阅读说明：本技术 一种矿井中的风量测量装置和测量方法 (Air quantity measuring device and method in mine ) 是由 陈杏藩 刘一石 于 2021-07-05 设计创作，主要内容包括：本发明公开了一种矿井中的风量测量装置和测量方法。光电转换与计算模块置于井上,传感测量模块置于井下,光电转换与计算模块和传感测量模块之间通过传递模块通信连接；传感测量模块的光纤固定于固定装置靠近矿井中来风的端面；传递模块的固定装置和金属外壳固接,传递模块的光纤和传感测量模块的光纤电连接,传递模块的光纤上端延伸到井上并和光电转换与计算模块连接；装置放置于井口在风速标定后进行多点风速测量。本发明实现井口截面的分布式通风量测量,可针对于湍流等截面风速分布不均匀的通风口的通风量的测量,保证了通风口的安全。(The invention discloses an air quantity measuring device and an air quantity measuring method in a mine. The photoelectric conversion and calculation module is arranged on the well, the sensing measurement module is arranged under the well, and the photoelectric conversion and calculation module and the sensing measurement module are in communication connection through the transmission module; the optical fiber of the sensing measurement module is fixed on the end face of the fixing device, which is close to the incoming wind in the mine; the fixing device of the transmission module is fixedly connected with the metal shell, the optical fiber of the transmission module is electrically connected with the optical fiber of the sensing measurement module, and the upper end of the optical fiber of the transmission module extends to the well and is connected with the photoelectric conversion and calculation module; the device is placed at a wellhead and carries out multi-point wind speed measurement after wind speed calibration. The invention realizes the distributed ventilation volume measurement of the cross section of the wellhead, can measure the ventilation volume of the ventilation opening with uneven wind speed distribution on the cross section of turbulence and the like, and ensures the safety of the ventilation opening.)

1. The utility model provides an amount of wind measuring device in mine which characterized in that: the device comprises a photoelectric conversion and calculation module (1), a transmission module (2) and a sensing measurement module (3), wherein the photoelectric conversion and calculation module (1) is arranged above the well, the sensing measurement module (3) is arranged under the well, and the photoelectric conversion and calculation module (1) and the sensing measurement module (3) are in communication connection through the transmission module (2);

the sensing measurement module (3) comprises a fixing device (301) and an optical fiber (302), the fixing device (301) is arranged along a plane perpendicular to the depth direction of the mine, and the optical fiber (302) is fixed on the end face, close to the incoming wind in the mine, of the fixing device (301);

the transmission module (2) comprises an optical fiber (201) and a shell (202), wherein the optical fiber (201) is sleeved in the shell (202); the lower end of the optical fiber (201) of the transfer module (2) is optically connected with one end of the optical fiber (302) of the sensing measurement module (3), and the upper end of the optical fiber (201) of the transfer module (2) extends to the ground and is connected with the photoelectric conversion and calculation module (1).

2. An air volume measuring device in a mine according to claim 1, characterized in that: the photoelectric conversion and calculation module (1) comprises a light source driving module (101), a light source (102), a 2 x 2 port optical coupler (103) and a photoelectric detector (104); the light source driving circuit (101) is connected with the light source (102), the light output end of the light source (102) is connected with one end of one side of the 2 x 2 optical coupler (103), the other end of one side of the 2 x 2 optical coupler (103) is connected with the photoelectric detector (104), and one end of the other side of the 2 x 2 optical coupler (103) is connected with the transmission module (2) through the optical fiber connecting port (107).

3. An air volume measuring device in a mine according to claim 1, characterized in that:

the LED illumination system also comprises a circuit resolving module (105) and a wireless WiFi transmission module (106), wherein the light source driving circuit (101) and the photoelectric detector (104) are connected to the circuit resolving module (105), and the circuit resolving module (105) is connected with an external computer through the wireless WiFi transmission module (106).

4. An air volume measuring device in a mine according to claim 1, characterized in that:

the fixing device (301) and the optical fiber (302) are both in a plane thread shape, and the plane where the plane thread is located is perpendicular to the depth direction of the mine.

5. An air volume measuring method in a mine applied to the device of any one of claims 1 to 4, characterized in that: the method comprises the following steps:

step 1: measuring wind speed and calibrating;

step 2: and (4) a method for measuring air volume.

6. The method for measuring the air volume in the mine shaft according to claim 4, wherein:

the step 1: measuring wind speed calibration, specifically:

step 1.1: simultaneously applying stress to the starting end and the terminating end of the optical fiber (302) in the sensing measurement module (3) and keeping the stress; a light source (102) emits a pulse light beam and starts timing, a backscattering light intensity signal generated after the pulse light beam backscatters in an optical fiber (302) in a sensing measurement module (3) is detected by a photoelectric detector (104), and the backscattering signal is analyzed to obtain the time t when the backscattering signal generated respectively reaching a starting end and a terminating end is detected by the photoelectric detector (104)_a,t_bRespectively as starting point time t_aAnd end time t_b；

Step 1.2: stress is relieved, the light source (102) emits pulse light beams and starts timing, backscattered light intensity signals generated after the pulse light beams are backscattered by the optical fiber (302) in the sensing and measuring module (3) are detected by the photoelectric detector (104), and the moment t of the starting end is collected_aAnd end time t_bAnd fitting a backscatter signal output function f (t) between the starting end and the terminating end according to the backscatter signals at the plurality of moments between the starting end and the terminating end by inputting the following formula:

f(t)＝k(t-t_a)+1

wherein, the backscattering signal output function f (t) represents the backscattering signal at the t moment relative to the starting point moment t under the fitting condition_aFitting power intensity ratio of the backscattering signals, t represents the current moment, and k represents an optical fiber transmission attenuation coefficient;

step 1.3: the sensing measurement module (3) is placed in a wind speed box with standard wind speed, and the wind speed box is opened to generate constant wind speed;

step 1.4: a light source (102) emits a pulse light beam and starts timing, a backscattering light intensity signal generated after the pulse light beam backscatters in an optical fiber (302) in a sensing measurement module (3) is detected by a photoelectric detector (104) to obtain a starting end time t_aAnd end time t_bThe backscattering signals at a plurality of moments in between are used as calibrated backscattering signals g (t);

step 1.5: calculating the normalized backscattering intensity corresponding to the stress between the starting end and the terminating end by adopting the following formula according to the calibrated backscattering signal g (t) and the backscattering signal output function f (t):

wherein the content of the first and second substances,representing the normalized backscatter intensity at time t in the actual situation;

step 1.6: calculating the wind speed in the wind speed box and the backscattering intensity of the total normalization functionThe scaling factor of (1);

step 1.7: and (3) repeating the step 1.3-1.6 for multiple times, changing the wind speed of the wind speed box in the step 1.3, and performing multiple tests, wherein the average value of the scale factor K is taken as a final scale factor.

7. The method for measuring the air volume in the mine shaft according to claim 4, wherein:

the step 2: the method for measuring the air volume specifically comprises the following steps:

step 2.1: the sensing measurement module (3) is placed at a ventilation port of a mine;

step 2.2: a light source (102) emits a pulse light beam and starts timing, a backscattering light intensity signal generated after the pulse light beam backscatters in an optical fiber (302) in a sensing measurement module (3) is detected by a photoelectric detector (104) to obtain the backscattering light intensity signalSet start time t_aAnd end time t_bThe backscattering signal of the time between is used as the backscattering signal g to be measured_m(t)；

Step 2.3: according to the scale factor K obtained in the step 1, a backscattering signal g to be detected_m(t) substituting the following formula to calculate the air volume V of the mine hole in unit time:

wherein S is the sectional area of the mine air duct.

Technical Field

The invention relates to an air quantity measuring device and method in the field of mine detection equipment, in particular to an air quantity measuring device, a calibration method and a measuring method in a mine.

Background

China is one of the most abundant countries in the world where coal storage is available. Coal resources are an important source of energy in China at present and also an important guarantee for the national famous economic development of China. However, the development environment in the mine is very severe, toxic gas, particle dust and the like may be generated in the development process, and the temperature and humidity conditions in the mine are also very severe. Therefore, in the process of mining the mine, the monitoring of the ventilation volume is very important work, which not only can ensure the life safety of miners, but also can improve the working environment quality of the miners.

The traditional air quantity detection system can be divided into a mechanical type, an electronic type and a pitot tube type according to the working principle, and has obvious defects when being applied to the mine environment. The mechanical anemometer has complex wind speed measurement steps, the accuracy of test data depends on the technical level of a wind meter, and the test data has artificial errors and is uncontrollable. Electronic type usually utilizes the thermocouple, measures the wind speed according to the change of probe temperature, and gas such as carbon monoxide, methane can exist in the mine, has very big negative effect to the safety of mine. And because the air volume is calculated by measuring the single-point air speed, the measurement result is inaccurate due to the influence of air turbulence in the complex environment of mine ventilation. The pitot tube has a complex measuring structure, and is easy to block and corrode in a dusty environment such as a mine ventilation opening.

The distributed acoustic wave detection system (DAS) has the advantages of wide monitoring range, continuous distribution, large response bandwidth, adaptability to severe environment and the like, and long-distance distributed measurement is carried out by utilizing back-scattered signals in optical fibers. The method is applied to ultra-long-distance environment monitoring and monitors the change of the external environment.

The actual position of the object strain is judged through the time difference of the back scattering, and after the distance L in the optical fiber and the self-pulse light are emitted, the detection time t of the back scattering signal of the point has the following relation:

L＝t·c/n

where c is the speed of light in vacuum and n is the effective index of refraction of a mode when light is transmitted through the fiber in that mode.

In the daily practice process, the following disadvantages in the background art are found:

1. the traditional technology estimates the air volume through single-point wind speed, and does not consider a method for measuring the air volume under the condition that turbulent flow exists in a mine.

2. In the traditional technology, an electronic device exists at a measuring tuyere, and the explosion risk exists in the extreme environment of a mine.

Disclosure of Invention

The invention aims to provide a wind speed measuring device and a wind speed measuring method in a mine, which aim to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides an amount of wind measuring device in mine:

the underground photoelectric conversion and calculation system comprises a photoelectric conversion and calculation module, a transmission module and a sensing measurement module, wherein the photoelectric conversion and calculation module is arranged on the ground, the sensing measurement module is arranged underground, and the photoelectric conversion and calculation module and the sensing measurement module are in communication connection through the transmission module;

the sensing measurement module comprises a fixing device and an optical fiber, the fixing device is arranged along a plane perpendicular to the depth direction of the mine, and the optical fiber is fixed on the end face, close to the incoming wind in the mine, of the fixing device; in the specific implementation, the wind in the mine is blown from bottom to top, the optical fiber is arranged on the bottom surface of the fixing device, and therefore the wind blows from bottom to top to apply stress to the optical fiber so as to realize wind speed measurement.

The transmission module comprises an optical fiber and a shell, the optical fiber is sleeved in the shell, the transmission module extends downwards to enter the underground and is electrically connected with the sensing measurement module, and the fixing device is fixedly connected with the shell so that the optical fiber of the transmission module is supported and fixed with the optical fiber of the sensing measurement module; the lower end of the optical fiber of the transmission module is optically connected with one end of the optical fiber of the sensing measurement module, and the upper end of the optical fiber of the transmission module extends to the ground and is connected with the optical fiber connection port of the photoelectric conversion and calculation module.

The photoelectric conversion and calculation module comprises a light source driving module, a light source, a 2 x 2 port optical coupler and a photoelectric detector; the light source driving circuit is connected with the light source, the light output end of the light source is connected with one end of one side of the 2 x 2 optical coupler, the other end of one side of the 2 x 2 optical coupler is connected with the photoelectric detector, and one end of the other side of the 2 x 2 optical coupler is connected with the transmission module through the optical fiber connection port.

The light source driving circuit and the photoelectric detector are connected to the circuit resolving module, and the circuit resolving module is connected with an external computer through the wireless WiFi transmission module. The circuit calculation module 105 employs a programmable computing chip. The wireless WiFi transmission module can be replaced by a wired information transmission module or a field monitoring module.

The fixing device and the optical fiber are both in a plane thread shape, and the plane where the plane thread is located is perpendicular to the depth direction of the mine.

Secondly, an air quantity measuring method in a mine comprises the following steps:

step 1: measuring wind speed and calibrating;

step 2: and (4) a method for measuring air volume.

The step 1: measuring wind speed calibration, specifically:

step 1.1: simultaneously applying stress to the starting end and the terminating end of the optical fiber in the sensing measurement module and keeping the stress; the light source emits a pulse light beam and starts timing, a backscattering light intensity signal generated after the pulse light beam backscatters at each position of an optical fiber in the sensing and measuring module is detected by the photoelectric detector, and the backscattering signal is analyzed to obtain the time t when the backscattering signal generated when the backscattering signal respectively reaches the starting end and the ending end is detected by the photoelectric detector_a，t_bRespectively as starting point time t_aAnd end time t_b；

Step 1.2: releasing stress, emitting pulse light beam by light source and starting timing, detecting the backscattered light intensity signal generated by backscattering the pulse light beam at each position of the optical fiber in the sensing and measuring module by photoelectric detector, and collecting the time t of the starting end_aAnd end time t_bAnd fitting a backscatter signal output function f (t) between the starting end and the terminating end according to the backscatter signals at the plurality of moments between the starting end and the terminating end by inputting the following formula:

f(t)＝k(t-t_a)+1

wherein, the backscattering signal output function f (t) represents the backscattering signal at the t moment relative to the starting point moment t under the fitting condition_aFitted power intensity ratio of the backscattered signal, i.e. f (t)_a)＝1，f(t_b) Less than 1; t denotes the current time, k denotesAn optical fiber transmission attenuation coefficient;

step 1.3: the sensing measurement module is placed in a wind speed box with standard wind speed, and the wind speed box is opened to generate constant wind speed;

step 1.4: the light source emits a pulse light beam and starts timing, a backscattering light intensity signal generated after the pulse light beam backscatters at each position of an optical fiber in the sensing and measuring module is detected by the photoelectric detector, and the moment t of the starting end is collected_aAnd end time t_bThe backscatter signals at a plurality of time instants in between are taken as calibrated backscatter signals g (t) and are expressed by discrete functions;

step 1.5: calculating the normalized backscattering intensity corresponding to the stress between the starting end and the terminating end by adopting the following formula according to the calibrated backscattering signal g (t) and the backscattering signal output function f (t):

wherein the content of the first and second substances,representing the normalized backscatter intensity at time t in the actual situation;

step 1.6: calculating the wind speed in the wind speed box and the backscattering intensity of the total normalization functionThe scaling factor of (1);

step 1.7: and (3) repeating the step 1.3-1.6 for multiple times, changing the wind speed of the wind speed box in the step 1.3, and performing multiple tests, wherein the average value of the scale factor K is taken as a final scale factor.

Different wind speeds have different scale factors K.

The step 2: the method for measuring the air volume specifically comprises the following steps:

step 2.1: the sensing measurement module is placed at a ventilation port of a mine;

step 2.2: the light source emits a pulse light beam and starts timing, a backscattering light intensity signal generated after the pulse light beam backscatters at each position of an optical fiber in the sensing and measuring module is detected by the photoelectric detector, and the moment t of the starting end is collected_aAnd end time t_bThe backscattering signal of the time between is used as the backscattering signal g to be measured_m(t) the waveforms of the data detected by the FPGA are shown in FIG. 5(5) and are expressed by discrete functions;

step 2.3: according to the scale factor K obtained in the step 1, a backscattering signal g to be detected_m(t) substituting the following formula to calculate the air volume V of the mine hole in unit time:

wherein S is the sectional area of the mine air duct.

According to the invention, the wind speed measuring device in the mine is set up and placed at the wellhead to carry out multi-point wind speed measurement, so that the wind speed integral of the wind port can be further calculated according to the wind speed to obtain the ventilation volume of the wellhead.

Compared with the prior art, the invention has the beneficial effects that:

due to the adoption of the technical means, the method effectively solves the problem that the air quantity is estimated through single-point air speed in the background technology, and a method for measuring the air quantity under the condition that turbulent flow exists in a mine is not considered. The wind speed signal in a larger range is obtained by carrying out integral calculation through a longer optical fiber coil, and the condition of the actual ventilation volume can be reflected better.

Meanwhile, the invention effectively solves the problem that electronic devices exist in the air port in the prior art, all the charged elements are moved out of the air port, and the charged elements are connected with the sensor through optical fibers, so that the explosion risk of carbon monoxide or methane in the air port is avoided.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only one embodiment of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1: the system structure schematic diagram of the air quantity measuring device in the mine;

FIG. 2: a schematic diagram of a computing module structure;

FIG. 3: a schematic three-dimensional structure diagram of the transmission module;

FIG. 4: a schematic diagram of a measurement module structure;

FIG. 5: and the measurement result and the resolving process waveform are shown schematically.

In the figure: the device comprises a photoelectric conversion and calculation module (1), a transmission module (2) and a sensing measurement module (3); the device comprises a light source driving module (101), a light source (102), a 2 x 2 port optical coupler (103), a photoelectric detector (104), a circuit calculating module (105), a wireless WiFi transmission module (106) and an optical fiber connecting port (107); an optical fiber (201), a housing (202); a fixing device (301) and an optical fiber (302).

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

as shown in fig. 1, the invention comprises a photoelectric conversion and calculation module 1, a transmission module 2 and a sensing measurement module 3, wherein the photoelectric conversion and calculation module 1 is arranged on the well, the sensing measurement module 3 is arranged under the well, and the photoelectric conversion and calculation module 1 and the sensing measurement module 3 are in communication connection through the transmission module 2;

as shown in fig. 4, the sensing and measuring module 3 includes a fixing device 301 and an optical fiber 302, the fixing device 301 is disposed along a plane perpendicular to the depth direction of the mine, and the optical fiber 302 is fixed on an end face of the fixing device 301 close to the incoming wind in the mine; the optical fiber 302 is fixed to the fixing device 301 by applying an adhesive and then irradiating ultraviolet. In particular, when a small diameter single mode fiber is used, the fiber diameter d_fThe width of the fixture 301 may be twice the diameter of the optical fiber, and the width d of the fixture 301 may be 250 μm. The air flow area is 80 times the width of the fixing device 301 and is a2 cm. The number of turns is determined by the diameter of the hole.

In the specific implementation, the wind in the mine flows from bottom to top, and the optical fiber 302 of the present invention is disposed on the bottom surface of the fixing device 301, so that the wind flows from bottom to top to apply pressure to the optical fiber 302, thereby realizing wind speed measurement.

As shown in fig. 4, the fixing device 301 and the optical fiber 302 may be both provided with a planar thread shape, so that the sensing and measuring module 3 is a planar thread shape as a whole, and a plane of the planar thread is perpendicular to the depth direction of the mine.

As shown in fig. 3, the transmission module 2 includes an optical fiber 201 and a housing 202, the optical fiber 201 is sleeved in the housing 202, and the optical fiber 201 is placed in the housing 202 to avoid damage. Meanwhile, the optical fiber 201 is fixed on the shell 202 in a segmented mode, and negative effects caused by tension generated by gravity on the optical fiber are avoided. The transmission module 2 extends downwards to enter the underground to be optically connected with the sensing measurement module 3, the lower end of the optical fiber 201 of the transmission module 2 is optically connected with one end of the optical fiber 302 of the sensing measurement module 3, and the upper end of the optical fiber 201 of the transmission module 2 extends to the well and is connected with the optical fiber connection port 107 of the photoelectric conversion and calculation module 1.

The fixing device 301 is fixedly connected to the housing 202, so that the optical fiber 201 of the transmission module 2 and the optical fiber 302 of the sensing and measuring module 3 are supported and fixed. The implementation can be to provide a reinforcing structure between the transmission module 2 and the sensing and measuring module 3, and the two ends of the reinforcing structure are respectively welded with the fixing device 301 and the housing 202, so as to reduce the vibration of the sensing and measuring fixing device 301 under the wind speed.

As shown in fig. 2, the photoelectric conversion and calculation module 1 includes a light source driving module 101, a light source 102, a 2 × 2 port optical coupler 103, and a photodetector 104; the light source driving circuit 101 is connected to the light source 102, the light output end of the light source 102 is connected to one end of one side of the 2 × 2 optical coupler 103, the other end of one side of the 2 × 2 optical coupler 103 is connected to the photodetector 104, one end of the other side of the 2 × 2 optical coupler 103 is connected to the transmission module 2 through the optical fiber connection port 107, the transmission module 2 is an optical fiber, and the other end of the other side of the 2 × 2 optical coupler 3 is used as a blank port and is connected to a pigtail. The optical time domain reflectometer module is mainly composed of a light source driving circuit 101, a light source 102, a 2 × 2 optical coupler 103, a photoelectric detector 104 and a circuit calculating module 105.

The specific implementation further comprises a circuit calculation module 105 and a wireless WiFi transmission module 106, the light source driving circuit 101 and the photoelectric detector 104 are connected to the circuit calculation module 105, and the circuit calculation module 105 is connected with an external computer through the wireless WiFi transmission module 106. The circuit calculation module 105 employs a programmable computing chip. The wireless WiFi transmission module 106 may be replaced with a wired information transmission module or a field monitoring module.

The circuit calculating module 105 controls the light source driving module 101 to drive the light source 102 to emit pulsed light to enter the 2 × 2 optical coupler 103, the pulsed light is transmitted to the optical fiber connection port 107 through the 2 × 2 optical coupler 103, the light emitted by the optical fiber connection port 107 is transmitted to the optical fiber 302 of the sensing and measuring module 3 through the optical fiber 201 of the transmission module 2, the light generates backscattered light intensity signals at each position inside the optical fiber during transmission along the optical fiber 302 of the sensing and measuring module 3, the backscattered light intensity signals are reversely reflected back to the 2 × 2 optical coupler 103, and then the backscattered light intensity signals are transmitted to the photodetector 104 through the 2 × 2 optical coupler 103 to be detected and received.

And sending signals detected and received by the photoelectric detector 104 to the circuit calculating module 105 for calculating the air volume per unit time through the mine, judging whether the ventilation volume meets a threshold value or not, and sending the ventilation volume to an external computer through the wireless WiFi transmission module 106.

The light transmitted to each position of the optical fiber 302 generates a back scattering light intensity signal, and the time for generating the back scattering light intensity signal is earlier the closer the position of the optical fiber 302 is to the 2 × 2 optical coupler 103, the shorter the optical path the back scattering light intensity signal passes through, and the earlier the time for detecting the back scattering light intensity signal is received.

The back scattering light intensity signals generated by the optical fibers 302 are different due to different wind speeds and different pressures applied to the optical fibers 302, and generate larger amplitude value changes, the photoelectric detector 104 detects and receives signals at different moments to judge the change of the back scattering light intensity signals, so that the source and the condition of the back scattering light intensity signals are determined, and the wind speed condition and the position are further judged.

The embodiment of the invention and the implementation condition are as follows:

step 1: measuring wind speed and calibrating:

step 1.1: simultaneously applying stress to the starting end and the terminating end of the optical fiber 302 in the sensing and measuring module 3 and maintaining the stress; the light source 102 emits a pulse light beam and starts timing, the output function of the pulse light beam emitted by the light source is shown in fig. 5(1), a backscattered light intensity signal generated after the pulse light beam is backscattered from each position of the optical fiber 302 in the sensing and measuring module 3 is detected by the photoelectric detector 104, the data waveform is shown in fig. 5(3), and the backscattered signal is analyzed to obtain the time t when the backscattered signal generated respectively reaching the start end and the end is detected by the photoelectric detector 104_a,t_bRespectively as starting point time t_aAnd end time t_b；

Step 1.2: the stress is relieved, the light source 102 emits a pulse light beam and starts timing, a backscattered light intensity signal generated after the pulse light beam is backscattered from each position of the optical fiber 302 in the sensing and measuring module 3 is detected by the photoelectric detector 104, and the moment t of the starting end is acquired_aAnd end time t_bThe collected light intensity waveforms of the backscattered signals at different times are shown in fig. 5(2) under the conditions that the external environment is not changed and the fiber backscattered signals and the attenuation are uniform.

According to the backscattering signals of a plurality of moments between the starting end and the terminating end, inputting the following formula, and fitting a backscattering attenuation rate function k between the starting end and the terminating end:

f(t)＝k(t-t_a)+1

wherein f (t) represents the backscatter signal at time t relative to t under fitting conditions_aThe fitted power intensity ratio of the time-of-day backscatter signal, i.e., f (t)_a)＝1，f(t_b) Less than 1; t represents the current time, k represents the optical fiber transmission attenuation coefficient;

step 1.3: the sensing measurement module 3 is placed in a wind speed box with standard wind speed, and the wind speed box is opened to generate constant wind speed;

step 1.4: the light source 102 emits a pulse beam and starts timing, and the pulse beam generates backward scattering at the position of the optical fiber 302 in the sensing and measuring module 3The scattered light intensity signal is detected by the photoelectric detector 104 and the time t of the starting end is collected_aAnd end time t_bThe backscatter signals at a plurality of time instants in between are used as a calibrated backscatter signal gt and are expressed by discrete functions, and the data waveform is shown as (4) in fig. 5;

step 1.5: calculating the normalized backscattering intensity corresponding to the stress between the starting end and the terminating end by adopting the following formula according to the calibrated backscattering signal gt and a backscattering signal output function f (t):

wherein the content of the first and second substances,representing the normalized backscatter intensity at time t in the actual situation;

step 1.6: calculating the wind speed in the wind speed box and the backscattering intensity of the total normalization functionThe scaling factor of (1);

step 1.7: and when the data signal of the detector is stable to be the bottom noise, repeating the steps 1.1-1.6 for a plurality of times to perform a plurality of tests, and taking the average value of the scale factor K as the final scale factor.

Step 2: a method for measuring wind speed.

Step 2.1: the sensing measurement module 3 is placed at the ventilation port of the mine;

step 2.2: the light source 102 emits a pulse light beam and starts timing, a backscattered light intensity signal generated after the pulse light beam is backscattered from each position of the optical fiber 302 in the sensing and measuring module 3 is detected by the photoelectric detector 104, and the time t of the starting end is acquired_aAnd end time t_bBack scattered signal at a plurality of time instants in betweenAs the back-scattered signal g to be measured_mt, expressed by discrete functions, the data waveform detected by the FPGA is shown in figure 5 (5);

step 2.3: according to the scale factor K obtained in the step 1, a backscattering signal g to be detected_mSubstituting t into the following formula to calculate the air volume V of the mine hole in unit time:

wherein S is the sectional area of the mine air duct.

On the basis of the invention, the following can be further expanded, including changing the support structure of the system.

Therefore, the optical fiber is wound and arranged on the end face of the vent, so that the distributed ventilation quantity measurement of the cross section of the wellhead can be realized, and the method has obvious advantages compared with the traditional single-point ventilation quantity measurement, and particularly aims at measuring the ventilation quantity of the vent with uneven wind speed distribution on cross sections such as turbulence and the like. Meanwhile, no electronic element is arranged in the well, so that the safety of the vent is greatly guaranteed.

The above disclosure is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of changes or modifications within the technical scope of the present invention, and shall be covered by the scope of the present invention.