Method for predicting the scope of spontaneous combustion of coal seams based on CO isotope and index gas concentration

Abstract

The present invention belongs to the technical field of coal seam spontaneous combustion prevention and control, and is specifically a method for predicting the scope of coal seam spontaneous combustion fire based on CO isotope and index gas concentration, comprising the following steps: S1 coal sample acquisition: taking coal samples from the coal seam with a core drill; S2 programmed temperature increase experiment: placing the coal sample in a programmed temperature increase device and heating it at a set heating rate; S3 instrument analysis: using an isotope analyzer and a gas chromatograph to respectively measure the CO isotope peak and CO concentration of the coal sample at different temperatures; S4 relationship equation establishment: by carrying out a CO concentration attenuation experiment, changing relevant parameters, collecting data and analyzing and fitting, determining the attenuation coefficient, and establishing a relationship equation between the fire source, CO concentration, seepage distance and outflow concentration; S5 fire prediction: taking gas at a preset distance on site and measuring the CO isotope concentration; comparing the measurement result with the result of the programmed temperature increase experiment in step S2 to determine the CO concentration at the ignition point. The present invention improves the accuracy and reliability of prediction and accurately predicts the scope of fire.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal seam spontaneous combustion prevention and control, and specifically is a method for predicting the scope of coal seam spontaneous combustion fire based on CO isotope and index gas concentration. Background Art

[0002] In the field of coal mining, spontaneous combustion of coal seams has always been an extremely serious problem, which seriously threatens the safe production of mines, the lives of miners, and the efficient development and utilization of coal resources.

[0003] The occurrence and development of coal seam spontaneous combustion fires are extremely complex and are affected by the interaction of many factors. Among them, the characteristics of coal itself play a key role. The coal quality of different coal seams, such as coal type, carbon content, volatile content, moisture content, etc., largely determines the degree of its spontaneous combustion tendency. Generally speaking, coal with high volatile matter and low ash content is more prone to spontaneous combustion. In terms of geological conditions, the burial depth, inclination, thickness and geological structure (such as faults, folds, etc.) of coal seams will have a significant impact on the occurrence of spontaneous combustion fires. For example, the conditions for oxidation and spontaneous combustion of coal seams buried deeper are relatively complex due to high ground pressure, high ground temperature and relatively less contact with air; while in geological structure areas, the degree of fragmentation of coal seams increases, which increases the contact area with air and provides favorable conditions for oxidation and spontaneous combustion of coal. Mining technical factors should not be ignored, such as coal mining methods, recovery speed, ventilation methods, etc. When the mining speed is slow, the time the remaining coal in the goaf is exposed to the air increases, and the possibility of oxidation and spontaneous combustion will greatly increase; unreasonable ventilation methods may lead to uneven air flow distribution in the goaf, oxygen accumulation in local areas, and accelerate the oxidation process of coal.

[0004] At present, the existing coal seam spontaneous combustion fire prediction technology has certain limitations. The traditional method mainly relies on the monitoring of the concentration of index gases to judge the state of coal seam spontaneous combustion, such as monitoring the concentration changes of gases such as carbon monoxide (CO), ethylene, and acetylene. However, this single index gas concentration monitoring method faces many challenges in practical applications, resulting in low prediction or monitoring accuracy, which is specifically manifested in:

[0005] On the one hand, the generation and release of index gas are interfered by many factors. For example, the mineral components in the coal seam may catalyze or inhibit the generation of gas, making the relationship between gas concentration and the spontaneous combustion state of the coal seam complex and unstable.

[0006] On the other hand, the geological conditions and coal quality of different coal seams vary greatly, making it difficult to accurately define the scope and extent of coal seam spontaneous combustion with a unified index gas concentration threshold. For example, in some high-gas coal seams, gas outbursts will dilute the concentration of index gases, thereby affecting the accurate judgment of spontaneous combustion fires; in some areas with complex geological structures, due to the heterogeneity of coal seams, the release pattern of index gases also shows a large degree of discreteness. Summary of the invention

[0007] In view of the defects of the prior art mentioned in the background technology, the present invention provides a method for predicting the scope of coal seam spontaneous combustion fire based on CO isotopes and index gas concentrations while overcoming the technical background problems.

[0008] To achieve the above technical purpose, the technical solution adopted by the present invention is: a method for predicting the scope of spontaneous combustion of coal seams based on CO isotopes and index gas concentrations, which specifically includes the following steps:

[0009] S1 Coal sample acquisition: Take coal samples from the coal seam using a core drill;

[0010] S2 programmed temperature experiment: the coal sample is placed in a programmed temperature device and heated at a set heating rate to simulate the oxidation process of the coal seam under different temperature conditions;

[0011] S3 Instrumental analysis: Use isotope analyzer and gas chromatograph to measure the CO isotope peak and CO concentration of coal samples at different temperatures;

[0012] S4 relationship equation establishment: By conducting CO concentration attenuation experiments, changing relevant parameters, collecting data and analyzing the fitting, determining the attenuation coefficient, and establishing the relationship equation between the fire source, CO concentration, seepage distance and outflow concentration, the relationship equation is C=C0·e -a·d ;

[0013] S5 Fire prediction: Take gas at a preset distance on site and measure the CO isotope concentration; compare the measurement results with the results of the programmed heating experiment in step S2 to determine the CO concentration at the ignition point; substitute the relationship equation to calculate the distance between the ignition point and the working position, so as to accurately predict the scope of natural fire in the coal seam.

[0014] As a preferred technical solution: in step S4, the relationship equation is C=C0·e -a·d ;

[0015] in:

[0016] C represents: the CO outflow concentration measured at a certain seepage distance, in ppm;

[0017] C0 represents: the initial CO concentration generated at the fire source, in ppm;

[0018] d represents: the seepage distance of CO from the fire source, in meters or other length units;

[0019] a is an attenuation coefficient in units (same length units as d) -1 ;

[0020] e is a natural constant.

[0021] As a preferred technical solution: in step S4, the specific steps of the CO concentration decay experiment are as follows:

[0022] (1) Building a CO concentration decay experimental platform

[0023] The platform simulates the seepage environment inside the coal seam, including setting up coal sample filling columns with different permeabilities or simulating coal seam tunnels; equipped with a gas supply system that can accurately control gas flow, pressure and concentration; and a sampling system with multiple gas sampling points set at different locations;

[0024] (2) Change the relevant parameters in the experiment

[0025] The relevant parameters of the design include seepage velocity, coal sample porosity, and initial CO concentration. Multiple experiments are conducted for each parameter combination, and the corresponding experimental parameters and time information are recorded.

[0026] (3) The large amount of experimental data collected was deeply analyzed and fitted, and the attenuation coefficient was determined using mathematical methods such as multivariate linear regression and nonlinear fitting, and a quantitative relationship equation between the fire source, CO concentration, seepage distance and outflow concentration was established.

[0027] As a preferred technical solution: in step S5, the preset distance is 10-15 meters.

[0028] As a preferred technical solution, the temperature program in step S2 includes the following specific steps:

[0029] (1) Place the coal sample collected from the coal seam into a programmed temperature device;

[0030] (2) The heating rate is set according to the actual heating rate range of coal seam spontaneous combustion;

[0031] (3) Start the programmed temperature rising device. During the heating process, continuously monitor the temperature changes in the device and record the heating time and the corresponding temperature value.

[0032] As a preferred technical solution: in step S3, the isotope analyzer and the gas chromatograph are implemented correspondingly to the programmed temperature device. When the programmed temperature device starts to operate, the isotope analyzer and the gas chromatograph are immediately started so that they are both connected to the gas collection outlet of the programmed temperature device;

[0033] The isotope analyzer uses high-precision laser absorption spectroscopy or mass spectrometry to accurately distinguish and measure the concentration changes of CO isotopes with different mass numbers in the gas released during the heating process of the coal sample, and records the corresponding temperature values ​​in real time, thereby obtaining the CO isotope peaks at different temperatures and their corresponding temperature data points;

[0034] The gas chromatograph uses a chromatographic column to separate and quantitatively analyze the CO in the gas released by the coal sample. Its detection principle is based on the difference in retention time of different gas components in the chromatographic column and the response characteristics of the detector to CO. By calibrating and optimizing the working parameters of the gas chromatograph, the CO concentration values ​​produced by the coal sample at different temperatures can be accurately determined.

[0035] Compared with the prior art, the present invention comprehensively analyzes the chemical reaction process of coal seam spontaneous combustion and the law of gas migration based on CO isotopes and the concentration of multiple index gases to accurately predict the scope of fire. By analyzing the characteristics of CO isotopes and combining the changes in the concentrations of index gases such as ethane and ethylene, a fire range prediction formula is constructed. This technology can provide a reliable decision-making basis for coal mine safety production, and is a key technological innovation for early warning and prevention of coal seam spontaneous combustion fires in the field of coal mine safety; this method comprehensively considers various aspects of CO isotope and index gas concentration information, effectively improves the accuracy and reliability of the prediction, and provides more powerful technical support for the prevention and control of coal seam spontaneous combustion fires. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the overall design diagram of this method.

[0037] Figure 2 This is a schematic diagram of the engineering process of this method. DETAILED DESCRIPTION

[0038] The following is combined with Figure 1-2 The present invention is described in detail with reference to embodiments.

[0039] The technical solution disclosed by the method is a technology for accurately predicting the scope of spontaneous combustion of coal seams, and a method for applying this technology is disclosed.

[0040] This method first uses a core drill to take coal samples from the coal seam, and then simulates the oxidation process of the coal seam under different temperature conditions by subjecting the coal samples to programmed temperature treatment. In this process, a high-precision isotope analyzer and a gas chromatograph are used to accurately measure the CO isotope peaks and CO concentrations produced by the coal samples at different temperatures. CO isotopes have unique tracer characteristics during the spontaneous combustion of coal seams, and the changes in their ratios can reflect different oxidation reaction paths and degrees. The changes in CO concentrations produced at different temperatures are closely related to the oxidation rate of the coal seam. Subsequently, through a carefully designed CO concentration decay experiment, the seepage characteristics and concentration change laws of CO in the coal seam are deeply studied. In the experiment, considering multiple factors such as the pore structure, permeability, temperature, and pressure of the coal seam, a relationship equation between the fire source, CO concentration, seepage distance, and outflow concentration is established. This relationship equation can quantitatively describe the propagation process of CO in the coal seam and reveal its attenuation law under different conditions. Finally, in actual coal seam monitoring, gas extraction operations are performed at the working position according to the pre-set distance to determine the CO isotope concentration. The measured results were carefully compared with the results obtained from the previous programmed temperature experiment to accurately determine the CO concentration characteristics of the coal seam ignition point. Then, based on the established relationship equation, the distance from the ignition point to the working position was accurately calculated by analyzing the CO concentration at the gas extraction point, thereby achieving an accurate prediction of the scope of coal seam spontaneous combustion fires.

[0041] The present invention will be further described below with reference to specific embodiments.

[0042] The method disclosed in the present invention for predicting the scope of spontaneous combustion of coal seams based on CO isotopes and index gas concentrations includes a coal sample collection and processing unit and a data acquisition and analysis unit. The coal sample collection and processing unit includes drilling coal samples and programmed temperature experiments; the data acquisition and analysis unit includes an isotope analyzer, a gas chromatograph analysis design, and the establishment of a relationship equation. The above method is used to accurately predict the scope of spontaneous combustion of coal seams, specifically including the following steps:

[0043] S1. Coal sampling: Coal samples are collected from coal seams using a core drill;

[0044] S2. Program temperature rise: Place the coal sample in a program temperature rise device and heat it up at a set heating rate;

[0045] S3. Instrumental analysis: Use isotope analyzer and gas chromatograph to measure the CO isotope peak and CO concentration of coal samples at different temperatures;

[0046] S4. Establishment of the relationship equation: Carry out CO concentration attenuation experiments, change relevant parameters, collect data and analyze and fit, and establish the relationship equation between the fire source, CO concentration, seepage distance and outflow concentration. The relationship equation is C=C0·e -a·d ;

[0047] S5. Fire prediction: Take gas at certain intervals on site, measure CO isotope concentration, compare with programmed temperature rise results to determine CO concentration at ignition point, substitute into relationship equation to calculate distance between ignition point and working position, so as to accurately predict spontaneous combustion range.

[0048] In this embodiment, the specific operation process of each step is as follows.

[0049] S1. Coal sample acquisition

[0050] (1) First, based on the geological data of the coal seam, previous spontaneous combustion conditions, and mine layout, a representative coal sampling area should be determined. This area should cover areas with different coal quality characteristics, geological structure influences, and ventilation conditions to ensure that the collected coal samples can fully reflect the conditions of the entire coal seam.

[0051] (2) Select a ZDY4000S drilling rig, whose drill bit must be able to effectively obtain complete coal core samples and minimize mechanical damage and thermal impact on coal samples during drilling. Drill and coring should be carried out in the coal seam according to the predetermined sampling plan. The sampling depth interval should be reasonably set according to the thickness and degree of variation of the coal seam. For example, a group of coal samples can be collected every 5-10 meters in thick coal seams, and the interval distance should be appropriately adjusted for thin coal seams.

[0052] (3) Each coal sample collected shall be marked and recorded in detail, including the three-dimensional coordinates of the sampling location, coal seam depth, coal seam inclination, coal sample appearance characteristics (such as color, gloss, texture, etc.) and surrounding geological information (such as lithology, fault distribution, etc.). The coal samples shall be properly packaged and transported to the laboratory promptly. During transportation and storage, the environmental conditions shall be strictly controlled to prevent the coal samples from being damp, oxidized or otherwise contaminated, so as to ensure the original characteristics of the coal samples.

[0053] S2. Temperature program

[0054] (1) Carefully place the coal sample collected from the coal seam into the programmed temperature heating device. In this embodiment, the programmed temperature heating device adopts AutoChemⅡ2920 model, which should have precise temperature control and uniform heating system, and can operate stably in a wide temperature range, for example, from room temperature to 1000℃ or even higher temperature range, and the temperature heating accuracy is controlled within ±1℃.

[0055] (2) According to the actual possible heating rate range of coal seam spontaneous combustion and previous research experience, set a reasonable heating rate, such as 2-10℃ / minute. Before heating, conduct a comprehensive inspection and calibration of the device to ensure that the temperature sensor, gas collection pipeline and other components are working properly and without leakage.

[0056] (3) Start the programmed temperature rising device. During the heating process, continuously monitor the temperature changes in the device and record the heating time and the corresponding temperature value. At the same time, keep the gas environment in the device stable. Inert gas (such as nitrogen) can be used as a protective gas to prevent unnecessary oxidation reactions of the coal sample during the heating process and interfere with the experimental results.

[0057] S3. Instrumental analysis

[0058] (1) When the temperature program device starts to operate, immediately start the isotope analyzer and the gas chromatograph and connect them to the gas collection outlet of the temperature program device. The isotope analyzer uses high-precision laser absorption spectroscopy or mass spectrometry technology to accurately distinguish and measure the concentration changes of CO isotopes with different mass numbers (such as ¹²CO and ¹³CO) in the gas released during the heating process of the coal sample, and record the corresponding temperature values ​​in real time, so as to obtain the CO isotope peaks at different temperatures and their corresponding temperature data points.

[0059] (2) The gas chromatograph uses a chromatographic column to separate and quantitatively analyze the CO in the gas released by the coal sample. Its detection principle is based on the difference in retention time of different gas components in the chromatographic column and the response characteristics of the detector to CO. By calibrating and optimizing the working parameters of the gas chromatograph (such as column temperature, carrier gas flow rate, detector sensitivity, etc.), the CO concentration values ​​generated by the coal sample at different temperatures are accurately determined. During the entire analysis process, the instrument is regularly calibrated and quality control checks are carried out to ensure the accuracy and reliability of the analysis data.

[0060] S4. Establishment of the relational equation

[0061] (1) Build a CO concentration attenuation experimental platform that simulates the seepage environment inside the coal seam, including setting up coal sample filling columns with different permeabilities or simulating coal seam tunnels, equipped with a gas supply system that can accurately control the gas flow, pressure and concentration, and a sampling system that sets multiple gas sampling points at different locations.

[0062] (2) Change the relevant parameters in the experiment, such as seepage velocity (achieved by adjusting the gas supply pressure and pipeline resistance), coal sample porosity (replacing coal samples with different pore structures or pre-treating coal samples), initial CO concentration (configuring CO mixed gas with different concentrations in the gas supply system), etc., and conduct multiple experiments for each parameter combination. During the experiment, gas samples are collected at different seepage distances (starting from the simulated fire source position, sampling points are set at certain distances, such as 0.5-5 meters), and the CO concentration in the outflowing gas is measured using a high-precision gas sensor or gas chromatograph, and the corresponding experimental parameters (seepage velocity, coal sample porosity, initial CO concentration, seepage distance, etc.) and time information are recorded.

[0063] (3) The large amount of experimental data collected was deeply analyzed and fitted, and mathematical methods such as multivariate linear regression and nonlinear fitting were used to establish a quantitative relationship equation between the fire source, CO concentration, seepage distance and outflow concentration. The equation is C = C0·e -a·d .

[0064] C represents: the CO outflow concentration measured at a certain seepage distance by using a special instrument for detecting CO concentration, such as a gas chromatograph, at the working position (in ppm, i.e., one part per million by volume, an appropriate concentration unit);

[0065] C0 means: the initial CO concentration (also in ppm) measured near the fire source using the same accurate CO concentration detection equipment at the beginning of the fire before being affected by excessive diffusion. It is closely related to the combustion conditions of the fire source, fuel type and other factors. It can be understood as the concentration value when the fire source just produces CO and has not yet undergone diffusion processes such as seepage.

[0066] d represents: the seepage distance that CO travels from the fire source (the unit can be meters or other length units). This distance reflects the length of CO propagation in the medium (such as soil, rock cracks, etc.), that is, the distance between the ignition point and the working position.

[0067] a is an attenuation coefficient in units (same length units as d) -1 It comprehensively reflects the influence of the medium on the attenuation of CO concentration. Its size is related to many factors such as the porosity, adsorption characteristics, and diffusion coefficient of the medium. The value of a will be different in different medium environments. In the formula, a is multiplied by d to form a constant. The unit of a corresponds to the length unit of d, and they are offset after multiplication. For example, if the unit of d is m, then the unit of a is m. -1Due to the influence of multiple factors such as coal seam texture and ventilation, it is necessary to simulate different coal seam textures, ventilation conditions and other scenes in the laboratory, combined with the actual on-site measurement data, and determined through data fitting or regression analysis.

[0068] e is a natural constant, also known as the Euler number, and its value is approximately 2.71828. It is used here to describe the attenuation of CO concentration with distance d.

[0069] These coefficients are closely related to the physical and chemical properties of coal samples, experimental conditions, etc. By fitting and verifying the data under different experimental conditions, the accuracy and applicability of the equation are continuously optimized, so that it can be widely used in the prediction of fire range under different coal seam conditions. The various data collected and analyzed are entered into the data analysis center, and the data analysis center calculates the final accurate distance data through the relationship formula.

[0070] S5. Fire prediction

[0071] (1) At the coal seam site, determine the reasonable gas sampling route and spacing based on the geological structure, ventilation system and existing spontaneous combustion monitoring data of the coal seam. Generally, along the coal seam inclination or strike direction, in areas where spontaneous combustion may occur and in areas close to work positions, gas sampling points are set at intervals of 10 to 50 meters.

[0072] (2) Use portable gas sampling equipment to collect a certain volume of gas samples at each sampling point, and then quickly send the samples to an on-site testing station or laboratory equipped with an isotope analyzer for CO isotope concentration measurement. During the measurement process, strictly follow the instrument operating procedures to ensure the accuracy of the measurement results.

[0073] (3) Compare and analyze the CO isotope concentration results measured on site with the CO isotope peak and corresponding temperature data obtained in the laboratory programmed temperature experiment. Determine the corresponding ignition point CO concentration value by finding the laboratory data point that best matches the CO isotope concentration characteristics measured on site. For example, if the ¹³CO / ¹²CO isotope ratio measured on site is similar to the ratio when the laboratory is programmed to 300°C, then the ignition point CO concentration is determined to be the CO concentration value corresponding to 300°C in the programmed temperature experiment.

[0074] (4) Substitute the determined CO concentration at the ignition point into the previously established relationship equation, and combine the known seepage conditions on site (such as the seepage velocity obtained through ventilation resistance measurement and wind flow simulation, the coal seam porosity estimated based on geological exploration data, etc.) to calculate the distance between the ignition point and the working position. For example, if the on-site seepage velocity is known to be 0.1 m / s and the coefficient a corresponding to the coal seam porosity is 0.2, substitute it into the equation C=C0·e -a·dThe calculation shows that the distance between the ignition point and the work position is 20 meters. Based on the distance between the ignition point and the work position, the fire range of the coal seam spontaneous combustion is determined with the ignition point as the center, combined with the actual geological conditions, ventilation conditions and other factors. This includes possible combustion center areas, high temperature impact areas, and potential spontaneous combustion spread directions, so as to achieve accurate prediction of the range of coal seam spontaneous combustion fires and provide a scientific basis for formulating effective fire prevention and control measures.

Claims

1. A method for predicting the scope of spontaneous combustion of coal seams based on CO isotopes and index gas concentrations, characterized in that: The specific steps include: S1 Coal sample acquisition: Take coal samples from the coal seam using a core drill; S2 programmed temperature experiment: the coal sample is placed in a programmed temperature device and heated at a set heating rate to simulate the oxidation process of the coal seam under different temperature conditions; S3 Instrumental analysis: Use isotope analyzer and gas chromatograph to measure the CO isotope peak and CO concentration of coal samples at different temperatures; S4 relationship equation establishment: By conducting CO concentration attenuation experiments, changing experimental parameters, collecting data and analyzing and fitting, the attenuation coefficient is determined, and the relationship equation between the fire source, CO concentration, seepage distance and outflow concentration is established. The relationship equation is C=C0·e -a·d ; in: C represents: the CO outflow concentration measured at a certain seepage distance, in ppm; C0 represents: the initial CO concentration generated at the fire source, in ppm; d represents: the seepage distance of CO from the fire source, in meters; a is an attenuation coefficient in units (same length units as d) -1 ; e is a natural constant; S5 Fire prediction: Take gas at a preset distance on site and measure the CO isotope concentration; compare the measurement results with the results of the programmed heating experiment in step S2 to determine the CO concentration at the ignition point; substitute the relationship equation to calculate the distance between the ignition point and the working position, so as to predict the scope of natural fire in the coal seam.

2. The method for predicting the scope of spontaneous combustion of coal seams based on CO isotopes and index gas concentrations according to claim 1, characterized in that: In step S4, the specific steps of the CO concentration decay experiment are as follows: (1) Building a CO concentration decay experimental platform The platform simulates the seepage environment inside the coal seam, including setting up coal sample filling columns with different permeabilities or simulating coal seam tunnels; equipped with a gas supply system that can accurately control gas flow, pressure and concentration; and a sampling system with multiple gas sampling points set at different locations; (2) Change the relevant parameters in the experiment The relevant parameters involved include seepage velocity, coal sample porosity, and initial CO concentration. Multiple experiments are conducted for each parameter combination, and the corresponding experimental parameters and time information are recorded. (3) The collected experimental data were deeply analyzed and fitted, and the attenuation coefficient was determined using multivariate linear regression and nonlinear fitting mathematical methods to establish a quantitative relationship equation between the fire source, CO concentration, seepage distance and outflow concentration.

3. The method for predicting the scope of spontaneous combustion of coal seams based on CO isotopes and index gas concentrations according to claim 1 is characterized in that: In step S5, the preset distance is 10-15 meters.

4. The method for predicting the scope of spontaneous combustion of coal seams based on CO isotopes and index gas concentrations according to claim 1 is characterized in that: The temperature program in step S2 includes the following specific steps: (1) Place the coal sample collected from the coal seam into a programmed temperature device; (2) The heating rate is set according to the actual heating rate range of coal seam spontaneous combustion; (3) Start the programmed temperature rising device. During the heating process, continuously monitor the temperature changes in the device and record the heating time and the corresponding temperature value.

5. The method for predicting the scope of spontaneous combustion of coal seams based on CO isotopes and index gas concentrations according to claim 1, characterized in that: In step S3, the isotope analyzer and the gas chromatograph are implemented correspondingly to the program temperature rising device. When the program temperature rising device starts to operate, the isotope analyzer and the gas chromatograph are immediately started so that they are both connected to the gas collection outlet of the program temperature rising device; The isotope analyzer uses high-precision laser absorption spectroscopy or mass spectrometry to accurately distinguish and measure the concentration changes of CO isotopes with different mass numbers in the gas released during the heating process of the coal sample, and records the corresponding temperature values ​​in real time, thereby obtaining the CO isotope peaks at different temperatures and their corresponding temperature data points; The gas chromatograph uses a chromatographic column to separate and quantitatively analyze the CO in the gas released by the coal sample. Its detection principle is based on the difference in retention time of different gas components in the chromatographic column and the response characteristics of the detector to CO. By calibrating and optimizing the working parameters of the gas chromatograph, the CO concentration values ​​produced by the coal sample at different temperatures can be accurately determined.

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