High-ground-temperature goaf coal spontaneous combustion inhibition simulation platform and method

Abstract

The invention relates to a high-ground-temperature goaf coal spontaneous combustion inhibition simulation platform and method. The simulation platform comprises a temperature and humidity adjusting system, a coal sample reaction system, a stopping agent spraying system and a gas collecting and detecting system. The temperature and humidity adjusting system controls the temperature and humidity of mixed air through an air generator, a drying chamber, a water tank chamber and a water bath thermotank so as to simulate a high-temperature and high-humidity environment. In the coal sample reaction system, a coal sample tank is filled with a coal sample, the temperature of the coal sample is controlled through a temperature control box, a gas inlet and a water outlet are formed in the bottom, a gas outlet is formed in the top, and the gas collection and detection system monitors gas products through a multi-parameter gas sensor. The inhibitor spraying system sprays an inhibitor to a coal sample through a high-pressure plunger pump, and the coal spontaneous combustion characteristic and the inhibition effect are analyzed in real time. The coal spontaneous combustion process under different environmental conditions is simulated by changing the temperature, the humidity and the oxygen concentration and adding the inhibitor, and the effects of different inhibitors are evaluated. The platform provides theoretical basis and experimental data for researching the spontaneous combustion characteristics and inhibition technology of the coal in the high-ground-temperature goaf, and has the characteristics of simplicity and convenience in operation and high efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of coal spontaneous combustion and inhibition, and relates to a high geothermal goaf coal spontaneous combustion and inhibition simulation platform and method. Background Art

[0002] Coal is one of the main energy sources in my country, and it accounts for a large proportion of energy consumption. With the extensive utilization of coal resources, coal mining has gradually developed to a deeper level, and the ground temperature around the working face has also risen, which has led to a high level of temperature of the coal seam surrounding rock and humidity of the roadway wind flow. The heat storage environment inside the goaf is good under the high geothermal environment. Affected by factors such as the mining activities of the working face, the complex geological conditions of the coal seam, and the changes in atmospheric parameters, the changes in wind resistance in multiple areas around the goaf, such as the layer, interlayer, and surface of the working face, lead to uneven distribution of pressure energy inside and outside the goaf, and there is a leakage pressure difference. In the high temperature, high humidity, and multi-void medium environment, the residual coal is continuously oxidized and heated, which causes the spontaneous combustion of coal in the goaf. The temperature and humidity inside the high geothermal goaf are unevenly distributed, and the factors affecting the spontaneous combustion of the residual coal are large, making it difficult to resist in a targeted manner.

[0003] Since the underground goaf is large and the spontaneous combustion and retardation effect of the coal in high temperature and high humidity environment is difficult to detect and quantitatively analyze, the establishment of a similar simulation experimental system is one of the effective means to study the spontaneous combustion characteristics and retardation effect of coal in high geothermal goaf in view of such actual on-site conditions in coal mines. Through the simulation experimental system, the evolution characteristics and retardation process of coal spontaneous combustion under high temperature and high humidity environment are studied, and the distribution law of the spontaneous combustion temperature field, gas products and heat transfer process of coal in high geothermal goaf are clarified. At the same time, the retardation effect and process of the retardant on the coal in high geothermal goaf is characterized, providing theoretical and experimental methods for the spontaneous combustion characteristics and retardation technology of coal in high geothermal goaf.

[0004] At present, the determination of spontaneous combustion characteristic parameters and the prevention and control of catalytic degradation of coal in goafs of high geothermal mines are mainly carried out through underground sampling and the use of a large-scale coal natural ignition experimental platform to test the spontaneous combustion characteristic parameters of coal. At the same time, the evaluation of the spontaneous combustion and catalytic degradation effect of coal in goafs also relies on the underground monitoring system to collect the spontaneous combustion characteristic gas, temperature and other parameters of coal in goafs for experimental comparison and verification. This method requires a large amount of sampling to verify the reliability of the data, and it is also impossible to intuitively and qualitatively analyze the relationship between the spontaneous combustion characteristics of coal in goafs of high geothermal temperatures and the catalytic degradation performance of catalytic degradation materials on site.

[0005] For conventional large-scale coal natural ignition experiments and programmed temperature rise experiments on coal spontaneous combustion, the required coal samples need to be collected on-site in the coal mine. However, it is impossible to obtain coal samples that meet the high temperature and high humidity environmental conditions in the high geothermal goaf on site, and the on-site monitoring and surveillance system has large measurement errors, and it is impossible to obtain a large amount of coal spontaneous combustion characteristic parameter data. Regarding the spontaneous combustion inhibition technology of coal in goafs under high temperature and high humidity environments, the site does not have the conditions for intuitive qualitative analysis of the inhibition effect. Summary of the invention

[0006] In view of this, the purpose of the present invention is to solve the above-mentioned problems and provide a platform and method for simulating spontaneous combustion and retardation of coal in high geothermal goaf areas.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A high-temperature goaf coal spontaneous combustion and retardation simulation platform, including a temperature and humidity adjustment system, a coal sample reaction system, an inhibitor spraying system and a gas collection and detection system;

[0009] The coal sample reaction system mainly includes a coal sample tank and a temperature control box; the coal sample tank is placed in the temperature control box; the coal sample tank is filled with coal sample, a screen is provided at the bottom of the coal sample, and a support frame is provided at the bottom of the screen to support the coal sample; an air inlet and a water outlet are provided at the bottom of the coal sample tank, and an air outlet is provided at the top of the coal sample tank; the gas collection and detection system is connected to the air outlet to detect the gas products released after the coal-oxygen composite reaction;

[0010] The temperature and humidity control system comprises an air generator, a drying chamber, a water tank chamber, and a water bath thermostat; the drying chamber and the water tank chamber are arranged in parallel between the air generator and the water bath thermostat, and rotor flowmeters are arranged at the entrances of the drying chamber and the water tank chamber; fresh air flows through the two rotor flowmeters and then enters the water tank chamber and the drying chamber, and then merges to form a mixed dry and wet air flow, and the air flow flows through the water bath thermostat to form a high-temperature and high-humidity mixed air, and the mixed air enters the air inlet of the coal sample tank through a connecting pipeline;

[0011] An atomizing nozzle is arranged on the top of the coal sample tank, and the inhibitor spraying system is connected to the atomizing nozzle, and the coal sample inhibitor is sprayed through the atomizing nozzle.

[0012] Furthermore, the inhibitor spraying system includes an inhibitor placement box and a high-pressure plunger pump; the inhibitor placement box is provided with a coal sample inhibitor, one end of the high-pressure plunger pump is connected to the inhibitor placement box, and the other end is connected to the atomizing nozzle; the outlet end of the high-pressure plunger pump is provided with a pressure gauge and a flow meter.

[0013] Furthermore, the gas collection and detection system includes a mining multi-parameter gas sensor and a computer; the mining multi-parameter gas sensor is connected to the gas outlet of the coal sample tank through a pipeline; and the computer is connected to the mining multi-parameter gas sensor.

[0014] Furthermore, the multi-parameter gas sensor for mining is a GD8 sensor, which transmits the collected data of methane, carbon monoxide, oxygen, temperature and pressure difference to a computer.

[0015] Furthermore, a thermocouple hole is vertically arranged every 3 cm in the middle of the coal sample tank, with a total of 5 holes for installing K-type thermocouples.

[0016] Furthermore, a temperature and humidity detector and a valve are provided at the outlet end of the water bath thermostat.

[0017] A method for simulating spontaneous combustion and inhibition of coal in high geothermal goaf areas adopts the high geothermal goaf area spontaneous combustion and inhibition simulation platform as described above to simulate the spontaneous combustion process of coal in a high temperature and high humidity environment. By changing the temperature, humidity, and oxygen concentration conditions and adding different inhibitors, the changes in the spontaneous combustion characteristic parameters of coal and the inhibition process and effect of coal samples in different temperature and humidity environments are intuitively and qualitatively analyzed, the inhibition performance of the inhibition material on the spontaneous combustion of coal in high geothermal goaf areas is characterized, and a basis is provided for optimizing the spontaneous combustion inhibitor of coal in goaf areas.

[0018] Further, the simulation analysis process adopts one or more combinations of the following methods;

[0019] (1) Determine the oxygen consumption rate of coal samples under different temperature, humidity and oxygen concentration environments to simulate coal oxidation in goaf;

[0020] (2) Determine the CO, CO2 and CH4 production rates of coal samples under different temperature conditions;

[0021] (3) Determine the critical temperature and cracking temperature of coal samples under different temperature conditions, as well as the spontaneous combustion reaction characteristics of coal when inhibitors are involved;

[0022] (4) Determine the activation energy and heat release intensity of coal samples under different humidity conditions, as well as the spontaneous combustion reaction characteristics of coal when inhibitors are involved.

[0023] The beneficial effects of the present invention are:

[0024] 1. The high geothermal goaf coal spontaneous combustion retardant simulation platform and method provided by the present invention can simulate the high geothermal goaf coal spontaneous combustion process under the premise of accurately providing a controllable high temperature and high humidity environment by designing a temperature and humidity adjustment system, a coal sample reaction system, an inhibitor spraying system and a gas collection and detection system. Its main advantage is to provide high temperature and high humidity mixed air for the coal sample oxidation reaction process, and at the same time, the coal body in the coal sample tank can be sprayed and retardant. Through the real-time gas detection system, the changes in coal spontaneous combustion characteristic parameters and the coal sample retardant process and effect under different temperature and humidity environments can be intuitively and qualitatively analyzed, and the linkage control of each system is realized, and the coal body temperature and gas product concentration in the coal sample tank are monitored in an all-round and three-dimensional manner, so as to achieve the purpose of optimizing the high geothermal goaf coal spontaneous combustion retardant, reduce the risk of coal spontaneous combustion in the goaf of high geothermal mines, and reduce the workload and error of the underground coal spontaneous combustion characteristic investigation, and improve the ability to accurately identify the risk of coal spontaneous combustion in high geothermal goaf coal.

[0025] 2. The present invention can investigate the spontaneous combustion characteristic parameters of coal under different temperature and humidity environments by detecting the temperature at different positions of the coal sample and the changing relationship of the gas products, and realizes the automatic spraying of coal spontaneous combustion inhibitors under high temperature and high humidity environments, and intuitively characterizes the inhibitory performance of the inhibitor, thereby providing targeted prevention and control of coal spontaneous combustion in goaf areas during actual production in high geothermal mines.

[0026] 3. The present invention is easy to operate, highly efficient, and has significant use effects, and has wide promotion and application value.

[0027] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 It is an overall schematic diagram of the high geothermal goaf coal spontaneous combustion and retardation simulation platform of the present invention.

[0030] Figure 2 It is a schematic diagram of the coal sample reaction system in the present invention.

[0031] Figure 3 It is a schematic diagram of the temperature and humidity adjustment system of the present invention.

[0032] Figure 4 It is a schematic diagram of the inhibitor spraying system in the present invention.

[0033] Figure 5 It is a schematic diagram of the gas collection and detection system in the present invention.

[0034] Figure numerals: 1-air generator; 2-flow meter I; 3-flow meter II; 4-drying chamber; 5-water tank chamber; 6-water bath thermostat; 7-valve I; 8-temperature and humidity detector; 9-valve II; 10-inhibitor placement box; 11-high-pressure plunger pump; 12-pressure gauge; 13-turbine flowmeter; 14-air inlet; 15-water outlet; 16-support frame; 17-100 mesh sieve; 18-coal sample; 19-thermocouple hole; 20-air outlet; 21-atomizing nozzle; 22-temperature control box; 23-multi-parameter gas sensor for mining; 24-computer. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and the features in the embodiments can be combined with each other without conflict.

[0036] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0037] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0038] See also Figures 1 to 5 , a high-temperature goaf coal spontaneous combustion and retardation simulation platform, including a temperature and humidity adjustment system, a coal sample reaction system, an inhibitor spraying system, and a gas collection and detection system;

[0039] The coal sample 18 reaction system mainly includes a coal sample tank and a temperature control box 22; the coal sample tank is placed in the temperature control box 22; the coal sample tank is filled with coal sample 18, and a 100-mesh screen 17 is provided at the bottom of the coal sample 18, and a support frame 16 is provided at the bottom of the 100-mesh screen 17 to support the coal sample 18; an air inlet 14 and a water outlet 15 are provided at the bottom of the coal sample tank; the water outlet 15 has a radius of 0.5 cm and is used to automatically discharge the moisture and residual inhibitor liquid generated during the spontaneous combustion and oxidation process of the coal. An air outlet 20 is provided on the top of the coal sample tank; the gas collection and detection system is connected to the air outlet 20 to detect the gas products released after the coal-oxygen composite reaction;

[0040] The temperature and humidity control system includes an air generator 1, a drying chamber 4, a water tank chamber 5, and a water bath thermostat 6; the water bath thermostat 6 adopts a CH / HCH series constant temperature transparent water bath, and the drying chamber 4 adopts a 506 series visible high-efficiency drying tube; the water tank chamber 5 adopts an ordinary container, and the container is filled with pure water; the drying chamber 4 and the water tank chamber 5 are arranged in parallel between the air generator 1 and the water bath thermostat 6, and the entrances of the drying chamber 4 and the water tank chamber 5 are respectively provided with a rotor flowmeter Ⅰ2 and a rotor flowmeter Ⅱ3, which are used to adjust the air flow entering the water tank chamber 5 and the drying chamber 4; the fresh air flows through the rotor flowmeter Ⅰ2 and the rotor flowmeter Ⅱ3 respectively, and then enters the water tank chamber 5 and the drying chamber 4, and then merges to form a mixed dry and wet air flow, and the air flow flows through the water bath thermostat 6 to form a high-temperature and high-humidity mixed air, and the mixed air enters the air inlet 14 of the coal sample tank through the connecting pipeline;

[0041] An atomizing nozzle 21 is arranged on the top of the coal sample tank, and the inhibitor spraying system is connected to the atomizing nozzle 21 , and the inhibitor of the coal sample 18 is sprayed through the atomizing nozzle 21 .

[0042] The inhibitor spraying system includes an inhibitor placement box 10 and a high-pressure plunger pump 11; a coal sample 18 inhibitor is arranged in the inhibitor placement box 10, one end of the high-pressure plunger pump 11 is connected to the inhibitor placement box 10, and the other end is connected to the atomizing nozzle 21; a pressure gauge 12 and a turbine flowmeter 13 are arranged at the outlet end of the high-pressure plunger pump 11, and the inhibitor flow rate is adjusted electrically.

[0043] The gas collection and detection system includes a mining multi-parameter gas sensor 23 and a computer 24; the mining multi-parameter gas sensor 23 is connected to the gas outlet 20 of the coal sample tank through a pipeline, and the sensor collects the gas in the coal sample 18 reaction system and transmits signal data to the computer 24 in real time.

[0044] The multi-parameter gas sensor 23 for mining is a GD8 sensor, which transmits the collected data of methane, carbon monoxide, oxygen, temperature and pressure difference to the computer 24. The multi-parameter gas sensor 23 for mining includes a liquid crystal display, a variety of sensors (CH4, CO, O2, C2H2, H2S, CO2, HCl, temperature, pressure difference), a self-priming air pump, a wireless ad hoc network module, a lithium manganese oxide battery, and an STM32F103RET single-chip processor, and is an intrinsically safe product. The self-priming air pump automatically extracts pipeline gas samples at a frequency of once every 2 seconds. After the gas sample enters the internal pipeline, it is detected by the sensor element. The obtained data is converted into electrical signals by the ADC data conversion module. The single-chip microcomputer processes the data uniformly. After the circuit board signal is converted, the value is displayed on the liquid crystal display through the single-chip microcomputer pre-programmed program. The gas concentration data is stored in the system after program processing, and can then be processed in the computer 24.

[0045] The coal sample tank is cylindrical, with a cross-sectional diameter of 10 cm and a tank height of 22 cm. A thermocouple hole 19 is set every 3 cm in the middle of the coal sample tank, with a total of 5 holes for installing K-type thermocouples with a length of 5 cm. The temperature control box 22 adopts an electric heating blast drying box, model WGL-65, with dimensions of 400*360*450 (depth*width*height).

[0046] A tee is provided at the outlet end of the water bath thermostat 6, which are respectively connected to the water bath thermostat 6, valve I7, and valve II9. The temperature and humidity detector 8 is connected to valve I7, and valve II9 is ​​connected to the air inlet 14 at the bottom of the coal sample tank. The temperature and humidity detector 8 adopts an HTC-2 temperature and humidity measuring instrument to measure the temperature and humidity of high-temperature and high-humidity gas for immediate adjustment.

[0047] A method for simulating spontaneous combustion and inhibition of coal in high geothermal goaf areas adopts the above-mentioned spontaneous combustion and inhibition simulation platform for coal in high geothermal goaf areas to simulate the spontaneous combustion process of coal in a high temperature and high humidity environment. By changing the temperature, humidity, and oxygen concentration conditions and adding different inhibitors, the changes in the spontaneous combustion characteristic parameters of coal in different temperature and humidity environments and the inhibition process and effect of coal sample 18 are intuitively and qualitatively analyzed, the inhibition performance of the inhibitory material on the spontaneous combustion of coal in high geothermal goaf areas is characterized, and a basis is provided for the optimization of the spontaneous combustion inhibitor of coal in goaf areas.

[0048] The coal sample processing method during the experiment is as follows:

[0049] ① Select the coal sample 18 required for the simulation experiment, remove the outer layer of coal that has been oxidized on the surface, and then crush it.

[0050] ②Sieve the coal sample 18 to select 200g of each coal sample 18 with a particle size of <0.9, 0.9~<3, 3~<5, 5~<7, 7~<10mm).

[0051] ③ Mix the five coal samples 18 with different particle sizes evenly and put them into a vacuum drying oven for vacuum drying at a constant temperature of 30°C for 12 hours.

[0052] ④ Place the vacuum-dried coal sample 18 into the coal sample tank on the laboratory bench and tightly close the tank opening.

[0053] Experimental process: Inhibitor treatment:

[0054] ① According to the research purpose, select chemical reagents, surfactants, flame retardants, etc. for spray treatment.

[0055] ② The optimally selected inhibitor is prepared into an aqueous solution according to the experimental plan and poured into the inhibitor placement box 10.

[0056] Spraying process:

[0057] ① When performing spray inhibition, first turn on the high-pressure plunger pump 11, adjust the flow rate, and adjust the pressure.

[0058] ② According to the design scheme, the appropriate parameters are adjusted, and the inhibitor solution reaches the atomizing nozzle 21 on the top of the coal sample tank through the pipeline to start spraying and inhibiting.

[0059] ③ After all the inhibitor solution is used for spray treatment, turn off the plunger pump, flow meter and pressure valve, and the spraying is finished.

[0060] The specific simulation analysis process adopts one or more combinations of the following methods:

[0061] (1) Determine the oxygen consumption rate of coal sample 18 under different temperature, humidity and oxygen concentration environments to simulate the oxidation of coal in the goaf;

[0062] Oxygen consumption rate is an important parameter to characterize the oxidation reaction of coal. The oxygen volume fraction at the outlet of the coal sample tank is measured experimentally, and the oxygen consumption rate is calculated according to the formula:

[0063]

[0064] Where V(O2) is the oxygen consumption rate, mol / (cm 3 ·s); Q is the air supply volume, cm 3 / s; S is the bottom area of ​​the coal sample tank, cm 2 ; L is the height of the coal body, cm; C1 and C2 are the oxygen concentrations at the inlet and outlet, mol / cm 3 .

[0065] According to the design parameters of this experimental platform, S = 78.5cm 2 , L=22cm, the inlet oxygen concentration is determined according to the design plan.

[0066] (2) Determine the production rates of 18CO, CO2 and CH4 of coal samples under different temperature conditions;

[0067] In the test bench, due to the oxygen consumption of the coal, the oxygen concentration decreases along the wind direction, while the CO and CO2 concentrations increase. The CO and CO2 generation rate of the coal at a certain point in the furnace is proportional to the oxygen consumption rate. The CO generation rate at the standard oxygen concentration is

[0068]

[0069] Similarly, the production rates of CO2 and CH4 are:

[0070]

[0071] In the formula, is the CO2 production rate; is the CH4 generation rate. Substituting the measured data into the above formula, the generation rates of CO, CO2 and CH4 can be calculated.

[0072] (3) Determine the critical temperature and cracking temperature of coal sample 18 under different temperature conditions, as well as the spontaneous combustion reaction characteristics of coal when an inhibitor is involved;

[0073] The critical temperature and the desiccation temperature are the characteristic parameters of the spontaneous combustion and oxidation characteristics of coal, which can characterize the spontaneous combustion ability of coal sample 18. The critical temperature is the first temperature point that causes the automatic acceleration of coal-oxygen recombination during the process of coal temperature rising from low to high at room temperature. The starting temperature of the second mutation in the relationship curve between the rate of change of CO production rate and temperature is the desiccation temperature.

[0074] (4) Determine the activation energy and heat release intensity of coal sample 18 under different humidity conditions, as well as the spontaneous combustion reaction characteristics of coal when an inhibitor is involved.

[0075] In the actual production process of the mine, the relative humidity of the air underground is high, and the coal absorbs water vapor from the air, causing its own oxidation characteristics to change to a certain extent. Changes in air humidity have a great influence on the changes in the apparent activation energy and heat release intensity of the coal. The apparent activation energy in the process of coal spontaneous combustion is the minimum energy required for the coal-oxygen reaction, and its size can reflect the difficulty of the coal-oxygen reaction. The greater the activation energy, the more difficult the reaction.

[0076] ln[ln(c1 / c2)]=ln(SLA / Q)-E / RT

[0077] The above formula is the calculation formula for coal body activation energy, where A is the pre-exponential factor, s -1 ; E is the reaction activation energy, J / mol; R is the gas constant, 8.314 J / (mol·K); T is the thermodynamic temperature of the coal, K.

[0078] The ability of coal to spontaneously generate heat is one of the key factors of coal's inherent spontaneous combustion. The heat release intensity is a parameter that characterizes the heat release of coal. The calculation formula is as follows:

[0079]

[0080] The gas flow parameters are determined by:

[0081] In order to reflect the dynamic continuous oxygen consumption process and gas composition changes of coal sample 18, the cross-sectional area of ​​the coal sample tank was calculated to be 78.5 cm according to the conditions similar to those of the large coal sample 18 test. 2 When the minimum air supply volume is:

[0082] Q 小 =Q 大 ×S 小 / S 大 =46.38~93.45(ml / min)

[0083] Where:

[0084] Q 小 , S 大 :respectively the air supply volume (ml / min) and cross-sectional area (cm 2 );

[0085] Q 小 / S 小 : is the air supply intensity of the test tube (cm 3 / (min.cm 2 );

[0086] Q 大 , S 大 :Respectively, the air supply volume of the large test bench (0.1~0.2m 3 / h) and cross-sectional area (0.2826m 2 );

[0087] Q 大 / S 大 : Air supply intensity of the large test bench (cm 3 / (min.cm 2 ));

[0088] Generally, the maximum oxygen consumption rate of coal sample 18 at room temperature is less than 2×10 -10 mol / (s·cm 3 ), the length of the test tube for coal loading is determined to be 20 cm, the resolution of the gas chromatograph is 0.5% (i.e. the maximum oxygen concentration is 20.89%), and in order to make the difference in oxygen concentration between the inlet and outlet of the test tube within the resolution range of the mining gas chromatograph, the maximum air supply volume is:

[0089]

[0090] Therefore, the experimental air supply volume range is between 46.38 and 210.4 (ml / min). This experimental bench selects a gas flow rate of 60ml / min. When the flow rate is 60ml / min, the contact time between the airflow and the coal sample 18 is:

[0091] t=L·f·S 小 / Q=(3.36~15.23)min

[0092] Where:

[0093] L: height of coal sample 18 in the test tube (18 cm);

[0094] F: void ratio (%);

[0095] S 小 :Test tube cross-sectional area (cm 2 );

[0096] Q: Air supply volume (cm 3 / min).

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A high geothermal goaf coal spontaneous combustion and retardation simulation platform, characterized by: It includes temperature and humidity control system, coal sample reaction system, inhibitor spraying system and gas collection and detection system; The coal sample reaction system mainly includes a coal sample tank and a temperature control box; the coal sample tank is placed in the temperature control box; the coal sample tank is filled with coal sample, a screen is provided at the bottom of the coal sample, and a support frame is provided at the bottom of the screen to support the coal sample; an air inlet and a water outlet are provided at the bottom of the coal sample tank, and an air outlet is provided at the top of the coal sample tank; the gas collection and detection system is connected to the air outlet to detect the gas products released after the coal-oxygen composite reaction; The temperature and humidity control system comprises an air generator, a drying chamber, a water tank chamber, and a water bath thermostat; the drying chamber and the water tank chamber are arranged in parallel between the air generator and the water bath thermostat, and rotor flowmeters are arranged at the entrances of the drying chamber and the water tank chamber; fresh air flows through the two rotor flowmeters and then enters the water tank chamber and the drying chamber, and then merges to form a mixed dry and wet air flow, and the air flow flows through the water bath thermostat to form a high-temperature and high-humidity mixed air, and the mixed air enters the air inlet of the coal sample tank through a connecting pipeline; An atomizing nozzle is arranged on the top of the coal sample tank, and the inhibitor spraying system is connected to the atomizing nozzle, and the coal sample inhibitor is sprayed through the atomizing nozzle.

2. The high geothermal goaf coal spontaneous combustion and retardation simulation platform according to claim 1 is characterized by: The inhibitor spraying system includes an inhibitor placement box and a high-pressure plunger pump; the inhibitor placement box is provided with a coal sample inhibitor, one end of the high-pressure plunger pump is connected to the inhibitor placement box, and the other end is connected to the atomizing nozzle; the outlet end of the high-pressure plunger pump is provided with a pressure gauge and a flow meter.

3. The high geothermal goaf coal spontaneous combustion and retardation simulation platform according to claim 1 is characterized by: The gas collection and detection system comprises a mine-used multi-parameter gas sensor and a computer; the mine-used multi-parameter gas sensor is connected to the gas outlet of the coal sample tank through a pipeline; and the computer is connected to the mine-used multi-parameter gas sensor.

4. The high geothermal goaf coal spontaneous combustion and retardation simulation platform according to claim 3 is characterized by: The multi-parameter gas sensor for mining is a GD8 sensor, which transmits the collected data of methane, carbon monoxide, oxygen, temperature and pressure difference to a computer.

5. The high geothermal goaf coal spontaneous combustion and retardation simulation platform according to claim 1 is characterized by: A thermocouple hole is set every 3 cm in the vertical direction in the middle of the coal sample tank, and there are 5 holes in total for installing K-type thermocouples.

6. The high geothermal goaf coal spontaneous combustion and retardation simulation platform according to claim 1 is characterized by: The outlet end of the water bath thermostat is provided with a temperature and humidity detector and a valve.

7. A method for simulating spontaneous combustion and retardation of coal in high-temperature goaf areas, characterized in that: The high geothermal goaf coal spontaneous combustion inhibition simulation platform as described in any one of claims 1 to 6 is used to simulate the coal spontaneous combustion process under high temperature and high humidity environment. By changing the temperature, humidity, and oxygen concentration conditions and by adding different inhibitors, the changes in the coal spontaneous combustion characteristic parameters and the coal sample inhibition process and effect under different temperature and humidity environments are intuitively and qualitatively analyzed, and the inhibition performance of the inhibition material on the spontaneous combustion of coal in the high geothermal goaf is characterized, providing a basis for the optimization of the goaf coal spontaneous combustion inhibitor.

8. The method for simulating spontaneous combustion and retardation of coal in high geothermal goaf areas according to claim 7 is characterized in that: The simulation analysis process adopts one or more combinations of the following methods: (1) Determine the oxygen consumption rate of coal samples under different temperature, humidity and oxygen concentration environments to simulate coal oxidation in goaf; (2) Determine the CO, CO2 and CH4 production rates of coal samples under different temperature conditions; (3) Determine the critical temperature and cracking temperature of coal samples under different temperature conditions, as well as the spontaneous combustion reaction characteristics of coal when inhibitors are involved; (4) Determine the activation energy and heat release intensity of coal samples under different humidity conditions, as well as the spontaneous combustion reaction characteristics of coal when inhibitors are involved.

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