Gas component detection method and system based on hot-wire method

Abstract

The invention relates to the technical field of gas detection, and provides a gas component detection method and system based on a hot-wire method. The method comprises the following steps: arranging a hot wire sensor in a coal sample tank of a coal sample gas injection displacement experimental device, and monitoring the concentration change of methane in the coal sample tank in real time; and determining the gas adsorption quantity of the coal sample in the coal sample tank according to the real-time change of the methane concentration through the constructed gas adsorption model. Therefore, the change of the concentration of methane in the coal sample tank is monitored in real time through the hot-wire sensor, the problem that the gas concentration cannot be detected in real time in a coal sample gas injection displacement experiment in an existing sampling detection method is solved, and the accuracy of real-time detection of the gas concentration is effectively improved; pressure disturbance caused by sampling and interference to the gas displacement process are avoided; and moreover, the whole-process dynamic monitoring of the gas concentration, the adsorption capacity and the adsorption rate in the gas displacement process can be realized, and important support is provided for the research of a coal sample gas injection displacement technology.

Description

Technical Field

[0001] This application relates to the field of gas detection technology, and in particular to a gas component detection method and system based on the hot wire method. Background Technology

[0002] Injecting carbon dioxide into coal seams to displace methane is a crucial technique for improving coalbed methane recovery and achieving efficient coalbed methane extraction. Carbon dioxide has a stronger adsorption capacity than methane; under the same conditions, coal adsorbs significantly more carbon dioxide than methane. When high-pressure carbon dioxide is injected into the coal seam, it is preferentially adsorbed by the coal, occupying more adsorption sites and displacing the adsorbed methane. This frees the methane, making it easier to extract. Summary of the Invention

[0003] The purpose of this application is to provide a gas component detection method and system based on the hot wire method, so as to solve or alleviate the problems existing in the prior art.

[0004] To achieve the above objectives, this application provides the following technical solution: This application provides a gas component detection method based on hot-wire method, comprising: installing a hot-wire sensor in the coal sample tank of a coal sample injection displacement experimental device to detect the methane concentration in the coal sample tank during the coal sample injection displacement experiment. Real-time monitoring of changes; using a constructed gas adsorption model, based on the methane concentration in the coal sample container. The real-time changes in the data are used to determine the amount of gas adsorbed in the coal sample within the coal sample container.

[0005] Preferably, based on the constructed hot wire concentration model, and according to the hot wire probe of the hot wire sensor under constant temperature conditions inside the coal sample container... Real-time power at any moment and / or real-time temperature To determine the contents of the coal sample container during the coal sample injection displacement experiment. methane concentration at time ; The hot wire concentration model is as follows: In the formula, The thermal conductivity of methane and carbon dioxide in the coal sample container during the coal sample injection displacement experiment; This is the real-time temperature of the hot wire probe. The absolute temperature during the gas injection and displacement experiment of the coal sample. The radius of the hot wire probe.

[0006] The preferred gas adsorption model is: In the formula, During the gas injection displacement experiment of coal samples The amount of methane adsorbed by the coal sample at any given time; The reference tank volume for the coal sample gas injection displacement experimental device; The first preset pressure of methane injected into the reference tank of the coal sample gas injection displacement experimental device during the sample gas injection displacement experiment; The first gas equilibrium pressure in the coal sample container and the reference container during the coal sample gas displacement experiment; Standard temperature, Standard atmospheric pressure The absolute temperature during the gas injection and displacement experiment of the coal sample; During the gas injection displacement experiment of coal samples The amount of carbon dioxide adsorbed by the coal sample at any given time; The second preset pressure for injecting carbon dioxide into the reference tank during the coal sample gas displacement experiment; The second gas equilibrium pressure in the coal sample container and the reference container during the coal sample gas displacement experiment; The free space volume inside the coal sample container during the coal sample gas displacement experiment; During the gas displacement experiment of coal samples, the coal sample container The methane concentration at time 1; During the gas displacement experiment of coal samples, the coal sample container The pressure of constant time.

[0007] Preferably, according to the formula: Calculate the free space volume inside the coal sample container in the coal sample injection displacement experiment. ; In the formula, The reference tank volume for the coal sample gas injection displacement experimental device; For reference, the gas pressure change inside the tank; This represents the change in gas pressure inside the coal sample container.

[0008] Preferably, the gas adsorption model also includes: In the formula, During the gas injection displacement experiment of coal samples Time to Time interval The rate of methane desorption within; The free space volume inside the coal sample container during the coal sample gas displacement experiment; Standard temperature, Standard atmospheric pressure The absolute temperature during the gas injection and displacement experiment of the coal sample; During the gas displacement experiment of coal samples, the coal sample container The methane concentration at time 1; During the gas displacement experiment of coal samples, the coal sample container The pressure of constant time; During the gas displacement experiment of coal samples, the coal sample container The methane concentration at time 1; During the gas displacement experiment of coal samples, the coal sample container The pressure of constant time; During the gas injection displacement experiment of coal samples Time to The rate of carbon dioxide adsorption between time points.

[0009] Preferably, the coal sample gas injection displacement experimental device includes: a gas source, a reference tank, a coal sample tank, a vacuum module, and a data acquisition module; The gas source is connected to the reference tank and is used to inject gas into the reference tank; The coal sample container is equipped with a pressure sensor and a hot wire sensor, and is connected to the reference container via a gas pipeline. The vacuum module is connected to the pipelines of the reference tank and the coal sample tank respectively, and can evacuate the reference tank and the coal sample tank during the coal sample gas injection displacement experiment. The data acquisition module is connected to a hot-wire sensor and a pressure sensor to acquire real-time parameters of the hot-wire sensor and real-time pressure inside the coal sample container during the coal sample injection displacement experiment. Specifically, when the hot-wire sensor is a constant-temperature type, the module acquires the real-time power of the hot-wire sensor. When the hot wire sensor is a constant current type, the real-time temperature of the hot wire sensor is obtained. and real-time power ; The coal sample container and the reference container were placed in the same constant temperature environment during the coal sample gas injection displacement experiment.

[0010] Preferably, in the coal sample gas displacement experiment, the coal sample container and the reference container are continuously evacuated. After injecting helium gas at a preset pressure into the reference container, the reference container and the coal sample container are connected. The free space volume inside the coal sample container is determined based on the gas pressure changes inside the reference container and the coal sample container. ; In the coal sample gas injection displacement experiment, after evacuating the reference tank, a first preset pressure was injected. After adding methane, connect the coal sample container to the reference container, and wait until the first gas equilibrium pressure is reached. Then, disconnect the coal sample container from the reference container; The reference tank was evacuated again, and the second preset pressure was injected. After removing carbon dioxide, reconnect the coal sample container to the reference container, and wait until the second gas equilibrium pressure is reached. Close the coal sample container to allow gas displacement within it; In response to gas displacement within the coal sample container, the pressure within the coal sample container... Real-time monitoring is performed, and the real-time parameters of the hot wire sensor installed on the coal sample container are recorded. The methane concentration in the coal sample container is calculated using a hot-wire concentration model based on real-time parameters from the hot-wire sensor; and the adsorption amounts of methane and carbon dioxide by the coal sample in the container are calculated using a gas adsorption model.

[0011] This application also provides a gas component detection system based on the hot-wire method, which detects gas during gas displacement using any of the above-described hot-wire method-based gas component detection methods. The system includes: The concentration monitoring unit is configured to install a hot-wire sensor in the coal sample container of the coal sample injection displacement experimental device to monitor the methane concentration in the coal sample container during the coal sample displacement experiment. Real-time monitoring of changes; The adsorption monitoring unit is configured to use a constructed gas adsorption model to detect methane concentration in the coal sample container. The real-time changes in the data are used to determine the amount of gas adsorbed in the coal sample within the coal sample container.

[0012] Beneficial effects: In the gas component detection method based on the hot-wire method provided in this application embodiment, a hot-wire sensor is installed in the coal sample tank of the coal sample injection displacement experimental device to detect the methane concentration in the coal sample tank during the coal sample injection displacement experiment. The changes are monitored in real time; then, based on the constructed gas adsorption model, the methane concentration in the coal sample container is analyzed. The real-time changes in the gas concentration within the coal sample container are used to determine the amount of gas adsorbed in the coal sample. This allows for the monitoring of methane concentration within the coal sample container using a hot-wire sensor. This method enables real-time monitoring of changes in gas concentration, overcoming the challenge of existing sampling and detection methods failing to detect gas concentration in real-time during coal sample gas displacement experiments. It effectively improves the accuracy of real-time gas concentration detection, avoids pressure disturbances caused by sampling and interference with the gas displacement process, and enables dynamic monitoring of gas concentration, adsorption capacity, and adsorption rate throughout the entire gas displacement process, providing important support for the research of coal sample gas displacement technology. Attached Figure Description

[0013] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein: Figure 1This is a schematic flowchart of a gas component detection method based on the hot-wire method according to some embodiments of this application; Figure 2 This is a schematic diagram of a coal sample gas injection displacement experimental device according to some embodiments of this application; Figure 3 This is a circuit diagram of a hot wire sensor provided according to some embodiments of this application; Figure 4 This is a schematic diagram of a gas component detection system based on the hot-wire method according to some embodiments of this application. Detailed Implementation

[0014] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will understand that modifications and variations can be made to the present application without departing from the scope or spirit of the present application. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention should fall within the scope of protection of the embodiments of the present invention.

[0015] In the gas displacement experiment of coal samples, the displacement process is a complex physical process accompanied by gas diffusion, adsorption-desorption equilibrium and composition changes. Experimental studies on the displacement of methane by injecting carbon dioxide into coal need to simultaneously monitor changes in gas pressure and gas concentration, and detect the process of carbon dioxide being adsorbed and the process of methane being displaced.

[0016] In experiments involving the injection of carbon dioxide to displace methane in coal, gas concentration and pressure are two key parameters. Currently, the common method for detecting gas concentration is to sample the gas from a coal sample container and detect it using a gas chromatograph. However, the sampling process causes a drop in gas pressure within the coal sample container, thus affecting the accuracy of the displacement process; furthermore, this sampling and detection method is difficult to implement in real-time.

[0017] Based on this, this embodiment proposes a gas component detection method based on the hot wire method. It utilizes a hot wire sensor to monitor the changes in methane concentration during the coal sample gas injection displacement experiment in real time, effectively solving the problem of difficulty in detecting gas concentration in coal sample gas injection displacement experiments. It does not require sampling and can monitor the changes in gas concentration in the tank in real time, providing important support for the research of coal gas injection displacement technology.

[0018] First, it should be noted that all temperatures in this embodiment are in Kelvin. For example... Figures 1 to 3 As shown, the gas component detection method based on the hot wire method includes: Step S101: Install a hot-wire sensor in the coal sample container of the coal sample injection displacement experimental device to monitor the methane concentration in the coal sample container during the coal sample injection displacement experiment. The changes are monitored in real time.

[0019] In this embodiment, the coal sample container is a cylindrical high-pressure sealed container used to hold coal samples and inject gas; the gas displacement process takes place inside the coal sample container. A threaded mounting hole is provided axially at the center of the top cover of the coal sample container for mounting a hot wire sensor. The hot wire sensor includes a control circuit and a hot wire probe. The control circuit can regulate the temperature of the hot wire sensor, and the hot wire probe extends into the interior of the coal sample container. Specifically, the hot wire sensor is encapsulated in a metal tube, which is threaded into the threaded mounting hole.

[0020] Here, the hot wire sensor can be either a constant-temperature (constant temperature) hot wire sensor or a constant-current (constant current) hot wire sensor. For a constant-temperature hot wire sensor, the hot wire temperature remains unchanged during the gas displacement experiment, while the hot wire power varies with the gas concentration and pressure inside the coal sample container. For a constant-current hot wire sensor, the current flowing through the hot wire remains unchanged during the gas displacement experiment, while the hot wire temperature varies with the gas concentration and pressure inside the coal sample container.

[0021] In this embodiment, the hot-wire sensor consists of a hot-wire probe composed of a thermistor and a control circuit. For a constant-temperature hot-wire sensor, the control circuit consists of a Wheatstone bridge, an operational amplifier, and a power supply. The four resistors form the Wheatstone bridge. and For fixed resistors, It is a variable resistor. It is a thermistor. It is an operational amplifier. It serves as an adjustable reference voltage source. The constant-temperature hot-wire sensor detects the imbalance signal output by the Wheatstone bridge, amplifies it, and drives the power supply to adjust the voltage, thereby rebalancing the Wheatstone bridge and maintaining a constant temperature during the operation of the hot-wire sensor.

[0022] In other words, to make the thermistor The temperature is kept constant, that is, the thermistor is kept at a constant temperature. To maintain a constant output voltage, the Wheatstone bridge's output voltage must be kept zero. Operational amplifier. With power supply Forming feedback control, when the thermistor A decrease in temperature causes a decrease in resistance, leading to an imbalance in the Wheatstone bridge, which in turn affects the operational amplifier. Increasing the output voltage thereby improving the thermistor Power causes its temperature to rise, and vice versa; furthermore, based on voltage and thermistor... The resistance value determines the real-time power of the thermistor. .

[0023] For constant current type hot wire sensors, a constant current power supply is used to power the hot wire, and its voltage is measured. The thermistor resistance is then calculated based on the voltage. The resistance value is used to further calculate its real-time temperature. and real-time power Regardless of whether a constant-temperature or constant-current hot-wire sensor is used, the relationship between the parameters of the hot-wire sensor and the gas concentration in the coal sample container (i.e., the hot-wire concentration model) is based on the real-time parameters (real-time power) of the hot-wire probe of the hot-wire sensor under constant-temperature conditions. and / or real-time temperature ), calculate the contents of the coal sample container during the coal sample injection displacement experiment. methane concentration at time The hot-line concentration model constructed is as follows: In the formula, The thermal conductivity of methane and carbon dioxide in the coal sample container during the coal sample injection displacement experiment; This is the real-time temperature of the hot wire probe. The absolute temperature during the coal sample gas injection displacement experiment (the coal sample gas injection displacement experiment is carried out under isothermal conditions, and the real-time temperature inside the coal sample container remains constant during the displacement process). The radius of the hot wire probe.

[0024] In other words, when a constant-temperature hot-wire sensor is used, the real-time changes in the power of the hot-wire sensor on the coal sample container, as well as the thermal conductivity of the gas (carbon dioxide, methane) in the coal sample container at the experimental temperature and pressure, reflect the changes in the methane concentration in the coal sample container. When a constant-current hot-wire sensor is used, the real-time changes in the temperature and power of the hot-wire sensor on the coal sample container, as well as the thermal conductivity of the gas (carbon dioxide, methane) in the coal sample container at the experimental temperature and pressure, reflect the changes in the methane concentration in the coal sample container.

[0025] In this embodiment, in the coal sample gas injection displacement device, the gas source is connected to the reference tank for injecting gas into the reference tank; the coal sample tank is equipped with a pressure sensor (first pressure sensor) and a hot wire sensor, and is connected to the reference tank via a gas pipeline; the vacuum module (vacuum pump) is connected to the pipelines of both the reference tank and the coal sample tank, specifically connected to the gas pipeline between the coal sample tank and the reference tank via a three-way valve, enabling vacuuming of the reference tank and the coal sample tank during the coal sample gas injection displacement experiment. Simultaneously, a pressure sensor (second pressure sensor) is also installed on the reference tank to monitor the gas pressure inside the reference tank.

[0026] The hot wire sensor and pressure sensor on the coal sample container, as well as the pressure sensor on the reference container, are all connected to the data acquisition module. This allows the module to acquire real-time parameters of the hot wire sensor during the experiment (and, when the hot wire sensor is a constant-temperature type, to acquire its real-time power). When the hot wire sensor is a constant current type, the real-time temperature of the hot wire sensor is obtained. and real-time power (and the real-time pressure in the coal sample container and reference container.)

[0027] In this embodiment, a constant temperature chamber is also set around the coal sample container and the reference container to keep the temperature constant during the experiment, so as to maintain a constant temperature for the coal sample gas displacement experiment; at the same time, there are methane cylinders, carbon dioxide cylinders and helium cylinders. Different types of gas source cylinders are connected to the reference container to inject different types of gas into the reference container at different stages of the experiment.

[0028] Before conducting the coal sample gas injection displacement experiment, a certain mass of coal sample was weighed and placed in the coal sample container. The airtightness of the experimental apparatus was then tested. After passing the airtightness test, the equipment was kept at a constant temperature in a constant-temperature chamber. Then, after continuously evacuating the reference container and the coal sample container for 6 hours using a vacuum pump, a helium cylinder was connected to the reference container. The helium cylinder was opened, and helium was injected into the reference container. Once the gas pressure in the reference container reached the set pressure, the helium cylinder was closed, and the coal sample container and the reference container were connected, allowing helium to flow from the reference container into the coal sample container. After the gas pressures in the coal sample container and the reference container reached equilibrium, the gas pressure change in the coal sample container was acquired using a first pressure sensor. The gas pressure change inside the reference tank is obtained through a second pressure sensor. And according to the formula: Calculate the free space volume inside the coal sample container in the coal sample injection displacement experiment. In the formula, The reference tank volume for the coal sample gas injection displacement experimental device; For reference, the gas pressure change inside the tank; This represents the change in gas pressure inside the coal sample container.

[0029] In the coal sample gas displacement experiment, the valve of the coal sample tank is opened and the valve of the reference tank is closed. The coal sample tank is continuously evacuated using a vacuum pump to degas the coal sample. After the evacuation is completed, the valve of the coal sample tank is closed and the valve of the reference tank is opened to connect the vacuum pump to the reference tank. The vacuum pump is then used to evacuate the reference tank. After the reference tank is evacuated, the valves of the vacuum pump and the reference tank are closed.

[0030] Connect the methane cylinder to the reference tank's injection port and inject methane into the reference tank. When the methane pressure in the reference tank reaches the first preset pressure... Then, close the methane cylinder, connect the coal sample container and the reference container, allowing the methane gas in the reference container to flow freely into the coal sample container until the coal sample container and the reference container reach gas pressure equilibrium (first gas equilibrium pressure). The connection between the coal sample container and the reference container is disconnected. At the same time, the coal sample in the coal sample container adsorbs the methane gas inside (to achieve pressure equilibrium).

[0031] After evacuating the reference container again using a vacuum pump, connect the carbon dioxide cylinder to the reference container's injection port and inject carbon dioxide gas into the reference container. When the carbon dioxide pressure inside the reference container reaches the second preset pressure... After closing the carbon dioxide cylinder, connect the coal sample container and the reference container, allowing the carbon dioxide in the reference container to flow freely into the coal sample container until the coal sample container and the reference container reach gas pressure equilibrium (second gas equilibrium pressure). ), disconnect the connection between the coal sample container and the reference container.

[0032] It should be noted that the gas pressure inside the coal sample container is monitored in real time by a first pressure sensor installed on the coal sample container. After the coal sample in the coal sample container has reached pressure equilibrium by adsorbing the methane gas, the reference container and the coal sample container are connected, allowing carbon dioxide in the reference container to flow freely into the coal sample container until the coal sample container and the reference container reach gas pressure equilibrium (second gas equilibrium pressure). ).

[0033] Then, the connection between the coal sample container and the reference container is disconnected, allowing carbon dioxide gas in the coal sample container to displace the methane gas adsorbed on the coal sample. During the gas displacement stage, the real-time parameters (real-time power) of the hot-wire sensor are monitored. or real-time temperature The first pressure sensor monitors the coal sample container in real time. The pressure of every moment Combined with pressure and the real-time temperature inside the coal sample container The thermal conductivity of methane and carbon dioxide was determined, and then the methane concentration in the coal sample container was calculated using a hot-wire concentration model. .

[0034] Step S102: Using the constructed gas adsorption model, based on the methane concentration in the coal sample container... The real-time changes in the data are used to determine the amount of gas adsorbed in the coal sample within the coal sample container.

[0035] The concentration inside the coal sample container was determined using a hot-wire concentration model. methane concentration at time Then, combined with the coal sample container The pressure of every moment and the absolute temperature inside the coal sample container The adsorption amounts of methane and carbon dioxide by the coal sample in the coal sample container were calculated using a gas adsorption model. Specifically, according to the formula: In the formula, During the gas injection displacement experiment of coal samples The amount of methane adsorbed by the coal sample at any given time; The reference tank volume for the coal sample gas injection displacement experimental device; The first preset pressure of methane injected into the reference tank of the coal sample gas injection displacement experimental device during the sample gas injection displacement experiment; The first gas equilibrium pressure in the coal sample container and the reference container during the coal sample gas displacement experiment; Standard temperature, Standard atmospheric pressure The absolute temperature during the gas injection and displacement experiment of the coal sample; During the gas injection displacement experiment of coal samples The amount of carbon dioxide adsorbed by the coal sample at any given time; The second preset pressure for injecting carbon dioxide into the reference tank during the coal sample gas displacement experiment; The second gas equilibrium pressure in the coal sample container and the reference container during the coal sample gas displacement experiment; The free space volume inside the coal sample container during the coal sample gas displacement experiment; During the gas displacement experiment of coal samples, the coal sample container The methane concentration at time 1; During the gas displacement experiment of coal samples, the coal sample container The pressure of constant time.

[0036] Therefore, according to the formula: When determining the gas displacement experiment in the coal sample container Time to Time interval The methane desorption rate and Time to The carbon dioxide adsorption rate between time points. Where, During the gas injection displacement experiment of coal samples Time to Time interval The rate of methane desorption within; The free space volume inside the coal sample container before the gas displacement experiment; Standard temperature, Standard atmospheric pressure The absolute temperature during the gas injection and displacement experiment of the coal sample; During the gas displacement experiment of coal samples, the coal sample container The methane concentration at time 1; During the gas displacement experiment of coal samples, the coal sample container The pressure of constant time; During the gas displacement experiment of coal samples, the coal sample container The methane concentration at time 1; During the gas displacement experiment of coal samples, the coal sample container The pressure of constant time; During the gas injection displacement experiment of coal samples Time to The rate of carbon dioxide adsorption between time points.

[0037] In this way, the methane concentration in the coal sample container can be monitored using a hot-wire sensor. By monitoring changes in gas concentration in real time and combining them with a constructed hot-line concentration model, this method overcomes the problem that existing sampling and detection methods cannot detect gas concentration in real time during coal sample gas injection displacement experiments. This effectively improves the accuracy of real-time gas concentration detection and avoids pressure disturbances caused by sampling and interference with the gas displacement process. Moreover, it enables dynamic monitoring of gas concentration, adsorption amount, and adsorption rate throughout the entire gas displacement process, providing important support for the research of coal sample gas injection displacement technology.

[0038] This embodiment also provides a gas component detection system based on the hot-wire method, which is used for gas detection during gas displacement using the gas component detection method based on the hot-wire method described in any of the above embodiments. Figure 4 As shown, the system includes: Concentration monitoring unit 401 is configured to install a hot-wire sensor in the coal sample container of the coal sample injection displacement experimental device to monitor the methane concentration in the coal sample container during the coal sample displacement experiment. Real-time monitoring of changes; Adsorption monitoring unit 402 is configured to use a constructed gas adsorption model to monitor the methane concentration in the coal sample container. The real-time changes in the data are used to determine the amount of gas adsorbed in the coal sample within the coal sample container.

[0039] In the description of this embodiment, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this embodiment, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0040] In this embodiment, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this embodiment. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A gas component detection method based on hot-wire method, characterized in that, include: A hot-wire sensor was installed in the coal sample container of the coal sample injection displacement experiment device to monitor the methane concentration in the coal sample container during the coal sample injection displacement experiment. Real-time monitoring of changes; By constructing a gas adsorption model, based on the methane concentration in the coal sample container... The real-time changes in the data are used to determine the amount of gas adsorbed in the coal sample within the coal sample container.

2. The method according to claim 1, characterized in that, Based on the constructed hot wire concentration model, and according to the hot wire probe of the hot wire sensor under constant temperature conditions inside the coal sample container... Real-time power at any moment and / or real-time temperature To determine the contents of the coal sample container during the coal sample injection displacement experiment. methane concentration at time ; The hot wire concentration model is as follows: In the formula, The thermal conductivity of methane and carbon dioxide in the coal sample container during the coal sample injection displacement experiment; This is the real-time temperature of the hot wire probe. The absolute temperature during the gas injection and displacement experiment of the coal sample. The radius of the hot wire probe.

3. The method according to claim 1, characterized in that, The gas adsorption model is as follows: In the formula, During the gas injection displacement experiment of coal samples The amount of methane adsorbed by the coal sample at any given time; The reference tank volume for the coal sample gas injection displacement experimental device; The first preset pressure of methane injected into the reference tank of the coal sample gas injection displacement experimental device during the sample gas injection displacement experiment; The first gas equilibrium pressure in the coal sample container and the reference container during the coal sample gas displacement experiment; Standard temperature, Standard atmospheric pressure The absolute temperature during the gas injection and displacement experiment of the coal sample; During the gas injection displacement experiment of coal samples The amount of carbon dioxide adsorbed by the coal sample at any given time; The second preset pressure for injecting carbon dioxide into the reference tank during the coal sample gas displacement experiment; The second gas equilibrium pressure in the coal sample container and the reference container during the coal sample gas displacement experiment; The free space volume inside the coal sample container during the coal sample gas displacement experiment; During the gas displacement experiment of coal samples, the coal sample container The methane concentration at time 1; During the gas displacement experiment of coal samples, the coal sample container The pressure of constant time.

4. The method according to claim 3, characterized in that, According to the formula: Calculate the free space volume inside the coal sample container in the coal sample injection displacement experiment. ; In the formula, The reference tank volume for the coal sample gas injection displacement experimental device; For reference, the gas pressure change inside the tank; This represents the change in gas pressure inside the coal sample container.

5. The method according to claim 3, characterized in that, Gas adsorption models also include: In the formula, During the gas injection displacement experiment of coal samples Time to Time interval The rate of methane desorption within; The free space volume inside the coal sample container during the coal sample gas displacement experiment; Standard temperature, Standard atmospheric pressure The absolute temperature during the gas injection and displacement experiment of the coal sample; During the gas displacement experiment of coal samples, the coal sample container The methane concentration at time 1; During the gas displacement experiment of coal samples, the coal sample container The pressure of constant time; During the gas displacement experiment of coal samples, the coal sample container The methane concentration at time 1; During the gas displacement experiment of coal samples, the coal sample container The pressure of constant time; During the gas injection displacement experiment of coal samples Time to The rate of carbon dioxide adsorption between time points.

6. The method according to claim 1, characterized in that, The coal sample gas injection displacement experimental device includes: a gas source, a reference tank, a coal sample tank, a vacuum module, and a data acquisition module; The gas source is connected to the reference tank and is used to inject gas into the reference tank; The coal sample container is equipped with a pressure sensor and a hot wire sensor, and is connected to the reference container via a gas pipeline. The vacuum module is connected to the pipelines of the reference tank and the coal sample tank respectively, and can evacuate the reference tank and the coal sample tank during the coal sample gas injection displacement experiment. The data acquisition module is connected to a hot-wire sensor and a pressure sensor to acquire real-time parameters of the hot-wire sensor and real-time pressure inside the coal sample container during the coal sample injection displacement experiment. Specifically, when the hot-wire sensor is a constant-temperature type, the module acquires the real-time power of the hot-wire sensor. When the hot wire sensor is a constant current type, the real-time temperature of the hot wire sensor is obtained. and real-time power ; The coal sample container and the reference container were placed in the same constant temperature environment during the coal sample gas injection displacement experiment.

7. The method according to claim 6, characterized in that, In the coal sample gas displacement experiment, the coal sample container and the reference container were continuously evacuated. After injecting helium gas at a preset pressure into the reference container, the reference container and the coal sample container were connected. The free space volume inside the coal sample container was determined based on the gas pressure changes inside the reference container and the coal sample container. ; After evacuating the reference tank, inject the first preset pressure. After adding methane, connect the coal sample container to the reference container, and wait until the first gas equilibrium pressure is reached. Then, disconnect the coal sample container from the reference container; The reference tank was evacuated again, and the second preset pressure was injected. After removing carbon dioxide, reconnect the coal sample container to the reference container, and wait until the second gas equilibrium pressure is reached. Close the coal sample container to allow gas displacement within it; In response to gas displacement within the coal sample container, the pressure within the coal sample container... Real-time monitoring is performed, and the real-time parameters of the hot wire sensor installed on the coal sample container are recorded. The methane concentration in the coal sample container is calculated using a hot-wire concentration model based on real-time parameters from the hot-wire sensor; and the adsorption amounts of methane and carbon dioxide by the coal sample in the container are calculated using a gas adsorption model.

8. A gas component detection system based on the hot-wire method, characterized in that, The gas detection system, employing the hot-wire method for gas component detection as described in any one of claims 1-7, comprises: The concentration monitoring unit is configured to install a hot-wire sensor in the coal sample container of the coal sample injection displacement experimental device to monitor the methane concentration in the coal sample container during the coal sample displacement experiment. Real-time monitoring of changes; The adsorption monitoring unit is configured to use a constructed gas adsorption model to detect methane concentration in the coal sample container. The real-time changes in the data are used to determine the amount of gas adsorbed in the coal sample within the coal sample container.

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