Device and method for detecting high-concentration methane solution in cold spring simulation cabin

Abstract

The invention relates to a device and a method for detecting a high-concentration methane solution in a cold spring simulation cabin, and belongs to the technical field of instrument testing and testing. A sampling tank is vacuumized by a vacuum pump, then a solution is injected, methane gas and liquid are separated by a gas-liquid separation technology in a negative pressure environment, the volume of the injected solution is measured by combining a mass flow meter, the volume fraction of methane in the separated mixed gas is analyzed by a gas chromatographic detector, and the concentration of residual methane in the solution is detected by a normal-pressure methane sensor. And the test control system integrates data and calculates the total concentration. The device and the method for detecting the high-concentration methane solution in the cold spring simulation cabin solve the precision problem of traditional dilution detection and chromatographic indirect measurement, realize accurate detection of the high-concentration methane solution, and are suitable for methane concentration detection in a high-concentration methane water environment of sediments in the cold spring simulation cabin.

Description

Technical Field

[0001] The present invention relates to the technical field of instrument and meter testing and experiment, and in particular to a detection device and a detection method for high-concentration methane solution in a cold seep simulation chamber. Background Art

[0002] Submarine cold seeps are complex geological and ecological systems, generally formed at the continental margins and deep-sea basins, mainly related to geological movements, sediment accumulation, and organic matter decomposition. A large amount of methane, hydrogen sulfide and other gases are generated by the decomposition of organic matter in submarine sediments. When these substances enter the ocean, they will affect the local marine chemical environment. Methane, as a greenhouse gas, has a potential impact on global climate change. Therefore, studying the migration law of submarine cold seep methane is of great significance for aspects such as climate change, marine chemical cycling, ecosystem protection, understanding of geological processes, resource development, and technological innovation.

[0003] According to the existing cold seep environment investigation and research data, the established environment in the cold seep chamber requires that the methane concentration in the sediment is not less than 25 mmol / L, and the methane concentration in the water body is not higher than 50 μmol / L.

[0004] In related technologies, the detection concentration of in-situ methane detection sensors in the seabed, such as METS methane sensors and HydroC / CH4 underwater methane sensors, generally does not exceed 100 μmol / L, which can be used for the detection of low-concentration methane solution in the water body of the cold seep chamber. For the high-concentration methane inside the sediment, it cannot be directly measured and needs to be indirectly measured after sampling and dilution outside the chamber. Due to the changes in temperature and pressure inside and outside the chamber, the sample concentration changes during the dilution and detection processes, and the detection accuracy of the high-concentration methane solution cannot be guaranteed.

[0005] In addition, sampling and detection by gas chromatography is also a relatively common methane concentration detection method in the industry at present. However, after pre-treatment steps such as sampling and making headspace of the sample by gas chromatography, what is generally measured is the volume fraction concentration of the gas to be measured, that is, the volume ratio of the gas to be measured to the mixed gas, and it cannot be directly quantitatively converted to the concentration of methane in the solution, that is, the amount of substance of the gas to be measured to the volume of the solution.

[0006] Therefore, how to directly and accurately detect the high-concentration methane solution in the chamber has become a problem that must be solved in the precise control of the methane concentration in the cold seep simulation chamber. Summary of the Invention

[0007] The applicant of the present invention aims at the above-mentioned disadvantages in the existing production technology, and provides a detection device and a detection method for high-concentration methane solution in a cold seep simulation chamber, so as to separate the gas and liquid of the high-concentration methane solution in the cold seep simulation chamber, and at the same time, the volumes of the separated gas and liquid can be accurately measured.

[0008] The technical solution adopted by the present invention is as follows: A detection device for high-concentration methane solution in a cold spring simulation chamber, comprising:

[0009] A first sampling tank and a second sampling tank, used for gas-liquid separation;

[0010] A vacuum pump, connected to the sampling tank, used for evacuating the sampling tank;

[0011] A mass flow meter, used for measuring the volume of the solution injected into the sampling tank;

[0012] An explosion-proof water pump, used for pumping the solution in the first sampling tank into the second sampling tank;

[0013] A gas chromatograph detector, used for analyzing the volume fraction of methane in the separated mixed gas;

[0014] An atmospheric pressure methane sensor, used for measuring the residual methane concentration in the solution after gas-liquid separation; and

[0015] A test control system, used for controlling the start and stop of the vacuum pump, solenoid valve and explosion-proof water pump, and collecting data from the mass flow meter, gas chromatograph detector and atmospheric pressure methane sensor;

[0016] Among them, the detection device for high-concentration methane solution in the cold spring simulation chamber calculates the total concentration of the high-concentration methane solution through gas-liquid separation combined with the data of the gas chromatograph and the atmospheric pressure sensor.

[0017] In one embodiment, it further includes a helium gas cylinder group, and the helium gas cylinder group is connected to the gas chromatograph detector through a ninth solenoid valve to provide carrier gas for gas chromatographic detection.

[0018] In one embodiment, digital pressure gauges are respectively equipped on the first sampling tank and the second sampling tank, and the digital pressure gauges are used for monitoring the negative pressure value after evacuation and the pressure change after injecting the solution.

[0019] In one embodiment, it further includes a plurality of solenoid valves, and the plurality of solenoid valves are arranged in the pipeline for controlling the flow paths of gases and liquids; the plurality of solenoid valves include a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, an eighth solenoid valve and a ninth solenoid valve;

[0020] Among them, the first solenoid valve is used to cooperate with the cold spring simulation chamber to inject the high-concentration methane solution into the first sampling tank;

[0021] The third solenoid valve is used to cooperate with the cold spring simulation chamber to inject the high-concentration methane solution into the second sampling tank;

[0022] The first sampling tank is evacuated by the vacuum pump in cooperation with the second solenoid valve;

[0023] The second sampling tank is evacuated by a vacuum pump in cooperation with a fourth electromagnetic valve;

[0024] A fifth electromagnetic valve cooperates with an explosion-proof water pump to inject the solution in the first sampling tank into the second sampling tank, and send the mixed gas separated in the second sampling tank to a gas chromatograph detector for detection;

[0025] A seventh electromagnetic valve, a ninth electromagnetic valve, a helium gas cylinder group, a gas chromatograph detector and a test control system cooperate with each other to complete the gas chromatography detection of the mixed gas, and obtain the volume fraction of methane gas in the separated mixed gas;

[0026] A sixth electromagnetic valve and an eighth electromagnetic valve are respectively used to drain the first sampling tank and the second sampling tank and discharge the gas naturally, facilitating the next sample detection.

[0027] In one embodiment, a waterproof electromagnetic valve and a waterproof cover are further included in the second sampling tank. The waterproof electromagnetic valve and the waterproof cover cooperate with an atmospheric pressure methane sensor, and the atmospheric pressure methane sensor is electrically connected to the test control system for measuring the remaining methane concentration in the solution after water-gas separation.

[0028] In one embodiment, the test control system calculates the standard volume of the remaining air in the sampling tank according to the ideal gas state equation, and determines the gas and liquid volumes after gas-liquid separation in combination with the mass flowmeter data.

[0029] On the other hand, the present invention also provides a method for detecting a high-concentration methane solution in a cold spring simulation cabin, including the following processes:

[0030] Evacuate the first sampling tank and the second sampling tank to a stable negative pressure;

[0031] Inject a high-concentration methane solution into the sampling tank for gas-liquid separation, and record the injection volume;

[0032] Measure the remaining methane concentration in the separated solution through an atmospheric pressure methane sensor;

[0033] Send the separated mixed gas into a gas chromatograph detector to analyze the methane volume fraction;

[0034] Combine the separated gas volume, solution volume and remaining concentration to calculate the total concentration of the high-concentration methane solution.

[0035] In one embodiment, the termination condition for evacuating the first sampling tank and the second sampling tank is that the pressure change of the digital pressure gauge equipped on the sampling tank is less than 0.01 bar.

[0036] In one of the embodiments, when the high-concentration methane solution is injected into the sampling tank, the solution injection flow rate is controlled by a mass flow meter until the pressure in the sampling tank is restored to 1 bar.

[0037] In one embodiment, when the separated mixed gas is sent into a gas chromatograph, helium is used as a carrier gas, and the mixed gas is sent into the gas chromatograph by a water exhaust method to ensure that the gas partial pressure is stable.

[0038] The beneficial effects of the present invention are as follows:

[0039] The present invention has a compact structure and a reasonable detection process. It avoids the errors of the traditional dilution method and the indirect measurement by gas chromatography by vacuum suction combined with gas-liquid separation technology, and can directly measure high-concentration methane solutions. In addition, the methane volume fraction in the separated gas is analyzed by a gas chromatograph, and the residual liquid concentration is measured by a normal pressure sensor. The data of the two are superimposed to ensure full range coverage.

[0040] The present invention also has the following advantages:

[0041] (1) The present invention uses helium carrier gas and water exhaust method to transport gas, combines Henry's law to control partial pressure, and eliminates the influence of temperature and pressure changes inside and outside the cabin on gas components;

[0042] (2) The test system of the present invention links the vacuum pump, solenoid valve and flow meter to monitor the pressure and flow in real time, realizing a one-button vacuum pumping-sampling-separation-detection process with small operation error;

[0043] (3) The explosion-proof water pump, waterproof solenoid valve and waterproof cover of the present invention work together to meet the safety detection requirements of the high pressure, high humidity and methane explosive environment of the cold spring simulation cabin. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0045] Figure 2 It is a schematic diagram of the working principle of the present invention.

[0046] Figure 3 It is a schematic diagram of the structural composition of the present invention.

[0047] Figure 4 This is a schematic diagram of the water-gas separation principle of the high-concentration methane solution of the present invention.

[0048] Figure 5 This is a schematic diagram of the high-concentration methane solution detection principle of the present invention.

[0049] in:

[0050] 110. a first mass flow meter; 120. a second mass flow meter;

[0051] 200, Vacuum pump;

[0052] 310, First solenoid valve; 320, Second solenoid valve; 330, Third solenoid valve; 340, Fourth solenoid valve; 350, Fifth solenoid valve; 360, Sixth solenoid valve; 370, Seventh solenoid valve; 380, Eighth solenoid valve; 390, Ninth solenoid valve;

[0053] 410, First flow regulating valve; 420, Second flow regulating valve;

[0054] 510, First digital pressure gauge; 520, Second digital pressure gauge;

[0055] 610, First sampling tank; 620, Second sampling tank;

[0056] 700, Explosion-proof water pump;

[0057] 800, Waterproof solenoid valve;

[0058] 900, Waterproof cover;

[0059] 1000, Atmospheric pressure methane sensor;

[0060] 1100, Helium gas cylinder group;

[0061] 1200, Gas chromatograph detector;

[0062] 1300, Test control system. Detailed implementation manners

[0063] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe in detail the specific implementation manners of the present invention with reference to the accompanying drawings. In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0064] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0065] In the present invention, unless otherwise clearly specified and defined, terms such as "installed", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0067] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0068] As Figures 1 to 5 shown, the present invention provides a detection device for high-concentration methane solution in a cold spring simulation chamber, comprising: a first mass flowmeter 110 and a second mass flowmeter 120;

[0069] a vacuum pump 200;

[0070] a first solenoid valve 310, a second solenoid valve 320, a third solenoid valve 330, a fourth solenoid valve 340, a fifth solenoid valve 350, a sixth solenoid valve 360, a seventh solenoid valve 370, an eighth solenoid valve 380 and a ninth solenoid valve 390;

[0071] The first flow regulating valve 410 and the second flow regulating valve 420;

[0072] The first digital pressure gauge 510 and the second digital pressure gauge 520;

[0073] The first sampling tank 610 and the second sampling tank 620;

[0074] The explosion-proof water pump 700;

[0075] The waterproof solenoid valve 800;

[0076] The waterproof cover 900;

[0077] The atmospheric pressure methane sensor 1000;

[0078] The helium gas cylinder group 1100;

[0079] The gas chromatograph detector 1200; and

[0080] The test control system 1300.

[0081] In this embodiment, the vacuum pump 200 and the second solenoid valve 320 cooperate with each other to initially evacuate the first sampling tank 610; the vacuum pump 200 and the fourth solenoid valve 340 cooperate with each other to initially evacuate the second sampling tank 620, so as to evacuate the air inside the first sampling tank 610 and the second sampling tank 620.

[0082] In this embodiment, the first mass flowmeter 110, the first solenoid valve 310, the first flow regulating valve 410 and the first digital pressure gauge 510 cooperate with each other to inject the high-concentration methane solution in the cold seep simulation chamber into the first sampling tank 610 for gas-liquid separation treatment;

[0083] The first mass flowmeter 110, the third solenoid valve 330, the second flow regulating valve 420 and the second digital pressure gauge 520 cooperate with each other to inject the high-concentration methane solution in the cold seep simulation chamber into the second sampling tank 620 for gas-liquid separation treatment.

[0084] In this embodiment, the explosion-proof water pump 700, the fifth solenoid valve 350 and the second mass flowmeter 120 cooperate with each other to inject the solution in the first sampling tank 610 into the second sampling tank 620, and send the mixed gas separated in the second sampling tank 620 to the gas chromatograph detector for detection.

[0085] In this embodiment, the seventh solenoid valve 370, the ninth solenoid valve 390, the helium gas cylinder group 1100, the gas chromatograph detector 1200, and the test control system 1300 cooperate with each other to complete the gas chromatography detection of the mixed gas and obtain the volume fraction of methane gas in the separated mixed gas.

[0086] In this embodiment, the waterproof solenoid valve 800, the waterproof cover 900, the atmospheric pressure methane sensor 1000, and the test and control system 1300 cooperate with each other to complete the measurement of the remaining methane concentration in the solution after water-gas separation.

[0087] In this embodiment, the sixth solenoid valve 360 and the eighth solenoid valve 380 are respectively used to drain the water in the first sampling tank 610 and the second sampling tank 620 and discharge the gas naturally, facilitating the next sample detection.

[0088] As Figure 5 shown, in other embodiments, a method for detecting high-concentration methane solution in a cold seep simulation chamber is further provided, including the following steps:

[0089] First step, obtain the remaining air volume data in the sampling tank: Start the vacuum pump 200, open the second solenoid valve 320 and the fourth solenoid valve 340, and evacuate the first sampling tank 610 and the second sampling tank 620 respectively until the pressure values of the first digital pressure gauge 510 and the second digital pressure gauge 520 tend to be stable. When the change of the digital pressure gauge is less than 0.01 bar, turn off the vacuum pump, close the second solenoid valve 320 and the fourth solenoid valve 340. At this time, record the negative pressure values of the current first sampling tank 610 and the second sampling tank 620 as P 真空 , according to the ideal gas state equation:

[0090] p0V 罐 = n0RT (Equation 1)

[0091] p 真空 V 罐 = n1RT (Equation 2)

[0092] n0 = V 罐 / V m (Equation 3)

[0093] In Equation 1, Equation 2, and Equation 3, the volumes of the first sampling tank 610 and the second sampling tank 620 are V 罐 , the initial pressure is one atmospheric pressure P0, n0 is the amount of substance of the initial air in the sampling tank, P 真空 is the negative pressure value of the first sampling tank 610 and the second sampling tank 620 after evacuation, n1 is the amount of substance of the remaining air in the first sampling tank 610 and the second sampling tank 620 after evacuation, and the molar volume of the gas is V mApproximately 22.4 L / mol, where R is the molar gas constant and T is the laboratory temperature. From Equations (1), (2), and (3), the amount of substance of the remaining air, n1, and the standard volume V of the remaining gas can be obtained. 剩 :

[0094]

[0095] Step 2: Quantitative gas-liquid separation of the high-concentration methane solution: Turn on the first mass flowmeter 110, open the first solenoid valve 310 and the first flow regulating valve 410;

[0096] The high-concentration methane solution enters the first sampling tank 610 and undergoes gas-liquid separation due to the negative pressure. The test control system 1300 controls the first flow regulating valve 410 to adjust the solution injection flow rate by detecting the pressure of the first digital pressure gauge 510. When the pressure of the first digital pressure gauge 510 rises to 1 bar, the first solenoid valve 310 and the first flow regulating valve 410 are closed, and the volume V of the injected high-concentration methane solution is recorded by the first mass flowmeter 110. 进1 , and the volume of the separated gas is V 罐 -V 进1 -V 剩 .

[0097] In the same way, by operating the first mass flowmeter 110, the second solenoid valve 320, and the second flow regulating valve 420, sampling of the sampling tank 2 is completed; the volume V of the injected high-concentration methane solution 进2 , and the volume of the separated gas is V 罐 -V 进2 -V 剩 ;

[0098] The volumes of the first sampling tank 610 and the second sampling tank 620 are exactly the same, and the injection solution and separation conditions are exactly the same. Therefore, the volumes and compositions of the separated liquid and gas are the same. After gas-liquid separation in the sampling tank, the pressure returns to 1 bar (close to one atmospheric pressure). The methane concentration remaining in the separated liquid is lower than the saturated solubility of methane under normal conditions, approximately 2000 μmol / L;

[0099] Step 3: Open the waterproof solenoid valve 800, the solution enters the waterproof cover 900, and the atmospheric methane sensor 1000 is opened for solution concentration detection, covering the highest methane saturated solubility under normal conditions;

[0100] The test control system 1300 collects and analyzes the data of the atmospheric methane sensor 1000. When the data of the atmospheric methane sensor 1000 is stable and changes less than 1.25 μmol / L within 10 s, the test and control system records the methane molar concentration data C remaining in the separated liquid 液 ;

[0101] Specifically, the atmospheric pressure methane sensor uses solu-blu CH4, with a measurement range of 0 - 2000 umol / L;

[0102] Step 4: Open the fifth solenoid valve 350, start the explosion-proof water pump 700, and inject the solution in the first sampling tank 610 into the second sampling tank 620;

[0103] During this process, according to Henry's law, since the gas and liquid components in the first sampling tank 610 and the second sampling tank 620 are the same, when the solution in the first sampling tank 610 is injected into the second sampling tank 620, the gas partial pressure in the second sampling tank 620 will not change, ensuring the stability of the gas components in the second sampling tank 620 and thus guaranteeing the measurement accuracy;

[0104] At the same time, open the seventh solenoid valve 370, use the water displacement method to send the mixed gas separated in the second sampling tank 620 to the gas chromatograph detector 1200. At the same time, open the ninth solenoid valve 390, and helium is sent from the helium gas cylinder group 1100 as the carrier gas to the gas chromatograph detector 1200. The gas chromatograph detector 1200 analyzes the mixed gas, and the test control system 1300 collects and analyzes it to obtain the volume concentration C of methane in the mixed gas 体积 :

[0105]

[0106]

[0107] In the formula, V 甲烷 is the volume of methane in the mixed gas separated from the high-concentration methane solution. From Formula 6 and Formula 7, the molar concentration C of the methane gas separated from the solution can be obtained 气：

[0108]

[0109] Thus, the molar concentration C of the high-concentration methane solution can be obtained 甲烷 = C 液 + C 气 , that is:

[0110]

[0111] In this embodiment, the present invention uses the test control system 1300 to integrally control the start and stop of the vacuum pump 200, solenoid valves, and explosion-proof water pump 700, and real-time collects the data of the mass flowmeter, digital pressure gauge, atmospheric pressure methane sensor 1000, and gas chromatograph detector 1200; the helium gas cylinder group 1100 provides a stable carrier gas for the gas chromatograph detector 1200 through the ninth solenoid valve 390 to ensure the analysis accuracy; the waterproof solenoid valve 800 and the waterproof cover 900 prevent the interference of the high-humidity environment on the atmospheric pressure methane sensor 1000.

[0112] The high-concentration methane solution detection device of the cold spring simulation chamber of the present invention has a reasonable structure. After evacuating the first sampling tank 610 and the second sampling tank 620 and injecting the sample solution, the water-gas separation of the high-concentration methane solution is realized. Combining the ideal gas state equation pV = nRT and the data of the mass flowmeter, the water-gas separation ratio is obtained. In addition, the solution in the first sampling tank 610 is pumped into the second sampling tank 620, and the gas in the second sampling tank 620 is sent to the gas chromatograph detector 1200 by the water exhaust method. The volume fraction of methane in the separated mixed gas is obtained through the gas chromatograph detector 1200. The methane concentration not separated in the solution is measured by the atmospheric pressure methane sensor 1000, and combined with the volume fraction of the separated methane, the methane concentration in the solution is finally detected.

[0113] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0114] The above-described embodiments only express the implementation manners of the present invention, and the description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A detection device for high-concentration methane solution in a cold spring simulation chamber, characterized in that Comprising: A first sampling tank and a second sampling tank for gas-liquid separation; A vacuum pump connected to the sampling tank for evacuating the sampling tank; A mass flow meter for measuring the volume of the solution injected into the sampling tank; An explosion-proof water pump for pumping the solution in the first sampling tank into the second sampling tank; A gas chromatograph detector for analyzing the volume fraction of methane in the separated mixed gas; An atmospheric pressure methane sensor for measuring the residual methane concentration in the solution after gas-liquid separation; and A test control system for controlling the start and stop of the vacuum pump, solenoid valves and explosion-proof water pump, and collecting data from the mass flow meter, gas chromatograph detector and atmospheric pressure methane sensor; Wherein, the high-concentration methane solution detection device in the cold seep simulation chamber calculates the total concentration of the high-concentration methane solution through gas-liquid separation combined with the data of the gas chromatograph and the atmospheric pressure sensor.

2. The high-concentration methane solution detection device for the cold spring simulation chamber according to claim 1, characterized in that It further includes a helium gas cylinder group, and the helium gas cylinder group is connected to the gas chromatograph detector through a ninth solenoid valve to provide carrier gas for gas chromatographic detection.

3. The high-concentration methane solution detection device for the cold spring simulation chamber according to claim 1, characterized in that, Digital pressure gauges are respectively equipped on the first sampling tank and the second sampling tank, and the digital pressure gauges are used to monitor the negative pressure value after evacuation and the pressure change after injecting the solution.

4. The high-concentration methane solution detection device for the cold spring simulation chamber according to claim 1, wherein, It further includes a plurality of solenoid valves, and the plurality of solenoid valves are arranged in the pipeline for controlling the flow paths of gases and liquids; The plurality of solenoid valves include a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, an eighth solenoid valve and a ninth solenoid valve; Wherein, the first solenoid valve is used to cooperate with the cold seep simulation chamber to inject the high-concentration methane solution into the first sampling tank; The third solenoid valve is used to cooperate with the cold seep simulation chamber to inject the high-concentration methane solution into the second sampling tank; The first sampling tank is evacuated by the vacuum pump in cooperation with the second solenoid valve; The second sampling tank is evacuated by the vacuum pump in cooperation with the fourth solenoid valve; The fifth solenoid valve cooperates with the explosion-proof water pump to inject the solution in the first sampling tank into the second sampling tank, and send the separated mixed gas in the second sampling tank to the gas chromatograph detector for detection; The seventh solenoid valve, the ninth solenoid valve, the helium gas cylinder group, the gas chromatograph detector and the test control system cooperate with each other to complete the gas chromatographic detection of the mixed gas, and obtain the volume fraction of methane gas in the separated mixed gas; The sixth solenoid valve and the eighth solenoid valve are respectively used to complete the drainage of the first sampling tank and the second sampling tank and the natural discharge of gas, facilitating the next sample detection.

5. The high-concentration methane solution detection device for the cold spring simulation chamber according to claim 1, characterized in that, A waterproof solenoid valve and a waterproof cover are further included in the second sampling tank. The waterproof solenoid valve and the waterproof cover cooperate with the atmospheric pressure methane sensor, and the atmospheric pressure methane sensor is electrically connected to the test control system for measuring the remaining methane concentration in the solution after water-gas separation.

6. The high-concentration methane solution detection device for the cold spring simulation cabin according to claim 1, characterized in that, The test control system calculates the standard volume of the remaining air in the sampling tank according to the ideal gas state equation, and determines the gas and liquid volumes after gas-liquid separation in combination with the mass flow meter data.

7. A detection method for high-concentration methane solution in a cold spring simulation chamber, characterized in that, Including the following processes: Evacuate the first sampling tank and the second sampling tank until the negative pressure is stable; Inject the high-concentration methane solution into the sampling tank for gas-liquid separation, and record the injection volume; Measure the residual methane concentration in the separated solution through the atmospheric pressure methane sensor; The separated mixed gas is sent to a gas chromatograph detector for analyzing the methane volume fraction; Combined with the separated gas volume, solution volume and residual concentration, calculate the total concentration of the high-concentration methane solution.

8. The method for detecting high-concentration methane solution in the cold spring simulation cabin according to claim 7, characterized in that The termination condition for evacuating the first sampling tank and the second sampling tank is that the pressure change of the digital pressure gauge equipped on the sampling tank is less than 0.01 bar.

9. The high-concentration methane solution detection method for the cold spring simulation chamber according to claim 7, wherein When injecting the high-concentration methane solution into the sampling tank, the solution injection flow rate is controlled by a mass flow meter until the pressure in the sampling tank returns to 1 bar.

10. The detection method for high-concentration methane solution in the cold spring simulation cabin according to claim 7, characterized in that, When sending the separated mixed gas to the gas chromatograph detector, helium is used as the carrier gas, and the mixed gas is sent to the gas chromatograph detector by the water displacement method to ensure the stability of the gas partial pressure.

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