Direct insertion type in-situ cooperative treatment device and method for polluted soil in fire area of coal field

Abstract

The invention discloses a coal field fire area polluted soil direct insertion type in-situ cooperative processing device and method.The device comprises a drilling barrel, a guide pipe component and an induction unit, and the guide pipe component is located in the drilling barrel and driven to move; the first guide pipe is used for injecting slurry, the third guide pipe is used for injecting liquid nitrogen, the second guide pipe is used for microwave heating, and the fourth guide pipe is used for exhausting; the sensing unit is used for measuring the temperature of a target area and the concentration of pollution gas; the control unit is used for receiving a measurement signal of the sensing unit and controlling microwave power, liquid nitrogen injection and slurry injection parameters of the radiation emission assembly; when the guide pipe part is close to the bottom end of the drill barrel, the corresponding guide pipe can communicate with the outer side of the drill barrel. According to the device, microwave heating can be conducted on a target area, organic pollutants are treated, rapid cooling and plugging of the target area are completed, the problem of reburning is avoided, and mutual coordination action of microwave power, liquid nitrogen injection and slurry injection parameters is achieved.

Description

Technical Field

[0001] This invention relates to coal fire soil pollution treatment technology, belonging to the field of coalfield fire zone combustion treatment, specifically to a direct-insertion in-situ co-treatment device and method for coalfield fire zone contaminated soil. Background Technology

[0002] my country's coal-rich areas have long faced the severe challenge of coal seam spontaneous combustion. Coalfield fires not only cause enormous waste of resources and serious ecological damage, but their combustion process also generates complex soil organic pollution problems. Persistent organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) and benzene series compounds (BTEX) seep into and accumulate in the soil under high temperatures, posing a long-term threat to regional soil safety and human health. Existing research and practice are highly focused on fire extinguishing and cooling itself, that is, injecting water (water mist), three-phase foam, gel foam, etc. into the fire area through the ground or boreholes to extinguish fire and cool it. Although these technologies can control the fire to a certain extent, they belong to a single fire extinguishing dimension and completely ignore the soil pollution problem caused by high-temperature combustion in the fire area. That is, after the fire is extinguished, pollutants remain in the soil, forming potential ecological risk sources. These pollutants are mainly volatile organic compounds, semi-volatile organic compounds, polycyclic aromatic hydrocarbons (PAHs), and even some persistent organic pollutants that are difficult to degrade. Conventional soil pollution remediation technologies mainly include chemical activation methods such as chemical oxidation and leaching, and physical technologies such as ex-situ thermal desorption. However, these technologies have certain drawbacks when applied to the special scenario of coalfield fire zones. For example, chemical methods may introduce secondary pollutants and alter soil properties, raising questions about their applicability and long-term effectiveness. Physical technologies such as ex-situ thermal desorption require excavation and transportation, resulting in complex construction, high costs, and a high risk of disrupting the stability of the fire zone, leading to air leakage and reignition. Furthermore, when combining fire prevention and reignition control with soil pollution remediation, it is difficult to achieve synergistic treatment. For instance, when using physical technologies such as thermal desorption, heat is conducted from the outside in, controllably heating the soil to a specific temperature and maintaining it for a certain time to ensure sufficient desorption of pollutants. This process is slow and time-consuming, while preventing coal seam combustion requires rapidly reducing soil temperature. The two treatment methods are difficult to coordinate, and the alternation of heat and cold may create micro-cracks, leading to numerous harmful fissures in the soil and rocks. Summary of the Invention

[0003] The purpose of this invention is to provide a direct-insertion in-situ co-treatment device for contaminated soil in coalfield fire zones. This device can not only heat the target area internally with microwaves to treat organic pollutants, but also rapidly cool and seal the target area to prevent reignition. It achieves synergistic action among microwave power, liquid nitrogen injection, and slurry injection parameters.

[0004] To achieve the above objectives, a direct-insertion in-situ co-treatment device for contaminated soil in coalfield fire zones includes: Processing unit, having A drill barrel is constructed for drilling operations and has a hollow internal structure. The conduit assembly, located inside the drill barrel cavity and driven to move along the drill barrel axis, has a first conduit connected to a grouting source for injecting grout into the target area, a third conduit connected to a liquid nitrogen source for injecting liquid nitrogen into the target area, a fourth conduit connected to a negative pressure source for discharging gas from the target area, and a second conduit with a radiation emission component inside, the radiation emission component being used to generate microwaves for staged heating of the target area. The sensing unit is used to measure the temperature and concentration of organic pollutants in the target area; The control unit receives measurement signals from the sensing unit and controls the microwave power, liquid nitrogen injection and slurry injection parameters, and exhaust opening and closing of the radiation emission component. The bottom of the drill barrel is provided with a through hole corresponding to the corresponding guide tube, and a sealing assembly is provided at each through hole. When the guide tube component is far away from the extreme position of the bottom of the drill barrel, the sealing assembly closes the through hole. When the guide tube component is close to the extreme position of the bottom of the drill barrel, the sealing assembly opens the through hole and makes the corresponding guide tube communicate with the outside of the drill barrel.

[0005] In some examples of the present invention, the sealing assembly has: The first cylindrical body is fixedly installed inside the through hole; The second cylinder is sealed and movable, connected to the first cylinder; the lower circumference of the second cylinder is provided with a slotted hole that is closed at the lower end. The elastic element causes the second cylinder to be subjected to an elastic force away from the through hole; under the elastic action and when the conduit component is not in contact with the second cylinder, the slot is closed by the inner wall of the first cylinder; when the conduit component moves downward and compresses the elastic element, the corresponding conduit connects with the second cylinder and squeezes the second cylinder to move so that the slot is located outside the first cylinder.

[0006] In some examples of the present invention, a disc is connected to both the upper and lower ends of the second cylinder; Under elastic action and when the guide tube component does not contact the second barrel, the lower disc does not extend beyond the bottom end of the drill barrel; The lower part of the conduit component is provided with a ring, the outer diameter of which is larger than the inner diameter of the second cylinder; the outer diameter of the corresponding conduit is smaller than the inner diameter of the second cylinder so that the corresponding conduit is inserted and connected to the second cylinder.

[0007] In some examples of the present invention, the outer side of the upper end of the drill barrel is rotatably mounted on the support platform and driven to rotate by a drive assembly, and the inner side of the upper end is rotatably connected to the support plate. The conduit assembly is fixedly connected to the lifting platform, and the lifting platform is circumferentially limited and axially moved by the support plate; or: The corresponding conduits in the conduit assembly are connected to the lifting platform respectively. Each lifting platform is circumferentially limited by the support plate and is driven to move axially.

[0008] In some examples of the present invention, the first guide tube, the second guide tube, and the third guide tube are evenly arranged circumferentially with the drill barrel axis as the center. The upper end of the drill barrel is equipped with an indicator corresponding to the position of the through hole. The lifting platform is equipped with an indicator sensor that identifies the indicator. The indicator sensor is connected to the control unit, and the control unit controls the operation of the drive component.

[0009] A method for treating contaminated soil in coalfield fire zones using a direct-insertion in-situ co-treatment device specifically includes the following steps: In some examples of the present invention, S1, the target area of ​​the coalfield fire zone is determined by exploration, the drill pipe is placed on top, and the drill pipe is driven to drill to the target depth; S2, after drilling reaches the target depth, the soil temperature and organic pollutant concentration data of the target area are monitored and acquired through the sensing unit; When the guide tube assembly inside the drill barrel is driven to move axially toward the bottom of the drill barrel to its limit position, the bottom of the drill barrel opens, allowing the corresponding guide tube to connect with the outside of the drill barrel. S3, when the concentration of organic pollutants is detected to meet the treatment concentration, the control unit controls the radiation emission component to start and emit microwaves to heat the target area. The heating includes: the first stage and the second stage. In the first stage, the soil is heated evenly to 50-150℃ using low power, causing easily decomposable organic pollutants to volatilize; in the second stage, the soil temperature is raised to 200-500℃ using high power, causing poorly soluble organic pollutants in the soil to volatilize. During microwave heating, the control unit controls the discharge of organic pollutant gases through the fourth conduit; S4, when the concentration of organic pollutants is detected to be lower than the set concentration, the fourth conduit is closed to stop venting, the control unit controls liquid nitrogen to enter the third conduit and discharge it from the lower end of the third conduit to the outside of the drill barrel to cool the target area with liquid nitrogen; S5, repeat steps S3 and S4, the "heating-cooling" cycle causes the organic pollutants to "break down" and fall off the soil matrix; when the concentration of organic pollutants is detected to be at a safe level and the temperature is lower than the first set temperature, the control unit controls the slurry to enter the first conduit and discharge it from the lower end of the first conduit to the outside of the drill tube, and performs pulse sudden grouting on the target area. S6, when the temperature of the target area continues to drop to the second set temperature, stop grouting, nitrogen injection and shut down the radiation emission component; the guide tube component is driven axially away from the bottom of the drill barrel and the bottom of the drill barrel is closed; finally, move to the next target area and repeat steps S1 to S4; In step S4, the control unit continuously monitors the temperature and controls the microwave power, liquid nitrogen, and grout injection parameters of the radiation emission component to maintain the temperature gradient. Located at 12-20℃ / min.

[0010] In some examples of the present invention, in step S5, the formula for calculating the temperature gradient is: in, , These are parameter constants; For microwave power, This refers to the amount of liquid nitrogen injected. This represents the tensile strength of the soil as it changes over time.

[0011] In some examples of the present invention, during the process of the control unit controlling the microwave power of the radiated emission component, when At this time, the control unit controls the microwave power of the radiating emission component to be in a low-power state; Let be the dielectric constant, and its calculation formula is: The loss factor is calculated using the following formula: in, The incident power of the radiating emission component, This is the reflected power; , concentration of organic pollutants With temperature Correction factor under coupling.

[0012] In some examples of the present invention, the , The specific steps to obtain it are as follows: For coalfield fire zones, pre-amplification sampling measurements were performed to measure the incident power in n groups. With reflected power And record the temperature under each measurement condition. and organic pollutant concentration Calculate the dielectric constant and loss factor for each group: In the laboratory, researchers determined the n sets of temperatures under the device. and organic pollutant concentration Simulations were performed separately to obtain n different experimental groups. The dielectric constant of the following With loss factor ; Then obtain the correction factor for each group: The correction factors of group n , Perform fitting, and then... , As this device is used at different concentrations of organic pollutants With temperature Correction factor under coupling.

[0013] In some examples of the present invention, in step S4, the pulse sudden grouting is performed as follows: grouting is initially performed at a pressure in the range of 0.7MPa-1.0MPa, and the pressure is increased by 0.5MPa in a step over 2 minutes until the maximum pressure reaches 2.5MPa.

[0014] Compared with existing technologies, this direct-insertion in-situ co-treatment device for contaminated soil in coalfield fire areas allows the guide tube component to move axially after drilling, connecting one end to the outside of the drill tube. This enables microwave heating and venting of the target area to treat organic pollutants. Simultaneously, nitrogen injection and grouting are used to rapidly cool and seal the target area, preventing reignition. The control unit controls microwave power, liquid nitrogen injection and grouting parameters, and venting closure, achieving coordinated operation. During drilling, the sealing assembly seals the bottom of the drill barrel, effectively preventing soil and other impurities from entering the drill barrel. When the guide tube component moves axially to open its sealing assembly, the corresponding guide tube is inserted into the second barrel to achieve a seal between them, preventing the corresponding medium from entering the drill barrel in reverse during the injection process. This method uses direct-insertion microwave heating to achieve precise energy delivery and efficient targeted treatment of deep-seated pollution. It is simple to construct and low in cost, and can directly eradicate organic pollutants in the soil, eliminating the risk of secondary pollution. Liquid nitrogen rapid cooling achieves rapid cooling of the target area, avoiding the problems of slow cooling and easy reignition of traditional thermal desorption technology. Liquid nitrogen cooling of the target area causes differential shrinkage of pollutants and soil particles, fatigue and cracking of firmly attached pollutants, which are then peeled off from the soil surface. The multiple cycles of heating and cooling allow organic pollutants to completely disintegrate and detach from the soil matrix, achieving full release and removal of organic pollutants and resulting in better treatment effects. In this method, the control unit continuously controls the microwave power of the radiation emission component, liquid nitrogen, and grouting injection parameters. Through the synergistic processing of these three factors, the cooling gradient is met, avoiding excessive temperature drop that could cause a large number of harmful cracks in the soil and rock. At the same time, the grout can penetrate into the micropores and the liquid nitrogen quenching prevents the formation of new cracks, thus achieving all-round filling. Attached Figure Description

[0015] Figure 1 This is an overall front view of the device of the present invention; Figure 2 This is a front view of the conduit component in the device of the present invention when it is pressed and moved against the second cylinder; Figure 3 This is an exploded view of the sealing assembly and drill barrel assembly in the device of the present invention; Figure 4 This is an exploded view of the sealing assembly in the device of the present invention; Figure 5 This is a simplified top view diagram showing the matching of the identification sensor and the identification element in the device of the present invention; Figure 6 This is a flowchart of the method of the present invention; In the diagram: 10. Drill barrel; 11. Drive assembly; 12. Through hole; 21. Support platform; 22. Lifting platform; 23. Support plate; 30. Sealing assembly; 31. First cylinder; 32. Second cylinder; 321. Slot; 322. Flared structure; 33. Elastic element; 40. First catheter; 50. Second conduit; 51. Radiation head; 60. Third catheter; 71. Identification sensor; 72. Identification component; 80. Fourth catheter. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “an” or “a” and similar terms do not necessarily indicate a quantity limitation. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0018] like Figure 1 , Figure 2 , Figure 3 As shown, this is a direct-insertion in-situ co-treatment device for contaminated soil in coalfield fire areas, comprising: Processing unit, having The drill barrel 10 is configured for drilling operations and has an internal cavity structure. The conduit assembly, located within the cavity of the drill barrel 10 and driven to move along the axis of the drill barrel 10, has a first conduit 40 connected to a grouting source for injecting grout into the target area, a third conduit 60 connected to a liquid nitrogen source for injecting liquid nitrogen into the target area, a fourth conduit 80 connected to a negative pressure source for discharging gas from the target area, and a second conduit 50 internally equipped with a radiation emission component for generating microwaves to perform staged heating of the target area; The sensing unit is used to measure the temperature and concentration of organic pollutants in the target area; The control unit receives measurement signals from the sensing unit and controls the microwave power, liquid nitrogen injection and slurry injection parameters, and exhaust opening and closing of the radiation emission component. The bottom end of the drill barrel 10 is provided with a through hole 12 corresponding to the corresponding guide tube, and a sealing assembly 30 is provided at each through hole 12; when the guide tube component is far away from the extreme position of the bottom end of the drill barrel 10, the sealing assembly 30 closes the through hole 12; when the guide tube component is close to the extreme position of the bottom end of the drill barrel 10, the sealing assembly 30 opens the through hole 12 and makes the corresponding guide tube communicate with the outside of the drill barrel 10. Specifically, the drill barrel 10 is threaded on its periphery and bottom to facilitate drilling into different geological conditions, or is inlaid with hard alloy drill bits for breaking soil and rock, thus opening a passage for the device to enter the coalfield fire zone. The conduit components move along the axis of the drill barrel 10. The first conduit 40 is used for injecting grout, i.e., the grouting source consists of a grout mixing tank, a high-pressure plunger pump, a delivery pipeline, a pressure control valve, etc. The first conduit 40 can be lined with a polytetrafluoroethylene (PTFE) anti-adhesion layer for storing and pumping consolidation and sealing grout. The second conduit 50 is a microwave channel for protecting the radiation emission assembly inside. The radiation emission assembly includes a microwave generator, a waveguide, and a silicon carbide ceramic-encapsulated radiator head 51. The waveguide has an alloy substrate, an outer wall composite zirconium nitride anti-oxidation coating, and an internally integrated directional coupler and receiving antenna, with a measurement accuracy of ±2℃ (0-1200℃ range). The radiation emission assembly can realize a dual-band adaptive microwave power source, i.e., containing 915MHz... The industrial microwave module and 2.45GHz magnetron array offer a continuously adjustable total power output range of 5-50kW, with a dual-band switching response time of <0.5s. Penetration depth or heating efficiency can be selected based on soil dielectric properties to meet various application requirements. The third conduit 60 is used for injecting liquid nitrogen; the liquid nitrogen source consists of a cryogenic storage tank, cryogenic booster pump, insulated delivery pipeline, flow control valve, etc., providing the cryogenic working fluid for liquid nitrogen injection into the third conduit 60. The fourth conduit 80 is the exhaust pipe, used to discharge heated gas and water vapor. The negative pressure source includes a vacuum pump, gas collection hood / pipeline, condenser separator, exhaust gas purification device, and gas flow and concentration sensors. The vacuum pump provides system negative pressure, and the pumping rate is adjustable (10-50m). 3 / h); Gas collection hood / pipeline is used to collect the gas generated during the treatment process; Condensation separator is used to cool high-temperature gas and separate and recover liquid pollutants (such as water and organic droplets); Tail gas purification device can be activated carbon adsorption tank or catalytic oxidizer, used to treat non-condensable harmful gases (such as VOCs and CO) to achieve emission standards; A main control valve that is controlled to open and close by the control unit can be installed at the outer end of the fourth conduit 80. The sensing unit includes a distributed fiber optic temperature measurement array, a temperature sensor, and a concentration collector. The temperature sensor can be installed on the inner wall of the drill barrel 10 and transmit information wirelessly or via an electric slip ring. The distributed fiber optic temperature measurement array is located in the coalfield fire zone and works in conjunction with the temperature sensor to obtain the soil temperature field around the borehole. The concentration collector is used to obtain the concentration of organic pollutants. In soil, the concentration of organic pollutants includes the concentration of organic pollutant gas in the soil and the concentration of organic pollutants attached to the soil. The concentration of organic pollutants attached to the soil can be obtained by sampling through sampling units. The sampling units are located near the drill barrel 10, for example, at intervals of 1m. As an example of soil sampling, the sampling unit includes a drill rod, a soil sampling tube, and a spiral rod. The drill rod is adjacent to the drill barrel 10 and extends synchronously to the target depth. The drill rod has a hollow structure inside. The soil sampling tube is coaxially located inside the hollow drill rod. The spiral rod is located inside the soil sampling tube and can be driven to rotate, extending into the soil below. Soil sampling is achieved by spiral rotation. Alternatively, the sampling unit includes a drill rod, a soil sampling rod, and a sampling slider. The soil sampling rod is driven to move and connected inside the drill rod, and is connected to the radially moving sampling slider through a movable connecting rod. Initially, both the soil sampling rod and the sampling slider follow the rotation of the drill rod to the target area. When the soil sampling rod is driven to move towards the bottom of the borehole, the connecting rod drives the driving slider to extend radially to perform soil sampling. The concentration of organic pollutant gases in the soil can be obtained by exhausting gases through an exhaust pipe. On one hand, the exhaust pipe can be set at the treatment unit, i.e., exhausting through the fourth conduit 80. On the other hand, the exhaust pipe can be set at the sampling unit, i.e., the sampling unit also includes an exhaust pipe connected to a negative pressure source for exhausting gases to the target area. One end of the exhaust pipe is located inside the drill rod. When soil is sampled, the inside of the borehole is connected to the outside, and the gas can be directly output through the exhaust pipe. The concentration collector can monitor the gas extraction efficiency and changes in pollutant concentration. The control unit receives and processes data streams from temperature and organic pollutant concentration in real time. Through the built-in collaborative optimization analysis module, it outputs collaborative control commands for microwave power, liquid nitrogen injection and slurry injection parameters, and exhaust opening and closing, so as to achieve adaptive processing. The main parameters of liquid nitrogen injection and slurry injection are injection volume, and injection pressure and injection speed are also included to ensure injection effect, so as to facilitate reasonable temperature reduction and filling of target area. The sealing assembly 30 can open and close the bottom end of the drill barrel 10. For example, when drilling, the sealing assembly 30 closes the bottom end of the drill barrel 10 to prevent soil from entering the drill barrel 10 during drilling. When the guide pipe component moves close to the bottom end of the drill barrel 10, the sealing assembly 30 opens the bottom end of the drill barrel 10 so that the corresponding guide pipe can be connected to the outside of the drill barrel 10 through the sealing assembly 30. This type of direct-insertion in-situ co-treatment device for contaminated soil in coalfield fire areas can be installed on a mobile vehicle. First, the core location of the coalfield fire area is confirmed based on the exploration results. The drill pipe 10 is moved above the target area. In the initial state, the guide pipe component is away from the bottom of the drill pipe 10, and the sealing component 30 seals the bottom of the drill pipe 10 to prevent soil from entering during the drilling process. The drill pipe 10 is then driven to drill to the target depth. After drilling reaches the target depth, the current temperature and organic pollutant concentration distribution data of the area are monitored and obtained through the sensing unit, and the combustion status and pollution range of the fire zone can be preliminarily assessed based on the monitoring data. When the target depth is reached, the drill barrel 10 stops drilling, and the guide pipe assembly is driven to move. This movement causes the corresponding guide pipe to move synchronously or individually along the axis of the drill barrel 10 towards the bottom sealing assembly 30. When the guide pipe assembly moves to a certain position, the sealing assembly 30 is opened. This opening allows the corresponding guide pipe to communicate with the outside of the drill barrel 10, that is, slurry or liquid nitrogen can be discharged from the corresponding guide pipe located outside the drill barrel 10, and gas can be discharged from the fourth guide pipe 80. When the sensing unit detects that the concentration of organic pollutants exceeds the set concentration, that is, when either the concentration of organic pollutant gas in the soil or the concentration of organic pollutants attached to the soil exceeds the standard, the control unit controls the radiation emission component to start heating the target area. That is, the microwave emitted by the microwave transmitter is emitted from the radiation head 51 through the waveguide, so that the soil has a large amount of heat under microwave radiation, which can weaken the adsorption force between pollutants and soil particles. A two-stage gradient irradiation strategy is adopted to melt heavy component pollutants (such as tar), increase fluidity, and peel them off from the soil pores, thus completing the treatment of organic pollutants in the soil. During microwave heating, the fourth conduit at end 80 is open, and the negative pressure source can quickly extract the volatilized organic pollutants, water vapor, etc., to prevent them from recondensing in the pores or spreading to the surrounding area. The pressure difference formed can become an additional driving force for the migration of pollutants to the collection point, accelerating the precipitation and removal process of deep pollutants. Continuous air extraction maintains the anaerobic environment and effectively prevents pollutants from burning at high temperatures. During the gas discharge process of the fourth conduit 80, when the sensing unit detects that the concentration of organic pollutants is lower than the set concentration, the control unit controls the closure of the fourth conduit 80 and then controls the liquid nitrogen to enter the third conduit 60, and discharges it from the lower end of the third conduit 60 to the outside of the drill barrel 10 to cool the target area with liquid nitrogen. This process utilizes the difference in shrinkage rate between organic pollutants and soil particles to generate shear stress, causing the pollutants to "disintegrate" and fall off from the soil matrix. Then, the injection of liquid nitrogen is stopped, completing one "heating-cooling" cycle. Then, microwave heating is performed again. Because the previous cycle has destroyed the physical structure of organic pollutants and soil, this heating can more efficiently migrate deep residual pollutants to the surface, and can fully release and remove organic pollutants. After multiple cycles, when the sensing unit detects that the concentration of organic pollutants is at a safe level and the temperature is below the first set temperature, the control unit synchronously controls the slurry to enter the first conduit 40 to fill the target area. During the temperature drop process, the control unit adjusts the temperature drop gradient. That is, based on the temperature monitoring by the sensing unit, the control unit controls the microwave power of the radiation emission component and the liquid nitrogen injection parameters to achieve precise closed-loop control of the process. The purpose is to avoid excessively rapid cooling that could cause a large number of harmful cracks in the soil and rock. During the grouting process, by controlling the slurry injection parameters, the slurry penetrates into the micropores formed by microwave thermal melting and the new cracks prevented by liquid nitrogen rapid cooling, achieving all-round filling. When the temperature continues to drop to the second set temperature, grouting and nitrogen injection are stopped, and the radiation emission components are shut off. The guide tube is moved axially away from the bottom of the drill barrel 10, and the sealing component 30 re-seals the bottom of the drill barrel 10. The drill barrel 10 is then raised or lowered to the next treatment layer, and the above steps are repeated until the entire contaminated area is treated. Finally, after inspection confirms that the temperature and pollutant indicators of the coalfield fire area meet the standards, the borehole is sealed.

[0019] In some examples of the present invention, such as Figure 2 , Figure 3 , Figure 4 As shown, the sealing assembly 30 has: The first cylindrical body 31 is fixedly installed inside the through hole 12; The second cylinder 32 is connected to the first cylinder 31 in a sealed and movable manner; the lower circumferential side of the second cylinder 32 is provided with a slot 321 and the lower end is closed; The elastic element 33 causes the second cylinder 32 to be subjected to an elastic force away from the through hole 12; under the elastic action and when the conduit component is not in contact with the second cylinder 32, the slot 321 is closed by the inner wall of the first cylinder 31; when the conduit component moves downward and compresses the elastic element 33, the corresponding conduit connects with the second cylinder 32 and squeezes the second cylinder 32 to move so that the slot 321 is located outside the first cylinder 31. Specifically, the drill barrel 10 has three through holes 12 at the bottom, and the first barrel 31 can be fixedly installed by bolts or other means; The second cylinder 32 moves axially and connects to the first cylinder 31, and is slidably sealed by a sealing assembly. The slot 321 at the bottom of the second cylinder 32 is used to connect the corresponding guide tube to the outside of the drill barrel 10, and the bottom end is closed to prevent the initial drilling soil from entering the drill barrel 10. One end of the elastic element 33 contacts the upper end of the second cylinder 32 and the other end contacts the first cylinder 31, so that the second cylinder 32 bears the elastic force away from the through hole 12. In this example, in the initial state, under the action of the elastic element 33, the second cylinder 32 is located at the extreme position far away from the through hole 12, and the slot 321 is closed by the inner wall of the first cylinder 31. When the guide tube component moves downward and contacts the second cylinder 32, the elastic element 33 is compressed, and the slot 321 is located outside the first cylinder 31. At this time, the corresponding guide tube is connected to the outside of the drill barrel 10 through the slot 321. Furthermore, such as Figure 3 , Figure 4 As shown, the upper and lower ends of the second cylinder 32 are both connected to a disc; Under elastic action and when the guide tube component does not contact the second cylinder 32, the lower disc does not extend beyond the bottom end of the drill barrel 10; The lower part of the conduit component is provided with a ring, the outer diameter of which is larger than the inner diameter of the second cylinder 32; the corresponding outer diameter of the conduit is smaller than the inner diameter of the second cylinder 32 so that the corresponding conduit is inserted into the second cylinder 32. Specifically, the second cylinder 32 has an "I"-shaped cross-section, which limits the movement of the second cylinder 32. The lower plate is detachable to ensure assembly. The ring at the bottom of the guide tube component is used to contact the upper plate to drive the second cylinder 32 to move. The through hole 12 can be a stepped hole, and the thickness of the stepped hole is greater than that of the lower plate, so that the lower plate can be hidden in the through hole 12, that is, the lower plate does not exceed the bottom end of the drill tube 10. At this time, it does not affect the bottom end of the drill tube 10 from contacting the soil for drilling. The corresponding guide tube is inserted into the second cylinder 32. This insertion can ensure a seal, so that the medium cannot enter the drill tube 10 in reverse during the injection process.

[0020] In some examples of the present invention, such as Figure 1 As shown, the drill barrel 10 is rotatably mounted on the support platform 21 on the outer side of its upper end and driven to rotate by the drive assembly 11, and is rotatably connected to the support plate 23 on the inner side of its upper end. The conduit assembly is fixedly connected to the lifting platform 22, and the lifting platform 22 is circumferentially limited and driven to move axially; or: The corresponding conduits in the conduit assembly are respectively connected to the lifting platform 22. Each lifting platform 22 is circumferentially limited by the support plate 23 and is driven to move axially. Specifically, the drill barrel 10 can be rotatably mounted on the support platform 21 via bearings, and the support platform 21 can be supported by a moving vehicle body; the drive assembly 11 can be a drilling motor, a drive wheel mounted on the output end of the drilling motor, and a driven wheel mounted on the drill barrel 10. The drive wheel is connected to the driven wheel through a transmission assembly to realize the drilling action of the drill barrel 10. The support plate 23 is connected to the drill barrel 10 by bearings to ensure that the guide tube component does not rotate with the drill barrel 10 during the drilling process. The lifting platform 22 can be connected to the support plate 23 by a key to ensure that the lifting platform 22 can drive the guide tube component to move axially. As an example, the conduit assembly is fixedly connected to the lifting platform 22. When the lifting platform 22 moves, it can drive the first conduit 40, the second conduit 50 and the third conduit 60 to move axially in unison. As another example, the first conduit 40, the second conduit 50, and the third conduit 60 are respectively connected to the support plate 23 via the lifting platform 22, and each conduit can move axially individually via the corresponding lifting platform 22.

[0021] In some examples of the present invention, such as Figure 5 As shown, with the axis of the drill barrel 10 as the center, the first guide tube 40, the second guide tube 50, and the third guide tube 60 are evenly arranged circumferentially; The upper end of the drill barrel 10 is provided with an identifier 72 corresponding to the position of the through hole 12. The lifting platform 22 is provided with an identifier sensor 71 that identifies the identifier 72. The identifier sensor 71 is connected to the control unit, and the control unit controls the action of the drive assembly 11. Specifically, the marking sensor 71 can be a color sensor, the marking element 72 can be a corresponding color, and the number of marking elements 72 can be the same as the number of through holes 12, so as to avoid the reduction of recognition accuracy caused by the marking elements 72 being adhered to by soil. In the initial state, the conduit component does not contact the sealing assembly 30, and the drill barrel 10 performs drilling operations normally. When drilling reaches the target depth, the speed of the drill barrel 10 can be detected by the speed sensor. When the speed decreases to the set range and the marking sensor 71 detects the corresponding marking element 72, the control unit controls the drive assembly 11 to stop, and the drill barrel 10 stops rotating. At this time, the corresponding conduit in the conduit component can correspond to the sealing assembly 30, avoiding misalignment that would prevent the conduit from being inserted into the second cylinder 32.

[0022] Furthermore, such as Figure 4 As shown, the upper disc body has a flared structure 322 in the middle and is connected to the interior; Specifically, in this example, the upper disc has a flared structure 322, which facilitates the insertion of the corresponding conduit into the second cylinder 32.

[0023] like Figure 6 As shown, this method for direct-insertion microwave in-situ synergistic treatment of contaminated soil in coalfield fire areas specifically includes the following steps: S1. The target area of ​​the coalfield fire zone is determined through exploration. The drill pipe 10 is placed on top and driven to drill to the target depth. S2, after drilling reaches the target depth, the soil temperature and organic pollutant concentration data of the target area are monitored and acquired through the sensing unit to preliminarily assess the combustion status and pollution range of the fire zone; When the guide tube component inside the drill barrel 10 is driven to move axially toward the bottom end of the drill barrel 10 to the limit position, the bottom end of the drill barrel 10 opens so that the first guide tube 40, the second guide tube 50, the third guide tube 60, and the fourth guide tube 80 can communicate with the outside of the drill barrel 10. S3, when the concentration of organic pollutants is detected to meet the treatment concentration, the control unit controls the radiation emission component to start, and can control the power to emit microwaves to heat the target area. The heating includes: the first stage and the second stage. In the first stage, the soil is heated evenly to 50-150℃ using low power, causing easily decomposable organic pollutants to volatilize; in the second stage, the soil temperature is raised to 200-500℃ using high power, causing poorly soluble organic pollutants in the soil to volatilize. During microwave heating, the control unit controls the discharge of organic pollutant gas from the fourth conduit 80; S4, when the concentration of organic pollutants is detected to be lower than the set concentration, the fourth conduit 80 is closed to stop venting, the control unit controls liquid nitrogen to enter the third conduit 60, and discharges it from the lower end of the third conduit 60 to the outside of the drill barrel 10 to cool the target area with liquid nitrogen. S5, repeat steps S3 and S4, the "heating-cooling" cycle causes the organic pollutants to "break down" and fall off the soil matrix; when the concentration of organic pollutants is detected to be at a safe level and the temperature is lower than the first set temperature, the control unit controls the slurry to enter the first conduit 40 and discharge it from the lower end of the first conduit 40 to the outside of the drill barrel 10 to perform pulse sudden grouting on the target area. S6, when the temperature of the target area continues to drop to the second set temperature, stop grouting, nitrogen injection and shut down the radiation emission component; the guide tube component is driven axially away from the bottom end of the drill barrel 10, and the bottom end of the drill barrel 10 is closed; finally, move to the next target area and repeat steps S1 to S4. In step S4, the control unit continuously monitors the temperature and controls the microwave power and liquid nitrogen injection parameters of the radiation emission component to maintain the temperature gradient. Located between 12℃ / min and 20℃ / min; Specifically, in step S3, the target area is heated by microwave to complete the treatment of organic pollutants. Then, in step S4, the target area is cooled by liquid nitrogen. The rapid and controlled cooling causes differential shrinkage of pollutants and soil particles, generating huge thermal stress at the interface between the two, which is enough to cause the firmly attached pollutants to fatigue, crack, and eventually peel off from the soil surface. At the same time, the inert atmosphere generated by the vaporization of liquid nitrogen can prevent pyrolysis from generating new pollutants. While cooling can remove organic pollutants from the soil matrix, rapid temperature drops can easily cause numerous harmful fissures in the soil and rock due to alternating hot and cold temperatures. These fissures directly affect soil strength and other properties. In this situation, the control unit uses monitored signals to control microwave power and liquid nitrogen injection parameters in real time, ensuring a proper temperature gradient. The injection rate is 12-20℃ / min. When the temperature reaches the set stable value, the control unit controls the grout injection parameters. Pulse sudden change grouting is used to allow the grout to penetrate into the micropores and liquid nitrogen rapid cooling to prevent the formation of new cracks, thus achieving all-round filling.

[0024] In some examples of the present invention, in step S5, the formula for calculating the temperature gradient is: in, , For parameter constants, This indicates the weight of the contribution of the heating to cooling power ratio to the temperature gradient. Indicates the mechanical and thermal properties of sandy soil, clay, clay loam, etc. For microwave power, This refers to the amount of liquid nitrogen injected. This represents the change in tensile strength of the soil over time. Specifically, Quantified the temperature gradient The greater the temperature gradient, the greater the internal thermal stress of the soil, and the easier it is for the soil to crack. The influence of the inherent physical and mechanical properties of the soil on its crack resistance was quantified; when the temperature gradient... When the temperature exceeds 20°C / min, the control unit will reduce the temperature. Increase ; , This can be achieved by controlling the microwave power and liquid nitrogen injection parameters of the radiation emission component through the control unit; It can be obtained by pre-burying distributed sensing optical fibers. For example, distributed sensing optical fibers can be pre-buryed in coalfield fire areas and buried in the soil in a grid or specific manner. When the device is activated, the soil will gradually deform or crack, and the sensing optical fibers will respond accordingly, causing changes in the characteristics of its transmitted optical signal (such as scattering and wavelength) to be monitored. , The parameters were obtained mainly by taking existing soil samples, heating them with microwaves, and cooling them with liquid nitrogen to observe whether the soil cracked. Points without cracks were then identified. Perform linear fitting, i.e.: The formula for calculating soil loss value is as follows: in, Clay content; when When the critical threshold of 1.0 is exceeded, it is predicted that harmful cracks will form in the soil. by The x-axis (independent variable) is used as the x-axis. Using the Y-axis (dependent variable), we obtain the fitted slope. Thus, parameters are obtained. At the same time, By fitting and solving the equation, we obtained the solution under its critical conditions. The value, which is the reciprocal of the slope of the safety boundary line, is... The reciprocal of the value; the higher the clay content, the smaller the critical value. Using the X-axis as the critical ( Using the Y-axis as an example, a linear fit was performed similarly to obtain the fitted slope. Thus, the parameters are obtained. .

[0025] In some examples of the present invention, during the process of the control unit controlling the microwave power of the radiating emission component, when At this time, the control unit controls the microwave power of the radiating emission component to be in a low-power state; is the dielectric constant, representing the complex dielectric constant of soil. The real part reflects the factors affecting the propagation speed and wavelength of microwaves; , where is the loss factor, and represents the complex permittivity of the soil. The imaginary part of the electromagnetic wave reflects the ability of a substance to convert into heat energy (dielectric loss). The greater the loss, the faster the electromagnetic wave attenuates in the substance. Specifically, dielectric constant The calculation formula is: Loss factor The calculation formula is: in, The incident power of the radiating emission component can be calculated by subtracting the distance loss from the original microwave power; The reflected power can be obtained from the receiving antenna and the directional coupler; , The concentration of organic pollutants ( ) and temperature ( The correction factor under coupling is represented by each Below, the ratio of measured data to basic predicted data; , The specific steps to obtain it are as follows: For the fire zone in this coalfield, direct-insertion sampling measurements are conducted beforehand. This can be done using equipment such as radiation emitting components and receiving components to measure the incident power in n groups. With reflected power And record the temperature under each measurement condition ( ) and organic pollutant concentrations ( The dielectric constant and loss factor of each group in this device are calculated as follows: In the laboratory, researchers determined the temperature based on n sets of conditions under the device ( ) and organic pollutant concentrations ( Simulations were performed separately, using specialized dielectric constant measuring instruments such as impedance analyzers and resonant cavities to obtain n sets of different dielectric constants under experimental conditions. The dielectric constant of the following With loss factor ; Thus, the correction factor for each group under the apparatus and experiment is obtained: The correction factors of group n , By performing a fitting, correction factors can be obtained for each temperature and organic pollutant concentration. , , the fitted , To evaluate the device at different concentrations of organic pollutants ( ) and temperature ( Correction factor under coupling; In this example, when At this time, the control unit controls the microwave power of the radiated emission component to switch from high loss to low loss. For example, the microwave with a frequency of 2.45 GHz and a power of 35 ± 5 kW in the second stage is adjusted to the microwave with a frequency of 915 MHz and a power of 15 ± 2 kW in the first stage, so as to avoid excessive energy attenuation and automatically switch to low frequency mode.

[0026] In some examples of the present invention, in step S4, the pulse sudden grouting is performed as follows: grouting is initially performed at a pressure of 0.7MPa-1.0MPa, and the pressure is increased by 0.5MPa in a step over 2 minutes until the maximum pressure reaches 2.5MPa; Specifically, this example uses pulse-induced grouting, which can effectively drive the grout to penetrate into the micropores formed by microwave thermal melting and the new cracks prevented by liquid nitrogen rapid cooling, thus achieving all-round filling.

[0027] Example This invention relates to a direct-insertion microwave in-situ synergistic treatment method for contaminated soil in coalfield fire zones, specifically including the following steps: S1, Drilling Positioning The target area of ​​the coalfield fire zone is determined by exploration. The mobile vehicle carrying this treatment device is moved to the target location. The drill barrel 10 is placed on top and driven to drill to the target depth. S2, Multi-field Perception After drilling reaches the target depth, the soil temperature field and the concentration distribution data of organic pollutants are monitored and acquired through the sensing unit to preliminarily assess the combustion status and pollution range of the fire zone. When the target depth is reached, the guide tube component inside the drill barrel 10 is driven to move axially toward the bottom end of the drill barrel 10 to the limit position, and the bottom end of the drill barrel 10 opens so that the corresponding guide tube communicates with the outside of the drill barrel 10. S3, Organic Pollutant Treatment When the concentration of organic pollutants exceeds 100 ppm, the first stage involves deep preheating and pollutant volatilization: the control unit controls the radiation emission component to start, using a highly penetrating 915 MHz frequency and a power of 15 ± 2 kW to irradiate the target area with high energy pulses for 8-12 minutes, so that the soil as a whole is uniformly heated to 50-150 ℃. This process causes a violent thermal effect inside the organic pollutants, promoting water evaporation and full volatilization and decomposition of organic pollutants. During the intermittent period, the heat does not have time to diffuse outward, thus protecting the surrounding matrix. The second stage involves molten vitrification: the control unit controls the radiation emission components to continue switching to the 2.45GHz frequency, which has a higher heating efficiency, and increases the power to 35±5kW, quickly raising the soil temperature to 200-500℃ and maintaining it for 5-8 minutes, so that the insoluble organic pollutants such as tar in the soil can be volatilized. During microwave heating, the control unit controls the discharge of organic pollutant gas from the fourth conduit 80; S4, Liquid nitrogen cooling When the concentration of organic pollutants is detected to be less than 50 ppm, the fourth conduit 80 is closed to stop venting, and the control unit controls liquid nitrogen to enter the third conduit 60. This process not only rapidly reduces the soil temperature, but the generated nitrogen also inerts the fire zone. During the cooling process, the control unit coordinates the microwave power with the liquid nitrogen injection to ensure a proper temperature gradient. The temperature is maintained at 12-20℃ / min to avoid excessively rapid cooling that could cause numerous harmful fissures in the soil and rocks. S5. After completing one "hot-cold" cycle, microwave heating is restarted. Since the physical structure of the pollutants has been disrupted in the previous cycle, this heating can more efficiently cause deep-seated residual pollutants to migrate to the surface. This process is repeated until the monitored concentration of organic pollutants remains consistently below 20 ppm, indicating that the pollutants have been fully released and removed at this stage. Simultaneously, when the temperature drops to 100-200℃, the control unit controls the grout to enter the first conduit 40. Initially, the modified consolidation grout is injected at a pressure of 0.8MPa, utilizing the residual heat of the soil to promote the fluidity of the grout and accelerate its chemical reaction. Subsequently, a circulation strategy of step-increase pressure of 0.5MPa every 2 minutes is adopted, with the maximum pressure reaching 2.5MPa. This pulse-induced grouting can effectively drive the grout to penetrate into the micropores formed by microwave thermal melting and the new cracks prevented by liquid nitrogen rapid cooling, achieving all-round filling and sealing. During the above process, the control unit adjusts the microwave power, liquid nitrogen and slurry injection parameters, and the opening and closing of the exhaust to achieve precise closed-loop control of the process. S6, Acceptance Processing When the temperature of the target area cools down to below 80°C, grouting and nitrogen injection are stopped, and the radiation emission components are turned off. This results in a composite functional sealing body with an upper porous mineralized layer that is rich in pores and easy to monitor, and a lower dense impermeable layer with excellent sealing performance, which permanently prevents reignition. The guide tube assembly is driven axially away from the bottom end of the drill barrel 10, and the bottom end of the drill barrel 10 is closed; finally, it is moved to the next target area and steps S1 to S4 are repeated.

[0028] The foregoing description, with reference to preferred embodiments, details an exemplary implementation of the direct-insertion in-situ co-treatment device for contaminated soil in coalfield fire zones proposed by the present invention. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of the present invention, and various combinations can be made to the various technical features and structures proposed by the present invention without exceeding the protection scope of the present invention, the protection scope of the present invention being determined by the appended claims.

Claims

1. A coalfield fire area contaminated soil direct insertion type in-situ synergistic treatment device, characterized in that, The device comprises: a processing unit having a drill cylinder (10) configured to drill a hole and having a hollow structure inside; a catheter component located in the hollow of the drill cylinder (10) and driven to move along the axis of the drill cylinder (10), having a first catheter (40) connected to a grouting source for injecting grout into a target area, a third catheter (60) connected to a liquid nitrogen source for injecting liquid nitrogen into the target area, a fourth catheter (80) connected to a negative pressure source for discharging gas from the target area, and a second catheter (50) internally provided with a radiation emitting assembly for generating microwaves to the target area for phase heating; a sensing unit for measuring the temperature of the target area and the concentration of organic pollutants; a control unit receiving the measurement signals of the sensing unit and controlling the microwave power of the radiation emitting assembly, the parameters of liquid nitrogen injection and grout injection, and the opening and closing of the exhaust; wherein the bottom end of the drill cylinder (10) is provided with through holes (12) corresponding to the respective catheters, and each through hole (12) is provided with a sealing assembly (30); when the catheter component is away from the limit position of the bottom end of the drill cylinder (10), the sealing assembly (30) closes the through hole (12); when the catheter component approaches the limit position of the bottom end of the drill cylinder (10), the sealing assembly (30) opens the through hole (12) and makes the corresponding catheter communicate with the outside of the drill cylinder (10).

2. The device according to claim 1, wherein the sealing assembly (30) comprises: a first cylinder (31) fixedly installed in the through hole (12); a second cylinder (32) movably connected with the first cylinder (31); the lower part of the second cylinder (32) is provided with a slot (321) and the lower end is closed; a resilient member (33) for applying elastic force to the second cylinder (32) away from the through hole (12); in the case of elastic action and without contact between the catheter component and the second cylinder (32), the slot (321) is closed by the inner wall of the first cylinder (31); when the catheter component moves downward and compresses the resilient member (33), the corresponding catheter is in abutment with the second cylinder (32) and extrudes the second cylinder (32) to move so that the slot (321) is located outside the first cylinder (31).

3. The device according to claim 2, wherein the upper and lower ends of the second cylinder (32) are connected with disc bodies; in the case of elastic action and without contact between the catheter component and the second cylinder (32), the lower disc body does not exceed the bottom end of the drill cylinder (10); the lower part of the catheter component is provided with a circular ring with an outer diameter greater than the inner diameter of the second cylinder (32); the outer diameter of the corresponding catheter is smaller than the inner diameter of the second cylinder (32) so that the corresponding catheter is connected with the second cylinder (32) by insertion.

4. The device according to any one of claims 1 to 3, wherein the upper end of the drill cylinder (10) is rotatably installed on the support platform (21) and driven to rotate by the driving assembly (11), and the inner side of the upper end is rotatably connected with the support plate (23). The conduit components are fixedly connected with the lifting platform (22), the lifting platform (22) is circumferentially limited by the support plate (23) and is axially movably connected by the driving shaft; Or: The corresponding conduits in the conduit components are respectively connected with the lifting platform (22), each lifting platform (22) is circumferentially limited by the support plate (23) and is axially movably connected by the driving shaft.

5. The coalfield fire area contaminated soil direct insertion in-situ co-processing device according to claim 4, characterized in that: The first conduit (40), the second conduit (50) and the third conduit (60) are uniformly arranged circumferentially around the axis of the drill cylinder (10); The upper end of the drill cylinder (10) is provided with an identification element (72) corresponding to the position of the through hole (12), the lifting platform (22) is provided with an identification sensor (71) for identifying the identification element (72), the identification sensor (71) is connected with the control unit, and the control unit controls the action of the driving assembly (11).

6. A method of treating coalfield fire zone contaminated soil by the direct insertion type in-situ synergistic treatment device according to claim 1, characterized in that, Specifically comprising the following steps: S1, determining the target area of the coalfield fire area through exploration, placing the drill cylinder (10) above and driving the drill cylinder (10) to drill to the target depth; S2, after drilling to the target depth, monitoring and obtaining the soil temperature and the concentration data of the organic pollutants in the target area through the sensing unit; When the conduit components in the drill cylinder (10) are driven to move axially to the limit position towards the bottom end of the drill cylinder (10), the bottom end of the drill cylinder (10) is opened to make the corresponding conduit communicate with the outside of the drill cylinder (10); S3, when the concentration of the organic pollutants meets the processing concentration, the control unit controls the radiation emitting assembly to start and emits microwaves to heat the target area, the heating includes a first stage and a second stage; In the first stage, the soil is uniformly heated to 50-150℃ at a low power to make the easily decomposable organic pollutants volatilize; in the second stage, the soil temperature is raised to 200-500℃ at a high power to make the difficultly soluble organic pollutants in the soil volatilize; When the microwave is heated, the control unit controls the organic pollutant gas to be discharged from the fourth conduit (80); S4, when the concentration of the organic pollutants is lower than the set concentration, the fourth conduit (80) is closed to stop discharging, the control unit controls the liquid nitrogen to enter the third conduit (60) and be discharged from the lower end of the third conduit (60) to the outside of the drill cylinder (10) to cool the target area with liquid nitrogen; S5, repeating steps S3 and S4, the "heating-cooling" cycle makes the organic pollutants "crumble" and fall off from the soil matrix; when the concentration of the organic pollutants is in the safe concentration and the temperature is lower than the first set temperature, the control unit controls the slurry to enter the first conduit (40) and be discharged from the lower end of the first conduit (40) to the outside of the drill cylinder (10) to pulse mutate the slurry injection to the target area; S6, when the temperature of the target area continues to decrease to the second set temperature, the slurry injection, nitrogen injection and the radiation emitting assembly are stopped; the conduit components are driven to move axially away from the bottom end of the drill cylinder (10), the bottom end of the drill cylinder (10) is closed; finally, the next target area is transferred and steps S1 to S4 are repeated; In step S4, the control unit continuously monitors the temperature and controls the microwave power of the radiation emitting assembly, the liquid nitrogen and the grouting injection parameters so that the temperature gradient is located between 12-20 °C / min.

7. The processing method of the coal field fire area contaminated soil direct insertion type in-situ synergistic treatment device according to claim 6, characterized in that, In step S5, the calculation formula of the temperature gradient is: wherein , is a parameter constant; is the microwave power, is the liquid nitrogen injection rate, is the tensile strength of the soil over time.

8. The processing method of the coal field fire area contaminated soil direct insertion type in-situ synergistic treatment device according to claim 6, characterized in that, When the control unit controls the microwave power of the radiation-emitting assembly in the process of controlling the microwave power of the radiation-emitting assembly, the control unit controls the microwave power of the radiation-emitting assembly to be in a low-power state; The dielectric constant is calculated by the formula: Loss factor, calculated as: wherein, is the incident power of the radiation emitting component, is the reflected power; , correction factor for organic contaminant concentration with temperature coupling.

9. The processing method of the coal field fire area contaminated soil direct insertion type in-situ synergistic treatment device according to claim 8, characterized in that, The , acquisition specifically comprises the following steps: For coalfield fire zones, pre-amplification sampling measurements were performed to measure the incident power in n groups. With reflected power And record the temperature under each measurement condition. and organic pollutant concentration Calculate the dielectric constant and loss factor for each group: In the laboratory, the experimenters simulate according to the n groups of temperature under the device and the concentration of organic pollutants respectively, obtain the dielectric constant and loss factor of the n groups of different under the experiment ;​ Further, the correction factor of each group is obtained: The correction factors of n groups are calculated , The fitting is performed, and the fitted , are taken as the correction factors of the device under different organic pollutant concentrations and temperature coupling.

10. The processing method of the coal field fire area contaminated soil direct insertion type in-situ synergistic treatment device according to any one of claims 6 to 9, characterized in that, In step S4, the pulse mutation grouting is: initially grouting at a pressure in the range of 0.7 MPa-1.0 MPa, and increasing the pressure by 0.5 MPa in steps of 2 min until the highest pressure reaches 2.5 MPa.

Images