Coal bed gas drive gas simulation experiment testing device

Abstract

This invention discloses a coalbed methane (CBM) gas-driven simulation experimental testing device, relating to the field of CBM extraction technology. It consists of a split-type testing chamber, with a control box installed at the bottom and an experimental shell assembled at the top, with a heat insulation layer sandwiched between them. The experimental shell is divided into a symmetrically arranged upper and lower chamber. A heat dissipation plate with an openable / closeable gas slot is fixed to the top of the outer side of the upper chamber. An upper inner shell and a lower inner shell are embedded within the internal space of the experimental shell, each containing an experimental furnace and a heating cylinder encased therein. The sidewalls of the testing chamber are connected to a first, second, and third storage chamber. Gas and liquid are directionally transported along conduits via a pump. Multi-directionally extendable pusher assemblies are installed on both sides of the experimental furnace to simulate formation stress, accurately replicating the environment of the coal and rock strata, thus making the test data more precise.

Description

Technical Field

[0001] This invention relates to the field of coalbed methane extraction technology, specifically to a coalbed methane gas-driven simulation experimental testing device. Background Technology

[0002] Coalbed methane displacement simulation experiments are a core research method for evaluating the effectiveness of gas displacement technology. By simulating the underground coal seam environment, they analyze the interaction mechanism between the displacement gas and the coal matrix and adsorbed methane, providing a theoretical basis for optimizing gas injection parameters (pressure, temperature, injection rate).

[0003] Existing experimental methods involve placing coal seam samples in a high-temperature reactor for monitoring. However, this method suffers from a limited monitoring environment, resulting in inaccurate test data for coal seam samples. Therefore, it is necessary to design a coalbed methane-driven gas simulation experimental testing device. Summary of the Invention

[0004] The purpose of this invention is to provide a coalbed methane-driven gas-simulation experimental testing device to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a coalbed methane gas-driven simulation experimental testing device, comprising a split-type test chamber, with a control box installed at the bottom and an experimental shell assembled at the top, with a heat insulation layer sandwiched between the two; the experimental shell is divided into an upper chamber and a lower chamber arranged symmetrically, with a heat dissipation plate with an openable and closable gas groove fixed to the top of the outer side of the upper chamber; the internal space of the experimental shell is embedded with an upper inner shell and a lower inner shell, the inner cavities of which respectively accommodate an experimental furnace and a heating cylinder wrapped around them; the side wall of the test chamber is connected to a first storage chamber, a second storage chamber, and a third storage chamber, and gas and liquid are directionally transported along a conduit by a pump; the experimental furnace is equipped with multi-directionally retractable push plate assemblies on both sides for loading simulated formation stress.

[0006] According to the above technical solution, the heat sink is composed of a hollow plate body with first air grooves symmetrically opened at the top and bottom of the plate body. An electrically controlled telescopic rod is fixed inside the plate body by a support rod. The end of the electrically controlled telescopic rod is connected to a sealing plate. The synchronous or asynchronous opening and closing of the first air grooves is realized by the displacement of the sealing plate.

[0007] According to the above technical solution, a gas recovery path is further included. The heat sink is connected to the first storage chamber through a second conduit. A second pump is installed in the middle section of the second conduit to draw the gas temporarily stored in the heat sink back to the first storage chamber.

[0008] According to the above technical solution, the inner wall of the heating cylinder is covered with uniformly arranged heating wires, and its two ends are connected to the second storage chamber and the third storage chamber through the third conduit and the fourth conduit, respectively. The third conduit is equipped with a third pump and the fourth conduit is equipped with a fourth pump to control the injection of different media into the experimental furnace.

[0009] According to the above technical solution, the pusher assembly includes a first telescopic rod and a first pusher plate arranged laterally at both ends of the experimental furnace, and a third telescopic rod and a third pusher plate arranged longitudinally at the top and bottom of the experimental furnace; the surface of the first pusher plate is provided with an array of grooves, and the grooves contain the second telescopic rod and the second pusher plate; multiple sets of fourth telescopic rods and fourth pushers are fixed inside the third pusher plate to form a multi-dimensional stress loading mechanism.

[0010] According to the above technical solution, the telescopic rods on the same push plate operate differentially according to a preset time sequence to simulate the non-uniform stress distribution of the formation.

[0011] According to the above technical solution, a kerosene circulation is formed between the insulation layer and the third storage compartment through a dual-loop pipeline, and the kerosene flows continuously between the third storage compartment and the insulation layer to maintain the thermal insulation performance.

[0012] According to the above technical solution, the kerosene in the third storage chamber is pressurized by the fourth pump and then fed into the heating cylinder through the fourth conduit and permeates into the experimental furnace, so that the coal and rock samples are mixed with the kerosene to simulate the oil-bearing fracture environment.

[0013] According to the above technical solution, the experimental furnace is connected to the upper inner shell and the lower inner shell through a second micro valve, and a first micro valve for balancing the air pressure is installed on the top of the heating cylinder.

[0014] According to the above technical solution, the control box has a built-in pressure sensing module and dynamic control program, which collects the pressure data in the chamber in real time and automatically adjusts the opening and closing range of the air tank, the output power of the pump, the displacement of the telescopic rod and the timing of the push plate action.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention, by setting a first push plate, a second push plate, a third push plate, and a fourth push plate, simulates the multi-directional non-uniform stress of coal and rock strata in a real geological environment, and reproduces the dynamic squeezing effect of strata movement by controlling the time difference of the telescopic rod, thereby improving the accuracy of experimental data.

[0016] By setting up a first storage chamber, a second storage chamber, a third storage chamber, and a multi-conduit pump system, the initial gas, displacement gas, and liquid (such as kerosene) are stored separately. The pumps and conduits enable directional transport and recycling of the medium, reducing the cost of experimental gas consumption. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0018] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention. Figure 1 ;

[0019] Figure 2 This is a schematic diagram of the overall three-dimensional structure of the present invention. Figure 2 ;

[0020] Figure 3 This is a schematic diagram of the overall exploded structure of the present invention;

[0021] Figure 4 This is a schematic diagram of the internal structure of the heat sink of the present invention;

[0022] Figure 5 This is a schematic diagram of the exploded structure of the test chamber of the present invention. Figure 1 ;

[0023] Figure 6 This is a schematic diagram of the exploded structure of the test chamber of the present invention. Figure 2 ;

[0024] Figure 7 This is a schematic diagram of the first push plate and the third push plate of the present invention;

[0025] Figure 8 This is a schematic diagram of the second pusher plate of the present invention;

[0026] Figure 9 This is a schematic diagram of the fourth pusher plate of the present invention;

[0027] The push plates in the above figures are schematic diagrams; in reality, adjacent push plates are arranged closely together.

[0028] In the diagram: 1. Test chamber; 2. Control box; 3. Experimental shell; 4. Insulation layer; 5. Upper shell; 6. First reinforcing rod; 7. Heat dissipation plate; 8. Plate; 9. First air slot; 10. Support rod; 11. Electrically controlled telescopic rod; 12. Sealing plate; 13. Lower shell; 14. Second reinforcing rod; 15. Upper inner shell; 16. Second air slot; 17. Lower inner shell; 18. Third air slot; 19. Experimental furnace; 20. Heating cylinder; 21. First storage chamber; 22. First conduit; 23. First... 24. Pump; 25. First micro valve; 26. Second conduit; 27. Second pump; 28. Third conduit; 29. ​​Fourth conduit; 30. Second storage compartment; 31. Third storage compartment; 32. Fourth pump; 33. Second micro valve; 34. First telescopic rod; 35. First push plate; 36. Groove; 37. Second telescopic rod; 38. Second push plate; 39. Third telescopic rod; 40. Third push plate; 41. Through hole; 42. Fourth telescopic rod; 43. Fourth push plate. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figure 1-9This invention provides a technical solution: a coalbed methane-driven gas simulation experimental testing device, comprising a test chamber 1, which is divided into upper and lower structures, with a control box 2 and an experimental shell 3 arranged sequentially from bottom to top. The control box 2 integrates a pressure sensor and an adaptive algorithm to dynamically adjust the opening and closing degree of the gas slots and the power of the pump. A heat insulation layer 4 is provided between the control box 2 and the experimental shell 3 to block the heat energy generated by the experimental shell 3 during the coalbed methane experiment. The experimental shell 3 has a symmetrical structure, with the upper part including an upper box body 5 located on the outermost side. A first reinforcing rod 6 is horizontally welded to the top of the upper box body 5, and a heat dissipation plate 7 is fixedly installed on the first reinforcing rod 6. The heat dissipation plate 7 serves both as a shield for the top of the upper box body 5 and as a pressure relief and heat dissipation device for the test chamber 1. The heat dissipation plate 7 includes a plate body 8, the interior of which is a hollow structure. Several first gas slots 9 are symmetrically arranged at the top and bottom of the plate body 8. One air trough 9 is located on the same vertical line and corresponds one to another. Two symmetrical support rods 10 are fixedly installed inside the plate body 8. Each support rod 10 is fixedly installed with an electrically controlled telescopic rod 11 on the side wall adjacent to the first air trough 9. A sealing plate 12 is fixedly installed at the end of the electrically controlled telescopic rod 11. The control box 2 drives the electrically controlled telescopic rod 11 to move, which in turn drives the sealing plate 12 to move, thereby opening and closing the first air trough 9. The heat sink 7 is controlled in two modes. The first mode is that the control box 2 drives the electrically controlled telescopic rods 11 at the top and bottom to move, which in turn drives the sealing plate 12 to move and open the first air trough 9, so that the hot air in the test chamber 1 can be discharged through the heat sink 7. The second mode is that the control box 2 drives the electrically controlled telescopic rod 11 at the bottom to move, which in turn drives the sealing plate 12 to move and open the first air trough 9 at the bottom, so that the gas in the test chamber 1 can enter the plate body 8 but not be discharged, in preparation for gas expulsion. At this time, the heat sink 7 is used as the gas expulsion site.

[0031] A first storage chamber 21 is provided on one side of the test chamber 1, and a first conduit 22 is provided on one side of the first storage chamber 21. The first conduit 22 extends into the test chamber 1 until it connects to the heating cylinder 20. Heating wires are evenly and densely attached to the inner wall of the heating cylinder 20, and the heating cylinder 20 is heated by the heating wires. A second conduit 25 is provided on the top of the plate 8, and a second pump 26 is provided at the connection between the second conduit 25 and the plate 8. The second conduit 25 is connected to the first storage chamber 21 through a sealed pipe, and the second pump 26 is driven so that the gas in the plate 8 is transported to the first storage chamber 21 through the second conduit 25 to realize the gas recovery.

[0032] The lower part includes a lower housing 13 located on the outermost side. A second reinforcing rod 14 is horizontally welded to the bottom of the lower housing 13. A heat insulation layer 4 is fixedly installed at the bottom of the second reinforcing rod 14. The heat insulation layer 4 serves both to shield the bottom of the lower housing 13 and to block heat energy.

[0033] An upper inner shell 15 is installed inside the upper housing 5. The upper inner shell 15 is fixed to the first reinforcing rod 6 by bolts. The two sides of the upper inner shell 15 are flat. A second air groove 16 is set on this flat surface. The gas in the test chamber 1 is transported to the space between the upper housing 5 and the upper inner shell 15 through the second air groove 16. Then the gas is transported to the heat sink 7. Different treatment methods are performed on the gas according to the control process of the heat sink 7.

[0034] The lower inner bladder shell 17 is installed inside the lower box 13. The lower inner bladder shell 17 is fixed to the second reinforcing rod 14 by bolts. The two sides of the lower inner bladder shell 17 are flat. A third air groove 18 is set on this flat surface. Gases of different temperatures generated by the heat insulation layer 4 are transmitted to the test chamber 1 through the third air groove 18.

[0035] An experimental furnace 19 is installed inside the upper inner shell 15 and the lower inner shell 17. A second micro valve 33 is provided around the experimental furnace 19, which connects the experimental furnace 19 to the inner shell. A heating cylinder 20 is installed inside the experimental furnace 19.

[0036] The upper and lower boxes are separate from the inner shell, making disassembly and maintenance convenient and adaptable to samples of different sizes;

[0037] Several first micro valves 24 are provided on the top surface of the heating cylinder 20;

[0038] The heating cylinder 20 is connected to the third conduit 27 and the fourth conduit 28 at its two ends respectively. The third conduit 27 is sealed to the second storage chamber 29, which stores the displacement gas. A third pump 30 is provided at the connection. The fourth conduit 28 is sealed to the third storage chamber 31, and a fourth pump 32 is provided at the connection.

[0039] The first conduit 22 in the first storage chamber 21 is connected to the first pump 23. The first pump 23 is driven to pump the gas medium into the first conduit 22, and then the gas medium is delivered to the heating cylinder 20 through the first conduit 22. The gas medium is delivered to the experimental furnace 19 by driving the first micro valve 24 to open.

[0040] Experimental preparation stage: Place the coal and rock sample into the experimental furnace 19, start the heating cylinder 20 to start heating, start the control box 2, and inject the initial gas (such as nitrogen) into the experimental furnace 19 through the first conduit 22 to ensure the pressure balance inside the experimental furnace 19. The sealing plate 12 closes the first gas tank 9 to prevent gas leakage.

[0041] Heating and thermal energy simulation stage: Start heating cylinder 20 to simulate the in-situ temperature of coal seam. Heat is conducted to coal and rock samples through heating cylinder 20. Adsorbed gases (such as methane) begin to desorb. Insulation layer 4 blocks the downward transfer of heat energy from experimental shell 3 to avoid the control box 2 being affected by high temperature.

[0042] Preparatory stage before gas purging: The control box 2 drives the second pump 26 to operate, and transports the initial gas (such as nitrogen) in the experimental furnace 19 to the first storage chamber 21 through the second conduit 25 to remove the initial gas once. The initial gas removal path is as follows: the initial gas enters the upper inner shell 15 from the experimental furnace 19, and then enters the heat dissipation plate 7 through the upper box 5.

[0043] Gas displacement test stage: Switch heat sink 7 to gas displacement mode: Control box 2 drives the upper and lower electric telescopic rods 11 to completely close the first gas tank 9, drive the third pump 30 to deliver the displacement gas (such as CO2) in the second storage chamber 29 to the third conduit 27, then deliver it to the heating cylinder 20 through the third conduit 27, and finally deliver the displacement gas to the experimental furnace 19 through the first micro valve 24. The control box 2 presets the displacement gas delivery time. When the delivery time is reached, the first gas tank 9 is opened, and the initial gas is expelled from the test chamber 1 by the displacement gas. The initial gas mixed with the displacement gas is not suitable for recovery, so it is directly discharged.

[0044] Displacement gas (such as CO2) is injected and enters the inner shell through the second micro valve 33, and then diffuses to the surrounding area of ​​the experimental furnace 19 to increase the diffusion area of ​​the displacement gas (such as CO2) and create the environment in which the coal and rock strata sample is located.

[0045] The displacement gas comes into contact with the coal and rock sample, replacing the adsorbed methane. The mixed gas enters the heat dissipation plate 7 through the second gas groove 16 of the upper box 5 for temporary storage.

[0046] Heat dissipation and pressure relief stage: After the experiment, the control box 2 starts the heat dissipation mode, opens the first air slot 9 at the top, and the high temperature gas is quickly discharged through the heat dissipation plate 7. The sealing plate 12 dynamically adjusts the opening and closing degree according to the pressure change to balance the pressure in the chamber and prevent the chamber from bursting. Multiple pressure sensors are set in the entire test chamber 1 to obtain the pressure values ​​of each space layer in the test chamber 1 in real time and transmit the data to the control box 2 in real time.

[0047] The heat sink 7 has the functions of pressure relief, temporary gas storage and gas venting channel, reducing reliance on external equipment. The heat dissipation or gas venting mode can be flexibly switched through the electrically controlled telescopic rod 11 to meet the dynamic needs of experiments.

[0048] First telescopic rods 34 are fixedly installed on the side walls of both ends of the experimental furnace 19. First push plates 35 are fixedly installed at the ends of the first telescopic rods 34. The shape of the first push plates 35 matches the longitudinal section of the experimental furnace 19. A through hole 41 is provided in the middle area of ​​the first push plate 35. The heating cylinder 20 passes through the through hole 41. The movement of the first push plate 35 does not affect the operation of the heating cylinder 20. Several grooves 36 are provided on the side wall of the first push plate 35. A second telescopic rod 37 is provided in each groove 36. A second push plate 38 is fixedly installed at the end of the second telescopic rod 37. Third telescopic rods 39 are installed at the top and bottom of the experimental furnace 19. A third push plate 40 is fixedly installed at the end of the third telescopic rod 39. The shape of the third push plate 40 matches the transverse section of the experimental furnace 19. Several fourth telescopic rods 42 are fixedly installed on the inner side wall of the third push plate 40. A fourth push plate 43 is fixedly installed at the end of the fourth telescopic rod 42.

[0049] After the displacement gas injection process for the coal and rock strata sample is completed, control box 2 monitors the coal and rock strata sample and acquires data before proceeding to the next step. First, it drives the first telescopic rod 34 to move, which in turn moves the first push plate 35. The first push plate 35 then compresses the coal and rock strata sample. After the first push plate 35 has compressed the coal and rock strata sample once and then resets, it drives the third telescopic rod 39 to move, which in turn moves the third push plate 40. The third push plate 40 then compresses the coal and rock strata sample. This cyclical compression of the coal and rock strata sample by the first push plate 35 and the third push plate 40 simulates the real geological stress environment experienced by the underground coal and rock strata sample. Control box 2 monitors the coal and rock strata sample and acquires data before proceeding to the next step, first driving the second telescopic rod... The second telescopic rod 37 moves, driving the second push plate 38 to move. The movement of the second telescopic rod 37 on the same first push plate 35 has a time difference, meaning the second push plate 38 on the same first push plate 35 operates asynchronously. Similarly, after the second push plate 38 completes its movement and resets, the fourth telescopic rod 42 is driven to move. The movement of the fourth telescopic rod 42 drives the fourth push plate 43 to move. The movement of the fourth telescopic rod 43 on the same third push plate 40 has a time difference, meaning the fourth push plate 43 on the same third push plate 40 operates asynchronously. This further simulates the state of the coal and rock strata under geological movement, more accurately reproducing the anisotropic mechanical behavior of the underground coal and rock strata. The control box 2 monitors the coal and rock strata samples and acquires data. The above process is the preliminary environmental simulation and monitoring process for the coal and rock strata.

[0050] Kerosene is stored in the insulation layer 4 and the third storage compartment 31. Two return pipes are set between the insulation layer 4 and the third storage compartment 31 to form a loop between the insulation layer 4 and the third storage compartment 31. This allows the kerosene in the third storage compartment 31 to continuously interact with the kerosene in the insulation layer 4 through the return pipes, keeping the temperature of the kerosene in the insulation layer 4 low and making it more effective at blocking heat.

[0051] After completing the monitoring of the coal and rock strata under the simulated geological movement, the control box 2 drives the fourth pump 32 to transport the kerosene in the third storage chamber 31 to the heating cylinder 20. Then, the kerosene is transported to the experimental furnace 19 through the first micro valve 24, so that the coal and rock strata sample is mixed with kerosene, further simulating the environment of the coal and rock strata sample underground. The control box 2 monitors the coal and rock strata sample and acquires data. Since the coal and rock strata have undergone multiple environmental simulations, their temperature is high. This equipment, with the support of the heat insulation layer 4 and the heating cylinder 20, directly preheats the kerosene transported to the experimental furnace 19, reducing the stacking of heating structures and greatly reducing the number of structures in the test chamber 1. The above process is the advanced environmental simulation monitoring process of the coal and rock strata.

[0052] After the control box 2 monitors the coal and rock layer sample of mixed kerosene and obtains data, the preliminary environmental simulation monitoring process of the coal and rock layer is repeated again, so that the control box 2 can obtain data on the pushing and pressing conditions of the coal and rock layer after being wrapped in kerosene, and further simulate the multi-directional compression of the formation.

[0053] Experimental principle: A coal and rock sample containing methane is placed in test chamber 1, and a displacement gas (such as CO2) is injected. The methane is precisely adsorbed and replaced, and parameters such as gas production, adsorption and desorption rate and deformation of coal and rock sample are monitored. The monitoring of coal and rock sample by control box 2 is existing technology and will not be described in detail here.

[0054] Formation condition simulation: It is necessary to reproduce the in-situ temperature (40-80℃), pressure (5-20MPa) and triaxial stress state (horizontal / vertical stress difference) of the coal seam.

[0055] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0056] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coalbed gas displacement gas simulation experiment testing device, comprising a test bin (1), the test bin (1) is divided into upper and lower structures, a control box (2) and an experiment shell (3) are sequentially arranged from bottom to top, characterized in that, The control box (2) is provided with a heat insulation layer (4) between the experimental shell (3); The experimental shell (3) is a symmetrical structure, comprising an upper box body (5) and a lower box body (13), the upper box body (5) is provided with a heat dissipation plate (7) on the top, the heat dissipation plate (7) comprises a hollow plate body (8), a supporting rod (10), an electric control telescopic rod (11) and a sealing plate (12), the top and bottom of the hollow plate body (8) are symmetrically provided with a first air groove (9), and the opening and closing of the first air groove (9) is controlled by the electric control telescopic rod (11) and the sealing plate (12). The experimental shell (3) is provided with an upper inner capsule shell (15) and a lower inner capsule shell (17), and the inner capsule shell is provided with an experimental furnace (19) and a heating cylinder (20). The test bin (1) is connected with a first storage bin (21), a second storage bin (29) and a third storage bin (31) on the side, and the gas and liquid are transported through the pipes and pumps, the second pipe (25) is arranged between the heat dissipation plate (7) and the first storage bin (21), and the gas is recovered through the second pump (26) arranged at the connection between the second pipe (25) and the hollow plate body (8). The experimental furnace (19) is provided with a multi-stage telescopic push plate structure at both ends, which is used for simulating the formation stress.

2. The coalbed gas displacement simulation experiment testing device according to claim 1, characterized in that, The heating cylinder (20) is provided with heating wires on the inner wall, and the two ends are connected with the second storage bin (29) and the third storage bin (31) through the third pipe (27) and the fourth pipe (28), and the third pump (30) and the fourth pump (32) are arranged, so that different media enter the experimental furnace (19).

3. The coalbed gas displacement simulation experiment testing device according to claim 2, characterized in that, The experimental furnace (19) is provided with a first telescopic rod (34) and a first push plate (35) at both ends, a third telescopic rod (39) and a third push plate (40) at the top and bottom, a plurality of recesses (36) are arranged on the side wall surface of the first push plate (35), a second telescopic rod (37) is arranged in each recess (36), a second push plate (38) is fixedly installed at the end of the second telescopic rod (37), a plurality of fourth telescopic rods (42) are fixedly installed on the inner side wall of the third push plate (40), and a fourth push plate (43) is fixedly installed at the end of the fourth telescopic rod (42), which is used for multidirectional stress simulation.

4. The coalbed gas displacement simulation experiment testing device according to claim 3, characterized in that, The telescopic rods on the same push plate have time difference control when running, and can simulate non-uniform formation stress.

5. The coalbed gas displacement simulation experimental testing device according to claim 4, characterized in that, The heat insulation layer (4) and the third storage bin (31) form a kerosene circulation loop through the backflow pipe, which is used for maintaining the low temperature of the heat insulation layer (4).

6. The coalbed gas displacement simulation experimental testing device according to claim 5, characterized in that, The kerosene in the third storage bin (31) is transported to the heating cylinder (20) through the fourth pump (32), and is mixed with the coal rock sample in the experimental furnace (19), and the coal rock sample of the mixed kerosene is monitored.

7. The coalbed gas displacement simulation experimental testing device according to claim 6, characterized in that, The experimental furnace (19) is communicated with the inner capsule shell through the second micro valve (33), and the first micro valve (24) is arranged on the top of the heating cylinder (20).

8. The coalbed gas drive simulation experimental testing device according to claim 7, characterized in that, The control box (2) is integrated with a pressure sensor and a self-adaptive algorithm, and dynamically adjusts the opening degree of the air groove, the power of the pump, the operation of the telescopic rod, the operation of the push plate and the medium transportation.

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