A device and method for detecting the spontaneous combustion cycle of coal.

Abstract

This invention provides a coal spontaneous combustion cycle detection device and method, comprising a detection cylinder with a heat-insulating cover plate snapped into its opening. A base frame is fixed near the bottom of the detection cylinder, and a sample chamber is placed on the base frame. Two hollow cavities are symmetrically formed within the vertical wall of the detection cylinder. A lifting and regulating mechanism is installed in each hollow cavity. A first heating mechanism is fixed to the other side of the lifting block of one lifting and regulating mechanism, and a second heating mechanism is fixed to the other side of the lifting block of the other lifting and regulating mechanism. The first and second heating mechanisms cooperate to heat the sample chamber. A thermocouple, an inlet pipe, and an exhaust pipe are also connected to the sample chamber. This invention enables precise heating of the area outside the sample chamber by the lifting block driving the first and second heating mechanisms, thereby improving heating accuracy and, consequently, detection accuracy.

Description

Technical Field

[0001] This invention belongs to the technical field of coal spontaneous combustion detection devices, specifically relating to a coal spontaneous combustion cycle detection device and its detection method. Background Technology

[0002] Spontaneous combustion of coal seams poses a serious threat to the safety of coal production and storage, causing enormous losses of coal resources and even triggering major accidents and disasters. The cause of spontaneous combustion in coal seams is that during the coal formation process, some coal seams do not metamorphose sufficiently, resulting in lower ignition points. During mining, the coal's structure undergoes certain transformations, releasing heat that accumulates within the seam. When the accumulated heat exceeds the seam's ignition point, spontaneous combustion occurs. Another cause is the presence of loose coal in the goaf during mining; this loose coal is a major cause of spontaneous combustion, and the more loose coal accumulates in the goaf, the greater the likelihood of spontaneous combustion. After mining is completed, inadequate sealing of the goaf, resulting in air leakage, and improperly sized isolation pillars, all contribute to increased airflow within the goaf, ultimately leading to spontaneous combustion.

[0003] To effectively prevent spontaneous combustion of coal, it is essential to predict the spontaneous combustion period of coal seams. By quantitatively detecting the shortest spontaneous combustion period of coal seams, the shortest spontaneous combustion period can be determined, thereby enabling the prevention and control of spontaneous combustion of coal.

[0004] Based on this, a coal spontaneous combustion cycle detection device and its detection method are proposed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a coal spontaneous combustion cycle detection device and detection method to address the shortcomings of the prior art, so as to solve the problems mentioned in the background art.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: a coal spontaneous combustion cycle detection device, including a detection cylinder, a heat insulation cover plate is snapped into the opening of the detection cylinder, a base frame is fixed inside the detection cylinder near the bottom, and a sample chamber is placed on the base frame;

[0007] Two hollow cavities are symmetrically formed in the vertical wall of the detection cylinder. Each hollow cavity is equipped with a lifting control mechanism, which includes a lead screw, a control knob, a threaded cylinder, and a lifting block. The lead screw is rotatably connected to the hollow cavity through a bearing seat. A first bevel gear is fixed to the top of the lead screw. The control knob is rotatably connected to the top of the side wall of the detection cylinder near the hollow cavity. A second bevel gear is fixed to the inner end of the control knob. The first and second bevel gears are meshed together. The threaded cylinder is threaded to the outer side of the lead screw. A vertical groove is formed on the inner side of the hollow cavity. The lifting block is slidably connected in the groove, and one end of the lifting block is fixed to the outer side of the threaded cylinder.

[0008] One of the lifting control mechanisms has a first heating mechanism fixed on the other side of the lifting block, and the other lifting control mechanism has a second heating mechanism fixed on the other side of the lifting block. The first heating mechanism and the second heating mechanism work together to complete the heating of the sample chamber.

[0009] The sample chamber is also connected to a thermocouple, an air inlet pipe, and an exhaust pipe.

[0010] Furthermore, the first heating mechanism consists of a mesh tube and a first heating wire. The outer top end of the mesh tube is fixedly connected to the lifting block of the lifting control mechanism, and the first heating wire is fixed in a spiral shape inside the mesh tube.

[0011] Furthermore, the second heating mechanism consists of a heat insulation cylinder and a second heating wire. The lower outer end of the heat insulation cylinder is fixedly connected to the lifting block of another lifting control mechanism. The second heating wire is fixed in a spiral shape inside the heat insulation cylinder.

[0012] Furthermore, the heating power of the second heating wire is less than that of the first heating wire, and the inner diameter of the heat insulation cylinder is greater than that of the mesh cylinder.

[0013] Furthermore, the sum of the lengths of the heat insulation cylinder and the mesh cylinder is greater than the length of the sample chamber.

[0014] Furthermore, a sample cover plate is snapped onto the top of the sample chamber, and the thermocouple and the exhaust pipe both extend through the sample cover plate into the interior of the sample chamber.

[0015] Furthermore, the air inlet pipe has a reciprocating extension section near the sample chamber, and the reciprocating extension section is located in the inner ring area of ​​the first heating mechanism.

[0016] Furthermore, the bottom end of the reciprocating extension section is provided with an air inlet that communicates with the sample chamber.

[0017] Further, the detection cylinder is a heat-insulating cylinder, and a heat-insulating pad is arranged inside the heat-insulating cover plate.

[0018] Further, the thermocouple is a high-temperature resistant thermocouple.

[0019] The detection method of the coal spontaneous combustion ignition period detection device includes the following steps:

[0020] S1. Load the prepared coal sample into the sample bin in normal temperature air, then put the sample bin into the detection cylinder, then cover the heat-insulating cover plate, and install the thermocouple, the air inlet pipe 8 and the exhaust pipe according to the preset positions;

[0021] S2. Use an external air pump to introduce air into the sample bin through the air inlet pipe, and use a flow meter installed on the external air pump to measure the air introduced into the sample bin. The exhaust pipe is externally connected with an exhaust gas analysis device;

[0022] S3. Use the first heating mechanism and the second heating mechanism to cooperate to heat the sample bin to the preset temperature. The specific heating process is as follows:

[0023] The preset detection temperature is t1. The heating temperature range of the first heating mechanism is 0 - t2 - t3, where t2 < t1 < t3. The heating temperature range of the second heating mechanism is 0 - t4 - t5, where t4 < t2 ≤ t1 ≤ t5 < t3;

[0024] During heating, first adjust the heights of the first heating mechanism and the second heating mechanism respectively, so that the coal sample in the sample bin 3 is within the surrounding range of the first heating mechanism and the second heating mechanism. Then start the first heating mechanism first and adjust the heating temperature to t2. When the heating temperature of the first heating mechanism rises to t2, maintain it for 15 minutes, and then start the second heating mechanism to the heating temperature t4. At this time, the second heating mechanism can provide supplementary heating for the first heating mechanism, so as to avoid the problem of insufficient heating rate when the first heating mechanism 5 is heated again;

[0025] Then adjust the heating temperature of the first heating mechanism to t3. While the first heating mechanism is heating up, use the thermocouple to synchronously and real-time observe the temperature in the sample bin. When the thermocouple detects that the instantaneous temperature reaches t1, simultaneously adjust the heating temperature of the second heating mechanism to t5. Then, after the first heating mechanism 5 is heated to the temperature t3, maintain it for 30 minutes, and turn off the first heating mechanism. The second heating mechanism continues to heat until the detection ends;

[0026] During the continuous heating process of the second heating mechanism, use the thermocouple to synchronously and real-time observe the temperature in the sample bin 3. If the temperature in the sample bin is less than t1, then start the first heating mechanism again and adjust the heating temperature to t2, and heat for 5 minutes. If the temperature in the sample bin is greater than or equal to t1, then do not start the first heating mechanism again;

[0027] S4. Then, by coordinating the data from the thermocouple, the inlet pipe, and the exhaust pipe, the spontaneous combustion cycle of the coal sample placed in the sample chamber 3 is determined.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. This invention involves symmetrically opening two hollow cavities within the vertical wall of the detection cylinder. Each hollow cavity is equipped with a lifting control mechanism. Rotating a control knob drives a lead screw, which in turn adjusts the height of a lifting block on the outer threaded cylinder. This allows for height adjustment of the lifting block. One lifting control mechanism has a first heating mechanism fixed to the other side of its lifting block, while the other lifting control mechanism has a second heating mechanism fixed to the other side of its lifting block. This allows the lifting block to precisely heat the area outside the sample chamber using both heating mechanisms, thereby improving heating accuracy and ultimately enhancing detection accuracy.

[0030] 2. The first heating mechanism of the present invention consists of a mesh cylinder and a first heating wire. The outer top of the mesh cylinder is fixedly connected to the lifting block of the lifting control mechanism. The first heating wire is spirally fixed inside the mesh cylinder. The second heating mechanism consists of a heat insulation cylinder and a second heating wire. The outer bottom of the heat insulation cylinder is fixedly connected to the lifting block of another lifting control mechanism. The second heating wire is spirally fixed inside the heat insulation cylinder. The first heating mechanism and the second heating mechanism cooperate with each other to complete the heating of the sample chamber. The heating power of the second heating wire is less than that of the first heating wire. The first heating wire can complete the main heating function through high-power heating. The second heating wire on the outside can heat the ambient temperature of the sample chamber, thereby improving the heating stability and the effectiveness of the heating curve, avoiding the occurrence of ambient temperature differences, ensuring the stability of the heating and warming process, and improving the detection accuracy. The specific heating process is as follows: The preset detection temperature is t1. The heating temperature range of the first heating mechanism is 0 - t2 - t3, where t2 < t1 < t3. The heating temperature range of the second heating mechanism is 0 - t4 - t5, where t4 < t2 ≤ t1 ≤ t5 < t3; During heating, first adjust the heights of the first heating mechanism and the second heating mechanism respectively, so that the coal sample in the sample chamber is within the surrounding range of the first heating mechanism and the second heating mechanism. Then start the first heating mechanism first and adjust the heating temperature to t2. When the heating temperature of the first heating mechanism rises to t2, maintain it for 15 minutes. At this time, the first heating mechanism can complete the preheating of the detection cylinder body. Then start the second heating mechanism to the heating temperature t4. At this time, the second heating mechanism can provide supplementary heating for the first heating mechanism, thereby avoiding the problem of insufficient heating rate when the first heating mechanism is heated again; Then adjust the heating temperature of the first heating mechanism to t3. While the first heating mechanism is heating up, use the thermocouple to synchronously and real-time observe the temperature in the sample chamber. When the thermocouple detects that the instantaneous temperature reaches t1, at the same time adjust the heating temperature of the second heating mechanism to t5. Then maintain it for 30 minutes after the first heating mechanism is heated to t3 temperature. Turn off the first heating mechanism, and the second heating mechanism continues to heat until the detection ends. The continuous heating of the second heating mechanism is uniform and stable, improving the detection accuracy; During the continuous heating process of the second heating mechanism, use the thermocouple to synchronously and real-time observe the temperature in the sample chamber. If the temperature in the sample chamber is less than t1, then start the first heating mechanism again and adjust the heating temperature to t2 and heat for 5 minutes. If the temperature in the sample chamber is greater than or equal to t1, then do not start the first heating mechanism again. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a cross-sectional view of the overall structure of the present invention;

[0032] Figure 2 is a top view of the overall structure of the present invention.

[0033] Description of the reference numerals:

[0034] 1-Detection cylinder; 11-Base frame; 12-Hollow cavity; 2-Heat insulation cover; 3-Sample chamber; 4-Lifting and adjusting mechanism; 41-Lead screw; 42-Adjusting knob; 43-Threaded cylinder; 44-Lifting block; 5-First heating mechanism; 51-Mesh cylinder; 52-First heating wire; 6-Second heating mechanism; 61-Heat insulation cylinder; 62-Second heating wire; 7-Thermocouple; 8-Inlet pipe; 81-Reciprocating extension section; 82-Inlet; 9-Exhaust pipe. Detailed Implementation

[0035] 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.

[0036] like Figure 1-2 As shown, the present invention provides a technical solution: a coal spontaneous combustion cycle detection device, including a detection cylinder 1, with a heat insulation cover plate 2 snapped into the opening of the detection cylinder 1. The detection cylinder 1 is an insulated cylinder, and a heat insulation pad is provided inside the heat insulation cover plate 2. The detection cylinder 1 and the heat insulation cover plate 2 can ensure the internal temperature of the detection cylinder 1, reduce the impact of external temperature changes on the detection accuracy, and improve the detection efficiency.

[0037] A base frame 11 is fixed near the bottom inside the detection cylinder 1. A sample chamber 3 is placed on the base frame 11. A sample cover plate 31 is snapped onto the top of the sample chamber 3. The sample chamber 3 is used to place the coal sample to be tested. By suspending it in the air through the base frame 11, the overall heating area can be increased, local temperature differences can be avoided inside the sample chamber 3, and the accuracy of the test can be improved.

[0038] Two hollow cavities 12 are symmetrically formed within the vertical wall of the detection cylinder 1. Each hollow cavity 12 is equipped with a lifting and adjusting mechanism 4, which includes a lead screw 41, an adjusting knob 42, a threaded cylinder 43, and a lifting block 44. The lead screw 41 is rotatably connected to the hollow cavity 12 via a bearing seat. A first bevel gear is fixed to the top of the lead screw 41. The adjusting knob 42 is rotatably connected to the side wall of the detection cylinder 1 near the top of the hollow cavity 12. A [missing information - likely a component or element] is fixed to the inner end of the adjusting knob 42. The second bevel gear meshes with the first bevel gear and the second bevel gear. The outer side of the lead screw 41 is threadedly connected to the threaded cylinder 43. The inner side of the hollow cavity 12 is provided with a vertical sliding groove. The lifting block 44 is slidably connected in the sliding groove, and one end of the lifting block 44 is fixed to the outer side of the threaded cylinder 43. By rotating the control knob 42, the lead screw 41 can be rotated. When the lead screw 41 rotates, it can drive the height adjustment of the lifting block 44 on the outer threaded cylinder 43, thereby completing the height adjustment function of the lifting block 44.

[0039] One of the lifting control mechanisms 4 has a first heating mechanism 5 fixed on the other side of the lifting block 44, and the other lifting control mechanism 4 has a second heating mechanism 6 fixed on the other side of the lifting block 44. Thus, the lifting block 44 can drive the first heating mechanism 5 and the second heating mechanism 6 to accurately heat the area outside the sample chamber 3, thereby improving the heating accuracy and thus improving the detection accuracy.

[0040] The first heating mechanism 5 consists of a mesh tube 51 and a first heating wire 52. The outer top end of the mesh tube 51 is fixedly connected to the lifting block 44 of the lifting control mechanism 4. The first heating wire 52 is fixed in a spiral shape inside the mesh tube 51.

[0041] The second heating mechanism 6 consists of a heat insulation cylinder 61 and a second heating wire 62. The lower outer end of the heat insulation cylinder 61 is fixedly connected to the lifting block 44 of another lifting control mechanism 4. The second heating wire 62 is fixed in a spiral shape inside the heat insulation cylinder 61. The first heating mechanism 5 and the second heating mechanism 6 cooperate with each other to complete the heating of the sample chamber 3.

[0042] To improve heating stability and the effectiveness of the temperature rise curve, the heating power of the second heating wire 62 is less than that of the first heating wire 52. The first heating wire 52 can complete the main heating function through high-power heating, while the outer second heating wire 62 can heat the ambient temperature of the sample chamber 3, avoiding ambient temperature differences and ensuring the stability of the heating process, thus improving the detection accuracy.

[0043] In order to facilitate the cooperation between the first heating mechanism 5 and the second heating mechanism 6, the inner diameter of the heat insulation cylinder 61 is larger than the inner diameter of the mesh cylinder 51.

[0044] The combined length of the heat insulation cylinder 61 and the mesh cylinder 51 is greater than the length of the sample chamber 3, thus allowing the entire sample chamber 3 to be placed within the temperature control area and avoiding local temperature differences.

[0045] The sample chamber 3 is also connected to a thermocouple 7, an air inlet pipe 8, and an exhaust pipe 9. The thermocouple 7 and the exhaust pipe 9 both extend through the sample cover plate 31 into the interior of the sample chamber 3.

[0046] A gas flow meter and a gas pump are connected to the inlet pipe 8. The inlet pipe 8 has a reciprocating extension section 81 near the sample chamber 3. The reciprocating extension section 81 is located in the inner ring area of ​​the first heating mechanism 5. The gas sent into the inlet pipe 8 can be heated in the reciprocating extension section 81, so that it can maintain the same temperature as the coal sample in the sample chamber 3 after entering the sample chamber 3, avoiding the impact of the detection accuracy caused by the input of air with temperature difference from the outside.

[0047] The bottom end of the reciprocating extension section 81 is provided with an air inlet 82 that communicates with the sample chamber 3, through which gas is sent into the sample chamber 3.

[0048] The thermocouple 7 is a high-temperature resistant thermocouple. The stability of the sample chamber 3 can be monitored in real time through the thermocouple 7, which is beneficial for subsequent analysis.

[0049] The exhaust pipe 9 is connected to an exhaust gas analysis device. Through the coordination of data from the thermocouple 7, the inlet pipe 8 and the exhaust pipe 9, as well as the coordination of the first heating mechanism 5 and the second heating mechanism 6, the high-precision detection of the spontaneous combustion cycle of the coal sample placed in the sample chamber 3 is completed.

[0050] The specific method is as follows, including the following steps:

[0051] S1. The prepared coal sample is placed into the sample chamber 3 in room temperature air, then the sample chamber 3 is placed into the detection cylinder 1, then the heat insulation cover 2 is put on, and the thermocouple 7, air inlet pipe 8 and exhaust pipe 9 are arranged in the preset positions to complete the process.

[0052] S2. An external air pump is used to introduce air into the sample chamber 3 through the air inlet pipe 8, and a flow meter installed on the external air pump is used to measure the air introduced into the sample chamber 3. An exhaust gas analysis device is connected to the exhaust pipe 9.

[0053] S3. The first heating mechanism 5 and the second heating mechanism 6 work together to heat the sample chamber 3 to the preset temperature. The specific heating process is as follows:

[0054] The preset detection temperature is t1, and the heating temperature range of the first heating mechanism 5 is 0 - t2 - t3, where t2 < t1 < t3. The heating temperature range of the second heating mechanism 6 is 0 - t4 - t5, where t4 < t2 ≤ t1 ≤ t5 < t3;

[0055] During heating, first adjust the heights of the first heating mechanism 5 and the second heating mechanism 6 respectively, so that the coal sample in the sample chamber 3 is within the surrounding range of the first heating mechanism 5 and the second heating mechanism 6. Then start the first heating mechanism 5 first and adjust the heating temperature to t2. When the heating temperature of the first heating mechanism 5 rises to t2, maintain it for 15 minutes. At this time, the first heating mechanism 5 can complete the preheating function in the detection cylinder 1. Then start the second heating mechanism 6 to the heating temperature t4. At this time, the second heating mechanism 6 can provide supplementary heating for the first heating mechanism 5, thus avoiding the problem that the heating rate is not enough when the first heating mechanism 5 is heated again;

[0056] Then adjust the heating temperature of the first heating mechanism 5 to t3. While the first heating mechanism 5 is heating up, use the thermocouple 7 to synchronously and real-time observe the temperature in the sample chamber 3. When the thermocouple 7 detects that the instantaneous temperature reaches t1, simultaneously adjust the heating temperature of the second heating mechanism 6 to t5. Then, after the first heating mechanism 5 is heated to the temperature t3, maintain it for 30 minutes, and turn off the first heating mechanism 5. The second heating mechanism 6 continues to heat until the detection ends. The continuous heating of the second heating mechanism 6 is uniform and stable, improving the detection accuracy;

[0057] During the continuous heating process of the second heating mechanism 6, use the thermocouple 7 to synchronously and real-time observe the temperature in the sample chamber 3. If the temperature in the sample chamber 3 is less than t1, then start the first heating mechanism 5 again and adjust the heating temperature to t2, and heat for 5 minutes. If the temperature in the sample chamber 3 is greater than or equal to t1, then do not start the first heating mechanism 5; <s

[0058] S4. Then, through the cooperation of the data on the thermocouple 7, the intake pipe 8 and the exhaust pipe 9, determine the coal spontaneous combustion ignition period of the coal sample placed in the sample chamber 3.

[0059] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to this process, method, article or device.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A detection method of a coal spontaneous combustion ignition period detection device, characterized by: The detection device includes a detection cylinder (1), a heat insulation cover plate (2) is clamped at the opening of the detection cylinder (1), a bottom frame (11) is fixed at the bottom of the detection cylinder (1), and a sample bin (3) is placed on the bottom frame (11); Two hollow cavities (12) are symmetrically arranged in the vertical wall of the detection cylinder (1), one lifting control mechanism (4) is arranged in each hollow cavity (12), the lifting control mechanism (4) includes a lead screw (41), a control knob (42), a threaded cylinder (43) and a lifting block (44), the lead screw (41) is rotatably connected in the hollow cavity (12) through a bearing seat, the top end of the lead screw (41) is fixed with a first bevel gear, the control knob (42) is rotatably connected at the top of the hollow cavity (12) on the side wall of the detection cylinder (1), the inner side end of the control knob (42) is fixed with a second bevel gear, the first bevel gear is meshed with the second bevel gear, the outer side of the lead screw (41) is threadedly connected with the threaded cylinder (43), the inner side of the hollow cavity (12) is provided with a vertical sliding groove, the lifting block (44) is slidably connected in the sliding groove, and the other side end of the lifting block (44) is fixed to the outer side of the threaded cylinder (43), the other side of the lifting block (44) of one of the lifting control mechanisms (4) is fixed with a first heating mechanism (5), the other side of the lifting block (44) of the other lifting control mechanism (4) is fixed with a second heating mechanism (6), and the first heating mechanism (5) and the second heating mechanism (6) cooperate to heat the sample bin (3); The first heating mechanism (5) is composed of a mesh cylinder (51) and a first heating wire (52), the mesh cylinder (51) is fixedly connected between the outer side top end of the mesh cylinder (51) and the lifting block (44) of the lifting control mechanism (4), the first heating wire (52) is spirally fixed in the mesh cylinder (51), the second heating mechanism (6) is composed of a heat insulation cylinder (61) and a second heating wire (62), the heat insulation cylinder (61) is fixedly connected between the outer side low end of the heat insulation cylinder (61) and the lifting block (44) of the other lifting control mechanism (4), the second heating wire (62) is spirally fixed in the heat insulation cylinder (61), the heating power of the second heating wire (62) is less than that of the first heating wire (52), the inner diameter of the heat insulation cylinder (61) is greater than that of the mesh cylinder (51), and the sum of the lengths of the heat insulation cylinder (61) and the mesh cylinder (51) is greater than the length of the sample bin (3); The sample bin (3) is further connected with a thermocouple (7), an air inlet pipe (8) and an air outlet pipe (9); The detection method comprises the following steps: S1, the coal sample is loaded into the sample bin (3) in the normal temperature air, then the sample bin (3) is placed in the detection cylinder (1), then the heat insulation cover plate (2) is covered, and the thermocouple (7), the air inlet pipe (8) and the air outlet pipe (9) are installed according to the preset position; S2, air is introduced into the sample bin (3) through the air inlet pipe (8) by using an external air pump, and the air introduced into the sample bin (3) is measured by using a flow meter installed on the external air pump, and the air outlet pipe (9) is externally connected with a gas discharge analysis device; S3, the sample bin (3) is heated to a preset temperature by using the first heating mechanism (5) and the second heating mechanism (6), and the specific precise temperature control heating process is as follows: The preset detection temperature is t1, the heating temperature range of the first heating mechanism (5) is 0-t2-t3, wherein t2≦t1<t3, and the heating temperature range of the second heating mechanism (6) is 0-t4-t5, wherein t4<t2≦t1≦t5<t3; When heating, the height of the first heating mechanism (5) and the second heating mechanism (6) is adjusted respectively, so that the coal sample in the sample bin (3) is in the surrounding range of the first heating mechanism (5) and the second heating mechanism (6), then the first heating mechanism (5) is started, and the heating temperature is adjusted to t2, when the heating temperature of the first heating mechanism (5) rises to t2, it is maintained for 15 minutes, then the second heating mechanism (6) is started to the heating temperature t4, at this time the second heating mechanism (6) can provide a heating supplement for the first heating mechanism (5), so that the problem of insufficient heating rate when the first heating mechanism (5) is heated again can be avoided; Then the heating temperature of the first heating mechanism (5) is adjusted to t3, and the thermocouple (7) is used to synchronously and real-timely observe the temperature in the sample bin (3) while the first heating mechanism (5) is heated, when the thermocouple (7) detects that the instantaneous temperature reaches t1, the heating temperature of the second heating mechanism (6) is adjusted to t5 at the same time, then the first heating mechanism (5) is heated to t3, and is maintained for 30 minutes after the first heating mechanism (5) is closed, and the second heating mechanism (6) continues to heat until the detection is completed; In the process of continuous heating of the second heating mechanism (6), the thermocouple (7) is used to synchronously and real-timely observe the temperature in the sample bin (3), if the temperature in the sample bin (3) is less than t1, the first heating mechanism (5) is started again to adjust the heating temperature to t2, and is heated for 5 minutes, if the temperature in the sample bin (3) is greater than or equal to t1, the first heating mechanism (5) is not started again; S4, then the data of the thermocouple (7), the air inlet pipe (8) and the air outlet pipe (9) are matched to complete the determination of the coal spontaneous combustion ignition period of the coal sample placed in the sample bin (3).

2. The detection method of the coal spontaneous combustion ignition period detection device according to claim 1, characterized in that, The top end of the sample bin (3) is clamped with a sample cover plate (31), and the thermocouple (7) and the air outlet pipe (9) both extend to the inside of the sample bin (3) through the sample cover plate (31).

3. The detection method of the coal spontaneous combustion ignition period detection device according to claim 1, characterized in that, The air inlet pipe (8) is provided with a reciprocating extension section (81) near the sample bin (3), and the reciprocating extension section (81) is arranged in the inner ring area of the first heating mechanism (5).

4. The detection method of the coal spontaneous combustion ignition period detection device according to claim 3, characterized in that, The bottom end of the reciprocating extension section (81) is provided with an air inlet (82) in communication with the sample bin (3).

5. The detection method of the coal spontaneous combustion ignition period detection device according to claim 1, characterized in that, The detection cylinder body (1) is an adiabatic cylinder body, the heat insulation cover plate (2) is provided with a heat insulation pad, and the thermocouple (7) is a high-temperature resistant thermocouple.

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