A deep metal mine step-by-step heat transfer simulation device and an experimental method thereof

Abstract

The application provides a deep metal mine step heat transfer simulation device and an experimental method thereof, and belongs to the technical field of deep metal mine heat transfer simulation. The device comprises a ground temperature simulation system, a heat and moisture exchange system, an airflow monitoring system and a collection control system. The ground temperature simulation system is used for establishing a controllable temperature field in a surrounding rock similar material to simulate heat conduction of the surrounding rock. The heat and moisture exchange system is arranged in the ground temperature simulation system and comprises a porous roadway lining and a seepage device. The roadway lining is integrally formed with the surrounding rock similar material and is used for simulating heat and moisture exchange of a roadway wall surface. The airflow monitoring system is in communication with the heat and moisture exchange system and is used for providing controllable airflow to the roadway and monitoring convective heat transfer parameters. The collection control system is connected with the ground temperature simulation system, the heat and moisture exchange system and the airflow monitoring system and is used for adjusting operation parameters and collecting data. The application solves the problems of excessive intermediate gap thermal resistance and lack of interface heat and moisture exchange in the existing experiments and truly reproduces the heat conduction and heat and moisture coupling process of a "surrounding rock-interface" in a deep mine.

Description

Technical Field

[0001] This invention belongs to the field of mine thermophysics and ventilation engineering technology, specifically a deep metal mine cascade heat transfer simulation device and its experimental method. Background Technology

[0002] As global shallow mineral resources are gradually depleted, metal mining is expanding into deeper areas at an unprecedented rate. When the mining depth exceeds 1,000 meters, mines generally face severe challenges of high ground stress and high ground temperature. Among these challenges, the high-temperature heat hazard caused by the geothermal gradient is particularly prominent, seriously threatening the health and safety of underground workers and drastically increasing the energy consumption for ventilation and cooling in the mine.

[0003] In deep mines, heat primarily originates from the surrounding rock and is transferred to the tunnel space through a complex cascade heat transfer chain. This process can be broadly divided into three main stages: First, heat conduction occurs within the deep surrounding rock from high-temperature zones to low-temperature zones (tunnel walls), the efficiency of which is influenced by lithology, water content, and fracture structure. Second, there is intense heat-moisture coupling exchange between the surrounding rock and the tunnel walls, including sensible heat transfer from the high-temperature walls and latent heat exchange caused by water seepage and evaporation from the walls. Finally, ventilation airflow carries heat away from the tunnels through forced convection heat transfer, the effectiveness of which is closely related to wind speed, tunnel geometry, and wall roughness. These three stages are interconnected and mutually coupled, jointly determining the final state of the underground thermal environment.

[0004] However, experimental research on this complete cascade heat transfer process faces significant challenges. Existing experimental methods have obvious limitations in reproducing and measuring this complex system:

[0005] (1) Incomplete simulation of heat transfer chain: Most experimental devices can only simulate one link in the cascade heat transfer, such as a single rock thermal conductivity test or a single pipe convection experiment. This decoupled research method cannot capture the dynamic feedback between links, such as the reverse influence of tunnel air temperature change on the surrounding rock temperature field gradient, resulting in a systematic bias in the understanding of the total thermal resistance and heat flow distribution of the system.

[0006] (2) The physical processes at the interface are oversimplified: Existing models usually treat the roadway wall as a smooth, dry isothermal or isothermal flow boundary, ignoring the wall seepage and water evaporation phase change processes that are common in deep mines. Latent heat exchange is a key factor affecting the temperature of the surrounding rock and the humidity of the roadway. Its absence leads to serious discrepancies between the simulation results and the actual working conditions, especially when predicting the wet-bulb temperature of the roadway.

[0007] (3) The interface contact thermal resistance is difficult to eliminate: If the existing experimental device adopts a sleeve structure to simulate the surrounding rock and the tunnel respectively, there are often tiny air gaps between the layers, resulting in excessive contact thermal resistance. It is impossible to truly reproduce the heat conduction conditions of the surrounding rock and the support body in deep strata, which seriously affects the accuracy of experimental data.

[0008] (4) Limited multi-physics field monitoring capability: Traditional measurement methods mostly use discrete point sensors, which make it difficult to obtain the fine distribution law of complex temperature stratification, velocity boundary layer and nonlinear temperature field inside the surrounding rock in the cross section of the roadway, thus limiting the in-depth understanding of the cascade heat transfer coupling mechanism.

[0009] Therefore, there is an urgent need to develop an experimental device and method that can fully simulate the entire process of heat transfer between the surrounding rock and the tunnel in deep metal mines, accurately control the interface heat and moisture exchange conditions, flexibly adapt to different tunnel geometries, and have high-precision multi-physics field monitoring capabilities, so as to provide a reliable scientific basis and experimental platform for the prediction of heat hazards in deep mines, the optimization design of ventilation systems, and the research and development of new cooling technologies. Summary of the Invention

[0010] The purpose of this invention is to provide a deep metal mine cascade heat transfer simulation device and its experimental method that solves the problems of incomplete heat transfer chain simulation, missing interfacial heat and moisture exchange process, limited study of roadway geometric features, and insufficient multi-physics field monitoring capabilities in the prior art.

[0011] The present invention provides a deep metal mine cascade heat transfer simulation device, comprising a geothermal simulation system, a heat and moisture exchange system, an airflow monitoring system, and a data acquisition and control system. The geothermal simulation system is used to establish a controllable temperature field in a surrounding rock-like material to simulate heat conduction in the surrounding rock. The heat and moisture exchange system, located within the geothermal simulation system, includes a porous tunnel lining and a seepage device. The tunnel lining is integrally formed with the surrounding rock-like material to simulate heat and moisture exchange on the tunnel wall. The airflow monitoring system is connected to the heat and moisture exchange system and is used to provide controllable airflow into the tunnel and monitor convective heat transfer parameters. The data acquisition and control system is connected to the geothermal simulation system, the heat and moisture exchange system, and the airflow monitoring system, and is used to adjust operating parameters and collect data.

[0012] In one embodiment of the above-mentioned simulation device, the geothermal simulation system includes a double-layer hollow cylindrical frame. The space between the outer and inner walls of the double-layer hollow cylinder is filled with thermal insulation material. A rock-like material is poured into the cavity enclosed by the inner wall. Multiple annular electric heating units are arranged radially in layers within the rock-like material, and the power of each annular electric heating unit is independently controllable. A multi-point thermocouple array is also pre-embedded in the rock-like material, and the detection points of the multi-point thermocouple array are distributed in a grid pattern.

[0013] In one embodiment of the above-mentioned simulation device, the seepage device of the heat and moisture exchange system includes a microporous seepage pipe network, which is tightly wrapped around the outer wall of the tunnel lining; the microporous seepage pipe network is connected to a water injection and pressurization port and a water outlet, and the water flow is controlled by an external multi-channel high-precision peristaltic pump; a thin-film heat flux meter array is attached to the inner wall of the tunnel lining for in-situ measurement of the wall surface heat flux density.

[0014] In one embodiment of the above-mentioned simulation device, the airflow monitoring system includes a variable frequency centrifugal fan, a temperature and humidity control unit, a three-dimensional coordinate moving platform, and a multi-parameter integrated probe; the variable frequency centrifugal fan is connected to the inlet of the tunnel lining through a flow stabilization section; the temperature and humidity control unit is integrated at the front end of the fan and includes a heating module, a cooling module, and a humidification / dehumidification module, used to adjust the temperature, humidity, and wind speed of the inlet airflow; the three-dimensional coordinate moving platform is set on a guide rail inside the tunnel and is driven by a stepper motor; the multi-parameter integrated probe is mounted on the three-dimensional coordinate moving platform and integrates a three-dimensional hot-wire anemometer, a T-type thermocouple, and a capacitive humidity sensor.

[0015] In one embodiment of the above-mentioned simulation device, the acquisition and control system is configured to dynamically adjust the power of each annular electric heating unit based on temperature data fed back from a multi-point thermocouple array, thereby constructing a non-uniform three-dimensional temperature field.

[0016] In one embodiment of the above-mentioned simulation device, the tunnel lining is made of porous ceramic material and is a replaceable structure; the integrated molding is achieved by pouring a rock-like material slurry through the grouting port, and the slurry is vented and cured through the slurry outlet.

[0017] In one embodiment of the above-mentioned simulation device, the three-dimensional coordinate moving platform includes a transverse driving mechanism and a longitudinal driving mechanism, which are used to drive the multi-parameter integrated probe to perform gridded moving scans in the axial, transverse and radial directions of the roadway, so as to realize the automated monitoring of the three-dimensional physical field.

[0018] A method for conducting experiments using the above-mentioned simulation device, comprising the following specific steps:

[0019] System preparation and model construction: A tunnel lining with a pre-installed microporous seepage network is fabricated. This network is connected to an external multi-channel high-precision peristaltic pump via a water injection and pressurization port and an outlet. The tunnel lining is fixed to the central axis of the geothermal simulation system. A rock-like material slurry with similar thermophysical properties is prepared and poured into the cavity between the tunnel lining and the outer shell of the geothermal simulation system through the injection port. The slurry is vented through the outlet. After solidification, a tightly contacted, stepped heat transfer solid model is formed. Simultaneously, a multi-point thermocouple array is deployed.

[0020] The first stage of simulation: The power of each ring electric heating unit is independently controlled by the acquisition and control system, and closed-loop adjustment is performed based on the feedback data of the multi-point thermocouple array until a stable three-dimensional temperature field conforming to the preset geothermal gradient is established in the surrounding rock model.

[0021] The second stage of simulation involves starting a multi-channel high-precision peristaltic pump to inject water into a microporous seepage network through a pressurized injection port. The water seeps from the network into the inner wall of the tunnel, forming wall seepage at a set flow rate and zoning pattern. Excess water is discharged from the outlet, simulating wall seepage and forming a stable sensible-latent heat coupling exchange boundary. The wall heat flux density is monitored in real time using a thin-film heat flux meter array.

[0022] The third stage of simulation: Start the variable frequency centrifugal fan and temperature and humidity control unit to deliver the set parameters of ventilation airflow into the roadway; drive the three-dimensional coordinate moving platform to control the multi-parameter integrated probe to move and position at different positions in the axial and radial directions of the roadway, and perform gridded scanning measurement of the velocity field, temperature field and humidity field of one or more key sections in the roadway.

[0023] Comprehensive data analysis: The collected data on surrounding rock temperature field, wall heat flow, and multi-physics field of the tunnel are comprehensively processed to calculate key parameters such as thermal resistance of surrounding rock, interfacial heat transfer coefficient, and convective heat transfer Nusselt number. The coupling influence of different lithologies, permeability and ventilation volume on the cascade heat transfer efficiency is analyzed.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. By integrating the porous roadway lining with a pre-installed microporous seepage network and a rock-like material into a single casting, interlayer contact thermal resistance was eliminated, and precise control of wall seepage was achieved. The thin-film heat flow meter array was directly attached to the lining wall for in-situ monitoring of heat flux density. This solved the problems of excessive inter-gap thermal resistance and lack of interfacial heat and moisture exchange in existing experiments, realistically reproduced the heat conduction and heat and moisture coupling process of the "surrounding rock-interface" in deep mines, improved the accuracy of experimental data, and provided a reliable basis for studying the influence of lithology and water content on heat transfer.

[0026] 2. Multiple independently controllable annular electric heating units are arranged radially in layers within the surrounding rock system. Combined with a pre-embedded multi-point thermocouple array, a controllable non-uniform three-dimensional temperature field is constructed through PID closed-loop regulation. This overcomes the limitations of traditional devices in simulating geothermal gradients and rock heterogeneity, and realizes dynamic feedback of heat conduction within the surrounding rock. This enables the experiment to accurately reproduce the actual working conditions of deep mines, improves the efficiency of heat conduction simulation, and provides a high-fidelity environment for the analysis of heat hazard sources.

[0027] 3. The integrated probe is driven by a programmable three-dimensional coordinate moving platform to perform gridded moving scans in the axial and radial directions of the tunnel. Combined with a variable frequency fan and a temperature and humidity control unit, the inlet airflow is adjusted. This solves the problem of insufficient monitoring capability of point sensors, and fully captures the velocity boundary layer, temperature stratification and humidity distribution in the convective heat transfer of the tunnel. The experimental monitoring efficiency is improved, and parametric analysis is supported, providing multi-dimensional data support for ventilation and cooling design. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall axial cross-section of an embodiment of the present invention.

[0029] Figure 2 for Figure 1 A cross-sectional schematic diagram of the Chinese embodiment.

[0030] Figure 3 for Figure 1 A magnified schematic diagram of a medium-temperature heat and humidity exchange system.

[0031] The attached figures are labeled as follows:

[0032] 1. Ground temperature simulation system; 11. Insulation filling material; 12. Grouting port; 13. Annular electric heating unit; 14. Multi-point thermocouple array; 15. Similar material; 16. Grout outlet; 2. Heat and moisture exchange system; 21. Replaceable tunnel lining; 22. Microporous seepage pipe network; 221. Water injection and pressurization port; 222. Water outlet; 23. Multi-channel high-precision peristaltic pump; 24. Thin-film heat flow meter array; 3. Airflow monitoring system; 31. Variable frequency centrifugal fan; 32. Temperature and humidity control unit; 33. Three-dimensional coordinate moving platform; 34. Multi-parameter integrated probe; 4. Data acquisition and control system. Detailed Implementation

[0033] The relevant technical solutions will now be clearly and completely described with reference to the accompanying drawings of the embodiments of the present invention. The described embodiments are only a part of the embodiments, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Combination Figure 1 and Figure 2 As can be seen, the deep metal mine cascade heat transfer simulation device disclosed in this embodiment includes a ground temperature simulation system 1, a heat and moisture exchange system 2, an airflow monitoring system 3, and a data acquisition and control system 4.

[0035] The geothermal simulation system 1 has a double-layered hollow cylinder as its main frame, with a heat and moisture exchange system 2 embedded in its central cavity; the airflow monitoring system 3 is connected to the inlet end of the tunnel lining 21 of the heat and moisture exchange system through a flow stabilization section; and the data acquisition and control system 4 is electrically connected to the sensors and actuators of each system through cables.

[0036] The main structure of the geothermal simulation system 1 is a double-layer stainless steel cylinder. The space between its outer and inner walls is filled with heat-insulating filling material 11 to reduce heat loss from the model to the outside. The cavity formed by the inner wall is filled with rock-like material 15 through the grouting port 12 and the air is vented during the pouring process through the grouting outlet 16.

[0037] A ring-shaped electric heating unit 13 is arranged radially in layers within a rock-like material 15, with each unit having independently controllable power. Simultaneously, a multi-point thermocouple array 14 is pre-embedded, with its detection points distributed in a grid pattern along the axial and radial directions. This is used to construct and monitor a controllable non-uniform surrounding rock three-dimensional temperature field to simulate deep geothermal gradients and rock mass heterogeneity.

[0038] The cables of the annular electric heating unit 13 and the multi-point thermocouple array 14 pass through the cylinder and are connected to the power control module of the acquisition and control system 4.

[0039] like Figure 3 As shown, the heat and moisture exchange system 2 is located in the central cavity of the geothermal simulation system 1, and includes a replaceable tunnel lining 21 made of porous ceramic material and a microporous seepage network 22 tightly wrapped around its outer wall.

[0040] The pipeline extends to the outside of the device, with a water injection and pressurization port 221 and a water outlet 222 installed, and passes through the surrounding rock to connect to an external multi-channel high-precision peristaltic pump 23.

[0041] The tunnel lining 21 and the rock-like material 15 are simultaneously poured and cured through the grouting port 12, forming an integrated structure. This allows the microporous seepage network 22 to be wrapped and fixed, thus obtaining structural protection. Furthermore, there is no gap between the outer wall of the lining and the surrounding rock, eliminating the contact thermal resistance between the lining and the surrounding rock and improving the continuity of cascade heat transfer.

[0042] A thin-film heat flow meter array 24 is attached to the inner wall of the tunnel lining to simulate and measure the sensible / latent heat coupling heat transfer process in different areas of the wall.

[0043] The thin-film heat flow meter array 24 is connected to the data acquisition and control system 4 via a signal line; the peristaltic pump 23 is controlled by the flow command of the data acquisition and control system 4.

[0044] The airflow monitoring system 3 includes a variable frequency centrifugal fan 31, a temperature and humidity control unit 32, a three-dimensional coordinate moving platform 33, and a multi-parameter integrated probe 34.

[0045] The variable frequency centrifugal fan 31 is connected to the inlet of the tunnel lining 21 through the flow stabilization section. The front end of the fan integrates a temperature and humidity control unit 32, which includes heating, cooling and humidification / dehumidification modules, and can provide the tunnel with inlet airflow with precise controllable wind speed, dry bulb temperature and relative humidity.

[0046] Inside the tunnel, a guide rail is set along the axial direction. A three-dimensional coordinate moving platform 33 driven by a stepper motor is set on the guide rail. A multi-parameter integrated probe 34 is mounted on the platform. The probe integrates a three-dimensional hot-wire anemometer, a T-type thermocouple and a capacitive humidity sensor, which can simultaneously measure the three-dimensional velocity components, temperature and relative humidity of the measuring point.

[0047] A transverse drive mechanism is set on the mobile platform 33 to realize the axial displacement of the multi-parameter integrated probe 34, and a longitudinal drive mechanism is set to realize the radial displacement of the probe; thereby realizing the flexible adjustment of the measurement point position in the three directions of axial, transverse and radial in the roadway, and realizing the automated variable position scanning of the complete three-dimensional field inside the roadway.

[0048] The variable frequency centrifugal fan 31 and the temperature and humidity unit 32 are controlled by the data acquisition and control system 4; the motion commands of the mobile platform 33 and the data transmission of the probe 34 are all realized through the system 4.

[0049] The data acquisition and control system 4 includes an industrial computer, a multi-channel data acquisition module, and a power control module. The industrial computer connects to the thermocouple array 14, the heat flux array 24, and the integrated probe 34 via the multi-channel acquisition module; it controls the electric heating unit 13 via the power module; and it controls the peristaltic pump 23, the fan 31, the temperature and humidity unit 32, and the moving platform 33 via the I / O module. Finally, based on the temperature data fed back from the thermocouple array 14, a PID algorithm dynamically adjusts the power of each annular electric heating unit 13.

[0050] This simulation device fully reproduces the cascade heat transfer chain of surrounding rock heat conduction, interfacial heat and moisture exchange, and tunnel convection in deep mines, achieving accurate simulation and monitoring of multi-physics coupled processes. The specific principle is as follows:

[0051] An annular electric heating unit 13 generates a controllable temperature gradient in the rock-like material 15 to simulate the conduction of geothermal energy into the tunnel. The insulating filling material 11 suppresses lateral heat dissipation, ensuring unidirectional heat transfer to the tunnel interface. A peristaltic pump 23 injects water into the microporous seepage network 22, where the water seeps into the tunnel lining 21 and evaporates, forming a boundary for sensible and latent heat exchange. A heat flux meter array 24 directly measures the wall heat flux density, eliminating contact thermal resistance errors. A moving platform 33 drives an integrated probe 34 to perform a three-dimensional mesh scan, simultaneously capturing the velocity boundary layer, temperature stratification, and humidity distribution. A temperature and humidity control unit 32 adjusts the inlet airflow parameters to simulate different ventilation conditions. The data acquisition and control system 4 monitors parameters in real time and adjusts the heating power, seepage volume, and ventilation conditions in a closed loop to achieve dynamic coupling simulation of cascade heat transfer.

[0052] The present invention also provides an experimental method for simulating the evolution of cascade heat transfer in deep metal mines based on the above-mentioned device, comprising the following steps:

[0053] 1. System preparation and model building:

[0054] A tunnel lining 21 with a pre-installed microporous seepage pipe network 22 is constructed. The microporous seepage pipe network 22 is connected to an external multi-channel high-precision peristaltic pump 23 through a water injection and pressurization port 221 and a water outlet 222. The tunnel lining 21 is fixed on the central axis of the geothermal simulation system 1. A slurry of a rock-like material 15 with similar thermophysical properties is prepared and poured into the cavity between the tunnel lining 21 and the outer shell of the geothermal simulation system through the slurry injection port 12. The slurry is vented through the slurry outlet 16. After the material solidifies, a tightly contacted stepped heat transfer solid model is formed. At the same time, a multi-point thermocouple array 14 is deployed.

[0055] 2. First-tier simulation:

[0056] The heating power of each annular electric heating unit 13 is independently adjusted by the acquisition and control system 4, and the temperature data fed back by the multi-point thermocouple array 14 is collected in real time. Using a PID closed-loop control algorithm, a stable three-dimensional temperature field that conforms to the actual geothermal gradient distribution of the target mine is gradually established within the surrounding rock similar material 15. This process simulates the heat conduction process from the high-temperature core to the tunnel wall inside the deep surrounding rock.

[0057] 3. Second-stage simulation:

[0058] After the surrounding rock temperature field stabilizes, the multi-channel high-precision peristaltic pump 23 is started, injecting water into the microporous seepage network 22 through the water injection and pressurization port 221, supplying water to different areas of the tunnel lining 21 with a set flow rate and spatial distribution pattern; the water permeates through the porous material to the inner wall surface, forming a wetted wall surface, and excess water is discharged from the outlet 222; under the action of the high-temperature surrounding rock, the water on the wall surface undergoes an evaporation phase change. At this time, the thin-film heat flow meter array 24 can simultaneously measure the sensible heat transfer from the surrounding rock and the latent heat exchange caused by water evaporation, truly replicating the thermal-humid coupling boundary conditions of the deep tunnel wall.

[0059] 4. Third-level simulation:

[0060] The variable frequency centrifugal fan 31 and the temperature and humidity control unit 32 are started to deliver ventilation airflow with precise controllable temperature, humidity and flow rate into the tunnel lining 21; the data acquisition and control system 4 drives the three-dimensional coordinate moving platform 33 to control the multi-parameter integrated probe 34 to automatically scan at different positions in the axial and radial directions of the tunnel according to the preset grid path, and simultaneously acquire the three-dimensional wind speed components, dry bulb temperature and relative humidity data of one or more key cross sections and axial positions in the tunnel, so as to fully capture the velocity boundary layer, temperature stratification and humidity distribution characteristics in the forced convection heat transfer process in the tunnel.

[0061] 5. Comprehensive data analysis:

[0062] The collected data on the temperature field distribution of the surrounding rock, the heat flux density of the wall, and the multi-physics field of the tunnel space were comprehensively processed. Key heat transfer parameters such as the thermal resistance of the surrounding rock, the comprehensive heat transfer coefficient of the interface, and the Nusselt number of convective heat transfer were calculated. The coupling influence of different lithologies, water content, seepage rate, and ventilation parameters on the efficiency of the three-stage heat transfer links was quantitatively analyzed, providing experimental basis for the verification of the heat hazard prediction model in deep mines and the optimization of ventilation and cooling schemes.

[0063] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A deep metal mine cascade heat transfer simulation device, characterized in that: This includes a geothermal simulation system, a heat and moisture exchange system, an airflow monitoring system, and a data acquisition and control system. The geothermal simulation system includes a double-layered hollow cylindrical frame for establishing a controllable temperature field within a rock-like material to simulate heat conduction in the surrounding rock. A heat and moisture exchange system, integrated within the geothermal simulation system, comprises a porous tunnel lining and a seepage device. The porous tunnel lining is integrally formed with the rock-like material. Through a grouting port, rock-like material slurry is filled into the cavity between the porous tunnel lining and the inner wall of the geothermal simulation system. The slurry is vented and solidified through an outlet. The heat and moisture exchange system simulates heat and moisture exchange on the tunnel wall. An airflow monitoring system, connected to the heat and moisture exchange system, provides controllable airflow into the tunnel and monitors convective heat transfer parameters. A data acquisition and control system, connected to the geothermal simulation system, the heat and moisture exchange system, and the airflow monitoring system, adjusts operating parameters and collects data.

2. The deep metal mine cascade heat transfer simulation device as described in claim 1, characterized in that: The outer and inner walls of the double-layer hollow cylindrical frame are filled with thermal insulation material, and the cavity enclosed by the inner wall is filled with rock-like material; multiple annular electric heating units are arranged radially in layers within the rock-like material, and the power of each annular electric heating unit is independently controllable; a multi-point thermocouple array is also pre-embedded in the rock-like material, and the detection points of the multi-point thermocouple array are distributed in a grid pattern.

3. The deep metal mine cascade heat transfer simulation device as described in claim 2, characterized in that: The seepage device of the heat and moisture exchange system includes a microporous seepage network, which is tightly wrapped around the outer wall of the porous tunnel lining. The microporous seepage network is connected to a water injection and pressurization port and a water outlet, and the water flow is controlled by an external multi-channel high-precision peristaltic pump. A thin-film heat flux meter array is attached to the inner wall of the porous tunnel lining for in-situ measurement of the wall surface heat flux density.

4. The deep metal mine cascade heat transfer simulation device as described in claim 1, characterized in that: The airflow monitoring system includes a variable frequency centrifugal fan, a temperature and humidity control unit, a three-dimensional coordinate moving platform, and a multi-parameter integrated probe. The variable frequency centrifugal fan is connected to the inlet of the porous tunnel lining through a flow stabilization section. The temperature and humidity control unit is integrated at the front end of the fan and includes a heating module, a cooling module, and a humidification / dehumidification module, used to regulate the temperature, humidity, and wind speed of the inlet airflow. The three-dimensional coordinate moving platform is set on a guide rail inside the tunnel and is driven by a stepper motor. The multi-parameter integrated probe is mounted on the three-dimensional coordinate moving platform and integrates a three-dimensional hot-wire anemometer, a T-type thermocouple, and a capacitive humidity sensor.

5. The deep metal mine cascade heat transfer simulation device as described in claim 2, characterized in that: The acquisition and control system is configured to use temperature data fed back from a multi-point thermocouple array and employ a PID closed-loop control algorithm to dynamically adjust the power of each annular electric heating unit in order to construct a non-uniform three-dimensional temperature field.

6. The deep metal mine cascade heat transfer simulation device as described in claim 1, characterized in that: The porous tunnel lining is made of porous ceramic material.

7. The deep metal mine cascade heat transfer simulation device as described in claim 4, characterized in that: The three-dimensional coordinate moving platform includes a transverse drive mechanism and a longitudinal drive mechanism, which are used to drive the multi-parameter integrated probe to perform gridded moving scans in the axial, transverse and radial directions of the roadway, so as to realize the automated monitoring of the three-dimensional physical field.

8. A method for conducting experiments using the apparatus according to any one of claims 1-7, characterized in that, The specific steps are as follows: System preparation and model construction: A porous tunnel lining with a pre-installed microporous seepage network is fabricated. The microporous seepage network is connected to an external multi-channel high-precision peristaltic pump through a water injection and pressurization port and an outlet. The porous tunnel lining is fixed on the central axis of the geothermal simulation system. A rock-like material slurry with similar thermophysical properties is prepared and poured into the cavity between the porous tunnel lining and the inner wall of the geothermal simulation system through the grouting port. The slurry is vented through the grouting outlet. After the material solidifies, a tightly contacted cascade heat transfer solid model is formed. At the same time, a multi-point thermocouple array is deployed. The first stage of simulation: The power of each ring electric heating unit is independently controlled by the acquisition and control system, and closed-loop adjustment is performed based on the feedback data of the multi-point thermocouple array until a stable three-dimensional temperature field conforming to the preset geothermal gradient is established in the surrounding rock model. The second stage of simulation involves starting a multi-channel high-precision peristaltic pump to inject water into a microporous seepage network through a pressurized injection port. The water permeates from the network into the porous tunnel lining wall, forming wall seepage at a set flow rate and zoning pattern. Excess water is discharged from the outlet, simulating wall seepage and forming a stable sensible-latent heat coupling exchange boundary. A thin-film heat flux array is used to monitor the wall heat flux density in real time. The third stage of simulation: Start the variable frequency centrifugal fan and temperature and humidity control unit to deliver the set parameters of ventilation airflow into the roadway; drive the three-dimensional coordinate moving platform to control the multi-parameter integrated probe to move and position at different positions in the axial and radial directions of the roadway, and perform gridded scanning measurement of the velocity field, temperature field and humidity field of one or more key sections in the roadway. Comprehensive data analysis: The collected data on surrounding rock temperature field, wall heat flow, and multi-physics field of the tunnel are comprehensively processed to calculate the thermal resistance of surrounding rock, interfacial heat transfer coefficient, and convective heat transfer Nusselt number. The coupling influence of different lithologies, permeability, and ventilation volume on the cascade heat transfer efficiency is analyzed.

Images