An experimental device and a synthesis method of natural gas hydrate with different components

Abstract

The application discloses a kind of experimental apparatus of synthesizing different component natural gas hydrate, it is related to natural gas hydrate synthesis technical field, it includes: hydrate generation unit, separable material adding unit, ball valve pressure maintaining unit and control and detection unit, hydrate generation unit includes hydrate generation bucket, the hydrate generation bucket is used to reaction generation with metal tracer particle hydrate;Separable material adding unit is used to add metal tracer particle in hydrate reaction process;Ball valve pressure maintaining unit is arranged between the material adding unit and the hydrate generation unit, for controlling the intercommunication and closure of both;Control and detection unit is used to control motor in the material adding unit moves according to instruction, and is used to receive, process and show the data of various sensors of the hydrate generation unit.The application can be synthesized while hydrate, can be added according to research needs even or layer by layer suitable metal tracer particle.

Description

Technical Field

[0001] This invention relates to the field of natural gas hydrate synthesis technology, specifically to an experimental apparatus and synthesis method for synthesizing natural gas hydrates with different compositions. Background Technology

[0002] Natural gas hydrate is a crystalline solid substance formed by gas molecules (mainly methane) and water under certain temperature and pressure conditions, commonly known as "combustible ice." Natural gas hydrate is widely distributed in nature, found in permafrost layers on land and in sedimentary layers on the seabed along continental margins. Its reserves are abundant and clean, making it a promising new clean energy source with extremely high resource value. Therefore, natural gas hydrate has been a research hotspot in the scientific and oil and gas industries in recent years. However, due to phase transitions caused by temperature and pressure changes during the extraction process, obtaining in-situ core samples of natural gas hydrate is extremely difficult, posing a significant challenge to basic research on natural gas hydrate.

[0003] Scientific research typically involves synthesizing hydrates in the laboratory before conducting experimental studies. However, the composition of seafloor natural gas hydrates is highly diverse. Laboratory synthesis devices usually employ methane gas and water under low-temperature, high-pressure conditions, often neglecting fine sand and gravel components present in seafloor natural gas hydrates. These components significantly influence the physical and mechanical properties of the hydrates. Since the physical and mechanical properties of hydrates play a crucial role in hydrate extraction, it is necessary to design an experimental apparatus capable of synthesizing natural gas hydrates with different compositions. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an experimental apparatus for synthesizing natural gas hydrates of different compositions. This apparatus allows for the uniform or layer-by-layer addition of suitable metal tracer particles during hydrate synthesis, depending on research needs. This invention also provides a method for synthesizing natural gas hydrates of different compositions, capable of synthesizing natural gas hydrates with metal tracer particles.

[0005] To achieve the above objectives, the present invention can adopt the following technical solutions:

[0006] An experimental apparatus for synthesizing natural gas hydrates of different compositions, comprising:

[0007] A hydrate generation unit includes a hydrate generation tank, which is used to react and generate hydrates with metal tracer particles.

[0008] A separable material addition unit for adding metal tracer particles during hydrate reaction;

[0009] A ball valve pressure-holding unit, disposed between the material adding unit and the hydrate generating unit, is used to control the connection and closure between the two; and,

[0010] The control and detection unit is used to control the motor in the material adding unit to move according to instructions, and to receive, process and display data from various sensors in the hydrate generation unit.

[0011] The experimental apparatus for synthesizing natural gas hydrates of different compositions as described above is further provided in which the material addition unit includes a fixed frame, a motor, a reducer, a material outlet chamber, and a brush. The motor and the material outlet chamber are fixed on the fixed frame. The output end of the motor is connected to the brush through the reducer. The brush is disposed in the material outlet chamber. The bottom surface of the material outlet chamber is provided with several honeycomb-shaped openings.

[0012] The experimental apparatus for synthesizing natural gas hydrates of different compositions as described above further includes a material addition chamber, which is fixed on the fixed frame sleeve, and the lower end of the material addition chamber is connected to the material outlet chamber through an inclined tube. The material addition chamber is also equipped with an electrically controlled valve for controlling the material discharge speed.

[0013] The experimental apparatus for synthesizing natural gas hydrates of different compositions as described above further includes a ball valve pressure-holding unit comprising a ball valve body and a ball valve control rod, wherein the ball valve control rod is used to control the inversion of the ball valve body to control the opening and closing of the ball valve.

[0014] The experimental apparatus for synthesizing natural gas hydrates of different compositions as described above further includes, in a control and detection unit, the control and detection unit comprising:

[0015] A temperature sensor, which is installed in the hydrate generation unit, is used to detect the ambient temperature for hydrate generation and to receive adjustment commands from the temperature controller.

[0016] A pressure sensor, which is installed in the hydrate generation unit, is used to detect the environmental pressure for hydrate generation;

[0017] A motor controller, which is connected to the motor control signal within the material adding unit;

[0018] A computer controller, which is connected to the control signals of the motor controller, the temperature controller, and the pressure sensor; and,

[0019] The program software running on the computer controller.

[0020] The experimental apparatus for synthesizing natural gas hydrates of different compositions as described above is further provided with a second air inlet, a second air outlet, a water inlet, and a water outlet equipped with electromagnetic valves.

[0021] The experimental apparatus for synthesizing natural gas hydrates of different compositions as described above is further provided that the hydrate generation tank is made of transparent plexiglass or special glass with strength meeting the set requirements.

[0022] The experimental apparatus for synthesizing natural gas hydrates of different compositions as described above further includes a first sealing end cap, a second sealing end cap, and a third sealing end cap. The first sealing end cap is located at the top of the material adding unit and is a solid circle. The second sealing end cap and the third sealing end cap are located at the upper and lower ends of the ball valve pressure holding unit, respectively, and both the second sealing end cap and the third sealing end cap are provided with through holes.

[0023] In the experimental apparatus for synthesizing natural gas hydrates of different compositions as described above, the material addition unit, the ball valve pressure holding unit, and the hydrate generation unit are further connected by several flange-type end caps, which are fixed by locking screws, and each end cap is provided with a sealing ring.

[0024] This invention also provides a method for synthesizing natural gas hydrates of different compositions, comprising the following steps:

[0025] The hydrate generation unit, the pressure-holding ball valve unit, and the material addition unit are installed sequentially from bottom to top. Metal tracer particles are pre-stored in the material addition chamber.

[0026] Water is added to the hydrate generation unit, and the pressure inside the hydrate generation unit is gradually increased to the set pressure. The second air inlet and the second air outlet are opened to allow natural gas to circulate inside the hydrate generation unit.

[0027] Adjust the temperature of the hydrate generation unit to the set temperature, and open the pressure-holding ball valve unit to allow the internal space of the material addition unit and the hydrate generation unit to be connected.

[0028] When the electrically controlled valve is opened, the metal tracer particles in the material addition chamber flow out through the inclined tube to the material outlet chamber; the metal tracer particles are then evenly swept into the honeycomb holes of the material outlet chamber by a brush, and the metal tracer particles fall evenly into the hydrate generation tank.

[0029] After the hydrate containing the metal tracer particles is formed, close the pressure-holding ball valve unit;

[0030] Release the pressure in the material addition unit, and after the pressure is released, replace the upper material addition unit with other experimental instruments to be tested, thus completing the switching of the test modules in the pressure-holding state of the experimental device.

[0031] Compared with existing technologies, the advantages of this invention are as follows: The apparatus of this invention, while synthesizing hydrates, can uniformly or layer-by-layer add suitable metal tracer particles according to research needs, and the release speed of the metal tracer particles can be appropriately controlled as needed, thereby changing the distribution and density of other metal tracer particles in the hydrate. Simultaneously, the upper material addition unit can be disassembled after hydrate synthesis while maintaining temperature and pressure, and replaced with other experimental equipment to conduct corresponding studies on the mechanical properties and other aspects of the synthesized hydrate. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the experimental apparatus for synthesizing natural gas hydrates of different compositions according to an embodiment of the present invention.

[0034] The components include: 1. Locking screw; 2. Material adding chamber; 3. Electrically controlled valve; 4. First air outlet; 5. Fixing frame; 6. Material outlet chamber; 7. Ball valve body; 8. Second air outlet; 9. Temperature controller; 10. Hydrate generation tank; 11. Hydrate sample; 12. Water inlet; 13. Hydrate fixing seat; 14. Test bench frame; 15. High-pressure sealing joint; 16. Sealing ring; 17. First sealing end cap; 18. Motor; 19. Reducer; 20. Brush; 21. First air inlet; 22. Second sealing end cap; 23. Ball valve control rod; 24. Third sealing end cap; 25. Temperature sensor; 26. Pressure sensor; 27. Water outlet; 28. Computer; 29. ​​Second air inlet. Detailed Implementation

[0035] 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 this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0036] Example:

[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, in the embodiments of this invention are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0038] It should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0039] In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] See Figure 1This invention provides an experimental apparatus for synthesizing natural gas hydrates of different compositions. During hydrate synthesis, suitable metal tracer particles can be added uniformly or layer by layer according to research needs. The release rate of the metal tracer particles can be appropriately controlled to alter the distribution and density of other metal tracer particles within the hydrate. Furthermore, the upper material addition unit can be detached after hydrate synthesis while maintaining temperature and pressure, and replaced with other experimental equipment to study the mechanical properties and other aspects of the synthesized hydrate.

[0042] See Figure 1 , Figure 1 An experimental apparatus for synthesizing natural gas hydrates of different compositions is demonstrated, comprising: a hydrate generation unit, a separable material addition unit, a ball valve pressure holding unit, and a control and detection unit. The hydrate generation unit includes a hydrate generation tank 10, used to generate hydrates containing metal tracer particles. The separable material addition unit adds metal tracer particles during the hydrate reaction. The ball valve pressure holding unit is positioned between the material addition unit and the hydrate generation unit to control their connection and closure. The control and detection unit controls the movement of a motor 18 within the material addition unit according to instructions and receives, processes, and displays data from various sensors in the hydrate generation unit. It is understood that by incorporating the separable material addition unit and the ball valve pressure holding unit, this apparatus allows for the uniform or layer-by-layer addition of suitable metal tracer particles during hydrate synthesis, depending on research needs. Furthermore, since the upper material addition unit is detachable, the apparatus can be disassembled after hydrate synthesis while maintaining temperature and pressure, and replaced with other experimental equipment to study the mechanical properties and other aspects of the synthesized hydrate.

[0043] As an optional implementation, in some embodiments, the material adding unit includes a fixed frame 5, a motor 18, a reducer 19, a material outlet chamber 6, and a brush 20. The fixed frame 5 is fixed with the motor 18 and the material outlet chamber 6. The output end of the motor 18 is connected to the brush 20 through the reducer 19. The brush 20 is disposed inside the material outlet chamber 6, and the lower surface of the material outlet chamber 6 has several honeycomb-shaped openings. Further, the material adding unit also includes a material adding chamber 2, which is fixed to the fixed frame 5, and the lower end of the material adding chamber 2 is connected to the material outlet chamber 6 through an inclined tube. The material adding chamber 2 is also provided with an electrically controlled valve 3 for controlling the material release speed. Further still, the ball valve pressure holding unit includes a ball valve body 7 and a ball valve control rod 23. The ball valve control rod 23 is used to control the rotation of the ball valve body 7 to control the opening and closing of the ball valve.

[0044] Specifically, the fixing sleeve 5 is installed inside the material adding unit to fix the material adding chamber 2, motor 18, reducer 19, and material outlet chamber 6. The output end of motor 18 is connected to brush 20 through reducer 19. Brush 20 is used to sweep the metal tracer particles in material outlet chamber 6 into the honeycomb-shaped openings. Preferably, the size of the openings in material outlet chamber 6 is slightly larger than the size of the metal tracer particles to be added. More preferably, material outlet chamber 6 can be replaced according to the size of the metal tracer particles. In addition, material adding chamber 2 is fixedly installed inside the material adding unit by fixing sleeve 5. Material adding chamber 2 stores metal tracer particles. The lower part of material adding chamber 2 is equipped with an electrically controlled valve 3. The electrically controlled valve 3 can be controlled by a control terminal to control the opening size of the valve, thereby controlling the release speed of metal tracer particles and thus changing the distribution and density of other metal tracer particles in the hydrate. Before testing, the ball valve is closed, such as... Figure 1 As shown. When this device is in use, the ball valve control lever 23 controls the ball valve body 7 to flip, at which point the ball valve opens. Simultaneously, the electrically controlled valve 3 opens the valve, allowing the metal tracer particles in the material addition chamber 2 to flow through the valve along the inclined tube into the material outlet chamber 6. The motor 18 drives the brush 20 to sweep the metal tracer particles in the material outlet chamber 6 into the honeycomb-shaped openings, whereby the metal tracer particles fall evenly into the hydrate generation tank 10, thereby generating natural gas hydrate containing metal tracer particles. Furthermore, the outer shell of the material addition unit is equipped with a first air inlet 21 and a first air outlet 4, allowing for pressurization of the material addition unit's interior. Even further, the material addition unit is also equipped with a high-pressure sealing connector 15, which, while maintaining a constant internal pressure within the material addition unit, connects the power supply and signal lines, and transmits power or signals.

[0045] As an optional implementation, in some embodiments, the control and detection unit includes: a temperature sensor 25, a pressure sensor 26, a motor controller, a computer controller, and program software running on the computer controller. The temperature sensor 25 is disposed within the hydrate formation unit to detect the ambient temperature for hydrate formation and to receive adjustment commands from the temperature controller 9. The pressure sensor 26 is disposed within the hydrate formation unit to detect the ambient pressure for hydrate formation. The motor controller is connected to the control signal of the motor 18 in the material addition unit. The computer controller is connected to the control signals of the motor controller, the temperature controller 9, and the pressure sensor 26. In this embodiment, by setting various sensors, the temperature, pressure, etc., within the device can be accurately monitored. By setting various controllers, the testing process of the device can be accurately controlled, thereby ensuring the accuracy of the test results.

[0046] As an optional implementation, in some embodiments, the hydrate generation unit is provided with a second air inlet 29, a second air outlet 8, a water inlet 12, and a water outlet 27, all equipped with electromagnetic valves. Further, the hydrate generation tank 10 is made of transparent plexiglass or special glass with strength meeting the set requirements. In this embodiment, to meet the visibility requirements of other experiments later, and to achieve pressure and heat preservation effects, the material of the hydrate generation tank 10 needs to be thick plexiglass or special glass with good light transmittance and high strength. For example, Pasmo special transparent material can be used; this transparent material has an optical transparency of up to 90%, is resistant to low temperature and high pressure, and with appropriate thickness, can even operate under ultra-high pressure conditions exceeding 200 MPa. Furthermore, the hydrate generation unit also includes a hydrate fixing seat 13, which is located at the bottom of the hydrate generation tank 10 and is used to support the generated hydrate sample 11.

[0047] As an optional implementation, in some embodiments, a first sealing end cap 17, a second sealing end cap 22, and a third sealing end cap 24 are further included. The first sealing end cap 17 is located at the top of the material adding unit and is a solid circle. The second sealing end cap 22 and the third sealing end cap 24 are located at the upper and lower ends of the ball valve pressure holding unit, respectively, and both the second sealing end cap 22 and the third sealing end cap 24 are provided with through holes. In this embodiment, this design of three sealing end caps can ensure the sealing performance of the device and also facilitate the smooth falling of metal tracer particles in the material adding unit onto the surface of the hydrate being generated through the through holes of the second sealing end cap 22 and the third sealing end cap 24 after the ball valve pressure holding unit is opened.

[0048] In the above embodiments, the material adding unit, the ball valve pressure holding unit, and the hydrate generating unit are further connected by several flange-type end caps, which are fixed by locking screws, and each end cap is provided with a sealing ring 16. In this embodiment, the upper and lower ends of the material adding unit, the ball valve pressure holding unit, and the hydrate generating unit are all connected by flange-type end caps, and the end caps are fixed to each other by locking screws 1 and sealed with sealing rings 16. This ensures the airtightness of the device and makes it easy to install and disassemble the device on the test bench 14.

[0049] This invention also provides a method for synthesizing natural gas hydrates of different compositions, comprising the following steps:

[0050] The hydrate generation unit, pressure-holding ball valve unit, and material addition unit are installed sequentially from bottom to top. Metal tracer particles are pre-stored in material addition chamber 2. The pressure-holding ball valve unit is closed before testing. Figure 1 As shown.

[0051] Water is added to the hydrate generation unit, and the pressure inside the hydrate generation unit is gradually increased to the set pressure by an air compressor. The second air inlet 29 and the second air outlet 8 are opened to allow natural gas to circulate inside the hydrate generation unit.

[0052] The temperature of the hydrate generation unit is adjusted to the set temperature by the temperature controller 9, preferably around 2°C. After the pressure stabilizes, the pressure-holding ball valve unit is opened to allow the internal space of the material addition unit and the hydrate generation unit to be connected.

[0053] When the electrically controlled valve 3 is opened, the metal tracer particles in the material addition chamber 2 flow out through the inclined tube at the lower end of the material addition chamber 2 to the material outlet chamber 6. At this time, the motor 18 is turned on by the switch controlled by the computer 28. The motor 18 outputs a rotation speed and the brush 20 evenly sweeps the metal tracer particles into the honeycomb holes of the material outlet chamber 6. The metal tracer particles will then fall evenly into the natural gas hydrate sample 11 that is being generated.

[0054] After the hydrate containing the metal tracer particles is formed, close the pressure-holding ball valve unit.

[0055] Release the pressure of the material adding unit, and after the pressure is released, remove the upper material adding unit by unscrewing the locking screw 1 between the devices and replace it with other experimental instruments to be tested, thus completing the switching of the test module of the experimental device under pressure holding state.

[0056] This synthesis method allows for the uniform addition of suitable metal tracer particles during hydrate synthesis. The release rate of these particles can be appropriately controlled to alter the distribution and density of other metal tracer particles within the hydrate. Furthermore, the upper material addition unit can be detached after hydrate synthesis, while maintaining temperature and pressure, and replaced with other experimental apparatus to study the mechanical properties and other aspects of the synthesized hydrate.

[0057] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0058] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An experimental apparatus for synthesizing natural gas hydrates of different compositions, characterized in that, include: A hydrate generation unit includes a hydrate generation tank, which is used to react and generate hydrates with metal tracer particles. A separable material addition unit for adding metal tracer particles during hydrate reaction; A ball valve pressure-holding unit, disposed between the material adding unit and the hydrate generating unit, is used to control the connection and closure between the two; and, The control and detection unit is used to control the motor in the material adding unit to move according to instructions, and to receive, process and display data from various sensors in the hydrate generation unit.

2. The experimental apparatus for synthesizing natural gas hydrates of different compositions according to claim 1, characterized in that, The material adding unit includes a fixed frame, a motor, a reducer, a material outlet chamber, and a brush. The motor and the material outlet chamber are fixed on the fixed frame. The output end of the motor is connected to the brush through the reducer. The brush is disposed in the material outlet chamber. The bottom surface of the material outlet chamber is provided with several honeycomb-shaped openings.

3. The experimental apparatus for synthesizing natural gas hydrates of different compositions according to claim 2, characterized in that, It also includes a material adding chamber, which is fixed on the fixed frame sleeve, and the lower end of the material adding chamber is connected to the material outlet chamber through an inclined tube. The material adding chamber is also equipped with an electrically controlled valve for controlling the material dropping speed.

4. The experimental apparatus for synthesizing natural gas hydrates of different compositions according to claim 1, characterized in that, The ball valve pressure-holding unit includes a ball valve body and a ball valve control rod, wherein the ball valve control rod is used to control the rotation of the ball valve body to control the opening and closing of the ball valve.

5. The experimental apparatus for synthesizing natural gas hydrates of different compositions according to claim 1, characterized in that, The control and detection unit includes: A temperature sensor, which is installed in the hydrate generation unit, is used to detect the ambient temperature for hydrate generation and to receive adjustment commands from the temperature controller. A pressure sensor, which is installed in the hydrate generation unit, is used to detect the environmental pressure for hydrate generation; A motor controller, which is connected to the motor control signal within the material adding unit; A computer controller, which is connected to the control signals of the motor controller, the temperature controller, and the pressure sensor; and, The program software running on the computer controller.

6. The experimental apparatus for synthesizing natural gas hydrates of different compositions according to claim 1, characterized in that, The hydrate generation unit is equipped with a second air inlet, a second air outlet, a water inlet, and a water outlet, each with an electromagnetic valve.

7. The experimental apparatus for synthesizing natural gas hydrates of different compositions according to claim 1, characterized in that, The hydrate generation tank is made of transparent plexiglass or special glass with strength that meets the set requirements.

8. The experimental apparatus for synthesizing natural gas hydrates of different compositions according to claim 1, characterized in that, It also includes a first sealing end cap, a second sealing end cap, and a third sealing end cap. The first sealing end cap is located at the top of the material adding unit and is a solid circle. The second sealing end cap and the third sealing end cap are located at the upper and lower ends of the ball valve pressure holding unit, respectively, and both the second sealing end cap and the third sealing end cap are provided with through holes.

9. The experimental apparatus for synthesizing natural gas hydrates of different compositions according to claim 1, characterized in that, The material adding unit, the ball valve pressure holding unit, and the hydrate generating unit are connected by several flange-type end caps, which are fixed by locking screws, and each end cap is provided with a sealing ring.

10. A method for synthesizing natural gas hydrates of different compositions, characterized in that, Includes the following steps: The hydrate generation unit, the pressure-holding ball valve unit, and the material addition unit are installed sequentially from bottom to top. Metal tracer particles are pre-stored in the material addition chamber. Water is added to the hydrate generation unit, and the pressure inside the hydrate generation unit is gradually increased to the set pressure. The second air inlet and the second air outlet are opened to allow natural gas to circulate inside the hydrate generation unit. Adjust the temperature of the hydrate generation unit to the set temperature, and open the pressure-holding ball valve unit to allow the internal space of the material addition unit and the hydrate generation unit to be connected. When the electrically controlled valve is opened, the metal tracer particles in the material addition chamber flow out through the inclined tube to the material outlet chamber; the metal tracer particles are then evenly swept into the honeycomb holes of the material outlet chamber by a brush, and the metal tracer particles will fall evenly into the hydrate generation tank. After the hydrate containing the metal tracer particles is formed, close the pressure-holding ball valve unit; Release the pressure in the material addition unit, and after the pressure is released, replace the upper material addition unit with other experimental instruments to be tested, thus completing the switching of the test modules in the pressure-holding state of the experimental device.

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