of the acoustic wave detection points in the closed area is as follows:

a. arranging the acoustic wave sensor in the drill hole for acoustic wave directional detection by using a detection drilling machine and a directional drill rod outside the closed area;

b. connecting the sound wave sensor and the detection host, testing the interference sound wave signal, and shielding the interference sound wave signal;

c. and the detection host collects and records the parameters of the acoustic wave sensor.

6. A sound wave detection system for a high-temperature fire zone position of a goaf under a coal mine is characterized by comprising a sound wave sensor module, a digital monitoring and transmitting module, a sound wave data analysis module, a storage module, a communication module and a display module; the sound wave sensor module is arranged at a measuring point of the sound wave sensor, and the digital monitoring transmission module, the sound wave data analysis module, the storage module, the communication module and the display module are integrated into a detection host; the sound wave sensor module receives sound wave signals of a detection area, and the detection host judges the danger and the position of the detection area; the acoustic wave sensor module and the detection host are used for realizing the steps of the acoustic wave detection method for the high-temperature fire zone position of the goaf under the coal mine according to any one of claims 1 to 5.

7. The acoustic detection system for the high-temperature fire zone position of the goaf in the coal mine according to claim 6, wherein the digital monitoring transmission module converts acoustic signals of a plurality of channels into digital signals and electric signals; the sound wave data analysis module analyzes the time domain and frequency domain characteristics of the sound wave data signals; the display module realizes data display, data storage and operation command input; the storage module stores the acoustic wave signals of the detection area received by the acoustic wave sensor module; the communication module realizes external communication information transmission, comprises a USB interface and is used for connecting an underground substation to further transmit data or export the data and carry out deep analysis.

8. The acoustic detection system for the high-temperature fire zone position of the goaf in the coal mine according to claim 6, wherein the frequency range of the acoustic sensor is 0-500KHz, including infrasonic signals between 0.01-20KHz, and also acoustic signals with frequency higher than 20 KHz; the outside cover of sound wave sensor is equipped with anti-interference metal shield cover, is provided with the opening on the metal shield cover, adjusts the ascending sound wave signal of opening position receipt fixed direction.

9. The acoustic detection system for the high-temperature fire zone position of the goaf under the coal mine according to claim 6, wherein the detection host transmits, converts, analyzes and stores the acoustic signals collected by the acoustic sensor module in real time, and specifically comprises: the sound wave sensor module converts the collected sound wave signals into electric signals, the digital monitoring transmission module amplifies and filters the collected sound wave signals, the sound wave signals generated by coal rock breakage are mainly filtered in the filtering process, and the sound wave signals form first-level storage; the acoustic wave data analysis module records and calculates the average value of the acoustic wave signal intensity of the measuring points of the acoustic wave sensor one by one, and judges the risk degree of spontaneous combustion of the coal bed; judging a measuring point of the acoustic wave sensor with coal bed spontaneous combustion danger, and further calculating the change slope of the acoustic wave intensity by the acoustic wave data analysis module to judge the change trend of the spontaneous combustion danger degree of the underground coal bed; and (4) carrying out inversion on the position of the underground coal seam spontaneous combustion high-temperature fire zone by a Krigin interpolation method, and judging the position of the underground coal seam spontaneous combustion high-temperature abnormal zone.

10. The acoustic detection system for the high-temperature fire zone position of the goaf under the coal mine according to claim 9, wherein the storage module is used for performing secondary storage on the analysis judgment result of the acoustic data analysis module, and the display module is used for displaying the analysis judgment result of the acoustic data analysis module in real time.

Technical Field

The invention relates to the technical field of mine safety, in particular to an acoustic wave detection method for a high-temperature fire zone position of a goaf under a coal mine and an acoustic wave detection system for realizing the method.

Background

The spontaneous combustion of coal is caused by spontaneous combustion of coal in the processes of mining, storing and transporting, the harm of the spontaneous combustion of coal is very serious, and all coal producing countries in the world are threatened by the spontaneous combustion of coal to different degrees. According to statistics, over 56% of coal seams have the characteristic of spontaneous combustion, coal spontaneous combustion poses great threat to underground production safety, in addition, the coal seams are difficult to extinguish by spontaneous combustion, and the total amount of coal lost due to coal seam spontaneous combustion exceeds 1000 million tons every year.

The detection of coal spontaneous combustion fire is the key of mine fire prevention and control, and most of the detection means commonly used at present are to judge the danger degree of fire and the position of a fire source according to the change of products such as a temperature field, an electromagnetic field, gas and the like generated in the oxidation and temperature rise process of coal. The commonly used detection methods of the fire source mainly comprise a drilling method, a geophysical prospecting method and a chemical prospecting method, wherein the drilling method is a very accurate detection method, but has high cost and is generally used as a verification method after detection; the geophysical prospecting method mainly comprises an infrared method, a remote sensing method, a transient electromagnetic method, a high-density resistivity method and the like, the chemical prospecting method mainly comprises a radon gas method, and the geophysical prospecting method and the chemical prospecting method are widely applied at present and make great progress in the aspects of detection and positioning of a coal field fire area; the method is also applied to the detection of the high-temperature abnormal area of the mine, but the high-temperature abnormal area of the mine cannot be determined quickly, with low cost and high precision at present due to the influence of the underground special environment.

The coal rock mass can release heat energy, elastic energy, electric energy, magnetic energy and the like in the damage and fracture process, and the acoustic signals are released in the form of waves in the deformation and fracture process of the coal rock mass. The coal rock sound wave detection technology can realize the positioning of a dangerous source, and the thermal damage and the breakage of the coal rock body caused by the temperature are accompanied by sound wave signals, so that the spontaneous combustion detection and the positioning of the coal bed can be realized through the sound wave signals. The wave spectrum of the sound wave is wide, wherein ultrasonic waves (higher than 20KHz) and infrasonic waves (lower than 20Hz) belong to the category of the sound wave, and the frequency and the wavelength are different. The sound wave has the advantages of longer wavelength and difficult attenuation in the transmission process, and the detection of the spontaneous combustion fire source of the mine coal through the sound wave has great advantages due to the transmission characteristic of the sound wave. At present, no detection method for determining the position of the high-temperature fire zone of the goaf under the coal mine by using sound waves is found.

Based on the above, it is desirable to provide a method and an apparatus for determining a high-temperature abnormal area of a mine quickly, with low cost and high accuracy, and analyzing the occurrence and development processes of spontaneous combustion of a coal seam.

Disclosure of Invention

The invention provides a sound wave detection method and system for a high-temperature fire zone position of a goaf under a coal mine, aiming at realizing rapid, low-cost and high-precision detection of the high-temperature fire zone position of the goaf under the coal mine and analyzing the occurrence and development processes of spontaneous combustion of a coal bed.

A method for detecting the acoustic wave of the position of a high-temperature fire zone in a goaf under a coal mine comprises the following steps,

determining the optimal frequency of a received sound wave signal, and arranging measuring points of a sound wave sensor;

step two, calculating the average value of the sound wave signal intensity at the measuring point of each sound wave sensor in real time, and judging the spontaneous combustion risk degree;

and step three, analyzing the change slope of the sound wave intensity to determine the change trend of the spontaneous combustion danger degree, and carrying out inversion on the position of the high-temperature fire zone of the spontaneous combustion coal bed by a Krigin interpolation method to locate the position of the high-temperature fire zone.

Preferably, the arrangement of the measuring points of the acoustic wave sensor is determined according to the hydrogeological condition of the coal bed, the spontaneous combustion characteristic of the coal body and the temperature rise acoustic wave characteristic of the coal rock, and the temperature rise acoustic wave characteristic of the coal rock is determined through a coal rock temperature rise acoustic wave test; and determining the optimal frequency, the test distance and the test point arrangement of the received acoustic signals according to the hydrogeological conditions, the coal spontaneous combustion characteristics and the coal rock temperature rise acoustic characteristics.

Preferably, the arrangement of the measuring points of the acoustic wave sensor comprises the arrangement of the measuring points in the stoping process and the arrangement of the acoustic wave detecting measuring points in the closed area, and the acoustic wave sensors are arranged at the measuring points of the acoustic wave sensor.

Further preferably, the arrangement of the measuring points in the extraction process is specifically as follows:

A. setting acoustic wave sensor measuring points at two positions where two stoping roadways and a working face hydraulic support intersect, and respectively setting 2 acoustic wave sensor measuring points in each stoping roadway, wherein each acoustic wave sensor is provided with a metal cover;

B. connecting the sound wave sensor and the detection host, testing the interference sound wave signal, and shielding the interference sound wave signal;

C. the detection host machine collects and records the parameters of the acoustic wave sensor, and the acoustic wave sensor and the detection host machine move along with the propulsion of the working face and test along the propulsion direction of the working face.

Further preferably, the arrangement of the closed area acoustic wave detection measuring points is specifically as follows:

a. arranging the acoustic wave sensor in the drill hole for acoustic wave directional detection by using a detection drilling machine and a directional drill rod outside the closed area;

b. connecting the sound wave sensor and the detection host, testing the interference sound wave signal, and shielding the interference sound wave signal;

c. and the detection host collects and records the parameters of the acoustic wave sensor.

A sound wave detection system for a high-temperature fire zone position of a goaf under a coal mine comprises a sound wave sensor module, a digital monitoring transmission module, a sound wave data analysis module, a storage module, a communication module and a display module; the sound wave sensor module is arranged at a measuring point of the sound wave sensor, and the digital monitoring transmission module, the sound wave data analysis module, the storage module, the communication module and the display module are integrated with the detection host; the acoustic wave sensor module receives acoustic wave signals of a detection area, and the detection host judges the danger and the position of the detection area; the acoustic wave sensor module and the detection host are used for realizing the steps of the acoustic wave detection method for the high-temperature fire zone position of the goaf under the coal mine.

It is also preferable that the digital monitoring transmission module converts the acoustic wave signals of the plurality of channels into digital signals and electrical signals; the sound wave data analysis module analyzes the time domain and frequency domain characteristics of the sound wave data signals; the display module realizes data display, data storage and operation command input; the storage module stores the acoustic wave signals of the detection area received by the acoustic wave sensor module; the communication module realizes external communication information transmission, comprises a USB interface and is used for connecting an underground substation to further transmit data or export the data and carry out deep analysis.

It is also preferred that the frequency range of the acoustic wave sensor is 0-500KHz, including infrasonic signals between 0.01-20KHz, as well as acoustic signals having frequencies above 20 KHz; the outside cover of sound wave sensor is equipped with anti-interference metal shield cover, is provided with the opening on the metal shield cover, adjusts the ascending sound wave signal of opening position receipt fixed direction.

It is also preferable that the detection host transmits, converts, analyzes and stores the acoustic wave signal collected by the acoustic wave sensor module in real time, specifically: the sound wave sensor module converts the collected sound wave signals into electric signals, the digital monitoring transmission module amplifies and filters the collected sound wave signals, the sound wave signals generated by coal rock breakage are mainly filtered in the filtering process, and the sound wave signals form first-level storage; the acoustic wave data analysis module records and calculates the average value of the acoustic wave signal intensity of the measuring points of the acoustic wave sensor one by one, and judges the risk degree of spontaneous combustion of the coal bed; judging a measuring point of the acoustic wave sensor with coal bed spontaneous combustion danger, and further calculating the change slope of the acoustic wave intensity by the acoustic wave data analysis module to judge the change trend of the spontaneous combustion danger degree of the underground coal bed; and (4) carrying out inversion on the position of the underground coal seam spontaneous combustion high-temperature fire zone by a Krigin interpolation method, and judging the position of the underground coal seam spontaneous combustion high-temperature abnormal zone.

It is also preferable that the storage module stores the analysis determination result of the acoustic wave data analysis module for the second stage, and the display module displays the analysis determination result of the acoustic wave data analysis module in real time.

The method has the advantages that the danger degree of coal spontaneous combustion is detected and judged according to the sound wave signal generated by heating and temperature rising of the coal rock by the sound wave detection method at the high-temperature fire zone position of the goaf under the coal mine, so that the method can analyze the occurrence and development process of coal spontaneous combustion in time and judge the high-temperature abnormal area of coal spontaneous combustion in space; through the unusual regional sound wave detection device of mine high temperature, can accurate detection sound wave's signal, sound wave signal propagation is difficult for receiving the interference, does not receive special environment's in the pit influence, and the accuracy is high, at the detection in-process, can convenient and fast to it is with low costs. The method can be applied to underground goafs, can also be used for underground broken coal pillars and mining working faces, and has important practical significance and economic benefit for mine fire prevention and control.

Drawings

In order to more clearly illustrate the embodiments or technical solutions of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a sound wave detection system for a high-temperature fire zone position in a goaf under a coal mine;

FIG. 2 is a schematic view of an arrangement of acoustic wave sensor measurement points;

FIG. 3 is a schematic flow chart of a method for detecting acoustic waves at a high-temperature fire zone in a goaf of an underground coal mine.

Detailed Description

Referring to fig. 1 to 3, the method and system for detecting acoustic waves at a high-temperature fire zone of a goaf in an underground coal mine provided by the invention have the following specific embodiments.

A method for detecting the acoustic wave of the position of a high-temperature fire zone in a goaf under a coal mine comprises the following steps,

step one.

And determining the optimal frequency for receiving the acoustic wave signal, and arranging the measuring points of the acoustic wave sensor.

Before the arrangement of the acoustic sensor measuring points, the hydrogeological conditions, the coal spontaneous combustion characteristics and the coal rock temperature rise acoustic characteristics of a coal bed need to be determined, wherein the coal rock temperature rise acoustic characteristics are determined through a coal rock temperature rise acoustic test; and determining the optimal frequency, the test distance and the test point arrangement of the received acoustic signals according to the hydrogeological conditions, the coal spontaneous combustion characteristics and the coal rock temperature rise acoustic characteristics.

Specifically, when an on-site test scheme is determined, the on-site test scheme needs to be formulated according to the geological conditions of a mine, the spontaneous combustion characteristics of coal and the heating acoustic wave characteristics of coal rocks; the geological conditions of the mine are analyzed according to the production profile and the hydrogeological background of the mine, so that the tested area and range are determined; the spontaneous combustion characteristic of the coal is to analyze the spontaneous combustion ignition period of the coal, the characteristic parameter change of the coal, thus have macroscopical understanding to the spontaneous combustion ignition characteristic of the goaf, the coal rock heats up the acoustic characteristic analysis and tests the coal rock temperature rise of the mine and the loaded infrasonic signal characteristic, optimum frequency in the laboratory, obtain the data base of earlier stage, test and get the concrete parameter according to the actual on-the-spot coal sample; and secondly, adjusting the acquisition frequency spectrum, the test distance and the test point arrangement of the acoustic wave sensor according to infrasound signals and frequency spectrum characteristics of a laboratory.

The arrangement of the measuring points of the acoustic wave sensor comprises the arrangement of the measuring points in the recovery process and the arrangement of the acoustic wave detection measuring points in a closed area, and the acoustic wave sensors are uniformly arranged at the measuring points of the acoustic wave sensor.

The arrangement of the measuring points in the stoping process is as follows:

A. setting acoustic wave sensor measuring points at two positions where two stoping roadways (including an air inlet roadway and an air return roadway) and a working surface hydraulic support intersect, and respectively setting 2 acoustic wave sensor measuring points in each stoping roadway, wherein the acoustic wave sensors are provided with metal covers;

B. connecting the sound wave sensor and the detection host, testing the interference sound wave signal, and shielding the interference sound wave signal;

C. the detection host machine collects and records the parameters of the acoustic wave sensor, and the acoustic wave sensor and the detection host machine move along with the propulsion of the working face and test along the propulsion direction of the working face.

When the goaf is closed, the arrangement of the acoustic detection measuring points in the closed area is as follows:

a. arranging the acoustic wave sensor in the drill hole for acoustic wave directional detection by using a detection drilling machine and a directional drill rod outside the closed area;

b. connecting the sound wave sensor and the detection host, testing the interference sound wave signal, and shielding the interference sound wave signal;

c. and the detection host collects and records the parameters of the acoustic wave sensor.

Regarding the arrangement of the measuring points of the acoustic wave sensor, taking fig. 2 as an example for further explanation, the following details are provided:

(1) when the underground is not closed, according to a formulated test scheme, firstly arranging acoustic sensors at the intersection of a machine lane (an air inlet lane, marked as 'inlet') and an air lane (a return air lane, marked as 'return') and a hydraulic support, fixing the acoustic sensors at the upper corner position, and placing 2 acoustic sensors, namely a broadband and a point-frequency sensor, in each lane; the anti-interference test is realized by adjusting the metal cover around the sensor; after the detection host is arranged, recording the positions 1 in and 1 back of the sensor; continuously testing signals in the goaf during underground maintenance; in the test process, peripheral interference sound wave signals are tested firstly, and the interference sound wave signals are further shielded; debugging the acquisition parameters of the detection host machine, and testing the acoustic wave signals in the goaf; before the working surface advances forwards, the acoustic wave sensor and the detection host are moved along the advancing direction of the working surface and are arranged forwards, and the test positions 2 in and 2 in are recorded, wherein the distance between the test point 1 and the test point 2 is 10 m. Further forward testing, points are recorded as 3 in and 3 back.

(2) When a space is sealed underground, determining a testing position according to the underground working face and the goaf position, wherein the testing position is 1-in and 1-back. And then, carrying out sound wave detection on the seal by using a detection drilling machine to carry a directional drill rod, recording sound wave test results at different positions, and carrying out analysis processing in the next step.

And step two.

And calculating the average value of the sound wave signal intensity at the measuring point of each sound wave sensor in real time, and judging the spontaneous combustion risk degree.

The sound wave data analysis module firstly filters the collected sound waves, analyzes the average value of the sound wave signals of each measuring point, analyzes the size range of the sound wave signals according to different formulated stages of coal spontaneous combustion, judges the risk degree of coal spontaneous combustion of each measuring point, and defines 3 grades according to the intensity of the sound waves, wherein the higher the intensity of the sound waves is, the higher the risk degree of coal spontaneous combustion is, and the grades of 1-3 correspond to no natural risk, potential spontaneous combustion risk and spontaneous combustion risk respectively. And the display module can display and early warn the dangers of each measuring point in real time.

And step three.

And analyzing the change slope of the sound wave intensity to determine the change trend of the spontaneous combustion danger degree, and carrying out inversion on the position of the high-temperature fire zone of the spontaneous combustion coal bed by a Krigin interpolation method to locate the position of the high-temperature fire zone.

The acoustic wave data analysis module analyzes the coal spontaneous combustion danger degree in the detection range of each measuring point, and simultaneously can analyze the dynamic change slope of the acoustic wave, when the harmonic mean value of the acoustic wave is increased in a multi-level progressive mode, the change trend of the coal spontaneous combustion danger degree in the detection area is judged, 3 grades are defined according to the slope, the higher the slope is, the higher the coal spontaneous combustion danger degree is, and the grades 1-3 correspond to no natural danger, potential spontaneous combustion danger and spontaneous combustion danger respectively. After the regional danger degree is judged in the same way, according to the test results at different test positions n 1. na, the system analyzes the sound wave intensity, calculates the main directions of the sound wave intensity of 2 test positions corresponding to the straight line in two lanes through an algorithm, so as to judge the direction of the sound wave field source, and judges the direction of the underground goaf fire source according to the method of the sound wave field source.

According to the analysis, determining the position coordinates of the coal spontaneous combustion high-temperature fire area, and carrying out inversion on the position of the coal spontaneous combustion high-temperature fire area by a Krigin interpolation method to realize the positioning of the position of the coal spontaneous combustion high-temperature fire area; the specific calculation process is that firstly, the sound wave intensity is calculated:

in the formula, Z (x)_i)^*Estimating the sound wave intensity of the point; lambda [ alpha ]_iIs the weight of the acoustic intensity; x is the number of_iThe coordinate position of the acoustic wave measuring point is shown; z (x)_i) The calculated point of the sound wave intensity is represented by the following equation:

wherein gamma (x)_i,x_j) The variation function on the acoustic wave time sequence is represented and calculated according to the variance of different measuring points, namely

μ is the Lagrange multiplier representing the time series of the acoustic wave.

The acoustic wave detection system for the high-temperature fire zone position of the goaf under the coal mine further has a danger analysis function of the mine spontaneous combustion high-temperature abnormal zone, and judges the danger and the development trend of the mine spontaneous combustion high-temperature abnormal zone by inputting the change trend rate of the harmonic average values of a plurality of different measuring points through a command button of a display module.

A sound wave detection system for a high-temperature fire zone position of a goaf under a coal mine comprises a sound wave sensor module, a digital monitoring transmission module, a sound wave data analysis module, a storage module, a communication module and a display module; the sound wave sensor module is arranged at a measuring point of the sound wave sensor, and the digital monitoring transmission module, the sound wave data analysis module, the storage module, the communication module and the display module are integrated with the detection host; the acoustic wave sensor module receives acoustic wave signals of a detection area, and the detection host judges the danger and the position of the detection area; the acoustic wave sensor module and the detection host are used for realizing the steps of the acoustic wave detection method for the high-temperature fire zone position of the goaf under the coal mine. A high-temperature fire zone position acoustic detection system for a goaf in a coal mine utilizes a fire zone formed by spontaneous combustion and continuous temperature rise of underground coal bodies to enable acoustic signals generated by a coal rock layer to be tested through an acoustic probe, and a detection host is used for analyzing the acoustic signals so as to judge the danger of an underground high-temperature abnormal area.

The digital monitoring transmission module converts the sound wave signals of the channels into digital signals and electric signals, wherein the digital monitoring transmission module comprises an A/D (analog/digital) converter, a signal amplifier and a band-pass filter. The A/D analog-to-digital converter converts the electric signal into a digital signal, the analog-to-digital converter can adopt TLC series chips, the sizes of input and output signals are required to have a linear proportional relation, the sampling rate is high, and the requirement for a central processing unit in later-stage sound wave data analysis is facilitated. The signal amplifier amplifies the sound wave signal tested by the sound wave sensor, the output power meets the requirement of the Ministry of industry and information, the automatic gain control is in a certain range, and the in-band fluctuation ratio is less than 3 dB. The signal amplifier amplifies the signal and transmits the signal to the filtering module, and the module has a secondary filtering function, wherein firstly, the stray signal is filtered, the flat sound wave signal is remained, and the signal lower than the sampling threshold is filtered.

The acoustic data analysis module analyzes time domain and frequency domain characteristics of the acoustic data signal. The sound wave data analysis module mainly comprises a central processing unit, wherein the central processing unit selects an MCS-51 series single chip microcomputer, and the clock frequency of the single chip microcomputer is required to reach more than 40MHz, so that the data processing is facilitated; because the data processing is followed by the memory module, the memory characteristics of the processor are not required to be high.

The display module realizes data display, data storage and operation command input, wherein the display module realizes data real-time display and analysis result display, and can operate and external communication through the communication module, contain the USB interface, can connect the substation in the pit and carry out transmission on next step, can carry out data derivation again. The communication module realizes external communication information transmission, comprises a USB interface and is used for connecting an underground substation to further transmit data or export the data and carry out deep analysis.

The storage module stores the sound wave signals of the detection area received by the sound wave sensor module, wherein the storage module can realize the storage of sound wave data, the storage module has a two-stage storage function, and the sound wave signals collected by the sound wave sensor are filtered out of interference signals in the external environment through a filter and are stored in a first stage; the signal analysis module analyzes and processes the filtered signals, the filtered signals are finally displayed on the display module and are subjected to secondary storage, and the acquired sound wave data can be stored through a single file to meet the 16G or larger data storage requirement.

The frequency range of the acoustic wave sensor is 0-500KHz, including infrasonic signals between 0.01-20KHz, and also acoustic signals with frequencies higher than 20 KHz. The outside cover of sound wave sensor is equipped with anti-interference metal shield cover, is provided with the opening on the metal shield cover, adjusts the opening position and receives the sound wave signal on the fixed direction.

The detection host machine is powered by an external direct-current power supply, the range of the power supply voltage is 18-9V, and the detection host machine can be continuously used for more than 6 hours. The used acoustic wave sensor can realize an anti-interference function, the metal cover capable of expanding the direction is arranged outside the acoustic wave sensor, and the acoustic wave sensor can detect the range of 0-180 degrees in front of an acoustic wave signal by adjusting the open area of the metal cover. In addition, the acoustic wave sensor includes 2 types, one is a broadband acoustic wave sensor, which receives acoustic waves with frequency between 0.01-20 KHz; one is a point-frequency acoustic wave sensor, the frequency is fixed; the dynamic response range of the two sensors is 128dB, and the two sensors can resist electromagnetic interference. The acoustic wave sensor frequency comprises 2 types, one type is a broadband acoustic wave sensor, the sensor frequency range of the acoustic wave is 0-500KHz, and the receiving frequency is an infrasonic wave signal covering 0.01-20 KHz; the sound wave signal with the frequency higher than 20KHz is covered; one is a point-frequency acoustic wave sensor, the frequency is fixed; the dynamic response range of the two sensors is 128dB, and the two sensors can resist electromagnetic interference.

In the field test process, the digital monitoring transmission system can convert the tested sound wave signals of 1-4 channels into digital signals, further convert the digital signals into electric signals in the transmission process, and the acquisition frequency can reach 0.1-500 kHz; the acoustic wave data analysis system can analyze the time domain and frequency domain characteristics of signals acquired by the system, the acquired data are stored through a single file, the system can meet the 16G data storage requirement, and the real-time analysis and processing functions can be realized; the display module is provided with a data display, a communication interface and a function button.

The detection host machine transmits, converts, analyzes and stores the sound wave signals collected by the sound wave sensor module in real time, and specifically comprises the following steps: the sound wave sensor module converts the collected sound wave signals into electric signals, the digital monitoring transmission module amplifies and filters the collected sound wave signals, the sound wave signals generated by coal rock breakage are mainly filtered in the filtering process, and the sound wave signals form first-level storage; the acoustic wave data analysis module records and calculates the average value of the acoustic wave signal intensity of the measuring points of the acoustic wave sensor one by one, and judges the risk degree of spontaneous combustion of the coal bed; judging a measuring point of the acoustic wave sensor with coal bed spontaneous combustion danger, and further calculating the change slope of the acoustic wave intensity by the acoustic wave data analysis module to judge the change trend of the spontaneous combustion danger degree of the underground coal bed; and (4) carrying out inversion on the position of the underground coal seam spontaneous combustion high-temperature fire zone by a Krigin interpolation method, and judging the position of the underground coal seam spontaneous combustion high-temperature abnormal zone. The storage module carries out secondary storage on the analysis judgment result of the sound wave data analysis module, and the display module displays the analysis judgment result of the sound wave data analysis module in real time.

It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.