Mining methane concentration monitoring system and monitoring method thereof

Abstract

The invention relates to the technical field of mine methane concentration monitoring, in particular to a mine methane concentration monitoring system and a monitoring method thereof.The mine methane concentration monitoring system comprises an anti-explosion shell, a molecular sieve used for absorbing redundant H20 and SO2 interference gas in underground air, an air inlet hole reflecting plate, an optical air chamber, a pyroelectric detector and an infrared light source; a molecular sieve, an air inlet hole reflecting plate and an optical air chamber are installed in the explosion-proof shell, the molecular sieve is tightly attached to the optical air chamber through the air inlet hole reflecting plate, and a pyroelectric detector and an infrared light source are installed in the optical air chamber. The method ensures stable operation of the system in a severe environment, accurately predicts the replacement time of the molecular sieve by adopting a filter equipment replacement period calculation method based on an optimization model, avoids unnecessary maintenance, and improves the operation efficiency of the system and the accuracy of detection data.

Description

Technical Field

[0001] The present invention relates to the technical field of mining methane concentration monitoring, in particular to a mining methane concentration monitoring system and a monitoring method thereof. Background Art

[0002] The mining methane concentration monitoring system is a device specially designed for monitoring the methane gas concentration in coal mines. It is essential to prevent gas explosions and other related safety accidents.

[0003] The existing underground methane concentration monitoring system of coal mines usually uses traditional methane sensors for monitoring. However, these systems have low intelligence and are difficult to link with other safety control systems. In addition, the optical system has high requirements for the working environment and may not work properly if it is directly placed underground. Therefore, a filter device is needed to absorb interfering gases in the air underground, such as water vapor (H2O) and sulfur dioxide (SO2), to ensure the long-term stable operation of the optical system.

[0004] At present, the filtering device usually uses molecular sieves to absorb these interfering gases. If the replacement cycle of the molecular sieve cannot be accurately calculated, then during the replacement of the molecular sieve, if it is replaced too early, the replacement frequency will increase, and if it is replaced too late, it will affect the accuracy of the detection data. Therefore, a mining methane concentration monitoring system and a monitoring method thereof are proposed to address the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a mining methane concentration monitoring system and a monitoring method thereof, so as to solve the problem that the filtering device usually adopts molecular sieves to absorb these interfering gases. If the replacement cycle of the molecular sieve cannot be accurately calculated, then during the process of replacing the molecular sieve, if it is replaced too early, the replacement frequency will increase, and if it is replaced too late, the accuracy of the detection data will be affected.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A mining methane concentration monitoring system and a monitoring method thereof, comprising an explosion-proof housing, a molecular sieve for absorbing excess H20 and SO2 interfering gases in underground air, an air inlet reflector, an optical air chamber, a pyroelectric detector and an infrared light source, wherein the molecular sieve, the air inlet reflector and the optical air chamber are installed inside the explosion-proof housing, the molecular sieve is closely attached to the optical air chamber through the air inlet reflector, the optical air chamber is installed with a pyroelectric detector and an infrared light source, the infrared light source is a thermal radiation type, the pyroelectric detector is configured with two independent probes, and a filter and an optical filter of 1.2 mm×1.2 mm are respectively provided, the optical air chamber is smooth inside, and an infrared light path is provided inside the reflector air chamber;

[0008] The molecular sieve is provided with an electronic tag, and a monitoring system is provided outside the molecular sieve. The monitoring system includes an information entry module for inputting model variables, an optimization model algorithm module, a positioning module and a display module. The model variables include a replacement cycle T, a filter device efficiency η(t), an initial filter efficiency η0, a minimum filter efficiency ηmin, a filter efficiency attenuation coefficient λ, a maintenance cost C(T), an average filter efficiency e(T), and an objective function f(T). According to the filter device efficiency η(t), the initial filter efficiency η0, the minimum filter efficiency ηmin, the filter efficiency attenuation coefficient λ, the maintenance cost C(T), and the average filter efficiency e(T) information input by the information entry module, an optimization model for calculating the optimization of the molecular sieve replacement cycle at the corresponding position is constructed, wherein the filter efficiency expression of the molecular sieve at time t is:

[0009] η(t)=η0·e -t

[0010] The expression of the optimization model for the molecular sieve replacement cycle optimization at the corresponding position is:

[0011]

[0012] Where: is the objective function of the optimization model for optimizing the molecular sieve replacement cycle at the corresponding position; st{ is the constraint condition of the optimization model, T min and T max are the minimum and maximum values ​​of the gas chamber working temperature, Hmin and Hmax are the minimum and maximum values ​​of the gas chamber relative humidity, respectively.

[0013] As a further optimization of the present invention, the molecular sieve is designed to be detachable and can be easily replaced through the side interface of the explosion-proof housing.

[0014] As a further optimization of the present invention, the wavelength of the filter and the optical filter arranged inside the pyroelectric detector is selected to match the absorption peak of methane, and the wavelength range of the light wave emitted by the infrared light source includes the characteristic absorption wavelength of methane, 3.31 μm.

[0015] As a further optimization of the present invention, the infrared light source has the function of automatically adjusting the light intensity, and dynamically adjusts the infrared light intensity according to the actual environmental conditions in the air chamber.

[0016] As a further optimized content of the present invention, the positioning module of the monitoring system adopts a wireless sensor network to achieve real-time positioning and data transmission of multiple monitoring points in the mine.

[0017] As a further optimized content of the present invention, the model variables also include ambient temperature, humidity and air pressure, and the optimization model algorithm module can dynamically adjust the replacement period of the molecular sieve according to these variables.

[0018] As a further optimized content of the present invention, the information entry module of the model variable input supports an automatic data collection function and can directly obtain real-time environmental data from the sensor network.

[0019] As a further optimized content of the present invention, the optical air chamber is designed with an anti-reflection coating.

[0020] As a further optimization of the present invention, the display module is equipped with a visual interface, which can display the methane concentration in the gas chamber, the working status of the equipment and the remaining life of the molecular sieve in real time, and provide early warning and alarm functions.

[0021] As further optimized contents of the present invention, S1: data acquisition: obtaining optical signals of methane concentration in the optical gas chamber by using a pyroelectric detector and an infrared light source;

[0022] S11: Setting and data collection: Setting the radiance I0 of the initial light, the length L of the air chamber, and the wavelength λ, and collecting data on the effective length L of the air chamber and the absorption coefficient a(v) on the v wave;

[0023] S12: Calculation of methane concentration: S121: Calculation of light intensity after passing through the gas chamber:

[0024] ∑I t (v)=∫I0(v)exp[-a(v)cL]dv

[0025] S122: Calculation of gas concentration to be measured:

[0026]

[0027] Where: I0(v) is the light intensity distribution information obtained by directly irradiating the interference system without passing through the gas chamber, I t (v) is the light intensity distribution information after the laser passes through the gas chamber and then through the interference system;

[0028] S2: Signal processing: The molecular sieve in the filter device is used to absorb interfering gases to ensure the normal operation of the optical system. The signal processing module amplifies and filters the optical signal;

[0029] S3: Optimization model: The monitoring system collects the working status information of the molecular sieve through the model variable input module, calculates the replacement cycle of the molecular sieve at different positions based on the optimization algorithm, and issues an alarm.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. In the present invention, the service life of the optical gas chamber is effectively extended, the interference of the underground environment on the optical system is reduced, and the stable operation of the system in harsh environments is ensured. At the same time, by adopting a filter equipment replacement cycle calculation method based on an optimization model, the replacement time of the molecular sieve is accurately predicted, unnecessary maintenance is avoided, and the operating efficiency of the system and the accuracy of the detection data are improved. At the same time, the system design is highly scalable and intelligent, and can be linked with other coal mine safety monitoring systems, providing effective protection for the safe production of mines;

[0032] 2. In the present invention, by providing core components such as an explosion-proof housing, an optical gas chamber and a pyroelectric detector, the normal operation of the system in the complex environment of a coal mine is ensured. By monitoring and optimizing the filtering equipment, the effective working time of the system is greatly extended. In addition, by providing electronic tags, the replacement time of the molecular sieve inside the methane concentration monitoring system installed at different locations can be calculated more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0034] Figure 2 The present invention is a flow chart of a mine methane concentration monitoring system and a monitoring method thereof.

[0035] In the figure: 1. explosion-proof housing; 2. molecular sieve; 3. air inlet reflector; 4. optical air chamber; 5. pyroelectric detector; 6. infrared light source. DETAILED DESCRIPTION

[0036] See also Figure 1-2 , the present invention provides a technical solution:

[0037] A mining methane concentration monitoring system and a monitoring method thereof, comprising an explosion-proof housing 1, a molecular sieve 2 for absorbing excess H20 and SO2 interfering gases in underground air, an air inlet reflector 3, an optical air chamber 4, a pyroelectric detector 5 and an infrared light source 6. The molecular sieve 2, the air inlet reflector 3 and the optical air chamber 4 are installed inside the explosion-proof housing 1. The molecular sieve 2 is in close contact with the optical air chamber 4 through the air inlet reflector 3. The pyroelectric detector 5 and the infrared light source 6 are installed inside the optical air chamber 4. The infrared light source 6 is a thermal radiation type. The pyroelectric detector 5 is configured with two independent probes, which are respectively provided with a filter plate and a filter plate of 1.2 mm×1.2 mm. The interior of the optical air chamber 4 is smooth, and an infrared light path is provided inside the reflective air chamber 4.

[0038] The molecular sieve 2 is provided with an electronic tag, and a monitoring system is provided outside the molecular sieve 2. The monitoring system includes an information entry module for inputting model variables, an optimization model algorithm module, a positioning module and a display module. The model variables include a replacement cycle T, a filter device efficiency η(t), an initial filter efficiency η0, a minimum filter efficiency ηmin, a filter efficiency attenuation coefficient λ, a maintenance cost C(T), an average filter efficiency e(T), and an objective function f(T). According to the filter device efficiency η(t), the initial filter efficiency η0, the minimum filter efficiency ηmin, the filter efficiency attenuation coefficient λ, the maintenance cost C(T), and the average filter efficiency e(T) information input by the information entry module, an optimization model for calculating the optimization of the replacement cycle of the molecular sieve 2 at the corresponding position is constructed, wherein the filter efficiency expression of the molecular sieve at time t is:

[0039] η(t)=η0·e -t

[0040] The expression of the optimization model for the replacement cycle optimization of molecular sieve 2 at the corresponding position is:

[0041]

[0042] Where: is the objective function of the optimization model for optimizing the replacement cycle of molecular sieve 2 at the corresponding position; st{ is the constraint condition of the optimization model, T min and T max are the minimum and maximum values ​​of the gas chamber working temperature, Hmin and Hmax are the minimum and maximum values ​​of the gas chamber relative humidity, respectively.

[0043] As a technical solution for further implementation of this scheme, the molecular sieve 2 adopts a detachable design and is conveniently replaced through the side interface of the explosion-proof housing 1. Through the above settings, the safety and convenience of the equipment during maintenance are ensured;

[0044] As a technical solution for further implementation of this scheme, the wavelength of the filter and the filter set inside the pyroelectric detector 5 is selected to match the absorption peak of methane, and the wavelength range of the light wave emitted by the infrared light source 6 includes the characteristic absorption wavelength of methane 3.31μm. Through the above setting, the detection accuracy of the system for methane concentration is improved;

[0045] As a further technical solution implemented in this scheme, the infrared light source 6 has the function of automatically adjusting the light intensity, and dynamically adjusts the infrared light intensity according to the actual environmental conditions in the air chamber 4. Through the above settings, the detection signal is optimized;

[0046] As a technical solution for further implementing this scheme, the positioning module of the monitoring system adopts a wireless sensor network to realize real-time positioning and data transmission of multiple monitoring points in the mine, so as to independently manage and optimize the molecular sieves (2) at different locations;

[0047] As a technical solution for further implementation of this scheme, the model variables also include ambient temperature, humidity and air pressure. The optimization model algorithm module can dynamically adjust the replacement cycle of the molecular sieve 2 according to these variables. Through the above settings, it can cope with changes in environmental conditions in the mine;

[0048] As a technical solution for further implementation of this scheme, the information entry module for model variable input supports automatic data collection function, which can directly obtain real-time environmental data from the sensor network, reduce manual intervention and improve the real-time response capability of the system;

[0049] As a technical solution for further implementation of this scheme, the optical air chamber 4 is designed with an anti-reflection coating to reduce optical interference and reflection loss, and improve the detection sensitivity and accuracy of the system;

[0050] As a technical solution for further implementation of this solution, the display module is equipped with a visual interface, which can display the methane concentration in the gas chamber, the working status of the equipment and the remaining life of the molecular sieve 2 in real time, and provide early warning and alarm functions. Through the above settings, it can ensure that the operator is informed of the equipment operation status in a timely manner;

[0051] As a technical solution for further implementation of this scheme, S1: data acquisition: obtaining the optical signal of the methane concentration in the optical gas chamber 4 through the pyroelectric detector 5 and the infrared light source 6;

[0052] S11: Setting and data collection: Setting the radiance I0 of the initial light, the length L of the air chamber, and the wavelength λ, and collecting data on the effective length L of the air chamber and the absorption coefficient a(v) on the v wave;

[0053] S12: Calculation of methane concentration: S121: Calculation of light intensity after passing through the gas chamber:

[0054] ΣI t (v)=∫I0(v)exp[-a(v)cL]dv

[0055] S122: Calculation of gas concentration to be measured:

[0056]

[0057] Where: I0(v) is the light intensity distribution information obtained by directly irradiating the interference system without passing through the gas chamber, I t (v) is the light intensity distribution information after the laser passes through the gas chamber and then through the interference system;

[0058] S2: Signal processing: The molecular sieve 2 in the filter device is used to absorb the interfering gas to ensure the normal operation of the optical system. The signal processing module amplifies and filters the optical signal;

[0059] S3: Optimizing the model: The monitoring system collects the working status information of the molecular sieve 2 through the model variable input module, calculates the replacement cycle of the molecular sieve 2 at different positions based on the optimization algorithm, and issues an alarm.

[0060] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A mine methane concentration monitoring system, comprising an explosion-proof housing (1), a molecular sieve (2) for absorbing excess H2O and SO2 interfering gases in underground air, an air inlet reflector (3), an optical air chamber (4), a pyroelectric detector (5) and an infrared light source (6), characterized in that: The explosion-proof housing (1) is internally installed with a molecular sieve (2), an air inlet reflector (3) and an optical air chamber (4); the molecular sieve (2) is closely attached to the optical air chamber (4) via the air inlet reflector (3); a pyroelectric detector (5) and an infrared light source (6) are internally installed in the optical air chamber (4); the infrared light source (6) is of a thermal radiation type; the pyroelectric detector (5) is configured with two independent probes, each of which is provided with a 1.2 mm×1.2 mm filter and a filter; the interior of the optical air chamber (4) is smooth, and an infrared light path is provided inside the reflector air chamber (4); The molecular sieve (2) is provided with an electronic tag, and a monitoring system is provided outside the molecular sieve (2), wherein the monitoring system comprises an information input module for inputting model variables, an optimization model algorithm module, a positioning module and a display module, wherein the model variables comprise a replacement cycle T, a filter device efficiency η(t), an initial filter efficiency η0, a minimum filter efficiency ηmin, a filter efficiency attenuation coefficient λ, a maintenance cost C(T), an average filter efficiency e(T), and an objective function f(T). Based on the filter device efficiency η(t), the initial filter efficiency η0, the minimum filter efficiency ηmin, the filter efficiency attenuation coefficient λ, the maintenance cost C(T), and the average filter efficiency e(T) information inputted by the information input module, an optimization model for calculating the optimization of the replacement cycle of the molecular sieve (2) at the corresponding position is constructed, wherein the filter efficiency expression of the molecular sieve at time t is: η(t)=η0·e -t The expression of the optimization model for the replacement cycle optimization of the corresponding molecular sieve (2) is: Where: The objective function of the optimization model for optimizing the replacement cycle of the molecular sieve (2) at the corresponding position; st{ is the constraint condition of the optimization model, Tmin and Tmax are the minimum and maximum values ​​of the working temperature of the air chamber, Hmin and Hmax are the minimum and maximum values ​​of the relative humidity of the air chamber.

2. A mining methane concentration monitoring system according to claim 1, characterized in that: The molecular sieve (2) is designed to be detachable and can be easily replaced through the side interface of the explosion-proof housing (1).

3. A mining methane concentration monitoring system according to claim 1, characterized in that: The wavelengths of the filter and the optical filter arranged inside the pyroelectric detector (5) are selected to match the absorption peak of methane, and the wavelength range of the light waves emitted by the infrared light source (6) includes the characteristic absorption wavelength of methane, 3.31 μm.

4. A mining methane concentration monitoring system according to claim 1, characterized in that: The infrared light source (6) has the function of automatically adjusting the light intensity, and dynamically adjusts the infrared light intensity according to the actual environmental conditions in the air chamber (4).

5. A mining methane concentration monitoring system according to claim 1, characterized in that: The positioning module of the monitoring system adopts a wireless sensor network to achieve real-time positioning and data transmission of multiple monitoring points in the mine.

6. A mining methane concentration monitoring system according to claim 1, characterized in that: The model variables also include ambient temperature, humidity and air pressure, and the optimization model algorithm module can dynamically adjust the replacement cycle of the molecular sieve (2) according to these variables.

7. A mining methane concentration monitoring system according to claim 1, characterized in that: The information entry module for the model variable input supports an automatic data collection function and can directly obtain real-time environmental data from the sensor network.

8. A mining methane concentration monitoring system according to claim 1, characterized in that: The optical air chamber (4) is designed with an anti-reflection coating.

9. A mining methane concentration monitoring system according to claim 1, characterized in that: The display module is equipped with a visual interface, which can display the methane concentration in the gas chamber, the working status of the equipment and the remaining life of the molecular sieve (2) in real time, and provide early warning and alarm functions.

10. A monitoring method for a mining methane concentration monitoring system according to any one of claims 1 to 9, characterized in that: S1: Data acquisition: obtaining the optical signal of methane concentration in the optical gas chamber (4) through the pyroelectric detector (5) and the infrared light source (6); S11: Setting and data collection: Setting the radiance I0 of the initial light, the length L of the air chamber, and the wavelength λ, and collecting data on the effective length L of the air chamber and the absorption coefficient a(v) on the v wave; S12: Calculation of methane concentration: S121: Calculation of light intensity after passing through the gas chamber: ∑I t (v)=∫I0(v)exp[-a(v)cL]dv S122: Calculation of gas concentration to be measured: Where: I0(v) is the light intensity distribution information obtained by directly irradiating the interference system without passing through the gas chamber, I t (v) is the light intensity distribution information after the laser passes through the gas chamber and then through the interference system; S2: signal processing: using the molecular sieve (2) in the filter device to absorb the interfering gas to ensure the normal operation of the optical system, the signal processing module amplifies and filters the optical signal; S3: Optimizing the model: The monitoring system collects the working status information of the molecular sieve (2) through the model variable input module, calculates the replacement cycle of the molecular sieve (2) at different positions based on the optimization algorithm, and issues an alarm.

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