Rock plate clamping device and method for convective heat transfer experiment in crack

Abstract

The invention relates to the technical field of rock core holders, and provides a rock plate clamping device and method for a convective heat transfer experiment in cracks, the rock plate clamping device comprises a device body, a first integrated block and a second integrated block are oppositely arranged on the two sides of the device body, and the device body further comprises a first gland and a second gland which are movably connected; the first gland and the second gland are both provided with containing grooves used for containing rock plates, the first gland and the second gland are connected, a simulated crack is formed between the two rock plates, the first gland and the second gland are both provided with filtrate outlets, and the two filtrate outlets are both communicated with the containing grooves. The convective heat transfer rule of the fluid in the crack is comprehensively and accurately evaluated, and more accurate convective heat transfer data is obtained by integrating the influence of fluid filtration on the convective heat transfer effect in the fluid crack.

Description

Technical Field

[0001] The present invention relates to the technical field of core holders, and in particular to a rock plate clamping device and method for a convective heat transfer experiment in a crack. Background Art

[0002] The flow and heat transfer of fluids in fractures are involved in the fields of reservoir reconstruction, oil and gas development, and high-temperature geothermal resource utilization. When the fluid flows through the surface of the fracture, heat exchange occurs with the solid matrix, and this flow and heat transfer process is continuous, which will cause changes in the fluid temperature, and the temperature rise can reach tens of degrees Celsius. The temperature change will affect the effective evaluation of the reservoir reconstruction effect and the geothermal resource utilization effect.

[0003] The simulation experiment of fluid flow and heat transfer in fractures is an effective means to study the law of convective heat transfer. As the core component of the flow and heat transfer simulation experiment system, the structure of the core holder is of great significance to the effect of the simulation experiment. Due to the pressure difference between the fluid in the fracture and the surrounding rock fluid, the loss of fluid to the formation is inevitable during the flow in the fracture. Fluid loss will directly affect the flow and heat transfer effect. Therefore, the influence of fluid loss must be considered in the simulation experiment. However, the existing core clamping devices used for flow and heat transfer of fluid in fractures are mainly loaded with cylindrical cores, and the influence of fluid loss on the flow and heat transfer of fluid in fractures is not considered.

[0004] The Chinese invention patent with patent number CN202310019516.X proposes an experimental device and interpretation method for simulating core seepage heat and mass transfer under high temperature and high pressure. The experimental system includes: a sampling component, a clamp component, a temperature and pressure control component, a sampling component and a host computer. The sampling component, the clamp component and the sampling component are connected in sequence, the temperature and pressure control component is connected to the sampling component and the clamp component, the host computer is connected to the clamp component, the temperature and pressure control component, the sampling component and the host computer and the sampling component. The beneficial effect of the present invention is: through the experimental device and method of the present invention, the fracture aperture, permeability and thermal conductivity of the core can be obtained, and then the seepage heat transfer process of the core can be characterized. Through multiple experiments, the influence of the core fracture aperture, permeability and thermal conductivity on the core seepage heat transfer can be explored.

[0005] Although the above technical scheme solves the research problem of the influence of physical factors on core seepage heat transfer, it does not consider the heat transfer effect caused by fluid loss. In addition, its technical scheme and interpretation method are complex and have certain disadvantages. Summary of the invention

[0006] The purpose of the present application is to provide a rock plate clamping device for convective heat transfer experiments in cracks, which can be used for convective heat transfer experiments in fluid cracks, comprehensively and accurately evaluate the convective heat transfer laws of fluids in cracks, and comprehensively consider the influence of fluid loss on the convective heat transfer effect in fluid cracks to obtain more accurate convective heat transfer data.

[0007] Another object of the present application is to provide a method for using a rock plate clamping device for a convective heat transfer experiment in a crack.

[0008] In order to solve the above technical problems, the technical solution adopted in this application is:

[0009] In the first aspect, an embodiment of the present application provides a rock plate clamping device for a convective heat transfer experiment in a crack, which includes a device body, a first integrated block and a second integrated block are arranged on both sides of the device body, the device body also includes a first pressure cover and a second pressure cover that are movably connected, the first pressure cover and the second pressure cover are both provided with a receiving groove for placing the rock plate, the first pressure cover and the second pressure cover are connected to form a simulated crack between the two rock plates, the simulated crack is connected to the receiving groove, the first integrated block is provided with a liquid inlet, the second integrated block is provided with a liquid outlet, both the liquid inlet and the liquid outlet are connected to the simulated crack, the first pressure cover and the second pressure cover are provided with a filtrate outlet, and both the filtrate outlets are connected to the receiving groove.

[0010] In order to consider the influence of fluid loss on the convective heat transfer effect in the fluid cracks, the present application creatively adds a structure of simulated cracks and two filtrate outlets. When the fluid flows in the simulated cracks, it will exchange heat with the rock plate, causing the temperature of the low-temperature fluid to rise and flow out from the outlet. During the flow, the filtrate will be lost into the rock plate through the cracks, and the filtrate will flow out from the two filtrate outlets of the first pressure cover and the second pressure cover, simulating the effect of fluid loss in the rock plate. During the experiment, the temperature of the experimental fluid when it flows into and out of the simulated cracks is continuously recorded. After the fluid temperature stabilizes, the experiment is terminated. At this time, the heat transfer data of the fluid after filtration can be obtained, and more accurate and comprehensive convective heat transfer data can be calculated based on this.

[0011] In some embodiments of the present application, the device body also includes two electric heating plates, which are respectively located in two receiving grooves and respectively abut against the inner wall of the first pressure cover and the inner wall of the second pressure cover. In order to simulate the convective heat transfer effect in the fluid cracks, an external electric heating plate is required to heat the rock plate to obtain the data required for the experiment. Since two rock plates are provided in the device, two groups of electric heating plates are required to heat the two rock plates respectively. The output end of the electric heating plate abuts against the rock plate, and the cold end abuts against the inner wall of the pressure cover, which can effectively transfer heat to the rock plate and heat from the end of the rock plate away from the simulated crack. After the temperature stabilizes, the overall temperature of the rock plate can be ensured to be constant. If heating is performed from the end close to the simulated crack, uneven heating of the rock plate may be caused, affecting subsequent experimental results.

[0012] In some embodiments of the present application, the device body further includes a plurality of rubber sleeves, which are respectively located in the two receiving grooves and respectively abut against the inner wall of the first pressure cover and the inner wall of the second pressure cover. The rubber sleeves play a sealing role, and the rubber sleeves circumferentially cover the rock plate, thereby increasing the direct fit between the rock plate and the pressure cover and preventing leakage of the fluid between the two.

[0013] In some embodiments of the present application, the above-mentioned device body also includes multiple confining pressure pipelines, which are respectively embedded in the first pressure cover and the second pressure cover, and one ends of the multiple confining pressure pipelines are respectively connected to the multiple rubber sleeves, and the other ends respectively pass through the outer walls of the first integrated block and the second integrated block to form multiple confining pressure interfaces. The set confining pressure pipelines are used to inject gas or water into the rubber sleeves to apply confining pressure to the rock slab. After the confining pressure is applied, the rubber sleeves will be close to the rock slab to ensure that the confining pressure on the rock slab is uniform, thereby preventing the fluid from leaking from the edge of the rock slab when flowing in the cracks.

[0014] In some embodiments of the present application, the device body also includes two temperature sensors, which are respectively located at the two ends of the simulated crack. Since the temperature of multiple groups of fluids flowing in and out needs to be recorded in the experiment, temperature sensors are respectively arranged at both ends of the simulated crack to read the temperature of the fluid before and after heat exchange.

[0015] In some embodiments of the present application, the openings of the above-mentioned liquid inlet and liquid outlet are provided with temperature sensor interfaces, and the temperature sensor is electrically connected to the temperature sensor interface. In order to more conveniently read the temperature of the temperature sensor, a temperature sensor interface is also provided at the position of the liquid inlet and the liquid outlet, and the two temperature sensors are electrically connected to the temperature sensor interface through the liquid inlet and the liquid outlet, respectively, and the temperature sensor interface is then electrically connected to a data acquisition instrument or a computer to read the temperature.

[0016] In some embodiments of the present application, gaskets are sleeved on the outer walls of the first integrated block and the second integrated block, and the first integrated block and the second integrated block are detachably connected to the first pressure cover and the second pressure cover, and the device itself requires high sealing, so an interference fit is required during connection to ensure the airtight effect of the connection. Since the integrated block and the pressure cover are made of metal, they will cause wear and even deformation after long-term use, affecting the sealing of the device. Therefore, gaskets are sleeved on the outer walls of the first integrated block and the second integrated block. The gaskets can play a buffering effect when the integrated block and the pressure cover are connected to prevent direct contact between the two. At the same time, the gaskets are soft, which makes it easier for the two to achieve an interference fit when connected, and further increase the sealing, improve the service life of the device, and reduce maintenance.

[0017] In some embodiments of the present application, the device body also includes a plurality of wires, and the plurality of wires are respectively embedded in the first pressure cover and the second pressure cover, and one end of the plurality of wires is respectively electrically connected to the two electric heating plates, and the other ends respectively pass through the outer walls of the first integrated block and the second integrated block to form a plurality of electrical interfaces to supply power to the electric heating plates. Since the device needs to be filled with rock slabs, the device as a whole is configured as a split structure, but in order to facilitate the inflow and outflow of liquid without destroying the simulated cracks and liquid inlets and outlets, a first integrated block and a second integrated block are configured, and the liquid inlets and outlets, the temperature sensor interface and the electrical interface are integrated on the integrated block. Therefore, configuring it as a separate split body can avoid the separation of the integrated interfaces caused by the non-split body. At the same time, the detachable structure also facilitates maintenance by users, thereby increasing the service life of the device.

[0018] In some embodiments of the present application, the first pressure cover and the second pressure cover are connected by two long bolts and two nuts. The first long bolt passes through the first pressure cover, the first integrated block and the second pressure cover in sequence and is connected to the first nut. The second long bolt passes through the first pressure cover, the second integrated block and the second pressure cover in sequence and is connected to the second nut to achieve the overall connection effect of the device.

[0019] In some embodiments of the present application, multiple long bolts and multiple nuts can be used for connection, and the connection method is the same as described above.

[0020] In some embodiments of the present application, the size of the rock block is 25×50×100 mm.

[0021] In some embodiments of the present application, the size of the electric heating plate is 50×100 mm.

[0022] In the second aspect, an embodiment of the present application provides a method for using a rock plate clamping device for a convective heat transfer experiment in a crack, which includes the following steps: S1, open a first pressure cover and a second pressure cover, and load two rock blocks of the same size into the first pressure cover and the second pressure cover respectively; S2, simulate a crack formed by two rock blocks, and adjust the positions of the two rock blocks to adjust the height of the simulated crack; S3, close the first pressure cover and the second pressure cover, and fill water into multiple rubber sleeves through multiple confining pressure interfaces and apply confining pressure to make the multiple rubber sleeves have an interference fit with the two rock blocks; S4, turn on two electric heating plates and adjust them to a set temperature. After the temperature stabilizes, a constant flow of fluid is pumped into the liquid inlet, and the temperature of the fluid when it flows in and the temperature when it flows out is recorded; S5, calculate the convective heat transfer coefficient of the fluid flowing and transferring heat in the simulated crack based on the recorded data.

[0023] In some embodiments of the present application, in the above step S2, the height adjustment range of the simulated crack is 0-5 mm, and the length and width of the simulated crack are 50×100 mm respectively.

[0024] In some embodiments of the present application, the calculation formula in the above step S5 is as shown in formula (1):

[0025]

[0026] Where h is the convective heat transfer coefficient, W / (m 2 ·K); c p is the specific heat capacity of the fluid, J / (kg·K); Q is the fluid flow rate, m 3 / s; ρ is the fluid density, kg / m 3 ; T in and T out are the inlet and outlet temperatures of the fluid, K; D is the height of the rock plate, m; L is the length of the rock plate, m; T c is the outer surface temperature of the rock plate, that is, the temperature of the electric heating plate, K.

[0027] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0028] 1. The simulated fractures and filtrate outlets can realize the influence of fluid loss on the convective heat transfer effect in the fluid fractures in the experiment, and the obtained heat transfer coefficient is more comprehensive and accurate.

[0029] 2. The first integrated block and the second integrated block are integrated with the liquid inlet and outlet, the temperature sensor interface and the electrical interface, which is convenient for use and maintenance by users, thereby increasing the service life of the device.

[0030] 3. The rubber sleeve can form an interference fit between the rock block and the gland, which has high sealing performance, prevents fluid leakage and increases the accuracy of experimental data. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic diagram of the structure of a rock plate clamping device for a convective heat transfer experiment in a crack provided in this application.

[0033] Icons: 100-first pressure cap; 200-second pressure cap; 300-first integrated block; 400-second integrated block; 410-gasket; 420-confining pressure pipeline; 421-confining pressure interface; 500-rock block; 510-electric heating plate; 520-rubber sleeve; 600-filtrate outlet; 700-simulated fracture; 710-liquid inlet; 720-liquid outlet. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0036] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0037] Example 1

[0038] Please refer to Figure 1 , Figure 1 Shown is a schematic structural diagram of an embodiment of the present application.

[0039] The present application provides a rock plate clamping device for a convective heat transfer experiment in a crack, comprising a device body, a first integrated block 300 and a second integrated block 400 are arranged on opposite sides of the device body, the device body also comprises a first pressure cover 100 and a second pressure cover 200 which are movably connected, the first pressure cover 100 and the second pressure cover 200 are both provided with a receiving groove for placing the rock plate, the first pressure cover 100 and the second pressure cover 200 are connected and form a simulated crack 700 between the two rock plates, the simulated crack 700 is connected with the receiving groove, the first integrated block 300 is provided with a liquid inlet 710, the second integrated block 400 is provided with a liquid outlet 720, the liquid inlet 710 and the liquid outlet 720 are both connected with the simulated crack 700, the first pressure cover 100 and the second pressure cover 200 are both provided with a filtrate outlet 600, and the two filtrate outlets 600 are both connected with the receiving groove.

[0040] In order to simulate the convective heat transfer effect in the fluid cracks, the device body also includes two electric heating plates 510, which are respectively located in the two receiving grooves and respectively abut against the inner wall of the first pressure cover 100 and the inner wall of the second pressure cover 200. The arranged electric heating plates 510 heat the rock plate to obtain the data required for the experiment. Since two rock plates are arranged in the device, two groups of electric heating plates 510 are required to heat the two rock plates respectively. The output end of the electric heating plate 510 abuts against the rock plate, and the cold end abuts against the inner wall of the pressure cover, which can effectively transfer heat to the rock plate and heat from the end of the rock plate away from the simulated crack 700. After the temperature stabilizes, the overall temperature of the rock plate can be ensured to be constant. If heating is performed from the end close to the simulated crack 700, uneven heating of the rock plate may be caused, affecting subsequent experimental results.

[0041] In order to prevent fluid from leaking from between the rock block 500 and the pressure cover, the above-mentioned device body also includes a plurality of rubber sleeves 520, which are respectively located in the two receiving grooves and respectively abut against the inner wall of the first pressure cover 100 and the inner wall of the second pressure cover 200. The rubber sleeves 520 play a sealing role. The rubber sleeves 520 circumferentially cover the rock plate, which can increase the direct fit between the rock plate and the pressure cover and prevent fluid leakage between the two.

[0042] In order to make the rubber sleeve 520 better fit the rock block 500, the above-mentioned device body also includes a plurality of confining pressure pipelines 420, and the plurality of confining pressure pipelines 420 are respectively embedded in the first pressure cover 100 and the second pressure cover 200, and one end of the plurality of confining pressure pipelines 420 is respectively connected to the plurality of rubber sleeves 520, and the other end respectively passes through the outer wall of the first integrated block 300 and the second integrated block 400 to form a plurality of confining pressure interfaces 421. The set confining pressure pipeline 420 is used to inject gas or water into the rubber sleeve 520 to apply confining pressure to the rock plate. After the confining pressure is applied, the rubber sleeve 520 will be close to the rock plate to ensure that the confining pressure on the rock plate is uniform, thereby preventing the fluid from leaking from the edge of the rock plate when flowing in the crack.

[0043] In order to obtain the temperature of the fluid before and after heat transfer, the above-mentioned device body also includes two temperature sensors, which are respectively located at the two ends of the simulated crack 700. Since the temperature of multiple groups of fluids flowing in and out needs to be recorded in the experiment, temperature sensors are respectively arranged at both ends of the simulated crack 700 to read the temperature of the fluid before and after heat exchange.

[0044] In order to read the temperature of the temperature sensor, the openings of the liquid inlet 710 and the liquid outlet 720 are provided with temperature sensor interfaces, and the temperature sensor is electrically connected to the temperature sensor interface. In order to more conveniently read the temperature of the temperature sensor, temperature sensor interfaces are also provided at the positions of the liquid inlet 710 and the liquid outlet 720. The two temperature sensors are electrically connected to the temperature sensor interfaces through the liquid inlet 710 and the liquid outlet 720, respectively, and the temperature sensor interfaces are then electrically connected to a data acquisition instrument or a computer to read the temperature.

[0045] In order to increase the sealing of the connection between the integrated block and the pressure cover, the outer walls of the first integrated block 300 and the second integrated block 400 are both sleeved with gaskets 410. The first integrated block 300 and the second integrated block 400 are both detachably connected to the first pressure cover 100 and the second pressure cover 200. The device itself requires high sealing, so an interference fit is required during connection to ensure the airtight effect of the connection. Since the integrated block and the pressure cover are both made of metal, they will cause wear and even deformation after long-term use, affecting the sealing of the device. Therefore, gaskets 410 are sleeved on the outer walls of the first integrated block 300 and the second integrated block 400. The gaskets 410 can play a buffering effect when the integrated block and the pressure cover are connected to prevent direct contact between the two. At the same time, the gaskets 410 are soft, which makes it easier for the two to achieve an interference fit when connected, and further increases the sealing, improves the service life of the device, and reduces maintenance.

[0046] In order to supply power to the electric heating plate 510, the device body further includes a plurality of wires, which are respectively embedded in the first pressure cover 100 and the second pressure cover 200, and one end of the plurality of wires are respectively electrically connected to the two electric heating plates 510, and the other ends respectively pass through the outer side walls of the first integrated block 300 and the second integrated block 400 to form a plurality of electrical interfaces to supply power to the electric heating plate 510.

[0047] In order to achieve the connection between the first pressure cover 100 and the second pressure cover 200, the first pressure cover 100 and the second pressure cover 200 are connected by two long bolts and two nuts. The first long bolt passes through the first pressure cover 100, the first integrated block 300 and the second pressure cover 200 in sequence and is connected to the first nut. The second long bolt passes through the first pressure cover 100, the second integrated block 400 and the second pressure cover 200 in sequence and is connected to the second nut to achieve the overall connection effect of the device.

[0048] When in use, the first gland 100 and the second gland 200 are opened, two rock blocks 500 with a size of 25×50×100 mm are respectively loaded into the first gland 100 and the second gland 200, and the two rock blocks 500 form a simulated crack 700, and the positions of the two rock blocks 500 are adjusted to adjust the height of the simulated crack 700. After adjustment, the first gland 100 and the second gland 200 are locked and closed by long bolts and nuts, and the first integrated block 300 and the second integrated block 400 are fixed at the same time, and the water pump and the surrounding The pressure interface 421 is connected, and then water is filled into the multiple rubber sleeves 520 from the multiple confining pressure interfaces 421 through a water pump and confining pressure is applied, so that the multiple rubber sleeves 520 have an interference fit with the two rock blocks 500, and the two electric heating plates 510 are turned on and adjusted to the set temperature. After the temperature is constant, a constant flow of fluid is pumped in from the liquid inlet 710, and the temperatures of multiple groups of fluids when they flow in and out are recorded. After the temperatures before and after the outflow are constant, the convective heat transfer coefficient of the fluid flowing in the simulated fracture 700 is calculated based on the recorded data.

[0049] Example 2

[0050] This embodiment 2 provides a method for a rock plate clamping device based on a convection heat transfer experiment in a crack, comprising the following steps:

[0051] S1, open the first gland and the second gland, and load two rock blocks with a size of 25×50×100 mm into the first gland and the second gland respectively;

[0052] S2, the simulated crack is formed by two rock blocks, and the positions of the two rock blocks are adjusted so that the height of the simulated crack is 2 mm;

[0053] S3, closing the first gland and the second gland, using a water pump to fill water into the multiple rubber sleeves from the multiple confining pressure interfaces and applying confining pressure, so that the multiple rubber sleeves have an interference fit with the two rock blocks;

[0054] S4, turn on the two electric heating plates and adjust the temperature to 380K. After the temperature stabilizes, pump a fluid with a pressure of 2MPa and a flow rate of 12mL / min from the liquid inlet. The temperature of the fluid when it flows in is 310K, and the temperature when it flows out is recorded in real time by the temperature sensor;

[0055] S5. Calculate the convective heat transfer coefficient of the fluid flowing in the simulated crack according to the calculation formula (1).

[0056] The calculation formula is shown in formula (1):

[0057]

[0058] Where h is the convective heat transfer coefficient, W / (m 2 ·K); c pis the specific heat capacity of the fluid, J / (kg·K); Q is the fluid flow rate, m 3 / s; ρ is the fluid density, kg / m 3 ; T in and T out are the inlet and outlet temperatures of the fluid, K; D is the height of the rock plate, m; L is the length of the rock plate, m; T c is the outer surface temperature of the rock plate, that is, the temperature of the electric heating plate, K.

[0059] Calculation process: In this embodiment, the fluid medium is pure water, and the thermal physical parameters are constant: density ρ = 1000 kg / m 3 Specific heat capacity c p =4208J / (kgK). Fluid pressure is 2MPa, filtrate outlet pressure is atmospheric pressure 0.1MPa, and filtration pressure difference is 1.9MPa. Flow rate Q = 0.2×10 -6 m 3 / s, fluid inlet temperature T in =310K, rock plate outer surface temperature T c =380K, rock plate length L = 0.1m, rock plate height D = 0.05m. The fluid outlet temperature T measured by the temperature sensor out =332K

[0060] According to formula (1), the convective heat transfer coefficient can be calculated as follows:

[0061]

[0062] Through this embodiment, the convective heat transfer coefficient can be calculated when considering the fluid loss in the fracture, and the calculation result is 62.76W / (m 2 ·K).

[0063] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rock plate clamping device for convection heat transfer experiment in cracks, characterized in that: include The device body has a first integrated block and a second integrated block disposed on opposite sides of the device body, and the device body further comprises a first pressure cover and a second pressure cover that are movably connected, the first pressure cover and the second pressure cover are both provided with a receiving groove for placing a rock plate, the first pressure cover and the second pressure cover are connected to form a simulated crack between the two rock plates, and the simulated crack is connected to the receiving groove; The first integrated block is provided with a liquid inlet, and the second integrated block is provided with a liquid outlet, and both the liquid inlet and the liquid outlet are connected to the simulated crack; The first pressure cover and the second pressure cover are both provided with a filtrate outlet, and the two filtrate outlets are both communicated with the containing tank.

2. A rock plate clamping device for convection heat transfer experiment in cracks according to claim 1, characterized in that: The device body further comprises two electric heating plates, which are respectively located in the two containing grooves and respectively abut against the inner wall of the first pressure cover and the inner wall of the second pressure cover.

3. The rock plate clamping device for convection heat transfer experiment in cracks according to claim 1 is characterized in that: The device body further comprises a plurality of rubber sleeves, which are respectively located in the two receiving grooves and respectively abut against the inner wall of the first pressure cover and the inner wall of the second pressure cover.

4. A rock plate clamping device for convection heat transfer experiment in cracks according to claim 3, characterized in that: The device body also includes a plurality of confining pressure pipelines, which are respectively embedded in the first pressure cover and the second pressure cover, and one end of the plurality of confining pressure pipelines is respectively connected to the plurality of rubber sleeves, and the other end passes through the outer side walls of the first integrated block and the second integrated block to form a plurality of confining pressure interfaces.

5. The rock plate clamping device for convection heat transfer experiment in cracks according to claim 1 is characterized in that: The device body also includes two temperature sensors, which are respectively located at two ends of the simulated crack.

6. A rock plate clamping device for convection heat transfer experiment in cracks according to claim 5, characterized in that: The openings of the liquid inlet and the liquid outlet are both provided with temperature sensor interfaces, and the temperature sensor is electrically connected to the temperature sensor interfaces.

7. The rock plate clamping device for convection heat transfer experiment in cracks according to claim 1 is characterized in that: Gaskets are sleeved on the outer walls of the first integrated block and the second integrated block.

8. A method for using a rock plate clamping device for a convection heat transfer experiment in a crack according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, opening the first gland and the second gland, and respectively loading two rock blocks of the same size into the first gland and the second gland; S2, the simulated crack is formed by the two rock blocks, and the positions of the two rock blocks are adjusted to adjust the height of the simulated crack; S3, closing the first gland and the second gland, and filling water or gas into the multiple rubber sleeves through the multiple confining pressure interfaces and applying confining pressure, so that the multiple rubber sleeves have an interference fit with the two rock blocks; S4, turning on the two electric heating plates and adjusting them to a set temperature, pumping a constant flow of fluid from the liquid inlet after the temperature stabilizes, and recording the temperature of the fluid when it flows in and when it flows out; S5. Calculate the convection heat transfer coefficient of the fluid flowing in the simulated fracture based on the recorded data.

9. The method for using the rock plate clamping device for convection heat transfer experiment in cracks according to claim 8 is characterized in that: In step S2, the height adjustment range of the simulated crack is 0-5 mm, and the length and width of the simulated crack are 50×100 mm respectively.

10. The method for using the rock plate clamping device for convection heat transfer experiment in cracks according to claim 8, characterized in that: The calculation formula in step S5 is shown in formula (1): Where h is the convective heat transfer coefficient, W / (m 2 ·K); c p is the specific heat capacity of the fluid, J / (kg·K); Q is the fluid flow rate, m 3 / s; ρ is the fluid density, kg / m 3 ; T in and T out are the inlet and outlet temperatures of the fluid, K; D is the height of the rock plate, m; L is the length of the rock plate, m; T c is the outer surface temperature of the rock slab, that is, the temperature of the electric heating plate, K.

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