Coal sample methane content detection device and detection method

Abstract

The invention relates to the technical field of coal mine methane content detection, in particular to a coal sample methane content detection device and method. The coal sample methane content detection device comprises a pulverizer, a coal sample tank is detachably installed on the pulverizer, the coal sample tank is used for containing a coal sample, and the downstream of the pulverizer is communicated with a flow meter; the air blower is mounted at the upstream of the crusher and is communicated with the coal sample tank; and the gas analysis assembly is communicated with the downstream of the flow meter and is used for monitoring the concentration of methane in the gas in real time. A coal sample is crushed into coal powder through a crusher, methane in the coal powder is blown to the downstream by utilizing an air blower to actively blow air, a gas analysis assembly detects the methane concentration and draws a time-varying curve of the methane concentration, and the methane content in the coal sample is estimated by utilizing the time-varying curve of the methane concentration, so that the methane content in the coal sample can be quickly and effectively estimated. And the air blower actively blows air, so that the stability of airflow can be ensured, and the detection accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mine methane content detection, and specifically relates to a device and a method for detecting the methane content of coal samples. Background Art

[0002] In addition to carbon dioxide directly or indirectly generated by coal mining enterprises due to the use of fossil fuels and electricity, carbon dioxide and a large amount of methane are generated during the mining process. Methane is a clean energy gas, and at the same time it is also the second largest greenhouse gas in the atmosphere after carbon dioxide. Methane emissions during coal mining need to be strictly controlled.

[0003] The detection of the residual methane content of coal samples usually adopts the degassing method and the natural desorption method. The degassing method mainly relies on a degassing device for degassing and degassing weighing after pulverization. After measuring the volume, the gas components are analyzed by chromatography to calculate the gas content. The desorption method is mainly to desorb in a constant temperature device, continuously record the readings of the gas meter, measure once every certain interval during natural desorption, perform weighing calculations, and analyze the gas components by chromatography to obtain the coalbed methane content. The degassing method requires continuous pumping during the degassing process of the coal sample, which takes a long time. The natural desorption method needs to be measured once every certain interval and needs to be measured for a cumulative total of eight hours, which also takes a long time.

[0004] In order to improve the detection efficiency and achieve rapid detection, a coal seam gas content detector is used for rapid detection in the prior art. By putting the coal sample into a crusher and connecting it to the detector, the detection result can be obtained within twenty minutes. However, there are currently problems with the existing rapid detection methods. The screening of coal samples during sampling is not standardized, which easily causes excessive methane to escape. At the same time, the crusher overheats and needs to be cooled, which will make the detected methane data inaccurate. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the methane data measured by the existing coal sample rapid detection device is inaccurate, so as to provide a device and a method for detecting the methane content of coal samples.

[0006] To solve the above technical problem, the present invention provides a device for detecting the methane content of coal samples, including:

[0007] A crusher, on which a coal sample tank is detachably installed. The coal sample tank is used to accommodate coal samples, and a flow meter is connected downstream of the crusher;

[0008] A blower, installed upstream of the crusher, and the blower is connected to the coal sample tank;

[0009] A gas analysis component, connected downstream of the flow meter, and the gas analysis component is used to monitor the methane concentration in the gas in real time.

[0010] Optionally, an embedded groove is provided on the pulverizer, the coal sample tank is embedded and installed in the embedded groove, an air inlet and an air outlet are provided on the embedded groove, the air inlet is communicated with a blower, the air outlet is communicated with a flowmeter, and a pair of ventilation ports are provided on the coal sample tank, and the pair of ventilation ports are respectively and hermetically connected with the air inlet and the air outlet.

[0011] Optionally, a control switch is installed on the ventilation port. When the coal sample tank is removed from the pulverizer, the control switch is in the closed state.

[0012] Optionally, a first ventilation pipe is communicated between the pulverizer and the gas analysis component, the flowmeter is installed on the first ventilation pipe, the length of the first ventilation pipe is not less than 30 cm, and the inner diameter of the first ventilation pipe is not more than 6 cm.

[0013] Optionally, a first control valve is installed between the pulverizer and the blower; and / or, a second control valve is installed between the pulverizer and the flowmeter.

[0014] Optionally, the gas blown by the blower is air or nitrogen.

[0015] Optionally, the gas analysis component is installed in a cabinet, and the cabinet is closed.

[0016] The present invention also provides a method for detecting the methane content of a coal sample. By applying the coal sample methane content detection device of the present invention, the detection method includes:

[0017] Sampling on-site in a coal mine, putting the coal sample into the coal sample tank and weighing to obtain the mass of the coal sample;

[0018] Install the coal sample tank on the pulverizer, start the pulverizer to crush the coal sample into coal powder, and cool it to room temperature;

[0019] Start the blower for ventilation, and the flowmeter and the gas analysis component respectively record the flowing gas flow rate and the methane concentration in the gas in real time, and draw a curve graph of the methane concentration changing with time;

[0020] Divide the curve graph of the methane concentration changing with time into n segments according to the detection frequency. The time points at both ends of each segment interval are t1 and t2 respectively. The average value of the methane concentration data measured by the detector at the time points t1 and t2 is the monitoring data of the gas analysis component in this segment interval. The methane concentration of each segment interval is as follows:

[0021]

[0022] The calculation formula for the methane content of each segment interval is as follows:

[0023]

[0024] Among them, is the methane content in the coal sample for each time interval, and the unit is cm3 ; i is the monitoring frequency, that is, the time difference for each section of the interval, with the unit of s; is the methane concentration detected by the detector for the nth section of the interval, with the unit of ppm; v is the gas flow reading in the ventilation duct monitored and displayed by the flowmeter;

[0025] The total methane content in the coal sample is as follows:

[0026]

[0027] Among them, is the total methane content in the coal sample, with the unit of cm 3 ; is the methane content in the coal sample for each time interval, with the unit of cm 3 ;

[0028] The calculation formula for the methane content in the unit coal sample is as follows:

[0029]

[0030] Among them, is the methane content of the unit coal sample, with the unit of cm 3 / g or m 3 / t; is the total methane content in the coal sample, with the unit of cm 3 ; m is the weight of the coal sample in the coal sample tank, with the unit of g.

[0031] Optionally, in the step of starting the crusher to crush the coal sample into coal powder, the grinding particle size of the coal powder is not greater than 0.25 mm.

[0032] Optionally, in the step of dividing into n sections according to the detection frequency, the time difference for each section of the interval is not greater than 0.5 s.

[0033] The technical solution of the present invention has the following advantages:

[0034] 1. The coal sample methane content detection device provided by the present invention includes: a crusher, on which a coal sample tank is detachably installed, the coal sample tank is used to accommodate the coal sample, and a flowmeter is connected downstream of the crusher; a blower, installed upstream of the crusher, and the blower is connected to the coal sample tank; a gas analysis component, connected downstream of the flowmeter, and the gas analysis component is used to monitor the methane concentration in the gas in real time.

[0035] The coal sample is crushed into pulverized coal by a crusher. After the methane in the pulverized coal is blown into the downstream by the active air blowing of the blower, the gas analysis component detects the methane concentration and draws a curve of the methane concentration changing with time. The methane content in the coal sample is estimated by using the curve of the methane concentration changing with time, which can quickly and effectively estimate the methane content in the coal sample. And because the blower blows air actively, it can ensure the stability of the air flow, improve the accuracy of detection, and has high economic, social and environmental benefits.

[0036] 2. The method for detecting the methane content in a coal sample provided by the present invention estimates the methane content in the coal sample by using the method of dividing intervals in mathematical analysis. This method saves more time compared with degassing, can quickly and effectively estimate the methane content in the coal sample, and has high economic, social and environmental benefits. Description of the Drawings

[0037] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Figure 1 It is a schematic structural diagram of the device for detecting the methane content in a coal sample provided in the embodiments of the present invention.

[0039] Figure 2 It is a schematic structural diagram of the crusher provided in the embodiments of the present invention.

[0040] Figure 3 It is a graph of the methane concentration changing with time provided in the embodiments of the present invention.

[0041] Figure 4 It is a graph of the methane concentration changing with time provided in another embodiment of the present invention.

[0042] Description of the reference numerals: 1. Blower; 2. Crusher; 3. Cabinet; 4. First control valve; 5. First filter screen; 6. Second filter screen; 7. Second control valve; 8. First ventilation duct; 9. Second ventilation duct; 10. Air switch group; 11. Display; 12. Methane concentration detector; 13. Flowmeter; 14. Coal sample tank. Detailed Embodiments

[0043] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0045] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] Figure 1 and Figure 2 Shown is a coal sample methane content detection device provided by this embodiment, including a pulverizer 2, a blower 1, and a gas analysis component.

[0048] A coal sample tank 14 is detachably installed on the pulverizer 2. The coal sample tank 14 is used to hold coal samples. A flow meter 13 is connected downstream of the pulverizer 2. The blower 1 is installed upstream of the pulverizer 2, and the blower 1 is connected to the coal sample tank 14. The gas analysis component is connected downstream of the flow meter 13, and the gas analysis component is used to monitor the methane concentration in the gas in real time.

[0049] In the detection device, the blower 1 is responsible for ventilating the pipeline of the device, and the gas introduced is air or nitrogen. The crusher 2 is arranged on one side of the blower 1. The cabinet 3 is connected downstream of the crusher 2 through a ventilation pipeline, and a gas analysis component is installed inside the cabinet 3. The first control valve 4 is arranged on the ventilation inlet side of the crusher 2; the second control valve 7 is arranged on the ventilation outlet side of the crusher 2. In order to prevent larger pulverized coal particles from entering the downstream flowmeter 13 or gas analysis component and damaging the equipment, a first filter screen 5 is installed on the air inlet side of the crusher 2, and a second filter screen 6 is installed on the air outlet side of the crusher 2. The flowmeter 13 is arranged at the air inlet of the cabinet 3, and the installation position is between the first ventilation pipeline 8. The coal sample tank 14 is arranged on the crusher 2 and can be detached to separately hold coal samples.

[0050] The first ventilation pipeline 8 is connected to the second control valve 7 at the outlet of the crusher 2, and is located between the second control valve 7 and the cabinet 3. A second ventilation pipeline 9 is connected to the air outlet of the cabinet 3 for exhausting gas. The length of the first ventilation pipeline 8 arranged between the cabinet 3 and the crusher 2 should be not less than 30 cm, and the diameter should be not more than 6 cm. The pore diameters of the first filter screen 5 and the second filter screen 6 should be much smaller than 0.25 mm.

[0051] The crusher 2 is provided with an embedded groove, and the coal sample tank 14 is embedded and installed in the embedded groove. The embedded groove is provided with an air inlet and an air outlet. The air inlet is connected to the blower 1, and the air outlet is connected to the flowmeter 13. The coal sample tank 14 is provided with a pair of ventilation ports, and the pair of ventilation ports are respectively and hermetically connected to the air inlet and the air outlet. A control switch is installed on the ventilation port. When the coal sample tank 14 is detached from the crusher 2, the control switch is in the closed state. A motor is arranged at the bottom of the embedded groove of the crusher 2, and after the motor is started, it can control the pulverization inside the coal sample tank 14.

[0052] To prevent dust from affecting the detection accuracy of the gas analysis component, the gas analysis component is installed in the cabinet 3, and the cabinet 3 is enclosed. The gas analysis component set in the cabinet 3 is a methane concentration detector 12. A control panel is also set in the cabinet 3. The control panel is provided with an air switch group 10 and a display 11. The air switch group 10 is electrically connected to the blower 1, the crusher 2, the first control valve 4, the second control valve 7, the methane concentration detector 12 and the display 11 to control the opening or closing of the blower 1, the crusher 2, the first control valve 4, the second control valve 7, the methane concentration detector 12 and the display 11. The display 11 is connected to the methane concentration detector 12, and the display 11 displays the detection data of the methane concentration detector 12 and the switch states of each component. The control panel in the cabinet 3 has the function of controlling the power of the blower 1 and the crusher 2. The control panel is provided with a status indicator light, and the status indicator light is set on one side of the air switch group. The parameters of the methane concentration detector 12 include the types of detected gases, the measuring range, the frequency and the accuracy. The gas detected by the methane concentration detector 12 is methane. The methane concentration detector 12 can use a laser detector or an infrared detector according to the gas analysis method. The detection range of the high-precision methane concentration detector 12 in the gas analysis component includes: 0 to 10,000 ppm. The frequency of the gas analysis component is 5 Hz, and the accuracy is 0.5 ppm. The flowmeter 13 uses dual measurement units. The dual measurement units are cm 3 and m 3 . The flowmeter 13 is used to measure the gas flow rate in the pipeline when monitoring the methane concentration.

[0053] When the mouth of the coal sample tank 14 is closed, it is in a sealed state. The bottom of the coal sample tank 14 is provided with double blades, which can be connected to the motor on the base of the crusher 2. After the motor starts, coal sample crushing can be carried out. Two ventilation openings are provided on both sides of the coal sample tank 14, which can be respectively connected to the inlet and outlet of the embedded groove of the crusher 2. When the coal sample tank 14 is connected to the crusher 2, it is in a sealed state. When it is not connected to the crusher 2, the two ventilation openings are in a sealed state, and the ventilation openings can be manually or electrically controlled to be switched. After the two ventilation openings of the coal sample tank 14 are connected to the crusher 2, the ventilation openings can be electrically controlled to be switched. The coal sample sampling port of the coal sample tank 14 is one of the two ventilation openings. When it is closed, it is in a sealed state. When it is not connected to the crusher 2, the coal sample sampling port can be manually switched.

[0054] The coal sample methane content detection device provided in this embodiment adopts the following detection method during the inspection work, including the following steps:

[0055] Take samples at the coal mine site. Immediately put the coal sample into the coal sample tank 14 and weigh it to obtain the mass of the coal sample. Transport the coal sample tank 14 to the detection device and connect the coal sample tank 14 to the pulverizer 2. Turn on the pulverizer 2 to crush the coal sample into coal powder, and after completion, cool it to room temperature; turn on the blower 1 and the valve for ventilation, and observe and record data through the methane concentration detector 12 and the flow meter 13; draw a curve of methane concentration changing with time according to the data recorded by the detector and the flow meter 13. Calculate the methane content in the coal sample using the segmented interval method, and the calculation method is as follows:

[0056] Divide the curve of methane concentration changing with time into n segments according to the detection frequency. Each segment interval is not greater than 0.5 s. In this embodiment, 0.2 s is selected. The time points at both ends of each segment interval are t1 and t2 respectively. The average value of the methane concentration data measured by the detector at time points t1 and t2 is the monitoring data of the gas analysis component in this segment interval. The methane concentration in each segment interval is as follows:

[0057]

[0058] The calculation formula for the methane content in each segment interval is as follows:

[0059]

[0060] Among them, is the methane content in the coal sample in each time interval, with the unit of cm 3 ; 0.2 is the detection frequency, that is, each segment interval, with the unit of s; is the methane concentration detected by the detector in the nth segment interval, with the unit of ppm; v is the reading of the gas flow rate in the ventilation duct monitored by the flow meter 13.

[0061] The total methane content in the coal sample is as follows:

[0062]

[0063] Among them, is the total methane content in the coal sample, with the unit of cm 3 ; is the methane content in the coal sample in each time interval, with the unit of cm 3 .

[0064] The calculation formula for the methane content in the unit coal sample is as follows:

[0065]

[0066] Among them, is the methane content of the unit coal sample, with the unit of cm 3 / g or m 3 / t; is the total methane content in the coal sample, with the unit of cm3 ; m is the weight of the coal sample in the coal sample tank 14, with the unit of g.

[0067] When weighing, it is necessary to weigh the weight of the coal sample tank 14 before sampling and after sampling. The weight after sampling minus the weight before sampling is the weight of the coal sample. The range of the coal sample weight should be not less than 100 g and not exceed the capacity of the coal sample tank 14 at most. The pulverizer 2 pulverizes the coal sample into coal powder, and the pulverized particle size of the coal powder should not be greater than 0.25 mm. The flow rate range per second in the blower 1 should be: 4000 cm 3 / s to 8000 cm 3 / s. The blower 1, the first control valve 4, and the second control valve 7 should be opened simultaneously. When recording data, it is necessary to observe the flowmeter 13 and record the gas flow rate at the position of the pipeline for monitoring the methane concentration. The curve graph of the methane concentration changing with time is recorded and plotted according to the detection frequency. The segmentation interval method is the subinterval method in mathematical analysis. Each part is divided into several parts according to the detection frequency. The methane content in each part interval is calculated respectively for the methane concentration in each part interval, and the sum of the methane content in each part interval is the methane content in the coal sample.

[0068] Taking a certain coal mine A as an example, the main type of coal in coal mine A is bituminous coal. The weight of the coal sample tank 14 before sampling is 500 g. Immediately after sampling the coal sample, the coal sample tank 14 is sealed. The weight of the coal sample tank 14 after sampling is 619.56 g, and the weight of the coal sample is obtained as 119.56 g.

[0069] Transport the coal sample tank 14 containing the bituminous coal sample taken from coal mine A to the rapid detection device, and immediately put it into the pulverizer 2 after opening. Keep the first control valve 4 and the second control valve 7 in the closed state, and control the opening of the pulverizer 2 through the control panel to pulverize the coal sample into coal powder with a particle size less than 0.25 mm. Simultaneously open the first control valve 4, the second control valve 7, and the blower 1 through the control panel, and adjust the flow rate per second of the blower 1 to the reading shown on the flowmeter 13 as 5000 cm 3 / s, and at the same time record the readings according to the data of the methane concentration detector 12 shown on the display 11 of the cabinet body 3.

[0070] According to the data record of the methane concentration detector shown on the display 11 of the cabinet body 3, draw a curve graph of the methane concentration changing with time, as Figure 3 shown. Divide the curve graph of the methane concentration changing with time into n segments according to the detection frequency. Each segment interval is 0.2 s. The time points at both ends of each segment interval are t1 and t2 respectively. The average value of the methane concentration data measured by the detector at the time points t1 and t2 is the monitoring data of the gas analysis component in this segment interval. The calculation formula for the methane concentration in each segment interval is as follows: Taking the data from 2.0 s to 2.2 s in the figure as an example, as Figure 3 shown, from which it can be obtained that:

[0071]

[0072] Taking the coal sample taken from Coal Mine A as an example, it is divided into 50 time intervals for summation, and the calculation formula is as follows:

[0073]

[0074] Taking the coal sample taken from Coal Mine A as an example, the weight of this coal sample is 119.56 g, from which it can be obtained that:

[0075]

[0076]

[0077] That is, the methane content in the coal sample from Coal Mine A is 2.16 cm 3 / g.

[0078] Taking a certain Coal Mine B as an example, the main type of coal in Coal Mine B is lignite. Before sampling, the weight of the coal sample tank 14 is weighed as 500 g. Immediately after sampling the coal sample, the coal sample tank 14 is sealed. After sampling, the weight of the coal sample tank 14 is weighed as 615.54 g, and the weight of the coal sample is obtained as 115.54 g.

[0079] Transport the coal sample tank 14 containing the lignite coal sample sampled from Coal Mine B to the rapid detection device, and immediately put it into the crusher 2 after opening. Keep the valve closed, control the opening of the crusher 2 through the control panel, and crush the coal sample into coal powder with a particle size less than 0.25 mm. Open the valve and the blower 1 simultaneously through the control panel, and adjust the flow rate of the blower 1 per second to the reading shown by the flow meter 13 as 4000 cm 3 / s, and at the same time record the readings according to the data of the methane concentration detector 12 shown on the display 11 of the cabinet 3. According to the data record of the methane concentration detector 12 shown on the cabinet 3, draw a curve graph of the change of methane concentration with time, as Figure 4 shown.

[0080] Taking the coal sample taken from Coal Mine B as an example, taking the data from the 3.2 s to the 3.4 s in the figure as an example, as Figure 4 shown, from which it can be obtained that:

[0081]

[0082]

[0083] Taking the coal sample taken from Coal Mine B as an example, the total methane content in the coal sample is divided into 50 time intervals for summation, and the calculation formula is as follows:

[0084]

[0085] Taking the coal sample taken from Coal Mine B as an example, the weight of this coal sample is 115.54 g. From this, it can be obtained that:

[0086]

[0087] That is, the methane content in the coal sample from Coal Mine B is 1.96 cm 3 / g.

[0088] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A device for detecting the methane content of a coal sample, characterized in that Comprising: A pulverizer (2) on which a coal sample tank (14) is detachably installed. The coal sample tank (14) is used to hold coal samples, and a flow meter (13) is connected downstream of the pulverizer (2); A blower (1) installed upstream of the pulverizer (2), and the blower (1) is connected to the coal sample tank (14); A gas analysis component connected downstream of the flow meter (13), and the gas analysis component is used to monitor the methane concentration in the gas in real time.

2. The coal sample methane content detection device according to claim 1, characterized in that, An embedded groove is provided on the pulverizer (2), and the coal sample tank (14) is embedded and installed in the embedded groove. An air inlet and an air outlet are provided on the embedded groove. The air inlet is connected to the blower (1), and the air outlet is connected to the flow meter (13). A pair of ventilation openings are provided on the coal sample tank (14), and the pair of ventilation openings are respectively sealed and connected to the air inlet and the air outlet.

3. The coal sample methane content detection device according to claim 2, characterized in that, A control switch is installed on the ventilation opening. When the coal sample tank (14) is removed from the pulverizer (2), the control switch is in a closed state.

4. The coal sample methane content detection device according to any one of claims 1 to 3, characterized in that, A first ventilation pipe (8) is connected between the pulverizer (2) and the gas analysis component. The flow meter (13) is installed on the first ventilation pipe (8). The length of the first ventilation pipe (8) is not less than 30 cm, and the inner diameter of the first ventilation pipe (8) is not greater than 6 cm.

5. The coal sample methane content detection device according to any one of claims 1 to 3, characterized in that, A first control valve (4) is installed between the pulverizer (2) and the blower (1); and / or, a second control valve (7) is installed between the pulverizer (2) and the flow meter (13).

6. The coal sample methane content detection device according to any one of claims 1 to 3, characterized in that, The gas blown by the blower (1) is air or nitrogen.

7. The coal sample methane content detection device according to any one of claims 1 to 3, characterized in that The gas analysis component is installed in a cabinet (3), and the cabinet (3) is enclosed.

8. A method for detecting the methane content of a coal sample, characterized in that, Applying the coal sample methane content detection device according to any one of claims 1 to 7, the detection method includes: Sampling at the coal mine site, putting the coal sample into the coal sample tank (14) and weighing to obtain the coal sample mass; Installing the coal sample tank (14) on the pulverizer (2), starting the pulverizer (2) to pulverize the coal sample into coal powder, and cooling it to room temperature; Starting the blower (1) for ventilation, the flow meter (13) and the gas analysis component respectively record the flowing gas flow rate and the methane concentration in the gas in real time, and draw a curve graph of the methane concentration changing with time; Dividing the curve graph of the methane concentration changing with time into n segments according to the detection frequency. The time points at both ends of each segment interval are t1 and t2 respectively. The average value of the methane concentration data measured by the detector at the time points t1 and t2 is the monitoring data of the gas analysis component in this segment interval. The methane concentration of each segment interval is as follows: The calculation formula for the methane content of each segment interval is as follows: Among them, is the methane content in the coal sample for each time interval, with the unit of cm 3 ; i is the monitoring frequency, that is, the time difference of each interval, with the unit of s; is the methane concentration detected by the detector for the nth interval, with the unit of ppm; v is the gas flow reading monitored and displayed by the flowmeter (13) in the ventilation duct; The total methane content in the coal sample is as follows: Among them, is the total methane content in the coal sample, with the unit of cm 3 ; is the methane content in the coal sample for each time interval, with the unit of cm 3 ; The calculation formula for the methane content per unit coal sample is as follows: Wherein, is the methane content of the unit coal sample, with the unit of cm 3 / g or m 3 / t; is the total methane content in the coal sample, with the unit of cm 3 ; m is the weight of the coal sample in the coal sample tank (14), with the unit of g.

9. The coal sample methane content detection method according to claim 8, characterized in that, In the step of starting the pulverizer (2) to pulverize the coal sample into coal powder, the pulverizing particle size of the coal powder is not greater than 0.25 mm.

10. The coal sample methane content detection method according to claim 8 or 9, characterized in that In the step of dividing into n segments according to the detection frequency, the time difference of each segment interval is not greater than 0.5 s.

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