Testing device and method for position migration of spontaneous combustion high-temperature point of loose coal body

Abstract

The invention relates to the technical field of coal seam high-temperature point migration, and discloses a loose coal spontaneous combustion high-temperature point position migration testing device and method, and the device comprises a furnace body, a first temperature measurement element, a gas concentration detection element, a gas conveying pipe, an air compressor, an electric heating box body, liquid and a second temperature measurement element. The method comprises the following steps: determining an oxygen concentration value C corresponding to an undetermined high-temperature point position Z to be an oxygen concentration upper limit value for maintaining a first high-temperature point position Z1 or an oxygen concentration lower limit value for maintaining a second high-temperature point position Z2 under the condition of Q1 '; and determining that the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is the oxygen concentration lower limit value for maintaining the second high-temperature point position Z2 under the condition of Q1 ''. According to the technical scheme, the situation that the position of the coal spontaneous combustion position is changed due to the fact that the oxygen concentration in the airflow enables the position of the coal seam high-temperature point to migrate is studied, and the accuracy of studying the migration result of the oxygen concentration in the airflow to the coal sample high-temperature point is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal seam high temperature point migration, and particularly relates to a testing device and method for loose coal spontaneous combustion high temperature point position migration. BACKGROUND

[0002] At present, in the actual underground coal seam mining process, the inner wall of the coal seam may appear cracks under the influence of its own stress in the mining process. The cracks will cause the air (containing oxygen) outside the coal seam to enter, and the oxygen concentration will change, which will cause the position of the high temperature point in the coal seam to migrate. It should be noted that the temperature at each position of the coal seam in the same environment is not consistent, and the points with the highest temperature at multiple positions are the high temperature points, and the positions of the points with the highest temperature are the high temperature point positions.

[0003] In the prior art, an invention patent with the application publication number CN105510383A discloses a coal shortest spontaneous combustion period and spontaneous combustion characteristic parameter testing device and method. The above device comprises a test furnace, a control system, a temperature monitoring system and a gas collection system. The test furnace comprises a furnace body and a furnace cover. The control system comprises a temperature control system and an air flow control system. The temperature control system comprises a temperature controller, a first heating resistance wire and a first voltage regulator. The air flow control system comprises an air compressor and an air flow temperature control water tank. The temperature monitoring system comprises a monitoring computer, a data acquisition module, a furnace body temperature monitoring sensor group and a coal sample temperature monitoring sensor group.

[0004] The above device can obtain the coal shortest spontaneous combustion period (i.e. time) and the spontaneous combustion characteristic parameters (for example, the oxidation exothermic intensity at the high temperature point).

[0005] However, in the actual coal seam mining process, due to the existence of cracks, the oxygen concentration in the coal seam will change, and the change of the oxygen concentration will cause the migration of the high temperature point position in the coal seam, that is, the change of the spontaneous combustion position.

[0006] Firstly, the above scheme only studies the upper and lower limits of the oxidation exothermic intensity at the high temperature point under a certain concentration, and does not study the case that the coal spontaneous combustion position changes due to the migration of the high temperature point position in the coal seam. Secondly, in the existing scheme, the second temperature sensor for monitoring the temperature of the coal sample is arranged on each layer of the cross-shaped partition in the furnace body, that is, the furnace body needs to maintain a relatively wide width to enable multiple second temperature sensors to be arranged at intervals in the horizontal direction. However, when the air flow passes into the coal sample, the above width of the furnace body will cause the oxygen in the air flow to diffuse to a position far away from the arrangement of the second temperature sensor, that is, the oxygen concentration around the second temperature sensor will decrease, which will reduce the accuracy of the research on the oxygen concentration in the air flow on the migration result of the high temperature point of the coal sample.

[0007] Therefore, there is an urgent need for a testing device for loose coal spontaneous combustion high temperature point position migration, which can study the high temperature point position migration when the oxygen concentration changes, so as to determine the position in the coal seam where spontaneous combustion is most likely to occur. SUMMARY

[0008] To solve the above technical problems, the present application provides a testing device for loose coal spontaneous combustion high temperature point position migration, which can study the case that the oxygen concentration in the gas flow causes the high temperature point position migration of the coal seam, thereby causing the change of the coal spontaneous combustion position. Secondly, by reducing the width of the furnace body, the oxygen in the gas flow entering the furnace body can be concentrated around each sensor group, i.e. around the first temperature measuring element and the gas concentration detecting element. The narrow width of the furnace body can reduce the diffusion of oxygen concentration around the sensor group and reduce the decrease of oxygen concentration around each sensor group, thereby greatly improving the accuracy of the research on the effect of oxygen concentration in the gas flow on the high temperature point migration of the coal sample.

[0009] The present application provides a testing device for loose coal spontaneous combustion high temperature point position migration, characterized by: a furnace for loading coal samples, the furnace comprising a furnace body for loading the coal samples, a furnace cover arranged at the top of the furnace body, a coal discharge port arranged at the bottom of the side wall of the furnace body,

[0010] A support frame arranged horizontally inside the furnace body and a support rod arranged vertically to the support frame, a plurality of sensor groups for detecting the temperature and oxygen concentration at the position of the coal sample are arranged at intervals on the support rod, each sensor group comprising a first temperature measuring element for detecting the temperature at the position of the coal sample and a gas concentration detecting element arranged at the position of the coal sample,

[0011] An air compressor for oxidizing the coal sample connected to the furnace body through a gas conveying pipe, an electric heating box arranged around the outer periphery of the gas conveying pipe for raising the temperature of the gas flow in the gas conveying pipe, a liquid arranged in the electric heating box for heat transfer, and a second temperature measuring element arranged in the liquid for detecting the temperature of the liquid,

[0012] A gas flow parameter measuring mechanism arranged on the gas conveying pipe between the air compressor and the electric heating box for measuring the gas flow parameters in the gas conveying pipe, the gas flow parameter measuring mechanism comprising a pressure gauge connected to the air compressor through the gas conveying pipe for measuring the gas flow pressure in the gas conveying pipe, a steady flow valve connected to the pressure gauge through the gas conveying pipe for controlling the flow speed of the gas flow in the gas conveying pipe, and a flow meter connected to the steady flow valve through the gas conveying pipe for measuring the flow speed of the gas flow in the gas conveying pipe,

[0013] A temperature controller connected with the second temperature measuring element for controlling the heating temperature of the electric heating box, a data acquisition module connected with the first temperature measuring element and the second temperature measuring element for recording temperature values, the data acquisition module is connected with the first temperature measuring element and the gas concentration detection element, and a computer device connected with the data acquisition module for analyzing the relationship between the oxygen concentration and the high temperature point migration position of the coal sample.

[0014] The width interval of the furnace body is [a, b] cm, and b is less than 200 cm, wherein a is the lower limit value of the furnace body width, and b is the upper limit value of the furnace body width.

[0015] The above-mentioned test device for loose coal spontaneous combustion high temperature point position migration, characterized in that: the a is 10 cm, and the b is 20 cm.

[0016] The above-mentioned test device for loose coal spontaneous combustion high temperature point position migration, characterized in that: the first temperature measuring element comprises a first thermocouple, and the second temperature measuring element comprises a second thermocouple.

[0017] The above-mentioned test device for loose coal spontaneous combustion high temperature point position migration, characterized in that: the gas concentration detection element comprises a gas sensor.

[0018] The above-mentioned test device for loose coal spontaneous combustion high temperature point position migration, characterized in that: further comprising a heat preservation layer arranged from inside to outside on the side wall of the furnace body for heat preservation of the furnace body, and the heat preservation layer comprises a first heat preservation layer, a second heat preservation layer and a third heat preservation layer.

[0019] The application provides a method for testing high temperature point position migration by using the test device for loose coal spontaneous combustion high temperature point position migration, characterized in that: step one, after collecting the coal sample underground, first, the coal sample is wrapped with a preservative film, second, the coal sample is wrapped with aluminum foil paper, then the coal sample is packed with a three-layer waterproof and oxidation-resistant nylon bag, and finally, the coal sample is transported to a laboratory where the coal sample is tested.

[0020] Step two, within 24 hours, after crushing, weighing and particle size analysis of the coal sample, the furnace body is inclined at an angle of 45° with the ground, the furnace cover is opened, the coal sample is loaded into the furnace body, when the coal sample covers a group of sensors at the top of the supporting rod, the furnace body is righted, the coal sample is slowly added until the furnace body is filled, and then the furnace body is sealed.

[0021] Step three, the computer device controls the temperature controller to heat the electric heating box body, the compressed air generated by the air compressor passes through the pressure gauge, the steady flow valve and the flow meter arranged between the air compressor and the electric heating box body in sequence, is heated by the electric heating box body, and finally enters the furnace body through the gas conveying pipe, so that the gas temperature of the gas conveying pipe entering the furnace body is consistent with the temperature of the coal sample in the furnace body;

[0022] Wherein, the first temperature measuring element installation point with the highest temperature detected by the plurality of first temperature measuring elements is defined as a high temperature point of the coal sample, the temperature detected by the first temperature measuring element corresponding to the high temperature point of the coal sample is defined as the temperature Tc of the high temperature point of the coal sample, and when the temperature Tc of the high temperature point of the coal sample reaches 170℃, the temperature controller stops heating;

[0023] The method for controlling the compressed air entering the gas conveying pipe by the air compressor includes adjusting the steady flow valve and checking the air supply amount displayed on the flow meter, so that the air supply amount is Q1;

[0024] Step four, when the air supply amount is Q1, in the first time period Δt1 monitored continuously, the first temperature measuring element installation point with the highest temperature detected by the plurality of first temperature measuring elements is defined as the first high temperature point position Z1, and after the first time period Δt1 again, the first temperature measuring element installation point with the highest temperature detected by the plurality of first temperature measuring elements is defined as the to-be-determined high temperature point position Z.

[0025] If the absolute value ΔZ1 of the offset distance difference between the to-be-determined high temperature point position Z and the first high temperature point position Z1 is less than the preset offset distance value ΔZ,

[0026] And the absolute value ΔT1 of the temperature difference between the temperature value T1 corresponding to the first high temperature point position Z1 and the temperature value T corresponding to the to-be-determined high temperature point position Z is less than the preset temperature deviation value ΔT,

[0027] And the absolute value ΔC1 of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high temperature point position Z is less than the preset oxygen concentration deviation value ΔC,

[0028] Then the to-be-determined high temperature point position Z is determined as the target high temperature point position in the stable state corresponding to the air supply amount Q1.

[0029] If the absolute value ΔZ1 of the offset distance difference between the to-be-determined high temperature point position Z and the first high temperature point position Z1 is greater than or equal to the preset offset distance value ΔZ,

[0030] Or the absolute value of the temperature difference between the temperature value T1 corresponding to the first high temperature point position Z1 and the temperature value T corresponding to the to-be-determined high temperature point position Z is greater than or equal to a preset temperature deviation value AT,

[0031] Or the absolute value of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high temperature point position Z is greater than or equal to a preset oxygen concentration deviation value AC,

[0032] Then it is determined that the to-be-determined high temperature point position Z is not the target high temperature point position in the stable state corresponding to the air supply amount Q1.

[0033] Step five, increase n air supply amount superimposition amounts AQ on the basis of the air supply amount Q1 every n first time intervals At1,

[0034] If the absolute value of the offset distance difference between the to-be-determined high temperature point position Z and the first high temperature point position Z1 is greater than or equal to the preset offset distance value AZ,

[0035] Or the absolute value of the temperature difference between the temperature value T1 corresponding to the first high temperature point position Z1 and the temperature value T corresponding to the to-be-determined high temperature point position Z is greater than or equal to the preset temperature deviation value AT,

[0036] Or the absolute value of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high temperature point position Z is greater than or equal to a preset oxygen concentration deviation value AC,

[0037] Then it is determined that the oxygen concentration value C corresponding to the to-be-determined high temperature point position Z under the condition of the sum Q1' of the air supply amount Q1 and the n air supply amount superimposition amounts AQ is the oxygen concentration upper limit value for maintaining the first high temperature point position Z1, or the oxygen concentration lower limit value for maintaining the second high temperature point position Z2.

[0038] If the absolute value of the offset distance difference between the to-be-determined high temperature point position Z and the first high temperature point position Z1 is less than the preset offset distance value AZ,

[0039] Or the absolute value of the temperature difference between the temperature value T1 corresponding to the first high temperature point position Z1 and the temperature value T corresponding to the to-be-determined high temperature point position Z is less than the preset temperature deviation value AT,

[0040] Or the absolute value of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high temperature point position Z is less than the preset oxygen concentration deviation value AC,

[0041] determining that the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is not the upper limit value of the oxygen concentration for maintaining the first high-temperature point position Z1 or the lower limit value of the oxygen concentration for maintaining the second high-temperature point position Z2 under the condition that the sum Q1' of the supply air quantity Q1 and the n supply air quantity superimposition quantities ΔQ is determined;

[0042] Step six, every n first time period Δt1, on the basis of the supply air quantity Q1', n supply air quantity superimposition quantities ΔQ are reduced,

[0043] if the absolute value ΔZ1 of the offset distance difference value between the to-be-determined high-temperature point position Z and the first high-temperature point position Z1 is greater than or equal to the preset offset distance value ΔZ,

[0044] or the absolute value ΔT1 of the temperature difference value between the temperature value T1 corresponding to the first high-temperature point position Z1 and the temperature value T corresponding to the to-be-determined high-temperature point position Z is greater than or equal to the preset temperature deviation value ΔT,

[0045] or the absolute value ΔC1 of the oxygen concentration difference value between the oxygen concentration value C1 corresponding to the first high-temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is greater than or equal to the preset oxygen concentration deviation value ΔC,

[0046] determining that the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is not the lower limit value of the oxygen concentration for maintaining the second high-temperature point position Z2 under the condition that the difference Q1'' of the supply air quantity Q1' and the n supply air quantity superimposition quantities ΔQ is determined;

[0047] if the absolute value ΔZ1 of the offset distance difference value between the to-be-determined high-temperature point position Z and the first high-temperature point position Z1 is less than the preset offset distance value ΔZ,

[0048] or the absolute value ΔT1 of the temperature difference value between the temperature value T1 corresponding to the first high-temperature point position Z1 and the temperature value T corresponding to the to-be-determined high-temperature point position Z is less than the preset temperature deviation value ΔT,

[0049] or the absolute value ΔC1 of the oxygen concentration difference value between the oxygen concentration value C1 corresponding to the first high-temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is less than the preset oxygen concentration deviation value ΔC,

[0050] determining that the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is not the lower limit value of the oxygen concentration for maintaining the second high-temperature point position Z2 under the condition that the difference Q1'' of the supply air quantity Q1' and the n supply air quantity superimposition quantities ΔQ is determined;

[0051] Step seven, repeating the execution of the N groups of step five and step six, a plurality of Q1' and the to-be-determined high-temperature point position Z, and a plurality of Q1'' and the to-be-determined high-temperature point position Z are obtained,

[0052] establishing a relationship curve between the plurality of groups Q1' and the to-be-determined high-temperature point position Z, and establishing a relationship curve between the plurality of groups Q1'' and the to-be-determined high-temperature point position Z, and analyzing the driving effect of increasing or decreasing the air supply on the migration of the to-be-determined high-temperature point position Z;

[0053] Step eight, when the temperature Tc of the high-temperature point of the coal sample detected by the first temperature measuring element corresponding to the high-temperature point of the coal sample is equal to 170 DEG C, the temperature controller stops heating the electric heating box, the air compressor stops the air flow into the furnace body,

[0054] When the temperature of the coal sample in the furnace body is less than 40 DEG C, first, the temperature controller, the data acquisition module, and the computer device are turned off, then the furnace body is inclined at an angle of 45 DEG with respect to the ground, and finally the coal sample is unloaded from the furnace body through the coal unloading port.

[0055] The beneficial effect is analyzed as follows:

[0056] In the prior art, first, the prior scheme only studies the upper and lower limits of the oxidation heat release intensity at the high-temperature point under a certain concentration, and does not study the case that the migration of the high-temperature point position of the coal seam causes the change of the coal spontaneous combustion position. Second, in the prior scheme, the second temperature sensor for monitoring the temperature of the coal sample is arranged on each layer of the cross-shaped partition frame in the furnace body, that is, the furnace body needs to maintain a relatively wide width to enable multiple second temperature sensors to be arranged at intervals in the horizontal direction. However, when the air flow is introduced into the coal sample, the above-mentioned wide furnace body will cause the oxygen in the air flow to diffuse to a position far away from the arrangement of the second temperature sensor, that is, the oxygen concentration around the second temperature sensor decreases, which reduces the accuracy of the research on the effect of the oxygen concentration in the air flow on the migration of the high-temperature point of the coal sample.

[0057] In the technical scheme provided by the present application, first, the migration of the high-temperature point position of the coal seam caused by the oxygen concentration in the air flow can be studied, thereby causing the change of the coal spontaneous combustion position.

[0058] Second, by reducing the width of the furnace body, the oxygen in the air flow introduced into the furnace body can be concentrated around each sensor group, that is, around the first temperature measuring element and the gas concentration detecting element. The narrow width of the furnace body can reduce the diffusion of the oxygen concentration around the sensor group and reduce the decrease of the oxygen concentration around each sensor group, thereby greatly improving the accuracy of the research on the effect of the oxygen concentration in the air flow on the migration of the high-temperature point of the coal sample.

[0059] Thirdly, the temperature of the liquid in the electric heating box is regulated by the temperature controller, so that when the gas flow in the gas conveying pipe enters the furnace body, the temperature of the gas flow is consistent with the temperature of the coal sample in the furnace body, the influence of the temperature of the gas flow on the temperature of the coal sample is reduced, and the accuracy of the result of the research on the influence of the oxygen concentration in the gas flow on the migration of the high temperature point of the coal sample is greatly improved.

[0060] The change of the coal spontaneous combustion position caused by the migration of the high temperature point of the coal seam is avoided in the prior art, that is, the change of the coal spontaneous combustion position caused by the migration of the high temperature point of the coal seam is neglected.

[0061] Therefore, by using the technical scheme of the present application, the change of the coal spontaneous combustion position caused by the migration of the high temperature point of the coal seam is researched, and the accuracy of the result of the research on the influence of the oxygen concentration in the gas flow on the migration of the high temperature point of the coal sample is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 A structural schematic view of a test device for the migration of the high temperature point of the spontaneous combustion of the loose coal body is provided in the present application.

[0063] Figure 2 A radial sectional view of the three layers of the heat preservation layer arranged outside the furnace body is provided in the present application. Figure 1

[0064] Explanation of reference signs:

[0065] Furnace body 1, furnace cover 2, support frame 3, support rod 4.

[0066] First temperature measuring element 5, gas concentration detecting element 6, gas conveying pipe 7.

[0067] Air compressor 8, electric heating box 9, liquid 10.

[0068] Second temperature measuring element 11, pressure gauge 12, flow stabilizing valve 13.

[0069] Flow meter 14, temperature controller 15, data acquisition module 16.

[0070] Computer device 17, first heat preservation layer 18, second heat preservation layer 19.

[0071] Third heat preservation layer 20, refractory brick layer 21, gas outlet pipe 22, valve 23, coal discharging port 24. DETAILED DESCRIPTION

[0072] The present application will be further described in detail below in combination with the embodiments and the drawings. It can be understood that the specific embodiments described herein are only used to explain the related application, and are not a limitation on the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for the convenience of description. ​

[0073] It should be noted that the features of the embodiments of the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments and in conjunction with the accompanying drawings.

[0074] In the prior art, firstly, the prior scheme only studies the upper and lower limits of the oxidation exothermic intensity at the high temperature point under a certain concentration, and does not study the change of the coal spontaneous combustion position caused by the migration of the high temperature point of the coal seam. Secondly, in the prior scheme, the second temperature sensor for monitoring the temperature of the coal sample is arranged on the cross-shaped partition frame of each layer of the furnace body in an interval, that is, the furnace body needs to maintain a relatively wide width to enable the multiple second temperature sensors to be arranged, however, when the gas flow is introduced into the coal sample, the above-mentioned width of the furnace body will cause the oxygen in the gas flow to diffuse to a position far away from the arrangement of the second temperature sensor, that is, the oxygen concentration around the second temperature sensor is reduced, which will reduce the accuracy of the research on the effect of the oxygen concentration in the gas flow on the migration of the high temperature point of the coal sample.

[0075] Based on this, the present application provides a test device for the migration of the high temperature point of the spontaneous combustion of the loose coal body, which can study the case that the oxygen concentration in the gas flow causes the migration of the high temperature point of the coal seam, thereby causing the change of the coal spontaneous combustion position. Secondly, by reducing the width of the furnace body 1, the oxygen in the gas flow introduced into the furnace body 1 can be concentrated around each sensor group, that is, around the first temperature measuring element 5 and the gas concentration detecting element 6. The narrower width of the furnace body 1 can reduce the diffusion of the oxygen concentration around the sensor group and reduce the decrease of the oxygen concentration around each sensor group, thereby greatly improving the accuracy of the research on the effect of the oxygen concentration in the gas flow on the migration of the high temperature point of the coal sample.

[0076] Figure 1 A structural schematic diagram of a test device for the migration of the high temperature point of the spontaneous combustion of the loose coal body is provided for the present application, Figure 2 For Figure 1 A radial sectional view of the three layers of heat preservation layers arranged outside the furnace body.

[0077] Referring to Figure 1 The present application provides a test device for the migration of the high temperature point of the coal seam, which comprises: a furnace for loading coal samples, the furnace comprising a furnace body 1 for loading coal samples, a furnace cover 2 arranged at the top of the furnace body 1, a coal discharge port 24 arranged at the bottom of the side wall of the furnace body 1,

[0078] A support frame 3 arranged horizontally and a support rod 4 arranged vertically to the support frame 3 are arranged inside the furnace body 1, a plurality of sensor groups for detecting the temperature and oxygen concentration at the position of the coal sample are arranged on the support rod 4 in an interval, each sensor group comprising a first temperature measuring element 5 for detecting the temperature at the position of the coal sample and a gas concentration detecting element 6 arranged at the position of the coal sample,

[0079] An air compressor 8 for oxidizing coal samples is connected to the furnace body 1 via a gas supply pipe 7; an electric heating chamber 9 is installed around the outer periphery of the gas supply pipe 7 to raise the temperature of the airflow in the gas supply pipe 7; a liquid 10 for transferring heat is installed in the electric heating chamber 9; and a second temperature measuring element 11 for detecting the temperature of the liquid 10 is installed in the liquid 10.

[0080] An airflow parameter measuring mechanism is installed on the air supply pipe 7 between the air compressor 8 and the electric heating box 9 to measure the airflow parameters in the air supply pipe 7. The airflow parameter measuring mechanism includes a pressure gauge 12 connected to the air compressor 8 through the air supply pipe 7 to measure the airflow pressure in the air supply pipe 7, a flow stabilizing valve 13 connected to the pressure gauge 12 through the air supply pipe 7 to control the airflow velocity in the air supply pipe 4, and a flow meter 14 connected to the flow stabilizing valve 13 through the air supply pipe 7 to measure the airflow velocity in the air supply pipe 7.

[0081] A temperature controller 15 connected to the second temperature measuring element 11 for controlling the heating temperature of the electric heating box 9; a data acquisition module 16 connected to the first temperature measuring element 5 and the second temperature measuring element 11 for recording temperature values; the data acquisition module 16 connected to the first temperature measuring element 5 and the gas concentration detection element 6; and a computer device 17 connected to the data acquisition module 16 for analyzing the relationship between oxygen concentration and the migration position of the high temperature point of the coal sample.

[0082] The width of furnace body 1 is in the range of [a, b] cm, where b is less than 200 cm. Here, a is the lower limit of the width of furnace body 1 and b is the upper limit of the width of furnace body 1.

[0083] The width of furnace body 1 refers to the inner diameter of furnace body 1 after it is horizontally cut.

[0084] It is understandable that the furnace body 1 can be pipe-shaped. The wider the furnace body 1 is, the larger the diameter of the pipe-shaped furnace body 1 will be; if the width of the furnace body 1 is narrower, the smaller the diameter of the pipe-shaped furnace body 1 will be.

[0085] The gas concentration (e.g., oxygen concentration) measured by the gas concentration detection element 6 can be in the unit of %vol (volume percentage).

[0086] The unit of air supply measured by flow meter 14 can be m³. 3 / min (cubic meters per minute).

[0087] In practice, the coal sample is first placed inside the furnace body 1. The width of the furnace body 1 is less than 200cm, which means that the width of the furnace body 1 is as narrow as possible. This reduces the diffusion of oxygen in the airflow around each sensor group to the surrounding areas, so that the oxygen concentration is concentrated around the coal sample, thereby improving the accuracy of the experiment on the migration of the high temperature point of the coal sample.

[0088] Second, start air compressor 8 and electric heating box 9 at the same time, the compressed air generated by air compressor 8 passes through gas pipe 7, the part of gas pipe 7 immersed in electric heating box 9 receives heat from liquid 10, first temperature measuring element 5 arranged in furnace body 1 can transmit the detected temperature of coal sample to computer equipment 17 through data acquisition module 16, second temperature measuring element 11 arranged in electric heating box 9 can transmit the detected temperature of liquid 10 (or gas flow in gas pipe 7) to computer equipment 17 through data acquisition module 16, computer equipment 17 can monitor (that is, save and record) the temperature of coal sample and gas flow, if the temperature of coal sample and gas flow is inconsistent, temperature controller 15 adjusts the temperature of liquid in electric heating box 9, so that the gas flow in gas pipe 7 is consistent with the temperature of coal sample in furnace body 1 when entering furnace body 1, and the influence of gas flow temperature on coal sample temperature is reduced, thereby reducing experimental error.

[0089] Third, the gas flow into furnace body 1 can oxidize and heat the coal sample in furnace body 1, and then study the influence of oxygen concentration in gas flow on the migration of high temperature point of coal sample.

[0090] It can be understood that the coal sample in furnace body 1 is oxidized and exothermic under the action of oxygen in the gas flow, and the exothermic heat will cause the temperature of the coal sample to rise, thereby causing the migration (that is, change) of the high temperature point position of the coal sample. The high temperature point position of the coal sample is the position most prone to spontaneous combustion. Therefore, studying the influence of oxygen concentration on the migration of the high temperature point position of the coal sample can provide a direction for subsequent fire prevention and extinguishing.

[0091] The beneficial effect reasoning analysis is as follows:

[0092] In the prior art, first, the existing scheme only studies the upper and lower limits of the oxidation exothermic intensity at the high temperature point under a certain concentration, and does not study the case that the migration of the high temperature point position of the coal seam causes the change of the coal spontaneous combustion position. Second, in the existing scheme, the second temperature sensor for monitoring the temperature of the coal sample is arranged on each layer of cross-shaped partition in the furnace body, that is, the furnace body needs to maintain a relatively wide width to enable multiple second temperature sensors to be arranged in the horizontal direction. However, when the gas flow is introduced into the coal sample, the above-mentioned width of the furnace body will cause the oxygen in the gas flow to diffuse to a position far away from the arrangement of the second temperature sensor, that is, the oxygen concentration around the second temperature sensor decreases, which reduces the accuracy of the research on the influence of the oxygen concentration in the gas flow on the migration of the high temperature point of the coal sample.

[0093] And in the technical scheme provided by the present application, first, the migration of the high temperature point position of the coal seam caused by the oxygen concentration in the gas flow can be studied, thereby causing the change of the coal spontaneous combustion position.

[0094] Secondly, by reducing the width of the furnace body 1, the oxygen in the gas flow into the furnace body 1 can be concentratedly distributed around each sensor group, i.e. around the first temperature measuring element 5 and the gas concentration detecting element 6, the narrow width of the furnace body 1 can reduce the diffusion of the oxygen concentration around the sensor group, reduce the decrease of the oxygen concentration distributed around each sensor group, thereby greatly improving the accuracy of the research on the oxygen concentration in the gas flow on the high temperature point migration result of the coal sample.

[0095] Thirdly, by controlling the temperature of the liquid in the electric heating box 9 through the temperature controller 15, when the gas flow in the gas conveying pipe 7 enters the furnace body 1, the temperature of the coal sample in the furnace body 1 is consistent, the influence of the gas flow temperature on the temperature of the coal sample is reduced, thereby greatly improving the accuracy of the research on the oxygen concentration in the gas flow on the high temperature point migration result of the coal sample.

[0096] The case that the high temperature point position migration of the coal seam leads to the change of the coal spontaneous combustion position is avoided, i.e. the case that the high temperature point position migration of the coal seam leads to the change of the coal spontaneous combustion position is ignored.

[0097] Therefore, by adopting the technical scheme of the present application, not only the case that the oxygen concentration in the gas flow causes the high temperature point position migration of the coal seam, thereby leading to the change of the coal spontaneous combustion position is researched, but also the accuracy of the research on the oxygen concentration in the gas flow on the high temperature point migration result of the coal sample is greatly improved.

[0098] In the foregoing embodiment, a test device for loose coal spontaneous combustion high temperature point position migration is introduced, and in another embodiment of the present application, the specific values of a and b in the width of the furnace body 1 are introduced.

[0099] For example, a is 10 cm and b is 20 cm.

[0100] In specific implementation, the narrower the width of the furnace body 1 is, the more concentrated the oxygen concentration distributed around the sensor group (i.e. the first temperature measuring element 5 and the gas concentration detecting element 6) is, and the more accurate the research on the oxygen concentration on the high temperature point migration result of the coal sample is.

[0101] In the foregoing embodiment, the specific values of a and b in the width of the furnace body 1 are introduced. In another embodiment of the present application, the specific types of the first temperature measuring element 5 and the second temperature measuring element 11 are introduced.

[0102] For example, the first temperature measuring element 5 includes a first thermocouple, and the second temperature measuring element 11 includes a second thermocouple.

[0103] In the foregoing embodiment, the specific types of the first temperature measuring element 5 and the second temperature measuring element 11 are introduced. In another embodiment of the present application, the specific type of the gas concentration detecting element 6 is introduced.

[0104] For example, the gas concentration detecting element 6 comprises a gas sensor.

[0105] In the foregoing embodiment, the heat preservation structure arranged on the outer periphery of the furnace body 1 is introduced. In another embodiment of the present application, a protection structure arranged on the bottom of the furnace body 1 is introduced.

[0106] For example, the heat preservation layer arranged on the side wall of the furnace body 1 from inside to outside for heat preservation of the furnace body 1 is further included, and the heat preservation layer comprises a first heat preservation layer 18, a second heat preservation layer 19, and a third heat preservation layer 20.

[0107] The first heat preservation layer 18 can be a carbon steel layer, the second heat preservation layer 19 can be a rock wool layer, and the third heat preservation layer 20 can be a stainless steel layer.

[0108] In the foregoing embodiment, the heat preservation structure arranged on the outer periphery of the furnace body 1 is introduced. In another embodiment of the present application, a protection structure arranged on the bottom of the furnace body 1 is introduced.

[0109] For example, the refractory brick layer 21 arranged on the bottom of the furnace body 1 for protection of the furnace body 1 is further included.

[0110] The refractory brick layer 21 arranged on the bottom of the furnace body 1 can effectively resist high-temperature corrosion, reduce deformation and damage of the furnace body 1, and prolong the service life of the furnace body 1.

[0111] In the foregoing embodiment, the protection structure arranged on the bottom of the furnace body 1 is introduced. In another embodiment of the present application, a structure arranged above the furnace body 1 for exhausting gas flow is introduced.

[0112] For example, the gas outlet pipe 22 arranged above the furnace cover 2 for exhausting gas flow and the valve 23 arranged on the gas outlet pipe 22 for controlling gas flow are further included.

[0113] In the foregoing embodiment, the structure arranged above the furnace body 1 for exhausting gas flow is introduced. In another embodiment of the present application, a method for testing the position migration of the high-temperature point of the loose coal body by using the testing device for position migration of the high-temperature point of the coal seam is introduced, and the method comprises the following steps:

[0114] Step one, after collecting the coal sample underground, the coal sample is firstly wrapped with a preservative film, secondly wrapped with aluminum foil paper, then packed with a three-layer waterproof and oxidation-resistant nylon bag, and finally transported to the laboratory where the testing device for position migration of the high-temperature point of the coal seam is located;

[0115] Step two, within 24 hours, after crushing, weighing, and particle size analysis of the coal sample, the furnace body 1 is inclined at 45° to the ground, the furnace cover 2 is opened, the coal sample is loaded into the furnace body 1, when the coal sample covers a group of sensors at the top of the supporting rod 4, the furnace body 1 is righted, the coal sample is slowly added until the furnace body 1 is filled, and then the furnace body 1 is sealed;

[0116] Step three, the computer device 17 controls the temperature controller 15 to heat the electric heating box 9, the compressed air generated by the air compressor 8 passes through the pressure gauge 12, the steady flow valve 13, and the flow meter 14 arranged between the air compressor 8 and the electric heating box 9 in sequence, is heated by the electric heating box 9, and finally enters the inside of the furnace body 1 through the gas conveying pipe 7, so that the gas temperature of the gas conveying pipe 7 entering the furnace body 1 is consistent with the temperature of the coal sample in the furnace body 1;

[0117] Among them, the installation point of the first temperature measuring element 5 with the highest temperature detected by the plurality of first temperature measuring elements 5 is defined as a high temperature point of the coal sample, the temperature detected by the first temperature measuring element 5 corresponding to the high temperature point of the coal sample is defined as the temperature Tc of the high temperature point of the coal sample, and when the temperature Tc of the high temperature point of the coal sample reaches 170℃, the temperature controller 15 stops heating;

[0118] The method for controlling the compressed air entering the gas conveying pipe 7 by the air compressor 8 includes adjusting the steady flow valve 13 and checking the air supply amount displayed on the flow meter 14, so that the air supply amount is Q1;

[0119] For example, the unit of the air supply amount can be cubic meters per minute.

[0120] Step four, when the air supply amount is Q1, within a continuously monitored first time period Δt1, the installation point of the first temperature measuring element 5 with the highest temperature detected by the plurality of first temperature measuring elements 5 is defined as a first high temperature point position Z1, and after the first time period Δt1 again, the installation point of the first temperature measuring element 5 with the highest temperature detected by the plurality of first temperature measuring elements 5 is defined as a to-be-defined high temperature point position Z.

[0121] If the absolute value ΔZ1 of the offset distance difference value between the to-be-defined high temperature point position Z and the first high temperature point position Z1 is less than a preset offset distance value ΔZ,

[0122] and the absolute value ΔT1 of the temperature difference value between the temperature value T1 corresponding to the first high temperature point position Z1 and the temperature value T corresponding to the to-be-defined high temperature point position Z is less than a preset temperature deviation value ΔT,

[0123] and an absolute value of an oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is less than a preset oxygen concentration deviation value AC,

[0124] then determining that the to-be-determined high-temperature point position Z is the target high-temperature point position in the stable state corresponding to the air supply amount Q1.

[0125] If an absolute value of a shift distance difference between the to-be-determined high-temperature point position Z and the first high-temperature point position Z1 is greater than or equal to a preset shift distance value AZ,

[0126] or an absolute value of a temperature difference between the temperature value T1 corresponding to the first high-temperature point position Z1 and the temperature value T corresponding to the to-be-determined high-temperature point position Z is greater than or equal to a preset temperature deviation value AT,

[0127] or an absolute value of an oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is greater than or equal to a preset oxygen concentration deviation value AC,

[0128] then determining that the to-be-determined high-temperature point position Z is not the target high-temperature point position in the stable state corresponding to the air supply amount Q1.

[0129] It should be noted that the first time period At1 can be 0.1 seconds, or 0.01 seconds, and is small enough.

[0130] Step five, every n first time periods At1, on the basis of the air supply amount Q1, an n air supply amount superposition amount AQ is added,

[0131] If an absolute value of a shift distance difference between the to-be-determined high-temperature point position Z and the first high-temperature point position Z1 is greater than or equal to the preset shift distance value AZ,

[0132] or an absolute value of a temperature difference between the temperature value T1 corresponding to the first high-temperature point position Z1 and the temperature value T corresponding to the to-be-determined high-temperature point position Z is greater than or equal to the preset temperature deviation value AT,

[0133] or an absolute value of an oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is greater than or equal to the preset oxygen concentration deviation value AC,

[0134] determining that the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is not the upper limit of the oxygen concentration value of the first high-temperature point position Z1 or the lower limit of the oxygen concentration value of the second high-temperature point position Z2 under the condition that the supply air volume Q1 and the sum Q1' of the n supply air volume superimposition amounts ΔQ are determined;

[0135] if the absolute value ΔZ1 of the offset distance difference value between the to-be-determined high-temperature point position Z and the first high-temperature point position Z1 is less than the preset offset distance value ΔZ,

[0136] or the absolute value ΔT1 of the temperature difference value between the temperature value T1 corresponding to the first high-temperature point position Z1 and the temperature value T corresponding to the to-be-determined high-temperature point position Z is less than the preset temperature deviation value ΔT,

[0137] or the absolute value ΔC1 of the oxygen concentration difference value between the oxygen concentration value C1 corresponding to the first high-temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is less than the preset oxygen concentration deviation value ΔC,

[0138] determining that the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is not the upper limit of the oxygen concentration value of the first high-temperature point position Z1 or the lower limit of the oxygen concentration value of the second high-temperature point position Z2 under the condition that the supply air volume Q1 and the sum Q1' of the n supply air volume superimposition amounts ΔQ are determined;

[0139] Step six, every n first time period Δt1, on the basis of the supply air volume Q1', reduce n supply air volume superimposition amounts ΔQ,

[0140] if the absolute value ΔZ1 of the offset distance difference value between the to-be-determined high-temperature point position Z and the first high-temperature point position Z1 is greater than or equal to the preset offset distance value ΔZ,

[0141] or the absolute value ΔT1 of the temperature difference value between the temperature value T1 corresponding to the first high-temperature point position Z1 and the temperature value T corresponding to the to-be-determined high-temperature point position Z is greater than or equal to the preset temperature deviation value ΔT,

[0142] or the absolute value ΔC1 of the oxygen concentration difference value between the oxygen concentration value C1 corresponding to the first high-temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is greater than or equal to the preset oxygen concentration deviation value ΔC,

[0143] determining that the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is not the upper limit of the oxygen concentration value of the first high-temperature point position Z1 or the lower limit of the oxygen concentration value of the second high-temperature point position Z2 under the condition that the supply air volume Q1 and the sum Q1' of the n supply air volume superimposition amounts ΔQ are determined;

[0144] If the absolute value ΔZ1 of the offset distance difference between the to-be-determined high-temperature point position Z and the first high-temperature point position Z1 is less than the preset offset distance value ΔZ,

[0145] or the absolute value ΔT1 of the temperature difference between the temperature value T1 corresponding to the first high-temperature point position Z1 and the temperature value T corresponding to the to-be-determined high-temperature point position Z is less than the preset temperature deviation value ΔT,

[0146] or the absolute value ΔC1 of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point position Z1 and the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is less than the preset oxygen concentration deviation value ΔC,

[0147] then it is determined that, under the condition that the difference Q1” between the air supply amount Q1’ and the n air supply amount superposition amounts ΔQ, the oxygen concentration value C corresponding to the to-be-determined high-temperature point position Z is not maintained at the lower limit value of the oxygen concentration of the second high-temperature point position Z2.

[0148] Step seven, repeatedly performing N groups of steps five and six to obtain multiple groups of Q1’ and the to-be-determined high-temperature point position Z, and multiple groups of Q1” and the to-be-determined high-temperature point position Z,

[0149] establishing a relationship curve between the multiple groups of Q1’ and the to-be-determined high-temperature point position Z, and establishing a relationship curve between the multiple groups of Q1” and the to-be-determined high-temperature point position Z, and analyzing the driving effect of increasing or decreasing the air supply amount on the migration of the to-be-determined high-temperature point position Z;

[0150] It should be noted that steps five and six can determine the upper and lower limit values of the oxygen concentration of the high-temperature point position when the air supply amount is increased or decreased, and step seven can determine the relationship curve between the high-temperature point position and the air supply amount. That is, the relationship between the high-temperature point position and the oxygen concentration value, and the relationship between the high-temperature point position and the air supply amount can be determined.

[0151] Step eight, when the temperature Tc of the high-temperature point of the coal sample detected by the first temperature measuring element 5 corresponding to the high-temperature point of the coal sample is equal to 170°C, the temperature controller 15 stops heating the electric heating box 9, and the air compressor 8 stops the air flow into the furnace body 1,

[0152] When the temperature of the coal sample in the furnace body 1 is less than 40°C, first, the temperature controller 9, the data acquisition module 16, and the computer equipment 17 are turned off, then the furnace body 1 is inclined at an angle of 45° with the ground, and finally the coal sample is unloaded from the furnace body 1 through the coal unloading port 24.

[0153] Any combination of the technical features in the above embodiments can be made, and for the sake of brevity, not all possible combinations are described above, however, as long as the combination of the technical features does not exist in contradiction, it shall be considered within the scope of the present disclosure.

[0154] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it shall not be understood as a limitation on the patent scope of the present application. It shall be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these shall be within the protection scope of the present application. Therefore, the protection scope of the present application patent shall be subject to the appended claims.

Claims

1. A testing device for the migration of the high-temperature point of spontaneous combustion in loose coal, characterized in that: include: A furnace for loading coal samples, the furnace comprising a furnace body (1) for loading the coal samples, a furnace cover (2) disposed on the top of the furnace body (1), and a coal unloading port (24) disposed at the bottom of the side wall of the furnace body (1). The furnace body (1) is equipped with a horizontally placed support frame (3) and a support rod (4) placed perpendicular to the support frame (3). Multiple sensor groups for detecting the temperature and oxygen concentration at the location of the coal sample are arranged at intervals on the support rod (4). Each sensor group includes a first temperature measuring element (5) for detecting the temperature at the location of the coal sample and a gas concentration measuring element (6) for detecting the oxygen concentration at the location of the coal sample. An air compressor (8) for oxidizing the coal sample is connected to the furnace body (1) via a gas supply pipe (7); an electric heating box (9) for raising the temperature of the airflow in the gas supply pipe (7) is disposed on the outer periphery of the gas supply pipe (7); a liquid (10) for transferring heat is disposed in the electric heating box (9); and a second temperature measuring element (11) for detecting the temperature of the liquid (10) is disposed in the liquid (10). An airflow parameter measuring mechanism is installed on the air supply pipe (7) between the air compressor (8) and the electric heating box (9) to measure the airflow parameters in the air supply pipe (7). The airflow parameter measuring mechanism includes a pressure gauge (12) connected to the air compressor (8) through the air supply pipe (7) to measure the airflow pressure in the air supply pipe (7), a flow stabilizing valve (13) connected to the pressure gauge (12) through the air supply pipe (7) to control the airflow velocity in the air supply pipe (4), and a flow meter (14) connected to the flow stabilizing valve (13) through the air supply pipe (7) to measure the airflow velocity in the air supply pipe (7). A temperature controller (15) connected to the second temperature measuring element (11) for controlling the heating temperature of the electric heating box (9); a data acquisition module (16) connected to the first temperature measuring element (5) and the second temperature measuring element (11) for recording temperature values; the data acquisition module (16) connected to the first temperature measuring element (5) and the gas concentration detection element (6); and a computer device (17) connected to the data acquisition module (16) for analyzing the relationship between oxygen concentration and the high-temperature point migration position of the coal sample. The width range of the furnace body (1) is [a, b] cm, where b is less than 200 cm, where a is the lower limit of the width of the furnace body (1) and b is the upper limit of the width of the furnace body (1).

2. The testing device for the migration of the high-temperature point of spontaneous combustion in loose coal as described in claim 1, characterized in that: a is 10cm and b is 20cm.

3. The testing device for the migration of the high-temperature point of spontaneous combustion in loose coal as described in claim 1, characterized in that: The first temperature sensing element (5) includes a first thermocouple, and the second temperature sensing element (11) includes a second thermocouple.

4. The testing device for the migration of the high-temperature point of spontaneous combustion in loose coal as described in claim 1, characterized in that: The gas concentration detection element (6) includes a gas sensor.

5. The testing device for the migration of the high-temperature point of spontaneous combustion in loose coal as described in claim 1, characterized in that: It also includes insulation layers arranged sequentially from the inside to the outside on the side wall of the furnace body (1) for heat preservation of the furnace body (1), the insulation layers including a first insulation layer (18), a second insulation layer (19) and a third insulation layer (20).

6. The testing device for the migration of the high-temperature point of spontaneous combustion in loose coal as described in claim 1, characterized in that: It also includes a refractory brick layer (21) disposed at the bottom of the furnace body (1) for protecting the furnace body (1).

7. The testing device for the migration of the high-temperature point of spontaneous combustion in loose coal as described in claim 1, characterized in that: It also includes an exhaust pipe (22) for discharging airflow located above the furnace cover (2), and a valve (23) for controlling airflow located on the exhaust pipe (22).

8. A method for testing the migration of high-temperature points using the testing device for the migration of spontaneous combustion high-temperature points in loose coal as described in claim 1, characterized in that: Step 1: After collecting coal samples underground, first wrap the coal samples with plastic wrap, then wrap them with aluminum foil, then pack them with a three-layer waterproof and anti-oxidation nylon bag, and finally transport the coal samples to the laboratory where the testing device for migrating the high temperature point of the coal seam is located. Step 2: Within 24 hours, after crushing, weighing and particle size analysis of the coal sample, tilt the furnace body (1) at 45° to the ground, open the furnace cover (2), and load the coal sample into the furnace body (1). When the coal sample covers the top set of sensor groups on the support rod (4), straighten the furnace body (1), slowly add the coal sample until the furnace body (1) is full, and then seal the furnace body (1). Step 3: The computer equipment (17) controls the temperature controller (15) to heat the electric heating box (9). The compressed air generated by the air compressor (8) passes through the gas supply pipe (7) and successively through the pressure gauge (12), the flow regulator (13), and the flow meter (14) set between the air compressor (8) and the electric heating box (9), and then passes through the electric heating box (9) for heating. Finally, it enters the furnace body (1) through the gas supply pipe (7), so that the temperature of the gas entering the furnace body (1) through the gas supply pipe (7) is consistent with the temperature of the coal sample in the furnace body (1). Among them, the installation point of the first temperature measuring element (5) with the highest temperature detected by multiple first temperature measuring elements (5) is defined as the high temperature point of the coal sample, and the temperature detected by the first temperature measuring element (5) corresponding to the high temperature point of the coal sample is defined as the temperature Tc of the high temperature point of the coal sample. When the temperature Tc of the high temperature point of the coal sample reaches 170°C, the temperature controller (15) stops heating. The method by which the air compressor (8) controls the compressed air supplied to the air supply pipe (7) includes: adjusting the flow regulator (13) and viewing the air supply volume displayed on the flow meter (14) so ​​that the air supply volume is Q1; Step 4: When the air supply is Q1, during the first continuous monitoring time period Δt1, the installation point of the first temperature measuring element (5) with the highest temperature detected by multiple first temperature measuring elements (5) is defined as the first high temperature point position Z1. After the first time period Δt1 is passed again, the installation point of the first temperature measuring element (5) with the highest temperature detected by multiple first temperature measuring elements (5) is positioned as the undetermined high temperature point position Z. If the absolute value ΔZ1 of the offset distance difference between the undetermined high temperature point position Z and the first high temperature point position Z1 is less than the preset offset distance value ΔZ... Furthermore, the absolute value ΔT1 of the temperature difference between the temperature value T1 corresponding to the first high-temperature point Z1 and the temperature value T corresponding to the undetermined high-temperature point Z is less than the preset temperature deviation value ΔT. Furthermore, the absolute value ΔC1 of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point Z1 and the oxygen concentration value C corresponding to the undetermined high-temperature point Z is less than the preset oxygen concentration deviation value ΔC. Then the location Z of the undetermined high temperature point is determined to be the target high temperature point location under the steady state corresponding to the air supply volume Q1. If the absolute value ΔZ1 of the offset distance difference between the undetermined high temperature point position Z and the first high temperature point position Z1 is greater than or equal to the preset offset distance value ΔZ... Alternatively, the absolute value ΔT1 of the temperature difference between the temperature value T1 corresponding to the first high-temperature point Z1 and the temperature value T corresponding to the undetermined high-temperature point Z is greater than or equal to the preset temperature deviation value ΔT. Alternatively, the absolute value ΔC1 of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point Z1 and the oxygen concentration value C corresponding to the undetermined high-temperature point Z is greater than or equal to the preset oxygen concentration deviation value ΔC. Then it is determined that the location of the undetermined high temperature point Z is not the target high temperature point location under the steady state corresponding to the air supply volume Q1. Step 5: After n time intervals Δt1 of the first time period, add n additional air supply amounts ΔQ to the air supply amount Q1. If the absolute value ΔZ1 of the offset distance difference between the undetermined high-temperature point position Z and the first high-temperature point position Z1 is greater than or equal to the preset offset distance value ΔZ... Alternatively, the absolute value ΔT1 of the temperature difference between the temperature value T1 corresponding to the first high-temperature point Z1 and the temperature value T corresponding to the undetermined high-temperature point Z is greater than or equal to the preset temperature deviation value ΔT. Alternatively, the absolute value ΔC1 of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point Z1 and the oxygen concentration value C corresponding to the undetermined high-temperature point Z is greater than or equal to the preset oxygen concentration deviation value ΔC. Under the condition that the air supply volume Q1 and the sum of the n air supply volumes ΔQ are Q1', the oxygen concentration value C corresponding to the undetermined high temperature point Z is the upper limit of the oxygen concentration for maintaining the first high temperature point Z1, or the lower limit of the oxygen concentration for maintaining the second high temperature point Z2. If the absolute value ΔZ1 of the offset distance difference between the undetermined high temperature point position Z and the first high temperature point position Z1 is less than the preset offset distance value ΔZ... Alternatively, the absolute value ΔT1 of the temperature difference between the temperature value T1 corresponding to the first high-temperature point Z1 and the temperature value T corresponding to the undetermined high-temperature point Z is less than the preset temperature deviation value ΔT. Alternatively, the absolute value ΔC1 of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point Z1 and the oxygen concentration value C corresponding to the undetermined high-temperature point Z is less than the preset oxygen concentration deviation value ΔC. Under the condition that the air supply volume Q1 and the sum of the n air supply volumes ΔQ are Q1', the oxygen concentration value C corresponding to the undetermined high temperature point Z is neither the upper limit of the oxygen concentration at the first high temperature point Z1 nor the lower limit of the oxygen concentration at the second high temperature point Z2. Step 6: After n time intervals Δt1 of the first time period, based on the air supply volume Q1', reduce the cumulative air supply volume by n times ΔQ. If the absolute value ΔZ1 of the offset distance difference between the undetermined high-temperature point position Z and the first high-temperature point position Z1 is greater than or equal to the preset offset distance value ΔZ... Alternatively, the absolute value ΔT1 of the temperature difference between the temperature value T1 corresponding to the first high-temperature point Z1 and the temperature value T corresponding to the undetermined high-temperature point Z is greater than or equal to the preset temperature deviation value ΔT. Alternatively, the absolute value ΔC1 of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point Z1 and the oxygen concentration value C corresponding to the undetermined high-temperature point Z is greater than or equal to the preset oxygen concentration deviation value ΔC. Under the condition that the difference Q1" between the air supply volume Q1' and the sum of the n air supply volumes ΔQ is determined, the oxygen concentration value C corresponding to the undetermined high temperature point Z is the lower limit value of the oxygen concentration to maintain the second high temperature point Z2. If the absolute value ΔZ1 of the offset distance difference between the undetermined high temperature point position Z and the first high temperature point position Z1 is less than the preset offset distance value ΔZ... Alternatively, the absolute value ΔT1 of the temperature difference between the temperature value T1 corresponding to the first high-temperature point Z1 and the temperature value T corresponding to the undetermined high-temperature point Z is less than the preset temperature deviation value ΔT. Alternatively, the absolute value ΔC1 of the oxygen concentration difference between the oxygen concentration value C1 corresponding to the first high-temperature point Z1 and the oxygen concentration value C corresponding to the undetermined high-temperature point Z is less than the preset oxygen concentration deviation value ΔC. Under the condition that the difference Q1" between the air supply volume Q1' and the sum of the n air supply volumes ΔQ is determined, the oxygen concentration value C corresponding to the undetermined high temperature point Z is not the lower limit value of the oxygen concentration for maintaining the second high temperature point Z2. Step 7: Repeat steps 5 and 6 N times to obtain multiple sets of Q1' and the location Z of the undetermined high-temperature point, and multiple sets of Q1" and the location Z of the undetermined high-temperature point. Establish the relationship curves between the multiple sets of Q1' and the location Z of the undetermined high temperature point, and establish the relationship curves between the multiple sets of Q1" and the location Z of the undetermined high temperature point, and analyze the driving effect of increasing or decreasing the air supply volume on the migration of the location Z of the undetermined high temperature point. Step 8: When the temperature Tc of the high-temperature point of the coal sample detected by the first temperature measuring element (5) is equal to 170°C, the temperature controller (15) stops heating the electric heating box (9), and the air compressor (8) stops supplying airflow into the furnace body (1). When the temperature of the coal sample in the furnace body (1) is less than 40°C, the temperature controller (9), data acquisition module (16), and computer equipment (17) are turned off first. Then the furnace body (1) is tilted at 45° to the ground. Finally, the coal sample is discharged from the furnace body (1) through the coal discharge port (24).

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