A strong magnetic temperature early warning device, system and method for fire zone in coal mine goaf

Abstract

The present invention relates to the field of geophysical exploration technology, and specifically discloses a strong magnetic temperature early warning device, system and method for a fire zone in a coal mine goaf area. The temperature sensing execution device of the device is used to generate a linear driving force when the temperature at the observation point reaches the early warning threshold; the strong magnetic controller of the device includes a control brake device, a closed shielding cover and a strong magnet arranged in the closed shielding cover, and the closed shielding cover includes a fixed hemisphere, a rotating hemisphere, and an axis connection mechanism. The rotating hemisphere is movably connected to the fixed hemisphere through the axis connection mechanism. The control brake device is used to convert the linear driving force into torque and act on the axis connection mechanism, so that the rotating hemisphere rotates and closes with the fixed hemisphere to form a closed sphere to shield the strong magnet. The present invention can realize long-term, stable, and external power-free temperature monitoring in the complex and harsh environment of the goaf, and can timely warn of the increase in temperature in the fire zone to ensure the safety of mine operations.

Description

Technical Field

[0001] The invention relates to the technical field of geophysical exploration, and in particular to a strong magnetic temperature early warning device, system and method for a fire zone in a coal mine goaf area. Background Art

[0002] Temperature warning in the fire zone of coal mine goaf is a key link in preventing fire and controlling the development of fire zone. However, the complex geological environment and harsh working conditions of goaf make the existing temperature warning technology face many challenges.

[0003] The sensors of the traditional wired temperature warning system include thermocouples and temperature measuring optical fibers, etc. Such equipment needs to be pre-laid on the coal wall side of the air intake and return airways before the working face is mined. Since the overlying rock layer in the goaf area will collapse after the working face is mined, the collapsed rock will exert huge pressure on the laid sensors and connecting cables, which can easily cause damage to the lines. However, personnel cannot enter the goaf area for maintenance, resulting in the inability to effectively warn the goaf area temperature.

[0004] Although traditional wireless temperature warning devices can avoid wiring problems, these devices rely on built-in batteries to drive and it is difficult to achieve long-term warnings for more than several years. At the same time, the complex geological conditions in the goaf make it difficult for wireless signals to effectively penetrate underground media, resulting in unstable or even interrupted signal transmission.

[0005] Therefore, the existing technology has problems such as line fragility, limited equipment life and signal transmission difficulties in the temperature warning of the fire zone in the coal mine goaf. There is an urgent need for a new device and its warning method that can adapt to high temperature environment and achieve long-term, stable and line-free temperature warning without external power support, so as to improve the reliability and effectiveness of fire zone monitoring. Summary of the invention

[0006] In view of the problems existing in the above-mentioned prior art, the present invention provides a strong magnetic temperature warning device and method for the fire zone in the goaf of a coalfield, which can realize long-term, stable and external power supply-free temperature monitoring in the complex and harsh environment of the goaf, and can timely warn of the increase in temperature in the fire zone to ensure the safety of mine operations. The present invention does not require complicated wiring or maintenance operations and can meet long-term monitoring and warning needs.

[0007] The invention discloses a strong magnetic temperature early warning device for a fire zone in a coal mine goaf, comprising a temperature sensing execution device and a strong magnetic controller, wherein the temperature sensing execution device is used to generate a linear driving force when the temperature at an observation point reaches a warning threshold.

[0008] The strong magnetic controller comprises: a control brake device, a closed shielding cover and a strong magnet arranged in the closed shielding cover. The closed shielding cover comprises: a fixed hemisphere, a rotating hemisphere and an axis connection mechanism. The rotating hemisphere is movably connected to the fixed hemisphere through the axis connection mechanism.

[0009] The control brake device is connected to the temperature sensing actuator and the strong magnetic controller respectively, and is used to convert the linear driving force into torque and act on the shaft connection mechanism, so that the rotating hemisphere rotates and closes with the fixed hemisphere to form a closed sphere to shield the magnetic field signal of the strong magnet.

[0010] Furthermore, the device also includes: a pressure-resistant non-metallic protective cover and a pressure-resistant non-metallic high-temperature resistant protective cover separated by a partition, wherein the temperature-sensing actuator is located in the pressure-resistant non-metallic protective cover, and a plurality of ventilation holes are provided on the side of the pressure-resistant non-metallic protective cover; the strong magnetic controller is located in the pressure-resistant non-metallic high-temperature resistant protective cover, and the inside and outside of the pressure-resistant non-metallic high-temperature resistant protective cover are coated with a high-temperature resistant heat-insulating coating; the partition is provided with a partition hole, and the control braking device passes through the partition hole to connect the temperature-sensing actuator and the strong magnetic controller.

[0011] Furthermore, the temperature sensing actuator is a straight-stroke pneumatic actuator, which is used to control the temperature warning range to 50°C~300°C when purified compressed nitrogen with a pressure of 0.3~0.8Mpa is injected into its cavity.

[0012] Furthermore, the shaft connection mechanism includes a hollow central axis and a rotating axis passing through the central axis. Through holes are respectively provided at the edges of the fixed hemisphere and the rotating hemisphere. The rotating axis passes through the through holes of the fixed hemisphere and the rotating hemisphere, so that the rotating hemisphere is movably connected to the fixed hemisphere. The central axis is respectively connected to the rotating hemisphere and the control braking device to drive the rotating hemisphere to rotate.

[0013] Further, the control brake device includes: a sliding guide device, a push-pull connector, a spring brake rod, a special-shaped gear, a driven gear, a fixing plate, and a control column;

[0014] Wherein, a plate connecting piece is provided on the back of the fixing plate for fixing and connecting with the fixing hemisphere;

[0015] The side surface of the special-shaped gear includes a gear tooth surface and an inclined surface, the inclined surface includes a sliding surface and a limiting surface, one end of the sliding surface is connected to one end of the limiting surface, and the other end of the sliding surface and the other end of the limiting surface are respectively connected to the gear tooth surface;

[0016] An arc-shaped sliding groove is provided on the front of the special-shaped gear, and a control column fixedly arranged relative to the fixed plate is clamped in the sliding groove above the sliding surface to limit the rotation stroke of the special-shaped gear;

[0017] The spring brake rod comprises: a rotating fixed shaft, a brake rod, a spring and a brake head. One end of the brake rod is movably connected to the fixed plate through the rotating fixed shaft, so that the brake rod can rotate in a plane parallel to the fixed plate with the rotating fixed shaft as the rotation center; a spring is arranged in the brake rod, and one end of the brake head inserted into the opening at the other end of the brake rod is connected to the spring, so that the brake head can be extended and retracted along the axial direction of the brake rod, and the other end of the brake head abuts against the sliding surface of the upper special-shaped gear and applies force, and can also slide on the sliding surface with the rotation of the brake rod to change the force application position;

[0018] One end of the push-pull connector is connected to the linear pneumatic actuator for transmitting the push-pull force of the linear pneumatic actuator; the other end of the push-pull connector is provided with a movable groove, the length of which is greater than the diameter of the brake rod, and the movable groove is clamped on the rod body of the brake rod to form a clearance fit structure, so that the brake rod can rotate with the linear push and pull of the push-pull connector;

[0019] The sliding guide device is arranged on the fixed plate, and the push-pull connector is clamped in the sliding guide device to restrict the linear push-pull range of the push-pull connector;

[0020] The driven gear meshing with the gear surface of the special-shaped gear is concentrically connected to the central shaft for driving the central shaft to rotate, and when the rotating hemisphere and the fixed hemisphere of the central shaft are closed, the limiting surface is clamped on the upper side of the sliding guide device.

[0021] Furthermore, the strong magnet is a strong magnetic cylinder, a strong magnetic fixing ring is arranged on the outside of the strong magnetic cylinder, a plurality of ring body connecting pieces are arranged on one side of the strong magnetic fixing ring, and the fixed hemisphere is fixedly connected to the ring body connecting piece;

[0022] A plurality of grooves corresponding to the ring body connecting piece are arranged on the edge of the rotating hemisphere, so that when the rotating hemisphere and the fixed hemisphere are closed, the grooves are snapped into the corresponding ring body connecting piece.

[0023] Furthermore, the fixed hemisphere, the rotating hemisphere and the rotating hemisphere are all Permalloy hemispheres;

[0024] The fixed hemisphere is a double-layer structure, the inner and outer layers of the double-layer structure are the inner hemisphere and the outer hemisphere respectively, the rotating hemisphere is the middle hemisphere, the inner diameter of the middle hemisphere is the outer diameter of the inner hemisphere, and the outer diameter of the middle hemisphere is the inner diameter of the outer hemisphere.

[0025] The present invention also discloses a coal mine goaf fire zone strong magnetic temperature early warning system, the system comprises: the coal mine goaf fire zone strong magnetic temperature early warning device as described above;

[0026] The system also includes: a magnetic anomaly receiver for detecting the magnetic field of the strong magnetic temperature early warning device in the fire area of ​​the coal mine goaf and generating magnetic field data;

[0027] A digital processor is used to determine the abnormal temperature status of the fire zone based on the magnetic field data.

[0028] The present invention also discloses a coal mine goaf fire zone strong magnetic temperature early warning method, which is based on the coal mine goaf fire zone strong magnetic temperature early warning device as described above, and comprises:

[0029] Arrange and debug the strong magnetic temperature early warning device in the fire area of ​​the coal mine goaf;

[0030] Every three days, the magnetic anomaly receiver is moved to different observation points to detect the strong magnetic temperature early warning devices in the fire areas of each coal mine goaf in turn, and the magnetic field value of each observation point is recorded;

[0031] During each measurement, ensure that the magnetic anomaly receiver remains stationary for at least 2 minutes at each observation point, and record the magnetic field data during this period. Analyze the magnetic field data, if the magnetic anomaly value of the strong magnetic temperature warning device in a coal mine goaf fire zone reaches or exceeds 1.2 times the normal value, it is confirmed that the temperature at the corresponding location has exceeded the warning threshold;

[0032] Issue an early warning to take appropriate emergency measures immediately according to the warning level.

[0033] Furthermore, the arrangement and debugging of the coal mine goaf fire zone strong magnetic temperature early warning device includes:

[0034] Setting of trigger threshold temperature T: According to the actual temperature warning threshold requirements of the production mine, the temperature warning threshold is set by injecting purified compressed nitrogen into the cavity of the temperature sensing actuator, and the range is 50°C to 300°C; the pressure of the injected purified compressed nitrogen is linearly related to the warning threshold and satisfies the following formula:

[0035] F=0.002T+0.2;

[0036] Wherein, F is the pressure of purified compressed nitrogen, MPa; T is the warning threshold of temperature, °C.

[0037] Deployment of strong magnetic temperature warning devices in fire zones of coal mine goafs: install one or several strong magnetic temperature warning devices in fire zones of coal mine goafs on the ground of air inlet lanes or return air lanes of the working face of the goafs, and ensure that they face the positions in the side lanes or side goafs where they can be detected by magnetic anomaly receivers; the spacing between strong magnetic temperature warning devices in fire zones of coal mine goafs shall not be less than 40 meters to cover a sufficient area.

[0038] Setting of magnetic anomaly receiver: Place the magnetic anomaly receiver at a position where it can detect the magnetic anomaly signal of the strong magnetic temperature early warning device in the fire zone of the coal mine goaf; the distance between the magnetic anomaly receiver and the strong magnetic temperature early warning device in the fire zone of the coal mine goaf shall not exceed 40 meters to ensure signal strength and accuracy; adjust the position and angle of the magnetic anomaly receiver so that it can detect changes in the magnetic field under optimal conditions.

[0039] Instrument debugging: adjust the push-pull connector in the strong magnetic temperature early warning device in the fire zone of the coal mine goaf to switch the rotating hemisphere inside it between the closed and open states; when in the open state, the strong magnetic temperature early warning device in the fire zone of the coal mine goaf releases a magnetic anomaly signal; when in the closed state, the magnetic field signal is shielded.

[0040] Use a magnetic anomaly receiver to detect the magnetic field change value. If the received magnetic anomaly value is greater than or equal to 1.2 times the normal magnetic value in the closed state, the instrument debugging is confirmed to be successful. Record the position of the strong magnetic temperature warning device in the fire zone of the coal mine goaf and the corresponding magnetic anomaly receiver, and register them with a number; if the instrument debugging fails, adjust the position of the strong magnetic temperature warning device or the magnetic anomaly receiver in the fire zone of the coal mine goaf until it meets the requirements.

[0041] The present invention has at least the following beneficial effects:

[0042] The present invention can realize long-term, stable, and external power-free temperature monitoring in the complex and harsh environment of the goaf, and can timely warn of temperature rise in the fire zone to ensure the safety of mine operations.

[0043] The present invention does not require complicated wiring or maintenance operations, and can adapt to the harsh environment of goaf areas and meet long-term monitoring and early warning needs.

[0044] Other beneficial effects of the present invention will be described in detail in the specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 The invention discloses a structural principle diagram of a strong magnetic temperature early warning device for a fire zone in a coal mine goaf.

[0047] Figure 2 It is a structural diagram of the closed shielding cover disclosed in the present invention in an open state.

[0048] Figure 3It is a structural diagram of the closed state of the closed shielding cover disclosed in the present invention.

[0049] Figure 4 It is a structural principle diagram of the control braking device disclosed in the present invention.

[0050] Figure 5 The utility model is a structural principle diagram of the spring brake rod disclosed by the present invention.

[0051] Figure 6 The invention discloses a schematic diagram of the arrangement structure of a strong magnetic temperature early warning device for a fire zone in a coal mine goaf.

[0052] Among them, 11-pressure-resistant non-metallic protective cover, 12-straight stroke pneumatic actuator, 111-vent, 21-pressure-resistant non-metallic high-temperature resistant protective cover, 22-strong magnetic controller, 2211-strong magnetic fixing ring, 2212-ring body connector, 2213-inner hemisphere, 2214-middle hemisphere, 2215-outer hemisphere, 2216-rotating axis, 2217-middle axis, 222-strong magnetic cylinder, 23-control brake device, 231-sliding guide device, 232-push-pull connector, 233-spring Brake rod, 2331-rotating fixed shaft, 2332-brake rod, 2333-spring, 2334-brake head, 234-special-shaped gear, 2341-sliding surface, 2342-limiting surface, 235-driven gear, 236-fixed plate, 237-plate connecting part, 238-control column, 901-inlet lane, 902-return air lane, 903-side lane, 904-installation position of strong magnetic temperature early warning device, 905-magnetic anomaly receiver observation point, 906-working face, 907-goaf. DETAILED DESCRIPTION

[0053] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0054] Embodiment 1

[0055] like Figures 1 to 5 As shown, this embodiment discloses a strong magnetic temperature warning device for a fire zone in a coal mine goaf, including a temperature sensing actuator and a strong magnetic controller 22, wherein the temperature sensing actuator can be placed at an observation point, and is used to generate a linear driving force when the temperature at the observation point reaches a warning threshold. Preferably, the temperature sensing actuator is a straight-stroke pneumatic actuator 12, which is used to control the temperature warning range to 50°C~300°C when purified compressed nitrogen with a pressure of 0.3~0.8Mpa is injected into its cavity.

[0056] The strong magnetic controller 22 includes: a control brake device 23, a closed shielding cover and a strong magnet arranged in the closed shielding cover, the closed shielding cover includes: a fixed hemisphere, a rotating hemisphere, and an axis connection mechanism, and the rotating hemisphere is movably connected to the fixed hemisphere through the axis connection mechanism. The fixed hemisphere can be a single-layer or multi-layer structure, and the multi-layer structure is conducive to improving the shielding effect. The specific structure is detailed below.

[0057] The control brake device 23 is connected to the temperature sensing actuator and the strong magnetic controller 22 respectively, and is used to convert the linear driving force into torque and act on the shaft connection mechanism, so that the rotating hemisphere rotates and closes with the fixed hemisphere to form a closed sphere to shield the magnetic field signal of the strong magnet. The control brake device can adopt the existing structure or the present invention. Figure 4 The disclosed structure is detailed below.

[0058] In some preferred embodiments of the present invention, the device also includes: a pressure-resistant non-metallic protective cover 11 and a pressure-resistant non-metallic high-temperature resistant protective cover 21 separated by a partition, wherein the temperature-sensing actuator is located in the pressure-resistant non-metallic protective cover 11, and a plurality of ventilation holes 111 are provided on the side of the pressure-resistant non-metallic protective cover 11; the strong magnetic controller 22 is located in the pressure-resistant non-metallic high-temperature resistant protective cover 21, and the inside and outside of the pressure-resistant non-metallic high-temperature resistant protective cover 21 are coated with a high-temperature resistant thermal insulation coating, so that the temperature in the strong magnetic controller 22 is always within 50°C; the partition is provided with a partition hole, and the control braking device 23 passes through the partition hole to connect the temperature-sensing actuator and the strong magnetic controller 22.

[0059] In some preferred embodiments of the present invention, the shaft connection mechanism includes a hollow central axis 2217 and a rotating axis 2216 passing through the central axis 2217. Through holes are respectively provided at the edges of the fixed hemisphere and the rotating hemisphere. The rotating axis 2216 passes through the through holes of the fixed hemisphere and the rotating hemisphere, so that the rotating hemisphere is movably connected to the fixed hemisphere. The central axis 2217 is respectively connected to the rotating hemisphere and the control braking device 23 to drive the rotating hemisphere to rotate.

[0060] In some preferred embodiments of the present invention, the control brake device 23 includes: a sliding guide device 231, a push-pull connector 232, a spring brake rod 233, a special-shaped gear 234, a driven gear 235, a fixing plate 236, and a control column 238.

[0061] A plate connecting piece 237 is provided on the back of the fixing plate 236 for fixing the fixing hemisphere.

[0062] The side surface of the special-shaped gear 234 includes a gear tooth surface and an inclined surface. The inclined surface includes a sliding surface 2341 and a limiting surface 2342. One end of the sliding surface 2341 is connected to one end of the limiting surface 2342, and the other end of the sliding surface 2341 and the other end of the limiting surface 2342 are respectively connected to the gear tooth surface.

[0063] An arc-shaped sliding groove is provided on the front side of the special-shaped gear 234 . A control column 238 fixedly arranged relative to the fixing plate 236 is clamped in the sliding groove above the sliding surface 2341 to limit the rotation stroke of the special-shaped gear 234 .

[0064] The spring brake rod 233 includes: a rotating fixed shaft 2331, a brake rod 2332, a spring 2333 and a brake head 2334. One end of the brake rod 2332 is movably connected to the fixed plate 236 through the rotating fixed shaft 2331, so that the brake rod 2332 can rotate in a plane parallel to the fixed plate 236 with the rotating fixed shaft 2331 as the rotation center; a spring 2333 is provided in the brake rod 2332, and one end of the brake head 2334 inserted into the opening at the other end of the brake rod 2332 is connected to the spring 2333, so that the brake head 2334 can be extended and retracted along the axial direction of the brake rod 2332, and the other end of the brake head 2334 is against the sliding surface 2341 of the upper special-shaped gear 234 and applies force, and can also slide on the sliding surface 2341 as the brake rod 2332 rotates to change the force application position.

[0065] One end of the push-pull connector 232 is connected to the linear pneumatic actuator 12 for transmitting the push-pull force of the linear pneumatic actuator 12; the other end of the push-pull connector 232 is provided with a movable groove, the length of which is greater than the diameter of the brake rod 2332, and the movable groove is clamped onto the rod body of the brake rod 2332 to form a clearance fit structure, so that the brake rod 2332 can rotate with the linear push and pull of the push-pull connector 232. The clearance fit described in this embodiment refers to a fit with a gap, and there is an extra space between the movable groove and the brake rod 2332, so that the brake rod 2332 can have a certain amount of room for movement in the movable groove.

[0066] The sliding guide device 231 is arranged on the fixed plate 236, and the push-pull connector 232 is clamped in the sliding guide device 231 to restrict the linear push-pull range of the push-pull connector 232. The push-pull range includes distance and direction, the direction is the axial direction of the sliding guide device 231, and the longest distance is the rightmost blocked end of the sliding guide device 231.

[0067] The driven gear 235 meshing with the gear surface of the special-shaped gear 234 is concentrically connected to the central axis 2217 for driving the central axis 2217 to rotate, and when the rotating hemisphere driven by the central axis 2217 is closed with the fixed hemisphere, the limiting surface 2342 is clamped on the top of the sliding guide device 231.

[0068] Based on the structure of the above disclosed control brake device 23, it can be known that its characteristic is that the closed shielding cover can only be in the open / closed state, and will not be in the half-open state. Figure 4When the spring brake rod 233 rotates counterclockwise, the upper end of the brake head 2334 thereon contacts the sliding surface 2341 and slides on it from right to left, and the force point gradually moves to the left. However, at this time, due to the existence of the sliding groove and the control column 238 above the sliding surface 2341, the force applied by the brake head 2334 still causes the special-shaped gear 234 to be forced in the counterclockwise direction. At this time, the special-shaped gear 234 does not rotate with the rotation of the spring brake rod 233. Until the spring brake rod 233 rotates counterclockwise and exceeds a certain position on the sliding surface 2341 (for example, the projection position of the midpoint of the sliding groove on the sliding surface 2341), the force point of the special-shaped gear 234 changes so that the special-shaped gear 234 is forced in the clockwise direction. At this time, the special-shaped gear 234 rotates and drives the driven gear 235 to rotate. When the control column 238 slides to the leftmost side of the sliding groove, the special-shaped gear 234 stops rotating. In addition, when the special-shaped gear 234 stops rotating, the limit surface 2342 is connected to the top of the sliding guide device 231, so that the force of the special-shaped gear 234 is balanced and more stable. Those skilled in the art can select the specific specifications and dimensions of each part of the control brake device 23 according to needs, and cooperate with the temperature sensing actuator to set the temperature warning threshold, so that when the temperature is higher than the corresponding warning threshold, the closed shielding cover will open quickly, and when it is lower than the corresponding warning threshold, the closed shielding cover will close quickly to shield the magnetic field signal.

[0069] In some preferred embodiments of the present invention, the strong magnet is a strong magnetic cylinder 222, a strong magnetic fixing ring 2211 is provided on the outside of the strong magnetic cylinder 222, a plurality of ring body connectors 2212 are provided on one side of the strong magnetic fixing ring 2211, and the fixed hemisphere is fixedly connected to the ring body connector 2212.

[0070] A plurality of grooves corresponding to the ring body connector 2212 are provided on the edge of the rotating hemisphere, so that when the rotating hemisphere and the fixed hemisphere are closed, the grooves are snapped into the corresponding ring body connector 2212 .

[0071] In some preferred embodiments of the present invention, the fixed hemisphere, the rotating hemisphere and the rotating hemisphere are all Permalloy hemispheres. Permalloy material is an alloy with high magnetic permeability, usually composed of iron (Fe) and nickel (Ni), and contains a small amount of other elements such as molybdenum or copper. Its key characteristics are high magnetic permeability and low coercivity, which can effectively guide the magnetic field and concentrate it inside itself, thus forming a relatively magnetically shielded area outside it. By making Permalloy into a closed box-like structure or covering it with shielding material, the internal magnetic field can be greatly reduced from entering the area outside the shielding area.

[0072] In some preferred embodiments of the present invention, the fixed hemisphere is a double-layer structure, the inner and outer layers of the double-layer structure are the inner hemisphere 2213 and the outer hemisphere 2215 respectively, and the rotating hemisphere is the middle hemisphere 2214, the inner diameter of the middle hemisphere 2214 is the outer diameter of the inner hemisphere 2213, and the outer diameter of the middle hemisphere 2214 is the inner diameter of the outer hemisphere 2215. When the middle hemisphere 2214 rotates without force, it is located at the same lower part as the inner hemisphere 2213 and the outer hemisphere 2215, and is located between the inner hemisphere 2213 and the outer hemisphere 2215, and the three hemispheres are arranged concentrically. Figure 3 As shown, when the temperature reaches the warning threshold, the middle hemisphere 2214 is forced to flip counterclockwise to the top of the double-layer structure and close to form a closed sphere. At this time, the edge of the left middle hemisphere 2214 is connected to the ring body connector 2212 through the groove to stably support the middle hemisphere 2214 and ensure the sealing effect. Because of the inner and outer diameter setting method of the above three-layer hemisphere, the edge joints of each adjacent layer are sealed, which improves the shielding effect. The advantage of the multi-shielding layer structure is that the signal shielding effect is better and the structure is more stable.

[0073] Embodiment 2

[0074] This embodiment discloses a strong magnetic temperature early warning system for a fire zone in a coal mine goaf. The system comprises: the strong magnetic temperature early warning device for a fire zone in a coal mine goaf as described in the first embodiment, and also comprises: a magnetic anomaly receiver and a digital processor.

[0075] The magnetic anomaly receiver is used to detect the magnetic field of the strong magnetic temperature early warning device in the coal mine goaf fire area and generate magnetic field data. The magnetic anomaly receiver can adopt existing devices, such as proton magnetometer and three-component fluxgate magnetometer.

[0076] A digital processor is used to determine the abnormal temperature status of the fire zone based on the magnetic field data.

[0077] Embodiment 3

[0078] This embodiment discloses a method for early warning of strong magnetic temperature in a fire zone of a coal mine goaf. The method is implemented based on the device for early warning of strong magnetic temperature in a fire zone of a coal mine goaf described in the first embodiment. The method comprises:

[0079] The strong magnetic temperature early warning device in the fire zone of the coal mine goaf is arranged and debugged.

[0080] Every three days, the magnetic anomaly receiver is moved to different observation points to detect the strong magnetic temperature warning devices in the fire areas of each coal mine goaf in turn, and record the magnetic field value of each observation point. This frequency can be flexibly adjusted according to the on-site conditions, but a three-day cycle can ensure that temperature changes are captured in a timely manner.

[0081] During each measurement, ensure that the magnetic anomaly receiver remains stationary for at least 2 minutes at each observation point, and record the magnetic field data during this period. Analyze the magnetic field data, if the magnetic anomaly value of the strong magnetic temperature warning device in a coal mine goaf fire zone reaches or exceeds 1.2 times the normal value, it is confirmed that the temperature at the corresponding location has exceeded the warning threshold. At this time, the area should be monitored more intensively and the measurement frequency should be increased (for example, once a day).

[0082] Issue an early warning to take appropriate emergency measures immediately according to the warning level.

[0083] Preferably, for long-term monitoring and maintenance, all measurement data are recorded and analyzed to determine the temperature trend of the fire area. If the long-term trend shows that the temperature continues to rise, preventive measures should be taken in advance to prevent the fire.

[0084] In some preferred embodiments of the present invention, the arrangement and debugging of the coal mine goaf fire zone strong magnetic temperature early warning device include:

[0085] Setting of trigger threshold temperature T: According to the actual temperature warning threshold requirements of the production mine, the temperature warning threshold is set by injecting purified compressed nitrogen into the cavity of the temperature sensing actuator, and the range is 50°C to 300°C; the pressure of the injected purified compressed nitrogen is linearly related to the warning threshold and satisfies the following formula:

[0086] F=0.002T+0.2;

[0087] Wherein, F is the pressure of purified compressed nitrogen, MPa; T is the warning threshold of temperature, °C.

[0088] like Figure 6 As shown, the arrangement method of the coal mine goaf fire zone strong magnetic temperature warning device disclosed in this embodiment is as follows: one or more coal mine goaf fire zone strong magnetic temperature warning devices (also referred to as strong magnetic temperature warning devices in this embodiment) are installed on the ground of the air inlet tunnel 901 or the return air tunnel 902 of the working face 906 of the goaf 907 (see Figure 6 The strong magnetic temperature early warning device is installed at position 904 in the side tunnel 903 (or the side goaf) and ensured to face the position where the magnetic anomaly receiver can be used for detection; the spacing between the strong magnetic temperature early warning devices is not less than 40 meters to cover a sufficient area.

[0089] Setting of magnetic anomaly receiver: Place the magnetic anomaly receiver at a position where it can detect the magnetic anomaly signal of the strong magnetic temperature warning device (see Figure 6The magnetic anomaly receiver observation point is 905); the distance between the magnetic anomaly receiver and the strong magnetic temperature early warning device is no more than 40 meters to ensure signal strength and accuracy; the position and angle of the magnetic anomaly receiver are adjusted so that it can detect changes in the magnetic field under optimal conditions.

[0090] Instrument debugging: adjust the push-pull connector 232 in the strong magnetic temperature early warning device so that the rotating hemisphere inside it switches between the closed and open states; when in the open state, the strong magnetic temperature early warning device releases a magnetic anomaly signal; when in the closed state, the magnetic field signal is shielded.

[0091] Use a magnetic anomaly receiver to detect the magnetic field change value. If the received magnetic anomaly value is greater than or equal to 1.2 times the normal magnetic value in the closed state, the instrument is confirmed to be debugged successfully. Record the position of the strong magnetic temperature early warning device and the corresponding magnetic anomaly receiver and register them with a number. If the instrument debugging fails, adjust the position of the strong magnetic temperature early warning device or the magnetic anomaly receiver until it meets the requirements.

[0092] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A strong magnetic temperature early warning device for fire areas in coal mine goafs, characterized in that: It includes a temperature sensing actuator and a strong magnetic controller, wherein the temperature sensing actuator is used to generate a linear driving force when the temperature at the observation point reaches a warning threshold; The strong magnetic controller includes: a control brake device, a closed shielding cover and a strong magnet arranged in the closed shielding cover, the closed shielding cover includes: a fixed hemisphere, a rotating hemisphere, and an axis connection mechanism, and the rotating hemisphere is movably connected to the fixed hemisphere through the axis connection mechanism; The control brake device is respectively connected to the temperature sensing actuator and the strong magnetic controller, and is used to convert the linear driving force into torque and act on the shaft connection mechanism, so that the rotating hemisphere rotates and closes with the fixed hemisphere to form a closed sphere to shield the magnetic field signal of the strong magnet; The temperature sensing actuator is a linear pneumatic actuator, which is used to set the temperature warning threshold by injecting purified compressed nitrogen into the cavity of the temperature sensing actuator; the pressure of the injected purified compressed nitrogen is linearly related to the warning threshold and satisfies the following formula: F=0.002T+0.2; Wherein, F is the pressure of purified compressed nitrogen, MPa; T is the warning threshold of temperature, °C.

2. The strong magnetic temperature early warning device for coal mine goaf fire area according to claim 1 is characterized in that: The device also includes: a pressure-resistant non-metallic protective cover and a pressure-resistant non-metallic high-temperature resistant protective cover separated by a partition, wherein the temperature-sensing actuator is located in the pressure-resistant non-metallic protective cover, and a plurality of ventilation holes are provided on the side of the pressure-resistant non-metallic protective cover; the strong magnetic controller is located in the pressure-resistant non-metallic high-temperature resistant protective cover, and the inside and outside of the pressure-resistant non-metallic high-temperature resistant protective cover are coated with a high-temperature resistant heat-insulating coating; the partition is provided with a partition hole, and the control braking device passes through the partition hole to connect the temperature-sensing actuator and the strong magnetic controller.

3. The strong magnetic temperature early warning device for coal mine goaf fire area according to claim 1 is characterized in that: The linear pneumatic actuator is used to control the temperature warning range to 50℃~300℃ when the purified compressed nitrogen with a pressure of 0.3~0.8Mpa is injected into its cavity.

4. The strong magnetic temperature early warning device for coal mine goaf fire area according to claim 1 is characterized in that: The shaft connection mechanism includes a hollow central shaft and a rotating shaft passing through the central shaft. Through holes are respectively provided at the edges of the fixed hemisphere and the rotating hemisphere. The rotating shaft passes through the through holes of the fixed hemisphere and the rotating hemisphere, so that the rotating hemisphere is movably connected to the fixed hemisphere. The central shaft is respectively connected to the rotating hemisphere and the control braking device to drive the rotating hemisphere to rotate.

5. The strong magnetic temperature early warning device for coal mine goaf fire area according to claim 4 is characterized in that: The control brake device includes: a sliding guide device, a push-pull connector, a spring brake rod, a special-shaped gear, a driven gear, a fixing plate, and a control column; Wherein, a plate connecting piece is provided on the back of the fixing plate for fixing and connecting with the fixing hemisphere; The side surface of the special-shaped gear includes a gear tooth surface and an inclined surface, the inclined surface includes a sliding surface and a limiting surface, one end of the sliding surface is connected to one end of the limiting surface, and the other end of the sliding surface and the other end of the limiting surface are respectively connected to the gear tooth surface; An arc-shaped sliding groove is provided on the front of the special-shaped gear, and a control column fixedly arranged relative to the fixed plate is clamped in the sliding groove above the sliding surface to limit the rotation stroke of the special-shaped gear; The spring brake rod comprises: a rotating fixed shaft, a brake rod, a spring and a brake head. One end of the brake rod is movably connected to the fixed plate through the rotating fixed shaft, so that the brake rod rotates in a plane parallel to the fixed plate with the rotating fixed shaft as the rotation center; a spring is arranged in the brake rod, and one end of the brake head inserted into the opening at the other end of the brake rod is connected to the spring, so that the brake head can be extended and retracted along the axial direction of the brake rod, and the other end of the brake head abuts against the sliding surface of the upper special-shaped gear and applies force, and slides on the sliding surface as the brake rod rotates to change the force application position; One end of the push-pull connector is connected to the linear pneumatic actuator to transmit the push-pull force of the linear pneumatic actuator; the other end of the push-pull connector is provided with a movable groove, the length of which is greater than the diameter of the brake rod, and the movable groove is clamped on the rod body of the brake rod to form a clearance fit structure, so that the brake rod rotates with the linear push and pull of the push-pull connector; The sliding guide device is arranged on the fixed plate, and the push-pull connector is clamped in the sliding guide device to restrict the linear push-pull range of the push-pull connector; The driven gear meshing with the gear surface of the special-shaped gear is concentrically connected to the central shaft for driving the central shaft to rotate, and when the rotating hemisphere and the fixed hemisphere of the central shaft are closed, the limiting surface is clamped on the upper side of the sliding guide device.

6. The strong magnetic temperature early warning device for coal mine goaf fire area according to claim 1 is characterized in that: The strong magnet is a strong magnetic cylinder, a strong magnetic fixing ring is arranged outside the strong magnetic cylinder, a plurality of ring body connecting pieces are arranged on one side of the strong magnetic fixing ring, and the fixed hemisphere is fixedly connected with the ring body connecting piece; A plurality of grooves corresponding to the ring body connecting piece are arranged on the edge of the rotating hemisphere, so that when the rotating hemisphere and the fixed hemisphere are closed, the grooves are snapped into the corresponding ring body connecting piece.

7. The strong magnetic temperature early warning device for coal mine goaf fire area according to claim 1 is characterized in that: Fixed hemisphere, rotating hemisphere and both are Permalloy hemisphere; The fixed hemisphere is a double-layer structure, the inner and outer layers of the double-layer structure are the inner hemisphere and the outer hemisphere respectively, the rotating hemisphere is the middle hemisphere, the inner diameter of the middle hemisphere is the outer diameter of the inner hemisphere, and the outer diameter of the middle hemisphere is the inner diameter of the outer hemisphere.

8. A strong magnetic temperature early warning system for fire areas in coal mine goafs, characterized in that: The system comprises: a strong magnetic temperature early warning device for a fire zone in a coal mine goaf as claimed in any one of claims 1 to 7; The system also includes: a magnetic anomaly receiver for detecting the magnetic field of the strong magnetic temperature early warning device in the fire area of ​​the coal mine goaf and generating magnetic field data; A digital processor is used to determine the abnormal temperature status of the fire zone based on the magnetic field data.

9. A strong magnetic temperature early warning method for fire areas in coal mine goafs, characterized in that: The method is implemented based on the coal mine goaf fire zone strong magnetic temperature early warning device according to any one of claims 1 to 7, and the method comprises: Arrange and debug the strong magnetic temperature early warning device in the fire area of ​​the coal mine goaf; Every three days, the magnetic anomaly receiver is moved to different observation points to detect the strong magnetic temperature early warning devices in the fire areas of each coal mine goaf in turn, and the magnetic field value of each observation point is recorded; During each measurement, ensure that the magnetic anomaly receiver remains stationary for at least 2 minutes at each observation point, and record the magnetic field data during this period; analyze the magnetic field data, and if the magnetic anomaly value of the strong magnetic temperature early warning device in a coal mine goaf fire zone reaches or exceeds 1.2 times the normal value, it is confirmed that the temperature at the corresponding location has exceeded the early warning threshold; Issue an early warning to take appropriate emergency measures immediately according to the warning level.

10. The coal mine goaf fire zone strong magnetic temperature early warning method according to claim 9, characterized in that: The arrangement and debugging of the coal mine goaf fire zone strong magnetic temperature early warning device include: Setting of trigger threshold temperature T: According to the actual temperature warning threshold requirements of the production mine, the temperature warning threshold is set by injecting purified compressed nitrogen into the cavity of the temperature sensing actuator, and the range is 50°C to 300°C; the pressure of the injected purified compressed nitrogen is linearly related to the warning threshold and satisfies the following formula: F=0.002T+0.2; Wherein, F is the pressure of purified compressed nitrogen, MPa; T is the temperature warning threshold, °C; Installation of strong magnetic temperature warning devices in the fire zone of coal mine goaf: install one or several strong magnetic temperature warning devices in the fire zone of coal mine goaf on the ground of the air inlet lane or return air lane of the working face of the goaf, and ensure that they face the position detected by magnetic anomaly receivers in the side lanes or side goafs; the distance between strong magnetic temperature warning devices in the fire zone of coal mine goaf shall not be less than 40 meters to cover a sufficient area; Setting of magnetic anomaly receiver: Place the magnetic anomaly receiver at the position where the magnetic anomaly signal of the strong magnetic temperature early warning device in the fire area of ​​the coal mine goaf is detected; the distance between the magnetic anomaly receiver and the strong magnetic temperature early warning device in the fire area of ​​the coal mine goaf should not exceed 40 meters to ensure the signal strength and accuracy; adjust the position and angle of the magnetic anomaly receiver so that it can detect the change of the magnetic field under the best conditions; Instrument debugging: Adjust the push-pull connector in the coal mine goaf fire zone strong magnetic temperature early warning device to switch the rotating hemisphere inside it between the closed and open states; when in the open state, the coal mine goaf fire zone strong magnetic temperature early warning device releases a magnetic anomaly signal; when in the closed state, the magnetic field signal is shielded; Use a magnetic anomaly receiver to detect the magnetic field change value. If the received magnetic anomaly value is greater than or equal to 1.2 times the normal magnetic value in the closed state, the instrument debugging is confirmed to be successful. Record the position of the strong magnetic temperature warning device in the fire zone of the coal mine goaf and the corresponding magnetic anomaly receiver, and register them with a number; if the instrument debugging fails, adjust the position of the strong magnetic temperature warning device or the magnetic anomaly receiver in the fire zone of the coal mine goaf until it meets the requirements.

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