A high-temperature and high-pressure experimental device and method for ultragravity testing

Abstract

This invention discloses a hypergravity high-temperature and high-pressure testing device and method. The method includes the following steps: installing the hypergravity high-temperature and high-pressure testing device; assembling the sample by placing it in the device; using a ground hydraulic station to drive the main oil cylinder and lifting cylinder for pressurization; after pressurizing to a preset pressure, raising the temperature to a preheating temperature and locking the pressure; after locking the pressure, disassembling the inlet and outlet oil lines of the main oil cylinder and lifting cylinder; starting the centrifuge, rotating it to the target value, and then raising the temperature at a preset heating rate to a preset temperature to begin the hypergravity high-temperature and high-pressure test; after the test, turning off the centrifuge and using the hydraulic station to drive the main oil cylinder and lifting cylinder for depressurization; after depressurization, removing the sample and ending the hypergravity high-temperature and high-pressure test. This invention's hypergravity high-temperature and high-pressure testing device is suitable for large long-arm centrifuges, simulating some long-term geological evolution, and maintaining stable oil pressure during the test.

Description

Technical Field

[0001] This invention relates to the field of ultragravity high temperature and high pressure experimental technology, specifically to an ultragravity high temperature and high pressure experimental device and experimental method. Background Technology

[0002] High-temperature and high-pressure (HTHP) experiments are commonly used techniques for studying the structure and physicochemical properties of materials within the Earth. When studying gravitational differentiation between silicate and metallic melts, the settling of crystals in silicate melts, and the permeability of silicate melts under normal gravity, the transport rates of the multiphase media are affected by gravity, making these phenomena difficult to measure accurately on a laboratory timescale. Hypergravity can enhance the relative motion between materials of different densities, shortening the time required for material transport. Combining hypergravity techniques with HTHP experiments allows for the reproduction of geological evolution on a millennia-long scale within the laboratory, such as crystallization within deep magma chambers and gravitational differentiation of mantle materials. Therefore, hypergravity HTHP experiments are a powerful tool for studying long-term geological evolution processes deep within the Earth.

[0003] Currently, several international teams are using drum centrifuges to study geological processes such as crystal migration in melts, gravitational differentiation between metals and silicate melts, and to determine physical properties of silicate melts, including viscosity and permeability, through high-temperature, high-pressure experiments under hypergravity. Drum centrifuges can provide greater gravitational acceleration, up to 2500g. However, due to their structural limitations, drum centrifuges have relatively small experimental space and load capacity, resulting in smaller sizes of the high-temperature, high-pressure equipment they can carry, thus limiting their temperature and pressure. For example, the small piston-cylinder press at ETH Zurich has a total mass of only 42kg, with a maximum pressure of only 1.8GPa and a maximum temperature of only 1250℃, which can only simulate the temperature and pressure environment of the top of the Earth's mantle. Furthermore, due to the short rotation radius of drum centrifuges, the hypergravity field they generate is relatively unstable and non-uniform. Compared to drum centrifuges, large long-arm centrifuges (with an effective rotation radius greater than 3m) offer greater experimental space and load capacity, and can generate a more stable and uniform centrifugal hypergravity field.

[0004] Currently, there are no suitable high-temperature and high-pressure experimental devices for large long-arm centrifuges, either domestically or internationally. Furthermore, traditional high-temperature and high-pressure devices are bulky and their pressurization systems cannot function properly under hypergravity. Therefore, how to construct a high-temperature and high-pressure device and experimental method suitable for large long-arm centrifuges, with large tonnage, small volume, and relatively stable oil pressure, is a technical challenge that we need to solve. Summary of the Invention

[0005] This invention provides an experimental method for simulating some long-term geological evolution in the laboratory, developed my country's first high-temperature and high-pressure experimental device for ultragravity suitable for large long-arm centrifuges, and established a high-temperature and high-pressure experimental method for ultragravity based on this device.

[0006] The technical solution adopted in this invention is:

[0007] I. A method for high-temperature and high-pressure testing under extreme gravity

[0008] Includes the following steps:

[0009] S1. Install the high-gravity, high-temperature and high-pressure test device in the basket of the centrifuge.

[0010] S2. Place the sample assembly into the pressure chamber of the high-gravity high-temperature and high-pressure test device. Connect the main oil cylinder and lifting cylinder of the high-gravity high-temperature and high-pressure test device to the hydraulic station outside the basket through pipelines. Use the hydraulic station to drive the main oil cylinder and lifting cylinder to pressurize the sample assembly.

[0011] The process of connecting the main cylinder and the lifting cylinder to the hydraulic station outside the scaffold via pipelines includes: detachably connecting the main cylinder stop needle valve and the lifting cylinder stop needle valve to the corresponding pipelines via quick connectors, and opening the main cylinder stop needle valve and the lifting cylinder stop needle valve.

[0012] S3. After pressurizing to the preset pressure, raise the temperature of the sample in the sample assembly to the preheating temperature, maintain the preheating time, and then lock the pressure by closing the main oil cylinder stop needle valve on the main oil cylinder and the lifting cylinder stop needle valve on the lifting cylinder.

[0013] The preheating temperature is set to be 100-300°C lower than the preset temperature, and the preheating time is 30-240 min; in step S5, the preset heating rate is 80-600°C / min.

[0014] S4. After the pressure is locked, disconnect the pipeline between the ultragravity high temperature and high pressure test device and the hydraulic station to disconnect the ultragravity high temperature and high pressure test device from the hydraulic station on the ground.

[0015] S5. Start the centrifuge and rotate it to the preset target g value (i.e., target centrifugal force). Then, according to the preset heating program, raise the temperature of the sample from the preheating temperature to the preset temperature at the preset heating rate, and start the hypergravity high temperature and high pressure test.

[0016] S6. After the high-gravity, high-temperature and high-pressure test is completed, the centrifuge is turned off, and the main oil cylinder and the lifting cylinder are connected to the hydraulic station outside the basket through pipelines. The hydraulic station is used to drive the main oil cylinder and the lifting cylinder to depressurize.

[0017] The process of connecting the main cylinder and the lifting cylinder to the hydraulic station outside the scaffold via pipelines includes: detachably connecting the main cylinder stop needle valve and the lifting cylinder stop needle valve to the corresponding pipelines via quick connectors, and opening the main cylinder stop needle valve and the lifting cylinder stop needle valve.

[0018] S7. After depressurization, use a special sampler to remove the sample from the pressure chamber and assemble it to end the ultragravity high temperature and high pressure test.

[0019] Specifically, the centrifuge is a long-arm centrifuge, and the electrical control cabinet and hydraulic station are both located on the ground.

[0020] II. A high-gravity, high-temperature, and high-pressure testing device

[0021] The high-temperature and high-pressure ultragravity test device is arranged in the basket of the centrifuge and mainly consists of a main oil cylinder, a main oil cylinder stop needle valve, a test chamber, a lifting cylinder, and a lifting cylinder stop needle valve. The main oil cylinder, the test chamber, and the lifting cylinder are arranged in order from top to bottom, and the lifting cylinder is connected to the basket of the centrifuge.

[0022] The test chamber is equipped with a pressure chamber for accommodating sample assembly. The main hydraulic cylinder can apply downward pressure to the entire test chamber, and the lifting cylinder can apply upward pressure to the sample assembly.

[0023] The main hydraulic cylinder is equipped with a main hydraulic cylinder stop needle valve, which is connected to the hydraulic station outside the suspended platform via a pipeline. The main hydraulic cylinder stop needle valve and the pipeline are detachably connected. Specifically, the rodless chamber port of the main hydraulic cylinder is connected to and communicates with the main hydraulic cylinder stop needle valve.

[0024] The lifting cylinder is equipped with a lifting cylinder stop needle valve, which is connected to the hydraulic station outside the suspended platform via a pipeline. The lifting cylinder stop needle valve and the pipeline are detachably connected. Specifically, the rodless chamber port of the lifting cylinder is connected to and communicates with the lifting cylinder stop needle valve.

[0025] Both the main cylinder stop needle valve and the lifting cylinder stop needle valve are detachably connected to their corresponding pipelines via quick connectors.

[0026] Furthermore, the other oil ports of the main oil cylinder and the lifting cylinder are detachably connected to one end of the corresponding pipeline via quick connectors, and the other end of the pipeline is connected to the corresponding interface of the hydraulic station.

[0027] Furthermore, pressure sensors are installed in the rodless chambers of both the main hydraulic cylinder and the lifting cylinder.

[0028] In a preferred embodiment of the present invention, the main oil cylinder has a maximum oil pressure of 70 MPa, a maximum output of 5 MN, and a piston rod stroke of 25 mm; the lifting cylinder has a maximum oil pressure of 20 MPa, a maximum output of 0.5 MN, and a piston rod stroke of 30 mm.

[0029] Specifically, the test chamber mainly consists of a support partition, an upper support plate, a pressure chamber ring, a piston, a thruster, a base, and a main drive head. The support partition, upper support plate, pressure chamber ring, and base are arranged sequentially from top to bottom. The pressure chamber ring and base are connected, and the base is connected to a lifting cylinder. The pressure chamber ring has a cylindrical cavity inside as a pressure chamber, which is used to place and assemble samples. The base has a cavity inside as a drive chamber, which is connected to the pressure chamber. The drive chamber has a piston, a thruster, and a main drive head arranged sequentially from top to bottom. The piston is connected to the thruster, the thruster is connected to the main drive head, and the piston rod of the lifting cylinder extends into the drive chamber and connects to the main drive head.

[0030] Specifically, the sample assembly mainly consists of a sleeve and a sample. The sample is placed inside the sleeve, which is equipped with a graphite heater as a sample heating element. The graphite heater is electrically connected to a programmable power supply, which is electrically connected to an electrical control cabinet. The electrical control cabinet controls the output current and voltage of the programmable power supply, thereby controlling the temperature.

[0031] Specifically, a thermocouple is installed inside the sleeve, which is used to collect the temperature of the sample, and the thermocouple is communicatively connected to the electrical control cabinet.

[0032] The beneficial effects of this invention are:

[0033] 1. The method of the present invention ensures that the pressure on the sample remains stable during the high-temperature and high-pressure test of hypergravity through the process of pressurization-preheating-locking, thereby further improving the accuracy of the test.

[0034] 2. This invention simplifies the press structure design: while ensuring that the main structure of the press meets the experimental conditions of a maximum 150g hypergravity, unnecessary components are eliminated as much as possible, and the three-dimensional spatial dimensions of the device are controlled within the range of 1.5m (length) × 1.4m (width) × 1.2m (height), with a theoretical thrust greater than 500t and a mass controlled below 2.67t.

[0035] 3. This invention separates the booster hydraulic system from the main body of the press and uses a locking device, namely a shut-off needle valve, to maintain the oil pressure of the press under hypergravity, while ensuring that the sample is subjected to stable pressure. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the ultragravity high temperature and high pressure test device in an embodiment of the present invention;

[0037] Figure 2 This is a flowchart of the hypergravity high temperature and high pressure test method in an embodiment of the present invention;

[0038] Figure 3This is a schematic diagram of the ultragravity high temperature and high pressure test device in an embodiment of the present invention;

[0039] Figure 4 This is a graph showing the changes in temperature, power, and oil pressure of the lifting cylinder over time during the hypergravity high temperature and high pressure test in this embodiment of the invention.

[0040] In the diagram, 1. Main cylinder, 2. Main cylinder shut-off needle valve, 3. Support plate, 4. Upper support plate, 5. Tungsten carbide sleeve, 6. Hardened steel sleeve, 7. Piston, 8. Propeller, 9. Base, 10. Main drive head, 11. Lifting cylinder, 12. Lifting cylinder shut-off needle valve, 13. Hydraulic station. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] The first aspect of this invention provides a method for conducting ultragravity, high temperature, and high pressure experiments. For example... Figure 2 As shown, the method of the present invention includes the following steps:

[0043] S1. Install the high-gravity, high-temperature and high-pressure test device in the basket of the centrifuge.

[0044] Specifically, the centrifuge is a long-arm centrifuge. In practice, the ultragravity high temperature and high pressure test device is installed by bolting the base plate to the inner wall of the bottom of the centrifuge basket.

[0045] S2. Place the sample assembly into the high-gravity high-temperature and high-pressure test device. Connect the main oil cylinder 1 and the lifting cylinder 11 of the high-gravity high-temperature and high-pressure test device to the hydraulic station 13 outside the basket through pipelines. Use the hydraulic station 13 to drive the main oil cylinder 1 and the lifting cylinder 11 to pressurize the sample assembly.

[0046] The sample assembly mainly consists of a sleeve and the sample. The sample is placed inside the sleeve, which is equipped with a graphite heater as the sample heating element. The graphite heater is electrically connected to a programmable power supply via a heating cable. The programmable power supply is electrically connected to an electrical control cabinet and supplies power to the graphite heater. The electrical control cabinet controls the temperature by controlling the output current and voltage of the programmable power supply. A thermocouple is installed inside the sleeve to collect the sample temperature. The thermocouple is communicatively connected to the electrical control cabinet and outputs the sample temperature to the cabinet.

[0047] The process of connecting the main cylinder 1 and the lifting cylinder 11 to the hydraulic station 13 outside the basket via pipelines includes: detachably connecting the main cylinder stop needle valve 2 and the lifting cylinder stop needle valve 12 to their respective pipelines via quick connectors; detachably installing the remaining pipelines on the quick connectors at the corresponding oil ports of the main cylinder 1 and the lifting cylinder 11; and after connecting all pipelines, opening the main cylinder stop needle valve 2 and the lifting cylinder stop needle valve 12.

[0048] Specifically, the hydraulic station 13 is located on the ground. In practice, the hydraulic station 13 is equipped with a booster pump, the high-pressure end of which is connected to the main oil cylinder 1 and the lifting cylinder 11 respectively.

[0049] S3. Use the oil pressure sensor of the main oil cylinder 1 and the oil pressure sensor of the lifting cylinder 11 to read the oil pressure in their respective cylinders in real time. When the pressure is increased to the preset pressure, that is, when the oil pressure of the main oil cylinder 1 and the lifting cylinder 11 both reach the preset oil pressure, use the electric control cabinet outside the basket to control the sample heating element to raise the temperature of the sample in the sample assembly to the preheating temperature according to the preset heating program. After maintaining the preheating time, lock the pressure by closing the main oil cylinder stop needle valve 2 on the main oil cylinder 1 and the lifting cylinder stop needle valve 12 on the lifting cylinder 11.

[0050] Specifically, the oil pressure of the main cylinder 1 and the lifting cylinder 11 refers to the oil pressure in their respective rodless chambers;

[0051] Specifically, the electrical control cabinet is located on the ground;

[0052] Specifically, the preheating temperature is set to be 100-300°C lower than the preset temperature, and the preheating time is 30-240 minutes.

[0053] S4. After the locking is completed, disconnect the pipeline between the main oil cylinder 1 and the hydraulic station 13, as well as the pipeline between the lifting cylinder 11 and the hydraulic station 13.

[0054] S5. Start the centrifuge and rotate it to the preset target g value. Then, use the sample heating element to raise the temperature of the sample in the sample assembly from the preheating temperature to the preset temperature at the preset heating rate according to the preset heating program, and start the hypergravity high temperature and high pressure test.

[0055] Specifically, the preset heating rate is 80–600 °C / min.

[0056] S6. After the high-gravity, high-temperature and high-pressure test is completed, the centrifuge is turned off, and the main oil cylinder 1 and the lifting cylinder 11 are connected to the hydraulic station 13 outside the basket through pipelines. The hydraulic station 13 is used to drive the main oil cylinder 1 and the lifting cylinder 11 to depressurize.

[0057] The process of connecting the main cylinder 1 and the lifting cylinder 11 to the hydraulic station 13 outside the basket via pipelines includes: detachably connecting the main cylinder stop needle valve 2 and the lifting cylinder stop needle valve 12 to their respective pipelines via quick connectors; detachably installing the remaining pipelines on the quick connectors at the corresponding oil ports of the main cylinder 1 and the lifting cylinder 11; and after connecting all pipelines, opening the main cylinder stop needle valve 2 and the lifting cylinder stop needle valve 12.

[0058] Furthermore, after the high-gravity, high-temperature, and high-pressure test is completed, the power supply to the programmable power supply is first cut off to quench the sample, and then the centrifuge is stopped.

[0059] S7. After the pressure is released, the piston rods of the main oil cylinder 1 and the lifting cylinder 11 return to their initial positions. The sample is then taken out from the pressure chamber using a special sampler and assembled, thus ending the high-gravity, high-temperature and high-pressure test.

[0060] A second aspect of the present invention provides a hypergravity high-temperature and high-pressure testing apparatus. The hypergravity high-temperature and high-pressure testing apparatus is arranged in the basket of a centrifuge, specifically a long-arm centrifuge.

[0061] like Figure 1 As shown, the high-gravity, high-temperature, and high-pressure experimental device of the present invention mainly consists of a main hydraulic cylinder 1, a main hydraulic cylinder stop needle valve 2, an experimental chamber, a lifting cylinder 11, and a lifting cylinder stop needle valve 12. The main hydraulic cylinder 1, the experimental chamber, and the lifting cylinder 11 are arranged sequentially from top to bottom. The lifting cylinder 11 is placed on the base plate, and the base plate is fixedly connected to the inner wall of the bottom of the centrifuge basket.

[0062] The test chamber is equipped with a pressure chamber for accommodating the assembled sample. The piston rod of the main hydraulic cylinder 1 can move downward, pressing the support partition 3 and the upper support plate 4 onto the pressure chamber ring, and applying downward pressure to the entire test chamber through the support partition 3 and the upper support plate 4. The piston rod of the lifting cylinder 11 can move upward and extend into the drive chamber, thereby applying upward pressure to the bottom end of the assembled sample through the pressure transmission components (main drive head 10, pusher 8, and piston 7).

[0063] The main hydraulic cylinder 1 has a main hydraulic cylinder stop needle valve 2 installed at its oil port. The main hydraulic cylinder stop needle valve 2 is connected to the hydraulic station 13 outside the suspended platform via a pipeline, and the main hydraulic cylinder stop needle valve 2 is detachably connected to the pipeline. The lifting cylinder 11 has a lifting cylinder stop needle valve 12 installed at its oil port. The lifting cylinder stop needle valve 12 is connected to the hydraulic station 13 outside the suspended platform via a pipeline, and the lifting cylinder stop needle valve 12 is detachably connected to the pipeline. Specifically: the oil port of the main hydraulic cylinder 1 is connected to one end of the main hydraulic cylinder stop needle valve 2, and the other end of the main hydraulic cylinder stop needle valve 2 is detachably connected to one end of the main hydraulic cylinder 1's inlet / outlet oil pipeline via a quick connector. The other end of the main hydraulic cylinder 1's inlet / outlet oil pipeline is connected to the hydraulic station 13. The oil port of the lifting cylinder 11 is connected to one end of the lifting cylinder stop needle valve 12. The other end of the lifting cylinder stop needle valve 12 is detachably connected to one end of the oil inlet and outlet pipeline of the lifting cylinder 11 via a quick connector. The other end of the oil inlet and outlet pipeline of the lifting cylinder 11 is connected to the hydraulic station 13.

[0064] Specifically, the main cylinder stop needle valve 2 and the lifting cylinder stop needle valve 12 are both detachably connected to the pipeline via quick connectors.

[0065] Specifically, both the main cylinder 1 and the lifting cylinder 11 can be single-rod double-acting cylinders. The rodless chamber port of the main cylinder 1 is connected to the main cylinder stop needle valve 2; the rodless chamber port of the lifting cylinder 11 is connected to the lifting cylinder stop needle valve 12. Quick connectors are installed at other ports for detachable connection to corresponding pipelines.

[0066] Furthermore, pressure sensors are installed in the rodless chambers of both the main cylinder 1 and the lifting cylinder 11. The pressure sensors are used to collect the oil pressure in the rodless chambers of the main cylinder 1 or the lifting cylinder 11. The pressure sensors are communicatively connected to the electrical control cabinet and transmit oil pressure signals to the electrical control cabinet.

[0067] As an optional embodiment of the present invention, the maximum oil pressure of the main oil cylinder 1 is 70 MPa, the maximum output force is 5 MN, and the piston rod stroke is 25 mm; the maximum oil pressure of the lifting cylinder 11 is 20 MPa, the maximum output force is 0.5 MN, and the piston rod stroke is 30 mm.

[0068] Specifically, the test chamber mainly consists of a support partition 3, an upper support plate 4, a pressure chamber ring, a piston 7, a thruster 8, a base 9, and a main drive head 10. The support partition 3, upper support plate 4, pressure chamber ring, and base 9 are arranged sequentially from top to bottom. The support partition 3 contacts the upper support plate 4, the upper support plate 4 contacts the pressure chamber ring, the pressure chamber ring is connected to the base 9, and the base 9 is connected to the cylinder body of the lifting cylinder 11. A cylindrical cavity is provided inside the pressure chamber ring as a pressure chamber, used for placing and assembling samples. A cavity is provided inside the base 9 as a drive chamber. The piston 7, thruster 8, and main drive head 10 are arranged sequentially from top to bottom within the drive chamber. The bottom end of the piston 7 is connected to the top end of the thruster 8, the bottom end of the thruster 8 is connected to the top end of the main drive head 10, and the piston rod of the lifting cylinder 11 extends into the drive chamber and connects to the bottom end of the main drive head 10.

[0069] Optionally, the piston 7 and the thruster 8 are made of tungsten carbide, while the base 9 and the main drive head 10 are made of steel.

[0070] During pressurization and testing, the piston rod of the main cylinder 1 abuts against the top surface of the support partition 3. The support partition 3 is connected to the upper support plate 4, which abuts against the top of the sample assembly. The top of the piston 7 extends into the pressure chamber and abuts against the bottom of the sample assembly. The piston rod of the main cylinder 1 applies downward pressure to the sample assembly through the support partition 3 and the upper support plate 4. The piston rod of the lifting cylinder 11 applies upward pressure to the sample assembly through the main drive head 10, the pusher 8, and the piston 7.

[0071] Specifically, the sample assembly mainly consists of a sleeve and a sample. The sample is placed inside the sleeve, which is equipped with a graphite heater as the sample heating element. The graphite heater is electrically connected to a programmable power supply via a heating cable. The programmable power supply is electrically connected to an electrical control cabinet and supplies power to the graphite heater. The electrical control cabinet controls the temperature by controlling the output current and voltage of the programmable power supply. A thermocouple is installed inside the sleeve to collect the sample temperature. The thermocouple is communicatively connected to the electrical control cabinet and outputs the sample temperature to the cabinet.

[0072] The high-gravity, high-temperature, and high-pressure testing device also includes a top plate for mounting the main hydraulic cylinder 1, a bottom plate for mounting the lifting cylinder 11, and a cooling water circuit. The top plate is positioned above the main hydraulic cylinder 1, and the bottom plate is positioned below the lifting cylinder 11. The bottom plate is bolted to the inner wall of the bottom of the basket. Multiple support columns are arranged between the top plate and the bottom plate, each support column being arranged vertically, with both ends connected to the top plate and the bottom plate, respectively. The cooling water circuit is arranged around the outside of the test chamber and is connected to a ground-based water chiller via water pipes. The cooling water circuit is used to circulate cooling water to prevent overheating and damage to instrument components.

[0073] Furthermore, lifting rings are installed on the top plate for transporting the ultra-gravity high temperature and high pressure test device.

[0074] Specific embodiments of the present invention are as follows:

[0075] Example

[0076] This embodiment uses, as follows: Figure 3 The supergravity piston-cylinder press shown has a total mass of 1.3t. Test experiments were conducted using this press under supergravity conditions of 100g (100 times gravity), a high temperature of 900℃, and an oil pressure of 29 bar in the main cylinder and lifting cylinder. The procedure is as follows:

[0077] S1. Transport the high-gravity piston-cylinder press, programmable power supply, and heating cables to the large long-arm centrifuge using a crane. Move the electrical control cabinet to the centrifuge control room. Secure the high-gravity piston-cylinder press in the centrifuge basket, and fix the programmable power supply at the centrifuge's rotation center. Connect and secure the water, electricity, and signal lines. Lead the control signal line from the electrical control cabinet, connect the signal to the centrifuge's rotation center via the centrifuge slip ring, and then connect from the rotation center to the high-gravity piston-cylinder press and the programmable power supply, transmitting the pressure and temperature signals to the press and programmable power supply respectively.

[0078] S2. After assembling the sample, place it in the super gravity piston-cylinder press, and then connect it to the hydraulic station 13 on the ground through the pipeline, set the pressure, and start pressurizing.

[0079] S3. After pressurizing to the target value of 29 bar, turn on the ground water chiller. After confirming that there is no water leakage in the entire cold water circuit, set the heating program in the program. First, raise the temperature to 300°C below the target value, i.e., 600°C, so that the entire sample assembly can be fully softened under high temperature and high pressure. Then, maintain this temperature for 60 minutes. Then, tighten the shut-off needle valves of the main oil cylinder and the lifting cylinder to lock the pressure (the purpose of locking the pressure is to prevent the hydraulic pump from being used or from being placed in the centrifuge basket under hypergravity. The shut-off needle valve can ensure that there is no oil leakage problem in the two oil cylinders under hypergravity).

[0080] S4. After the pressure is locked, remove the oil pipe from the gravity piston-cylinder press and check whether each component is safe and in normal use. After the inspection is completed, remove all auxiliary equipment, shut down the centrifuge chamber, and prepare for rotation.

[0081] S5. Start the centrifuge and rotate it to the preset target g value (multiple of gravity). After the g value stabilizes, increase the temperature to the target temperature at 200℃ / min.

[0082] S6. During the centrifuge cycle, constantly monitor the centrifuge room to prevent any abnormalities. If any abnormality is detected, immediately stop the centrifuge and disconnect the compressor power supply for rectification. If no abnormalities are found, after completing the experiment, first disconnect the compressor power supply, quench the sample, and then stop the centrifuge.

[0083] S7. After the centrifuge has stabilized completely, turn off the water chiller. Open the centrifuge chamber and reconnect the ground hydraulic station to the compressor to depressurize.

[0084] S8. After depressurization, remove the sample to complete the experiment.

[0085] In hypergravity, high temperature and high pressure experiments, four factors can affect the oil pressure of the lifting cylinder.

[0086] ① During the centrifuge acceleration process, the mass of the tungsten carbide piston and piston rod increases, leading to an increase in oil pressure. Figure 4 (P1-P2);

[0087] ②Increase in sample temperature. When the temperature is increased to the target value, the overall assembly temperature rise will lead to an increase in oil pressure. Figure 4 (P2-P3);

[0088] ③ Once the sample temperature stabilizes, the entire sample assembly tends to reach equilibrium, and the oil pressure will decrease. Figure 4 (P3-P4);

[0089] ④ Increased ambient temperature also increases oil pressure. When the centrifuge rotates, friction with the air causes the ambient temperature to rise. Due to heat conduction, the oil temperature inside the cylinder rises, causing the hydraulic oil to expand and the oil pressure to increase. Figure 4(P4-P5)

[0090] Throughout the entire hypergravity, high temperature, and high pressure experiment, the oil pressure of the lifting cylinder can be controlled within ±5%.

[0091] In summary, the high-gravity, high-temperature, and high-pressure experimental device provided by this invention is applicable to large long-arm centrifuges and can simulate some long-term geological evolution in the laboratory. During the experiment, the oil pressure and the pressure on the sample can remain stable.

[0092] The above specific embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

[0093] The above description is only a preferred embodiment of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of this patent application are included in the scope of this patent application.

Claims

1. A method for conducting high-temperature and high-pressure tests under extreme gravity, characterized in that, Includes the following steps: S1. Install the high-gravity, high-temperature, and high-pressure test device in the basket of the centrifuge; S2. Place the sample assembly into the pressure chamber of the high-gravity high-temperature and high-pressure test device, connect the main oil cylinder (1) and the lifting cylinder (11) of the high-gravity high-temperature and high-pressure test device to the hydraulic station (13) outside the basket respectively, and use the hydraulic station (13) to drive the main oil cylinder (1) and the lifting cylinder (11) to pressurize. S3. After pressurizing to the preset pressure, raise the temperature of the sample in the sample assembly to the preheating temperature, maintain the preheating time, and then lock the pressure by closing the main oil cylinder stop needle valve (2) on the main oil cylinder (1) and the lifting cylinder stop needle valve (12) on the lifting cylinder (11). S4. After the pressure is locked, disconnect the pipeline between the high gravity high temperature and high pressure test device and the hydraulic station (13); S5. Start the centrifuge and rotate it to the preset target value. Then, raise the temperature of the sample from the preheating temperature to the preset temperature according to the preset heating rate, and start the high-gravity high-temperature and high-pressure test. S6. After the high-gravity, high-temperature and high-pressure test is completed, the centrifuge is turned off, and the main oil cylinder (1) and the lifting cylinder (11) are connected to the hydraulic station (13) outside the basket through pipelines. The hydraulic station (13) is used to drive the main oil cylinder (1) and the lifting cylinder (11) to depressurize. S7. After depressurization, remove the sample for assembly, thus ending the high-gravity, high-temperature and high-pressure test.

2. The method for conducting ultragravity high-temperature and high-pressure tests according to claim 1, characterized in that: In steps S2 and S6, the process of connecting the main cylinder (1) and the lifting cylinder (11) to the hydraulic station (13) outside the basket includes: detachably connecting the main cylinder stop needle valve (2) and the lifting cylinder stop needle valve (12) to the corresponding pipelines through quick connectors, and opening the main cylinder stop needle valve (2) and the lifting cylinder stop needle valve (12).

3. The method for conducting ultragravity, high temperature, and high pressure tests according to claim 1, characterized in that: The centrifuge is a long-arm centrifuge, and the electrical control cabinet and hydraulic station (13) are both located on the ground.

4. The method for conducting ultragravity high temperature and high pressure tests according to claim 1, characterized in that: In step S3, the preheating temperature is set to be 100-300°C lower than the preset temperature, and the preheating time is 30-240 min; in step S5, the preset heating rate is 80-600°C / min.

5. A high-temperature, high-pressure testing apparatus for use in any one of the high-gravity high-temperature, high-pressure testing methods as described in claims 1 to 4, characterized in that: The high-temperature and high-pressure ultragravity test device is arranged in the basket of the centrifuge and mainly consists of a main oil cylinder (1), a main oil cylinder stop needle valve (2), a test chamber, a lifting cylinder (11) and a lifting cylinder stop needle valve (12); the main oil cylinder (1), the test chamber and the lifting cylinder (11) are arranged from top to bottom, and the lifting cylinder (11) is connected to the basket of the centrifuge. The test chamber is equipped with a pressure chamber for accommodating sample assembly. The main hydraulic cylinder (1) can apply downward pressure to the test chamber, and the lifting cylinder (11) can apply upward pressure to the sample assembly. The main cylinder (1) is equipped with a main cylinder stop needle valve (2), which is connected to the hydraulic station (13) outside the basket through a pipeline. The pipeline is detachably connected to the main cylinder stop needle valve (2). The lifting cylinder (11) is equipped with a lifting cylinder stop needle valve (12), which is connected to the hydraulic station (13) outside the basket through a pipeline. The pipeline is detachably connected to the lifting cylinder stop needle valve (12).

6. The ultragravity high temperature and high pressure test apparatus according to claim 5, characterized in that: Both the main cylinder stop needle valve (2) and the lifting cylinder stop needle valve (12) are detachably connected to the corresponding pipelines via quick connectors.

7. The high-temperature and high-pressure experimental device for ultragravity according to claim 5, characterized in that: The rodless chamber port of the main cylinder (1) is connected to the main cylinder stop needle valve (2); the rodless chamber port of the lifting cylinder (11) is connected to the lifting cylinder stop needle valve (12); pressure sensors are provided in the rodless chambers of both the main cylinder (1) and the lifting cylinder (11).

8. The high-temperature and high-pressure experimental device for ultragravity according to claim 5, characterized in that: The maximum oil pressure of the main oil cylinder (1) is 70MPa, the maximum output is 5MN, and the piston rod stroke is 25mm; the maximum oil pressure of the lifting cylinder (11) is 20MPa, the maximum output is 0.5MN, and the piston rod stroke is 30mm.

9. The high-temperature and high-pressure experimental device for ultragravity according to claim 5, characterized in that: The test chamber is mainly composed of a support partition (3), an upper support plate (4), a pressure chamber ring, a piston (7), a thruster (8), a base (9), and a main drive head (10). The support partition (3), the upper support plate (4), the pressure chamber ring, and the base (9) are arranged from top to bottom. The pressure chamber ring and the base (9) are connected, and the base (9) is connected to the lifting cylinder (11). The pressure chamber ring has a columnar cavity inside as a pressure chamber, which is used to place the sample assembly. The base (9) has a cavity inside as a drive chamber, which is connected to the pressure chamber. The drive chamber has a piston (7), a thruster (8), and a main drive head (10) arranged from top to bottom. The piston (7) is connected to the thruster (8), and the thruster (8) is connected to the main drive head (10). The piston rod of the lifting cylinder (11) extends into the drive chamber and is connected to the main drive head (10).

10. The high-temperature and high-pressure experimental device for ultragravity according to claim 9, characterized in that: The sample assembly mainly consists of a sleeve and a sample. The sample is placed inside the sleeve, which is equipped with a graphite heater as a sample heating element. A thermocouple is installed inside the sleeve to collect the temperature of the sample.

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