A detection device for signature gases of raw coal spontaneous combustion and a spontaneous combustion early warning method

Abstract

The present invention discloses a detection device for the characteristic gases of raw coal spontaneous combustion, which relates to the technical field of raw coal spontaneous combustion detection and includes an inert gas container, an inert gas temperature control device connected to the inert gas container, a coal sample bottle connected to the inert gas temperature control device, a filtering mechanism connected to the coal sample bottle, a sampling mechanism connected to the filtering mechanism, a characteristic gas content detector connected to the sampling mechanism, and a control mechanism. A method for early warning of raw coal spontaneous combustion includes the steps of establishing a database by controlling experimental conditions and carrying out early warning of spontaneous combustion. The present invention can establish a raw coal spontaneous combustion database for different types of raw coal, different particle sizes of raw coal, different oxygen concentrations, different temperature information, and different characteristic gas contents, completely revealing the law of raw coal spontaneous combustion, so as to be able to predict the spontaneous combustion point of raw coal during the storage, transportation or mining of raw coal, and effectively avoid the occurrence of raw coal spontaneous combustion through prediction.

Description

Technical Field

[0001] The present invention relates to the technical field of raw coal spontaneous combustion detection, and particularly relates to a detection device for characteristic gases of raw coal spontaneous combustion and a spontaneous combustion early warning method. Background Art

[0002] Coal spontaneous combustion is an objective phenomenon existing in nature and has existed for millions of years. During the process of coal oxidation and temperature rise, index gases such as CO, CO2, alkanes, alkenes, and alkynes are released. The generation rates of these gases change regularly with the increase of coal temperature and can reflect the ignition state during coal spontaneous combustion. Among them, CO runs through the whole process of coal spontaneous combustion ignition, and can generally be detected above 50°C, with a relatively high concentration when it appears; alkanes (ethane, propane) appear almost simultaneously with CO and run through the whole process, but their concentrations are lower than that of CO, and there are different manifestation rules in different coal types; alkenes appear later than CO and alkanes. Ethylene can be detected at about 110°C and is a marker gas for the accelerated oxidation stage of the coal spontaneous combustion ignition process. When it starts to be generated, its concentration is slightly higher than that of alkyne gases; alkynes appear the latest and only appear in a relatively high temperature range, with an obvious temperature difference and time difference from the previous two, and are the products of the coal spontaneous combustion ignition entering the intense oxidation stage (i.e., the combustion stage).

[0003] Currently, the main index gases for coal spontaneous combustion ignition at home and abroad are CO, C2H6, CH4, C2H4, C2H2, △O2 (△O2 is the oxygen consumption) and other auxiliary indexes generated by them. In the patent documents retrieved by the applicant, there is still a lack of a device for detecting the content of characteristic gases of raw coal spontaneous combustion and predicting the spontaneous combustion ignition temperature of raw coal based on the content of characteristic gases. If a relevant device is developed, it can early warn the spontaneous combustion phenomenon of raw coal in storage, transportation and mining. Summary of the Invention

[0004] To solve the problems of the prior art, the present invention provides a detection device for characteristic gases of raw coal spontaneous combustion and a spontaneous combustion early warning method. The device can detect the content of characteristic gases of raw coal and reveal the law of raw coal spontaneous combustion based on the content of characteristic gases, so as to realize the prediction of raw coal spontaneous combustion phenomenon.

[0005] To solve the above problems, the technical solution of the present invention is as follows:

[0006] A detection device for the characteristic gases of raw coal spontaneous combustion, comprising an inert gas container, an inert gas temperature control device connected to the inert gas container, a coal sample bottle connected to the inert gas temperature control device, a filtering mechanism connected to the coal sample bottle, a sampling mechanism connected to the filtering mechanism, a characteristic gas content detector connected to the sampling mechanism, and a control mechanism. The coal sample bottle is equipped with a spontaneous combustion video acquisition device, an oxygen delivery device, and an oxygen content determination device. The inert gas container is connected to the inert gas temperature control device through a flow control mechanism. The inert gas is adjusted to a set temperature by the inert gas temperature control device and then transported to the coal sample bottle, and the coal sample characteristic gas is carried by the coal sample bottle into the filtering mechanism. The filtering mechanism inputs the filtered gas into the sampling mechanism, and the sampling mechanism inputs the sampled gas into the characteristic gas content detector. The control mechanism is electrically connected to the power supply module and is signal-connected to the spontaneous combustion video acquisition device, the oxygen content determination device, and the characteristic gas content detector through wires. The control mechanism is configured to control the flow control mechanism, the inert gas temperature control device, the oxygen delivery device, and the sampling mechanism.

[0007] Preferably, the inert gas container is a nitrogen container. The output end of the nitrogen container is connected to a first connecting pipe. The flow control mechanism is a first flow pump provided on the first connecting pipe. The first flow pump is electrically connected to the control mechanism through a wire.

[0008] Preferably, the inert gas temperature control device includes a muffle furnace, a circulation pipe, a second flow pump, and a serpentine heat transfer pipe. The first connecting pipe is a heat-insulating pipe. One end of the first connecting pipe away from the inert gas container penetrates through the muffle furnace and enters the heating chamber of the muffle furnace. The serpentine heat transfer pipe is provided in the heating chamber. The gas inlet end of the serpentine heat transfer pipe is connected to the end of the first connecting pipe. The other end of the serpentine heat transfer pipe is connected to a second connecting pipe. The second connecting pipe is a heat-insulating pipe. The second connecting pipe penetrates through the outer surface of the muffle furnace and is connected to the top of the coal sample bottle. A first electromagnetic valve and a second electromagnetic valve are respectively provided on the first connecting pipe and the second connecting pipe. The circulation pipe is U-shaped. One end of the circulation pipe is connected to the first connecting pipe between the first electromagnetic valve and the muffle furnace, and the other end is connected to the second connecting pipe between the second electromagnetic valve and the muffle furnace. A third electromagnetic valve and a fourth electromagnetic valve are respectively provided at both ends of the circulation pipe. A second flow pump is also provided on the circulation pipe. A first temperature sensor is installed in the pipe body of the second connecting pipe between the end of the circulation pipe and the muffle furnace. The first temperature sensor is signal-connected to the control mechanism through a wire. The first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve, the fourth electromagnetic valve, and the second flow pump are respectively electrically connected to the control mechanism through wires.

[0009] Preferably, the coal sample bottle includes a first sleeve and a second sleeve coaxially arranged inside the first sleeve. A coal sample storage space is formed between the inner wall of the first sleeve and the outer wall of the second sleeve. The top end of the second sleeve abuts against the lower surface of the top cover of the first sleeve. The end of the second connecting pipe penetrates through the top cover and enters the second sleeve. A number of air holes are evenly distributed on the side wall of the second sleeve. An annular ventilation sieve is connected between the outer edge of the bottom end of the second sleeve and the inner surface of the first sleeve. A transition air chamber is formed between the bottom end of the second sleeve and the bottom end of the first sleeve. An exhaust pipe is connected to the outer surface of the side wall of the transition air chamber. The spontaneous combustion video acquisition device includes a plurality of mounting plates evenly distributed on the outer surface of the first sleeve. A high-definition camera opposite to the outer wall of the first sleeve is installed on the mounting plate. An observation window is provided on the side wall of the first sleeve opposite to the high-definition camera. The oxygen delivery device includes an oxygen cylinder, a third flow pump and a third connecting pipe. One end of the third connecting pipe is connected to the oxygen cylinder, and the other end penetrates through the side wall of the first sleeve and communicates with the coal sample storage space. A fifth solenoid valve is provided on the third connecting pipe. The third flow pump is arranged on the third connecting pipe. The oxygen content measuring device is an oxygen concentration sensor installed on the side wall of the first sleeve and communicating with the coal sample storage space. The oxygen concentration sensor and the high-definition camera are respectively connected to the control mechanism through wires for signal connection. The control mechanism is respectively connected to the third flow pump and the fifth solenoid valve through wires for electrical connection.

[0010] Preferably, a sixth solenoid valve is provided at the end of the exhaust pipe facing the coal sample bottle. A fourth connecting pipe is connected to the pipe wall on the side of the exhaust pipe far from the sixth solenoid valve. A fourth flow pump and a filtering mechanism are provided on the fourth connecting pipe. A seventh solenoid valve is connected to the end of the exhaust pipe far from the fourth connecting pipe. A second temperature sensor and a pressure sensor are installed inside the pipe wall between the seventh solenoid valve and the sixth solenoid valve. The control mechanism is respectively connected to the sixth solenoid valve, the seventh solenoid valve and the fourth flow pump through wires for electrical connection, and is respectively connected to the second temperature sensor and the pressure sensor through wires for signal connection.

[0011] Preferably, the end of the fourth connecting pipe is connected to a fifth connecting pipe. The sampling mechanism includes a pneumatic ten-way automatic sampling valve provided on the fifth connecting pipe. The end of the fifth connecting pipe far from the pneumatic ten-way automatic sampling valve is connected to a signature gas content detector. The signature gas content detector is a chromatographic TCD detector. The control mechanism is respectively connected to the ten-way automatic sampling valve and the chromatographic TCD detector through wires for electrical connection.

[0012] Preferably, a central hole is provided in the top cover. A connecting pipe is provided at the upper end of the central hole. The end of the second connecting pipe is screwed to the connecting pipe. The top cover is screwed to the top end of the first sleeve.

[0013] A method for early warning of raw coal spontaneous combustion, comprising the following steps:

[0014] Step 1: Sample loading: Disassemble the connection between the connecting pipe and the second connecting pipe, unscrew the top cover, evenly add the coal sample into the annular coal sample storage space, record the pre-measured average particle size of the coal sample, screw on the top cover, and connect the second connecting pipe; the operator inputs the raw coal particle size information to the control mechanism through the human-computer interaction device;

[0015] Step 2: Turn on the start button of the control mechanism. Under the control of the control mechanism, the first flow pump starts working to input nitrogen into the serpentine heat pipe. The muffle furnace is pre-set to a first temperature. The nitrogen is heated in the muffle furnace. When the first temperature sensor detects that the temperature is qualified, the second solenoid valve is opened to allow the nitrogen to enter the coal sample bottle. When the first temperature sensor detects that the temperature is not enough, the third solenoid valve and the fourth solenoid valve are opened, and the first flow pump, the first solenoid valve, and the second solenoid valve are closed. The nitrogen is sucked by the second flow pump through the circulation pipe and enters the serpentine heat pipe for circulation and heating to the specified temperature. At the same time, the sixth solenoid valve 32 is closed, the third flow pump and the fifth solenoid valve are opened, and the oxygen concentration in the coal sample bottle is detected by the oxygen concentration sensor. When the oxygen concentration in the coal sample storage space reaches the set standard, the third flow pump and the fifth solenoid valve are closed, and the oxygen concentration sensor transmits the oxygen concentration signal to the control mechanism.

[0016] Step 3. Under the control of the control mechanism, the first flow pump pushes the nitrogen heated to the set temperature into the second sleeve by conveying nitrogen, and distributes it to the coal sample storage space through a number of air holes; in this process, the high-definition camera collects video information of the raw coal storage space corresponding to the angle, and the control mechanism records and stores the video information and the position information of the corresponding high-definition camera; the sixth solenoid valve is opened, and the nitrogen-doped coal powder and the raw coal characteristic gas enter the exhaust pipe through the annular ventilation screen; when the second temperature sensor detects that the temperature of the gas in the exhaust pipe matches the set temperature of the nitrogen, the fourth flow pump is opened, and the gas is pumped into the filter mechanism through the fourth connecting pipe, and enters the pneumatic ten-way automatic sampling valve through the filtering mechanism; the control mechanism realizes quantitative sampling by controlling the pneumatic ten-way automatic sampling valve, and the sampled gas enters the chromatographic TCD detector through the fifth connecting pipe; the control mechanism controls the seventh solenoid valve according to the data of the pressure sensor, and when the pressure in the exhaust pipe exceeds the set value, the seventh solenoid valve opens to exhaust, and the pressure in the coal sample bottle is stabilized by controlling the seventh solenoid valve;

[0017] Step 4: The control mechanism establishes a correspondence between the video information collected by the high-definition camera, the temperature information of the gas in the coal sample bottle detected by the second temperature sensor, and the raw coal particle size information according to a preset program, and uses them as raw data to start building a database;

[0018] Step 5: Repeat Steps 1 - 4. By setting the muffle furnace to the second temperature, the third temperature... the Nth temperature, establish a first data set of the spontaneous combustion temperature points of the same raw coal sample at different temperatures and the same oxygen concentration; repeat Steps 1 - 4. By setting the muffle furnace to the second temperature, the third temperature... the Nth temperature and changing the oxygen concentration in the raw coal storage space, establish a second data set of the spontaneous combustion temperature points of the same raw coal sample at different temperatures and different oxygen concentrations; replace the type of the raw coal sample and repeat the above steps to establish a third data set of the spontaneous combustion temperature points of different raw coal samples at different temperatures and the same oxygen concentration and a fourth data set of the spontaneous combustion temperature points at different temperatures and different oxygen concentrations; change the particle size of the raw coal, update the first data set, the second data set, the third data set, and the fourth data set, and form corresponding fifth data set, sixth data set, seventh data set, and eighth data set.

[0019] Step 6: Prediction of the spontaneous combustion point of raw coal: According to the type information, particle size information, oxygen concentration information of the raw coal in storage, transportation or mining, as well as the marker gas concentration information collected on site and the temperature information of the raw coal storage location, retrieve the temperature point of the spontaneous combustion of the raw coal from the database and give an early warning.

[0020] The automatic detection device for the sealing quality of a roller of the present invention has the following beneficial effects: The present invention can establish a database for the spontaneous combustion of raw coal for different types of raw coal, different particle sizes of raw coal, different oxygen concentrations, different temperature information, and different marker gas contents, and completely reveal the law of the spontaneous combustion of raw coal, so as to be able to predict the spontaneous combustion point of the raw coal during the storage, transportation or mining of the raw coal. Through the prediction, the occurrence of the spontaneous combustion of the raw coal can be effectively avoided. Description of the Drawings

[0021] Figure 1 The structural schematic diagram of the present invention;

[0022] Figure 2 The sectional structural schematic diagram of the coal sample bottle of the present invention;

[0023] 1: Inert gas container, 2: First solenoid valve, 3: Muffle furnace, 4: Serpentine heat transfer pipe, 5: First connecting pipe, 6: Circulation pipe, 7: Third solenoid valve, 8: Second connecting pipe, 9: Fourth solenoid valve, 10: Second flow pump, 11: Mounting plate, 12: Second solenoid valve, 13: Second sleeve, 14: Coal sample storage space, 15: Oxygen concentration sensor, 16: Annular ventilation sieve, 17: Sieve holes, 18: Transition air chamber; 19: Exhaust pipe, 20: Second temperature sensor, 21: Pressure sensor, 22: Seventh solenoid valve, 23: Fourth flow pump, 24: Filter mechanism, 25: Pneumatic ten-way automatic sampling valve, 26: Chromatographic TCD detector, 27: Control mechanism, 28, High-definition camera; 29: Observation window, 30: Oxygen cylinder, 31: Third flow pump, 32: Sixth solenoid valve, 33: First sleeve, 34, Ventilation holes; 35: Raw coal, 36, Raw coal pressure sensor; 37: First temperature sensor. Detailed implementation manners

[0024] The following is a detailed description of the embodiments of the present invention in a step-by-step manner. This description is only for the preferred embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0025] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the purpose 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, as well as a specific orientation structure and operation. Therefore, it should not be construed as a limitation to the present invention.

[0026] Example 1, as Figure 1-2 shown:

[0027] A detection device for the signature gases of raw coal spontaneous combustion, comprising an inert gas container 1, an inert gas temperature control device connected to the inert gas container 1, a coal sample bottle connected to the inert gas temperature control device, a filtering mechanism connected to the coal sample bottle, a sampling mechanism connected to the filtering mechanism, a signature gas content detector connected to the sampling mechanism, and a control mechanism 27. The coal sample bottle is equipped with a spontaneous combustion video acquisition device, an oxygen delivery device, and an oxygen content determination device. The inert gas container 1 is connected to the inert gas temperature control device through a flow control mechanism. The inert gas is adjusted to a set temperature by the inert gas temperature control device and then delivered to the coal sample bottle, and the raw coal signature gas is carried by the coal sample bottle into the filtering mechanism. The filtering mechanism inputs the filtered gas into the sampling mechanism, and the sampling mechanism inputs the sampled gas into the signature gas content detector. The control mechanism is electrically connected to the power supply module and is signal-connected to the spontaneous combustion video acquisition device, the oxygen content determination device, and the signature gas content detector through wires. The control mechanism is configured to control the flow control mechanism, the inert gas temperature control device, the oxygen delivery device, and the sampling mechanism.

[0028] In this embodiment, the signature gases can be one or several of the coal spontaneous combustion index gases: CO, C2H6, CH4, C2H4, C2H2, △O2 (△O2 is the oxygen consumption). By controlling the temperature of nitrogen, the coal sample can reach the set temperature, and the types and concentrations of the signature gases at this temperature can be measured. By observing the spontaneous combustion phenomenon through video, the spontaneous combustion point temperature of the raw coal can be accurately grasped, and a corresponding relationship can be established between this spontaneous combustion point temperature, the concentration of the signature gases, the particle size of the raw coal, the oxygen concentration in the raw coal sample, and the temperature of the raw coal sample. Through this corresponding relationship, a database can be further established. Through the complete database, the law of raw coal spontaneous combustion can be revealed. This law includes the information of the process before and after spontaneous combustion, that is, it records how spontaneous combustion occurs little by little and how it becomes more and more intense. Based on the database, the prediction of the raw coal spontaneous combustion point can be realized.

[0029] Example 2 is as Figure 1-2 shown:

[0030] On the basis of Example 1, this embodiment discloses:

[0031] The inert gas container 1 is a nitrogen container. The output end of the nitrogen container is connected to a first connecting pipe 5. The flow control mechanism is a first flow pump (not shown in the figure) provided on the first connecting pipe 5. The first flow pump is electrically connected to the control mechanism through a wire.

[0032] The described inert gas temperature control device includes a muffle furnace 3, a circulation pipe 6, a second flow pump 10, and a serpentine heat-permeable pipe 4. The first connecting pipe 5 is a heat-insulating pipe. One end of the first connecting pipe 5 away from the inert gas container 1 penetrates through the muffle furnace 3 and enters the heating chamber of the muffle furnace. The serpentine heat-permeable pipe 4 is arranged in the heating chamber. The air inlet end of the serpentine heat-permeable pipe 4 is connected to the end of the first connecting pipe 5. The other end of the serpentine heat-permeable pipe 4 is connected to a second connecting pipe 8. The second connecting pipe 8 is a heat-insulating pipe. The second connecting pipe 8 penetrates through the outer surface of the muffle furnace and is connected to the top of the coal sample bottle. First solenoid valves 2 and second solenoid valves 12 are respectively arranged on the first connecting pipe 5 and the second connecting pipe 8. The circulation pipe 6 is U-shaped. One end of the circulation pipe 6 is connected to the first connecting pipe between the first solenoid valve 2 and the muffle furnace 3, and the other end is connected to the second connecting pipe between the second solenoid valve 12 and the muffle furnace 3. Third solenoid valves 7 and fourth solenoid valves 9 are respectively arranged at both ends of the circulation pipe 6. A second flow pump 10 is also arranged on the circulation pipe. A first temperature sensor 37 is installed in the pipe body of the second connecting pipe 8 between the end of the circulation pipe and the muffle furnace. The first temperature sensor 37 is signal-connected to the control mechanism through a wire. The first solenoid valve 2, the second solenoid valve 12, the third solenoid valve 7, the fourth solenoid valve 9, and the second flow pump 10 are respectively electrically connected to the control mechanism 27 through wires.

[0033] It should be noted that the nitrogen capacity in the serpentine pipe should fully meet the requirements of the sampling volume. At the same time, nitrogen can be pre-filled in the circulation pipe to avoid the mixing of other gases. The first connecting pipe and the second connecting pipe are both heat-insulating pipes to avoid heat loss. The muffle furnace can set the heating temperature as needed. By controlling the circulation pipe and the second flow pump, the temperature of nitrogen can accurately reach the experimental detection standard.

[0034] Example 3 is as Figure 1-2 shown:

[0035] On the basis of Example 2, this example is improved as:

[0036] The described coal sample bottle includes a first sleeve 33 and a second sleeve 13 coaxially arranged inside the first sleeve 33. A coal sample storage space 14 is formed between the inner wall of the first sleeve 33 and the outer wall of the second sleeve 13. The top end of the second sleeve 13 abuts against the lower surface of the top cover of the first sleeve 33. The end of the second connecting pipe 8 penetrates through the top cover and enters the second sleeve 13. A number of ventilation holes 34 are evenly distributed on the side wall of the second sleeve 13. An annular ventilation sieve 16 is connected between the outer edge of the bottom end of the second sleeve 13 and the inner surface of the first sleeve 33. A transition air chamber 18 is formed between the bottom end of the second sleeve 13 and the bottom end of the first sleeve 33. An exhaust pipe 19 is connected to the outer surface of the side wall of the transition air chamber 18. The spontaneous combustion ignition video acquisition device includes a plurality of mounting plates 11 evenly distributed on the outer surface of the first sleeve. A high-definition camera 28 opposite to the outer wall of the first sleeve 33 is mounted on the mounting plate 11. An observation window 29 is provided on the side wall of the first sleeve 33 opposite to the high-definition camera 28. The oxygen delivery device includes an oxygen cylinder 30, a third flow pump 31 and a third connecting pipe (not marked in the figure). One end of the third connecting pipe is connected to the oxygen cylinder 30, and the other end penetrates through the side wall of the first sleeve and communicates with the coal sample storage space 14. A fifth solenoid valve (not shown in the figure) is provided on the third connecting pipe. The third flow pump 31 is arranged on the third connecting pipe. The oxygen content measuring device is an oxygen concentration sensor 15 installed on the side wall of the first sleeve 33 and communicating with the coal sample storage space 14. The oxygen concentration sensor 15 and the high-definition camera 28 are respectively connected to the control mechanism 27 through wires for signal connection. The control mechanism 27 is respectively connected to the third flow pump 21 and the fifth solenoid valve through wires for electrical connection. The observation window can be made of transparent heat-resistant material, such as PAM board.

[0037] A sixth solenoid valve 32 is provided at the end of the exhaust pipe 19 facing the coal sample bottle. A fourth connecting pipe (not marked in the figure) is connected to the pipe wall on the side of the exhaust pipe 19 away from the sixth solenoid valve 32. A fourth flow pump 23 and a filtering mechanism 24 are provided on the fourth connecting pipe. The end of the exhaust pipe 19 away from the fourth connecting pipe is connected to a seventh solenoid valve 22. A second temperature sensor 20 and a pressure sensor 21 are installed inside the pipe wall between the seventh solenoid valve 22 and the sixth solenoid valve 32. The control mechanism 27 is respectively connected to the sixth solenoid valve 32, the seventh solenoid valve 22 and the fourth flow pump 23 through wires for electrical connection, and is respectively connected to the second temperature sensor 20 and the pressure sensor 21 through wires for signal connection.

[0038] The end of the fourth connecting pipe is connected to a fifth connecting pipe. The sampling mechanism includes a pneumatic ten-way automatic sampling valve 25 provided on the fifth connecting pipe. The end of the fifth connecting pipe away from the pneumatic ten-way automatic sampling valve is connected to a signature gas content detector, and the signature gas content detector is a chromatographic TCD detector 26. The control mechanism 27 is electrically connected to the ten-way automatic sampling valve 25 and the chromatographic TCD detector 26 through wires.

[0039] The top cover is provided with a central hole, and a connecting pipe is provided at the upper end of the central hole. The end of the second connecting pipe 8 is screwed to the connecting pipe, and the top cover is screwed to the top end of the first sleeve 33.

[0040] Example 4 is as Figure 1-2 shown:

[0041] Based on Example 3, this example discloses:

[0042] A method for early warning of spontaneous combustion of raw coal, including the following steps:

[0043] Step 1, sample loading: Disconnect the connection between the connecting pipe and the second connecting pipe, unscrew the top cover, evenly add coal samples to the annular coal sample storage space, record the average particle size of the coal samples measured in advance, screw on the top cover, and connect the second connecting pipe; the operator inputs the particle size information of the raw coal to the control mechanism through the human-computer interaction device; since the spontaneous combustion of raw coal is also greatly related to the particle size of the raw coal, the present invention takes the particle size information as one of the control parameters. Generally speaking, the smaller the particle size, the larger the contact area with air, and the easier it is to occur spontaneous combustion;

[0044] Step 2, turn on the start button of the control mechanism. Under the control of the control mechanism, the first flow pump works to input nitrogen into the serpentine heat pipe. The muffle furnace is preset with a first temperature, and the nitrogen is heated in the muffle furnace. When the first temperature sensor detects that the temperature is qualified, the second solenoid valve is opened to allow nitrogen to enter the coal sample bottle; when the first temperature sensor detects that the temperature is insufficient, the third solenoid valve and the fourth solenoid valve are opened, the first flow pump, the first solenoid valve, and the second solenoid valve are closed, and the nitrogen is sucked through the second flow pump through the circulation pipe into the serpentine heat pipe for circulating heating to the specified temperature; at the same time, the sixth solenoid valve 32 is closed, the third flow pump and the fifth solenoid valve are opened, and the oxygen concentration in the coal sample bottle is detected through the oxygen concentration sensor to make the oxygen concentration in the coal sample storage space reach the set standard. Then the third flow pump and the fifth solenoid valve are closed, and the oxygen concentration sensor transmits the oxygen concentration signal to the control mechanism; it should be noted that the adjustment of the oxygen concentration in the present invention is a simulation of the oxygen concentration difference in the actual raw coal storage environment, and fine-tuning based on different oxygen concentrations can detect the influence of oxygen concentration on the spontaneous combustion of raw coal, so as to provide data reference for controlling the oxygen concentration of the storage environment;

[0045] Step 3: Under the control of the control mechanism, the first flow pump pushes the nitrogen heated to the set temperature into the second sleeve by transporting nitrogen, and distributes it into the coal sample storage space through a number of air permeable holes. Such transportation can make the nitrogen evenly distributed in the coal sample. The coal sample is heated to the same temperature by nitrogen at a certain temperature. By controlling the temperature, it is detected at what temperature range and concentration the marker gas occurs; during this process, the high-definition camera collects the video information of the raw coal storage space corresponding to the angle where it is located, and the control mechanism records and stores the video information and the position information of the corresponding high-definition camera. The video information can be processed into picture information through a software program, and this picture information can record the process and degree of spontaneous combustion of the raw coal; open the sixth solenoid valve, and the nitrogen doped with coal powder and the raw coal marker gas enter the exhaust pipe through the annular ventilation sieve. When the second temperature sensor detects that the temperature of the gas in the exhaust pipe matches the set temperature of the nitrogen (here, "matches" means allowing a small error. After all, there will be a small heat loss during the transportation of nitrogen), open the fourth flow pump (here, the temperature of the nitrogen is matched with the temperature in the coal sample bottle, so that the raw coal can be tested at the set temperature), pump the gas into the filtering mechanism through the fourth connecting pipe (such filtering mechanisms are common technologies, mainly to filter out the coal powder contained in the gas, and a molecular-level filtering device can be used), and enter the pneumatic ten-way automatic sampling valve through the filtering mechanism. The control mechanism realizes quantitative sampling by controlling the pneumatic ten-way automatic sampling valve. When the pumping speed of the fourth flow pump is constant, the amount of sampling per unit time is certain. The sampling amount is controlled by controlling the sampling time of the pneumatic ten-way automatic sampling valve. The sampled gas enters the chromatographic TCD detector through the fifth connecting pipe. The principle of this instrument for detecting gas content is prior art and will not be elaborated; the control mechanism controls the seventh solenoid valve according to the data of the pressure sensor. When the pressure in the exhaust pipe exceeds the set value, the seventh solenoid valve opens for exhaust. By controlling the seventh solenoid valve, the pressure in the coal sample bottle is stabilized, avoiding the interference of unstable pressure on the spontaneous combustion ignition point of the coal sample;

[0046] Step 4: The control mechanism establishes a corresponding relationship among the video information collected by the high-definition camera, the temperature information of the gas in the coal sample bottle detected by the second temperature sensor, and the raw coal particle size information according to the preset program, and starts to establish a database with this as the original data;

[0047] Step 5: Repeat Steps 1-4. By setting the muffle furnace to the second temperature, the third temperature, ..., the Nth temperature, establish the first data set of spontaneous combustion temperature points of the same raw coal sample at different temperatures and the same oxygen concentration; repeat Steps 1-4. By setting the muffle furnace to the second temperature, the third temperature, ..., the Nth temperature and changing the oxygen concentration in the raw coal storage space, establish the second data set of spontaneous combustion temperature points of the same raw coal sample at different temperatures and different oxygen concentrations; replace the type of the raw coal sample and repeat the above steps to establish the third data set of spontaneous combustion temperature points of different raw coal samples at different temperatures and the same oxygen concentration and the fourth data set of spontaneous combustion temperature points at different temperatures and different oxygen concentrations; change the particle size of the raw coal and update the first data set, the second data set, the third data set, and the fourth data set to form the corresponding fifth data set, sixth data set, seventh data set, and eighth data set; raw coal refers to the coal obtained by screening and processing raw coal dug from the ground or underground to remove gangue, pyrite, etc. The raw coal produced in coal mines without washing and processing is also called raw coal. It includes natural coke and low-quality coal, excluding low-calorie coal, etc. It can be classified into peat, lignite, bituminous coal, and anthracite according to its carbonization degree. Replacing the type of raw coal can broaden the scope of the database and make the present invention have a wide range of application scenarios.

[0048] Step 6: Prediction of the spontaneous combustion point of raw coal: According to the type information, particle size information, oxygen concentration information of the raw coal in storage, transportation or mining, the concentration information of the marker gas collected on site, and the temperature information of the raw coal storage location, retrieve the temperature point of the spontaneous combustion of the raw coal from the database and issue a warning. For example, for Class A raw coal; the particle size is B, the oxygen concentration is C, the concentration of the marker gas is D, and the temperature information is E. Substitute the data of ABCDE into the database for retrieval, find the corresponding experimental data, and predict how much the temperature needs to rise further to cause spontaneous combustion or how much the oxygen concentration needs to increase further to cause spontaneous combustion or how much the particle size needs to change to cause spontaneous combustion or how much the concentration of the marker gas needs to increase further to cause spontaneous combustion based on the data set corresponding to the experimental data. Based on the above prediction and analysis, the transportation, storage, and mining environments of the raw coal can be controlled to prevent spontaneous combustion accidents.

Claims

1. A detection device for the signature gas of raw coal spontaneous combustion, characterized in that: It includes an inert gas container, an inert gas temperature control device connected to the inert gas container, a coal sample bottle connected to the inert gas temperature control device, a filtering mechanism connected to the coal sample bottle, a sampling mechanism connected to the filtering mechanism, a signature gas content detector connected to the sampling mechanism, and a control mechanism; The coal sample bottle is equipped with a spontaneous combustion video acquisition device, an oxygen delivery device, and an oxygen content determination device. The inert gas container is connected to the inert gas temperature control device through a flow control mechanism. The inert gas is adjusted to a set temperature by the inert gas temperature control device and then transported to the coal sample bottle, and the original coal signature gas is carried by the coal sample bottle into the filtering mechanism; The filtering mechanism inputs the filtered gas into the sampling mechanism. The sampling mechanism inputs the sampled gas into the signature gas content detector. The control mechanism is electrically connected to the power supply module and is signal-connected to the spontaneous combustion video acquisition device, the oxygen content determination device, and the signature gas content detector through wires. The control mechanism is configured to control the flow control mechanism, the inert gas temperature control device, the oxygen delivery device, and the sampling mechanism; The inert gas temperature control device includes a muffle furnace, a circulation pipe, a second flow pump, and a serpentine heat pipe. The first connecting pipe is a heat-insulating pipe. One end of the first connecting pipe away from the inert gas container penetrates through the muffle furnace and enters the heating chamber of the muffle furnace; The serpentine heat pipe is arranged in the heating chamber. The air inlet end of the serpentine heat pipe is connected to the end of the first connecting pipe. The other end of the serpentine heat pipe is connected to a second connecting pipe. The second connecting pipe is a heat-insulating pipe. The second connecting pipe penetrates through the outer surface of the muffle furnace and is connected to the top of the coal sample bottle; The coal sample bottle includes a first sleeve and a second sleeve coaxially arranged inside the first sleeve. A coal sample storage space is formed between the inner wall of the first sleeve and the outer wall of the second sleeve; The top end of the second sleeve abuts against the lower surface of the top cover of the first sleeve. The end of the second connecting pipe penetrates through the top cover and enters the second sleeve. A number of ventilation holes are evenly distributed on the side wall of the second sleeve. An annular ventilation sieve is connected between the outer edge of the bottom end of the second sleeve and the inner surface of the first sleeve. A transition air chamber is formed between the bottom end of the second sleeve and the bottom end of the first sleeve. An exhaust pipe is connected to the outer surface of the side wall of the transition air chamber; The spontaneous combustion video acquisition device includes a plurality of mounting plates evenly distributed on the outer surface of the first sleeve. A high-definition camera opposite to the outer wall of the first sleeve is mounted on the mounting plate. An observation window is provided on the side wall of the first sleeve opposite to the high-definition camera. The oxygen delivery device includes an oxygen cylinder, a third flow pump, and a third connecting pipe. One end of the third connecting pipe is connected to the oxygen cylinder, and the other end penetrates through the side wall of the first sleeve and communicates with the coal sample storage space. A fifth solenoid valve is provided on the third connecting pipe; The control mechanism is configured with a human-computer interaction device. The human-computer interaction device is provided with an original coal particle size input window. The original coal particle size is the average particle size of the coal sample measured in advance.

2. The detection device for the signature gas of raw coal spontaneous combustion according to claim 1, characterized in that: The inert gas container is a nitrogen container. The output end of the nitrogen container is connected with a first connecting pipe. The flow control mechanism is a first flow pump arranged on the first connecting pipe. The first flow pump is electrically connected with the control mechanism through a wire.

3. The detection device for the signature gas of raw coal spontaneous combustion according to claim 2, characterized in that: A first solenoid valve and a second solenoid valve are respectively arranged on the first connecting pipe and the second connecting pipe. The circulation pipe is U-shaped. One end of the circulation pipe is connected with the first connecting pipe between the first solenoid valve and the muffle furnace, and the other end is connected with the second connecting pipe between the second solenoid valve and the muffle furnace. A third solenoid valve and a fourth solenoid valve are respectively arranged at both ends of the circulation pipe. A second flow pump is also arranged on the circulation pipe; A first temperature sensor is installed in the pipe body between the end of the second connecting pipe and the muffle furnace of the circulation pipe. The first temperature sensor is signal-connected with the control mechanism through a wire. The first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve and the second flow pump are respectively electrically connected with the control mechanism through wires.

4. The detection device for the signature gas of raw coal spontaneous combustion according to claim 3, characterized in that: The third flow pump is arranged on the third connecting pipe; the oxygen content measuring device is an oxygen concentration sensor installed on the side wall of the first sleeve and communicated with the coal sample storage space. The oxygen concentration sensor and the high-definition camera are respectively signal-connected with the control mechanism through wires. The control mechanism is respectively electrically connected with the third flow pump and the fifth solenoid valve through wires.

5. The detection device for the signature gas of raw coal spontaneous combustion according to claim 4, characterized in that: A sixth solenoid valve is arranged at one end of the exhaust pipe facing the coal sample bottle. A fourth connecting pipe is connected to the pipe wall on the side of the exhaust pipe away from the sixth solenoid valve; A fourth flow pump and a filtering mechanism are arranged on the fourth connecting pipe. One end of the exhaust pipe away from the fourth connecting pipe is connected with a seventh solenoid valve. A second temperature sensor and a pressure sensor are installed in the pipe wall between the seventh solenoid valve and the sixth solenoid valve; The control mechanism is respectively electrically connected with the sixth solenoid valve, the seventh solenoid valve and the fourth flow pump through wires, and is respectively signal-connected with the second temperature sensor and the pressure sensor through wires.

6. The detection device for the signature gas of raw coal spontaneous combustion according to claim 5, characterized in that: The end of the fourth connecting pipe is connected with a fifth connecting pipe. The sampling mechanism includes a pneumatic ten-way automatic sampling valve arranged on the fifth connecting pipe; One end of the fifth connecting pipe away from the pneumatic ten-way automatic sampling valve is connected with the signature gas content detector. The signature gas content detector is a chromatographic TCD detector. The control mechanism is respectively electrically connected with the ten-way automatic sampling valve and the chromatographic TCD detector through wires.

7. The detection device for the signature gas of raw coal spontaneous combustion according to claim 6, characterized in that: The top cover is provided with a central hole. A connecting pipe is arranged at the upper end of the central hole. The end of the second connecting pipe is screwed with the connecting pipe. The top cover is screwed with the top end of the first sleeve.

8. A method for early warning of spontaneous combustion of raw coal, characterized by Using the detection device for the signature gas of raw coal spontaneous combustion according to claim 7, the following steps are included: Step 1. Sample loading: Disconnect the connection between the connecting pipe and the second connecting pipe, unscrew the top cover, evenly add coal samples to the annular coal sample storage space, record the average particle size of the coal samples measured in advance, screw on the top cover, and connect the second connecting pipe; the operator inputs the particle size information of the raw coal to the control mechanism through the man-machine interaction device. Step 2. Press the start button of the control mechanism. Under the control of the control mechanism, the first flow pump operates to input nitrogen into the serpentine heat pipe. The muffle furnace is preset with the first temperature. The nitrogen is heated in the muffle furnace. When the first temperature sensor detects that the temperature is qualified, the second solenoid valve is opened to allow nitrogen to enter the coal sample bottle. When the first temperature sensor detects that the temperature is insufficient, open the third solenoid valve and the fourth solenoid valve, close the first flow pump, the first solenoid valve, and the second solenoid valve, and suck nitrogen through the second flow pump into the serpentine heat pipe through the circulation pipe for cyclic heating to the specified temperature. Meanwhile, close the sixth solenoid valve, open the third flow pump and the fifth solenoid valve, detect the oxygen concentration in the coal sample bottle through the oxygen concentration sensor, make the oxygen concentration in the coal sample storage space reach the set standard, close the third flow pump and the fifth solenoid valve, and the oxygen concentration sensor transmits the oxygen concentration signal to the control mechanism. Step 3. Under the control of the control mechanism, the first flow pump pushes the nitrogen heated to the set temperature into the second sleeve by transporting nitrogen, and distributes it to the coal sample storage space through a number of air permeable holes. During this process, the high-definition camera collects the video information of the raw coal storage space corresponding to the angle where it is located, and the control mechanism records and stores the video information and the position information of the corresponding high-definition camera. Open the sixth solenoid valve. The nitrogen-doped coal powder and the characteristic gas of the raw coal enter the exhaust pipe through the annular air permeable sieve. When the second temperature sensor detects that the temperature of the gas in the exhaust pipe matches the set temperature of the nitrogen, open the fourth flow pump, pump the gas through the fourth connecting pipe into the filtering mechanism, and then into the pneumatic ten-way automatic sampling valve. The control mechanism realizes quantitative sampling by controlling the pneumatic ten-way automatic sampling valve. The sampled gas enters the chromatographic TCD detector through the fifth connecting pipe; the control mechanism controls the seventh solenoid valve according to the data of the pressure sensor. When the pressure in the exhaust pipe exceeds the set value, the seventh solenoid valve is opened for exhaust, and the pressure in the coal sample bottle is stabilized by controlling the seventh solenoid valve. Step 4. The control mechanism establishes a corresponding relationship between the video information collected by the high-definition camera, the temperature information of the gas in the coal sample bottle detected by the second temperature sensor, and the raw coal particle size information according to the preset program, and starts to establish a database as the original data. Step 5. Repeat Steps 1-4. By setting the muffle furnace to the second temperature, the third temperature... the Nth temperature, establish the first data set of the spontaneous combustion temperature points of the same raw coal sample at different temperatures and the same oxygen concentration; repeat Steps 1-4. By setting the muffle furnace to the second temperature, the third temperature... the Nth temperature, change the oxygen concentration in the raw coal storage space, and establish the second data set of the spontaneous combustion temperature points of the same raw coal sample at different temperatures and different oxygen concentrations. Change the type of raw coal sample, repeat the above steps, and establish a third data set of spontaneous combustion temperature points for different raw coal samples at different temperatures and the same oxygen concentration, as well as a fourth data set of spontaneous combustion temperature points at different temperatures and different oxygen concentrations; Change the particle size of the raw coal, update the first data set, the second data set, the third data set, and the fourth data set, and form corresponding fifth data set, sixth data set, seventh data set, and eighth data set; Step 6, Prediction of spontaneous combustion point of raw coal: Retrieve the temperature point of spontaneous combustion of raw coal from the database according to the type information, particle size information, oxygen concentration information of the raw coal stored, transported or mined, the concentration information of the landmark gas collected on site, and the temperature information of the raw coal storage location, and give an early warning.

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