Seepage heat transfer data detection device based on multistage fracture network rock sample

Abstract

The invention relates to the technical field of rock sample detection, and discloses a seepage heat transfer data detection device based on a multistage fracture network rock sample. A heat exchange working medium injection device of the device is connected with a first pressure adjusting device and a heat exchange working medium cooling circulation device. The heat-fluid-solid coupling pressure chamber is connected with the first pressure adjusting device, the second pressure adjusting device, the heat exchange working medium cooling circulation device, the temperature control device and the temperature detection device. By means of the device, interference of other temperature factors can be eliminated, flowing heat exchange is conducted only through the heat exchange working medium, heat loss in the device is completed only through the heat exchange working medium, a real scene in the mine-heat co-mining process is restored, and all measured parameters have authenticity and accuracy.

Description

Technical Field

[0001] The present application relates to the technical field of rock sample detection, and in particular, to a seepage heat transfer data detection device based on multi-level fracture network rock samples. Background Art

[0002] As a new technology, the relevant research conditions and specific implementation of mineral-heat co-mining are more complicated and face many challenges. Due to the good overall stability of deep ore rocks, the efficient mining of minerals requires the use of mining technologies such as excavation, blasting, and caving to expand and connect the ore rock cracks under the coupling of high temperature, high osmotic pressure and high ground stress until a large area of ​​complex fracture network is formed. This special mining method will inevitably form a rock formation geological morphology in which a large area of ​​rubble area and a small number of through-diagenetic fractures coexist. During geothermal mining in the middle, the permeability of the rock mass itself is relatively large, and a rock formation geological morphology of (rock matrix pores + a large number of microcracks + a small number of main cracks) will be formed. Therefore, the present application aims to propose a seepage heat transfer data detection device based on a multi-stage fracture network rock sample to conduct effective seepage-heat transfer experiments and data detection on this special multi-stage fracture network rock sample. Summary of the invention

[0003] The present application provides a seepage heat transfer data detection device based on multi-level fracture network rock samples, which can perform effective seepage-heat transfer tests and data detection on special multi-level fracture network rock samples, restore the actual working conditions in the mining-heat co-mining process, and then measure various data of the rock samples in the mining-heat co-mining process.

[0004] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0005] According to one aspect of an embodiment of the present application, a device for detecting seepage heat transfer data based on a multi-stage fracture network rock sample is provided, the device comprising: a heat exchange medium injection device, a first pressure regulating device, a second pressure regulating device, a heat exchange medium cooling circulation device, a heat-fluid-solid coupling pressure chamber, a temperature control device and a temperature detection device;

[0006] The heat exchange medium injection device is respectively connected to the first pressure regulating device and the heat exchange medium cooling circulation device, and the heat-fluid-solid coupling pressure chamber is respectively connected to the first pressure regulating device, the second pressure regulating device, the heat exchange medium cooling circulation device, the temperature control device and the temperature detection device;

[0007] The heat exchange medium injection device is used to output the heat exchange medium, and the heat exchange medium enters the heat-fluid-solid coupling pressure chamber after passing through the first pressure regulating device, and flows into the heat exchange medium cooling circulation device after flowing heat exchange in the heat-fluid-solid coupling pressure chamber to cool the heat exchange medium after flowing heat exchange, and the cooled heat exchange medium is transported to the heat exchange medium injection device;

[0008] The second pressure regulating device is used to adjust the pressure of the thermal-fluid-solid coupling pressure chamber, and the thermal-fluid-solid coupling pressure chamber includes a built-in rock sample, a clamping device, a first sleeve device, a second sleeve device and a plurality of temperature measuring lines; the rock sample is provided with a through hole penetrating the rock sample, the first sleeve device is sleeved in the through hole, and the first sleeve device is filled with a heat insulating material to prevent the heat exchange medium from flowing into the through hole, so that the heat exchange medium flowing into the rock sample only flows in the matrix pores and cracks of the rock sample;

[0009] The second sleeve device is sleeved on the outer surface of the rock sample, the first sleeve device and the second sleeve device are connected by a plurality of temperature measuring lines, the plurality of temperature measuring lines are arranged in the rock sample, and each of the temperature measuring lines is connected to the temperature detection device; the clamping device is used to clamp the two ends of the rock sample, the clamping device is connected to the annular inner wall of the thermal-fluid-solid coupling pressure chamber, the heat exchange medium enters from the annular inner wall of the thermal-fluid-solid coupling pressure chamber, flows through the clamping device into the rock sample, and the temperature detection device detects the temperature of the heat exchange medium in the rock sample through each of the temperature measuring lines.

[0010] In one embodiment of the present application, based on the above scheme, the thermal-fluid-solid coupling pressure chamber further includes a mixing device, a fluid inlet and a fluid outlet, and the mixing device is arranged at both ends of the rock sample; the clamping device includes a front clamp and a rear clamp, and the front clamp and the rear clamp are fixed by screws; the front clamp and the rear clamp are both provided with a heat-insulating water injection channel, and the two heat-insulating water injection channels are communicated with the mixing device, and graphite gaskets are provided in the gaps formed between the front clamp and the rear clamp and the second sleeve device respectively; the fluid inlet and the fluid outlet are respectively arranged in the two heat-insulating water injection channels, and the two heat-insulating water injection channels are filled with heat-insulating materials; the annular inner wall is a hollow chamber and is arranged inside the thermal-fluid-solid coupling pressure chamber, and the fluid inlet and the fluid outlet are both communicated with the annular inner wall;

[0011] The mixing device is provided with a plurality of flow openings. After the heat exchange medium enters from the fluid inlet, it flows through the heat-insulating water injection channel of the front clamp and then passes through the plurality of fluid openings of the mixing device and is dispersedly injected into the rock sample.

[0012] In one embodiment of the present application, based on the aforementioned scheme, the thermal-fluid-solid coupling pressure chamber also includes an oil outlet hole, an oil filling hole, an exhaust hole, an annular heating belt and an opening and closing valve arranged in the annular inner wall, and the oil filling hole and the exhaust hole are connected to the opening and closing valve; the annular outer wall of the thermal-fluid-solid coupling pressure chamber and the annular interior are filled with insulation material, and the annular heating belt is wrapped around the outer surface of the annular inner wall.

[0013] In one embodiment of the present application, based on the aforementioned scheme, the heat-fluid-solid coupling pressure chamber also includes an internal oil bath chamber, a safety device, an axial pressure chamber and a confining pressure device, the oil bath chamber is connected to the annular inner wall, and the rock sample is arranged in the oil bath chamber; the annular inner wall includes a chamber front wall, a first chamber rear wall and a second chamber rear wall; the confining pressure device is connected to the chamber front wall, the inner side surface of the first chamber rear wall is connected to the axial pressure chamber, and the first chamber rear wall is connected to the second chamber rear wall; the safety device is respectively connected to the outer side surface of the first chamber rear wall and the outer side surface of the second chamber rear wall.

[0014] In one embodiment of the present application, based on the aforementioned scheme, the first pressure regulating device includes a pressure stabilizing device, a mass flow meter, a preheating device, a first ball valve, a first oil filter and a first filter connected in sequence; the pressure stabilizing device is connected to the heat exchange medium injection device, and the first filter is connected to the fluid inlet.

[0015] In one embodiment of the present application, based on the aforementioned scheme, the heat exchange medium cooling circulation device includes a back pressure valve, a first temperature sensor, a first pressure sensor, a cooler, a first check valve, a second oil filter, a third pressure sensor, a second filter, a pressure difference sensor and a first low-temperature coolant circulation pump connected in parallel at both ends of the cooler; the back pressure valve is connected to the heat exchange medium injection device, and the pressure difference sensor is connected to the annular inner wall.

[0016] In one embodiment of the present application, based on the above scheme, a first passage and a second passage are provided between the first pressure regulating device and the heat exchange medium cooling circulation device, the first passage is composed of a second check valve, a first regulating valve and a second ball valve connected in sequence; the second check valve is respectively connected to the cooler and the first check valve, and the second ball valve is respectively connected to the pressure stabilizing device and the mass flow meter;

[0017] The second passage is composed of a second regulating valve and a third ball valve connected in sequence, the second regulating valve is connected to the cooler and the first check valve respectively, and the third ball valve is connected to the preheating device and the first ball valve respectively.

[0018] In one embodiment of the present application, based on the aforementioned scheme, the heat exchange medium injection device includes a gas storage bottle, a fourth ball valve, a liquid storage tank, a fifth ball valve, a third filter, a plunger pump, a third pressure sensor and a safety valve connected in sequence, and the safety valve is also connected to the preheating device; the heat exchange medium injection device also includes a second low-temperature coolant circulation pump, and the second low-temperature coolant circulation pump is respectively connected to the liquid storage tank and the plunger pump, and the liquid storage tank is also connected to the back pressure valve.

[0019] In one embodiment of the present application, based on the aforementioned scheme, the second pressure regulating device includes a first pressure regulating pipeline and a second pressure regulating pipeline, and the first pressure regulating pipeline and the second pressure regulating pipeline are both connected to the axial pressure chamber; the first pressure regulating pipeline is composed of a first electric pressure pump, a third regulating valve, and a fourth pressure sensor connected in sequence, and the second pressure regulating pipeline is composed of a second electric pressure pump, a fourth regulating valve and a fifth pressure sensor connected in sequence.

[0020] Beneficial effects of the present application: The present application places the rock sample in a heat-fluid-solid coupling pressure chamber, sleeves the outer surface of the rock sample through a second sleeve device, and clamps the rock sample through a clamping device, so that the heat exchange medium can only enter from both ends of the rock sample. The heat exchange medium flowing into the rock sample can only flow in the matrix pores and cracks of the rock sample through the first sleeve device filled with heat insulation material, and a temperature measuring line is set in the cracks of the rock sample, and the temperature measuring line connects the first sleeve device and the second sleeve device. The real temperature data of the rock sample in the mining condition and the real temperature data of the heat exchange medium flowing in the rock sample are detected through a temperature detection device connected to the temperature measuring line, thereby eliminating the interference of other temperature factors and truly restoring the actual mining condition of the rock sample.

[0021] Furthermore, the heat-fluid-solid coupling pressure chamber is externally connected with a first pressure regulating device, a second pressure regulating device and a heat exchange medium cooling circulation device. The heat exchange medium is injected through the heat exchange medium injection device and flows through the first pressure regulating device, so that the first pressure regulating device adjusts the various parameters such as the pressure and temperature of the heat exchange medium, so that the pressure and temperature of the heat exchange medium after adjustment can be consistent with the temperature setting value in the actual mining condition. At the same time, the pressure in the heat-fluid-solid coupling pressure chamber is adjusted by the second pressure regulating device, so that the pressure in the heat-fluid-solid coupling pressure chamber is consistent with the pressure setting value in the actual mining condition. In this way, a real mining condition under a full simulation state is formed. Then, the heat exchange medium after the heat exchange flow is recycled through the heat exchange medium cooling circulation device, and after cooling, it is input into the heat exchange medium injection device again. There is no need to add the cooled heat exchange medium. The heat exchange medium is recycled under the condition of simulating the real mining condition, thereby improving the resource utilization rate.

[0022] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0024] Figure 1 It is an overall block diagram of a seepage heat transfer data detection device based on a multi-stage fracture network rock sample according to an embodiment of the present application;

[0025] Figure 2 It is a specific structural diagram of a seepage heat transfer data detection device based on a multi-stage fracture network rock sample according to an embodiment of the present application;

[0026] Figure 3 It is a schematic diagram showing clamping of a rock sample in an axial pressure chamber according to an embodiment of the present application;

[0027] Figure 4 is a schematic diagram of a mixing tank and a second sleeve device according to an embodiment of the present application;

[0028] Figure 5 is an internal structure diagram of a heat-fluid-solid coupling pressure chamber according to an embodiment of the present application;

[0029] Figure 6It is a side cross-sectional view showing the clamping of a rock sample in an axial pressure chamber according to an embodiment of the present application.

[0030] Reference numerals

[0031] Gas cylinder 1, liquid storage tank 2, plunger pump 3, second low-temperature coolant circulation pump 4, pressure stabilizing device 5, mass flow meter 6, preheating device 7, thermal-fluid-solid coupling pressure chamber 8, temperature control device 9, first electric booster pump 10, third ball valve 11, third regulating valve 12, fourth pressure sensor 13, second electric booster pump 14, fourth regulating valve 15, fifth pressure sensor 16, fourth ball valve 17, fifth ball valve 18, third filter 19, safety valve 20, first ball valve 21, first oil filter 22, first filter 23, back pressure valve 24, first temperature sensor 25, first pressure sensor 26, cooler 27, first low-temperature coolant circulation pump 28, first check valve 29, second oil filter 30, third pressure sensor 31, second filter 32, differential pressure sensor 33, temperature detection device 34, The second check valve 35, the first regulating valve 36, the second ball valve 37, the second regulating valve 38, the fluid inlet 8-1, the fluid outlet 8-2, the thermocouple lead-out pipe 8-3, the front clamp 8-4, the rear clamp 8-5, the first chamber rear wall 8-6, the safety device 8-7, the axial pressure chamber 8-8, the second chamber rear wall 8-9, the confining pressure device 8-10, the chamber front wall 8-11, the annular inner wall 8-12, the outlet Oil hole 8-13, opening and closing valve 8-14, oil filling hole 8-15, exhaust hole 8-16, annular heating belt 8-17, first sleeve device 8-18, through hole 8-19, rock sample 8-20, thermal insulation water injection channel 8-21, screw 8-22, second sleeve device 8-23, temperature measuring line 8-24, oil bath chamber 8-25, thermal insulation material 8-26, graphite gasket 8-27, mixing device 8-28. DETAILED DESCRIPTION

[0032] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0033] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0034] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or micro-control node devices.

[0035] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0036] It should be noted that the "multiple" mentioned in this article refers to two or more. "And / or" describes the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0037] The following is a detailed introduction to the technical background of the embodiments of the present application:

[0038] Ore-heat co-mining is a new concept first proposed by my country, and there is no precedent in the world. Although the basic theories and technical reserves in the development and utilization of high-temperature rock geothermal resources at home and abroad are relatively mature, as a new technology, the relevant research conditions and specific implementation of mine-heat co-mining are more complicated and face many challenges. Since the overall stability of deep ore rocks is usually good, the efficient mining of minerals requires the use of mining technologies such as excavation, blasting, and caving to expand and connect the cracks of ore rocks under the coupling of high temperature, high osmotic pressure and high ground stress until a large-scale complex fracture network is formed. This special mining method will inevitably form a rock formation geological form with a large area of ​​​​gravel areas and a small number of through-diagenetic fractures. If the permeability of the rock mass itself is usually large during geothermal mining in the middle, a rock formation geological form (multi-level fracture network) of (rock matrix pores + a large number of microcracks + a small number of main fractures) will be formed. Among them, how to conduct seepage-heat transfer test research on rock samples 8-20 in this special multi-level fracture network is the key work. In the embodiments of the present application, the rock sample 8-20 of the multi-stage fracture network can be loaded into the clamping component, and the relevant parameters can be measured, and then the seepage-heat migration characteristics in the multi-stage fracture network rock sample 8-20 can be obtained through calculation and rule summary.

[0039] In actual work, it is found that most of the existing numerical simulations focus on the simulation of medium- and long-term mining conditions of geothermal mining under complex geological conditions, that is, the non-constant heat source loading of multi-stage fracture network rock sample 8-20, which is difficult to achieve in the test. Multi-stage fracture network rock sample 8-20 refers to a special rock sample 8-20 composed of matrix pores + a large number of microcracks + a small number of diagenetic cracks; non-constant heat source heating refers to the oil in the oil bath chamber 8-25 being stopped after being heated to a certain temperature. The oil temperature also changes due to the heat exchange between the heat exchange medium and the rock sample 8-20, and the heat loss in the system is only completed by the heat exchange medium. However, the oil in the oil bath chamber 8-25 of the existing seepage-heat transfer test device is directly pressurized by an external pressure pump, which not only has the risk of high-temperature oil leakage, but also continuously generates heat exchange with the outside world, causing fluctuations in the oil bath heat source. Furthermore, the existing device needs to apply axial pressure through external equipment, which is extremely inconvenient to move and test. Moreover, since the entire heat-fluid-solid coupled triaxial pressure chamber continuously exchanges heat with the outside world during the application of the above-mentioned confining pressure and axial pressure, it is difficult to achieve a non-constant heat source loading situation, that is, a situation in which the heat loss in the system is completed only by the heat exchange medium.

[0040] The implementation details of the technical solution of the embodiment of the present application are described in detail below:

[0041] According to one aspect of the present application, a device for detecting seepage heat transfer data based on a multi-level fracture network rock sample is provided. Figure 1 1 is an overall block diagram of a seepage heat transfer data detection device based on a multi-stage fracture network rock sample according to an embodiment of the present application. Figure 2 This is a specific structural diagram of a seepage heat transfer data detection device based on a multi-level fracture network rock sample according to an embodiment of the present application, which is described in detail as follows:

[0042] The seepage heat transfer data detection device based on the multi-stage fracture network rock sample proposed in the embodiment of the present application includes: a heat exchange medium injection device, a first pressure regulating device, a second pressure regulating device, a heat exchange medium cooling circulation device, a heat-fluid-solid coupling pressure chamber 8, a temperature control device 9 and a temperature detection device 34;

[0043] The heat exchange medium injection device is respectively connected to the first pressure regulating device and the heat exchange medium cooling circulation device, and the heat-fluid-solid coupling pressure chamber 8 is respectively connected to the first pressure regulating device, the second pressure regulating device, the heat exchange medium cooling circulation device, the temperature control device 9 and the temperature detection device 34;

[0044] The heat exchange medium injection device is used to output the heat exchange medium. The heat exchange medium enters the heat-fluid-solid coupling pressure chamber 8 after passing through the first pressure regulating device, flows into the heat exchange medium cooling circulation device after flow heat exchange in the heat-fluid-solid coupling pressure chamber 8, so as to cool the heat exchange medium after flow heat exchange, and transport the cooled heat exchange medium to the heat exchange medium injection device;

[0045] The second pressure regulating device is used to adjust the pressure of the thermal-fluid-solid coupling pressure chamber 8, and the thermal-fluid-solid coupling pressure chamber 8 includes a built-in rock sample 8-20, a clamping device, a first sleeve device 8-18, a second sleeve device 8-23 and a plurality of temperature measuring lines 8-24; the rock sample 8-20 is provided with a through hole 8-19 penetrating the rock sample 8-20, the first sleeve device 8-18 is sleeved in the through hole 8-19, and the first sleeve device 8-18 is filled with a heat insulating material to prevent the heat exchange medium from flowing into the through hole 8-19, so that the heat exchange medium flowing into the rock sample 8-20 flows only in the matrix pores and cracks of the rock sample 8-20;

[0046] The second sleeve device 8-23 is sleeved on the outer surface of the rock sample 8-20, and the first sleeve device 8-18 and the second sleeve device 8-23 are connected by multiple temperature measuring lines 8-24. Multiple temperature measuring lines 8-24 are arranged in the rock sample 8-20, and each of the temperature measuring lines 8-24 is connected to the temperature detection device 34; the clamping device is used to clamp the two ends of the rock sample 8-20, and the clamping device is connected to the annular inner wall 8-12 of the thermal-fluid-solid coupling pressure chamber 8. The heat exchange medium enters from the annular inner wall 8-12 of the thermal-fluid-solid coupling pressure chamber 8, flows through the clamping device and enters the rock sample 8-20, and the temperature detection device 34 detects the temperature of the heat exchange medium in the rock sample 8-20 through each of the temperature measuring lines 8-24.

[0047] Specifically, the rock sample 8-20 is placed in the heat-fluid-solid coupling pressure chamber 8, and the second sleeve device 8-23 is sleeved on the outer surface of the rock sample 8-20, and the rock sample 8-20 is clamped by the clamping device, so that the heat exchange medium can only enter from the two ends of the rock sample 8-20. The first sleeve device 8-18 filled with heat insulation material allows the heat exchange medium flowing into the rock sample 8-20 to only flow in the rock sample 8-20 for heat exchange, and a temperature measuring line 8-24 is set in the crack of the rock sample 8-20. The temperature measuring line 8-24 is a thermocouple. The temperature measuring line 8-24 connects the first sleeve device 8-18 and the second sleeve device 8-23. The temperature detection device 34 connected to the temperature measuring line 8-24 is used to detect the real temperature data of the rock sample 8-20 in the mining condition, thereby eliminating the interference of other temperature factors and truly restoring the actual mining condition of the rock sample 8-20.

[0048] Furthermore, the heat-fluid-solid coupling pressure chamber 8 is externally connected with a first pressure regulating device, a second pressure regulating device and a heat exchange medium cooling circulation device. The heat exchange medium is injected through the heat exchange medium injection device and flows through the first pressure regulating device, so that the first pressure regulating device regulates the pressure and temperature of the heat exchange medium, so that the regulated pressure and temperature of the heat exchange medium can be consistent with the temperature setting value in the actual mining condition. At the same time, the pressure in the heat-fluid-solid coupling pressure chamber 8 is regulated by the second pressure regulating device, so that the pressure in the heat-fluid-solid coupling pressure chamber 8 is consistent with the pressure setting value in the actual mining condition. In this way, a real mining condition under a full simulation state is formed. Then, the heat exchange medium after the heat exchange flow is recycled through the heat exchange medium cooling circulation device, and after cooling, it is input into the heat exchange medium injection device again. There is no need to add cooled heat exchange medium, and the heat exchange medium is recycled under the condition of simulating the real mining condition, thereby improving resource utilization.

[0049] The present application can realize data measurement of the seepage-heat transfer process of multi-stage fracture network rock samples 8-20 under the action of non-constant heat source, and simulate the mining conditions during geothermal mining under complex geological conditions, which corresponds to the actual situation of non-constant heat source loading of multi-stage fracture network rock samples 8-20 which is difficult to achieve in the experiment.

[0050] Furthermore, the heat-fluid-solid coupling pressure chamber 8 also includes a mixing device 8-28, a fluid inlet 8-1 and a fluid outlet 8-2, and the mixing device 8-28 is arranged at both ends of the rock sample 8-20; the clamping device includes a front clamp 8-4 and a rear clamp 8-5, and the front clamp 8-4 and the rear clamp 8-5 are fixed by a screw 8-22; the front clamp 8-4 and the rear clamp 8-5 are both provided with an insulating water injection channel 8-21, and the two insulating water injection channels 8-21 are connected to the mixing device 8-28. The front clamp 8-4 and the rear clamp 8-5 are connected to the second sleeve device 8-23, and the gaps formed between them are provided with graphite gaskets 8-27; the fluid inlet 8-1 and the fluid outlet 8-2 are respectively arranged in the two insulating water injection channels 8-21, and the two insulating water injection channels 8-21 are filled with insulating materials; the annular inner wall 8-12 is a hollow chamber, and is arranged inside the thermal-fluid-solid coupling pressure chamber 8, and the fluid inlet 8-1 and the fluid outlet 8-2 are both connected to the annular inner wall 8-12;

[0051] Among them, the mixing device 8-28 is provided with a plurality of flow openings. After the heat exchange medium enters from the fluid inlet 8-1, it flows through the heat-insulating water injection channel 8-21 of the front clamp 8-4, passes through the plurality of fluid openings of the mixing device 8-28 and is dispersedly injected into the rock sample 8-20.

[0052] like Figure 3 and Figure 4 As shown, the first sleeve device 8-18 can be specifically a steel sleeve, and the second sleeve device 8-23 can be specifically a copper sleeve. The specially made multi-stage fracture network rock sample 8-20 is first inserted into the steel sleeve from the through hole 8-19 and then into the copper sleeve 8-23 from the outer side. The steel sleeve and the copper sleeve have multiple 0.8 mm small holes at the same position for the temperature measuring line 8-24 to pass through, so that the temperature measuring line 8-24 can connect the first sleeve device 8-18 and the second sleeve device 8-23, and is led out from the thermocouple lead-out tube 8-3 set in the through hole 8-19 and connected to the temperature detection device 34. In this way, the temperature detection device 34 can accurately measure the temperature at different measuring points in the rock sample 8-20 through the temperature measuring line 8-24. It should be noted that Figure 3 The rock samples 8-20 shown are only half of the real rock samples in the actual scene. Figure 3 The rock sample 8-20 is cut in half only to more clearly see the interior of the entire device, so that the interior of the rock sample 8-20 and the location of each device can be more clearly seen.

[0053] The external pressure of the rock causes the copper sleeve to deform, thereby ensuring that there is no gap between the rock and the two sleeves, and the high-pressure fluid only flows through the matrix pores and cracks of the rock sample 8-20. The steel sleeve is filled with insulation material to prevent the heat exchange medium from passing through, so that the heat exchange medium can only flow in the cracks. The rock sample 8-20 is then loaded into the clamping device, and a graphite gasket 8-27 is put on part of the clamping device, and finally a copper sleeve is put on the outer side of the rock sample 8-20 and the clamping device. The pressure difference between the oil bath and the fluid inside the rock sample causes the copper sleeve to deform, thereby ensuring that there is no gap between the rock sample 8-20 and the first sleeve device 8-18, and the high-pressure fluid only flows inside the rock sample. The graphite gasket 8-27 deforms and expands under the combined action of oil pressure and mechanical force, and fits tightly with the copper sleeve, so that the heat exchange medium and the oil bath will not leak from each other. The fluid inlet 8-1 and the fluid outlet 8-2 in the heat-insulating water injection channel 8-21 in the clamping device are used for the flow of heat exchange medium, so that the heat exchange medium enters the interior of the rock sample 8-20.

[0054] The complex arrangement of the clamping device, copper sleeve, rock sample 8-20, and graphite gasket 8-27 is to prevent the fluid (heat exchange medium) from flowing in the gap between the rock and the copper sleeve. The pressure difference between the oil bath and the fluid in the rock sample causes the copper sleeve to deform, thereby ensuring that there is no gap between the rock and the sleeve, and the high-pressure fluid only flows through the matrix pores and cracks. The graphite gasket 8-27 deforms and expands under the combined action of oil pressure and mechanical force, and fits tightly with the copper sleeve, so that there is no leakage between the fluid and the oil bath. The channels in the front clamp 8-4 and the rear clamp 8-5 are used for fluid flow and the extraction of thermocouples.

[0055] A mixing device 8-28 is also provided between the clamping device and the rock sample 8-20. The mixing device 8-28 is a device with multiple flow openings. The heat exchange medium enters the mixing device 8-28 from the fluid inlet 8-1 of the heat-insulating water injection channel 8-21. Due to the multiple flow openings, the heat exchange medium enters the rock sample 8-20 from each flow opening in a dispersed manner. This is to reduce the difference between the liquid temperature at the fluid inlet 8-1 of the clamping device and the liquid temperature at the inlet of the rock sample 8-20. When the injected heat exchange medium is injected into the surface of the rock sample 8-20, it only contacts the steel axial pressure pressurization part (a part of the clamping device that can be used for axial pressure pressurization and heating) at the port of the clamping device, and the temperature changes after being heated by the clamping device.

[0056] Mixing devices 8-28 are respectively arranged at the contact point between the rock sample 8-20 and the clamping device, that is, at both ends of the fluid inlet 8-1 and the fluid outlet 8-2, for dispersing the injected liquid. The mixing device 8-28 is a porous component made of high-strength heat-insulating material, through which the fluid can freely enter and exit. There are multiple pyramid-shaped protrusions on the surfaces of both ends of the mixing device 8-28. The mixing device 8-28 can make the fluid (heat exchange medium) evenly mixed at the inlet and outlet of the rock sample 8-20. At the same time, it avoids the situation where the fluid inlet 8-1 directly contacts the surface of the rock sample 8-20, resulting in uneven pressure on the surface of the rock sample 8-20. That is, the mixing device 8-28 changes the point loading to the surface loading of the liquid inlet on the surface of the rock sample 8-20 from point loading, avoiding excessive and uneven local pressure caused by point loading.

[0057] A temperature measuring point, that is, a thermocouple lead-out tube 8-3, can be arranged in the mixing device 8-28. By comparing the temperature of the mixing device 8-28 with the temperature before entering the clamping device, the functional relationship is obtained, and then the temperature of the fluid entering the clamping device is controlled, and the accuracy of the temperature entering the rock sample 8-20 is further improved, so that the temperature of the heat exchange medium before entering the rock sample 8-20 reaches the required set value, and the accuracy and authenticity of the test are further improved.

[0058] The following are the steps for making the specially made rock sample 8-20:

[0059] When formally preparing the special rock samples 8-20, 10 cylindrical porous matrix rock samples with a diameter of 100mm and a height of 200mm are taken from a complete rock, and their porosity is obtained using nuclear magnetic resonance technology, and their permeability is obtained by placing them in a pulse attenuation permeameter. A circular hole with a diameter of 21+0.5mm (that is, the through hole 8-19 described in the embodiment of the present application) is drilled in the center of the sample (rock sample 8-20). The diameter of the circular hole is slightly larger than the diameter of the 20mm detection steel sleeve for sensor wiring. The rock samples are placed in a high-temperature furnace and heated to several groups of different high temperatures, taken out and quickly placed in 20°C water to obtain 10 different rock samples 8-20 containing a large number of microcracks and porous matrices. At this time, the permeability of the rock is determined by the permeability of the microcracks (k f 1-k f 10 ) and the permeability of matrix pores (k m 1-k m 10) is composed of CT scanning technology to obtain images of the interior of the rock and perform binarization processing to distinguish the pores and cracks in the rock matrix. Finally, the volume fraction of pores and cracks is determined through three-dimensional reconstruction and voxel calculation. Two peaks can be clearly found on the display of the void size and void volume fraction. The void volume fraction corresponding to the larger void size is the crack rate, while the smaller one is the porosity. The total permeability (k1-k 10 ). Because the empirical relationship between porosity and permeability of matrix pores has been obtained, the permeability of microcracks at this time can be obtained by the difference between total permeability and permeability of matrix pores. With the help of data processing software such as matlab, the functional relationship between the fracture rate of microcracks and their permeability can be obtained. Use a sand wire cutter to cut the processed rock sample 8-20 into a multi-crack sample with a certain rough feature, and take the main cracks with different crack widths. Finally, use a 0.8mm drill bit to drill multiple holes 8-19 from the inner surface of the multi-crack sample as required for arranging temperature measuring lines 8-24, etc., and the above-mentioned special rock sample 8-20 is prepared. Its basic parameters such as the porosity and permeability of matrix pores, the fracture rate and permeability of microcracks, the fracture opening of the main fracture, and the distribution morphology of the fracture network have been obtained, which can be used for numerical simulation and theoretical verification.

[0060] Furthermore, Figure 5 and Figure 6 As shown, Figure 5 is a schematic diagram of the interior of the thermal-fluid-solid coupling pressure chamber 8, Figure 6 It is a schematic diagram of the axial pressure chamber 8-8. The heat-fluid-solid coupling pressure chamber 8 also includes an oil outlet hole 8-13, an oil filling hole 8-15, an exhaust hole 8-16, an annular heating belt 8-17 and an opening and closing valve 8-14 arranged in the annular inner wall 8-12, and the oil filling hole 8-15 and the exhaust hole 8-16 are connected to the opening and closing valve 8-14; the annular outer wall and the annular inner wall of the heat-fluid-solid coupling pressure chamber 8 are filled with insulation material 8-26, and the annular heating belt 8-17 is arranged on the top of the annular inner wall 8-12.

[0061] The heat-fluid-solid coupling pressure chamber 8 also includes an internal oil bath chamber 8-25, a safety device 8-7, an axial pressure chamber 8-8 and a confining pressure device 8-10, wherein the oil bath chamber 8-25 is connected to the annular inner wall 8-12, and the rock sample 8-20 is arranged in the oil bath chamber 8-25; the annular inner wall 8-12 includes a chamber front wall 8-11, a first chamber rear wall 8-6 ​​and a second chamber rear wall 8-9; the confining pressure device 8-10 is connected to the chamber front wall 8-11, the inner side surface of the first chamber rear wall 8-6 ​​is connected to the axial pressure chamber 8-8, and the first chamber rear wall 8-6 ​​is connected to the second chamber rear wall 8-9; the safety device 8-7 is respectively connected to the outer side surface of the first chamber rear wall 8-6 ​​and the outer side surface of the second chamber rear wall 8-9.

[0062] Specifically, the heat-fluid-solid coupling pressure chamber 8 is provided with a confining pressure device 8-10, an annular heating belt 8-17, an annular inner wall 8-12, an axial pressure device (composed of the chamber front wall 8-11 of the annular inner wall 8-12 and the front clamp 8-4) and a safety device 8-7, and the above six devices are all removable. The oil bath chamber 8-25 is used to store heated and pressurized oil. The confining pressure device 8-10 is connected to the annular inner wall 8-12 and is used to pressurize the oil in the oil bath chamber 8-25. The annular heating belt 8-17 is closely connected to the annular inner wall 8-12 and is used to heat the oil in the oil bath chamber 8-25.

[0063] The axial pressure pressurizing device is composed of the chamber front wall 8-11 of the annular inner wall 8-12 and the front clamp 8-4, which is used to apply axial pressure to the rock sample 8-20. The safety device 8-7 is composed of two semicircles, which can be embedded in the front clamp 8-4 or the rear clamp 8-5 after assembly to prevent the front clamp 8-4 or the rear clamp 8-5 from being separated from the oil bath chamber 8-25 during the application of axial pressure, thereby preventing the front clamp 8-4 or the rear clamp 8-5 from being dangerously separated from the oil bath chamber 8-25. The assembled axial pressure chamber 8-8 is connected to the rock sample 8-20 and the clamping device, and the axial pressure chamber 8-8 is assembled. Then, the axial pressure chamber 8-8 is covered with a copper sleeve (i.e., the first sleeve device 8-18) and connected to various external devices and microcomputer detection equipment, and the entire thermal-fluid-solid coupling triaxial pressure chamber is assembled, completing the preparation steps for the test.

[0064] The following are the specific steps in the test process:

[0065] After the air inside the confining pressure device 8-10 and the axial pressure pressurizing device is exhausted, the top oil filling port and exhaust port of the axial pressure chamber 8-8 are opened, and bath oil is added until the entire oil bath chamber 8-25 is filled, and the opening is closed and the screws are tightened. Add pressure oil to the cavity of the confining pressure device 8-10 to apply axial pressure σ1 and confining pressure σ3, close the on-off valve 8-14, and use the annular heating belt 8-17 to heat the liquid oil temperature in the oil bath chamber 8-25 to the target temperature T0. After the temperature stabilizes, under the action of heat transfer, the outer surface temperature of the sample, the liquid oil temperature of the oil bath chamber 8-25, the surface temperature of the clamping device, and the temperature of the axial pressure chamber 8-8 are all consistent with the surface temperature of the annular heating belt 8-17, all of which are T0; at this time, due to the change in the temperature of the liquid oil in the axial pressure chamber 8-8, the axial pressure and confining pressure have changed, and it is necessary to open the on-off valve 8-14 again to adjust the axial pressure and confining pressure to σ1 and σ3 respectively, and then close the on-off valve 8-14. If a seepage-heat transfer test of a multi-stage fracture network rock sample 8-20 with a constant heat source (continuous heating to maintain the oil bath temperature constant) is conducted, the microcomputer is used to detect and control the annular heating belt 8-17 to heat and maintain the liquid oil in the pressure chamber at the target temperature T0 after the test starts. If a seepage-heat transfer test of a multi-stage fracture network rock sample 8-20 with a non-constant heat source (the oil bath is heated to a certain temperature and then stops heating, and only the heat exchange medium exchanges heat) is conducted, the annular heating belt 8-17 is closed and the heating is stopped. If a long-term heat exchange test is conducted, since the temperature of the liquid oil inside the axial pressure chamber 8-8 changes greatly, the confining pressure and the axial pressure change, and it is necessary to detect the pressure change through a microcomputer and set a confining pressure change threshold value such as 5%. Whenever the confining pressure changes beyond this threshold value, the on-off valve 8-14 will be reopened to pressurize the axial pressure and the confining pressure to σ1 and σ3 respectively, and the on-off valve 8-14 will be closed again. Since the oil pressure inside the confining pressure device 8-10 is much smaller than the liquid oil pressure in the axial pressure chamber 8-8, the added oil will not affect the overall heat. A heat-insulating sleeve (i.e., the first sleeve device 8-18) is arranged outside the axial pressure chamber 8-8, and the pressurized pipe is wrapped with a heat-insulating material 8-26. The opening and closing valve 8-14 prevents the exchange of pressure oil. At this time, it can be considered that the total heat loss of the entire system of the heat-fluid-solid coupling pressure chamber 8 is caused by the heat exchange medium.

[0066] The chamber front wall 8-11 is provided with a confining pressure device 8-10 and a chamber front wall 8-11, and the oil pressure in the oil bath chamber 8-25 is indirectly controlled by the confining pressure device 8-10, while the temperature control device 9 controls the temperature of the oil in the oil bath chamber 8-25. Avoid the risk of leakage of high-temperature oil, and prevent the high-temperature oil from continuously exchanging heat with the outside world, causing the problem of fluctuation of the oil bath heat source. When conducting the seepage-heat transfer test study of the non-constant heat source multi-stage fracture network rock sample 8-20, because the hydraulic oil capacity in the confining pressure device 8-10 is much smaller than the oil capacity in the oil bath chamber 8-25, the outside of the pressurized pipe is wrapped with an insulating material 8-26, and the entire heat-fluid-solid coupling pressure chamber 8 is wrapped in the insulating material 8-26. When the confining pressure is controlled by an external electric booster pump, the heat loss can be ignored. If traditional equipment is used, the bath oil in the oil bath chamber 8-25 is directly pressurized, and there is a large amount of heat exchange.

[0067] Furthermore, the second pressure regulating device includes a first pressure regulating pipeline and a second pressure regulating pipeline, and the first pressure regulating pipeline and the second pressure regulating pipeline are both connected to the axial pressure chamber 8-8; the first pressure regulating pipeline is composed of a first electric pressure pump 10, a third regulating valve 12, and a fourth pressure sensor 13 connected in sequence, and the second pressure regulating pipeline is composed of a second electric pressure pump 14, a fourth regulating valve 15 and a fifth pressure sensor 16 connected in sequence.

[0068] Specifically, the second pressure regulating device is also the axial pressure and confining pressure loading device, which includes a first pressure regulating pipeline and a second pressure regulating pipeline, wherein the first pressure regulating pipeline is composed of a first electric pressure pump 10, a third regulating valve 12, and a fourth pressure sensor 13 connected in sequence, and the second pressure regulating pipeline is composed of a second electric pressure pump 14, a fourth regulating valve 15, and a fifth pressure sensor 16 connected in sequence, and the temperature control device 9 is monitored and controlled by a microcomputer to ensure the temperature applied to the outside of the rock samples 8-20 during the entire test process. The fourth pressure sensor 13 and the fifth pressure sensor 16 are monitored by a microcomputer to control the first electric pressure pump 10 and the second electric pressure pump 14 for axial pressure and confining pressure loading, respectively, to achieve stable loading of the axial pressure and confining pressure of the rock samples 8-20.

[0069] Specifically, when conducting a seepage-heat transfer test study on a non-constant heat source multi-stage fracture network rock sample 8-20, due to the large change in the temperature of the liquid oil inside the pressure chamber, the confining pressure and the axial pressure change, and it is necessary to detect the pressure change through a microcomputer and set a confining pressure change threshold such as 5%. Whenever the pressure change exceeds this threshold, reopen the on-off valve 8-14 to increase the pressure to the axial pressure and the confining pressure to maintain pressure stability, and close the on-off valve 8-14 again.

[0070] Furthermore, the first pressure regulating device includes a pressure stabilizing device 5, a mass flow meter 6, a preheating device 7, a first ball valve 21, a first oil filter 22 and a first filter 23 which are connected in sequence; the pressure stabilizing device 5 is connected to the heat exchange medium injection device, and the first filter 23 is connected to the fluid inlet 8-1.

[0071] The heat exchange medium cooling circulation device includes a back pressure valve 24, a first temperature sensor 25, a first pressure sensor 26, a cooler 27, a first check valve 29, a second oil filter 30, a third pressure sensor 31, a second filter 32, a pressure difference sensor 33 and a first low-temperature coolant circulation pump 28 connected in parallel at both ends of the cooler 27; the back pressure valve 24 is connected to the heat exchange medium injection device, and the pressure difference sensor 33 is connected to the annular inner wall 8-12.

[0072] A first passage and a second passage are provided between the first pressure regulating device and the heat exchange medium cooling circulation device, the first passage being composed of a second check valve 35, a first regulating valve 36 and a second ball valve 37 connected in sequence; the second check valve 35 is connected to the cooler 27 and the first check valve 29 respectively, and the second ball valve 37 is connected to the pressure stabilizing device 5 and the mass flow meter 6 respectively;

[0073] The second passage is composed of a second regulating valve 38 and a third ball valve 11 connected in sequence. The second regulating valve 38 is connected to the cooler 27 and the first check valve 29 respectively, and the third ball valve 11 is connected to the preheating device 7 and the first ball valve 21 respectively.

[0074] The heat exchange medium injection device includes a gas cylinder 1, a fourth ball valve 17, a liquid storage tank 2, a fifth ball valve 18, a third filter 19, a plunger pump 3, a third pressure sensor 31 and a safety valve 20 connected in sequence, and the safety valve 20 is also connected to the preheating device 7; the heat exchange medium injection device also includes a second low-temperature coolant circulation pump 4, and the second low-temperature coolant circulation pump 4 is respectively connected to the liquid storage tank 2 and the plunger pump 3, and the liquid storage tank 2 is also connected to the back pressure valve 24.

[0075] The second pressure regulating device includes a first pressure regulating pipeline and a second pressure regulating pipeline, and the first pressure regulating pipeline and the second pressure regulating pipeline are both connected to the axial pressure chamber 8-8; the first pressure regulating pipeline is composed of a first electric pressure pump 10, a third regulating valve 12, and a fourth pressure sensor 13 connected in sequence, and the second pressure regulating pipeline is composed of a second electric pressure pump 14, a fourth regulating valve 15 and a fifth pressure sensor 16 connected in sequence.

[0076] Specifically, after the debugging of the thermal-fluid-solid coupling triaxial pressure chamber is completed, the gas cylinder 1 and the fourth ball valve 17 between the gas cylinder 1 and the liquid storage tank 2 are opened, and the gaseous CO2 (carbon dioxide) in the gas cylinder 1 enters the test system, that is, enters the liquid storage tank 2, is cooled to a liquid state in the liquid storage tank 2, and the liquid CO2 enters the plunger pump 3 after filtration. By adjusting the opening of the back pressure valve 24 to control the pressure difference before and after the back pressure valve 24, that is, the pressure difference between the test section and the liquid storage tank 2, CO2 can be pressurized to the supercritical pressure state required for the test in the plunger pump 3. By adjusting the plunger pump 3, the mass flow rate of the liquid CO2 in the system reaches the set value, the liquid CO2 enters the pressure stabilizing device 5 to eliminate the pressure fluctuation, and the mass flow rate of the liquid CO2 is measured by the mass flowmeter 6. By adjusting the parallel pipeline (i.e., the first passage and the second passage) set before the mass flowmeter 6, the flow fluctuation of the liquid CO2 caused by the piston compression of the pump when the flow rate is small is reduced as much as possible. After the liquid CO2 passes through the preheating device 7, there is a bypass (second passage) and a main passage, and the main passage is the liquid passage along the first ball valve 21, the first oil filter 22 and the first filter 23. By controlling the ball valves of the main passage and the bypass, the liquid CO2 can flow instantaneously through the heated rock sample. The liquid CO2 enters the rock cracks for flow heat exchange, and then is cooled to the required temperature through the cooler 27, and returns to the liquid storage tank 2 through the back pressure valve 24 to form a closed flow loop. In summary, the present application obtains the fluid temperature, pressure, flow rate and other information at the inlet and outlet of the rock sample 8-20 with the help of a mass flow meter 6, various pressure sensors, a differential pressure sensor 33 and various temperature sensors (i.e., a temperature detection device 34), and obtains the internal temperature information with the help of a thermocouple (temperature measuring line 8-24) arranged inside the rock sample 8-20.

[0077] In summary, the present application can measure the temperature change at any position by adopting a specially designed wiring method. A mixing device 8-28 is designed at the junction of the clamping device and the rock sample 8-20 to avoid the uneven fluid temperature near the contact point between the clamping device and the rock sample 8-20, accurately control the fluid temperature of the core test section, and further ensure the accuracy of the test.

[0078] Special rock samples 8-20 are designed to simulate the special geology of the coexistence of heat extraction process (rock matrix pores + a large number of microcracks + a small number of main cracks) in the mineral-heat co-extraction project, and provide basic experimental parameters, such as the porosity and permeability of the porous matrix, the fracture rate and permeability of the microcracks, the fracture aperture of the diagenetic fractures, and the distribution of the fracture network.

[0079] Therefore, the present application can realize the data measurement of the multi-stage fracture network rock sample 8-20 in the seepage-heat transfer process under the action of non-constant heat source, which corresponds to the non-constant heat source loading of the multi-stage fracture network rock sample 8-20 which is difficult to realize in the test. The separation of heating and pressurization is realized by embedding the confining pressure device 8-10 in the front wall of the heat-fluid-solid coupling pressure chamber 8, and the axial pressure pressurization device is composed of the rear clamp 8-5 and the first chamber rear wall 8-6 ​​and the second chamber rear wall 8-9, so that the whole device can be wrapped in the heat insulation material 8-26. While realizing the simultaneous application of confining pressure and axial pressure, the heating is stopped after the oil bath is heated to a certain temperature, realizing the test scenario in which heat is exchanged only by the heat exchange medium.

[0080] In addition, the above-mentioned figures are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present application, and are not intended to be limiting. It is easy to understand that the processes shown in the above-mentioned figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0081] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be performed without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A seepage heat transfer data detection device based on multi-level fracture network rock samples, characterized in that: The device comprises: a heat exchange medium injection device, a first pressure regulating device, a second pressure regulating device, a heat exchange medium cooling circulation device, a heat-fluid-solid coupling pressure chamber, a temperature control device and a temperature detection device; The heat exchange medium injection device is respectively connected to the first pressure regulating device and the heat exchange medium cooling circulation device, and the heat-fluid-solid coupling pressure chamber is respectively connected to the first pressure regulating device, the second pressure regulating device, the heat exchange medium cooling circulation device, the temperature control device and the temperature detection device; The heat exchange medium injection device is used to output the heat exchange medium, and the heat exchange medium enters the heat-fluid-solid coupling pressure chamber after passing through the first pressure regulating device, and flows into the heat exchange medium cooling circulation device after flowing heat exchange in the heat-fluid-solid coupling pressure chamber to cool the heat exchange medium after flowing heat exchange, and the cooled heat exchange medium is transported to the heat exchange medium injection device; The second pressure regulating device is used to adjust the pressure of the thermal-fluid-solid coupling pressure chamber, and the thermal-fluid-solid coupling pressure chamber includes a built-in rock sample, a clamping device, a first sleeve device, a second sleeve device and a plurality of temperature measuring lines; the rock sample is provided with a through hole penetrating the rock sample, the first sleeve device is sleeved in the through hole, and the first sleeve device is filled with a heat insulating material to prevent the heat exchange medium from flowing into the through hole, so that the heat exchange medium flowing into the rock sample only flows in the matrix pores and cracks of the rock sample; The second sleeve device is sleeved on the outer surface of the rock sample, and the first sleeve device and the second sleeve device are connected by a plurality of temperature measuring lines, and the plurality of temperature measuring lines are arranged in the cracks of the rock sample, and each of the temperature measuring lines is connected to the temperature detection device; the clamping device is used to clamp the two ends of the rock sample, and the clamping device is connected to the annular inner wall of the thermal-fluid-solid coupling pressure chamber, and the heat exchange medium enters from the annular inner wall of the thermal-fluid-solid coupling pressure chamber, flows through the clamping device and enters the rock sample, and the temperature detection device detects the temperature of the heat exchange medium in the rock sample through each of the temperature measuring lines.

2. The device for detecting seepage heat transfer data based on multi-level fracture network rock samples according to claim 1, characterized in that: The thermal-fluid-solid coupling pressure chamber also includes a mixing device, a fluid inlet and a fluid outlet, wherein the mixing device is arranged at both ends of the rock sample; the clamping device includes a front clamp and a rear clamp, wherein the front clamp and the rear clamp are fixed by screws; the front clamp and the rear clamp are both provided with a heat-insulating water injection channel, wherein the two heat-insulating water injection channels are both communicated with the mixing device, and graphite gaskets are respectively arranged in the gaps formed between the front clamp and the rear clamp and the second sleeve device; the fluid inlet and the fluid outlet are respectively arranged in the two heat-insulating water injection channels, and the two heat-insulating water injection channels are filled with heat-insulating materials; the annular inner wall is a hollow chamber, and is arranged inside the thermal-fluid-solid coupling pressure chamber, wherein the fluid inlet and the fluid outlet are both communicated with the annular inner wall; The mixing device is provided with a plurality of flow openings. After the heat exchange medium enters from the fluid inlet, it flows through the heat-insulating water injection channel of the front clamp and then passes through the plurality of fluid openings of the mixing device and is dispersedly injected into the rock sample.

3. The seepage heat transfer data detection device based on multi-level fracture network rock samples according to claim 2 is characterized in that: The thermal-fluid-solid coupling pressure chamber also includes an oil outlet hole, an oil filling hole, an exhaust hole, an annular heating belt and an opening and closing valve arranged in the annular inner wall, and the oil filling hole and the exhaust hole are connected to the opening and closing valve; the annular outer wall of the thermal-fluid-solid coupling pressure chamber and the annular interior are filled with insulation material, and the annular heating belt is wrapped around the outer surface of the annular inner wall.

4. The device for detecting seepage heat transfer data based on multi-level fracture network rock samples according to claim 3, characterized in that: The heat-fluid-solid coupling pressure chamber also includes an internal oil bath chamber, a safety device, an axial pressure chamber and a confining pressure device. The oil bath chamber is connected to the annular inner wall, and the rock sample is arranged in the oil bath chamber; the annular inner wall includes a chamber front wall, a first chamber rear wall and a second chamber rear wall; the confining pressure device is connected to the chamber front wall, the inner side surface of the first chamber rear wall is connected to the axial pressure chamber, and the first chamber rear wall is connected to the second chamber rear wall; the safety device is respectively connected to the outer side surface of the first chamber rear wall and the outer side surface of the second chamber rear wall.

5. The device for detecting seepage heat transfer data based on multi-level fracture network rock samples according to claim 4, characterized in that: The first pressure regulating device includes a pressure stabilizing device, a mass flow meter, a preheating device, a first ball valve, a first oil filter and a first filter which are connected in sequence; the pressure stabilizing device is connected to the heat exchange medium injection device, and the first filter is connected to the fluid inlet.

6. The device for detecting seepage heat transfer data based on multi-level fracture network rock samples according to claim 5, characterized in that: The heat exchange medium cooling circulation device includes a back pressure valve, a first temperature sensor, a first pressure sensor, a cooler, a first check valve, a second oil filter, a third pressure sensor, a second filter, a pressure difference sensor and a first low-temperature coolant circulation pump connected in parallel at both ends of the cooler; the back pressure valve is connected to the heat exchange medium injection device, and the pressure difference sensor is connected to the annular inner wall.

7. The device for detecting seepage heat transfer data based on multi-level fracture network rock samples according to claim 6, characterized in that: A first passage and a second passage are provided between the first pressure regulating device and the heat exchange medium cooling circulation device, the first passage being composed of a second check valve, a first regulating valve and a second ball valve connected in sequence; the second check valve is respectively connected to the cooler and the first check valve, and the second ball valve is respectively connected to the pressure stabilizing device and the mass flow meter; The second passage is composed of a second regulating valve and a third ball valve connected in sequence, the second regulating valve is connected to the cooler and the first check valve respectively, and the third ball valve is connected to the preheating device and the first ball valve respectively.

8. The device for detecting seepage heat transfer data based on multi-level fracture network rock samples according to claim 7, characterized in that: The heat exchange medium injection device includes a gas storage bottle, a fourth ball valve, a liquid storage tank, a fifth ball valve, a third filter, a plunger pump, a third pressure sensor and a safety valve connected in sequence, and the safety valve is also connected to the preheating device; the heat exchange medium injection device also includes a second low-temperature coolant circulation pump, and the second low-temperature coolant circulation pump is respectively connected to the liquid storage tank and the plunger pump, and the liquid storage tank is also connected to the back pressure valve.

9. The device for detecting seepage heat transfer data based on multi-level fracture network rock samples according to claim 8, characterized in that: The second pressure regulating device includes a first pressure regulating pipeline and a second pressure regulating pipeline, and the first pressure regulating pipeline and the second pressure regulating pipeline are both connected to the axial pressure chamber; the first pressure regulating pipeline is composed of a first electric pressure pump, a third regulating valve, and a fourth pressure sensor connected in sequence, and the second pressure regulating pipeline is composed of a second electric pressure pump, a fourth regulating valve and a fifth pressure sensor connected in sequence.

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