A similar experimental system and method for measuring the dynamic progression characteristics of spontaneous combustion of coal

Abstract

To disclose a similar experimental system and method to measure dynamic progression characteristics of spontaneous ignition of coal in the field of coal mining.SOLUTION: A gas supply system blends nitrogen and oxygen into dried air; a coal sample tank adds coal samples based on similar order and span size when a roof collapses and fills a goaf; a programmable heating furnace adjusts a furnace temperature and sets a programmed heating rate; a gas chromatograph analyzes gas samples collected from an exhaust port of a dynamic sample-adding coal tank, and records the temperature of the coal samples collected by a temperature sensor after completing addition of the coal samples; and a data collection host obtains the temperature of coal, exhaust components, and concentrations during a dynamic sample addition process, calculates oxidation oxygen consumption rate, heat generation rate, etc. using an oxidation kinetics method, and determines dynamic rules and progression of spontaneous ignition of residual coal in the goaf during a dynamic mining process. As a result, it is possible to measure dynamic progression characteristics of spontaneous coal ignition by dynamically adding the coal samples.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to the field of coal mining technology, and more particularly to an analogue experimental system and method for measuring the dynamic progression characteristics of spontaneous combustion of coal. [Background technology]

[0002] The main characteristics of thermal and mechanical disasters in mining areas are concealment, connectivity, dynamics, and complexity, which makes the disasters high-risk, difficult to identify, difficult to predict, and difficult to prevent. The coal mining face is a dynamic system, as shown in Figure 1, with the progress of the face, the boundary between the face and the mining area moves, the length of the air supply and return airways shortens, and the mining area lengthens. Once any area in the mining area is formed, the depth of burial in the mining area increases dynamically as mining continues, which determines that the mining area and the problems related to it change dynamically. As shown in the area marked with a red circle in Figure 1, in the dynamic change process of the mining area, the already formed area in the mining area will gradually collapse and pressure will appear over time, and then stabilize. The collapsed coal rock will gradually be compressed repeatedly, and the increase rate will gradually decrease. As mining continues, the thickness, porosity, and air permeability of the residual coal in any existing area in the mining area will gradually decrease, the air leakage rate will also decrease, and the concentration of gas such as gas will increase. The changes in the air leakage flow field and the accumulation and crushing expansion characteristics of the residual coal will lead to changes in the oxygen supply and heat release state in the mining area, and changes in the emission and distribution of toxic and harmful gases, which will inevitably cause dynamic changes in the spontaneous combustion phenomenon of the residual coal in the mining area, especially the dynamic changes in the "three zone" distribution of spontaneous combustion. During the working process of the face, there is a certain distance between the high temperature area and the high oxygen concentration area of ​​the residual coal in the air-gas section, and this distance changes dynamically. During dynamic advancement, this distance decreases continuously, and the temperature rise rate of the air-gas section increases continuously. With the dynamic advancement of the face and the gradual recovery of the stress in the air-gas section, the porosity of the residual coal in the air-gas section decreases dynamically, and the degree of crushing increases dynamically, which ultimately causes dynamic changes such as air leakage, gas movement, and spontaneous combustion of the residual coal in the air-gas section. To study the characteristics and progress of spontaneous combustion of the residual coal in the air-gas section, a dynamic method is needed to accurately grasp all the characteristics and progress of spontaneous combustion in the air-gas section.During the working process of the face, the residual coal in the mining area will experience air leakage and high oxygen concentration, and will begin to self-heat under suitable conditions, causing the start of spontaneous combustion. After that, the residual coal in the area will be continuously compressed and crushed, the air leakage flow rate and oxygen concentration will decrease, and the concentration of gas etc. will continue to increase, and the spontaneous combustion will progress dynamically. This dynamic progression process has strong complexity, variability and randomness, and the spontaneous combustion of the residual coal will occur in a transitional form in the dynamic coupling process of seepage flow, heat transfer and mass transfer, and will constantly evolve. Therefore, when studying and preventing the spontaneous combustion problem of the residual coal in the mining area during normal mining, it is necessary to pay attention to the dynamic changes of the factors related to the mining area.

[0003] As mining progresses, the amount of residual coal in the mining area gradually increases. The newly exposed residual coal in the shallow area has a short contact time with oxygen, while the residual coal formed for a long time in the deep area has a long contact time with air. However, due to the continuous loading by the face, the amount of air flow received by the deep residual coal decreases, and the received air flow gradually changes into gas consumed by the oxidation of the shallow residual coal. The gas consumed by the newly increased residual coal in the shallow area not only has a low oxygen content, but also a slightly higher temperature, and the CO, CO2, CH4 and gaseous hydrocarbon gases in the gas composition gradually increase. This has a significant impact on the oxidation of the early residual coal in the deep area or the residual coal along the air leakage route. Therefore, based on the formation sequence of the residual coal in the mining area and the rule of roof loading, combined with the flow route of the air leakage in the mining area, it is necessary to determine the relevant coal sample addition and air flow inflow sequence, so that the more realistic and similar rules of the oxidation and spontaneous combustion of the residual coal in the mining area can be obtained.

[0004] Therefore, how to design an analogous experimental system and method for measuring the dynamic progress characteristics of spontaneous combustion of residual coal in a sampling area, which can realize the dynamic addition of coal samples, is an issue that must be addressed by those skilled in the art. Summary of the Invention [Problem to be solved by the invention]

[0005] In view of this, the present invention provides an analogous experimental system and method for measuring the dynamic progression characteristics of spontaneous combustion of coal, thereby solving the problems described in the background art. [Means for solving the problem]

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A similar experimental system for measuring the dynamic progress characteristics of spontaneous combustion of coal includes a gas supply system, a program heating chamber, a coal sample tank for dynamic sample addition, a gas chromatograph, a temperature testing device, and a data collection host, the two inlets of the gas supply system are connected to a nitrogen cylinder and an oxygen cylinder respectively, the outlet of the gas supply system is connected to the coal sample tank for dynamic sample addition, the coal sample tank for dynamic sample addition is connected to the gas chromatograph and the temperature testing device respectively, and the output terminals of the gas chromatograph and the temperature testing device are both connected to the data collection host; A gas supply system is used to blend nitrogen and oxygen into the dry air and supply it to the coal sample tank for dynamic sample addition; The dynamic sample addition coal sample tank is used to add coal samples according to the similar sequence and span size when the roof collapses and fills the mining area during the initial and regular loads of the coal face during the mining process, thus completing the dynamic progression similar experiment of spontaneous combustion of the remaining coal in the mining area. The programmable heating chamber is used to adjust the furnace temperature and set the programmable heating rate. A gas chromatograph was used to analyze and test gas samples taken from the exhaust of a dynamic sample addition coal tank. a temperature checking device is used to record the temperature of the coal sample collected by a temperature sensor within the coal sample after the addition of the coal sample is completed; The data collection host obtains the coal temperature, exhaust components and concentrations during the dynamic sample addition process, and after the experiment is completed, the oxidation kinetics method is used to calculate the oxidation oxygen consumption rate and heat release rate according to the coal temperature, exhaust components and concentrations, which are used to judge the dynamic rules and progress of spontaneous combustion of residual coal in the mining area during the dynamic mining process.

[0008] Optionally, the apparatus may further include a gas supply system output on-off valve, a three-way pipe, a gas passage on-off valve, and a gas flow meter, and the blended dry air passes through the gas supply system output on-off valve, the three-way pipe, the gas passage on-off valve, and the gas flow meter, and enters into two dynamic sample addition coal sample tanks, respectively.

[0009] Optionally, the coal sample tank of dynamic sample addition includes: a raw material supply hopper; a coal sample tank plug; a 304 stainless steel connecting pipe; a raw material supply pipe opening and closing valve; a temperature sensor; a coal sample tank intake pipe; a copper mesh for preventing the coal sample from leaking; an exhaust pipe; and a coal sample tank bracket; The outlet of the raw material supply hopper is opposite to the position of the coal sample tank plug, the coal sample tank plug is inserted into the 304 stainless steel connecting pipe, and the 304 stainless steel connecting pipe is inserted into the coal sample tank; The 304 stainless steel connecting pipe is equipped with a raw material supply pipe opening and closing valve, and several temperature sensors are installed along the depth direction in the coal sample tank. The dry air blended by the gas supply system flows into the coal sample tank from the top through the coal sample tank intake pipe, and a copper mesh to prevent the coal sample from leaking and an exhaust pipe are installed near the bottom inside the coal sample tank, and a coal sample tank bracket is installed under the coal sample tank.

[0010] Optionally, the temperature checking device is connected to the temperature sensor by a temperature transmission data line. Optionally, the exhaust pipe is connected to a gas chromatograph.

[0011] A similar experimental method for measuring dynamic progress characteristics of spontaneous combustion of coal, which is applied to the similar experimental system for measuring dynamic progress characteristics of spontaneous combustion of coal described above, S1, the spontaneous combustion period of the residual coal in the sampling area is set to t days, and the initial weighting time is set to t 1 The periodic weighting time is t rdays, the mining speed is vm / d, and the depth or length of the mining area is t according to the mining of the face. v above which the residual coal in the mining area spontaneously combusts; S2, mixing nitrogen and oxygen into the dry air according to the ratio of nitrogen and oxygen in the air through the two gas supply systems, and the mixed dry air passes through the gas supply system output opening and closing valve, the three-way pipe, the gas passage opening and closing valve and the gas flow meter, and respectively enters into the two dynamic sample addition coal sample tanks, and at this time, the gas supply and intake pipe passages are blocked; S3. At the start of the experiment, first put the initial weighted coal sample into the two dynamic sample addition coal sample tanks. If the total height of the effective added coal sample in the dynamic sample addition coal sample tank is assumed to be L, the height of the initial added coal sample is JPEG0007678436000001.jpg1630; S4, open the nitrogen cylinder, and allow nitrogen to flow into the coal sample tank for dynamic sample addition through the gas supply system. Start the heating program of the heating box, and set the heating rate to h t °C / min, and the initial ambient temperature is T e The temperature starts to rise as s If so, the total time required for similar experiments is JPEG0007678436000002.jpg1755, and within the experimental cycle expressing an equivalent conversion between the time of the analogous experimental process and the actual firing period t in JPEG0007678436000003.jpg1442; S5, adjust the flow rate of nitrogen, and open the oxygen cylinder so that oxygen and nitrogen are mixed in the ratio of 21:79 according to the gas flow rate required for the experiment, and mixed with the dry air with a flow rate of Q by the gas supply system, and enter the intake pipe passage; S6, according to the time required for the experiment, gas samples are taken from the exhaust port of the coal sample tank of dynamic sample addition, and analyzed and tested by gas chromatography. The gas sample is taken every time the furnace temperature actually increases by 10°C from 40°C to the end of the experiment, and the gas sample is completed before the regular weighting and coal sample addition. S7, after the experiment started JPEG0007678436000004.jpgAfter 1737 minutes, the first regular weighting coal sample was added, and the height of the coal sample added each time the weighting was increased. JPEG0007678436000005.jpg2254; S8. After adding several times, when the number of times of dynamic addition of the coal sample and the amount of the coal sample reach the planned purpose of the experiment, the experiment is stopped, and the adding process of the coal sample and the corresponding position of the corresponding temperature sensor are recorded; S9, based on the coal oxidation kinetic theory, according to the oxygen concentration, carbon oxide concentration, and hydrocarbon gas concentration of the gas sample test, the height of the coal sample in the calculation formula or the height difference between the intake and exhaust ends is dynamically changed according to the coal sample height, performing a kinetic calculation; S10, determining an indicator gas generation rule, an oxidation dynamic indicator change rule, and a coal sample temperature rise rule in the dynamic sample addition process based on the coal oxidation oxygen consumption rate and heat generation rate in the dynamic sample addition process, and determining the dynamic rule and progress of spontaneous combustion of residual coal in the mining area in the dynamic mining process.

[0012] Alternatively, the spontaneous combustion period of the remaining coal in the extraction section is the time it takes for the temperature of the coal in the extraction section to rise from the downhole temperature to 70°C.

[0013] As can be seen from the above technical proposal, compared with the prior art, the present invention provides an analogous experimental system and method for measuring the dynamic progression characteristics of spontaneous combustion of coal, and provides an experimental detection system and method for the rules of oxidation and spontaneous combustion of residual coal in the process of the mining area dynamically expanding and the residual coal dynamically increasing with the mining face mining. The main beneficial effects include that the analogous experimental system and method can gradually add coal samples based on the actual dynamic expansion rule of the mining area, and can effectively analogize the difference in oxidation time and oxidation degree of residual coal in the mining area due to differences in mining time, and the oxidation kinetic calculation results obtained by the dynamic analogous experimental system and method can reflect the step-by-step characteristics and average characteristics of the oxidation kinetics of residual coal in different regions or depths formed at different times in the actual mining area, and can significantly improve the prediction accuracy and reliability of the spontaneous combustion state of residual coal in the uneven, asymmetric and dynamic mining area. [Brief description of the drawings]

[0014] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art are briefly described below; of course, the drawings described below are only embodiments of the present invention, and those skilled in the art can obtain other drawings based on the drawings provided without exerting creative efforts.

[0015] [Figure 1] 4 is a dynamic distribution diagram of the residual coal range in the flow field and concentration field of the mining area during the mining process provided by the present invention; [Diagram 2] FIG. 2 is a schematic diagram of an analogous experimental system for measuring the dynamic progression characteristics of spontaneous combustion of coal provided by the present invention. [Diagram 3] FIG. 2 is a schematic diagram showing a simulation of a coal sample addition process caused by roof collapse by initial loading and periodic loading provided by the present invention. [Figure 4(a)] 4A and 4B are diagrams showing the temperature change in the coal sample tank with constant height and dynamic sample addition, respectively, provided by the present invention. [Figure 4(b)]4A and 4B are diagrams showing the temperature change in the coal sample tank with constant height and dynamic sample addition, respectively, provided by the present invention. [Diagram 5] FIG. 2 is a diagram showing the change in oxygen concentration provided by the present invention. [Figure 6] FIG. 2 is a graph showing the change in carbon monoxide concentration provided by the present invention. [Figure 7] FIG. 2 is a graph showing the change in carbon dioxide concentration provided by the present invention. [Figure 8] FIG. 2 is a diagram showing the change rule of oxygen consumption rate provided by the present invention. [Figure 9] FIG. 2 is a diagram showing the carbon monoxide production rules provided by the present invention. [Figure 10] FIG. 1 is a diagram showing the carbon dioxide production rules provided by the present invention. [Figure 11] FIG. 2 is a diagram showing the variation rule of the maximum heat release rate provided by the present invention. [Figure 12] FIG. 2 is a diagram showing the variation rule of the minimum heat dissipation rate provided by the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The following provides a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention, but of course, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and all other embodiments obtained by those skilled in the art without paying creative labor based on the embodiments of the present invention are all within the scope of the claims of the present invention.

[0017] The present invention provides an analogous experimental system for measuring the dynamic progress characteristics of spontaneous combustion of coal, as shown in FIG. 2, which includes a gas supply system 3, a program heating box 19, a coal sample tank for dynamic sample addition, a gas chromatograph 21, a temperature test device 20, and a data collection host 22, the two inlets of the gas supply system 3 are respectively connected to a nitrogen cylinder 2 and an oxygen cylinder 1, the outlet of the gas supply system 3 is respectively connected to the coal sample tank for dynamic sample addition, the coal sample tank for dynamic sample addition is respectively connected to the gas chromatograph 21 and the temperature test device 20, and the output terminals of the gas chromatograph 21 and the temperature test device 20 are both connected to the data collection host 22; The gas supply system 3 is used to mix nitrogen and oxygen into the dry air and supply it to the coal sample tank for dynamic sample addition; The coal sample tank for dynamic sample addition is used to add coal samples 9 in a similar order and span size when the roof collapses and fills the mining area during the initial and regular loads of the coal face during the mining process, completing a similar experiment on the dynamic progression of spontaneous combustion of residual coal in the mining area. The programmable heating box 19 is used to adjust the furnace temperature and set the programmable heating rate. A gas chromatograph 21 is used to analyze and test gas samples taken from the exhaust of the dynamic sample addition coal tank; A temperature check device 20 is used to record the temperature of the coal sample collected by the temperature sensor 13 in the coal sample 9 after the addition of the coal sample 9 is completed; The data collection host 22 obtains the coal temperature, exhaust components and concentrations during the dynamic sample addition process, and after the experiment is completed, uses the oxidation kinetics method to calculate the oxidation oxygen consumption rate, heat release rate, etc. according to the coal temperature, exhaust components and concentrations, which are used to judge the dynamic rules and progress of spontaneous combustion of residual coal in the mining area during the dynamic mining process.

[0018] Further, it includes a gas supply system output opening and closing valve 4, a three-way pipe 5, a gas passage opening and closing valve 6, and a gas flow meter 7, and the blended dry air passes through the gas supply system output opening and closing valve 4, the three-way pipe 5, the gas passage opening and closing valve 6 and the gas flow meter 7, and enters into two dynamic sample addition coal sample tanks, respectively.

[0019] In addition, the dynamic sample addition coal sample tank includes a raw material supply hopper 8, a coal sample tank plug 10, a 304 stainless steel connection pipe 11, a raw material supply pipe opening and closing valve 12, a temperature sensor 13, a coal sample tank intake pipe 15, a copper mesh 16 for preventing the coal sample from leaking, an exhaust pipe 17, and a coal sample tank bracket 18. The outlet of the raw material supply hopper 8 faces the position of the coal sample tank plug 10, the coal sample tank plug 10 is inserted into the 304 stainless steel connecting pipe 11, and the 304 stainless steel connecting pipe 11 is inserted into the coal sample tank; A raw material supply pipe opening and closing valve 12 is installed on the 304 stainless steel connection pipe 11, and several temperature sensors 13 are installed along the depth direction in the coal sample tank. The dry air blended by the gas supply system 3 flows into the coal sample tank from the top through the coal sample tank intake pipe 15, and inside the coal sample tank, a copper mesh 16 to prevent the coal sample from leaking and an exhaust pipe 17 are installed near the bottom, and a coal sample tank bracket 18 is installed under the coal sample tank.

[0020] Furthermore, the temperature inspection device 20 is connected to the temperature sensor 13 by a temperature transmission data line 14 .

[0021] Furthermore, the exhaust pipe 17 is connected to a gas chromatograph 21 .

[0022] The similar experimental system for measuring the dynamic progression characteristics of spontaneous combustion of coal shown in Figure 2 constructed in this embodiment includes a gas supply system, a programmable heating system, a dynamic sample addition tank system, a temperature monitoring system, etc., and can realize the dynamic addition of coal samples 9 and the free collection of gas samples. During the initial loading and regular loading in the mining face process, when the roof collapses and fills the collection area, coal samples 9 can be added according to a similar sequence and span size. At the same time, the system dynamically adds air to the top of the coal samples 9 and supplies air flow by exhausting it from the tail.

[0023] This embodiment further discloses a similar experimental method for measuring the dynamic progress characteristics of spontaneous combustion of coal, which is applied to the similar experimental system for measuring the dynamic progress characteristics of spontaneous combustion of coal, S1, the spontaneous combustion period of the residual coal in the sampling area (the time required for the temperature of the coal in the sampling area to rise from the downhole temperature to 70°C) is t days, and the initial weighting time is t 1 The periodic weighting time is t r days, the mining speed is vm / d, and the depth or length of the mining area is t according to the mining of the face. v above which the residual coal in the mining area spontaneously combusts; S2, nitrogen and oxygen are mixed into the dry air according to the ratio of nitrogen and oxygen in the air through the two gas supply systems 3, and the mixed dry air is passed through the gas supply system output opening and closing valve 4, the three-way pipe 5, the gas passage opening and closing valve 6 and the gas flow meter 7 into the two dynamic sample addition coal sample tanks, respectively, and at this time, the gas supply and intake pipe passages are blocked; S3. At the start of the experiment, first put the initial weighted coal sample 9 into the two dynamic sample addition coal sample tanks. If the total height of the effective added coal sample 9 in the dynamic sample addition coal sample tank is assumed to be L, the height of the initial added coal sample is JPEG0007678436000006.jpg1728; S4, open the nitrogen cylinder 2, and allow nitrogen to flow into the coal sample tank for dynamic sample addition through the gas supply system 3. Start the heating program of the heating box 19, and set the heating rate to ht °C / min, and the initial ambient temperature is T e The temperature starts to rise as s If so, the total time required for similar experiments is JPEG0007678436000007.jpg1756, and within the experimental cycle expressing an equivalent conversion between the time (minutes) of the analogous experimental process and the actual firing period t (days) in JPEG0007678436000008.jpg1643; S5, adjust the flow rate of nitrogen, and according to the gas flow rate required for the experiment, open the oxygen cylinder 1 and mix the oxygen and nitrogen in a ratio of 21:79 with the dry air mixed by the gas supply system 3 with a flow rate of Q, and enter the intake pipe passage; S6, according to the time required for the experiment, gas samples are taken from the exhaust port of the coal sample tank of dynamic sample addition, and analyzed and tested by the gas chromatograph 21. The gas sample is taken every time the furnace temperature actually increases by 10°C from 40°C until the experiment is completed, and the gas sample is completed before the regular loading and coal sample addition. S7, after the experiment started JPEG0007678436000009.jpgAfter 1740 minutes, the first regular weighting of coal sample 9 was added, and the height of the coal sample added each time weighting was performed was JPEG0007678436000010.jpg2155; S8. The above sequence and process takes time. JPEG0007678436000011.jpg Every time it increases for 1838 minutes, JPEG0007678436000012.jpg214 Adding a 1 cm high coal sample 9, and adding it several times. When the number of times of adding the coal sample and the amount of the coal sample reach the planned purpose of the experiment, the experiment is stopped, and the adding process of the coal sample 9 and the corresponding position of the corresponding temperature sensor 13 are recorded as shown in FIG. 3 and Table 1. S9, based on the coal oxidation kinetic theory, according to the oxygen concentration, carbon oxide concentration, hydrocarbon gas concentration, etc. of the gas sample test, the height of the coal sample or the height difference between the intake and exhaust ends in the calculation formula is dynamically changed according to the coal sample height, performing a kinetic calculation; S10. Based on the coal oxidation oxygen consumption rate and heat generation rate during the dynamic sample addition process, the indicator gas generation rule, the oxidation dynamic indicator change rule, and the coal sample temperature rise rule during the dynamic sample addition process are identified, and the dynamic rule and progress of spontaneous combustion of residual coal in the mining area during the dynamic mining process are determined.

[0024] [Table 1]

[0025] Specifically, assuming a mining advance of 6m / d, ignition period of 30d, initial loading distance of 30m, and regular loading span of 15m, spontaneous combustion in the air-sinking area should occur after 30 days, that is, when the air-sinking area depth exceeds 180m. Therefore, based on the calculation standard of the air-sinking area depth of 180m, the remaining 150m minus the initial loading of 30m is calculated with a regular loading span of 15m, and 10 subsequent loadings are required. During the experiment, the program heating rate was 0.5℃ / min, and the furnace temperature around the experiment increased from 30℃ to 210℃, and the experiment took 360 minutes. According to the research plan and method of the similar experimental system, tank 1 was used as the control experimental tank to directly add 36 cm of coal sample at the beginning, and tank 2 was used as the coal sample corresponding to the initial loading to add 6 cm of coal sample at the beginning. During the loading period of the subsequent cycle, the two-stage regular loading was combined into one, that is, the two regular loadings were combined into one coal sample adding opportunity, that is, five coal samples were added during the period. The specific coal sample adding process is shown in Table 2.

[0026] [Table 2]

[0027] The temperature change rules obtained during the experimental process are shown in Figures 4(a) and 4(b), and the change rules of the oxygen, carbon monoxide, and carbon dioxide concentrations during the experimental process are shown in Figures 5 to 7. Using oxidation dynamics theory and methods, the oxygen concentrations, carbon monoxide concentrations, and carbon dioxide concentrations obtained in Figures 5 to 7 were combined to calculate the change rules of the oxygen consumption rate, carbon monoxide production rate, carbon dioxide production rate, and maximum and minimum heat release rates shown in Figures 8 to 12.

[0028] According to the relevant mechanical calculation results, when the furnace temperature is below 160°C, that is, after the fourth addition of coal samples (simulating the seventh to eighth periodic loading), the average oxygen consumption rate and maximum heat release rate of coal in the process of dynamic addition of coal according to the roof periodic loading rule in the air-gathering area are gradually lower than those of the control group, and the relative difference between the two gradually increases, but before that, the difference between the two is not so large. Therefore, it can be determined that the oxygen consumption rate gradually increases during the dynamic addition of coal, and when the periodic loading exceeds eight times, the increase in the oxygen consumption rate and maximum heat release rate of the remaining coal in the air-gathering area gradually decreases compared to the non-dynamic process. The experimental results show that the dynamic experimental system and experimental method constructed in this embodiment can obtain the progress of spontaneous combustion of coal in the process of dynamic addition of coal samples.

[0029] Each embodiment in this specification is described in a progressive manner, with emphasis on the differences between each embodiment and other embodiments, and the same or similar parts between each embodiment may be referred to each other. The above description of the disclosed embodiments enables a person skilled in the art to realize or use the present invention. A number of modifications to these embodiments will be apparent to a person skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not limited to these embodiments shown in this specification, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. [Explanation of symbols]

[0030] 1 Oxygen Cylinder 2 Nitrogen Cylinders 3 Gas supply system 4 Gas supply system output opening and closing valve 5 3-way pipe 6 Gas passage opening and closing valve 7 Gas flow meter 8. Raw material supply hopper 9 Coal samples 10 Coal sample tank plug (female thread) 11 304 stainless steel connecting pipe 12 Raw material supply pipe opening and closing valve 13 Temperature Sensor 14 Temperature transmission data line 15 Coal sample tank intake pipe 16 Coal sample leakage prevention copper mesh 17 Exhaust pipe 18 Coal sample tank bracket 19 Programmable Heating Chamber 20 Temperature Inspection Device 21 Gas chromatograph 22 Data Collection Host

Claims

1. A similar experimental system for measuring the dynamic progression characteristics of spontaneous combustion of coal, comprising: a gas supply system, a program heating chamber, a coal sample tank for dynamic sample addition, a gas chromatograph, a temperature inspection device, and a data collection host, wherein two inlets of the gas supply system are connected to a nitrogen cylinder and an oxygen cylinder respectively, an outlet of the gas supply system is connected to the coal sample tank for dynamic sample addition, the coal sample tank for dynamic sample addition is connected to the gas chromatograph and the temperature inspection device respectively, and the output terminals of the gas chromatograph and the temperature inspection device are both connected to the data collection host; the gas supply system is used to blend nitrogen and oxygen into dry air and supply it to the coal sample tank of the dynamic sample addition; The coal sample tank for dynamic sample addition is used to add coal samples according to the similar sequence and span size when the roof collapses and fills the mining area during the initial and regular loading of the coal face during the mining process, thereby completing a dynamic progression similar experiment of spontaneous combustion of the remaining coal in the mining area; The programmable heating chamber is used to adjust the furnace temperature and set the programmable heating rate; said gas chromatograph is used to analyze and test gas samples taken from the exhaust of said dynamic sample addition coal sample tank; the temperature checking device is used to record the temperature of the coal sample collected by a temperature sensor in the coal sample after addition of the coal sample is completed; The data collection host acquires the coal temperature and exhaust components and concentrations during the dynamic sample addition process, and after the experiment is completed, calculates the oxidation oxygen consumption rate and heat release rate according to the coal temperature and the exhaust components and concentrations using a reaction kinetic method related to oxidation, which are used to determine the dynamic rule and progress of spontaneous combustion of residual coal in the mining area during the dynamic mining process.

2. 2. The analog experimental system for measuring the dynamic progression characteristics of spontaneous combustion of coal according to claim 1, further comprising a gas supply system output on-off valve, a three-way pipe, a gas passage on-off valve, and a gas flow meter, wherein the blended dry air passes through the gas supply system output on-off valve, the three-way pipe, the gas passage on-off valve, and the gas flow meter, and enters each of the two coal sample tanks of the dynamic sample addition.

3. The dynamic sample addition coal sample tank includes: a raw material supply hopper; a coal sample tank plug; a 304 stainless steel connection pipe; a raw material supply pipe opening and closing valve; the temperature sensor; a coal sample tank intake pipe; a copper mesh for preventing the coal sample from leaking; an exhaust pipe; and a coal sample tank bracket; The outlet of the raw material supply hopper faces the position of the coal sample tank plug, the coal sample tank plug is inserted into the 304 stainless steel connecting pipe, and the 304 stainless steel connecting pipe is inserted into the coal sample tank; The raw material supply pipe opening and closing valve is installed on the 304 stainless steel connection pipe, and several temperature sensors are installed in the coal sample tank along the depth direction; 2. The analogous experimental system for measuring the dynamic progress characteristics of spontaneous combustion of coal according to claim 1, wherein the dry air mixed by the gas supply system flows into the coal sample tank from the top through the coal sample tank intake pipe, the copper mesh for preventing the coal sample from leaking and the exhaust pipe are installed near the bottom inside the coal sample tank, and the coal sample tank bracket is installed under the coal sample tank.

4. The simulation experiment system for measuring the dynamic progress characteristics of spontaneous combustion of coal as claimed in claim 3, wherein the temperature inspection device is connected to the temperature sensor by a temperature transmission data line.

5. The simulation experiment system for measuring the dynamic progress characteristics of spontaneous combustion of coal according to claim 3, wherein the exhaust pipe is connected to the gas chromatograph.

6. A method for measuring dynamic progress characteristics of spontaneous combustion of coal, which is applied to the similar experimental system for measuring dynamic progress characteristics of spontaneous combustion of coal according to any one of claims 1 to 5, S1, the spontaneous combustion period of the residual coal in the sampling area is set to t days, and the initial loading time is set to t １ days, and the periodic weighting time is t ｒ days, the mining driving speed is v m / d, and the depth or length of the mining area is t ｖ exceeding the limit, the residual coal in the mining area spontaneously combusts; S2, mixing nitrogen and oxygen into dry air according to the ratio of nitrogen and oxygen in air through two gas supply systems, and the mixed dry air passes through the gas supply system output opening and closing valve, the three-way pipe, the gas passage opening and closing valve and the gas flow meter, and enters into two dynamic sample addition coal sample tanks, respectively, and at this time, the gas supply and intake pipe passages are blocked; S3. At the start of the experiment, first put the initial weighted coal sample into the two coal sample tanks of the dynamic sample addition. If the total height of the effective added coal sample in the coal sample tank of the dynamic sample addition is assumed to be L, the height of the initially added coal sample is [0010] and simplifying it to S4: Open the nitrogen cylinder, and allow nitrogen to flow into the coal sample tank of the dynamic sample addition system through the gas supply system alone. Start the heating program of the heating box, and set the heating rate to h ｔ ° C. / min, and the initial ambient temperature is T ｅ The temperature starts to rise as ｓ If so, the total time required for similar experiments is [0025] and within the experiment cycle [0030] expressing an equivalent conversion between the time of the analogous experimental process and the actual firing period t; S5, adjust the flow rate of nitrogen, and open the oxygen cylinder according to the gas flow rate required for the experiment, and mix the nitrogen with the dry air with a flow rate of Q by the gas supply system, and enter the intake pipe passage; S6, according to the time required for the experiment, gas samples are taken from the exhaust port of the coal sample tank of the dynamic sample addition, and analyzed and tested by gas chromatography. The gas sample is actually taken every time the furnace temperature increases by 10°C from 40°C to the end of the experiment, and the gas sample is completed before the regular loading and the coal sample addition. S7, After the experiment started [0045] At 10 minutes, the first regular weighting of the coal sample was added, and the height of the coal sample added each time the weighting was increased. [0050] and S8. After adding several times, when the number of times of dynamic addition of the coal sample and the amount of the coal sample reach the planned purpose of the experiment, stop the experiment and record the adding process of the coal sample and the corresponding position of the corresponding temperature sensor; S9: A step of performing a calculation related to the reaction kinetics based on the reaction kinetics related to the oxidation of coal, in accordance with the coal sample height or the difference in height between the intake and exhaust ends in the calculation formula being dynamically changed according to the oxygen concentration, carbon oxide concentration, and hydrocarbon gas concentration of the gas sample test; S10. A similar experimental method for measuring the dynamic progress characteristics of spontaneous combustion of coal, comprising: a step of identifying an indicator gas production rule and an oxidation-related kinetic indicator change rule, and a coal sample temperature rise rule in the dynamic sample addition process based on the coal oxidation oxygen consumption rate and heat release rate in the dynamic sample addition process, and determining the dynamic rule and progress of spontaneous combustion of residual coal in the mining area in the dynamic mining process.

7. The method for measuring the dynamic progress characteristics of spontaneous combustion of coal according to claim 6, wherein the spontaneous combustion period of the residual coal in the extraction section is the time required for the temperature of the coal in the extraction section to rise from the downhole temperature to 70°C.

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