Experimental device and method for researching influence of atmosphere humidity on normal-temperature oxidation of coal

Abstract

The invention discloses an experimental device and method for studying the influence of atmosphere humidity on normal-temperature oxidation of coal, and the device comprises a water bath box which is filled with a heating liquid; the top of the reaction kettle is detachably connected with a kettle cover, and the reaction kettle is filled with a coal sample; a coal body grinding assembly; the atmosphere constant humidity system comprises a humidity detection device, a humidification device, a dehumidification device and an interaction pipeline; an atmosphere circulation device; the vacuumizing device comprises a vacuum pump; the parameter detection system is composed of a temperature sensor I, a temperature sensor II, a temperature sensor III, a humidity sensor I, a CO2 sensor, a CO sensor, an O2 sensor, a temperature sensor IV, a humidity sensor II and a computer monitoring device; a power supply system; and controlling a gas circulation path. Through the synergistic effect of the dry air cylinder, the humidity configuration device and the humidification and dehumidification device, accurate regulation and dynamic stability of the atmosphere humidity in the reaction kettle can be realized.

Description

Technical Field

[0001] This invention relates to the field of coal mine safety technology, and in particular to an experimental apparatus and method for studying the effect of atmospheric humidity on the oxidation of coal at room temperature. Background Technology

[0002] Coal mines contain various harmful gases, including CO, H2S, and nitrogen oxides. Among these, CO is one of the most serious and common harmful gases posing a threat to coal miners. Generally, it is believed that high concentrations of CO originate primarily from spontaneous combustion and oxidation of coal underground. However, in recent years, with the large-scale mining of low-rank coal in regions such as Xinjiang and Inner Mongolia, abnormally high CO concentrations (CO > 24 ppm) have been observed in areas such as the upper corners and return airways of goafs, even without obvious signs of spontaneous combustion (such as increased temperature, coal wall condensation, or tar smell), seriously threatening safe coal mine production. Existing research indicates that low-rank coal, due to its low development grade and high reactivity, can react with oxygen in the air at room temperature, releasing high concentrations of CO. Therefore, scientifically exploring the room-temperature oxidation characteristics of low-rank coal in in-situ coal mine environments is of great significance for understanding and preventing abnormal CO production during normal mining of low-rank coal.

[0003] At present, various research institutions and universities have conducted extensive research on testing devices for the room temperature oxidation characteristics of coal, including but not limited to China Coal Technology & Engineering Group Shenyang Research Institute Co., Ltd., Taiyuan University of Technology, Liaoning University of Engineering and Technology, China University of Mining and Technology, and Anhui University of Science and Technology. However, although these experimental devices can explore the room temperature oxidation characteristics of coal to a certain extent, there are still many shortcomings, which are reflected in: (1) Under room temperature conditions, one of the important influencing factors affecting the reaction of coal with external oxygen is the moisture content in the coal body. The higher the moisture content in the coal body, the easier it is for the pores on the surface of the coal body to be blocked, and the less likely oxygen is to react with the coal body. Conversely, the lower the moisture content, the easier it is for the coal body to react with oxygen. Low-rank coal has a relatively high moisture content, which can reach 50-60%. Moreover, due to the large changes in humidity of the coal mine intake air atmosphere throughout the year, the moisture migration characteristics of low-rank coal are different, and the room temperature oxidation characteristics are naturally very different. At present, there is a lack of experimental equipment research on the effect of atmospheric humidity on coal oxidation at room temperature; (2) Different cutting and crushing strengths of coal bodies in the working face will inevitably lead to different coal oxidation capacity at room temperature, and this aspect has not yet been incorporated into the design of experimental equipment for the effect of coal oxidation at room temperature.

[0004] To address the aforementioned technical problems, this invention provides an experimental apparatus and method for studying the effect of atmospheric humidity on the oxidation of coal at room temperature. Summary of the Invention

[0005] The purpose of this invention is to provide an experimental apparatus and method for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides an experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, comprising: A water bath, wherein the water bath is filled with a heating liquid, which is water or silicone oil; A reaction vessel is placed inside a water bath. The top of the reaction vessel is detachably connected to a vessel lid. The reaction vessel is filled with a coal sample. A sealing strip is installed at the bottom of the vessel lid. A coal grinding assembly, comprising a grinding motor and a cutting blade, wherein the grinding motor is mounted on the reactor lid and the cutting blade is arranged inside the reactor and is driven by the grinding motor. The atmosphere humidification system consists of nitrogen cylinders, oxygen cylinders, dry air cylinders, pressure reducing valves, digital flow meters, and humidity configuration devices. A constant humidity system, comprising a humidity detection device, a humidification device, a dehumidification device, and an interconnecting pipeline; An atmosphere circulation device, comprising a circulation pump, wherein the circulation pump is used to control the gas circulation within the reactor; A vacuuming device, comprising a vacuum pump, wherein the vacuum pump is used to create a vacuum inside the reaction vessel; The parameter detection system comprises temperature sensor I, temperature sensor II, temperature sensor III, humidity sensor I, CO2 sensor, CO sensor, O2 sensor, temperature sensor IV, humidity sensor II, and a computer monitoring device. The power supply system includes a power supply device; The gas flow path control includes valves I, II, III, IV and V, and the waste gas is discharged through the exhaust port.

[0007] According to the experimental apparatus provided by the present invention for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, the water bath can achieve constant control of the liquid medium temperature between 10℃ and 30℃, thereby realizing constant simulation of the ambient temperature of underground coal samples.

[0008] According to the experimental apparatus provided by the present invention for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, the grinding motor in the coal grinding assembly can control the cutting speed and running time of the cutting blade, thereby achieving control over different cutting intensities of the coal sample.

[0009] According to the experimental apparatus provided by the present invention for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, the atmospheric humidity preparation system can control the combination of different gas flow rates by a digital flow meter, and adjust the preset humidity by a humidity configuration device to prepare atmospheres with different nitrogen / oxygen ratios and different humidity.

[0010] According to the experimental apparatus provided by the present invention for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, temperature sensor I is used to detect the liquid temperature in the water bath, temperature sensor II is used to detect the atmospheric temperature at the bottom of the reaction vessel, temperature sensor III is used to detect the internal temperature of the coal sample, humidity sensor I is used to detect the atmospheric humidity after the coal-oxygen reaction, CO2 sensor, CO sensor, and O2 sensor are used to detect the concentrations of CO2, CO, and O2 in the atmosphere above the reaction vessel, temperature sensor IV is used to detect the atmospheric temperature above the reaction vessel, humidity sensor II is used to detect the gas humidity at the humidity configuration device, and computer monitoring device is used to control the real-time acquisition frequency of the detection parameters and data export.

[0011] According to the experimental apparatus provided by the present invention for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, the vacuum pump is used to evacuate the reaction vessel and pipelines when valves I and V are closed and valves II, III and IV are open, thereby desorbing and removing the original gases present in the coal sample.

[0012] According to the experimental apparatus provided by the present invention for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, the circulating pump can circulate the gas inside the reactor when valves I and IV are closed and valves II and III are open.

[0013] According to the experimental apparatus provided by the present invention for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, the constant humidity system connects the humidity detection device with the gas inside the reactor through an interactive pipeline. When the humidity detection device detects that the humidity inside the reactor is less than or greater than the initial atmospheric humidity, the humidification device or the dehumidification device is activated to draw in the gas inside the reactor and humidify or dehumidify it. Then, the gas is introduced into the reactor through the interactive pipeline to achieve constant humidity of the atmosphere inside the reactor.

[0014] According to the experimental apparatus provided by the present invention for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, the power supply device is used to provide electrical energy.

[0015] An experimental method for studying the effect of atmospheric humidity on the oxidation of coal at room temperature includes the following steps: Step 1: Install the cutting blades of the coal grinding assembly, load 1.2-3 kg of coal sample into the reactor, place the sealing strip and tighten the reactor lid, check the sealing of the gas supply line and exhaust line, and inject heating liquid into the water bath. Step 2: Turn on the power supply, open the water bath, and set the heating liquid temperature to 10-30℃; Step 3: Open valves I and V, close valves II, III and IV, open the nitrogen cylinder, and flush the coal sample inside the reactor with nitrogen at a flow rate of 20 L / min for 30 minutes to carry out the original gas in the coal sample out of the reactor and discharge it through the exhaust port. Step 4: Close the nitrogen cylinder, close valves V and I, open valves II, III and IV, turn on the vacuum pump, and evacuate the reactor for 30 minutes to promote the desorption and discharge of the original gases in the coal sample. Step 5: Repeat steps 3 and 4 at least 3 times to completely remove the original gases present in the coal sample. Step 6: The room temperature oxidation characteristics of coal under different atmospheric humidity conditions are investigated using the controlled variable method.

[0016] The present invention discloses the following technical effects: This invention achieves precise control and dynamic stability of the humidity within a reactor by utilizing the synergistic effects of a dry air cylinder, a humidity configuration device, and humidification and dehumidification systems, coupled with real-time monitoring and feedback from dual humidity sensors. Compared to traditional devices that suffer from ambiguous humidity control and susceptibility to environmental interference, this invention accurately simulates different humidity conditions. Furthermore, by combining a humidity configuration system with a synergistic ratio of humidity and gas components, it effectively eliminates the interference of humidity fluctuations on experimental results. This provides a stable and controllable experimental environment for studying the quantitative impact of atmospheric humidity on the oxidation of coal at room temperature, significantly improving the accuracy and repeatability of experimental data.

[0017] This invention integrates multi-point temperature sensors, gas sensors, and computer monitoring devices, enabling simultaneous real-time acquisition of key parameters such as temperature in different areas of the coal sample, humidity inside the reactor, O2 consumption rate, and CO and CO2 generation. This allows for dynamic data tracking and automated recording. Compared to traditional single-parameter detection methods, it comprehensively captures the correlation between humidity and various physicochemical parameters during coal oxidation, clearly revealing the influence mechanism of humidity on the coal oxidation reaction rate, exothermic characteristics, and gaseous product release. This provides comprehensive and systematic data support for in-depth analysis of the humidity mechanism in coal oxidation at room temperature.

[0018] This invention integrates functional modules such as gas distribution, humidity control, circulation, vacuuming, and waste gas treatment. Multiple valves precisely control the gas flow path, and the detachable reaction vessel and grinding components facilitate coal sample loading, equipment cleaning, and operational mode switching. Simultaneously, the vacuuming device eliminates air interference, the atmosphere circulation device ensures reaction uniformity, and waste gas is treated through a dedicated exhaust port to avoid the risk of harmful gas leakage. This integrated design significantly simplifies experimental procedures, shortens preparation time, balances experimental efficiency and operational safety, and is adaptable to coal oxidation experiments under varying humidity conditions, demonstrating strong versatility. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the experimental apparatus used in this invention to study the effect of atmospheric humidity on the oxidation of coal at room temperature.

[0021] The components include: 1. Water bath; 2. Reactor; 3. Reactor lid; 4. Coal sample; 5. Mill motor; 6. Cutting blade; 7. Nitrogen cylinder; 8. Oxygen cylinder; 9. Dry air cylinder; 10. Pressure reducing valve; 11. Digital flow meter; 12. Humidity configuration device; 13. Humidity detection device; 14. Humidification device; 15. Dehumidification device; 16. Interconnected pipeline; 17. Circulation pump; 18. Vacuum pump; 19. Temperature sensor I; 20. Temperature sensor II; 21. Temperature sensor III; 22. Humidity sensor I; 23. CO2 sensor; 24. CO sensor; 25. O2 sensor; 26. Temperature sensor IV; 27. Humidity sensor II; 28. Computer monitoring device; 29. ​​Power supply device; 30. Valve I; 31. Valve II; 32. Valve III; 33. Valve IV; 34. Valve V; 35. Exhaust port. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Reference Figure 1 This invention provides an experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, comprising: Water bath 1, which is filled with a heating liquid, which is water or silicone oil; Reactor 2 is placed inside water bath 1. The top of reactor 2 is detachably connected to a lid 3. Reactor 2 is filled with coal sample 4. A sealing strip is installed at the bottom of lid 3. The coal grinding assembly includes a grinding motor 5 and a cutting blade 6. The grinding motor 5 is mounted on the vessel cover 3, and the cutting blade 6 is arranged inside the reactor 2 and is driven by the grinding motor 5. The atmosphere humidification system consists of a nitrogen cylinder 7, an oxygen cylinder 8, a dry air cylinder 9, a pressure reducing valve 10, a digital flow meter 11, and a humidity configuration device 12. The atmosphere humidity control system includes a humidity detection device 13, a humidification device 14, a dehumidification device 15, and an interactive pipeline 16. An atmosphere circulation device, including a circulation pump 17, is used to control the gas circulation inside the reactor 2. A vacuum pumping device, including a vacuum pump 18, is used to evacuate the reactor 2. The parameter detection system consists of temperature sensor I 19, temperature sensor II 20, temperature sensor III 21, humidity sensor I 22, CO2 sensor 23, CO sensor 24, O2 sensor 25, temperature sensor IV 26, humidity sensor II 27, and computer monitoring device 28. The power supply system includes a power supply device 29; The gas flow path control includes valves I 30, II 31, III 32, IV 33 and V 34, and the exhaust gas is discharged through exhaust port 35.

[0025] With further optimization, the water bath can achieve constant temperature control of any liquid medium between 10℃ and 30℃, thus realizing constant simulation of the environmental temperature of underground coal samples.

[0026] Further optimization of the scheme: the grinding motor 5 in the coal grinding assembly can control the cutting speed and running time of the cutting blade 6, thereby achieving control over different cutting intensities of the coal sample.

[0027] Further optimization of the scheme: the atmosphere humidification system can control the combination of different gas flow rates by digital flow meter 11, and adjust the preset humidity by humidity configuration device 12 to prepare atmospheres with different nitrogen / oxygen ratios and different humidity.

[0028] Further optimization of the scheme: Temperature sensor I 19 is used to detect the liquid temperature in the water bath; Temperature sensor II 20 is used to detect the atmosphere temperature at the bottom of reactor 2; Temperature sensor III 21 is used to detect the temperature inside coal sample 4; Humidity sensor I 22 is used to detect the humidity of the atmosphere after the coal-oxygen reaction; CO2 sensors 23, CO sensors 24, and O2 sensors 25 are used to detect the concentrations of CO2, CO, and O2 in the atmosphere above reactor 2; Temperature sensor IV 26 is used to detect the temperature of the atmosphere above reactor 2; Humidity sensor II 27 is used to detect the gas humidity at the humidity configuration device; and computer monitoring device 28 is used to control the real-time acquisition frequency of the detection parameters and data export.

[0029] The scheme is further optimized so that vacuum pump 18 is used to evacuate the reactor 2 and pipelines when valves I 30 and V 34 are closed and valves II 31, III 32 and IV 33 are open, thereby desorbing and extracting the original gas in coal sample 4.

[0030] With further optimization, the circulating pump 17 can circulate the gas inside the reactor 2 when valves I 30 and IV 33 are closed and valves II 31 and III 32 are open.

[0031] To further optimize the scheme, the constant humidity system connects the humidity detection device 13 with the gas inside the reactor 2 through the interactive pipeline 16. When the humidity detection device 13 detects that the humidity inside the reactor 2 is less than or greater than the initial humidity, the humidification device 14 or the dehumidification device 15 is activated to draw in the gas inside the reactor 2 and humidify or dehumidify it. Then, the gas is introduced into the reactor 2 through the interactive pipeline 16 to achieve constant humidity of the atmosphere inside the reactor 2.

[0032] The scheme was further optimized, and power supply device 29 was used to provide electrical energy.

[0033] An experimental method for studying the effect of atmospheric humidity on the oxidation of coal at room temperature includes the following steps: Step 1: Install the cutting blade 6 of the coal grinding assembly, load 1.2-3 kg of coal sample 4 into the reaction vessel 2, place the sealing strip and tighten the vessel lid 3, check the sealing of the gas supply pipeline and the exhaust pipeline, and inject heating liquid into the water bath 1. Step 2: Turn on the power supply device 29, turn on the water bath 1, and set the temperature of the heating liquid to 10-30℃; Step 3: Open valve I 30 and valve V 34, close valve II 31, valve III 32 and valve IV 33, open nitrogen cylinder 7, and flush the coal sample 4 inside the reactor 2 with nitrogen at a flow rate of 20 L / min for 30 min. This will carry the original gas in the coal sample 4 out of the reactor 2 and discharge it through exhaust port 35. Step 4: Close nitrogen cylinder 7, close valve V34 and valve I30, open valve II31, valve III32 and valve IV33, turn on vacuum pump 18, and evacuate reactor 2 for 30 minutes to promote the desorption and discharge of the original gases in coal sample 4. Step 5, repeat steps 3 and 4 at least 3 times to completely remove the original gas present in coal sample 4; Step 6: The room temperature oxidation characteristics of coal under different atmospheric humidity conditions are investigated using the controlled variable method.

[0034] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0035] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, characterized in that, include: Water bath (1), the water bath (1) is filled with heating liquid, the heating liquid is water or silicone oil; The reactor (2) is placed inside the water bath (1). The top of the reactor (2) is detachably connected to the lid (3). The reactor (2) is filled with a coal sample (4). A sealing strip is installed at the bottom of the lid (3). A coal grinding assembly, comprising a grinding motor (5) and a cutting blade (6), wherein the grinding motor (5) is mounted on the reactor cover (3), and the cutting blade (6) is arranged inside the reactor (2) and is in transmission cooperation with the grinding motor (5); The atmosphere humidification system consists of a nitrogen cylinder (7), an oxygen cylinder (8), a dry air cylinder (9), a pressure reducing valve (10), a digital flow meter (11), and a humidity configuration device (12); A constant humidity system, comprising a humidity detection device (13), a humidification device (14), a dehumidification device (15), and an interactive pipeline (16). An atmosphere circulation device, comprising a circulation pump (17) for controlling the gas circulation within the reactor (2); A vacuum pumping device, comprising a vacuum pump (18) for evacuating the reactor (2); The parameter detection system consists of temperature sensor I (19), temperature sensor II (20), temperature sensor III (21), humidity sensor I (22), CO2 sensor (23), CO sensor (24), O2 sensor (25), temperature sensor IV (26), humidity sensor II (27), and computer monitoring device (28). A power supply system, the power supply system including a power supply device (29); The gas flow path control includes valve I (30), valve II (31), valve III (32), valve IV (33) and valve V (34), and the exhaust gas is discharged through the exhaust port (35).

2. The experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature according to claim 1, characterized in that, The water bath can achieve constant temperature control of the liquid medium between 10℃ and 30℃, thus realizing constant simulation of the environmental temperature of underground coal samples.

3. The experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature according to claim 1, characterized in that, The grinding motor (5) in the coal grinding assembly can control the cutting speed and running time of the cutting blade (6) to achieve control over different cutting intensities of the coal sample.

4. The experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature according to claim 1, characterized in that, The atmosphere humidification system can be controlled by a digital flow meter (11) to combine different gas flow rates, and the preset humidity can be adjusted by a humidity configuration device (12) to prepare atmospheres with different nitrogen / oxygen ratios and different humidity.

5. The experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature according to claim 1, characterized in that, Temperature sensor I (19) is used to detect the liquid temperature in the water bath. Temperature sensor II (20) is used to detect the temperature of the atmosphere at the bottom of the reactor (2). Temperature sensor III (21) is used to detect the temperature inside the coal sample (4). Humidity sensor I (22) is used to detect the humidity of the atmosphere after the coal-oxygen reaction. CO2 sensor (23), CO sensor (24), and O2 sensor (25) are used to detect the concentrations of CO2, CO, and O2 in the atmosphere above the reactor (2). Temperature sensor IV (26) is used to detect the temperature of the atmosphere above the reactor (2). Humidity sensor II (27) is used to detect the humidity of the gas at the humidity configuration device. The computer monitoring device (28) is used to control the real-time acquisition frequency and data export of the detection parameters.

6. The experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature according to claim 1, characterized in that, The vacuum pump (18) is used to evacuate the reactor (2) and pipelines when valve I (30) and valve V (34) are closed and valve II (31), valve III (32) and valve IV (33) are open, so as to desorb and extract the original gas in the coal sample (4).

7. The experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature according to claim 1, characterized in that, The circulating pump (17) can circulate the gas inside the reactor (2) when valve I (30) and valve IV (33) are closed and valve II (31) and valve III (32) are open.

8. The experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature according to claim 1, characterized in that, The constant humidity system connects the humidity detection device (13) with the gas inside the reactor (2) through an interactive pipeline (16). When the humidity detection device (13) detects that the humidity inside the reactor (2) is less than or greater than the initial humidity, the humidification device (14) or the dehumidification device (15) is activated to draw in the gas inside the reactor (2) and humidify or dehumidify it. Then, the gas is introduced into the reactor (2) through the interactive pipeline (16) to achieve constant humidity of the atmosphere inside the reactor (2).

9. The experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature according to claim 1, characterized in that, The power supply device (29) is used to provide electrical energy.

10. An experimental method for studying the effect of atmospheric humidity on the oxidation of coal at room temperature, based on the experimental apparatus for studying the effect of atmospheric humidity on the oxidation of coal at room temperature as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Install the cutting blade (6) of the coal grinding assembly, load 1.2-3 kg of coal sample (4) into the reactor (2), place the sealing strip and tighten the reactor lid (3), check the sealing of the gas supply line and the exhaust line, and inject heating liquid into the water bath (1); Step 2: Turn on the power supply device (29), turn on the water bath (1), and set the temperature of the heating liquid to 10-30℃; Step 3: Open valve I (30) and valve V (34), close valve II (31), valve III (32) and valve IV (33), open nitrogen cylinder (7) and flush the coal sample (4) inside the reactor (2) with nitrogen flow rate of 20L / min for 30min, and carry the original gas in the coal sample (4) out of the reactor (2) and discharge it through exhaust port (35); Step 4: Close the nitrogen cylinder (7), close valve V (34) and valve I (30), open valve II (31), valve III (32) and valve IV (33), turn on the vacuum pump (18), and evacuate the reactor (2) for 30 minutes to promote the desorption and discharge of the original gas in the coal sample (4); Step 5, repeat steps 3 and 4 at least 3 times to completely remove the original gas present in the coal sample (4); Step 6: The room temperature oxidation characteristics of coal under different atmospheric humidity conditions are investigated using the controlled variable method.

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