Supercritical CO2 storage method in coal seam geology

Abstract

The invention discloses a method for sealing supercritical CO2 in coal seam geology, which comprises the following steps: S1, sample preparation: cutting a raw coal block into a cylindrical sample, and then pretreating the sample; s2, preparing the device; putting the treated sample into a supporting sleeve, then putting the supporting sleeve into a clamping structure, sealing through a sealing structure, then completing the installation of an injection system and a monitoring system, and setting test conditions; s3, starting a test, injecting supercritical CO2 into the sample through an injection system to complete the test, and recording radial displacement, axial displacement and temperature change of the coal body in the whole test process; and S4, repeatedly testing, namely respectively changing the pretreatment conditions of the sample, the supercritical CO2 injection pressure and the supercritical CO2 injection rate, repeatedly testing, and researching the mechanism and the rule of supercritical CO2 coal seam storage. The process of injecting the supercritical CO2 into the coal seam is studied through an indoor test, and land storage of the CO2 is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of CO2 geological storage and exploitation, and particularly relates to a method for supercritical CO2 storage in coal seams geology. Background Technique

[0002] Since the Industrial Revolution, the extensive exploitation and use of fossil fuels have caused a sharp increase in the concentration of CO2 in the atmosphere, leading to serious ecological and environmental problems such as climate variability and global warming. Therefore, how to achieve CO2 emission reduction has become the key to coping with climate change and solving the problem of global warming. Carbon sequestration (CCS: Carbon Capture and Storage; CCUS: Carbon Capture, Utilization and Storage) has received increasing attention due to its potential to actively mitigate climate change. Carbon sequestration is a systematic technical project integrating CO2 capture, transportation, and storage. Terrestrial carbon sequestration technology is one of the methods, which stores CO2 in the form of gas or supercritical fluid under a low-permeability rock cap. Summary of the Invention

[0003] The present invention intends to provide a method for supercritical CO2 storage in coal seams geology, and realizes the terrestrial storage of CO2 by studying the process of supercritical CO2 injection into coal seams through indoor experiments.

[0004] For this reason, the technical solution adopted by the present invention is as follows: A method for supercritical CO2 storage in coal seams geology, comprising the following steps:

[0005] S1: Specimen preparation. Cut the raw coal block into a cylindrical specimen, then process it through a grinding machine to make the flatness of its end face within ±0.02 mm, and then pre-treat the specimen;

[0006] S2: Equipment preparation. Sheath a high-temperature ring compression sleeve outside the support sleeve with the specimen, then install the support sleeve into the clamping structure and seal it through the sealing structure, then connect the injection system to the clamping structure, and at the same time install the monitoring system. Then set the injection pressure value, heating temperature, and rate of CO2 in the injection system, and apply axial pressure and confining pressure to the specimen according to the test requirements;

[0007] S3: Start the test. Inject supercritical CO2 into the specimen through the injection system to complete the test, and at the same time record the radial displacement, axial displacement, and temperature change of the coal body during the whole process of the test, and analyze the change of the coal body after injecting supercritical CO2;

[0008] S4: Repeat the tests, separately change the pre-treatment conditions of the specimens, the injection pressure and rate of supercritical CO2, repeat the tests, and record the radial displacement, axial displacement and temperature changes of the coal body during the whole process of the tests under different conditions, so as to study the mechanism and laws of supercritical CO2 sequestration in coal seams.

[0009] As an optimization of the above solution, the pre-treatment includes soaking treatment with an alkali solution.

[0010] Further preferably, the clamping structure includes a mounting plate and a ductile specimen tube which is arranged with upper and lower through holes. A pressurization system for realizing triaxial pressurization of the specimen is arranged on the clamping structure; the pressurization system includes a high-temperature circumferential pressure sleeve arranged between the specimen tube and the support sleeve and an axial pressure mounting plate arranged below the mounting plate through a connecting column. The high-temperature circumferential pressure sleeve is equipped with a circumferential pressure tracking system. An axial pressure cylinder is arranged on the axial pressure mounting plate, and a cooling sleeve with water inlet and outlet is arranged between the axial pressure cylinder and the specimen tube.

[0011] Further preferably, the sealing structure includes floating plugs arranged at the upper and lower ends of the specimen tube. Between each floating plug and the specimen tube, multiple high-temperature gaskets and double V-shaped combined graphite components are sequentially arranged from inside to outside. On the end of each floating plug, a bolt pre-tightening and pressing structure for ensuring reliable sealing of the sealing structure is arranged. An inlet communicated with the injection system and an outlet for discharging redundant gas are arranged in the floating plug, and the inlet and the outlet are respectively arranged in different floating plugs.

[0012] Further preferably, the bolt pre-tightening and pressing structure includes an upper bolt pre-tightening and pressing structure and a lower bolt pre-tightening and pressing structure corresponding to the upper and lower floating plugs. The upper bolt pre-tightening and pressing structure includes a first flange sleeved on the upper end of the specimen tube and a second flange sleeved on the upper end of the upper floating plug. The first flange and the second flange are connected by mounting bolts. At a position close to the upper end of the floating plug, a T-shaped upper top block is arranged, and the lower end of the upper top block can be inserted into the upper end of the specimen tube. A lower notch for the upper top block to be inserted into is arranged at the lower end of the second flange, and an upper tightening bolt capable of pressing on the upper top block is arranged on the second flange;

[0013] The lower bolt pre-tightening and pressing structure includes a third flange sleeved on the lower end of the specimen tube and a fourth flange sleeved at a position close to the lower end of the lower floating plug. The third flange is arranged on the mounting plate located at its lower end, the upper end of the fourth flange is located inside the mounting plate. At a position close to the lower end of the lower floating plug, a T-shaped lower top block is arranged, and the upper end of the lower top block can be inserted into the lower end of the specimen tube. An upper notch for the lower top block to be inserted into is arranged at the upper end of the fourth flange, and a lower tightening bolt capable of pressing on the lower top block is arranged on the fourth flange.

[0014] Further preferably, the mounting disc is arranged on the flipping assembly, the flipping assembly includes a flipping bracket, both ends of the mounting disc are horizontally provided with flipping shafts, the other ends of the flipping shafts are rotatably arranged on the flipping seats, the flipping seats are arranged on the flipping bracket, and the bottom of the flipping bracket is provided with a traveling mechanism for driving the whole flipping assembly to move and fixing the position after movement.

[0015] Further preferably, the injection system includes a storage container for containing CO2, a constant pressure pump for realizing the flow of CO2, a heater for heating CO2, and a fluid buffer tank for ensuring that the injected CO2 is in a supercritical state. The storage container, the constant pressure pump, the heater, and the fluid buffer tank are sequentially connected through an injection pipeline, and a monitoring structure for monitoring its pressure and temperature is arranged on the fluid buffer tank. A pressure vessel for buffering pressure fluctuations during heating is connected in parallel to the heater, and a control valve is arranged on the fluid buffer tank.

[0016] Further preferably, the monitoring system includes a radial monitoring sensor and an axial monitoring sensor. There are at least two rows of radial monitoring sensors, and at least four radial monitoring sensors are arranged in different directions in each row. The radial monitoring sensors pass through the specimen tube and contact the specimen. The radial detection sensors are arranged on a sensor bracket, and the sensor bracket is arranged on the mounting disc. The radial monitoring sensors at any two farthest positions are set as temperature monitoring sensors; the axial monitoring sensor is arranged between the axial pressure mounting plate and the detection plate.

[0017] The beneficial effects of the present invention: It can record the radial displacement, axial displacement, and temperature change of the coal body during the process of injecting supercritical CO2 into the coal body. After changing the pretreatment conditions of the specimen, the injection pressure and rate of supercritical CO2, the mechanism and law of injecting supercritical CO2 into the coal seam for storage can be studied through comparison. Description of the Drawings

[0018] Figure 1 It is a flow schematic diagram of the present invention.

[0019] Figure 2 It is a schematic diagram of the test device in the present invention.

[0020] Figure 3 It is a schematic diagram of the clamping structure in the present invention.

[0021] Figure 4 It is a three-dimensional schematic diagram of the clamping structure in the present invention.

[0022] Figure 5 It is a schematic diagram of the clamping structure and the flipping assembly in the present invention.

[0023] Figure 6 It is a schematic diagram of the pressure vessel in the present invention.

[0024] Figure 7 This is a schematic diagram of the back pressure valve in the present invention.

[0025] Reference numerals: inlet - 1, outlet - 2, specimen tube - 3, mounting disc - 4, support sleeve - 5, floating plug - 6, high - temperature gasket - 7, graphite assembly - 8, inlet provided - 9, first flange - 10, second flange - 11, upper top block - 12, upper tightening bolt - 13, third flange - 14, fourth flange - 15, lower top block - 16, high - temperature ring pressing sleeve - 20, connecting column - 21, axial pressure mounting plate - 22, axial pressure cylinder - 23, cooling sleeve - 24, flipping bracket - 29, flipping shaft - 30, flipping seat - 31, traveling mechanism - 32, storage container - 33, constant - pressure pump - 34, heater - 35, fluid buffer tank - 36, pressure vessel - 37, base - 37a, cylinder body - 37b, piston - 37c, pressure cap - 37d, plug - 37e, control valve - 38, lower tightening bolt - 45. Detailed implementation manners

[0026] The present invention will be further described below through embodiments in conjunction with the accompanying drawings:

[0027] As Figures 1-6 shown, a supercritical CO2 sequestration method in coal seam geology includes the following steps:

[0028] The first step is specimen preparation. For specimen preparation, cut the raw coal block into a cylindrical specimen, then process it through a grinding machine to make the flatness of its end face within ±0.02 mm, and then pre - treat the specimen. The pre - treatment can be soaking the specimen in alkali solution, or of course, no pre - treatment can be carried out.

[0029] The second step is device assembly. Sheath a high - temperature ring pressing sleeve outside the support sleeve with the specimen, then install the support sleeve into the clamping structure and seal it through the sealing structure, then connect the injection system to the clamping structure, and at the same time install the monitoring system. Then set the injection pressure value, heating temperature and rate of CO2 in the injection system, and apply axial pressure and confining pressure to the specimen according to the test requirements.

[0030] The clamping assembly includes a mounting disc 4 and a specimen tube 3 with ductility, and the specimen tube 3 is arranged to penetrate through up and down. To reduce the heat exchange between the specimen tube and the outside, a heat insulation sleeve or a heat preservation sleeve is arranged outside the specimen tube. Preferably, the specimen tube and the support sleeve are made of nickel - based alloy materials, specifically high - temperature aviation materials, such as imported alloy 718 or domestic material 4169. It has high temperature resistance, high pressure resistance and corrosion resistance, does not deform after repeated use, still has high strength under high temperature and high pressure, and even has a tensile strength of 1500 N / mm 2 at 800 °C high - temperature condition, and the yield strength reaches 800 N / mm 2, the elongation rate can reach over 30%.

[0031] A pressurization system for realizing axial compression and confining pressure pressurization of the specimen to simulate the surrounding environment of the coal body is provided on the clamping structure. The pressurization system includes a high-temperature confining pressure sleeve 20 arranged between the specimen tube 3 and the support sleeve 5, and an axial pressure mounting plate 22 arranged below the mounting disc 4 through a connecting column 21. The high-temperature confining pressure sleeve 20 is equipped with a confining pressure tracking system. An axial pressure cylinder 23 is arranged on the axial pressure mounting plate 22. Preferably, a cooling sleeve 24 with water inlet and outlet is arranged between the axial pressure cylinder 23 and the specimen tube 3 to prevent the temperature of the specimen tube from affecting the axial pressure cylinder.

[0032] Preferably, the confining pressure tracking system includes a confining pressure tracking pump and a confining pressure tracking pipeline communicated with the high-temperature confining pressure sleeve. The confining pressure tracking pump is equipped with a control panel, a safety pressure relief function, etc., and can realize differential pressure tracking, automatic pressure lifting and lowering, display of pressure data, feedback system, etc. through a control terminal; it has a manual control function for pressure lifting and lowering.

[0033] The sealing structure includes floating plugs 6 arranged at the upper and lower ends of the specimen tube 3. Between each floating plug 6 and the specimen tube 3, multiple high-temperature gaskets 7 and double V-shaped combined graphite components 8 are sequentially arranged from inside to outside. When the internal pressure extrudes outward, the self-sealing rubber ring deforms, making its outer diameter fit more closely with the specimen tube and its inner diameter fit more closely with the high-temperature confining pressure sleeve, thus realizing reliable sealing. An inlet 1 communicated with the injection system and an outlet 2 for discharging excess gas are arranged in the floating plug 6. The outlet 2 and the inlet 1 are respectively arranged in different floating plugs 6. Preferably, an additional inlet 9 is also arranged on the floating plug 6 provided with the outlet 2.

[0034] Preferably, the high-temperature gasket material is a super-high-temperature material imported from the United States. It has good elasticity even at 1000°C and can be used for frequent loading and unloading, and can be arbitrarily stamped into formed sealing gaskets. Using double V-shaped combined graphite components as the sealing components has the characteristics of reliable sealing and convenient loading and unloading. At the same time, it blocks the boundary cross-flow between the confining pressure sleeve and the sample, playing a role in eliminating the boundary effect.

[0035] To ensure the reliable sealing of the sealing structure, a bolt pre-tightening and pressing structure for ensuring the reliable sealing of the sealing structure is arranged at the end of each floating plug 6. The bolt pre-tightening and pressing structure includes an upper bolt pre-tightening and pressing structure and a lower bolt pre-tightening and pressing structure arranged up and down. That is, the upper bolt pre-tightening and pressing structure is used to lock the upper floating plug, and the lower bolt pre-tightening and pressing structure is used to lock the lower floating plug.

[0036] The upper bolt pre-tightening and jacking structure includes a first flange 10 sleeved on the upper end of the specimen tube 3 and a second flange 11 sleeved on the upper end of the upper floating plug 6. The first flange 10 and the second flange 11 are connected by mounting bolts. At a position near the upper end of the floating plug 6, a T-shaped upper jacking block 12 is provided, and the lower end of the upper jacking block 12 can be inserted into the upper end of the specimen tube 3. At the lower end of the second flange 11, a lower notch for the upper jacking block 12 to be inserted into is provided, and an upper jacking bolt 13 capable of jacking on the upper jacking block 12 is provided on the second flange 11.

[0037] The lower bolt pre-tightening and jacking structure includes a third flange 14 sleeved on the lower end of the specimen tube 3 and a fourth flange 15 sleeved at a position near the lower end of the lower floating plug 6. The third flange 14 is arranged on the mounting plate 4 located at its lower end, and the upper end of the fourth flange 15 is located inside the mounting plate 4. At a position near the lower end of the lower floating plug 6 at the lower end, a T-shaped lower jacking block 16 is provided, and the upper end of the lower jacking block 16 can be inserted into the lower end of the specimen tube 3. At the upper end of the fourth flange 15, an upper notch for the lower jacking block 16 to be inserted into is provided, and a lower jacking bolt 45 capable of jacking on the lower jacking block 16 is provided on the fourth flange 15.

[0038] The sealing structure is jacked tightly by multiple jacking bolts and jacking blocks to prevent the outward movement of the sealing structure when the internal pressure rises. Preferably, the screws are made of high-strength heat-resistant materials and will not produce sticking phenomena at high temperatures.

[0039] To achieve horizontal and vertical flipping, the mounting plate 4 is arranged on the flipping assembly. The flipping assembly includes a flipping bracket 29. At both ends of the mounting plate 4, rotating shafts 30 are horizontally arranged. The other ends of the rotating shafts 30 are rotatably arranged on the flipping seats 31, and the flipping seats 31 are arranged on the flipping bracket 29. At the bottom of the flipping bracket 29, a traveling mechanism 32 for driving the entire flipping assembly to move and fix the position after moving is provided.

[0040] The injection system includes a storage container 33 for accommodating CO2, a constant-pressure pump 34 for realizing the flow of CO2, a heater 35 for heating CO2, and a fluid buffer tank 36 for ensuring that the injected CO2 is in a supercritical state. The storage container 33, the constant-pressure pump 34, the heater 35, and the fluid buffer tank 36 are all connected in sequence through an injection pipeline. A monitoring structure for monitoring its pressure and temperature is provided on the fluid buffer tank 36. A pressure vessel 37 for buffering pressure fluctuations during heating is connected in parallel to the heater 35, and a control valve 38 is provided on the fluid buffer tank.

[0041] As Figure 6As shown, the pressure vessel 37 is a piston-type pressure vessel, specifically including a cylinder body 37b disposed on a base 37a. A piston 37c is slidably disposed within the cylinder body 37b, and a washer and a sealing ring are provided between the piston 37c and the cylinder body 37b to ensure the sealing between the piston and the cylinder body. Pressure caps 37d for closing the cylinder body 37b are provided at both the upper and lower ends of the cylinder body 37b. A plug 37e is provided on the pressure cap 37d, and a flow passage for the fluid to pass through is provided on the plug 37e. The pressure vessel is made of high-strength material and is sealed and isolated using an O-ring. In addition to the isolation function, the important function of the piston is to transmit the power of the power liquid to the working medium for operation. There is no pulse phenomenon, and it can stably transmit pressure and flow rate with low pressure loss. During the entire test process, it is necessary to ensure that the fluid types in the pressure vessel and the storage vessel are the same.

[0042] The specific structure of the heater 35 includes a heat transfer body with a main body made of cast aluminum material. An electric heating tube is spirally disposed on the heat transfer body and a heating passage for the fluid to pass through, and the heating passage is located outside the electric heating tube. Heat insulation material is provided outside the heat transfer body, and the heat insulation material is made of ceramic fiber blanket.

[0043] The monitoring system includes a radial monitoring sensor 25 and an axial monitoring sensor 26. At least two rows of radial monitoring sensors 25 are provided, and at least four radial monitoring sensors 25 are provided in each row in different directions. The radial monitoring sensor 25 passes through the specimen tube 3 and contacts the specimen, and a sealing ring and a gasket are provided between the radial monitoring sensor and the specimen tube. The radial detection sensor 25 is disposed on a sensor bracket 27, and the sensor bracket 27 is disposed on the mounting plate 4. The radial monitoring sensors 25 at the two positions farthest apart are set as temperature monitoring sensors. The axial monitoring sensor 26 is disposed between the axial pressure mounting plate 22 and the detection plate 28, and the detection plate 28 is disposed at the lower end of the lower floating plug 6.

[0044] Preferably, a collection container for collecting gas is provided through a pipeline at the outlet. Of course, a gas analyzer for analyzing the gas composition in the collection container can also be provided.

[0045] The third step is to start the test. Supercritical CO2 is injected into the specimen through the injection system to complete the test. At the same time, the radial displacement, axial displacement, and temperature change of the coal body during the entire test process are recorded, and the change of the coal body after injecting supercritical CO2 is analyzed.

[0046] The fourth step is to repeat the test. The pretreatment conditions of the specimen, the injection pressure and rate of supercritical CO2 are changed respectively, and the test is repeated. The radial displacement, axial displacement, and temperature change of the coal body during the entire test process under different conditions are recorded, and the mechanism and law of supercritical CO2 coal seam sequestration are studied. The pretreatment conditions include the composition of the alkali solution, the concentration of the alkali solution, etc.

Claims

1. A supercritical CO2 sequestration method in coal seam geology, characterized in that: It includes the following steps: S1: Specimen preparation. Cut the raw coal block into a cylindrical specimen, then process it through a grinding machine to make the flatness of its end face within ±0.02 mm, and then pre-treat the specimen. S2: Equipment preparation. Sheath a high-temperature ring pressing sleeve outside the support sleeve with the specimen, then install the support sleeve into the clamping structure and seal it through the sealing structure. Then connect the injection system to the clamping structure, and at the same time install the monitoring system. Then set the injection pressure value, heating temperature and rate of CO2 injection in the injection system, and apply axial pressure and confining pressure to the specimen according to the test requirements. S3: Start the test. Inject supercritical CO2 into the specimen through the injection system to complete the test. At the same time, record the radial displacement, axial displacement and temperature change of the coal body during the whole test process, and analyze the change of the coal body after injecting supercritical CO2. S4: Repeat the test. Respectively change the pre-treatment conditions of the specimen, the injection pressure and rate of supercritical CO2, repeat the test, and record the radial displacement, axial displacement and temperature change of the coal body during the whole test process under different conditions, and study the mechanism and law of supercritical CO2 coal seam sequestration.

2. The supercritical CO2 sequestration method in coal seam geology according to claim 1, characterized in that: The pre-treatment includes alkali solution soaking treatment.

3. A method for supercritical CO2 sequestration in coal seam geology according to claim 1, characterized in that: The clamping structure includes a mounting plate (4) and a ductile specimen tube (3). The specimen tube (3) is arranged to penetrate up and down. A pressurizing system for realizing axial pressure and confining pressure pressurization of the specimen is arranged on the clamping structure. The pressurizing system includes a high-temperature ring pressing sleeve (20) arranged between the specimen tube (3) and the support sleeve (5) and an axial pressure mounting plate (22) arranged below the mounting plate (4) through a connecting column (21). The high-temperature ring pressing sleeve (20) is equipped with a ring pressure tracking system. An axial pressure cylinder (23) is arranged on the axial pressure mounting plate (22), and a cooling sleeve (24) with water inlet and outlet is arranged between the axial pressure cylinder (23) and the specimen tube (3).

4. A method for supercritical CO2 sequestration in coal seam geology according to claim 3, characterized in that: The sealing structure includes floating plugs (6) arranged at the upper and lower ends of the specimen tube (3). Between each floating plug (6) and the specimen tube (3), multiple high-temperature gaskets (7) and double V-shaped combined graphite components (8) are sequentially arranged from inside to outside. A bolt pre-tightening and pressing structure for ensuring reliable sealing of the sealing structure is arranged at the end of each floating plug (6). An inlet (1) communicated with the injection system and an outlet (2) for discharging redundant gas are arranged in the floating plug (6), and the inlet (1) and the outlet (2) are respectively arranged in different floating plugs (6).

5. A method for supercritical CO2 sequestration in coal seam geology according to claim 4, characterized in that: The bolt pre-tightening and jacking structure includes an upper bolt pre-tightening and jacking structure and a lower bolt pre-tightening and jacking structure corresponding to the upper and lower floating plugs. The upper bolt pre-tightening and jacking structure includes a first flange (10) sleeved on the upper end of the specimen tube (3) and a second flange (11) sleeved on the upper end of the upper floating plug (6). The first flange (10) and the second flange (11) are connected by mounting bolts. At a position near the upper end of the floating plug (6), a T-shaped upper jacking block (12) is provided, and the lower end of the upper jacking block (12) can be inserted into the upper end of the specimen tube (3). A lower notch for the upper jacking block (12) to be inserted into is provided at the lower end of the second flange (11), and an upper jacking bolt (13) capable of jacking on the upper jacking block (12) is provided on the second flange (11). The lower bolt pre-tightening and jacking structure includes a third flange (14) sleeved on the lower end of the specimen tube (3) and a fourth flange (15) sleeved at a position near the lower end of the lower floating plug (6). The third flange (14) is arranged on a mounting plate (4) located at its lower end. The upper end of the fourth flange (15) is located inside the mounting plate (4). At a position near the lower end of the lower floating plug (6), a T-shaped lower jacking block (16) is provided, and the upper end of the lower jacking block (16) can be inserted into the lower end of the specimen tube (3). An upper notch for the lower jacking block (16) to be inserted into is provided at the upper end of the fourth flange (15), and a lower jacking bolt (45) capable of jacking on the lower jacking block (16) is provided on the fourth flange (15).

6. A method for supercritical CO2 sequestration in coal seam geology according to claim 3, characterized in that: The mounting plate (4) is arranged on a flipping assembly. The flipping assembly includes a flipping bracket (29). Horizontal rotating shafts (30) are arranged at both ends of the mounting plate (4). The other ends of the rotating shafts (30) are rotatably arranged on rotating seats (31). The rotating seats (31) are arranged on the flipping bracket (29). A traveling mechanism (32) for driving the whole flipping assembly to move and fix its position after movement is provided at the bottom of the flipping bracket (29).

7. A method for supercritical CO2 sequestration in coal seam geology according to claim 1, characterized in that: The injection system includes a storage container (33) for accommodating CO2, a constant pressure pump (34) for realizing the flow of CO2, a heater (35) for heating CO2, and a fluid buffer tank (36) for ensuring that the injected CO2 is in a supercritical state. The storage container (33), the constant pressure pump (34), the heater (35), and the fluid buffer tank (36) are sequentially connected through an injection pipeline. A monitoring structure for monitoring its pressure and temperature is provided on the fluid buffer tank (36). A pressure vessel (37) for buffering pressure fluctuations during heating is connected in parallel to the heater (35). A control valve (38) is provided on the fluid buffer tank.

8. A method for supercritical CO2 sequestration in coal seam geology according to claim 3, characterized in that: The monitoring system includes a radial monitoring sensor (25) and an axial monitoring sensor (26). The radial monitoring sensor (25) is provided with at least two rows, and at least four radial monitoring sensors (25) are arranged in each row in different directions. The radial monitoring sensor (25) contacts the specimen after passing through the specimen tube (3). The radial detection sensor (25) is arranged on a sensor bracket (27), and the sensor bracket (27) is arranged on a mounting plate (4). The radial monitoring sensors (25) at any two farthest positions are set as temperature monitoring sensors. The axial monitoring sensor (26) is arranged between an axial pressure mounting plate (22) and a detection plate (28).

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