Suspension positioning type double-hole multi-row stepped cooling device and method for coal mine tunnel

Abstract

The invention discloses a suspension positioning type double-hole multi-row stepped cooling device and method for a coal mine tunnel, and the device comprises a multi-stage double-hole cooling calandria module, a cooling circulation module, a temperature monitoring and control module, and a suspension type push-pull positioning module. The multi-stage double-hole cooling calandria module is installed on the suspension type push-pull positioning module and communicates with the cooling circulation module, the temperature detection and control module is arranged on the multi-stage double-hole cooling calandria module, and the multi-stage double-hole cooling calandria module comprises a plurality of cooling units arranged in the axial direction of a coal mine tunnel. The cooling unit comprises a double-hole semicircular pipe and a plurality of double-hole horizontal pipes, the two ends of each double-hole horizontal pipe are connected to the double-hole semicircular pipe, and the distance between every two adjacent double-hole horizontal pipes is smaller than the pipe diameter. Through the regulation and control mechanism of multi-stage gradient heat exchange, the problems that a traditional cooling technology is low in heat exchange efficiency and poor in space adaptability are solved, the heat exchange efficiency is greatly improved compared with a traditional cooling mode, the cooling effect is remarkable, and safety is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mine cooling, and particularly relates to a hanging and positioning type double-hole multi-row stepped cooling device and method for coal mine roadways. Background Art

[0002] During the coal mining process, with the increase of the mine depth and the improvement of the mechanization degree, the problem of high temperature underground becomes increasingly prominent. The high temperature environment not only seriously affects the health and safety of workers, but also accelerates the aging of equipment, increases energy consumption, and even causes potential safety hazards such as gas accumulation.

[0003] At present, the commonly used cooling technologies in coal mines mainly include mechanical ventilation, refrigeration unit cooling, spray cooling, and local ice application, etc., but all have significant limitations: 1. Traditional ventilation cooling: It relies on the air flow to carry away heat, but the ventilation resistance in deep roadways is large, the air flow circulation efficiency is low, it is difficult to effectively reduce the temperature in high temperature areas, and the energy consumption is relatively high.

[0004] 2. Application of refrigeration units: It is necessary to configure large-scale refrigeration equipment and complex pipeline systems, which have problems such as large initial investment, high operation and maintenance costs, and occupation of roadway space. Moreover, the cold loss is serious during long-distance cold quantity transportation.

[0005] 3. Spray cooling technology: It cools down by the evaporation heat absorption of water mist, but it will increase the humidity of the roadway, resulting in equipment corrosion, floor sludging, deteriorating the working environment, and may also cause roof stability problems in the long term.

[0006] 4. Application of phase change materials (PCM): In the existing technology, there are already cooling schemes using phase change materials for heat storage / heat release, but most of them use single-stage phase change modules, with a narrow temperature regulation range, insufficient cooling rate, and lack of effective heat recovery and circulation control mechanisms, resulting in low utilization rate of phase change materials and unstable cooling effect.

[0007] In addition, the installation methods of existing cooling devices are mostly fixed, which are difficult to adapt to complex and changeable roadway structures, and lack intelligent monitoring and regulation means, unable to respond to underground temperature fluctuations in real time, resulting in it being difficult to balance the cooling efficiency and safety. Summary of the Invention

[0008] The main object of the present invention is to provide a hanging and positioning type double-hole multi-row stepped cooling device for coal mine roadways, aiming to solve the above technical problems.

[0009] To achieve the above object, a suspended and positionable double-hole multi-row stepped cooling device for coal mine roadways proposed by the present invention includes a multi-stage double-hole cooling row pipe module, a cooling circulation module, a temperature monitoring and control module, and a suspended push-pull positioning module. The multi-stage double-hole cooling row pipe module is installed on the suspended push-pull positioning module and is connected to the cooling circulation module. The temperature detection and control module is arranged on the multi-stage double-hole cooling row pipe module. The multi-stage double-hole cooling row pipe module includes a plurality of cooling units arranged along the axial direction of the coal mine roadway. Each cooling unit includes a double-hole semi-circular pipe and a plurality of double-hole horizontal pipes. The two ends of the double-hole horizontal pipes are connected to the double-hole semi-circular pipe, and the distance between adjacent double-hole horizontal pipes is less than the pipe diameter.

[0010] In one embodiment, both the double-hole semi-circular pipe and the double-hole horizontal pipes include a cooling outer pipe and a cooling and temperature-reducing inner pipe. A phase change material is provided inside the cooling outer pipe, and a cooling medium is provided inside the cooling and temperature-reducing inner pipe.

[0011] In one embodiment, the cooling circulation module includes a cooling device and a circulation pump. The circulation pump is connected to the cooling and temperature-reducing inner pipe.

[0012] In one embodiment, the temperature monitoring and regulation module includes a thermocouple, a solid-liquid interface scale window, inlet and outlet valves. The thermocouple is arranged on the inner wall of the cooling outer pipe, the inner wall of the cooling and temperature-reducing inner pipe, the surrounding rock, and inside the roadway. The solid-liquid interface scale window is installed on the cooling unit.

[0013] In one embodiment, the solid-liquid interface scale window is made of a heat-insulating transparent material, and scale lines are engraved on the surface of the solid-liquid interface scale window.

[0014] In one embodiment, the suspended push-pull positioning module includes a roof anchor cable hook, a steel wire rope, a base hook, a hanging base, a slide rail, and a double-hole cooling row pipe hook. The hanging base is connected to the roof anchor cable hook through the steel wire rope, and the cooling unit is connected through the double-hole cooling row pipe hook.

[0015] In addition, the present invention also provides a suspended and positionable double-hole multi-row stepped cooling method for coal mine roadways. The suspended and positionable double-hole multi-row stepped cooling method for coal mine roadways is applied to the suspended and positionable double-hole multi-row stepped cooling device for coal mine roadways as described above. The suspended and positionable double-hole multi-row stepped cooling method for coal mine roadways includes: S100. Thermodynamic adaptation design of key parameters of the cooling device. Import the on-site geothermal geological condition parameters into the numerical model, and calculate the surrounding rock temperature under different cooling key parameter schemes for the T R service life of the roadway n The cooling rate Δ of the roadway environment temperature within T years, and the total cooling heatQ all 、 The average value of the range of solid phase ratio ave The average temperature drop of the section parallel to the last stage double-hole cooling pipe Δ T EP , the phase transition temperature is determined according to the following formula T PCM , step phase change temperature difference Δ T PCM , Spacing between double-hole cooling pipes at each level L 1 and cooling time t cool : ; S200, underground installation of cooling device and its solid phase initialization, phase change temperature is adjusted to T PCM The temperature difference of the step phase change is Δ T PCM Phase change material is put into the cooling outer tube through the filling inlet, and all modules are lowered to the tunnel position where cooling is needed through the auxiliary shaft. Multi-stage double-hole cooling pipe module, cooling circulation module, temperature monitoring and control module and suspended push-pull positioning module are installed in sequence. After the installation is completed, the suspended push-pull positioning module is started, and each stage of double-hole cooling pipe is moved according to the spacing through the slide rail. L 1 Push it to the corresponding position and fix it, arrange the thermocouple and solid-liquid interface scale window to the specified position, and then connect the pipelines and equipment. After the installation is completed, observe the scale of the solid-liquid interface scale window, start the cooling cycle module to perform solid phase initialization setting for the phase change material, and stop the initialization operation when the scale of the solid-liquid interface scale window is 1.0; S300, the circulating refrigeration mode of the cooling device is started and operated, and the temperature monitoring and control module is started to monitor the data in real time and control the device. When the ambient temperature of the underground tunnel is higher than the phase change temperature of the phase change material, the multi-stage double-hole cooling pipe module is automatically started, and the phase change material begins to absorb ambient heat and undergoes phase change. When the temperature monitoring and control module reads that the solid-liquid interface scale window points to 0.0, the cooling equipment, circulating pump, and water inlet and outlet valves in the cooling circulation module are started, and the cooling medium begins to flow in the cooling inner tube, absorbing the phase change heat of the phase change material and introducing the phase change heat into the cooling equipment. When the temperature monitoring and control module reads that the solid-liquid interface scale window points to 0.7, the cooling equipment, circulating pump, and water inlet and outlet valves in the cooling circulation module are closed, completing the refrigeration cycle within one operation cycle, and cooling is carried out in this cycle.

[0016] In the technical solution of the present invention, through the regulation mechanism of multi-stage gradient heat exchange, the problems of low heat exchange efficiency and poor space adaptability of traditional cooling technologies are solved. The heat exchange efficiency is greatly improved compared with traditional cooling methods, the cooling effect is remarkable, and the safety is further enhanced.

[0017] The adoption of a modular suspension structure can break through the limitations of roadway space. At the same time, through the circulating water system and waste heat recovery technology, the operating cost is greatly saved, the equipment has a long service life, the work efficiency is significantly improved, the physical and mental health of underground workers is guaranteed, providing a scientific basis and process optimization plan for the prevention and control of heat damage in deep coal mine mining, and promoting the transformation of the industry towards green, low-carbon, efficient and safe directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0019] Figure 1 It is a schematic structural diagram of a hanging and positioning type double-hole multi-row cascade cooling device for coal mine roadways according to an embodiment of the present invention; Figure 2 It is a schematic diagram of the principle of staggered enhanced ventilation and heat exchange according to an embodiment of the present invention; Figure 3 It is a layout diagram of the solid-liquid interface scale window according to an embodiment of the present invention; Figure 4 It is a phase change temperature cloud map of the embodiment of the present invention running for 120 h; Figure 5 It is a solid phase ratio diagram of the embodiment of the present invention running for 120 h; Figure 6 It is a solid phase ratio curve graph of the embodiment of the present invention running for 120 h; Figure 7 It is a cooling curve of the embodiment of the present invention running for 120 h.

[0020] Explanation of the reference numerals in the drawings: 1. Multi-stage double-hole cooling pipe module; 2. Cooling circulation module; 3. Temperature monitoring and control module; 4. Hanging and push-pull positioning module; 5. Cooling outer pipe; 6. Phase change material; 7. Filler inlet; 8. Cooling and cooling inner pipe; 9. Double-hole horizontal pipe; 10. Double-hole semi-circular pipe; 11. Cooling medium; 12. Cooling equipment; 13. Circulation pump; 14. Thermocouple; 15. Solid-liquid interface scale window; 16. Inlet and outlet valves; 17. Roof anchor cable hook; 18. Steel wire rope; 19. Base hook; 20. Hanging base; 21. Slide rail; 22. Double-hole cooling pipe hook.

[0021] The realization, functional features, and advantages of the present invention will be further described in conjunction with embodiments and with reference to the accompanying drawings. Detailed Embodiments

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0024] In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0025] Moreover, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] The present invention provides a hanging and positioning type double-hole multi-row stepped cooling device for coal mine roadways.

[0027] As Figures 1-7 shown, the hanging and positioning type double-hole multi-row stepped cooling device for coal mine roadways provided by the embodiment of the present invention includes a multi-stage double-hole cooling row pipe module 1, a cooling circulation module 2, a temperature monitoring and control module 3, and a hanging and push-pull positioning module 4. The multi-stage double-hole cooling row pipe module 1 is installed on the hanging and push-pull positioning module 4 and is connected to the cooling circulation module 2. The temperature detection and control module is arranged on the multi-stage double-hole cooling row pipe module 1. The multi-stage double-hole cooling row pipe module 1 includes a plurality of cooling units arranged along the axial direction of the coal mine roadway. The cooling unit includes a double-hole semi-circular pipe 10 and a plurality of double-hole horizontal pipes 9. Both ends of the plurality of double-hole horizontal pipes 9 are connected to the double-hole semi-circular pipe 10, and the distance between adjacent double-hole horizontal pipes 9 is less than the pipe diameter.

[0028] Both the double-hole semi-circular pipe 10 and the double-hole horizontal pipe 9 include a cooling outer pipe 5 and a cooling and temperature-reducing inner pipe 8. A phase change material 6 is provided inside the cooling outer pipe 5, and a cooling medium 11 is provided inside the cooling and temperature-reducing inner pipe 8.

[0029] In this embodiment, the cooling cycle module 2 includes a cooling device 12 and a circulation pump 13, and the circulation pump 13 is communicated with the cooling and temperature-reducing inner pipe 8.

[0030] The temperature monitoring and control module includes a thermocouple 14, a solid-liquid interface scale window 15, and inlet and outlet valves 16. The thermocouple 14 is arranged on the inner wall of the cooling outer pipe 5, the inner wall of the cooling and temperature-reducing inner pipe 8, the surrounding rock, and the roadway. The solid-liquid interface scale window 15 is installed on the cooling unit. The solid-liquid interface scale window 15 is made of a heat-insulating transparent material, and scale lines are engraved on the surface of the solid-liquid interface scale window 15.

[0031] The hanging, push-pull and positioning module 4 includes a roof anchor cable hook 17, a steel wire rope 18, a base hook 19, a hanging base 20, a slide rail 21, and a double-hole cooling pipe row hook 22. The hanging base 20 is connected to the roof anchor cable hook 17 through the steel wire rope 18, and the cooling unit is connected through the double-hole cooling pipe row hook 22.

[0032] The present invention provides a hanging and positioning type double-hole multi-row stepped cooling method for coal mine roadways, which includes the following steps: 1) Numerical model construction: According to the geothermal geological conditions of the mining area and the underground environment parameters, etc., a matching size framework of the cooling device is built. A numerical model of the underground cooling device model is established by using COMSOL software. Multi-physical field coupling analysis is carried out by using the laminar flow, Darcy's law, and porous media heat transfer module. The natural convection effect generated by the phase change of the phase change material 6 is ignored, the deformation caused by temperature change and the contact thermal resistance between different materials are ignored, and the surrounding rock and the multi-stage double-hole cooling pipe row module 1 are considered to be isotropic and the mass transfer effect is ignored.

[0033] 2) Thermodynamic adaptation design of key parameters of the cooling device: Import the on-site geothermal geological condition parameters into the numerical model, and calculate the cooling rate Δ of the roadway environment temperature within the roadway service life n years under different cooling key parameter schemes T 、total cooling heat Q all 、average value of the solid-phase ratio range ave and the average cooling of the parallel section of the last-stage double-hole cooling pipe row Δ T EP , and determine the phase change temperature according to the following formula (1) T PCM 、stepped phase change temperature difference ΔT PCM and the spacing of double-hole cooling pipes at each level L 1 and the cooling time t cool and other key parameters: (1) Set the simulation time step and total time of the numerical model to 1 min and 120 h respectively. After comprehensive consideration of the geothermal geological conditions of the coal mine and the influence of the underground environment, the key parameters of the cooling device are obtained through calculation and simulation verification T PCM 、Δ T PCM 、 L 1 and t cool The most optimal values of are 29°C, 5°C, 0.5 m and 6 h respectively. The optimal cooling effect is as Figures 2-7 shown.

[0034] (2) Install the cooling device underground. Lower the cooling device to the position that needs to be cooled underground through the hoisting equipment, and start the hanging push-pull positioning module 4 for construction. According to the structural characteristics of the roadway roof, customize the hanging base 20 in advance, equipped with the steel wire rope 18, the base hook 19, and the slide rail 21. Arrange the thermocouple 14 and the solid-liquid interface scale window 15 to the specified positions in advance, and then connect each pipeline and equipment. Load the phase change material 6 into the inner part of the cooling outer tube 5 through the filler inlet 7, and adjust the spacing of the double-hole cooling pipes at each level L 1 size. After the assembly is completed, the device is lifted to the specified position through the suspension pulley and hung on the roof cable anchor hook 17.

[0035] (3) Solid-phase initialization of the cooling device. After the device is built, observe the scale of the solid-liquid interface scale window 15, and start the cooling cycle module 2 to perform solid-phase initialization settings on the phase change material 6. When the scale of the solid-liquid interface scale window 15 is 1.0, stop the initialization operation.

[0036] 4) After the circulating refrigeration mode of the cooling device is started and operated, after completing step 3), the temperature monitoring and control module 3 is started to perform real-time data monitoring and device control work. When the ambient temperature in the underground roadway is higher than the phase change temperature of the phase change material 6, the multi-stage double-hole cooling and drainage pipe module 1 is automatically started, and the phase change material 6 begins to absorb ambient heat and undergoes a phase change. When the temperature monitoring and control module 3 reads that the scale of the solid-liquid interface scale window 15 points to 0.0, the cooling equipment 12, the circulation pump 13, and the inlet and outlet valves 16 in the cooling circulation module 2 are started. The cooling medium 11 begins to flow in the cooling inner tube 8, absorbs the phase change heat of the phase change material 6, and brings the phase change heat into the cooling equipment 12. When the temperature monitoring and control module 3 reads that the scale of the solid-liquid interface scale window 15 points to 0.7, the cooling equipment 12, the circulation pump 13, and the inlet and outlet valves 16 in the cooling circulation module 2 are closed, that is, a refrigeration cycle within an operating cycle is completed, and so on in a cycle; 5) The regulation method of the cooling circulation system. Correspondingly, on the basis of step 4), the temperature changes of the surrounding rock, the phase change material 6, and the cooling medium 11 monitored by the thermocouple 14 are finally reflected as the specific readings at the mouth of the solid-liquid interface scale window 15, and the operating efficiency of the cooling circulation module 2 is controlled according to the specific readings at the mouth of the solid-liquid interface scale window 15.

[0037] ① Installation parameters. The solid-liquid interface scale window 15 is arranged at a position higher than the junction of the inner and outer pipes and the first row of left columns h ( h > R , R is the radius of the cooling outer pipe) m, that is, the place where the phase change occurs sufficiently. It is made of heat-insulating transparent material and wraps both the cooling inner tube 8 and the cooling outer pipe 5 at the same time. A thin-layered phase change module is added to a cross-section at the center position of the cooling outer pipe 5, and scale lines are set on the surface.

[0038] ② Working principle. When no phase change occurs, that is, in the initial state, the phase change material 6 is located at the scale line 1.0 position. After the phase change occurs, the solid-liquid interface begins to appear and its position continuously drops. For example, when the solid-liquid interface boundary reaches the scale line 0.8 position, the solid phase ratio of the phase change material 6 reaches 80%. When at the scale line 0.0 position, the solid phase ratio of the phase change material 6 reaches 0%, indicating that the phase change material 6 has completely absorbed heat and melted.

[0039] ③ Control method. When the position of the solid-liquid interface in the solid-liquid interface scale window 15 drops to 0.0 after the phase change of the phase change material 6 at high temperature underground, the inlet and outlet valves are automatically opened, the circulation pump 13 and the cooling equipment 12 are started. The rotation speed of the circulation pump 13 can be appropriately increased or the circulation flow rate of the cooling medium 11 can be increased according to the actual situation to enhance the heat dissipation effect. When the solid-liquid interface scale line reaches the scale 0.7 position, the valve is closed, the circulation pump 13 is closed, and the cooling equipment 12 continues to work. It stops working after the medium cools down, and so on in a cycle.

[0040] 6) The whole life cycle health operation and maintenance of the downhole cooling device. The temperature monitoring and control module 3 adjusts the device parameters in a timely manner according to the on-site monitoring data. Since the multi-stage double-hole cooling and drainage pipe module 1 is used for a long time, problems such as wear and leakage of the phase change material 6 may occur. It is necessary to regularly check the integrity of the device. Once liquid leakage occurs, it needs to be repaired in a timely manner, and the phase change material 6 needs to be replenished. Similarly, the cooling circulation module 2, the temperature monitoring and control module 3, and the suspended push-pull positioning module 4 need to be regularly maintained to ensure the normal operation of the cooling device throughout its life cycle.

[0041] Through the regulation mechanism of multi-stage gradient heat exchange, this application solves the problems of low heat exchange efficiency and poor space adaptability of traditional cooling technologies. The heat exchange efficiency is greatly improved compared with traditional cooling methods, the cooling effect is remarkable, and the safety is further enhanced.

[0042] The adoption of a modular suspension structure can break through the limitations of the roadway space. At the same time, through the circulating water system and waste heat recovery technology, the operation cost can be greatly saved, the equipment has a long service life, the work efficiency is significantly improved, the physical and mental health of underground workers is guaranteed, and a scientific basis and process optimization plan for preventing heat damage in deep coal mine mining are provided, promoting the transformation of the industry towards green, low-carbon, efficient and safe directions.

[0043] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the concept of the present invention, or directly / indirectly applied to other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A hanging and positioning type double-hole multi-row stepped cooling device for coal mine roadways, characterized in that The hanging and positioning type double-hole multi-row stepped cooling device for coal mine roadways includes a multi-stage double-hole cooling row pipe module, a cooling circulation module, a temperature monitoring and control module, and a hanging and push-pull positioning module. The multi-stage double-hole cooling row pipe module is installed on the hanging and push-pull positioning module and is connected to the cooling circulation module. The temperature detection and control module is arranged on the multi-stage double-hole cooling row pipe module. The multi-stage double-hole cooling row pipe module includes a plurality of cooling units arranged along the axial direction of the coal mine roadway. The cooling unit includes a double-hole semi-circular pipe and a plurality of double-hole horizontal pipes. The two ends of the double-hole horizontal pipe are connected to the double-hole semi-circular pipe, and the distance between adjacent double-hole horizontal pipes is less than the pipe diameter.

2. The hanging and positioning type double-hole and multi-row stepped cooling device for coal mine roadways according to claim 1, characterized in that, Both the double-hole semi-circular pipe and the double-hole horizontal pipe include a cooling outer pipe and a cooling and cooling inner pipe. A phase change material is arranged in the cooling outer pipe, and a cooling medium is arranged in the cooling and cooling inner pipe.

3. The hanging and positioning type double-hole multi-row stepped cooling device for coal mine roadways according to claim 2, wherein, The cooling circulation module includes a cooling device and a circulation pump. The circulation pump is connected to the cooling and cooling inner pipe.

4. The hanging and positioning type double-hole multi-row stepped cooling device for coal mine roadways according to claim 2, characterized in that, The temperature monitoring and regulation module includes a thermocouple, a solid-liquid interface scale window, an inlet and outlet valve. The thermocouple is arranged on the inner wall of the cooling outer pipe, the inner wall of the cooling and cooling inner pipe, the surrounding rock and in the roadway. The solid-liquid interface scale window is installed on the cooling unit.

5. The hanging and positioning type double-hole and multi-row stepped cooling device for coal mine roadways according to claim 4, wherein The solid-liquid interface scale window is made of a heat-insulating transparent material, and scale lines are engraved on the surface of the solid-liquid interface scale window.

6. The hanging and positioning type double-hole and multi-row stepped cooling device for coal mine roadways according to claim 1, wherein, The hanging and push-pull positioning module includes a roof anchor cable hook, a steel wire rope, a base hook, a hanging base, a slide rail and a double-hole cooling row pipe hook. The hanging base is connected to the roof anchor cable hook through the steel wire rope, and the cooling unit is connected through the double-hole cooling row pipe hook.

7. A hanging positioning type double-hole multi-row stepped cooling method for coal mine roadways, characterized in that, The hanging and positioning type double-hole multi-row stepped cooling method for coal mine roadways is applied to the hanging and positioning type double-hole multi-row stepped cooling device for coal mine roadways as described in any one of claims 1-6. The hanging and positioning type double-hole multi-row stepped cooling method for coal mine roadways includes: S100. Thermodynamic adaptation design of key parameters of the cooling device. Import the on-site geothermal geological condition parameters into the numerical model to calculate the surrounding rock temperature under different key parameter schemes without cooling, T R of the roadway service life n The cooling rate Δ of the roadway environmental temperature within T years, the total cooling heat Q all 、 The average value of the extreme difference in solid phase proportion ave and the average cooling value Δ of the parallel cross-section of the last-stage double-hole cooling drain pipe T EP . Determine the phase change temperature according to the following formula T PCM , the cascade phase change temperature difference Δ T PCM , the spacing of each stage of double-hole cooling drain pipe L 1 and the cooling time t cool : ； S200, downhole installation of the cooling device and its solid-phase initialization, preparing a phase-change material with a phase-change temperature of T PCM and a stepped phase-change temperature difference of Δ T PCM The phase-change material is filled into the interior of the cooling outer tube through the filler inlet, and all modules are lowered to the roadway position in the mine that needs to be cooled through the auxiliary shaft. The multi-stage double-hole cooling pipe module, the cooling circulation module, the temperature monitoring and control module, and the suspended push-pull positioning module are installed in sequence. After the installation is completed, the suspended push-pull positioning module is started, and each stage of the double-hole cooling pipe is pushed to the corresponding position according to the spacing L 1 and fixed. The thermocouple and the solid-liquid interface scale window are arranged at the designated positions, and then each pipeline and equipment are connected. After the construction is completed, observe the scale of the solid-liquid interface scale window, and start the cooling circulation module to perform solid-phase initialization settings on the phase-change material. When the scale of the solid-liquid interface scale window is 1.0, stop the initialization operation; S300. Start the circulating refrigeration mode of the cooling device, start the temperature monitoring and control module to perform real-time data monitoring and control work of the device. When the ambient temperature in the underground roadway is higher than the phase change temperature of the phase change material, the multi-stage double-hole cooling row pipe module is automatically started, and the phase change material begins to absorb the ambient heat and undergoes a phase change. When the temperature monitoring and control module reads that the scale of the solid-liquid interface scale window points to 0.0, start the cooling device, the circulation pump and the inlet and outlet valve in the cooling circulation module. The cooling medium starts to flow in the cooling and cooling inner pipe, absorbs the phase change heat of the phase change material, and brings the phase change heat into the cooling device. When the temperature monitoring and control module reads that the scale of the solid-liquid interface scale window points to 0.7, close the cooling device, the circulation pump and the inlet and outlet valve in the cooling circulation module, that is, complete a refrigeration cycle within an operating cycle, and cool down in such a cycle.

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