Method and system for monitoring leakage of underground gas pipeline in real time

Abstract

The invention discloses a method and system for monitoring leakage of an underground gas pipeline in real time, and the method comprises the steps: generating a sawtooth wave modulation signal through a DAC (Digital-to-Analog Converter) output device, superposing the sawtooth wave modulation signal into a constant-current drive axle, and driving a 1653nm laser head to output a pulse modulation signal; the temperature control unit controls the laser diode to be at a constant temperature; laser with the wavelength of 1653 nm passes through a gas cavity containing methane gas and enters a photodiode; the algorithm unit reversely solves the concentration of methane in the gas cavity after Fourier transform; the encryption framing unit performs encryption framing on the methane concentration when the methane concentration exceeds a threshold value; the NB radio frequency module forwards the encrypted character string to the upper computer receiving unit and the underground gas supervision department mobile equipment through the base station; and the upper computer receiving unit and the mobile equipment of the underground gas supervision department decrypt and calculate to obtain related information of the equipment and the concentration of methane in the gas cavity. According to the underground gas pipeline leakage method disclosed by the invention, the leakage condition of the gas pipeline is remotely monitored in real time and early warning is performed, so that the personal and property loss risk is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of underground gas pipeline leakage detection, and relates to a method and system for real-time monitoring of underground gas pipeline leakage. Background Art

[0002] Generally, gas pipelines are buried 0.8 m deep underground. There may be leakage risks at joints or pressure-bearing parts over the years. According to different pressures of gas pipelines, the pressures can be divided into high pressure (4.0 - 1.6 Mpa), sub-high pressure (1.6 - 0.4 Mpa), medium pressure (0.4 - 0.01 Mpa), and low pressure (less than 0.01 Mpa). If there is a leakage point in the gas pipeline, there is a certain relationship between the gas concentrations at different locations within 150 m from the leakage point and the pipeline pressure, diffusion time and diffusion distance, and soil density. If a gas pipeline leaks and is not discovered and disposed of in time, it will cause inestimable explosion risks. Summary of the Invention

[0003] The present invention provides a method and system for real-time monitoring of underground gas pipeline leakage to solve the problem that it is difficult to monitor the leakage of gas pipelines in real time by existing underground gas pipeline leakage detection methods.

[0004] The present invention provides the following technical solutions:

[0005] In a first aspect, the present specification provides a method for real-time monitoring of underground gas pipeline leakage, including:

[0006] A DAC outputter 106 generates a sawtooth wave modulation signal, superimposes the sawtooth wave modulation signal into a constant current drive bridge 103, and drives a 1653 nm laser head 101 to output a pulse modulation signal;

[0007] The temperature control unit controls a laser diode in the 1653 nm laser head 101 to be at a preset constant temperature within a preset time range according to the pulse modulation signal, and the 1653 nm laser head 101 outputs a laser with a wavelength of 1653 nm;

[0008] The laser with a wavelength of 1653 nm passes through a gas chamber containing methane gas and enters a photodiode 102. The photodiode 102 converts the received laser into an electrical signal to obtain an electrical signal containing the monitored gas concentration information;

[0009] The electrical signal containing the monitored gas concentration information is amplified and sampled to obtain sampled data. An algorithm unit performs Fourier transform and inverse calculation on the sampled data to obtain the methane concentration in the gas chamber, and sends the methane concentration in the gas chamber to an encryption and framing unit 109;

[0010] The encryption framing unit 109 determines whether the methane concentration in the gas chamber exceeds a preset alarm concentration threshold. If so, it encrypts and frames the device-related information and the methane concentration in the gas chamber to obtain an encrypted string, and sends the encrypted string to the NB radio frequency module 110;

[0011] The NB radio frequency module 110 forwards the encrypted string to the host computer receiving unit 111 and the mobile device of the underground gas supervision department via the base station;

[0012] The host computer receiving unit 111 and the mobile device of the underground gas supervision department decrypt and calculate the encrypted string to obtain the device-related information and the methane concentration in the gas chamber.

[0013] In a second aspect, the present invention provides a system for real-time monitoring of underground gas pipeline leakage, including:

[0014] A pulse modulation module for controlling the DAC output 106 to generate a sawtooth wave modulation signal, superimposing the sawtooth wave modulation signal into the constant current drive bridge 103, and driving the 1653nm laser head 101 to output a pulse modulation signal;

[0015] A laser output module for controlling the temperature control unit to control the laser diode in the 1653nm laser head 101 to be at a preset constant temperature within a preset time range according to the pulse modulation signal, and the 1653nm laser head 101 outputs a laser with a wavelength of 1653nm;

[0016] A photoelectric conversion module for controlling the laser with a wavelength of 1653nm to pass through a gas chamber containing methane gas and enter the photodiode 102, and the photodiode 102 converts the received laser into an electrical signal to obtain an electrical signal containing the monitored gas concentration information;

[0017] A sampling and calculation module for amplifying and sampling the electrical signal containing the monitored gas concentration information to obtain sampling data, and the algorithm unit performs Fourier transform and inverse calculation on the sampling data to obtain the methane concentration in the gas chamber, and sends the methane concentration in the gas chamber to the encryption framing unit 109;

[0018] An encryption framing module for controlling the encryption framing unit 109 to determine whether the methane concentration in the gas chamber exceeds a preset alarm concentration threshold. If so, it encrypts and frames the device-related information and the methane concentration in the gas chamber to obtain an encrypted string, and sends the encrypted string to the NB radio frequency module 110;

[0019] An information forwarding module for controlling the NB radio frequency module 110 to forward the encrypted string to the host computer receiving unit 111 and the mobile device of the underground gas supervision department via the base station;

[0020] The decryption and calculation module is used to control the host computer receiving unit 111 and the mobile device of the underground gas supervision department to perform decryption and calculation on the encrypted string, so as to obtain the device-related information and the methane concentration in the gas chamber.

[0021] The method and system for real-time monitoring of underground gas pipeline leakage provided by the embodiments of the present invention bury the buried gas pipeline monitoring device 0.4 m above key areas such as gas pipeline joints and gas pipeline bends and within a range of 50 m around, and remotely monitor the gas pipeline leakage situation in real time, prompt early warnings in a timely manner, and reduce the risks of personal and property losses, thereby solving the problem that it is difficult to monitor the gas pipeline leakage situation in real time by the existing underground gas pipeline leakage detection methods. Brief Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the components of a system for implementing a method for real-time monitoring of underground gas pipeline leakage in an embodiment of the present invention.

[0023] Other features and advantages of the present invention will be described in the following description, and, in part, will be obvious from the description, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the written description, claims, and drawings. Detailed Embodiments

[0024] To make the objectives, technical solutions, and advantages of this specification clearer, the technical solutions of this specification will be clearly and completely described below in conjunction with specific embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this specification.

[0025] As described herein, the term "including" and its various variants can be understood as open-ended terms, which mean "including but not limited to", and the term "one embodiment" can be understood as "at least one embodiment".

[0026] The inventor found that the existing underground gas pipeline leakage detection methods have the problem of being difficult to monitor the gas pipeline leakage situation in real time. In view of this, in the embodiments of the present invention, by remotely monitoring the gas pipeline leakage situation in real time, early warnings are prompted in a timely manner, and the risks of personal and property losses are reduced.

[0027] Embodiment 1

[0028] The embodiments of the present invention provide a method for real-time monitoring of underground gas pipeline leakage. Figure 1Schematic diagram of the components of a system for executing the method, which is executed by a processor and includes the following steps:

[0029] Step 1: The DAC output 106 generates a sawtooth modulation signal, superimposes the sawtooth modulation signal into the constant current drive bridge 103, and drives the 1653nm laser head 101 to output a pulse modulation signal;

[0030] Step 2: The temperature control unit controls the laser diode in the 1653nm laser head 101 to be at a preset constant temperature within a preset time range according to the pulse modulation signal, and the 1653nm laser head 101 outputs a laser with a wavelength of 1653nm;

[0031] Step 3: The laser with a wavelength of 1653nm passes through a gas chamber containing methane gas and enters the photodiode 102. The photodiode 102 converts the received laser into an electrical signal to obtain an electrical signal containing the monitored gas concentration information;

[0032] Step 4: The electrical signal containing the monitored gas concentration information is amplified and sampled to obtain sampled data. The algorithm unit performs Fourier transform and inverse calculation on the sampled data to obtain the methane concentration in the gas chamber, and sends the methane concentration in the gas chamber to the encryption and framing unit 109;

[0033] Specifically, the TIA amplifier 104 converts the electrical signal containing the monitored gas concentration information from an nA-level current signal to an mV-level voltage signal, and sends the mV-level voltage signal to the ADC sampler 105; the ADC sampler 105 samples the mV-level voltage signal at a preset sampling frequency to obtain sampled data, and sends the sampled data to the algorithm unit 108; the algorithm unit 108 performs Fourier transform on the sampled data to obtain the sampled data after Fourier transform, and according to the Lambert-Beer law, performs inverse calculation on the sampled data after Fourier transform to obtain the emission signal amplitude and the methane concentration in the gas chamber; the preset sampling frequency is four times the frequency of the sawtooth modulation signal generated by the DAC output 106.

[0034] Step 5: The encryption and framing unit 109 determines whether the methane concentration in the gas chamber exceeds a preset alarm concentration threshold. If so, it encrypts and frames the device-related information and the methane concentration in the gas chamber to obtain an encrypted string, and sends the encrypted string to the NB radio frequency module 110;

[0035] In a specific implementation, the device-related information includes the current time, device code, real-time temperature, soil compactness, and device location.

[0036] Step Six: The NB radio frequency module 110 forwards the encrypted string to the host computer receiving unit 111 and the mobile device of the underground gas supervision department via the base station.

[0037] Step Seven: The host computer receiving unit 111 and the mobile device of the underground gas supervision department decrypt and calculate the encrypted string to obtain the device-related information and the methane concentration in the gas chamber.

[0038] In a specific embodiment, after the host computer receiving unit 111 and the mobile device of the underground gas supervision department decrypt and calculate the encrypted string to obtain the device-related information and the methane concentration in the gas chamber, the following steps are further included: The host computer receiving unit 111 obtains a predicted leak point and a large data chart of gas diffusion based on the device-related information and the methane concentration in the gas chamber; The host computer determines the leakage location and leakage concentration based on the predicted leak point and the large data chart of gas diffusion, and pops up a corresponding alarm prompt page.

[0039] Embodiment Two

[0040] The embodiment of the present invention further provides a method for real-time monitoring of underground gas pipeline leakage. This method is executed by a processor and includes the following steps:

[0041] Step One: The DAC outputter 106 generates a sawtooth wave modulation signal, which is superimposed into the constant current drive bridge 103 to drive the 1653nm laser head 101 to output a pulse modulation signal.

[0042] Step Two: The pulse modulation signal uses the temperature control unit 107 to control the semiconductor temperature control device so that the 1653nm laser head is at a constant temperature, ensuring that the laser wavelength output by the laser head is always 1653nm.

[0043] Step Three: The emitted laser monitors the gas chamber and then enters the photodiode 102 to output an electrical signal, and the electrical signal includes the monitored gas concentration.

[0044] Step Four: The electrical signal is an nA-level current signal, which is amplified by the TIA amplifier 104 and outputs an mV-level voltage signal.

[0045] Step Five: The mV-level voltage signal is sampled by the ADC sampler 105, and the sampling frequency is four times the frequency of the sawtooth wave signal, and sampling data is output.

[0046] Step Six: The sampling data is processed by the algorithm unit 108 and, through the inverse calculation using Lambert-Beer's law as shown in formula (1), outputs the amplitude of the transmitted signal and the methane concentration in the gas chamber obtained by the inverse calculation of the received signal.

[0047] Step 7: If the methane concentration is greater than the set alarm concentration, it is encrypted and framed by the encryption and framing unit 109. The encrypted frame includes the gas concentration, real-time temperature, and soil compactness.

[0048] Step 8: The encrypted framed string is forwarded to the host computer receiving unit 111 and the supervisor's mobile phone through the NB radio frequency module 110 via the base station.

[0049] Step 9: The host computer receiving unit 111 calculates the longitude, latitude, and gas concentration of the device after decryption and calculation.

[0050] Step 10: The host computer receiving unit inputs the gas concentration at multiple points, real-time temperature, preset pipeline pressure, and soil compactness into the algorithm, and outputs a prediction of the leakage point and a large data chart of gas diffusion.

[0051] Step 11: The gas diffusion chart and the predicted leakage point strongly remind relevant personnel of the predicted location of the gas leakage point.

[0052] In a specific embodiment, the absorption amount is calculated according to the following formula to invert the concentration:

[0053] I 0 (λ) = I(λ)exp(-σ(λ)NL)

[0054] I 0 (λ) - transmitted light intensity; I(λ) - incident light intensity; σ(λ) - absorption cross-section of the measured gas;

[0055] N - concentration of the measured gas; L - length of the sample cell. (1)

[0056] In specific implementation, the Lambert-Beer law and the TDLAS principle are used to measure the gas concentration above the gas pipeline. The Lambert-Beer law states that when a parallel beam of monochromatic light passes through a homogeneous non-scattering light-absorbing substance, its absorbance is proportional to the concentration of the light-absorbing substance, that is, photons of a specific wavelength carry fixed energy that can cause the outer electrons of atoms to undergo energy level transitions; TDLAS refers to tunable diode laser absorption spectroscopy, which can obtain the specific absorption spectrum range of the gas. Through theoretical calculation and multiple experiments, it can be obtained that using monochromatic light with a wavelength of 1653 nm and the method and system described herein to measure the gas concentration above the gas pipeline has the best effect, and the absorption wavelengths of other substances are relatively small; a sawtooth wave modulation signal is output through the DAC output and superimposed on a constant current source to drive a 1653 nm laser. Using the above principle, an ADC chip is used to measure the electrical signal after absorption by the photodiode, and the gas concentration is calculated after analysis by the algorithm unit.

[0057] In specific implementation, the method and system provided in this embodiment also use Internet of Things technology to remotely alarm and push the leakage location and leakage concentration to the upper computer receiving unit. That is, it is pushed to the underground gas pipeline management platform through the NB radio frequency module, marking the leakage area and real-time pushing the gas diffusion range, so as to locate the leakage point as quickly as possible to the greatest extent and protect the safety of personnel and property.

[0058] In specific implementation, the gas pipe stake burying scheme described in this embodiment includes but is not limited to: burying the gas pipe stake 0.4 m above the key area, and radiating outward from this point, and adding to bury the gas pipe stake every 50 m in a scheme parallel to the pipeline. The gas pipe stake will monitor the gas concentration in real time, and the gas concentration at each point is remotely pushed to the upper computer through the Internet of Things technology. The upper computer calculates the gas leakage location based on the gas concentration at different points, the on-site real-time temperature, the soil density and the distance from the gas monitoring point, and pops up an emergency alarm and predicts the leakage point location, strongly reminding the relevant personnel to dispose of the leakage point as required as soon as possible to reduce the loss of personnel and property.

[0059] In a specific implementation manner, as Figure 1 shown, this embodiment relates to the field of underground gas pipeline leakage detection, and particularly relates to a buried gas pipeline leakage monitoring method and system. The system includes: a 1653 nm laser head 101, a photodiode 102, a constant current drive bridge 103, a TIA amplifier 104, an ADC sampler 105, a DAC output unit 106, a temperature control unit 107, an algorithm unit 108, an encryption and framing unit 109, an NB radio frequency module 110, and an upper computer receiving unit 111.

[0060] In a specific implementation manner, the DAC output unit generates a sawtooth wave signal; the sawtooth wave signal is used as a laser excitation source and a constant current source to modulate and excite a 1653 nm laser; the temperature control unit keeps the laser diode at a constant temperature and emits monochromatic light with a wavelength of 1653 nm; after the laser is absorbed by the methane gas contained in the gas chamber, it enters the photodiode and is converted into an electrical signal; the electrical signal is amplified by the TIA amplifier and then collected by the ADC; after the collection is completed, it is Fourier-transformed by the algorithm unit to calculate the methane concentration; if the methane concentration exceeds the set value, the current time, device code, and methane concentration are framed into a string by the encryption and framing unit; the string is sent to the upper computer receiving unit and the mobile phone of the underground gas supervision department respectively through the NB radio frequency unit by text message; the upper computer pops up a page to alarm and prompt the leakage location and leakage concentration.

[0061] The above embodiment buries the buried gas pipe stake equipment at 0.4 m above the key areas such as gas pipeline joints and gas pipeline bends and within a range of 50 m around, remotely monitors the leakage of the gas pipeline in real time, and timely gives early warnings to reduce the risk of personal and property losses.

[0062] Embodiment 3

[0063] Based on the same technical concept, an embodiment of the present invention also provides a system for real-time monitoring of underground gas pipeline leakage. Since the principle of solving problems by the above system is similar to that of the method for real-time monitoring of underground gas pipeline leakage, therefore, for the implementation of the above system, reference can be made to the implementation of the method, and the repeated parts will not be elaborated.

[0064] An embodiment of the present invention provides a system for real-time monitoring of underground gas pipeline leakage, including:

[0065] A pulse modulation module, configured to control the DAC output 106 to generate a sawtooth wave modulation signal, superimpose the sawtooth wave modulation signal into the constant current drive bridge 103, and drive the 1653nm laser head 101 to output a pulse modulation signal;

[0066] A laser output module, configured to control the temperature control unit to control the laser diode in the 1653nm laser head 101 to be at a preset constant temperature within a preset time range according to the pulse modulation signal, and the 1653nm laser head 101 outputs a laser with a wavelength of 1653nm;

[0067] A photoelectric conversion module, configured to control the 1653nm wavelength laser to pass through a gas chamber containing methane gas and enter the photodiode 102, and the photodiode 102 converts the received laser into an electrical signal to obtain an electrical signal containing the monitored gas concentration information;

[0068] A sampling and solving module, configured to amplify and sample the electrical signal containing the monitored gas concentration information to obtain sampling data, and the algorithm unit performs Fourier transform and inverse solution on the sampling data to obtain the methane concentration in the gas chamber, and sends the methane concentration in the gas chamber to the encryption and framing unit 109;

[0069] An encryption and framing module, configured to control the encryption and framing unit 109 to judge whether the methane concentration in the gas chamber exceeds a preset alarm concentration threshold. If so, encrypt and frame the device-related information and the methane concentration in the gas chamber to obtain an encrypted string, and send the encrypted string to the NB radio frequency module 110;

[0070] An information forwarding module, configured to control the NB radio frequency module 110 to forward the encrypted string to the host computer receiving unit 111 and the mobile device of the underground gas supervision department through the base station;

[0071] A decryption and solving module, configured to control the host computer receiving unit 111 and the mobile device of the underground gas supervision department to perform decryption and solution on the encrypted string to obtain the device-related information and the methane concentration in the gas chamber.

[0072] In summary, in the embodiment of the present invention, the buried gas pipeline monitoring device is buried 0.4 m above key areas such as gas pipeline joints and gas pipeline bends and within a range of 50 m around, to remotely monitor the leakage of the gas pipeline in real time, prompt warnings in a timely manner, and reduce the risks of personal and property losses, thereby solving the problem that it is difficult to monitor the leakage of underground gas pipelines in real time by the existing underground gas pipeline leakage detection methods.

[0073] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0074] Those skilled in the art know that in addition to implementing the system and its various subsystems, modules, and units provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the system and its various subsystems, modules, and units provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, etc. to achieve the same functions. Therefore, the system and its various subsystems, modules, and units provided by the present invention can be regarded as both the structure within the hardware components and the software modules for implementing the method.

[0075] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A method for real-time monitoring of underground gas pipeline leakage, characterized in that: include: The DAC output device (106) generates a sawtooth wave modulation signal, and the sawtooth wave modulation signal is superimposed into the constant current driving bridge (103), so as to drive the 1653nm laser head (101) to output a pulse modulation signal; The temperature control unit controls the laser diode in the 1653nm laser head (101) to be at a preset constant temperature within a preset time range according to the pulse modulation signal, and the 1653nm laser head (101) outputs laser light with a wavelength of 1653nm; The laser light with a wavelength of 1653 nm passes through the gas cavity containing methane gas and is emitted into the photodiode (102). The photodiode (102) converts the received laser light into an electrical signal to obtain an electrical signal containing information on the concentration of the monitored gas. Amplifying and sampling the electrical signal containing the monitored gas concentration information to obtain sampling data, the algorithm unit performs Fourier transform and reverse calculation on the sampling data to obtain the methane concentration in the gas cavity, and sends the methane concentration in the gas cavity to the encryption frame unit (109); The encryption framing unit (109) determines whether the methane concentration in the air cavity exceeds a preset alarm concentration threshold, and if so, encrypts and frames the device-related information and the methane concentration in the air cavity to obtain an encrypted string, and sends the encrypted string to the NB radio frequency module (110); The NB radio frequency module (110) forwards the encrypted string to a host computer receiving unit (111) and a mobile device of an underground gas regulatory department via a base station; The host computer receiving unit (111) and the mobile device of the underground gas supervision department decrypt and solve the encrypted character string to obtain the device-related information and the methane concentration in the gas cavity.

2. The method according to claim 1, characterized in that The electrical signal containing the monitored gas concentration information is amplified and sampled to obtain sampled data, the algorithm unit performs Fourier transform and reverse calculation on the sampled data to obtain the methane concentration in the gas cavity, and the methane concentration in the gas cavity is sent to the encryption frame unit (109), specifically including: The TIA amplifier (104) converts the electrical signal containing the monitored gas concentration information from a nA level current signal into an mV level voltage signal, and sends the mV level voltage signal to the ADC sampler (105); The ADC sampler (105) samples the mV level voltage signal at a preset sampling frequency to obtain sampling data, and sends the sampling data to the algorithm unit (108); The algorithm unit (108) performs Fourier transform on the sampled data to obtain the sampled data after the Fourier transform, performs reverse calculation on the sampled data after the Fourier transform according to the Lambert-Beer law to obtain the amplitude of the transmitted signal and the methane concentration in the air cavity, and sends the methane concentration in the air cavity to the encryption frame unit (109).

3. The method according to claim 2, characterized in that The preset sampling frequency is four times the frequency of the sawtooth wave modulation signal generated by the DAC output device (106).

4. The method according to claim 1, characterized in that: The device related information includes current time, device code, real-time temperature, soil compaction level, and device location.

5. The method according to claim 1, characterized in that After the host computer receiving unit (111) and the mobile device of the underground gas supervision department decrypt and solve the encrypted string to obtain the device-related information and the methane concentration in the gas cavity, the method further includes: The host computer receiving unit (111) obtains a big data chart of predicted leakage points and gas diffusion according to the device related information and the methane concentration in the gas cavity; The host computer determines the leakage location and leakage concentration according to the predicted leakage point and gas diffusion big data chart, and pops up a corresponding alarm prompt page.

6. A system for executing the method for real-time monitoring of underground gas pipeline leakage according to any one of claims 1 to 5, characterized in that: include: A pulse modulation module, used for controlling a DAC output device (106) to generate a sawtooth wave modulation signal, superimposing the sawtooth wave modulation signal into a constant current driving bridge (103), and driving a 1653nm laser head (101) to output a pulse modulation signal; A laser output module, used to control the temperature control unit to control the laser diode in the 1653nm laser head (101) to be at a preset constant temperature within a preset time range according to the pulse modulation signal, so that the 1653nm laser head (101) outputs laser light with a wavelength of 1653nm; A photoelectric conversion module is used to control the laser light with a wavelength of 1653 nm to pass through the gas cavity containing methane gas and enter the photodiode (102), wherein the photodiode (102) converts the received laser light into an electrical signal to obtain an electrical signal containing information on the concentration of the monitored gas; A sampling and solving module is used to amplify and sample the electrical signal containing the monitored gas concentration information to obtain sampling data, and the algorithm unit performs Fourier transform and reverse solving on the sampling data to obtain the methane concentration in the gas cavity, and sends the methane concentration in the gas cavity to the encryption framing unit (109); An encryption framing module, used to control the encryption framing unit (109) to determine whether the methane concentration in the air cavity exceeds a preset alarm concentration threshold, and if so, encrypt and frame the device-related information and the methane concentration in the air cavity to obtain an encrypted string, and send the encrypted string to a NB radio frequency module (110); An information forwarding module, used to control the NB radio frequency module (110) to forward the encrypted string to a host computer receiving unit (111) and a mobile device of an underground gas supervision department via a base station; The decryption and solution module is used to control the host computer receiving unit (111) and the mobile device of the underground gas supervision department to decrypt and solve the encrypted string to obtain the device-related information and the methane concentration in the gas cavity.

7. The device according to claim 6, characterized in that The sampling and solving module includes a signal conversion module, a data sampling module and a data solving module, wherein: The signal conversion module is used to control the TIA amplifier (104) to convert the electrical signal containing the monitored gas concentration information from a nA level current signal into an mV level voltage signal, and send the mV level voltage signal to the ADC sampler (105); The data sampling module is used to control the ADC sampler (105) to sample the mV level voltage signal at a preset sampling frequency to obtain sampling data, and send the sampling data to the algorithm unit (108); The data solving module is used to control the algorithm unit (108) to perform Fourier transform on the sampled data to obtain the sampled data after the Fourier transform, and to perform reverse solving on the sampled data after the Fourier transform according to the Lambert-Beer law to obtain the amplitude of the transmitted signal and the methane concentration in the air cavity, and to send the methane concentration in the air cavity to the encryption framing unit (109).

8. The device according to claim 7, characterized in that The preset sampling frequency is four times the frequency of the sawtooth wave modulation signal generated by the DAC output device (106).

9. The device according to claim 6, characterized in that The device related information includes current time, device code, real-time temperature, soil compaction level, and device location.

10. The device according to claim 6, characterized in that It also includes a chart drawing module and an alarm prompt module, among which: The chart drawing module is used to control the host computer receiving unit (111) to obtain a large data chart of predicted leakage points and gas diffusion according to the device related information and the methane concentration in the gas cavity; The alarm prompt module is used to control the host computer to determine the leakage location and leakage concentration according to the predicted leakage point and gas diffusion big data chart, and pop up a corresponding alarm prompt page.

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