Goaf high-temperature point detecting and positioning method based on demagnetization phenomenon

Abstract

The invention provides a goaf high-temperature point detection and positioning method based on a demagnetization phenomenon, and the method comprises the steps: selecting a high-temperature-resistant and high-thermal-sensitivity magnetic material which has a remarkable demagnetization effect in a specific temperature range; the magnetic materials are uniformly arranged in the coal mine goaf, the data acquisition module is arranged, the magnetic change of the magnetic materials is monitored through the data acquisition module, monitoring data are uploaded to the upper computer, the upper computer analyzes the magnetic change of the materials, the temperature change condition of the magnetic materials is judged, and the position of the high-temperature point of the goaf is locked. The problems that in a traditional detection method, generally, a detector needs to carry detection equipment to make close contact with a high-temperature point, namely, active close-distance detection is needed, and remote automatic detection cannot be achieved are solved. Belongs to the field of mine composite disaster prevention.

Description

Technical Field

[0001] The invention relates to a method for detecting and locating high-temperature points in goaf areas based on a demagnetization phenomenon, and belongs to the field of prevention and control of composite disasters in mines. Background Art

[0002] Mine fires caused by spontaneous combustion of coal waste coal resources, pollute the environment, cause casualties, and may even cause secondary disasters such as gas or coal dust explosions. One of the manifestations of spontaneous combustion of coal is heat accumulation. Therefore, if the high-temperature points in the goaf can be detected in advance, it will be effective to prevent the occurrence of combined disasters of spontaneous combustion of coal and gas explosion. At present, the detection methods of high-temperature points in goaf mainly include gas detection method, temperature measurement method, radio electromagnetic wave method and tracer gas method. These methods can detect high-temperature points in goaf, but they all have limitations. The most important defect is that the existing detection methods generally require the detection personnel to bring the detection equipment to close contact with the high-temperature points, and cannot achieve long-distance automatic detection. Summary of the invention

[0003] The present invention provides a method for detecting and locating high-temperature points in goaf areas based on the demagnetization phenomenon, so as to solve the problem that traditional detection methods generally require detection personnel to bring detection equipment into close contact with high-temperature points, that is, active close-range detection is required, and long-range automatic detection cannot be achieved.

[0004] In order to solve the above problems, a method for detecting and locating high-temperature points in goaf areas based on the demagnetization phenomenon is proposed. A high-temperature resistant and highly thermally sensitive magnetic material is selected, which has a significant demagnetization effect within a specific temperature range. The material is evenly arranged in the goaf of the coal mine, and a data acquisition module is arranged. The magnetic changes of the magnetic material are monitored through the data acquisition module, and the monitoring data is uploaded to the host computer. The host computer analyzes the magnetic changes of the material to judge the temperature changes at the magnetic material, and locks the position of the high-temperature point in the goaf.

[0005] The specific implementation of the above method is as follows:

[0006] Material selection: choose a high temperature resistant and highly sensitive thermomagnetic material that has a significant demagnetization effect within a specific temperature range;

[0007] Layout planning: According to the geological structure, spatial distribution and possible high-temperature point locations of the goaf, the thermomagnetic materials should be reasonably arranged to ensure comprehensive coverage and uniform distribution;

[0008] Data acquisition module is equipped, and each magnetic material is equipped with a data acquisition module to collect magnetic change data of the magnetic material in real time;

[0009] Data transmission: The collected data is transmitted to the host computer through wired or wireless means for subsequent processing and analysis;

[0010] Data reception and storage, the host computer receives and stores data from various magnetic materials;

[0011] Data analysis: analyzing the relationship between magnetic changes and temperature of magnetic materials, and identifying materials with significant magnetic changes;

[0012] High temperature point inference: According to the degree and trend of magnetic change, the location, temperature range and change trend of the high temperature point can be inferred, and the temperature and location of the goaf area can be determined according to the thermal demagnetization curve of the magnetic material;

[0013] High temperature point positioning: accurately locate the high temperature points in the goaf based on the data analysis results;

[0014] The early warning mechanism is set up, and the early warning threshold is set. When the temperature of the high-temperature point exceeds the preset threshold, the early warning mechanism is automatically triggered, and relevant personnel are notified in time to take countermeasures.

[0015] In the above method, the magnetic material is NdFeB magnetic material, NiMnIn alloy or Fe-Ga alloy. The magnetism of NdFeB magnetic material, NiMnIn alloy and Fe-Ga alloy is greatly affected by temperature changes. The magnetic properties of these materials in high temperature applications show significant temperature dependence.

[0016] In the above method, the data acquisition module is a magnetic measuring instrument, and a vibrating sample magnetometer VSM or the like can be selected to measure the magnetization intensity of the sample.

[0017] The aforementioned method further includes an external magnetic field device, which generates a magnetic field of a specific strength at a specific position, the generated magnetic field covers the magnetic material, and then the magnetic change of the magnetic material is monitored by a data acquisition module;

[0018] Considering the economical applicability and the magnetic field strength capable of covering the magnetic material, the external magnetic field device is selected from: solenoid, Helmholtz coil, electromagnet or MFG-64 series four-pole electromagnet.

[0019] Considering both economy and practicality, solenoids and Helmholtz coils are more economical options, while electromagnets and MFG-64 series four-pole electromagnets offer more functions and higher magnetic field strength, but at a slightly higher cost.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The change in magnetic strength of thermomagnetic materials at high temperatures can directly reflect the existence of high-temperature areas. This method has a direct indicative effect on detecting high-temperature points in goafs, especially those high-temperature areas caused by spontaneous combustion of coal.

[0022] 2. Compared with the traditional contact temperature measurement method that relies more on direct contact temperature measurement, the use of thermal magnetic materials for detection can avoid direct contact with high-temperature areas by measuring the magnetic field of magnetic materials at a long distance, thus reducing the safety risks during the detection of goaf areas.

[0023] 3. Traditional temperature measurement methods can usually only measure the temperature at a certain point, and the coverage area is relatively small. However, through reasonable arrangement and selection of thermal magnetic materials, it is possible to detect a larger range of goaf areas, which helps to fully understand the distribution and changes of high-temperature points.

[0024] 4. Using thermomagnetic materials to detect high-temperature points in goafs can monitor the temperature changes in various areas of the goaf in real time. Reasonable arrangement of thermomagnetic materials comprehensively and cross-covers all areas of the goaf without omission. Sensors can monitor the changes in the material's magnetic field in real time, thereby providing real-time feedback on the temperature of each area of ​​the goaf.

[0025] 5. Compared with some high-end detection technologies, the cost of using thermal magnetic materials for detection is relatively low, and the materials can be arranged when the goaf is safe. The operation and arrangement are simple and safe, and it is easier to be widely used in actual production.

[0026] The present invention has low cost and simple operation method, and can realize remote and automatic high-temperature point monitoring, thereby improving the safety and efficiency of goaf area monitoring and providing real-time and accurate temperature distribution data for mine area management. It has many advantages that traditional temperature measurement methods do not have, and is highly safe and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the flow chart for high-temperature point detection and positioning in goaf areas. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] Example

[0030] This embodiment provides a method for detecting and locating high-temperature points in goaf areas based on the demagnetization phenomenon. The specific method is as follows:

[0031] 1. Material selection: NdFeB magnetic materials, NiMnIn alloys or Fe-Ga alloys are selected as magnetic materials. The magnetism of NdFeB magnetic materials, NiMnIn alloys and Fe-Ga alloys is greatly affected by temperature changes. The magnetic properties of these materials in high-temperature applications show significant temperature dependence.

[0032] 2. Layout planning: According to the geological structure, spatial distribution and possible high-temperature point locations of the goaf, the thermal magnetic materials should be reasonably arranged to ensure comprehensive coverage and uniform distribution;

[0033] 3. Data acquisition module is equipped. Each magnetic material is equipped with a data acquisition module to collect magnetic change data of the magnetic material in real time;

[0034] The data acquisition module is a magnetic measuring instrument, and a vibrating sample magnetometer VSM is selected to measure the magnetization intensity of the sample.

[0035] 4. Apply an external magnetic field, generate a magnetic field of a specific strength at a specific position through an external magnetic field device, the generated magnetic field covers the magnetic material, and then monitor the magnetic change of the magnetic material through a data acquisition module;

[0036] Taking into account the economical applicability and the magnetic field strength that can be generated to cover the magnetic material, the external magnetic field device can be selected from: solenoid, Helmholtz coil, electromagnet or MFG-64 series four-pole electromagnet.

[0037] The solenoid is an economical and applicable magnetic field generating device with the characteristics of good uniformity, small size, and high magnetic field. It can generate AC and DC magnetic fields, and there is a good linear relationship between current and magnetic field. It is suitable for various research institutes, colleges and universities, and enterprises to conduct material magnetism or detection experiments, and is used in various disciplines such as materials, electronics, biology, medicine, aerospace, chemistry, and applied physics.

[0038] The Helmholtz coil is composed of two flat coaxial single coils. A spherical uniform magnetic field is generated between the two coils. The size of the uniform magnetic field is changed by changing the current. It has the characteristics of adjustable magnetic field, high uniformity, high sensitivity, and large uniform area. The magnetic field is generally below 1000GS. It is suitable for generating standard magnetic fields, offsetting and compensating the earth's magnetic field, simulating geomagnetic environment, etc.

[0039] The electromagnet consists of two flat coaxial single coils. The magnetic field in each coil is derived from pure iron, and a uniform magnetic field is generated in the gap between the two pieces of pure iron. The magnetic field can be changed by changing the current. It has the characteristics of adjustable magnetic field, large uniform area, strong magnetic field, etc. The maximum magnetic field is up to 10T.

[0040] MFG-64 series four-pole electromagnets can generate various types of magnetic fields according to different operations and configurations, such as DC uniform magnetic field, gradient magnetic field, rotating magnetic field and alternating magnetic field, etc. They are suitable for various research institutions, universities, corporate research institutes to carry out hysteresis research, magnetization coefficient measurement, Hall effect research, magneto-optical experiments, multi-level magnetic ring magnetization, nuclear magnetic resonance, magnetic measurement, magnetic material orientation, spin magnetic resonance demonstration, biological research, etc.

[0041] Considering both economy and practicality, solenoids and Helmholtz coils are more economical options, while electromagnets and MFG-64 series four-pole electromagnets offer more functions and higher magnetic field strength, but at a slightly higher cost.

[0042] 5. Data transmission: The collected data is transmitted to the host computer through wired or wireless means for subsequent processing and analysis;

[0043] 6. Data reception and storage: the host computer receives and stores data from various magnetic materials;

[0044] 7. Data analysis: analyze the relationship between the magnetic change of magnetic materials and temperature, identify the magnetic materials with significant magnetic changes, and determine the specific location of the magnetic materials with significant magnetic changes;

[0045] You can choose to measure the hysteresis loop or magnetization curve of the magnetic material at different temperatures to observe the change of magnetic parameters (such as magnetization intensity, coercive force, etc.) with temperature, so as to judge the temperature change of the material;

[0046] Or the temperature change of magnetic materials can be monitored by using the magnetocaloric effect, that is, the temperature change that occurs when a magnetic material is magnetized by an external magnetic field under adiabatic conditions;

[0047] 8. High temperature point inference: according to the degree and trend of magnetic change, the location, temperature range and change trend of the high temperature point can be inferred;

[0048] 9. High temperature point positioning: accurately locate the high temperature points in the goaf according to the data analysis results;

[0049] 10. Set up an early warning mechanism and set the early warning threshold. When the temperature of a high-temperature point exceeds the preset threshold, the early warning mechanism will be triggered and relevant personnel will be notified in time to take countermeasures.

[0050] Example 2

[0051] Magnetic susceptibility measurement is one of the basic methods for evaluating the magnetic properties of materials. It reflects the magnetic strength of a material by measuring the ratio of the magnetization intensity of the material under an external magnetic field to the magnetic field intensity (i.e., magnetic susceptibility).

[0052] The basic principle of static magnetic susceptibility measurement is to use electromagnets or permanent magnets to generate a stable magnetic field and measure the magnetization intensity of the sample in the magnetic field to obtain the magnetic susceptibility value.

[0053] Magnetic susceptibility is a physical quantity that describes the degree of magnetization of a substance in a magnetic field. It is defined as the ratio of the magnetization intensity (M) of the substance to the external magnetic field intensity (H), that is, χ = M / H. The magnitude of the magnetic susceptibility is closely related to the magnetic properties of the substance. Different types of substances have different magnetic susceptibilities. By measuring the magnetization intensity of a sample in a stable magnetic field and using the above formula, the magnetic susceptibility value of the sample can be calculated.

[0054] 1. Project objectives

[0055] Through the high-temperature point detection and positioning method in goaf areas based on the demagnetization phenomenon, long-distance and automated monitoring of high-temperature points in goaf areas can be achieved, avoiding close contact of detection personnel with dangerous areas and improving the safety and efficiency of goaf area monitoring.

[0056] 2. Technical implementation steps

[0057] 2.1 Material selection and performance testing

[0058] Objective: To select suitable thermomagnetic materials to ensure sensitivity, high temperature resistance, stability and economy.

[0059] 1) Material screening

[0060] Preliminary materials: NdFeB magnetic material, NiMnIn alloy, Fe-Ga alloy.

[0061] Alternative materials: Ferrites, oxide magnetic materials (such as nickel-zinc ferrite) as economical alternative options.

[0062] 2) Experimental verification

[0063] Experimental content: Test the change of magnetization intensity of each material in different temperature ranges (such as 50-300℃).

[0064] Determine the thermal demagnetization curve (magnetization versus temperature) of a material.

[0065] Experimental conditions: The ambient temperature was controlled by a standard thermostatic device; the magnetization intensity was measured using a vibrating sample magnetometer (VSM).

[0066] Evaluation indicators: thermal magnetic sensitivity (magnetic change caused by unit temperature change); high temperature resistance (whether the material's magnetism is stable under long-term exposure to high temperature); cost (economic efficiency in mass application).

[0067] 3) Result evaluation and material determination

[0068] After experiments, the best material, NdFeB or NiMnIn alloy, is finally selected, and a demagnetization curve database of the material is established.

[0069] 2.2 Goaf layout planning

[0070] Objective: Arrange magnetic materials reasonably to cover possible high-temperature areas and ensure comprehensive monitoring and economical layout.

[0071] 1) Goaf analysis

[0072] Obtain geological structure map and spatial distribution information of goaf areas.

[0073] Determine the locations where high temperature points may occur (such as gas accumulation areas, mining operation areas, etc.).

[0074] 2) Layout strategy

[0075] Material layout point design: adopt grid layout, set a layout point every 5-10 meters (the specific spacing is adjusted according to the size of the goaf and budget); appropriately encrypt the layout in areas with high possibility of high temperature points (such as gas accumulation points);

[0076] Arrangement of data acquisition modules: A magnetic measurement module is installed near each magnetic material to collect magnetic data in real time. It would be best if there is a long-distance magnetic measurement module, but it is currently technically difficult.

[0077] 3) Layout

[0078] The magnetic material is fixed in a high temperature resistant shell. The shell material is selected from corrosion-resistant and high temperature resistant materials (such as ceramics or high temperature resistant plastics). The high temperature resistant shell has air holes to transfer heat to the magnetic material through air.

[0079] The magnetic material is fixed by hanging, burying or supporting to ensure its stable operation in the harsh environment of the goaf.

[0080] 2.3 Data acquisition and transmission module design

[0081] Objective: Collect magnetic data in real time and transmit it to the host computer efficiently.

[0082] 1) Data acquisition module

[0083] Hardware selection:

[0084] Main sensor: Hall effect sensor or magnetoresistive sensor (cost-effective and suitable for long-term operation).

[0085] Control unit: low power MCU (such as STM32 series).

[0086] Power supply mode: lithium battery or solar power supply module is used to ensure the energy supply for long-term operation of the goaf.

[0087] Software design: sampling frequency, collecting magnetic data every 10 seconds (adjustable according to demand); data preprocessing, performing simple processing such as denoising and filtering on the collected data.

[0088] 2) Data transmission

[0089] Wireless data transmission:

[0090] LoRa: Suitable for scenarios with large-scale distribution in mining areas and low power consumption requirements.

[0091] Wi-Fi: Suitable for small and medium-sized mining areas, with high transmission rate.

[0092] The data transmission module and the acquisition module are integrated into one, and are transmitted to the host computer through a wireless gateway.

[0093] 2.4 Data analysis and high temperature point location

[0094] Objective: Analyze the temperature distribution in the goaf through changes in magnetic data and locate the high-temperature points.

[0095] 1) Data reception and storage

[0096] The host computer receives the data stream from the goaf and stores the data in real time through a database (such as MySQL or NoSQL).

[0097] The data of each sampling point include: magnetic change (unit magnetization intensity); sampling time; sampling point number (corresponding geographical location).

[0098] 2) Temperature estimation and high temperature point inference

[0099] Modeling the relationship between magnetic properties and temperature:

[0100] Based on the material demagnetization curve obtained in the laboratory, a mathematical model of magnetism and temperature is established.

[0101] High temperature point identification algorithm:

[0102] By comparing the magnetic change data of the sampling points, areas where the magnetism is significantly weakened are identified.

[0103] A threshold setting is introduced (such as the magnetic drop exceeds 50%) to determine whether there is a high temperature point.

[0104] 3) High temperature point positioning

[0105] Combining the geographical location and magnetic change data of the sampling points, an interpolation algorithm (such as Kriging interpolation) is used to draw a temperature distribution map of the goaf area. The location of the high-temperature point is locked and the temperature change trend is predicted.

[0106] Interpolation algorithm is a method to estimate unknown data points between known data points. For goaf, the magnetic change data of sampling points are discretely distributed, and through interpolation algorithm, a continuous temperature distribution map can be calculated between sampling points.

[0107] The data of unknown points are estimated spatially smoothly using mathematical models (such as Kriging interpolation). Kriging interpolation is an interpolation algorithm widely used in geological exploration and environmental science, and is particularly suitable for scenes with strong spatial continuity such as goafs.

[0108] Kriging interpolation is a linear interpolation method based on spatial autocorrelation, and its core includes the following steps:

[0109] A determines the location and data value of the sampling point

[0110] The data of the sampling points include:

[0111] Geographic location: The two-dimensional coordinates (x, y) of the sampling point.

[0112] Magnetic change value: magnetic data of the sampling point (such as magnetization intensity change).

[0113] For example:

[0114] Sampling point number Coordinates (x,y) Magnetic change value M A (10,20) 50 B (15,25) 40 C (20,30) 30

[0115] B. Calculate the variance function

[0116] The semivariance describes the spatial correlation between sampling points, that is, the relationship between the distance between two sampling points and their data differences.

[0117] Calculation formula:

[0118]

[0119] in:

[0120] h is the distance between the sampling points (called the hysteresis distance).

[0121] Z(x i ) is the data value of sampling point i (eg, magnetic change value).

[0122] N(h) is the number of pairs of sampling points with a spacing of h.

[0123] The variogram curve usually shows the following trend:

[0124] When the distance is smaller, the correlation is stronger and the data values ​​differ less.

[0125] As the distance increases, the correlation decreases and the data values ​​become more different.

[0126] C builds a variogram model

[0127] According to the calculated variation function curve, fit a mathematical model, such as:

[0128] Spherical model; Exponential model; Gaussian model

[0129] Parameters of the variogram model:

[0130] Sill: The maximum value at which the variogram reaches a stable level, representing the variance of the data.

[0131] Range: The distance at which the variogram reaches the sill, indicating the range where spatial correlation disappears.

[0132] Nugget: The variation value at zero distance, indicating measurement error or small-scale variation.

[0133] D Kriging weight calculation

[0134] According to the variogram model, the weight of each sampling point to the interpolation point is calculated. The estimated value of the Kriging interpolation is the weighted average of the sampling point data:

[0135]

[0136] in:

[0137] Z * (x0) is the estimated value of the interpolation point x0.

[0138] λ i is the weight of sampling point i, calculated by the Kriging equations.

[0139] Z(x i ) is the data value of sampling point i.

[0140] The Kriging equations ensure that: the sum of the weights is 1; the interpolation error is minimized.

[0141] Draw the temperature distribution map of the goaf: After calculating the temperature value in the entire goaf grid through Kriging interpolation, the temperature distribution map can be generated.

[0142] Gridded goaf: Divide the goaf into regular grids, with each grid node being an interpolation point. For example, assume the goaf is 100m×100m.

[0143] If a grid is divided every 1m, there are 100\times100=10,000 interpolation points in total.

[0144] Interpolate each grid node: For each node in the grid, use Kriging interpolation to calculate its temperature value based on the geographical location and magnetic variation value of the sampling point.

[0145] Temperature distribution plotting: Visualize the interpolated temperature values ​​as a heat map or isotherm map:

[0146] a. Heat map: temperature values ​​are represented by color gradients (for example, red represents high temperature areas and blue represents low temperature areas).

[0147] b. Isotherm map: Draw contour lines of different temperature values ​​to show the temperature distribution trend.

[0148] Software tools: Use Python's PyKrige or scipy.interpolate library to implement Kriging interpolation; use matplotlib or plotly library to draw heat maps or isotherm maps.

[0149] 2.5 External magnetic field enhancement device

[0150] Objective: To enhance the stability and anti-interference of magnetic signal detection.

[0151] 1) Equipment selection

[0152] Choose between solenoids or Helmholtz coils to generate a uniform magnetic field.

[0153] Power supply options: High-efficiency battery or DC power supply to ensure long-term operation.

[0154] 2) Operation mode

[0155] The external magnetic field device works in conjunction with the data acquisition module:

[0156] Turn on the external magnetic field for a short time before sampling to enhance the signal of magnetic materials.

[0157] After sampling is completed, the magnetic field is turned off to save energy.

[0158] 3. Economic efficiency and cost estimation

[0159] Cost estimation (per point): 100-200 yuan for thermal magnetic materials; 300-500 yuan for data acquisition module; 200-300 yuan for wireless transmission module; 500-1000 yuan for external magnetic field device, total (per point) 1100-2000 yuan. For a goaf with 100 points, the total budget is between 110,000 yuan and 200,000 yuan (excluding R&D costs). The operating costs are mainly electricity and maintenance costs.

[0160] Obviously, the magnetic susceptibility index listed above is only one of the indicators for detecting the magnetism of materials, and the measurement method is only an enumeration of many magnetic measurement methods, which is only a part of the present invention, not all examples. The preferred embodiments of the present invention disclosed above are only used to help explain the present invention, without exhaustively describing all the details. According to the contents of this specification, more modifications and changes can be made. Based on the examples of specific methods in the present invention, all other embodiments and various modifications or supplements obtained by ordinary technicians in this field without making creative work, as long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, belong to the scope of protection of the present invention.

[0161] In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiments and comparative examples. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments in a suitable manner.

Claims

1. A method for detecting and locating high-temperature points in goaf areas based on demagnetization phenomenon, characterized in that: Select a high temperature resistant and highly thermally sensitive magnetic material which has a significant demagnetization effect within a specific temperature range; They are evenly arranged in the goaf of the coal mine, and a data acquisition module is arranged. The magnetic changes of the magnetic material are monitored through the data acquisition module, and the monitoring data is uploaded to the host computer. The host computer analyzes the magnetic changes of the material to determine the temperature changes at the magnetic material and lock the position of the high-temperature point in the goaf.

2. According to claim 1, a method for detecting and locating high-temperature points in goaf areas based on demagnetization phenomenon, characterized in that: The specific method is as follows: Material selection: choose a high temperature resistant and highly sensitive thermomagnetic material that has a significant demagnetization effect within a specific temperature range; Layout planning: According to the geological structure, spatial distribution and possible high-temperature point locations of the goaf, the thermomagnetic materials should be reasonably arranged to ensure comprehensive coverage and uniform distribution; A data acquisition module is provided for each magnetic material to collect magnetic change data of the magnetic material in real time; Data transmission: The collected data is transmitted to the host computer through wired or wireless means for subsequent processing and analysis; Data reception and storage, the host computer receives and stores data from various magnetic materials; Data analysis: analyzing the relationship between magnetic changes and temperature of magnetic materials, and identifying magnetic materials with significant magnetic changes; High temperature point inference: according to the degree and trend of magnetic change, the location, temperature range and change trend of the high temperature point can be inferred; High temperature point positioning: accurately locate the high temperature points in the goaf based on the data analysis results; The early warning mechanism is set up, and the early warning threshold is set. When the temperature of the high-temperature point exceeds the preset threshold, the early warning mechanism is automatically triggered, and relevant personnel are notified in time to take countermeasures.

3. The method for detecting and locating high-temperature points in goaf areas based on demagnetization phenomenon according to claim 1 is characterized in that: The magnetic material is NdFeB magnetic material, NiMnIn alloy or Fe-Ga alloy.

4. The method for detecting and locating high-temperature points in goaf areas based on demagnetization phenomenon according to claim 1 is characterized in that: The data acquisition module is a vibrating sample magnetometer VSM, which is used to measure the magnetization intensity of the sample.

5. The method for detecting and locating high-temperature points in goaf areas based on demagnetization phenomenon according to claim 1, characterized in that: It also includes an external magnetic field device, which generates a magnetic field of specific strength at a specific position. The generated magnetic field covers the magnetic material, and then the magnetic changes of the magnetic material are monitored by the data acquisition module.

6. A method for detecting and locating high-temperature points in goaf areas based on demagnetization phenomenon according to claim 5, characterized in that: The external magnetic field device is a solenoid, a Helmholtz coil, an electromagnet or a MFG-64 series four-pole electromagnet.

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